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THE  CHEMICAL  NEWS,  July  9,  1897. 


THE 


CHEMICAL  NEWS 


JOURNAL     OF     PHYSICAL     SCIENCE. 


WITH   WHICH   IS  INCORPORAT-BD  THB  "CHEMICAL  GAZETTE." 


%  ^anxunl  ai  Urattttal  ^J^^mistrj} 


IN  ALL  ITS  APPLICATIONS  TO 


PHARMACY,  ARTS,  AND    MANUFACTURES. 


EDITED   BY 


WILLIAM      CROOKES,      F.R.S,,     &c. 


VOLUME  LXXV.— 1897. 


LONDON : 
PUBLISHED  AT  THE  OFFICE,  66-7,  CREED  LANE,  LUDGATE  HILL,  E.C. 

AND  SOLD  BY  ALL  BOOKSELLERS. 


MDCCCXCVII,  I  tn  (<^>*» 


{Chemical  News, 
July  9, 1897 


LONDON: 

PRINTED      BY     EDWIN     JOHN      DAVEY 

6    &    7,    CREED    LANE,    LU1>GATE    HILL, 

E.C. 


THE     CHEMICAL    NEWS 


VOLUME      LXXV. 


EDITED    BY    WILLIAM    CROOKES,    F.R.S.,  S'C. 


No.  1936.— JANUARY  i,  1897. 


SEA-WATER  MICROBES  IN    HIGH  LATITUDES. 

By  E.  FRANKLAND,  D.C.L.,  F.R.S., 
and  W.  T.  BURGESS,  F.I.C. 

The  badleriology  of  sea-water  is  beginning  to  receive 
deserved  attention  from  biologists,  for  it  lies  at  the  very 
foundation  of  the  marine  flora  and  fauna,  as  badteria 
doubtless  form  the  initial  food  of  higher  marine  organisms ; 
unless  indeed  there  be  a  still  more  minute  world  of  living 
matter  too  small  for  discovery  by  our  present  modes  of 
investigation. 

In  the  year  1892,  Mr.  H.  L.  Russell  examined  at  the 
biological  station  in  Naples,  a  number  of  samples  of  sea- 
water  colledted  at  various  depths  in  the  Bay  of  Naples. 
The  water  at  or  near  the  surface  was  found  to  contain  a 
number  of  colonies  per  c.c,  varying  from  64  at  four  kilo- 
metres from  land,  to  six  at  fifteen  kilometres.  There  was, 
however,  no  constant  relation  between  the  numbers  of 
badteria  and  the  distance  from  land  ;  thus,  at  eleven  kilo- 
metres from  land  78  per  c.c.  were  found.  On  the  other  hand, 
Sanlelice  and  de  Giaxa  found  a  rapid  reduAion  on  receding 
from  the  shore,  but  only  within  a  distance  of  three  kilo- 
metres. 

In  1894  ^-  Cassedebat  studied  the  a(5tion  of  sea-water 
upon  pathogenic  organisms,  and  found  that  in  sterilised 
sea-water  Staphylococcus  aureus  died  in  twenty-two  to 
twenty  four  days,  Citreus  in  nineteen  to  twenty-two  days, 
B.  Friedldnder  in  thirty-five  to  forty  days,  B.  Anthracis 
in  twenty-one  to  twenty  four  days,  B.  of  green  diarrhaea 
in  sixteen  to  twenty  days.  Spirillum  Deneke  in  twenty- 
two  to  twenty-five  days,  Proteus  vulgaris  in  twenty-three 
to  twenty-six  days.  The  cholera  bacillus  lived  more  than 
thirty-five  days,  but  the  typhoid  bacillus  died  in  forty- 
eight  hours. 

The  most  complete  ba(5teriological  investigation  of  sea- 
water  hitherto  undertaken  was  made  by  Drs.  Bernhard 
Fischer  and  E.  Bassenge,  and  the  results  are  published  in 
the  Centralblatt  fiir  Bacteriologie,  1894,  "v.,  657.  They 
include  microbe  determinations  in  the  waters  of  the 
Atlantic,  English  Channel,  the  Baltic,  and  the  North  Sea. 
The  places  where  the  samples  were  taken  range  from 
8°  S.  Lat.  to  60°  N.,  and  were  coUeded  at  various  seasons 
during  the  celebrated  Plankton  expedition,  and  on  a 
voyage  to  and  from  the  West  Indies.  The  plate  cultures 
were  made  with  gelatin  containing  2  per  cent  of  agar- 
agar  dissolved  in  a  little  sterilised  sea-water,  and  the  final 


investigation  of  the  pure  cultures  was  made  in  the  Baifterio- 
logical  Institute  at  Kiel. 

The  maximum  number  of  microbes  found  at  the  surface 
was  29,400,  the  minimum  o,  and  the  mean  in  175  samples 
1083.  The  mean  was  only  surpassed  26  times  ;  seven 
samples  developed  no  organisms,  fifty-seven  developed 
from  one  to  twenty-five  colonies,  seventeen  from  twenty- 
six  to  fifty,  and  fourteen  from  fifty-one  to  one  hundred 
colonies  per  c.c.  The  highest  numbers  were  found  near 
land,  thus  confirming,  in  this  resped,  the  observations 
of  Sanfelice  and  de  Giaxa  in  the  Bay  of  Naples.  It  was 
also  found  that  sunshine  affeded  the  number  of  ba<5leria 
at  the  surface. 

During  the  recent  solar  eclipse  expedition  to  Vadso,  we 
were  able  to  extend  these  observations  up  to  71°  N.  lat.. 
Captain  Eilertsen,  of  the  Bergen  Company's  steamer 
Neptun  kindly  stopping  the  ship  whilst  we  took  the 
samples.  The  water  for  baderiological  examination  was 
colledted  at  about  2  feet  from  the  surface  in  glass  tubes 
(previously  exhausted,  sealed,  and  sterilised)  by  means  of 
the  apparatus  devised  by  one  of  us  and  described  in  the 
Chem.  News,  Ixx.,  p.  54.  The  colonies  were  counted 
after  about  five  days  incubation  at  20°  C. 

Sample  No.  i  :  Vest  Fjord,  five  miles  from  land,  lat. 
68°  N.,  at  6  a.m.  Aug.  5,  1896;  No.  of  colonies,  mean  of 
two  cultivations,  51  per  c.c. 

Sample  No.  2 :  Off  Loppen,  about  three  miles  from 
land,  lat.  70°  12'  N.,  at  10  a.m.  August  6,  1896.  Unfor- 
tunately, the  note  of  the  number  of  colonies  counted,  in 
duplicate  cultivations  of  this  and  of  the  following  sample, 
has  been  lost ;  but  the  average  number  in  each  case  did 
not  differ  materially  from  that  obtained  from  the  Vest 
Fjord  water. 

Sample  No.  3  :  Off  the  North  Cape,  about  two  miles 
from  land,  lat.  71°  10'  N.,  temperature  of  sea  7-8°  C, 
I  a.m.  August  7,  1896.  A  blank  culture  plate,  similarly 
treated  in  every  way,  did  not  yield  a  single  colony. 

No  sample  was  taken  in  the  Varanger  Fjord  on  account 
of  proximity  to  land  and  the  towns  of  Vardo  and  Vadso. 
The  temperature  of  the  sea  in  the  Fjord  at  7  a.m.  on 
August  8  off  Vadso  was  9*0°  C. 

We  have  to  apologise  for  this  very  fragmentary  record  of 
baderial  life  in  the  Ardlic  Ocean,  but  we  trust  that  it  may 
have  the  effed  of  diredling  the  attention  of  ar(5tic  and 
antariStic  voyagers  to  the  subjecft ;  for,  in  view  of  the 
important  relations  existing  between  microbes  and  animal 
life  in   the  ardtic  regions,  it  is  very  desirable  thut  these 


Calcium  Carbide — A  New  Reducing  Agent. 


{Chemical  Nbwb, 
Jan.  1, 1897. 


observations  should  be  carried  on  up  to  higher  latitudes, 
especially  where  the  temperature  of  the  sea  does  not  rise 
above  0°  C. 


ON    THE    SPECTRA    OF     COPPER,    SILVER, 

AND     GOLD.* 

By  J.  M.  EDER  and  E.  VALENIA. 

Our  former  preliminary  research  had  shown  that  the  ele- 
ments copper,  silver,  and  gold  give  continually  new  results 
on  the  variable  spedlra  of  the  elements,  for  these  elements 
yield  spark- spedra  extremely  rich  in  lines  for  surpassing 
the  corresponding  arc-spedra  in  number  and  sharpness. 
These  researches  were  commenced  two  years  ago,  but 
could  not  then  be  completed,  as  the  spedlrograph  with  a 
quartz  prism  at  the  disposal  of  the  authors  had  too  slight 
a  dispersion  in  the  less  refrangible  regions,  and  the 
spectrograph  with  a  compound  glass  prism  supplied  this 
deficiency  in  the  blue  and  the  violet  as  far  as  the  begin- 
ning of  the  ultra-violet,  but  was  not  sufficiently  eifeiS^ive 
in  the  visible  part. 

We  obtained  two  excellent  Rowland's  concave  gratings 
with  a  very  short  focus,  giving  an  admirable  definition  if 
the  light  was  very  strong.  We  seledled  one  which  pro- 
duced the  spedra  of  the  first,  second,  and  third  order 
with  great  clearness.  The  spedra  on  both  sides  of  the 
grating  never  show  a  pefedly  equal  brightness. 

The  ultra-violet  of  the  first  order,  of  A  =  3900,  at  about 
2500  is  moderately  bright,  but  from  \  2500  very  faint.  The 
spedrum  of  the  second  order  is  decidedly  darker  on  the 
red,  the  yellow,  and  the  green  than  the  spedrum  of  the 
first  order,  which  is  in  this  region  three  times  brighter 
than  the  latter.  On  the  contrary,  the  brightness  of  the 
Bpedrum  of  the  second  order  is  very  great.  From  A.  2800 
to  A.  1900  we  worked  with  the  quartz  spedrograph  with 
one  prism,  which  in  these  regions  is  far  superior  to  the 
grating  spedrograph  in  brightness  and  in  resolving  power. 
The  spedrum  of  the  third  order  is  with  our  grating  very 
bright ;  in  the  ultra-violet  of  \  2200  it  is  about  equal  in 
brightness  to  the  ultra-violet  of  the  second  order,  per- 
haps somewhat  brighter.  Consequently  the  spedrum  of 
the  second  order  is  interseded  by  very  luminous  lines  of 
the  third  order,  which  require  to  be  separated  out  and 
identified,  and  then  furnish  an  exceedingly  sharp  control 
for  the  measurements  of  the  spedrum  of  the  second 
order.  The  violet  and  ultra-violet  near  the  Fraiinhofer 
line  H  come  up  so  strongly  in  the  spedrum  of  the  third 
order  as  even  to  penetrate  light  yellow  glass,  and  can  be 
eliminated  only  by  dark  yellow  glasses  or  concentrated 
strata  of  picric  acid.  The  spedrum  of  the  fourth  order 
was  plainly  visible  in  the  grating  which  we  used,  but  its 
brightness  is  small. 

The  authors  reproduce  an  important  illustration  from 
Ames's  memoir,  "  The  Concave  Grating  in  Theory  and 
Pradice,"  taken  from  the  yohns  Hopkins  University  Cir- 
cular, No.  273,  1889. 

As  a  source  of  error  in  working  with  the  grating- 
spedrograph  are  mentioned  the  so-called  ghostly  lines, 
which  sometimes  appear  as  rather  sharp  lines  at  almost 
equal  distances,  or  sometimes  as  a  unilateral  expansion 
of  very  intense  lines. 

1.  The  copper  lines  5782,  5218,  and  5105  correspond 

to  the  lowest  temperature  prevailing  in  the  Bunsen 
fiame. 

2,  The  same  lines  with  an  accession  of  Cu  ^  =  5700, 

5292,  5153,  4704,  4651,  and  4275,  pertain  to  the 
rather  higher  temperature  of  the  faint  sparks 
springing  on  between  eledrodes  saturated  with 
copper  chloride. 


•  An  especial  reprint  from  the  Transactions  of  the  Mathematical 
and  Natural  Science  Class  0/  the  Imperial  Academy  oj  Sciences, 
Vienna,  1896. 


3.  All  the  lines  occur  in  the  arc-spedrum,  and  at  the 

highest  temperatures  of  the  arc-spedrum,  and 
must  consequently  be  considered  as  constant  lines 
peculiar  to  copper  at  the  most  variable  temper- 
atures. 

4.  In  the  arc-spedrum  there  occur  far  more  lines  than 

in  the  cases  described  under  i  and  2,  which  holds 
good  especially  for  the  more  strongly  refrangible 
lines.  As  especially  charaderistic  lines,  in  addition 
to  those  mentioned  under  i  and  2,  we  mention 
A  =  4o62,  3308,  3275,  3247,  2392. 

5.  In  the  spark-spedrum  all  the  main  lines  mentioned 

under  i,  2,  and  3  occur  also  as  principal  lines.  In 
addition  there  appear  many  very  intense  new  lines 
which  are  wanting  in  the  arc-  and  the  fiamC' 
spedra,  whilst  some  strong  Cu  lines  of  the  arc- 
spedra  recede  or  disappear  at  the  high  temperature 
of  the  spark  of  the  Leyden  jar. 

As  regards  these  phenomena,  the  Cu-spedrum  must  be 
regarded  as  very  variable  according  to  the  temperature. 

Silver,  even  in  the  strongest  Leyden  jar  spark,  is  less 
luminous  than  copper  or  gold.  When  the  Ruhmkorff 
spark  strikes  over,  the  atmospheric  lines  come  up  very 
strongly,  so  that  we  were  compelled  to  work  in  an  atmo- 
sphere of  hydrogen.  But  even  in  this  case  the  subordi- 
nate rays  of  the  Ag-spedrum  were  but  feebly  luminous. 
A  number  of  the  silver  lines  in  the  green  part  of  the 
spedrum  are  extended  into  bands,  but  there  are  many 
sharp  lines,  and  in  the  more  refrangible  part  of  the 
spedrum  sharp  lines  predominate. 

The  spedrum  of  silver  must  be  considered  as  variable, 
since  it  becomes  extremely  rich  in  lines  by  the  accession 
of  intense  silver  lines  in  the  hot  Leyden  spark.  The 
moderately  bright  lines  of  the  arc-spedrum  are  mostly 
retained,  but  are  often  surpassed  in  intensity  and  sharp- 
ness by  the  new  lines  of  the  spark-spedrum. 

The  spedrum  of  gold  is  less  known  than  the  spedra  of 
copper  and  silver.  The  lines  of  Lecoq,  A  =  56oi,  5230, 
5210,  4437,  4338,  and  4064,  do  not  belong  to  gold.  5601 
and  5210  belong  to  palladium,  5228  and  4442  to  platinum, 
and  4355  to  air  (nitrogen). 

Kriiss  was  in  error  in  ascribing  the  line  4064  (more 
corredly  4065)  to  nitrogen,  since  it  appears  distindly  in 
an  atmosphere  of  pure  hydrogen. 

The  authors  have  observed  660  lines  in  the  spark- 
spedrum  of  gold,  50  of  which  are  common  to  the  spark 
and  arc  spedra,  but  more  than  500  are  new  lines. 


CALCIUM     CARBIDE:    A    NEW     REDUCING 
AGENT. 

By  H.  N.  WARREN,  Principal,  Liverpool  Research  Laboratory. 

Since  the  introdudion  of  this  remarkable  substance,  it  is 
significant  that  scientific  men  have  been  content  to  allow 
the  produd  to  rank  solely  as  a  water  decomposer,  and 
thus  regard  the  produdion  of  acetylene  the  only  available 
produd. 

Researches  of  a  somewhat  lengthy  description,  which 
have  lately  been  carried  out  at  the  above  laboratory,  in- 
volve the  use  of  calcium  carbide  as  a  metallurgical 
reducing  agent. 

In  the  first  instance  an  excess  of  litharge  was  heated 
to  redness  in  contad  with  the  carbide,  in  a  clay  crucible, 
the  readion  being  accompanied  by  vivid  incandescence, 
resulting  in  the  formation  of  metallic  lead  and  calcium 
oxide,  CaO. 

A  further  portion  was  now  seleded,  in  which  the  pro- 
portion of  carbide  excelled  that  of  the  litharge  ;  this  was 
further  subdivided  into  various  smaller  portions,  each 
portion  being  exposed  to  various  temperatures,  resulting 
in  a  regulus  of  calcium  and  lead  of  varying  percentage, 
together  with  the  expulsion  of  CO3. 


CHBUICAt  NbWS)  1 

Jan.  I,  1897.      I 


Manufacture  of  Calcium  Carbide. 


The  alloys  thus  formed  are  all  more  or  less  brittle,  and 
to  a  certain  extent  sonorous  when  struck,  their  melting- 
point  ranking  below  that  of  pure  lead,  and  are  slowly,  but 
completely,  decomposed  in  contadl  with  aqueous  vapour, 
the  rea(5lion  being  much  less  energetic  than  that  afforded 
by  alloys  of  lead  with  the  alkaline  metals.  Stannic 
oxide,  cupric  oxide,  and  also  ferric  oxide,  at  corresponding 
higher  temperatures,  were  readily  reduced,  yielding  re- 
sults of  no  pra&ical  value ;  in  the  case  of  the  cupric 
alloys  those  samples  containing  under  i  per  cent  of  cal- 
cium being  rendered  cold-short  and  breaking  under  very 
small  strain,  whilst,  on  the  other  hand,  iron  containing 
calcium  approaches  in  appearance  that  of  ferro-manga- 
nese,  being  even  more  brittle,  and  very  oxidisable  in  con- 
tact with  water. 

In  a  further  operation,  oxides  of  manganese,  nickel, 
cobalt,  and  even  chromium,  molybdenum,  and  tungsten, 
were  readily  reduced,  yielding  calcium  alloys.  Results 
of  experiments,  comprising  the  redudlive  a(5tion  of  the 
carbide  upon  the  earthy  chlorides  and  their  haloids,  will 
be  shortly  to  hand.  The  already  partial  success  of  these 
readions  seem  to  point  most  conclusively  towards  a  new 
and  powerful  reducing  agent,  which  at  the  same  time, 
considering  the  market  value  of  the  carbide  in  question, 
could  not  fail  to  replace  both  sodium  and  potassium. 


Liverpool  Research  Laboratory, 
18,  Albion  Street,  Everton,  Liverpool. 


THE  MANUFACTURE  OF  CALCIUM   CARBIDE.* 
By  J.  T.  MOREHEAD  and  G.  de  CHALMOT. 

So  universal  is  the  interest  in  acetylene  gas  and  so  dif- 
ferent the  estimates  and  opinions  as  to  the  cost  of  calcium 
carbide  as  a  source  of  the  cheap  produdlion  of  acetylene 
gas,  that  we  have  thought  it  desirable  to  place  on  record 
the  data  from  our  a(5tual  experience  in  the  produdtion  of 
calcium  carbide  in  quantities.  The  works  of  the  Willson 
Aluminium  Company  have  been  running  night  and  day 
since  May  ist,  1895,  producing  calcium  carbide.  These 
works  are  daily  duplicating  the  results  here  given  and  can 
expand  indefinitely.  Each  individual  step,  except  water 
power,  as  taken  at  Spray,  N.  C,  is  capable  of  being 
changed  in  the  dire(5lion  of  reducing  the  cost  of  the  out- 
put, as  these  efforts  have  been  attended  with  the  clumsi- 
ness, lack  of  adaptability,  and  excessive  cost  that  is 
incident  to  all  efforts  along  an  untrodden  path.  Still  we 
can  produce  calcium  carbide  at  less  than  25  dols.  per 
ton,  including  wear  and  tear  and  interest  on  capital. 

Beyond  looking  after  the  dynamos,  no  special  training 
is  necessary,  as  neither  metallurgical  nor  chemical  skill 
is  required  in  the  operations.  We  grind  and  mix  coke 
and  lime,  start  the  water  wheel,  see  that  the  arc  is 
formed,  shovel  in  the  mixture  of  lime  and  coke,  and  the 
volt-  and  ammeter  show  when  to  lower  or  raise  the  car- 
bon pencils,  which  is  done  by  means  of  a  screw  located  in 
the  dynamo  room,  away  from  the  furnace.  We  can 
measure  with  an  ordinary  yard  stick  on  this  screw  the 
height  of  the  piece  of  carbide  in  the  furnace.  We  stop 
when  we  have  raised  the  carbon  pencils  33  inches,  switch 
the  current  off  to  another  furnace  and  repeat  the  opera- 
tion. The  carbide  in  the  former  furnace,  as  soon  as 
cooled  and  brought  in  contact  with  water,  is  all  ready  to 
do  perfed  work  in  generating  acetylene  gas  ;  it  will  pro- 
ceed with  this  work  without  help  and  will  make  room 
therefor  in  spite  even  of  bands  of  steel. 

Water  power  costs  us  6  dols.  per  horse  power.  Water 
in  the  raceways  ready  for  the  water  wheels  is  now  offered 
in  enormous  quantities  to  the  Willson  Aluminium  Com- 
pany at  the  rate  of  5  dols.  per  horse  power  per  year. 


*  Read  Sept.  3rd  before  the  Springfield  meeting  of  the  A.A.A.S.  by 
one  of  us  (M).  We  have  made  since  then  several  additions,  so  as  to 
make  the  article  complete  up  to  the  present  time.  From  the  Journal 
of  the  American  Chemical  Society,  April,  1896. 


These  powers  are  located  at  different  places,  where  coke 
and  lime  can  be  had  cheaply,  and  also  cheap  transporta* 
tion  for  the  carbide  to  the  market. 

The  technical  description  of  our  process  which  follows 
herewith  was  written  by  G.  de  Chalmot,  who  has  had  for 
some  time  personal  supervision  of  the  operations  of  the 
Willson  Aluminium  Company. 

In  the  year  1888  Mr.  T.  L.  Willson  started  a  series  of 
experiments  with  a  view  of  reducing  refradory  ores  in  the 
eledric  furnace,  and  among  other  valuable  things  he 
made  calcium  carbide.* 

We  will  first  give  a  short  description  of  the  furnace 
and  a  general  outline  of  the  process,  then  enlarge  some- 
what on  the  details.  The  furnace  used  in  Spray,  N.  C, 
is  built  of  ordinary  brick  (a  sedtional  front  view  is  given 
in  Fig.  i).  The  front  side  is  formed  by  four  iron  doors, 
the  one  above  the  other.  The  upper  two  remain  closed 
usually.  The  chimney  is  attached  near  the  top  of  the 
furnace,  and  commences  with  a  flue,  m,  in  the  corner. 
The  furnace  measures  at  the  bottom  inside  2j  by  3  feet. 
The  eledric  current  enters  at  the  bottom  and  top.  The 
bottom  eledrode  is  an  iron  plate,  a,  covered  with  8  inches 
of  carbon,  b.  For  this  covering  we  use  pieces  of  carbon 
pencils  or  a  mixture  of  coke  and  coal  tar.  Sixteen 
copper  cables  of  075  inch  in  diameter,  c,  convey  the  elec- 
tricity from  the  dynamos  to  the  bottom  eleftrode. 

Sixteen  other  cables  are  connedled  with  the  top  elec- 
trode, d.  The  top  eleftrode  is  composed  of  six  carbon 
pencils,  e,  each  4  inches  square  and  36  inches  long.  Six 
pencils  are  arranged  in  three  pairs  behind  each  other,  and 
are  cut  out  at  the  top  so  as  to  fit  in  the  carbon  holder,/. 
They  are  enveloped  together  by  a  sheet  of  iron,  g-,  which 
is  shown  in  the  right-handed  furnace  of  Fig.  1.  They 
really  form  one  pencil.  The  carbon  holder  is  screwed  to 
a  copper  bar,  h,  which  is  three  inches  square,  and  to 
which  the  copper  cables  are  connedted.  This  bar  is  fas- 
tened by  a  chain  that  runs  over  two  pulleys  to  a  long 
upright  screw,  i.  On  this  screw  is  a  nut  which  forms  the 
centre  of  a  wheel,  k.  By  turning  the  wheel  the  screw  can 
be  raised  or  lowered.  The  man  who  attends  to  the  wheel 
has  the  volt-  and  ammeter  before  him.  The  eledlric 
current  is  generated  in  two  dynamos  to  which  trans- 
formers are  conneded,  and  which  can  give  a  current  of 
from  50  to  100  volts.  The  power  is  furnished  by  a  water 
wheel  of  300  horse  power  under  28  feet  fall. 

Two  of  the  furnaces  have  been  working  for  twelve 
months,  and  they  have  given  satisfadion,  except  for  work- 
ing not  sufficiently  economically.  In  the  furnaces  built 
for  the  Niagara  Falls  Carbide  plant  many  changes  which 
we  suggested  have  been  adopted,  looking  to  economy  of 
produdlion.  We  give  here  a  short  description  of  these 
furnaces  (Figs.  2  and  3). 

In  Spray  it  is  necessary  to  allow  the  furnace  to  cool 
before  emptying  it.  In  order  to  use  one  and  the  same 
furnace  continuously,  the  bottom  of  the  furnace  is  re- 
placed by  an  iron  car,  a,  which  runs  on  a  track,  and  in 
which  carbide  is  formed.  When  the  car  is  filled  the  pen- 
cils, b,  have  been  lifted  entirely  out  of  it.  The  current  is 
then  shut  off,  door  c  is  opened,  the  full  car  is  run  out  and 
replaced  by  an  empty  car.  The  pencils  are  lowered 
again  to  the  bottom  of  the  car  and  a  new  run  is  com- 
menced. 

The  bottom  of  the  car  is  covered  with  from  4  to  8 
inches  of  carbon.  When  the  contents  of  the  car  have 
sufficiently  cooled  outside  the  furnace,  which  will  take 
from  six  to  twelve  hours,  the  body  of  the  car  is  lifted  from 
the  track  by  the  trunnions,  d,  and  turned  over.     The  con- 


*  We  will  note  here  that  Moissan,  who  discovered  this  process  for 
making  carbide,  independently  of  Mr.  Willson,  communicated  inci- 
dentally, at  the  meeting  of  the  French  Academy  of  December  12th, 
1892  [Compt.  Rend.,  115,  1033)  that  a  carbide  of  calcium  is  formed  if 
calcium  oxide  is  heated  in  an  eleftric  furnace  with  carbon  eledtrodes. 
He  investigated  the  compound  much  later  (Compt.  Rend.,  118,  50). 
Mr.  Willson,  who  sent,  during  the  summer  of  1892,  samples  of 
carbide,  for  examination,  to  Lord  Kelvin,  of  the  Glasgow  University, 
clearly  antedates  Moissan.  See  Journal  of  Franklin  Institute  of 
1895,  page  333.— Note. 


Manufacture  of  Calcium  Carbide, 


5  Crbuical  Nbws, 
I       Jan.  I,  1897. 


Fig.  I. 

time  at  one  point,  for  which  the  arc  has  always  a  great 
tendency.  This  will  materially  increase  the  efficient  use 
of  the  heat  of  the  arc.  Under  the  track  of  the  car  is  the 
bin,  h,  in  which  the  unreduced  material  is  colledted  that 
will  fall  from  the  car  when  this  is  taken  out.  This  mate- 
rial can  from  time  to  time  be  taken  out  through  the  door  i. 
The  carbon  holder  is  more  complicated  than  in  the  Spray 
furnace.  Twelve  carbons  are  used,  and  the  holder  is 
therefore  about  twice  as  heavy.  It  is  not  advisable  to 
suspend  this  carbon  holder  from  a  copper  bar,  which 
moreover  becomes  rather  hot  in  this  closed  furnace. 
The  carbon  holder  is  therefore  attached  to  a  rod,  /,  which 
is  composed  of  three  slabs.  The  inner  one  is  of  copper, 
and  measures  6  by  ij  inches,  and  the  outer  ones  are  of 
iron  and  are  6  inches  by  i.  Since  it  is  not  pradical  to 
attach  the  twelve  carbons  in  their  iron  casing  to  the  car- 
bon holder  in  the  furnace,  the  holder  itself  is  composed  of 
two  pieces,  m  and  «,  which  slide  into  each  other.  The 
aggregate  of  pencils  is  connedted  to  piece  n  outside  the 
furnace,  and  the  whole  is  placed  in  the  car  a.  Rod  /  is 
so  far  lowered  that  piece  m  will  easily  slide  into  piece  «, 
and  the  connexion  can  easily  be  effedled.     Iron  plates,  0, 1 


tents  are  dropped  on  a  grate  formed  of  iron  bars,  on  which 
the  piece  of  carbide  remains,  while  the  unreduced  material 
falls  through  into  a  lower  room,  where  it  is  colledted  to  be 
used  again  for  the  formation  of  carbide.  The  mixture  of 
lime  and  coke  is  fed  into  the  car  through  the  flues,  e, 
which  extend  along  the  whole  length  of  the  car.  The 
rods,/,  which  bear  four  blades,  extend  through  the  whole 
breadth  of  the  feeding  flues.  These  rods  are  turned  auto- 
matically, and  the  faster  they  turn  the  more  material  is 
fed  into  the  car.  In  order  to  stoke  the  furnace  automati- 
cally, the  car  is  attached  to  an  iron  bar,  g',  by  two  hangers 
and  a  coupling  in  front  of  the  car.  Bar  g  extends  through 
the  back  wall  of  the  furnace,  and  is  automatically  moved 
forward  and  backward  for  about  2  inches  and  about 
twenty  times  per  minute.  The  car  is  thus  also  rolled 
backward  and  forward  on  the  track  for  about  2  inches 
each  time.  Every  time  that  the  car  stops  or  starts  it  gets 
a  little  jerk  which  is  sufficient  to  fill  up  the  holes  made  by 
the  escaping  gases  in  the  loose  material.  This  motion  of 
the  car  further  prevents  the  arc  being  located  for  a  longer 


M 


'/y//////,y/A 


■■///////,'/A 


Chbhical  Nbws, I 
Jan.  1, 1897.      I 


Quantitative  Analysis  of  Spectra, 


are  placed  between  the  carbon  holder  proper  and  the 
pencils.  These  plates,  0,  are  about  i  inch  thick.  They 
are  fastened  to  the  inside  of  the  carbon  holder  by  pins 
which  are  inserted  in  the  holder,  and  fit  in  holes  of  the 
plates.  These  plates  can  be  easily  removed  and  replaced. 
It  will  sometimes  happen  that  a  small  arc  is  started  be- 
tween the  pencils  and  the  inside  of  the  carbon  holder, 
and  a  part  of  the  carbon  holder  will  melt.  In  the  case 
that  the  plates  0  are  used  one  can  simply  replace  these 
plates.  The  car  a  forms  one  of  the  eledrodes,  and  is 
conne(5led  with  the  bottom  cables,  q,  by  two  clamps,  p. 
The  lower  clamp  is  stationary  and  the  upper  one  can  be 
opened.  The  clamps  are  tightened  around  the  appendage 
z  of  the  car  by  a  wedge  and  screw,  5.  When  the  clamps 
are  fastened  the  slide  t  is  lowered  so  as  to  shut  the  open- 
ing. The  eleftric  connexion  with  the  car  can  also  be 
and  is  better  made  through  the  bar  ^,  which  in  that  case 
is  composed  of  an  iron  and  a  copper  slab.  It  may  also  be 
made  by  two  copper  bars  which  run  alongside  of  the  car 
and  are  pressed  against  it  with  springs.  The  furnace  is 
entirely  closed.  When  it  is  started  the  door  c  is  shut, 
but  the  door  u  is  kept  open  till  the  carbon  monoxide, 
which  is  formed  in  the  readlion,  has  replaced  the  air  in 
the  furnace.  This  point  is  reached  when  the  flame 
comes  out  of  this  door.  Door  u  is  then  also  closed  and 
the  gases  escape  through  the  chimney,  v.  The  use  of 
door  M  prevents  explosions  of  the  carbon  monoxide  in 
the  closed  furnace.  Chimney  v  begins  just  over  the  car 
The  carbon  holder  and  the  rod  I  are  therefore  not  in' 
the  current  of  the  hot  gases.  The  upper  part  of  the 
furnace  is  cooled  moreover  by  an  air  jacket,  w,  through 
which  a  draught  of  air  is  maintained.  The  cold  air 
enters  through  openings  x  and  the  warm  air  is  led  ofT  by 
chimney  >».  The  warm  air  may  be  utilised  for  heating 
the  building.  The  chimney  gases  pass  through  flues  or 
rooms,  in  which  the  lime  dust  is  collected  by  proper 
means.  Owing  to  valuable  suggestions  of  our  super- 
intendent, Mr.  J.  C.  King,  this  furnace  is  called  the  King 
Furnace.  Besides  these  two  types  of  furnaces,  several 
others  have  been  proposed. 

In  order  to  start  our  present  furnace,  we  shut  the 
lower  iron  door  and  lower  the  pencils  to  the  bottom  of 
the  furnace.  The  current  is  turned  on  and  the  mixture 
of  coke  and  lime  fed  in,  the  arc  being  kept  covered 
with  the  mixture  as  high  as  one  foot  around  the  pencils. 
It  is  then  easier  to  keep  the  arc  steady.  It  is  neces- 
sary to  stoke  from  time  to  time,  for  the  gases  which 
are  formed  in  the  arc  constantly  make  channels  through 
the  material,  and  especially  if  unslacked  lime  is  used. 
These  channels  will  not  fall  in,  and  less  material  will 
come  into  the  arc.  The  feeding  in  of  the  material  is 
continued  for  several  hours.  If  the  attendant  at  the 
hand  wheel  sees  that  the  voltage  becomes  low,  he  raises 
the  pencils.  If  the  arc  should  be  broken  the  amperage 
becomes  zero  and  the  voltage  high,  and  in  that  case  the 
pencils  are  quickly  lowered.  After  shutting  off  the 
current  it  is  well  to  allow  the  furnace  to  cool  two  or 
three  hours  before  emptying  it. 

(To  be  continued). 


QUANTITATIVE    ANALYSIS    OF    SPECTRA. 

A  NEW  method  has  been  elaborated  by  G.  and  H.  Kriiss, 
and  is  now  published  by  H.  Kriiss  after  the  death  of  G. 
Kriiss  {Zeit.  Analyt.  Chemie). 

If  a  substance  in  a  layer  of  a  substance,  of  a  thick- 
ness =  I,  enfeebles  by  absorption  the  light  which  it 
transmits  from  the  intensity — 

I  toil 
n 

(and  has  therefore  the  enfeebling  fador  K  for  the  stra- 


tum I),  the  intensity  I'  of  the  light  passing  through  a 
stratum  of  the  thickness  m  will  be — 


(I) 


r  = 


(This  applies  stridlly  for  monochromatic  light  with  only 
one  fadtor  of  enfeeblement). 

If  we  assume  the  original  strength  of  the  light  =  i, 
we  obtain  the  equation — 


(2) 


I'=_L. 
n  m 


Therefore  log.  «   =    -  '°g-  ^'  . 
in 

Ir  we  call  e  the  coefificient  of  extin(5lion  of  the  sub- 
stance concerned,— that  is,  the  reciprocal  value  of  the 
thickness  of  the  stratum  which  is  necessary  to  reduce 
the  transmitted  light  to  jV'h  of  >ts  original  intensity,— 
then  when — 

»t  «  i  r  will  =  T»(,. 
e 

Hence  follows  log.  n  =  e,  or  also — 


(3) 


_  log.  I' 


m 


If  we  work  with  the  stratum  m  =  i  we  have— 
(4)     ..     «  =  log.  I'. 

The  coefficient  of  extinftion  is  hence  equal  to  the 
negative  logarithm  of  the  residual  brightness.  When 
this  has  been  determined  for  the  stratum  =  i  it  may  be 
taken  diredly  from  the  proper  tables. 

The  authors  justly  point  out  that  to  many  the  process 
is  rendered  less  intelligible  by  the  circumstance  that  We 
do  not  measure  the  thickness  of  the  stratum  at  which  the 
brightness  is  reduced  down  to  ^^,  but  in  its  stead  that 
effedled  by  a  constant  depth  of  stratum  which  is  of 
different  thickness  for  each  body. 

In  order  to  draw  a  conclusion  as  to  the  concentration 
of  a  solution  from  its  coefficient  of  extindtion  as  thus 
determined,  we  must  consider  that  the  reduction  of 
brightness  depends  only  on  the  quantity  of  the  absorbent 
substance  present  in  a  given  depth  of  the  solution,  so 
that  a  greater  concentration  of  the  liquid  at  the  same 
depth  must  have  the  same  effecft  as  the  introdudlion  of 
a  corresponding  deeper  stratum  of  a  solution  of  an  un- 
changed concentration.  Hence  it  follows  that  the  ratio 
of  the  concentration,  c,  to  the  coefficient  of  extincflion,  e, 
for  each  absorbent  substance,  is  a  constant  which  must 
depend  on  the  kind  of  the  substance.  It  is  known  as  the 
absorbed  proportion — 

(5)     ..     A=£, 
e 

whence,  if  A  is   known,  the  concentration   follows  from 
the  measurement  of  e. 


(6) 


c  =  A.  ^. 


The  authors,  in  order  to  obviate  the  above  difficulty, 
have  modified  the  procedure,  so  that  the  depth  of  the 
stratum,  w,  which  occasions  a  certain  redudlion  of  bright- 
ness, is  really  measured- 

If  the  intensity,  I,  of  the  light,  is  reduced  to  I'  by  a 
stratum,  wi,  of  a  solution  of  the  concentration,  c,  whilst 
a  stratum  of  the  thickness  i  of  a  solution  of  the  same 
substance  of  the   concentration  i  reduces  the  light   to 

—  ,  we  have — 


(7) 


If  we  put — 


I'  = 


X 


Isomerism  in  the  Pyrazol  Series. 


iCrbuical  Mbws. 
\      Jan.  1, 1807. 


then  follows  x  =i  x  =  n  m  c,  ot  log.  «  =  w  c,  log.  n. 


without   succeeding  in  exadlly  ascertaining  the  experi- 
mental conditions  favourable  to  the  formation  of  either 


(8) 


m  log.  n 

»,  the  specific  power  of  absorbing  light,  is  for  each 
substance  a  constant ;  accordingly  also  log.  «i  respefting 
its  reciprocal  value,  we  call  k.    Thus  we  have — 


(9) 


c^i. 


This  magnitude  k  is  nothing  better  than  the  absorptive 
ra^io  A  as  above  reduced,  for  we  had  above  c  =  A.  c,  and 
we  have  here  further  (if »«  is  selefted  so  that  x  =  lo),— 


whence  there  follows — 


X 

m 
m 


The  apparatus  used  by  the  authors  cannot  be  intelli- 
gibly described  without  the  accompanying  figure. 

In  using  the  apparatus  we  pour  into  one  of  the  vertical 
tubes  the  solvent  liquid,  and  into  the  other  the  liquid  to 
be  examined,  and  we  allow  the  light  from  a  Hiibner 
refleAing  prism  to  fall  upon  a  spedtro-photometer,  so  ad- 
justed that,  with  equal  illumination,  one-half  of  the  field 
of  vision  has  only  one-tenth  the  brightness  of  the  other 
half.— Zeit.  Analyt.  Chemie. 


CASES    OF   ISOMERISM    IN   THE   PYRAZOL 

SERIES. 

By  R.  VON  ROTHENBURG. 

I.  The  Question  of  the  Constitution  of  the  {c)-Phenyl- 
pyrazol  Series. 
I  HAVE  mentioned  in  the  Berichte  (xxvii.,  789)  that  I  have 
obtained  Buchner's  phenylpyrazol,  melting  at  228',  along 
with  other  more  fusible  produdls,  by  the  aftion  of  hydrazin 
hydrate  upon  benzaldehyd, 

Knorr,  by  the  reciprocal  adlion  of  the  same  substances, 
has  obtained  merely  phenylpyrazol,  melting  at  78°.  He 
believes,  on  the  basis  of  theoretical  speculations,  that  the 
phenylpyrazol  melting  at  228°  must  be  (4)-phenyipyrazol, 
and  hence  declares  my  statement  as  "  puzzling." 

Recently,  Buchner  has  contradided  the  views  of  Knorr, 
and  shown  that  neither  his  theoretical  expositions  nor 
their  experimental  proofs  are  in  all  respects  trustworthy. 

Before  anew  taking  part  in  the  discussion,  it  seems 
advisable  to  describe  accurately  the  experiment  which  I 
formerly  instituted. 

Crude  benzoylaldehyd  —  obtained  in  the  ordinary 
manner — was  mixed  with  i  mol.  hydrazin  hydrate  in  an 
alcoholic  solution,  producing  a  violent  reaftion.  The 
mixture  was  then  heated  for  some  time  in  the  water-bath, 
poured  into  several  times  its  volume  of  water,  the  oil  was 
taken  up  in  benzene,  separated  from  the  water,  and  the 
basic  constituents  were  withdrawn  from  the  oil  by  means 
of  dilute  hydrochloric  acid.  The  solution  thus  obtained 
yielded  the  platinum  salt  which  I  have  described  {loo. 
cit.),  and  after  neutralising  with  soda  a  crystalline  mass 
which,  on  fradtional  crystallisation,  yielded  first  slightly 
yellowish  crystals  melting  at  228°,  and  subsequently  frac- 
tions fusible  below  100°,  which  I  have  already  described 
as  an  isomer.  The  yield  of  produa  fusible  at  228°  was 
about  10  per  cent  of  the  amount  to  be  theoretically  ex- 
peiSted. 

That  both  phenylpyrazols  (melting-points  228*^  and  78°) 
should  be  obtainable  from  benzaldehyd  does  not  agree 
with  Knorr's  theory  of  the  pyrazol  nucleus,  but  it  does  not 
clash  with  the  behaviour  of  phenylhydrazin  with  benzoyl- 
aldehyd;  the  less  so,  as  both  pyrazolswere  also  obtained 
by  means  of  diazoacetic  ester,  and  in  various  proportions, 


isomer. 

In  spite  of  the  brilliant  experimental  researches  of 
Knorr  on  the  pyrazols,  which  showed  the  formation  of 
only  one  methylpyrazol  from  oxymethylenaceton,  which 
allowed  the  same  methylpyrazol  to  be  obtained  from  two 
isomers  of  the  phenol  series,  and  in  spite  of  the  produc- 
tion of  a  (3,  4, 4,  5)-tetramethylpyrazol,  no  unobjedtionable 
proof  has  been  furnished  that  also  (3)-  and  (5)-phenyl- 
pyrazol  must  be  identical,  since  it  is  evident  that  the 
methyl  and  the  phenyl-group  must  have  a  very  different 
influence. 

(5)-Phenylpyrazol,  or  pyrazol  (5). carbonic  acid,  must 
be  obtainable  by  the  oxidation  of  the  (5)-phenyIpyrazolin 
obtained  by  me  from  cinnamelydenazin.  May  I,  since  I 
cannot  at  present  execute  these  experiments,  address  to 
Dr.  Buchner  the  request  that  he  would  include  these  in- 
vestigations within  the  scope  of  the  oxidations  which 
he  has  in  view  ? 

Buchner  has  pointed  out  that  a  resorcin  fusion  performed 
at  too  high  a  temperature  is  no  proof  for  the  presence  of 
an  o-dicarbonic  acid  ;  since  resorcin  alone,  if  heated  for 
a  long  time  at  a  sufficiently  high  temperature,  or  in  pre- 
sence of  a  condensation  agent,  yields  strongly  fluorescent 
melts.     Knorr  has  totally  overlooked  this  fadl. 

Buchner's  resorcin  fusion  at  a  sufficiently  low  tem- 
perature, and  my  synthesis  of  hydrazin  hydrate,  require 
imperatively  that  phenylpyrazol  (228°)  must  not  be  re- 
garded as  (3)-  or  (5) -phenylpyrazol. 

If  Knorr  does  not  view  Buchner's  or  my  statements 
as  founded  on  air,  he  must  admit  that  phenylpyrazol 
(228°)  cannot  be  (4)-phenyIpyrazol. 

2.  On  the  Synthesis  of  Antipyrine. 
About  a  year  ago  I  described  {Berichte,  xxvi.,  2974)  a 
method  for  obtaining  a  phenylpyrazolon  (melting-point 
155°),  previously  obtained  by  different  methods,  and  I 
assigned  it  the  constitution — 

n:=z:ch 

I  I 
C6H5N      CH2 

CO 

On  the  contrary,  F.  Stolz  advocated  the  formula — 
C6H5N CH 

II  II 
HN        CH 

\/ 

CO 

He  grounded  his  opinion  essentially  upon  the  circum- 
stance that  the  isomeric  phenylpyrazolon  melting  at  n8° 
must  have  the  formula  which  I  assumed  for  the  phenyl- 
pyrazolon melting  at  155°,  since  it  is  formed  from  oxal- 
acetic  ester  hydrazon.  I  did  not  then  touch  upon  this 
point,  as  the  produdlion  of  phenylpyrazolon  melting  at 
118°  from  oxalacetic  ester  hydrazon  takes  place  in  a 
manner  which  admits  of  no  inference  as  to  its  constitu- 
tion.  On  the  other  hand,  formalacetic  ester  forms  with 
phenylhydrazin  not  the  phenylpyrazolon  fusible  at  n8°, 
but  that  melting  at  155°. 

Stolz  certainly  contests  that  this  pyrazolon  can  here 
come  into  consideration,  but  he  has  not  found  it  neces- 
sary in  any  manner  to  establish  his  opinion.  Why,  lastly, 
has  he  not  obtained  (i)-phenylpyrazolon  from  oxalacetic 
ester  and  phenylhydrazin  in  the  same  manner  in  which  I 
obtained  pyrazolon  itself  by  means  of  hydrazin  hydrate  ? 

In  the  meantime  there  have  appeared  memoirs  and 
patent  specifications  which  induce  me  to  oppose  energeti- 
cally the  constitutional  formula  of  Stolz  as  entirely 
untenable. 

If,  as  Stolz  assumes,  phenylpyrazolon  fusible  at  118° 
were  really  the  lower  homologue  of  Knorr's  (i)-phenyl. 
(3)-methylpyrazolon    fusible    at    127°,    both    would    be 


Substituted  Glycolic  Esters  and  Glycolhydrazid, 


OHBMicAL  News,  I 
Jan.  1, 1897.      f 

obtainable  in  an  analogous  manner  by  the  circuitous  way 
of  phenylethoxylpyrazol  ;  but  this  is  not  the  case. 

Whilst  the  hydrazones  of  the  /3-ketonic  esters  when 
heated  alone  pass  into  normal  pyrazolones,  with  abscis- 
sion of  alcohol,  they  are  converted  by  acid  conJensation 
agents  into  alkyloxypyrazols,  and  by  concentrated  sul- 
phuric acid  into  indol-derivatives. 

It  seems  to  me  free  from  doubt  that  the  formation  of 
indol,  and  that  of  the  alkyloxypyrazols,  occasionally  occur 
colledively,  and  the  non-symmetric  hydrazines  formed 
split  off  ammonia  or  water. 

It  is  not  surprising  that  in  an  acid  solution  the  more 
basic  pyrazol  is  formed  rather  than  the  very  feebly  basic 
pyrazolon.  It  can  be  explained  only  under  these  supposi- 
tions, that  we  do  not  obtain  from  acetacetic  ester  pyra- 
zolon Knorr's  pyrazolon  fusible  at  127°. 

From  the  (i)-phenylpyrazolon-(3)-carbonic  ester  the 
Hochst  Colour  Works  obtain  (i)-phenyl-(2)  methyliso- 
pyrazolon  of  the  melting-point  117°. 

From  Walker's  (i)-phenylethoxylpyrazol  there  is  cer- 
tainly also  formed  a  phenylmethylisopyrazolon  fusible  at 
117°,  but  it  must  be  (2)-phenyl-(i)-methylisopyrazolon, 
which  melts  at  about  the  same  temperature.  The 
melting-points  of  the  (i,  2)-  and  (2,  i)-isomers  are  so 
near  together  that  they  cannot  be  used  for  charaderising 
and  distindtion. 

Knorr's  pyrazolon  (127°),  as  already  remarked,  is  dif- 
ferent from  the  "  phenylmethoxypyrazol  "  obtained  on 
treating  the  phenylhydrazon  of  a(5tetacetic  ester  with  acid 
condensing  agents  and  saponifying  the  alkyloxypyrazol. 
Consequently,  their  lower  homologues  may  be  different. 
The  pyrazolon  derivative, — 

C6H5N CCH3 

I  II 

CH3N        CH      , 

\/ 

CO 

must  be  pseudoantipyrin. 

The  halogen-cretonic  acid,  produced  according  to  the 
German  patent  No.  64444,  's  pseudoantipyrin,  as  Krauth 
has  shown.  This  question  is  of  no  little  scientific  interest, 
since  the  antipyrins  of  the  type — 

RiN CR2 

I  II 

CfiHeN        CH 

\/ 
CO 

are  antipyretic  medicines,  whilst  those  of  the  type — 

C6I-I5N CR2 

I         II 
RiN        CH 

\/ 

CO 

are  poisons. 

As  appears  from  the  above  explanations,  the  elabora- 
tion of  the  pyrazolon  region  carried  out  by  Stolz  and  the 
Hochst  Colour  Works  is,  from  a  scientific  point  of  view, 
not  unobjedionable. 

The  German  Patent  No.  66808  declares  it  possible  to 
obtain  pyrazolon  derivatives  by  the  oxidation  of  /3-amido- 
crotonicanilidon,  which  is  known  to  be  impossible. 

Finally,  the  Hochst  Colour  Works  have  not  been  able 
to  refrain  from  announcing  the  notorious  antipyrin  alcohol 
for  a  patent,  on  January  5,  1892. 

3.  On  the  Pyrazolon-iulpho  Acids. 

C.  Walker  recently  describes  some  sulpho-acids  of  the 
pyrazolons  which  he  has  obtained  by  means  of  concen- 
trated sulphuric  acid  from  the  hydrazones  of  substituted 
acetacetic  esters.  To  these  sulpho-acids  he  ascribes  a 
peculiar  and  at  least  improbable  constitution. 

Walker's  formulae  prove  anew  to  what  improbable 
assumptions  the  obstinate  adherence  of  Neff  and  his 


school  to  the  oxycrotonic  formula  of  acetacetic  ester  and 
the  isoconstitution  of  the  normal  pyrazolons  must  lead. 

4.  On  the  Isomeric  Benzoylphenylmethylpyrazolons. 
Neff  believes,  as  is  well  known,  that  he  has  demonstrated 
for   (i)-phenyl-(3)-methylpyrazolon   (fusible  at  127°)  the 
formula — 

HN C.CH, 

I         II 
C6H5N        CH 

CO 

because  he  has  succeeded  in  producing  two  isomeric 
monobenzoyl-derivatives.  The  proof  has,  however,  been 
in  no  respedt  supplied.  He  overlooks  that  all  the  other 
readions  of  this  pyrazolon  fusible  at  127°  can  be  much 
more  easily  explained  by  the  formula — 


N: 


-CCH, 


CeHjN        CHa  . 

\/ 
CO 

How  will  he  explain  the  solubility  of  the  pyrazolons  and 
the  insolubility  of  antipyrin  in  alkali  by  means  of  his 
formulae  ? — Journal  fur  Praktische  Chemie,  New  Series, 
vol.  li.,  p.  157. 


ON    SUBSTITUTED    GLYCOLIC    ESTERS   AND 

GLYCOLHYDRAZID. 

By  TH.  CURTIUS  and  A.  SCHWAN. 

This  paper  forms  the  fifth  part  of  a  prolonged  account 
of  the  hydrazides  and  azides  of  organic  acids,  appearing 
under  the  name  of  Th.  Curtius. 

Some  years  ago  one  of  the  present  writers  found  that  if 
benzoylglycolic  ester  is  exposed  to  the  adlion  of  2  mols. 
diammonium  hydrate  benzhydrazid  and  amidoglycocoll 
are  produced  with  abscission  of  water  and  alcohol. 

This  remarkable  readion  yielded  the  first  representa- 
tives of  two  classes  of  organic  substances  hitherto 
unknown,  the  primary  acidylhydrazides  and  the  hydrazin 
acids. 

As  subsequent  researches  had  shown  that  primary 
acidylhydrazides  are  quite  generally  formed  by  the  a(5tion 
of  hydrazin  hydrate  upon  acid  esters,  we  might  have 
expeifted  that  benzoylglycolic  ester  with  i  mol.  hydrazin 
hydrate  would  yield  benzoylglycol  hydrazid.  The  latter 
would  then  be  resolved  by  the  adion  of  a  second  mol.  of 
the  base  into  benzhydrazid  and  glycolhydrazid. 

One  of  the  authors  had  previously  expressed  the  view 
that  the  last-named  substance  would  correspond  to  the 
constitutional  formula  NHzNH'CHa'COOH,  and  that 
therefore,  in  addition  to  benzhydrazid,  there  would  appear 
hydrazinacetic  acid  or  amidoglycocoll  on  the  scission  of 
benzoylglycolic  ester. 

We  have  established  that  our  view  here  given  is  correA, 
and  that  the  substance  in  question  is  the  hydrazid  of 
glycolic  acid,  CHaCOH^CONHNHz. 

In  the  adlion  of  alcohols  or  acids  upon  diazoacetic  ester 
one  of  us  has  found  a  method  for  producing  substituted 
glycolic  esters  of  any  kind.  By  means  of  this  process  we 
have  obtained  a  series  of  such  bodies,  hippurylglycolic 
ester,  oxalylglycuric  ester,  succinylglycolic  ester,  benzyl- 
glycolic  ester,  and  glycolic  ester. 

The  organic  acids  readt  in  some  cases  explosively  upon 
diazoacetic  ester  even  in  the  cold,  especially  oxalic  acid. 
With  other  acids  the  readlion  occurs  only  in  heat,  but 
then  very  energetically. 

Pure  water  or  alcohol  readls  only  with  extreme  diffi- 
culty upon  perfe(5tly  pure  diazoacetic  ester,  so  that  it  has 


8 


Derivatives  of  Columbium  and  Tantalum. 


(  Chemical  News, 
1       Tan.  1, 1897, 


not  been  pradicable  thus  to  obtain  a  good  yield  of  glycol 
esters. 

As  for  the  effeds  of  hydrazin  hydrate  upon  these  esters 
the  rea(aion  might  either  take  place  as  with  ordinary 
esters,  so  that  glycolhydrazides  are  produced  in  which 
the  hydrogen  of  the  hydroxyl  group  is  substituted  by  an 
alkyl  or  acidyl  group,  or — as  the  substituted  glycolic 
esters  might  be  regarded  as  double  esters — there  might 
readt  simultaneously,  the  one  attacking  the  esterified 
carboxyl  group,  and  the  other  the  etherified  hydroxyl 
group. 

Investigation  has  shown  that  upon  alkylglycolic  esters 
there  readts  only  one  mol.  of  hydrazin  hydrate,  forming 
alkylglycol  hydrazid  and  splitting  off  alcohol,  whilst  in 
the  acidyl-glycolic  esters  there  always  reacft  two  mols.  of 
hydrazin  hydrate. 

As  for  the  constitution  of  the  so-called  hydrazin-acetic 
acid  we  have  to  consider  firstly  its  formation  from  glycolic 
ester.  Hydrazin  hydrate  adts  violently  upon  this  sub- 
stance even  in  the  cold.  On  evaporation  there  remains 
hydrazid  in  massive  crystals.  But  if  in  place  of  glycolic 
acid  we  employ  alkylised  glycolic  acids,  then  if  the  sub- 
stance in  question  is  to  be  regarded  as  hydrazin  acetic 
acid,  hydrazin  acetic  acid  should  also  be  formed  with 
abscission  of  alcohol,  instead  of  which  we  always  obtain 
alkylised  glycol-hydrazid. 

Finally,  the  remarkable  instability  of  the  so-called 
amidoglycocoll  in  an  aqueous  solution  as  against  dilute 
mineral  acids,  compels  us  to  regard  the  compound  as 
glycolhydrazid. 

The  authors  then  describe  the  preparation  and  properties 
of  glycolic  ester,  of  phenylglycolic  ester,  of  benzylglycolic 
ester  [C11H14O3] ,  of  ethylglycolic  ester,  hipperylglycolic 
ester  [CiiHi303N],oxalylglycolic  ethyl  ester  [C10H14O8], 
Buccinylglycolic  ester  [CizHisOs]. 

The  authors  next  study  the  adion  of  hydrazin  hydrate 
on  the  substituted  glycolic  esters. 


DETERMINATION    OF    PHOSPHORUS    IN 
ASH    OF    COAL    AND     COKE. 
By  LOUIS  CAMPREDON. 


THE 


The  proportion  of  phosphorus  in  the  ash  of  coal  or  of 
coke  yielded  on  carbonisation  is  particularly  important, 
when  the  fuel  is  cast  into  the  blast-furnace,  for  the  manu- 
failure  of  fine  castings  in  which  the  percentage  of  phos- 
phorus has  to  be  as  low  as  possible.  In  faft,  all  the 
phosphorus  introduced  into  the  melted  mass  with  the  ash 
of  the  reduftive  combustible  enters  into  the  metal. 

Procedures   Followed. 

All  authorites  agree  in  advising  the  determination  of 
the  phosphorus  in  the  ash  given  by  the  combustible  when 
burning,  and  not  in  the  combustible  itself.  The  opinion 
of  various  authors  concerning  the  mode  of  attacking  the 
ash,  so  as  to  dissolve  the  phosphorus  contained,  differs 
slightly. 

The  attack  with  hydrochloric  acid  is  recommended  by 
Fresenius,  by  Post,  and  Munck.  The  last  mentioned 
adds  :  "  There  is  no  reason  to  fear  that  in  this  primitive 
treatment  iron  phosphate  may  remain  undissolved.  In 
the  experiments  made  on  this  point  the  contrary  has 
always  resulted ;  even  the  residue  appeared  very  rich  in 
iron." 

On  the  other  hand,  Blair,  Baron  Juptner  von  Jonstorff, 
as  well  as  Arnold,  recommend  the  fusion  of  the  ash  as 
the  preferable  if  not  the  only  method. 

Comparative  Trials. 

I  have  made  numerous  comparative  trials  on  the  ash 
of  coals  from  English  sources,  proceeding  as  follows  :  — 

I.  Attack  with  Hydrochloric  Acid.— I  treated  o-6oo 
grm.  and  i"200  grm.  of  ash  very  finely  powdered  in  a 


pear-shaped  phial,  covered  with  a  watch  glass  with  30  to 
40  c.c.  of  strong  hydrochloric  acid.  A  heat  of  80 — 100° 
was  applied  by  means  of  the  water-bath  or  the  sand- 
bath  for  fifteen  to  twenty  hours.  It  was  evaporated  to 
dryness  to  render  the  silica  insoluble;  it  was  then  taken 
up  with  a  few  c.c.  of  aqua-regia  composed  of  equal 
volumes  of  nitric  and  hydrochloric  acid.  Heat  was 
applied,  and  there  were  further  added  5  c.c.  of  nitric  acid 
to  expel  the  hydrochloric  acid.  Lastly,  it  was  diluted 
with  cold  water,  and  the  whole  poured  into  a  flask 
graduated  from  60  to  120  c.c.  The  volume  is  made  up 
and  the  whole  filtered  through  a  dry  filter-paper.  We 
take  50  or  100  c.c.  of  the  liquid  (corresponding  to  0.5  or 
I  grm.  of  the  substance),  neutralise  with  ammonia, 
acidify  slightly  with  nitric  acid,  heat  to  60°  in  a  small 
pear-shaped  flask,  and  effedt  the  precipitation  by  adding 
20  to  30  c  c.  of  molybdic  solution.  Allow  the  mixture  to 
settle  for  two  to  three  hours  at  30  to  40°  C,  filter  the 
phosphomolybdic  precipitate  through  a  double  tared 
filter  ;  wash  with  water  acidulated  with  nitric  acid  (40  c.c. 
acid  per  litre) ;  dry  the  filter  at  105°  and  weigh. 

The  weight  of  the  phosphomolybdate  multiplied  by 
o'oi63  gives  the  weight  of  the  phosphorus. 

2.  Fusion  with  Alkaline  Carbonates. — Melt  o*6oo  grm. 
coal  with  3  grms.  of  a  mixture  of  equal  weights  sodium 
and  potassium  carbonates,  and  keep  it  in  a  state  of  fusion 
in  a  platinum  crucible  for  ten  to  fifteen  minutes.  When 
cold  the  mass  is  taken  up  in  water  acidulated  with  hydro- 
chloric acid.  The  liquid  is  poured  into  a  porcelain 
capsule,  adding  then  an  excess  of  hydrochloric  acid,  and 
evaporating  to  dryness.  The  process  is  continued  as  in 
the  first  method. 

To  obtain  accurate  results  it  is  necessary  to  fuse  with 
alkaline  carbonates  and  precipitate  with  molybdic  solution 
according  to  the  diredtions  of  the  present  paper. — Comptes 
Rendtts,  cxxiii.,  No.  23. 


DERIVATIVES    OF    COLUMBIUM 
TANTALUM.* 
By  MARY  ENGLE  PENNINGTON. 


AND 


Among  the  more  metallic  members  of  Group  V.  of  the 
Periodic  system  are  the  elements  columbium  and  tanta* 
lum,  which,  though  almost  a  century  old  and  counting 
among  their  devotees  such  investigators  as  Rose,  Her- 
mann, Marignac,  Rammelsberg,  and  others  of  equal  fame, 
still  offer  many  interesting  problems  to  the  student  of 
inorganic  chemistry.  Comparatively  few  of  the  com- 
pounds of  these  elements  have  been  prepared.  Those 
which  have  been  studied  narrowly  enough  to  afford  an 
accurate  knowledge  of  their  chemical  behaviour  form  a 
much  shorter  list.  The  early  literature  is,  in  many 
instances,  very  contradidlory,  due  to  the  supposed  exist- 
ence of  such  elements  as  pelopium  and  ilmenium, 
engendering  as  they  did  the  fruitful  controversy  between 
Hermann  and  Marignac,  which  controversy  resulted  in 
the  tacit  acceptance  by  the  chemical  world  of  Marignac's 
statement,  that  columbium  is  elementary.  The  old 
doubt,  however,  appears  to  have  been  revived  through 
the  very  careful  work  of  Kriiss  in  1887,  on  the  oxides  of 
these  metals,  their  separation  from  each  other  and  also 
from  the  oxides  which  accompany  them  in  their  apparent 
minerals. 

He  found  through  the  fradtional  crystallisation  of  the 
double  fluoride  of  columbium  and  potassium,  and  by 
determining  the  atomic  value  of  the  various  fradtions, 
that  something  apparently  contaminated  the  columbium. 
In  some  fradlions  the  values  obtained  were  far  too  low. 
This  he  accounted  for  by  proving  the  presence  of  titanium. 


*  From  the  author's  thesis  presented  to  the  University  of  Penn- 
sylvania for  the  degree  of  th.D,,  1895.  From  the  Joitrn.  Amer. 
Chem.  Soc,  xviii.,  January,  1896. 


Cbruical  News,  i 
Jan.  1, 1897.      I 


Derivatives  of  Columbium  and  Tantalum, 


Other  portions,  however,  were  much  too  high,  and  this, 
it  was  csrefully  proved,  was  not  due  to  adhering  tantalum. 
Just  what  the  substance  was  which  gave  in  one  fraction 
an  Rv  having  almost  double  the  accepted  atomic  mass 
was  left  undecided. 

A  careful  consideration  of  this  question  in  the  light  of 
the  various  researches,  makes  it  seem  not  improbable 
that  the  compounds  of  columbium,  as  we  know  them,  are 
not  perfedly  free  from  contaminating  substances.  The 
many  difficulties  encountered  in  the  separation  of  this 
oxide  from  others  usually  occurring  with  it,  and  the 
insufficiency  of  the  prevailing  methods  of  separation, 
seem  to  demand  a  more  exa(5t  knowledge  of  the  behaviour 
of  the  element  in  the  purest  condition  obtainable,  and 
also  when  mixed  with  the  oxides  of  tantalum  and  titanium 
which  usually  adhere  to  it. 

It  was  with  the  hope  that  some  additional  light  might 
be  thrown  upon  the  general  deportment  of  the  derivatives 
of  these  elements  that  this  research  was  undertaken. 

The  material  used  was  obtained  from  a  columbite  from 
Wakefield,  N.H.  An  abundant  supply  of  the  mineral 
was  secured  through  the  kindness  of  Prof.  S.  P.  Sharpies, 
of  Boston,  in  whose  possession  it  had  been  for  some 
years,  though  it  had  never  been  analysed.  Wakefield  is 
a  new  locality  for  columbite.  The  deposit  was  discovered 
while  mining  for  felspar.  Near  the  columbite  is  quite  a 
deposit  of  beryl. 

Analysis  of  Wakefield  Columbite, 

The  mineral  occurs  in  large  black  lustreless  masses- 
Scattered  over  the  surface  are  little  patches  of  a  brigh* 
yellow  substance.  These  proved  to  be  uran-ochre,  and 
gave  evidence  of  the  presence  of  the  uranium  which  was 
later  found  in  the  mineral.  Felspar  occasionally 
penetrated  the  mass,  though  in  small  quantity.  The 
specific  gravity  of  picked  material  was  found  to  be  5*662 
at  4°  C. 

Decomposition  was  efJ'etSed  by  the  method  usually 
employed  for  this  class  of  minerals. 

Fusion  with.  Acid  Potassium  Sulphate. — The  finely 
divided  mineral  was  allowed  to  stand  over  calcium 
chloride  for  some  hours.  The  desired  amount  of  this 
dry,  and  almost  impalpable,  powder  was  weighed  off  and 
mixed  with  at  least  nine  times  its  weight  of  fused  potas- 
sium bisulphate.  This  must  be  an  intimate  mixture. 
Great  care  should  be  exercised  when  the  heat  is  first 
applied,  else  loss  by  spattering  will  occur.  Frequent 
stirring  tends  to  prevent  this,  and  also  hastens  the 
decomposition. 

Some  trouble  was  experienced  by  the  fusion  "  climbing," 
and  leaving  far  up  on  the  sides  of  the  crucible  particles 
of  mineral  which  could  neither  be  driven  down  by  heat  or 
forced  down  by  a  platinum  rod.  To  colledt  these  particles 
the  crucible  containing  the  clear  quiet  fusion  was  slightly 
tilted  and  the  adhering  portions  covered  with  a  little 
bisulphate.  Then  by  gently  heating  the  whole  mass  was 
driven  down  until  it  met  the  main  portion  of  the  fusion. 
All  decompositions  by  this  method  were  made  in  a  large 
platinum  crucible  or  platinum  dish.  The  latter  was  pre- 
ferred. If  the  mineral  is  fine  enough  the  fusion  is  com- 
plete in  about  five  hours. 

The  fused  mass  was  taken  up  in  a  large  quantity  of 
water,  and  boiled  out  with  water  several  times.  The 
insoluble  portion  consisted  of  the  oxides  of  columbium, 
tantalum,  titanium,  tin,  tungsten,  and  any  silica  which 
was  present.  Small  quantities  of  these  oxides  invariably 
remained  dissolved,  although  the  solution  was  boiled  for  a 
long  time;  it  is,  therefore,  advisable  to  let  the  filtrate 
stand  twenty-four  hours,  then  re-filter. 

The  moist  oxides,  according  to  Headden  {Amer.  your. 
Sci.,  xli.,  91,  1891),  should  "be  digested  with  yellow 
ammonium  sulphide  "  to  remove  all  tin,  tungsten,  &c. 
Rose  recommends  that  yellow  ammonium  sulphide  should 
be  simply  poured  over  them,  and  that  this  solution  should 
be  evaporated  to  dryness  and  gently  ignited,  to  render 
the  columbium   and   tantalum  oxides  which  have  been 


dissolved  by  the  alkali,  insoluble.  Wohler  ("  Mineral 
Analyze,"  p.  140)  claims  that  it  is  sufficient  to  treat  the 
metallic  oxides  upon  the  filter  with  yellow  ammonium 
sulphide.  As  some  uncertainty  existed  as  to  the  best 
course  to  pursue,  the  effetfl  of  ammonium  sulphide  when 
mixed  with  these  oxides  for  a  longer  or  shorter  period  of 
time  was  studied. 

Heating  in  a  porcelain  dish  on  the  water-bath  for 
three  hours  gave  i'i5  per  cent  of  the  mixed  oxides  ;  one 
and  one  half  days,  i*6o  per  cent;  three  days,  1*85  per 
cent;  one  week,  2*24  per  cent.  By  pouring  the  sulphide 
over  the  oxides  on  the  filter,  as  Rose  and  Wohler  advise, 
0*24  per  cent  of  the  mixed  oxides  was  obtained. 

Apparently,  the  moist  metallic  oxides  are  more  readily 
dissolved  by  ammonium  sulphide  than  is  generally  sup- 
posed, and,  therefore,  when  working  with  columbites 
containing  the  acid  oxides,  care  must  be  taken,  or  a  very 
appreciable  error  may  result. 

The  ammonium  sulphide  solution  was  precipitated  by 
dilute  hydrochloric  acid,  and  the  precipitate  was  filtered, 
and  washed  with  hydrogen  sulphide  water,  alcohol,  ether, 
carbon  disulphide  and  ether.  The  mixed  sulphides  were 
carefully  heated  in  the  air,  then  reduced  in  a  current  of 
hydrogen  gas.  The  residue  treated  with  dilute  hydro- 
chloric acid  gave  tin  in  solution,  and  left  undissolved  a 
small  quantity  of  a  black  compound  which  proved  to  be 
the  tetroxide,  Cb204,  with  possibly  a  little  tantalum. 

The  moist  oxides  when  treated  with  ammonium  sul- 
phide have  not  only  the  acids  removed,  but  the  iron  con- 
tained in  them  is  changed  to  sulphide.  This  is  dissolved 
out  by  dilute  sulphuric  acid.  Filter  off  the  oxides  and 
wash  them  thoroughly  with  boiling  water.  A  pump  is 
usually  necesssary  because  of  the  precipitate  being  finely 
divided,  and  having  a  tendency  to  clog  the  pores  of  the 
filter.  By  this  treatment  the  oxides  should  be  entirely 
freed  from  iron  and  manganese.  Nevertheless  ignition 
gave  a  powder  having  a  distindl  pinkish  yellow  hue, 
showing  the  presence  of  these  elements.  The  oxides 
were,  therefore,  re-fused  with  potassium  bisulphate  and 
treated  as  before.  The  second  fusion  gave  a  produA 
lighter  in  colour,  yet  not  perfedlly  white.  Another  fusion 
was  resorted  to,  and  no  loss  in  weight  was  observed,  as  a 
small  amount  of  iron  still  adhered  to  the  oxides.  In  (&& 
a.  perfectly  white  mixture  of  the  oxides  has  not  been  ob- 
tained by  this  method. 

The  sulphuric  acid  solution  of  the  iron  which  remained 
with  the  insoluble  oxides  was  added  to  the  aqueous  ex- 
tradion  of  the  fusion.  This  solution  now  contained  iron, 
manganese,  uranium,  and  calcium,  with  a  large  excess  of 
sulphuric  acid  and  alkali  salt.  Yttrium,  cerium,  and  cal- 
cium were  looked  for  according  to  the  plan  presented  in 
Rose's  "  Handbuch  der  Analytischen  Chemie,"  ii.,  335, 
which  is,  in  brief,  this  : — The  greater  part  of  the  free  acid 
is  neutralised  with  sodium  carbonate  ;  sodium  acetate  is 
added,  so  that  acetic  acid  is  in  large  excess.  The  earths 
are  precipitated  by  ammonium  oxalate,  the  precipitate 
being  allowed  to  stand  twenty-four  hours.  From  3  grms. 
of  mineral  only  a  very  small  amount  was  obtained.  This 
was  too  small  a  quantity  to  investigate  further,  so  that  if 
any  rare  earths  are  present  in  the  mineral  they  exist  in 
traces. 

To  the  filtrate  which  contained  iron,  manganese,  and 
uranium,  were  added  ammonium  sulphide  and  ammonium 
carbonate.  The  iron  and  manganese  were  precipitated 
as  sulphides,  while  uranium  was  held  back  by  the  ammo- 
nium carbonate.  Beryllium,  if  present,  would  have  been 
found  here.  This  element  was  sought  for,  since  the 
locality  from  which  the  mineral  came  made  it  a  probable 
constituent,  but  none  was  deteded.  The  sulphides 
having  been  filtered  out,  the  filtrate  was  made  acid  with 
hydrochloric  acid,  the  carbon  dioxide  boiled  off,  then  the 
uranium  precipitated  by  ammonium  hydroxide.  The 
uranium  hydrate  was  filtered,  washed,  ignited,  and 
weighed  as  U3O8.  The  sulphides  of  iron  and  manganese 
were  dissolved  off  the  filter  in  hydrochloric  acid,  oxidised, 
and   separated   by  the  basic  acetate  method,  the  man- 


10 


Problems  of  the  Natural  Sciences. 


CsbmicalNbws 
Jan.  I,  1807. 


ganese  being  finally  weighed  as  manganese  pyro- 
phosphate. 

The  water  contained  in  this  columbite  was  determined 
by  heating  in  a  boat  in  a  glass  tube,  and  colleding  the 
aqueous  vapour  in  a  weighed  calcium  chloride  U-tube. 

In  the  literature  relating  to  columbites  and  allied 
minerals,  while  a  ferrous  content  is  given,  the  method  by 
which  it  was  determined  is  omitted.  Perhaps  this  is  due 
to  the  fadt  that  the  customary  decomposition  with  sul- 
phuric acid  in  a  sealed  tube  naturally  suggests  itself,  yet 
in  applying  this  course  to  the  columbite  under  examina- 
tion unexpefted  difificulties  were  encountered.  The 
experience  is  at  least  interesting. 

To  be  continued). 


NOTICES  OF  BOOKS. 


Oh  certain  Main  Pyoblems  of  the  Natural  Sciences,  and  in 
particular  on  (I.)  The  Mechanical  Processes  which  lie  at 
the  Foundation  of  the  Electrical  Phenomena.  A  Discourse 
by  Dr.  Anton  K.  Grunwald,  Extraordinary  Professor 
of  Mathematics  at  the  Imperial  and  Royal  Technical 
High  School  of  Prague.  Delivered  at  the  Annual 
Meeting  of  the  Royal  Bohemian  Society  of  Sciences, 
January  31st,  1895.  Prague :  Published  by  the  Royal 
Bohemian  Society  of  Sciences.  ("  Ueber  gewisse 
Haupt  aufgalben  der  Naturwissenschaften,  und  zwor 
(I.)  Ueber  die  Mechan  Vorgange  welche  den  Eledtr. 
zu  Grunde  liegen  "). 

Professor  Grunwald  is  already  most  favourably  known 
to  British  physicists  for  his  mathematical  investigations 
on  spedlroscopic  phenomena.  We  find  him  now  taking 
up  a  much  wider  question.  In  his  introdudlory  remarks 
he  announces  that,  with  the  present  discourse,  he  purposes 
commencing  a  series  of  unassuming  presentations  on 
some  main  questions  of  the  Natural  Sciences.  Their 
solution  by  the  co-operation  of  experimental  and  theo- 
retical research  will  alone  render  it  possible  for  us  one 
day  to  elaborate  an  accurate  representation — satisfaftory 
to  our  craving  for  causality — of  that  certainly  small  por- 
tion of  the  universe  which  lies  within  our  reach.  He 
considers  that,  though  his  present  theme  is  in  appearance 
merely  and  specially  physical,  yet  in  reality  it  extends 
into  the  weightiest  questions,  not  merely  of  physics,  but 
also  of  chemistry,  physical  astronomy,  and  even  of  physi- 
ology. His  immediate  subjedt  is  the  mechanical  pro- 
cedures which  lie  at  the  basis  of  elecftrical  phenomena, 
or,  as  the  author  puts  it  more  cautiously  and  modestly, 
which  seem  thus  to  lie  at  the  foundation. 

The  misfortune  is  that  Professor  Griinwald's  expositions 
are  apt  to  be  only  dimly  intelligible  to  other  than 
physico-mathematical  specialists.  Had  he  been  able  to 
give  some  brief  instances  showing  how  his  views  lead  us 
into  questions  oS  chemistry  and  physiology,  he  would 
have  reached  a  wider,  and  certainly  not  less  appreciative, 
circle  of  disciples. 

As  a  summary  of  his  results,  he  expresses  himself  to 
the  eiTedt  that  the  exad  mathematical  elaboration  of  the 
mechanical  theory  of  ele>5lrical  phenomena  still  requires 
difficult  and  profound  study.  We  must  especially  get  rid 
of  the  unsatisfaftory  conception  of  actiones  in  distans — 
between  matter  and  matter  on  the  one  hand,  and  between 
matter  and  ether  on  the  other — as  mysterious  non- 
mediated  effeds  through  a  space  supposed  void  and 
entirely  without  influence. 

In  its  place  must  come  the  new  conception  of  these 
phenomena  opened  out  by  Faraday,  Maxwell,  Helmholtz, 
Lord  Kelvin,  Hertz,  Boltzmann,  and  other  illustrious 
minds,  who  regard  such  phenomena  merely  as  the  conse- 
quences of  a  chain  of  regular  transferences  of  motion — 
or  rather  of  semblances  of  motion— passiing  from  body  to 


body  within  a  dynamic  space  which  co-operates  with  them 
in   an  essential,  or  indeed  decisive,  manner. 

According  to  the  author's  view,  bodies  are  distinguished 
from  each  other,  as  relatively  independent  substances,  by 
the  substances  of  movement,  and  by  their  different 
position  in  universal  dynamic  space.  The  true  inde- 
pendent and  self-existing  substance  is  the  universe  itself. 


Quantitative   Estimation   of   Sugars.     With  explanatory 
notes  by   Dr.  Ernest  Wein.     Translated,  with  addi- 
tions, by  William  Frew,  Ph.D.  (Munich),  Wellpark 
Brewery,   Glasgow.       London :    E.   &    F.    N.    Spon. 
New  York  :  Spon  and  Chamberlain.     Pp.  128.     1896. 
The  translator  points  out  in  his  preface  that  to  obtain 
comparable   results   of  Fehling's  procedure   certain  pre- 
cautions are  needful.     He,  in  common  with   Dr.  Wein, 
condemns  the  use  of  a  fixed  fador  for  converting  either 
copper  oxide  or   metallic   copper  into   its  equivalent   of 
sugar.     A  common  error  committed  is  to  boil  the  mixed 
solutions  longer  than  the  prescribed  time.     Another  error 
is  to  add  the  cold  Fehling's  solution,  heat  and  then  boil 
for  the  specified  time.     In  every  case  sugar  solution  must 
first  be  added  when  the  Fehling's  solution  is  in  vigorous 
ebullition,  and  then  continuing  to  boil  for  the  specified 
I  time. 

The  arrangement  for  filtering  off  the  precipitate  of 
cuprous  oxide  in  a  Soxhlet  tube  is  fully  described. 

Soxhlet  tube  filled  is  shown  as  a  frontispiece.  The  bulk 
of  the  work  consists  of  tables  for  the  determination 
respeflively  of  invert  sugar  in  presence  of  beet-sugar,  of 
invert  sugar,  of  levulose  and  starch,  and  the  volumetric 
determination  of  dextrose  and  maltose. 

Dr.  Wein's  work  in  its  original  German  form  is  highly 
approved  of  by  pradical  men  on  the  European  continent, 
and  it  may  be  considered  surprising  that  an  English 
version  has  not  appeared  at  an  earlier  date.  Dr.  Frew's 
translation  only  requires  to  be  known  to  be  highly 
valued. 


Notes  on  Qualitative  Analysis.     Arranged  for  the  Use  of 
Students  of  the  Rensselaer  Polytechnic  Institute.     By 
P.    Mason,   Professor   of  Chemistry.     Third  Edition. 
Easton,  Pennsylvania:  Chemical  Publishing  Company 
Pp.  56.     1896. 
Like  not  a  few  authors  of  elementary  works  on  chemistry 
the   writer   admits   that  the  world   is  overstocked   with 
publications    of    a    similar    chara(5ler,   and    makes    the 
familiar  excuse  that  he  seeks  to  meet  the  requirements 
of  his  own  classes.     In   the  preface  he  informs  us  that 
it  is  his  practice  to  hold  a  daily  "  quiz-class  "  upon  points 
conneded  with  laboratory  work.     A  "quiz  class"  is,  we 
conjei5lure,  what  is  known  in  Germany  as  a  repetitoriumi 
In  the  text  we  can  find  nothing  objectionable,  nor  any- 
thing which  has  not  been  said  already  elsewhere. 


Notes  for  Chemical  Students.     By  Peter  T.  Austen, 
Ph.D.,  F.C.S.,  Professor  of  Chemistry  in  the  Polytechnic 
Institute  of  Brooklyn,     Second  Edition.     New  York: 
John  Wiley  and  Sons.     London:  Chapman  and  Hall, 
Ltd,     Pp,  no,     1896. 
A  BOOK,  we  submit,  rarely  rises  in  public  estimation  if 
the  author  finds  it  necessary  to  tender  an  apology  for  its 
appearance.     But  Professor  Austen  has  little  occasion  in 
this  manner  to  crave  favour,  since  his  work  is  quite  able 
to   plead   its   own  cause.     We   may,    indeed,   in    some 
respeds  take  exception  to  Dr.   Austen's   nomenclature. 
He  writes  "liter"  for  "  litre."     From  the  names  of  the 
halogens  he  lops  off  the  final  e,  writing  chlorin,  bromin, 
&c.     But   vvhy^  not  chlor,  brom,  &c,  ?     Carbonous  oxid 
and   carbonic  oxid  are,  if   we  may  use  the    expression, 
somewhat  uncomfortable    synonyms    for    carbon    mon- 
oxide and  dioxide. 


Chbuical  Nbws.  ] 
Jan.  I,  1897.       ] 


Chemical  Notices  jrom  Foreign  Sources, 


II 


In  a  quotation  apparently  from  Professor  Schiff,  the 
author  candidly  admits  that  we  have  not  the  slightest  idea 
of  how  to  bridge  the  gap  between  matter  and  sensation, 
and  proceeds  as  if  the  existence  of  matter  were  an 
undoubted  fadt.  He  holds  that  "  few  words  have  been 
more  abused  than  '  affinity.'  " 

The  secftion  on  *'  water  fadlors"  brings  under  our  notice 
a  source  of  error  which  the  American  student  encounters 
over  and  above  those  which  we  enjoy.  The  U.S.  gallon 
represents  only  8*3311  lbs.  distilled  water,  whilst  the 
British  Imperial  gallon  weighs  10  lbs.  Hence  confusion 
and  misunderstanding  may  arise.  The  author  regrets 
that  the  use  of  the  two  vol.  unit  in  chemical  calculations 
is  frequently  omitted  in  English  and  American  text-books. 

Vest'pocket  Medical  Dictionary.  By  Albert  H.  Buck, 
M.D.  London:  Bailliere,  Tindall,  and  Cox.  Pp.  529. 
1896. 
The  objedl  of  this  small  but  useful  work  is  to  explain  the 
technical  terms  and  abbreviations  encountered  in  medical 
literature,  which  multiply  with  such  uncanny  rapidity  as 
to  puzzle,  not  merely  scientific  men  whose  specialities 
lie  outside  the  medical  profession,  but  even  pradlitioners 
who  have  graduated  prior  to  the  last  ten  or  twelve  years. 
It  will  occasionally  save  gentlemen  of  the  daily  press 
from  ludicrous  mistakes.  We  were  once  staggered  to 
read  in  an  eminent  political  and  literary  organ,  of  a  noted 
charadler  dying  from  a  gun-shot  wound  in  the  peritonitis  ! 
This  little  book  will  preserve  reporters  and  editors  from 
committing  themselves  in  such  a  manner. 


General  Catalogue  of  the  National  Millenary  Exhibition 
at  Budapest,  1896.  ("  Catalogue  General  de  I'Exposition 
Nationale  du  Millennaire,  Budapest,  1896  ").  Group 
XVIII.    Chemical    Industry.       Edited    by    Dr.    Leo 

LlEBERMAN. 

The  total  number  of  works  here  enumerated  as  chemical 
is  1253,  employing  5702  men.  Of  these,  however,  goo 
are  engaged  at  the  various  gas-works.  In  the  production 
of  soap  and  candles  there  are  engaged  735  hands,  and  in 
the  metal  trades  697.  Chemical  manures  engage  55 
persons,  margarine  8,  and  gunpowder  3,  though  the 
powder  mills  are  given  as  8  (  ?).  The  match  industry  is 
eaid  to  be  decreasing.  Some  of  the  branches  of  chemistry 
are  in  a  flourishing  state,  whilst  others  are  far  from  satis- 
fying the  demands  of  the  country. 


CHEMICAL 


NOTICES    FHOM 
SOURCES. 


FOKtlGN 


Note.— All  degrees  of  temperature  are  Centigrade  unless  otherwise 
expressed. 

Comptes  Rendus  Hebdomadaires  des  Seances,  de  V Academic 

des  Sciences.     Vol.  cxxiii.,  No.  23,  December  7,  1896. 

Pleurisy  in  Man  studied  by  the  aid  of  Kontgen 
Rays. — Ch.  Bouchard. — A  purely  medical  paper. 

Composition  of  the  Gases  evolved  from  the  Mine- 
ral Waters  of  Bagnoles  de  I'Orme.— Ch.  Bouchard 
and  M.  Desprez.— The  gases  would  have  the  following 
composition  in  volumes  :— Carbonic  acid,  5-0;  nitrogen, 
90-5  ;  argon,  4-5  ;  helium,  traces  ;  total,  loo-o.  The 
presence  of  argon  has  been  recognised  in  other  sulphur 
springs.  The  waters  of  Bagnoles  are  not  sulphuretted, 
but  they  are  silicated  like  those  of  Canterets. 

Fr.  Landolph  submits  to  the  judgment  of  the  Academy 
a  memoir  on  the  optical  analysis  of  urine,  and  the  exa(a 
determmation  of  the  proteids,  ihe  glucosides,  and  the 
non-fermentable  saccharoidal  matters. 

Determination  of  Phosphorus  in  the  Ash  of  Coal 
and  Coke.— Louis  Campredon.— (See  p.  8). 


Property  of  Discharging  Ele(5trised  Condu(!tor8 
communicated  to  Gases  by  X  Rays,  by  Flames,  and 
by  Eletftric  Sparks.  —  Emilie  Villari.  —  A  reply  to  the 
criticism  of  Ed.  Brany  {Comptes  Rendus,  Oft.  28th  last). 

On  Lithium  Nitride. —  M.  Guntz.  —  Hydrogen,  on 
thermo-chemical  considerations,  must  decompose  lithium 
nitride,  as  it  is  readily  observed  on  heating  LisN  in 
a  current  of  hydrogen. 

Formation  Heat  of  Selenic  Acid  and  of  some 
Seleniates. — Rene  Metzner. — A  thermo-chemical  paper. 
On  comparing  the  different  numbers  with  the  corresponding 
values  for  sulphuric  acid  they  are  all  found  lower, 
except  the  heat  of  hydration.  Whilst  sulphurous  acid 
fixes  oxygen  direftly,  the  oxidation  of  dissolved  selenious 
acid  is  never  diredt. 

Analysis  of  Industrial  Copper  by  an  Ele(5lrolytic 
Procedure  — M.  A.  Holland.— This  paper  will  be  inserted 
in  full. 

On  Ozone  and  the  Phenomena  of  Phosphores- 
cence. —  Marius  Otto.  — The  luminosity  produced  when 
ozone  and  water  are  in  contact  is  due  to  the  presence  in 
the  latter  of  organic  matters,  animal  and  vegetable.  Most 
organic  matters  are  capable  of  producing  phenomena  of 
phosphorescence  with  ozone. 

New  Ammunition  Bread.  —  Ballard,  —  This  bread, 
unlike  the  old  biscuit,  contains  salt  and  yeast. 

No.  24,  December  14,  1896. 

The  Rontgen  Rays  applied  to  the  Diagnoses  of 
Pulmonary  Tuberculosis.  —  Ch.  Bouchard.  —  In  the 
diseases  of  the  thorax  radioscopy  gives  instruction  com- 
parable in  all  points  to  that  obtained  by  percussion. 

On  Selenium  Anhydride.  —  Rene  Metzler.  —  A 
thermo-chemical  paper.  The  endothermic  charafter  is 
observed  very  distindly  on  treating  monohydrated  selenic 
acid  with  phosphoric  anhydride,  according  to  the  pro- 
cedure by  which  Berthelot  succeeded  in  preparing  nitric 
anhydride. 

Analysis  of  Industrial  Copper  of  the  Ele<5trolytic 
Process  ;  Determinations  of  Antimony,  Sulphur,  and 
Alien  Metals.— A.  Holland.— Arsenic  and  antimony  are 
determined  in  the  mother-liquor  from  which  the  copper 
has  been  precipitated  eledtrolytically.  Nickel  and  cobalt 
are  determined  eledlrolytically  in  the  solution  of  the 
double  sulphate  and  ammoniacal  sulphate  ;  iron  is  deter- 
mined  by  permanganate.  If  the  original  copper  was  rich 
in  silver,  the  copper  which  has  been  deposited  upon  the 
cone  is  dissolved,  as  it  contains  all  the  silver.  In  the 
contrary  case  a  fresh  portion  of  the  copper  is  dissolved  in 
nitric  acid,  and  the  nitric  solution— filtered  if  needful— is 
vvith  a  chloride.  The  lead  is  determined  in  a  fresh  por- 
tion of  the  original  substance,  and  is  dissolved  in  dilute 
nitric  acid.  The  sulphur  is  determined  as  barium  sul- 
phate. 

Antimono-tungstic  Compounds.— L.  A.  Hallopeau; 
— Antimonic  hydrate  can  combine  with  tungstic  acid  to 
form  antimoni-tungstic  compounds,  comparable  to  the 
phospho-tungstic  and  arsenio-tungstic  combinations. 

Researches  on  Cobalt  and  Nickel  Sulphides.— G. 
Chasneau.— It  results,  from  the  author's  experiments,  that 
the  alkaline  polysulphides,  if  saturated  in  the  cold  with 
sulphur,  give  in  cobaltous  salts  a  black  persulphide, 
C02S7,  insjluble  in  alkaline  monosulphides,  but  soluble, 
on  the  contrary,  in  these  sulphides  if  saturated  with  sul- 
phur. Under  the  same  conditions  the  nickelous  salts 
give  a  black  sulphide,  which  appears  to  correspond  with 
that  of  cobalt,  but  which,  contrary  to  the  latter,  is 
scarcely  soluble  in  sodium  polysulphide,  but  decidedly 
soluble  in  the  monosulphide. 

New  Process  for  the  Determination  of  Glycerin, 
— F.  Bourdas  and  Sig.  de  R^czkowski.— This  paper  will 
be  inserted  in  full. 


12 


Meetings  for  the  Week. 


i  Cbbmical  News, 
1      Jan.  I,  1897. 


MISCELLANEOUS. 

Society  of  Public  Analysts. — The  Annual  Meeting 
of  the  Society  will  take  place  on  Wednesday,  January 
13,  1897,  at  the  Chemical  Society's  Rooms,  Burlington 
House,  Piccadilly,  at  5  o'clock  p.m.  The  Year's 
Accounts  will  be  presented.  The  retiring  President  will 
deliver  his  Annual  Address.  The  following  Papers  are 
announced  : — "  Some  Analyses  of  Water  from  an  Oyster 
Fishery,"  "  Note  on  Weighing  Out  Fats,"  "  Remarks  on 
Formaldehyde,"  by  Chas.  E.  Cassal ;  "A  Specific  Gravity 
Pipette,"  by  W.  F.  Keating  Stock  ;  "  A  Modified  Schmidt 
Process,"  by  R.  W.  Woosnam. 


MEETINGS    FOR    THE    WEEK. 


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Estimation  0/  Manganese  in  Spiegels,  &c. 


13 


THE    CHEMICAL     NEWS 


Vol.  LXXV.,  No.  1937. 


THE    ESTIMATION    OF     MANGANESE     IN 
SPIEGELS,  &c. 
By    H.    BREARLEY. 

The  acetate  method  of  separating  iron  and  manganese  is 
very  old.  Its  surname,  whatever  it  may  have  been,  is 
little  heard  of  now.  This  is  rather  complimentary, 
because  the  much  used  methods  are  the  more  prone  to 
suffer  this  change.  Amid  the  quick  young  methods  it 
seems  to  have  lost  virtues  it  was  once  credited  with. 
There  is  more  than  a  rumour,  too,  that  its  consort, 
precipitating  with  bromine  and  ammonia,  and  weighing 
as  Mn304,  is  not  so  reliable  as  it  was  formerly  supposed 
to  be. 

Experience  of  the  method  in  this  laboratory  has  always 
been  very  satisfaftory ;  but  that  opinion  is  by  no  means 
unanimous  may  be  seen  from  the  following  references. 

Blair  ("  Chemical  Analysis  of  Iron,"  Second  Edition, 
p.  108)  distrusts  the  Mn304,  and  recommends  weighing 
as  Mn2P207.  A  similar  opinion  is  expressed  in  Crookes's 
••  Sele<a  Methods  "  (Third  Edition,  p.  191).  Fresenius 
("  Quantitative  Analysis,"  Seventh  Edition,  p.  205)  says 
that  accurate  results  cannot  be  got  with  pyrophosphate 
unless  the  Mn  is  re-determined  in  the  filtrate  and  wash- 
ings; whilst  the  oxides,  ignited  out  of  contaift  with 
reducing  gases,  are  finally  converted  with  Mn304,  whose 
weight  remains  unaltered.  Arnold  ("  Steel  Works 
Analysis,"  p.  81)  says  the  ignition  should  be  made  in  a 
hot  muffle  furnace,  or  the  residue  may  not  stridtly  con- 
form to  the  formulae  Mn304,  which,  under  the  above 
conditions,  it  will  possess.  Reddrop  and  Ramage  (Jour. 
Client.  Soc,  1895,  P-  268)  show  that  the  ordinary  gravi- 
metric method  agrees  with  Pattinson's  and  the  new  one 
they  describe. 

Great  stress  has  been  laid  on  the  evidence  afforded  by 
Pickering's  researches  (Chem.  News,  xliii.,  226). 
McKenna  (Chem.  News,  Ixiii.,  184)  objeds  to  Mn304  on 
the  evidence  afforded  by  these  papers,  but  later  shows 
that  ammonium  manganous  phosphate  is  soluble  whether 
washed  with  water,  ammonium  nitrate,  or  dilute  ammonia. 
Pickering  himself  recognises  that  his  results  are  probably 
vitiated  by  the  permeability  of  the  platinum  basins  and 
consequent  reducing  adlion  of  the  gases.  The  experi- 
ments of  Morse  and  Burton  (Chem.  News,  Ixvii.,  175) 
made  to  test  the  point,  furnish  evidence  in  the  same 
diredion.  It  is  plain  that  changes  might  take  place  in 
an  open  platinum  basin,  over  a  Bunsen  flame,  which  could 
not  happen  in  a  mufifle  at  full  red  heat.  Under  the  latter 
conditions  concordant  results  are  always  obtained. 

The  general  instrudlions  for  separating  Fe  and  Mn  are  : 
iron  in  ferric  state,  cold  solution,  neutral  or  thereabouts, 
and  an  excess  of  acetate.  In  case  of  spiegels  and  high 
manganese  alloys,  the  acetate  precipitate  is  always  re-dis- 
solved and  re-precipitated  to  ensure  a  complete  separa- 
tion. It  was  thought  that  the  modification  applied  to 
iron  and  nickel  (Chem,  News,  Ixxiv.,  16)  might  apply 
also  to  iron  and  manganese,  and  thus  obviate  the  need 
for  a  second  precipitation. 

The  excess  of  acetate  necessary  is  variously  stated 
•'  more  than  sufficient  excess  to  change  all  the  iron  and 
^nanganese  by  double  decomposition  to  neutral  acetates" 
(Crookes).  30  c.c.  ammonium  acetate*  when  half-a-grm. 
of   Spiegel   is    operated   on "    (Arnold).       "  Two    grms. 

.  *  Ammonium  acetate  used  throughout  refers  to  liquid  acetic  acid 
(33  per  cent),  neutralised  with  liquid  ammonia. 


sodium   acetate   (crystallised)  to   precipitate   i   grm.  of 
iron  "  (Blair), 

To  show  the  effedl  of  free  acetic  acid  5  grms.  of  spiegel 
were  dissolved  and  divided  into  five  lots,  neutralised, 
made  up  to  nearly  1000  c.c.  with  cold  water,  60  c.c. 
ammonium  acetate  added  to  each,  and  boiled.  The  hot 
solution  was  made  up  to  a  litre,  cheesed,*  500  c.c.  super- 
natant liquid  filtered  off,  precipitated,  ignited  to  constant 
weight,  &c.  The  temperature  at  which  the  iron  solutions 
became  turbid  was  noted  first  at  slight,  and  second,  at 
decided  turbidity.  A  "standard"  sample  was  estimated 
at  the  same  time  by  precipitating,  washing,  re-precipi- 
tating, &c.,  and  gave  first  separation  2i'6i6  per  cent; 
second  separation,  0*389  per  cent ;  third  separation, 
0*063  P^i"  ^^'^^  f  total,  22*068  per  cent. 

The  results  of  the  five  test  estimations  are  colledted  in 
the  following  table: — 


No. 
I. 

II. 
III. 
IV. 

V. 


Acetic 
acid. 

o  c.c. 

10  ,, 

20  ,, 

40  „ 

70  .. 


Per  cent 
manganese. 

2066 
21*14 
21*88 
22*02 
22*06 


Temperature  of 
turbidity. 

56-60°  C 
63-65  .. 
65-67  *. 
72-74  •! 
80-82  „ 


The  FejOs,  along  with  the  Mn304,  was  certainly  less 
than  00002  (except  in  V.),  and  this  mostly  due  to  a 
trace  of  iron  in  the  bromine.  The  filtrates  from  the  basic 
acetates  were  all  clear  ;  the  precipitates  and  excess  of 
solution  were  left  over-night,  and  it  was  found  that  the 
precipitates  were  bulky  inversely  as  the  acid  addition  ; 
I,  was  about  three  times  as  large  as  V.,  the  others  were 
intermediate.  The  supernatant  liquids  oftheI,,II,,and  III. 
contained  no  iron,  IV,  a  trace,  and  V.  a  decided  quantity. 
The  precipitates  also  varied  in  colour.  I  propose  to 
examine  these  physical  properties  more  closely. 

To  wash  the  precipitated  MnOa  when  it  has  been  trans, 
ferred  to  the  filter  "till  free  from  ammonia  salts"  or 
"  thoroughly  "  is  very  troublesome,  and  sometimes  impos- 
sible on  account  of  the  tendency  it  has  to  run  through  the 
filter  as  the  ammonia  salts  disappear.  There  seems  no 
reason  why  it  should  be  washed  at  all  in  ordinary  cases, 
since  all  the  ammonia  salts  are  volatile.  Determinations 
with  and  without  washing  give  closely  agreeing  results, 
aud  two  filtrates  (about  800  c.c.)  evaporated  to  dryness 
and  ignited  gave  o*oi68  and  0*0134  grm.  residue,  which 
was  mostly  SiOg.  Not  more  than  10  c.c.  of  this  solution 
can  be  in  the  precipitate,  and  not  more  than  5  c.c.  need  be 
if  it  is  thoroughly  aspirated,  so  that  any  error  introduced 
is  insignificant,  for  technical  work  at  any  rate.  This,  of 
course,  does  not  apply  when  sodium  acetate  is  used  or 
the  spiegel  contains  unusual  impurities. 

Some  corrections  which  must  be  made  when  an  aliquot 
part  of  a  hot  solution  is  taken,  as  above,  will  be  men- 
tioned later. 

The  great  difference  between  the  avidities  of  nitric 
and  hydrochloric  and  acetic  acid  suggested  the  idea  of 
adding  acetic  acid  to  the  freshly  dissolved  spiegel,  and 
then  as  much  dilute  ammonia  as  would  neutralise  the 
free  HN03and  HCl,  form  the  required  amount  of  acetate 
and  leave  sufficient  free  acetic  acid.  Tlie  details  need 
not  be  given,  since  the  matter  is  curious  rather  than 
serviceable.  After  everything  had  been  added  the  solu- 
tion was  dark  coloured,  but  quite  clear.  The  percentage 
found  on  the  sample  previously  mentioned  was  21*93.  A 
fortnight  later  two  others  in  the  same  way  gave  21*92  and 
22*05  per  cent. 

These  modifications  shorten  the  ordinary  method  with 
its  re-precipitations,  without  in  any  way  impairing  its 
accuracy.  But  there  is  still  the  tedium  of  weighing  and 
and  re-weighing,  and  the  contamination  of  the  Mn304 
and  Cu,  Ni,  Co,  &c.,  in  case  they  are  present  in  the 
sample. 

*  "  Cheesed  "  means  to  wrap  a  duster  round  the  beaker,  and  then 
(old  another  over  the  cover  to  prevent  cooling. 


14 


Estimation  of  Manganese  in  Spiegels,  &c. 


CrbmicalNbws 
Jan.  8, 1807. 


I  am  not  aware  that  Guyard's  method  of  estimating 
manganese  has  ever  been  applied  to  the  acetate  filtrate. 
Of  this  method  Sutton  ("  Volumetric  Analysis,"  Fifth 
Edition,  p.  190)  says  "  Nickel,  cobalt,  zinc,  alumina  in 
moderate  quantity  are  of  no  consequence.  The  method 
is  easy  of  execution,  and  gives  good  results  in  cases 
where  it  can  be  properly  applied,  but  such  instances  are 
few." 

Hopefully  the  filtrate  was  nearly  neutralised  with 
ammonia,  and  the  standard  permanganate  run  in.  The 
end  reaftion  was  fugitive,  and  the  results  at  best  were 
only  fair.  If  a  pink  colour  was  produced,  the  precipitate 
at  once  filtered  off,  solution  acidified  in  H2SO4,  and 
excessof  permanganate  determinedwithFeS04,  theresults 
were  always  too  high ;  and  if  filtered  and  allowed  to 
stand  the  colour  gradually  disappeared,  and  MnOa  was 
precipitated.  This  readtion  continued  long  after  all  the 
manganese  was  precipitated,  but  was  less  decided  in  cold 
than  hot  solutions.  It  was  found  finally  to  be  due  to  the 
ammonium  acetate  and  other  ammonium  salts.  This 
point  was  much  elucidated  later  by  reading  that 
"  ammonia  boiled  with  a  neutral  solution  of  potassium 
permanganate  was  converted  into  potassium  nitrate " 
(Tamm,  Chem.  News,  xxv.,  26). 

The  more  acetate,  the  greater  discrepancy ;  so  that 
with  as  little  as  was  necessary  both  of  acetate  and  acetic 
acid  the  disturbing  readion  might  be  inappreciable  in  the 
cold.  But  how  little  acetate  and  acid  could  be  used  to 
efifedl  a  perfedt  separation  with  one  precipitation  ? 

Experiment  showed  that  10  c.c.  of  ammonia  acetate 
would  precipitate  i  grm.  of  bar  iron  in  i  litre  of  solution. 
The  supernatant  solution  was  slightly  turbid,  but  filtered 
crystal  clear  through  asbestos.  20  c.c.  of  acetic  acid 
with  the  same  acetate  did  not  prevent  precipitation,  but 
the  solution  needed  twice  filtering  to  make  it  crystal 
clear. 

A  series  of  estimations  made  are  given  in  the  following 
table.  It  shows  the  efTedl  of  varying  the  acetate  and 
acid  under  constant  conditions,  thus  answering  the 
question  at  issue,  and  also  supplementing  the  table  given 
above. 

Solutionsof  bar  iron  and  MnCla  were  mixed  to  approxi- 
mate a  20  per  cent  spiegel.  The  solution  was  made  up 
anew  for  each  vertical  column,  as  available  leisure  did  not 
admit  of  consecutive  work  on  the  series,  the  variation 
between  column  and  column  is  probably  due  to  this  cause. 
To  support  this  view  the  samples  marked  with  an  asterisk  in 
columns  10  and  60  were  made  on  the  same  solution  and 
side  by  side. 


Acetate 
acid. 

Ammonium  / 

Uetate, 

10  c.c. 

15  c.c. 

30  c.c. 

60  c.c. 

0  C.C. 

20-48* 

20*29 

20-00 

19-50 

5   » 

— 

2035 

— 

— 

10  „ 

— 

20-37 

20-38 

1974 

20  „ 

— 

20-35 

20-46 

19-91 

40  >. 

— 

— 

20-48 

20-19 

60  „ 

"~" 

~ 

~ 

20-18 
20-47 

Acetic 


Ammonium  Acetate. 


icid. 

10. 

15- 

30. 

60. 

0 

20-0 

19-94 

19-52 

19-33 

5 

— 

20*00 

— 

— 

10 

— 

20-02 

19-90 

19-56 

20 

— 

20-00 

19-98 

1973 

40 

— 

— 

20-00 

20-01 

60 

— 

— 

— 

20-00 

If  we  assume  that  each  perfeft  separation— the  one 
with  most  acid  in — represents  an  even  20  per  cent,  and 
calculate  the  other  results  proportionately,  the  influence 
of  acid  and  acetate  is  more  readily  seen. 


Wright  and  Menke's  (jfonr,  Chem.  Soc,  1880)  modifica- 
tion of  Guyard's  method,  some  very  good  results  were 
obtained. 

Soda  acetate  in  minimum  quantity  with  soda  salts 
behaves  well  in  either  hot  or  cold  solutions.  Half-a-grm. 
of  crystals,  after  neutralising  i  grm.  bar  iron  with 
sodium  carbonate,  brought  down  a  precipitate,  but  left  a 
supernatant  yellowish  liquid  no  amount  of  filtering  would 
decolourise.  Three-quarter  grm.  of  crystals  gave  a  clear 
filtrate,  and  the  tint  imparted  by  two  drops  of  N/io 
KMn04  was  not  appreciably  affefted  when  the  solution 
was  heated  to  boiling.  The  difficulty  might  have  been 
eliminated  at  once  by  using  soda  salts,  but  it  was  thought 
desirable  to  retain  ammonia  if  possible,  so  that  the  gravi- 
metric  or  volumetric  methods  might  be  applied  to  the 
filtrate  at  will. 

Briefly  the  method  is — Dissolve  spiegel  in  HCl,  oxidise 
the  iron  with  HNO3,  neutralise  with  soda  or  ammonia, 
and  precipitate  Fe  with  acetate  (sodium  or  ammonium)  in 
minimum  quantity.  Nearly  neutralise  filtrate,  and 
titrate  with  permanganate.  This  outline  is  given  so  that 
there  may  be  something  to  definitely  refer  to.  The 
method  of  titration  preferred  is  Wright  and  Menke's  in 
cold  solutions.  This  is  better  than  titrating  in  hot  solu- 
tions because  the  KMn04  is  less  likely  to  be  afTedled  by 
accidental  or  unavoidable  organic  matter,  &c.  This  is 
strongly  emphasised  by  my  experience.  No  distilled 
water  v/as  handy,  our  ordinary  tap  water  was  used,  and 
titration  performed  in  hot  solutions.  The  results  were 
very  unsatisfa(5tory.  Of  course,  ordinary  water  ought  not 
to  have  been  used,  but  such  a  contingency  in  aftual  work 
is  not  unimaginable. 

The  following  mixtures  of  iron  and  manganese  chloride 
solutions,  mixed  to  approximate  spiegels  and  ferro-man- 
ganese,  show  that  the  method  gives  exceedingly  accurate 
results. 


Per  cent  manganese 
Present.    Found. 


N/io  KMnOtCapprox.) 
required  by — 


10 
10 
20 
20 
40 
60 


10*09 
9-99 
19-99 
19-99 
40-00 
59-87 


Theory. 
30-03  C.C. 

30'03  .. 

60*06  ,, 

60*06  ,, 

89-5  ,. 

89-5  M 


Sample. 

30-3 

30*0 

59-96 

59*96 

89*5 

89-3 


Salts 
used. 

Soda. 

Ammonia 

Soda 

Ammonia 

Soda 

Soda 


Keeping  the  ammonia  salts  as  low  as  possible,  and  pre- 
cipitating with  only  10  c.c,  of  acetate,  and  titrating  with 


I  am  obliged  to  Mr.  R.  L,  Lefifler,  the  chemist  in  this 
laboratory,  for  making  a  trial  of  the  method.  I  furnished 
him  with  an  account  of  the  method  and  some  solutions 
marked  with  the  approximate  composition.  He  reported 
as  follows  : — 

Given  as  (per  cent)  ..  ..  1200  23*00  40*00  65-00  82-00 
Found  (per  cent)  ..  ..  10-76  21-99  40-16  64-40  79-78 
They  really  contained  (p. c.)  10-80  22-00  40-00  64-00  80*00 

Soda  salts  were  used  throughout. 

When  so  small  a  quantity  of  acetate  is  used,  the  iron 
solution  must  be  neutralised  pretty  accurately,  or  it  will 
not  be  clearly  precipitated.  A  trouble  of  this  kind  might 
be  obviated  by  adding  soda  carbonate  to  slight  turbidity, 
and  dissolve  in,  say,  5  acetic  acid.  The  influence  of  this 
acetic,  even  when  larger  amounts  of  soda  acetate  are 
used,  is  seen  from  the  following  amounts  of  permanganate 
used. 

Acetic  Soda  acetate  (20  c.c.=3  grm.  crystals), 

acid.  20.  30.  40.  60  c.c. 

o  c.c.        59-5        589        SS'i  56-5  c.c. 

5    I.  ••  59-9        59-85        59-4   .. 

The  quantity  theoretically  required  was  59-75. 

In  such  cases  as  the  foregoing,  where  an  aliquot  part 
of  a  hot  solution  containing  a  precipitate  is  filtered  off, 
there  are  certain  corredions  need  making.  Say  the  total 
bulk  of  solution  and  precipitate  is  1000  c.c,  and  500  c.c. 
of  the  clear  solution  is  filtered  off.  From  this  500  c.c. 
there  must  be  subtraded  (i)  half  the  volume  of  the  pre- 


CitCIIICAt.  Nbws,1 
Jan.  8, 1897.     I 


Estimation  of  Manganese  in  Spiegels,  &c. 


15 


cipitale  ;  (2)  the  volume  contradled  from  the  temperature 
when  1000  c.c.  is  measured  to  the  temperature  when  500 
c.c.  is  measured  ;  (3)  a  slight  corredlion  due  to  the  con- 
centration of  the  solution  while  filtering,  &c.  In  case  of 
Bpiegels  the  volume  corre(5lion  for  bulk  of  precipitate  is 
less  than  i  c.c,  so  of  no  moment.  The  corredtion  for 
contradion  was  carefully  considered.  The  most  conve- 
nientway  seemed  to  be  to  note  the  temperature  in  the  litre 
flask,  the  temperature  in  the  half  litre,  and  calculate  the 
contradtion  due  to  cooling.  To  this  end  the  contradlion 
of  an  ordinary  20  per  cent  Spiegel  filtrate  was  observed, 
and  found  to  behave  so  much  like  water  that  Kopp's 
tables  for  that  body  have  since  been  used.  In  some 
scores  of  cases  observed  the  temperatures  have  not  varied 
more  than  2°  C.  under  uniform  conditions  of  working.  It 
is  not  easy  to  fix  a  value  for  the  third  error.  It  depends 
on  the  form  of  vessel  used,  the  rapidity  of  filtration,  and 
other  incidents  which  vary  in  an  indeterminable  way. 
Arnold  {"  Steel  Works  Analysis,"  p.  82)  allows  5  c.c, 
when  the  volume  of  solution  is  600  c.c,  and  later  only 
I  c.c.  when  the  volume  is  300  c.c.  These  also  include 
the  volume  of  the  precipitate. 

It  were  best  to  avoid  this  error  altogether  if  possible. 
The  following  means  were  taken  to  minimise,  if  not  alto- 
gether eliminate  it  : — The  precipitation  was  made  in 
flasks,  Taylor  pattern,  marked  at  1000°  C. ;  the  boiling 
solution  was  transferred  to  a  litre  flask  with  graduated 
neck,  the  volume  noted,  and  the  litre  inverted  in  the  pre- 
cipitating flask.  The  precipitate  readily  settled,  and  then 
the  clear  solution  was  filtered  by  the  arrangement  shown 
in  the  figure.  The  filtration  is  very  rapid,  because  little 
or  no  precipitate  falls  on  the  filter. 


If  small  quantities  of  suspended  precipitate  made  no 
difference  to  the  subsequent  titration,  the  filter  tube  might 
be  dispensed  with,  and  half  a  litre  simply  syphoned  off. 
Results  of  experiments  in  which  the  iron  was  introduced 
as  an  emulsion  of  the  precipitated  basic  acetate  were — 


Grm. 

Grm. 

Grm, 

Grm. 

Fe  present     . . 

0*0000 

o'ooo7 

00033 

0*0050 

C.c, 

C.c. 

C.c. 

C.c, 

KMn04Used.. 

3175 

31-8 

3175 

31-6 

Throughout  these  experiments  the  precipitated  MnOa 
was  frequently  dissolved  in  ferrous  am.  sulphate,  and 
the  excess  titrated  with  standard  bichromate.  This  is  an 
obvious  way  of  confirming  an  estimation. 

One  other  point,  the  standardisation  of  the  permanga- 
nate solution,  needs  to  be  carefully  noted.  Simple 
standardisation  with  bar  iron  or  flower  wire,  dissolved  with 
precaution  in  H2SO4,  has  always  given  a  value  1  or  2  per 


cent  below  what  we  had  good  reason  to  suppose  was  the 
real  percentage.  McD.  Irby  (Chemical  News,  xxx.,  142) 
has  shown  that  the  small  amounts  of  carbon  present  in 
the  iron  has  an  effedl  amounting  to  between  i  and  2  per 
cent,  so  that  the  iron  solution  needs  to  be  oxidised  to 
destroy  the  carbonaceous  matter,  then  reduced  and  the 
titration  performed.  As  this  point  seems  to  be  generally 
overlooked,  and  as  it  introduces  an  error  of  several  tenths 
per  cent  on  a  20  per  cent  spiegel,  it  is  being  studied  in 
connexion  with  a  series  of  experiments  on  Sarnstrom's 
method  of  estimating  manganese.  Up  to  now  we  have 
found  it  convenient  and  accurate  to  standardise  with  a 
Spiegel  containing  a  known  percentage  of  manganese, 
or  with  a  manganese  salt  whose  purity  was  beyond 
question.  The  value  of  the  last  lot  of  permanganate 
determined  by  three  separate  spiegels  was— 

1.  0001662  Mn  per  z  c.c. 

2.  o'ooi667  ,, 

3.  o'ooi664  ,, 
By  pure  manganese  salt  O'ooi664            „ 

Conclusion. 

After  the  gravimetric  part  of  this  paper  was  done,  I 
was  under  the  impression  that  separating  iron  and  man- 
ganese in  presence  of  considerable  quantities  of  acetic 
acid  was  a  new  idea  ;  and  the  same  may  be  said  of  pre- 
cipitating with  minimum  amounts  of  acetate,  I  think  i 
will  make  this  paper  more  complete  than  otherwise  if  I 
give  the  references  of  papers  that  have  come  to  my 
notice. 

Debray  (Chemical  News,  xxi.,  53).—"  The  acetate  of 
sesquioxide  of  iron  separated,  on  boiling,  into  acetic  acid 
and  colloidal  oxide Colloidal  oxide  of  iron  is  in- 
soluble in  ammonia  salts,  even  in  presence  of  a  large 
quantity  of  acetic  acid." 

Jewett  (Chemical  News,  xl.,  5J73)  shows  that,  with 
large  quantities  of  soda  acetate,  acetic  acid — amounting  to 
5  per  cent  of  the  volume  of  solution— causes  the  complete 
separation  of  Zn  and  Mn  from  iron,  and  a  nearly  com- 
plete separation  in  case  of  Ni  and  Co.  On  the  authority 
of  E.  H.  Smith,  the  same  paper  states  that  iron  could  not 
be  precipitated,  in  presence  of  large  amounts  of  acetic 
acid,  by  increasing  the  soda  acetate.  My  observations 
are  contrary  to  this.  The  error  may  be  seen  by  precipi- 
tating, in  presence  of  70  c,c.  acetic  acid,  with  minimum 
acetate  and  several  grms. 

Kessler  (Chemical  News,  xxvii.,  14), — -'The  loss  ex- 
perienced in  the  estimation  of  the  manganese  by  the 
acetate  (soda)  method  is  mainly  due  to  the  fadt  that  too 
large  a  quantity  of  acetate  of  soda  is  employed,  in  con- 
sequence of  which  a  portion  of  chloride  of  manganese  is 
converted  into  acetate,  which  salts  is  readily  converted 
into  protoxide  and  acid." 

I  am  sorry  to  have  unknowingly  gone  over  previously 
trodden  ground,  but  the  persistent  way  in  which  the  in- 
strudlions  to  use  unnecessarily  large  amounts  of  acetate 
and  neutralise  all  free  acid  are  repeated,  even  in  the  most 
recent  text-books,  makes  it  perhaps  not  altogether  inop- 
portune that  this  matter  should  be  again  brought  forward. 
It  is  plain  that  the  results  here  set  forth  point  to  a  modi- 
fication of  the  method  previously  proposed  for  nickel 
and  iron  separation,  in  the  interest  of  economy,  if  not 
accuracy, 

Mr,  Leffler  suggests  that  the  volumetric  method  be 
applied  to  steels.  For  steels  of  the  ordinary  class  it  offers 
no  advantages  over  a  number  of  already  well-known 
methods,  such  as  Ford  and  Williams'.  In  those  cases, 
where  several  percents  of  chromium  are  present,  it  may 
prove  useful,  since  such  steels  are  frequently  not  com- 
pletely soluble  in  nitric  acid. 

The  various  points  enumerated  are  here  colledted  into 

The  Method. 
Dissolve  I   to  i'5  grms.  of  the  spiegel  (20  per  cent)  or 
proportionate  amounts   of  other  uianganiferous  irons,  in 


I6 


Manufacture  of  Calcium  Carbide, 


i  CHBkicAL  News, 
\       Jan.  8,  1897. 


hydrochloric  acid,  and  oxidise  the  iron  with  nitric  acid. 
If  the  silica  present  is  likely  to  interfere  with  the  neutral- 
isation, pass  through  a  small  asbestos  filter.  Neutralise 
with  soda  carbonate,  dilute  to  about  goo  c.c,  and  add  soda 
acetate  at  the  rate  of  20  c.c.  per  i  grm.  of  iron.  Ammo- 
nia and  ammonia  acetate  may  be  used,  bearing  in  mind 
its  limitations.  See  that  the  boiling  solution  touches  the 
litre  mark  on  the  flask.  Transfer  to  the  litre  measure  with 
graduated  neck.  Note  temperature  and  volume,  and  re- 
place in  the  precipitating  flask.  Cheese,  syphon,  or  filter 
off  half  the  noted  volume,  and  take  the  temperature.  Cool, 
destroy  the  free  acid  with  soda  carbonate,  and  then  make 
slightly  acid  with  acetic  or  dilute  sulphuric.  Run  the 
amount  of  permanganate  into  a  flask,  and  add  10  c.c, 
ZnS04,  and  run  in  the  manganese  solution  with  constant 
shaking.  This  may  readily  be  done  by  placing  a  wide- 
stem  funnel  in  the  larger  flask,  holding  it  in  position  with 
the  first  finger  of  the  right  hand ;  the  lower  fingers  grasp 
the  neck  with  the  flask  resting  against  the  thick  of  the 
hand;  the  solution  is  shaken,  while  the  left  hand  pours 
the  manganese  solution  through  the  nearly  stationary 
funnel.  The  percentage  of  manganese  in  spiegel  is  gene- 
rally approximately  known.  Failing  this  an  approxima- 
tion may  be  speedily  obtained  by  syphoning  off  an 
additional  250  c.c.  and  precipitating  hot  (Guyard). 

The  well-shaken  liquid  containing  the  small  excess  of 
permanganate  is  allowed  to  settle  a  few  minutes,  an 
aliquot  part  filtered  off,  acidified,  and  determined  with 
ferrous  ammonia  sulphate  and  permanganate. 

After  correding  the  figures  for  volume  contraAion  the 
calculations  need  no  further  explanation. 

The  following  values,  from  Kopp's  tables  for  water, 
given  here,  will  save  further  reference. 

If  the  volume  of  water  =  i  at  0°  C,  it  changes  when 
heated  to  the  following  volumes  : — 

70°  C,  I '02225  ;  85°  C,  I  "03189; 
75°  „  ro2S44;  90°  „  i '03540; 
80°  „    1 '02858;  95°  „     1-03909. 

Reagents  required  :— 

Potassa  permanganate  3'i56  grms.  per  litre. 
Soda  acetate     ..      ..  37*5  ,, 

Zfnc  sulphate  ..     ..    200  ,, 


a  piece  of  carbide  of  from  300  to  400  pounds.  The  car- 
bide itself  is  crystalline.  The  crystals  are  especially  well 
developed  near  the  top,  and  are  more  perfedt  with  an 
excess  of  coke,  low  voltage,  and  when  allowed  to  cool 
slowly.  The  centre  of  the  piece  of  carbide  stays  liquid 
for  some  time  after  the  electric  current  has  been  shut  off. 
The  liquid  part,  however,  is  of  the  same  quality  as  the 
rest  of  the  piece.  We  have,  in  facft,  tapped  out  of  the 
furnace  carbide  which  was  very  pure  and  yielded  5*59 
cubic  feet  of  gas  per  pound.  We  do  not  wish  to  express 
an  opinion  as  to  the  practicability  of  tapping  the  carbide 
as  soon  as  it  is  formed.  We  will  only  mention  that  Mr. 
Price,  in  Newark,  has,  with  a  view  of  tapping  the  car- 
bide, construdled  and  patented  a  new  furnace,  and  that 
one  of  us  (C.)  has  also  devised  a  furnace  for  the  same 
purpose. 

Carbide  of  average  quality  (about  5  cubic  feet  of  gas 
per  pound)  often  has  a  reddish  colour,  especially  if  it  has 
been  made  with  a  current  of  high  voltage.  Carbide  of 
bad  quality  is  often  greyish  or  blackish,  or  will  show 
streaks  of  graphite.  Pure  carbide  yields  more  than  5'go 
cubic  feet  of  gas  per  pound.  It  has,  however,  been  found 
to  be  more  economical  to  produce  carbide  that  yields  only 
about  5  cubic  feet  of  gas  per  pound.  Samples  of  carbide 
of  different  qualities  contained  : — 


Laboratoryi  Norfolk  Works,  Sheffield. 


THE  MANUFACTURE  OF  CALCIUM   CARBIDE.* 
By  J.  T.  MOREHEAD  and  G.  de  CHALMOT. 

(Continued  from  p.  5), 

The  carbide  is  always  found  in  one  piece  between  the 
pencils  and  the  bottom.  It  has  a  conical  form,  being 
broader  at  the  base,  and  can  be  2.J  feet  high  in  our 
furnace.  It,  however,  never  has  so  great  a  diameter  as  to 
fill  up  the  whole  capacity  of  the  furnace.  The  carbide  is 
therefore  entirely  surrounded  by  a  cover  of  the  mixture  of 
lime  and  coke.  This  mixture  is  so  bad  a  condudor  of 
heat  that  the  brick  walls  of  the  furnace  are  not  attacked. 
It  is  very  easy  to  separate  the  carbide  from  the  loose 
mixture,  for  the  latter  never  melts  together,  while  the 
carbide  is  hard  and  solid.  The  pieces  of  carbide  are 
covered  with  a  thin  coating  which  is  a  little  thicker  at  the 
top  of  the  piece,  and  the  same  may  be  re-ground  and  again 
used.  This  coating  contains  mainly  carbon,  but  also  car- 
bide and  calcium  oxide.  It  seldom  yields  more  than  half 
a  cubic  foot  of  gas  per  pound,  but  in  some  cases  it  yields 
1*77  and  even  2'io  cubic  feet.  This  coating,  however,  is 
of  little  importance.  If  the  mixture  is  well  made  this 
coating  seldom  exceeds  from  twenty  to  thirty  pounds  on 


*  Read  Sept.  3rd  before  the  Springfield  meeting  of  the  A.A.A.S.  by 
one  of  us  (M ).  We  have  made  since  then  several  additions,  so  as  to 
make  the  article  complete  up  to  the  present  time.  From  the  Journal 
of  the  American  Chemical  Society,  April,  1896. 


Table  I. 

Cubic  feet 

Carbide. 

Free  calcium 

Carbon 

Other  im 

gas  per 

Per 

oxide. 

Per 

purities. 

pound. 

cent. 

Per  cent. 

cent. 

Per  cent. 

57 

966 

o'6 

— 

2'8 

55 

93-2 

4'2 

— 

2-6 

5'i 

864 

9-5 

— 

4' I 

5-025 

847 

io'7 

i'6 

3.0 

3-6 

6i'o 

275 

32 

8-3 

3-45 

58-5 

I'l 

25'6 

148 

The  upper  part  of  a  piece  of  carbide  is  often  purer  than 
the  under  part. 

The  coke  to  be  used  should  not  contain  much  ash.  Our 
coke  contains  about  7  per  cent  of  ash.  The  carbide  ob- 
tained with  a  coke  of  from  10  to  11  per  cent  of  ash  was 
perceptibly  inferior  to  that  obtained  with  our  usual  coke. 
It  was  found  impradicable  to  make  a  good  quality  of  car- 
bide with  a  coke  of  27  per  cent  ash.  It  is  well  that  there 
should  not  be  more  than  10  per  cent  of  ash  in  the  coke. 
The  coke  should  be  ground  very  fine,  and  it  should  pass 
through  a  fifty-mesh  sieve.  The  lime  need  not  be  as  fine 
as  the  coke.  The  largest  pieces  should  pass  through  a 
ten-mesh  sieve.  If  the  lime  is  coarser  the  quality  of  the 
carbide  becomes  inferior.  That  the  state  of  the  pulverisa- 
tion of  the  lime  is  important  can  be  seen  by  a  comparison 
of  the  average  amount  of  gas  per  pound  (4'97  cubic  feet), 
obtained  with  unslacked  lime  (Table  II.),  and  that  ob- 
tained with  air  slacked  lime  (5*27  cubic  feet.  Table  III.). 
The  unslacked  lime  was  in  several  instances  not  quite  as 
fine  as  the  slacked  lime.  Unslacked  lime  is  decidedly 
preferable  to  air  slacked  lime,  as  we  will  see  afterwards. 

The  lime  which  we  use  contains  ij  per  cent  magnesia 
and  I  per  cent  of  other  impurities.  The  anhydrous  lime 
should  contain  95  per  cent  calcium  oxide  and  no  more 
than  5  per  cent  impurities.  The  presence  of  magnesia  is 
especially  detrimental  to  the  produdlion  of  carbide.  We 
could  not  obtain  a  good  quality  of  carbide  with  a  lime  in 
the  following  analysis: — Insoluble,  0*24  per  cent;  silica, 
o'78  per  cent  ;  ferric  oxide  and  alumina,  o'68  per  cent; 
calcium  oxide,  92'83  per  cent;  magnesium  oxide  5*47  per 
cent.  Further  experiments  showed  that  2^  per  cent  of 
magnesia  in  the  mixture  has  a  marked  influence  on  the 
produdion.  The  lime  used  for  making  carbide  should  not 
contain  over  3  per  cent  of  magnesia.  That  magnesia  has 
such  a  bad  influence  upon  the  formation  of  carbide  is  pro- 
bably due  to  its  forming  a  veil  between  the  carbon  and  the 
lime  particles,  preventing  their  combination.  Magnesia 
does  not  unite  either  with  lime  or  with  carbon.  The 
latter  fad  was   first  shown  by  Moissan  {Compt.  Rend., 


Chbuicai  NbW8|I 
Jan.  8, 1897.       f 


Manufacture  of  Calcium  Carbide. 


17 


1181  506),  and  our  own  experiments  in  this  line  fully  con- 
firm his  results.  The  lime  and  the  coke  must  be  mixed 
very  well  or  the  carbide  will  be  of  inferior  quality,  and 
there  will  be  much  coating.  Besides  the  carbide  some 
mixture  remains  in  the  furnace.  More  carbon  than  lime 
burns  out  or  volatilises  in  an  open  furnace.  It  is  there- 
fore necessary  to  add  carbon  to  this  mixture  before  using 
it  again.  The  amount  to  be  added  is  calculated  from  the 
result  of  an  analysis  of  the  mixture.  If  coke  is  added  in 
the  proper  proportions  the  unsmelted  portion  of  the  mate- 
rial can  be  returned  at  least  three  times  into  the  furnace 
and  still  yield  good  carbide.  The  impurities  of  the  lime 
and  the  coke  ashes  remain  as  well  in  the  carbide  as  in  the 
residual  mixture.  It  is  therefore  a  good  pradice  to  add 
charcoal  instead  of  coke  to  the  mixture,  so  as  not  per- 
ceptibly to  increase  the  amount  of  ash.  The  mixture 
that  comes  from  the  furnace  is  red  hot,  and  it  will  stay 
hot  for  days.  It  will  lose  a  large  amount  of  carbon  if 
allowed  to  lay  in  heaps  in  the  air.  It  is  better  to  mix  in 
the  necessary  amount  of  carbon  and  use  the  mixture  at 
once  again.  One  can  also  keep  the  mixture  in  air-tight 
sheet-iron  tanks.  If  the  lime  has  been  unslacked  the 
mixture  cools  much  quicker  and  does  not  lose  as  much 
carbon  after  it  has  been  taken  from  the  furnace.  In  the 
case  of  slacked  lime  water  gas  is  probably  formed  in  large 
amounts.  The  carbon  pencils  must  be  well  cared  for  in 
order  that  they  last  for  a  long  time.  If  sufHcient  coke  is 
put  in  the  mixture  they  are  not  attacked  much  at  the  end. 
They  will  shorten  from  0*05  to  cio  inch  for  every  hour 
running.  They  become  thinner  for  being  exposed  to  the 
air  when  hot.  They  are  mainly  attacked  after  the  eledric 
current  has  been  shut  off,  for  if  the  furnace  is  working  the 
gases  from  the  arc  come  up  around  the  carbons  and  shut 
the  air  off.  In  order  to  save  the  carbons  best  it  is  there- 
fore well  to  keep  the  furnaces  running  with  as  little  in- 
terruption as  possible.  In  the  closed  furnace,  which  we 
have  described,  the  carbons  will  be  surrounded  by  non- 
oxidising  gases,  which  will  save  them  materially.  In  the 
open  furnaces  in  Spray  we  surround  the  carbons  with  a 
sheet-iron  cover  that  reaches  from  the  carbon  holder  to 
within  four  inches  of  the  bottom  end  of  the  carbons. 
This  jacket  is  fastened  with  iron  wires  to  the  carbon 
holder.  The  space  between  the  carbons  and  the  jacket 
is  packed  with  a  mixture  of  coke  and  coal  tar  or  pitch. 
This  mixture  is  baked  by  surrounding  the  carbons  and 
jacket  with  the  red  hot  material  that  comes  from  the 
furnace,  or  by  placing  them  in  a  fire.  The  jacket  will 
generally  last  as  long  as  the  carbons.  One  set  of  the 
carbons  in  an  open  furnace,  and  with  interrupted  opera- 
tions, will  last  on  an  average  about  100  hours.  These 
figures  hold  good  where  a  current  of  from  1700  to  2000 
amperes  is  used.  The  voltage  has  no  perceptible  influ- 
ence on  the  result.  Working  with  say  1700  amperes  and 
100  volts,  and  generating  about  225  horse  power,  the  pro- 
du(5lion  of  carbide  per  hour  can  be  reckoned  to  be  easily 
eighty-five  pounds,  and  one  set  of  carbons  can  therefore 
make  at  least  8500  pounds  of  carbide,  even  in  an  open 
furnace.  If  the  furnace  is  used  continuously  the  carbons 
will  last  at  least  from  200  to  300  hours,  and  the  cost  of 
pencils  for  one  ton  of  carbide  will  be  about  i  dol. 

The  analytical  part  of  our  work  has  been  very  simple. 
After  the  piece  of  carbide  has  been  broken  open  with  a 
hammer,  two  or  more  samples,  representing  as  nearly  as 
possible  the  average  quality  of  the  carbide,  and  of  about 
eight  ounces  each,  are  taken.  These  samples  are  broken 
in  pieces  of  about  half  an  inch  in  diameter,  and  from  two 
to  three  ounces  are  taken  for  one  gas  test.  The  material 
is  put  into  a  dry  bottle  of  about  one  quart  capacity, 
which  is  provided  with  a  rubber  stopper,  through  which 
two  glass  tubes  pass.  The  one  tube  bears  a  stop  cock 
and  drop  funnel,  the  other  tube  condudls  the  gas  through 
a  series  of  [J  tubes  and  then  through  a  small  gas  meter. 
The  funnel  is  filled  with  water,  and,  by  opening  the  stop- 
cock, water  is  allowed  to  drop  slowly  on  the  carbide. 
The  acetylene  gas  is  generated  and  is  cooled  in  the  (J 
tubes  before  it  passes  to  the  gas-meter.    Much  water 


vapour  is  condensed  in  the  U  tubes,  for  the  gases  gene- 
rated in  the  bottle  are  hot.  We  make  a  correcStion  for  the 
temperature  of  the  gas  as  it  passes  the  gas-meter.  We 
do  not  take  into  consideration  the  small  amount  of  gas 
which  passes  through  the  gas  meter  by  the  expansion  of 
the  gas  in  the  bottle  when  the  latter  becomes  hot,  and 
because  a  part  of  the  bottle  becomes  filled  with  water. 
The  error  arising  herefrom  is  of  no  consequence,  for  the 
volume  of  the  bottle  is  only  one  quart,  and  the  volume  of 
the  gas  which  passes  from  the  gas  meter  is  from  \  cubic 
foot  to  I  cubic  foot.  The  water,  moreover,  becomes 
saturated  with  acetylene.  Our  figures  show  the  amount 
of  moist  gas  at  the  temperature  of  60°  F. 

In  order  to  determine  the  lime  in  the  mixture,  two  and 
five-tenths  grms.  are  boiled  with  a  slight  excess  of  hydro- 
chloric acid  of  known  strength  in  a  250  c.c.  bottle.  The 
bottle  is  cooled  and  filled  up.  The  liquid  is  filtered,  and 
in  50  c.c.  of  the  filtrate  the  excess  of  acid  is  determined 
by  titration.  The  coke  is  determined  by  boiling  2  grms. 
of  mixture  with  25  c.c.  of  12  per  cent  hydrochloric  acid 
and  filtering  off  the  coke  on  a  Gooch  crucible.  These 
methods  do  not  make  a  claim  to  absolute  accuracy,  but 
they  can  be  quickly  executed  and  give  a  good  estimate  of 
the  relation  in  which  the  coke  and  lime  are  present  in  the 
mixture,  as  the  following  figures  show.  The  coke  used 
for  the  original  mixture  contained  7-33  per  cent  of  ash. 
The  coke  that  remained  from  the  mixture  that  had  been 
boiled  with  12  per  cent  hydrochloric  acid  contained  65*5 
per  cent  of  ash,  and  the  coke  which  remained  by  the  same 
treatment  from  a  similar  mixture  that  had  been  once  in 
the  furnace  contained  7/0  per  cent  ash.  The  amount  of 
lime  found  in  mixtures  by  titration,  and  that  found  by 
gravimetric  analysis,  varied  only  by  from  i  to  J  per  cent 
when  the  small  amount  of  magnesia  in  the  lime  was 
known  and  taken  into  consideration.  In  controlling  the 
different  runs  we  have  proceeded  as  follows : — 

The  carbide  was  weighed  and  the  coating  on  it  deter- 
mined either  by  taking  it  off  and  weighing  it  or  by  esti- 
mating it  on  small  and  clean  pieces.  By  deduifting  the 
weight  of  the  coating  from  the  weight  of  the  piece  of 
carbide  we  obtain  the  net  yield  of  carbide.  The  gas 
therein  is  determined,  the  figure  accepted  being  the 
average  of  the  result  of  the  analyses  of  at  least  two 
samples.  In  order  to  determine  the  power  used,  we 
multiply  the  voltage  by  the  amperage  and  divide  the  pro- 
du(5t  by  746  to  obtain  the  number  of  horse  power  gene- 
rated by  the  dynamos.  In  order  to  make  a  more  proper 
comparison  we  found  it  necessary  to  dedudt  the  loss  of 
voltage  sustained  in  the  carbon  pencils.  Our  pencils 
were  made  in  different  fadories  and  had  a  different  re- 
sistance. We  therefore  determined  the  difference  in 
voltage  as  indicated  by  the  usual  reading  of  our  meter 
and  the  voltage  at  the  end  of  the  carbon  pencils.  We 
touch  the  end  of  each  pencil  alternately  with  an  iron  rod 
that  is  connedted  with  the  volt  meter  by  a  copper  wire. 
We  call  net  power  the  power  generated  by  the  dynamos 
less  the  average  loss  in  the  six  carbon  pencils.  Our 
meters  are  placed  in  the  primary  circuit  and  we  have  not 
taken  into  account  the  losses  of  amperage  in  the  trans- 
formers and  those  sustained  by  leakage.  We  have  fur- 
ther found  that  the  readings  of  our  meters  are  about  6 
per  cent  higher  than  those  of  standard  Weston  meters. 
It  may  therefore  be  safely  relied  upon  that  all  our  esti- 
mates for  the  production  of  carbide  per  horse  power  are 
too  low.  The  error  is,  however,  in  all  cases  in  the  same 
dire(51:ion,  so  that  it  cannot  have  materially  influenced 
our  deductions,  which  are  based  upon  a  comparison  of 
our  results. 

In  the  carbide  there  is  also  a  considerable  loss  of 
voltage,  and  therefore  of  power.  We  found,  for  example, 
sixty-five  volts  in  the  bottom  cables  and  only  fifty  volts  at 
the  top  of  a  2J  feet  high  piece  of  carbide  just  under  the 
arc.  This  makes  a  loss  of  six  volts  for  each  foot  of  car- 
bide. The  average  produdion  during  six  to  eight  hours 
of  continuous  working  is  as  large  as  that  during  two  or 
three  hours  at  the  same  power.     It  is,  however,  not  ad- 


i8 


Derivatives  of  Colutnbium  and  Tantalum. 


f  Chbuical  News, 
I       Ian.  8,  1897. 


visable  to  make  the  carbide  pieces  higher  than  2  i  feet, 
since  then  the  resistance  of  the  carbide  will  begin   to 
materially  reduce  the  quantity  of  the  produ^ion. 
(To  be  continued). 


The  quantitative  analysis  of  this  columbite  by  fusing 

with  bisulphate,  as  above  described,  gave  the  following 

results : —  „ 

B.  C.  D.  E. 


DERIVATIVES    OF    COLUMBIUM    AND 

TANTALUM* 

By  MARY  ENGLE  PENNINGTON. 

{Contiuued  rrom  p.  10). 

The  mineral  was  ground  very  fine  and  heated  in  sealed 
tubes  with  sulphuric  acid  (i  part  of  concentrated  acid  to 
2  parts  water),  the  resulting  decomposition  being  titrated 
with  permanganate,  with  the  following  results  :— 

Per  cent  FeO. 

0"5  grm.  heated  one  day  at  210°  C i'3i6 

o*5  grm.  heated  two  days  at  230°  C.       . .     i'4i6 
o"5  grm.  heated  five  days  at  230°  C.       . .     5 "50 

It  seemed  probable  that  this  was  not  the  total  amount 
of  ferrous   iron  in  the  columbite;  hence  attention  was 
direfied  to  an  old  method  which  is  rarely  used,  yet  seerns 
to  be  worthy  of  greater  attention  than  has  been  given  it. 
Berzelius  first  suggested  the  method,  though  it  is  gene- 
rally credited  to  Hermann.     The  finely  ground  mineral  is 
mixed   with   fused  and  finely  divided   borax.     A  small 
platinum  crucible  is  completely  filled  with  this  mixture, 
then  covered  with  a  platinum  lid,  and  the  whole  placed  in 
a  larger   platinum   crucible.     Dry  magnesium   oxide   is 
packed  around  and  over  the  inner  crucible  until  it  is  com- 
pletely  covered,  and  so  excluded  from  air  contadl.     The 
heat  of  a  good  Bunsen  lamp  is  applied  for  one-half  hour, 
when  the  decomposition  is  complete.    Longer  heating,  or 
too  rapid  cooling,  causes  the  fusion  to  adhere  very  tightly 
to  the  crucible,  and  loss   may  result  on  endeavouring  to 
remove  it.   When  the  whole  is  quite  cold,  the  small  crucible 
is  taken  out,  freed  from  adhering  magnesium  oxide  and 
weighed.     The  fusion,  which  is   a  clear  green  glass,  is 
then  freed  from  the  crucible  by  sharply  tapping ;  a  piece 
may  be  broken  off,  weighed,  ground  in  a  tnortar,  dissolved 
in  water  and  sulphuric  acid,  and  titrated  with  potassium 
permanganate.     Or,  if  the  amount  of  ferrous  iron  is  not 
large,  it  is  better  to  crush  the  whole  fusion  in  a  diamond 
mortar,  then  place  in   a  flask  provided  with   a  Bunsen 
valve,  dissolve  in  water  and  suiphuric  acid,  and  titrate. 
To  prevent  the  oxidation  of  the  iron  during  its  solution, 
a  quantity  of  sodium  carbonate  was  placed  in  the  flask 
with  the  ground  fusion,  and  the  water  and  sulphuric  acid 
added  carefully  to  this  mixture.   When  a  strong  evolution 
of  carbon  dioxide  had  continued  for  several  minutes,  the 
cork  carrying  the  Bunsen  valve  was  quickly  inserted,  and 
the  flask  put  aside  until  solution  had  taken  place.     It  is 
necessary  to  shake  the  flask  from  time  to  time,  otherwise 
the   finely  divided  oxides   which   separate   will   enclose 
some  particles  of  the  fusion,  and  the  result  will  be  low. 
In  one  or  two  hours  the   insoluble  residue   should   be  a 
perfectly  white,  fine,  homogeneous  mass.     The  flask  is 
then  opened,  more  sulphuric  acid  added  if  necessary,  and 
the  iron    titrated  with    permanganate.      A   number  of 
fusions  were  made  according  to  this  method,  the  amount 
of    ferrous   oxide    found    being    6'426    per    cent.      The 
method  seems  to  be,  so  far  as  columbite  is  concerned, 
perfedlly  trustworthy.    It  is  rapid  and  the  manipulation  is 
not  difficult.     The   oxides  which  separated  out  were  per- 
feftly  white.     In  one  experiment  they  were  filtered  off, 
washed  with  hot  water,  ignited,  and  weighed.     The  per- 
centage of  mixed  oxides,  77*94  per  cent,  agrees  quite  well 
with  that  obtained  by  the  bisulphate  method. 

*  From  the  author's  thesis  presented  to  the  University  of  Penn- 
sylvania for  the  degree  of  Ph.D.,  1895.  From  the  Journ.  Amer. 
Chem.  Soc,  xviii.,  January,  1896. 


iOsf 

:>z  ) 


TajOj 

Cba 

TiOa 

FeaOs 

SnOa  \ 

WO3  J 

MnO.. 


A. 
78-61 


12*30 

115 

8-96 


I '60 
8-32 

101*02    102*79 


79*04    79'00    77*96    78*70 

13-83     13*62     13*58      — 
1*85      2*24 


1*84 
J -08      — 


—     100*86     — 


One-half  grm.  of  material  was  used  in  each  case, 
The  ferric  oxide,  as  given  above,  includes  the  ferrous, 
which,  estimated  by  the  method  of  Berzelius,  equals 
6-42  per  cent. 

In  a  sixth  analysis  3  grms.  of  material  were  taken 
and  due  attention  was  paid  to  those  constituents  which 
former  analyses  had  shown  to  be  present,  but  in  such 
small  quantities  that  their  determination  was  not  trust- 
worthy.   The  results  in  this  case  were  :— 

Per  cent. 
TaaOj) 

CbaOsj. 78*04 

TiOj    ) 


WO3 
SnOa 
U3O8 
FeaOa 
FeO  . 
CaO  . 
MnO. 
H2O. 


Total 


0*24 

0-48 
5-22 
6-42 

0*02 
8-96 
1*22 

100*60 


An  interesting  point  in  the  composition  of  this  colum- 
bite is  the  ferric  oxide.  Hermann  records  one  analysis 
of  some  fragments  of  a  columbite  from  Miask  containing 
several  per  cent  of  it,  and  so  far  as  I  am  aware  this  is 
the  only  columbite  in  which  this  constituent  is  mentioned. 
He  also  gives  a  Miask  columbite  containing  0*50  per 
cent  of  uranium  oxide.  Genth  mentions  a  trace  of 
uranium  in  a  columbite  analysed  by  him. 

While  no  effort  was  made  to  separate  the  metallic 
oxides  quantitatively,  it  was  found  from  the  preparation 
of  pure  material  that  the  columbium  was  in  decided 
excess.  Titanic  acid  was  proved  to  be  present,  and  silica 
was  found  in  very  small  quantities. 

Many  of  the  recorded  analyses  in  which  separations  of 
columbic  and  tantalic  oxides  are  given,  fail  to  state  whether 
any  attempt  had  been  made  to  eliminate  or  to  prove  the 
presence  of  titanium  or  silica.  Given  a  mixture  of  tan- 
talum, columbium,  and  titanium,  the  analyst  will  have 
no  difficulty  in  separating  tantalum  from  columbium  by 
Marignac's  double  fluoride  method.  But  the  titanium 
double  fluoride,  when  mixed  with  the  columbium  salt, 
shows  an  abnormal  solubility  which  makes  its  separation 
very  doubtful.  This  point  will  be  more  fully  discussed 
later. 

Fusion  with  Sodium  Thiosulphate.— It  occurred  to  me 
to  try  the  decomposition  of  the  mineral  by  fusion  with 
sodium  thiosulphate,  believing  that  in  this  way  tungsten 
and  tin  would  be  converted  into  sulpho-salts,  and  could 
then  be  more  effeaually  removed  from  the  other  constitu- 
ents. Without  entering  into  detail,  I  may  say  the  attempt 
was  fruitless. 

Decomposition  by  the  Gibbs  Method.—Some  years  ago 
Dr.  Gibbs  published  a  procedure  {Am.  J.  Sci.  Arts,  xxxyii., 
357,  1864)  for  the  decomposition  of  the  columbite  mine- 
rals ;  and  as  my  desire  was  to  investigate  the  different 
methods  of  decomposition,  I  naturally  turned  to  this 
suggestion.  In  mineral  literature  this  course  is  given  a 
second  place  to  the  bisulphate  decomposition.     My  own 


CHRMtcAL  News,  I 
Jan.  8, 1897.      I 


Derivatives  of  Columbium  and  Tantalum, 


19 


experience  compels  tne  to  prefer  it  to  the  latter 
method.  The  details  of  the  Gibbs  method  are,  in  brief, 
as  follows  : — 

The  mineral  must  be  fine,  yet  need  not  be  in  an  impal- 
pable powder,  as  is  necessary  in  the  bisulpha'.e  decomposi- 
tion ;  it  was  intimately  mixed,  by  grinding  in  a  mortar,  with 
three  times  its  weight  of  potassium  fluoride  ;  the  mixture 
was  transferred  to  a  platinum  crucible  and  made  into  a 
paste  with  concentrated  hydrofluoric  acid.  The  mass 
heated  up  at  once,  and  for  some  minutes  the  decomposi- 
tion proceeded  without  the  application  of  heat.  It  was 
found  advantageous  to  let  this  mixture  of  acid  salt  and 
mineral  stand  for  several  hours,  stirring  occasionally,  and 
adding  more  acid  if  the  mass  became  hard.  It  was  then 
heated  on  a  water-bath  until  the  excess  of  acid  was  driven 
off.  After  thoroughly  drying  on  an  iron  plate,  the 
free  flame  was  applied.  Hydrofluoric  acid  was  driven 
out  of  the  acid  potassium  fluoride,  and  at  length  the  whole 
mass  fused  and  formed  a  clear,  quiet,  easily  handled  fusion, 
which,  upon  cooling,  became  a  beautiful  pink-violet  in 
colour. 

The  decomposition  is  not  complete  until  every  part  of 
the  mixture  has  assumed  this  colour,  which  does  not 
change  on  further  heating.  In  the  early  part  of  the 
fusion  a  deep  blue  colour  appears.  If  the  adlion  be  in- 
terrupted at  this  point  an  incomplete  decomposition  will 
result. 

The  violet  mass  was  taken  up  with  water  and  hydro- 
fluoric acid  in  a  platinum  dish,  then  boiled  and  filtered. 
This  extra(5tion  should  be  repeated  several  times.  If  the 
decomposition  is  not  quantitative,  the  solution  in  water 
is  much  hastened  by  first  grinding  the  fusion.  Any  silica 
which  may  have  been  present  in  the  mineral  will  remain 
as  potassium  silicofluoride.  This  being  a  gelatinous 
compound,  it  is  likely  to  enclose  fine  particles  of  the 
fusion  and  prevent  their  solution.  If  the  amount  of 
silica  is  not  large,  a  separation  may  usually  be  effeded  by 
treating  with  concentrated  hydrofluoric  acid  ;  but  if  much 
silica  be  present  it  is  safer  to  evaporate  to  dryness  with 
alitile  sulphuric  acid,  and  take  up  the  remaining  potassium 
sulphate  with  water.  If  any  insoluble  substance  is  left 
it  may  be  dissolved  in  hydrofluoric  acid  and  added  to  the 
main  portion  of  the  solution. 

If  an  analysis  of  the  mineral  is  desired,  hydrogen  sul- 
phide gas  may  now  be  passed  through  the  acid  filtrate, 
whereby  any  tin,  tungsten,  or  molybdenum  present  will  be 
precipitated  as  sulphide.     Filter,  and  separate  as  usual. 

The  filtrate  was  evaporated  to  dryness,  and  enough 
sulphuric  acid  added  to  expel  all  the  hydrofluoric  acid. 
The  excess  of  acid  was  driven  off  on  an  iron  plate,  not 
over  a  free  flame,  and  the  oxides  of  columbium,  tantalum, 
and  titanium  precipitated  by  boiling  with  a  large  quan- 
tity of  water.  The  boiling  must  be  continued  for  several 
hours  to  insure  a  complete  precipitation,  but  it  is  not  so 
difficult  to  bring  down  the  metallic  oxides  under  these 
conditions  as  in  the  bisulphate  decomposition.  Filter, 
and  wash  the  oxides  with  hot  water,  first  by  decantation, 
then  on  the  filter.  The  ignition  of  the  oxides  gave  a  per- 
fectly white,  fine  powder;  and  this,  fused  with  sodium 
carbonate  or  potassium  fluoride,  yielded  a  colourless  mass 
when  cold.  The  oxides  obtained  from  the  bisulphate 
never  did  so,  but  formed  with  the  carbonate  a  tinge  of 
green,  and  with  the  fluoride  a  tinge  of  pink,  showing  the 
presence  of  manganese,  and  probably  of  iron. 

The  filtrate  from  the  mixed  oxides  contained  iron,  man- 
ganese, and  uranium.  These  were  separated  by  am- 
monium sulphide  and  ammonium  carbonate,  following 
the  plan  given  under  the  bisulphate  method. 

When  the  objeft  is  simply  the  extradion  of  pure  mixed 
oxides,  the  above  procedure  may  be  somewhat  varied. 
The  fusion  is  made  just  as  usual,  then  taken  up  with 
vvater  insufficient  for  perfed  solution,  and  a  small  quan- 
tity of  hydrofluoric  acid,  boiled,  and  filtered.  On  cooling, 
the  filtrate  will  be  found  to  be  an  almost  solid  mass  of 
the  columbium  double  fluoride,  2KF.CbOF3.H2O,  which 
separates  as  a  beautiful  shining  salt  and  consists  of  thin 


laminae.  At  first  the  tantalum  double  fluoride  remains 
undissolved,  or  is  dissolved  only  in  small  quantity,  as  it 
is  a  very  insoluble  salt  compared  with  the  columbium 
compound,  but  if  too  much  hydrofluoric  acid  is  added  the 
tantalum  will  be  discovered  with  the  columbium  potas- 
sium fluoride,  and  larger  amounts  of  iron  and  manganese 
will  also  contaminate  it.  From  a  very  concentrated 
solution  of  the  columbium  double  fluoride,  such  as  would 
be  obtained  by  this  method,  any  tantalum  double  fluoride 
will,  if  present,  separate  almost  immediately.  These 
needles  should  be  examined  under  a  microscope  for  the 
thin  transparent  plates  of  the  columbium  salt.  When 
these  begin  to  appear  filter  at  once  and  use  a  pump. 
The  plates  are  a  good  indication  that  all  tantalum  is 
separated.  The  filtrate,  on  standing,  will  usually  give 
the  columbium  salt,  but  it  may  have  to  be  concentrated  a 
little.  The  first  crop  of  crystals  may  be  coloured  pink  by 
manganese  or  iron.  Re-crystallisation,  however,  removes 
this.  The  next  crop  is  fairly  pure.  When  working  with 
large  quantities  a  very  satisfacftory  approximate  separation 
of  columbium  from  tantalum  may  be  obtained  by  this 
method  of  extradion. 

As  boiling  with  pure  water,  or  even  with  water  contain- 
ing a  small  amount  of  hydrofluoric  acid,  decomposes  the 
tantalum  potassium  fluoride  and  leaves  an  insoluble 
compound,  2(2KF.TaF5)Ta205,  while  the  columbium 
double  salt  is  praftically  unafifedted,  this  treatment  leaves 
us  in  the  end  a  white,  finely-divided  mass  which  is  almost 
free  from  columbium.  By  heating  this  residue  on  a  water- 
bath  with  a  rather  concentrated  solution  of  hydrofluoric 
acid  and  a  little  potassium  fluoride,  the  tantalum  potas- 
sium fluoride  is  obtained,  and  may  be  purified  by  re-crys- 
tallisation. 

The  Gibbs  method  was  used  for  the  preparation  ot 
rather  large  quantities  of  tantalum  and  columbium  potaS' 
slum  fluorides.  I  think  it  preferable  to  the  bisulphate  de- 
composition and  subsequent  solution  of  the  oxides  in 
hydrofluoric  acid  in  that  it  does  not  consume  so  much 
time,  and  iron  and  manganese  are  more  readily  elimi- 
nated. The  only  objedion  is  that  large  platinum  vessels 
are  needed  ;  as  a  substitute  for  these,  rubber  beakers  and 
funnels  were  sometimes  used. 

The  method  finally  adopted  is  as  follows  : — 

Separation  of  Columbium  and  Tantalum  by  their  Potas- 
sium Double  Fluorides, — The  pure  mixed  oxides  were 
placed  in  a  platinum  crucible  with  three  times  their 
weight  of  potassium  fluoride,  then  moistened  with  hydro- 
fluoric acid  as  described  under  the  decomposition  of  the 
mineral  by  the  Gibbs  method.  By  treating  the  fusion 
with  water  and  hydrofluoric  acid  an  almost  perfedt  solu- 
tion was  obtained,  since  only  a  trace  of  silica  was  present. 
Concentration  gave  the  long  pointed  needles  of  tantalum 
potassium  fluoride,  2KF.TaF5.  These  were  filtered  and 
the  solution  again  concentrated.  The  crystal  crop  should 
be  examined  under  the  microscope,  as  it  may  be  a  mix- 
ture of  tantalum  and  columbium.  Usually  it  is  only 
tantalum. 

If  a  considerable  excess  of  hydrofluoric  acid  and  potas- 
sium fluoride  is  present  in  the  mother-liquor,  the  next 
crop  of  crystals  may  be  a  complex  mass  about  which  the 
analyst  can  come  to  no  definite  conclusion.  The  fradion 
consists  principally  of  long  crystals  much  like  the  tita- 
nium double  fluoride,  and,  to  make  the  matter  more 
puzzling,  these  crystals  are  not  so  soluble  as  those  sepa- 
rating at  the  same  time.  They  may  be  obtained  pure  by 
treating  the  mixture  with  a  few  drops  of  water  and  quickly 
filtering.  Re-crystallisation  from  pure  water  gives  the 
laminated  salt  2KF.CbOF3.H2O.  If  the  acid  and  potas- 
sium fluoride  are  not  in  large  excess,  usually  two,  and 
sometimes  three,  crops  of  the  laminated  salt  are  formed, 
but  in  time  the  long  needles  are  almost  sure  to  make 
their  appearance.  These  needles  were  tested  for  tita- 
nium, but  no  satisfadory  evidence  of  its  presence  was 
obtained. 

When  the  solution  is  very  concentrated  large  thin 
plates  separate  from  it.    These  do  not  give  the  readion 


20 


Formation  oj  Antimony  Cinnabar. 


t  CHBMiCAt,  News, 
\      Jan.  8,  1897. 


with  gallotannic  acid,  but  they  readl  with  zinc,  hydro- 
chloric acid,  and  potassium  thiocyanate.  This  test  for 
columbium  compounds  will  be  noiiced  later.  Re-crys- 
tallisation does  not  give  the  laminated  salt.  The  crystals 
are  always  found,  and  are  by  no  means  in  small  quantity. 
With  zinc  and  hydrochloric  acid  they  give  a  greenish 
colour  which  quickly  becomes  brown.  They  were  re- 
peatedly re-crystallised,  then  decomposed  with  sulphuric 
acid.  The  oxide  obtained  was  white,  and  at  19°  C.  had  a 
specific  gravity  of  4'57. 

The  oxide  was  placed  in  a  platinum  retort  connedted 
with  a  platinum  condenser;  hydrofluoric  acid  was  poured 
over  it,  and  a  free  flame  was  applied.  The  volatile  pro- 
dudts  were  colleded  in  water  in  a  platinum  dish.  Several 
evaporations  were  necessary  for  the  volatilisation  of  this 
oxide.  The  solution  in  the  dish  was  then  treated  with  a 
small  quantity  of  potassium  fluoride  and  concentrated. 
The  same  large,  thin  plates  crystallised  out.  These 
crystals  were  very  beautiful,  being  frequently  over  an  inch 
in  length  and  ij  inches  in  width.  They  were  so  trans- 
parent that  often  their  presence  in  the  dish  was  altogether 
unnoticed. 

Analyiis. 


Substances  taken. 
Grm. 

o'50OO 


K2SO4  found. 
Grm. 

0*5268 


CbjOj  found, 
tirm. 

00059 


This  analysis  would  indicate  that  the  salt  is  probably 
acid  potassium  fluoride  with  a  small  quantity  of  the 
double  fluoride  of  columbium,  yet  it  must  not  be  forgotten 
that  the  readions  given  above  cannot  be  regarded  as  con- 
clusive evidence  of  the  presence  of  columbium. 

Because  of  the  brown  colour  with  zinc  and  hydrochloric 
acid  these  crystals  were  also  tested  for  titanium.  Its 
presence  could  not  be  detected. 

(To  be  continued). 


FORMATION 


OF 

By  J 


ON   THE 

ANTIMONY 
H.  LONG. 


CINNABAR. 


The  composition  of  the  pigment  known  as  antimony 
cinnabar  has  been  stated  by  several  different  formulae,  as 
may  be  seen  by  consulting  the  leading  hand-books  of 
chemistry.  The  substance  was  usually  considered  as  a 
mixture  of  sulphide  and  oxide  or  as  an  oxysulphide  with 
the  formula  862820.  The  formula  86283  is  found  also 
in  some  of  the  older  works,  and  Baubigny  (Comptes  Rendus, 
Odober  22,  1894)  has  shown  that  this  is  undoubtedly  the 
correft  one.  Experiments  made  by  myself,  and  described 
in  this  Journal  in  February,  1895,  led  me  to  adopt  the 
same  formula. 

The  compound  is  usually  prepared  by  boiling  a  solu- 
tion of  antimony  chloride  or  tartrate  with  sodium  thio- 
sulphate  or  crude  calcium  thiosulphate.  As  obtained 
from  the  acid  solution  of  the  chloride,  the  pro- 
dud  is  not  pure  and  not  of  constant  composition,  being 
frequently  mixed  with  oxychloride.  This  mixture  is  a 
mechanical  one,  and  analysis  made  from  it  has  no  value 
in  establishing  a  formula.  The  precipitate  obtained  by 
boiling  a  mixture  of  pure  solutions  of  tartar  emetic  and 
sodium  thiosulphate,  on  the  other  hand,  has  a  constant 
composition,  and  numerous  analyses  I  have  made  of  it  in 
the  past  year  lead  to  the  formula  already  given  {loc.  cit.). 

By  analogy  with  other  formulae  established  in  the  paper 
referred  to,  I  suggested  there  that  the  readion  between 
the  tartrate  and  thiosulphate  may  be  represented  by  this 
equation  : — 

2KSb0C4H406-l-Na2S203  +  H20  = 

=  2KNaC4H406-i-Sb203+H2S203, 


the  oxide  and  thiosulphate  then  ading  on  each  other  to 
form  sulphide  : — 

8b203-t-2H2S203  =  Sb2S3  +  2H20-hS02-t-50. 
The   oxygen   and   sulphur   dioxide  are  not  liberated   as 
such,  but  held  as  polythionates  with  the  excess  of  thio- 
sulphate used. 

To  throw  further  light  on  the  readlion  I  have  attempted 
the  formation  of  the  cinnabar  by  other  methods.  While 
the  produdt  is  sulphide  of  antimony,  it  appears  that  it 
can  be  made  with  its  charadteristic  colour  only  by  the 
decomposition  of  a  tiiiosulphate.  All  attempts  to  obtain 
the  true  precipitate  by  adion  of  hydrogen  sulphide  or 
alkali  sulphides  and  sulphur  dioxide  on  antimony  solu- 
tions  failed.  The  only  body  formed  was  the  amorphous 
sulphide,  often  mixed  with  sulphur.  On  the  other  hand, 
by  the  adion  of  a  neutral  or  acid  mixture  of  an  antimony 
compound  and  a  thiosulphate  on  each  other,  the  cinnabar 
red  produdt  is  the  only  one  formed.  If  the  mixture  is 
made  alkaline  by  the  addition  of  a  drop  or  two  of 
ammonia  water,  no  sulphide  whatever  precipitates.  A 
small  amount  of  hydraied  oxide  of  antimony  separates, 
but  the  decomposition  of  the  thiosulphate  is  prevented. 
On  the  addition,  now,  of  enough  weak  acid  to  neutralise 
the  ammonia  a  yellow  precipitate  soon  appears,  but  this 
speedily  changes  to  deep  bright  red.  The  formation  of 
the  true  cinnabar  seems  to  begin  by  the  appearance  of  a 
yellowish  intermediate  produdt,  which  is  compatible  with 
the  above  equations. 

In  this  connexion  it  is  interesting  to  note  the  behaviour 
of  pure  antimony  trioxide  with  solutions  of  thiosulphate. 
The  readion  of  the  latter  with  a  soluble  antimony  com- 
pound is  comparatively  rapid,  and  experiments  were 
made  to  show  the  adion  of  the  oxide  under  the  same 
conditions.  It  was  found  that  the  latter,  when  added  to 
a  strong  or  weak  neutral  thiosulphate  solution,  is  unable 
to  effed  a  decomposition  in  the  cold  or  by  application  of 
heat.  When  the  mixture  is  boiled  the  oxide  remains 
perfedly  white.  This  is  true  even  after  heating  in  an 
autoclave  under  a  pressure  of  eighteen  atmospheres. 

It  was  found,  however,  that  with  the  addition  of  a  little 
acid  to  the  mixture  of  oxide  and  thiosulphate  a  readion 
followed  after  a  time,  although  it  never  became  complete. 
In  a  series  of  experiments  a  constant  weight,  0*576  grm. 
of  the  pure  precipitated,  washed,  and  dried  oxide  was 
taken  and  mixed  with  water,  and  a  constant  weight  of 
sodium  thiosulphate  in  solution,  in  each  case  0*992  grm. 
of  the  salt.  Definite  volumes  of  half  normal  hydrochloric 
acid  were  then  added,  and  water  enough  to  make  the 
total  volume  50  c.c.  in  each  case.  The  mixtures  were 
made  in  small  Erlenmeyer  flasks,  loosely  stoppered,  and 
were  very  frequently  shaken.  The  amounts  of  hydro- 
chloric taken  are  given  in  the  table  below.  The  readions 
became  apparent  only  after  several  minutes,  and,  after 
five  hours,  had  advanced  so  far  in  the  mixtures  numbered 
one  and  two,  that  the  produds  had  become  orange. 
The  readions  in  the  other  flasks  were  less  marked,  but 
later  became  strong.  The  mixtures  were  made  on 
Odober  yth,  and  were  shaken  many  times  daily  through 
two  months  ;  in  fad,  as  long  as  any  change  of  colour  in 
them  was  noticed.  On  December  3rd  the  amount  of  sul- 
phide of  antimony  present  was  found  by  the  method  of 
Rivot,  oxidation  by  chlorine  after  preliminary  treatment 
with  strong  potassium  hydroxide  solution.  The  sulphur 
is  found  as  sulphate,  and  the  amount  of  sulphide  formed 
in  each  case  is  shown  by  the  table. 

Amount  BaSO,        SbjO, 

No.      cfSbaOg.     NajSaOa.  N/2HCI.  HjO.        found,      converted. 
Grm.  Grm.         C.c.       C.c.  Grm.  Grm. 

1  0*576  0992  2  48  0*155  0*064 

2  0*576        o'gga  4        46        0*293        o*i2i 

3  0-576        0992  8        42        0*384        0*158 

4  0*576        0*992         12        38        0*427        0*176 

5  0*576        0*992         16        34        0*454        o'^S? 

In  mixtures  one  and  two  no  evolution  of  sulphur  dioxide 
could  be  deteded  by  the  odour  or  by  tests,  but  in  the 


CBBUICAL  MBWS,  I 
Jan.  8,  1897.       t 


Detection  oj  Caramel  in  Wines. 


21 


others  it  was  apparent,  weak  in  3  and  strong  in  4  and  5. 
No  free  sulphur  was  precipitated  in  any  case,  or  at  any 
rate  could  not  be  found  in  the  final  produd.  Although 
but  a  small  part  of  the  oxide  was  adually  converted,  the 
colour  of  the  produdts  in  mixtures  i  and  2  was  a  deep 
cinnabar,  and  perfedtly  charafteristic.  The  amounts  of 
sulphide  formed  or  of  oxide  converted  are  not  proportional 
to  the  volumes  of  acid  used,  and  are  much  less  than 
should  be  found  on  the  assumption  that  the  readion 
begins  by  the  produdtion  of  antimony  chloride  from  the 
oxide.  If  this  were  true,  the  sulphide  formed  by  means 
of  the  soluble  thiosulphate  should  increase  with  the  acid 
taken.  The  readlion  appears  to  take  place  between  the 
oxide  and  thiosulphuric  acid  liberated  by  the  hydrochloric 
acid,  as  was  suggested  by  several  experiments.  In  one 
case  0*500  grm.  of  antimony  oxide  was  treated  with 
10  c.c,  of  half  normal  hydrochloric  acid  and  30  c.c.  of 
water,  as  before,  and  allowed  to  stand  twenty  minutes, 
with  frequent  shaking.  The  mixture  was  then  filtered, 
and  to  the  filtrate  i  grm.  of  sodium  thiosulphate  in 
10  c.c.  of  water  was  added.  In  a  short  time  a  precipitate 
of  sulphur  formed,  perfedlly  light  coloured,  showing  the 
absence  of  even  a  trace  of  the  antimony.  The  rapidity 
with  which  the  thiosulphate  was  decomposed  showed 
that  the  hydrochloric  acid  taken  must  be  in  the  filtrate 
and  not  in  the  residue,  as  oxychloride  for  instance. 
Titration  of  the  filtrate  showed  this  in  a  similar  case.  In 
a  second  experiment  the  acid  and  thiosulphate,  in 
amounts  equal  to  those  of  the  last  experiment,  were 
mixed,  and  after  the  lapse  of  one  minute  the  now 
opalescent  mixture  was  added  to  some  antimony  oxide. 
Although  the  readion  between  the  first  substances  had 
gone  into  its  second  stage,  showing  that  the  hydrochloric 
acid  was  now  certainly  in  combination,  a  precipitation  of 
antimony  sulphide  began  almost  immediately,  and  in  a 
short  time  the  cinnabar  colour  was  distind. 

Thiosulphuric  acid  is  usually  spoken  of  as  quite 
unstable,  but  Landolt  has  shown  (^Ber.d.  Chem.Ges.,  xvi., 
2958)  that  in  dilute  solutions  it  may  exist  many  seconds, 
even  minutes.  The  interval  before  precipitation  is 
lengthened  by  dilution.  If  decomposition  begins  in  pre- 
sence of  compounds  of  the  heavy  metals,  a  sulphide, 
sulphur  dioxide,  and  polythionates  may  form.  A  large 
excess  of  thiosulphuric  acid  is  necessary  to  complete  the 
reaftion  in  this  manner,  as  suggested  by  the  experiments 
of  Vortmann  {Ber.  d.  Chem.  Ges.,  xxii.,  2307). 

In  Experiment  No.  i  of  the  table  above  the  amount  of 
hydrochloric  acid  taken  is  just  one-eighth  of  that  neces- 
sary to  complete  this  readtion  with  the  thiosulphate  : 

2HCI  -h  NajSzOj  =  2NaCl  +  HjSaOg. 

By  full  conversion  enough  acid  would  be  liberated  to 
complete  the  equation  assumed  at  the  beginning, 

Sba03-f2HaSa03  =  Sb2S3-f2H20  +  S02-f50, 

with  the  amounts  of  oxide  and  thiosulphate  taken.  It 
follows,  therefore,  that  not  over  one-eighth  of  the  antimony 
oxide  taken  should  be  found  converted  into  sulphide,  and 
the  result  of  the  experiment  shows  slightly  less  than  this. 
According  to  this  theory  we  should  have  0*072  grm.  of 
oxide  changed.  The  test  shows  0-064  grm.  In  the 
second  and  following  experiments  the  amount  of  oxide 
converted  is  relatively  still  less.  The  acid  taken  in  the 
last  experiment  is  sufficient  to  decompose  all  of  the 
thiosulphate  and  thus  permit  the  conversion  of  all  of  the 
oxide.  But  the  result  shows  that  slightly  less  than  one- 
third  the  oxide  has  been  changed.  In  the  first  experi- 
ment no  escape  of  sulphur  dioxide  was  noticed,  while  in 
the  last  it  was  quite  marked,  and  this  fadt  has  doubtless 
some  connedion  with  the  low  amount  of  sulphide  formed. 
The  readlion  which  takes  place  in  a  weak  solution  of 
thiosulphuric  acid  is  evidently  different  from  that  in  the 
strong  solution,  inasmuch  as  the  greater  portion  of  the 
sulphur  seems  to  be  given  off  as  sulphide  in  the  one  case 
and  as  sulphur  dioxide  in  the  other. 


In  the  somewhat  similar  readlion  with  arsenious  oxide 
Vortmann  (loc.  cit.)  suggests  this  equation— 

As203  +  9H2S203  =  AsaS3-f3H2S406-H3S02-f6H20, 
in  which  but  one-sixth  of  the  sulphur  present  is  used  to 
form  sulphide.    By  increasing  the  amount  of  hydrochloric 
acid  added  to  the  thiosulphate  the  decomposition  of  the 
latter  is  hastened. 

It  is  possible  that  after  a  time,  with  increased  libera^ 
tion  of  sulphur  dioxide,  the  formation  of  sulphide  may  be 
retarded,  as  was  suggested  by  this  experiment,  I  mixed 
half  a  grm.  of  the  antimony  oxide  with  one  grm.  of  sodium 
thiosulphate  in  10  c.c.  of  water,  and  added  10  c.c.  of  half 
normal  hydrochloric  acid  and  30  c.c.  of  moderately  strong 
solution  of  sulphur  dioxide  free  from  air.  By  using  water 
instead  of  the  last  solution,  precipitation  would  appear  in 
a  few  minutes,  but  in  this  case  it  was  delayed  several 
hours,  and  then  but  a  slight  amount  of  yellowish  produdl 
appeared.  The  thiosulphate  is  therefore  protedted  from 
decomposition  by  the  presence  of  the  sulphur  dioxide. 

The  cinnabar  is  easily  formed  from  the  oxychloride  of 
antimony  without  addition  of  acid.  Some  recently  pre- 
cipitated and  well  washed  oxychloride  was  mixed  with 
water  and  thiosulphate  solution  of  the  strength  used 
before.  The  charadteristic  colour  soon  appeared,  and  in 
a  short  time  the  whole  produdt  seemed  to  be  cinnabar. 
The  readtion  is  doubtless  aided  by  the  hydrochloric  acid 
liberated  by  the  decomposition  of  the  oxychloride  in  pre- 
sence of  water.  The  acid  in  turn  attacks  the  thiosulphate, 
and  so  the  process  becomes  continuous  and  rapid.  These 
readlions  are  all  much  hastened  by  application  of  heat 
and  the  quantitative  relations  are  also  altered,  but  at  a 
temperature  of  20°  C.  thiosulphuric  acid  seems  to  be  the 
adlive  precipitating  agent  in  the  cases  investigated. — 
yournal  of  the  American  Chemical  Society,  xviii.,  No.  4. 


DETECTION  OF  CARAMEL  IN  WINES. 

POSSIBLE  CONFUSION  WITH   THE    COAL-TAR 

COLOURS. 

By  A.  J.  DA  CRUZ  MAGALHAES. 

Caramel  is  frequently  employed — at  least  in  Portugal— 
to  give  a  fadtitious  appearance  of  age  to  white  liqueur 
wines.  There  exist  methods  for  the  recognition,  and 
even  for  the  quantitative  determination,  of  caramel  in 
wines,  but  we  do  not  find  in  literature  any  indication  as 
to  the  possible  confusion  between  the  coal-tar  colours 
and  those  of  caramel.  Now  this  confusion  may  take 
place,  and  lead  to  grave  errors. 

In  the  course  of  some  researches  on  the  colouring 
matter  of  Portuguese  wines  I  was  led  to  try,  on  a  liqueur 
wine  from  Oporto  which,  as  I  afterwards  recognised,  had 
been  strongly  caramelised,  the  general  readlions  given 
for  the  detedtion  of  coal-tar  colours.  The  following  are 
the  results  : — 

1.  I  boiled  100  c.c.  of  wine  for  ten  minutes  with  10  c.c. 
of  a  solution  of  potassium  sulphate  and  a  flock  of  mor- 
danted  wool.  The  wool  was  dyed  and  retained  its  orange- 
yellow  colour  after  plentiful  washings  in  water  and  with 
ammonia. 

2.  20  c.c.  of  wine  were  mixed  with  10  c.c.  lead  sub- 
acetate  and  were  filtered  after  agitation.  The  filtrate 
passed  through  with  a  distindt  orange-red  colour,  and 
gave  up  its  colour,  on  shaking,  to  amylic  alcohol. 

3.  100  c.c.  of  wine,  supersaturated  with  ammonia,  and 
shaken  up  with  amylic  alcohol,  gave  up  their  orange- 
yellow  colour  to  this  solvent. 

4.  10  c.c.  of  wine  were  agitated  (both  in  cold  and  in 
heat)  with  o'2  grm.  yellow  mercury  oxide  for  one  minute, 
and  filtered  after  settling.  The  filtrate  was  coloured  an 
orange-yellow  in  each  case. 

We  might  therefore   infer  that  the  wine  in  question 


22 


Government  Laboratory  of  Tasmania, 


f  Crbuical  NbwSi 

I       Jan.  8,  1897. 


was  coloured  an  orange-yellow  with  one  or  more  coal-tar 
derivatives. 

I  repeated  the  same  experiments  with  a  wine  of  the 
same  type,  of  my  own  vintage,  to  which  I  had  added  pure 
caramel  made  with  ordinary  sugar.  The  results  were  ah- 
Bolutely  the  same. 

On  operating  with  the  same  wine  without  the  addition 
of  caramel  nothing  similar  was  obtained. 

I  repeated  these  experiments  with  pure  caramel ;  the 
results  obtained  were  exadtly  those  to  which  I  had  added 
caramel.  Without  any  doubt  the  colours  of  caramel 
may  therefore  be  confounded  with  those  derived  from 
coal. 

To  throw  light  on  a  second  point  of  this  interesting 
subjeft,  I  prepared  caramel  from  dextrose  and  saccharose, 
both  very  pure. 

The  two  solutions  of  caramel  thus  prepared  were 
treated  with  lead  boric  acetate  and  agitated  with  amylic 
alcohol.  This  remained  colourless  with  dextrose  caramel ; 
with  saccharose  caramel  the  alcohol  took  a  deep  orange- 
yellow. 

If  both  were  supersaturated  with  ammonia  and  then 
shaken  up  with  amylic  alcohol,  the  first  gave  a  greenish- 
yellow  colour  to  the  alcohol,  and  the  second  a  very  deep 
orange-yellow. 

With  the  former  ether  takes  no  colour,  but  it  takes  an 
orange-yellow  with  the  latter. 

Mordanted  wool  took  a  yellow  colour  with  the  former, 
but  an  orange-yellow  with  the  latter. 

Cazeneuve'stest  does  not  alter  the  original  colour  of  the 
two  solutions. 

The  author  is  continuing  the  researches. — CompUs 
Rendus,  cxxiii.,  No.  21. 


that  it  has  escaped  the  attention  of  chemists  for  so  long 
a  time  ? 

The  examination  of  the  ash  of  bituminous  and  anthra- 
cite coal  shows  the  presence  of  titanic  oxide.  The  results 
of  some  determinations  are  as  follows : — 


Jellico  (Tenn.)  bituminous  coal 
Coal  Creek  (Tenn.)  bituminous  coal 
Pocahontas  (Va.)  bituminous  coal    .. 
Middlesborough  (Ky.)  bituminous  coal 
Pennsylvania  anthracite  coal     .. 


THE  OCCURRENCE  OF   TITANIUM. 
By  CHARLES  E.  WAIT, 

It  is  not  my  present  purpose  to  repeat  what  has  been 
already  frequently  published  relative  to  the  presence  of 
titanium  in  minerals,  typical  rocks,  meteorites,  clays, 
soils,  blast  furnace  produds,  &c.  I  wish  merely  to  call 
attention  to  the  fad  that  some  of  the  bodies  with  which 
we  have  much  to  do  contain  titanium,  and  that,  probably 
owing  to  the  difficulties  formerly  experienced  in  its  esti-  J 
mation,  it  has  been  more  frequently  overlooked  than  is 
generally  supposed. 

In  the  recent  examination  of  food  materials,  under  the 
diredtion  of  the  United  States  Department  of  Agricul- 
ture, I  have  had  occasion  to  make  analyses  of  the  ashes 
of  some  plant  materials,  and,  this  having  led  to  further 
investigations,  I  was  interested  and  surprised  to  find 
titanium  present  in  every  piant  ash  thus  far  examined. 

This  is,  in  fad,  surprising,  as  it  is  stated  by  some 
writers  (Roscoe  and  Schorlemmer)  "  that  it  does  not 
appear  to  form  part  of  the  animal  or  vegetable  kingdom." 

The  amount  of  titanic  oxide  found  in  the  ash  of  some 
vegetable  material  is  as  follows:  — 

Oak  wood       0-31  per  cent 

Apple  and  pear  wood  (mixed)     ..  o'2i        ,, 

Apple      ..     o'li        „ 

Cow  peas o'oi        ,, 

Cottonseed  meal 0*02        ,, 

From  the  above  determinations  we  are  reasonably  safe 
in  assuming  that  titanium  is  assimilated  by  plants.  If 
this  is  true,  it  seems  very  strange  that  reference  to  this 
fadt  has  not  been  made  by  recent  writers  upon  agricul- 
tural chemical  analysis,  and  upon  the  chemistry  of  vege- 
table life. 

In  fadt,  in  consulting  treatises  on  ash  analysis  with 
tables  (Wolff;,  I  do  not  find  any  mention  whatever  of 
the  presence  of  titanium.     If  this  is  a  fadt,  can  it  be  true 


0-69  per  cent 
o"95        ., 
oy4        •* 
083        „ 

2-59 

With  reference  to  the  presence  of  titanic  oxide  in  the 
ash  of  coal,  it  may  be  fairly  assumed  that,  partly  owing 
to  the  infiltration  of  clay  and  earthy  materials,  it  would 
be  found  there,  but  is  it  fair  to  assume  that  its  presence 
is  wholly  accounted  for  in  that  way  ?  If  mention  has 
been  made  of  the  presence  of  titanium  in  the  ash  of  coal, 
it  has  thus  far  escaped  my  attention. 

The  method  employed  in  the  above  determination  is 
that  of  A.  Weller  {Ber.  d.  Chem.  Ges.,  1882),  which  is 
based  upon  the  fad  that  hydrogen  peroxide,  when  added 
to  a  solution  of  titanium,  produces  a  compound  of  an  in- 
tensely yellow  colour.  There  are  precautions  necessary 
in  the  execution  of  this  method  which  have  already  been 
pointed  out  {yourn,  Amer.  Chem.  Soc.  xiii.,  210.) 

It  will  be  my  pleasure  to  report  additional  notes  at  an 
early  day  concerning  the  presence  of  titanium  in  the  vege- 
table kingdom.  Valuable  service  has  been  rendered  in 
the  above  work  by  Messrs.  J.  O,  LaBach  and  C.  O. 
Hill. — yournal  of  the  American  Chemical  Society,  xviii., 
p.  402. 


GOVERNMENT    LABORATORY   OF    TASMANIA, 

By  the  courtesy  of  Mr.  W.  F.  Ward,  Assoc.  Royal  School 
of  Mines,  we  have  been  favoured  with  the  report  of  the 
Government  Laboratory  for  the  year  1895. 

There  has  been  a  falling  off  in  the  number  of  samples 
analysed  for  municipalities  and  private  individuals, 
though  the  work  in  the  latter  case  is  largely  gratuitous, 
and  in  the  former  exclusively  so.  On  the  other  hand  the 
work  done  for  the  Government  more  than  compensates 
this  deficiency.  The  increase  of  duty  on  "oils" 
imported  for  eight  months  more  than  defrays  twice  over 
the  total  yearly  cost  of  the  laboratory.  The  departments 
of  mines,  railways,  police,  health,  and  agriculture  obtain 
more  or  less  analytical  work  free  of  cost.  On  the  other 
hand.  Customs'  duties  have  to  be  paid  even  on  the 
chemicals  imported  for  the  use  of  the  laboratory.  So 
that  this  department  is  much  more  than  self-supporting. 

The  total  number  of  samples  analysed  in  the  Govern- 
ment laboratories  during  the  year  1895  was  2197,  1550. 
of  which  were  teas,  12  of  which  were  found  adulterated 
or  defedive.  Only  one  sample  of  coffee  was  examined 
and  condemned  as  consisting  one  half  of  chicory.  Seven 
samples  of  spirit  of  wine  tested  for  the  Customs  were  not 
sufficiently  methylated,  i.e.,  not  made  undrinkabie.  On 
this  we  may  remark  that  we  have  known  methylic 
alcohol  (not  methylated  spirits)  be  drunk  to  a  serious 
extent  by  men  engaged  in  dye  and  colour  works.  It  does 
not  appear  that  Tasmania  has  adopted  the  absurdity  of 
requiring  an  addition  of  mineral  "  naphtha  "  to  methyl- 
ated  spirits.  The  Tasmanian  fiscal  authorities,  as  well 
as  those  in  the  Home  Kingdoms,  should  awake  to  the 
faft  that  a  minimum  of  Dippel's  animal  oil  renders 
alcohol  undrinkabie  without  interfering  with  its  technical 
uses. 

Nineteen  samples  of  water  have  been  analysed.  The 
composition  of  two  may,  it  is  hoped,  prove  exceptional. 
One  of  them  contained  0"98  part  of  albumenoid  ammonia 
per  million  of  water,  as  well  as  i'3  grains  per  gallon  of 
chlorine.  Another  contained  97  grs.  per  gallon  of 
chlorine.     Much  of  this  was  in  the  state  of  magnesium 


Chbuical  News. 
Jan.  8,  1897. 


Academic  des  Sciences. 


23 


chloride.  The  water  was  taken  from  the  premises  of  a 
milk-vendor.  Quackery  flourishes  in  the  Colonies  as  well 
as  in  the  Home  Kingdoms.  A  "  self-cure  "  for  nervous 
debility,  advertised  and  sold  at  one  guinea  per  ounce,  was 
found  to  be  merely  Peruvian  bark  in  powder,  the  present 
retail  price  per  ounce  being  about  one  shilling ! 

A  fatal  case  of  poisoning  with  strychnine  is  cited. 
Thirty-six  grs.  of  the  poison  were  separated  from  the 
contents  of  the  sugar  basin.  There  is  also  mention  of 
wholesale  malicious  poisoning  in  Queensland.  There  is 
no  mention  of  poisoning  with  any  substance  unknown  to 
European  pharmacologists.  In  this  direction  much 
work  remains  to  be  done,  and  much  of  it  might  be  done 
by  local  analysts. 

It  will  not  be  deemed  an  unpardonable  digression  if  we 
mention  that  malicious  poisoning — as  we  learn  from 
private  sources — is  exceedingly  rife  in  South  Africa.  The 
deadly  drug,  or  drugs,  are  introduced  into  the  victim  in 
the  state  of  snuff,  of  which  the  Kaffirs  are  passionately 
fond.  But  they  will  now  rarely  accept  a  pinch  from  a 
stranger  without  careful  scrutiny.  To  return  to  Mr. 
Ward's  report,  a  number  of  samples  of  ores  and  tailings 
have  been  examined  for  the  Secretary  of  Mines.  In  addi- 
tion to  gold  and  silver,  nickel,  cobalt,  copper,  tin,  anti- 
mony, bismuth,  zinc,  and  lead  have  been  determined. 
We  find  no  mention  of  platinum.  A  sample  from 
M.  Dundas  contained  silver  at  the  rate  of  1*057  °2S.  per 
ton,  and  gold  specimens  gave  60  to  63  ozs.  Arsenical 
pyrites  are  found,  and  prove  a  source  of  great  annoyance. 


PROCEEDINGS    OF    SOCIETIES. 


ACADEMIE   DES   SCIENCES. 

At  the  meeting  of  the  Academie  des  Sciences,  on  Mon- 
day, Dec.  2ist,  M.  A.  CoRNU  delivered  the  following  Pre- 
sidential Address: — 

When  Lavoisier,  Schwann,  and  Cagniard  Latour 
studied  the  fermentation  of  beer,  and  Pasteur,  taking 
up  the  question,  patiently  followed  the  development 
of  those  microscopic  beings  in  generations  called  spon- 
taneous in  the  diseases  of  wine  or  of  silk-worms,  who 
could  have  foreseen  that  a  day  would  come  when  this 
admirable  research  would  have  so  important  a  bearing 
on  the  welfare  of  humanity,  demonstrating  that  these 
infinitely  minute  beings  rank  among  the  most  important 
fadlors  of  human  life.  Pasteur,  in  his  long  and  fruitful 
career,  has  taught  us  that  it  is  possible  to  specify  these 
organisms — to  combat  and  even  to  diredl  them,  accord- 
ing as  they  are  our  allies  or  our  enemies.  They  have  the 
power  of  conferring  immunity  or  of  conducing  us  in- 
fallibly to  death. 

The  public  see  only  final  success;  they  mostly  ignore 
the  starting  point  of  such  researches  ;  they  ignore  the 
efforts  and  the  perseverance  required  to  lead  to  what  is 
vulgarly  called  a  pradlical  discovery  ;  they  are  even  prone 
to  disdain  abstradt  science,  and  to  estimate  the  merit  of 
the  savant  by  the  immediate  market  value  of  his  dis- 
coveries. 

Utilitarianism  is,  in  faft,  one  of  the  maladies  of  the 
present  age,  perhaps  one  of  the  gravest,  because  it  tends 
to  crush  the  upward  flight  of  the  human  spirit,  and  to 
fetter  it  to  the  exclusive  worship  of  material  interests. 

Prof.  Rontgen's  discovery  of  the  X  rays  has  been,  both 
for  the  public  and  for  savants,  the  scientific  event  of  the 
year.  The  speaker  gave  a  luminous  summary  of  the 
researches  which  have  led  to  this  discovery,  laying  due 
emphasis  on  the  "  brilliant  experiments  "  of  Mr.  Crookes. 
The  Rontgen  rays  are  spoken  of  as  a  fresh  benefit  to  be 
placed  to  the  credit  of  pure  science.  After  touching  on 
the  merit  of  the  illustrious  savants  recently  lost  to  the 
Academy  and  to  science,  the  speaker  mentioned  that  this 


year  the  Arago  medal  has  been  conferred  in  duplicate  on 
M.  Antoine  d'Abbadie  and  on  Prof.  Sir  W.  Thompson, 
now  known  as  Lord  Kelvin.  He  on  a  recent  occasion 
had  pronounced  France  as  the  alma  mater  of  his  sci- 
entific youth.  It  is  added  that  modern  nations,  though 
bent  under  the  yoke  of  material  interests,  and  crushed 
under  the  treacherous  law  of  iron  and  blood,  are  still 
able  on  great  occasions  to  raise  their  eyes  to  the  serene 
regions  above  hatred  and  envy  and  to  join  in  celebrating 
the  great  men  whose  labours  increase  the  common  patri- 
mony  of  intelligence  at  the  same  time  as  the  well-being 
of  mankind. 


NOTICES  OF  BOOKS. 


The  Practical  Methods  of  Organic  Chemistry.  By 
LuDWiG  Gatterman,  Ph.D.,  Extraordinary  Professor 
in  the  University  of  Heidelberg,  with  numerous  illus- 
trations, translated  by  William  Shober,  Ph.D., 
Instructor  in  Organic  Chemistry  in  the  Lehigh 
University.  Authorised  translation.  New  York:  The 
Macmillan  Company.  London:  Macmillan  and  Co., 
Ltd.     1896.     Pp.  329. 

We  have  here  an  excellent  work  written  in  German, 
translated  by  an  American,  and  printed  in  America.  The 
language  and  the  orthography  employed  are  not  in  ail 
cases  idiomatic  English  as  written  and  spoken  on  this 
side  of  the  Atlantic.  Thus  we  find  magenta  invariably 
designated  by  the  term  "  fuchsine." 

In  the  first  or  general  part  we  have  instrudions  for. 
necessary  operations,  well  thought  out  and  clearly 
described.  We  may  call  particular  attention  to  the 
direaions  for  fraftional  distillation,  to  the  management  of 
autoclaves,  and  distillation  at  reduced  pressures. 

Next  follow  the  methods  for  ultimate  organic  analysis, 
the  determination  of  nitrogen  being  performed  exclusively 
by  the  method  of  Dumas. 

We  now  come  to  the  special  part;  the  performance  of 
synthetical  operations  in  the  aliphatic,  aromatic,  pyridine, 
and  quinolene  series.  Lastly  comes  an  inorgaiiic  part, 
viz.,  instrudions  for  obtaining  in  a  state  of  purity  sub- 
stances  required  as  reagents  in  organic  research.  It  vfill 
be  at  once  observed  that  the  author  does  not  give  a  series 
of  recipes.  He  described  representative  reaiStions,  e.g., 
the  nitration  of  a  hydro-carbon,  the  redudlion  of  a  nitro- 
compound  to  an  amine,  the  redudtion  of  a  nitro-compound 
to  an  azoxy-azo  or  hydrazo  compound.  The  student 
who  has  carefully  worked  out  these  diredtions  in  the 
laboratory  will  find  himself  prepared  for  entering  upon 
the  wide  fields  of  organic  research  without  losing  his 
way.  One  who  has  made  no  such  preparation  is  in  danger 
of "  messing  about "  at  random,  and  if  he  comes  upon 
something  valuable  may  not  recognise  what  he  has  done. 

We  therefore  strongly  recommend  the  careful  study  of 
this  work,  regretting  only  that  the  distinguished  pub- 
lishers have  not  seen  their  way  to  having  the  English 
translation  executed  by  an  Englishman  and  brought  out 
in  England. 

Catalogue  of  Chemical  Apparatus,  Balances,  Drying. 
Ovens,  Furnaces,  Laboratory  Stands,  dfc,  also  special 
and  general  Glass  Apparatus,  Hydrometers,  Thermo- 
meters, Porcelain  and  Clay  Ware,  Jena  Laboratory 
Glass  Ware,  and  Glass  Tubing.  A.  Gallenkamp  and 
Co.,  2,  4,  and  6,  Cross  Street,  Finsbury,  E.C.     1896. 

An  important  feature  in  this  catalogue  is  the  special 
description  of  Jena  laboratory  glass.  This  ware,  we  are 
told,  surpasses  the  best  Bohemian  glass,  Kavalier's  make, 
in  its  insolubility  in  water,  whether  at  ordinary  tempera- 
ture or  at   80°.     On  treatment  with   caustic  soda  it  is 


24 


Chemical  Notices  Jrom  Foreign  Sources. 


I  Cbbmical  Nbws, 
I      Jan.  8.  1897. 


slightly  inferior  to  Bohemian  glass,  but  it  has  the 
superiority  as  regards  resistance  to  sodium  carbonate. 
The  Jena  glass  has  a  great  power  of  resisting  sudden 
changes  of  temperature.  Medium  sized  flasks,  containing 
boiling  toluidin  (200°),  bear  immersion  in  cold  water. 
Jena  laboratory  glass  can  be  heated  over  a  Bunsen  flame 
without  wire  gauze. 

Evaporating  basins  are  catalogued  of  Berlin,  Thiiringen, 
and  Meissen  porcelain,  as  well  as  of  aluminium  and 
enamelled  steel,  of  pure  nickel,  platinum,  silver,  and 
platinum  gold  for  melting  potash.  There  is  mention  of 
autoclaves  for  bearing  a  pressure  of  50  atmospheres,  and 
apparatus  for  boiling  in  a  vacuum  or  at  a  reduced  pres- 
sure. Fletcher's  devices  for  the  produdlion  and  distribu- 
tion of  heat  are  quoted  in  great  variety.  Apparatus  for 
pradlical  distillation  as  devised  by  Hempel,  Linneman, 
Glinsky,  and  others,  are  also  quoted  and  shown. 

Of  filter-pumps  there  is  also  good  variety,  of  the  con- 
strudtions  of  Fischer,  Bunsen,  Volhard,  Finkener,  Geissler, 
Alvergniart,  and  others,  as  also  filtering  apparatus  in 
conjunftion  with  pumps. 

Various  kinds  of  filter  paper  are  quoted,  some  of  which 
retain  such  precipitates  as  zinc  sulphide. 

The  balances  and  weights  described  are  those  of 
Sartorius,  Becker,  Verbeck  and  Peckholdt,  and  Bertnger. 

Baderiological  apparatus  is  figured  and  described  at 
great  length. 

Spedtroscopes  figure  here  at  length  unusual  in  cata- 
logues of  laboratory  requisites.  Catalogues  of  microscopes, 
including  the  renowned  instruments  of  Zeiss,  will,  it  is 
said,  be  supplied  on  application. 

Of  chemicals  we  find  only  a  list  of  standard  solution. 
Experimentalists  may  often  find  here  some  newly  devised 
Apparatus  which  will  prove  exceedingly  useful.  We 
cannot  help  expressing  our  regret  that  Messrs.  Gallen- 
kamp  find  themselves  unable  to  get  their  printing  done  in 
Britain. 


Assistant  Wanted  in  a  London  Laboratory. — 
Full  particulars  to  Box  M.,  Chemical  News  Office,  Boy  Court, 
Ludgate  Hill,  London,  E.G. 

Chemical  Student,  who  has  been  a  pupil  for 
the  last  year  and  a  half  in  well-known  Agricultural  Labora- 
tory, bnd  previously  at  the  Royal  College  of  Science,  seeks  employ- 
ment.— Address,  S.,  29,  Park  Hill,  Clapham. 


Chemist,  Analytical  and  Research,  and 
Badteriologist,  desires  Appointment  as  Assistant  to  Public 
Analyst,  with  a  view  to  ultimate  Succession  or  Partnership.  Many 
years'  experience  in  Public  Analytical  Chemistry  and  Toxicology. 
Experienced  in  correspondence  and  in  framing  reports.  Highest 
references  if  desired. — Address,  "  Partner,"  Chemical  News  Office, 
Boy  Court,  Ludgate  Hill,  London,  E.G. 

Gentleman  (27),  French,  desires  Situation  as 
chemist  or  Assistant.  Six  years'  experience  in  Paris,  two  in 
London.  Good  Analyst,  Assayer,  and  Ete(5tro-Chemist ;  well  up  in 
the  extradtion  of  metals  by  eleftric  process,  principally  Gold. — Ad- 
dress, C.  H.  G.,  19,  Berwick  Street,  Oxford  Street,  W. 

Gentleman  of  much  experience  in  Chemistry, 
accustomed  to  the  control  of  men,  and  speaking  French, 
German,  and  English,  seeks  position  of  trust  in  Manufa(5lory  or  in 
Chemical  Laboratory. — Apply  to  Ackermann,  Mining  Engineer 
(Civil),  of  the  Mining  School  of  Paris,  132,  Alderney  Street,  S.W. 


CHEMICAL 


NOTICES   FROM 
SOURCES. 


FOREIGN 


Revue  Universelle  des  Mines  et  de  la  Metallurgie. 
Series  3,  Vol.  xxxv..  No.  2. 
Uses  of  Acetylene.— R.  K.  Duncan  proposes  to  set 
out  from  acetylene  to  form,  either  by  way  of  polymeri- 
sation of  benzene,  CeHe,  whence  there  may  be  obtained 
the  innumerable  series  of  aromaticcompounds,  or  ethylene 
by  the  adlion  of  nascent  H.  Acetylene,  on  account  of 
its  endothermic  charader  and  its  explosive  properties, 
cannot  compete  with  coal  gas  or  eleftricity  for  the  light- 
ing  of  cities.  This  compound  was  first  met  with  by 
Davy  in  1836,  and  described  in  full  by  Borchen  in  1891. 
It  yields  per  kilo.  280—300  litres  of  acetylene  gas.  Acety- 
lene is  less  poisonous  than  ordinary  coal  gas.  Its  lia- 
bility to  explosion  is  a  serious  obstacle  to  its  use  on  the 
large  scale. 

Action  of  Coal  Gas  upon  Caoutchouc— Goss- 
heintz.— Black  tubing  is  the  least  suitable,  then  the  red 
quality,  but  the  grey  kind  is  the  best. 

Treatment  of  Rich  Iron  Ores  and  Use  of  Acid 
Slags.— Franz  Biittgesbach.— The  author  has  made  use 
of  ores  containing  68  to  70  per  cent  of  iron,  with  the 
addition  of  sufficient  slags  free  from  iron  to  such  an 
extent  that  the  slag  may  reach  at  least  25  per  cent  of  the 
cast  metal. 

Series  3,  Vol.  xxxv.,  No.  3. 
Copper  Industry  in  Japan.— Japan  now  occupies  the 
fourth  rank  among  the  copper-yielding  countries-!  In 
1892  it  produced  20,000  tons  of  copper.  The  ore  is  dis- 
tributed over  the  entire  country.  The  yield  will  soon 
exceed  that  of  Chili. 


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Optical  Analysis  oj  Urine, 


25 


THE    CHEMICAL     NEWS 


Vol.  LXXV.,  No.  1938. 


A  RAPID   DETERMINATION 

OF    THE 

EQUIVALENT    OF    SULPHURIC  ACID  AND   ITS 

PLACE  IN  THE  TEACHING  OF  CHEMISTRY. 

By  WILLIAM  ACKROYD,  F.I.O. 

The  quantitative  experiments  on  neutralisation  usually 
given  to  elementary  students  are  few  in  number,  and  of 
one  type ;  the  following  variation  is  suggested  as  part  of 
a  scheme  of  quantitative  work. 

a  c.c.  of  aqueous  sulphuric  acid  are  found  to  be  neu- 
tralised by  b  c.c.  of  solution  of  sodium  hydroxide. 

To  a  c.c.  of  the  acid  a  weighed  quantity  of  magnesium 
is  added  (from  o-i  to  0*2  grm.),  and  when  all  atftion  has 
ceased  b  c.c.  of  the  alkali  are  added.  The  indicator 
used  (methyl  orange)  shows  that  all  the  free  acid  has 
been  neutralised,  and  it  may  readily  be  proved  that  all 
the  metal  is  precipitated  as  hydroxide.  Now  run  in, 
from  the  burette,  sulphuric  acid  of  known  strength  until 
the  magnesium  hydroxide  is  exaiftly  neutralised. 

From  the  data  obtained  calculate  the  equivalent  of  sul- 
phuric acid. 

£^n[M»/>/^.— Strength  of  sulphuric  acid  used,  0-04945 
grm.  per  c.c.  20  c.c,  of  the  acid  requires  21-5  c.c.  of 
alkali  for  neutralisation,  o  146  grm.  of  magnesium  is 
dissolved  in  20  c.c.  of  the  acid,  and  after  addition  of  the 
necessary  21*5  c.c.  of  alkali  i2'4  c.c.  of  the  acid  are  re- 
quired to  neutralise  the  magnesium  hydroxide.  Whence, 
taking  12  to  be  the  magnesium  equivalent,  we  get— 
I2"4X  0*04945x12 

o'i46  ^    ^ 

Other  students  obtained  the  numbers  49*9,  497,  487 
&c.,  and  the  figures  give  some  idea  of  the  degree  of 
accuracy  to  be  expeded  under  ordinary  circumstances. 
The  time  taken  for  the  estimation  is  much  under  an 
hour. 

By  neutralising  the  magnesium  hydroxide  with  hydro- 
chloric  acid  of  known  strength,  the  equivalent  of  this  acid 
may  be  similarly  ascertained.  Results  within- a  unit  of 
the  accepted  number  are  readily  obtained. 

A  recent  alteration  of  the  syllabus  of  the  Science  and 
Art  Department  has  introduced  the  salutary  course  of 
taking  quantitative  work  from  the  commencement  instead 
of  leaving  it  until  the  student's  third  year.  These  first 
efforts  are  necessarily  only,  in  many  cases,  rough  ap- 
proximations, but  they  serve  to  familiarise  the  worker 
with  the  laws  of  combination  in  definite  and  reciprocal 
proportions,  equivalents,  &c.  The  methods  to  be  em- 
ployed, and  their  order,  are  left  to  the  discretion  of  the 
teacher,  who  has  the  help  of  such  excellent  little  works 
as  those  of  Ramsay,  Reynolds,  and  Tilden. 

I  take  it  that  in  an  ideal  course  for  the  elementary 
student  each  quantitative  experiment  ought  to  be  pre- 
ceded by  the  qualitative  work  necessary  for  its  compre- 
hension, and  it  ought  to  require  as  little  time  as  possible 
for  its  performance,  so  that  it  can  be  tried  often ;  the 
experiments  ought  to  follow  one  another  in  logical  order, 
each  one  more  or  less  built  on  those  going  before,  with 
the  continuity  found  in  a  series  of  geometrical  problems, 
and  collateral  work  in  theory  and  practice  should  proceed 
abreast  with  them. 

The  determination  of  equivalents  will  form  the  back- 
bone of  the  work,  and  magnesium,  because  of  its  purity 
and  rapidity  of  aftion,  lends  itself  admirably  for  the  pur- 
pose, as  in  the  following  experiments  : — 


1.  Determination  of  the  magnesium  equivalent  by  find- 
ing what  weight  of  it  is  required  to  liberate  ii'l6  litres 
of  hydrogen  at  normal  temperature  and  pressure,  i.e., 
I  grm.  from  sulphuric  acid. 

2.  Determination  of  the  oxygen  equivalent  by  finding 
how  much  of  it  combines  with  12  grms.  of  magnesium 
in  the  course  of  ignition  of  the  latter  in  a  porcelain 
crucible. 

3.  Determination  of  the  sulphuric  and  hydrochloric 
acid  equivalents  by  finding  what  weight  of  each  is  re- 
quired to  neutralise  the  hydroxide  formed  from  I2  parts 
by  weight  of  magnesium. 

4.  Determination  of  the  equivalent  of  caustic  soda  by 
finding  what  weight  of  it  neutralises  an  equivalent  of  sul- 
phuric acid. 

In  this  order,  where  each  experiment  is  based  on  a  pre- 
ceding one,  the  equivalents  i  (assumed),  12,  8,  49,  36*5, 
and  40,  would  be  obtained  for  H,  Mg,  O,  H2SO4,  HCI, 
and  NaOH  respedively,  and  each  experiment  is  typical 
of  others  which  will  suggest  themselves  to  the  teacher. 
I  think  it  is  of  importance  to  stick  to  the  unit  weight 
of  hydrogen  for  comparisons,  as  subsequently  there  is 
nothing  to  unlearn.  Where  many  units  of  other  ele- 
ments are  employed  in  empirical  comparisons,  as,  e.g.^ 
the  ratio  i  :  0*66  in  experiment  2,  instead  of  12  :  8,  much 
confusion  arises  in  many  minds,  and  the  ratio  12  :  8  is 
equally  available  as  an  example  of  combination  in  fixity 
of  proportions. 

It  appears  therefore  inadvisable  to  follow  the  historic 
order  in  this  respeft  with  elementary  students,  however 
interesting  it  may  be  when  they  have  a  better  grasp  of 
the  subjei^t. 


OPTICAL   ANALYSIS   OF   URINE   AND 
EXACT   DETERMINATION   OF   THE   PROTEIDS, 

THE  GLUCOSIDES,  AND  THE 

NON-FERMENTIBLE   SACCHAROID   MATTERS. 

By  F.  LANDOLPH. 

I.  Sugar  in  Urine. — Normal  healthy  urine  always  con- 
tains from  001  to  o*20  grm.  sugar  per  litre;  the  exaA 
determination  can  only  be  effedled  by  fermentation.  Set- 
ting out  from  0*40  grm.  of  sugar  per  litre,  the  physician 
should  turn  his  attention  to  the  slow  and  progressive 
development  of  diabetes,  which  may  be  considered 
established  when  2  grms.  per  litre  of  fermentible  sugar 
is  found.  There  are  only  pathological  urines  contain- 
ing albumen,  pus,  &c.,  which  often  contain  no  trace  of 
sugar. 

2.  Optical  Determination  of  Sugar, — The  saccharimeter 
is  generally  incompetent  to  demonstrate  the  presence  of 
I  grm.  to  2  grms.  sugar  per  litre,  because  normal  urine 
always  defleds  from  1°  to  3°  to  the  left.  It  is  only  on 
setting  out  from  2°  to  3°  deviation  to  the  right  that  we 
are  almost  certain  of  the  presence  of  sugar  in  the  urine, 
and  it  is  only  beyond  10  grms.  per  litre  that  the  dia- 
betometer  gives  us  fairly  exacft  results ;  the  more  ex&€t 
the  higher  the  quantity.  Hence,  to  obtain  results  be- 
yond dispute,  it  is  indispensable  to  have  recourse  to  fer- 
mentation, whilst  for  quantities  above  20  grms.  per  litre 
the  two  methods  give  approximately  the  same  results. 

3.  Direct  Coefficient  and  Indirect  Coefficients  of  Re- 
duction.— The  direft  coefficient  of  redudion  can  only  be 
obtained  with  urine  boiled  and  filtered,  because  raw  urine 
in  treatment  with  the  cupopotassic  liquid  always  holds  a 
certain  quantity  of  cuprous  oxide  in  solution.  To  10  c.C. 
of  urine  boiled  and  filtered  we  use  10  c.c.  water  and 
40  c.c.  of  Fehling's  solution.  We  heat  the  mixture  to 
ebullition,  and  keep  it  up,  when  once  the  readtion  has 
commenced  (which  generally  requires  from  three  to  five 
minutes),  for  twenty  minutes ;  we  filter,  wash  the  cuprous 
oxide  with  boiling  water,  dry,  and  ignite.  The  weight 
of  copper  oxide  obtained,  calculated  per  thousand,  gives 


25 


Separation  of  Manganese  from  Tungstic  Acid. 


CbbmicalNbws 
Jan.  15,  i8q7. 


the  direct  coefficient  of  reduftion;  the  third  of  this 
weight  gives  fairly  well  the  quantity  of  non-fermentible 
saccharoid  matter  in  a  litre  of  urine,  deducing  the  quan- 
tity of  oxide  corresponding  to  the  fermentible  sugar  and 
the  quantity  of  oxide  corresponding  to  the  uric  acid,  of 
which  one  part  is  approximately  equal  to  four  parts  of 
copper  oxide. 

A  quantity  of  non-fermentible  saccharoid  matter  ex- 
ceeding 3  grms.  per  litre  is  the  certain  sign  forerunning 
diabetes.  Further,  for  these  salts  of  urine  with  strongly 
diabetic  disposition  the  duration  of  the  introduiSion  of  the 
reaAion  often  does  not  exceed  half  a  minute. 

To  obtain  the  indirect  coefficients  of  redudlion,  we  first 
split  up  (at  first  in  raw  urine,  and  then  in  a  portion  boiled 
and  filtered),  the  mucine  and  analogous  proteids,  as  well 
as  the  glucosides  of  mineral  acids.  We  then  fix  in  the 
urine  thus  treated,  filtered,  and  adjusted  to  their  primi- 
tive volume,  the  coefficients  of  redudlion  as  for  the  de- 
termination of  the  dired  coefficient  of  redudtion.  The 
difference  between  the  figures  of  the  two  indiredl  co- 
efficients gives  the  quantity  of  mucine  in  copper  oxide, 
and  the  difference  between  the  diredt  coefficient  of  the 
boiled  and  filtered  urine  and  the  indiredt  coefficient  of 
the  same  urine  boiled  and  filtered  gives  the  quantity  of 
the  glucosides  in  copper  oxide,  the  third  part  of  which 
represents  the  weight  of  these  compounds. 

4.  Polaristrobometric  Examination  of  Urine. — When  a 
urine  contains  pus  and  analogous  pathogenic  elements, 
the  defleiStion  to  the  left  in  the  very  sensitive  polaristro- 
bometer  of  P5ster  and  Streit  becomes  stronger,  reaching 
5°,  and  even  8^  which  is  evidently  due  to  the  polarising 
force  of  the  nuclei  of  the  granulated  leucocytes  of  pus. 
In  this  case  it  even  happens  that  the  field  of  vision  be- 
comes totally  obscure  in  an  extent  of  some  degrees. 
This  faft  is  especially  very  important  when  the  cellules 
and  pus  granules  have  already  disappeared  under  the 
microscope,  since  this  procedure  alone  permits  us  to 
know  if  there  has  been  an  anterior  presence  of  pathogenic 
elements  or  not. 

Analogous  studies  are  pursued  to  recognise  and  de- 
termine the  nitrogenous  organic  compounds  preceding 
aWiViminwxiA.—ComptesRendus,  cxxiii.,  No.  26. 


THE    SEPARATION    OF    VANADIUM    FROM 

ARSENIC. 

By  CHARLES  FIELD  and  EDGAR  F.  SMITH. 

As  vanadium  and  arsenic  occur  associated  in  minerals 
and  likewise  in  artificial  products,  their  separation  becomes 
a  matter  of  consequence. 

The  course  usually  pursued  in  carrying  out  this  sepa- 
ration is  that  long  since  recommended  for  the  removal  of 
vanadic  acid  from  its  solutions ;  namely,  its  precipitation 
as  ammonium  metavanadate.  Other  methods  have 
recently  appeared  in  the  literature  bearing  on  analysis. 
Reference  is  here  made  especially  to  the  publication  of 
Fischer  ("  Bestimmung  von  Vanadinsaure,"  Dissertation, 
Rostock,  1894). 

Experiments  made  in  this  laboratory  on  the  behaviour 
of  vanadates  (Journ.  Am,  Chem.  Soc,  xvi.,  578)  and 
arsenates  (Ibid.,  xvii.,  682)  heated  in  an  atmosphere  of 
hydrochloric  acid  gas,  in  which  both  acids  were  volatilised, 
suggested  the  thought  that  if  the  sulphides  of  vanadium 
and  arsenic  were  exposed  to  the  same  vapours  perhaps 
they  would  show  a  variation  in  deportment.  And  so  it 
has  proved.  Perfedly  dry  arsenic  trisulphide,  previously 
washed  with  alcohol,  carbon  disulphide,  and  ether,  then 
dried  at  100°  C,  when  exposed  in  a  porcelain  boat,  placed 
in  a  combustion  tube,  was  almost  completely  expelled 
from  the  retaining  vessel  at  the  ordinary  temperature. 
The  last  traces  were  driven  out  at  a  temperature  little 
above  150°  C.  Brown  vanadium  sulphide,  in  a  perfeAly 
dry  condition,  treated  in   the   same   manner,  was    not  ' 


altered.  It  only  remained  then  to  prepare  mixtures  of 
known  amounts  of  the  two  sulphides  and  subjeft  them  to 
the  adtion  of  the  acid  vapour.  To  this  end  the  following 
experiments  were  made: — 

I. — 0*1303  grm.  of  vanadium  sulphide, 
0"i302  grm.  of  arsenic  sulphide. 
The  arsenic  sulphide  was  volatilised  without  difficulty 
and  left  o'i2g7  grm.  of  vanadium  sulphide. 

II. — 0-1290  grm.  of  vanadium  sulphide, 
0*2242  grm.  of  arsenic  sulphide, 
gave  after  exposure  of  one  hour  to  hydrochloric  acid 
vapour  a  residue  of  vanadium  sulphide,  weighing  0*1297 
grm. 

III. — 0*0828  grm.  of  vanadium  sulphide, 
0*0582  grm.  of  arsenic  sulphide, 
left  0*0827  grm.  of  vanadium  sulphide. 

IV. — 0*1306  grm.  of  vanadium  sulphide, 
0*2028  grm.  of  arsenic  sulphide, 
gave  a  residue  of  0*1308  grm,  of  vanadium  sulphide. 
V. — 0*1403  grm.  of  vanadium  sulphide, 
0*2409  grm.  of  arsenic  sulphide, 
left  0*1404  grm.  of  vanadium  sulphide. 

The  temperature  in  these  experiments  was  not  allowed 
to  exceed  250°  C,  as  beyond  that  point  there  is  danger 
of  affedting  the  vanadium  and  causing  its  partial  volatili< 
sation. 

The  method  worked  so  well  and  with  such  evidently 
favourable  results  that  the  following  course  was  adopted 
in  the  analysis  of  a  specimen  of  the  mineral  vanadinite. 
0*2500  grm.  of  air-dried  and  finely  divided  material  was 
placed  in  a  porcelain  boat ;  the  latter  was  then  introduced 
into  a  combustion  tube  and  gently  heated  in  a  current  of 
dry  hydrochloric  acid  gas.  By  this  treatment  vanadic 
and  arsenic  oxides  were  expelled,  leaving  lead  phosphate 
and  chloride.  The  receiver  containing  the  vanadium 
and  arsenic  was  made  alkaline  and  digested  with  ammo- 
nium  sulphide.  From  the  solution  of  the  sulpho-salts  the 
vanadium  and  arsenic  sulphides  were  set  free  by  a  dilute 
acid.  After  washing  and  careful  drying  these  sulphides 
were  separated  as  indicated  in  the  preceding  lines,  then 
changed  to  oxides  and  determined  in  the  usual  manner. 
The  sum  of  the  total  constituents  determined  as  lead 
oxide,  phosphoric  oxide,  vanadic  and  arsenic  oxides,  with 
some  lead  chloride,  amounted  to  0*2501  grm. 

The  method,  in  addition  to  being  satisfactory  in  the 
analytical  way,  certainly  forms  a  very  excellent  means  of 
purifying  and  freeing  vanadium  from  arsenic. — journal  of 
the  American  Chemical  Society,  xviii..  No.  12. 


THE     SEPARATION     OF    MANGANESE     FROM 

TUNGSTIC    ACID. 

By  WALTER  T.  TAGGART  and  EDGAR  F.  SMITH. 

The  necessity  of  obtaining  pure  tungstic  acid  from  time 
to  time,  using  wolframite  as  the  starting  out  material, 
has  frequently  suggested  the  inquiry  as  to  what  course 
would  probably  prove  the  best  in  the  quantitative  separa- 
tion of  this  acid  from  oxides,  such  as  those  of  iron  and 
manganese. 

In  the  experiments  recorded  in  this  communication  only 
the  results  obtained  from  a  study  of  mixtures  of  a  man- 
ganous  salt  and  a  soluble  alkali  tungstate  will  be  given. 
The  diredions  taken  in  the  experimentation  were,  ist,  to 
effe(ft  the  separation  by  the  use  of  yellow  ammonium  sul- 
phide  in  the  presence  of  ammonium  chloride ;  2nd,  to 
eliminate  the  acid  oxide  by  the  use  of  an  alkaline  car- 
bonate. 

Following  the  first  course,  mixtures  of  definite  amounts 
of  ammonium  tungstate  and  manganous  chloride  were 
made.    To  these  was  added  water  and  a  considerable 


CRBMiCAL  News,  I 
Jan.  15, 1897.     I 


Separation  of  Bismuth  from  Lead, 


27 


excess  of  yellow  ammonium  sulphide,  together  with 
ammonium  chloride.  The  mixtures  were  digested  on  a 
water-bath  at  70°  C.  for  several  hours,  and  the  vessels 
containing  them  were  then  closed  and  allowed  to  stand 
during  the  night.  The  manganese  sulphide  was  filtered 
out,  and,  after  solution,  was  changed  into  sulphate  and 
weighed  as  such,  or  it  was  finally  obtained  as  protosesqui- 
oxide  in  the  customary  way. 

Results, 
Manganous  oxide  Manganous  oxide 

present.  found. 

Grm.  Grin. 

O'igso  o'2i2l 

o'ig49  0*2255 

o'tzQO  o'lyoS 

o'i287  0*1720 

0*1291  0*1760 

In  every  trial  tungstic  acid  adhered  to  the  metallic 
oxide. 

In  trying  the  second  suggestion  the  soluble  tungstate 
and  the  soluble  manganous  salt  were  digested  for  some 
hours  in  a  platinum  dish,  upon  a  water-bath,  with  an 
excess  of  a  10  per  cent  potassium  carbonate  solution, 
after  which  the  whole  was  evaporated  to  dryness,  the 
residue  boiled  up  with  water,  the  manganous  carbonate 
filtered  out,  washed,  and  finally  converted  into  protoses- 
quioxide. 

Results 

Manganous  oxide  Manganous  oxide 

present.  found. 

Grm.  Grm. 

0*1949  0*1516 

0*1949  0*1534 

Several  trials  were  made  using  a  50  per  cent  solution  o^ 
potassium  carbonate. 

Results. 

Manganous  oxide  Manganous  oxide 

present.  found. 

Grm.  Grm. 

0*1951  0*1745 

0*1950  01528 

The  experimental  evidence  given  in  the  preceding 
paragraphs  leaves  no  doubt  as  to  the  insufficiency  of  the 
two  methods  which  were  tried  in  effedling  the  desired 
separation.  It  is  probable  that  fusion  with  an  alkaline 
carbonate  will  alone  answer  for  this  purpose.  How  com- 
plete that  course  would  be  can  only  be  ascertained  by 
careful  experimentation. 

In  the  course  of  analysis  molybdenum  is  quite  often 
obtained  as  sulphide.  Its  conversion  into  a  weighable 
form  is  attended  with  more  or  less  difficulty.  Trials  made 
in  connexion  with  its  estimation  show  that  if  the  sul- 
phide, as  generally  obtained,  be  dried,  then  intimately 
mixed  with  anhydrous  oxalic  acid,  its  careful  ignition  to 
trioxide  can  be  made  quite  rapidly. 

Results. 

Molybdenum  trioxide  Molybdenum  trioxide 

taken.  found. 

Grm.  Grm. 

0*3000  0*3009 

0*3000  0*2990 

0*1007  0*1011 

— journal  of  the  American  Chemical  Society,  xviiit,  No.  12* 


On  Dibromo  1—3  Propene.  —  R.  Lospieau.  —  Epi- 
dibromhydrine,  /3:  CHBr=CH-CH2Br,  is  a  colourless 
liquid  which  irritates  the  eyes  and  the  skin.  Its  density 
at  0°  is  2-097.  If  cooled  to  -75°  it  congeals,  but  after- 
wards melts  at  -52°.  It  boils  at  155— 156°.  Its  mole- 
ciilar  weight  is  '=200°.— Contptes  Rendus,  cxxiii.,  No.  25. 


THE   SEPARATION   OF  BISMUTH  FROM  LEAD. 
By  ARTHUR  L.  BENKERT  and  EDGAR  F.  SMITH. 

Many  methods  have  been  suggested  to  effedt  this  separa- 
tion. In  a  recent  issue  of  the  Zeiischrift  fiiir  Angewandte 
Chemie  (1895,  P-  53o)i  O'av  Steen  reviews  thirteen  of 
these  methods,  and  concludes  that  an  early  proposal  of 
Rose  {Ann.  Chem.  Phys.  Pogg.,  ex.,  425),  in  which  the 
lead  is  thrown  out  as  chloride  and  weighed  as  sulphate, 
another  by  Lowe  {yourn.  Prakt.  Chem.,  Ixxiv.,  348),  in 
which  the  bismuth  is  removed  as  basic  nitrate,  and  a  late 
suggestion^made  by  Jannasch  (Ber.  Chem.  Ges.,  xxv.,  124), 
viz.,  the  expulsion  of  the  bismuth  as  bromide  from  a 
mixture  of  lead  and  bismuth  sulphides  by  an  air  current 
carrying  bromine,  are  the  most  satisfadlory.  At  least  these 
methods  gave  Steen  the  best  results.  The  separation  of 
bismuth  from  lead  frequently  confronts  the  analyst,  and 
any  novelty  in  this  diredion  cannot  be  absolutely  devoid 
of  interest;  hence  the  present  communication,  which 
brings  data  that  may  perhaps  prove  of  service  in  the 
hands  of  others  who  are  interested  in  the  solution  of  this 
analytical  problem. 

It  will  be  recalled  that  Herzog  (Ztschr.  Anal.  Chem., 
xxvii.,  650)  proposed  to  separate  bismuth  from  lead  by 
precipitating  the  former  as  basic  acetate.  The  method 
required  considerable  time  for  execution,  and  in  other 
hands  than  those  of  its  author  apparently  has  not  yielded 
entirely  satisfadory  results. 

An  idea  closely  related  to  that  of  Herzog  would  be  the 
substitution  of  a  formate  solution  for  that  of  the  acetate. 
This  was  done,  with  results  that  are  very  interesting. 

Solutions  of  lead  nitrate  and  bismuth  nitrate  in  nitric 
acid  were  made  up  of  such  strength  that  20  c.c.  of  the 
first  contained  0*2076  grm.  of  lead  oxide,  and  20  c.c.  of 
the  second  0*1800  grm.  of  bismuth  trioxide.  The  lead 
and  bismuth  were  accurately  determined  after  dilution  to 
a  litre.  20  c.c.  of  these  two  nitrate  solutions  were  then 
introduced  into  a  beaker  glass,  carefully  diluted  and 
almost  neutralised  with  sodium  carbonate,  or  until  the 
incipient  precipitate  dissolved  slowly,  when  considerable 
sodium  formate  solution  of  sp.  gr.  1*084  and  a  few  drops 
of  aqueous  formic  acid  were  added.  The  total  dilution 
of  the  liquid  was  250  c.c.  It  was  gradually  heated  to 
boiling  and  held  at  that  point  for  five  minutes.  The  pre- 
cipitate was  then  allowed  to  subside,  but  was  filtered 
while  yet  hot.  The  basic  formate  separates  rapidly,  and 
is  easily  washed  if  not  boiled  too  long.  It  was  washed 
with  hot  water,  then  dissolved  in  dilute  nitric  acid,  and 
precipitated  with  ammonium  carbonate.  The  ignited 
bismuth  trioxide  weighed  too  much  ;  it  contained  lead. 
However,  the  impure  oxide  was  dissolved  in  nitric  acid, 
diluted  to  250  c.c,  and  after  the  addition  of  sodium  car- 
bonate to  almost  complete  neutralisation,  sodium  formate 
and  free  formic  acid  were  added  as  before,  and  the  pre- 
cipitation of  basic  formate  repeated.  This  precipitate 
after  solution  and  the  bismuth  thrown  out  by  ammonium 
carbonate,  gave  0*1804  grm.  of  bismuth  oxide  instead  of 
o*i8oo  grm.  as  required  by  theory.  Seven  additional 
separations,  in  which  the  quantities  of  bismuth  and  lead 
were  the  same  as  indicated  above,  gave — 

o*i8o6  grm.  of  BijOs. 
0*1806        ,,        „ 
0*1803        •>        » 

0*1804  M  II 

0*1804  „  „ 
01805  „  „ 
0*1796        „        „ 

The  conditions  in  these  determinations  were  similar  to 
those  previously  outlined. 

With   a   solution   containing   0*3600   grm.  of  bismuth 
oxide   and   0*2076   grm.  of  lead  oxide,  operating   in  an 
analogous  manner,  two  results  were  obtained  ; — 
o'3595  grm.  of  BizOj. 
0-3605 
nstead  of  the  required  0*3600  grm. 


28 


Determination  of  Atomic  Masses  by  the  Electrolytic  Method,    {*'""'"|',8"77'' 


The  residual  bismuth  trioxide  was  examined  for  lead, 
but  none  was  found. — journal  of  the  American  Chemical 
Society,  xviii.,  No.  12. 


DETERMINATION     OF    THE    ATOMIC     MASSES 

OF    SILVER,     MERCURY,     AND     CADMIUM, 

BY    THE    ELECTROLYTIC    METHOD.* 

By  WILLETT  LEPLEY  HARDIN. 

Introduction. 
A  GLANCE  at  the  literature  on  the  determinations  of  the 
atomic  masses  of  silver,  cadmium,  and  mercury,  will  show 
that,  with  the  exception  of  cadmium,  the  eleiSrolytic 
method  has  not  been  tried.  Aside  from  the  fadt  that  cer- 
tain errors  involved  in  the  washing  and  drying  of  the 
precipitates  are  eliminated  by  this  method,  its  simplicity 
at  once  gives  it  preference  over  the  usual  methods  of 
gravimetric  determinations.  Inasmuch  as  these  three 
metals  are  completely  precipitated  from  certain  of  their 
solutions  by  the  eledtric  current,  and  as  it  is  desirable  to 
determine  the  atomic  mass  of  any  element  by  different 
methods,  it  was  thought  advisable  to  apply  this  method 
in  a  re-determination  of  the  atomic  masses  of  these 
elements. 

General  Considerations, 

Before  taking  up  the  different  metals  separately,  the 
following  general  considerations  may  be  mentioned  : — 

1.  A  careful  preliminary  study  was  made  in  the  selec- 
tion of  compounds.  Some  compounds,  which  from  a 
theoretical  standpoint  seemed  to  offer  certain  advantages, 
were  found  by  experiment  not  to  meet  the  requirements 
of  exaft  determinations.  Salts  which  can  be  sublimed 
were  used  whenever  possible  ;  and  in  all  cases  only  those 
salts  were  used  which  form  well-defined  crystals. 

2.  All  reagents  used  were  either  prepared  or  purified  by 
myself,  and  carefully  tested  for  impurities. 

3.  The  metals  were  deposited  in  platinum  dishes  of 
about  200  c.c.  capacity  and  about  65  grms.  in  weight. 
When  the  precipitation  was  complete,  before  interrupting 
the  current,  the  solution  was  syphoned  from  the  platinum 
dish,  pure  water  being  added  at  the  same  time :  this  was 
continued  until  the  solvent  used  was  completely  removed 
from  the  dish.  The  current  was  then  interrupted,  and  the 
deposit  washed  several  times  with  boiling  water,  with  the 
hope  of  removing  any  occluded  hydrogen.  After  drying, 
the  dishes  were  placed  in  a  vacuum  desiccator  over  anhy- 
drous calcium  chloride,  and  allowed  to  remain  in  the 
balance  room  until  their  temperature  was  the  same  as 
that  of  the  room.  Atmospheric  dust  was  excluded  from 
the  platinum  dishes  during  the  process  of  deposition  by 
means  of  two  glass  plates  which  formed  a  complete  cover  ; 
the  moisture  which  collefted  on  this  cover  was  washed 
back  into  the  dish  from  time  to  time.  The  dishes  were 
handled  with  nickelled  tongs  tipped  with  rubber. 

4.  The  balance  used  was  made  expressly  for  this  work 
by  Henry  Troemner,  of  Philadelphia.  The  beam  and 
pans  were  made  of  aluminum,  the  beam  being  about 
20  cm.  long.  The  framework  was  plated  with  gold  to 
prevent  corrosion.  The  sensibility  for  different  loads  and 
the  ratio  of  the  length  of  the  two  arms  were  carefully 
determined.  The  balance  is  sensitive  to  the  fortieth  of  a 
m.grm.,  and  the  sensibility  is  almost  independent  of  the 
load  up  to  75  grms.  The  difference  in  the  length  of  the 
two  arms  is  so  slight  that  no  correftion  need  be  applied. 
The  balance  was  kept  in  a  large  quiet  room  of  nearly 
constant  temperature. 

The  larger  weights  used  were  made  of  brass,  and  the 
fraitions  of  a  grm.  made  of  platinum.     The  weights  were 

♦  Contribution  from  the  John  Harrison  Laboratory  of  Chemistry 
No.  13.  From  the  author's  thesis  presented  to  the  Faculty  of  the 
University  of  Pennsylvania  for  the  degree  of  Ph.D. — From  the 
Journal  0/ the  American  Chemical  Society,  xviii.,  p.  990. 


all  previously  compared  against  each  other,  and  stan- 
dardised with  reference  to  the  largest  weight.  The 
small  corre(5lions  found  in  comparing  them  were  tabulated 
and  applied  to  all  results.  The  weighings  were  made  by 
the  method  of  oscillations.  The  temperature  and  baro- 
metric pressure  were  noted  at  the  time  of  each  weighing, 
and  all  weighings  were  reduced  to  a  vacuum  standard. 
As  the  density  of  the  atmosphere  at  the  time  of  weighing 
the  empty  platinum  dish  was  different  from  that  at  the 
time  of  weighing  the  dish  and  deposit  together,  the  fol- 
lowing formula  was  applied  to  obtain  the  weight  of  the 
deposit  in  vacuo : — 


Weight  of  (dish  +  deposit)  — 


weight  of  dish 


('-!-})' 


'+S-7 

I  +  -  -  -     =  weight  of  deposit  in  vacuo. 

Where  A  =  density  of  air  at  the  time  of  weighing  the 

empty  dish. 
A'  e=  density  of  air  at  the  time  of  weighing  the 

dish  +  deposit. 
A  =  density  of  platinum  dish. 
A'  =  density  of  metallic  deposit. 
/=  density  of  weights. 

As  the  weights  were  all  standardised  with  reference  to 
the  loo-grm.  brass  weight,  it  is  evident  they  must  all  be 
calculated  as  having  the  same  density,  equal  to  that  of 
brass. 

5.  The  atomic  masses  of  the  different  elements  in- 
volved  in  the  calculation  of  results  were  taken  from 
Clarke's  latest  report  (J.  Am.  Chem.  Soc,  xviii.,  197). 

Part  I. 
Determination  of  the  Atomic  Mass  of  Silver. 
The  mean  of  all  the  earlier  determinations,  as  calcu- 
lated by  Clarke,  gives   107*923   for  the  atomic  mass  of 
silver, — a  result  almost  identical  with  the  mean  (i07'93; 
O  =  16)  of  the  determinations  of  Stas. 

Preparation  of  Pure  Metallic  Silver. 
The  silver  used  in  this  work  was  purified  by  the  Stas 
method.  Two  hundred  grms.  of  silver,  about  99  per  cent, 
pure,  were  dissolved  in  dilute  hot  nitric  acid.  The  solution 
was  evaporated  to  dryness,  the  nitrate  heated  to  fusion 
and  maintained  in  a  fused  condition  until  the  oxides  of 
nitrogen  were  no  longer  evolved.  The  residue,  after 
cooling,  was  dissolved  in  as  little  cold  water  as  possible, 
and  after  standing  forty-eight  hours  the  solution  was 
filtered  through  a  double  filter  to  remove  any  suspended 
matter.  The  clear  solution  was  then  diluted  with  thirty 
times  its  volume  of  distilled  water,  and  to  it  was  added 
an  excess  of  pure  hydrochloric  acid.  The  silver  chloride 
which  separated  was  allowed  to  subside,  and  was  then 
thoroughly  washed  by  decantation,  at  first  with  water 
containing  a  little  hydrochloric  acid,  and  finally  with  pure 
water.  The  precipitate  was  then  colledled  on  a  cheese- 
cloth filter,  pressed  strongly,  and  allowed  to  dry.  When 
perfedly  dry,  the  silver  chloride  was  powdered  finely  and 
digested  for  three  days  with  aqua  regia ;  it  was  then 
thoroughly  washed  by  decantation  with  distilled  water. 
After  obtaining  the  pure  chloride  of  silver,  it  was  neces- 
sary to  purify  the  caustic  potash  and  milk-sugar  used  in 
reducing  the  chloride  to  the  metallic  state.  The  caustic 
potash  was  heated  to  the  boiling-point,  and  to  it  was  added 
a  concentrated  solution  of  potassium  sulphide  to  precipi- 
tate  any  heavy  metals  which  might  be  present.    The 


CRIUICAL  NBW8,  ) 

Jan.  15, 1897.     f 


Manufacture  of  Calcium  Carbide. 


Bolution  was  filtered,  and  the  filtrate  digested  for  some 
time  with  freshly  precipitated  silver  oxide,  and  again  fil- 
tered to  remove  the  excess  of  potassium  sulphide.  The 
milk-sugar  was  purified  in  a  similar  manner.  The  silver 
chloride  was  then  placed  in  large  porcelain  dishes  and 
covered  with  a  solution  of  caustic  potash  and  milk-sugar. 
The  dishes  were  placed  on  a  water-bath,  and  heated  to  a 
temperature  of  70°  to  80°  until  the  redudlion  to  finely 
divided  metallic  silver  was  complete.  The  alkaline  solu- 
tion was  then  poured  off,  and  the  grey  metallic  silver  was 
washed  with  distilled  water  until  the  alkaline  rea(5tion  dis- 
appeared. The  metal  was  then  digested  with  pure  dilute 
sulphuric  acid,  and  finally  washed  with  dilute  ammonia 
water.  The  silver  thus  obtained  was  mixed,  when  dry, 
with  5  per  cent  of  its  weight  of  fused  borax  containing 
10  per  cent  of  pure  sodium  nitrate.  The  mixture  was 
fused  in  a  clay  crucible  and  the  silver  poured  into  a  mould. 
The  metal  obtained  in  this  way  was  almost  snow-white  in 
appearance,  and  dissolved  completely  in  nitric  acid  to  a 
colourless  solution. 

Preparation  of  Pure  Nitric  Acid. 

To  obtain  pure  nitric  acid,  one-half  litre  of  the  com- 
mercial C.  P.  acid  was  mixed  with  an  equal  volume  of 
concentrated  C.  P.  sulphuric  acid  and  distilled  from  a 
retort  provided  with  a  knee-tube  and  condenser.  The 
first  portion  of  the  distillate  was  rejetSted.  The  process 
was  stopped  when  half  of  the  nitric  acid  present  had  been 
distilled  over.  The  distillate  was  mixed  with  an  equal 
volume  of  pure  sulphuric  acid  and  re-distilled.  The  second 
distillate  was  colleded  in  a  flask,  the  mouth  of  which  was 
closed  with  glass  wool.  When  the  process  was  complete 
the  flask  was  closed  with  a  doubly  perforated  cork,  and 
placed  in  a  water-bath  at  a  temperature  of  40°.  A  current 
of  pure  dry  air  was  then  condudled  through  the  acid  to 
remove  any  oxides  of  nitrogen.  The  acid  was  kept  in  a 
dark  place. 

Experiments  on  Silver  Oxide. 

If  pure,  dry  silver  oxide  could  be  prepared,  the  atomic 
mass  of  silver  could  be  compared  dire(5tly  with  that  of 
oxygen,  A  large  number  of  experiments  were  made  on 
this  compound  with  the  hope  of  determining  the  ratio  of 
the  atomic  mases  of  these  two  elements. 

Preparation  of  Silver  Oxide. 

A  portion  of  the  pure  metallic  silver  was  dissolved  in 
pure  dilute  nitric  acid,  and  the  solution  evaporated  to 
crystallisation.  The  crystals  of  silver  nitrate  were  dis- 
solved in  pure  water,  and  to  the  solution  was  added  a 
Bolution  of  pure  sodium  hydroxide,  prepared  by  throwing 
pieces  of  metallic  sodium  on  distilled  water  in  a  platinum 
dish.  The  25  grms.  of  silver  oxide  prepared  in  this  way 
were  washed  by  decantation  with  20  litres  of  water.  The 
material  was  then  dried  at  the  ordinary  temperature,  after 
which  it  was  finely  powdered  and  dried  for  twenty- four 
hours  in  an  air-bath  at  100°.  The  oxide  was  kept  in  a 
weighing  tube  in  a  dark  place. 

Several  analyses  were  made  by  dissolving  a  weighed 
portion  of  the  material  in  pure  potassium  cyanide,  eledro- 
lysing  the  solution,  and  weighing  the  resulting  metallic 
silver.  The  observations  invariably  gave  less  than  95  for 
the  atomic  mass  of  silver.  The  oxide  was  re-dried  at  a 
temperature  of  125°,  and  analysed  as  before,  but  the  quan- 
tity of  silver  obtained  was  far  below  that  calculated  for 
the  compound  AgjO.  Observations  were  also  made  on 
material  dried  at  140°  and  150°.  The  results  showed  that 
it  was  impossible  to  prepare  the  silver  oxide  in  a  pure, 
dry  condition. 

After  making  these  observations  my  attention  was 
called  to  an  article  by  Carey  Lea  (Am.  f.  Sci,,  xliv,,24o), 
in  which  were  given  the  results  of  a  series  of  analyses  of 
silver  oxide  dried  at  different  temperatures  varying  from 
100'  to  170°,  These  observations  prove  conclusively  that 
oxygen  is  given  off  at  a  much  lower  temperature  than 
that  required  to  remove  the  last  traces  of  moisture. 
From  these  observations  and  the  results  obtained  by  my- 


29 


self,  it  was  evident  that  any  further  attempt  to  determine 
the  atomic  mass  of  silver  from  the  oxide  would  be  useless. 
Although  no  careful  study  was  made  as  to  the  nature  of 
this  compound,  it  might  be  added  that,  from  my  own  ob- 
servations, it  seems  very  probable  that  the  oxide  contains 
some  hydrogen  in  the  form  of  hydroxyl. 

(To  be  continued). 


THE  MANUFACTURE  OF  CALCIUM  CARBIDE.* 
By  J.  T.  MOREHEAD  and  G.  de  CHALMOT, 

(Continued  from  p.  18). 

Taking  into  account  the  weight  of  the  produA,  the  time 
in  which  it  has  been  produced,  and  the  number  of  horse- 
power used,  we  calculate  for  each  run  the  amount  of 
pounds  produced  per  horse-power  in  twenty-four  hours. 
By  multiplying  these  figures  by  the  number  of  cubic  feet 
of  gas  produced  per  pound  we  obtained  the  number  of 
cubic  feet  of  gas  produced  per  horse-power  in  twenty-four 
hours.  In  the  accompanying  table  we  give  the  results  of  ex* 
periments,  wherein  everything  has  been  determined, 
wherein  both  unslacked  and  slacked  lime  have  been  used, 
and  voltage,  amperage,  and  duration  of  runs  were  varied. 
Since  these  results  were  obtained  we  have  had  many 
visitors  from  all  parts  of  the  country,  and  for  each  party 
we  have  made  a  test  run.  The  results  of  these  runs 
have  all  confirmed  our  previous  results,  with  one  excep- 
tion, which  was  due  to  the  presence  of  5§  per  cent 
magnesia  in  the  lime. 

It  is  obvious  that  the  results  obtained  from  unslacked 
lime  are  far  better  than  those  with  air-slacked  lime.  This 
is  undoubtedly  due  to  a  loss  of  power  used  in  decomposing 
the  hydrated  lime.  The  unslacked  lime  used  by  us  con- 
tained, after  being  ground,  from  5  to  9  per  cent  of  water. 
In  pradice  it  is  necessary  to  use  the  mixture  that  comes 
from  the  furnace  again.  This  mixture  always  contains 
some  carbonate  of  lime  ;  but  if  it  be  mixed  when  still  hot 
with  the  necessary  amount  of  carbon,  and  put  again  into 
the  furnace,  the  lime  has  no  opportunity  to  slack.  The 
unslacked  lime  has  the  further  advantage  that  it  weighs 
less  and  is  much  less  bulky,  and  that  the  mixtures  made 
from  it  cool  much  faster  than  those  made  from  slacked 
lime.  The  only  disadvantages  of  unslacked  lime  are, 
that  it  must  be  ground,  and  that  mixtures  made  from  it 
require  more  stoking  if  put  into  the  furnace.  The  mix- 
tures of  unslacked  lime  can  stand  up  against  the  sides  of 
the  furnace  under  a  very  steep  incline,  and  they  can  leave 
a  hole  all  around  the  pencils.  The  mixture  to  be  used 
should,  on  an  average,  contain  100  parts  of  lime  and  64 
to  65  parts  of  carbon,  in  order  to  obtain  a  carbide  of  about 
5  cubic  feet  of  gas  per  pound.  If  the  voltage  is  increased 
to  100  it  is  better  to  take  a  little  more  carbon  (100  lime 
and  66  to  67  carbon).  If  the  voltage  is  65  or  less,  63  to  64 
parts  of  carbon  are  sufficient.  If  the  amount  of  carbon 
is  increased  the  carbide  becomes  purer,  but  there  is  often 
more  coating. 

The  largest  amount  of  gas  per  horse-power  is  obtained 
if  the  carbide  yields  about  5  cubic  feet  of  gas  per  pound. 
The  yield  of  carbide  in  pounds  varies  inversely  with  the 
quality.  In  the  following  table  we  give  the  results  of  a 
series  of  experiments  made  with  slacked  lime  and  with  a 
current  of  65  volts  and  from  1700  to  2000  amperes. 
Several  of  these  experiments  have  not  been  taken  up  in 
Table  JI.,  becaue  the  amount  of  slag  on  all  the  pieces  of 
carbide  has  not  been  determined. 

Carbide  has  been  made  successfully  in  Spray  by  the 
use  of  both  the  diredl  and  the  alternating  current.  We 
cannot  express  an  opinion  as  to  what  current  can  be  used 


*  Read  Sept.  3rd  before  the  Springfield  meeting  of  the  A.A.A.S.  by 
one  of  us  (M ).  We  have  made  since  then  several  additions,  so  as  to 
make  the  article  complete  up  to  the  present  time.  Fiom  the  Journal 
of  the  American  Chemical  Society,  April,  1896. 


30 


Manufacture  of  Calcium  Carbide^ 


i  CBBklCAL  NbWS, 

I     Jan.  15, 1897. 


Date. 

June  27 
July    2 

..       I 

June  24 

„      28 

July  18 

M      19 

„       5 

»       9 

Aug.  10 

..      13 
July  31 


Time  of 
experiment. 
Hours. 
2-50 
300 
2*25 
3-20 
2*50 
3-00 

3*00 

375 
4-50 
6-00 
6-00 
7*oo 


Jnne  25 
>•  29 
II  ig 
„  22 
Aug.  14 
July  12 
II  26 
II  12 
»  6 
II  23 
II  22 
II  22 
II  25 
II  20 
it  23 
>i      24 


5 '00 

4*00 
5*50 
4'oo 
4-50 

375 
8-00 
5-50 
5*00 
3 '00 

2-00 
2*00 

9*00 
4*00 
5*00 
8-00 


Volts. 

100 
100 
100 
100 
100 

65 
65 
65 
65 
65 
65 

75 


100 
100 


75 
85 
75 
85 
80 

65 
65 
65 
65 
65 
65 
65 


Amperes. 

1700 
1666 
1700 
1600 
1700 
2000 

igoo 
2000 
2000 
1800 
1800 
1800 


Table  II. 

Lobs  of 

voltage  in 

the  pencils 

Per  cent. 

7-0 

8-0 

lO'O 

7'o 

lO'O 

5*0 
5'o 
5'0 
5*o 
8-0 
8-0 
8-5 


— Unslacked  Lime. 


Horse- 
power, 

214 
205 
205 
214 
205 
165 
158 
165 
165 
144 
144 
166 


Production 

in  24  hours, 

including  slag. 

Pounds. 

987 
10-34 
io'66 
1 1  "50 
1 1 70 

9-63 
io'40 

8-38 

g'5o 

g"34 
1083 

11-44 
Average     . , 


Net  pro- 

dudtion. 

Pounds. 

942 

g76 

lO'IO 

1073 

II-IO 

915 

9'62 
8-I5 
9-05 
g'oo 

10-44 

io'53 
g75 


Table  III. — Air-slacked  Lime. 


1700 
1700 
1700 
1600 
1700 
1800 
1800 

1775 
1020 
1800 
1800 
1800 
1800 
1800 
1800 
1800 


7-0 

lO'O 

7-0 

7'o 
7-0 

3  5 
5'o 
S-o 
3-0 
5'o 
5'o 
5'0 
5-0 
5*o 
50 
50 


214 
205 
214 
igg 

I5g 
igS 
172 

185 
200 
150 
150 
150 
150 
150 
150 
150 


Per  horse-power. 
8-34 
8-78 

925 
g-8o 
7-88 

8-40 

878 
6-83 
7*13 

7*20 

772 

8 -60 

g-02 

9-30 

Average     . . 


7-96 
8-34 

965 
7-13 
6-33 
7-23 
7-32 
8-i6 
6-40 
6-40 
6-40 
7-27 
8-00 
8-00 
803 
7'5i 


Cubic  feet  Cubic  feet 

of  gas  per     of  gas  per  horse- 
hour,  power  in  24  hrs. 


4-83 
5*25 
4-65 

4 '93 

475 
495 
4-83 
5-40 

4'9g 
5"3g 
4-82 

4-83 
497 


Per  pound. 
530 
4-98 
4-89 

474 
550 
5'55 
5  33 
5*32 
5'" 
578 
5"62 
5-64 
5'54 
5-OI 
5-07 

4'97 
5-27 


45 -50 
5i"24 
47-06 
52-90 
52-72 
45*29 
46-46 
44-01 
4516 
48-51 
50-32 
50-86 
48-33 


42-19 
4i"53 

4575 
3g'22 

35*1:3 
38-54 
38-g4 
41-70 
56 -gg 

3597 
36-09 
40-28 
4008 
40-56 

39gi 
39-52 


Date. 
July  23 
June  14 
July  22 

„      22 

..  25 
Aug.  14 
May  21 

„  22 
July  26 
June  4 
July  20 
June  5 
May  28 

.,  23 
July  23 
June  8 

I.  24 
July  II 
Aug.  12 
May  31 
Aug.   8 


Table  IV. 

Produftion  per  horse- 
power including  slag. 
Pounds. 

685 

7-10 

7-13 
7-20 
7-72 
7-88 
8-IO 
8-30 
8-40 
8-46 
8-6o 
8-76 
8-80 
8-82 
9-02 
9-06 
930 
9-30 

9-44 

9-87 

10-52 


Cubic  feet 

of  gas 
per  pound. 

5-78 
5-80 
5*62 
5-64 
5-54 
5-50 
5-20 
5-10 
5  "33 
5-52 
5-01 

4'94 
5-20 
5*io 

5-07 
5-10 

4 '97 
4-33 
4-51 
4-30 
4-23 


to  the  best  advantage,  for  we  are  not  able  to  compare 
results.  All  of  the  results  communicated  in  this  paper 
have  been  obtained  by  the  use  of  the  alternating  current. 
That  eledrolysis  plays  a  part  in  the  carbide  manufaduring 
process  of  Mr.  Wilson  is  therefore  cut  of  the  question, 
and  we  do  not  need  to  use  a  furnace  of  the  Moissan  con- 
strudion  to  prove  this.  It  is  not  desirable  to  increase  the 
amperage  over  2000  if  only  six  carbons  of  4  inches  square 
are  used.  The  higher  the  amperage  the  greater  the  loss 
of  voltage  in  the  pencils,  and  therewith  that  of  power. 
The  carbons  will  also  last  longer  if  the  amperage  is  low, 
because  they  do  not  become  so  hot.     Lastly,  we  did  not 


obtain  as  great  a  yield  per  horse-power  if  the  amperage 
was  high  and  the  voltage  correspondingly  low.  We  ob- 
tained the  best  yield  of  gas  per  horse-power  by  using  a 
current  of  100  volts,  which  can  be  seen  by  comparing  the 
average  of  the  results  given  in  Table  II. 


Volts. 
Unslacked  f    100 
lime    ..I65— 75 


Slacked 
lime  • 


100 

75-85 

65 


Table  V. 

Horse- 
power. 

205—214 
144—165 

200—214 

i5g— 100 

150 


No.  of 
experi- 
ment. 

5 
7 

3 
5 
7 


Average  cubic 

feet  of  gas  per 

horse' powef 

in  24  hours. 

49-88 

47-23 

43-15 
3871 
38-55 


It  must  be  taken  into  account  that  we  measured  the 
primary  current,  and  that  the  losses  of  amperage  in  the 
transformers  probably  have  been  higher  when  we  did  not 
use  the  highest  voltage,  f.  <.,  100.  We  do  not  know  in 
how  far  it  would  be  advisable  to  increase  the  voltage  over 
100,  since  our  dynamos  cannot  give  us  a  current  of  more 
than  100  volts.  We  believe,  however,  that  the  heat 
yielded  by  an  arc  of  100  volts,  and  from  1700  to  2000 
amperes,  is  about  the  largest  amount  to  be  profitably  used 
for  the  produdion  of  carbide  in  one  furnace  with  six 
pencils,  as  it  is  used  in  Spray.  We  base  our  assumption 
on  the  following  fads  : — The  quality  of  the  carbide  be- 
comes better  if  the  voltage  decreases.  We  experienced 
some  trouble  in  obtaining  large  carbide  crystals  with  an 
arc  of  100  volts  and  1700  amperes,  and  in  order  to  obtain 
a  carbide  that  yields  more  than  5  cubic  feet  of  gas  per 
pound  the  mixture  should  contain  an  excess  of  carbon. 
If  a  current  of  100  volts  and  1700  amperes  is  used,  the 
furnace  requires  more  attendance  and  stoking  than  if  a 
lower  power,  and  especially  a  lower  voltage,  is  used. 
The  higher  the  voltage  the  faster  the  pencils  must  be 


Chruical  Nbws,  I 
Jan.  15, 1897.     I 


Derivatives  of  Columbium  and  Tantalum, 


31 


raised,  for  if  the  voltage  is  low  (50  or  65)  the  carbide 
spreads  oat  much  more  than  if  the  voltage  is  high  (100 
volts).  In  the  latter  case  the  carbide  builds  up  as  a  long 
thin  piece,  and  it  is  oftener  necessary  to  empty  the  fur- 
nace. As  to  the  time  that  one  furnace  should  be  used 
continuously,  we  wish  to  say  that  we  did  not  perceive  a 
difference  in  the  quantity  and  quality  of  the  produdt 
whether  we  ran  three  hours  or  from  three  to  nine  hours. 
We  must,  however,  remark  that  in  the  case  where  we  used 
100  volts  and  1700  amperes  with  mixtures  of  unslacked 
lime  we  could  not  continue  running  for  much  more  than 
three  hours,  because  the  construdlion  of  the  furnace  did 
not  admit  of  raising  the  pencils  quite  3  feet.  With 
slacked  lime  we  made  also  with  this  high  power  very 
satisfadtory  runs  of  five  and  five  and  a  half  hours.  During 
the  first  hour  the  produdtion  is  somewhat  lower.  It 
seems  that  more  heat  is  lost  probably  for  heating  up  the 
furnace. 

The  mixture  used  in  all  of  the  following  experiments 
contained  lime  50*08  per  cent,  and  coke  (of  92*17  percent 
of  carbon),  39'22  per  cent.  The  current  was  of  65  volts 
and  1800  amperes,  the  loss  of  voltage  in  the  pencils  5  per 
cent,  and  the  net  horse-power  150. 


Table  VI. 

Time  of 

Produdtion 

Cubic  feet 

Cubic  feet 

experiment. 

per  hour 

of  gas 

of  gas 

Hours. 

in  pounds. 

per  pound. 

per  hour. 

I 

37 

563 

208*31 

3 

40 

5'62 

224-80 

2 

40 

5*64 

225*60 

3 

40 

578 

237*20 

(To  be  continued). 

DERIVATIVES    OF    COLUMBIUM    AND 

TANTALUM.* 

By  MARY  ENGLE  PENNINGTON. 

(Continued  from  p.  20). 

Qualitative  Reactions, 
Throughout  this  investigation  the  following  questions 
constantly  arose  :  How  shall  the  purity  of  the  columbium 
and  tantalum  compounds  be  determined.  When  is 
columbium  free  from  tantalum  ?  When  is  it  free  from 
titanium  ? 

In  the  earlier  work  upon  columbium  we  find  Hermann 
describing  a  new  element  which  he  obtained  from  the 
mother  liquors  of  the  columbium  potassium  fluoride. 
This  element,  he  states,  gave  a  dark  brown  solution  when 
reduced  with  zinc  and  hydrochloric  acid,  while  the  pure 
columbium  compound  gave  a  blue  colour.  Both  these 
solutions,  on  standing  in  the  air,  reverted  to  the  white 
hydrate.  Marignac  replied  that  the  brown  colour  was 
not  due  to  ilmenium,  but  to  titanium,  a  view  which  is  now 
generally  accepted. 

He  also  declares  that  a  brown  colour  is  produced  when 
the  potassium  columbium  oxyfluoride  is  treated  with  zinc 
and  hydrochloric  acid,  the  acid  being  in  considerable 
excess.  Then,  by  titrating  with  permanganate,  he  found 
that  an  intermediate  oxide  had  been  formed,  to  which  he 
gave  the  formula  CbsOs. 

Crystals  of  the  columbium  salt,  prepared  as  described 
above,  continued  to  give  this  brown  solution  even  after 
they  had  been  subjedled  to  five  or  six  re-crystallisations. 
Following  the  plan  of  Kriiss  and  Nilson  {Ber.  d.  Chem. 
Ges.,  XX.,  1676),  the  atomic  value  of  the  oxide  contained 
in  such  crystals  was  determined  by  decomposing  with 
sulphuric  acid,  weighing  the  pentoxide  and  the  potassium 
sulphate,  then,  by  the  ratio  2K2SO4  ;Cb205,  determining 


♦  From  the  author's  thesis  presented  to  the  University  of  Penn- 
sylvania for  the  degree  of  Ph.D.,  1895,  From  the  Journ.  Amer. 
Chem,  Soc,  xviii.,  January,  i8g6. 


the  value  for  Cbv.  This  was  found  to  be  85*7.  Iron  and 
manganese  has  been  eliminated  ;  titanium  therefore  was 
the  probable  cause  of  this  low  atomic  value.  The  salt 
used  was  perfeAly  white,  yielding  a  pure  white  oxide. 
This  oxide  was  tested  for  titanium  by  the  most  delicate 
reactions  known  for  the  metal,  but  its  presence  could  not 
be  proved  by  any  of  them. 

I.  Colour  and  Reduction  Reactions, — It  has  been  found 
that  the  qualitative  tests  given  in  the  various  text-books 
for  these  three  elements  do  not  always  hold  good  when 
the  solution  used  is  a  double  fluoride.  As  it  is  in  this 
form  that  the  separations  are  usually  made,  it  has  been 
thought  advisable  to  note  the  aiftion  of  some  of  the 
common  reagents  on  these  salts. 

Gallotannic  acid,  which  is  considered  the  most  charac- 
teristic test  for  columbium  salts,  behaves  differently  with 
different  double  fluorides.  An  acid  solution  of  the  lami- 
nated salt  gives  almost  instantly  a  deep  brick-red  pre- 
cipitate. The  salt,  crystallising  in  long  needles,  gives  a 
lighter  red  precipitate  which  does  not  separate  so  rapidly. 
The  large,  thin,  transparent  plates  previously  mentioned 
give  only  a  slight  precipitate,  and  this  is  yellow  in  colour. 
These  readions  are  most  delicate  if  the  salt  be  dissolved 
in  water,  a  drop  of  hydrochloric  acid  added,  then  a  little 
gallotanic  acid  dissolved  in  alcohol.  After  standing 
several  hours  all  the  precipitates  assume  the  same  colour 
— a  dark  brick-red. 

Tantalum  double  fluoride  gives  a  sulphur-yellow  colour 
with  gallotannic  acid.  This,  however,  on  standing,  be* 
comes  brick-red,  as  the  columbium  does. 

Titanium  compounds  are  said  to  give  a  brownish  colour 
with  gallotannic  acid,  which  changes  quickly  to  an  orange- 
red.  The  potassium  titanium  fluoride  gave  a  straw-yellow 
colour  with  this  reagent ;  in  time  a  flaky  precipitate  forms, 
but  the  colour  does  not  materially  alter. 

The  following  colour  readtion  serves  for  the  detedtion 
of  very  small  quantities  of  columbium,  and  is  applicable 
to  any  soluble  columbium  compound.  An  excess  of 
potassium  thiocyanate  is  added  to  a  small  quantity  of  the 
dissolved  substance ;  then  some  pieces  of  zinc  followed 
by  strong  hydrochloric  acid.  At  once  the  solution  be- 
comes a  bright  golden  brown,  which,  if  much  columbium 
be  present,  may  be  almost  red.  A  brisk  and  continued 
evolution  of  the  gas  does  not  alter  this  tint,  which  is 
also  stable  for  more  than  twenty-four  hours  in  the  acid 
solution.  Neither  titanium  nor  tantalum  give  any  re- 
adtion  with  potassium  thiocyanate  under  the  above  con- 
ditions. 

Hyposulphurous  acid,  HaSOa,  gives  noteworthy  colour 
readtions  with  these  salts.  The  tests  were  condudted  in 
the  following  manner : — A  few  cubic  centimetres  of  a 
concentrated  solution  of  sulphur  dioxide  were  placed  in 
a  test-tube  provided  with  a  cork,  and  granulated  zinc  was 
added.  The  liquid  changed  to  a  greenish  colour,  and 
hydrogen  was  liberated.  As  soon  as  the  evolution  of 
the  gas  had  ceased  the  solution  containing  the  hypo- 
sulphurous  acid  was  poured  into  the  salt  solution  to  be 
tested. 

A  solution  of  titanium  double  fluoride  gave  an  orange- 
yellow  colour  at  once.  The  oxide,  when  treated  in  like 
manner,  became  yellow. 

Columbium  double  fluoride  gave  no  colour,  but  a  white 
hydrate  was  soon  precipitated.  Columbic  oxide  gave  a 
slight  yellow  tinge. 

Tantalum  double  fluoride  gave  no  colour,  but  after 
standing  a  white  precipitate  separated.  Tantalic  oxide 
remained  colourless  when  treated  with  hyposulphurous 
acid. 

The  white  precipitates  from  the  tantalum  and  colum- 
bium salts  were  probably  hydrates  due  to  the  oxidation 
of  the  acid  and  its  consequent  adtion  upon  these  salts. 

Zinc  and  hydrochloric  acid  gave  no  readlion  with  the 
double  fluoride  of  tantalum.  With  titanium  a  clear  deli- 
cate green  was  obtained.  The  columbium  salts  always 
gave  a  colour  with  these  reagents.  The  solution  is  at 
first  dark  blue,  then  a  greenish  brown,  and  finally  a  dark 


32 


Derivatives  of  Columbium  and  Tantalum, 


(Crbmioal  News, 
I     Ian.  15, 1897. 


Lead  acetate. 
Mercuric  chloride. 

Mercurous  nitrate. 
Potassium  chromate. 


Potassium  bichromate. 
Potassium  cyanide. 
Potassium  ferrocyanide. 

Potassium  thiocyanate. 


Potassium  iodide. 

Disodium  hydrogen    phos- 
phate. 
Silver  nitrate. 

Sodium  bisulphite. 
Sodium  pyrophosphate. 
Hypophosphorous  acid. 
Sodium  metaphosphate. 
Potassium  bromide. 


zKF.CbOFa.HjO, 
White  precipitate. 
Slight    precipitate     in     24 

hours. 
Yellow  precipitate. 
White  precipitate,    soluble 

in   H2O.     Partly  soluble 

K2Cr04  solution. 

White  precipitate  on  boiling. 
Green-blue    precipitate    on 

boiling. 
White  precipitate. 


White,  granular  precipitate. 
Iodine  is  liberated. 


White  precipitate. 


2KF.TaF4. 
White  precipitate. 

Yellowish-green  precipitate. 


Precipitate  after  standing. 

White  precipitate. 

Yellow  precipitate  on  boil- 
ing. 

White  precipitate  soluble  in 
the  cold.  Comes  down 
by  boiling. 

White  granular  precipitate. 


White  precipitate. 


White      precipitate 

standing. 
White      precipitate 

standing. 
White  precipitate. 
Slight  cloudiness. 

Slight  cloudiness. 


after 
after 


sKF.TiFt. 
White  precipitate. 


Yellowish-green  precipitate. 
Precipitate  soluble  in  water. 


White  precipitate. 
Precipitate  on  boiling. 


No  precipitate,  but  iodide  is 

liberated. 
White  precipitate. 


White  precipitate. 

Precipitate. 

Precipitate. 


•brown.  Frequently  a  brown  precipitate  separates,  which, 
on  standing,  becomes  white. 

The  hydrochloric  acid  solution  of  columbic  oxide,  and 

-also  the  potassium  columbium  fluoride,  were  tested  with 
hydrogen  peroxide,  this  being  accepted  as  one  of  the  most 
delicate  reagents  for  titanium.  No  yellow  colour  in  either 
case  was  obtained. 

2.  Reactions  with  Wet  Reagents, — A  number  of  the 
ordinary  reagents  have  been  tried  with  these  salts,  the 
results  being  given  in  the  table  above.  The  readions 
for  the  greater  number  are  very  different  when  the  metal 
tested  is  as  double  fluoride.  The  ferrocyanides,  in  par- 
ticular, have  quite  abandoned  their  ordinary  colours  with 
these  compounds. 

Disodium  hydrogen  phosphate,  when  added  to  titanium 
double  fluoride,  precipitates  the  titanium  completely. 
The  flltrate,  tested  with  ammonium  hydroxide,  gave  no 
precipitate.  Columbium  double  fluoride,  on  the  con- 
trary, is  not  affe&ed  by  this  reagent.  After  boiling  a  long 
time  in  a  platinum  dish  a  few  white  flocks  were  observed 
in  the  solution,  but  in  such  small  quantity  that  they  were 
disregarded.  Whether  this  behaviour  may  or  may  not  be 
made  the  basis  of  a  separation  of  these  two  elements  is 
not  yet  determined,  because  of  the  difficulty  in  getting 
rid  of  the  phosphoric  acid.  Fusion  with  sodium  car- 
bonate, extradtion  with  water,  and  subsequent  precipita- 
tion by  sulphuric  acid  gives  a  mixture  of  sodium  salt 
and  columbic  oxide.  Some  columbium  remains  in  solu- 
tion. Fusion  with  potassium  acid  sulphate  is  more  satis- 
faftory,  yet  is  not  complete. 

Deportment    of   Tantalum,    Columbium,    and    Titanium 
Double  Fluorides  toward  the  Electric  Current. 

1.  A  solution  of  potassium  columbium  double  fluoride, 
2KF.CbOF3.H2O,  in  water,  was  treated  with  a  small 
amount  of  sodium  acetate.  The  precipitate  formed  was 
dissolved  in  acetic  acid,  and  through  this  solution  a 
current  of  one  ampere,  obtained  from  a  thermopile,  was 
condudled  for  five  hours.  A  white  precipitate,  seemingly 
a  hydrate,  was  formed.  On  breaking  the  current,  this 
rapidly  went  into  solution. 

2.  (a)  A  solution  of  the  salt  in  water  was  subjei5led  to 
the  same  current  for  eight  hours.  Almost  immediately 
the  bottom  of  the  platinum  dish  was  covered  with  a 
blue  deposit.  This  gradually  spread  over  the  whole 
surface  exposed  to  the  adtion  of  the  current,  and  be- 
came in  a  short  time  iridescent.  As  the  deposit  in- 
creased, the  deep  blue  tint  changed  to  more  of  a  grey, 


and  remained  so  until  the  current  was  broken.  It  was 
washed  quickly  with  water,  then  with  alcohol,  and  it  was 
dried  on  the  hand. 

o'i3i5  grm.  of  the  salt  was  taken  ;  the  deposit  weighed 
o*0282  grm.  This  metallic-looking  substance  did  not 
alter  in  the  air,  but,  on  subjecting  it  to  a  red  heat,  a 
white,  shining,  apparently  crystalline  compound  resulted. 
It  was  readily  soluble  in  hydrofluoric  acid. 

{b)  A  second  experiment,  with  o'2i95  grm.  of  the  sub- 
stance, gave,  under  the  same  conditions,  a  deposit  weigh- 
ing 0*0388  grm.  This,  when  ignited  in  the  air,  burned 
to  a  white  oxide  weighing  o-o3i2  grm.  The  blue  com- 
pound is,  in  all  probability,  a  lower  hydrated  oxide  of 
columbium. 

3.  The  eledrolysis  of  an  aqueous  solution  of  a  sodium 
columbate  gave  a  white  flocculent  hydrate,  not  adherent 
to  the  dish.  The  precipitation  was  not  complete.  A 
current  of  one  ampere  was  employed  for  a  period  of 
seven  hours. 

4.  With  a  much  stronger  current  (two  amperes),  a 
solution  of  the  double  salt  2KF.CbOF3.H2O,  gave  first 
a  white  hydrate,  then,  beneath  the  outer  edge  of  the 
anode  appeared  a  dark  brown  ring  which  gradually  grew 
in  towards  the  centre  of  the  dish,  never  reaching  it, 
however,  but  stopping  when  about  half  an  inch  in 
width. 

This  brown  substance  was  slightly  adherent  to  the 
dish,  but  just  as  soon  as  the  current  was  broken,  and 
the  liquid  poured  off,  it  reverted  to  the  white  hydrate. 
This  change  was  so  rapid  that  it  was  impossible  to  sepa- 
rate the  brown  from  the  white  substance. 

Thinking  that  this  brown  compound  might  be  a  con- 
taminating element,  about  i  grm.  of  the  double  salt  was 
dissolved  in  water  and  eledlrolysed  until  the  brown  ring 
had  appeared.  Then  the  liquid  was  poured  into  another 
dish  as  quickly  as  possible,  and  the  current  run  through 
again.  The  brown  ring  appeared  as  before,  and  was 
treated  in  the  same  manner.  After  changing  the  dish 
four  times  only  a  trace  of  brown  could  be  seen.  When 
the  remaining  solution  was  evaporated  it  was  found  that 
almost  the  entire  quantity  of  the  columbium  had  been 
precipitated.  The  brown  substance  here  formed  resem- 
bles in  its  behaviour  that  produced  in  a  like  solution  by 
zinc  and  hydrochloric  acid. 

The  resistance  of  this  solution  is  very  high. 

5.  Potassium  tantalum  fluoride,  in  aqueous  solution, 
was  subjected  to  the  adlion  of  a  current  of  two  amperes 
for  six  hours.    A  small  quantity  of  hydrate  was  found  in 


CatHICALNBWS,  I 

Jan.  15, 1897.    f 


Derivatives  of  Columbium  and  Tantalum, 


33 


the  liquid,  and  on  the  dish  a  very  slight  iridescent  de< 
posit  mixed  with  some  white  hydrate. 

6.  Potassium  titanium  fluoride  was  treated  in  the  same 
manner  as  the  previous  salt.  A  small  quantity  of  hydrate 
was  found  here,  some  of  which  adhered  to  the  dish.  The 
iridescent  deposit,  however,  was  wanting. 

Action  of  Hydrofluoric  Acid  upon  the  Oxides  of  Tantalum, 
Columbium,  Titanium,  and  Silicon. 

The  well-known  volatility  of  the  oxides  of  tantalum 
and  columbium,  when  healed  with  hydrofluoric  acid,  led 
to  the  hope  that  in  this  behaviour  might  lie  a  separation 
from  titanium,  and  also  from  silica. 

Rose  states  that  a  very  appreciable  loss  occurs  when 
the  first  two  oxides  are  treated  as  suggested,  but  he 
makes  no  attempt  to  separate  them  from  the  latter  two. 
To  this  end  i  grm.  of  the  mixed  oxides  of  tantalum  and 
columbium  was  evaporated  to  dryness  with  hydrofluoric 
acid,  the  residue  being  heated  over  the  free  flame  for  a 
few  minutes.  By  this  treatment  dense  white  vapours 
were  driven  off.  Upon  weighing  the  residual  oxides  they 
were  found  to  equal  0*5464  grm.  A  second  evaporation 
gave  further  loss,  but  as  both  columbium  and  tantalum 
continued  to  remain,  the  method  is  without  value. 

The  separation  of  silica  from  these  oxides  can  be  ac- 
complished by  the  heat  of  an  iron  plate  after  evaporating 
to  dryness  on  a  water-bath.  The  final  heating  must  be 
carefully  done,  and  the  acid  should  not  be  in  too  great 
excess. 

I  have  never  found  it  impossible  to  dissolve  either  the 
mixed  or  the  pure  oxide  in  hydrofluoric  acid,  even  though 
strongly  ignited.  It  is  true,  concentrated  acid  is  neces- 
sary, and  a  little  time  is  often  required,  but  a  perfedt 
solution  does  take  place. 

Tantalic  oxide,  containing  columbic  oxide,  is  far  more 
soluble  in  hydrofluoric  acid  than  the  pure  oxide.  The 
same  behaviour  has  been  observed  with  pure  columbic 
oxide,  though  it  is  not  so  pronounced  as  with  tantalic 
oxide.  Titanium  dioxide,  ignited,  is  very  difficultly 
soluble  in  this  reagent,  though  columbic  oxide,  containing 
titanic  oxide,  went  quickly  into  solution. 

Double  Fluorides  of  Tantalum.  Columbium,  and  Tita- 
nium, with  Rubidium  and  Ccesium. 

The  potassium  double  fluorides  of  tantalum  and  colum- 
bium have  been  found  of  great  service  in  separating 
these  two  metals.  Marignac  first  showed  that  a  separa- 
tion could  be  effected  through  these  salts,  and  he  also 
demonstrated  that  the  sodium  and  ammonium  salts  were 
inapplicable. 

Of  the  potassium  double  fluorides  of  tantalum  and 
columbium  we  possess  considerable  information.  A 
number  have  been  isolated  and  studied.  The  sodium 
salts  crystallise  so  poorly  that  their  history  is  not  so 
well  known.  It  seemed  probable  that  rubidium  and 
caesium  would  form  double  fluorides  of  definite  crys- 
talline charader  with  these  three  metals.  At  least,  a 
study  of  their  behaviour  might  be  found  instrudive.  Be- 
fore taking  up  their  preparation,  however,  the  simple 
fluorides  of  rubidium  and  caesium  may  be  discussed. 

Rubidium  Fluoride  (RbF). — An  examination  of  the 
literature  on  rubidium  showed  that  its  fluoride  had  not 
been  prepared.  In  order  to  procure  this  rubidium  iodide 
was  dissolved  in  water,  and  moist  silver  oxide  added  to 
precipitate  the  iodine.  The  solution  of  rubidium  hydrate 
resulting  was  filtered  off  and  evaporated  in  porcelain 
dishes.  A  very  appreciable  quantity  of  silver  oxide  was 
held  in  solution  by  the  rubidium  hydroxide,  so  that  it  was 
necessary  to  evaporate  it  almost  to  dryness,  then  to  take 
it  up  in  the  smallest  possible  quantity  of  water,  and  filter. 
This  treatment  may  have  to  be  repeated  two  or  three 
times  before  the  solution  is  perfeftly  colourless.  When 
quite  free  from  silver,  the  concentrated  solution  was  made 
slightly  acid  with  hydrofluoric  acid,  and  evaporated.  If 
hydrofluoric  acid  be  present  it  is  almost  impossible  to 
obtain  crystals,  a  thick  syrup  being  formed  which  defies 


all  attempts  in  this  diredtion.  The  solution  is  therefore 
evaporated  with  water  several  times  until  the  excess  of 
acid  is  expelled.  The  rubidium  fluoride  then  crystallises 
in  long,  transparent  plates.  These  were  drained,  and 
dried  between  filter  paper.  The  salt  was  anhydrous. 
Conversion  into  sulphate  by  evaporating  with  sulphuric 
acid  gave,  from  0*5  grm.  of  the  salt,  0*5236  grm.  ru* 
bidium  sulphate.  This  corresponds,  therefore,  to  the 
formula  RbF. 

Casium  Fluoride. — Caesium  chloride  was  dissolved  in 
water,  and  the  chlorine  precipitated  by  moist  silver 
oxide.  The  solubility  of  the  oxide  of  silver  in  caesium 
hydrate  is  even  greater  than  in  rubidium  hydrate,  there* 
fore  some  difficulty  was  experienced  in  obtaining  a  hy- 
drate free  from  silver.  It  was  finally  accomplished  by 
evaporating  to  dryness  repeatedly,  taking  up  the  caesium 
hydrate  in  a  very  small  quantity  of  water,  and  filtering 
it.  The  pure  hydrate  was  then  neutralised  with  hydro- 
fluoric acid  and  evaporated.  A  thick  syrup  was  obtained 
which  refused  to  crystallise.  Upon  heating  in  an  air 
bath  to  130°  C,  a  crystalline  mass  formed,  but  it  was 
always  in  such  a  sticky  condition,  and  absorbed  mois- 
ture so  rapidly,  that  it  could  not  be  analysed  satis- 
fa(5torily.  This  mass  was  dissolved  in  water  and  added 
to  the  solutions  of  the  metals  in  hydrofluoric  acid. 

Double  Fluoride  of  Columbium  and  Rubidium. — One- 
half  grm.  of  columbic  oxide  was  dissolved  in  hydro- 
fluoric acid  and  the  calculated  quantity  of  rubidium 
fluoride  added.  The  solution  was  evaporated  on  a  water- 
bath  to  expel  the  excess  of  acid.  The  residue  was 
taken  up  in  hot  water  and  allowed  to  crystallise  spon- 
taneously. White  microscopic  plates  separated.  These 
were  filtered  off,  dried  between  filter  paper,  and  analysed. 
Two-tenths  grm.  of  the  dry  salt  gave — 


Found. 

Calculated  for 
2RbF.CbF4. 

Difference. 

CbaOs    .. 
RbF      .. 

0*0670 
0-1048 

0*0673 
0*1049 

—  0*0003 
-O'OOOI 

The  formula  of  the  salt  is  therefore  zRbF.CbFs,  corre- 
sponding to  the  tantalum  salt  usually  obtained  with 
potassium  fluoride. 

The  filtrate  from  this  first  crop  of  crystals  was  slightly 
concentrated,  when  small,  shining,  or  even  iridescent 
crystals,  apparently  plates,  separated.  Upon  standing  a 
short  time,  these  changed  over  into  crystals  like  those 
first  mentioned.  This  salt  is  very  soluble  in  water  con- 
taining hydrofluoric  acid,  and  also  in  pure  water.  It  is 
insoluble  in  alcohol. 

Double  Fluoride  of  Rubidium  and  Tantalum. —Ra- 
bidium  fluoride  in  slight  excess  was  added  to  tantalic 
oxide  dissolved  in  hydrofluoric  acid.  Small  white  needles 
crystallised  out.  An  excess  of  acid  must  be  present, 
otherwise  heat  decomposes  the  double  salt,  giving  a  fine, 
white,  insoluble  compound,  as  is  the  case  with  the  potas- 
sium salt. 

Analyis  of  ^^  grm,  gave 

Cakulated  for 
Found.  2  RbF.TaFi.         Difference. 

Ta205        ..     0*0915  0*0913  -+-0*0002 

RbF  ..     o*o86i  0*0859  -f-o*ooo2 

Double  Fluoride  of  Titanium  and  Rubidium. — The  pre- 
paration of  this  salt  was  conducted  as  described  with  pre- 
ceding salts.  The  crystals  here  were  also  microscopic 
needles.  Some  difficulty  was  at  first  experienced  in  com- 
pletely drying  the  salt,  but  this  was  overcome  by  several 
re-crystallisations  from  pure  water,  when  an  anhydrous 
produ(a  was  obtained.  One-tenth  grm.  of  the  salt  gave, 
on  analysis — 

Calculated  for 
Found.  sRbF.TiF*.         Difference, 

Grm.  Grm. 

TiOj  ..     0*0238  0*0240  —0*0002 

RbF  ..     0*0622  o*o526  —0*0004 


34 


Chemical  Notices  from  Foreign  Sources 


f  Chemical  News, 
\     Jan.  15,  1807. 


Double  Fluorides  of  Tantalum  and  Ctzsium.* — This 
double  salt  was  formed  by  the  addition  of  a  solution  of 
the  caesium  hydrate  in  hydrofluoric  acid  to  a  solution  of 
tantalic  oxide  in  hydrofluoric  acid.  Very  beautiful  white 
needles  separated,  which  were  not  easily  soluble  in  water, 
and  were  not  decomposed  by  re-crystallisation  from  pure 
water.  The  aqueous  solution  may  be  evaporated  on  a 
water-bath  with  perfed  safety,  this  salt  being  apparently 
much  more  stable  than  either  the  potassium  or  rubidium 
salt. 

The  crystals  were  dried  in  the  air,  then  heated  to 
125°  C.  in  an  air-bath.  No  loss  in  weight  was  observed. 
0'25  grm.  gave,  on  analysis — 

Calculated  for 
Found.  isCsF.TaFj.         Difference 

TaaOs      ..     0-02I2  o-oaij  -0*0005 

CsF  ..     ..     0*2232  0-2228  —0*0004 

The  formula  deduced  from  the  analytical  data  varies 
widely  from  that  generally  followed  by  tantalum  double 
fluorides.  Neither  is  it  in  accordance  with  Remsen'slaw 
for  the  double  halides  {Am.  Chem.  y.,  ii.,  291),  though  it 
will  be  observed  that  its  fluorine  content  bears  a  simple 
ratio  to  the  fluorine  in  combination  with  the  tantalum. 

Double  Fluoride  of  Columbium  and  CcEsium,— This 
double  salt  was  formed  in  the  manner  described  for  the 
preparation  of  the  caesium  tantalum  fluoride.  It  is  very 
soluble  in  water  containing  hydrofluoric  acid,  and  in  pure 
water,  from  which  it  crystallises  in  needles.  These,  when 
pure,  are  anhydrous.  Boiling  with  pure  water  does  not 
decompose  the  salt.  Analysis  of  ^^  grm.  gave  the  fol- 
lowing result : — 

Calculated  for 
Found.  7C8F.CbF4.         Difference. 

CbaOs       ..     o*02i6  0*0213  -1-0*0003 

CsF  ..     ..     0*1694  0*1698  -0*0004 

This  salt,  which  appears  to  be  7C8F.CbF5,  is  even 
more  erratic  in  its  constitution  than  the  tantalum  caesium 
compound.  There  is  apparently  no  relation  here  between 
the  fluorine  in  combination  with  the  columbium  and  the 
number  of  molecules  of  caesium  fluoride  present. 

Double  Fluoride  of  Titanium]  and  Ccesium. — This  salt 
separates  in  very  small,  shining  crystals  when  caesium 
fluoride  is  added  to  a  rather  concentrated  solution  of 
titanic  oxide  in  hydrofluoric  acid.  It  is  more  readily 
soluble  in  water  than  the  tantalum  caesium  compound, 
and  is  not  decomposed  by  pure  water.  The  air-dried 
crystals  showed  no  loss  in  weight  after  heating  for  some 
time  at  125°  C.  An  analysis  of  0*25  grm.  gave  the  fol- 
lowing amounts  of  titanic  oxide  and  caesium  fluoride  : — 

Calculated  for 
Found.  4CsF.TiF4.  Difference. 

TiOa        ..     0*0269  0*0271  -f-o*ooo2 

CsF  ..     ..     0*207 1  0*2076  —0*0005 

The  figures  point  to  the  formula  4CsF.TiF4.  This  is 
a  departure  from  the  usual  titanium  double  fluorides,  and 
agrees  with  the  law  laid  down  by  Remsen  for  these  salts. 

When  we  consider  the  atomic  masses  of  tantalum, 
columbium,  and  titanium,  the  first  182,  the  second  94, 
and  the  third  48,  and  also  consider  the  quantities  of 
caesium  fluoride  which  unite  with  a  molecule  of  each  of 
the  metallic  fluorides,  we  find  that  with  tantalum  the 
quantity  (fifteen)  is  nearly  twice  that  with  columbium 
(seven),  and  the  latter  almost  double  that  (four)  uniting 
with  titanium,  just  as  182  is  about  twice  94,  and  94 
nearly  twice  48. 

These  new  caesium  compounds  tend  to  confirm  the  con- 
clusion drawn  by  Wells  and  others  {Amer.  yourn.  Set., 
xlvii.)  from  their  work  on  the  caesium  double  halides.  The 
compounds  investigated  by  these  chemists  show  that  the 
caesium  double  halides  are  not  wholly  conformable  to 
Remsen's  law. 

*  This  and  all  the  other  caesium  double  fluorides  are  being  subjefted, 
at  this  writing,  to  further  study  in  this  laboratory.— E.  F.  Smith. 


The  method  of  analysis  pursued  for  the  determination 
of  these  double  salts  is,  briefly,  as  follows  : — 

The  dry  substance  was  decomposed  in  a  platinum 
crucible  by  a  few  drops  of  concentrated  sulphuric  acid. 
The  hydrofluoric  acid  was  driven  off,  and  the  excess  of 
sulphuric  acid  was  then  expelled  on  a  sand-bath.  The 
temperature  must  be  just  sufficient  to  drive  off  the  acid. 
The  metallic  oxide  was  obtained  from  the  sulphate  by 
long  boiling  with  a  large  quantity  of  water.  It  was  then 
filtered,  washed  about  twenty  times  with  boiling  water, 
ignited,  and  weighed.  The  filtrate  containing  the  alka- 
line sulphate  was  evaporated,  the  excess  of  acid  neutralised 
with  ammonium  carbonate,  and  the  solution  then  evapo- 
rated to  dryness  on  a  water-bath.  A  saturated  solution 
of  ammonium  carbonate  was  added,  and  the  mixture 
evaporated  again  to  dryness.  The  ammonium  salts  were 
expelled  by  careful  heating.  Constant  weight  can  gene- 
rally be  obtained  after  two  or  three  evaporations  with 
ammonium  carbonate.  The  rubidium  sulphate  decrepi- 
tates on  heating,  which  necessitated  great  care  while 
expelling  ammonium  salts,  and  also  rendered  the  method 
proposed  by  Kriass  (heating  in  a  stream  of  ammonia  gas) 
untrustworthy.  The  alkalies  were  then  weighed  as 
normal  sulphate,  and  the  caesium  or  rubidium  content 
calculated.  This  method,  while  slow,  has  been  found 
very  satisfadlory  for  these  rare  alkalies. 
(To  be  continued). 


OBITUARY. 


THE  LATE  DR.  EMIL  DU  BOIS  REYMOND. 

This  most  distinguished  physiologist  concluded  his  fruit- 
ful and  honourable  career  on  December  the  26th.  The 
deceased,  perhaps  our  highest  authority  in  the  wide  and 
interesting  region  of  animal  eledtricity,  was  born  at  Berlin 
on  November  7th,  1818.  As  his  name  indicates,  he  was 
of  French  descent.  He  studied  firstly  theology,  at  the 
University  of  Berlin,  but  soon  turned  his  attention  to  the 
more  congenial  subjedt  of  medicine,  becoming  one  of  the 
most  prominent  pupils  of  Johannes  Miiller,  and  soon 
acquired — as,  indeed,  he  richly  merited — a  world-wide 
celebrity.  In  1851  he  was  eledled  a  member  of  the  Royal 
Prussian  Academy  of  Sciences,  and  in  1867  he  was 
appointed  Perpetual  Secretary,  an  office  which  he  filled 
up  to  his  death.  His  eminence  was  needed  as  a  counter- 
poise to  the  quackery  which  was  and  is  still  seeking  to 
degrade  the  study  of  animal  elei5tricity. 


CHEMICAL    NOTICES   FROM    FOREIGN 
SOURCES. 


Note.— All  degrees  of  temperature  are  Centigrade  unless  otherwise 

expressed. 

Com/lies  Rendus  Hebdomadaires  des  Seances,  de  VAcademie 
des  Sciences.    Vol.  cxxiii.,  No.  26,  December  28,  1896. 

An  interesting  ceremony  took  place  at  the  Institute 
Pasteur  on  the  transfer  of  the  remains  of  the  late  illus- 
trious iavant  to  the  crypt  specially  designed  for  his  recep- 
tion. The  principal  personages  present  were: — M. 
Rambaud,  the  Minister  of  Public  Instruction,  on  behalf  of 
the  Government;  M.  Baudin,  President  of  the  Municipal 
Council,  on  behalf  of  the  city  of  Paris  ;  Sir  Joseph  Lister, 
President  of  the  Royal  Society  of  London,  Foreign  Asso- 
ciate of  the  Academy  of  Sciences,  on  behalf  of  the  Royal 
Society,  and  of  the  Royal  College  of  Surgeons  of  London  ; 
I  Sir  W.  Priestley,  on  behalf  of  the  Universities  of  Edin- 


SBBMICAL  NBVfTSi  I 

Jan.  15, 1897.     ' 


Chemical  Notices  from  Foreign  Sources, 


35 


burgh  and  St.  Andrews;  Sir  Dyce  Duckworth,  on  behalf 
of  the  Royal  College  of  Physicians  of  London  ;  M.  A. 
Cornu,  President  of  the  Academy  of  Sciences  ;  M.  Berge- 
ron, Perpetual  Secretary  of  the  Academy  of  Medicine; 
M.  L.  Passy,  Perpetual  Secretary  of  the  Society  of  Agri- 
culture ;  and  M.  Duclaux,  Dire(5ltor  of  the  Institute 
Pasteur, 

New  Application  of  Radioscopy  to  the  Diagnosis 
of  Maladies  of  the  Thorax. —  Ch.  Bouchard.  —  Details 
of  some  cases  of  no  chemical  interest. 

The  Energy  expended  by  a  Muscle  in  Static  Con- 
tradlion  for  the  Maintenance  of  a  Charge  after 
Respiratory  Exchanges.  —  A.  Chauvereau,  with  the 
collaboration  of  M.  Tissot.  —  The  conclusion  from  the 
authors'  first  series  of  experiments  is,  that  the  quantities 
of  oxygen  absorbed  and  of  carbonic  acid  exhaled — /.  e.,  of 
the  energy  expended  for  the  maintenance  of  a  charge — 
increase  with  the  muscular  contradion,  although  the 
charge  remains  constant.  The  conclusion  from  the  second 
series  of  experiments  is  that  the  oxygen  absorbed  and  the 
carbonic  acid  exhaled — i.  e.,  the  energy  brought  into  play 
for  the  maintenance  of  a  charge — increase  sensibly  in  the 
same  manner  as  such  a  charge. 

New  Radioscopic  FaiAs  concerning  Intrathoracic 
Lesions  —  J.  Bergonie.  —  This  paper  has  no  chemical 
bearings. 

A(5tien  of  Lithium  upon  Carbon  and  certain  Car- 
bides.— M.  Giintz. — This  paper  will  be  inserted  at  some 
length. 

On  the  Chlorine  Carbide,  C3CI3. — Paul  Lemoult. — A 
thermo-chemical  paper. 

A(5\ion  of  the  Carbonic  Acid  of  Waters  upon  Iron. 
— P.  Petit. — The  a(5lion  of  iron  upon  calcium  bicarbonate 
and  upon  carbonic  acid  in  solution  enables  us  to  explain 
the  attack  of  iron  pipes  and  tanks  in  certain  waters.  It 
gives  also  the  mechanism  of  the  purification  of  waters  by 
iron,  and  the  purification  of  syrups  by  iron-filings  in  the 
sugar  manufacture. 

A(5\ion  exerted  upon  Solutions  of  Alkaline  Haloid 
Salts  by  the  Acids  present.  —  A.  Ditte.  —  On  adding 
the  acid  to  the  solution  of  a  neutral  salt,  we  determine  at 
first  a  decrease  of  the  solubility,  but  it  does  not  increase 
without  limit  with  the  quantity  of  acid  added. 

Adtion  of  Phosphorus  upon  Platinum. — A.  Granger. 
— Until  recently  only  platinum  biphosphide  was  known. 
In  1884  two  American  chemists,  Clarke  and  Joslin, 
obtained  a  definite  compound,  PtsPs,  which  dissolves  par- 
tially in  aqua  regia,  leaving  an  insoluble  protophosphide, 
PtP.  The  dissolved  matter  contains  the  biphosphide, 
PtP2.  The  author,  on  repeating  this  experiment,  ob- 
tained a  subphosphide,  PtzP.  At  white  redness  the  mass 
retained  only  4  per  cent  as  phosphorus. 

Adtion  on  Gaseous  Hydrochloric  Acid  upon  the 
Alkaline  Sulphites. — Albert  Colson. — Experiment  shows 
that,  contrary  to  the  opinion  of  some  savants  of  authority, 
sodium  sulphate,  S04Na2,  is  attacked  in  the  cold  by  dry 
HCl.  There  exist  small  series  of  tensions  of  hydrochloric 
acid  gas. 

The  Redudtion  of  Tungsten  by  Coke  in  the  Eledric 
Furnace. — Ed.  Defacqz. — This  memoir  will  be  inserted 
in  full. 

New  Instances  of  Normal  Rotatory  Dispersion  — 
Ph.  A.  Guyeand  P.  A.  Melikion.  —  The  substances  being 
arranged  according  to  the  increasing  values  of  [a]D  we 
remark  that  the  specific  rotatory  dispersions  remain  of 
the  same  order  of  magnitude,  but  they  are  not  propor- 
tional to  the  specific  rotatory  power. 

Transformation  of  the  Sulphonated  Campho- 
phenols  into  Dinitro-orthocresol. — P.  Cazeneuve. 

On  Hexa-diimediol. — R.  Lespieau. 
The   Congelation-point   of  Milk.  —  J.  Winter.  —  A 
controversial  memoir  in  reply  to  MM.  Bordas  and  Genin, 


A  Contribution  to  the  Study  of  the  Borneols  and 
their  Ethers.— J.  Minguin.  —  These  last  papers  are  not 
adapted  for  abstradlion. 

Optical  Analysis  of  Urine  and  Exadt  Determina' 
tions  of  the  Proteids,  Glucosides,  and  Non-ferment- 
ible  Saccharoid  Matters F.Landolph.— (See  p.  25). 


Hevue  Universelle  des  Mines  et  de  la  Metallurgie, 
Series  3,  Vol.  xxxvi.,  No.  i. 
Determination  of  Sulphur  in  tha  Produdls  of 
Siderurgy. — The  methods  for  the  determination  of  sul- 
phur in  siderurgical  produAs  are  classified  under  the 
following  heads : — Procedures  for  the  diredt  oxidation  of 
sulphur  by  the  moist  or  the  dry  method,  followed  by  pre- 
cipitation as  barium  sulphate  either  with  or  without  a 
previous  elimination  of  iron  ;  procedure  for  diredt  chlori- 
nation  by  the  dry  method,  and  precipitation  as  barium 
sulphate ;  procedures  by  hydrogenisation  of  the  sulphur 
in  the  dry  way ;  procedures  of  evolution,  HjS  being 
liberated  by  the  adlion  of  dilute  acids  and  either  oxidised 
to  form  SO3  or  absorbed  by  saline  solutions  ;  mixed  pro- 
cedures. This  lengthy  memoir,  which  extends  to  90  pages, 
requires  the  accompanying  figures. 


MISCELLANEOUS. 


To  Soda  and  Ultramarine  Manufadturers.  —  Rud 
C,  Gittermann  writes  as  follows  from  Odessa,  South 
Russia,  under  date  January  8th,  1897  • — "  I'  '"^y  interest 
your  readers  that  we  are  in  great  want  here  of  manufac- 
tories of  soda  and  ultramarine,  and  that  competent 
English  makers  of  these  articles  are  sure  to  make  their 
fortunes  by  establishing  here.  A  part  of  the  necessary 
capital  could  needs  be  found  here.  If  this  interests  any 
of  your  readers  I  shall  be  happy  to  give  details  on 
enquiry." 

Our  Weights  and  Measures. — A  Pradlical  Treatise 
on  the  Standard  Weights  and  Measures  in  use  in  the 
British  Empire,  with  some  account  of  the  Metric  System, 
by  H.  J.  Chaney,  will  be  published  early  in  January.  It 
will  contain  much  information  derived  from  authorised 
sources,  and  the  writer's  position  as  Superintendent  of 
the  Standards  Department,  Board  of  Trade,  assures  us 
that  the  information  given — information  now  for  the  first 
time  published — will  be  of  pradtical  use  to  local  officers, 
and  especially  to  traders  generally.  It  is  hoped  also  that 
the  book  will  even  be  of  use  to  the  chemist  and  physicist, 
and  that  the  antiquarian  will  find  something  of  interest  in 
its  pages.  The  information  given  with  reference  to 
"  metric  "  weights  and  measures  should  be  of  particular 
use  to  scientific  authorities  and  to  manufadturers. 


MEETINGS    FOR    THE    WEEK. 


Monday,  i8th.— Society  of  Arts,  8.    (Cantor  Lectures).    "  Material 
and  Design  in  Pottery,"  by  Wm.  Burton,  F.C.S. 

Society  of  Chemical  Industry,  8.     "  The  Character 

of  the  London  Water  Supply,"  by  W.J.  Dibdin, 
F.I.C,  F.C.S. 
Tuesday,  igth.— Royal  Institution,  3.     "  Animal  Eleftricity,"  by 

Prof.  A.  D.  Waller,  F.R.S. 
Wednesday,  20th.— Society  of  Arts,  8.    «'  The  Roller  Boat  of  Mens. 

Bazin,"  by  Emile  Gautier. 
Thursday,  21st.— Royal  Institution,  3.  "  Some  Secrets  of  Crystals," 
by  Prof.  H.  A.  Miers,  F.R.S. 

Chemical,  8.  "  Studies  of  the  Properties  of  Highly 

Purified  Substances — I.  The  Influence  of  Mois- 
ture on  the  Produftion  of  Ozone  from  Oxygen, 
and  on  the  Stability  of  Ozone;  II.  The  Be- 
haviour of  Chlorine,  Bromine,  and  Iodine  with 
Mercury;  III.  The  Behaviour QfCt^lorine under 


36 


Meetings  for  the  Week, 


ICHBHICAt.  NBWS. 
Jan.  IS,  1897. 


the  Influence  of  the  Silent  Discharge  of  Elec- 
tricity and  in  Sunlight,"  by  W.  A.  Shenstone. 

•'  "Adlion  of  Diastase  on  Starch,"  Part  III.,  by 

A.  R.  Ling  and  T.  L.  Baker.  "  The  Solution, 
Density,  and  Cupric  Reducing  Power  of  Dex- 

'  trose,  Levulose,  and  Invert-Sugar,"  by  Horace 

}.    Browne,   F.R.S.,  G.  Harris   Morris,  Ph.D., 
.  H.  Millar.    "  Derivatives  of  Maclunn,"  Part 
I.,  by  A.  G.  Perkin. 
Friday,  sjnd. — Royal  Institution,  9.  "  Properties  of  Liquid  Oxygen," 
by  Prof.  Dewar,  F.R.S. 
^^,  Physical,  3.  "An  Exhibition  of   some  Simple  Appa- 

ratus," by  W.  B.  Croft,  M.A.    '•  On  the  Passage  of 
Elediricity  through  Gases,"  by  E.  C.  Baly. 
SaTUKDAY,  23rd. — Royal    Institution,   g.      '*  Negledled   Italian   and 
French  Composers/'  by  Carl  Armbruster. 


Errata. — P.  14,  col.  i,  line  23  from  top,  for  "  Potass.  Nitrate  "  read 
"Potass.  Nitrite."  P.  15,  col.  2,  line  33  from  bottom, /or  "large 
amounts  "  read  "  larger  amounts." 


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SATURDAY  (January  23)  at  Three  o'clock,  CARL  ARM- 
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Professor  DEWAR,  M.A.,  LL.D.,  F.R.S. 

Superintendent  of  the  Laboratory : 

Dr.  Alexander  Scott,  M.A.,  D.Sc. 

This  Laboratory,  which  has  been  founded  by 
Dr.  LuDwiQ  Mono,  F.R.S.,  as  a  Memorial  of  Davy  and 
Faraday  "  for  the  purpose  of  promoting  original  research  in  Pure  and 
Physical  Chemistry,"  will  be  opsn  on  the  i8ih  of  January. 

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and  Potash,  in  large  or  small  quantities,  and  either  solid 
or  in  solution,  at  ROBERT  RUMNEY'S,  Ardwick  Chemical 
WsriES,  Manefaeat:r. 


ACETONE Answering  all  requirements. 

J^GXID  .A-CIETIC— Purest  and  sweet. 

DBOZR-A-CIC—Cryst.  and  powder. 

CITIRIC— Cryst.  made  in  earthenware. 

C^  A  TiTiTr^— From  best  Chinese  galls,  pure. 

S-A-IjICSTIjIO— By  Kolbe's  process. 

1?_A.Isri:snC— For  Pharmacy  and  the  Arts. 

LIQUID  CHLORINE 

(Compressed  in  steel  cylinders). 

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POTASS.  PERMANGANATE-Cryst.,  large  and  small, 

SULPHOCYANIDE    OF    AMMONIUM. 

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Chemical  Mbw8»  ) 
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Manufacture  of  Calcium  Carbide^ 


THE    CHEMICAL     NEWS. 

Vol.  LXXV.,  No.  1939. 
TUNGSTEN    HEXABROMIDE. 

By  HERBERT  A.  SCHAFFER  aud  EDGAR  F,  SMITH. 

The  most  recent  work  upon  tungsten  bromides  is  that  of 
Roscoe  {Ann.  Chem.,  Liebig,  clxii.,  362),  who  endeavoured 
to  prepare  a  hexabromide,  but  obtained  instead  a  penta 
derivative  from  which  the  dibromide  was  subsequently 
made.  By  reference  to  the  literature  bearing  upon  this 
subjeift  it  will  be  noticed  that  bromine,  diluted  with  carbon 
dioxide,  was  made  to  &&.  upon  tungsten  metal  exposed  to 
a  red  heat.  Experimental  evidence  is  at  hand  that 
tpngsten  at  high  temperatures  deoxidises  carbon  dioxide, 
thus  allowing  ample  opportunity  for  the  production  of 
oxybromides,  which,  in  spite  of  the  greatest  care,  are 
sure  to  appear  in  larger  or  smaller  amount.  The  thought 
also  suggested  itself  that  possibly  the  "  red  heat  "  at 
which  the  aftion  was  allowed  to  occur  might  have  been 
detrimental  and  have  indeed  prevented  the  formation  of 
the  hexabromide. 

Hence,  we  determined  to  operate  in  an  atmosphere  of 
nitrogen  and  to  apply  a  very  gentle  heat  to  the  vessel 
containing  the  tungsten.  In  this  connexion  it  may  be 
mentioned  that  the  nitrogen  was  conduced  through  a 
series  of  vessels  charged  with  chromous  acetate,  sulphuric 
acid,  caustic  potash,  and  phosphorus  pentoxide,  respec- 
tively. It  then  entered  an  empty  vessel,  into  which  dry 
bromine  was  dropped  from  a  tap-funnel,  and  after  passing 
through  a  tall  tower,  filled  with  calcium  chloride,  entered 
a  combustion  tube  resting  in  a  Bunsen  furnace.  The 
anterior  portion  of  the  combustion  tube  was  contracfted  at 
intervals,  forming  a  series  of  bulbs,  and  at  its  extremity 
was  connedled  with  an  empty  Woulflf  bottle,  followed  by 
a  calcium  chloride  tower,  and  finally  a  receiver  filled  with 
soda  lime  and  broken  glass.  A  steady  current  of  nitrogen 
was  conduded  through  this  system  for  a  period  of  three 
days.  On  the  fourth  day  bromine  was  introduced.  The 
tungsten  contained  in  the  combustion  tube  was  heated 
very  gently.  In  a  short  time  brown  vapours  appeared. 
These  condensed  to  a  liquid  beyond  the  boat  and  eventu- 
ally passed  into  blue-black  crystalline  masses  that  sepa- 
rated from  the  walls  of  the  tube,  when  perfedly  cold,  with 
a  crackling  sound.  Very  little  heat  was  required  to  melt 
them,  and  they  could  with  care  be  re-sublimed  in  distinft 
blue-black  needles.  The  latter  was  colleded  in  one  of 
the  bulbs  (No.  2)  previously  mentioned.  Other  produdts 
were  observed  and  isolated.  All  were  analysed.  Bulb 
No.  I— that  nearest  the  tungsten  metal— contained  a 
black  velvety  compound,  which  upon  analysis  showed 
the  presence  of  tungsten  dibromide.  Bulb  No,  2  con- 
tained 0*2x03  grm.  of  the  blue-black  crystals,  which 
yielded  0-0577  grm.  of  tungsten,  or  27-43  per  cent,  and 
0"i543grin«  of  bromine,  or  73-53  per  cent.  The  theoretical 
requirements  of  tungsten  hexabromide  are  27  72  per  cent 
tungsten  and  72*28  per  cent  bromine.  The  bromine  per- 
centage  found  is  high.  This  may  be  due  to  traces  of 
bromine  that  had  not  been  driven  out  from  the  crystalline 
deposit,  or  to  adherent  silver  tungstate,  as  some  tungstic 
acid  remained  in  the  solution  from  which  the  silver 
bromide  was  precipitated. 

A  fresh  portion  of  the  blue-black  crystals  was  prepared 
as  before  and  analysed.  The  bromine  determination  was 
unfortunately  lost.  The  determination  of  the  tungsten 
resulted  as  follows: — 0-4351  grm.  of  material  gave  0*1222 
grm.  of  tungsten,  or  2808  per  cent, 

A  third  preparation  was  made.     On  subjedting  0*1775 
grm.  of  it  to  analysis  these  results  were  obtained  : — 
0*0496  grm.  tungsten  or  27-94  per  cent. 
0*1266  grm.  bromine  or  71*32  per  cent. 


37 


Tabulating  the  series,  we  have  :— 

Requijred 

for  hexa- 

Found  Mean,     bromide. 

Per  cent.  Per  cent.  Per  cent.  Per  cent.  Per  cent," 

Tungsten  ..  2743      28-08      2794      27*81      27*72 

Bromine    ..  73*53      71*32         —        72*33      72-2* 

These  figures  give  evidence  that  the  body  analysed. is 
tungsten  hexabromide.  * 

In  analysing  the  third  portion  of  the  blue-black  needles 
the  bromine  was  determined  by  placing  the  material  in  a 
small  Erlenmeyer  bulb,  covering  it  with  nitric  acid  and 
then  distilling.  The  liberated  bromine  was  passed  into 
a  silver  nitrate  solution. 

The  tungsten  hexabromide  prepared  by  us  consists,  as 
already  observed,  of  blue-black  needles.  Moderately 
elevated  temperatures  decompose  the  compound.  It 
gives  off  fumes  when  brought  in  conta<a  with  the  air. 
Water  decomposes  it  with  the  formation  of  a  royal-blue 
coloured  oxide.  Ammonia  water  dissolves  it,  the  solution 
remaining  colourless.  A  vapour  density  determination 
resulted  negatively,  as  decomposition  was  apparent  early 
in  the  experiment.— Frow  the  journal  of  the  American^ 
Chemical  Society,  December,  1896. 


THE   MANUFACTURE  OF  CALCIUM  CARBIDE.* 

By  J.  T.  MOREHEAD  and  G.  de  CHALMOT. 

(Concluded  from  p.  31), 

We  have  now  still  to  consider  a  very  important  question, 
namely,  how  much  coke  and  lime  are  necessary  to  produce 
one  pound  of  carbide.  The  formation  of  carbide  takin" 
place  according  to  the  following  formula, —  - 

CaO  -f  3C  =  CO  4-  CaC2, 
56         36        28  64 

0*563  pound  of  carbon  and  0*875  pound  of  calcium  oxide 
are  theoretically  necessary  to  yield  one  pound  of  carbide. 
The  carbide  of  5  cubic  feet  of  gas  per  pound  contains, 
however,  free  calcium  oxide.  We  therefore  might  expeft 
that  more  calcium  oxide  and  less  carbon  are  used.  In 
prcdlice,  however,  some  calcium  oxide  and  carbon  are 
volatilised  or  burned.  For  a  succession  of  experiments 
we  have  weighed  the  mixture  that  was  put  into  the 
furnace  and  that  which  was  taken  out,  and  analysed 
both.  We  have  experienced  considerable  trouble  in 
weighing  the  red  hot  material  accurately,  and  in  obtaining 
fair  samples.  We  have  therefore  not  been  able  to  observe 
as  to  how  far  the  consumption  of  calcium  oxide  and  of 
carbon  is  influenced  by  the  circumstances  that  alter  the 
quantity  and  quality  of  the  produdt.  We  found,  however, 
that  less  mixture  is  used  if  properly  stoked,  and  if  the  arc 
is  kept  covered.  We  found  also  that  the  losses  of 
carbon  are  always  more  considerable  than  those  of  cal- 
cium  oxide. 

Table  VIII. 
No.  of  ex-  Mixture  into  the  furnace.       .Mixture  out  of  the  furnace, 
periment.      CaO.  C.  CaO.  C. 

Per  cent.  Per  cent.  Per  cent.  Per  cent. 

5470  36-32  57*01  36*89 


2  54*5 1 

3  5623 

4  55  "66 

5  5970 

6  56-65 

7  55  44 

8  5064 

9  52*08 
10  4934 


34-18 
36*46 
36*51 

34*43 
36-09 
36-32 
34-43 
29*39 
3385 


57*29 
57 'oo 

55-47 
58-16 
55-60 

5493 
51-81 
52-09 
41*45 


3336 
35*62 
35*02 

32*94 
3261 
3109 
34*29 
28-90 
28-27 


*  Read  Sept.  3rd  before  the  Springfield  meeting  of  the  A.A.A.S.  by 
one  of  us  (M ).  We  have  made  since  then  several  additions,  so  as  to 
make  the  article  complete  up  to  the  present  time.  From  the  Journal 
of  the  American  Chemical  Society,  April,  1896. 


38 


Derivatives  of  Columbium  and  Tantalum^ 


Number 

Amount  of 

Amount  of 

of  experi- 

CaO put  into 

C  put  into 

ment. 

the  furnace. 

the  furnace 

Lbs. 

Lbs. 

Z 

675 

448 

2 

739 

463 

3 

859 

557 

4 

612 

402 

i 

851 

491 

-.'r** 

go6 

577 

^'7 

1067 

699 

8 

552 

375 

9 

374 

211 

10 

675 

461 

Table  VII. 

CaO  obtained 

C  obtained         Amount 

Amount         ProduAion 

Amount  of 

from  the 

from  the             of  CaO 

of  C               of  clean 

CaO  per  lb. 

furnace. 

furnace.              used. 

used.             carbide. 

of  carbide. 

Lbs. 

Lbs.                  Lbs. 

Lbs.                 Lbs, 

Lbs. 

417 

270                   258 

178                   19s 

1-32 

415 

242                   324 

221                     285 

1-13 

601 

375                 258 

182                     190 

1-36 

415 

262                 197 

140                     190 

i'04 

498 

282                 353 

209                     280 

1-26 

478 

280                 428 

297                375 

I-I4 

420 

238                 647 

461                555 

1-17 

253 

167                 299 

208                223 

1-34 

207 

115                 167 

96                132 

1-27 

244 

134                 431 

327                345 

1-25 

Average     . .     . . 

..       1-228 

(  Chemical  News, 
I     Jan.  22, 1897. 


Amount  of 
C  used  per 
lb.  of  carbide  ■ 

Lb. 

0*91 

078 

0-96 

074 

075 

079 

083 

095 

073 
0-95 
0-837 


The  average  figures  of  Table  VII.  are  rather  high,  for 
where  much  coke  and  lime  have  been  used  this  is  cer- 
tainly partly  due  to  losses  of  material  by  weighing  into 
and  out  of  the  furnace,  and  also  by  insufficient  stoking. 
In  the  King  furnace,  the  under  part  of  which  shuts  her- 
metically tight  and  excludes  draught,  and  which  is  stoked 
mechanically,  the  amount  of  coke  and  lime  necessary  for 
making  one  pound  of  carbide  will  certainly  be  much 
reduced.  In  the  figures  given  in  Table  VII.  we  have  left 
the  outside  coating  out  of  the  calculation.  In  a  plant 
where  the  acetylene  gas  is  generated  at  once  from  the 
carbide  it  would  pay  to  use  this  coating  also  for  making 
gas.  From  Table  VII.  we  see  that  a  very  large  per- 
centage of  the  mixture  is  not  aded  on  by  the  arc.  We 
have,  however,  reduced  this  amount  to  one-third  of  the 
mixture,  and  could  reduce  it  still  more  without  either 
injuring  the  furnace,  the  quantity  and  quality  of  the 
carbide,  and  without  increasing  the  amount  of  carbon  and 
lime  necessary  for  making  one  pound  of  carbide.  In  the 
furnace  used  in  Spray  the  inside  is  square  instead  of 
©diagonal,  and  tlie  dimensions  are  rather  too  large.  We 
thereore  feed  more  material  into  the  furnace  than  is 
necessary. 

Besides  coke  we  have  used  several  other  .carbonaceous 
materials  for  making  carbide.  We  have  used  soft  coal, 
anthracite,  charcoal,  pitch,  tar,  rosin,  and  asphalte,  and 
obtained  in  all  cases  carbide.  Most  of  these  materials 
are  not  of  sufficient  importance  to  be  taken  into  con- 
sideration, and  we  will  only  add  some  words  about  the 
first  three. 

Charcoal,  owing  to  its  small  percentage  of  ash,  yields  a 
very  pure  carbide.  The  only  drawback,  besides  its  price, 
is  that  it  is  so  light  that  the  gases  carry  it  off  to  a  con- 
siderable amount.  It  is  therefore  necessary  to  add  from 
5  to  10  per  cent  more  carbon  to  the  mixture  if  charcoal  is 
used  than  if  coke  is  used. 

We  used  a  soft  coal  which  contained  volatile  matter 
19-84  per  cent  and  ash  1-48.  The  mixture  with  soft  coal 
gave  a  tenific  blaze.  The  carbide  was  covered  with  a 
large  amount  of  very  porous  slag,  in  which  there  was 
much  graphite.  The  average  of  results  of  two  runs  are 
6-41  pounds  per  hoisepower  in  twenty-four  hours  and 
4-33  cubic  feet  of  gas  per  pound,  which  equals  27-75  cubic 
teet  of  gas  per  horse-power  in  twenty-four  hours. 

We  used  anthracite  coal,  which  contained  volatile 
matter  7-95  per  cent  and  ash  4-02  per  cent.  We  made 
two  runs  with  slacked  and  two  with  unslacked  lime. 
There  was  no  appreciable  difference  in  the  use  of  slacked 
and  unslacked  lime.  The  average  result  of  the  four  runs 
was  7-64  pounds  per  horse-power  in  twenty-four  hours 
and  4-03  cubic  feet  of  gas  per  pound,  which  equals  30  79 
cubic  feet  per  horse-power  in  twenty-four  hours.  These 
results  are  much  lower  than  those  obtained  with  coke. 
We  cannot  therefore  recommend  the  use  of  either 
anthracite  or  soft  coal  for  making  carbide.  The  su- 
periority of  coke  and  charcoal  over  anthracite  is  probably 
due  to  the  porosity  of  the  former  materials,  which  must 


facilitate  the  volatilisation  of  the  carbon  in  the  eledtric 
arc,  which   probably    must    precede    the    formation    of 

carbide. 


DERIVATIVES    OF    COLUMBIUM     AND 

TANTALUM.* 

By  MARY  ENGLE  PENNINGTON. 

(Concluded  from  p.  34). 

Products  obtained  on  Heating  the  Oxides  of  Tantalum 

and  Columbium  with  Phosphorus  Pentachloride. 
One-half    grm.   of    columbic  oxide   was    heated   with 
phosphorus  pentachloride,  the  quantity  being  calculated 
from  the  following  equation  : — 

Cb205-h5PCl5  =  2CbCl5-|-5POCl3. 

The  experiment  was  conduced  in  a  sealed  tube  from 
which  all  air  had  been  expelled,  the  temperature  being 
maintained  at  180—200°  C.,  for  seven  hours.  The  re- 
sulting mass  was  moist,  and  a  dirty  green.  The  tube 
was  opened,  conneded  quickly  with  a  small  test-tube, 
and  then  heated  in  an  air-bath.  A  small  quantity  of 
liquid  distilled  into  the  front  part  of  the  tube.  This  was 
a  yellowish  green,  and  gave  with  water  a  white  precipi- 
tate,  apparently  a  hydrated  columbic  oxide. 

At  a  higher  temperature,  about  200°  C,  yellow  vapours 
coUedled  in  the  cool  portion  of  the  tube.  These  settled 
on  the  glass  as  yellow,  oily  drops,  and  on  cooling  solidi- 
fied, long  yellow  needles  being  detected  here  and  there. 
Nearly  all  of  the  substance  in  the  tube,  however,  re- 
mained as  the  greenish  mass,  which  had  become  dry. 
No  change  was  observed  on  heating  above  360°  C.  The 
tube  was  then  wrapped  in  copper  gauze  and  heated  with 
a  Bunsen  lamp.  The  green  substance  swelled  up,  be- 
came white,  iridescent,  and  almost  filled  the  tube.  No 
green  colour  remained.  Analysis  of  this  compound 
showed  it  to  be  columbium  oxychloride,  CbOCl3.  The 
long  yellow  needles  which  had  been  observed  in  the  front 
part  of  the  tube  changed  gradually  on  heating,  and  be- 
came white  and  iridescent  like  the  remainder  of  the 
substance. 

This  behaviour  indicated  the  formation  of  a  penta- 
chloride which  was  then  changed  to  oxychloride  by  the 
small  quantity  of  air  which  entered  the  tube  when  it  was 
connedled  with  the  receiver. 

A  second  tube,  heated  for  eight  hours  at  230—235°  C, 
gave  a  dark  yellow,  semi-fluid  mass.  Great  care  was 
taken  in  this  experiment  to  exclude  all  traces  of  mois- 
ture, and  the  distillation  was  condudled  under  reduced 
pressure.  Phosphorus  oxychloride  in  considerable  quan- 
tity distilled  over,  leaving  in  the  tube  a  yellow  crystalline 

♦  From  the  author's  thesis  presented  to  the  University  of  Penn- 
sylvania for  the  degree  of  Ph.D.,  1895.  From  the  Journ.  Amer. 
Chem.  Soc,  xviii.,  January,  1896. 


Crrmical  News,  ) 
Jan.  22, 1897.      ) 


Derivatives  of  Columbium  and  Tantalum, 


39 


substance,  which,  on  treating  with  water,  decomposed 
with  hissing  and  an  evolution  of  hydrochloric  acid  gas. 
This  compound  was  analysed  according  to  the  method  of 
Marignac  [Ann  Chim.  Phys.,  viii.,  5).  The  ignited  oxide 
weighed  o'5642  grm.  As  only  i  grm.  of  columbic  oxide 
was  used  in  the  experiment,  the  contaminating  substance 
was  sought,  and  was  found  to  be  phosphorus.  Two 
fusions  with  bisulphate  were  necessary  /or  the  extradlion 
of  this  element.  Phosphoric  acid  was  also  found  in  the 
filtrate  from  the  pentoxide. 

The  question  now  arose  regarding  the  position  of  this 
phosphorus.  Is  there  a  compound  formed  containing 
columbium,  phosphorus,  and  chlorine,  or  is  the  phos- 
phorus content  due  to  an  incomplete  expulsion  of  the 
excess  of  phosphorus  pentachloride  ? 

Another  experiment  was  therefore  tried  under  the  fol- 
lowing conditions  :— One-half  grm.  columbium  pentoxide 
was  heated  with  the  calculated  quantity  of  phosphorus 
pentachloride  at  a  temperature  not  exceeding  210°  C.  for 
eight  hours.  The  tube  contained  a  yellow  mass  as  be- 
fore. It  was  placed  in  an  air-bath  and  connedled  with  a 
chlorine  generator,  the  receiver  having  been  previously 
filled  with  chlorine.  At  190°  C.  a  very  volatile  substance 
colledled  in  the  front  part  of  the  receiver.  This  was  a 
lemon  yellow,  and,  when  analysed,  gave  i5"85  per  cent 
columbium  and  6-095  P^r  cent  phosphorus. 

At  190 — 200°  C,  long  yellow  needles  colleded  ;  some 
of  these  were  nearly  half  an  inch  in  length.  Analysis 
gave  27'37  per  cent  columbium  and  32'i9  per  cent 
phosphorus. 

The  substance,  which  did  not  volatilise  at  200°  C, 
was  brownish-yellow,  and  apparently  crystalline.  Analysis 
gave  28*11  per  cent  columbium,  and  1*34  per  cent  phos- 
phorus. 

In  none  of  these  analyses  could  the  chlorine  content  be 
determined,  because  of  the  violence  with  which  water  ads 
upon  the  compounds,  resulting  invariably  in  the  loss  of 
some  hydrochloric  acid. 

It  seemed  probable  that  the  brownish-yellow  residue  in 
the  tube  was  columbium  pentachloride,  enclosing  a  small 
quantity  of  phosphorus  pentachloride.  To  determine  all 
three  elements,  the  following  method  was  used: — 

The  more  volatile  compounds  having  been  removed  by 
distillation  in  a  stream  of  chlorine  gas,  the  residual 
substance  was  quickly  weighed  and  thrown  into  a  dilute 
solution  of  silver  nitrate.  The  precipitate  of  silver 
chloride,  silver  phosphate,  and  hydrated  columbic  oxide 
was  then  filtered,  and  washed  on  the  filter  with  dilute 
nitric  acid.  The  phosphoric  acid  obtained  was  deter- 
mined by  a  magnesium  mixture.  Dilute  ammonium 
hydroxide  was  then  poured  over  the  mixture  of  silver 
chloride  and  columbic  oxide.  It  was  found  that  all  the 
silver  salt  could  not  be  removed  by  this  means.  The 
mixture  was  therefore  transferred  to  a  porcelain  crucible 
and  reduced  in  a  stream  of  hydrogen  gas,  the  metallic 
silver  being  dissolved  out  with  dilute  nitric  acid,  then 
precipitated  as  chloride.  The  columbium  remained  in 
the  form  of  a  violet  compound,  which,  on  ignition  in  the 
air,  went  over  to  pentoxide. 

A  small  quantity  of  phosphorus  was  obtained,  which 
was  calculated  into  pentachloride  and  deduced  from  the 
material  taken. 

Rose  states  that  a  columbate  of  silver,  CbaOs.AgaO, 
is  formed  on  the  addition  of  silver  nitrate  to  a  solution 
of  sodium  columbate.  As,  upon  the  addition  of  water 
to  columbium  pentachloride,  an  almost  perfedl  solution 
is  produced  for  a  few  moments,  the  columbium  in  solu- 
tion may  combine  with  the  silver.  In  such  a  case  the 
silver  chloride  finally  weighed  would  represent  both  the 
silver  in  combination  with  chlorine  and  that  with 
columbium. 

The  analytical  results  are  as  follows: — 
Substance  taken  =  0"89i7  grm. 
Phosphorus  found  =  0*02596  grm. 
This,  as  phosphorus  pentachloride,  requires  0-14829  grm. 
of  chlorine. 


Substance  taken  minus  PCl5  =  07i75  grm. 
Columbium  found  =  0*2485  grm. 
Columbium  required  =  0*2484  grm. 
Chlorine  found  =  0*66509  grm. 

Taking  from  this  0*14829  grm.  of  chlorine,  which  is  in 
combination  with  phosphorus,  we  have  ch]orine  =  o-5i68 
grm. ;  columbium  pentachloride  requires  0*4691  grm.  Cal- 
culating the  quantity  of  silver  which,  according  to  Rose's 
formula,  would  combine  with  the  amount  of  columbium 
oxide  found,  and  deduding  the  chlorine  corresponding 
to  it,  0*4699  grm.  of  chlorine  is  found  to  be  in  combination 
with  the  columbium. 

The  volatile  compounds  mentioned  above  were  re- 
calculated into  phosphorus  pentachloride  and  columbium 
pentachloride.  It  was  found  that,  by  removing  the  phos- 
phorus as  pentachloride,  satisfactory  analyses  for  colum- 
bium pentachloride  were  obtained  from  the  residues. 

Tantalic  oxide  was  also  heated  with  phosphorus  penta- 
chloride, the  same  conditions  being  maintained  as  in  the 
columbium  experiments.  A  yellow  mass  was  formed, 
lighter  in  colour  than  the  columbium  compound,  and  only 
slightly  moist.  The  tube  was  placed  in  an  air-bath,  and 
distilled  at  a  temperature  not  exceeding  245°  C.  This 
distillation  was  conduded  under  reduced  pressure.  A 
small  quantity  of  phosphorus  oxychloride  distilled  over, 
and  in  the  front  part  of  the  tube  a  little  phosphorus  penta- 
chloride colleded.  The  tantalum  compound  remaining 
was  light  yellow,  dry,  and  powdery — apparently  amor- 
phous. It  combined  with  water  with  hissing,  liberating 
tantalic  oxide,  which  contained  no  phosphorus.  A  small 
quantity  of  this  element  was  found  in  the  filtrate  from 
the  oxide.  It  was  calculated  into  phosphorus  penta- 
chloride, and  deducted  from  the  total  quantity. 

Weight  of  substance  taken  =  0*6700  grm. 
Weight  of  tantalum  found  =  0*3389  grm. 
Required  tantalum  =  0*3391  grm. 

Tantalum  pentachloride  is,  therefore,  formed  when 
tantalic  oxide  is  heated  with  phosphorus  as  penta- 
chloride. 

Reduction  of  the  Compounds  of  Columbium  and  Tantalum 
to  Metal, 

Two  experiments  aiming  at  the  preparation  of  colum- 
bium and  tantalum  in  the  metallic  state  have  been  tried 
during  this  research,  and  I  regret  exceedingly  that  lack  of 
time  has  prevented  a  more  careful  study  of  the  reactions 
obtained.  It  is  my  intention  to  go  more  deeply  into  the 
subjedt  than  I  have  been  able  to  do. 

Experiment  i. — An  iron  cylinder,  3  inches  in  diameter, 
having  an  inch  bore,  was  charged  in  the  following  man- 
ner:— First,  a  layer  of  dry  salt,  then  a  layer  of  metallic 
sodium,  above  which  were  placed  about  7  grms.  of 
potassium  tantalum  fluoride,  this  being  followed  by 
another  layer  of  sodium.  The  cylinder  was  then  tightly 
packed  with  dry  salt,  and  a  heavy  lid  screwed  on.  It 
was  then  placed  in  a  wind  furnace,  the  temperature  of 
which  was  comparatively  low.  In  less  than  one  half-hour 
it  was  found  that  the  cylinder  had  melted  down,  and  no 
trace  of  the  charge  could  be  found. 

Experiment  2. — Marignac  obtained  an  alloy  of  colum- 
bium and  aluminum  by  heating  the  potassium  double 
fluoride  with  aluminum  scales  in  a  carbon  crucible.  In 
the  experiment  to  be  described  columbic  oxide  was  used, 
salt  and  cryolite  being  employed  as  a  flux.  The  following 
layers  were  placed  in  a  graphite  crucible: — 

1.  Salt. 

2.  Cryolite. 

3.  Aluminum  clippings. 
/                         4.  Columbic  oxide. 

5.  Aluminum  clippings. 

6.  Cryolite. 

7.  Salt. 

The  proportion  of  these  substances  used  were:  — 


4'o        Determination  of  Atomic  Masses  by  the  Electrolytic  Method. 


I  CHBUICAL  NBWS) 

I     Jan.  22,  1807. 


2  parts  CbaOs. 
10  parts  cryolite. 
15  parts  aluminum. 

X  parts  sodium  chloride. 

The  graphite  lid  was  firmly  luted  on  with  fire-clay,  the 
crucible  was  buried  in  a  wind  furnace  which  was  kept  at 
a  white  heat  for  eight  hours.  At  the  end  of  this  time  it 
was  found  that  the  graphite  crucible  had  been  severely 
attacked.  It  .was  reduced  to  a  shapeless  mass,  but  on 
breaking  a  powdery  substance  was  found,  in  which  were 
contained  many  little  metallic  buttons  varying  in  size 
from  a  large  pea  to  those  of  microscopic  proportions. 
These  were  carefully  picked  out,  and  various  reagents 
tried  upon  them. 

Single  acids  do  not  attack  them.  Aqua  regia  makes  a 
■slight  impression  on  long  heating.  Fusion  with  bisul- 
phate  affords  only  a  partial  decomposition.  The  substance 
is  exceedingly  light;  it  is  dark  grey,  and  does  not  alter  in 
the  air.  A  partial  oxidation  occurs  after  prolonged  heating 
in  the  air.    The  substance  is  not  brittle. 

Summary. 
I.  The  decomposition  of  columbite  is  more  readily  and 
satisfaiflorily  accomplished  by  the  Gibbs  than  by  the  bi- 
sulphate  method.  This  method  is  also  more  valuable  for 
the  preparation  of  large  quantities  of  pure  oxides. 
-  2.  The  qualitative  rea(5lions  of  columbium,  tantalum, 
and  titanium,  when  existing  as  double  fluorides,  are  not 
the  same  as  when  the  metals  exist  as  tantalates,  colum- 
bates,  and  titanates. 

3.  The  adtion  of  the  eledric  current  upon  tantalum  and 
columbium  double  fluorides  gives  a  lower  hydrated  oxide. 
The  precipitation  is  not  complete. 

4.  It  was  hoped  that  in  preparing  the  double  fluorides 
of  columbium,  tantalum,  and  titanium  with  rubidium  and 
caesium,  a  difference  in  solubility  of  the  salts  would  be 
found  which  would  afford  a  better  separation  of  these 
metallic  oxides  under  discussion.  This  hope  has  not  been 
realised. 

5.  Heating  the  oxides  of  columbium  and  tantalum  in 
sealed  and  vacuous  tubes  with  phosphorus  pentachloride 
yields  the  pentachlorides  of  these  metals  and  phosphorus 
oxychloride. 

I  take  pleasure  in  acknowledging  the  kindness  shown, 
and  the  interest  taken  in  the  preceding  work,  by  Dr. 
Edgar  F.  Smith,  of  the  University  of  Pennsylvania,  in 
whose  laboratory  it  was  carried  out. 


DETERMINATION     OF    THE    ATOMIC     MASSES 

OF     SILVER,     MERCURY,     AND     CADMIUM, 

BY    THE     ELECTROLYTIC     METHOD.* 

By  WILLETT  LEPLEY  HARDIN. 

(Continued  from  p.  29). 

First  Series. 
Experiments  on  Silver  Nitrate. 
The  nitrate  of  silver  seems  to  fulfil  the  conditions  neces- 
sary  for  accurate  analyses,  inasmuch  as  it  is  stable  and 
crystallises  in  well-defined  crystals,  which  can  be  fused 
without  decomposition. 

Preparation  of  Silver  Nitrate. 
The  material  used  in  these  experiments  was  prepared 
by  dissolving  pure  silver  in  pure  aqueous  nitric  acid  in  a 
porcelain  dish.    An  excess  of  silver  was  used,  and  after 
complete  saturation  the  solution  was  poured  off  from  the 
metal  into  a  second  dish,  and  evaporated  to  crystallisa- 
tion.   The  perfeftly  transparent  rhombic  plates  of  silver 

♦  Contribution  from  the  John  Harrison  Laboratory  of  Chemistry 
No.  13.  From  the  author's  thesis  presented  to  the  Faculty  of  the 
University  of  Pennsylvania  for  the  degree  of  Ph.D. — From  the 
Journal  of  the  Ameiican  Chemical  Society,  xviii.,  p.  990. 


nitrate  which  separated  were  dissolved  in  pure  water  and 
re-crystallised.  The  crystals  were  then  carefully  dried, 
placed  in  a  platinum  crucible  which  rested  in  a  larger 
platinum  dish,  and  gradually  heated  to  fusion.  After 
cooling,  the  perfedlly  white  opaque  mass  was  broken  up 
and  placed  in  a  ground-glass  stoppered  weighing-tube,  and 
kept  in  a  desiccator  in  a  dark  place. 

Mode  of  Procedure. 
The  platinum  dish  in  which  the  deposit  was  made  was 
carefully  cleaned  with  nitric  acid  and  dried  to  constant 
weight.  It  was  then  placed  in  a  desiccator  over  anhy- 
drous calcium  chloride, and  this,  together  with  the  desic- 
cator  containing  the  tube  of  silver  nitrate,  was  placed  in 
the  balance  room,  where  they  were  allowed  to  remain 
until  their  temperatures  were  the  same  as  that  of  the 
room.  After  weighing  the  platinum  dish,  the  tube  of 
silver  nitrate  was  weighed  and  part  of  the  salt  removed 
to  the  dish,  after  which  the  tube  was  re-weighed.  The 
difference  in  the  two  weighings,  of  course,  represented 
the  weight  of  silver  nitrate  used  in  the  experiment. 
Enough  water  to  dissolve  the  nitrate  was  added  to  the 
dish,  and  then  a  solution  of  potassium  cyanide,  made  by 
dissolving  75  grms.  of  pure  potassium  cyanide  in  i  litre 
of  water,  was  added  until  the  silver  cyanide  first  formed 
was  completely  dissolved.  The  dish  was  then  filled  to 
within  a  quarter  of  an  inch  of  the  top  with  pure  water, 
and  the  solution  eledrolysed  with  a  gradually  increasing 
strength  of  current.  The  following  Table  will  show  the 
strength  of  current  and  the  time  through  which  itadled:— 
Time  of  aiftion.  Strength  of  current. 

2  hours..     ..     N.Dioo=o  015  amperes. 
4    i»      ••     ..     N.Dioo=o-o30        „ 
6     „      ..      ..     N.Dioo  =  oo75         „ 
4     i>      ••      ..     N.Dioo  =  o*i50         „ 

4 N.Dioo  =  o'40o        „ 

By  gradually  increasing  the  strength  of  current  in  this 
way  the   silver  came  down    in  a  dense  white   deposit. 
When  the  deposition  was  complete,  before  interrupting 
the  current,  the  liquid  was  syphoned  from  the  dish,  pure 
water  being  added  at  the  same  time.    This  was  continued 
until  the  cyanide  was  completely  removed.     The  dish 
with  the  deposit  was  washed   several  times  with  boiling 
water,  and  carefully  dried.    It  was  then  placed  in  a  desic- 
cator, and  allowed  to  remain  in  the  balance  room  until 
its  temperature  was  the  same  as  that  of  the  room,  when 
it  was  re-weighed. 
Weight  of  platinum  dish  =  7i'27302  grms. 
Weight  of  silver  nitrate  =  o'siigS  grm. 
Temperature,  22°. 
Barometric  pressure,  770  m.m. 
Weight  of  platinum  dish  +  silver  deposit  =  7i'47io4 

grms. 
Temperature,  22°. 
Barometric  pressure,  760  m.m. 
Density  of  silver  nitrate  =  4'328. 
I)  brass  weights  =  8'5. 

M  platinum  dish  =  21-4. 

t»  metallic  silver  =  10*5. 

It  atmosphere  at  the  time  of   weighing  the 

empty  dish  and  silver  nitrate  =  o*ooi2i2. 
I,  atmosphere   at   the   time  of   weighing  the 

platinum  dish  -f-  silver  deposit  =  o'ooiigS. 
Computing  on  this  basis  we  have  the  following : — 


o'BiigSl  I  + 


0'00I2I2 
T328 


5I2\_ 


71*27302 


1  + 


8-5 
AgN03  in  vacuo. 

0'00I2I2      0*00I2I2  — 


0*31202  ss  weight  of 


21*4 


8-5 


i-l- 


o'Ooiig6     0*001 ig6 


21*4 


8-5       _ 


=  7i*272gi  =  wt.of 


platinum  dish  at  22°  and  760  m.m. 


Crbuical  NbW8,  ) 
Jan.  22, 1897.     ) 


London  Water  Supply. 


41 


7X '47104 -71*27291  =  0*19813  =  weight  of  deposit  at  22° 
and  760  m.m. 


0*i98i3(  I  + 


0*001196     o'onitg6 


)= 


0*19812  =  weight  of 


10*5  8*5 

deposit  in  vacuo. 
Taking  0  =  i6  and  N  =  i4*04,  the  atomic  mass  of  silver 
_  0*I98T2  X  62  04 
(31202  —  19812} 

Ten  observations   on   silver  nitrate  computed   in  the 
foregoing  manner  are  as  follows  : — 


=  107-914. 


Weight 

Weight            Atomic  mass 

of  AgNOa. 

of  Ag. 

of  silver. 

Grms. 

Grm. 

I 

0*31202 

0*19812 

107-914 

2 

0*47832 

0-30370 

107-900 

3 

0*56742 

036030 

107-923 

4 

0-57728 

036655 

107-914 

5 

0-69409 

0-44075 

107-935 

6 

0*86367 

0-54843 

107932 

7 

o-868ir 

0*55130 

107-960 

8 

o*937»6 

059508 

107-924 

9 

1-06170 

0-67412 

107907 

10 

I -19849 

0-76104 

107-932 

Mean    .. 

..      =  107-924 

Maximum 

. .      =  107-960 

Minimum 
Difference 

=  107-900 

=       0*060 

Probable  error    =  +  0-005 

Computing  the  atomic  mass  of  silver  from  the  total 
quantity  of  material  used  and  metal  obtained,  we  have 
107-926. 

(To  be  continued). 


INTERNATIONAL   EXHIBITION    AT    BRUSSELS' 
1897. 

The  rage  for  those  displays  known  as  "  international 
expositions  "  still  continues.  Regardless  of  the  fadl  that 
few  persons  are  benefitted  by  such  gatherings,  except 
railways,  hotel  proprietors,  and  the  small  but  noisy  class 
who  might  be  called  professional  exhibitionists,  most 
States  still  think  it  their  duty  or  their  policy  to  challenge 
the  world  to  an  industrial  competition.  This  season 
Belgium  holds  the  arena.  Its  Exhibition  will  include  a 
sedtion  of  the  Sciences  divided  into  the  following  seven 
classes:  Mathematics  and  astronomy,  physics,  chemistry, 
geology  and  geography,  biology,  anthopology,  and  biblio- 
graphy. Participators  will  have  nothing  to  pay  for  space, 
and  will  have  to  pay  reduced  freights  for  the  conveyance  I 
of  their  exhibits.  | 

We  cannot,  however,  here  refrain  from  reminding  our-  | 
selves  that  any  and  every  advance  or  improvement  in 
any  science  will  not  fail  to  have  become  known  to  the 
world  through  the  scientific  and  technical  press,  so  that  the 
communications  and  exhibits  at  such  gatherings  will  have 
lost  much  of  their  novelty.  We  have  much  pleasure  in 
admitting  that  there  is  here  no  class  for  political  economy, 
which,  whenever  tolrtated,  slides  inevitably  into  party 
politics  with  its  usual  amenities.  The  Belgian  Govern- 
ment proposes  a  series  of  questions,  and  offers  for  the  best 
solutions  prizes  amounting  to  the  modest  aggregate  of 
20,000  francs.  Pamphlets  giving  full  particulars  may  be 
obtained  on  application  to  the  General  Commissariat  of 
the  Government,  at  17,  Rue  de  la  Presse,  Brussels. 

Among  the  problems  to  be  solved  in  the  chemical  class 
must  be  mentioned — 

To  establish  the  constitution  of  camphor  by  means  of 
reaiftions,  both  analytical  and  synthetic,  to  differentiate 
the  optical  isomers  by  means  of  new  chemical  readions. 


A  practical  method  for  transforming  without  great 
expense  atmospheric  nitrogen  into  ammonia. 

A  practical  method  for  the  preparation  of  chlorine  from 
CaCl,  more  economical  than  those  already  in  use. 

A  new  process  for  fixing  the  azo>colourupon  the  various 
textile  fibres  preferable  to  those  hitherto  known. 

The  acid  HI  being  not  easy  to  prepare,  to  find  an 
essentially  pradical  method  for  its  produdlion. 

An  improvement  in  the  procedures  of  fradtibnated  dis* 
tillation. 

Under  biology  there  is  the  demand  for  new  researches 
of  living  beings  by  means  of  the  X  rays. 


LONDON     WATER    SUPPLY. 
Report  on  the  Composition  and  Quality  of  Daily 
Samples    of   the  Water   Supplied  to    London 
FOR  THE  Month  Ending  Decembeb  3ist,  1896. 

By  WILLIAM  CROOKES,  F.R.S., 

and 

PROFESSOR  DEWAR,  F.R.S. 


To  Major-General  A.  De  Courcy  Scott,  R.E., 
Water  Exatniner,  Metropolis  Water  Act,  1871. 

London,  January  iitb,  1897. 
Sir, — We  submit  herewith,  at  the  request  of  the 
Diredors,  the  results  of  our  analyses  of  the  175  samples 
of  water  colledled  by  us  during  the  past  month,  at  the 
several  places  and  on  the  several  days  indicated,  from  the 
mains  of  the  London  Water  Companies  taking  their 
supply  from  the  Thames  and  Lea. 

In  Table  I.  we  have  recorded  the  analyses  in  detail  of 
samples,  one  taken  daily,  from  Dec.  1st  to  Dec.  3i8t 
inclusive.  The  purity  of  the  water,  in  respedl  to  organic 
matter,  has  been  determined  by  the  Oxygen  and  Com- 
bustion processes;  and  the  results  of  our  analyses  by 
these  methods  are  stated  in  Columns  XIV.  to  XVIII. 

We  have  recorded  in  Table  II.  the  tint  of  the  several 
samples  of  water,  as  determined  by  the  colour-meter 
described  in  a  previous  report. 

In  Table  III.  we  have  recorded  the  oxygen  required  to 
oxidise  the  organic  matter  in  all  the  samples  submitted 
to  analysis. 

Of  the  175  samples  examined  all  were  found  to  be  clear, 
bright,  and  well  tiltered. 

Rain  has  fallen  at  Oxford  on  almost  every  day  during 
the  month,  there  being  but  nine  days  when  none  was 
recorded  ;  the  average  tall  for  the  month  of  December  is 
2'io  inches,  the  adual  fall  this  month  has  been  3*13  inches, 
giving  an  excess  of  1-03  inches.  The  deficiency  for  the 
whole  year  amounts  to  3*53  inches,  or  13-3  percent,  on  a 
thirty  years'  average  of  25*72  inches. 

The  details  of  the  raintali  are  shown  in  the  following 
table  :— 

Rain/all  in  Inches  at  Oxford,  Month  by  Month,  during 
the  Year  1896. 


Aaual 

Mean  of 

Difference  from 

fall. 

30  years. 

the 

mean. 

January     .. 

0*63 

2*16 

-  1-53 

— 

February   .. 

0*36 

1-76 

—  1*40 

— 

March 

2*45 

1-50 

— 

+  0-95 

April          .. 

0*58 

1-66 

-1*08 

— 

May    ..     .. 

020 

1-83 

-1*63 

— 

June  ..     .. 

2-42 

2-11 

— 

+  0*031 

July    ..      .. 

1-40 

2-68 

-1*28 

— 

August 

2*01 

2*32 

-0-31 

— 

September. 

.    5-47 

2*43 

— 

+304 

Oaober      . 

2-85 

2*75 

— 

+0*10 

November. 

0-79 

2-42 

-1*63 

— 

December.. 

3-13 

2*10 

— 

+  1*03 

22*29      25*72         -8'86         +5"43 


42 


Examination  of  the  Products  of  Starch  Hydrolysis.      { 


ChbuicalNbws 

Jan.  22,  iSq7. 


Month. 

January 
February 
March  .  • 
April  .. 
May  .. 
June    . . 


July     .. 
August  . 
September 
Odlober 
November  , 
December  , 


Thames, 

unfiltered. 

1824 

1453 
2160 

1833 
I30I 
2081 


Five  Thames- 
derived  Companies 
filtered. 
36 
26 

41 
33 
21 

32 


New  River 
unfiltered. 
1525 
1368 
1938 
150I 
950 
836 


New  River 
filtered. 

31 
29 
27 
17 
25 

35 


River  Lea, 
unfiltered. 

2005 

II09 

1900 

1643 

I216 

1729 


River  Lea 

(East  London), 

filtered. 

24 

28 

29 

34 
73 
28 


177s 

31 

1353 

27 

1600 

36  I 

2731 

21 

1886 

22 

2859 

33 

"33 

17 

361 

3 

537 

5 

1331 

II 

709 

4 

1642 

H 

2691 

19 

671 

4 

742 

14 

2223 

21 

1054 

20 

1178 

6 

4613 

60 

2729 

57 

1825 

15 

36  Mean  of  zst  6  months. 


2453  24  1235  18  1464  14  Mean  of  2nd  6  months. 

2114  27  1294  22  1532  25  Mean  of  12  months. 


It  will  be  seen  that  the  large  excess  of  3*04  inches  in 
September  has  been  mainly  instrumental  in  reducing  a 
deficiency  which  was  becoming  very  serious. 

Our  bafleriological  examinations  of  the  waters  during 
the  month  of  December  give  the  following  results  :— 

Colonies 
per  c.c. 

Thames  water,  unfiltered 4613 

Thames  water,  from  the  clear  water  wells  of 

the  five  Thames-derived  supplies.,    highest  248 

Ditto        ditto              lowest  6 

Ditto        ditto             ..     {13  samples)    mean  60 

New  River  water,  unfiltered 2729 

New  River  water,  from  the  Company's  clear 

water  well 57 

River  Lea  water,  unfiltered       '  ..  1825 

River  Lea  water  from  the  East  London  Com- 
pany's clear  water  well  15 

The  accompanying  table  shows  the  bacterial  variations 
during  the  year. 

These    results    show   that,   taking    the   whole    year's 
badteriological  examinations,   the  high   efficiency  of  the 
filtration  and  the  excellent  charadter  of  the  London  waters 
have  been  uniformly  maintained. 
We  are,  Sir, 

Your  obedient  Servants, 

William  Crookes. 
James  Dewar. 

J  ■ '  ■  ■  ■  ■  -'-•■ — 

PROCEEDINGS    OF    SOCIETIES. 


CHEMICAL  SOCIETY. 
Ordinary  Meeting,  December  ijth,  1896. 

Mr.  A.  G.  Vernon  Harcourt,  President,  in  the  Chair. 

Messrs.  Alexander  Scott,  Frederick  B.  Power,  W.  W. 
Cobb,  and  Claude  M.  Thompson  were  formally  admitted 
Fellows  of  the  Society. 

Certificates  were  read  for  the  first  time  in  favour  of 
Messrs.  Alfred  Cartmell,  Alexandra  Road,  Burton-on- 
Trent ;  William  Diamond,  Pye  Bridge,  Alfreton  ;  William 
Buckland  Edwards,  5,  Garlinge  Road,  Brondesbury,  N.W.; 
Vaughan  Harley,  M.D  ,  25,  Hariey  Street,  W. ;  Fred 
Ibbotson,  B.Sc,  g,  Melbourn  Road,  Spring  Vale,  Shef- 
field ;  David  Smiles  Jerdan,  M.A.,  B.Sc,  68,  Union  Street, 
Greenock ;  Edward  Rosling,  Melbourne,  Chelmsford ; 
Henry  Potter  Stevens,  B.A.,  14,  Lower  Sloane  Street, 


Chelsea,  S.W.,  Harry  Thompson,  Walton  House,  West 
Parade,  Anlaby  Road,  Hull. 

The  certificate  of  the  following  candidate,  recommended 
by  the  Council,  under  Bye-law  I.,  par.  3,  was  also  read  : — 
Jyoti  Bhusan  Bhaduri,  Presidency  College,  Calcutta. 

Of  the  following  papers  those  marked  •  were  read  : — 

•165.  "  On  the  Experimental  Methods  employed  in  the 
Examination  of  the  Products  of  Starch-hydrolysis  by 
Diastase."  By  Horace  T.  Browne,  F.R.S.,  G.  Harris 
Morris,  Ph.D.,  and  J.  H.  Millar. 

The  paper  is  divided  into  the  following  sedlions  :  (i)  the 
determination  of  solids  from  solution-density ;  (2)  deter- 
mination of  specific  rotary  power ;  (3)  the  relation  of 
[o]jto  [o]d;  (4)  determination  of  cupric  reducing  power; 
(5)  limits  of  accuracy  of  the  methods. 

The  authors  state  that  this  account  is  a  preface  to  a 
series  of  papers  dealing  with  the  question  of  starch- 
hydrolysis,  and  is  a  critical  review  of  the  experimental 
methods  which  have  been  employed  by  different  observers 
who  have  approached  this  subjedt.  An  attempt  has  also 
been  made  to  remove  the  misunderstanding  which  still 
exists  as  to  the  relations  of  the  different  systems  of 
notation. 

The  determination  of  the  total  solids  from  the  density 
of  the  solution  by  the  employment  of  the  "divisor" 
method  admits  of  great  accuracy  if  the  solution-densities 
of  the  pure  substance  have  been  previously  determined. 

The  "  divisors "  at  varying  concentration  have  been 
determined  for  cane  sugar,  maltose,  dextrose,  levulose, 
soluble  starch,  and  the  mixed  products  of  starch-hydro- 
lysis of  various  grades,  and  the  results  have  been  plotted 
out  in  the  form  of  curves  whose  equation  is  given  in 
each  case.  The  pure  substances  used  in  construding 
these  curves  were  dried  in  a  vacuum  over  phosphoric 
pentoxide  at  temperatures  from  100°  to  130°. 

For  mixed  starch  hydrolytic  produfls  the  divisor  for 
equal  concentrations  increases  with  the  specific  rotatory 
power,  and  in  such  a  regular  manner  that  when  the  value 
of  R  is  known,  the  divisor  at  any  given  concentration  can 
be  calculated.  From  the  relation  wJiich  this  divisor  bears 
to  the  divisor  of  the  apparent  maltose  present  in  the 
mixed  hydrolytic  produds,  it  is  deducible  that  the  divisor 
for  the  amylin  constituent  is  constant  for  equal  con- 
centrations, even  in  starch  produds  of  very  different 
grades  of  hydrolysis. 

In  the  sedion  on  specific  rotary  power,  the  methods  of 
exadl  determination  are  discussed,  and  the  relations  of  [«];, 
[«]j3'86,  and  [a]D  are  defined  for  substances  of  equal  dis- 
persive power.  As  the  dispersive  power  of  cane  sugar  is 
sensibly  different  from  that  of  dextrose  and  starch  hydro- 
lytic produdls  obtained  by  diastase,  the  factors  for  the 


^'"".'afisgT''}     Action  of  Hydrogen  Peroxide ^  &c.,  on  Cobaltous  Salts, 


43 


conversion  of  [a]j  into  [a]D  are  not  identical  in  these 
cases.  Much  confusion  of  these  relations  has  also  been 
introduced  by  the  unrecognised  fadl  that  [a]j  has  been 
referred  to  two  distinct  rays  in  the  yellow  of  different 
refrangibility. 

The  cupric-redudtion  of  maltose  and  of  the  produdls  of 
starch  transformation  is  constant  only  when  the  con- 
ditions of  experiment  are  identical.  These  are  exadlly 
defined  for  the  authors'  method  of  procedure,  and  the 
reducing  values  are  given  in  tabular  form,  and  are  com- 
pared with  those  of  other  observers. 

*i66.  "  On  the  Specific  Rotation  of  Maltose  and  of 
Soluble  Starch."  By  Horace  T.  Brown,  F.R.S., 
G.  Harris  Morris,  Ph.D.,  and  J.  H.  Millar, 

The  authors'  determinations  of  the  specific  rotatory 
power  of  maltose  at  a  temperature  of  i5'5°  do  not  confirm 
the  statement  of  Meissl  that  the  values  of  [ajo  vary  with 
the  concentrations  between  2  and  20  per  cent,  but  con- 
firm  the  general  statement  of  Ost  that  between  these 
limits  the  specific  rotatory  power  is  constant.  At  higher 
concentrations  than  20  per  cent  the  specific  rotatory 
power  diminishes  slightly. 

The  aftual  results  point  to  a  value  of  [a]D  =  i37'93°, 
which  is  sensibly  greater  than  Ost's  value  of  i37'46''  at 

i5-5°- 

This  discrepancy  is  due  to  the  fadl  that  Ost  employed 
weighed  quantities  of  hydrated  maltose  which  had  been 
dried  in  a  desiccator  over  sulphuric  acid.  The  authors 
find  that  even  after  six  weeks'  drying  in  this  manner, 
hydrated  maltose  contains  0*46  per  cent  more  water  than 
corresponds  to  CizHaaOn'HjO.  If  Ost's  numbers  are 
correded  for  this  they  give  values,  up  to  20  per  cent  con- 
centrations, of  [a]D  =  i38'i2°  at  I5'5°,  a  result  almost 
exadtly  identical  with  that  of  the  authors. 

The  specific  rotatory  power  of  soluble  starch  for  con- 
centrations of  2*5  to  4*5  per  cent  is  at  I5'5°,  [a]D  =  202'o°. 

*i67.  "On  the  Relation  of  the  Specific  Rotatory  and 
Cupric-reducing  Powers  of  the  Products  0}  Starch-hydro- 
lysis by  Diastase."  By  Horace  T.  Brown,  F.R.S. , 
G.  Harris  Morris,  Ph.D.,  and  J.  H.  Millar. 

When  starch  is  transformed  by  diastase,  a  certain 
relation  is  always  found  to  subsist  between  the  cupric 
redudion  and  specific  rotatory  power  of  the  hydrolytic 
produdls.  This  relation  can  be  expressed  in  such  a 
manner  as  to  be  entirely  independent  of  any  view  we  may 
hold  as  to  the  true  nature  of  the  transformation  produds, 
and  it  is  of  so  exadl  a  nature  that  if  one  property  is  known 
the  other  can  be  predidted  with  certainty.  This  is  true 
not  only  for  the  mixed  hydrolytic  produdls,  but  for  any 
fractionated  portion  of  them. 

The  authors  regard  this  faft  as  lying  at  the  root  of  the 
whole  question  of  starch  hydrolysis,  and,  as  it  is  still  not 
admitted  by  most  continental  workers,  they  bring  forward 
a  large  amount  of  fresh  evidence  which  they  regard  as 
absolutely  conclusive. 

The  results  of  the  examination  of  70  different  starch 
transformations  are  given,  some  of  them  mixed  produdls, 
others  fraAionated  produds,  the  specific  rotatory  and 
cupric-reducing  powers  being  given  in  the  various  nota- 
tions in  use.  When  the  experimental  results  are  plotted 
on  a  system  of  redangular  co-ordinates,  the  degrees  of 
specific  rotation  between  soluble  starch  and  maltose  being 
represented  on  the  line  of  ordinates,  and  the  cupric 
reducing  powers  from  soluble  starch  to  maltose  on  the 
line  of  abscissae,  the  values  all  fall  pradtically  on  a  straight 
line  joining  the  points  of  intersedion  of  the  co-ordinates 
corresponding  to  the  optical  and  reducing  properties  of 
soluble  starch  and  of  maltose  respedively. 

The  properties  of  soluble  starch  being  R  =  o,  [o]d  =  202°, 
and  of  maltose,  R=  100  and  [a]D  =  i38'o°,  then  the  rela- 
tion of  specific  rotation  and  cupric  redudlion  for  any 
mixture  or  fradionation  of  the  starch-hydroiytic  produds 
will  be  expressed  by  I.a]D  =  202- 0-64  R. 

The  differences  in  the  calculated  and  observed  values 


for  the  70  cases  of  hydrolysis  examined  are  given,  and  are 
shown  to  be  very  small  indeed. 

The  authors  have  examined  the  published  results  of 
C.  J.  Lintner  and  of  Ost,  both  of  whom  have  denied  the 
existence  of  any  relation  between  [a]D  and  R,  and  find 
that,  when  rightly  interpreted,  they,  for  the  most  part, 
stridtly  conform  to  the  law  of  relation  expressed  above. 

Discussion. 

Dr.  Armstrong,  after  commenting  on  the  value  of  the 
information  brought  under  the  notice  of  the  Society  by 
Mr.  Horace  Brown  and  his  co-workers,  and  on  the 
remarkable  accuracy  with  which  starch  could  now  be 
estimated,  expressed  the  hope  that  it  would  be  possible 
ere  long  to  determine  what  really  took  place  when  starch 
was  hydrolysed;  he  thought  it  was  time  that  we  should 
no  longer  be  content  merely  to  determine  certain  analytical 
fadors;  we  ought  rather  to  seek  for  chemical  methods 
which  would  render  it  possible  to  separate  and  isolate  the 
produdls. 

Mr.  A.  R.  Ling  asked  what  value  the  authors  found 
for  the  cupric  reducing  power  of  maltose  when  Wein's 
method  was  used. 

Dr.  G.  H.  Morris,  in  reply,  said  that  they  found  that 
Wein's  tables  give  results  about  5  per  cent  too  low  when 
the  cupric  redudlion  of  maltose  is  estimated  by  Wein's 
method,  and  the  copper  obtained  calculated  into  maltose 
by  the  table ;  in  other  words,  perfedly  pure  maltose  gives 
R  =  95 — 96  instead  of  100. 

•168.  "  The  Action  of  Hydrogen  Peroxide  and  other 
Oxidising  Agents  on  Cobaltous  Salts  in  presence  of  Alkali 
Bicarbonate."     By  R.  G.  Durrant,  M.A. 

Similar  green  solutions  may  be  obtained  by  adding 
hydrogen  peroxide,  sodium  hypochlorite,  chlorine,  bromine, 
or  ozone  to  cobaltous  salts  in  presence  of  alkali  bicar- 
bonates— or  by  adding  a  cobaltous  salt  to  the  anode  of 
previously  eledlrolysed  potassium  carbonate. 

The  green  colour  is  not  destroyed  by  excess  of  cold 
acetic  acid,  but  is  rendered  rather  bluer  in  tint.  This 
acetic  solution  is  reduced  by  hydrogen  peroxide. 

The  evidence  so  far  obtained  shows  (i)  that  the  cobalt 
is  in  the  "  cobaltic  state."  This  is  proved  by  the 
results  of  three  volumetric  methods — in  which 
standard  sodium  hypochlorite,  hydrogen  peroxide, 
and  sodium  sulphite  are  respedlively  employed— green 
precipitates,  produced  from  the  green  solutions,  gave 
results  showing  that  the  available  oxygen  closely 
approximates  to  that  to  be  expeded  from  cobaltic 
hydrate, 

(2)  That  the  green  colour  of  the  solutions  and  of  the 
precipitates  appears  not  to  be  due  to  a  particular 
alkali,  since  (i.)  identical  tints  were  obtained  with 
the  five  different  alkali  bicarbonates,  (ii.)  potassio- 
cobaltic  nitrite  gives  no  green  colour  with  bicar- 
bonates,  (iii.)  green  precipitates  washed  free  from  all 
alkali,  and  digested  with  cold  weak  acetic  acid,  give 
green  filtrates. 

(3)  That  carbon  dioxide  is  necessary  both  for  the 
formation  and  preservation  of  the  green  colour.  The 
green  colour  of  the  acetic  solution  remains  only  so 
long  as  carbon  dioxide  is  present.  The  green  pre- 
cipitates (free  from  alkali)  retain  carbon  dioxide  so 
long  as  they  remain  green,  and  lose  it  when  they 
become  brown.  It  is,  therefore,  possible  that  the 
green  cobaltic  compound  is  of  the  nature  of  a  car- 
bonate. 

Discussion. 

Several  speakers,  including  the  President,  expressed 
the  view  that  whilst  the  author  had  made  it  clear  that 
the  green  substance  was  a  cobaltic  compound,  further 
proof  was  needed  of  the  suggestion  that  the  salt  formed 
was  a  cobaltic  carbonate. 

Dr.  Rideal  mentioned  that  sodium  peroxide,  as  well  as 
hydrogen  peroxide,  gave  rise  to  the  green  colour,  pro- 
vided that  an  alkali  bicarbonate  was  also  present. 


44 


Ditneikytketohexamethylene, 


i  CBBhlCAL  NbWS, 
\     Jan.  22,  1807. 


Dr.  Armstrong  said  that  he  would  like  to  give  expres- 
sion to  the  opinion  that  the  time  was  come  to  determine 
what  should  be  their  course  of  aiSlion  with  regard  to  the 
publication  of  the  discussions  that  took  place  at  the  meet- 
ings ;  of  late  there  had  been  an  almost  entire  absence 
from  the  Proceedings  of  reports  of  the  remarks  made  in 
the  room,  although  these  had  often  been  of  a  nature 
which  made  it  desirable  that  they  should  be  brought 
under  the  notice  of  the  Fellows  generally.  If  the  secre- 
taries could  not  undertake  the  work,  steps  should  be 
taken  to  procure  a  proper  report.  Personally  he  had  had 
no  difficulty  in  obtaining  reports  during  the  nine  years  in 
which  he  had  charge  of  the  Proceedings,  and  he  did  not 
believe  that  there  would  be  any  difficulty.  Without  such 
reports  the  Proceedings  were  of  little  value. 

Professor  Dijnstan  said  that  Fellows  attending  the 
meetings  were  aware  that  it  was  not  often  that  a  compre- 
hensive discussion  foUov/ed  the  reading  of  an  ordinary 
paper.  All  important  remarks  and  suggestions  made  at 
the  meetings  had  been  recorded  in  the  Proceedings,  and 
although  no  attempt  had  been  made  to  record  everything, 
and  there  might  occasionally  be  room  for  difference  of 
opinion  as  to  what  was  important,  he  was  always  glad 
to  receive  from  speakers,  after  the  meeting,  reports  of 
their  remarks,  which  he  believed  had  been  in  nearly  every 
case  inserted  in  the  Proceedings.  He  had,  however,  not 
thought  it  desirable  to  print  Dr.  Armstrong's  remarks, 
of  the  omission  of  which  Dr.  Armstrong  now  complained, 
made  on  two  recent  occasions,  proposing  to  record  the 
time  occupied  by  readers  of  papers.  The  method  adopted 
by  the  speaker's  predecessor  in  office  in  reporting  dis- 
cussions had  given  rise  to  much  dissatisfaiflion.  If  the 
present  plan  was  not  thought  sufficient,  then  a  shorthand 
report  of  the  discussions  could  be  taken.  As  a  matter  of 
fadt,  however,  the  main  value  of  the  Proceedings  lies  in  its 
beingthemeansof  bringingat  an  earlydateunderthe notice 
of  the  Fellows,  not  merely  remarks  and  suggestions  made 
at  the  meetings,  but  concise  abstradls  of  the  papers  read, 
the  full  publication  of  which  could  not  take  place  in  the 
Journal  until  much  later. 

The  President  remarked  that  if  a  full  report  of  the 
proceedings  were  considered  desirable,  its  preparation 
could  not  be  included  in  the  duties  of  the  Honorary 
Secretaries.  He  was  disposed  to  think,  however,  that  if 
It  were  generally  known  that  the  Secretaries  were  ready 
to  receive  from  speakers  after  the  meeting  a  few  sentences 
giving  the  substance  of  their  remarks,  that  this  would 
meet  the  case  in  nearly  every  instance. 

169.  ••  Electrical  Conductivity  of  Diethylammoniiim 
Chloride  in  Aqueous  Alcohol."  By  James  Walker, 
Ph.D.,  D.Sc,  and  F.  J.  Hambly,  F.I.C. 

The  authors  have  determined  the  condudlivityof  diethyl- 
ammonium  chloride  dissolved  in  pure  water,  and  in  lo'i, 
30*7,  49'2,  72*0, 90"3,  and  99*0  per  cent  alcohol,  by  volume, 
at  dilutions  ranging  from  10  litres  to  8000  litres.  Tables 
and  curves  have  been  constructed,  showing  the  variation 
of  the  molecular  condudlivity  and  the  degree  of  dissocia- 
tion with  varying  dilution  and  varying  proportions  of 
alcohol. 

170.  "  Formation  of  Substituted  Oxytriazoles  from 
Phenylsemicarbazide.'"  By  George  Young,  Ph.D.,  and 
Henry  Annable. 

The  adtion  which  takes  place  when  a  mixture  of  phenyl- 
Bemicarbazide  and  benzaldehyde  is  oxidised,  has  been 
re-investigated,  and  the  views  expressed  by  one  of  the 
authors  in  a  previous  paper  {Trans.,  1895,  Ixvii.,  1063) 
have  been  confirmed.  The  following  aldehydes  yield 
oxytriazoles  by  this  adtion  :  metanitrobenzaldehyde, 
paranitrobenzaldehyde,  metatoluic  aldehyde,  terephthalic 
aldehyde,  cinnamic  aldehyde. 

The  authors  have  failed  to  obtain  oxytriazoles  from 
formaldehyde,  acetaldehyde,  paraldehyde,  isobutyric 
aldehyde. 

-    171.  "  a-Bromocamphorsulpholactone.^'      By   C  Revis 
and  F.  .Stanley  Kipping,  Ph.D.,  D.Sc. 


When  obromocamphor  is  treated  with  anhydrosuK 
phuric  acid,  or  with  chlorosulphonic  acid,  it  is  converted 
into  o-bromocamphorsulphonic  acid  {Trans.,  1893,  Ixiii., 
548).  In  the  course  of  some  experiments  on  the  pre- 
paration of  this  sulphonic  acid,  it  was  found  that  when 
70  per  cent  anhydrosulphuric  acid  is  added  to  a  solution 
of  a-bromocamphor  in  chloroform,  the  produdt  consists, 
to  some  extent,  of  a  crystalline  compound  which  is 
insoluble  in  water. 

This  substance  has  the  composition  CioHi3BrS04 
(found  C  =  38-8,  H  =  4'3,  Br=25i,  S  =  9'7  per  cent.; 
calculated  C  =  39"o,  H  =  4'2,  Br  =  25  8,  S=io'3  per  cent). 
It  appears  to  be  a  bromocamphorsulpholadlone,  and  its 
formation  is  doubtless  due  to  the  oxidation  of  hydrogen 
to  hydroxyl  accompanying  sulphonation,  water  being  then 
eliminated  from  the  hydroxysulphonic  acid  ;  it  is,  probably, 
closely  related  to  the  dibromocamphorsulpholadlone, 
CioHi2Br2S04,  recently  described  (Lapworth  and  Kip- 
ping, Proc,  1896,  xii.,  77),  and  it  lesembles  the  latter  in 
ordinary  properties.  It  crystallises  from  chloroform  and 
ethylic  acetate  in  lustrous  transparent  plates  or  prisms, 
melts  at  about  290°,  and  is  moderately  easily  soluble  in 
boiling  acetic  acid,  chloroform,  and  ethylic  acetate.  It 
is  very  stable,  and  separates,  unchanged,  from  a  solu- 
tion in  nitric  acid  (sp.  gr.  i*4),  even  after  heating  for 
some  time ;  it  seems  not  to  be  attacked  by  cold  potash 
(sp.  gr.  i'3),  and,  even  on  boiling,  it  is  only  slowly  dis- 
solved. 

Dr.  Lapworth  has,  independently,  observed  the  forma- 
tion of  this  ladlone  from  a-bromocamphor  and  anhydro- 
sulphuric acid. 

172.  "  Dimethylketohexamethylene."  By  F.  Stanley 
Kipping,  Ph.D.,  D.Sc. 

In  a  recent  paper  on  camphoric  acid  {Amer.  Chem. 
jfourn.,  1896,  xviii.,  685),  Noyes  describes  the  prepara- 
tion, from  dihydrocampholytic  acid,  of  a  ketone  which 
forms  an  oxime  melting  at  112 — 113°,  and  possesses  an 
odour  similar  to  that  of  camphoroxime.  On  comparing 
the  melting  point  of  this  oxime  with  that  of  the  isomeric 
oxime  of  dimethylketohexamethylene,  he  found  that,  for 
the  latter,  the  author  had  given  the  melting  point  114 — 
115°  (Trans,,  1895,  'xvii.,  349),  whereas  Zelinsky  had 
given  it  as  104 — 105°  (Ber.,  1895,  28,  781).  Noyes  him» 
self  then  prepared  dimethylketohexamethylene  oxime, 
and  found  the  melting  point  to  be  120 — 122". 

The  possible  identity  of  the  two  oximes  in  question 
being  a  matter  of  great  importance — for,  if  their  identity 
were  established,  much  light  would  be  thrown  on  the 
constitution  of  camphor  —  the  author  has  prepared 
dimethylketohexamethylene  by  the  improved  method 
recently  described  (Kipping  and  Edwards,  Proc,  1896, 
xii.,  188),  and  has  made  further  experiments  with  this 
substance. 

The  oxime,  prepared  in  the  usual  manner,  is  at  first 
very  oily,  apparently  from  the  presence  of  unchanged 
ketone,  but  it  soon  becomes  a  semi-solid  crystalline  mass  ; 
when  freed  from  oil  and  re-crystallised  once  or  twice,  it 
melts  quite  sharply  at  about  114°,  but  further  purification 
raises  the  melting  point  to  ii7"5°  (uncorr.),  at  which 
point  it  remains,  even  after  six  successive  crystallisations 
from  different  solvents.  This  melting  point  and  that 
previously  recorded  were  taken  with  an  ordinary  standard 
thermometer ;  observations  made  with  a  short  thermo- 
meter, the  thread  of  which  was  entirely  immersed,  gave 
a  m.  p.  of  Ii8"5 — 119°.  Noyes  does  not  state  whether 
the  m.  p.  120 — 122°,  is  corredled,  nor  how  the  observation 
was  made,  and  the  range  of  2°  would  seem  to  indicate 
that  the  substance  did  not  melt  sharply ;  he  also  leaves 
the  identity  of  his  dimethylketohexamethylene  oxime 
with  the  oxime  of  the  ketone  which  he  obtained  from 
camphor  an  open  question. 

Noyes  suggests  that  the  several  preparations  of  the 
oxime  obtained  respedlively  by  Zelinsky,  by  himself,  and 
by  the  author,  may  be  mixtures  of  stereoisomerides,  and 
the  latter  has  therefore  directed  attention  to  this  possi- 


Cbbmical  News,  I 
Jan.  22, 1807.     I 


Enantiomorphism. 


45 


bility ;  there  are  certainly  indications  of  the  presence  of 
more  than  one  substance  in  the  crude  oxime,  as  a  few 
crystals,  melting  not  sharply  at  about  75°,  have  been 
separated ;  nevertheless,  the  only  crystalline  producft 
which  has  yet  been  isolated  in  any  quantity  is  that  which 
melts  sharply  and  constantly  at  1185 — 119°  (corr). 

This  oxime  crystallises  from  a  mixture  of  chloroform 
and  light  petroleum  in  lustrous  transparent  prisms,  which 
have  been  examined  by  Mr.  Pope.  "  The  crystals  consist 
of  monosymmetric  prisms,  which  show  the  forms  |ioo|) 

{001 1 ,  -jiiol,  and  I  III  I;  the  plane  of  symmetry  is 
the  optic  axial  plane,  and  an  optic  axis  emerges  normally 
to  the  face  (100).  Some  faces  give  good  refle(5tions,  but 
parallel  faces  do  not  give  images  at  180°  to  one  another, 
a  behaviour  which  is  frequently  observed  in  the  case  of 
mixtures."  This  indication  that  the  oxime  may  be  a 
mixture,  in  spite  of  its  constant  melting  point,  must  be 
borne  in  mind,  and  if  confirmed,  the  different  melting 
points  of  the  various  preparations  would  be  accounted  for. 

In  order  to  facilitate  the  identification  of  dimethyl- 
ketohexamethylene,  the  author  has  prepared  the  semi- 
carbazone  ;  this  compound  slowly  separates  in  crystals  on 
warming  the  ketone  with  a  solution  of  semicarbazone 
hydrochloride  and  sodium  acetate  in  dilute  alcohol. 
After  re-crystallisation  it  melts  at  about  196°,  and  further 
treatment  does  not  seem  to  change  its  melting  point.  A 
sample  dried  at  100°  gave  0  =  59-26,  H  =  g'36  percent; 
calculated  for  C9H17N3O,  C  =  59'o2,  H  =  9-29  per  cent. 

Dimethylketohexamethylene  semicarbazone  is  fairly 
soluble  in  cold  chloroform,  but  less  so  in  cold  benzene  and 
ethylic  acetate,  and  crystallises  best  from  methyl  alcohol 
in  the  form  of  small  translucent  well-defined  prisms. 
Heated  slowly  from  about  175°,  and  using  a  short  thermo- 
meter, it  begins  to  sinter  at  about  190°,  and  melts  com- 
pletely at  about  200 — 201°,  effervescing, but  not  darkening; 
the  m.  p.  depends  on  the  size  of  the  crystals  and  on  the 
rate  of  heating.  The  crude  semicarbazone  seemed  to  be 
homogeneous,  and  the  yield  appeared  to  be  good,  but  as, 
on  re-crystallising  the  preparation  from  boiling  acetic 
acid,  most  of  it  suffered  decomposition,  further  experi- 
ments are  necessary  to  prove  that  only  one  semicarba- 
zone exists. 

173.  •'  The  Localisation  of  Deliquescence  in  Chloral 
Hydrate  Crystals."     By  William  Jackson  Pope. 

Chloral  hydrate  crystallises  from  solution  in  large 
monosymmetric  plates,  showing  the  forms  lioo}-,  |oii|> 
and  |iiiK  and  having  the  axial  ratios — 

a:b:  £  =  1-6369  :  i  :  1-3951,  18  =  59°  5' ; 
these  crystals  consists  of  the  same  modification  of  chloral 
hydrate  as  was  obtained  in  previous  experiments  (Pope, 
Proc,  1896,  xii.,  142),  and  described  as  the  biaxial 
modification,  stable  at  ordinary  temperatures.  The 
crystals  deliquesce  in  the  air,  but  in  a  peculiar  manner  ; 
the  forms  \oii\  and  |iii}  rapidly  absorb  water 
vapour,  and  after  a  few  minutes  exposure  become  covered 
with  a  layer  of  solution,  whilst  the  faces  of  the  form 
■|ioo|  remain  perfedly  bright  during  a  considerable 
time.  The  attraftion  for  moisture  exercised  by  the 
pinacoid  \  100  \  is  thus  much  less  than  that  exhibited  by 
the  other  two  forms. 

It  is  consequently  concluded  that  crystal  deliquescence, 
like  crystal  solubility  and  other  properties,  varies  with  the 
direction  in  the  crystal  perpendicular  to  which  its 
intensity  is  measured. 

174.  •'  Enantiomorphism.**  By  William  Jackson 
Pope  and  Frederic  Stanley  Kipping. 

Crystals  of  the  two  enantiomorphous  forms  of  a  sub- 
stance which  exhibits  circular  polarisation  only  in  the 
crystalline  state,  and  in  which  the  circular  polarisation 
is  an  inherent  property  of  the  crystal  struAure,  i.e.,  of  a 
substance  belonging  to  Class  26  (Pope,  Trans.,   1896, 


Ixix.,  971),  should  be  deposited  from  the  optically  inadlive 
solution  in  equal  numbers,  unless  any  disturbing  fadtor  is 
operative  favouring  the  deposition  of  crystals  of  one 
particular  enantiomorphous  form,  as,  for  example,  contadt 
of  the  slightly  supersaturated  solution  with  a  crystal  of 
that  form.  The  truth  of  this  statement  can  be  demon- 
strated from  our  present  knowledge  of  crystal  siruAure, 
and  is  also  evident  from  a  consideration  of  the  recent 
work  of  Landolt  {Ber.,  1896,  xxix.,  2404),  who  showed 
that  the  crystalline  powder  of  sodium  chlorate,  which 
rapidly  separates  from  aqueous  solution,  consists  of 
almost  equal  quantities  of  dextro-  and  laevo-rotatory 
crystals.  The  authors  have  extended  these  observations, 
and  by  taking  a  number  of  different  crops  of  the  large 
crystals  deposited  by  spontaneous  evaporation  of  sodium 
chlorate  solution,  have  ascertained  that  the  average 
numbers  of  dextro-  and  lasvo-crystals  deposited  are  the 
same,  in  absence  of  any  disturbing  fadlor. 

It  seemed  probable  that  if  a  substance  which  is  optically 
adive  in  solution  is  introduced  into  an  aqueous  solution 
of  sodium  chlorate,  the  presence  of  the  former  would 
favour  the  deposition  of  chlorate  crystals  of  one  particular 
enantiomorph,  and  experiments  were  consequently  made 
to  test  this  view.  About  5  per  cent  of  some  substance, 
such  as  dextrose,  mannitol,  and  isodulcitol,  was  dissolved 
in  a  saturated  sodium  chlorate  solution,  and  the  crystals 
of  the  salt  deposited  on  spontaneous  evaporation  exam- 
ined; a  great  preponderance  of  laevo- crystals  separated 
from  the  dextrose  solutions  whilst  m  the  separation  from 
the  isodulcitol  solutions  the  dextro-crystals  were  in 
excess.  The  mannitol  solutions  deposited  rather  more 
laevo  than  dextro-crystals  ;  a  number  of  crops  from  each 
solution  were  colledled,  and  similar  behaviour  was  noticed 
with  each  crop. 

This  seledlive  deposition  would  seem  to  indicate,  as 
would,  indeed,  be  expedted,  from  a  consideration  of  the 
equilibria  possible  in  such  systems,  that  the  solubility  of 
a  dextro-enantiomorph  of  Class  26  (see  above)  in  a  liquid 
containing  an  optically  adive  substance,  differs  from  the 
solubility  of  the  Isevo-enantiomorph  in  the  same  solvent. 
Solubility  determinations,  and  also  determinations  of  the 
rates  of  growth  of  dextro-  and  laevo-crystals  of  sodiuiti 
chlorate  in  optically  adlive  solutions  are  in  progress. 

There  would  seem  to  be  no  d  priori  reason  why  a  sub- 
stance optically  adive  in  solution  only  and  possessing  a 
high  specffic  rotation,  should  exert  more  directive 
influence  on  the  deposition  of  crystals  of  Class  2b  than 
an  optically  adive  substance  of  very  low  specific  rotation, 
the  only  condition  necessarily  favouring  the  deposition  of 
crystals  of  a  particular  enantiomorph  being  that  there 
should  be  an  asymmetric  compound  in  solution.  Using 
methods  such  as  those  indicated  above,  it  might,  there- 
fore, be  possible  to  determine  with  ease  and  rapidity 
whether  certain  substances  which,  although  containing 
asymmetric  carbon  atoms,  are  optically  inadlive  in  solu- 
tion, are  really  asymmetric  compounds,  the  inadtivity  in 
solution  being  due  to  a  compensation  brought  about 
amongst  the  four  different  groups  attaehed  to  one  asym- 
metric atom.  Experiments  respediing  this  point  are  in 
progress. 

Several  cases,  such  as  that  of  camphorsulphonic 
chloride  (Kipping  and  Pope,  Trans.,  1893,  Ixiii.,  560),  are 
known  in  which  equal  quantities  of  optical  antipodes, 
when  crystallised  together,  apparently  do  not  form  a 
racemic  compound.  In  the  light  of  the  foregoing  results 
it  should  be  possible  to  effed  a  partial  separation  of  such 
mixtures,  and  even  of  racemic  compounds,  by  crystallising 
them  from  a  solution  containing  an  optically  adlive  sub- 
stance. Experiments  on  the  separation  of  a  number  of 
racemic  compounds,  and  of  inadlive  mixtures  of 
optical  antipodes  by  methods  based  on  the  above  con- 
siderations, have  been  commenced,  but  the  results  are 
not  yet  sufficiently  conclusive  to  warrant  any  definite 
statements  respedting  them. 

Premising  the  truth  of  the  considerations  stated  above, 
Eakle's  observation  {Zeit,/,  Kryst.,  1896,  xxvi.,  562}  that 


46 


Inorganic  Chemical  Preparations, 


I  Chemical  News, 
(      Jan.  22,  1807. 


a  sodium  periodate  solution  containing  sodium  nitrate 
deposits  more  lasvo-  than  dextro-crystals  of  the  periodate, 
is  quite  incomprehensible. 

Important  Notice  to  Authors  of  Papers. 

The  attention  of  authors  is  diredled  to  the  following 
resolution  of  the  Council. 

••  No  title  shall  be  included  in  the  list  of  titles  of  papers 
to  be  brought  before  a  Meeting  of  the  Society,  unless  the 
paper  and  an  abstradt  of  it  are  in  the  hands  of  the  Secre- 
taries at  least  three  days  before  the  date  of  the  Meeting  ; 
and  no  announcement  of  titles  can  be  made  in  the  Pro- 
ceedings until  the  papers  have  been  received  by  the 
Secretaries." 


NOTICES  OF  BOOKS. 


Register  of  the  Associates  and  Old  Students  of  the  Royal 
College  of  Chemistry,  the  Royal  School  of  Mines,  and 
the  Royal  College  of  Science,  with  Historical  Iniro- 
duAion  and  Biographical  Notices  and  Portraits  ot  Past 
and  Present  Professors.  By  Theodore  G.  Chambers, 
Assoc.  R.S.M.  London  :  Hazell,  Watson,  and  Viney, 
Limited,  1896.     8vo.,  pp.  230. 

The  "Department,"  as  it  is  often  styled  in  brief,  is  not 
by  any  means  sufficiently  known  either  to  its  admirers  or 
to  its  critics.  Its  origin,  its  development,  its  past  his- 
tory, and  its  future  prospedts  are  all  debatable  subjedls. 

The  first  step  towards  the  formation  of  the  establish- 
ment in  question  was  taken  in  1832  by  Sir  Henry  de  la 
Beche.  He  suggested  that  a  collection  should  be  formed 
and  placed  under  the  charge  of  the  Office  of  Works.  The 
institution  thus  founded  was  named  the  Museum  of 
Economic  Geology,  and  was  to  contain  specimens  of 
various  mineral  substances  used  for  roads  or  construct- 
ing public  works  or  buildings,  employed  for  useful  pur- 
poses or  from  which  useful  metals  are  extradted. 

The  building  first  occupied  was  No.  6,  Craig's  Court, 
and  Richard  Phillips,  F.R.S.,  an  eminent  analyst,  was 
appointed  curator.  In  the  laboratory  of  the  Institution 
samples  of  ores,  soils,  and  general  minerals  were  analysed 
at  a  fixed  moderate  charge.  The  establishment  was 
transferred  from  Craig's  Court  to  Jermyn  Street  in  1849, 
and  during  the  following  years  boxes  and  hampers  which 
had  been  lying  for  years  at  Craig's  Court  were  opened 
and  their  contents  classified  and  arranged.  In  1851  the 
formal  opening  of  the  museum  took  place  under  the 
chairmanship  of  Prince  Albert.  In  1854  Huxley  was 
appointed  Professor  of  Natural  History,  vice  E.  Forbes, 
who  had  accepted  the  Chair  of  Natural  History  at  the 
University  of  Edinburgh.  Robert  Hunt  resigned  the 
ledtureship  on  physical  science,  and  Professor  Sir  G.  G. 
Stokes  was  appointed  in  his  stead.  It  must  be  men- 
tioned that  Prof.  Forbes,  F.R.S.,  in  an  introductory 
ledlure  on  the  "  Educational  Uses  of  Museums,"  com- 
mented rather  sarcastically  on  the  apathy  evinced  by  the 
public. 

With  the  inauguration  of  the  "  Department  "  a  change 
ensued.  Whereas  the  Diredtor-General  of  the  Geological 
Survey  and  Diredor  of  the  School  of  Mines  had  hitherto 
reported  diredl  to  a  Minister  of  State,  he  had  now  to  con- 
dua  his  communications  through  Mr.  Henry  Cole,  who, 
in  1854,  was  constituted  Inspedtor.  General  of  Schools 
and  Museums,  his  title  being  afterwards  changed  to 
Secretary  of  the  Department  of  Science  and  Art  and 
Diredtor  of  the  South  Kensington  Museum. 

Lyon  Playfair  resigned  his  appointment  in  1858,  and 
Captain  F.  Donnelly  virtually  obtained  the  executive  con- 
trol of  the  Department  of  Science  and  Art,  a  striking 
feature  being  the  preponderating  military  charadter  of  the 
"  Department."  It  is  sarcastically  said  abroad  that 
Britain  puts  her  army  and  navy  under  the  chief  control 


of  civilians,  and  by  way  of  compensation  hands  over  the 
guidance  of  scientific  education  to  soldiers. 


Inorganic    Chemical    Preparations,      By    Frank    Hall 
Thorp,  Ph.D.,  Instructor  in    Industrial  Chemistry   in 
the   Massachusetts  Institute  of  Technology.      Boston 
(U.S.A.)  and  London  :  Ginn  and  Co.     1896.    Pp.  238. 
This  excellent  work  consists  of  two  main  sedlions; — An 
introdudlory  or  general   portion,  and  a  second  or  experi- 
mental part.     The  former  contains  general  experimental 
diredlions,  and  is  very  judiciously  drawn  up.      We  find  a 
simple    precaution    against    the    tiresome    phenomenon 
known  as  "  creeping."    Dr.  Thorp  recommends  the  edges 
of  the  beaker  and  the  evaporating  dish  to  be  smeared  with 
a  very  thin  layer  of  paraffin  oil  or  vaseline. 

On  hydrometers  the  author  speaks  very  sensibly  and 
emphatically.  For  liquids  heavier  than  water  he  pro- 
nounces Baume's  hydrometer  an  utterly  unscientific 
instrument,  whose  readings  bear  no  very  diredl  relation  to 
true  specific  gravity.  An  investigation  made  a  few  years 
ago  reveals  some  thirty-four  different  scales  none  of 
which  were  corredt;  yet,  in  spite  of  its  demonstrably 
fallacious  character,  it  prevails  largely  in  America  and  on 
the  European  Continent  among  people  who  are  loud  in 
their  condemnation  of  Britain  for  her  tardiness  in  adopting 
the  decimal  system  of  weights  and  measures.  With  us 
it  is  comparatively  little  used  for  liquids  heavier  than 
water. 

An  appendix  shows  the  approximate  atomic  weights 
and  valencies  of  the  elements. 


A  Short  Catechism  of  Chemistry  arranged  for  Beginners, 

being  an  Introduction   to    the  Study  of  the  Science  by 

means    of    Question    and    Answer.       By    Alfred    J. 

Wilcox.       London:    Simpkin,    Marshall,    Hamilton, 

Kent,   and   Co.   (Ltd.).     Middlesbrough:  T.  Woolston. 

Entered  at  Stationers'  Hall.     Pp.  16. 

If  there  is  still  room   for  another  elementary  work  on 

chemistry,  we  may  still  ask  whether  the  form  of  question 

and   answer  possesses    any   decided    recommendations  ? 

The  complaint   is  generally  made  that  the   pupil  learns 

without  understanding. 

In  the  remarks  on  the  word  "  Elements  "  we  are  told 
that  four  of  them  are  gases, — oxygen,  hydrogen,  nitrogen, 
and  chlorine.  Now  if  the  author  does  not  recognise  the 
elementary  charadter  of  argon  and  helium,  he  must  surely 
class  fiuorine  among  the  gases.  It  is  to  be  noted  that  the 
author,  in  his  Preface,  tells  us  that  "his  practice  of  fre- 
quently revising  with  his  class  the  elements  of  the  Science 
has  —  and  especially  before  an  examination  —  invariably 
given  excellent  results."  This  we  do  not  in  the  least 
dispute;  the  catechetical  system  is  likely  to  enable  the 
pupil  to  answer  questions  whether  he  knows  or  not. 


Catalogue  of  Books  by  Meyer  and  Miiller,  51,  Markgrafen- 
Strasse,  Berlin,  W.  ("  Wegweiserdurch  die  Litterature 
der  Chemischen  Technologie  "). 
A  publishers'  trade  catalogue,  containing  not  a  few 
curious  works,  such  as  "  Margarita  Philosophica  "  (1583), 
by  G.  Reisch,  "Pandora,"  the  stone  of  the  Muse,  by 
means  of  which  the  old  philosophi  and  also  Theophrast 
Paracelsus  ennobled  the  imperfeCt  metals  by  the  power 
of  fire  (1588) ;  Helmont  (Opera  omnia,  1648) ;  Guaita, 
St.  de,  "  Essais  de  Sciences  Maudites."  II.  Le  Serpent 
de  la  Genese.  I.  "  Le  Temple  de  Satan":  this  book  is 
of  as  recent  a  date  as  1891 ! 


El  Kamlic  de  Komposizion   ke   esperimenta   el  Aqua   de 

"■  El  Salto  "  durante   el   Imbierno.     By   K.    Newman. 

Santiago  de  Chile.    1896. 

The  author's  conclusions  are: — The  water  of  El  Salto 

undergoes  during  the  winter  a  chemical  and  bacteriological 


Jbbmical  Nbws,  I 
Jan.  22. 1897.     I 


Chemical  Notices  Jrom  Foreign  Sources, 


alteration,  which  causes  it  to  lose  its  quality  and  pota- 
bility. In  June  and  July  there  existed  in  the  water  of 
£1  Salto  a  micro-organism  with  all  the  charaders  of 
B,  Colt  communis. 


CORRESPONDENCE. 


47 


I   THE  CYANIDE  PROCESS  FOR  GOLD 
EXTRACTION. 

To  the  Editor  of  the  Chemical  News. 
Sir, — Kindly  publish  for  me,  as  an  old  subscriber  to 
the  Chemical  News,  the  singular  and  unexpe(5led  faft 
that  aqueous  solutions  of  cyanogen  do  not  exert  the  least 
solvent  adion  on  gold  or  silver.  Of  course  as  the  gas 
decomposes  there  is  a  slight  solvent  adlion,  but  even  this 
is  far  too  slow  and  destrudtive  of  the  gas  to  make  ex- 
traftion  of  gold  a  commercial  success.  This  must  prove 
to  be  interesting  to  cyanide  men. 

I  found  this  fa(5t  while  engaged  as  an  expert  in  the  case 
Government  re  McDollin  and  Co.,  and  published  it  here 
September  17th  last,  in  a  paper  to  our  Pnilosophical 
Society. — I  am,  &c., 

William  Skey, 
Analyst  to  the  Home  Department,  N.Z, 

The  Mines  Department,  Wellington,  N.Z., 
December  5.  i8g6. 


CHEMICAL 


NOTICES    FROM 
SOURCES. 


FOREIGN 


Note.— All  degrees  of  temperature  are  Centigrade  unless  otherwise 

expressed. 

Comptes  Rendus  Hebdomadaires  des  Seances,  deVAcademte 
dcs  Sciences.  Vol.  cxxiv.,  No.  i,  January  4,  1897. 
Position  of  the  Academy  of  Sciences.  —  The  fol- 
lowing changes  have  talcen  place  in  the  membership  of 
the  French  Academy  of  Sciences  : — Deaths  since  January 
1st,  1896 :  Resol,  Tisserand,  Fizeau,  Daubree,  Trecul, 
Reiset,  Sappey.  There  have  been  eledled  :  Bertrand, 
Michel  Levy  (in  the  Sedlion  of  Mineralogy)  ;  Muntz 
(Sedtion  of  Rural  Economy).  Among  the  free  Academi- 
cians, i.e.,  those  not  attached  to  any  especial  sedlion, 
Ronche.  The  following  members  have  still  to  be  re- 
placed :  Resol  (Sedlion  of  Mechanics),  Tisserand  (Astro- 
nomy), Fizeau  (General  Pnysics),  Trecul  (Botany), 
Sappey  (Anatomy  and  Zoology),  and  Tchenichef  (Foreign 
Associate).  The  following  correspondents  are  deceased  : 
Gylden  and  Gould  (Astronomy),  Prestwich  (Mineralogy), 
Kekule  (Chemistry),  Baron  von  Miiller  (Botany),  Marquis 
de  Menabree  (Rural  Economy).  The  correspondents 
eledled  (Sedlion  of  Astronomy)  are  :  Gill,  vice  Cayley, 
deceased;  Van  de  Sande  Bakhuyzen,  vice  Newcomb, 
eledled  Foreign  Associate;  Cnristie,  z»tc«  Hind,  deceased. 
The  following  correspondents  have  still  to  be  replaced  : 
Gylden  and  Gould,  deceased  (Astronomy) ;  Kekule,  de- 
ceased (Chemistry) ;  Prestwich,  deceased  (Mmeralogy)  ; 
Baron  Miiller,  deceased  (Rural  Economy)  ;  Marquis  de 
Menabrea,  deceased  (Rural  Economy) ;  Loven,  deceased 
(Anatomy  and  Zoology). 

Effedls  of  the  Combined  Variation  of  the  Two 
Fadlors  of  the  Expenditure  of  Muscular  Energy  on 
the  Value  of  the  Respiratory  Exchanges. — A,  Chau- 
veau,  with  the  assistance  of  J.  Tissot. —  This  paper  is  too 
little  and  too  doubtfully  chemical  in  its  charadler  to  merit 
insertion  or  abstradlion  in  the  Chemical  News. 

Adlion  exerted  upon  the  Alkaline  Haloid  Salts  by 
the  Bases  wnich  they  contain. — A.  Ditte. — The  alka- 
line bases  exert  upon  the  alkaline  haloid  salts  a  precipi- 
tating adlion  analogous  to  that  produced  by  the 
corresponding  acids. 


Adlion  of  Ammonia  upon  Tellurium  Bichloride.— 
Rene  Metzner.— Ammonia  ads  upon  tellurium  bicnloride 
in  a  manner  which  differs  according  to  the  temperature 
applied.  At  200°  to  250°  the  readlion,  which  is  very 
slow,  is  represented  by — 

3TeCi4  -f  16NH3  =  3Te  -f  i2NH4Cl-f-4N. 
At  0°  the  ammonia  combines  with  tellurium  chloride.  At 
a  lower  temperature  we  may  obtain  combination  of  tellu- 
rium and  nitrogen.  When  the  operation  succeeds  the 
apparatus  contains,  after  the  washing  is  completed,  a 
substance  of  a  fine  lemon-yellow  colour,  of  the  compo- 
sition TeN.  This  nitride  is  friable  and  amorphous.  It 
detonates  with  extreme  violence  if  struck,  producing  a 
black  vapour  of  tellurium  in  an  impalpable  powder.  Tellu- 
rium nitride  is  not  attacked  either  by  water  or  dilute 
nitric  acid.  In  contadl  with  potassia  it  gives  off  all  its 
nitrogen  in  the  state  of  ammonia. 

The  Absorption  of  Hydrogen  Sulphide  by  Liquid 
Sulphur.— H.  Belabon. — Liquid  sulphur  maintained  at 
a  temperature  above  170°,  in  presence  of  sulphuretted 
hydrogen  gas,  absorbs  a  notable  quantity  of  this  gas. 
The  quantity  of  gas  absorbed  is  so  much  the  greater  as 
the  temperature  is  higher,  the  pressure  remaining  the 
same.  In  all  cases  the  gas  escapes  at  the  moment  of  the 
solidification  of  the  sulphur ;  the  gaseous  liberation  is  a 
consequence  of  solidification.  Pure  hydrogen  is  not  ab- 
sorbed by  liquid  sulphur. 

Produdlion  of  Vanilline  by  means  of  Vanillo. 
Carbonic  Acid.— Ch.  Gassmann.— The  author  boils  i  part 
of  this  acid  with  2  parts  of  aniline  until  the  escape  of 
carbonic  acid  has  ceased.  There  is  formed  a  substituted 
benzylidene-aniline,  which  is  separated  from  excess  of 
aniline  by  means  of  a  current  of  steam.  The  vanilline- 
aniline  is  finally  split  up  by  a  brief  ebullition  with  dilute 
sulphuric  acid  at  50  per  cent.  The  vanilline  formed  is 
isolated  by  extradion  with  ether,  from  which  it  easily 
crystallises. 

The  Transformation  of  Eugenol  into  Isoeugenol. 
— Ch.  Gessmann.— Not  adapted  for  useful  abstradlion. 

A  New  Method  for  Determining  Sulphur  in  Iron. 
— W.  Schulte.— In  order  to  evade  the  disadvantages  of 
the  bromine  method  and  of  working  with  barium  sulphate 
the  author  dissolves  the  iron  in  dilute  hydrochloric  acid, 
condudls  the  gases  evolved  through  a  solution  of  cadmium 
acetate  acidulated  with  acetic  acid,  and  transforms  the 
resulting  cadmium  sulphide  in  order  to  bring  it  into  a 
state  capable  of  easy  determination  into  copper  sulphide 
by  the  addition  of  an  acid  solution  of  copper  sulphate. 
The  copper  sulphide  is  ignited  and  weighed  as  copper 
oxide.  One  atom  of  sulphur  yields  exadlly  i  mol.  of 
copper  oxide;  31-98  8=79-14  CuO.  It  is  not  admissible 
to  pass  the  gases  evolved  into  the  copper  solution,  since 
phosphorus  and  arsenic  occasion  separations.  We  pre- 
pare in  the  first  place  three  solutions.  I.  25  grms.  cad- 
mium acetate  (or  5  grms,  cadmium  acetate  -f-  20  grms. 
zinc  acetate)  and  200  c.c.  glacial  acetic  acid  per  litre; 
II.  dilute  hydrochloric  acid  (i-f-2)  ;  III.  80  grms.  copper 
sulphate  and  175  c.c,  concentrated  sulphuric  acid  per 
litre.  The  apparatus  consists  of  a  boiling  flask,  into 
which  are  introduced  10  grms.  comminuted  iron,  a  funnel 
tube  with  a  cock  for  the  introdudlion  of  200  c.c.  hydro- 
chloric acid,  a  bent  glass  tube  as  a  reflux  refrigerator,  and 
a  receiver  with  an  appendix  and  a  second  safety  receiver. 
Into  the  receiver  there  are  introduced  40  to  50  c.c.  of  the 
cadmium  solution.  The  development  of  gases  is  effedled 
in  the  cold,  heat  is  then  applied  with  a  Bunsen  burner  so 
as  to  complete  the  solution  of  10  grms.  iron  in  ninety 
minutes.  Tne  cadmium  compound  in  the  receiver  is  then 
transformed  with  6—7  c.c.  of  the  copper  solution,  the 
copper  sulphide  is  then  filtered  off  and  ignited.  If  it  is 
intended  in  this  manner  to  determine  zinc  and  manganese 
sulphides  in  iron  sulphide,  the  portion  operated  upon 
must  not  exceed  0-15  grm.  For  10  grms.  iron  the  entire 
process  requires  two-and-a-half  hours,— S<«A/  md,  Gisen 


48 


Meetings  for  the  Week. 


(Chemical  Nbws 
(      Jan.  22, 1897. 


MISCELLANEOUS. 

Mica. — Messrs.  Wiggins  and  Sons,  Mica  Merchants, 
have,  after  rebuilding,  returned  to  their  old  address,  102 
and  103,  Minories,  both  of  which  buildings  are  entirely 
devoted  to  their  business. 

Royal  Institution. — On  Saturday,  Jan.  23,  Mr.  Carl 
Armbruster  will  deliver  the  first  of  three  lec5lures  on 
•'  Negledted  Italian  and  French  Composers  "  (with  nume- 
rous vocal  illustrations).  The  Friday  Evening  Meetings 
of  the  members  will  commence  on  Jan.  22,  when  Prof. 
Dewar  will  deliver  a  ledure  on  "  Properties  of  Liquid 
Oxygen."  Prof.  J.  C.  Bose,  Professor  of  Presidency 
College,  Calcutta,  will  deliver  his  discourse  on  "  The 
Polarisation  of  the  Eledric  Ray "  on  Friday  evening, 
Jan,  29th,  and  not  on  Feb.  5th  as  previously  announced. 
The  discourse  on  this  night  will  be  delivered  by  the  Bishop 
of  London,  who  will  take  as  his  subjed  "  The  Picturesque 
in  History." 

Sensitive  Litmus>Paper. — Ronde. — The  strong  alka- 
line cubes  occurring  in  commerce  are  covered  with  twelve 
to  fifteen  times  their  quantity  of  water,  and  allowed  to 
stand  for  one  day.  The  deep  blue  mixture  is  then  treated 
with  sulphuric  acid  until  it  becomes  a  light  red,  and 
heated  on  a  steam-bath  for  fifteen  minutes.  To  the 
liquid,  which  generally  turns  blue  again,  dilute  sulphuric 
acid  is  added  until  the  filter-paper  becomes  of  a  reddish- 
violet  on  immersion.  When  cold  it  is  strained  through  a 
cloth,  and  the  liquid  is  so  adjusted,  by  the  addition  of 
drops  of  dilute  sulphuric  acid  or  traces  of  powdered 
litmus,  that  pieces  of  filter-paper,  if  immersed  and 
quickly  dried,  take  the  desired  red  or  blue  tint.  This 
method  readily  yields  papers  of  a  sensitiveness  i  =  150,000. 
—Pharm.  Zeitung  and  Chem.  Zeitting. 

Royal  Academy  of  Sciences  of  Turin.  —  From  a 
courteous  communication  from  the  Academy  we  learn 
that  from  January  ist,  1897,  to  the  end  of  December, 
1898,  this  prize  will  be  awarded  to  any  scientific  author  or 
inventor,  of  whatever  nationality,  who,  during  the  years 
1895 — 98,  shall,  in  the  judgment  of  the  Royal  Academy 
of  Sciences  of  Turin,  have  made  the  most  important  dis- 
covery or  published  the  most  valuable  work  on  physical 
and  experimental  science.  The  prize  (deducing  income- 
tax  !)  will  be  9600  francs.  Candidates  must  send  in  this 
work  {in  print)  to  the  President  of  the  Academy  within 
the  stated  time.  MSS.  will  be  disregarded.  Unsuccess- 
ful work  will  not  be  returned.  —  Signed,  G.  Corb  (Presi- 
dent) ;  E.  D.  Ondic  (Secretary  of  the  Commission) ; 
Turin,  January  ist,  1897. 


MEETINGS    FOR    THE    WEEK. 

MoNDAV,  25th.— Society  of  Arts,  8.     (Cantor  Leftures).     "Material 

and  Design  in  Pottery,"  by  Wm.  Burton,  F.C.S. 

Tuesday,  26th.— Royal   Institution,  3.     "  Animal   Eleftricity,"   by 

Prof.  A.  D.  Waller,  F.R.S. 

— .  Society  of  Arts,  8.    "  The  Artistic  Treatment   of 

Heraldry,"  by  W.  H.  Si.  John  Hope,  M.A. 

Wednesday,  27th.— Society  of  Arts,  8.     "  Voice  Produftion,"  by 

William  Nicholl. 
Thursday,  28th.— Royal  Institution,  3-  "  Some  Secrets  of  Crystals," 
by  Prof.  H.  A.  Miers,  F.R.S. 
—  Society  of  Arts,  4.30  (at  the  Imperial  Institute). 

"The   Moral   Advancelof  the  Peoples  of  India 
during    the    Reign    of    Queen    Victoria,"    by 
William  Lee-Warner,  M.A.,  C.S.I. 
-^  Society  of  Arts,  8.    *'  The  Mechanical  Produ<5tIon 

of  Cold,"  by  Prof.  James  A.  Ewing,  M.A.,  F.R.S. 
Friday,  29th.— Royal    Institution,  9.      "  The    Polarisation    of    the 
Eleftric    Ray,"    by    Professor   Jagadis    Chunder 
Bose,  M.A..  D.Sc. 
Saturday,  30th.— Royal    Institution,  9.      "  Negledled   Italian    and 
French  Composers,"  by  Carl  Armbruster. 


FOR  SALE.  —  The  Chemical  Gazette, 
Complete  Set  (unbound  and  uncut),  17  volumes  ;  from  Novem- 
ber, 1842,  to  December,  1859.— Address,  "Publisher,"  Chemical 
News  Office,  Boy  Court,  Ludgate  Hill,  London,  E.C. 


Analytical    Chemist    (26)     desires     Post     in 

•^^  Laboratory  or  Work.  Assistant  for  over  two  years  to  leading 
London  Chemist,  to  whom  reference  may  bs  made. — Address, 
'  Assistant,"  Chbmical  News  Office,  Boy  Court,  Ludgate  Hillf 
London,  E.C. 

Chemical  Student,  who  has  been  a  pupil  for 
the  last  year  and  a  half  in  well-known  Agricultural  Labora- 
tory, and  previously  at  the  Royal  College  of  Science,  seeks  employ- 
ment.— Address,  S.,  29,  Park  Hill,  Clapham. 

pOR    SALE.—"  Journal    of   the    Chemical 

■^  Society,"  1877  to  1896,  unbound,  cut,  in  good  condition  ;  also 
about  ICO  Chemical,  &c.,  books.  Particulars  supplied.— Willis,  18, 
Dagmar  Road,  Camberwell. 

\X/'anted,    a    Pupil-Assistant    in    a    London 

'  *  Laboratory.  Applicants  must  have  a  good  knowledge  of 
General  and  Analytical  Chemistry.  Small  salary. — Apply,  "  X.  V.," 
Chemicai.  News  Office,  Boy  Court,  Ludgate  Hill,  London,  E.C. 

WALL- PAPER  STAINER  wants  Direaions 

^  ^  how  to  mix  Colours  and  other  Chemicals  for  the  manufac* 
fafture  of  SANITARY  WALL-PAPERS.  Will  be  paid  after  suc- 
cessful experiment.  Best  machinery  already  provided. — Communi- 
cate with  Moeller  and  Condrup,  78,  Fore  Street,  London,  E.C. 

T   IVERPOOL  COLLEGE  of  CHEMISTRY, 

J— '  Duke  Street.— TO  BE  LET,  ist  February,  1897.  Established 
in  1S48  by  the  late  Dr.  Sheridan  Muspratt — Apply  to  Walton 
Batcheloor,  ij,  Stanley  Street,  Liverpool. 

RED-WOOD    LAKES 

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as  Crimson  Lake,  Cochineal  Red,  Purple  Lake,  &c., 

Supplied  as  a  SPECIALITY  by 

Dr.  BODENSTEIN  and   KAESTNER, 

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(Established  1840), 

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Mr.  J.  G.  LORRAIN,  M.I.E.E.,  M.I.M.E,  M.S.C.I., 

Fellow  of  the  Chartered  Institute  of  Patent  Agents, 
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Chbuical  Nbws,  \ 
Jan.  29, 1897.     t 


Unity  0/  the  Atomic  Weights^ 


49 


THE    CHEMICAL     NEWS 

Vol.  LXXV.,  No.  1940. 


THE    UNITY    OF    THE    ATOMIC    WEIGHTS. 

By  KARL    SEUBERT. 

In  a  Report  by  F,  W.  Kiister,  on  the  Progress  of  Physical 
Chemistry  in  the  year  1895,  which  lately  appeared  in  the 
Zeit.  Anorg.  Chem.,  it  is  mentioned  that  "  all  the  more 
recent  determinations  of  the  atomic  weight  of  hydrogen 
show  in  accordance  that  the  relation  0  :  H  lies  between 
16 :  i'007  and  16 :  1*008  (or,  in  the  old  style,  H  :  O  between 
I :  I5'87  and  i :  I5"88)."  We  read  further  that  this  result, 
which  is  not  novel,  will  scarcely  prevent  the  value 
H :  O  =  I :  i5'96  from  being  still  quietly  employed.  I  cannot 
share  the  apprehension  of  my  colleague,  Kiister.  I  have  at 
once,  after  Morley's  great  work  had  become  known  to  me 
in  its  details,  recognised  the  inadmissibility  of  the  value 
I5*96,  and  have  expressed  this  convidtion  on  the  next 
opportunity.  The  remaining  adherents  of  the  "  old 
style  "  may  probably  think  with  me,  since  what  formerly 
led  us  to  the  assumption  of  the  value  O  =  i5-i6  is  no 
longer  valid,  this  number  no  longer  presenting  the  result 
of  the  most  trustworthy  experimental  determinations  of 
the  atomic  weight  of  oxygen  in  reference  to  the  atomic 
weight  of  hydrogen  taken  as  unity.  This  result  has 
seemed  for  some  time  probable,  but  the  question  was  too 
much  contested  to  admit  of  a  full  decision,  and  a  certain 
reserve  appeared  to  me  the  more  imperative  as  now  and 
then  determinations  spoke  in  favour  of  the  older  values 
15-96  and  16.  At  present  we  may,  however,  admit  that 
Morley's  relation,  O  :  H  =  i5;879:  i,  approaches  so  closely 
to  the  truth  that  it  will  not  in  future  undergo  any  modifi- 
cation of  importance.  The  uncertainty,  in  all  probability, 
amounts  to  not  more  than  a  unit  in  the  second  decimal 
place,  or  about  0'o6  per  cent  of  entire  value.  Hence  the 
atomic  weight  of  oxygen  now  ranks  among  those  most 
accurately  determined,  and  its  possible  error  becomes 
perceptible  only  in  the  higher  values  of  atomic  weights, 
and  even  there  in  decimal  places  which  in  any  case  must 
be  held  doubtful. 

There  is  near  at  hand  an  expedient  to  avoid  the  un- 
pleasantness involved  in  the  uncertainty  and  the  change 
in  the  atomic  weight  of  oxygen  by  fixing  this  value  arbi- 
trarily, and  thus  rendering  it  independent  of  the  issue  of 
stochiometrical  determinations.  This  expedient  must, 
however,  be  used  with  the  utmost  possible  limitation.  I 
should  not  delay  for  a  moment  to  vote  to-day  for  0  =  i6, 
if  the  result  of  the  most  recent  investigations  on  the 
atomic  weight  of  oxygen  evinced  considerable  deviations 
and  uncertainties  which  rendered  a  seledion  among  the 
different  values  impossible  ;  but,  on  the  contrary,  these 
researches,  almost  without  exception,  lead  to  a  value 
derived  from  an  experimental  investigation  condudled  on 
a  large  scale  and  in  an  unexceptional  manner,  and  invest 
it  with  a  degree  of  probability  which  attaches  to  our  best 
determinations  of  atomic  weights.  If,  therefore,  a  number 
must  be  established  for  the  atomic  weight  of  oxgen,  that 
value  has  the  first  claim  which— according  to  our  present 
experience — gives  our  atomic  weights  a  rational  unity,  the 
atomic  weight  of  hydrogen. 

An  advantage  which  has  been  put  forward  in  favour  of 
the  assumption  O  =  16  is,  that  then  a  number  of  atomic 
weights  can  be  reproduced  with  sufficient  accuracy  by 
whole  numbers ;  but  this  plea  is  not  sufficient  to  turn  the 
scale  in  its  favour.  The  new  atomic  weights  are  certainly 
less  convenient  in  this  respedl. 

They  show  that  Front's  hypothesis,  both  in  its  original 
form  and  in  the  modification  proposed  by  Dumas,  is  not 
refuted  by  experiment.    The  atomic  weights  of  the  ele- 


'  ments — if  we  disregard  desultory  exceptions — are  neither 

multiples  of  the  atomic  weights  of  hydrogen  nor  of  0*5 
nor  0-25,  therewith  the  conclusions  attached  to  this  sup- 
posed regularity  become  baseless. 

0=16.  H=i. 

Aluminium      ..     ..        Al  27*11  26-go 

Antimony        ..     ,.         Sb  HQ'Q  iigo 

Arsenic As  75-1  74*5 

Barium Ba  I37*43  I36'40 

Beryllium        ..     ..  Be  g'05  SgS 

Bismuth Bi  208  *g  207*3 

Boron       B  10*94  10*85 

Bromine Br  79*96  79'35 

Cadmium        ....  Cd  ii2*o  iii'i 

Carbon C  12*00  ll'gi 

Calcium Ca  40*01  3g7i 

Caesium Cs  I33'0  132*0 

Cerium Ce  140*3  I3g"2 

Chlorine CI  35*46  35'i9 

Chromium      ..     ,.  Cr  52*14  5i'74 

Cobalt     Co  59*6  59*1 

Copper Cu  63*60  63*12 

Didymium       ..     ..  Di  142*5  141*4 

Erbium E  166*4  165*1 

Fluorine F  19*10  18*96 

Gallium   ..     ..     ,,  Ga  70*1  69*6 

Germanium     ..     .,  Ge  72*5  719 

Gold Au  197*2  195*7 

Hydrogen        ....  H  1*008  I'oo 

Indium In  114*0  113*1 

Iridium Ir  193*0  191*5 

Iron Fe  56*02  55'6o 

Iodine       I  12686  125*90 

Lanthanum     .,      ..  La  I38'3  i37'3 

Lead Pb  20691  205*35 

Lithium Li  7*03  697 

Magnesium    ..     .,  Mg  24*26  24*18 

Manganese     ..     .,  Mn  54  94  54*52 

Mercury Hg  200*3  198*8 

Molybdenum..      ,.  Mo  96*03  95*3i 

Nickel      Ni  58*9  58*4 

Niobium Nb  93*9  93*2 

Nitrogen N  14*04  13  94 

Osmium Os  190*8  189*3 

Oxygen O  i6*oo  15*88 

Palladium        ..      ..  Pd  106*3  105*0 

Phosphorus     ....  P  31*03  30*80 

Platinum Pt  194*8  I93'3 

Potassium       ....  K  3912  38*83 

Rhodium Rh  103*0  102*2 

Rubidium        ..     ..  Rb  85*4  84*8 

Ruthenium      .,     .,  Ru  101*7  100*9 

Scandium       ..     ..  Sc  44*05  43*75 

Selenium Se  7g'07  78*47 

Silver       Ag  I07*g2  107*11 

Silicon Si  28*38  28*16 

Sodium Na  23*05  22*88 

Strontium        ..     ..  Sr  87*62  86*96 

Sulphur S  32*06  31*82 

Tantalum        ..     .,  Ta  182*5  i8ii 

Tellurium        ..      ..  Te  127*5  126-6 

Thallium Tl  204*2  202*7 

Thorium Th  232*5  230*7 

Tin Sn  119*10  118*20 

Titanium Ti  48*1  47*8 

Tungsten        ....  W  184*1  182*7 

Uranium U  23g*4  237*6 

Vanadium       ....  V  51*2  50*8 

Ytterbium       ..     ..  Yb  173*0  171*7 

Yttrium Y  88*g  88*3 

Zinc Za  65*41  64*91 

Zirconium       ..     ..  Zr  90-6  89*g 

If  Kiister  further  remarks  that  •*  the  selection  of  hydro- 
gen as  the  unit  of  the  atomic  weights  has  been  often 
branded  as  illogical,  and  practically  not  to  be  upheld,"  I 


50 


Toxicological  Behaviour  of  Picric  A  cid. 


(Chbmical  News, 
\     Ian.  29, 1897. 


cannot  share  his  opinion.  It  seems  to  me  most  natural 
and  logical  to  refer  the  atomic  weights  to  the  smallest  of 
all — that  of  hydrogen — as  the  unit.  If  this  is  not  feasible 
from  prai^ical  reasons,  another  unit  must  be  seleded 
out  of  the  series  of  the  atomic  weights,  as  it  has  been 
done  in  the  case  of  specific  gravities.  The  unquestionably 
inconvenient  numbers  which  result  on  referring  to 
O  =  I  have  led  to  the  expedient  of  taking  the  atomic 
weight  of  oxygen  =  1600,  and  thus  creating  a  unit  iden- 
tical with  no  known  atomic  weight,  though  it  approximates 
to  that  of  hydrogen.  Per  se,  this  choice  is  illogical,  and 
the  number  16  only  obtains  meaning  with  reference  to 
hydrogen.  It  represents  makeshift,  founded  on  the  idea 
that  the  reference  to  hydrogen  as  unit  would  be  in  prin- 
ciple more  accurate.  Practically  we  have  obtained  such 
a  relation  by  assuming  O  =  i5'879,  for  which  we  may  more 
briefly  substitute  I5'88,  for  in  all  probability  future  re- 
searches will  modify  this  value  so  little  that  the  influence 
of  such  a  correction  will  be  felt  in  most  atomic  weights 
only  in  places  which  are  already  uncertain.  It  is  very 
questionable  whether  the  advantages  held  out  for  the 
calculation  0  =  i6'oo  will  counterbalance  the  advantage 
of  a  really  rational,  logical  unit. — Zeit.  Anorg.  Chem. 


NOTE    ON    THE    DETERMINATION    OF 

EQUIVALENT    OF    SODIUM. 

By  WM.  FRENCH. 

For  the  determination  of  the  equivalent  of  sodium  by 
junior  students  I  have  adopted  the  following  method, 
which  I  find  has  many  advantages  over  the  sodium 
amalgam  method  mentioned  in  most  pradtical  text-books. 


accompanying  sketch  will  explain  the  experimental  part 
of  the  process.  The  tube  b  is  completely  filled  by  the 
stoppered  burette,  A,  with  dilute  alcohol  (of  such  strength 
that  sodium  dissolves  in  it  at  a  gentle  rate).  A  piece  of 
sodium  is  quickly  weighed  and  placed  in  the  small  dry 
flask,  c,  which  is  fitted  on  to  the  cork  connedled  to  a 
water  syphon  aspirator  in  the  usual  way.  Dilute  alcohol 
is  then  run  on  to  the  sodium  from  the  burette,  and  the 
volume  of  water  displaced  after  due  cooling  and  levelling 
in  the  measuring  cylinder,  d,  minus  the  volume  of  alcohol 
run  in  from  the  burette,  gives  the  volume  of  hydrogen 
evolved,  from  which  the  equivalent  of  sodium  can  be 
calculated. 
Grammar  School,  Bury. 


I  have  not  seen  a  notice  of  this  modification  in  any  of 
the  numerous  works  on  praAical  chemistry,  and  assume, 
therefore,  that  it  is  certainly  not  generally  adopted.   The 


THE  TOXICOLOGIGAL   BEHAVIOUR    OF 

PICRIC    ACID    AND     ITS     SALTS,    AND    OF 

CERTAIN    KINDRED     SUBSTANCES. 

By  Dr.  TH.  BOKORNY. 

Free  picric  acid  is  a  powerful  poison  for  algae  ;  in  a 
0*5  per  cent  solution  they  dried  within  fifteen  minutes ;  in 
0*1  and  o'05  per  cent  solutions  within  twenty-four  hours. 
Many  fungi  are  not  quite  so  sensitive  to  picric  acid. 

Free  picric  acid  is  no  powerful  poison  for  fungi.  With 
algae  a  concentration  of  0*05  per  cent  is  sufficient  for 
poisoning,  whilst  fungi  require  one  of  o*i  per  cent. 
Ammonium  picrate  is  for  low  organisms  a  more  powerful 
poison  than  potassium  picrate. 

In  a  solution  of  orthobenzoic  acid  of  0*2  to  o'l  and  0*65 
per  cent  all  life  of  algae  and  low  animals  was  extinguished 
in  five  hours. 

Potassium  nitrobenzoate  in  a  02  per  cent  solution 
destroys  all  animal  and  vegetable  life  within  six  hours. 

According  to  Weyl,  Martins  yellow  or  dinitro-a-naphthol 
is  a  strong  poison  for  dogs,  the  fatal  dose  being  03  grm. 
per  kilo,  living  weight.  Naphthol  yellow  S,  a  sulpho-acid 
of  dinitro-a-naphthol,  is  harmless.  A  comparison  between 
ortho-  and  para-nitrophenol  shows  that  the  para-  com- 
pound is  somewhat  more  poisonous  to  algae  and  infusoria 
than  the  ortho-compound.  It  would  be  interesting  to 
carry  out  a  comparison  between  para-  and  ortho-com- 
pounds in  an  extensive  series  of  organic  compounds. — 
ClumikerZeitung. 


DETERMINATION     OF    BISMUTH. 
By  W.  MUTHMANN  and  F.  MAWROW. 

The  authors  have  shown  some  time  ago  that  hypophos- 
phorous  acid  is  suitable  for  the  determination  of  copper, 
and  especially  for  its  separation  from  cadmium  and  zinc. 
Experiments  with  bismuth  have  now  shown  that  with  suit- 
able precautions  it  may  be  completely  precipitated  as  metal 
by  the  reagent  above  named.  Hence  there  results  a  method 
of  separation  and  determination  which  in  many  cases 
surpasses  in  accuracy  and  expedition  the  methods  hitherto 
known.     We  shall  briefly  describe  it. 

The  solution  of  the  bismuth  salt,  not  too  strongly 
acid,  is  mixed  with  an  excess  of  hypophosphorous  acid, 
and  heated  on  the  water-bath  until  the  supernatant  liquid 
has  become  perfedtly  clear,  and  a  further  addition  of  the 
reagent  heated  to  ebullition  produces  no  further  coloura- 
tion. The  metal  separates  out  in  the  form  of  a  reddish- 
grey  spongy  mass,  which  can  be  easily  filtered  and 
washed.  It  is  colleded  upon  a  weighed  filter  or  in  a 
Gooch  crucible,  washed  with  boiling  water  and  then  with 
absolute  alcohol,  and  dried  at  105°.  The  original  solu- 
tion is  best  used  in  a  state  of  moderate  concentration, 
and  a  few  c.c.  of  hypophosphorous  acid  are  forthwith 
added. 


Chbmical  Mbws,  I 
Jan.  29,  1807.     I 


Method  of  Determining  Manganese  in  Iron  Ores, 


Our  experiments  have  been  carried  out  with  bismuth 
oxychloride  washed  up  in  a  little  water  and  dissolved  by 
the  addition  of  a  few  drops  of  hydrochloric  acid.  The 
liquid  after  filtration  was  tested  each  time  for  bismuth  by 
the  introduction  of  hydrogen  sulphide.  There  only 
appeared  a  faint  brown  colouration  if  heat  had  not  been 
applied  for  a  sufficient  time.  In  four  experiments  there 
were  used  respectively— 

BiOCl.  Obtained.  Bi  per  cent. 

o'ii58  grm.  o'ogae  grm.  79*96 

0*1559    ..  0-1250     „  80-17 

0-I20I     „  0-0963     „  8o-i8 

0-1068    „  00857     ».  80*24 

The  average  percentage  being  8o'i3,  and  the  calculated 
result  8o'i5. 

The  method  is  doubtless  applicable  for  the  separation 
of  bismuth  from  metals  which  are  not  precipitated  from 
their  solutions  by  hypophorous  acid,  especially  from  zinc 
and  cadmium. — Zeit.  Anorg.  Chemie,  xiii.,  p.  207. 


51 


SARNSTROM'S    METHOD    OF    DETERMINING 

MANGANESE     IN     IRON     ORES. 

By  C.  T,  MIXER  and  H.  W.  DUBOIS. 

About  a  year  ago  we  had  occasion  to  use  a  volumetric 
method  which  would  allow  the  determination  of  manga- 
nese in  iron  ores  ranging  in  amounts  up  to  15  per  cent, 
and  give  results  in  half-an-hour  which  would  check  with 
gravimetric  determinations  within  two-tenths  per  cent  for 
ores  as  high  as  15  per  cent,  and  within  a  few  hundredths 
of  a  per  cent  for  ores  under  i  per  cent. 

We  found  in  use  in  a  neighbouring  laboratory  a  method 
which  was  generally  known  as  the  "  Swedish  Method." 
This  method  was  found  to  fulfil  the  above  conditions, 
and  seems  to  have  sufficient  merit  to  be  more  widely 
known. 

The  first  suggestion  upon  which  the  method  is  based 
was  made  by  Guyard,*  although  his  method  of  operating 
it  did  not  give  very  satisfaftory  results. 

The  first  description  of  the  method  in  its  present  practi- 
cable form  was  made  by  C.  G.  Sarnstrom,  in  the  Vern- 
kontorets  Antialer  (Sweden),  1881,  p.  401.! 

The  principle  upon  which  this  method  depends  is  the 
readtioti  which  takes  place  when  a  manganese  compound 
higher  in  oxygen  than  the  manganous  state,  is  dissolved 
in  hydrochloric  acid,  forming  a  higher  chloride,  which  is 
readily  shown  by  the  dark  coloured  solution.  When  this 
solution  is  boiled,  it  rapidly  decolourises,  being  com- 
pletely converted  into  manganous  chloride,  not  easily 
oxidised  by  the  air  while  in  the  acid  solution. 

In  neutral  or  alkaline  solutions  the  manganous  com- 
pound has  a  slight  tendency  to  oxidise  in  contact  with  the 
air,  but  we  have  never  deteded  any  appreciable  oxidation 
under  the  conditions  which  we  follow. 

The  separation  of  the  iron  and  the  manganese  is  effected 
in  such  a  way  that  the  iron  is  precipitated  as  hydroxide, 
and  the  manganese  left  in  the  manganous  condition  in 
solution.  Sodium  carbonate  is  used  to  precipitate  the 
iron  as  hydroxide,  and  no  trouble  is  experienced  in  the 
precipitation  of  the  manganese  as  a  carbonate,  provided 
that  only  a  very  slight  excess  is  employed  beyond  that 
necessary  to  completely  precipitate  the  iron.  It  is  advis- 
able to  add  the  sodium  carbonate  in  the  form  of  a  solu- 


♦  Guyard,  Chem.  News,  viii.,  292;  the  following  references  relate 
to  the  subsequent  modifications  of  the  method ;  Habich,  Ztschr.  Anal 
C/iewt.,  Ill  ,  474  i  Winkler,  Ztschr.  Anal.  Chem.,  iii.,  423;  Morawski 
und  Stingl,  Jottrn.  Pmkt.  Chem.  (N.F.),  xviii.,  96:  Volhard.  Ann 
C/jem.  (Liebig),  cxcviii  ,318. 

t  Also  published  in  Berg  und  Hiittenm.,  Zeitung,  xl  ,  425.  A  review 
of  the  original  article  appears  in  the  Ztschr.  Anal.  Chem.,  xxii.,  &a. 
We  aie  indebted  to  Mr  Hugo  Carlsson,  Chief  Chemist  ot  the  Johnson 
Works  of  Lorain,  Ohio,  for  calling  oar  attention  to  Sarnstrom's 
original  publication  and  for  furnishing  us  a  translation  of  the  same. 


tion,  towards  the  completion  of  the  precipitation  of  the 
iron,  to  avoid  such  an  excess. 

Sarnstrom  employs  sodium  bicarbonate,  which  has  the 
advantage  that  a  greater  amount  of  carbon  dioxide  is 
generated,  preventing  subsequent  oxidation  of  the  man- 
ganous salt  by  the  oxygen  of  the  air.  Manganese  bicar- 
bonate is  formed,  which  is  readily  soluble  in  the  solution 
containing  carbon  dioxide. 

It  is  always  desirable  to  test  the  sodium  carbonate  or 
bicarbonate  for  organic  matter. 

The  results  given  below  show  the  necessity  of  avoiding 
an  excess  of  sodium  carbonate  (the  same  is  true  of  the 
bicarbonate)  in  the  precipitation  of  the  iron.  Aliquot 
portions  of  a  solution  of  manganese  containing  3*i4  per 
cent  manganese  gravimetrically  determined,  gave  only 
261  per  cent  when  treated  with  such  an  excess.  Another 
ore  giving  869  per  cent  under  the  proper  conditions  of 
this  method,  when  treated  with  an  excess  of  sodium  car- 
bonate gave  5-38  per  cent. 

After  the  precipitation  of  the  irpii  in  the  hot  solution, 
the  manganese  being  in  the  manganous  state,  is  oxidised 
by  potassium  permanganate,  according  to  the  following 
formula  : 

3MnO+2KMn04+H20  =  2KOH-t-5MnOa, 
which  is  the  same  reaction  which  takes  place  in  Volhard'a 
method.  As  the  titration  takes  place  direCtly,  without 
filtering,  the  precipitate  of  ferric  hydroxide  is  an  advant- 
age, especially  in  low  manganese  ores,  as  it  serves  to 
collect  the  fine  precipitate  of  manganese  dioxide  and 
causes  it  to  settle  more  rapidly. 

In  ores  very  low  in  iron  it  is  desirable  to  add  ferric 
chloride  in  order  to  obtain  the  requisite  amount  of  the 
iron  precipitate. 

The  Method. — Weigh  half  a  grm.  ore  into  a  No.  o  beaker, 
add  15  c.c.  of  hydrochloric  acid,  i-i  sp.  gr.,  and  boil  until 
the  residue  is  clear.  If  necessary  fuse  the  residue  with 
sodium  carbonate.  Add  a  few  drops  of  nitric  acid  to 
oxidise  any  ferrous  iron  or  organic  matter.  In  magnetic 
ores  more  of  course  will  be  necessary.  It  is  well  to  test 
for  ferrous  iron.  Evaporate  a  short  time  to  expel  any 
nitrous  acid  that  may  have  been  formed.  It  is  advisable 
to  have  a  good  amount  of  free  hydrochloric  acid  present 
to  generate  carbon  dioxide  in  the  precipitation  with  sodium 
carbonate.  The  solution  is  then  washed  into  a  No.  3 
beaker  or  a  flask,  which  is  then  filled  about  two-thirds  full 
with  boiling  distilled  water,  and  solid  sodium  carbonate 
or  bicarbonate  added  until  the  iron  is  completely  precipi- 
tated, which  is  readily  indicated  by  the  characteristic 
spongy  appearance  of  the  precipitated  ferric  hydroxide. 
A  solution  of  the  salt  is  preferable  for  the  final  precipita- 
tion in  order  to  avoid  an  excess. 

The  solution  should  be  about  80°  C.  when  it  is  titrated* 
with  potassium  permanganatedireCtly,withoutfiltering,  and 
with  intervals  of  vigorous  stirring  and  settling  of  the  iron 
and  manganese  precipitates,  until  the  supernatant  liquid 
shows  a  permanent  faint  pink  colour.  The  first  appear- 
ance of  the  pink  colour  must  not  be  taken  as  an  indication 
that  the  oxidation  is  complete,  as  gentle  heating  and 
vigorous  stirring  will  allow  more  potassium  permanganate 
to  be  added  before  the  permanent  pink  appears.! 

Multiplying  the  burette  reading  by  two  represents  the 
equivalent  for  one  grm.,  and  this  multiplied  by  the  per- 
manganate value  in  manganese,  which  is  the  iron  value 
multiplied  by  02946,  gives  the  percentage  of  manganese. 

In  case  of  over-titration,  it  is  practicable  to  titrate  back 
with  a  carefully  standardised  solution  of  manganous 
chloride,  which  is  prepared  by  evaporating  15  c.c.  potas- 
sium permanganate  down  to  3  or  4  c.c,  adding  a  few 
drops  of  hydrochloric  acid  and  boiling  as  long  as  chlorine 
comes  off.  The  solution  should  be  neutralised  with 
sodium  carbonate,  and  diluted  to  lo  c.c,  when  i  c.c.  is 
equal  to  i  c.c.  of  potassium  permanganate. 

*  Which  should  be  done  immediately  after  the  neutralisation,  in 
order  to  avoid  any  opportunity  for  oxidation. 

t  This  is  a  very  important  point  not  only  in  relation  to  this  method, 
but  in  all  methods  where  potassium  permanganate  is  used.         


52 


Metal  Separations  by  means  of  Hydrochloric  A  cid  Gas, 


;  Chbhical  Nbws, 

Jan.  29,  1897. 


(Ford's) 
Per  cent. 
5298 


44'3 


Sarnstrom  states  that  the  method  is  reliable  for  high 
manganese  ores  and  ferro-manganese  "  where  it  is  not 
necessary  to  determine  the  manganese  closer  than  a  few 
tenths  of  i  per  cent." 

Our  experience  does  not  confirm  this.  The  results 
average  from  i  to  2  per  cent  too  low,  so  that  we  do  not 
consider  the  method  at  all  reliable  for  high  percentages 
of  manganese. 

The  following  are  some  results  which  show  this  : — 

Gravimetric 
Sarnstrom. 
Per  cent. 

Illinois  ore   *.     ..    52-06  (i) 
„  ....     51-91  (2) 

1 51*40  (3) 

„  ....     51-78  (4) 

..  ••     ••    51-37  (5) 

5i'37  (6) 

No.  595 42-07 

..      4235 

42*90  — 

,, 42-60  — 

In  analyses  from  No.  i  to  No.  4  sodium  carbonate  was 
used  for  the  precipitation.  To  determine  whether  the 
employment  of  sodium  bicarbonate  would  be  advantageous, 
No.  6  was  so  treated,  while  at  the  same  time  No.  5  was 
precipitated  with  sodium  carbonate,  yielding  the  same 
result.  We  have  tried  sodium  bicarbonate  with  low  man- 
ganese ores,  but  have  never  noticed  any  pradtical  advan- 
tages, while  theoretically,  as  we  have  pointed  out  above, 
there  should  be  an  advantage  in  the  employment  of 
sodium  bicarbonate. 

This  discrepancy  with  high  percentages  of  manganese 
may  possibly  be  accounted  for  by  the  fadt  that  the  large 
precipitate  of  manganese  dioxide  may  adt  in  a  purely 
mechanical  way  in  protedling  the  final  amounts  of  the 
manganous  chloride  from  being  fully  oxidised  to  dioxide 
by  the  potassium  permanganate.  It  is  to  be  noted  in  this 
connexion  that  Volhard's  method  does  not  generally  give 
reliable  results  with  such  high  percentages  of  manganese. 

The  following  are  some  results  obtained  by  this  and 
other  methods : — 


Samstrom 

. 

Volhard. 

Gravimetric. 

A.  Magnetic   . 
Specular    . 

B.  Mixture  of 
blue  granu- 
lar and  red 
hematite 

.     0*07 

0-30 

•       0-32 

0-28 

o-io 
o-o8» 

0-31 
0-29 

0-07 

0*29 
0-30 

C.  Limonite    . 

.     1-03 

1*02 

I '09 

11           < 
D.  Silicious  or 

.     1-05 
e     2-98 

1-05 
3*o8 

2*93 

Cary  Empire  . 

M                  II 

3*07 
.     3  93 
.     3-88 

3*07 

T.  V.  Church 

Illinois  Steel  Co. 

■3  "94 

Dexter  No.  2 

6-04 
.  ■  602 

6*02 

6-01 

6-01 

— 

— 

Davis  ore.. 
Newark  ore     . 

.     878 

.     i'48 

A.  G 

Duques 

8-62                  L8  86 
.  McKenna,         ( (Ford's) 
ne  Steel  Works     1-50 

No.  57      ..     . 
No.  218    ..     . 

.     5*39 
.     559 

5*39 
559 

— 

In  the  determination  of  small  amounts  of  manganese 
this  method  presents  an  advantage  over  Volhard's  method 
in  giving  a  more  distinift  end  reaction. 

"The  method  can  be  used  for  iron  and  steel  determina- 
tions if  the  usual  precautions  are  taken  to  oxidise  the 
carbon.  But  it  is  not  so  well  adapted  to  these  on  account 
of  the  impradicability  of  taking  large  amounts  for  analysis. 
— journal  of  the  American  Chemical  Society,  xviii.,  April, 
1896. 

*  This  was  so  low  as  to  necessitate  filtering  through  asbestos  in 
order  to  see  end  reaction  by  Volhard's  method. 


METAL    SEPARATIONS    BY     MEANS    OF 

HYDROCHLORIC    ACID    GAS.* 

By  J.  BIRD  MOVER. 

Introduction. 
The  aftion  of  gaseous  haloid  acids  upon  metallic  oxides 
and  their  salts  is  a  field  of  investigation  which,  though 
not  of  recent  origin,  has  been  but  lately  developed.  It 
was  Debray  {Comp.  Rend.,  xlvi.,  logS,  and  Ann.  Chem. 
(Liebig),  cviii.,  250)  who  first  called  attention  to  the 
volatility  of  molybdic  acid  in  a  stream  of  hydrochloric  acid 
gas,  with  the  formation  of  MoO(OH)2Cl2. 

E.  Pechard  (Comp.  Rend,,  cxiv.,  173)  applied  this  and 
showed  that  molybdic  acid  was  completely  eliminated 
and  separated  from  tungstic  acid  by  its  volatility  in  a 
current  of  hydrochloric  acid.  Since  that  time  nothing 
further  has  been  done  with  single  haloid  acids,  in  gas 
form,  until  quite  recently.  Compounds  have  been  decom- 
posed, salts  volatilised,  and  separations  made,  by  means 
of  other  gases  and  mixtures,  which  may  be  as  effedive  as 
hydrochloric  acid,  but  are  not  devoid  of  trouble  nor 
nearly  so  neat. 

Smith  and  Oberholtzer  (yourn.  Amer.  Chem.  Soc,  xv., 
1),  repeated  and  confirmed  Pechard's  work  in  regard  to 
the  separation  of  molybdic  acid  from  tungstic  acid,  and 
in  addition  showed  that  gaseous  hydrobromic,  hydriodic, 
and  hydrofluoric  acids  aded  similarly.  Later,  Smith  and 
Maas  (Ztschr.  Anorg,  Chem.,  v.,  280)  made  use  of  the 
volatilisation  of  molybdic  acid  for  a  close  atomic  mass 
determination  of  molybdenum. 

Smith  and  Hibbs  (yourn.  Amer.  Chem.  Soc,  xvi.,  578) 
showed  that  vanadium  behaved  like  molybdenum. 
Hydrochloric  acid  gas  completely  eliminates  vanadic 
acid  from  sodium  vanadate.  A  little  later  they  investi- 
gated the  adion  of  hydrochloric  acid  upon  the  members 
of  Group  V.  of  the  periodic  system  (Ibid.,  xvii.,  6S2). 

The  sodium  salts  of  nitric,  pyrophos-phoric,  pyroarsenic, 
and  pyroantimonic  acids  were  used.  They  found  nitrogen, 
arsenic,  and  antimony  to  be  volatile  in  gaseous  hydro- 
chloric acid,  and  made  it  the  basis  of  a  separation  of 
phosphoric  acid  from  nitric  acid.  Lead  arsenate  changed 
completely  to  chloride,  the  arsenic  being  volatilised,  thus 
affording  a  good  quick  separation.  Smith  and  Meyer 
{Ibid.,  xvii.,  735)  tried  the  adion  of  all  the  haloid  acids 
upon  the  elements  of  Group  V.  of  the  periodic  system. 
They  worked  with  sodium  salts  and  observed: — I.  That 
nitrogen  was  expelled  completely  by  all  the  haloid  acids. 
II,  That  phosphoric  acid  was  not  aded  upon.  III.  That 
arsenic  acid  was  fully  expelled  by  hydrochloric,  hydro- 
bromic, and  hydriodic  acids,  but  only  partially  by  hydro- 
fluoric acid.  IV.  That  antimony  was  completely  volati- 
lised by  hydrochloric  acid.  There  was  no  work  done  on 
bismuth.  V.  Vanadium  went  over  completely  in  hydro- 
chloric acid,  but  only  partially  in  hydrobromic  and  hydro- 
fluoric acids.  VI.  Columbium  forms  volatile  produds 
with  hydrochloric  and  hydrobromic  acids.  No  knowledge 
of  didymium  was  obtained.  VII.  Tantalum  is  only 
slightly  volatile  in  hydrochloric  acid. 

P.  Jannasch  and  F.  Schmidt  (Ztschr.  Anorg.  Chem., 
ix.,  274)  repeated  some  of  the  work  of  Smith  and  Hibbs, 
in  which  they  confirmed  the  separation  of  arsenic  from 
lead.  They  anticipated  a  slight  portion  of  my  work,  and 
in  addition  separated  arsenic  acid  from  iron,  tin  from 
lead,  tin  from  copper,  and  tin  from  iron,  in  a  stream  of 
hydrochloric  acid  gas. 

The  position  of  bismuth  in  the  periodic  system  makes 
it  natural  to  suppose  that  it  too  will  be  volatile  in  hydro- 
chloric acid  gas.  This  I  have  shown  to  be  true,  and  was 
thus  enabled  to  separate  it  from  lead  and  copper.  The 
adion  of  hydrobromic  acid  on  bismuth  trioxide  was  also 
tried  ;  it  formed  the    bromide  and  then  volatilised.     It 


*  From  author's  thesis  presented  to  the  Faculty  of  the  University 
of  Pennsylvania  for  the  degree  of  Ph.D.,  1896.  From  the  Joum. 
Amer.  Chem.  Soc,  xviii.,  December,  1896. 


Crrmical  News,  i 
Jan.  29,  1897.      I 


Metal  Separations  by  means  of  Hydrochloric  Acid  Gas, 


53 


requires  a  higher  temperature  and  longer  aftion  than  with 
hydrochloric  acid.  Because  of  lack  of  time,  I  have  been 
compelled  to  abandon  the  experiments  instituted  with  a 
view  of  affedting  separations,  in  atmospheres  of  hydro- 
bromic  acid  and  hydriodic  acid  gas,  and  have  confined 
my  labours  to  hydrochloric  acid  gas. 

Method  of  Work. 

The  hydrochloric  acid  gas  was  generated  by  dropping 
concentrated  sulphuric  acid  from  a  separatory  funnel  upon 
concentrated  hydrochloric  acid  contained  in  a  three  litre 
flask.  The  gas  evolved  at  the  ordinary  temperature  was 
dried  by  passing  it  through  two  sulphuric  acid  drying 
bottles  and  then  through  a  calcium  chloride  tower,  when 
it  was  considered  sufficiently  dry  for  the  purpose.  The 
substance  to  be  aded  upon  was  weighed  out  in  a  porce- 
lain boat,  and  the  latter  was  placed  in  a  combustion  tube 
of  hard  glass. 

The  tube  had  previously  been  rinsed  with  alcohol  and 
then  with  ether  to  remove  all  moisture.  The  ether  was 
removed  by  drawing  a  current  of  dry  air  through  the  tube. 
This  tube  was  connedled  to  a  two  necked  bulb  receiver 
containing  about  300  c.c.  of  distilled  water.  When 
working  with  arsenic  10  c.c.  of  niiric  acid  were  added. 
The  connedting  tube  from  the  combustion  tube  to  the 
bulb  receiver  was  made  to  enter  the  receiver  and  dip 
below  the  surface  of  the  water,  thus  catching  all  volatile 
produds,  as  well  as  taking  up  the  hydrochloric  acid  gas. 
To  insure  safety  from  the  loss  of  volatile  produdts,  a  small 
flask  containing  water  was  attached  to  the  bulb  receiver. 
The  apparatus  was  controlled  at  both  ends  by  stop-cocks. 
This  is  necessary  to  prevent  backward  sud\ion  on  discon* 
nedling  the  apparatus.  After  the  readtion  was  completed 
the  boat  was  removed  to  a  sulphuric  acid  desiccator 
from  which  the  air  could  be  exhausted.  In  general,  the 
procedure  was  similar  to  that  employed  by  Hibbs 
(Thesis,  1896). 

I. — Behaviour  of  Antimony  Trioxide, 
Antimony  oxide,  labelled  chemically  pure,  was  dis- 
solved in  hydrochloric  acid  and  precipitated  with  a  large 
amount  of  water.  After  washing  by  decantation  it  was 
re-dissolved  and  re-precipitated.  This  procedure  was 
repeated  several  tfmes,  when  it  was  precipitated  by 
ammonium  carbonate,  washed,  and  ignited.  The  pure 
oxide  obtained  in  this  manner  was  subjedled  to  the  adlion 
of  hydiochloric  acid  gas,  and  it  was  found  to  volatilise 
completely.  In  each  trial  a  one-tenth  grm.  of  the  oxide 
was  adted  upon.  The  temperature  varied  between  150° 
and  190°  C.  It  was  determined  in  the  following  way: — 
The  combustion  tube  was  slipped  through  two  holes  made 
in  the  sides  o(  a  copper  drying  oven. 

A  veiy  slow  current  of  gas  was  used  as  the  antimony 
seemed  to  volatilise  more  readily  and  completely  if  the 
current  was  slow  and  the  heat  gentle.  This  1  aitribute, 
on  refledlion,  to  the  fadt  that  1  ignited  the  oxide  too 
strongly  (to  a  red  heat)  in  its  preparation.  It  dissolved 
with  difficulty  m  concentrating  hydrochloric  acid.  Lack 
of  time  prevented  the  repetition  of  this  experiment  and 
the  separation  of  antimony  from  lead  and  copper,  in 
which  this  substance  was  used.  About  eight  hours  was 
the  time  required  for  the  volatilisation  ;  very  probably  a 
shorter  time  would  be  required  if  the  oxide  had  been 
obtained  by  gentle  ignition. 

II, — Behaviour  of  Lead  Oxide. 

Pure  lead  oxide  was  obtained  from  re-crystallised  nitrate 
by  careful  ignition.  This  oxide  changed  completely  into 
chloride  at  the  ordinary  temperature,  and  it  was  only 
necessary  to  apply  a  gentle  heat  to  complete  the  change 
and  entirely  remove  the  water  formed.  No  volatilisation 
was  noticed  until  a  temperature  of  225°  was  reached  ;  at 
this  point  the  lead  chloride  slightly  volatilised. 

1  think  it  possible  to  estimate  lead  as  chloride,  if  the 
temperature  is  kept  under  200°.  A  weighed  amount  of 
lead  oxide  was  adted  upon  by  hydrochloric  acid  gas  in  the 


cold  for  two  hours,  and  theo  heated  sufficiently  to  remove 
all  the  water  formed. 

The  boat  was  cooled  in  the  gas,  and  then  placed  in  a 
sulphuric  acid  desiccator  and  allowed  to  stand  one-half 
hour.     It  was  then  weighed. 

Experiments, 

Lead  Lead  Lead 

oxide  chloride  chloride 

taken.  obtained,  required.  Difference) 

Grm.            Grm.           Grm.  Grm. 

Experiment  I.  o'loiy  0*1267  o"i267  o'oooo 

„         II.   o'lois  o'i258  o"i265  —0*0007 

„        III.   o*ii6g  0*1454  0*1447  +0*0007 

The  lead  chloride  dissolved  in  hot  water  without  residue, 

III. — The  Separation  of  Antimony  from  Lead. 
The  oxides  were  carefully  weighed  and  thoroughly 
mixed  in  a  porcelain  boat.  Hydrochloric  acid  gas  was 
passed  over  them  in  the  cold,  until  the  lead  oxide  had 
been  entirely  changed  to  the  chloride.  It  was  then  heated 
with  the  smallest  flame  obtainable  from  a  fish-tail  burner, 
placed  about  two  inches  below  the  tube. 

Antimony  Lead  Lead  Lead 

trichloride  chloride  chloride  chloride 

taken.  taken.  obtained,  required. 

Grm,  Grm.  Grm.  Grm. 

Experiment  I.       0*1015  o*ii8g  0*1470  0*1482 

„         II.       0*1090  0*1021  0*1266  0*1272 

„       III.       0*1350  0-0852  0*1057  0-1062 

,,        IV.       0*1250  0*1671  0*2069  0*2083 

The  time  required  was  seven  hours.  The  lead  chloride 
was  immediately  weighed.  It  dissolved  completely  in 
hot  water,  and  this  solution  was  tested  by  means  of 
Marsh's  apparatus  for  antimony,  without  finding  the 
latter  present.  Experiment  II.  was  slightly  varied  by 
first  moistening  the  oxides  with  a  drop  of  hydrochloric 
acid. 

IV. — Behaviour  of  Bismuth  Oxide. 

Bismuth  nitrate,  as  pure  as  could  be  obtained,  was  dis- 
solved  in  nitric  acid  and  then  thrown  down  with  a  large 
quantity  of  water.  The  precipitate  was  carefully  washed 
by  decantation.  This  operation  was  repeated  several 
times. 

It  was  then  dissolved  in  acidulated  water  and  precipi- 
tated with  ammonium  hydroxide  and  ammonium  car- 
bonate. This,  on  ignition,  gave  pure  oxide,  which,  heated 
in  a  stream  of  hydrochloric  acid  gas,  completely  volatilised 
as  chloride.  Here  the  same  treatment  is  necessary  as 
obtained  for  antimony.  A  slow  current  of  gas  and  a  low 
heat  were  best  adapted  for  the  volatilisation  (a  tempera- 
ture of  130°,  or  roughly,  the  heat  afforded  by  a  fish-tail 
burner  placed  two  inches  below  the  combustion  tube,  with 
a  flame  an  eighth  of  an  inch  high).  The  bismuth  chloride 
sublimed  nicely,  forming  a  white  crystalline  mass  beyond 
the  boat,  which  could  be  readily  driven  along  by  a  gentle 
heat. 

V. — The  Separation  of  Bismuth  from  Lead. 

The  same  material  was  used  as  in  the  preceding  experi- 
ments. The  weighed  oxides  were  thoroughly  mixed  in  a 
porcelain  boat.  Usually  the  gas  was  allowed  to  adt  in 
the  cold  for  an  hour,  which  changed  the  oxides  completely 
to  chlorides. 

The  same  conditions  prevailed  as  under  bismuth  oxide 
alone.  If  an  attempt  was  made  to  hasten  the  readtion  by 
heating  higher  than  180°,  a  little  lead  would  volatilise. 
This  sublimate,  slightly  yellow  in  colour,  would  appear 
diredlly  over  the  boat  and  could  not  be  driven  along  the 
tube  like  bismuth  ;  hence  it  was  readily  detedled. 

The  separation  of  bismuth  from  lead  requires  much 
care,  as  it  is  not  as  sharp  as  could  be  desired.  It  is  also 
difficult  to  tell  exadlly  when  the  last  traces  of  bismuth 
have  been  driven  out  of  the  boat,  as  there  was  no  colour 
change  to  indicate  it,  both  metals  forming  white  chlorides. 
The  separation  is  complete  in  from  six  to  seven  hours. 
At  the  end  of  the  separation  the  position  of  the  boat  waa 


5^ 


Determination  of  Atomic  Masses  by  the  Electrolytic  Method.    {^"In'^^s^;*'* 


changed  and  the  adlion  continued  ;  if  no  further  sublima- 
tion occurred  it  was  cooled  and  removed  to  a  desiccator. 
The  weight  was  taken  after  standing  one-half  hour  over 
sulphuric  acid.  With  care  bismuth  can  be  separated 
from  lead  in  this  manner. 

Lead.  Bismuth       Lead          Lead 

oxide  trioxide    chloride  chloride 

taken.  taken,    obtained,  required.  Difference. 

Grm.  Grm.         Grm.         Grm.          Grm. 

Experiment  I.  o"ioi4    0*2020    0*1261    0*1264    — 0*0003 

„    II.  0*1006   00642   0*1252   0*1254   —  0-O0O2 

„     III.  0*1038    o  1003    0*1294    0-1302     —  O'OOOS 
,,     IV.   0*1412    0*1260    0*1759    0*1759       00000 

The  chloride  of  lead  dissolved  completely  in  hot  water. 
It  showed  no  bismuth.    The  sublimate  contained  no  lead. 

(To  be  continued). 


THE    DETERMINATION    OF    ATOMIC    MASSES 

OF    SILVER,    MERCURY,    AND    CADMIUM, 

BY    THE    ELECTROLYTIC    METHOD.* 

By  WILLETT  LEPLEY  HARDIN. 

(Continued  from  p.  41). 

Second  Series. 
Experiments  on  Silver  Acetate. 
The  fadl  that  silver  forms  well-crystallised  salts  with  a 
number  of  organic  acids  makes  the  comparison  of  the 
atomic  mass  of  silver  with  the  combined  atomic  masses 
of  carbon,  hydrogen,  and  oxygen,  a  matter  of  no  great 
difficulty.  From  certain  preliminary  experiments  the 
acetate  of  silver  seemed  to  fulfil  the  conditions  necessary 
for  accurate  determinations. 

Preparation  of  Silver  Acetate, 
The  purest  commercial  sodium  acetate  was  dissolved  in 
water,  the  solution  filtered  and  re-crystallised.  After 
three  crystallisations  the  material  was  dissolved  in  pure 
water,  and  to  the  rather  concentrated  solution  was  added 
a  solution  of  silver  nitrate,  prepared  in  the  manner  already 
indicated.  The  white  curdy  precipitate  which  separated, 
after  washing  with  cold  water,  was  dissolved  in  hot  water, 
the  solution  filtered  and  evaporated  to  crystallisation. 
The  silver  acetate  separated  in  brilliant  sword-shaped 
crystals.  After  pouring  off  the  solution  the  crystals  were 
quickly  rinsed  with  cold  water  and  placed  between  filters 
to  remove  the  adhering  moisture.  The  material  was 
allowed  to  remain  in  contadl  with  the  filters  only  for  a 
short  time.  It  was  then  placed  in  a  platinum  dish,  and 
when  apparently  dry  the  crystals  were  broken  up  into  a 
finely  divided  condition  and  dried  forty-eight  hours  in  a 
vacuum  desiccator.  This  work  was  carried  on  in  a 
darkened  room,  and  the  silver  acetate  obtained  was 
placed  in  a  weighing  tube,  and  kept  in  a  desiccator  in  a 
dark  place. 

Mode  of  Procedure. 

The  method  of  operation  was  similar  to  that  described 
under  silver  nitrate.  After  weighing  the  silver  acetate 
its  aqueous  or  cyanide  solution  was  eleftrolysed  and  the 
weight  of  the  resulting  metallic  silver  determined.  The 
results  obtained  from  the  aqueous  solution  were  some- 
times vitiated  by  the  separation  of  silver  peroxide  at  the 
anode.  To  prevent  this,  potassium  cyanide  was  sometimes 
added.  The  results,  however,  from  the  two  solutions  were 
praftically  the  same  when  no  peroxide  separated.  From 
the  aqueous  solution  the  silver  was  deposited  in  a  crys- 
talline form.  The  strength  of  current  and  time  of  adlion 
were  the  same  as  for  silver  nitrate. 

*  Contribution  from  the  John  Harrison  Laboratory  of  Chemistry 
No.  13.  From  the  author's  thesis  presented  to  the  Faculty  of  the 
University  of  Pennsylvania  for  the  degree  of  Ph.D.— From  the 
Journal  of  the  American  Chemical  Society,  xviii.,  p.  999. 


Ten  observations  on  silver  acetate  reduced  to  a  vacuum 
standard  on  the  basis  of — 

3-241  =  density  of  silver  acetate, 

10*5  =  „         metallic  silver, 

24*4  =  „         platinum  dish, 

8*5  =  „         weights. 

and  computed  for  the  formula  AgCzHsOj,  assuming  the 
atomic  masses  of  carbon,  hydrogen,  and  oxygen  to  be 
12*01,  i*oo8,  and  16  respedively,  are  as  follows  : — 


Weight 

Weight          Atomic  mass 

of  AgC^HsOj. 

of  Ag. 

of  silver. 

Grms, 

Grm. 

I 

0*32470 

0*20987 

107*904 

2 

0*40566 

0*26223 

107-949 

3 

0*52736 

0-34086 

107-913 

4 

0*60300 

038976 

107-921 

5 

0-67235 

0-43455 

107-896 

b 

0-72452 

0*46830 

I07'9i6 

7 

0-78232 

0-50563 

107-898 

8 

0*79804 

0-51590 

107-963 

9 

0*92101 

0-59532 

107-925 

10 

1-02495 

0*66250 

107-923 

Mean    .. 

..      =  107-922 

Maximum 

..      =  107-963 

Minimum 

. .      =  107-896 

Difference    ..     =      0*067 
Probable  error    =i  0-005 

Computing  from  the  total  quantity  of  material  used 
and  metal  obtained,  we  have  107-918  for  the  atomic  mass 
of  silver. 

Experiments  on  Silver  Succinate, 

Silver  succinate  was  prepared  in  a  manner  similar  to 
that  of  silver  acetate.  The  commercial  C.  P.  succinic 
acid  was  re-crystallised  three  times;  the  ammonium  salt 
was  then  prepared  and  its  aqueous  solution  precipitated 
with  a  solution  of  pure  silver  nitrates.  The  precipitate 
of  silver  succinate  was  thoroughly  washed  by  decantation 
with  pure  water  and  carefully  dried.  After  drying  for 
several  hours  in  an  air-bath  at  50°,  the  material  was 
ground  in  an  agate  mortar  to  a  finely  divided  powder,  and 
was  then  re-dried  for  twenty-four  hours  in  an  air-bath  at 
a  temperature  of  60°.  The  white  powder  obtained  in  this 
way  was  placed  in  a  weighing  tube  and  kept  in  a  desic- 
cator. 

The  method  of  analysis  was  similar  to  that  of  silver 
acetate.  A  weighed  portion  of  the  material  was  dissolved 
in  a  little  potassium  cyanide  in  a  platinum  dish.  After 
diluting  with  pure  water,  the  solution  was  eleiStrolysed 
and  the  resulting  deposit  weighed.  The  strength  of  cur- 
rent and  time  of  aftion  were  the  same  as  for  silver  nitrate. 
The  results  computed  for  the  formula  C4H404Ag2  were 
not  constant,  and  were  invariably  from  one  to  two  units 
lower  than  those  obtained  from  silver  nitrate  and  silver 
acetate.  The  material  was  then  dried  at  a  temperature  of 
75°,  but  the  results  obtained  were  not  satisfaiStory. 

The  two  most  probable  causes  for  these  low  results 
are: — 

First,  the  difficulty  of  removing  the  last  traces  of  im- 
purities from  a  precipitate  like  that  of  silver  succinate. 
The  experience  throughout  this  work  has  been,  that  to 
remove  all  the  impurities  from  a  finely  divided  precipitate 
by  washing  is  almost  impossible. 

Second,  the  difficulty  met  in  drying  material  of  this 
kind.  This  same  difficulty  was  met  in  the  experiments 
on  silver  oxide  which,  as  shown  by  Lea,  retained  moisture 
up  to  165°. 

Third  Series. 
Experiments  on  Silver  Benzoate. 

The  preceding  work  on  silver  acetate  and  silver  succi- 
nate shows  the  necessity  of  selecting  compounds  which 
form  well-defined  crystals.  Perhaps  no  organic  salt 
of  silver  fulfils  the  conditions  necessary  for  accurate 
analysis  better  thati  silver  benzoate. 


CRBMtCAL  NBWS,  I 

Jan.  29,  1897.     I 


Aluminum  Analysis, 


55 


Preparation  of  Silver  Benzoate. 

The  purest  commercial  benzoic  acid  was  re-sublimed 
three  times  from  a  porcelain  dish  into  a  glass  beaker. 
The  produ(5t  thus  obtained  was  dissolved  in  pure  aqueous 
ammonia,  and  the  solution  evaporated  to  crystallisation. 
The  ammonium  salt  was  then  dissolved  in  distilled  water, 
and  to  the  solution  was  added  a  solution  of  pure  silver 
nitrate.  The  white  precipitate  of  silver  benzoate  which 
separated  was  washed  with  cold  water  ;  it  was  then  dis- 
solved in  hot  water,  the  solution  filtered,  and  evaporated 
to  crystallisation.  The  salt  separated  in  fine  needles, 
which  clung  together  in  arborescent  masses.  After  re- 
moving the  liquid  from  the  beaker,  the  crystals  were 
quickly  rinsed  with  cold  water  and  placed  between  filters 
to  remove  the  adhering  moisture.  When  apparently  dry 
they  were  broken  up  into  small  fragments  and  dried  forty- 
eight  hours  in  a  vacuum  desiccator.  The  material  was 
then  placed  in  a  glass-stoppered  weighing-tube  and  kept 
in  a  dark  place. 

Mode  of  Procedure, 

The  details  of  the  method  of  operation  are  the  same  as 
those  given  under  silver  nitrate.  A  weighed  portion  of 
the  material  was  dissolved  in  a  dilute  solution  of  potas- 
sium cyanide  in  a  platinum  dish.  The  solution  was  then 
eledtrolysed  and  the  resulting  metal  weighed.  The 
strength  of  current  and  time  of  aftion  were  the  same  as 
for  silver  nitrate. 

Before  the  results  could  be  reduced  to  a  vacuum 
standard  it  was  necessary  to  determine  the  specific 
gravity  of  silver  benzoate.  This  was  done  by  means  of  a 
specific  gravity  bottle,  the  liquid  used  being  chloroform. 
The  mean  of  two  determinations  gave  2*082  for  the  spe- 
cific gravity  of  silver  benzoate. 

Ten  results  on  this  compound,  reduced  to  a  vacuum 
standard  on  the  basis  of — 

2*082  =  density  of  silver  benzoate, 
io'5  =  >»         metallic  silver, 

2I'4  =  „  platinum  dish, 

8-5  =  „  weights, 

and  computed  for  the  formula  C^HsAgOj,  assuming  i2'oi, 
I'ooS,  and  16  to  be  the  atomic  masses  of  carbon,  hydro- 
gen, and  oxygen,  respeftively,  are  as  follows  :— 

Weight  "Weight  Atomic  mass 

of  C^HjsAgOj.  of  Ag.  of  silver. 

Grms.  Grm. 

1  0'4o858  o' 19255  107*947 

2  0*46674  0*21999  107*976 

3  0'484I9  0*22815  107*918 

4  0*62432  0*29418  107*918 

5  0*66496  0*31340  107964 

6  0*75853  0*35745  107*935 

7  0*76918  0*36247  107*936 

8  0*81254  0-38286  107*914 

9  0*95673  0*45079  107908 
10               1*00840  0*47526  107*962 

Mean  ..  ,.  =  107*938 
Maximum  ..  =  107*976 
Minimum    ..     =    107*908 


Difference  ..      =       o*o68 
Probable  error    =  ^  0*005 

Computing  from  the  total  quantity  of  material  used 
and  metal  obtained,  we  have  107*936  for  the  atomic  mass 
of  silver. 

Summary. 

In  discussing  the  work  on  the  atomic  mass  of  silver, 
two  possible  sources  of  error  suggest  themselves  : — 

First,  the  hydrogen  which  is  continually  being  set  free 
in  the  process  of  eledtrolysis  may,  in  part,  be  occluded  by 
the  metallic  silver.  As  already  pointed  out,  the  metallic 
deposits  were  washed  several  times  with  boiling  water, 
with  the  hope  of  removing  any  occluded  gases  ;  but 
whether  this  effedted  a  complete  removal  of  all  the 
occluded  gases  was  not  determined. 


Second,  the  condensation  of  moisture  on  the  platinum 
dish  might  be  urged  as  a  possible  source  of  error.  But  it 
must  be  remembered  that  the  dish  was  dried  in  the  same 
manner  each  time  and  kept  for  several  hours  in  a  desiccator 
and  that  the  atmosphere  inside  the  balance  was  kept  dry 
by  means  of  several  beakers  of  anhydrous  calcium  chlo- 
ride, and  that  the  temperature  of  the  balance  room 
throughout  the  work  was  almost  constant.  Under  these 
conditions  there  is  but  little  chance  of  error  from  different 
amounts  of  moisture  condensed.  Moreover,  the  variation 
in  the  different  weighings  of  the  same  dish  was  very 
slight. 

The  advantages  of  the  method  are  evident  :— 

First,  the  great  advantage  of  the  method  is  its  extreme 
simplicity. 

Second,  the  nature  of  the  compounds  used  and  of  me- 
tallic  silver  renders  them  well  adapted  to  weighing. 

Third,  the  method  was  such  as  to  eliminate  the  errors 
incident  to  the  ordinary  gravimetric  methods  of  analysis. 

Of  the  three  series,  the  first  is  probably  entitled  to  the 
greatest  weight.  That  the  silver  nitrate  was  pure  and 
free  from  moisture  seems  beyond  question.  However, 
the  close  agreement  of  the  last  two  series  with  the  first 
indicates  that  the  acetate  and  benzoate  of  silver  were 
also  free  from  moisture. 

Giving  equal  weight  to  each  of  the  three  series,  we 
have  the  following  as  the  general  mean  computed  from 
the  separate  observation  : — 

Atomic  mass  of  silver. 

First  series 107*924 

Second  „       107*922 

Third      „       107938 

General  mean  =»  107*928 

Compijting  the  general  mean  from  the  total  quantities 
of  material  used  and  metal  obtained,  we  have  :— 

Atomic  mass  of  silver. 

First  series 107*926 

"^         "  107*918  • 


Second 
Third 


107936 


General  mean  =  107*927 

Combining  this   with  the  first  general  mean  we  have 
107*9275  as  the  final  result  for  the  atomic  mass  of  silver. 

(To  be  continued). 


ALUMINUM    ANALYSIS.* 
By  JAMES  OTIS  HANDY. 

Although  the  aluminum  industry  is  not  a  large  one  in 
the  sense  that  the  iron  industry  is,  it  is  growing  very 
rapidly.  The  output  of  the  United  States  in  1894  was 
550,000  pounds,  and  in  1895  it  was  about  850,000 
pounds.  The  Pittsburg  Redudion  Company,  with  works 
at  New  Kensington,  near  Pittsburg,  Pa.,  and  at  Niagara 
Falls,  N.  Y.,  is  the  only  American  producer  of  aluminum. 
The  material  is  made  by  the  eledrolysis,  in  carbon-lined 
pots,  of  alumina  dissolved  in  a  fused  bath  of  fluorides. . 
The  produa  of  each  pot  is  ladled  out  at  intervals,  and  is 
graded  according  to  the  analyses  of  the  Pittsburg  Testing 
Laboratory,  Limited.  Some  of  the  aluminum  is  sold  as 
it  is  made,  and  some  is  alloyed  to  modify  its  physical 
properties.  Alloys  of  aluminum  with  3  per  cent  nickel, 
or  with  3  to  7  per  cent  copper,  or  similar  amounts  of  zinc, 
are  very  useful,  on  account  of  increased  strength  with 
only  slightly  increased  specific  gravity.  The  aluminum 
at  present  produced  with  the  best  ores  available  contains 
from — 


♦  From  the  Journal  of  the  American  Chemical  Society,  Sept.,  1896. 


56 


Aluminum  Analysis. 


Chemical  News, 
Jan.  29,  1807, 


99  to  99'9  per  cent  of  aluminum. 

o'3  to  0-05  per  cent  of  silicon   (combined  and 

graphitic). 
0*50  to  o'o  per  cent  of  copper. 
0*20  to  00  per  cent  of  iron. 
Carbon  is  sometimes  present  in  aluminum. 

Second  grade  aluminum  contains  96  to  gS  per  cent 
aluminum,  silicon  and  iron  making  up  the  remainder. 
Aside  from  analyses  of  metallic  aluminum,  there  are 
required,  in  the  pursuit  of  the  aluminum  industry,  analyses 
of  alloys  of  copper,  nickel,  manganese,  chromium,  tung- 
sten, zinc,  and  titanium,  with  aluminum ;  aluminum 
solders,  containing  tin,  zinc,  and  phosphorus;  aluminum 
hydrate,  bauxite,  and  eie(ftrode  carbons  ;  hydrofluoric  acid 
and  fluorides. 

Analysis  of  Commercial  Aluminum.     (95  to  ggg  per 
cent,  pure). 

In  the  analysis  of  aluminum  we  are  offered  a  choice  of 
solvents. 

Solubility  of  aluminum  : — Hydrochloric  acid  of  33  per 
cent  (i.e.,  i  part  of  hydrochloric  acid  of  V2  sp.  gr.  to 
2  parts  water)  is  a  rapid  solvent. 

Sulphuric  acid  of  25  per  cent  dissolves  aluminum  com- 
pletely on  long  boiling. 

Nitric  acid  of  i-fg  sp.  gr.  dissolves  aluminum  on  pro- 
longed boiling. 

Acid  mixture  : — A  mixture  of  the  three  acids,  which  we 
term  "  Acid  Mixture"  is  made  of — 

100  c.c.  nitric  acid  of  i'42  sp.  gr. 

300  c.c.  hydrochloric  acid  of  i'2o  sp.  gr. 
600  c.c.  sulphuric  acid  of  25  per  cent. 

It  is  a  very  useful  solvent  for  aluminum,  because  it  sup* 
plies  oxidising  conditions  during  solution  and  so  prevents 
loss  of  combined  silicon  as  hydride.  The  sulphuric  acid 
content  of  the  acid  mixture  furnishes  a  means  of  rapidly 
dehydrating  the  silica. 

Sodium  hydroxide  solution  of  33  per  cent  is  a  useful 
solvent  when  it  is  desired  to  separate  the  metallic  im- 
purities from  the  bulk  of  the  aluminum  at  once.  Weaker 
solutions  do  not  work  as  quickly  or  completely.  Solution 
succeeds  best  in  an  Erlenmeyer  flask. 

Fifteen  c.c.  of  the  sodium  hydroxide  solution  suffice  for 

1  grm.  of  aluminum. 

Commercial  soda  lye  may  be  used  if  dissolved  and 
filtered  through  asbestos. 

Other  Reagents  and  Standard  Solutions  used  in  Aluminum 
Analysis. 

Sodium  carbonate,  chemically  pure. 

Soda  ash  :  "  Solvay  "  soda  ash,  a  saturated  solution  in 
water,  Altered. 

Powdered  zinc  :  pradically  free  from  iron  and  copper. 

Fifteen  per  cent  nitric  wash :  (15  parts  1*42  nitric  acid 
to  85  parts  water). 

Standard    potassium    permanganate :     5*76    grms.    in 

2  litres.     One  c.c.  equals  0005  grm.  iron. 

Standard  potassium  cyanide:  45  grms.  in  2  litres.  One 
c.c.  is  made  to  equal  0*005  grm.  copper. 

Special  Apparatus. 

Two  narrow  glass  tubes,  graduated  roughly,  one  to  hold 
I  grm.  of  powdered  zinc,  and  the  other  i  grm.  of  chemi- 
cally pure  sodium  carbonate. 

The  evaporating  dishes  which  are  used  are,  preferably, 
about  4J  inches  in  diameter,  and  are  covered  with  5-inch 
glasses. 

The  Erlenmeyer  flasks  are  of  about  12-ounce  capacity, 
and  furnished  with  porcelain  crucible  covers. 

The  Method. 
Determination  of  Silicon,  Iron,  and  Copper  in  Commer- 
cial Aluminum. — One  grm.  of  aluminum  drillings  is  dis- 
solved in  a  4J-inch  evaporating  dish  in  30  c.c.  of  "  acid 


mixture."  If  the  drillings  are  thin  it  is  best  to  add  only 
15  c.c.  at  first.  Placing  cold  water  on  the  cover-glass 
sometimes  prevents  loss  from  too  energetic  foaming. 
Solution  having  been  completed  by  warming  slightly, 
evaporate  quickly  to  strong  fumes  of  sulphuric  acid,  and 
continue  heating  for  five  minutes.  Experience  will  show 
on  what  parts  of  the  hot  plate  these  solutions  can  be 
evaporated  without  spattering  at  the  time  when  aluminum 
sulphate  begins  to  crystallise  out.  Remove  the  dishes 
from  the  plate  by  means  of  an  iron  fork,  and  in  a  few 
moments  add  to  the  contents  of  each  75  to  100  c.c.  of 
water  and  10  c.c.  of  25  per  cent  sulphuric  acid,  break  up 
the  residue  in  each  dish  with  a  short  heavy  glass  rod, 
and  place  the  dishes  back  on  the  hot  plate.  Boil  until 
all  aluminum  sulphate  dissolves.  Add  to  each  dish  i  grm. 
of  metallic  zinc  powder,  measured.  Be  careful  to  pour 
the  zinc  into  the  middle  of  the  liquid.  If  it  touches  the 
sides  of  the  dish  it  sometimes  becomes  firmly  fixed  there. 
Keep  the  dish  contents  at  60°  to  70°  C.  until  the  zinc  has 
dissolved,  leaving  the  iron  reduced  and  the  copper  preci- 
pitated. Filter  and  wash  well  with  hot  water.  Cool, 
titrate  the  filtrates withstandard  potassium  permanganate. 
One  c.c.  equals  0-50  per  cent  iron  when  i  grm.  of  aluminum 
has  been  used.  Placing  new  receivers  under  the  funnels, 
treat  each  residue  twice  with  hot  15  per  cent  nitric  acid 
wash.  Wash  out  with  water,  and  in  the  solutions  thus 
obtained  titrate  the  copper  with  standard  potassium 
cyanide,  after  adding  saturated  soda  ash  solution  until  the 
precipitated  copper  carbonate  re-dissolves.  The  end  point 
of  the  titration  is  very  satisfactory.  The  cyanide  solution 
should  be  standardised  with  copper  of  known  purity  in 
about  the  amount  usually  found,  viz.,  0*005  'o  o'oio  grm. 
The  residue  of  silicon  and  silica  are  burned  of!  in  num- 
bered crucibles,  and  each  fused  with  i  grm.  of  chemically 
pure  sodium  carbonate  (measured).  The  crucible  con- 
taining the  fused  mass  is  placed  in  15  c.c.  of  water  in  the 
porcelain  dish  originally  used,  and  25  c.c.  of  25  per  cent 
sulphuric  acid  are  added.  Solution  takes  place  quickly 
without  separation  of  silica,  and  after  rinsing  out  and 
removing  the  crucible,  the  solution  is  evaporated  to  five 
minutes  fuming  on  the  hot  plate.  After  cooling  add  75 
to  100  c.c.  of  water,  and  boil  to  disintegrate  the  silica. 
Filter  and  wash  well  with  water.  Burn  off  and  weigh 
silica  and  crucible,  treat  with  hydrofluoric  acid  and  a 
drop  of  sulphuric  acid  if  impurity  is  suspeded.  Evaporate, 
ignite,  and  weigh  again.  Loss  equals  silica;  calculate 
to  silicon. 

Determination  of  Crystalline  {Graphitic)  Silicon  in 
Aluminum. — Dissolve  i  grm.  of  aluminum  in  30  c.c.  of  33 
per  cent  hydrochloric  acid  (two  parts  of  water  to  one  of 
hydrochloric  acid)  in  a  platinum  dish;  add  about  2  c.c. of 
hydrofluoric  acid,  stir,  and  filter  at  once  through  a  No.  o 
9  cm.  filter,  contained  in  a  funnel  which  has  been  thinly 
coated  with  paraffin.  Wash  with  water  and  burn  off  in  a 
platinum  crucible.  Fuse  with  i  grm.  of  sodium  carbonate, 
cool  in  15  c.c.  of  water  in  a  four-and-a-half-inch  evapo- 
rating dish.  Add  20  c.c.  of  25  per  cent  sulphuric  acid. 
Rinse  out  the  crucible.  Evaporate  to  fumes,  cool,  add 
75  c.c.  of  water,  boil  up,  and  filter  off  the  silica.  Wash, 
ignite,  and  weigh.     Calculate  to  silicon. 

The  determinations  of  silicon,  copper,  and  iron  are  the 
every-day  methods  of  grading  aluminum.  It  is  recognised 
that  sodium  and  carbon  occasionally  exist  in  aluminum, 
and  they  are  determined  by  methods  described.  In  cer- 
tain samples  it  is  desirable  to  know  the  approximate  per- 
centage of  graphitic  and  combined  silicon.  These  deter- 
minations are  also  described.  We  determine  nitrogen, 
if  present,  by  a  special  method. 

(To  be  continued). 


The  Chemical  Society,— At  the  last  meeting  of  the 
Chemical  Society  it  was  announced  that  Mr.  J.  J. 
Tustin  had  made  a  donation  of  one  thousand  guineas  to 
the  Research  Fund  of  the  Society. 


I'RBMICAL  NbWS,  ) 

Jan.  29,  1897.      I 


Passage  of  Electricity  through  Gases. 


57 


PROCEEDINGS    OF    SOCIETIES. 

PHYSICAL    SOCIETY. 
Ordinary  Meeting,  January  22nd,  1897. 

Prof.  Ayrton,  Vice-President,  in  the  Chair. 

Mr.  Croft  gave  an  exhibition  of  some  simple  apparatus. 

The  exhibition  included  an  ingenious  form  of  clip  to  fit 
on  an  upright  retort  stand ;  a  nicol  used  for  projefting 
the  rings  and  brushes  in  crystals,  with  which  it  is  suffi- 
cient to  use  the  ordinary  condenser  of  the  lantern,  the 
source  of  light  having  been  moved  further  away  from  the 
lens  than  is  usual ;  some  photographs  showing  caustics, 
conical  refradion,  and  diflfradtion ;  a  stand  for  magnets, 
&c.,  when  demonstrating  the  attradion  and  repulsion  of 
poles  ;  a  stand  for  the  suspension  of  objects  for  experi- 
ments on  diamagnetism  ;  a  holder  for  X  ray  tubes,  con- 
sisting of  a  spiral  of  wire  fitting  round  the  exhaustion  tube 
of  the  bulb  ;  an  X  ray  photograph  taken  by  means  of  a 
Wimshurst  machine  ;  a  model  of  Michelson's  interference 
experiment ;  an  arrangement  to  show  subjedive  colours, 
in  which  a  double  lantern  is  arranged  to  give  two  partly 
overlapping  discs.  A  sheet  of  green  glass  is  placed  before 
one  lantern,  and  the  light  of  the  other  decreased  till  the 
illumination  of  the  two  discs  is  the  same.  The  overlap 
then  appears  white,  while  the  remainder  of  the  uncoloured 
disc  appears  red. 

Prof.  SiLVANUs  Thompson  said  he  was  surprised  that 
•'  patent  plate "  was  sufficiently  good  for  Michelson's 
experiment.  Had  the  author  tried  illuminating  the  discs 
in  his  subjedive  effed  experiment  for  a  very  short 
interval,  so  that  the  eye  would  not  have  time  to  wander 
from  one  disc  to  the  other  ? 

Mr.  Griffith  said  that  if  you  looked  through  a  tube 
at  one  disc  at  a  time,  one  appeared  green  and  the  other 
white. 

The  Chairman  said  the  point  seemed  to  be,  could  you 
fatigue  the  eye  simultaneously,  or  must  it  be  successive  ? 

Prof.  SiLVANUS  Thompson  said  two  common  one-inch 
microscope  objedives  were  very  suitable  for  projeding 
rings  and  brushes. 

Mr.  E.  C.  Baly  read  a  paper  on  the  "  Passage  of  Elec- 
tricity through  Gases." 

In  this  paper,  which  is  of  a  purely  controversial  nature, 
the  author  brings  forward  as  arguments  that  eledrical 
condudion  in  gases  is  not  of  an  eledrolytic  nature  the 
following: — (i)  That  the  sign  of  the  supposed  gaseous 
ion  is  variable.  (2)  The  initial  resistance  of  a  gas.  (3) 
The  invalidity  of  Ohm's  law.  (4)  The  permanence  of  the 
supposed  gaseous  eledrolyte.  (5)  That  every  mixture  of 
gases  must  equally  be  an  eledrolyte.  (6)  That  the 
potential  gradient  in  a  vacuum-tube  when  the  current  is 
passing  has  been  shown  to  be  very  uneven.  It  is  very 
steep  in  the  cathode  glow,  and  is  by  no  means  a  regular 
decline  between  the  eledrodes. 

Prof.  Armstrong  said  it  was  difficult  to  know  from 
what  point  of  view  the  author  had  treated  the  question. 
The  first  part  of  the  paper  consisted  almost  entirely  of  a 
criticism  of  Prof.  J.  J.  Thomson's  theory  and  experiments. 
Prof.  Thomson,  however,  is  not  the  only  observer  who 
has  dealt  with  this  subjed.  The  author's  arguments 
seemed  vitiated  by  the  fad  that  he  has  looked  upon  the 
subjed  from  one  very  narrow  standpoint  only,  viz.,  the 
ionic  hypothesis,  and  Lord  Kelvin,  for  instance,  does  not 
believe  in  the  truth  of  the  ionic  hypothesis  even  in  the 
case  of  liquids.  Prof.  Thomson  has  shown  that  the 
phenomena  depend  on  the  dryness  of  the  gas,  so  that  the 
condudion  cannot  depend  on  the  gaseous  molecule  alone. 
In  the  case  of  condudion  induced  by  a  neighbouring  dis- 
charge, this  might  be  due  to  the  expulsion  of  condensed 
vapour  from  the  walls  of  the  vessel.  It  would  appear 
that  in  the  dry  state  gases  are  not  ele(5lrolytes. 


Mr,  Enright  said  he  thought  it  was  not  correA  to  say 
no  work  was  done  in  eledrolysis. 

Prof.  SiLVANUS  Thompson  said  that  the  pursuit  of  the 
analogy  between  the  condudivity  in  gases  and  liquids 
was  apt  to  lead  one  too  far.  Thus,  if  you  compare  the 
condudion  in  a  mixture  of  H  and  CI  with  eledrolysis, 
your  analogy  will  be  a  false  one  unless  you  import  into 
the  term  eledrolysis  the  idea  of  chemical  separation  as 
taking  place  in  the  solution.  If  a  current  separated  a 
mixture  of  powdered  zinc  and  sulphur,  it  could  not  be 
called  a  case  of  eledrolysis. 

Prof.  Armstrong  said  an  experiment  of  Prof.  Dewar's 
was  very  instrudive.  He  had  shown  that  if  you  cool  the 
surface  of  a  Crookes  tube  the  discharge  stops.  It  was 
quite  inconceivable  that  at  these  low  pressures  the  gas 
became  liquefied,  so  that  this  experiment  seemed  to  show 
that  condudivity  depends  on  the  presence  of  a  vaporous 
eledrolyte. 

Mr.  Enright  asked  if  Prof.  Armstrong  knew  how  the 
presence  of  an  eledrolyte  assisted  condudion. 

In  a  communication  Prof.  J.  J.  Thomson  said  that  in 
the  decomposition  of  steam  by  a  spark,  the  fad  that  in 
the  tube  as  a  whole  the  amount  of  steam  decomposed  is 
greater  than  the  amount  of  gases  liberated  in  a  volta- 
meter in  series  was  no  objedion  to  the  condudivity  being 
eledrolytic.  The  only  condition  imposed  by  the  laws  of 
eledrolysis  was  that  the  excess  of  H  or  O  at  one  terminal, 
and  of  O  or  H  at  the  other,  should  correspond  to  the 
amount  of  eledricity  passing  through  the  tube.  Thus, 
suppose  in  a  water  voltameter  a  number  of  metal  parti- 
tions are  fixed  so  that  the  current  has  to  pass  across  these 
plates.  Then  at  each  plate  H  will  be  given  off  on  one 
side  and  O  on  the  other,  and  by  making  the  partitions 
sufficiently  numerous  the  total  quantity  of  gases  given  off 
for  the  passage  of  a  given  current  may  be  made  as  large 
as  we  please.  The  excess  at  the  terminals  would  not  be 
afTeded  at  all  by  these  partitions.  In  the  experiments 
made  by  Mr.  Rutherford  and  himself  (Prof.  Thomson), 
they  did  not  observe  any  polarisation  when  the  con- 
dudivity was  produced  by  Rontgen  rays.  With  reference 
to  Mr.  Baly's  objedions  to  the  eledrolytic  theory,  (i) 
There  is  no  reason  to  think  that  under  conditions  other 
than  in  solution  the  atom  of  hydrogen  may  not  have  a 
negative  charge.  (2)  The  eledrolytic  theory  leads  us  to 
exped  that  it  would  require  a  finite  eledromotive  force  to 
send  a  discharge  through  a  gas.  Before  such  a  discharge 
can  take  place,  the  molecules  must  be  split  up,  and  this 
requires  an  eledric  field  of  finite  strength.  (3)  In  the 
case  of  a  gas  the  eledric  field  has  to  ionise  the  molecules, 
/  so  that  an  increase  in  the  strength  of  the  field  will  not 
only  (as  in  the  case  of  a  liquid  eledrolyte)  increase  the 
speed  of  the  ions,  but  it  will  also  increase  their  number, 
and  thus  the  current  will  increase  faster  than  the  eledro- 
motive force.  {4)  The  ion  once  used  can  again  combine, 
and  since  the  ionisation  is  done  by  the  eledric  field  it  can 
be  again  split  up  and  used  again.  If,  however,  the  ion- 
isation has  been  done  by  external  sources,  as,  for  example, 
by  Rontgen  rays,  then  we  find  that  the  condudivity 
decreases  as  the  current  passes.  (5)  There  seems  to  be 
no  reason  on  the  eledrolytic  theory  why  in  a  mixture  of 
HCl  and  CI  some  of  the  current  should  not  go  through 
the  chlorine.  (6)  A  variable  potential  gradient  would  be 
produced  if  the  ions  moved  with  different  velocities.  Mr. 
Baly's  process  in  the  positive  column  appears  to  be  the 
same  as  on  the  eledrolytic  theory,  minus  the  atomic 
charges. 

In  a  communication  Prof.  Schuster  said :  Mr.  Baly 
criticises  what  he  calls  the  eledrolytic  theory,  but  direds 
his  arguments  against  a  form  of  the  theory  which  is,  as 
far  as  the  writer  knows,  upheld  by  no  one.  Mr.  Baly 
appears  not  to  have  read  the  original  papers  in  which  the 
fundamental  points  of  the  theory  upheld  by  J.  J.  Thom- 
son and  the  writer  (Prof.  Schuster)  are  explained.  If  he 
had  done  so  he  could  not  have  given  as  an  objedion  to 
the  theory  that  the  condudivity  of  a  gas  increases  with 
the  E.M.F.    The  essential  difference  between  a  liquid 


58 


Proximate  Constituents  of  Coal. 


r  CHEMICAL  News, 
1      Jan.  29,  1807, 


and  a  gas  is  that  in  the  liquid  the  number  of  ions  is  fixed 
by  the  chemical  constitution  of  the  liquid,  while  in  a  gas 
dissociation  has  first  of  all  to  be  produced  by  the  current 
itself,  and  hence  the  number  of  ions  depends  on  the  cur- 
rent. In  the  paper  referred  to  by  Mr.  Baly,  in  which  the 
fadt  that  when  a  spark  is  passed  through  a  gas  the  gas 
ceases  to  insulate  for  some  distance  round  the  spark  is 
described,  the  explanation  that  this  was  due  to  a  difficulty 
of  passage  of  the  eledlricity  from  the  eledlrode  into  the 
gas  was  especially  disclaimed,  the  explanation  given 
being  substantially  the  same  as  that  now  given  by  Mr. 
Baly.  Mr.  Baly  asks  what  becomes  of  the  ions  that  are 
set  free  ?  The  answer,  of  course,  is  that  they  re-combine. 
The  view  that  stratifications  are  due  to  compound  mole- 
cules, and  do  not  probably  occur  in  pure  gases,  is  not  new. 
With  reference  to  the  author's  statement  about  "  measure- 
ments made  by  Wheatstone  and  J.  J.  Thomson  prove 
that  the  eleAricity  travels  along  the  positive  column  from 
the  anode  to  the  cathode,  and  that  its  velocity  is  about 
half  that  of  light,"  Prof.  Thomson's  results  show  that 
the  breakdown  of  the  insulating  power  of  air  takes  place 
in  the  manner  described,  but  this  does  not  show  anything 
as  to  what  happens  when  the  discharge  has  reached  the 
steady  state.  Mr.  Baly  is  quite  wrong  in  the  excess 
charges  he  assigns  to  different  parts  of  the  vacuum  tube. 
Experiments  on  the  excess  charges  can  count  for  nothing 
unless  they  are  done  with  continuous  currents.  Mr. 
Baly  is  further  wrong  in  stating  that  the  fall  of  potential 
is  rapid  in  the  glow ;  on  the  contrary,  it  is  very  small 
in  the  glow,  being  very  rapid  in  the  dark  space 
between  the  glow  and  the  cathode.  Mr.  Baly  adopts 
Prof.  Thomson's  view  as  to  the  formation  of  molecular 
chains,  but  in  a  form  very  difficult  to  accept.  The  whole 
foundation  of  Mr.  Baly's  theory  is  upset  by  his  wrong 
assumptions  as  to  the  excess  charges  in  different  parts  of 
the  tube. 

The  Author,  in  his  reply,  said,  that  on  some  points  he 
had  been  misunderstood.  He  thought  that  the  increase 
in  conduftivity  could  not  be  due  to  vapour  driven  off  from 
the  sides,  for  ultra-violet  light  also  produced  such  an 
increase.  If  Rontgen  rays  produce  ionisation,  then  there 
ought  to  be  a  reduction  in  the  density  of  the  gas. 


NOTICES  OF  BOOKS. 

Rontgen  Rays,  and  Phenomena  of  the  Anode  and  Cathode. 
By  Edward  P.  Thompson,  M.E.,  E.E.  With  con- 
cluding Chapter  by  Prof.  William  A.  Anthony.  New 
York  :  D.  Van  Nostrand  Company. 

This  book  is  really  a  colledion  of  abstracts  from 
papers  dealing  with  ele<5trical  discharges  generally, 
and  with  the  produdlion  of  X  rays  in  particular  ;  it  is  well 
printed,  and  the  illustrations  are  good,  but  there  seems 
to  be  an  idea  in  the  mind  of  the  printer  that  these  latter 
need  to  be  uniformly  distributed  through  the  book,  with 
the  result  that  within  the  first  70  pages  or  so  we  have  no 
less  than  seven  illustrations  all  referring  to  matter 
beyond  pages  100.  The  first  60  pages  are  occupied 
with  details  of  experiments  on  anodic  and  cathodic  phe- 
nomena made  long  previous  to  Rontgen's  discovery,  the 
reason  for  this  being,  as  the  author  points  out  in  his 
preface,  "  that  the  student  and  general  reader,  whose 
objedt  is  to  become  acquainted  with  the  properties  of 
cathodic  and  X  rays,  might  better  understand  them." 
This  is  very  commendable,  only  we  are  rather  afraid  that 
the  general  reader  will  be  in  danger  of  confusion,  while 
for  the  student  the  abstracts  are  far  too  meagre  to  be  of 
much  value  beyond  that  of  an  index  to  the  publications. 

The  book  contains  far  too  much  of  the  sensational 
newspaper  charader  that  seems  quite  out  of  place ; 
for  instance,  a  whole-page  illustration  of  "  Edison's 
beneficent  X-ray  exhibit  "  at  the  Eledrical  Exposition  in 
i8g6  is  given  on  page  37,  and  is  referred  to  on  page  71  as 


an  instance  when  "  thousands  of  people,  through  the 
beneficence  of  Dr.  Edison,  were  permitted  to  see  the 
shadows  of  their  bones  surrounded  by  living  flesh  I  " 

How  this  will  enable  either  students  or  general  readers 
to  become  better  acquainted  with  X  rays  is  difficult  to 
comprehend. 

Another  personal  illustration,  given  on  page  122,  seems 
equally  superfluous  ;  in  this  a  Sprengel  pump  is  shown 
of  such  an  obsolete  form,  that  if  the  physicist  in  question 
really  used  such  an  apparatus  the  wonder  is  that  he  ever 
produced  any  successful  results  at  all. 

The  abstracts  of  the  most  important  papers  are  good. 
The  review  of  Spottiswoode  and  Moulton's  paper  on 
Sensitive  Discharges,  Mr.  Crookes's  on  Radiant  Matter, 
and  Lenard's  Experiments,  show  that  the  author  has 
thoroughly  investigated  the  subjetft ;  but  again  we  must 
point  out  that  they  seem  too  technical  for  the  general 
reader,  and  the  student  had  far  better  refer  to  original 
papers  for  an  intelligent  knowledge  of  the  experiments 
and  the  conclusions  drawn  from  them.  This  cannot  be 
got  from  an  abstraft,  no  matter  how  carefully  it  may  have 
been  made. 

In  several  places  there  are  statements  that  cannot  fail 
to  mislead  an  uninformed  reader.  For  instance,  on  page 
47  Perrin's  experiment  to  find  out  if  the  cathodic  rays 
carry  negative  charges  is  given  with  illustrations,  but  it 
is  not  stated  that  this  was  fully  demonstrated  five  years 
previously  by  Mr.  Crookes  in  his  Address  before  the 
Institute  of  Eledtrical  Engineers. 

On  page  96  a  standard  X-ray  tube  is  shown  with  two 
concave  cathodes,  one  at  either  end,  and  this  is  stated 
to  have  been  "  first  proposed  by  Prof.  Elihu  Thompson." 
As  this  form  of  tube  immediately  suggested  itself  to  many 
workers  on  the  subjeft,  it  was  proposed  by  numbers  of 
people  in  the  early  days  of  X-ray  work,  and  it  is  difficult 
to  see  the  value  of  a  claim  to  priority,  especially  in  view 
of  the  fadt  that  it  does  not  appear  to  have  fulfilled  the 
hopes  of  those  who  proposed  it.  With  regard  to  the  so- 
called  "focus  tube,"  which  is  really  an  unimportant 
modification  of  Mr.  Crookes's  incandescent  platinum 
tube,  it  is  said  that  King's  College  published  a  descrip- 
tion of  it,  and  that  Mr.  Shallenberger  was  the  first,  as  far 
as  the  author  knew,  to  originate  it.  It  is  perfectly  well 
known  in  England,  at  least,  that  the  use  of  this  tube  was 
fully  described  by  Mr.  Jackson,  of  King's  College,  towhose 
energy  much  of  the  subsequent  success  of  practical 
skiography  is  due,  and  it  seems  a  pity  that  his  name  is 
not  given. 

Great  prominence  is  given  to  the  calcium-tungstate 
screen  for  X-ray  work.  This  material,  although  it  pos- 
sesses the  advantage  of  cheapness,  is  much  inferior  to 
barium  or  potassium  platinocyanide. 

On  the  whole,  we  cannot  but  feel  disappointed  that  the 
book,  which,  as  the  author  says,  is  got  up  regardless  of 
expense,  should  be  of  no  more  use  than  a  compilation  of 
abstracts. 


CORRESPONDENCE. 

REPORT     OF    COMMITTEE    ON 
THE    PROXIMATE    CONSTITUENTS    OF    COAL. 

To  the  Editor  of  the  Chemical  News> 
Sir,— In  the  Chemical  News  (vol.  Ixxiv.,  p.  292)  there 
appeared  a  letter  from  Messrs.  Cross  and  Bevan  relating 
to  the  above  report.  To  this  I  should  have  replied  before 
had  not  my  vacation  intervened,  during  which  I  was 
unable  to  refer  to  the  papers  cited  in  the  letter. 

As  Secretary  of  the  Committee,  and  mainly  responsible 
for  the  drawing  up  of  the  Report,  I  would  wish,  in  the 
first  place,  to  take  the  onus  of  the  shortcomings  of  the 
Report  on  my  own  shoulders,  and,  secondly,  to  disavow 
entirely  any  ihtentioh  to  disparage  oi:  belittle  in  any  Way 


^rbmicalNkws,  ) 
Jan.  29,  1897.     I 


Chemical  Notices  from  Foreign  Sources, 


59 


the  work  of  Messrs.  Cross  and  Bevan  on  this  subjedt. 
That  the  scope  of  their  investigations  had  not  been 
properly  appreciated  by  me  arose  entirely  from  the  fadt 
that  I  was  not— as  I  ought  certainly  to  have  been— aware 
of  the  extent  of  their  investigations.  The  perusal  of 
their  papers  published  in  1881,  and  in  the  Philosophical 
Magazine  of  1882,  has  led  me  to  realise  something  of 
what  they  have  done  toward  furthering  our  knowledge  of 
the  relations  of  coal.  I  wish,  therefore,  to  acknowledge 
the  justice  of  their  claim  to  priority  for  the  method  of 
attacking  this  problem  by  the  aftion  of  chlorinating 
agents. — I  am,  &c., 

P.  Phillips  Bedson. 

The  Durham  College  of  Science, 
Newcastle-upon-Tyne,  January  20,  1897. 


CHEMICAL  NOTICES  FROM  FOREIGN 
SOURCES. 

NoTB.— All  degrees  of  temperature  are  Centigrade  unless  otherwise 
expressed. 

Comptes  Rendus  Hebdomadaires  des  Seances,  deV Academic 
des  Sciences.     Vol.  cxxiv.,  No.  2,  January  ir,  1897. 

Obituary. — M.  Loewy  gave  an  account  of  the  career 
and  researches  of  Prof.  B.  A.  Gould,  the  illustrious  astro- 
nomer, of  Cambridge  (U.S.A.),  who  died  on  November 
26th  last.  The  deceased  was  one  of  the  first  who  suc- 
cessfully applied  photography  to  the  determination  of  the 
positions  of  the  stars. 

The  Academy  proceeded  to  nominate  a  Commission 
charged  with  the  appointment  of  a  young  French  savant^ 
to  whom  will  be  granted  the  "  encouragement  "  founded 
by  the  Royal  Society  of  London  in  memory  of  the 
eminent  physicist  Joule. 

M.  Berthelot  presented  to  the  Academy  a  volume 
entitled  "  Seriae  intorne  alia  Teorie  Moleculare  ad 
Atomica  ad  alia  Notazone  Chimica,"  by  S.  Cannizzaro. 
This  volume  has  been  printed  by  occasion  of  the  70th 
anniversary  of  the  birth  of  the  eminent  chemist,  at  the 
expense  of  an  international  subscription  (July  13,  1896). 

Density  of  Ozone, — Marius  Otto. — The  density  is  ij 
times  that  of  oxygen,  i.e.,  i"6584. 

Decomposition  of  Metallic  Sulphates  by  Hydro- 
cbloric  Acid.  — Albert  Colson.  —  If  the  adtion  of  hydro- 
chloric acid  upon  sulphates  is  assimilable  to  heterogeneous 
dissociations  two  conclusions  are  necessary  : — i.  Sulphuric 
acid  at  about  15°  will  not  attack  lead  chloride  placed  in  an 
atmosphere  of  hydrochloric  acid  gas.  The  attack  takes 
place  only  if  the  pressure  is  sufficiently  reduced.  Not 
merely  is  the  principle  of  mechanical  equivalence  appli- 
cable to  these  phenomena  of  displacement,  but  Carnot's 
principle  intervenes  in  a  decided  manner. 

Polymerisation  of  some  Cyanic  Compounds,  being 
a  Redtification  of  some  of  tbe  Author's  former 
Paper  on  Cy^C\^. — Paul  Lamoult. — A  thermo-chemical 
paper. 

A(5tion  of  Potassium  Cyanide  upon  the  Olides 
I — 4. — Edmond  Blaise. — The  author  is  seeking  to  effedt 
the  synthesis  of  dimethyl  2-2  pentanedioic  acid  by  the 
aftion  of  potassium  cyanide  upon  bromo  —2  —  ,  ethyl 
—  a  —  ,  pentanoate — 

^S3>CBr-CH2-CH2-COa-C3H5-KCN  =  KBr-|- 
/-iTT^>C  -  CHa  — CHa 

CN  CO2-C2H5, 

and  saponification  of  the  nitrile  ether  obtained. 

Phosphoric  Ethsrs  of  AUylic  Alcohol. — J.  Cavalier, 
—  The  author  is  studying  the  monoallyl-phosphoric, 
diallylic  and  triallyl-phosphoric  acids. 


A  Difference  between  the  "  Top  "  and  "Bottom" 
Yeasts. —P.  Petit. — Top  yeast  consumes  more  than 
double  the  amidic  nitrogen  of  bottom  yeast,  and,  on  the 
contrary,  much  ammonial  nitrogen. 


MEETINGS    FOR    THE    WEEK. 

Monday,  Feb.  ist.— Society  of  Arts,  8.  (Cantor  Leftures).  "Material 
and  Design  in  Pottery,"  by  Wm.  Burton,  F.C.S. 
Tuesday,  and.— Royal  Institution,  3.     "Animal  Elearicity,"  by 
Prof.  A.  D.  Waller,  F.R.S. 

Society  of  Arts,  8.      "  The  Progress  of  the  British 

Colonial  Empire  during  the  past    Sixty  Years  of 

Her    Majesty's  Reign,"   by  the    Right  Hon.   Sir 

Charles  W.  Dilke,  Bart.,  M. P. 

Wednesday,  3rd.— Society  of  Arts,  8.    "The  Recommendations  of 

the  Recess  Committee  for  the  Development  of 

Ireland's  Industrial  Resources,"  by  The  Right 

Hon.  Horace  Plunkett,  M.P. 

Society  of  Public  Analysts,  8.      "  The  Composi- 

tion of  Meat  Extrafts  and  similar  Produfts," 
by  Otto  Hehner.  "  The  Distillation  of  Form- 
aldehyd  from  Aqueous  Solution,"  by  Norman 
Leonard,  B.Sc,  Harry  M.  Smith,  and  H. 
Droop  Richmond.  "  Some  Ana'yses  of  Water 
from  an  Oyster  Fishery,"  "  Remarks  on  Form- 
aluehyd  "  (postponed  from  last  meeting),  by 
Charles  E.  Cassal.  ' 

Thursday,  4th.— Royal  Institution,  3.    "  Some  Secrets  of  Crystals  " 
by  Prof.  H.  A.  Miers,  F.R.S. 

Society  of  Arts,  8.    "  The  Mechanical  Produaioa 

of  Cold,"  by  Prof.  James  A.  Ewing,  M.A.,  F.R,S. 

Chemical,  8.     "The   Oxidation  of  Nitrogen,"  by 

Lord  Rayleigh.  "  Researches  in  the  Stilbene 
Series,  1.,"  by  J.  J.  Sudborough,  Ph.D. 
"  Diortho -substituted  Benzoic  Acids.  III. 
Hydrolysis  of  Substituted  Benzamines,"  by 
J.  J.  Sudborough,  Percy  G.  Jackson,  and  L.  L. 
Lloyd.  "Apparatus  for  Steam  Distillation," 
by  F.  E.  Matthews,  Ph.D.  "  Oxidation  of  Sul- 
phurous  Acid  by  Potassium  Permanganate,"  by 
T.  S.  Dymond  and  F.  Hughes. 

Friday,  5th.— Royal  Institution,  9.  "  The  Pidturesque  in  History,' 
by  The  Right  Kev.  The  Lord  Bishop  of  London, 

Saturday,  6th.— Royal  Institution,  9.  "  Neglefted  Italian  and 
French  Composers,"  by  Carl  Armbruster. 


LATELY  PUBLISHED,  Vol.  III.,  86a\pages,  with  248  Illustrations 
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WITH  THE  COLLATERAL  BRANCHES. 
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at  the  Federal  Polytechnic  School,  Zurich  ;  Formerly  Manager  of 
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G-.A.IjXjICI— From  best  Chinese  galls,  pure. 

S.A.Xjia"Y"XjIC-By  Kolbe's  process. 

T.A.IN'IinC— For  Pharmacy  and  the  Arts. 

LIQUID  CHLORINE 

(Compressed  in  steel  cylinders). 

FORMALIN    (40?!'  CHjO)— Antiseptic  and  Preservative. 

POTASS.  PERMANGANATE— Cryst.,  large  and  small, 

SULPHOCYANIDE    OF   AMMONIUM. 

BARIUM. 

POTASSIUM. 

TARTAR    EM  ETIC-Cryst.  and  Powder. 

TRIPOLI  AND  METAL  POWDERS. 

ALL  CHEMICALS   FOR  ANALYSIS   AND  THE  ARTS. 

Wholesale  Agents— 

Am  &  M,  ZIMMERMANN, 

6  &  7,  CROSS    LANE,  LONDON,  E.G. 


Chemical  Nbws, 
Feb.  5,  1897. 


Determtnaiion  of  A  tomic  Masses  by  the  Electrolytic  Method.. 


61 


THE    CHEMICAL     NEWS. 


Vol.  LXXV.,  No.  1941. 


ON  SOME  CHROMATIC  REACTIONS  PRODUCED 

BY   ORGANIC   ACIDS,    PRINCIPALLY 

TARTARIC,     CITRIC,     AND     MALIC     ACIDS. 

By  E.  PINERNA, 
Professor  of  Chemistry  in  the  University  of  Valladolid. 

The  reagent  employed  by  me  contains  of  a  fresh  solution 
of  uaplitliol  /?  in  concentiateiJ  sulphuric  acid  (8-napthol- 
sulphuric  acid).  It  is  prepared  with  0*02  grm.  of  naph- 
thol-/3  anii  i  c.c.  of  sulphuric  acid,  1-83. 

Five  centigrms.  of  each  of  the  organic  acids,  or  the 
residue  left  on  the  evaporation  of  their  solutions,  gradu- 
ally heated  in  a  little  porcelain  capsule  with  a  spirit  flame, 
after  having;  added  from  10  to  15  drops  of  the  reagent, 
produce  the  following  tints: — 

Tartaric  acid,  pure,  gives  at  first  a  blue  colour,  and  on 
continuing  gradually  to  heat,  it  produces  a  very  decided 
green  colouration.  On  adding  water  to  the  liquid  result- 
ing from  the  readion,  after  it  has  cooled  (15  to  20  times 
its  volume),  the  colour  changes  fo  a  persistent  reddish- 
yellow. 

Citric  acid,  pure,  gives  an  intense  blue  colour  which 
does  not  change  to  a  bright  green  even  when  it  is  heated 
gently  for  a  long  time.  On  pouring  fifteen  or  twenty 
times  its  bulk  of  water  on  the  liquid  after  cooling,  the 
solution  remains  colourless  or  takes  a  light  yellow 
colour.  A  small  quantity  of  tartaric  acid  added  to  the 
citric  acid  is  sufficient  to  produce  the  above-mentioned 
indigo-green  colour. 

With  pure  citric  acid  we  never  obtain  the  strong  green 
colouration  so  charaderistic  of  tartaric  acid.  A  dull 
blue-green  corresponds  to  the  presence  of  10  or  12  per 
cent  of  tartaric  acid. 

Malic  acid,  pure,  first  gives  a  greenish  yellow  colour, 
and  on  continuing  the  gradual  adion  of  heat  a  bright 
yellow  colour.  When  the  amount  of  acid  is  very  small 
the  colouration  is  well  seen  by  shaking  the  capsule 
so  that  the  liquid  resulting  from  the  readtion  moistens  the 
interior  side,  and  the  portion  which  remains  on  the  sides 
is  of  a  very  perceptible  yellow  colour.  The  addition  of 
water  changes  the  colour  to  a  bright  orange. 

All  the  readions  of  these  organic  acids  are  charaderistic, 
and  can  be  produced  with  great  facility. 

It  is  only  necessary  to  pay  great  attention  to  the 
employment  of  heat,  and  to  notice  the  moment  when  any 
colouration  commences,  and  then  to  remove  the  capsule 
from  the  fire,  waiting  till  the  change  has  terminated 
before  re-commencing  to  heat  (if  necessary)  until  there 
appear  the  colours  corresponding  to  each  of  the  acids 
indicated  above. 

The  readions  produced  by  other  organic  acids  are 
different  in  colour  and  tint,  but  are  not  so  charaderistic 
or  brilliant  as  those  already  pointed  out.  One  must  pro- 
ceed to  separation  by  solvents  of  the  colouring  matters 
produced.  Other  coloured  readions  are  produced  with 
nitrites,  nitrates,  and  chlorates.  On  adding  ten  drops  of 
the  above  described  reagent  to  hve  centigrms.  of  sodium 
nitrite  with  three  or  four  drops  of  water,  a  very  strong 
red  colouration  is  produced,  and  the  addition  of  water 
does  not  change  it. 

On  pouring  ten  drops  of  a  solution  of  resorcin  in  sul- 
phuric acid  (o-i  grm.  of  resorcine  in  i  c.c.  of  sulphuric 
acid  at  66°)  on  five  centigrms.  of  sodium  or  potassium 
nitrate,  there  is  produced  at  first  a  red-brown  colouration, 
and  then  a  very  intense  violet,  changing  to  orange  on  the 
addition  of  water. 


With  potassium  chlorate  (two  centigrms.  of  chlorate 
suffices)  a  very  intense  green  colour  is  produced,  changing 
to  brown  on  the  addition  of  water. 


THE    DETERMINATION     OF    ATOMIC     MASSES 

OF     SILVER,     MERCURY,     AND     CADMIUM, 

BY     THE     ELECTROLYTIC     METHOD.* 

By  WILLETT  LEPLEY  HARDIN. 

(Continued  from  p.  55). 

Part  II. 
Determination  of  the  Atomic  Mass  of  Mercury, 
From  ail  the  earlier  dt-terininations  Clarke  gives  200  as 
the  most  probable  value  for  the  atomic  mass  of  mercury, 
assuming  oxygen  equal   to  16. 

Experiments  on  Mercuric  Oxide. 
A  large  number  of  experiments  were  made  with  a  view 
of  determining  the  ratio  of  mercury  to  oxygen  in  mercuric 
oxide.  The  method  proved  to  be  unsatisfadory,  although 
apparently  very  good  results  were  obtained  in  some  pre- 
liminary experiments.  The  cause  of  this  close  agreement 
of  results  will  be  explained  in  the  details  of  the  work. 

Preparation  of  Pure  Mercuric  Oxide. 
The  purest  commercial  mercuric  chloride  was  carefully 
sublimed  from  a  porcelain  dish  into  a  glass  funnel.  The 
sublimed  portion  was  dissolved  in  water,  the  solution 
filtered,  and  evaporated  to  crystallisation.  The  crystals 
were  then  thoroughly  dried  and  carefully  re-sublimed. 
The  produd  obtained  in  this  way  consisted  of  white 
crystalline  leaflets  which  dissolved  completely  in  water. 
Pure  sodium  hydroxide  was  then  prepared  by  throwing 
pieces  of  metallic  sodium  on  pure  water  contained  in  a 
platinum  dish.  To  the  pure  sodium  hydroxide  was  added 
a  solution  of  mercuric  chloride,  the  former  always  being 
in  excess.  The  yellow  mercuric  oxide  which  separated 
was  washed  for  several  days  by  decantation  with  hot 
water.  The  material  was  then  dried  twenty-four  hours  in 
an  air  bath  at  105°. 

Mode  of  Procedure. 
In  a  series  of  preliminary  experiments  made  in  the 
spring  of  1895,  a  weighed  portion  of  mercuric  oxide  pre- 
pared in  the  above  manner  was  dissolved  in  a  dilute  solu- 
tion of  potassium  cyanide  in  a  platinum  dish.  The  solu- 
tion was  then  eledrolysed  and  the  weight  of  the  resulting 
metallic  mercury  determined.  Inasmuch  as  the  results 
obtained  in  these  preliminary  experiments  were  not  re- 
duced to  a  vacuum  standard,  it  was  thought  advisable  to 
weigh  the  empty  platinum  dish  after  removing  the  metallic 
deposit  in  order  that  the  two  weighings  might  be  made 
under  approximately  the  same  conditions.  The  results 
for  the  most  part  agreed  very  closely  and  differed  very 
little  from  the  results  obtained  by  other  methods.  Six 
observations  computed  for  the  formula  HgO,  assuming 
the  atomic  mass  of  oxygen  to  be  16,  are  as  follows : — 

Atomic  Masses  of  Silver,  Mercury,  and  Cadmium. 


Weight  of  HgO. 

Weight  of  Hg. 

Atomic  mass 

Grm. 

Grm. 

of  mercury. 

I 

0*26223 

0-24281 

200-05 

2 

0-23830 

0-22065 

200-02 

3 

0-23200 

0-21482 

200'o6 

4 

O-14148 

013100 

200  '00 

5 

0-29799 

0-27592 

200-03 

b 

0-19631 

0'l8l77 

200*02 

Mean 

=200*03. 

♦  Contribution  from  the  John  Harrison  Laboratory  of  Chemisti-y 
No.  13.  From  the  author's  thesis  presented  to  the  Faculty  of  the 
University  of  Pennsylvania  for  the  degree  of  Ph.D. — From  the 
Journal  of  the  American  Chemical  Society,  xviii.,  p.  990. 


62         Determination  of  A  tomic  Masses  by  the  Electrolytic  Method. 


Cbbuical  Mbw8, 
Feb.  5,1807. 


These  results  were  seledled  from  a  larger  series.  After 
making  the  above  observations  it  was  noticed  that  the 
platinum  dish  had  gradually  decreased  in  weight  through- 
out the  work.  This  decrease  in  weight  indicated  that 
the  mercury  deposit  had  formed  an  amalgam  with  the 
platinum  dish,  which  was  soluble  in  hot  nitric  acid.  To 
ascertain  whether  such  was  the  case  or  not  the  platinum 
dish,  after  weighing,  was  filled  with  a  solution  of  the 
double  cyanide  of  mercury  and  potassium  and  the  solution 
eledtrolysed.  On  dissolving  the  mercury  deposit  in  cold 
nitric  acid  a  dark  coloured  film  remained  on  the  sides  of 
the  dish.  The  dish  was  then  carefully  washed,  dried,  and 
re-weighed,  and  found  to  be  heavier  than  at  the  beginning 
of  the  operation,  showing  that  the  mercury  had  not  been 
completely  removed.  The  dark  film  was  then  dissolved 
in  hot  nitric  acid  and  the  dish  again  weighed.  This  last 
weight  being  less  than  that  at  the  beginning  showed  that 
some  of  the  platinum  had  been  dissolved  from  the  dish. 
The  nitric  acid  solution  of  the  dark  film  was  evaporated 
to  dryness  and  ignited  to  remove  the  mercury.  The 
residue  was  dissolved  in  aqua  regia,  the  solution  evapo- 
rated to  dryness,  and  enough  water  added  to  dissolve  the 
small  residue.  A  little  concentrated  ammonium  chloride 
was  then  added  to  the  solution,  and  the  double  chloride 
of  ammonium  and  platinum  separated  as  a  yellow  crystal- 
line  powder.  This  proved  conclusively  that  the  mercury 
deposit  had  united  with  the  platinum  dish  to  form  an 
amalgam  which  was  soluble  in  hot  nitric  acid.  Hence 
the  results  given  for  mercuric  oxide  are  of  no  value  in 
determining  the  atomic  mass  of  mercury. 

A  series  of  careful  experiments  was  then  made  on  the 
oxide  dried  at  different  temperatures.  To  avoid  any  error 
from  the  amalgam  which  formed  with  each  deposit,  the 
platinum  dish  was  weighed  at  the  beginning  of  each  observa- 
tion, the  temperature  and  barometric  pressure  being  noted 
at  the  same  time.  The  results  obtained  from  the  oxide 
dried  at  a  temperature  of  105°  gave  from  180  to  185  for 
the  atomic  mass  of  mercury.  The  material  was  then 
dried  at  a  temperature  of  125°,  but  the  increase  in  the 
amount  of  mercury  obtained  was  very  slight.  Fmally, 
with  material  dried  at  150°,  the  results  obtained  for  the 
atomic  mass  of  mercury  were  all  below  195°. 

The  most  probable  causes  for  these  low  results  are: — 

First,  the  difficulty  of  removing  the  last  traces  of 
alkalies  from  the  mercuric  oxide. 

Second,  the  difficulty  met  in  the  complete  removal  of  the 
moisture  from  an  amorphous  precipitate.  This  difficulty 
as  well  as  the  first  was  referred  to  in  the  experiments  on 
silver  oxide. 

Third,  mercuric  oxide  does  not  form  a  clear  solution 
with  potassium  cyanide.  There  seems  to  be  a  slight  re- 
dudtion  of  the  oxide  to  the  metallic  state.  It  is  difficult 
to  determine  whether  this  reduced  portion  unites  com- 
pletely with  the  metallic  deposit  or  is  partially  removed 
in  the  process  of  washing.  The  latter  is  probably  true, 
and  it  may  be  that  a  different  method  of  analysis  would 
give  more  accurate  results  for  this  compound. 

First  Series. 
Experiments  on  Mercuric  Chloride. 
The  material  used  in  this  series  of  experiments  was 
prepared  from  the  commercial  C.  P.  mercuric  chloride. 
The  product  was  first  dissolved  in  water,  the  solution 
filtered  and  evaporated  to  crystallisation.  The  crystals 
were  dried  and  carefully  sublimed  from  a  porcelain  dish 
into  a  glass  funnel.  The  sublimed  portion  was  dissolved 
in  water,  the  solution  filtered  and  evaporated  to  crystal- 
lisation. These  crystals  were  dried  as  before  and  care- 
fully re-sublimed.  The  material  was  then  placed  in  a 
weighing  tube  and  kept  in  a  desiccator. 

Mode  of  Procedure. 

The  method  of  operation  was  similar  to  that  already 

described  under  the   different   compounds  of  silver.     A 

weighed  portion  of  the  mercuric  chloride  was  dissolved  in 

a  little  potassium  cyanide  and  the  solution  ele^rolysed. 


The  deposit  was  washed  and  dried  and  handled  in  every 
way  like  the  deposits  of  silver.  The  strength  of  the  cur- 
rent and  time  of  aftion  were  as  follows: — 

Time  of  a£lion.  Strength  of  current. 

4  hours     N.Dioo=o'02  amperes. 

N.Dioo  =  o-05         „ 


N.Dioo  =  oio 
N.Dioo  =  o-30 


A  current  of  gradually  increasing  strength  deposits  the 
mercury  in  extremely  small  globules,  which  can  be 
washed  and  handled  more  easily  than  the  larger  globules 
obtained  by  using  a  strong  current  at  first.  In  cases 
where  more  than  one-half  grm.  of  metal  was  deposited 
the  strong  current  was  allowed  to  &&.  two  hours  longer. 

Ten  results  on  mercuric  chloride  reduced  to  a  vacuum 
standard  on  the  basis  of 

5"4i  =  density  of  mercuric  chloride, 
^3'59=  II  II  metallic  mercury, 
2i'4  =       ,,       ,,    platinum  dish, 

8*5   =       ,1      11    weights, 

and  computed  from  the  formula  HgClj,  assuming  35*45 
to  be  the  atomic  mass  of  chlorine,  are  as  follows  : — 


I 
3 

3 
4 
5 
6 

7 
8 

9 
10 


Weight 
of  HgClj. 

Grms. 
0-45932 

o"54735. 

056002 

063586 

0-64365 

073281 

0-86467 

1-06776 

1-07945 

I -5 1402 

Mean  .. 

Maximum 

Minimum 


Weight 
ofHg. 
Grm. 
0-33912 
0-40415 
0-41348 
0-46941 
0-47521 
o'54ioi 
0-63840 
078825 
079685 
1*11780 

=  200' 
=  200 
=      199 


Atomic  mass 
of  mercury. 

200*030 
200-099 
200-053 
199-947 
200-026 
199-988 
200-838 
199-946 
199-917 
200*028 


006 
099 
917 


Difference  ..      =       0-182 
Probable  error    =^o-oii 

Computing  from  the  total  quantity  of  material  used  and 
metal  obtained  we  have  199-996  for  the  atomic  mass  of 
mercury. 

Second  Series. 

Experiments  on  Mercuric  Bromide. 

The  bromine  used  in  these  experiments  was  prepared 

by  distilling   the  commercial    C.   P.   bromine  twice  over 

manganese  dioxide.     Any  trace  of  chlorine  which  might 

be  present  would  be  removed  by  this  method. 

Preparation  0/  Mercuric  Bromide. 
Fifty  grms.  of  metallic  mercury  were  placed  in  a  beaker 
and  covered  with  water.  Pure  bromine  was  then  added 
until  the  mercury  was  completely  saturated.  The  con- 
tents of  the  beaker  were  then  digested  with  hot  water 
until  the  mercuric  bromide  dissolved ;  the  solution  was 
filtered  and  evaporated  to  crystallisation.  The  white 
crystals  of  mercuric  bromide  which  separated  were 
thoroughly  dried  and  carefully  sublimed  from  a  porcelain 
dish  into  a  glass  funnel.  Only  the  middle  portion  of  the 
sublimate  was  used  in  the  experiments.  The  produdl 
obtained  in  this  way  consisted  of  brilliant  crystalline 
leaflets  which  dissolved  completely  in  water.  The 
material  was  kept  in  a  weighing  tube  in  a  desiccator. 

Mode  of  Procedure. 
The  method  of  analysis  was  exadly  like  that  described 
under  mercuric  chloride.     A  weighed  portion  of  the  mer- 
curic bromide  was  dissolved  in  dilute  potassium  cyanide 
in  a  platinum  dish.    The  solution  was  then  eleArolys«d 


Chrmical  Nsws, 
Feb.  St  1S97.     I 


Metal  Reparations  by  means  of  Hydrochloric  A  cid  Gas, 


63 


and  the  resulting  metal  weighed.  The  strength  of  current 
and  time  of  adtion  were  the  same  as  for  mercuiic  chloride. 
Ten  results  on  mercuric  bromide  reduced  to  a  vacuum 
standard  on  the  basis  of 

5-92  =  density  of  mercuric  bromide, 
I3"59  =  II         metallic  mercury, 

21*4  =  ,,         platinum  dish, 

8*5  =  „         weights, 

and  computed  for  the  formula  HgBrj,  assuming  79'95  to 
be  the  atomic  mass  of  bromine,  are  as  follows  : — 


Weight 

Weight           Atomic  mass 

of  HgBfj. 

ofHg. 

of  mercury. 

Grtns. 

Grm. 

I 

070002 

0*38892 

199898 

2 

0*56430 

0*31350 

199-876 

3 

0-57142 

0-31750 

199-938 

4 

077285 

0-42932 

199-832 

5 

0*80930 

0-44955 

199814 

6 

0*85342 

O-474I6 

199  91 1 

7 

1*11076 

0*61708 

199-869 

8 

1*17270 

065145 

199  840 

9 

1*26186 

0-70107 

199899 

10 

1*40142 

0*77870 

199-952 

Mean    .. 

..      =   199-883 

Maximum 

..      =  199*952 

Minimum 

..       =  199*814 

Difference    ..      =      0*138 
Probable  error    =io-oio 

Computing  from  the  total  quantity  of  material  used  and 
metal  obtained,  the  atomic  mass  of  mercury  is  199*885. 
(To  be  continued). 


METAL    SEPARATIONS    BY     MEANS     OF 

HYDROCHLORIC    ACID    GAS.» 

By  J.  BIRD  MOVER. 

(Continued  from  p,  54). 

VI. — Behaviour  of  Cupric  Oxide. 
Pure  copper  nitrate  was  made  by  re-crystallisation.  It 
was  then  ignited  in  a  porcelain  crucible  at  a  dull  red  heat, 
until  it  became  constant  in  weight.  The  pure  black 
oxide  was  then  subjei5ted  to  the  adion  of  hydiochloiic 
acid  gas.  In  Experiment  I.,  the  boat  containing  the 
oxide  was  heated  at  the  outset  to  175°.  It  was  taken  out 
after  two  hours,  placed  over  sulphuric  acid  for  half-an-hour, 
and  weighed.  The  weight  showed  that  the  copper  oxide 
had  hardly  been  aded  upon.  It  had  only  been  super- 
ficially changed  to  chloride.  It  was  then  moistened  with 
two  or  three  drops  of  hydrochloric  acid,  dried  in  a  rapid 
current  of  the  gas,  and  heated  two  hours  longer.  This 
resulted  in  the  complete  transformation  into  chloride. 
The  anhydrous  chloride  thus  obtained,  liver  brown  in 
colour,  was  placed  in  a  desiccator  from  which  the  air  was 
exhausted.  This  was  done  to  remove  all  the  gas  that 
might  be  retained,  and  prevented  a  too  rapid  absorption 
of  moisture. 

Copper  chloride  absorbs  moisture,  but  not  so  rapidly  as 
to  prevent  weighing  in  this  form  : — 

Copper  Copper 

oxide  chloride 

taken.  obtained. 

Grm.  Grm. 


Experiment  I. 

II. 

..        IlL 


0*1011 

0*1025 
0*1034 


0*1708 
0*1726 
0-1756 


Copper 
chloride 
required. 

Grm. 
0*1713 
0-1736 
0*1752 


Difference, 
Grm. 

—  0*0005 

—  0*0010 
4-0*0004 


In  Experiment  II.  the  change  was  completed  in  the 
cold  by  prolonged  adlion  through  four  hours.  It  was 
then  heated  about  ten  minutes  at  the  end  to  drive  out 
the  moisture  that  had  formed.  In  all  the  experiments 
cited,  the  copper  chloride,  after  weighing,  was  found  to 
dissolve  completely  in  cold  water. 

VII. — The  Separation  of  Antimony  from  Copper. 

The  same  material  was  used  as  in  the  preceding 
experiments. 

The  weighed  oxides  were  thoroughly  mixed.  The 
antimony  was  completely  volatilised,  leaving  copper 
chloride  which  was  weighed  as  such.  The  volatile  anti- 
mony chloride  was  caught  in  the  bulb  receiver  at  the  end 
of  the  tube.  The  bulb  and  tube  were  washed  out  with 
acidulated  water  into  a  beaker,  and  the  antimony  thrown 
down  with  hydrogen  sulphide.  The  antimony  sulphide 
was  filtered,  thoroughly  washed,  and  while  moist  dis- 
solved in  strong  hydrochloric  acid.  The  hydrogen  sulphide 
evolved  was  conduced  into  bromine  water  and  oxidised 
to  sulphuric  acid,  which  was  estimated  as  usual  and  the 
antimony  calculated. 

The  length  of  time  required  was  eight  hours.  On 
several  occasions  the  experiment  was  interrupted  at  the 
end  of  four  hours,  but  invariably  the  separation  was 
incomplete,  and  on  dissolving  out  the  copper  chloride 
formed,  black  copper  oxide  and  white  antimony  oxide 
were  plainly  evident.  In  some  cases  the  mixture  of 
oxides  was  moistened  with  a  couple  of  drops  of  hydro- 
chloric acid,  and  then  evaporated  down  in  a  stream  of 
acid  gas  by  heating  the  tube  over  a  water-bath.  This 
treatment  seemed  to  facilitate  matters,  but  it  is  not  alto- 
gether advisable,  because  the  copper  chloride  has  a 
tendency  to  creep  over  the  sides  of  the  boat.  It  is  quicker 
in  the  end  to  separate  them  in  the  dry  condition,  allowing 
plenty  of  time  for  the  readlion.  The  copper  chloride 
obtained  was  perfedly  soluble  in  cold  water  and  con- 
tained no  antimony.  It  could  readily  be  changed  to 
oxide  and  weighed  if  thought  necessary. 


Experiment  I 
„  II 
.,     Ill 


Antimony 

trioxide 

taken. 

Grm. 

.    o-io68 

.    0-1062 

.    01022 


IV.    0*1198 


Copper 
oxide 
taken. 
Grm. 
0-1040 
01053 
O  1020 
0-1020 

Antimony 

trioxide 

taken. 

Grm. 

0-1068 


Copper      Copper 

chloride      chloride 

obtained,    required.  Difference. 


Grm. 
0*1750 
0*1774 
0-1726 
0-1722 

Antimony 
trioxide 
found. 
Grm. 
0-1059 


Grm. 

0-1745 
0-1784 
o  1728 
0-1728 


Grm. 
-{-00005 

—  O'OOIO 

—  00002 

—  00006 


Difference. 

Grm. 
-f  0-0009 


Experiment  I. 

VIII. — The  Separation  of  Bismuth  from  Copper. 
The  pure  oxides  were  mixed   and  treated  as  direded 


under  bismuth  and  lead. 

Copper 
oxide 
taken. 
Grm. 
0-1030 
0*1004 
0-1026 
o-ioig 


Bismuth    Copper 
trichloride  chloride 
taken,     obtained. 


Copper 

chloride  Difference, 
required. 


Experiment  I. 

II. 

„       III. 

IV. 


Grm, 

—  0-0007 

—  00012 
-t-00003 

—  00008 


♦  From  author's  thesis  presented  to  the  Faculty  of  the  University 
of  Penns>lvania  for  the  degree  of  rh.D.,  1896.  From  tbe  Journ. 
Amer.  Chem.  Soc,  xviii.,  December,  i8gG. 


Grm.  Grm.  Grm. 

0-1069  0-1738     0-1745 

0*1077  0-1701      0-1713 

o-iobo  0-1741      0*1738 

0-1058  0*1718     0-1726 
Bismuth         Bismuth 
trioxide  trioxide 

obtained.        required.         Difference. 
Grm.  Grm.  Grm. 

Experiment  I.        0-1076        0-1069         +00007 
The  time  required  in  each  of  these  trials  was  seven 
hours.     It  seemed  to  be  advantageous  to  raise  the  tem- 
perature and  heat  sharply  for  about  ten  minutes  at  the 
end,  to  insure  the  complete  removal  of  the  bismuth. 

Moistening  with  acid  helped  the  reaftion,  but  subjeded 
it  to  the  same  danger  of  creeping  as  noted  under  antimony 
and  copper. 


64 


Metal  Separations  by  means  of  Hydrochloric  A  cid  Gas, 


;hbuical  News, 
Feb.  5,  1897. 


The  bismuth  was  estimated  as  follows :  It  was  washed 
out  of  the  tube  and  bulb  with  acidulated  water,  and  then 
precipitated  as  sulphide.  The  bismuth  sulphide  was 
filtered,  washed,  and  dissolved  in  nitric  acid.  It  was 
thrown  out  of  the  solution  with  ammonium  hydroxide 
and  ammonium  carbonate  as  hydrated  oxide,  and  then 
filtered,  dried,  and  ignited.  It  was  weighed  as  oxide. 
The  residue  of  copper  chloride  in  the  boat  dissolved  in 
cold  water  and  showed  no  bismuth. 

IX. — Action  of  Gaseous  Hydrochloric  Acid  on  Sodium 
Pyroarsenate. 

Hibbs  (yourn.  Amer.  Chem.  Soc,  xviii.,  1044)  showed 
that  arsenic  was  completely  volatilised  from  sodium  pyro- 
arsenate, leaving  weighable  sodium  chloride.  In  fad,  so 
clean  was  the  elimination  of  arsenic  that  he  made  it  the 
basis  of  an  arsenic  atomic  mass  determination,  with 
admirable  success. 

In  working  up  the  separation  of  arsenic  from  other 
metals  it  was  necessary  to  start  with  the  pure  sodium 
salt.  After  purification  I  decided  to  test  it,  by  weighing 
the  salt  produced  by  the  aiJiion  of  the  acid  gas  upon  it. 
Several  determinations  gave  close  results,  proving  the 
salt  pure. 

Chemically  pure  arsenate  was  procured.  It  was 
re-crystallised  and  then  ignited  (not  too  strongly)  for  an 
hour.  The  pyroarsenate  obtained  was  used  in  precipi- 
tating the  various  arsenates  investigated. 


Sodium 

pyroarsenate 

taken. 

Sodium 
chlo.-ide 
obtained. 

Sodium 
chloride 
required 

Experiment  I. 
II. 

Grm. 
0'202I 
0'1039 

Grra. 
01330 
0*0691 

Grm. 

0-1335 
o'o686 

X. — The  Separation  of  Arsenic  from  Copper. 

Pure  sodium  pyroarsenate  was  used  to  precipitate  the 
copper  salt. 

Copper  sulphate  was  re-crystallised  five  times,  a  few 
good  crystals  were  dissolved  and  the  two  solutions  mixed. 
A  green  copper  arsenate  was  precipitated.  It  was  washed 
and  dried  at  100°.  Salkowski  (yourn.  Prakt.  Chem.,  civ., 
129)  observes  that  copper  arsenate  still  contains  water 
above  130°.  My  salt  had  the  composition — 
CujAsaOs  +  2H2O. 

Hydrochloric  acid  gas  completely  changes  it  in  the 
cold  to  chloride.  A  slight  heat  drives  out  the  arsenic 
and  water  and  leaves  a  brown  anhydrous  copper  chloride, 
which  can  be  weighed  as  such.  Care  was  taken  to 
remove  all  the  acid  gas  before  weighing. 

The  arsenic  was  washed  out  of  the  bulb  into  a  beaker ; 
this  was  warmed  with  nitric  acid  to  insure  oxidation,  and 
then  it  was  precipitated  from  an  ammoniacal  solution 
with    *'  a    magnesia     mixture."      It     was     weighed    as 

MgaAsjO;. 

"  Copper 

chloride 
obtained. 

Grm. 
o'o850 
0*0998 
0*0860 


Experiment  I. 

II. 

„         III. 

„  IV. 

V. 


Copper 
arsenate 

taken. 

Grm. 
0*1067 
0*1240 
0*1072 
0*1155 
0*1042 


00924 
0*0832 


Copper 
chloride 
required. 

Grm. 
0*0851 
0*0991 
0*0856 
0*0923 
0*0833 


Difference. 
Grm. 

—  0*0001 
+  0*0007 
-f  0*0004 
-fOOOOI 

—  0*0001 


Experiment  I.  AS2O5  obtained,  0*0498  grm.  ;  AS2O5 
required,  00487  grm. 

The  residue  of  copper  chloride  completely  dissolved  in 
water.  It  showed  no  arsenic  when  tested  in  a  Marsh 
apparatus. 

XI. — The  Separation  of  Arsenic  from  Silver, 

Silver  arsenate  was  made  by  precipitating  silver  nitrate 

with   sodium    arsenate.     Care   was   taken    to   have   the 

nitrate  in  excess.     The  reddish-brown  arsenate  of  silver 

was  washed  with  boiling  water,   until  the  washings  no 


longer  showed  silver  when  tested  with  hydrochloric  acid. 
It  was  dried  at  110°. 

As  was  expeded,  the  acid  gas  attacked  it  even  in  the 
cold.  In  fadt  the  adion  was  so  vigorous  that  a  couple 
of  analyses  were  spoiled  by  spattering.  The  trouble 
arose  from  the  fad  that  the  arsenate  was  not  finely 
powdered.  Heat  was  generated  in  the  readion  suffi- 
ciently to  send  over  a  portion  of  the  water  formed. 
Experiment  I.  was  run  in  the  cold  for  one  hour  and  then 
heated  sharply  for  a  few  minutes  to  expel  the  arsenic  and 
water.  The  result  was  only  0*46  per  cent  too  high,  but 
indicated  that  the  salt  should  be  heated  longer,  and  not 
necessarily  as  high  to  remove  all  the  arsenic. 

The  succeeding  experiments  were  heated  from  one  to 
two  hours  at  150°  with  better  results : — 


Silver 

Silver 

Silver 

arsenate 

chloride 

chloride 

taken. 

obtained. 

required. 

Difference 

Grm. 

Grm. 

Grm. 

Grm. 

Experiment  I. 

0*2542 

0*2381 

0*2363 

+  o*ooi8 

n. 

0*2325 

0*2163 

0*2l6l 

+  O*0002 

in. 

0*2084 

0*1952 

0*1938 

+  0*0014 

IV. 

02070 

0*1927 

0*1924 

+  0*0003 

Experiment  I.  Ag  obtained  =  70*45  per  cent ;  Ag 
required  =  69 '99  per  cent. 

The  residues  in  Experiments  II.,  III.,  and  IV.  were 
dissolved  and  tested  for  arsenic.     None  was  found. 

XII. — The  Separation  of  Arsenic  from  Cadmium. 

Chemically  pure  cadmium  sulphate  was  precipitated  by 
a  solution  of  sodium  pyroarsenate.  Stirring  brought  out 
a  gelatinous  arsenate,  which  changed  by  additional  stir- 
ring to  a  granular  salt.  This  was  thoroughly  washed  and 
dried  at  110°.  It  had  the  composition  Cd3As208  +  2H20. 
Salkowski  (loc.  cit.)  observes  that  a  red  heat  is  necessary 
to  fully  dehydrate  this  salt. 

The  moisture  and  arsenic  were  completely  expelled  at 
150°,  leaving  a  uniform  mass  of  cadmium  chloride.  It 
was  weighed  as  such  after  standing  over  sulphuric  acid 
for  one-half  hour.     The  arsenic  was  determined  as  usual. 

CdgAs20g4-  Cadmium  Cadmium 

2H2O  chloride  chloride 

taken.  obtained,  required.  DifTerence. 

Grm.            Grm.  Grm.  Grm. 

Experiment  I.   0*2359  0*1965  0*1977  —0*0012 

„           II.    0*1166  0*0968  0*0968  O'OOOO 

,,         III.   0*1030  0*0857  0*0855  +O*O002 

„        IV.   o"ii38  0*0947  0*0946  +0*0001 

„          V.  0*1043  0*0870  00867  +0*0003 

CdgAs208+       As^Os  AS2O4 

2H5JO  taken,  obtained,  required.  Difference. 

Grm,            Grm.           Grm.  Grm. 

Experiment  I.   0*2359  0*0813  00822  0*0009 

The  cadmium  chloride  dissolved  perfedly  in  water,  and 
showed  no  arsenic  when  tested  in  a  Marsh  apparatus. 

XIII. — The  Action  of  Hydrochloric  Acid  Gas  on 
Ferric  Oxide. 

Pure  oxide  of  iron  was  heated  in  a  stream  of  acid  gas. 
The  behaviour  of  iron  is  rather  peculiar,  as  it  very  readily 
changes  into  chloride,  and  then  only  partially  volatilises 
On  heating  to  200°  the  greater  part  is  driven  over  as  flaky 
crystals  of  ferric  chloride.  The  remainder  consists  of  a 
white  mass,  which  refuses  to  go  over  on  prolonged  adion 
and  also  on  raising  the  temperature. 

This  residue  was  soluble  in  water  and  did  not  read 
with  potassium  thiocyanate,  but  immediately  gave  a  blue 
precipitate  with  ferricyanide.  Redudion  was  therefore 
evident;  this  is  also  noted  by  Jannasch  and  Schmidt 
{loc.  cit.).  The  temperature  at  which  ferric  chloride 
usually  goes  into  the  ferrous  condition  is  above  looo'^. 

Care  was  taken  to  prepare  perfedly  pure  hydrochloric 
acid  gas.  Chemically  pure  acids  were  used  to  this  end. 
The  adion,  however,  was  the  same  in  all  cases. 


CasMicAt  mbws, 

Feb.  5,  1897.       I 


Nickelo-nickelic  Hydrate. 


XIV.— The  Separation  of  Arsenic  from  Iron. 

Chemically  pure  ferrous  ammonium  sulphate  was  care- 
fully oxidised  with  nitric  acid,  it  was  taken  up  in  water, 
filtered,  and  then  crystallised  several  times.  The  best 
crystals  were  seleded,  and  a  solution  made  to  precipitate 
the  arsenate.  A  white  precipitate  tinged  with  yellow  was 
formed.  It  was  washed  by  decantation  and  then  filtered 
and  washed  until  the  washings  no  longer  gave  Prussian 
blue  with  ferrocyanide.  It  was  then  dried  and  gently 
ignited. 

The  acid  gas  adts  on  it  quickly  in  the  cold,  and  it 
becomes  a  light  green  liquid.  In  evaporating  off  the 
moisture  the  chloride  of  iron  was  carried  over  with  the 
arsenic. 

In  a  second  trial,  with  the  temperature  lower  and  occa- 
sionally removing  the  source  of  the  heat  altogether,  when 
ebullition  threatened  to  cause  spattering,  ferric  chloride 
was  obtained  without  loss.  This  v/as  gradually  heated  a 
little  higher  to  remove  all  the  arsenic. 

The  chloride  of  iron  was  dissolved,  oxidised,  precipi- 
tated with  ammonium  hydroxide,  and  estimated  as  usual. 
The  result  was  fair,  and  the  produdl  tested  showed  the 
absence  of  arsenic,  but  all  succeeding  experiments  failed. 
Either  the  substance  spattered  or  the  iron  went  along 
with  the  arsenic. 

Jannasch  and  Schmidt  {loc.  cit.)  separated  arsenic  from 
iron  by  placing  their  material  in  a  large  hard  glass  bulb 
and  evaporating  down  to  dryness  with  nitric  acid  in  an 
air  current.  This  is  not  applicable  when  a  porcelain 
boat  is  employed.  They  then  volatilised  the  arsenic  in 
hydrochloric  acid  gas  at  120°. 

(To  be  continued). 


NICKELO-NICKELIC    HYDRATE,   Ni304.2H20. 
By  WILLIAM  L.  DUDLEY. 

In  studying  the  adlion  of  fused  sodium  dioxide  on  metals, 
I  have  obtained  interesting  crystalline  compounds,  some 
of  which  at  least  have  never  been  described.  Only  one  of 
them  has  been  carefully  investigated,  and  it  proves  to  be 
nickelo-nickelic  hydrate,  having  the  formula  Ni304.2H20. 

It  is  prepared  by  fusing  sodium  dioxide  in  a  nickel 
crucible  with  metallic  nickel  at  a  cherry-red  heat.  The 
aftion  of  the  oxide  upon  the  nickel  proceeds  with  moderate 
rapidity,  and  in  a  few  minutes  scaly  crystals  appear 
floating  in  the  fused  mass.  The  crystals  multiply  steadily 
until,  in  the  course  of  an  hour,  the  contents  of  the  crucible 
is  thick  with  them,  and  comparatively  little  liquid 
remains.  After  cooling,  the  crucible  is  submerged  in  a 
beaker  of  distilled  water,  and  the  undecomposed  sodium 
dioxide,  together  with  the  sodium  oxide,  dissolves  out, 
leaving  the  crystals  which  rapidly  settle  to  the  bottom  of 
the  liquid.  The  crystals  should  be  washed  several  times 
with  boiling  water  by  decantation,  and  finally  thrown  in  a 
filter.  It  is  quite  difficult  to  wash  out  all  the  alkali,  which 
adheres  with  unusual  persistence.  Probably  the  best 
plan  to  adopt  is  to  put  the  crystals  in  a  Soxhlet  extradlion 
apparatus,  and  wash  with  water  until  no  colouration  is 
obtained  with  phenolphthalein.  I'his  requires  about  fifty 
hours  of  continuous  washing.  The  crystals  should  then 
be  dried  at  no°  C,  and  a  magnet  passed  carefully  through 
them  to  remove  any  particles  of  metallic  nickel  which 
may  have  eroded  and  not  been  completely  adted  upon. 

The  crystals  are  lustrous  and  almost  black,  with  a 
slight  brown-bronze  hue.  They  are  soft,  and  grind  in  a 
mortar  much  like  graphite.  The  crystals  seem  to  be 
hexagonal  plates,  but  measurements  of  the  angles  have 
not  been  made.  They  dissolve  slowly  in  acids,  forming 
nickelous  salts.  Hydrochloric  acid  evolves  chlorine ; 
sulphuric  and  nitric  acids,  oxygen.  They  are  insoluble 
in  water  and  in  solutions  of  the  alkalies.  The  compound 
is  not  magnetic.     The  specific  gravity  is  3*4115  at  32°  C. 


At  130°  C.  the  compound  does  not  undergo  decomposi- 
tion, but  at  about  140°  C.  it  begins  to  lose  weight ;  at 
240°  C.  the  weight  remains  constant.  At  a  red  heat 
further  loss  is  sustained  and  the  residue  remaining  is 
nickelous  oxide.  The  loss  from  130°  C.  to  240°  C.  is  due 
to  water  driven  off,  and  at  a  red  heat  this  loss  is  due  to 
the  evolution  of  oxygen. 

The  compound  proved  to  be  Ni304.2HaO,  as  is  shown 
by  the  results  of  the  analysis  : — 

Loss  of  HaO  on  heating  from  130°  C.  to  240°  C. : — 

Per  cent. 

First  determination 13-00 

Second        „  I3'i3 

Theory  for  Ni304.2H20 13-05 

The  residue  remaining  after  heating  to  240°  C.  is 
Ni304.  On  heating  this  residue  to  redness  the  loss  of 
oxygen  was  found  to  be: — 

Per  cent. 

Loss  of  oxygen 663 

Theory 6*67 

The  total  loss  of  water  and  oxygen  obtained  on  heating 
the  compound  from  130°  C.  to  redness  was  :— 

Per  cent. 

First  determination 18-gi 

Second        „  18-88 

Theory  for  Ni304.2H20 18-86 

The  oxygen  given  off  on  heating  to  redness  was  deter* 
mined  by  calcining  the  compound  in  an  atmosphere  of 
carbon  dioxide,  and  colledting  in  Schiffs  apparatus  over 
potassium  hydroxide  solution.    The  result  gave  : — 

Per  cent. 

Oxygen 5-93 

Theory  for  Ni304.2H20 5-84 

The  nickel  was  determined  and  found  to  be  : — 

Per  cent. 

Nickel 6367 

Theory , 63-72 

In  all  of  the  calculations  the  atomic  weight  of  nickel 
was  taken  to  be  58-56,  and  oxygen  16. 

The  compound  made  in  a  nickel  crucible  of  commerce 
is  not  pcrfedlly  pure,  as  the  sample  obtained  was  found 
to  contain  o-yr  per  cent  of  cobalt,  the  presence  of  which, 
however,  would  make  no  appreciable  difference  in  the 
results  of  the  analyses.  No  method  has  been  found  for 
freeing  the  compound  from  this  impurity,  and  it  appears 
at  present  as  if  the  only  plan  would  be  to  use  a  chemically 
pure  nickel  crucible  in  making  it,  for  no  crucible  will 
withstand  the  adion  of  fused  sodium  dioxide.  Porcelain, 
iron,  silver,  gold,  and  platinum  crucibles  are  rapidly 
attacked. 

The  presence  of  water  in  this  compound  seems  curious, 
but  it  may  be  due  to  the  presence  of  sodium  hydroxide  in 
the  sodium  dioxide.  Again  it  may  be  due  to  the  water 
added  to  dissolve  the  soluble  residue  from  the  crystals. 
The  first  explanation  seems  to  be  the  more  plausible  since 
the  crystals  are  formed  in  the  mass  while  it  is  fused,  and 
they  are  not  produced  upon  the  addition  of  the  water.  If 
such  is  the  case  it  would  seem  that  the  water  driven  off 
between  130°  C.  and  240°  C.  is  from  the  breaking  down  of 
a  true  hydrate,  rather  than  the  expulsion  of  water  of 
crystallisation. 

A  cobalto-cobaltic  hydrate,  C03O4.2H2O,  has  been 
described  (Genth  and  Gibbs,  Amer.  yourn.  Sci.,  xxiii., 
257),  but  it  was  obtained  by  exposing  to  moist  air,  C03O4, 
prepared  by  heating  cobalt  carbonate.  Ni304,  prepared 
by  heating  nickelo-nickelic  hydrate  to  240°  C,  is  hygro- 
scopic, and  absorbs  about  7^^  per  cent  of  water  from  the 
air  at  30°  C,  which  is  completely  lost  at  110°  C,  show- 
ing that  no  hydrate  is  formed  under  these  conditions. 

The  study  of  the  adion  of  fused  sodium  dioxide  on 
the  metals  will  be  continued  here,  and  it  is  hoped  that 
some  more  data  can  be  contributed  soon. — yournal  of  the 
American  Chemical  Society,  xviii.,  OAober,  1896. 


66 


Aluminum  Analysis. 


OHBMicAL  News, 
Feb.  5,  i8q7. 


ALUMINUM     ANALYSIS.* 

By  JAMES  OTIS  HANDY. 
(Continued  from  p.  56). 


Determination  of  Sodium  in  Aluminum. 
One  grm.  of  drillings  is  dissolved  in  a  porcelain  evapo- 
rating dish  in  50  c.c.  of  1*3  sp.  gr.  nitric  acid  and  sufficient 
hydrochloric  acid  to  effed  solution.  Boil  down  until  all 
hydrochloric  acid  has  been  removed.  Rinse  the  solution 
into  a  large  platinum  dish  and  evaporate  to  dryness. 
Heat  over  a  good  Bunsen  burner  until  nitric  oxide  fumes 
cease  to  be  evolved.  Grind  the  residue  finely.  Mix  it 
by  grinding  with  i  grm.  of  chemically  pure  ammonium 
chloride  and  8  grms.  of  chemically  pure  calcium  carbonate. 
Heat  the  mixture  in  a  large  covered  platinum  crucible. 
For  the  first  fifteen  minutes  have  a  Bunsen  burner  flame 
just  touching  the  bottom  of  the  crucible,  and  for  the  next 
forty-five  minutes  have  the  whole  crucible  heated  bright 
red  by  a  full  Bunsen  burner  flame.  Cool,  and  treat  the 
residue  with  hot  distilled  water  until  it  becomes  just 
friable  under  pressure.  Avoid  adding  an  excess  of  water 
beyond  that  necessary  to  make  the  sintered  mass  just 
friable.  Grind  it  in  a  Wedgwood  mortar,  and  rinse  out 
with  hot  distilled  water.  Filter,  rejedling  the  well-washed 
residue,  and  treat  the  filtrate  at  the  room  temperature 
with  saturated  ammonium  carbonate  solution  in  slight 
excess.  Stir  very  thoroughly.  The  precipitated  calcium 
carbonate  is  at  first  flocculent,  but  on  standing  for  about 
ten  minutes  it  becomes  crystalline.  Filter  into  a  platinum 
dish  ;  rejedt  the  residue,  and  evaporate  the  solution  on 
the  water-bath  to  dryness.  Heat  carefully  to  dull  redness 
to  expel  ammonium  salts.  Dissolve  the  residue  in  a  little 
water,  and  add  a  few  drops  of  ammonium  carbonate  solu- 
tion.  If  this  produces  a  precipitate,  add  sufficient  ammo- 
nium carbonate  solution  to  precipitate  all  of  the  remaining 
lime.  Stir  well,  wait  ten  minutes,  filter,  evaporate  to 
dryness,  heat  to  dull  redness,  and  weigh  sodium  chloride. 
Dedudt  any  sodium  chloride  found  in  a  blank  determina- 
tion, using  acids,  &c.,  as  above,  and  finally  8  grms.  of 
calcium  carbonate  and  i  grm.  of  ammonium  chloride. 

NaCl  X  0'393i6  =  Na. 

Care  should  be  taken  when  heating  up  the  residue  of 
sodium  chloride,  &c.,  after  evaporating  on  the  water-bath. 
If  the  platinum  dish  and  contents  are  heated  for  a  few 
minutes  on  sheet  asbestos  on  the  hot  plate  before  placing 
over  the  lamp,  spattering  may  be  avoided.  Sodium  is 
generally  absent  from  aluminum,  but  it  has  been  found 
in  amounts  as  high  as  0*20  per  cent,  and  is  considered  a 
cause  of  the  cccasional  deterioration  of  the  metal  in 
water. 

Determination  of  Carbon  in  Aluminum.    {Moissan^s 

Method  Modified). 
Triturate  2  grms.  of  drillings  in  a  Wedgwood  mortar 
with  10  to  15  grms.  of  mercuric  chloride,  powdered  and 
dissolved,  or  partly  dissolved,  in  about  15  c.c.  of  water, 
Readion  takes  place  rapidly,  and  a  heavy  grey  residue  is 
left.  Persistent  trituration  removes  the  last  particles  of 
metallic  aluminum.  Evaporate  on  the  water-bath  to 
dryness.  The  dry  residue  is  heated  in  a  current  of  pure 
hydrogen  to  expel  mercuric  compounds.  The  remaining 
material  is  then  placed  in  a  boat  in  a  combustion-tube 
and  burned  off  as  in  carbon  determination  in  steel.  The 
carbon  dioxide  is  caught  as  barium  carbonate,  and  the 
excess  of  barium  hydroxide  determined  by  means  of 
standard  acid.  We  are  working  on  a  more  generally 
applicable  method  for  carbon  in  alummum. 

Determination  of  Nitrogen  in  Aluminum. 
Aluminum,  when  overheated  in  re-melting,  is  believed 
to  have  the   property  of  combining  with  nitrogen.     The 
metal  becomes  weaker.      Moissan's   method    for  deter- 

*  Fiom  the  Journal  of  the  American  Chemical  Society,  Sept.,  1896. 


mining  nitrogen  in  aluminum  may  be  found  in  Complex 
Rendus,  cxix.,  12.  Nitrogen  thus  absorbed  would  un- 
doubtedly exist  as  nitride  of  aluminum,  and  solution  of 
sodium  hydroxide  with  subsequent  distillation  would  seem 
to  be  the  best  method  of  procedure.  We  are  working  up 
this  method. 

Determination  0}  Aluminum  in  Metallic  Aluminum. 

Dissolve  I  grm.  of  metal  in  30  c.c.  of  33  per  cent 
hydrochloric  acid  in  a  porcelain  dish  and  evaporate 
cautiously  to  complete  dryness.  Re-dissolve,  by  boiling 
with  10  c.c.  of  concentrated  hydrochloric  acid  and  75  c.c. 
of  water.  Wash  into  a  12-ounce  beaker  ;  dilute  to  250 
c.c,  and  pass  hydrogen  sulphide  until  saturated.  Filter 
into  a  beaker  and  boil  off  hydrogen  sulphide.  Oxidise  by 
adding  i  c.c.  of  concentrated  nitric  acid  and  continuing 
to  boil  for  ten  minutes.  Cool,  and  make  the  solution  up 
to  500  c.c.  Remove  50  c.c.  of  the  solution,  and,  having 
diluted  to  250  c.c.  and  heated  to  boiling,  add  ammonium 
hydroxide  in  slight  excess  and  boil  well  for  twenty 
minutes.  Let  settle;  filter,  and  wash  thoroughly  with 
hot  water.  It  is  necessary  to  wash  the  precipitate  off 
from  the  filter,  break  it  up,  and  wash  it  back  again. 
Finally  burn  off  in  a  thin-walled  platinum  crucible, 
igniting  most  intensely,  and  weighing  the  instant  the 
crucible  and  contents  are  cool.  We  have  found  that 
alumina  is  one  of  the  most  difficult  oxides  to  dehydrate 
completely,  and  when  dehydrated  it  absorbs  atmospheric 
moisture  even  more  rapidly  than  calcium  oxide  does. 
Moissan  prefers  to  precipitate  aluminum  by  ammonium 
sulphide.  Having  prepared  a  solution  in  hydrochloric 
acid,  he  takes  an  amount  equal  to  0*15  grm.  of  aluminum, 
neutralises  it  in  the  cold  with  ammonia,  and  precipitates 
it  by  ammonium  sulphide  which  has  been  recently  pre- 
pared. He  then  digests  for  one  hour,  filters,  washes 
with  hot  water,  ignites,  and  weighs. 

Analysis  of  Alloys  of  Aluminum  with  Smaller  Amounts 
of  other  Metals. 

Copper  Alloys. — Three  to  thirty  per  cent  copper,  and  no 
zinc  or  nickel. 

Dissolve  i  grm.  or  i  grm.  in  15  c.c,  of  33  per  cent 
sodium  hydroxide  solution  in  an  Erlenmeyer  flask  of 
12-ounce  capacity.  If  the  flask  is  covered  and  set  in  a 
warm  place,  solution  is  complete  in  a  few  minutes,  even 
if  the  drillings  are  quite  coarse.  Dilute  to  30  c.c.  with 
hot  water,  and  filter  through  a  coarse  lintless  filter-paper 
(Whitall,  Tatum,  and  Co.'s  5-inch).  Wash  well  with  hot 
water.  Dissolve  residue,  after  washing  it  off  the  filter- 
paper  into  a  12-ounce  beaker,  by  warming  with  5  c.c.  of 
concentrated  nitric  acid.  Cool,  add  saturated  commercial 
sodium  carbonate  solution  until  re-solution  occurs.  Titrate 
with  standard  potassium  cyanide  solution  to  the  disap- 
pearance of  the  blue  colour.  Standardise  the  cyanide  for 
about  the  same  amount  of  copper. 

For  commercial  reasons  20  per  cent  alloys  are  made  in 
the  reduction  pots,  and  these  alloys  are  subsequently  used 
for  making  copper  alloys  of  low  percentage. 

Determination  of  Nickel  in  Aluminum  Alloys. 

The  3  per  cent  nickel  alloy  is  now  used.  The  addition 
of  3  per  cent  of  nickel  increases  the  tensile  strength  of 
aluminum  by  several  thousand  pounds  per  square  inch. 

One  grm.  of  drillings  is  dissolved  in  15  c.c.  of  33  per 
cent  sodium  hydroxide  solution  in  a  12-ounce  Erlenmeyer 
flask.  Dilute  to  50  c.c,  and  filter  through  a  5-inch  lint- 
less  paper,  washing  the  residue  thoroughly  with  hot  water. 
Rinse  the  residue  back  into  the  ilask,  and  add  3  to  5  c.c. 
of  concentrated  nitric  acid,  and  a  drop  of  concentrated 
hydrochloric  acid.  Boil,  and  when  dissolved  cool,  and 
make  up  to  250  c.c.  In  100  c.c.  determine  the  copper  by 
neutralising  with  ammonia,  adding  2  c.c.  of  concentrated 
hydrochloric  acid,  warming,  and  passing  hydrogen  sul- 
phide.  Filter  and  wash  with  ammonium  sulphide.  Burn 
it  off  carefully  in  a  porcelain  crucible,  and,  having 
weighed,  dissolve  in  5  c.c.  of  concentrated  nitric  acid. 


OHSyiCAL  NbW8,I 

Feb.  5,  1897.     I 


A  luminum  A  nalysis* 


67 


Then  dilute  to  20  c.c,  add  excess  of  sodium  carbonate 
solution,  and  titrate  with  standard  potassium  cyanide. 
Boil  the  filtrate  from  the  cupric  sulphide,  oxidise  with 
I  c.c.  of  nitric  acid,  and  precipitate  with  ammonium 
hydroxide.  Do  not  boil,  but  digest  for  a  few  minutes 
just  below  the  boiling-point.  Filter,  wash,  re-dissolve  in 
hot  15  per  cent  nitric  acid  wash.  Dilute  to  150  c.c,  and 
again  precipitate  with  excess  of  ammonium  hydroxide, 
being  careful  to  avoid  boiling  or  prolonged  digestion. 
Filter  and  wash.  Burn  off  and  weigh  ferric  oxide,  &c. 
In  a  second  100  c.c.  of  the  main  solution,  precipitate 
nickel  hydroxide,  cupric  oxide,  ferric  hydroxide,  &c.,  by 
33  per  cent  chemically  pure  sodium  hydroxide  solution, 
added  in  slight  excess  to  the  boiling  solution.  Boil  for 
fifteen  minutes,  filter,  and  wash  most  thoroughly  with 
hot  water.  Burn  off  and  weigh  nickel  oxide,  cupric 
oxide,  and  ferric  oxide.  Deducft  cupric  oxide  and  ferric 
oxide  already  found.  Calculate  nickel  oxide  to  metallic 
nickel. 

Analysis  of  Aluminum-Manganese  Alloys. 
Determination  of  Manganese. — Place  i  grm.  of  drillings 
in  a  i2-ounce  beaker.  Add  30  c.c.  of  33  per  cent  hydro- 
chloric acid  (one  part  of  concentrated  hydrochloric  acid 
to  two  parts  of  water).  When  dissolved  add  25  c.c.  of 
nitric  acid  (1*42),  and  boil  down  to  10  c.c.  Add  50  c.c.  of 
colourless  nitric  acid  (i'42),  and  boil.  Precipitate  the 
manganese  with  powdered  potassium  chlorate,  added 
cautiously,  and  proceed  as  described  under  manganese  in 
steel  by  Williams's  method  (Blair's  "  Chemical  Analysis 
of  Iron  "). 

Analysis  of  Chromium-Aluminum  Alloy. 
Determination  of  Chromium.  —  Dissolve  i  grm.  in  a 
i2-ounce  beaker  in  30  c.c.  of  33  per  cent  hydrochloric 
acid,  and  when  dissolved  add  50  c.c.  of  sulphuric  acid 
(i'84),  and  evaporate  carefully  until  fumes  of  sulphur 
trioxide  escape.  Cool,  add  60  c.c.  of  water,  and  boil. 
After  five  minutes,  if  all  aluminum  sulphate  has  been 
dissolved,  add  powdered  potassium  permanganate  until 
the  solution  has  a  distind  pink  colour.  Boil  until  the 
excess  of  potassium  permanganate  is  decomposed.  Filter 
through  washed  asbestos,  and  determine  the  chromium 
in  the  filtrate  as  in  chrome  steel  (Galbraith's  method. 
See  Blair's  •'  Chemical  Analysis  of  Iron"). 

Analysis  of  Tungsten-Aluminum  Alloy. 
Determination  oj  Tuw^sfeM.— Dissolve  i  grm.  in  33  per 
cent  hydrochloric  acid  in  a  4J-inch  evaporating  dish.  Add 
30  c.c.  of  nitric  acid  (i'42),  and  evaporate  to  dryness. 
Re-dissolve  in  30  c.c.  of  hydrochloric  acid  (i"2o),  dilute 
to  about  go  c.c,  and  boil  for  two  hours.  Filter  and  wash 
thoroughly.  Burn  off  and  weigh  Si  -|-  Si02-f-W03  -f-  cru- 
cible. Treat  with  3  drops  of  25  per  cent  sulphuric  acid 
and  about  2  c.c.  of  hydrochloric  acid.  Evaporate  care- 
fully over  an  Argand  burner,  re-ignite,  and  weigh  crucible 
and  silicon  and  tungstic  oxide.  Fuse  with  i  grm.  of 
sodium  carbonate,  cool,  place  in  dish,  and  add  15  c.c.  of 
water  and  20  c.c.  of  25  per  cent  sulphuric  acid,  remove 
crucible,  and  evaporate  until  white  fumes  escape.  Cool, 
re-dissolve  in  about  50  c.c.  of  water.  Filter,  wash,  ignite, 
and  weigh  silica  (from  silicon),  tungstic  oxide,  and  cru- 
cible. Treat  with  sulphuric  acid  and  hydrofluoric  acid, 
evaporate,  ignite,  and  re-weigh.  Loss  equals  silica. 
Calculate  to  silicon,  and  add  to  the  weight  of  silica  lost 
by  treatment  of  first  insoluble  residue.  Dedudt  this  sum 
from  the  weight  of  silicon,  silica,  and  tungstic  oxide  first 
found,  and  the  remainder  equals  tungstic  oxide.  Calcu- 
late to  tungsten. 

Analysis  of  Aluminum-Titanium  Alloy. 
Determination  of  Titanium. — Two  grms.  of  the  alloy 
in  a  i2-ounce  Erienmeyer  flask  are  dissolved  by  addition 
of  50  c.c  of  10  per  cent  potash  solution.  Dilute  with 
distilled  water  to  about  125  c.c,  boil  up,  and  filter  as 
quickly  as  possible.    Wash  ten  times  with  boiling  water. 


Burn  off  the  residue  in  a  porcelain  crucible,  crush  it  in  a 
Wedgwood  mortar,  fuse  in  a  large  platinum  crucible  with 
10  grms.  of  potassium  bisulphate.  Condudt  the  fusion 
exaAly  as  follows : — Choose  a  good  Bunsen  burner,  and 
protedl  it  from  draught  by  a  sheet-iron  chimney ;  make 
the  flame  i^  inches  long,  and  place  the  triangle  carrying 
the  upright  crucible  just  at  the  point  of  the  flame.  In- 
crease the  heat  gradually  until  in  ten  minutes  the  lower 
fourth  of  the  crucible  is  red  hot.  Allow  it  to  remain  at 
this  temperature  ten  minutes,  moving  the  lid  slightly  to 
one  side  every  two  minutes,  and  giving  the  crucible  (held 
firmly  in  the  tongs)  a  gentle  rotating  movement,  then  turn 
up  the  light  until  the  flame  reaches  the  top  of  the  crucible 
and  envelopes  it.  Five  minutes  of  this  treatment  melts 
down  any  potassium  bisulphate,  &c,  which  have  risen  on 
the  sides.  The  flame  is  lowered  and  the  lower  fourth  heated 
for  ten  minutes  longer.  Cool,  dissolve  in  about  200  c.c 
of  water ;  filter,  rejedling  the  residue,  if  ignition  and 
treatment  with  hydrofluoric  acid  show  it  to  be  only 
silica.  If  it  contains  anything  more,  fuse  with  4  grms.  of 
potassium  bisulphate  again.  The  filtrate  contains  all  the 
titanic  oxide  and  the  ferric  oxide.  Add  ammonia  until  a 
slight  permanent  precipitate  is  formed,  then  add  dilute 
sulphuric  acid  from  a  pipette  or  burette  until  this  precipi- 
tate just  re-dissolves.  Finally  add  i  c.c.  more  of  25  per 
cent  sulphuric  acid,  and  dilute  to  300  c.c.  If  the  solution 
is  high  in  iron  (which  will  be  indicated  by  its  distindl 
yellow  colour)  sulphur  dioxide  gas  must  be  run  into  it 
until  it  is  decolourised  and  smells  strongly  of  sulphur 
dioxide;  but  if  the  solution  is  nearly  colourless,  indicating 
a  low  percentage  of  iron,  only  sulphur  dioxide  water 
need  be  added  for  the  redudtion.  Boil  well  for  one  hour, 
adding  water  saturated  with  sulphur  dioxide  occasionally. 
Filter  off  the  titanic  oxide  through  double  filters,  and 
wash  well  with  hot  water.  Burn  off  and  weigh  as  titanic 
oxide.  If  the  precipitate  is  yellow,  indicating  the  pre- 
sence of  iron,  it  may  be  fused  with  i  grm.  of  potassium 
bisulphate,  the  fusion  dissolved  in  10  c.c.  of  dilute  sul- 
phuric acid,  and  the  iron  determined  in  this  solution  by 
reducing  with  i  grm.  of  zinc,  and  titrating  with  perman- 
ganate. This  is  not  often  necessary.  Calculate  titanic 
oxide  to  titanium.     TiOj  X  o-6  =  Ti. 

Determination  of  Zinc  in  Zinc-Aluminum  Alloys.  First 
Method. 
Dissolve  I  grm.  in  30  c.c  of  33  per  cent  hydrochloric 
acid  in  a  i2-ounce  beaker.  Dilute  to  200  c.c,  and  heat 
nearly  to  boiling.  Pass  hydrogen  sulphide  till  all  copper 
is  precipitated.  Filter  and  boil  off  hydrogen  sulphide, 
oxidise  with  i  c.c  nitric  acid  by  boiling  ten  minutes. 
Add  sodium  hydroxide  solution  until  neutral,  then  make 
barely  acid  with  hydrochloric  acid,  and  stir  until  the 
aluminum  hydroxide  all  dissolves.  Add  10  grms.  of 
sodium  acetate  and  500  c.c.  of  water,  boil  up,  and  filter 
at  once.  Dissolve  the  washed  precipitate  in  hydrochloric 
acid,  and  repeat  the  acetate  separation.  Heat  the 
united  filtrates  to  boiling  and  pass  hydrogen  sniphide. 
Filter  off  the  zinc  sulphide  on  double  filters,  wash 
thoroughly  with  hot  water.  Burn  off  in  a  porcelain  cru- 
cible, and  weigh  zinc  oxide.  Calculate  to  zinc  This 
method  may  be  used  when  only  a  small  quantity  of  the 
sample  is  available;  but  when  this  is  not  the  case,  it  is 
better  to  use  the  method  given  below. 

Determination  of  Zinc  in  Zinc-Aluminum  Alloy.  Second 
Method. 
Dissolve  I  grm.  of  drillings  in  33  per  cent  sodium 
hydroxide  solution  in  a  12-ounce  Erienmeyer  flask.  Filter 
as  soon  as  dissolved  through  a  4-inch  lintless  filter-paper. 
Wash  thoroughly  with  hot  water.  Rinse  the  residue  of 
zinc,  iron,  copper,  silicon,  &c.,  back  into  the  flask.  This 
may  require  25  c.c.  of  water.  Add  5  c.c.  of  hydrochloric 
acid  and  boil.  Dilute  to  150  c.c.  with  hot  water  and  pass 
hydrogen  sulphide.  Filter  and  boil  off  hydrogen  sulphide, 
re-oxidise  by  adding  i  c.c.  nitric  acid  and  boiling  ten 
minutes.    Add  sodium  hydroxide  till  neutral,  then  add 


68 


Constitution  of  Benzene, 


{Chemical  NkWb, 
Feb.  5,  1897. 


dilute  hydrochloric  acid  till  just  acid,  and  then  10  gims, 
of  sodium  acetate,  and  300  c.c.  of  boiling  water,  and  boil 
for  five  minutes.  Wash  well.  If  the  precipitate  is  small 
re-solution  and  re-precipitation  are  not  necessary.  Pass 
hydrogen  sulphide  through  the  filtrate.  Filter  off  zinc 
sulphide  through  double  filters.  Wash  well.  Ignite  in  a 
porcelain  crucible,  heating  finally  over  the  blast  to  zinc 
oxide.     ZnOxo'8o32  =  Zn. 

Analysis  of  Aluminum  Solders. 
Determination  0/ Tin,  Phosphorus,  and  Z««c.— Alumi- 
num solders  generally  contain  phosphor-tin  and  zinc.  As 
presented  for  analysis  they  usually  consist  of  a  soldered 
joint,  from  which  the  solder  must  be  scraped  and  analysed. 
The  analysis,  therefore,  involves  a  separation  of  the 
elements  aluminum,  zinc,  tin,  and  phosphorus.  It  is  a 
difficult  matter  to  determine  whether  aluminum  was  a 
constituent  of  the  solder  when  only  a  soldered  joint  is 
available  for  examination.  It  is  best  to  dissolve  all 
adhering  aluminum  from  the  pieces  chosen  for  analysis  by 
treatment  with  33  per  cent  sodium  hydroxide  solution, 
after  which  the  residue  is  filtered  off,  dried,  and  weighed 
out  for  analysis.  Dissolve  or  decompose  three-tenths  to 
five-tenths  grm.  in  a  twelve-ounce  beaker  by  means  of 
20  c.c.  of  nitric  acid  (i'42).  If  necessary,  5  c.c.  of  hydro- 
chloric acid  (i'2)  may  be  used  to  effeft  complete  decom- 
position. Evaporate  to  complete  dryness  on  a  hot  plate. 
Cool,  add  25  c.c.  of  nitric  acid  (i'i3),  and  boil  thoroughly. 
Filter.  The  residue  contains  all  of  the  tin,  most  of  the 
phosphorus,  and  possibly  some  zinc.  Burn  it  off  in  a 
porcelain  crucible,  and,  after  pulverising  the  residue  in  an 
agate  mortar,  mix  it  with  2  grms.  of  sodium  carbonate 
and  2  grms.  of  sulphur,  fuse  it  in  a  covered  porcelain 
crucible  over  a  Bunsen  burner  for  about  half-an-hour. 
Give  it  three  minutes  of  gentle  blast  flame  at  the  last. 
Cool,  boil  out  with  150  c.c.  of  water  in  a  twelve  ounce 
covered  beaker.  Filter  and  wash.  Extracft  any  possible 
zinc  sulphide,  &c.,  from  the  residue  by  dissolving  in  nitric 
acid,  boiling  off  hydrogen  sulphide,  and  adding  this  to 
the  first  filtrate  obtained  after  evaporating  to  dryness  with 
nitric  acid.  The  sodium  sulphide  solution  contains  the 
tin  and  phosphorus.  Add  it  to  hydrochloric  acid  until 
just  acid.  Warm  slightly  and  pass  hydrogen  sulphide. 
Filter  off  stannous  sulphide  and  wash  thoroughly  with  hot 
water.  Burn  off  in  a  porcelain  crucible  and  weigh  stannic 
oxide.  Calculate  to  metallic  tin.  rhe  filtrate  from  the 
stannous  sulphide  is  boiled  to  expel  hydrogen  sulphide, 
and  then  oxidised  by  adding  2  c.c.  of  nitric  acid  and 
boiling  for  fifteen  minutes  more.  Filter  off  any  sulphur 
which  separates,  and  in  this  filtrate,  which  should  amount 
to  only  about  100  c.c,  precipitate  the  phosphorus  by 
adding  pure  sodium  hydroxide  solution  till  alkaline,  then 
nitric  acid  till  distindly  acid,  heating  to  85°  C,  and 
adding  50  c.c.  of  filtered  molybdate  solution.  Stir  or 
shake  well  for  five  minutes,  filter  on  a  weighed  filter 
paper,  and  after  washing  with  one  per  cent  nitric  acid 
wash,  dry  at  100°  C,  and  weigh.  Yellow  precipitate 
multiplied  by  o"oi63  equals  phosphorus.  The  nitric  acid 
solution  obtained  after  evaporating  the  first  solution  to 
dryness,  &c.,  is  now  neutralised  with  sodium  hydroxide 
solution,  and  then  made  just  acid  with  hydrochloric  acid. 
Ten  grms.  of  sodium  acetate  are  now  added,  and  300  c.c. 
of  water  (hot).  Boil  up  for  five  minutes,  then  filter  and 
wash.  If  the  precipitate  is  of  considerable  size,  it  is  pro- 
bable that  aluminum  was  a  constituent  of  the  solder. 
Re-dissolve  it  in  a  little  hydrochloric  acid,  neutralise, 
acidify,  and  make  a  basic  acetate  separation  as  before. 
Precipitate  the  zinc  in  the  acetate  solutions  by  hydrogen 
sulphide.  Filter,  wash,  ignite  in  a  porcelain  crucible,  and 
weigh  as  zinc  oxide.  Calculate  to  metallic  zinc.  Dis- 
solve the  precipitate  of  aluminum  acetate  in  hydrochloric 
acid,  dilute  to  250  c.c,  and  precipitate  with  ammonia. 
After  filtering,  washing,  igniting,  and  weighing  as 
alumina,  calculate  to  metallic  aluminum.  Solders  con- 
taining lead  are  sometimes  met  with.  In  such  cases, 
evaporate  the  nitric  acid  filtrate  from  the  metastannic 


acid  to  small  bulk,  add  25  c.c.  of  25  per  cent  sulphuric 
acid,  and  evaporate  until  white  fumes  escape.  Cool,  add 
100  c.c.  of  water,  stir,  an  d  let  stand  for  an  hour  in  a  warm 
place.  Filter  and  wash  with  water  containing  5  per  cent 
sulphuric  acid.  Burn  off  in  a  porcelain  crucible  at  a  low 
temperature.  Re  oxidise  any  reduced  lead  oxide,  and 
restore  its  sulphur  trioxide  by  adding  a  few  drops  of  nitric 
acid  and  sulphuric  acid  and  evaporating.  Finally  weigh 
lead  sulphate.  Calculate  to  metallic  lead.  Zinc  is  deter- 
mined  in  the  lead  sulphate  filtrate. 

Analysis  0/ Alumina.' 
Alumina  is  made  from  bauxite  or  cryolite.    It  is  usually 
purchased  in  the  hydrated  form. 

(To  be  continued). 


PROCEEDINGS    OF    SOCIETIES. 


EDINBURGH 


UNIVERSITY 
SOCIETY. 


CHEMICAL 


At  a  meeting  of  the  Edinburgh  University  Chemical 
Society  on  the  nth  January,  a  paper  was  read  by  Dr. 
Macdonald  on  the"  Constitution  of  Benzene." 

The  different  formulas  from  time  to  time  proposed  for 
benzene  were  discussed  and  criticised.  It  was  pointed 
out  that  for  the  study  of  all  ordinary  benzene  derivatives, 
Kekule's  hexagonal  formula  had  proved  the  most  service- 
able. The  identity  of  3-  and  5-methylpyrazole  is  much 
akin  to  the  benzene  tautomerism,  and  points  more  clearly 
to  re-arrangement  of  single  and  double  bonds  such  as 
proposed  in  Kekule's  oscillation  hypothesis.  This  hypo- 
thesis is  difficult  to  accept  in  detail,  but  for  a  working 
hypothesis  it  is  sufficient  to  assume  that  in  certain 
peculiar  conditions  of  ring  symmetry  double  linkings  are 
not  fixed.  The  disturbing  agent  might  be  found  in  the 
intra-molecular  energy.  Assuming  this  to  take  the  form 
of  energy  of  motion  round  the  ring,  the  single  and  double 
bonds  would  then  repiesent  something  like  the  phases  pf 
a  wave  motion. 

At  the  Fourth  Ordinary  Meeting,  held  on  Monday,  Jan. 
25th,  1897  (^^'■-  Macdonald  in  the  chair),  Dr.  Dobbin 
read  a  paper  on  the  subjed — "  Who  Introduced  the  Use 
of  the  Balance  into  Chemistry  ?  " 

After  quoting  a  variety  of  statements  from  current  text- 
books, which  more  or  less  emphatically  attributed  to 
Lavoisier  the  discovery  of  the  law  of  the  conservation  of 
matter,  and  the  first  employment  of  the  balance  in  investi- 
gating theoretical  questions  in  chemistry,  the  author  of 
the  paper  remarked  upon  the  startling  character  of  these 
statements  to  any  person  who  had  read  Black's  research 
on  "  Magnesia  Alba,"  and  quoted  a  few  passages  from 
Black  in  support  of  the  statement  that  every  step  in  his 
investigation  has  been  made  good  by  appeal  to  diredt  quan- 
titative experiments.  He  next  quoted  a  passage  from  *'  La 
Revolution  Caimique,"  showing  that  Berthelot  was  well 
aware  of  the  fa<5t  that  these  views  regarding  Lavoisier 
were  entirely  at  variance  with  the  true  state  of  matters. 

Dr.  Dobbin  then  went  on  to  mention  that,  so  far  as  he 
was  aware,  the  well  known  and  often  quoted  experiment 
of  van  Helmont  upon  the  supposed  formation,  from  water 
only,  of  164  pounds  weight  of  the  substance  of  a  willow 
tree — the  weight  of  the  earth  in  which  this  willow  grew 
having  varied  only  by  about  two  ounces  in  five  years — 
was  the  earliest  attempt  to  determine  the  accuracy  of  a 
view  concerning  a  matter  of  scientific  fadl  by  appeal  to 
quantitative  experiment.  It  was  further  pointed  out  that 
Boyle  made  very  frequent  use  of  the  quantitative  method 
of  investigation  in  dealing  with  the  most  diverse  subjects, 
and  that  his  inspiration  in  this  direi5tion  was  very  probably 
derived  from  van  Helmont. 


UriKMICAL  NBWA,  1 

Feb.  5,  1897.      / 


Manufacture  and  Properties  of  Structural  Steel, 


69 


The  author  concluded  his  paper  by  pointing  out,  with 
regard  to  Lavoisier's  examination  of  the  alleged  con- 
version of  water  into  earth,  that  every  essential  point  in 
the  investigation,  and  in  the  mode  of  carrying  it  out,  was 
to  be  found  discussed  or  suggested  in  the  works  of  Boyle, 
of  which  we  know  that  Lavoisier  was  an  attentive 
student.  So  far  as  he  had  been  able  to  ascertain,  atten- 
tion had  not  previously  been  called  to  this  fadt  by  the 
historians  of  chemistry. 


NOTICES  Of  BOOKS. 


The  Manufacture   and   Properties    of  Structural    Steel, 

By   Harry   Hume   Campbell,   S.B.     New  York  and 

London  :  The  Scientific  Publishing  Co.     8vo.,  pp.  397. 

1896. 
If  we  were  called  upon  to  classify  this  valuable  work  we 
should  feel  at  a  loss.  A  chemical  treatise  it  certainly  is 
not,  seeing  that  the  metal  which  it  discusses  is  charadler- 
ised  not  by  its  chemical  composition,  qualitative  or  quan- 
titative, and  is  hence  named  •' structural  steel."  Chemical 
considerations  are  certainly  not  overlooked,  but  they  play 
here  a  relatively  less  weighty  part  than  they  do,  eg.,  in 
tissue-printing  or  in  alkali-making.  If  we  bear  in  mind 
that  steel  and  iron  works  are  in  the  hands  of  engineers, 
and  that  the  authorities  here  quoted  are  the  proceedings 
of  societies  for  civil  and  mechanical  engineering  we  must 
place  this  work  under  the  category  of  "  engineering." 

The  author  in  his  first  chapter  brings  forward  the 
"  errancy  "  of  scientific  records — a  painful  subjedt  under 
a  strange  name.  Errors  are  shown  in  Howe's  "Metal- 
lurgy of  Steel." 

These  variations  in  the  results  of  experiments  are  due 
to  the  accumulation  of  petty  errors.  It  is  of  some  con- 
solation to  find  that  the  variations  here  cited  are  not  in 
chemical  composition,  but  in  physical  properties,  such  as 
ultimate  strength,  elastic  limit,  percentage  of  elongation, 
redudion  of  area,  and  percentage  of  elastic  ratio.  But 
variations  in  chemical  composition  are  also  quoted.  The 
different  methods  of  determining  carbon  vary  to  an  extent 
unexpected  as  unsatisfaftory. 

The  author  remarks — as  it  might  be  fairly  expedted — 
that  the  comparison  of  miscellaneous  records  is  perfedlly 
useless  and  misleading.  "  Even  the  results  of  two 
different  well-condudted  laboratories  may  not  be  trustingly 
placed  together.  This  may  be  done  if  the  two  works  in 
question  exchange  samples  and  find  that  both  obtain 
similar  results  from  the  same  metals,  but  under  no  other 
circumstances  is  the  comparison  valid." 

In  the  determination  of  phosphorus  similar  but  more 
important  errors  are  committed. 

The  authorconcludes  this  chapter  with  thepithy  didtum  : 
"  The  making  of  steel  was  once  a  trick;  it  was  then  an 
art ;  it  is  now  a  business." 

Chapter  IV.  leans  to  the  definition  of  steel,  a  task 
which  though  apparently  simple  has  never  yet  been 
accomplished  to  the  satisfadlion  of  all  concerned.  "  A 
true  formula,"  says  an  author,  "  must  apply  not  only  to 
all  the  metals  commonly  designated  by  the  term,  but  to 
all  compounds  which  ever  have  been  or  ever  will  be 
worthy  of  the  name,  including  the  special  alloys  made  by 
the  use  of  chromium,  tungsten,  nickel,  and  other  elements 
introduced  to  give  peculiar  qualities  for  special  purposes." 

After  criticising  various  proposed  definitions  the  author 
gives  the  following  standards  as  embodying  current  usage 
in  America,  and  become  universal  also  in  Britain  and  in 
France.  In  other  lands  the  authority  of  famous  names, 
backed  by  conservatism  (word  wrongly  used!)  govern- 
mental prerogative,  has  fixed  for  the  present  in  metal- 
lurgical literature  a  list  of  terms  which  I  have  tried  to 
show  is  not  only  difficult  but  fundamentally  false. 

The  author  understands  therefore  by  the  term  wrought 


iron  the  produd  of  the  puddling  furnace  or  the  sinking 
fire.  On  the  other  hand,  "  by  the  tcr  n  steel  is  meant  the 
produce  of  the  cementation  process,  or  the  malleable 
compounds  of  iron  made  in  the  crucible,  the  converter,  or 
the  open-hearth  furnace." 

In  subsequent  chapters  we  have  accounts  of  the  acid 
and  the  basic  Bessemer  processes,  as  also  the  open-hearth 
process  in  its  acid  and  basic  modifications. 

In  Chapter XVII.  follows  an  investigation  ofthe  influence 
of  certain  elements  on  the  physical  properties  of  steel,  the 
pre-eminence  in  injurious  effedls  being  ascribed  to  phos- 
phorus. "  Safety  increases  as  phosphorus  decreases,"  and 
the  engineer  may  calculate  just  how  much  he  is  willing 
to  pay  for  greater  protedtion  from  accident. 

A  relatively  high  proportion  of  copper  has  in  certain 
experiments  given  a  slightly  higher  elastic  ratio  and  a 
better  elongation  and  redudlion  of  area.  These  results 
are  scarcely  to  be  viewed  as  conclusive. 

Aluminium  has  little  effedt  upon  tensile  strength,  while 
it  does  not  injure  the  dudtility  in  proportions  under  2  per 
cent. 


Notes  on  the  Qualitative  Analyns  arranged  for  the  Use  of 
Studettts  of  the  Rensselaer  Polytechnic  Institute.  By  W. 
P.  Mason,  Professor  of  Chemistry.  Third  Edition. 
Easton,  Pennsylvania,  Chemical  Publishing  Co.  1896. 
i2mo.,  pp.  56. 

In  the  Preface  to  this  little  book  we  find  the  admission 
that  "  the  market  is  unquestionably  much  overstocked 
with  books  upon  this  subjedl,"  and  the  author  puts  for- 
ward as  his  only  excuse  that  it  meets  the  requirements 
of  his  own  classes.  He  further  expresses  the  opinion 
that,  were  it  not  for  the  "  expense  of  printing,  every 
teacher  of  chemistry  would  use  a  text-book  made  by 
himself  with  either  pen  or  scissors."  Sad,  indeed,  if  true  1 
He  hopes  that  those  who  use  the  matter  here  given  may 
be  led  so  to  think  for  themselves  as  to  "  create  a  desire 
to  know  rather  than  an  anxiety  to  pass."  This  is  a  very 
laudable  aspiration,  but  we  doubt  if  there  is  anything 
calculated  to  create  this  desire  in  this  book  rather  than 
in  not  a  few  others.  In  the  recognition  of  certain  ele- 
ments the  author  makes  use  of  the  spedtroscope  and  of 
blowpipe  readlions. 


An  Introduction  to  the  Study  of  Chemistry.  By  W.  H. 
Perkin,  Jun.,  Ph.D.,  F.R.S.,  Professor  of  Organic 
Chemistry  in  the  Owens  College,  Manchester;  and 
Bevan  Lean,  D.Sc,  B.A.,  Assistant  Ledlurer  and 
Demonstrator,  and  late  Berkely  Fellow  of  the  Owens 
College,  Manchester.  London:  Macmillan  and  Co., 
Ltd.     New  York  :  The  Macmillan  Co.     1896.    Pp.  399. 

This  is  a  gratifying  book.  The  student  is  trained  to  re- 
discover, or,  as  the  case  may  be,  to  re-demonstrate  for 
himself,  the  cardinal  fadtor  and  laws  of  chemical^science. 
Hence,  instead  of — as  is  too  generally  the  case — closing 
the  book  with  the  sad  refledlion  that  the  contents,  how 
true  soever,  are  a  mere  rechauffee  of  what  has  been  many 
times  said  before,  we  are  in  a  position  to  congratulate  the 
authors  and  still  more  their  pupils  and  readers.  They 
are  reminded  in  the  Preface,  according  to  a  quotation 
from  Prof.  H.  A.  Miers,  that  "  the  order  in  which  pro- 
blems have  presented  themselves  to  successive  genera- 
tions is  the  order  in  which  they  may  be  most  naturally 
presented  to  the  individual." 

In  carrying  out  this  plan  the  author  gives  an  abstradl 
of  the  birth  of  chemistry  drawn  fron  the  invaluable  work 
of  Berthelot.  The  passages  cited  fully  support  the 
maxim  that  conclusions  must  be  tested  by  experiment 
and  by  measurement.  Virgil's  strange  recipe  for  gene- 
rating a  swarm  of  bees  from  the  putrid  carcase  of  a 
bullock  may  be  traced  to  the  inability  of  the  classical 
world  to  distinguish  bees  from  certain  carrion-hunting 
Diptera. 


70 


Chemical  Notices  from  Foreign  Sources. 


Chemical  News, 
Feb.  5,  1807. 


In  the  chapter  on  the  metric  system  the  authors  do  not 
overlook  its  occasional  inconveniences,  e.g.,  its  unsuit- 
ableness  to  retail  trade.  They  do  not  mention  the 
pedantic  refusal  of  French  and  other  instrument 
makers  to  admit  of  any  weights  except  the  multiples 
and  submultiples  of  10.  Had  they  been  willing,  instead 
of  the  French  arrangement  of  5,  5,  2.  2,  i,  to  adopt  the 
English  scale,  6,  3,  2,  i,  they  would  have  found  the 
metric  system  gain  in  popularity. 

We  are  most  favourably  impressed  with  Messrs. 
Perkin  and  Lean's  book,  and  hope  that  it  may  be  widely 
appreciated. 

The  Progress  of  Medical  Chemistry,  comprising  its  Appli- 
cation to  Physiology,  Pathology,  and  the  Practice  of 
Medicine.  By  J.  L.  W.  Thudichum,  M.D.,  F.R.C.S.L. 
London:  Baiiliere,  Tindall,  and  Cox.     i8g6.     Pp.212. 

We  have  here  a  handy  book,  which  will  prove  of  great 
value  to  the  earnest  student  of  animal  chemistry,  in  per- 
haps  its  most  complicated  region.  The  charader  of  the 
work  is  decidedly  controversial,  and  it  possesses  a  not  un- 
pleasant acidulous  flavour. 

The  controversy  is  mainly  direded  against  the  shade  of 
the  late  Professor  F.  Hoppe-Seyler,  Briicke,  E.  Salkowsky, 
Kossel,  Freitag,  &c.  We  must  not,  however,  suppose 
that  Dr.  Thudichum's  hand  and  pen  are  raised  against 
all  his  contemporaries  engaged  in  the  same  class  of  re- 
searches. 

The  author  commences  his  work  by  comments  on  the 
"  Rise  of  Specialism,  Limited."  In  a  succeeding  paragraph 
he  enlarges  on  the  reign  of  the  phagocyte,  and  the  asto- 
nishing feats  of  this  creature  of  the  baderiological 
imagination,  "among  which  none  was  more  surprising 
than  that  by  which  it  put  all  chemistry  to  shame — namely, 
chemotaxis." 

We  have  an  elaborate  discussion  of  the  protagon 
question,  which  we  hope  after  all  its  changing  phases 
may  now  be  considered  as  definitively  settled.  Dr.  Thu- 
dichum tells  us  that  the  effedt  of  the  analytical  operations 
of  Kossel  and  Freytag  is  entirely  retrograde,  as  they 
"  carelessly  repeat  indecisive  data,  ignore  fadts  which 
have  been  proved  for  many  years,  iterate  refuted  errors, 
try  to  displace  proved  fads,  substitute  erroneous  names 
and  dates  for  true  ones,  and  in  the  only  part  of  their  ope- 
ration which  might  have  furnished  something  original 
and  new  fail  in  a  manner  which  is  the  necessary  result 
of  disregard  for  the  accepted  principles  of  scientific 
research." 

Towards  the  end  of  the  book  we  have  a  very  interesting 
chapter  on  *'  Shady  Side  of  Biological  Science,"  otherwise 
the  ghosts  of  spurious  researches.  Following  the  ex- 
ample of  Babbage,  he  divides  spurious  researches  into 
four  groups  —  forgeries,  hoaxes,  cooked  and  trimmed 
results. 

In  addition  come  the  blundenngs,  made  not  necessarily 
in  bad  faith. 

We  may  thank  Dr.  Thudichum  for  some  innovations  in 
nomenclature  which  are  decided  improvements.  For 
alcohols  in  its  generic  sense  he  would  say  "  cohols." 
•'  Quantation  "  is  a  convenient  abbreviation  for  quantita- 
tive determination. 


CORRESPONDENCE. 


Dimorphism  of  the  Succinates  of  the  Camphols 
-{-a  and  -a;  Isomorphism  of  the  Succinates  of  the 
Camphols  +aand  —a,  and  of  the  Succinates  of  the 
Isocamphols  -i-j8  and  -/3.— J.  Minguin.— As  the  crys- 
talline form  of  the  succinates  approximates  decisively  to 
that  of  borneol  and  that  of  camphor,  it  should  seem  that 
a  transformation  of  CO  into  the  CHOR  of  camphor  does 
not  sensibly  affed  the  crystalline  form,  whilst  a  trans- 
formation effeded  in  CHj  makes  itself  more  ieh.—Comptes 
Rendus,  cxxiv.,  No.  2. 


ON    THE    RELATION    OF   THE   SPECIFIC 

ROTATORY  AND    CUPRIC    REDUCING   POWERS 

OF     THE     PRODUCTS     OF     STARCH 

HYDROLYSIS   BY   DIATASE. 

To  the  Editor  of  the  Chemical  News. 
Sir, — The  paper  by  Messrs.  Brown,  Morris,  and  Millar, 
read  before  the  Chemical  Society  on  December  17th, 
i8g6,  and  subsequently  abstraded  and  appearing  in  the 
Chemical  News,  Ixxiv.,  43,  confirms  my  own  experience 
in  starch  estimation  in  various  produds  by  the  O'SuUivan 
process.  I  have  found  that,  without  exception,  there  is 
a  constant  relation  between  the  cupric  reducing  power 
and  the  specific  rotatory  power,  and  am,  therefore,  glad 
to  see  a  confirmation  of  my  own  work  by  such  eminent 
chemists  as  the  authors  of  the  above  paper. — I  am,  &c., 

J.  Arthur  Wilson. 

Newchurcb,  Rossendale, 
Jan.  27,  1897. 


CHEMICAL    NOTICES    FROM    FOREIGN 
SOURCES. 

Note. — All  degrees  of  temperature  are  Centigrade  unices  otherwise 

expressed. 

Zeitschrift  fur  Analytische  Chemie. 
Vol.  xxxvi..  Part  i. 

A  Contribution  to  the  Chemistry  of  Animal  Fats. 
—  Carl  Amthor  and  Julius  Zinc.  —  An  elaborate  paper, 
not  admitting  of  abstradion. 

Determination  of  Formaldehyd. — Dr.  G.  Romijn. — 
For  the  examination  of  pure  solutions  of  formaldehyd 
the  iodometric  method  is  to  be  preferred,  on  account  of 
its  great  accuracy  and  convenient  execution.  The  me- 
thods of  Brochet  and  Cambier  and  the  potassium  cyanide 
method  may  also  be  recommended.  But  if  the  presence 
of  other  aldehyds  is  to  be  feared  the  potassium  cyanide 
method  is  suitable,  and,  along  with  the  iodometric 
method,  will  in  many  cases  permit  of  the  entire  analysis 
of  the  mixture.  Legler's  method  will  never  bear  a  com- 
parisun  with  the  other  three  methods. 

Behaviour  of  the  Shellac  Acids  in  the  Separation 
of  Fatty  Acids  and  Resin  Acids,  according  to  Glad- 
ding and  Twitchell. —  F.  Ulzer  and  Rudolf  Defris. — 
It  appears  that  samples  are  sold  under  the  name  of 
shellac  which  consist  of  a  mixture  of  shellac  and  ordi- 
nary colophonium. 

Determination  of  Thoria  in  Thorin. — E.  Hintz  and 
H.  Weber. — This  memoir  will  be  inserted  in  full. 

Determination  of  Fatty  Matter  in  Miik. — H.  Frese- 
nius. — The  author  evaporates  the  sample  over  purified 
quartz-sand,  and  extrads  the  dry  residue  with  ether  in  a 
suitable  apparatus.  After  distilling  off  the  ether,  the 
residual  fat  is  dried  for  one  hour  in  a  weighing-glass  at 
100°,  and  weighed. 

A  Simple  and  Universally  Applicable  Method  for 
Determining  the  Water  in  Silicates. — P.  Jannasch  and 
P.  Weingaten  (^Zeit.  Anorg.  Chem.). — This  paper  requires 
the  accompanying  illustration. 

A  Technical  Pyrometer. — W.  C.  Heraus  and  Keiser 
and  Schmidt. — Tnis  instrument  depends  on  the  same  prin- 
ciple as  that  of  Le  Chatelier,  and  is  described  in  the 
Zeit.  fur  Instrumentenkunde. 

Determination  of  Arsenic— R.  Engel  and  J.  Bernard. 
— From  the  Comptes  Rendus. 


Ubbmical  NBWS,  I 
Feb.  5. 1897.      I 


Chemical  Notices  from  Foreign  Sources, 


71 


Produ<5tion  of  Chlorine  for  Laboratory  Purposes. 
—  F.  A.  Gooch  and  D.  A.  Kreider  {Ztit.  fur  Anorg. 
C  hemic). 

Analysis  of  Purified  Zinc.  —  F.  Mylius  and  O. 
Fromm  {Zeit.  fur  Anorg.  Chemie).— This  memoir  will  be 
inserted  in  full. 

Quantitative  Determination  and  Separation  of 
Copper. — F.  Mawrow  and  W.  Muttmann  {Zeit.  fur 
Anorg.  Chemie).— This  memoir  will  be  inserted  in  extenso. 
Detection  of  Formaldehyd. —  G.  Romijn  [Nederland 
Tijdschrift  voor  Pharm.  Chem.  en  Toxicologie).  —  The 
author  is  of  opinion  that  formaldehyd  may  best  be  recog- 
nised by  conversion  into  hexamethylamin  by  means  of 
ammonia.  At  ordinary  temperatures  this  transformation 
is  efTeAed  in  eighteen  to  twenty  hours.  At  higher  tem- 
peratures the  conversion  is  very  rapid.  The  addition  of 
lormaldehyd  to  ammoniacal  liquids  as  a  disinfectant  is 
therefore  of  little  value.  Romijn  gives  a  number  of  re- 
actions for  the  identification  of  hexamethylamin. 

Determination  of  Nitrogen  in  presence  of  Ni- 
trates. —  H.  C.  Sherman.  —  From  the  jfournal  of  the 
American  Chemical  Society. 

Execution  of  the  Gravimetric  Determination  o 
reducing  Sugar  by  means  of  Fehling's  Solution. — 
Abstracts  are  here  given  of  recent  papers  by  Nihoul, 
Griinhut,  Killing,  Piager,  Farnsteiner,  and  Hefelmann. 

Occurrence  and  Determination  of  Copper  in 
Organic  Substances,  especially  in  Foods. — From  the 
Archiv  Jur  Hygiene,  Chemiker  Zeitung,  and  Kaiserlich 
Gesundheits  amte. 

Normal  Constituents  of  Betrwort  which  may  be 
supposed  to  be  Abnormal.  —  J.  Brand  [ZeU.fur  Brau- 
wesen  and  Dingier' s  Polyt.  Journal,  also  Berichte,  xxvii., 
3115).  —  Of  these  substances  the  principal  is  maltol, 
C6H6O3.     It  is  probably  a  methyl-pyromeconic  acid. 

Examinationof  Mace.— E.  Spaeth.— The  fatof  genuine 
mace  is  yellowish  brown,  while  that  of  Bombay  mace  is 
light  yellow. 

Volumetric  Determination  of  Lead.  — A.  C.  Becbe. 
From  the  Chemical  News. 

Determination  of  Dry  Matter  in  Peat. — H.  Puchnor 
(Lonw.  Versuchstationen). — Not  suitable  for  abridgment. 

Behaviour  of  Stannous  Chloride  with  Essential 
Oils. — E.  Hirschsohn.— The  author  has  previously  ob- 
served that  the  ethereal  oil  obtained  from  Gurgun  balsam 
by  means  01  watery  vapour,  if  boiled  with  stannous 
chloride,  gives  a  red  colour  passing  into  violet  and  blue. 
He  proposes  examining  a  series  of  ethereal  oils  by  this 
reaction. — (Pharm.  Zeitung  Rusiland). 

Alkaloidal  Siearates  and  their  Therapeutic  Appli- 
cation. —  F.  Zonandi.  —  The  author  has  examined  the 
preparation  and  properties  of  the  morphin,  atropin,  and 
cocain  stearates. 

Action  of  Morphine  and  of  Acetanilide  upon  Mix' 
tures  of  Ferric  Salts  and  Potassium  Ferricyanide. — 
E.  Schaer  (Archiv  der  Pharmacie). — This  paper  is  more 
of  theoretical  than  analytical  importance. 

Detection  and  Determination  of  Sodium  Salicyl- 
ate in  presence  of  Icbthyol  (jfourn.  de  Pharmacie). — 
Vissen  dries  the  mixture  with  fine  sand  on  the  water-bath, 
and  extracts  in  the  Soxhlet  apparatus  with  anhydrous 
ether. 

Testing  the  Purity  of  Apiol. — G.  Francois  {journal 
de  Pharmacie  and  Pharm.  Central-Halle). 

Atomic  Weight  of  Tungsten.— R.  Schneider.  —  The 
mean  from  all  the  author's  experiments  is  184-01. 

Atomic  Weight  of  Helium.  — M.  A.  Langlet  (Zeit. 
Anorg.  Chemie). — The  mol.  of  helium,  like  that  of  argon, 
contains  only  one  atom,  and  its  atomic  weight  must  be 
taken  as  =  4* 


MISCELLANEOUS. 

Harben  Gold  Medal. — At  a  meeting  of  the  Harben 
Nomination  Committee  held  last  month  in  connection 
with  the  British  Institute  of  Public  Health,  Professor 
Max  von  Pettenkofer,  Scientific  Director  of  Liebig's  Ex- 
tract of  Meat  Company,  was  nominated  Harben  Gold 
Medallist  for  1897.  '^^^  medal  was  founded  in  1895  by 
Henry  Harben,  Esq.,  J. P.,  for  the  recognition  of  eminent 
service  to  the  public  health,  and  one  presentation  is  made 
every  year. 

Institute  of  Chemistry.— January  Examinations, 
1897  — Candidates  who  passed  the  practical  examination 
for  the  Associateship  : — Walter  Harry  Barlow,  Finsbury 
Technical  College;  Charles  Beavis,  Ph.D.  (Wiirzburg), 
Universities  of  Bonn  and  Wiirzburg,  and  with  Dr.  Quirin 
Wirtz,  F.I.C.  (for  Fellowship);  Cecil  Joslin  Brooks,  King's 
College,  London ;  Ernest  Mostyn  Hawkins,  Finsbury 
Technical  College,  London  ;  Charles  J.  S.  Makin,  Royal 
College  of  Science,  London,  and  the  Fresenius  Laboratory, 
Wiesbaden;  William  Moore,  Laboratories  of  the  Pharma- 
ceutical Society,  University  College,  London,  and  with 
Professor  John  Attfield,  F.R.S.,  F.I.C. ;  Sigmund  Salomon 
G.  Rosenblum,  University  of  Warsaw,  Fresenius  Labora- 
tory, Wiesbaden,  and  with  Dr.  Samuel  Rideal,  F.I.C. 
Intermediate  Examination. — Reginald  Arthur  Berry,  Cam- 
bridge  University  ;  John  Alfred  Foster,  under  the  late 
Dr.  A.  Norman  Tate,  F.I.C  ,  Professor  V.  B.  Lewes, 
F.I.C. ;  Robert  Dexter  Littlefield,  University  College, 
London,  and  also  with  Dr.  John  Muter,  F.I.C,  and  Mr. 
W.  A.  H.  Naylor,  F.I.C.  Final  Examination  for  the 
Associateship  (In  Branch  A.,  Mineral  Analysis). — Frank 
Collingridge,  B.Sc,  (Lond.),'UniverBity  College,  London 
(passed  "Intermediate."  July,  1896);  William  Ranson 
Cooper,  M.A.,  B.Sc,  (R.U.I,),  Royal  University  of  Ire- 
land, and  King's  College,  London;  John  Allsopp  Walker, 
B.A.  (Oxon.),  Oxford  University.  (In  Branch  E.,  Analysis 
of  Water,  Food,  and  Drugs). — Raymond  St.  George  Ross, 
Owens  College,  Manchester,  and  Dresden  Polytechnic 
(for  Fellowship).  Examiners  :  Professor  Percy  F.  Frank- 
land,  F.R.S.,  F.I.C,  and  Otto  Hehner,  Esq.,  F.I.C. 

City  and  Guilds  of  London  Institute  for  the 
Advancement  of  Technical  Education. — The  follow- 
ing  is  the  Scheme  for  the  Leathersellers'  Company's 
Research  Fellowships  in  Chemistry,  founded  and  De- 
cember, 1896,  during  the  Mastership  of  Dr.  W.  H. 
Perkin,  F.R.S.  :— 

I. — Number  and  Amount  of  Fellowships. 

1.  The  Grant  of  £1^^  a  year  offered  by  the  Leather- 
sellers'  Company  shall  be  applied  in  founding  one  or 
more  Fellowships,  entitled  '•  Leathersellers  Company's 
Research  Fellowships,"  for  the  encouragement  of  Higher 
Research  in  Chemistry  in  its  relation  to  Manufactures. 

2.  The  amount  of  the  grant  attached  to  each  Fellow- 
ship shall  be  determined  by  the  Executive  Committee  of 
the  Institute,  regard  being  had  as  far  as  practicable  to  the 
nature  of  the  Research,  the  time  required  to  complete  it, 
and  the  merits  of  the  candidate  ;  subjeCt  in  all  things  to 
the  approval  of  the  Company. 

II. — Conditions  of  Eligibility. 

1.  Applications  for  Fellowships  shall  be  made  in 
writing,  addressed  to  the  Honorary  Secretary  of  the  In- 
stitute, at  the  Head  Office,  Gresham  College,  E.C,  and 
shall  state  the  name  of  the  proposed  research  and  the 
qualifications  of  the  candidate. 

2.  The  Fellowships  shall  be  open  to  natural  born  British 
subjects,  who  are — 

a.  Students  of  the  Institute  who  have  completed  a  full 

three  years'  course  of  instruction  in  the  Chemical 
Department  of  the  Central  Technical  College,  or 

b.  Candidates  duly  qualified  in  the  methods  of  Chemi- 

cal Research  in  its  relation  to  manufactures,  with- 
out restriction  as  to  age  or  place  of  previous  study, 
but  preferably  to  class  (a) . 


72 


Meetings  for  the  Week. 


f  Chemical  News, 
\       Feb  5,  1897. 


III. — Award. 

1.  The  Fellowships  shall  be  awarded  by  the  Executive 
Committee  with  the  consent  of  the  Company  in  accord- 
ance with  this  Scheme,  or  with  such  modifications  as  the 
Company  may  from  time  to  time  approve. 

2.  The  Executive  Committee  shall  appoint  a  special 
Committee  to  receive  applications,  and  seleiSt  candidates, 
and  to  report  thereon,  and  upon  the  progress  of  researches  ; 
and  such  Committee  shall  include  the  representative  or 
representatives  for  the  time  being  of  the  Company  on  the 
Executive  Committee. 

3.  The  Executive  Committee  shall  report  to  the  Com- 
pany the  award  of  each  Fellowship,  and  at  the  close  of 
each  session  shall  report  the  results  or  progress  of  the 
Research  or  Researches  undertaken  during  the  session. 

W.— Tenure. 

1.  Every  Fellowship  shall  be  tenable  for  part  of  a  year 
or  for  one  year,  and  may  be  renewed  for  a  second  or  third 
year,  but  in  no  case  shall  be  held  for  a  further  period. 

2.  Holders  of  Fellowships  shall  devote  their  whole  time 
to  the  prosecution  of  research,  unless  otherwise  sandtioned 
by  the  Executive  Committee,  and  shall  report  as  required 
on  their  work. 

3.  The  Researches  shall  be  carried  out  at  the  Central 
Technical  College,  and  the  holders  of  Fellowships  shall 
be  subjedt  to  the  regulations  of  the  College  and  the  super- 
vision of  the  Board  of  Studies. 

4.  The  Company  reserve  to  themselves  the  right  at  any 
time  to  modify  this  Scheme,  or  to  withdraw  all  or  any  of 
the  Fellowships. 

F.  A.  Abel,  Chairman  of  the  Executive  Committee. 
John  Watney,  Honorary  Secretary. 


MEETINGS    FOR    THE    WEEK, 


MoNDAV,  8th.— Society  of  Arts,   8.     (Cantor  Lectures).    "  Material 

and  Design  in  Pottery,"  by  Wm.  Burton,  F.C.S. 
Tuesday,   gth. — Royal   Institution,  3.     "  Animal    Eledtricity,"  by 
Prof  A.  D.  Waller.  F.R.S. 

Society  of  Arts,  8.      ''  Lithography   as   a    Mode  of 

Artistic  Expression,"  by  George  McCuUoch. 
Wednesday,  loth.— Society  of  Arts,  8.     "  The  Chemistry  of  Tea," 

by  David  Crole. 
Thursday,  nth.— Royal  Institution,  3.      "  The  Problems  of  Arftic 
Geology,"  by  J.  W.  Gregory,  D.Sc,  F.R.S. 

Society  of  Arts,  4.30  (at  Imperiallnstitute).  "The 

Progress  of   Science   Teaching   in   India,"  by 
Prof.  J.  C.  Bose. 

Society  of  Arts,  8.    "  The  Mechanical  ProduAion 

of  Cold,"  by  Prof.  James  A.  Ewing,  M.A.,  F.R.S. 
Friday,  I2th. —  Royal   Institution,   9.      "Recent   Advances  in   Seis- 
mology," by  Professor  John  Milne,  F.R.S.,  F.G.S. 
Saturday,    13th.— Royal    Institution,  9.      "  The    Growth    of    the 
Mediterranean  Route  to  the  East,"  by  Walter 
Frewen  Lord. 


Recently  Published,  with  Illustrations,  in  Demy  Bvo.,  cloth. 

PRICE  12s.  6d. 

PRACTICAL    STUDIES 

:F:Bi?.:M:Ei#Tj^.Tioisr, 

Being  Contributions  to  the  Life-History  of  Micro-Organisms. 

By  EMIL.  CHR.  HANSEN,  Ph.D.,  Professor  and  Direftor  at  the 

Carlsberg  Laboratory,  Copenhagen.     Translated  by  Alex.  K. 

Miller,  Ph.D.,  Manchester,  and  Revised  by  the  Author. 

London  :    E,  &  F.  N.  SPON,  Ltd.,  125,  Strand. 

RED-WOOD    LAKES 

Free  from  Aniline, 

as  Crimson  Lake,  Cochineal  Red,  Purple  Lake,  &c., 

Supplied  as  a  SPECIALITY  by 

Dr.  BODENSTEIN  and   KAESTNER, 

Red-Colour   Manufa(5lurers, 

(Established  1840), 

SAALFELD-ON-5AALE,  GERMANY. 


A  ssistant  wanted  in  London  Laboratory;  one 

*■  ■^  accustomed  to  Mellurgical  Work. — Address  Bo.x  No.  99,  Che- 
mical News  Office,  6  &  7,  Creed  Lane,  Ludgate  Hill,  London,  E.G. 

A  nalyticaland  Manufacfluring  Chemist  wanted. 

■*^^  One  with  a  good  knowledge  of  the  Manufafture  of  Small 
Chemicals  preferred. — Please  apply,  in  stri(5t  confidence,  giving  full 
information  as  to  age,  experietice,  and  salary  required,  to  "  Manu- 
fa(5turer,"  Chemical  News  Office,  6  &  7,  Creed  Lane,  Ludgate  Hill, 
London,  E.G. 


A  nalytical  Chemist  (26)  well  acquainted  with 

■^^  the  manufa(5lure  of  the  raw  materials,  and  of  the  Aniline  and 
Coal  Tar  Dyes,  is  now  open  for  engagement  as  Chemist  to  a  Works 
engaged  in  this  industry.  Well  acquainted  with  all  the  processes  of 
dyeing  and  inorganic  research  work.  An  accurate  and  reliable 
analyst ;  highest  testimonials. — Address  "  Aniline,"  Chemical  News 
Office,  6  &  7,  Creed  Lane,  Ludgate  Hill,  London,  E.C. 


Analytical  Chemist,  eleven  years'  experience, 
desires  post  in  Laboratory  or  Works,  home  or  abroad.  Experi- 
enced in  the  management  of  men  and  machinery  ;  has  taken  highest 
University  Honours. — Address,  stating  particulars,  to  *'  Analyst," 
chemical  News  Office,  6  &  7,  Creed  Lane,  Ludgate  Hill, 
London,  E.C. 


Gentleman,  aged  27,  qualified  Analytical  Che- 
mist, of  some  years'  training  and  experience,  wishes  to  enter 
an  established  firm  or  company  with  a  view  to  future  partnership  or 
advancement. — Address  "  Chemist,"  care  of  Deacon's  Advertising 
Offices,  Leadenhall  Street,  E.C. 


Chemist,  Dipl.,  open  for  engagement.  Nine 
years'  i;rai5tical  experience  in  large  English  Alkali  Works  ; 
has  had  charge  of  men  and  machinery  ;  well  up  in  the  manufadlure 
of  Sulphuric  Acid,  Caustic,  Bleach,  Chlorate,  Bichromates,  Manga- 
nate  of  Soda,  Strontia  Salts,  Copper  Sulphate,  and  in  large  scale 
eleiStro-chemical  work.  —  Address,  "  Diploma,"  Chemical  News 
Office,  6  &  7,  Creed  Lane,  Ludgate  Hill,  London,  E.C. 


PATENTS,  DESIGNS,  AND  TRADE  MARKS  ACTS, 
1883  TO  1888. 

INJOTICE      IS      HEREBY     GIVEN,     that 

-^^  HENRY  ROBERT  ANGEL,  of  7,  St.  Helen's  Place, 
London,  E.C,  has  applied  for  leave  to  amend  the  Specification  filed 
in  pursuance  of  the  Application  for  Letters  Patent,  No.  335,  of  1896, 
for  "Improvements  in  the  Manufa(5iure  of  Caustic  Soda,  Carbonate 
of  Soda,  and  Sulphide  of  Sodium." 

Particulars  of  the  proposed  amendments  were  set  forth  in  the 
Illustrated  Official  Journal  (Patents),  issued  on  the  27th  January,  1897. 
Any  person,  or  persons,  may  give  notice  of  opposition  to  the 
amendment  (on  Form  G)  at  the  Patent  Office,  25,  Southampton 
Buildings,  London,  W.C.,  within  one  calendar  month  from  the  date 
of  the  said  Journal. 

(Signed)        H.  READER  LACK, 

Comptroller  General. 

CARPMAEL&CO., 

24,  Soutnampton  Buildings, 

London,  W.C. 

Agents  for  Applicant. 

Mr.  J.  G-.  LORRAIN,  M.I.E.E.,  M.I.M.E,  M.S.C.I., 

Fellow  of  the  Chartered  Institute  of  Patent  Agents, 

Norfolk  House,  Norfolk  Street,  London,  W.C. 

"  PATENTEE'S  HANDBOOK  "  Post  Feee  on  application. 


THE   ALKALI-MAKER'S   HANDBOOK. 

BY 

GEORGE   LUNGE,  Ph.D., 

Professor  of  Technical  Chemistry,  Zurich, 

and 

FERDINAND  HURTER,  Ph.D., 

Consulting  Chemist  to  the  United  Alkali  Co.,  Limited. 

Tables   and   Analytical    Methods   for   ManufatSurers   of 
Sulphuric   Acid,    Nitric    Acid,    Soda,    Potash,    and 
Ammonia.    Second  Edition,  Enlarged  and  thoroughly 
Revised.     In  crown  8vo.,  with  Illustrations,  los.  6d. ; 
strongly  bound  in  half  leather,  12s, 
"  The  present  edition  gives  abundant  evidence  that  care   is  being 
taken  to  make  the  book  a  faithful  record  of  the  condition  of  contem- 
porary quantitative  analysis."— Prof.  T.  E.  Thorpe  in  Nature. 
"  That  excellent  book." — The  late  Prof.  W.  Dittmar. 
"  It  is  an  excellent  book,  and  ought  to  be  in  the  hands   of  every 
chemist."— Prof.  I.  J.  Hummel. 

London:    WHITTAKER  &  CO.,  Paternoster  Square,  E.C. 


Cbbmioal  MBWB,  I 
Feb.  n.  1897.     I 


Efficiency  0/  the  Hermite  Bleaching  Solution. 


73 


THE    CHEMICAL     NEWS 


Vol.  LXXV.,  No.  1942. 


NOTE    ON     THE    LIMIT    OF    ACCURACY 

ATTAINABLE  IN  COLORIMETRY. 

By  CHARLES  W.  FOLKARD. 

As  the  result  of  a  large  number  of  experiments  in  1893 
and  1896,  the  author  has  come  to  the  conclusion  that 
analytical  processes  depending  on  the  exadt  imitation  of 
the  colour  of  a  solution  of  unknown  strength  by  another 
solution  containing  a  known  amount  of  the  substance  (as 
in  Nesslerising,  &c.),  are  capable  of  affording  results  of 
far  greater  accuracy  than  has  been  generally  supposed. 

By  taking  proper  precautions  it  is  possible  to  work 
colorimetricallyto  within  one-fortieth  or  one-fiftieth  (say, 
2  per  cent),  and  by  averages  to  within  i  per  cent  of  the 
quantity  of  substance  present  («.§'.,  copper  in  ammoniacal 
solution). 

This  was  at  first  so  startling  that  publication  was 
deferred,  but  further  experience  has  afforded  ample  con- 
firmation as  regards  azure  blue,  yellow,  and  red  solutions, 
and  the  object  of  this  note  is  to  ascertain  if  other  ob- 
servers (more  particularly  works'  chemists)  have  been 
led  to  a  similar  conclusion  in  the  course  of  their  daily 
practice. 

Ealing,  February  5, 1897. 


THE    EFFICIENCY    OF    THE     HERMITE 

BLEACHING     SOLUTION. 

By  CLAYTON  BEADLE. 

As  far  as  I  am  aware  there  are  no  published  results  of 
experiments  upon  the  bleaching  efiSciency  of  the  Hermite 
bleaching  solution  in  comparison  with  that  of  a  solution 
of  bleaching-powder  upon  the  bleaching  of  cotton  and  linen 
fibre.  All  the  published  results — viz.,  those  of  Messrs. 
Cross  and  Bevan,  and  Professor  Piftet — are,  I  believe, 
upon  the  bleaching  of  wood  pulp. 

I  made  a  series  of  experiments  to  determine  whether 
the  Hermite  solution  still  gave  the  same  efficiency  when 
used  for  bleaching  cotton  and  linen  rags  and  rag  half- 
stuff.  For  this  purpose  a  small  beater  was  used,  similar 
in  construdtion  to  the  paper-maker's  hollander.  I  took 
half-stuff  produced  from  second  quality  linen  rags  and 
from  second  quality  cotton  rags.  Before  doing  experi- 
ments in  the  small  beater,  I  mixed  a  known  weight  of 
each  of  the  half-stuffs  with  a  carefully  ascertained  volume 
of  Hermite  solution,  also  with  bleaching-powder  solu- 
tion, the  chlorine  strength  of  each  having  been  carefully 
ascertained. 

The  time  required  to  bleach  the  materials  to  a  full 
white  was  noted,  and  when  the  bleaching  was  complete 
the  available  chlorine  in  the  residual  liquors  was  deter- 
mined, and  the  amount  of  chlorine  consumed  by  the 
fibre  calculated.    The  following  are  the  results  : — 

Put  in. 


Dry 

weight. 

Strength  Percent 

Half-stuff. 

Liquor.          per  litre,    on  fibre 

Grms. 

Grms. 

I. 

Linen     . . 

1 62 '6 

Hermite     ..      2'8         i7'2 

2. 

•1        •• 

i62'6 

Bleaching  pd.    3*i6       i9"4 

S> 

Cotton  .. 

1762 

Hermite     ..      2'8         is-g 

4- 

II        •  • 

I76'2 

Bleaching  pd.    3*16       i8'o 

C0N6UUBD. 

Chlorine. 

Chlorine. 

Time  oi 

Grms. 

P.c.  on  fibre. 

bleaching. 

I. 

2 '44 

1-5 

30  mms 

2. 

372 

2-29 

4  hrs. 

3- 

4-0 

2*27 

2  hrs. 

4- 

6'49 

3-68 

10  hrs. 

The  efficiency  of  chlorine  in  the  Hermite  liquid  as 
compared  with  that  of  chlorine  in  ordinary  bleaching- 
powder  is  claimed  by  the  inventors  to  be  as  5  is  to  3. 
This  has  been  substantiated  by  the  results  of  Messrs. 
Cross  and  Bevan,  and  Professor  Pidet. 

3:5::!:  1-66. 

Comparing  this  with  the  experiments  above, — 


I  and  2. 
3  and  4. 


Hermite. 
1-5  : 
2*27    ; 


Bleaching 
powder. 

2-35 
3-68 


154 
165 


These  results  therefore  confirm  fairly  closely  those  of 
other  observers.  The  next  two  experiments  were  done 
with  a  view  of  finding  how  long  the  Hermite  solution 
took  to  exhaust  itself  if  the  chlorine  put  in  was  the  exaA 
amount  necessary,  according  to  the  above  experiments,  to 
do  the  bleaching.  The  rate  of  bleaching  was  much 
slower  than  if  the  chlorine  had  been  used  greatly  in 
excess.  After  three  days,  however,  the  liquid  only  con- 
tained the  least  possible  trace  of  chlorine,  and  the  fibre 
appeared  to  be  perfedly  bleached. 

The  preceding  experiments  were  all  done  with  "  still " 
liquor.  In  the  following  experiments  the  half-stuff  was 
put  into  the  small  beater,  and  the  Hermite  liquor  allowed 
to  flow  round  the  beater,  and  washed  out  again  by  means 
of  a  washing  drum,  from  whence  it  was  delivered  to  a 
store  tank  and  then  again  to  the  beater.  The  total 
amount  of  liquor  was  first  of  all  measured  both  into  the 
beaker  and  into  the  store  tank,  from  which  a  sample  was 
taken  and  tested  for  chlorine.  This  experiment  was  not 
done  under  the  most  favourable  circumstances,  as  the 
liquor  was  drawn  from  the  store  tank  and  not  from  the 
electrolysing  tank  whilst  the  eledtrolysis  was  going  on, 
which  I  think  would  have  made  a  considerable  difference 
to  the  results. 

Put  in. 
Volume  of 
liquid. 


Half-stuff. 

Linen     . 
Cotton   . 


Weight  of 
chlorine. 


Weight 
dry  fibre. 

Grms. 
.   542 

•  470 


56*I2 
56'i2 


Strength 
per  litre. 
Grms. 

2*64 

2'64 


Per  cent 
on  fibre. 


27-3 
31-5 


5-6 
5-6 


Consumed. 
Per  cent  on 
fibre. 

1-03 
1*20 


Time. 
40  mins. 
60     „ 


It  is  evident  that  the  circulating  liquor  is  more  econo- 
mical than  the  non-circulating. 


Non-circulating  Circulating 

Half-               chlorine  chlorine 

stuff.              consumed.  consumed. 

Linen  ..          1*5  1*03 

Cotton..          2*27  I  "20 


Saving  by 

circulating  over 

non-circulating. 

30  p.c. 

47   t, 


My  results  confirm  those  of  other  observers  as  regards 
the  rapidity  of  bleaching  by  the  Hermite  solution,  which 
I  found  to  bleach  very  rapidly,  doing  as  much  work  in 
thirty  minutes  as  bleaching-powder  solution  of  the  same 
strength  would  do  in  three  hours.  I  also  found  that 
Hermite  solution  will  bleach  in  one  treatment,  when  any 
amount  of  bleaching-powder  will  fail  to  do  so  without  an 
intermediate  acid  treatment.  It  can  be  used  either  circu- 
lating or  stored  in  tanks  for  use  like  ordinary  bleaching- 


74 


Viscose  and  Viscoid. 


'  CHBHICAt  NBWt, 
Feb.  la,  1897. 


powder,  but  the  latter,  as  we  have  seen,  does  not  give 
such  good  results. 

Laboratory,  West  Street,  Eritb, 
January  2|,  1897. 


VISCOSE    AND    VISCOID.* 
By  CLAYTON  BEADLE. 

In  August,  1894  (yournal  of  the  Franklin  Imtitute, 
cxxxviii..  No.  824),  I  had  the  honour  of  reading  a  paper 
before  the  Franklin  Institute  upon  some  new  cellulose 
derivatives  which  had  been  discovered  and  partly  worked 
out  by  my  colleagues,  Messrs.  C.  F.  Cross  and  E.  J.  Bevan, 
and  myself.  Mr.  Arthur  D.  Little,  of  Boston,  took  up 
the  subjed  on  this  side  of  the  water,  and  the  samples 
which  we  showed  you  at  that  time  were  produced  by  him. 
Since  then  we  have  added  considerably  to  our  knowledge 
of  these  derivatives.  The  basis  of  these  products  is  a 
substance  to  which  we  have  given  the  name  "Viscose." 
Viscose  is  chemically  cellulose  xanthate,  the  preparation 
and  constitution  of  which  is  fully  explained  and  set  forth 
in  my  previous  paper  (vide  ut  supra). 

The  dry  regenerated  cellulose  obtained  from  the  viscose 
solution  we  have  named  "  Viscoid." 

It  is  impossible,  in  a  paper  of  this  length,  to  give  a 
history  of  all  the  work  ws  have  done  in  the  last  two 
years  in  connection  with  viscose  ;  so  I  have  chosen  to 
confine  myself  to  certain  branches  of  the  work,  the 
description  of  which,  I  trust,  will  prove  interesting  to  the 
members  of  the  Institute. 

Manufacture  of  Alkali  Cellulose. 

In  the  manufadlure  of  viscose  on  a  large  scale,  we  first 
endeavoured  to  discover  what  materials  could  be  utilised, 
and  in  the  course  of  our  work  we  found  that  any  kind  of 
cellulose  could  be  used,  provided  that  it  was  fairly  pure. 
The  fibres,  however,  should  be  very  short  indeed ;  the 
process  depends  as  much  upon  the  length  of  the  fibre  as 
upon  the  purity  of  the  eellulose.  As  an  instance  of  this, 
if  raw  cotton  be  used  without  any  disintegration  it  is 
almost  impossible  to  mercerise  it  and  convert  it  into  vis- 
cose ;  but  if  the  fibre  be  disintegrated  so  as  to  break  up 
the  ultimate  fibre  into  pieces  of  about  one-twentieth  of 
the  length  of  the  original,  the  mercerisation  and  conver- 
sion into  viscose  is  rapid  and  complete.  With  regard  to 
the  purity  of  the  fibre,  bleached  wood  generally  yields  a 
better  viscose  than  unbleached  wood,  but  it  is  next  to 
impossible  to  convert  mechanical  wood  (i.  e.,  wood  dis- 
integrated by  mechanical  means,  and  containing  a  large 
amount  of  resin  and  other  impurities)  into  viscose.  The 
alkali  cellulose  often  requires  to  be  kept  for  several  d  ays 
before  treatment  with  carbon  bisulphide;  but  when  the 
disintegration  of  the  fibre  is  thorough,  and  the  mixture 
with  caustic  properly  effected,  the  maturing  of  the  alkali 
cellulose  is  almost  unnecessary. 

One  great  precaution,  which  at  first  we  lost  sight  of, 
was  to  prepare  the  alkali  cellulose  without  conta(a  with 
the  atmosphere. 

This  we  discovered  by  analysing  a  number  of  samples. 
We  found  that  on  an  average  about  50  per  cent  of  the 
alkali  had  been  carbonated  during  mercerisation,  and  thus 
rendered  useless  for  the  readtion.  Alkali  cellulose  is  con- 
verted by  the  aftion  of  the  CO2  of  the  atmosphere  into 
sodium  carbonate  and  cellulose  without  our  knowing  it. 
This  change  was  the  cause  of  a  large  number  of  failures, 
which  necessitated  condudting  a  series  of  trials  under 
varying  conditions,  in  which  we  determined  the  amount 
of  alkali  carbonated. 

At  last  we  arrived  at  a  method  of  producing  the  alkali 
cellulose  by  which  only  5  per  cent  to  10  per  cent  of  the 
total  soda  is  converted  into  carbonate. 


Journal  of  the  Franklin  Institute^  January,  1897. 


Yield  of  Viscoid. 

A  great  deal  of  work  has  been  done  upon  the  amount 
of  viscoid  yielded  by  different  celluloses.  Pure  cotton 
yields  somewhat  more  than  its  own  weight.  This  is  due 
to  a  change  in  the  cellulose  molecule  (vide  Beadle,  yourn. 
of  the  Franklin  Inst.,  cxxxviii.,  No.  824).  Wood,  on  the 
other  hand,  even  when  thoroughly  bleached  and  pure,  un- 
dergoes a  considerable  loss,  which  amounts  often  to  20 
per  cent.  This  is  due  to  the  formation  of  soluble  produds 
during  mercerisation. 

We  have  followed  this  very  carefully,  and  it  appears  that 
bleached  wood  pulp  contains  oxycellulose,  which  is  largely 
dissolved  by  caustic  soda.  Under  certain  conditions  the 
regenerated  cellulose  has  no  strength,  as  when  films  made 
from  viscose  solution  are  found  to  be  rotten.  Very  great 
care  has  to  be  taken  in  the  manufadure  of  viscose  to 
insure  that  the  regenerated  cellulose  is  not  injured  by  the 
treatment.  A  knowledge  of  this  can  be  acquired  only  by 
experience,  and  those  who  are  thoroughly  acquainted  with 
the  manufacture  of  viscose  can  often  tell  at  a  glance,  from 
the  appearance  of  the  alkali  cellulose  or  the  viscose  solu- 
tion, whether  a  satisfadtory  produd  will  be  obtained.  These 
conditions  are  now  well  understood  by  us,  so  that  we  can 
insure  that  the  cellulose  is  always  regenerated  in  the 
proper  physical  condition  required  for  the  particular  pur- 
pose  to  which  it  is  to  be  applied. 

Production  of  Veneers. 

Mention  was  made  in  my  previous  paper  (Journal  of 
the  Franklin  Institute,  vol.  cxxxviii..  No.  824)  of  cutting 
pieces  from  the  coagulum  and  annealing  them  under  pres- 
sure  for  the  produdtion  of  sheets.  This  has  been  worked 
at  on  a  larger  scale.  The  viscose  has  been  run  into 
redlangular  moulds,  and  the  coagulation  of  the  mass  has 
been  effedled  by  exposure  to  a  hot  damp  atmosphere. 
These  masses,  weighing  from  250  to  400  pounds,  have 
been  dehydrated  by  exposing  them  to  an  atmosphere 
which  is  gradually  raised  in  temperature.  When  the 
blocks  have  been  sufificiently  hardened,  they  are  cut  into 
sheets  about  24  X  18  inches,  by  a  guillotine  specially 
construdted  for  the  purpose.  By  an  automatic  gear  the 
bed  on  which  the  guillotine  rested  was  made  to  travel 
forward  at  every  stroke  of  the  knife,  and  the  amount  of 
travel  could  be  regulated  at  will,  so  that  sheets  of  any 
thickness  could  be  cut.  By  this  means  we  were  able  to 
cut  about  twenty  sheets  per  minute. 

The  sheets  were  deprived  of  the  chemical  by-produdts, 
and  then  submitted  to  heavy  pressure,  by  means  of  which 
the  cellulose  hydrate  was  dehydrated  down  to  a  compadl 
sheet  of  cellulose.  We  had  a  difficulty  by  this  method  in 
obtaining  our  dehydrated  sheets  free  from  strudure.  They 
had  a  tendency  to  split  in  laminae.  The  fradture  had 
every  appearance  of  slaty  cleavage  (Chemical  News, 
vol.  Ixx.,  p.  139),  and  the  planes  of  cleavage  were  found 
always  to  be  at  right-angles  to  the  diredtion  in  which  the 
pressure  was  applied.  With  thin  sheets  we  had  less 
trouble,  and  I  believe  the  reason  of  this  was  that  the 
sheet  was  thinner  than  the  laminae.  In  order  to  avoid 
this  difficulty  with  thicker  sheets,  we  were  obliged  to 
dehydrate  the  coagulum  to  a  greater  extent,  by  exposure 
to  a  hot  atmosphere  of  steam  before  applying  the  pres- 
sure. The  fad  of  pressure  on  the  coagulum  giving  rise 
to  slaty  cleavage,  prevented  us  from  applying  pressure 
for  moulding  solid  articles  from  the  coagulum.  This 
is  obvious  when  we  take  into  consideration  the  fadl 
that  the  dehydrated  laminae  formed  on  the  outer  sur- 
faces by  the  first  application  of  pressure,  prevents 
the  egress  of  moisture  from  the  interior,  and,  as  it  were, 
seals  the  interior  from  further  dehydration.  We  found  it 
next  to  impossible  to  mould  articles  of  any  thickness  under 
pressure  from  the  coagulum  for  this  reason,  even  on  the 
application  of  a  pressure  of  several  tons  to  the  square  inch. 
When,  however,  the  sheets  are  almost  dried  by  exposure  to 
warm  air,  or  by  one  of  the  processes  described  subsequently 
for  the  produdtion  of  solids,  they  can  be  embossed  and 


Ohkmical  News, I 
Feb.  12,1897.     / 


•Report  of  Commitiee  on  A  tomic  Weights. 


75 


stamped  into  small  articles,  such  as  buttons,  which  are 
sufficiently  strudlureless  for  all  pradtical  purposes. 

When  the  sheets  are  completely  dried  they  offer  too 
great  a  resistance  for  moulding  under  pressure.  Viscoid 
sheets  can  be  produced  by  the  above  process  in  almost 
any  colour,  either  translucent  or  opaque,  and  they  can  be 
prepared  in  such  a  way  that  they  are  either  soft  and 
pliable,  or  stiff  and  horny  like  celluloid.  Under  pressure 
they  can  be  embossed  in  various  patterns. 
(To  be  continued). 


THIRD    ANNUAL    REPORT    OF    COMMITTEE 

ON     ATOMIC     WEIGHTS. 

RESULTS     PUBLISHED     DURING    1895.* 

By  F.  W.  CLARKE. 

To  THE  Members  of  the  American  Chemical  Society. 
Your  committee  upon  atomic  weights  respedtfuUy  sub- 
mits the  following  report,  summarising  the  work  done  in 
this  branch  of  chemistry  during  1895 — a  year  which  may 
be  well  called  eventful  in  the  history  of  the  science.  Two 
new  elements,  argon  and  helium,  have  been  made  known 
to  the  world,  and  from  the  most  unexpedted  sources  ;  the 
colledive  works  of  Stas  have  been  published  by  the 
Belgian  Academy,  as  a  monument  to  his  memory  ;  Prof. 
Morley's  great  research  upon  oxygen  is  at  last  finished ; 
and  a  goodly  number  of  other  important  determinations 
have  appeared.  Incidentally,  but  pertinently,  I  may  also 
call  attention  to  the  Marignac  memorial  lecture  by  Cieve 
{jfourn.  Ghent.  Soc,  June,  1895),  in  which  the  atomic 
weight  researches  of  the  former  chemist  are  well  out- 
lined ;  and  to  the  extraordinary  number  of  papers  upon 
the  periodic  law,  which  have  been  called  out  by  the  dis- 
covery of  argon  and  helium.  These  papers  fall  outside 
the  scope  of  this  report,  and  they  are  numerous  enough 
to  almost  warrant  a  bibliography  of  their  own. 

The  H  :  O  Ratio. — Prof.  Morley's  work  upon  this  funda- 
mental constant  has  been  published  in  full  by  the  Smith- 
sonian Institute, t  and  divides  itself  naturally  into  four 
parts: — First,  the  density  of  oxygen;  second,  that  of  hy- 
drogen ;  third,  the  volumetric  composition  of  water  ;  and 
fourth,  its  gravimetric  synthesis. 

For  the  density  of  oxygen,  or  rather  the  weight  of  i  litre 
at  0°,  760  m.m..  at  sea-level,  and  in  latitude  45°,  three 
sets  of  measurements  are  given,  with  the  following  mean 
values  in  grms.  : — 

Series  I      i'42879  J;  0*000034 

,,      2      I '42887  ^  0000048 

„      3      i"429i7  ^  o"oooo48 

As  the  third  series,  on  experimental  grounds,  is  re- 
garded by  Morley  as  the  best,  he  assigns  it  double  weight, 
and  on  this  basis  the  general  mean  of  all  three  becomes  — 
1*42900  i  o'oooo34. 

For  the  weight  of  a  litre  of  hydrogen  under  similar 
standard  conditions,  five  series  of  determinations  are 
given,  as  follows  : — 

Series  i o'o89938 

,,      2 0*089970 

,,      3 o"o89886  J;'  0*0000049 

,,      4 0*089880  ^  0*0000088 

„       5 0*089866  ;J;  0*0000034 

The  hydrogen  of  the  first  and  second  series  was  prob- 
ably contaminated   by  traces    of  mercurial  vapour,   and 


*  Read  at  the  Cleveland  Meeting,  December  31, 1895.  From  the 
Journal  of  the  American  Chemical  Society,  xviii.,  No.  3. 

+  "  On  the  Density  of  Oxygen  and  Hydrogen,  and  on  the  Ratio  of 
their  Atomic  Weigiits."  By  Edward  W.  Morley.  Smithsonian 
Contributions  to  Knowledge,  1895.  410.  xi.  +  117  pages.  40  cuts. 
Abstract  in  Am.  Chem.  Joxirn.,  xvii.,  267  (gravimetric);  and  Ztschr. 
Phys.  Chem.,  xvii.,  Sy  {gsiBeoua  densities);  also  note  ia  Am.  Chem, 
Journ.,  xvii.,  396. 


these  results  are  therefore  rejedted  by  Morley.  For  the 
third,  fourth,  and  fifth  series  the  eledlrolytic  gas  was 
occluded  in  palladium  and  transferred  to  the  measuring 
globes  without  the  intervention  of  stopcocks;  thus 
avoiding  contaiSt  with  mercury  and  leakages  of  external  air. 
Their  general  mean  is — 

0*089873  J;  0*0000027. 
Dividing  the  weight  found  for  oxygen  by  this  value  for 
hydrogen  the  ratio  becomes — 

15*9002. 

For  the  volumetric  ratio  O  :  2H,  Morley  finds  the 
value  I  :  2*00269.  Applying  this  as  a  correction  to  the 
density  ratio,  we  have  for  the  atomic  weight  of  oxygen — 
O  =  15*879. 

In  his  synthesis  of  water  Morley  differs  from  all  of  his 
predecessors  in  that  he  weighed  both  constituents  sepa- 
rately, and  also  the  water  formed.  In  other  words,  his 
syntheses  are  complete,  and  take  nothing  for  granted. 
The  weights  in  grms.  are  as  follows  : — 


I 
2 
3 
4 
5 
6 

7 
8 

9 
10 
II 
12 


O  used. 

25*9176 

25-8531 

30*3210 

30*5294 

30*4700 

30*5818 

30*4013 

30*3966 

30*3497 

30*3479 

29-8865 

30*3429 


H  used. 
3*2645 
3-2559 
3"8i93 
3-8450 
3-8382 
3-8523 
3-8297 
3*8286 
3-8225 
3*8220 

3-7637 
3*8211 


Water  found. 
29*1788 
291052 

34-1389 
Lost 

34-3151 
34-4327 
34*2284 
34*2261 
34-1742 
34-1743 
33-6540 
34-1559 


From   these  data  two  sets  of  values  for  the  atomic 
weight  of  oxygen  are  derivable ;  one  from  the  ratio  H :  O, 


the  other  from  the  ratio  H  ; 
joined. 


H2O.      These  sets  are  sub- 


H  :0. 

1  15*878 

2  15881 

3  15-878 

4  15*880 

5  15-877 

6  15-877 

7  15-877 

8  15-878 

9  15-879 

10  15*881 

11  15881 

12  15*882 


Mean.. 


15*8792 


H  :  HjO. 

15-877 
15*878 

15-873 

15*881 
15*876 
15-875 
15-879 
15*881 
15-883 
15-883 
15-878 

15*8785 


From  the  density  work  the  value  found  was  15-879,  and 
the  mean  of  this  with  the  two  synthetic  results  is — 
O  =  15*8789. 

Hence,  for  all  pradical  purposes,  the  atomic  weight  of 
oxygen  may  be  put  at  15*88,  with  an  uncertainty  of  less 
than  one  unit  in  the  second  decimal. 

It  is  impradlicable,  in  a  report  of  this  kind,  to  go  into 
the  details  of  so  elaborate  an  investigation  as  this  of 
Morley's,  and  a  bare  statement  of  results  must  suffice. 
The  research,  however,  is  one  of  the  most  perfedl  of  its 
kind,  every  source  of  error  having  been  considered  and 
guarded  against,  and  it  will  doubtless  take  its  place  in 
chemical  literature  as  a  classic.  Independently  of  its 
main  purpose,  the  book  is  almost  a  manual  on  the  art  of 
weighing  and  measuring  gases,  and  no  experimenter  who 
engages  upon  work  of  that  kind  can  afford  to  overlook  it. 

More  recently  still,  a  new  determination  of  the  atomic 
weight  of  oxygen  has  been  published  by  Julius  Thomsen 
(^Ztschr.  Anorg.  Chem.,  xi.,  14),  whose  method  is  quite 
novel.    First,  aluminum,  in  weighed  quantities,  was  dis- 


76 


Metal  Separations  by  means  of  Hydrochloric  A  cid  Gas*    { 


Chemical  Nbwb, 
Feb.  12, 1897. 


solved  in  caustic  potash  solution.  In  one  set  of  experi- 
ments the  apparatus  was  so  construdled  that  the  hydrogen 
evolved  was  dried  and  then  expelled.  The  loss  of  weight 
of  the  apparatus  gave  the  weight  of  the  hydrogen  so 
liberated.  In  the  second  set  of  experiments  the  hydrogen 
passed  into  a  combustion  chamber  in  which  it  was  burned 
with  oxygen,  the  water  being  retained.  The  increase  in 
weight  of  this  apparatus  gave  the  weight  of  oxygen  so 
taken  up.  The  two  series,  reduced  to  the  standard  of  a 
unit  weight  of  aluminum,  gave  the  ratio  between  oxygen 
and  hydrogen. 

The  results  of  the  two  series,  reduced  to  a  vacuum  and 
stated  as  ratios,  are  as  follows: — 


p;^^^    Weight  of  H^ 
Weight  of  Al 
First. 
o'liiSo 
o'liiys 
0*11194 
0*11205 
o'liiSg 

0'II200 

0*11194 
0*11175 
O'liigo 
0*11182 
0*11204 

0'II202 

0*11204 
0*11179 
0*11178 

0*II202 

0-III88 
o*iii86 
o'liiSs 
0*11190 
0*11187 


Second,  Weighlom 
Weight  of  Al 
Second. 


o*i 

0*88799 
0*88774 
0-88779 
0-88785 
0*88789 
0-88798 
0*88787 
0-88773 
0*88798 
0-88785 

0*88787^0*000018 


7-9345  ±  o-ooii. 


0*11190^0*000015 

Dividing  the  mean  of  the  second  column  by  the  mean 
of  the  first,  we  have  for  the  equivalent  of  oxygen  :— 

0*88787  ^  o*ooooi8 
0*11190  i  0*000015 
Hence, — 

O  =   15-8690  i  0*0022. 

The  details  of  the  investigation  are  somewhat  compli- 
cated, and  involve  various  corredtions  which  need  not  be 
considered  here.  The  result  as  stated  includes  all  cor- 
redlions  and  is  evidently  good.  The  ratios,  however,  can- 
not be  reversed  and  used  for  measuring  the  atomic  weight 
of  aluminum,  because  the  metal  employed  was  not  abso- 
lutely  pure. 

The  Stas  Memorial.— As  a  monument  to  the  memory  of 
the  late  Jean  Servais  Stas,  more  appropriate  than  statue 
or  column  of  stone,  the  Belgian  Academy  has  published 
his  collecaed  works  in  three  superb  quarto  volumes.*  All 
of  his  great  investigations  are  here  gathered  together, 
and  in  the  third  volume,  entitled  "  Oeuvres  Posthumes," 
some  hitherto  unpublished  data  are  given  for  the  impor- 
tant ratio  between  potassium  chloride  and  silver.  These 
data  are  represented  by  two  series :  one  made  with  a  uni- 
form sample  of  silver,  and  chloride  from  various  sources  ; 
the  other  with  constant  chloride,  but  with  silver  of  diverse 
origin;  the  aim  being  to  establish  experimentally  the 
fixed  charadter  of  each  substance.  The  first  series  is 
complete ;  of  the  second  series  only  one  experiment  was 
found  recorded  among  Stas's  papers. 

The  quantity  of  potassium  chloride  equivalent  to  100 
parts  of  silver  was  found  to  be  as  follows : — 


♦  "Jean  Servais  Stas.  Oeuvres  Completes.'   Edited  by  W.  Spring. 
Bruxelles,  1894. 


69*1227 
69*1236 
69' 1234 
69*1244 
69- 1 235 
69-1228 
69*1222 
69-1211 
69*1219 
69-1249 
69-1238 
69*1225 
6g'i2ii 


Mean  of  first  series 
Second  series  .     . . 


69-1229 
69-1240 

These  results  give  an  effective  confirmation  to  Stas's 
determinations  of  1882. 

(To  be  continued). 


METAL    SEPARATIONS    BY    MEANS    OF 

HYDROCHLORIC    ACID    GAS.* 

By  J.  BIRD  MOVER. 

(Concluded  from  p.  65). 

XV. — Separation  of  Arsenic  from  Zinc. 
In  some  preliminary  work  zinc  oxide  was  treated  with 
acid  gas  at  200°.  It  completely  changed  to  chloride,  and 
was  not  volatile.  Pure  zinc  sulphate  was  used  to  pre- 
cipitate the  arsenate ;  it  was  washed,  dried,  and  ignited 
to  150°.  The  same  difHculty  appeared  as  was  encountered 
under  iron.  Zinc  arsenate  melts  down  to  a  liquid  mass 
as  soon  as  the  acid  gas  strikes  it,  which  is  extremely  hard 
to  evaporate  without  spattering,  A  small  glass  cover  was 
placed  over  the  boat,  which  tended  to  lessen  the  spat- 
tering, but  did  not  entirely  prevent  it. 

The  zinc  was  estimated  by  taking  the  chloride  up  in  a 
little  hydrochloric  acid  and  running  it  down  with  pure 
mercuric  oxide.  It  was  then  ignited  and  weighed  as  zinc 
oxide.  One  good  result  was  obtained,  but  generally  the 
residues  of  zinc  contained  arsenic  and  the  results  were  far 
from  being  concordant. 

XVI. — The  Separation  of  Arsenic  from  Cobalt  and  Nickel. 

Cobalt  and  nickel  were  precipitated  as  arsenates  in  the 
usual  manner,  with  a  solution  of  pyroarsenate. 

Cobalt  nitrate,  a  Merck  preparation,  was  carefully  puri- 
fied ;  considerable  manganese  was  found  and  eliminated. 

This  gave  the  pink  salt  C03A82O8+8H2O,  which  was 
ignited  to  the  blue  anhydrous  compound. 

Cobalt  arsenate  is  very  readily  attacked  by  the  acid  gas 
in  the  cold,  yielding  a  pink  chloride.  A  slight  heat,  not 
much  above  120°,  changed  it  to  the  blue  chloride  and 
drove  out  the  arsenic.  At  first  it  was  quickly  weighed  as 
chloride,  then  it  was  taken  up  in  a  little  hydrochloric  acid 
and  evaporated  down  with  mercuric  oxide.  On  ignition, 
black  C03O4  was  obtained  and  weighed. 

The  arsenic  was  eliminated  as  usual. 


C03AS2O8  taken 
C0CI2  obtained 
C0CI2  required 
C03O4  obtained 
C03O4  required 
Difference 
AS2O5  obtained 
AS2O5  required 
Difference       . . 


Experiment  I. 

Experiment  II 

Grm. 

Grm. 

0*1509 

0*2029 

0*1309 

— 

0*1293 

— 

0*0738 

0*0969 

0*0731 

0*0983 

+  0-0007 

—  0*0014 

0*0770 

— 

0-0764 

— 

+  0*0006 

— 

*  From  author's  thesis  presented  to  the  Faculty  of  the  University 
of  Pennsylvania  for  the  degree  of  Ph.D.,  1-896.  From  the  jfourn. 
Amer.  Chem.  Soc,  xviii.,  December,  1896. 


*^f".'"S^^T''}  Determination  of  Atomic  Masses  by  the  Electrolytic  Method.         79 


NiaAszOs+SHjO  taken 

NiO  obtained 

NiO  required 

Difference       


On  testing  the  cobalt  residue  by  the  Marsh  test,  no 
trace  of  arsenic  was  found.  No  cobalt  was  found  in  the 
sublimate.  Some  of  the  first  experiments  gave  cobalt 
too  low ;  it  was  thought  that  they  had  been  heated  too 
high,  but  testing  showed  no  volatilised  cobalt. 

A  temperature  of  125°  is  sufficient  to  drive  out  all  of 
the  arsenic,  and  at  this  temperature  there  is  no  danger  of 
volatilising  the  cobalt. 

In  working  with  nickel,  the  green  arsenate  was  simply 
dried  in  the  first  experiment.  It  therefore  had  the  com- 
position Ni3As208+8H20. 

Hydrochloric  acid  gas  attacked  it  in  the  cold.  A  slight 
heat  drives  out  the  arsenic  and  moisture  and  leaves  a 
salmon-coloured  chloride.  The  nickel  chloride  was 
changed  to  oxide  by  evaporating  it  with  nitric  acid  and 

igniting. 

Experiment  I. 
Grm. 

0"I502 

..      ..  0-0554 

..      ..  0-0561 

-  0*0007 

In  Experiments  II.  and  III.  the  salt  was  made  anhy- 
drous by  ignition. 

Experiment  II.  Experiment  III. 
Grm.  Grm. 

NiaAsaOs  taken     ..     ..  o'ii66  0-1040 

NiO  obtained 0-0577  0-0523 

NiO  required 0*0575  0-0513 

Difference       ■ho*ooo2  -i-o'ooio 

AS2O5  obtained      ....  —  0-0515 

A82O3  required       .  >     . .  —  0*0526 

Difference       —  -o'ooii 

The  Marsh  test  showed  no  arsenic  with  the  nickel. 

XVII. — Behaviour  of  Minerals  in  Hydrochloric  Acid  Gas. 

Niccolite. — One  half  grm.  of  the  mineral  was  finely 
powdered  and  subjected  to  the  adtion  of  acid  gas  for  a 
day,  at  a  temperature  of  200°  C.  It  was  only  very  slightly 
affedted. 

A  second  portion  was  dissolved  in  nitric  acid  and 
evaporated  down  in  a  porcelain  dish.  It  was  then  trans- 
ferred to  a  boat  and  evaporated  to  dryness.  To  remove 
all  the  acid  it  was  heated  in  an  oven  to  110°  for  half  an 
hour.  The  dry  substance  was  adled  upon  by  the  acid  gas  in 
the  cold  for  five  hours*  It  changed  completely  to  chloride. 
A  temperature  of  150°  for  an  hour  removed  all  the  mois- 
ture and  arsenic. 

The  nickel  chloride  was  evaporated  down  with  nitric 
acid,  ignited,  and  weighed  as  NiO.  The  arsenic  was  esti- 
mated as  usual. 

Per  cent. 

Nickel  found        4379 

Nickel  calculated       43'6o 

Difference o-ig 

Arsenic  found      56*66 

Arsenic  calculated      56*40 

Difference 0*26 

Undoubtedly  there  is  still  a  wide  field  open  in  regard  to 
the  behaviour  of  hydrochloric  acid  gas  upon  mineral 
species.  Smith  and  Hibbs  {loc.  cit.)  showed  that  mime- 
tite  lost  its  arsenic  quantitatively,  when  heated  in  a 
stream  of  acid  gas.  In  this  laboratory  others  are  being 
investigated  with  favourable  indications.  The  direiSt  em- 
ployment of  hydrochloric  acid  gas  upon  a  powdered 
mineral  would  simplify  many  a  tedious  gravimetric  pro- 
cess, leaving  the  separated  elements  in  a  desirable  con- 
dition for  further  treatment. 

In  the  case  of  a  mineral  such  as  niccolite,  where  it  must 
first  be  decomposed  with  nitric  acid  and  then  transferred 
to  a  boat,  the  advantage  is  not  so  great,  This,  however, 
can  -be  modified,  so  that  the  time  fador  is  reduced  and 
the  advantage  of  the  method  still  retained.  Instead  of 
using  a  boat,  which  has  no  advantage  unless  the  non* 


volatile  chlorides  are  to  be  weighed  directly,  a  hard  glass 
bulb  can  be  substituted.  The  mineral  is  placed  in  the 
bulb,  dissolved  in  nitric  acid,  and  evaporated  down  by  the 
aid  of  a  current  of  air  drawn  through  the  bulb. 

The  residual  oxides  are  then  separated  in  a  stream  of 
hydrochloric  acid  gas  as  usual. 


THE    DETERMINATION     OF    ATOMIC     MASSES 

OF     SILVER,     MERCURY,     AND     CADMIUM, 

BY    THE    ELECTROLYTIC    METHOD.* 

By  WILLETT  LEPLEY  HARDIN. 

(Continued  from  p.  63). 

Part  II.  {continued). 
Third  Series. 
Experiments  on  Mercuric  Cyanide. 
A  SERIES  of  observations  was  made  on  several  organic 
salts  of  mercury  with  a  view  of  selefti  g  a  compound 
suitable    for    atomic    mass    determinations.       Mercuric 
acetate  and  other  similar  salts  were  found  to  be  unstable 
in  the  air  and  unsuited  for  accurate  analyses.     Mercuric 
cyanide,  on  the  other  hand,  was  found  to  be  perfectly 
stable  and  to  form  well-defined  crystals. 

Preparation  of  Hydrocyanic  Acid. 
Five  hundred  grms.  of  potassium  ferrocyanide  were 
placed  in  a  two  litre  retort  connected  with  a  condenser. 
A  cooled  mixture  of  300  grms.  of  pure  sulphuric  acid  and 
700  c.c.  of  distilled  water  was  then  poured  into  the  retort, 
and  the  mixture  carefully  heated  until  the  hydrocyanic 
acid  was  distilled  over  into  the  receiver.  The  produdl 
obtained  was  re-distilled  and  used  immediately  in  the 
preparation  of  mercuric  cyanide. 

Preparation  of  Mercuric  Cyanide. 
Fifty  grms.  of  mercuric  oxide,  prepared  as  already 
described  in  the  experiments  on  mercuric  oxide,  were 
dissolved  in  pure  warm  hydrocyanic  acid.  The  solution 
was  then  filtered  and  evaporated  to  crystallisation.  The 
transparent  crystals  of  mercuric  cyanide  which  separated 
were  dissolved  in  pure  water  and  re-crystallised.  The 
produdt  obtained  by  the  second  crystallisation  was  quickly 
rinsed  with  cold  water  and  dried  for  six  hours  in  an  air 
bath  at  a  temperature  of  50°.  The  crystals  were  then 
ground  to  a  finely  divided  powder  in  an  agate  mortar  and 
re-dried  for  twenty- four  hours  in  an  air  bath  at  a  tempera- 
ture of  55°.  The  dry  white  powder  was  then  placed  in  a 
weighing  tube  and  kept  in  a  desiccator. 

Mode  of  Procedure. 

The  mode  of  procedure  with  mercuric  cyanide  was 
somewhat  different  from  that  of  the  preceding  experi' 
ments,  in  that  no  potassium  cyanide  was  used  in  pre- 
paring the  solution  for  eledlrolysis.  A  weighed  portion 
of  the  material  was  dissolved  in  pure  water  in  a  platifium 
dish.  When  the  crystals  had  completely  dissolved,  the 
dish  was  filled  to  within  a  quarter  of  an  inch  of  the  top 
with  water,  after  which  one  drop  of  pure  sulphuric  acid 
was  added.  The  solution  was  then  ele<5lrolysed,  and  the 
resulting  metal  weighed.  The  strength  of  the  current 
and  the  time  of  adlion  were  the  same  as  for  mercuric 
chloride.  In  the  last  four  experiments,  where  rather  large 
quantities  of  mercury  were  deposited,  the  strong  current 
was  allowed  to  ad  from  two  to  six  hours  longer. 

The  results  of  ten  experiments  on  mercuric  cyanide, 
reduced  to  a  vacuum  standard  on  the  basis  of — 


♦  Contribution  from  the  Joha  Harrison  Laboratory  of  diemist'y 
No.  13.  From  the  author's  thesis  presented  to  the  Faculty  of  the 
University  of  Pennsylvania  for  the  degree  of  Ph.D.— From  the 
Journal  of  the  American  Chemical  Society,  xvtii.,  p.  990. 


78         Determination  of  Atomic  Masses  by  the  Electrolytic  Method. 

4'o  =  density  of  mercuric  cyanide, 
13'59  =  M  metallic  mercury, 

21*4    =  „  platinum  dish, 

8-5    =  „  weights, 

and  computed  for  the  formula  Hg(CN}2,  assuming  i2'oi 
and  14*04  to  be  the  atomic  masses  of  carbon  and  nitrogen, 
respe^ively,  are  as  follows  : — 

Weight  Weight  Atomic  masa 

of  Hg(CN)j.  ofHg.  of  mercury. 

Grms.  Grm. 

1  0'55776  0*44252  200*063 

2  0*63290  0*50215  200*092 

3  0*70652  0*56053  200*038 

4  0*80241  0*63663  200*075 

5  0*65706  0*52130  200*057 

6  081678  0-64805  200*103 

7  1*07628  0*85392  200*077 

8  1*22615  0*97282  200*071 

9  1*66225  1*31880  200*057 
10             2*11170  1*67541  200*077 

Mean  ..  ..  =  200*071 
Maximum  ..  =  200*103 
Minimum    ..     =    200*038 


Chbuical  Nbwbi 

Feb.  12,  1807. 


Difference  ..     =       0065 
Probable  error    =      0*005 

From  the  total  quantity  of  material  used  and  metal 
obtained  the  atomic  mass  of  mercury  is  200*070. 

Fourth  Series. 

According  to  Faraday's  law  the  quantities  of  different 
metals  deposited  from  their  solutions  by  the  same  current 
are  proportional  to  their  equivalent  weights.  In  this 
series  of  experiments  an  attempt  was  made  to  determine 
the  ratio  of  the  atomic  mass  of  mercury  to  that  of  silver 
by  passing  the  same  current  through  the  solutions  of  the 
two  metals  and  weighing  the  two  resulting  deposits.  If 
the  proper  conditions  could  be  obtained,  this  would 
certainly  be  the  simplest  and  most  diredt  method  for  com- 
paring the  equivalent  weights  of  different  metals.  But  so 
many  difiSculties  were  met  that  the  method  on  the  whole 
was  not  satisfadtory. 

In  the  "  Revision  of  the  Atomic  Weight  of  Gold  " 
{Atner.  Chem.  yourn.,  xii.,  182),  Mallet  made  use  of  this 
method,  and  in  a  series  of  careful  preliminary  experi- 
ments determined  the  conditions  most  favourable  to  its 
application.  From  a  number  of  experiments  made  by 
passing  the  same  current  through  two  different  solutions 
of  copper  sulphate,  using  pure  eledrotype  copper  for  both 
anode  and  cathode  in  each  solution,  Mallet  found  ; — 

First. — Other  conditions  being  the  same,  the  difference 
in  the  quantities  of  metal  deposited  from  solutions  of 
unequal  concentrations  was  very  slight  and  somewhat 
variable,  but  the  tendency  was  toward  a  slightly  larger 
quantity  from  the  more  concentrated  solution. 

Second. — With  equal  quantities  of  metal  in  the  two 
solutions,  and  unequal  quantities  of  free  acid,  the  differ- 
ence in  the  results  obtained  were  almost  insignificant 
and  somewhat  variable  in  diredtion,  the  tendency  being 
toward  a  slightly  larger  quantity  from  the  less  acid  solu- 
tion. 

Third. — Other  conditions  being  the  same,  a  difference 
in  the  temperature  of  the  two  solutions  invariably  caused 
a  slightly  larger  deposit  from  the  cooler  solution. 

Fourth. — Other  conditions  being  the  same,  a  difference 
in  the  size  of  the  copper  plates,  and  hence  a  difference  in 
the  •'current  density,"  caused  a  slightly  greater  deposit 
on  the  smaller  plate. 

Fifth. — A  difference  in  the  distance  between  the  two 
plates  did  not  produce  a  constant  difference  of  result,  but 
the  tendency  was  toward  a  slightly  larger  deposit  on  the 
cathode  plate  farther  separated  from  its  anode. 

From  the  foregoing  experiments  it  is  evident  that  the 
conditions  most  favourable  to  this  method  are,  that  the 
two  solutions  should  be  equally  concentrated,  of  the  same 


temperature,  and  should  contain  equal  amounts  of  free 
acid,  or  when  the  double  cyanides  are  used,  equal  quanti- 
ties of  free  potassium  cyanide.  And,  moreover,  that  the 
two  cathodes  and  also  the  two  anodes  should  be  of  the 
same  size,  and  that  the  distance  between  the  anode  and 
cathode  should  be  the  same  in  both  solutions.  These 
conditions  were  closely  observed  throughout  this  work. 

Arrangement  of  Apparatus. 

The  deposits  in  this  series  of  experiments  were  made 
in  two  platinum  dishes  of  equal  capacity  and  equal 
internal  area.  The  anode  in  each  case  consisted  of  a 
coil  of  rather  large  platinum  wire,  the  two  coils  being  of 
the  same  shape  and  size.  The  dishes  were  insulated 
from  each  other  by  means  of  two  glass  stands.  The 
platinum  coils  were  completely  immersed  in  the  solutions, 
and  the  portion  of  the  wire  near  the  surface  of  the  liquid 
was  covered  with  paraffin  to  prevent  surface  contadt.  The 
current,  after  passing  through  the  two  solutions,  was 
allowed  to  pass  through  a  hydrogen  voltameter  in  order 
that  its  strength  might  be  observed  at  any  time. 

In  the  second  arrangement  of  apparatus  the  platinum 
dishes  were  made  the  anodes,  and  two  pieces  of  platinum 
foil  of  the  same  shape  and  size  were  used  for  the  cathodes. 
The  results,  however,  from  this  second  arrangement  were 
not  as  satisfadlory  as  from  the  first. 

Mode  of  Procedure. 

A  solution  of  the  double  cyanide  of  silver  and  potassium 
was  placed  in  one  of  the  platinum  dishes,  and  a  solution 
of  the  double  cyanide  of  mercury  and  potassium  in  the 
other.  The  quantities  of  silver  and  mercury  present  in 
their  solutions  were  approximately  proportional  to  their 
equivalent  weights.  Each  solution  contained  a  slight 
excess  of  potassium  cyanide.  The  dishes  were  placed 
in  their  positions,  and  the  anodes  immersed  some  time 
before  the  current  was  allowed  to  ad.  When  the  tem- 
perature of  the  two  solutions  was  the  same  as  that  of  the 
room  the  connection  was  made,  and  the  same  current 
allowed  to  pass  through  the  two  solutions.  The  quantity 
of  metal  deposited  was  never  allowed  to  exceed  one-half 
of  the  metal  present  in  the  solution  at  first.  Before 
interrupting  the  current,  the  solutions  were  syphoned  from 
the  two  platinum  dishes  at  the  same  time  with  two 
syphons  of  the  same  bore.  The  deposits  were  then 
washed  several  times  with  boiling  water,  carefully  dried, 
and  their  weights  determined.  Experiments  were  made 
with  currents  of  different  strength,  and  with  solutions  of 
various  degrees  of  concentration.  The  results  obtained 
were  far  from  being  satisfactory.  The  strength  of  current 
which  seemed  best  adapted  to  the  work  was  that  which 
deposited  about  one-tenth  of  a  grm,  of  silver  per  hour. 

From  a  large  number  of  experiments,  only  seven  results 
were  obtained  which  seem  of  any  value  in  determining 
the  atomic  mass  of  mercury.  And  it  must  be  added  that 
many  others  were  rejedled,  not  because  they  were  known 
to  be  vitiated  in  anyway,  but  because  the  results  obtained 
for  the  atomic  mass  of  mercury  differed  from  those 
obtained  from  other  methods.  It  is  possible  that,  in  a 
large  number  of  experiments  the  condition  would  be  more 
favourable  in  some  than  in  others,  but  whether  the  close 
agreement  of  the  results  seledled  was  due  to  this  or  to 
the  balancing  of  errors  could  not  be  determined.  , 

Seven  results  computed  on  the  basis  of  107*92  for  the 
atomic  mass  of  silver  are  as  follows.     (See  next  column). 

Computing  from  the  total  quantities  of  mercury  and 
silver  obtained  we  have  199*971  for  the  atomic  mass  of 
mercury. 

Although  the  cause  of  the  large  variation  in  the  rejeded 
observations  could  not  be  definitely  determined,  several 
sources  of  error  suggest  themselves. 

First,  small  quantities  of  hydrogen  were  undoubtedly 
set  free  in  the  process  of  eledlrolysis,  and  unless  these 
quantities  were  always  equal  in  the  two  solutions,  which 
is  not  probable,  an  error  would  be  introduced. 

Second,  in  some  solutions  an  error  might  easily  be 


CtaBUICAL  NlWSil 

Feb.  12,  1897.     I 


Aluminum  Analysts, 


79 


Atomic  mass 

Weight  of  Hg. 

Weight  of  Ag. 

of  mercury. 

Grm. 

Grm. 

I 

O'06l26 

0*o66lo 

200-036 

2 

0-06190 

0-06680 

200-007 

3 

0'078i4 

0*08432 

200-021 

4 

0*10361 

0-lll8l 

200*011 

5 

0'15201 

0-16402 

200-061 

6 

0-26806 

0*28940 

199-924 

7 

0-82808 

0*89388 

199-929 

Mean    .. 

..      =199 

996 

Maximum 

..        =s  200 

061 

Minimum 
Difference 

..        =    199-924 

..        =         0 

137 

introduced  by  a  change  in  the  atomicity  of  mercury,  but 
in  a  solution  of  the  double  cyanide  of  mercury  and  potas- 
sium this  change  is  hardiy  probable. 

Third,  the  occlusion  of  hydrogen  by  the  two  metallic 
deposits  would  also  be  a  possible  source  of  error;  but 
only  small  errors  could  be  introduced  in  this  way. 

To  account  for  the  difference  of  several  units  in  the 
results,  the  source  of  error  first  mentioned  seems  by  far 
the  most  probable. 

Summary. 

In  the  discussion  of  the  results  obtained  in  the  different 
series  of  observations  on  the  compounds  of  silver,  the 
probable  sources  of  error  and  likewise  the  advantages  of 
the  method  were  pointed  out.  The  same  discussion 
applies  equally  well  to  the  observations  on  mercury. 

It  is  evident  that  the  first  three  series  of  observations 
on  mercury  are  entitled  to  more  weight  than  the  last 
series.  Just  why  the  results  on  mercuric  bromide  should 
be  lower  than  those  on  mercuric  chloride  is  not  clear. 
Both  compounds  are  certainly  well  adapted  to  atomic 
mass  determinations,  inasmuch  as  they  can  be  purified 
by  both  crystallisation  and  sublimation.  The  most  pro- 
bable impurity  in  mercuric  bromine  would  be  mercuric 
chloride,  but  that  would  tend  to  increase  rather  than 
lower  the  results.  The  series  of  observations  on  mercuric 
cyanide  have,  perhaps,  one  advantage  over  the  others,  in 
that  no  potassium  cyanide  was  used.  The  results  obtained 
in  this  series  are  still  higher  than  those  obtained  from 
mercuric  chloride,  and  almost  two-tenths  of  a  unit  higher 
than  those  obtained  from  mercuric  bromide.  However, 
as  the  same  care  was  exercised  in  the  purification  of  the 
material  for  each  of  the  three  series,  and  as  there  was  no 
apparent  error  in  either  case,  equal  weight  must  be  given 
to  each  of  the  three  series  in  determining  the  most  pro- 
bable value  of  the  atomic  mass  of  mercury.  And,  as  the 
mean  of  the  last  series  is  almost  identical  with  the  mean 
of  the  first  three,  equal  weight  can  be  given  to  this  series 
without  introducing  any  error. 

Computing  the  general  mean  from  the  separate  observa- 
tions we  have : — 

Atomic  mass  of  mercury. 

First  series       200-006 

Second  „  199-883 

Third     ,,  200*071 

Fourth  ,,  199-996 

General  mean  =  199*989 

From  the  total  quantities  of  material  used  and  metal 
obtained,  the  general  mean  is  : — 

Atomic  mass  of  mercury. 

First  series       199-996 

Second  „  ,.     199-885 

Third     ,,  200-070 

Fourth  , 199*971 


Combining  this  with  the  first  general  mean  we  have  :- 

Atomic  mass  of  mercury. 
First  general  mean   . .     . .     =  199*989 
Second     „         ,,       ..      ..      =  199-91 1 


General  mean  —  199*981 


Most  probable  mean  of  all  the  results  =  199*985 
or  200  for  the  atomic  mass  of  mercury. 
(To  be  continued). 


ALUMINUM    ANALYSIS.* 

By  JAMES  OTIS  HANDY. 

(Concluded  from  p.  68). 

Hydrated  Alumina. 
Hydrated   alumina  is  analysed   for  water,  silica,  and 
sodium  carbonate. 

Water. — Ignite  i  grm.  in  a  closely  covered  crucible,  at 
first  gently  and  then  intensely  for  fifteen  minutes  over  the 
strongest  blast.  The  loss  on  ignition  includes  water  and 
the  carbon  dioxide  of  the  sodium  carbonate.  Calculate 
the  carbon  dioxide  from  the  sodium  oxide  found  and  de- 
dudt  it  from  the  loss  on  ignition. 

Silica. — Hydrated  alumina  is  soluble  in  sulphuric  acid 
of42°B.  The  silica,  however,  is  left  undissolved.  42° 
B.  sulphuric  acid  is  made  by  mixing  900  c.c.  of  concen- 
trated sulphuric  acid  with  1290  c.c.  of  water.  Five  grms. 
of  hydrated  alumina  are  treated  with  twenty-five  c.c.  of 
42°  B.  sulphuric  acid  and  heated  until  the  alumina  appears 
to  be  all  dissolved.  Dilute  to  100  c.c.  and  boil.  Filter, 
wash,  ignite,  and  fuse  the  residue  with  one  grm.  of  potas- 
sium bisulphate  and  cool.  Dissolve  in  water,  filter,  wash, 
ignite,  and  weigh  in  crucible,  treat  with  sulphuric  acid 
and  hydrofluoric  acid,  evaporate,  ignite,  and  weigh  again. 
Loss  equals  silica. 

Soda. — The  method  of  the  determination  of  soda  is  the 
same  in  calcined  and  hydrated  alumina.  The  method  is 
that  of  J.  L.  Smith,  and  is  described  under  *'  Sodium  in 
Aluminum."  Calculate  sodium  chloride  to  sodium  car- 
bonate, if  the  sample  is  hydrated,  and  to  sodium  oxide  if 
the  sample  is  calcined  alumina. 

Calcined  Alumina. 

Water  and  soda  are  determined  as  in  hydrated  alumina. 

Silica, — Fuse  i  grm.  of  the  finely  ground  alumina  with 
10  grms.  of  potassium  bisulphate.  If  this  does  not  make 
a  clear  fusion  add  2  grms.  of  bisulphate  and  heat  up  again. 
Dissolve  the  fusion  when  cool  in  water  and  filter.  Burn 
off  the  insoluble  residue.  Fuse  it  with  i  grm.  of  sodium 
carbonate  and  cool  in  fifteen  c.c.  of  water  in  a  four-and- 
a-half-inch  evaporating  dish.  Add  twenty-five  c.c.  of  25 
per  cent  sulphuric  acid.  When  all  soluble  matter  has 
dissolved,  remove  the  crucible  and  evaporate  down  until 
sulphuric  acid  fumes  escape.  Cool,  dilute  with  water, 
boil,  filter,  ignite,  and  weigh  silica  plus  crucible,  treat 
with  sulphuric  and  hydrofluoric  acids,  and  weigh  again. 
Loss  equals  silica. 

Analysis  of  Bauxite. 
(Method  adopted.  May,  1895.) 

No  unusual  apparatus  or  reagents  are  required. 

One  and  five-tenths  grms.  of  very  finely  ground  bauxite 
(previously  dried  at  100°  C.  and  bottled),  is  taken  for 
analysis.  Weigh  into  a  five-inch  porcelain  evaporating 
dish  and  dissolve  in  fifty  c.c.  of  acid  mixture.  This  mix- 
ture is  the  same  as  that  used  for  aluminum  analysis. 
Boil  the  solution  down  until  fumes  escape  and  keep  the 
residue  fuming  strongly  for  about  fifteen  minutes.  Cool, 
add  100  c.c.  of  water,  stir  and  then  boil  for  ten  minutes. 
Filter,  wash  well  with  water,  receiving  the  filtrate  in  a 
beaker  of  about  300  c.c.  capacity.  The  filtrate  and  washings 

*  From  the  Journal  of  the  American  Chemical  Society,  Sept.|  i8g6. 


8o 


Action  of  Wagner's  Reagent  upon  Caffeine. 


I  CbbmicalNbws, 
t      Feb.  12,  i8g7. 


should  amount  to  about  175  c.c.  Burn  off  the  insoluble 
residue  (which  consists  chiefly  of  silica,  with  a  little 
titanic  acid,  oxide  of  iron,  and  alumina)  and  weigh  it  in 
the  crucible,  add  three  drops  of  25  per  cent  sulphuric  acid 
and  about  five  c.c.  of  hydrofluoric  acid  and  evaporate 
slowly  to  dryness.  Ignite  very  strongly  and  weigh. 
The  loss  in  weight  equals  silica.  Add  to  the  residue  in 
the  crucible  i  grm.  of  potassium  bisulphate  and  fuse 
quickly  and  thoroughly  over  a  Bunsen  burner,  cool  and 
place  the  crucible  in  the  beaker  containing  the  main  sul- 
phuric acid  solution.  The  small  residue  from  this  fusion 
will  be  silica,  and  is  to  be  added  to  the  silica  already 
found.  Having  obtained  the  sulphate  solution  containing 
all  the  alumina,  ferric  oxide,  and  titanic  oxide,  make  it  up 
to  550  c.c.  and  mix.  Then  fifty  c.c.  will  equal  three- 
tenths  grm.  bauxite.  Take  fifty  c.c.  and  dilute  to  300  c.c. 
Add  two  c.c.  of  concentrated  hydrochloric  acid  and  am- 
monia in  slight  excess,  boil  for  five  minutes,  let  the  pre- 
cipitate settle,  filter,  and  wash  very  thoroughly  with  hot 
water.  Test  the  filtrate  for  further  alumina  by  boiling. 
Burn  off  the  filter  paper  and  ignite  the  precipitate  very 
strongly  after  crushing  all  the  lumps  of  alumina.  Weigh 
alumina,  ferric  oxide,  and  titanic  oxide. 

Titanic  Acid, — Take  too  c.c.  of  the  original  sulphate 
solution  (six-tenths  grm.),  add  ammonia  until  a  slight 
permanent  precipitate  is  formed,  then  add  sulphuric  acid 
from  a  pipette  or  burette  until  this  precipitate  just  re-dis- 
solves. Finally  add  i  c.c.  more  of  25  per  cent,  sulphuric 
acid  and  dilute  to  400  c.c.  If  the  bauxite  is  high  in  iron 
(which  will  be  indicated  by  the  distindt  yellow  colour  of 
this  solution)  sulphur  dioxide  gas  must  be  run  into  it 
until  it  is  decolourised  and  smells  strongly  of  sulphur 
dioxide,  but  if  the  solution  is  nearly  colourless,  indicating 
a  low  percentage  of  iron,  only  sulphur  dioxide  water  need 
be  used  for  the  redu(^ion.  Boil  well  for  one  hour,  adding 
water  saturated  with  sulphur  dioxide  occasionally.  Filter 
ofTthe  titanic  oxide  through  double  filters,  and  wash  well 
with  hot  water.  If  the  precipitate  is  yellow,  indicating 
the  presence  of  iron,  it  can  be  fused  with  i  grm.  of  potas- 
sium bisulphate,  the  fusion  dissolved  in  water,  and  the 
iron  determined  in  this  solution  by  reducing  with  zinc 
and  titrating  with  permangate.  This  is  not  often  neces- 
sary. 

Oxide  of  Iron. — Take  50  c.c.  of  the  sulphate  solution, 
add  10  c.c.  of  dilute  sulphuric  acid,  and  i  grm.  of  granu- 
lated zinc,  and  set  the  beaker  in  a  warm  place.  When 
reduced,  filter  and  titrate  the  iron  with  standard  potassium 
permanganate.  More  zinc  is  used  for  bauxites  high  in 
iron. 

Method  for  Iron  Determination,  using  a  larger  Quantity 
of  Bauxite.     (Applicable  to  Purest  Ores). 

Place  a  half  grm.  of  the  finely  powdered  ore  in  a  large 
platinum  crucible,  and  add  3  c.c.  of 25  percent,  sulphuric 
acid  and  5  c.c.  of  hydrochloric  acid,  and  evaporate  very 
slowly  to  fumes  ;  drive  off  the  excess  of  sulphuric  acid  by 
heat,  boil  out  the  residue  with  water,  and  add  10  c.c.  of 
dilute  sulphuric  acid.  Remove  the  crucible  and  reduce 
with  zinc,  as  above,  and  titrate. 

Water  and  Organic  Matter. — Ignite  three-tenths  grm. 
cautiously  at  first  and  finally  very  strong  in  a  covered 
crucible.  The  loss  of  weight  equals  water  and  organic 
matter. 


ON    THE    ACTION    OF    WAGNER'S     REAGENT 

UPON    CAFFEINE,    AND 

A  NEW    METHOD   FOR   THE    ESTIMATION 

OF    CAFFEINE.* 

By  M.GOMBERG. 

The  use  of  iodine  in  potassium  iodide  as  a  general  quali- 
tative reagent   for   alkaloids   dates  as  far  back  as  1839 


.  *  From  the  jfournal  of  the  American  Chemical  Society,  xviii..  No.  4- 


(Bouchardat,  Comp.  Rend.,  ix.,  475).  It  was,  however, 
R.  Wagner  {Dingl.  Poly,  ^ourn.,  clxi.,  40 ;  Ztschr.  Anal. 
Chem.,  i.,  102)  who  first  employed  it  for  the  quantitative 
estimation  of  vegetable  bases,  and  this  solution  has  since 
been  known  as  Wagner's  reagent.  He  based  his  con- 
clusion upon  trials  with  solution  of  quinine  and  cincho- 
nine,  showing  that  under  approximately  similar  conditions 
they  always  require  the  same  amount  of  iodine  for  com- 
plete precipitation.  Hence  empirical  fadtors  could  be 
established  which  would  enable  one  to  use  a  standard 
solution  of  iodine  for  the  titration  of  all  such  alkaloids  as 
form  insoluble  superiodides.  The  method,  however,  was 
not  frequently  employed,  for  the  reason  that  there  was 
no  experimental  proof  as  to  the  constancy  of  composition 
of  the  precipitates.  Moreover,  it  was  noticed  that  some 
of  the  precipitates  give  up  a  portion  of  their  iodine  to 
water,  i.e.,  they  are  not  completely  insoluble.  Hence 
concordant  results  could  not  be  obtained.  Later,  Schweis- 
singer  {Arch.  d.  Pharm.,  Ixiv.,  615,  1885)  applied  this 
method  to  the  estimation  of  strychnine  and  brucine.  His 
results  have  led  him  to  the  conclusion  that  while  the 
method  is  very  satisfadtory  for  strychnine,  it  is  far  from 
being  so  for  brucine.  Recently  Kippenberger  (Ztschr. 
Anal.  Chem.,  xxxiv.,  317 ;  xxxv.,  10),  in  his  research  upon 
the  isolation  and  separation  of  alkaloids  for  toxicological 
purposes,  has  reviewed  the  subjedt  of  the  ai^ion  of 
Wagner's  reagent  upon  alkaloids,  and  gives  considerable 
prominence  to  this  as  one  of  the  best  methods  for  the 
estimation  of  the  vegetable  bases.  His  method  of  pro- 
cedure was  pradlically  the  same  as  that  first  proposed  by 
Wagner.  The  alkaloid  is  dissolved  in  acidulated  water, 
and  to  the  solution  a  tenth  or  twentieth  normal  solution 
of  iodine  in  potassium  iodide  is  gradually  added  until  all 
the  alkaloid  is  precipitated  and  the  supernatant  liquid 
shows  a  slight  excess  of  iodine.  Instead  of  filtering  and 
washing  the  precipitate,  as  was  done  by  Wagner  and 
Schweissinger,  Kippenberger  allows  the  precipitate  to 
settle,  and  either  decants  or  filters  off  an  aliquot  portion 
of  the  mother-liquid  for  the  estimation  of  iodine  not  taken 
up  by  the  alkaloid.  The  estimation  of  iodine  is  always 
done  by  means  of  a  standard  solution  of  sodium  thio- 
sulphate. 

It  has  been  usually  assumed,  for  reasons  not  entirely 
clear,  that  the  composition  of  the  precipitates  is 
Alk.HI.I2,  i.e.,  diiodides  of  the  hydriodides  of  the  alka- 
loids are  formed.  Of  the  three  atoms  of  iodine  only  two 
can  be  estimated  diredtly  by  titration  with  sodium  thio- 
sulphate.  The  hydriodic  acid  is  supposed  to  come  from 
the  potassium  iodide,  while  the  two  "  superiodine  "  atoms 
are  furnished  by  the  free  iodine  dissolved  in  the  potassium 
iodide.  The  quantity  of  an  alkaloid  precipitated  by  a 
known  volume  of  Wagner's  reagent  is  calculated  on  this 
assumption,  2I:  molecular  weight  of  alkaloid  :  :  amount 
of  iodine  taken  up  :  ;«r  =  amount  of  alkaloid.  Schweis- 
singer found  that  the  method  of  calculation  agrees  entirely 
with  the  theoretical  figures  for  strychnine.  Kippenberger 
has  called  into  question  the  corredtness  of  this  mode  of 
calculation.  He,  too,  assumes  that  the  composition  of 
the  precipitates  is  to  be  represented  by  the  formula 
Alk.HI,l2,  but  he  claims  that  all  three  atomsof  iodine  are 
supplied  by  the  free  iodine,  and  none  by  the  potassium 
iodide.  Therefore  the  calculation  of  the  amount  of  alka- 
loid precipitated  is  to  be  done,  according  to  Kippenberger, 
by  the  use  of  the  proportion,  3I :  molecular  weight  of 
alkaloid  :  :  amount  of  iodine  taken  up  :  x  =  amount  of 
alkaloid. 

The  hydriodic  acid,  it  is  supposed  by  Kippenberger, 
results  from  the  interadlion  of  iodine  and  water, 

2l-|-2H20  =  2HI-f-Ha02, 
a  readtion  which  is  facilitated  or  induced  by  the  avidity 
of  the  alkaloids  to  form  insoluble  periodides  of  the  hydrio- 
dides. His  reasons  for  assuming  that  such  a  peculiar 
readlion  takes  place  under  the  simple  conditions  of  pre- 
cipitation are  too  lengthy  to  be  given  here.  AH  his  argu. 
ments  rest  upon  the  assumption  that  all  alkaloids  form 


^V^^A'^^s^''}  Analytical  Methods  involving  the  Use  of  Hydrogen  Dioxide,  8i 


periodides  of  uniform  composition,  Alk.HI.Iji  and  that 
the  same  alkaloid  gives  always  the  same  periodide.  Now, 
there  is  no  reason,  d  priori,  why  this  should  be  the  case, 
Jorgenson's  {yourn.  Prakt.  Chem.,  1870-78,  [2],  ii.,  433, 
&c.)  extended  researches  show  that  different  alkaloids, 
when  treated  under  apparently  the  same  conditions,  give 
periodides  of  entirely  different  compositions.  Thus, 
morphine  gives  with  Wagner's  reagent  Alk.HI.I3  (Jorgen- 
Bon,  1870,  yourn.  Prakt.  Chem.,  [2],  ii.,  438);  codeine 
furnishes  with  excess  of  Wagner's  reagent  Alk.HI.I4; 
and  caffeine,  as  will  be  shown,  gives  Alk.HI.I4,  ^^-  ^'  '^ 
safe  to  say  that  not  until  we  ascertain  exadly  the  com- 
position of  the  different  periodides  as  produced  under  the 
conditions  of  titrations,  will  the  use  of  Wagner's  reagent 
for  quantitative  purposes  be  placed  upon  a  sound  basfs. 

I  have  dwelt  at  such  length  upon  this  subje(5t,  because 
the  method  for  the  estimation  of  caffeine  presently  to  be 
described,  is  based  upon  experimental  evidence  which  is 
entirely  contradictory  to  Kippenberger's  conclusions. 
Whatever  the  cause  may  be  with  other  alkaloids,  his 
theory  as  to  the  production  of  hydriodic  acid  from  iodine 
and  water  does  not  hold  good  in  the  case  of  caffeine. 

Wagner,  in  describing  his  method,  gives  a  list  of  alka- 
loids which  are  completely  precipitated  by  iodine  solution, 
and  also  mentions  that  "  caffeine,  theobromine,  piperine, 
and  urea  are  not  precipitated  at  all  "  {loc,  cit.,  41).  His 
statement,  so  far  at  least  as  caffeine  is  concerned,  has 
stood  since  then  uncontradicted.  It  has  found  its  way 
not  only  into  standard  treatises  and  text-books,*  but  even 
into  periodical  literature  of  recent  date.  As  late  as  1894, 
Kunze  {Ztschr.  Anal.  Chem.,  xxxiii.,  23),  in  reviewing  the 
chemistry  of  caffeine  and  theobromine,  calls  attention  to 
this  peculiarity  of  the  two  alkaloids.  The  non-precipita- 
tion of  caffeine  by  Wagner's  reagent  has  come  to  be 
recognised  as  a  distinguishing  feature  of  this  alkaloid 
from  almost  all  other  vegetable  bases. 

And  yet  this  is  entirely  contrary  to  aCtual  fadts.  Instead 
of  forming  an  exception,  caffeine  conforms  to  all  the 
requirements!  necessary  in  the  application  of  this  test. 
It  is  well  known  that  most  of  the  alkaloids  as  such  are 
insoluble,  or  only  very  slightly  soluble  in  water;  they 
require  the  presence  of  some  acid  for  their  complete  solu- 
tion. In  other  words,  alkaloids  in  the  form  of  their  salts 
are  soluble  in  water.  Whenever  Wagner's  reagent  is 
applied  for  the  precipitation  of  an  alkaloid,  it  is  always 
applied  to  a  solution  of  some  salt  of  it,  preferably  acidu- 
lated with  sulphuric  or  hydrochloric  acid.  Therefore, 
even  when  strictly  neutral  salts  of  alkaloids  are  employed, 
there  is  still  the  possibility  of  the  formation  of  hydriodic 
acid,  or  rather  of  the  hydriodides  of  the  alkaloid,  as,  for 
instance,  Alk.HCH-KI  =  Alk.HI-|-KCl.  The  hydriodide 
thus  produced  is  at  once  precipitated  as  a  periodide.  Now, 
it  so  happens  that  caffeine  is  tolerably  soluble  in  water, 
and  it  has  become  customary  to  work  with  solutions  of 
caffeine  as  a  free  alkaloid,  and  not  in  the  form  of  its  salts. 
The  question  as  to  whether  solutions  of  free  alkaloids  are 
precipitated  with  Wagner's  reagent  has  not,  to  my  know- 
ledge, been  studied.  My  preliminary  experiments  in  that 
direction  show  that  at  least  some  alkaloids  (morphine, 
atropine,  strychnine,  &c.),  are  precipitated.  I  have  not 
examined  yet  whether  these  periodides  are  identical  in 
composition  with  those  produced  from  the  salts  of  the 
alkaloids.  But  so  far  as  caffeine  is  concerned,  it  is  true 
that  a  neutral  solution  of  it  gives  no  precipitate  when 
treated  with  a  solution  of  iodine  in  potassium  iodide. 
When,  however,  the  addition  of  Wagner's  reagent  is 
either  followed  or  preceded  by  the  addition  of  some  dilute 
acid,  there  is  at  once  thrown  down  a  dark-reddish  pre- 

♦  Prescott,"  Organic  Analysis,"  p.  80;  Allen,  "Coram.  Organic 
Analysis,''  iii.,  (2),  481 ;  Fluckiger,  "  Reaflions  "(Nagelvoort's  Trans- 
lation), p.  26 ;  not  affed^ed  by  Wagner's  reagent  in  either  neutral  or 
acid  solutions  ;  Dragendorff,  1888.  Ermittelung  von  Giften  says  that 
caffeine  gives  a  dirty-brown  precipitate.  From  the  text  it  is  not 
improbable  he  used  iodine  in  hydriodic  acid. 

i  This  test  is  perhaps  most  frequently  made  in  a  neutral  solution, 
representing,  as  customary  state  free  caffeine  and  normal  suits  of 
other  alkaloids. 


cipitate,  remaining  amorphous  even  on  long  standing.* 
The  composition  of  this  periodide  is,  as  will  be  shown, 
C8H10N4O2.HI.I4.  It  was  obtained  for  analysis  in  many 
different  ways — by  using  either  caffeine  or  iodine  in  ex- 
cess, and  by  employing  different  acids.  The  periodide 
produced  is,  however,  always  of  the  same  composition. 
The  precipitates  were  allowed  to  settle,  filtered  by  means 
of  a  pump,  washed  with  water  to  remove  the  excess  of 
potassium  iodide,  dried  on  porous  plates,  and  finally  in  a 
vacuum  over  sulphuric  acid. 

(To  be  continued). 


SOME     ANALYTICAL     METHODS     INVOLVING 

THE     USE    OF    HYDROGEN     DIOXIDE.f 

By  B.  B.  ROSS. 

The  use  of  hydrogen  peroxide  as  a  laboratory  reagent, 
although  originally  restricted  to  a  few  operations  of  minor 
importance,  has  within  recent  years  met  with  a  much 
wider  extension,  and  its  numerous  applications  in  both 
qualitative  and  quantitative  analysis  render  it  at  present 
almost  indispensable  in  every  well-equipped  analytical 
laboratory. 

Among  the  more  interesting  applications  of  this  sub- 
stance in  quantitative  estimations  are  those  which  are 
based  on  the  reaction  which  takes  place  when  an  excess 
of  hydrogen  dioxide  is  brought  in  contact  with  an  acid 
solution  of  chromic  acid,  and  Baumann  {Zeitschr.  Anal. 
Chem.,  xxxi.,  436)  several  years  since  described  quite  fully 
a  number  of  analytical  processes  growing  out  of  the  re- 
action referred  to. 

In  the  process  for  the  estimation  of  chromic  acid  in 
soluble  chromates  as  outlined  by  Baumann,  the  substance 
under  examination  is  first  brought  into  a  state  of  solution, 
and  the  not  too  concentrated  liquid  is  transferred  to  a 
generating  flask  of  special  construction. 

Ten  c.c.  of  dilute  sulphuric  acid  are  next  added,  after 
which  from  5  to  10  c.c.  of  commercial  hydrogen  peroxide 
are  run  in  from  a  small  closed  vessel  connected  with  the 
generating  flask,  while  the  oxygen  which  is  evolved,  after 
the  vigorous  shaking  of  the  contents  of  the  flask,  is  col- 
lected over  water  in  an  azotometer. 

The  following  equations  given  by  Baumann  illustrate 
the  chemical  changes  connected  with  the  above-described 
reaction : — 

KzCrzOy-f  HaOj-f  H2S04  =  K2S04-f  2H2O -f  CrjOy ; 
Cr207-f3H2S04-f4H202  =  Cr2(S04)3+7H20-h08. 

From  these  equations  it  will  be  seen  that  for  2  mole- 
cules of  chromic  acid,  or  i  molecule  of  potassium  di- 
chromate,  there  are  evolved  8  atoms  of  oxygen,  giving 
an  equivalent  of  445*3  c.c.  of  oxygen  (measured  at  0°  C. 
and  760  m.m.  pressure)  for  each  grm.  of  chromic  acid 
which  may  be  present. 

The  writer,  soon  after  the  appearance  of  the  original 
article  by  Baumann,  made  a  number  of  experimental 
tests  of  this  method,  with  a  view  to  applying  it  to  some 
other  analytical  processes,  and  still  more  recently  has 
conducted  a  series  of  tests  for  the  purpose  of  determining 
the  adaptability  of  Baumann's  method  to  the  indirect 
volumetric  estimation  of  iron. 

In  the  dichromate  method  for  the  volumetric  deter- 
mination of  iron,  as  commonly  employed,  the  end-point 

*  Almost  the  same  can  be  said  of  theobromine,  making  allowance 
for  the  difference  of  solubility  of  the  alkaloid  in  water.  A  saturated 
solution  of  it  (containing  one  part  of  theobromine  to  1600  of  water) 
gives  no  precipitate  with  Wagner's  reagent,  but  on  the  addition  of  a 
drop  of  acid  there  separates  in  a  short  time  a  crystalline  periodide. 
Contrary  to  usual  statements,  1  find  that  theobromine  in  acid  solu- 
tions gives  a  heavy  precipitate  with  Wagner's  reagent,  of  a  peculiar 
dirty-blue  colour. 

t  Read  at  the  Buffalo  Meeting,  August  22,  i8g6.  From  tbt  Joumal 
0  the  American  Chemical  Society,  xviii.i  p.  gi8. 


82 


Analytical  Methods  involving  the  Use  of  Hydrogen  Peroxide,   {^Feb!^itS7^*' 


of  the  oxidation  process  is  ascertained  by  the  readion 
with  potassium  ferricyanide. 

As  the  end  of  this  readtion  is  almost  invariably  difficult 
to  determine,  particularly  if  zinc  has  been  employed  as  a 
reducing  agent,  the  dichromate  process  has  met  with  but 
limited  application. 

In  order  to  apply  the  principle  of  the  chromic  acid 
method  of  Baumann  to  the  estimation  of  iron,  an  excess 
of  dichromate  solution  was  employed  in  all  of  the  tests 
and  experimental  determinations,  the  amount  of  the 
excess  of  chromic  acid  being  determined  by  the  volume 
of  oxygen  evolved  upon  treatment  with  hydrogen  dioxide. 

The  mode  of  procedure  adopted  was  as  follows: — 

A  dichromate  solution  was  prepared  by  dissolving  4*9 rj 
grms.  of  C.  P.  crystallised  potassium  dichromate  in  water 
and  diluting  to  a  bulk  of  i  litre. 

The  iron  solution  employed  in  standardising  the 
dichromate  and  permanganate  solutions  was  obtained  by 
dissolving  iron  wire  in  dilute  sulphuric  acid,  the  solution 
being  reduced  with  metallic  zinc,  as  usual,  previous  to 
titration. 

The  dichromate  solution  was  also  titrated  against  a 
freshly-prepared  solution  of  ammonium  ferrous  sulphate, 
the  strength  of  which  had  been  determined  by  titration 
with  permanganate  solution,  which  had  also  been  care- 
fully standardised  by  means  of  iron  v/ire. 

In  order  to  ascertain  the  strength  of  the  dichromate 
solution  by  the  hydrogen  dioxide  method,  about  15  c.c.  of 
the  dichromate  solution  is  run  into  the  generating  flask 
above  referred  to,  and  there  is  also  added  an  amount  of 
ferric  sulphate  solution  (free  from  ferrous  sulphate)  equi- 
valent to  about  o*o6  to  o"io  grm.  of  iron.  The  objedl  of 
employing  the  ferric  sulphate  in  this  standardisation  is  to 
supply  approximately  the  same  conditions  as  obtain  in  the 
process  for  the  a<5lual  determination  of  iron. 

The  amount  of  oxygen  given  off  from  chromic  acid  in 
the  presence  of  ferric  sulphate  is  slightly  less  than  that 
evolved  when  ferric  sulphate  is  absent,  but  the  amount  of 
ferric  iron  present  may  vary  considerably  without  affedting 
the  volume  of  oxygen  liberated. 

To  the  contents  of  the  generating  vessel  about  10  c.c. 
of  dilute  sulphuric  acid  are  now  added,  and  the  flask  is 
then  connected  by  means  of  a  rubber  tube  with  a  Schuize's 
azotometer,  which  has  been  filled  with  water  to  the  zero 
point. 

From  5  to  10  c.c.  of  hydrogen  dioxide  are  next  run  in 
from  a  small  closed  vessel  connedted  with  the  generating 
flask,  and  the  mixed  liquid  is  then  shaken,  at  first  gently, 
and  afterwards  vigorously.  The  tube  leading  from  the 
flask  to  the  azotometer  should  be  provided  with  a  stop- 
cock, which  should  be  closed  before  and  opened  imme- 
diately after  each  shaking. 

The  last  trace  of  the  oxygen  liberated  will  not  be  dis- 
engaged until  after  the  lapse  of  about  five  minutes,  but  it 
is  not  necessary  to  continue  the  shaking  during  the  whole 
of  this  period.  After  equalising  the  height  of  the  water  in 
the  two  tubes  of  the  azotometer,  the  volume  of  oxygen  is 
noted,  and  is  easily  corredled  for  temperature  and  pressure 
by  reference  to  proper  tables. 

In  order  to  test  the  strength  of  the  dichromate  solution 
by  means  of  iron  wire,  a  given  weight  of  the  wire  is  dis- 
solved in  dilute  sulphuric  acid,  the  solution  reduced  with 
zinc,  as  usual,  and  rapidly  transferred  to  the  generating 
flask  (filtering,  if  necessary). 

An  excess  of  dichromate  solution  is  now  run  in,  hydro- 
gen dioxide  is  added,  and  the  oxygen  is  set  free  and 
colledted  as  before  described. 

If  a  large  excess  of  dichromate  has  been  used  in  the 
preliminary  test,  duplicate  tests  should  be  made  with  em- 
ployment of  a  small  excess,  say  from  2  to  3  c.c.  of  the 
dichromate. 

The  strength  of  the  solution  can  then  be  readily  calcu- 
lated by  difference,  and,  if  necessary,  the  results  can  be 
checked  by  still  further  tests. 

In  the  determination  of  iron  in  ores  by  this  process, 
the  solutions  of  ferric  iron  are  reduced  by  zinc,  as  in  the 


common  permanganate  method,  and  the  remainder  of  the 
process  is  conduded  just  as  described  for  the  standardisa- 
tion of  the  dichromate  by  means  of  iron  wire. 

In  additit  n  to  numerous  tests  of  solutions  of  pure  iron, 
several  estimations  of  iron  in  iron  ores  were  made  by  this 
process,  the  results  obtained  being  compared  with  those 
secured  by  the  permanganate  method. 

The  following  are  the  results  of  the  tests  of  the  iron 
ores  referred  to : — 


Permanganate  method.      Dichromate 
Mean  of  several  method, 

determinations. 


Iron  ore  No.  i  . . 


Iron  ore  No.  2  . . 


40*92 


5471 


40-59 
41-25 
5535 
55-43 
55-50 


In  the  determination  of  iron  in  ores  by  this  process,  it 
is  best,  as  in  the  case  of  the  tests  with  iron  wire,  to  em- 
ploy only  a  small  excess  of  the  dichromate  solution,  after 
making  a  preliminary  determination,  as  the  results  are 
much  more  accurate  with  a  small  than  with  a  large  excess 
of  chromic  acid. 

While  a  sufficient  number  of  determinations  have  not 
been  made  to  ascertain  the  probable  value  of  this  method 
as  an  independent  process  for  the  estimation  of  iron, 
nevertheless  some  of  the  results  secured  would  seem  to 
warrant  the  conclusion  that  it  might  prove  of  utility  as  a 
check  method,  it  being  easy  of  execution  and  not  at  all 
time-consuming. 

The  following  equation  represents  the  changes  which 
take  place  when  the  dichromate  is  brought  in  contadt  with 
the  iron  solution  after  redudlion  : — 

6FeS04-HK2Cr207  4-7H2S04  = 

=  3Fe2(S04)3-hK2S04-fCr2(S04)3-t-7H20. 

The  writer  has  also  attempted  to  apply  the  principle  of 
the  chromic  acid  method  above  described  to  the  estima- 
tion of  invert  sugar,  or  rather  to  the  determination  of  the 
amount  of  cuprous  oxide  thrown  down  from  Fehling's 
solution  in  the  process  commonly  employed  for  estimating 
reducing  sugars. 

The  following  equation  represents  the  changes  which 
take  place  when  cuprous  oxide  is  brought  in  contadl 
with  potassium  dichromate  in  the  presence  of  dilute  sul- 
phuric acid  : — 

3Cu20  +  K2Cr2074-ioH2S04  = 

=  6CuS04+K2S04+Cr2(S04)3  +  ioH20. 

The  cuprous  oxide  thrown  down  from  the  sugar  sola- 
tion  under  examination  is  brought  upon  an  asbestos  filter 
connedted  with  a  filter-pump,  and  thoroughly  and  rapidly 
washed  with  hot  water.  The  filter  and  contents  are  next 
transferred  to  the  generating  flask  of  the  apparatus  before 
described,  and  after  the  addition  of  dilute  sulphuric  acid 
an  excess  of  dichromate  is  run  in. 

Very  thorough  and  long-continued  agitation  of  the 
contents  of  the  flask  is  necessary  in  order  to  efifedt  the 
complete  oxidation  and  solution  of  the  cuprous  oxide, 
and  the  hydrogen  peroxide  must  not  be  added  until  the 
solution  is  complete. 

The  oxygen  liberated  on  the  addition  of  the  hydrogen 
dioxide  is  colledled,  and  the  volume  noted  as  before 
described.  The  equivalent  amounts  of  chromic  acid, 
cuprous  oxide,  and  invert  sugar  can  be  easily  calculated 
from  the  data  thus  secured. 

This  method,  while  apparently  satisfadtory  from  a  theo- 
retical standpoint,  has  so  far  failed  to  give  sufficiently 
uniform  results,  one  of  the  chief  objedtions  to  the  process 
being  the  difficulty  attendant  upon  the  solution  of  the 
cuprous  oxide. 

With  improvements  in  the  details  of  manipulation  of 
the  process,  however,  it  is  quite  possible  that  more  satis- 
fadtory  results  could  be  obtained. 


CbbiJioal  Nbws 
Feb.  12,  1897. 


Tutorial  Chemistry, 


S? 


NOTICES  OF  BOOKS. 


The  University  Tutorial  Series,    The  Tutorial  Chemistry. 
Part  I.— Non-metals.     By  G.  H.  Bailv,  D.Sc,  Ph.D. 
Heidelberg,  Ledlurer  on  Chemistry  in  the  Vi(5loria  Uni- 
versity,    Edited  by  William  Briggs,  M.A.,   F.C.S., 
F.R.A.S.,  Principal  of  University  Correspondence  Col- 
lege.   London  :  W.  B.  Clive,  University  Correspondence 
College    Press.      Warehouse,    13,    Booksellers   Row, 
Strand,  W.C.     Pp.  226. 
We  must  confess  our  partial   inability   to   explain    the 
nature  or  charaderistics  of  "  tutorial    chemistry."     We 
know  that  certain  Universities,  such  as,  e.g.,  Oxford  and 
Cambridge,   call    themselves    ''tutorial,"    whilst   others, 
such   as  Munich  and  Heidelberg,  rank  as  investigational, 
and  one  at  least,  that  of  London,  is  purely  examinational. 
But  how  any  given  Science,  or  modification  of  a  Science, 
can  be  called  tutorial  we  doubt.     From  our  inspedion  of 
the  volume  before  us  we  should  think  that  tutorial  che- 
mistry    must     approximate     closely     to     examinational 
chemistry,  or  to  the  preparatory  work  required  for  passing 
examinations.  If  the  Correspondence  College  facilitates 
the  process  of  "  passing,"  and  thus  helps  to  shake  public 
faith  in   the   Chinese    system    of    higher  education  now 
dominant  in  Britain,  it   will  have  done  a  valuable  and 
needful  work. 

The  author  and  editor  very  justly  contend  that  it  is 
unwise  in  the  earlier  stages  to  overburden  the  student 
with  chemical  theory.  They  are  also,  in  our  opinion, 
right  in  referring  the  study  of  the  principles  of  light, 
heat,  and  eledtricity  to  works  on  physics. 

The  leading  truths  and  laws  of  chemistry  are  here  ex- 
pounded in  a  most  masterly  manner  ;  made,  in  fadl, 
accessible  to  very  moderate  capacities,  if  only  perse- 
veringly  and  honestly  applied  to  the  task. 

There  is  no  attempt  to  introduce  novel  matter  or  to 
initiate  the  student  into  research,  either  of  which  aim 
would  have  been  distindly  outside  the  plan  of  the  work, 
if  not  outside  the  entire  scope,  of  the  University  Corre- 
spondence College.  Within  that  scope,  if  we  rightly 
apprehend  it,  a  better  manual  could  scarcely  be  written. 


The  Australian  Medical  Directory  and  Handbook  ;  in- 
cluding a  Short  Account  of  the  Climatic  and  Sea-side 
Health    Resorts    in    Australia,    Tasmania,    and    New 
Zealand.     Edited  and  Compiled    by  Ludwig  Bruck, 
Fourth    Edition,    corrected    up    to    September,    1896. 
(Copyright).      Sydney:  L.  Bruck,    Medical  Publisher. 
London  :  Bailliere,  Tindall,  and  Cox.     i8g6. 
The  scope  of  this  useful  work  is  somewhat  wider  than  it 
would  appear  from  the  title.     It  comprehends  also  Fiji 
and  the  British  portion  of  New  Guinea.     We  are  glad  to 
find  that  the  author  calmly  ignores  all  the  non-qualified 
pradlitioners,  who  are  now  so  numerous. 

There  is  an  abstract  of  the  Medical  Ads  of  Australia, 
Tasmania,  New  Zealand,  and  Fiji.  There  is  a  list  of  the 
medical  and  allied  scientific  societies  in  Australasia. 
Some  of  them  are  of  high  standing,  and  have  done  good 
work.  Such  are,  e.g.,  the  Royal  and  the  Linnean  Societies 
of  New  South  Wales,  the  former  of  which  bodies  has  a 
medical  and  a  microscopical  sedtion.  The  Intercolonial 
Medical  Congress  of  Australasia  is  an  itinerant  body  after 
the  pattern  of  the  British  Association. 

The  scale  of  fees  legally  recoverable  by  medical  men 
are  certainly  not  exorbitant,  and,  in  comparison  with  the 
wages  of  mechanics,  servants,  &c.,  may  be  called  paltry. 
In  the  local  Medical  Diredory  for  each  Colony,  the  alti- 
tudes to  the  various  towns  above  sea  level  are  given, 
and  a  rough  view  of  the  racial  charader  of  the  popula- 
tion. We  are  sorry  to  see  to  what  an  extent  the 
"heathen  Chinee"  predominates  in  some  localities.  An 
interesting  feature  is  the  chapter  on  health-resorts.  Here 
we  find    given  the  average  rainfall,   the  extreme  and 


average  temperatures,  and  the  kind  of  constitution  for 
which  they  are  most  adapted. 

At  some  of  the  littoral  towns  sea-bathing  is  mentioned 
as  one  of  the  local  attradions  or  beneficent  features. 
The  abundance  or  scarcity  of  sharks  in  the  sea — a  point 
of  great  importance — is  not  mentioned.  At  some  places 
a  range  for  bathing  is  fenced  in  with  iron  chains, 


City  and  Guilds  of  London  Institute  for  the  Advancement 

of  Technical  Education.      Examinations   Department. 

Report  of  the  Work  of  the  Department  for  the  Session 

1895-96.     Exhibition  Road,  London,  S.W.     1896. 

The  adivity  of  the  Examination  Department  is  greater 

and  wider  than  we  might  exped  from  its  unhappy  name. 

It  includes  the  arrangement  of  courses  of  instrudion  in 

technical  subjeds,  the  consideration  of  the  qualifications 

of  teachers. 

A  distindion  seems  to  have  been  made  between  the 
certificate  granted  to  students  who  have  attended  a  course 
of  lessons  at  a  recognised  school  and  that  given  to  can- 
didates who  produce  no  evidence  of  such  training.  The 
results  are  said  to  have  been  very  satisfadory. 

The  total  number  of  subjeds  is  62,  but  in  five  of  these 
no  examinations  have  adually  been  held.  Of  the  greatest 
percentage  of  failures,  viz.,  76,  i  per  cent  was  in  litho- 
graphy, and  the  smallest,  oo'o,  were  in  the  alkali  and  soap 
manufadure,  in  the  lace  manufadure,  and  in  ship 
carpentry. 

At  Aylesbury  there  was  one  candidate  for  examination, 
who  passed. 


La  Unifikazion  da  las  Medidas.  Par  K.  Newman.  Val- 
paraiso :  Karlos  Kabazon.  1897. 
Chili  is  a  perfed  focus  of  reforms,  especially  ortho- 
graphic. Senhor  K.  Newman's  publications  remind  us  of 
our  old  friend  the  Fonetic  Nuz.  The  present  objed  of 
the  author  is  to  advocate  the  metric  system  "  pure  and 
simple."  He  urges  its  adoption  by  all  nations  in  its 
original  polysyllabic  nomenclature,  in  preference  to  the 
more  convenient  form  devised  in  Holland. 

The  names  proposed  by  the  French  revolutionary  com- 
mission may  be  unobjedionable  for  wholesale  transadions, 
but  for  the  retail  business  of  daily  life  they  have  proved 
themselves  impradicable. 

We  should  recommend  K.  Newman,  when  advocating 
any  reform,  to  do  so  in  a  language  "  understanded  of  the 
people,"  and  not  bring  it  in  a  novel  and  fantastic  ortho- 
graphy. 

MISCELLANEOUS. 

Royal  Institution.  — A  General  Monthly  Meeting  of 
the  Members  of  the  Royal  Institution  was  held  on 
Feb.  ist,  Sir  James  Crichton-Browne,  M.D.,  F.R.S., 
Treasurer  and  Vice-President,  presiding.  The  following 
were  eleded  Members :— Mr.  Alfred  Louis  Cohen,  Mrs. 
Delaforce,  Sir  Charles  A.  Elliott,  K.C.S.I.,  LL.D.,  Mr. 
John  Lawson  Johnson,  Dr.  A.  Liebmann,  Mr.  T.  George 
Longstaff,  Mr.  Howard  Marsh,  F.R.C.S.,  the  Rev.  E.  G. 
C.  Parr,  M.A.,  Mr.  Charles  Rose,  and  Mr.  Edward  P. 
Thompson.  The  special  thanks  of  the  Members  were 
returned  to  Sir  Frederick  Abel,  Bart.,  K.C.B.,  for  a 
donation  of^^so,  and  to  Mr.  J.  Wolfe  Barry,  C.B.,  for  a 
donation  oi ^25  to  the  fund  for  the  pronwiion  of  Experi- 
mental Research  at  Low  Temperatures. 

NOTES    AND    QUERIES,  ~ 

♦**  Our  Notes  and  Queries  column  was  opened  for  the  purpose  of 
giving  and  obtaining  information  liltely  to  be  of  use  to  our  readers 
generally.  We  cannot  undertake  to  let  this  column  be  the  means 
of  transmitting  merely  private  information,  or  such  trade  notices 
as  should  legitimately  come  in  the  advertisement  columns. 
Epsom  Salts.— A  correspondent  asks  whether  Epsom  salts  are 

best  reduced  to  the  state  of  a  dry  powder  by  hot  cylinders  or  in  an 

oven,  and  then  rolling  in  a  mill. 


84 


Meetings /or  the  Week. 


(  Chbuical  Nbws, 
I     Feb.  12, 1897. 


MEETINGS    FOR    THE    WEEK. 

Monday,  15th.— Society  of  Arts,  8.    (Cantor  Leftures).    "Industrial 
Uses  of  Cellulose,"  by  C.  F.  Cross,  F.C.S. 

Society  of  Chemical  Industry,  8.    Adjourned  Dis- 

cussion on  Mr.  W.  J.  Dibdin's  Paper  on  "  The 
Character  of  the  London  Water  Supply." 
Tuesday,  i6th.— Royal   Institution,  3.     "  Animal    EleiSricity,"  by 
Prof.  A.  D.  Waller,  F.R.S. 

Society  of  Arts,  8.  "  The  Progress  of  Canada  during 

the  past  Sixty  Years  of  Her  Majesty's  Reign," 
by  Joseph  G.  Colmer,  C.M.G. 
Wednesday,  17th.— Society  of  Arts,  8.   "  Light  Railways,"  by  Ever- 

ard  R.  Caltbrop. 
Thursday,' iSth.— Royal  Institution,  3.     "  The  Problems  of  Ardtic 
Geology,"  by  J.  W.  Gregory,  D.Sc,  F.R.S. 
—^  Chemical,  8.   "  The  Oxidation  of  Sulphurous  Acid 

by  Potassium  Permanganate,"  by  T.  S.  Dymond 
and  F.  Hughes.      "  Sodamide  and  some  of  its 
Substitution  Derivatives,"  and  "  Rubidamide," 
I  by  A.  W.  Titherley.  M.Sc,  Ph.D. 
— —  Society  of  Arts,  8.    "  The  Mechanical  Production 

of  Cold,"  by  Prof.  James  A.  Ewing,  M.A.,  F.R.S. 
Friday,  19th.— Royal  Institution,  9.     •'  The  Approaching  Return  of 
the  Great  Swarm   of  November   Meteors,"  by  G. 
Johnstone  Stoney,  M.A.,  F.R.S. 
Saturday,   zoih. — Royal    Institution,  3.      "  The    Growth   ot    the 
Mediterranean  Route  to  the  East,"  by  Wa  Iter 
Frewen  Loid. 


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-«»^«^AL  NBw», .,  }Jq^  Soon  shall  Students  begin  the  Study  <>f  Qualitattve  A  nalysis. 


85 


THE    CHEMICAL     NEWS 


Vol.  LXXV.,  No.  1943. 


HOW  SOON  SHALL  THE  STUDENT  BEGIN 

THE    STUDY    OF    QUALITATIVE     ANALYSIS  ? 

By  ALFRED  C.  BEEBE. 

In  the  following  paper  I  shall  attempt  to  show  at  what 
8tat»e  of  laboratory  work  the  student  can  most  advanta- 
geously be  introduced  to  the  study  of  qualitative  analysis. 

To  the  teachers  who  begin  the  laboratory  course  with 
qualitative  analysis  I  have  nothing  to  say.  But  to  the 
teachers  who  require  the  student  to  devote  all,  or  a  large 
part,  of  the  first  months  in  the  laboratory  to  the  study 
of  the  preparation  and  properties  of  the  non-metallic 
elements,  I  wish  to  present  some  arguments  for  replacing 
that  department  of  the  subjed  by  the  study  of  qualitative 
analysis. 

I  have  three  objedlions  to  requiring  the  student 
beginning  laboratory  work  to  perform  experiments  relating 
to  the  non-metallic  elements.  First,  the  experiments  are 
more  or  less  dangerous.  Second,  the  student  nearly 
always  fails  to  connedl  the  different  experiments  with 
each  other.  Third,  the  work  does  not  awaken  and  hold 
the  student's  interest  as  well  as  qualitative  analysis  does. 
Of  course,  the  student  must  have  a  good  knowledge  of 
the  properties  and  preparation  of  the  non-metallic 
elements,  but  it  seems  to  me  this  is  best  gained  from 
leftures,  illustrated  by  the  proper  experiments  given  by 
the  teacher  before  the  entire  class.  I  wish  to  say  that  I 
think  this  part  of  the  subjedt  is  often  made  so  unneces- 
sarily complex  that  the  student's  ideas  of  it  are  very  con- 
fused and  hazy.  Let  the  first  ideas  of  chemistry,  both  in 
the  leifture  room  and  the  laboratory,  be  as  simple  as  the 
subjedl  will  permit.  The  details  are  easy  enough  to  learn 
afterwards  if  they  be  necessary. 

Let  me  consider  at  greater  length  the  three  objedions 
made  above  to  the  study  in  the  laboratory  of  the  non- 
metallic  elements  by  the  beginner. 

First :  Danger.  A  university  professor  said  to  me 
recently,  "  I  always  dread  hydrogen  day  ;  I  am  nervous 
every  minute  the  students  are  working  with  this  dangerous 
gas,  for  I  feel  as  if  a  serious  explosion  migiit  occur  at  any 
time  when  students  have  as  little  experience  as  the 
beginner  possesses."  This  state  of  mind  is,  I  believe,  not 
uncommon  among  teachers  who  require  their  students 
to  experiment  with  hydrogen  soon  after  beginning  the 
laboratory  work.  I  feel  sure  that  almost  every  teacher 
knows  of  several  serious  explosions  with  hydrogen,  and 
of  many  more  that  might  have  been  serious  except  for 
good  luck.  Considering  these  fads  it  seems  to  me 
unwise  to  expose  the  student  to  this  unnecessary  danger, 
for  no  amount  of  chemical  knowledge  can  repay  a  pupil 
for  the  loss  of  his  eyesight.  The  danger  is,  however, 
much  lessened  by  some  months'  experience  in  the  labora- 
tory, and  then  explosive  gases  may  be  given  to  the  pupils 
should  the  teacher  think  fit  to  do  so.  The  preparation 
of  oxygen  is  attended  with  more  or  less  danger,  and  I 
know  of  several  serious  accidents  from  this  cause.  Phos- 
phorus is  not  a  substance  to  trust  a  beginner  with,  and 
yet  I  know  some  widely  used  text-books  which  give  this 
dangerous  substance  to  the  pupil  soon  after  his  entrance 
to  the  laboratory.  One  text-book  even  goes  so  far  as  to 
give  work  with  the  iodide  of  nitrogen  ! 

The  handling  of  acids,  the  use  of  chlorine,  bromine,  &c., 
make  trouble  enough  without  adding  work  on  explosive 
gases  like  hydrogen,  or  work  with  dangerous  substances 
like  phosphorus. 


Qualitative  analysis,  on  the  other  hand,  has  no  experi> 
ments  that  are  even  moderately  dangerous.  Of  course, 
dangerous  experiments  may  be  included  in  the  branch  of 
the  subjedl,  but  they  are  unnecessary,  while  for  the  non- 
metallic  elements  they  form  an  essential  part  of  the 
course. 

Second:  Unconnedledness.  Although  the  experiments 
on  the  non-metallic  elements  are  connedled  it  is  very 
difficult,  in  mv  experience,  to  make  the  student  see  that 
connedlion.  For  instance,  after  oxygen  is  experimented 
with  no  further  work  on  that  subje(5t  is  required,  and  the 
teacher  must  be  continually  asking  review  questions  if 
the  subjed  is  to  remain  fresh  in  the  student's  mind.  After 
several  weeks'  experimenting  has  been  done,  the  amount 
of  back  work  becomes  too  large  for  the  teacher  to  review, 
and  as  the  experiments  do  not  require  repetition,  those  on 
one  element  seem  to  have  almost  no  connexion  with 
those  on  other  elements.  I  have  taken  some  trouble  to 
look  into  this  matter,  and  have  heard  so  many  students 
complain  about  it,  that  I  consider  it  an  important  point. 
Qualitative  analysis,  on  the  other  hand,  requires  that 
experiments  once  learned  be  remembered,  for  the  future 
work  uses  them  repeatedly,  since  each  day's  work  in  a 
good  text-book  on  this  subjed  is  closely  related  to  what 
has  gone  before  and  what  is  to  follow.  This  fad  and  the 
repetition  necessary  while  analysing  unknown  substances 
oblige  the  student  to  remember  his  work,  and  he  goes  out 
of  the  laboratory  with  a  scheme  for  analysis  contaming 
fads  as  valuable  as  those  relating  to  the  non-metallic 
elements,  fixed  with  reasonable  firmness  in  his  mind, 
instead  of  a  confused  mass  of  material  such  as  the  work 
on  the  non-metallic  elements  too  often  leaves.  Even 
reasonable  repetition  will  not  fix  seemingly  unconneded 
fads,  while  conneded  phenomena  almost  fix  themselves 
in  the  mind. 

Third  :  Interest.  In  no  part  of  th^work  in  the  chemical 
laboratory  is  so  much  interest  sho#n  as  in  the  analysis 
of  unknown  solutions  and  substances.  This  one  fad 
would,  to  me,  be  sufficient  argument  for  the  use  of  quali- 
tative analysis  for  the  student's  first  laboratory  work.  It 
were  a  waste  of  words  for  me  to  say  that  we  should 
endeavour  to  awaken  and  sustain  the  student's  interest  in 
a  subjed  as  much  as  possible,  for  every  teacher  knows 
how  smoothly  and  advantageously  things  run  when  a 
s^enuine  interest  is  taken  in  any  sort  of  work  or  study. 
From  my  experience,  as  student  and  teacher,  I  feel  per- 
fedly  confident  that  qualitative  analysis  is  much  more 
fitted  to  do  this  than  the  study  of  the  non-metallic 
elements.  The  student  feels  he  is  a  real  chemist  as  soon 
as  he  analyses  his  first  "  unknown  solution."  Be  that 
solution  ever  so  simple  he  realises  that  he  has  acquired  a 
new  power,  and  in  most  cases  he  becomes  anxious  to 
increase  it.  This  feeling  of  independence  is  helped  if  no 
results  to  experiments  are  given  in  his  text-book,  for  he 
thereby  becomes  an  original  investigator,  and  not  merely 
a  student  who  is  required  to  perform  certain  experiments 
which  shall  agree  with  his  text-book.  This  attitude 
sharpens  the  observing  and  reasoning  faculties  immensely. 
The  interest  shown  in  qualitative  analysis  is  oftentimes 
amazing.  For  example,  I  have  often  seen  the  majority 
of  a  university  class  work  from  four  to  six  hours  extra  a 
week  simply  from  interest  in  this  branch  of  the  subjed. 
I  know  of  one  teacher  whose  student  became  so  interested 
in  qualitative  analysis,  that  in  self-defence  he  had  to 
refuse  to  remain  in  the  laboratory  more  than  two  hours 
after  the  regular  hour  for  closing  had  come.  This  last 
happened  in  a  public  high  school,  with  a  class  of  boys 
and  girls  averaging  sixteen  years  old,  where  we  surely  ought 
to  find  average  work.  Some  of  this  interest  maybe  due  to 
the  teachers,  but  from  the  fad  that  it  is  not  an  uncommon 
experience,  I  am  inclined  to  think  that  much  of  it  is  due 
to  the  fascination  of  qualitative  analysis.  I  have  never 
seen  any  such  results  from  the  study  of  the  non  metallic 
elements. 

Summing  up  the  advantages  of  the  study  of  qualitative 
analysis  for  the  beginner,  when  compared  with  the  study 


66 


Viscose  and  Vtscoid. 


of  the  non-metallic  elements,  I  think  I  may  say  that  the 
former  is  less  dangerous,  more  connected,  and  holds  the 
student's  interest  much  better. 
Savanna,  111. 


VISCOSE    AND    VISCOID.* 

By  CLAYTON  BEADLE. 
(Concluded  from  p.  75). 

Production  of  Viscoid. 

For  Use  in  Turning,  Syc. — Viscoid  is  prepared  by  coagu- 
lating the  viscose  in  the  same  way  as  described  above  for 
the  produ&ion  of  veneers  or  sheets,  but  the  moulds  are 
circular  instead  of  redtangular.  As  might  well  be  sup- 
posed, the  difficulties  of  coagulating  the  viscose  increase 
with  the  diameter  of  the  cylinder.  Great  care  has  to  be 
taken  in  the  early  stages  to  prevent  the  material  from 
cracking.  Immediately  after  coagulation  takes  place  there 
is  a  considerable  shrinkage,  and  unless  the  coagulation 
proceeds  uniformly  throughout  the  mass  there  is  danger 
of  it  cracking.  The  time  of  coagulation  increases  with 
the  diameter.  The  moulds  in  which  the  material  is 
coagulated  are  specially  construAed,  and  made  of  a  ma- 
terial which  is  unaifedled  by  the  viscose,  and  the  interior 
surface  has  to  be  such  that  the  coagulum  does  not  adhere 
to  it,  otherwise  it  is  sure  to  crack  on  shrinking.  After 
setting,  the  solid  cylinders  of  coagulum  are  removed  from 
their  moulds.  At  this  stage  they  are  elastic  and  pliable, 
somewhat  like  rubber,  but  have  to  be  handled  with  great 
care.  They  consist  of  about  15  per  cent  of  cellulose, 
7  per  cent  of  chemical  by-produi^s,  and  78  per  cent  of 
water  of  hydration. 

Washing. — They  are  next  placed  in  water  for  the  re- 
moval of  the  by-produds.  We  have  done  much  work  to 
determine  the  best  conditions,  and  the  cheapest  and  most 
eifedtive  method  for  getting  rid  of  the  by-products. 

When  the  cylinders  of  coagulum  are  placed  vertically 
in  tanks  provided  with  false  perforated  bottoms  and 
immersed  in  water,  the  by-produdls  are  found  to  diffuse 
out  and  creep  down  the  sides  of  the  coagulum  and  to 
accumulate  in  the  space  below  the  false  bottom.  This 
adtion  is  so  perfedt  that  often,  when  the  water  is  undis- 
turbed, the  top  portion  contains  only  a  trace  of  by- 
produdls  and  the  lower  portion  is  heavily  charged  with 
them.  The  removal  of  by-produdts  is  accelerated  by  the 
use  of  hot  water.  We  find  that  the  time  required  for  the 
removal  of  the  by-produds  varies  as  the  square  of  the 
diameter  of  the  coagulum.  During  washing  the  coagulum 
undergoes  a  further  shrinkage,  so  that  when  the  washing 
is  complete  the  coagulum  contains  about  20  per  cent  of 
cellulose. 

Drying. — The  washed  coagulum  is  next  removed  from 
the  tanks  and  dehydrated  or  dried.  The  dehydration  of 
the  coagulum  has  presented  us  with  some  very  interesting 
problems,  which  we  have  to  a  large  extent  solved.  When 
the  washed  material  is  exposed  to  the  air,  it  gradually 
contradls  and  loses  weight,  and  this  goes  on  until  it  is 
finally  deprived  of  moisture,  and  nothing  is  left  but  the 
dry  viscoid.  We  found  it  difficult  to  ensure  that  the 
material  should  retain  its  proper  shape  on  drying.  With 
"rack"  or  air  drying  at  from  90°  to  110°  F.,  a  solid 
cylinder  remains  flat  at  the  ends,  provided  that  the  length 
is  four  times  that  of  the  diameter.  If  it  is  less  than  this 
it  has  a  tendency  to  become  concave  on  the  ends,  and  it 
becomes  more  concave  up  to  a  certain  point  as  the  length 
diminishes  in  proportion  to  the  diameter.  The  sides  of  a 
solid  cylinder  have  a  tendency  sometimes  to  become  con- 
vex in  proportion  as  the  ends  become  concave.  Unless 
drying  is  uniform,  a  cylinder  of  ij  inches  diameter,  and 
less,  will  bend  less  towards  the  driest  s-ide.  With  larger 
cylinders  this  is  not  so  noticeable.     When  cylinders  are 

♦  Journal  of  the  Franklin  Institute,  January,  1897. 


f  Chbuical  Nbws, 
I      Feb.  19,  1897. 

placed  upon  a  rack  that  is  not  perforated,  the  top  end 
contradis  and  dries  the  most  rapidly,  so  that  the  cylinder 
becomes  tapered  towards  the  top.  When  the  rack  is  per- 
forated so  as  to  allow  of  the  free  passage  of  air,  the 
cylinder  is  sometimes  found  to  be  smallest  at  the  bottom. 
Sometimes  the  cylinders  are  irregular  in  diameter  or 
warped  in  final  drying.  During  the  process  of  drying 
the  coagulum  is  in  a  semi-plastic  state,  and  when  the 
drying  is  uneven  is  under  considerable  stress.  The  vis- 
coid is  caused  to  flow  in  the  diredtion  to  relieve  the 
stress,  so  that,  when  finally  dried  and  rigid,  it  is  found  to 
have  assumed  its  original  shape.  It  generally,  however, 
leaves  some  marks  of  its  temporary  distortion.  The  time 
of  drying,  so  far  as  our  determinations  hare  gone,  varies 
as  the  square  of  its  diameter. 

When  hot  air  is  used  the  rate  of  drying  cannot  be  in- 
creased beyond  a  certain  degree  without  serious  injury  to 
the  solid.  The  solid,  by  constant  exposure  to  hot  air, 
becomes  skin-dried,  whilst  the  interior  remains  compara- 
tively moist.  The  outer  dried  skin  offers  a  great 
resistance  to  the  passage  of  further  moisture,  and  so  the 
drying  is  very  much  retarded.  If,  under  these  conditions, 
the  moisture  is  able  to  escape  from  the  interior,  the 
exterior — being  dry  and  consequently  rigid— offers  great 
resistance  to  the  contradlion  of  the  interior,  and  the  con- 
sequence is  that  fradure  often  takes  place.  If  the  drying 
be  not  quite  so  rapid  as  to  produce  fradlure,  the  interior 
is  under  tremendous  stress,  and,  when  the  cylinder  is  cut 
in  sedlion,  cleavage  often  takes  place  in  the  diredlion  of 
the  length  of  the  cylinder.  When,  however,  the  drying  is 
condudled  much  slower,  the  moisture— which  is  always 
tending  to  pass  from  the  wetter  to  the  drier  portions — 
finds  a  way  of  escape,  and  is  removed  from  the  surface 
by  the  atmosphere.  We  have  been  able  to  overcome 
these  difficulties,  and  the  produdi  obtained  is  almost  free 
from  strudture.  The  washed  or  unwashed  coagulum  has 
a  natural  inclination  to  contradl  when  surrounded  by  a 
hot  medium,  even  when  the  same  has  no  drying  capacity 
whatever.  The  rate  of  contradtion  increases  with  the 
temperature  ;  thus,  a  coagulum  containing  10  per  cent 
of  cellulose  will  rapidly  contradt  to  about  half  its  bulk  on 
immersion  in  boiling  water.  When  heated  in  this  way 
there  is  no  indication  of  case  hardening.  There  is  a 
limit,  however,  to  this  contradlion.  We  tried  the  effedt 
of  saturated  steam  at  different  pressures  upon  cylinders  of 
washed  coagulum,  which  contained  about  15  per  cent  of 
cellulose.  The  pressure  was  varied  from  3  to  8  atmo- 
spheres  ;  the  time  of  exposure  was  one  hour  in  each  case. 
The  average  contradtion  was  about  25  per  cent.  The 
experiments  go  to  show  that  there  is  little  or  no  difference 
between  the  3  atmospheres  or  8  atmospheres  on  the 
amount  of  contradtion.  As  the  diameter  increases  the 
rate  of  contradlion  diminishes.  The  next  set  of  trials 
were  made  to  determine  what  effedl  time  had  upon  the 
shrinkage  in  an  atmosphere  of  saturated  steam  at  4  atmo- 
spheres. Taking  the  original  weight  as  loo,  after  one 
hour's  treatment,  the  weight  became  82-9. 

After  two  hours,  the  weight  became  74*5 
»    three     „  „  „        657 

..     four      „  „  „        63-0. 

The  above  was  on  a  piece  of  washed  coagulum,  con- 
taining about  15  per  cent  of  cellulose.  We  next  took 
some  unwashed  coagulum,  containing  about  n  per  cent 
of  cellulose,  and  suspended  it  in  an  atmosphere  of  satu- 
rated steam  at  4  atmospheres.  It  lost  44*8  per  cent 
during  the  first  hour,  147  during  the  second  hour;  there- 
fore it  had  contradled  during  the  two  hours'  treatment  to 
40-5  per  cent  of  its  original  weight.  A  receptacle  was 
placed  immediately  beneath  the  coagulum  to  catch  the 
by.produdts,  which  were  found  to  be  recovered  without 
dilution.  With  blocks  of  double  the  diameter  of  the 
above,  ».  «.,75m.m.,  the  weight  after  two  hours' treat- 
ment was  56-6  per  cent  of  the  original.  The  effedl  of 
saturated  steam  is  to  produce  a  rapid  contradlion  of  the 
coagulum,  if  it  contains  from  lo  to  15  per  cent  of  cellulose, 


Cbbmical  Nbws,  I 
Feb.  19, 1897.     I 


Vtscose  and  Viscoid, 


87 


and  this  contraction  is  rapid  until  a  concentration  of  about 
20  per  cent  of  cellulose  is  reached.  By  a  prolonged 
treatment  in  saturated  steam  the  coagulum  gradually  con- 
tradls  until  it  contains  about  25  per  cent  of  cellulose, 
beyond  which  point  it  does  not  alter. 

Ivory  coloured  Viscoid. 

Ordinary  viscose  has  about  the  colour  and  consistency 
of  molasses,  and  yields  a  viscoid  which  has  the  general 
appearance  of  horn.  We  set  to  work  to  produce  viscoid 
in  imitation  of  ivory,  and  whilst  doing  this  we  discovered 
a  new  combination  of  viscose,  which  gave  rise  to  a  creamy 
white  solution.  This  was  found  to  last  longer  in  the 
liquid  form  than  the  ordinary  viscose.  On  drying  down 
it  yielded  a  produd  which  is  a  very  fair  substitute  for 
ivory.  It  has  a  specific  gravity  of  i8  to  i"85.  We  had 
several  sets  of  billiard  balls  turned  from  this,  and  they 
were  found  to  play  very  well  indeed.  The  angle,  how- 
ever, at  which  the  balls  left  each  other  after  striking  was 
somewhat  less  than  that  of  ivory  balls.  With  the  plain 
viscoid  balls,  which  have  a  sp.  gr.  of  15,  the  angle  is 
greater  than  that  of  ivory,  and  we  believe  it  possible  to 
mix  these  two  compositions  in  such  a  way  that  both  the 
specific  gravity  and  the  angle  at  which  they  leave 
each  other  after  striking  resemble  that  of  ivory.  This 
"  ivory  "  viscoid  has  been  used  for  various  articles,  such 
as  acorns  for  blind-cords,  knife-handles,  brush-backs,  &c. 

Viscoid  for  Electrical  Work, — The  plain  viscoid  was 
carefully  tested  to  determine  its  insulating  properties.  It 
is  about  equal  to  vulcanised  fibre  for  insulating  purposes. 
It  appears  that  if  great  care  is  taken  to  thoroughly 
remove  the  last  traces  of  by-produds,  and  to  well  season 
the  viscoid,  the  insulating  properties  can  be  made  much 
superior  to  vulcanised  fibre.  Cellulose,  when  completely 
deprived  of  moisture,  is  almost  a  perfei^  insulator,  and  its 
insulation  diminishes  as  the  hygroscopic  moisture  in- 
creases. Viscoid  will  probably  replace  vulcanised  fibre 
to  a  large  extent  for  eledtrical  work,  but  at  present  it  is 
very  much  inferior  to  vulcanite.  It  is  likely  that  we  shall 
find  some  means  of  improving  it,  so  that  it  may  be  made 
to  replace  that  substance. 

Black  Viscoid, — We  next  set  to  work  to  prepare  an 
ebony-black  viscoid,  and  after  about  six  months'  work  we 
have  obtained  a  uniform  black  viscoid,  which  in  some 
respedts  appears  to  be  superior  to  the  plain  substance. 
The  ebony  viscoid  will  probably  have  a  greater  range  of 
utility  than  any  of  the  other  produds  we  have  obtained. 
A  jet-black  is  preferable  to  white  or  any  colour  for 
machine-tool  handles,  &c. 

Blue  Viscoid, — We  have  obtained  a  somewhat  more 
expensive  produ(5l,  very  much  resembling  lapis  laxuli. 
This  is  very  nice  for  turning  and  carving,  and  takes  a 
very  high  polish,  and  looks  very  well  when  made  into 
fancy  articles,  such  as  umbrella  and  walking  •  stick 
handles. 

Various  Colours. — We  have  now  got  viscoid  in  a  large 
variety  of  colours  and  shades,  and  have  also  succeeded 
in  producing  grained  and  mottled  efiedls,  which  have  a 
very  pretty  appearance  when  turned  and  polished.  We 
see  no  reason  why  viscoid  should  not  be  used  in  place  of 
celluloid  for  many  purposes.  Some  samples  have  been 
kept  two  or  three  years,  and  they  do  not  discolour. 
Keeping  the  viscoid  for  a  long  time  appears  rather  to 
improve  it  than  otherwise. 

Paper  Sizing, 
Mr.  Little  mentioned  this  application  of  viscose  in  his 
paper  (^jfournal  of  the  Franklin  Institute,  cxxxviii.,  No. 
824).  Viscose  is  now  being  extensively  used  in  paper- 
mills  for  this  purpose.  It  does  not  size  the  paper  in  the 
sense  that  rosin  does,  although  when  viscose  is  used  a 
large  proportion  of  the  rosin  can  be  dispensed  with.  It 
is  added  to  the  beater,  and  a  chemical  substance  is  after- 
wards added  which  precipitates  the  cellulose  among  the 
fibres  as  a  flocculent  mass.  The  effedl  that  it  has  upon 
the  paper  is,  of  course,  dependent  upon  the  amount  used. 


It  strengthens  the  paper  from  30  to  100  per  cent,  and  the 
paper  produced  with  viscose,  besides  being  much  stronger, 
is  also  harder,  has  a  better  "  feel "  and  rattle,  and  admits 
of  a  much  better  surface  when  calendered.  It  also  assists 
in  the  retention  of  clay,  and  prevents  the  loss  of  short 
fibres  which,  as  a  rule,  pass  through  the  wire  cloth  of  the 
machine.  It  therefore  gives  a  larger  output  to  the 
machine.  It  is  chiefly  used  in  the  manufadure  of 
"  wrappings  "  and  bag  papers,  but  it  is  coming  into  use 
also  for  news  and  other  papers.  Where  additional 
strength  is  not  required,  it  enables  the  paper-maker  to 
use  a  lower-class  and  weaker  fibrous  material,  without 
prejudicing  either  the  strength  or  quality  of  his  paper. 
By  this  means  it  decreases  the  cost  of  producftion.  The 
precipitation  of  the  cellulose  requires  a  great  deal  of 
skill.  Unless  care  is  taken  to  ensure  the  right  conditions, 
and  to  add  the  precipitating  agents  in  the  right  propor- 
tions, the  cellulose  is  precipitated  as  a  non-adhesive  mass, 
which  gives  neither  strength  nor  hardness  to  the  paper. 
It  is  necessary  to  know  exadlly  the  conditions  of  working 
in  each  mill  before  good  results  can  be  ensured,  but  when 
once  these  are  known  and  understood  there  is  no  difficulty 
in  obtaining  uniform  results. 

The  Nature  of  Hygroscopic  Moisture  in  Cellulose, 
The  behaviour  of  viscoid  on  drying  in  the  mass  opened 
up  some  very  interesting  problems.  It  appeared  to  throw 
light  upon  the  hygroscopic  moisture  of  celluloses.  I  had 
previously  observed  {Nature,  xlix..  No.  457)  that  the 
cotton  fibre,  when  deprived  of  moisture  (either  by  drying 
in  an  air-bath  at  105°  C,  or  in  a  desiccator  over  sulphuric 
acid)  and  exposed  to  the  air,  rose  in  temperature  rapidly 
for  about  eight  minutes.  It  reached  a  temperature  of 
about  4i°  F.  above  that  of  the  atmosphere,  where  it 
remained  nearly  stationary  for  a  few  minutes.  It  then 
fell  gradually,  and  after  about  seventy  minutes'  exposure 
it  again  reached  the  temperature  of  the  surrounding  atmo- 
sphere. I  endeavoured  to  find  what  connexion  this  had 
with  the  rate  at  which  bone-dry  cotton  fibre  assumed  its 
hygroscopic  moisture.  I  found  that  cotton  fibre  took 
about  seventy  minutes,  and,  by  weighing  the  cotton  at 
different  intervals,  and  comparing  the  rate  of  gain  in 
weight  with  the  rate  of  increase  in  temperature,  I  was 
led  to  the  conclusion  that  the  two  were  closely  connecfted. 
The  same  experiments  were  repeated  with  anhydrous 
viscoid  which  had  been  ground  to  a  powder  before  drying. 
The  viscoid  first  of  all  suddenly  fell  below  the  temperature 
of  the  atmosphere.  It  fell  much  slower  than  the  cotton 
fibre,  and  even  at  the  end  of  160  minutes'  exposure  it  was 
still  about  3°  above  the  atmospheric  temperature.  At 
this  point  it  had  only  recovered  about  90  per  cent  of  its 
hygroscopic  moisture,  and  it  only  came  to  a  constant 
weight  after  about  210  minutes'  exposure.  By  grinding 
viscoid  to  a  much  finer  powder  than  was  used  for  the 
above,  and  repeating  the  experiments,  a  much  more 
regular  curve  was  obtained,  and  the  hygroscopic  mois.ure 
was  very  much  diminished  ;  but  the  time  required  for  the 
material  to  fall  to  the  temperature  of  the  atmosphere  was 
not  lessened.  I  took  some  cotton-wool  which  I  ground 
to  a  fine  powder,  and  I  found  that,  although  it  took  about 
sixty  minutes  to  recover  its  hygroscopic  moisture,  it  con- 
tained only  about  4  per  cent  instead  of  7  per  cent 
moisture.  All  these  experiments  were  repeated  with 
similar  results.  From  this  it  is  evident  that  the  hygro- 
scopic moisture  of  a  cellulose,  whether  amorphous  or  in 
the  fibrous  condition,  is  dependent  not  only  upon  the 
charaifter  of  the  cellulose  itself,  but  also  upon  the  extent 
to  which  the  cellulose  is  disintegrated.  This  is  contrary 
to  accepted  views  on  the  subject.  It  is  only  when  parti- 
cles of  viscoid  are  below  a  certain  size  that  the  hygro- 
scopic moisture  is  materially  diminished.  It  appears 
that  the  cellulose  that  composes  the  cell-walls  of  the 
ultimate  fibre  is  under  certain  stress  when  deprived  of 
moisture,  in  the  same  way  that  lumps  of  viscoid  are 
when  they  are  dried,  and  that  the  amount  of  stress  deter- 
mines the  amount  of  moisture  that  it  will  take  up  to 


88 


Rtport  of  Commiitee  on  Atomic  Weights. 


CllbailCAL  Nbws, 

^      Feb.  19,  1897. 


relieve  the  stress.  Cellulose  expands  when  hydrated, 
and  it  appears  that  the  hygroscopic  moisture  is  really 
water  of  hydration  of  the  cellulose,  and  that  it  tends  to 
hydrate  in  proportion  to  the  stress  that  exists  in  the 
anhydrous  cellulose.  This  accounts  for  the  fadt  that  the 
smaller  particles  of  viscoid  contain  less  hygroscopic 
moisture  than  the  larger;  also,  which  is  more  marked, 
disintegrated  cotton  fibre  contains  much  less  hygroscopic 
moisture  than  when  the  fibre  is  left  intadl.  I  have 
prepared  small  particles  of  viscoid,  which,  when  bont 
dry,  would  fly  to  pieces  on  being  scratched,  like  "  Prince 
Rupert  Drops;  "  but  tlie  same  particles,  on  being  placed 
in  a  damp  atmosphere,  swell  somewhat  and  recover  their 
strength. 

Particles  can,  on  the  other  hand,  be  prepared  in  such 
a  way  that  they  do  not  exhibit  brittleness,  and  they 
expand  to  a  much  less  degree  on  being  placed  in  a  moist 
atmosphere.  The  results  all  tend  to  the  same  conclu 
sion,  in  my  mind,  as  to  the  nature  of  hygroscopic  moisture 
in  cellulose. 


THIRD     ANNUAL     REPORT    OF    COMMITTEE 

ON     ATOMIC     WEIGHTS. 

RESULTS     PUBLISHED     DURING    1895.* 

By  F.  W.  CLARKE. 

(Ooutinued  from  p.  76). 

Cobalt. — The  atomic  weight  of  cobalt  has  been  re- 
determined by  Thiele  ("  Die  Atomgewichts  bestimmung 
des  Kobalts,"  a  doctoral  dissertation,  Basel,  1895).  First, 
carefully  purified  oxide  of  cobalt,  CoO,  was  reduced  in 
hydrogen.     The  weight  and  results  are  as  follows  : — 

Residual  Co.  Loss  of  O.         Atomic  weight  of  Co. 

0-90068  ,        0-24429  58-843 

079159  0-21445  58-912 

1-31558  0-35716  58-788 

Mean 58-848 

Reduced  to  vacuum  standards  this  becomes — 
Co  =  58-826, 
when  O  =  1596. 

In  a  second  method  metallic  cobalt  was  dissolved  in 
hydrochloric  acid,  and  the  solution  evaporated  to  dryness 
with  special  precautions  against  dust.  The  chloride  thus 
obtained  was  then  dried  at  150"  in  a  stream  of  pure 
gaseous  hydrochloric  acid,  so  that  basic  salts  could  not 
be  formed.  F"^riim  the  weight  of  cobalt  and  of  cobalt 
chloride  the  ratio  Co:  Cla  is  determined.  The  chlorine 
was  afterwards  re-estimated  as  silver  chloride,  giving  liie 
ratio  Co  :  2AgCl.  The  weights  are  subjoined  :  — 
Co  taken.  CI  taken  up.  AgCl. 

0-7010  0-8453  — 

0-3138  0-3793  — 

0-2949  0-3562  1*4340 

0-4691  0-5657  2-2812 

0-5818  0-7026  2-8303 

0-5763  0-6947  — 

0-5096  0-6142  2-4813 

Hence,  with  Cl  =  35-37,  and  Ag  =  i07  66,  Co  = 
Co  :  Clj.  Co  :  2AgCl. 

5866  — 

5852  — 

5857  58-828 

5866  58-825 

5852  58803 
58-68  — 

58  69  58*750 


Mean  58  64 


Mean  58801 


♦   Kcaii  at  the  Clevtlaud   Mteiaig,  DecciLbtr  31,  royj. 
Journal  of  the  American  Chemical  Society,  xviii..  No.  3. 


The  second  column  is  subje<ft  to  a  small  conevSlion  for 
dissolved  silver  chloride,  which  reduces  the  mean  to 
00  =  58770.  Reduced  to  a  vacuum  this  becomes  58-765, 
and  the  value  from  the  Co  :  CI2  ratio  becomes  58*61. 
Thiele  regards  00  =  58  765  as  the  most  probable  value  to 
be  derived  from  his  experiments.  This  becomes — 
With  0  =  16  00  =  58-912 

,,     0  =  15-88        00  =  58-470 

In  my  report  for  1894  I  gave  Winkler's  work  on  cobalt 
and  nickel,  which  iiivolved  their  ratios  to  iodine.  In  a 
supplementary  paper  Winkler  [Ztschr.  Anorg.  Chem.,  viii., 
291)  gives  some  similar  experiments  with  iron,  intended 
to  show  that  errors  due  to  metallic  occlusion  of  hydrogen 
are  absent  from  his  determinations.  He  succeeds  in 
proving  that  such  errors,  if  they  exist,  must  be  very  small. 
Thiele  also  considered  their  possibility,  and  guarded 
against  them  in  the  preparation  of  his  cobalt. 

Zinc. — Atomic  weights  re-determined  by  Richards  and 
Rollers  (Ztschr.  Anorg.  Chem.,  x.,  i  ;  calculations  made 
with  0=i6,  Ag=io7  93,  and  Br  =  79-955),  who  used  the 
bromide  method.  Zinc  bromide,  carefully  purified,  was 
ireated  gravimetrically  with  standard  silver  solution.  The 
weights  and  results  are  subjoined  : — 

First,  ZnBra :  2AgBr. 

ZaBr,^.  AgBr.  Atomic  weight  of  Zn. 

1-69616  282805  65-469 

1-98x98  3*30450  65-470 

170920  284549  65-487 

235079  391941  65-470 

2-66078  443751  65400 


Mean.. 

65459 

Second,  same  ratio. 

ZnBrj. 

AgBr.               Atom 

ic  weight  of  Zn 

2-33882 
1-97142 
2-14985 
2-00966 

3  90067 
3*28742 
358539 
3*35074 

65-400 

65*434 
65-402 

65463 

Mean.. 

65*425 

Third,  ZnBr^  :  Agz. 

ZnBrj. 

Ag.                  Atoir 

ic  weight  of  Zn 

2  33882 
1-97142 
2-14985 
2-00966 

2-24063 
1-88837 
205971 
1-92476 

65-409 

65*444 
65-396 
65*472 

Mean..  ..     65-430 

Two  additional   series  of  data   are  given  by  Richards 
alone,  as  follows  : — 

Fust,  ZnBrj  :  Ai-j. 

ZnBrj.  Ag.  Atomic  weight  of  Zn. 

6-23833  5-9766  65-403 

5*26449  5*0436  65-404 

9-36283  8-9702  65-392 


ZnBr^. 
2  65 847 
2-30939 
5*26449 


Mean..     ..     65-402 
Second,  ZnBrj:  2AgBr. 

AgBr.  Atomic  weight  of  Zn. 

443358  65-410 

3-85149  65-404 

8-77992  65-404 


Mean.. 


65-406 

The  final  mean  adopted  by  Richards  is  65-404.      With 
0  =  15-88  this  becomes — 

Zn   =  64-913. 
Cadmium. — Mr.  Buchei's  paper,*  as  iis  title  indicates, 


*  ••  An  Examiiiaiioii  of  some  Methods  Employed  in  Determining 
the  Atomic  Weight  of  Cadmium,"  by  Jjhu  E.  Biichtr.  Johns 
Hiipkms  University  doctoral  dissertation.  Baltimore  (Friedenwald), 
1895. 


CBBMICAL  MBWS,  I 

Feb.  19,  1897.     I 


Report  of  Commtttee  on  A  tomtc  Weights, 


89 


is  a  study  of  methods  rather  than  a  final  determination  of 
atomic  weight ;  but  the  results  recorded  in  it  compare 
well  with  those  reached  by  others.  His  starting-point  is 
metallic  cadmium,  purified  by  nine  distillations  in  vacuo, 
and  from  this  material,  with  pure  reagents,  his  various 
preparations  were  made.  Vacuum  weights  are  given,  and 
the  antecedent  values  used  in  calculation  are  O,  16 ;  S, 
32-059  ;  C,  12-003  ;  CI,  35-45 ;  Br.  79-95 ;  and  Ag,  107-93. 
First,  cadmium  oxalate,  dried  for  fifty  hours  at  150  , 
was  decomposed  by  heat,  and  so  reduced  to  oxide.  The 
variations  are  mainly  attributed  to  imperfed  dehydration 
of  the  oxalate.     Weights  and  results  are  as  follows  : — 


Oxalate. 
1-97674 
I -94912 
1-97686 
1-87099 
i"3755o 
i*333i3 
1-94450 
2*01846 


Oxide. 
1-26474 
1-24682 
1-25886 
1-19675 
0-87994 
0-85308 
1-24452 
I-29210 


Atomic  weight  of  Cd. 
III-74 
111-83 
111-85 
III-81 
11 1-86 
111-96 
112-02 
112*09 


Mean..     ..     111-89 

Second,  cadmium  oxalate  was  transformed  to  sulphide 
by  heating  in  a  stream  of  hydrogen  sulphide.     The  data 

are  : — 

Oxalate.  Sulphide.  Atomic  weight  of  Cd. 

2*56319  1*84716  II2'25 

2-18364  1*57341  iiTig 

2-11643  1-52462  112-03 

3-13105  225582  112-12 


Mean.. 


112-15 


Third,  cadmium  chloride,  dried  at  300°  in  a  stream  of 
dry,  gaseous  hydrochloric  acid,  was  precipitated  by  silver 
nitrate,  and  the  silver  chloride  was  colleifted  with  all 
necessary  precautions.  The  weights  and  results  are  sub- 
joined : — 

CdCI,. 

3-09183 

2-26100 

1*35729 

2*05582 

1*89774 

3*50367 

2*70292 

4-24276 

3-40200 

4-60659 

2*40832 

2*19144 

2*84628 

2-56748 

2*31003 

1-25008 

1*96015 

2*29787 

1-94227 

I -10976 

1*63080 


AgCl, 

4-83856 

3-53854 
2-12431 

321727 
2-97041 

5-48473 
4-23087 
6-63598 

5-32314 
7-20386 

3-76715 
3*42724 

4-45477 
4*01651 
3-61370 
1-95652 
3-06541 

3-59391 
303811 

1-73547 
2-55016 

Mean..  ..  112*39 

Fourth,  cadmium  bromide  was  analysed  in  much  the 
same  way  as  the  chloride.  The  weights  and  results  are 
as  follows : — 


Atomic  weight  of  Cd. 
112-34 
112-33 
112-32 
112-34 
112-31 
112-28 
112-30 
112-44 
112-37 
112*47 
112-42 
112-46 
112-32 
112*41 
112-41 
112-32 
112-47 
112-45 
112-42 
112-47 
112-48 


CdBr,, 

AgBr. 

Atomic  weight  of  Cd 

4-3994 1 

6-07204 

112  35 

3-18030 

4-38831 

112-42 

3-60336 

4-97150 

112-45 

4*04240 

5-58062 

112-29 

3-60505 

4-97519 

112-38 

Fifth,  cadmium  sulphate  was  formed  by  synthesis  from 
metallic  cadmium.  1-15781  grms.  cadmium  gave  2-14776 
cadmium  sulphate.  Hence  Cd  =  112-35.  As  any  impurity 
in  the  sulphate  would  tend  to  lower  the  atomic  weight 
found,  this  is  probably  a  minimum  value. 

Sixth,  metallic  cadmium  was  converted  into  oxide  by 
solution  in  nitric  acid  and  ignition  of  the  nitrate.  The 
ignition  was  performed  in  double  crucibles,  both  porce- 
lain in  Experiments  1  and  2,  the  inner  one  of  platinum  in 
the  rest  of  the  series.     Weights  and  results  as  follows  : — 


Cd. 
1-26142 
0-99785 


1-11321 
1-02412 
2*80966 


CdO. 
1*44144 
1-40135 


Atomic  weight  of  Cd. 
112-12 
112*04 


Mean.. 


1*27247 

i'«7054 
3*21152 


Mean.. 


112*08 

111*84 
111*91 
ixi'87 

111*87 


Mean.. 


112-38 


In  this  case  additional  experiments  were  made  to  dis- 
cover the  sources  of  error,  leading  to  corredions  which 
bring  the  results  near  to  those  found  in  the  chloride  and 
bromide  series.  Each  of  the  methods  is  quite  fully  dis- 
cussed, and  the  sources  of  error  are  noted.  With  0  =  i6, 
112-39  seems  to  be  a  close  approximation  to  the  true 
atomic  weight  of  cadmium. 

Molybdenum. —  Seubert  and  Pollard  {Ztschr.  Anorg. 
Chem.,  viii.,  434;  calculations  on  the  basis  of  Oa-15-96), 
by  two  distin(a  methods,  have  re-determined  the  atomic 
weight  of  this  element.  First,  molybdenum  trioxide  was 
dissolved,  in  weighed  quantities,  in  a  standard  solution  of 
caustic  soda.  The  excess  of  soda  was  then  measured  by 
titration  with  standard  sulphuric  acid  and  lime  water.  In 
another  set  of  experiments  the  volumetric  value  of  the 
caustic  soda  had  been  estimated  with  standard  hydro- 
chloric acid,  while  the  last  compound  had  also  been 
determined  gravimetrically  in  terms  of  silver  chloride. 
Hence  the  data,  all  considered  together,  give  from  their 
true  end  terms,  the  ratio  M0O3  :  2AgCl,  although  in  a 
very  indiredt  manner  ;  and  for  this  indirection  the 
authors  give  good  reasons.  The  weights  and  results, 
considering  only  the  end  terms,  are  as  follows : — 


MoO,. 
3-6002 
3-5925 
373" 
3*8668 
3-9361 
3*8986 
3-9630 
3-9554 
39147 
3-8543 
3-9367 


AgCl. 
7-1709 
7-1569 

7-4304 
7-7011 
7*8407 
77649 
7-8941 
7-8806 
7-7999 
7-6767 
7-8437 


Atomic  weight  of  Mo. 

95-734 
95-708 

95757 
95-749 
95-720 
95-740 
95-723 
95-694 
95-686 

95-740 
95-688 


Mean.. 


95-722 


Reduced  to  vacuum  standards  this  becomes  Mo=95-729. 
With  0  =  16,  Mo  =  95-969;  and  with  0  =  15-88,  Mo= 
95 •249- 

Another  series  of  determinations,  in  confirmation  of  the 
first,  was  made  by  the  old  method  of  reducing  molybdenum 
trioxide  in  hydrogen.  The  weights  and  results  are  sub- 
j  oined : — 

MoOg.  Mo. 

1-8033  1-2021 

1*7345  1-1564 

3-9413  2-6275 

1-5241  i-oi6o 

4-0533  2*7027 


Atomic  weight  of  Mo. 
95-736 
95-777 
95756 
95-741 
95-813 


Mean.. 


95765 


go 


Action  of  Wagner* s  Reagent  upon  Caffeine. 


Chemical  NbWs, 

Feb.  ig,  1807. 


Reduced  to  vacuum,  Mo  =  95735,  a  value  very  close  to 
the  other.  When  0  =  16,  the  atomic  weight  of  molyb- 
denum is  very  near  the  even  number  96. 

(To  be  continued). 


ON 


THE    ACTION     OF    WAGNER'S     REAGENT 
UPON    CAFFEINE,    AND 
A  NEW    METHOD    FOR   THE   ESTIMATION 
OF    CAFFEINE.' 

By  M.GOMBERG. 
(Continued  from  p.  81). 


I.  This  sample  was  obtained  by  slowly  adding  a  solution 
of  iodine  in  potassium  iodide  to  a  solution  of  caffeine 
acidulated  with  sulphuric  acid.  The  iodine  was  added 
until  the  supernatant  liquid  was  decidedly  red.  The 
whole  was  allowed  to  stand  three  hours,  filtered,  washed, 
and  dried  as  described  above.  The  total  iodine  was  esti- 
mated in  the  usual  way,  i.e.,  by  suspending  a  weighed 
sample  in  water,  adding  sulphurous  acid  solution,  then 
silver  nitrate  and  nitric  acid;  filtered,  washed,  and  dried. 
The  "  exterior  "  iodine,  j.«.,  the  iodine  not  as  hydriodic 
acid,  was  estimated  by  dire(5t  titration  with  standard  so- 
dium thiosulphate. 

o'2oo2  grm.  gave  for  total  iodine  0'2785  grm.  Agl. 
0-2358        „        ,,      exterior  „      0-1433     „     I. 

II.  This  sample  was  obtained  by  adding  to  an  acidulated 
solution  of  caffeine  enough  iodine  to  precipitate  about 
one-half  of  the  caffeine  present. 

0-2563  grm.  gave  for  total  iodine  0-3591  grm.  Agl. 
0-1659        ,,         ,,    exterior    ,,      0-0997      n     ^• 

III.  A  neutral  solution  of  caffeine  was  mixed  with  an 
excess  of  Wagner's  reagent,  and  to  the  mixture  dilute 
sulphuric  acid  was  gradually  added  so  long  as  a  precipi- 
tate was  produced. 

0*4039  grm.  gave  for  total  iodine  0-5668  grm.  Agl. 
0-1424        „         „     exterior    „     0-0866      ,,     I. 

IV.  Filtrates  from  I.  and  III,  on  long  standing,  gave  a 
deposit  of  dark  blue  needle-like  crystals,  which  were  col- 
leded,  washed,  and  dried  as  before. 

0-7884  grm.  gave  for  total  iodine  1-1064  gri"-  Agl. 
0-4450         ,,        ,,     exterior    ,,      0-2685      n     !• 

V.  This  was  obtained  by  re-crystallising  the  amorphous 
precipitate  from  methyl  alcohol. 

0*2890  grm.  gave  for  exterior  iodine  0-1756  grm.  I. 

VI.  Obtained  by  re-crystallising  the  amorphous  per- 
iodide  from  hot  ethyl  acetate. 

*  From  the  Journal  of  the  American  Chemical  Society,  xviii.,  No.  4- 


0-4807  grm.  gave  for  total  iodine  0-6709  grm.  Agl. 
0-2777         ,,        „     exterior    ,,      0-1622      ,,     I. 

Calculated  for      Per  Found. 

C,Hi,N«0,HI.l4.cent.  I.          II.         III.        IV.        V.         VI. 

Total  iodine..  7644  75-12  7566  75-84  75-83      —    75-40 

Exterioriodine 61-15  6079  6o-ii  6o-8i  60-34  60-76  60-22 

When  some  of  the  periodide  is  treated  with  a  solution 
of  sulphur  dioxide,  and  then  extrafled  with  chloroform, 
it  furnishes  unchanged  caffeine. 

The  composition  of  this  periodide  of  caffeine  appears 
to  be  difTer«nt  from  that  described  by  Tilden  (yourn. 
Chem.  Soc,  xviii.,  99, 1865),  which  he  obtained  by  exposing 
to  sunlight  an  alcoholic  solution  of  caffeine  containing 
some  hydriodic  acid.  The  slow  oxidation  of  the  hydriodic 
acid  furnished  the  iodine,  and  the  compound  thus  ob- 
tained has  the  composition,  according  to  Tilden, 
2(C8HioN402HI-l2)-3H20.  It  is  a  lower  periodide  than 
the  one  which  is  obtained  when  iodine  dissolved  in  potas- 
sium iodide  is  diredlly  added  to  caffeine,  as  the  latter  has 
the  composition  C8H10N4O2.HI.I4.  Tilden  also  men- 
tions that  by  the  addition  of  alcoholic  iodine  to  a  solution 
of  caffeine  in  weak  sulphuric  or  hydriodic  acid,  he  ob- 
tained a  deposition  of  black  granules,  which  upon  analysis 
furnished  about  75  per  cent  of  total  iodine.  He  says  that 
it  probably  consists  of  a  compound  containing  nine  atoms 
of  iodine.  But  there  is  hardly  any  doubt  that  he  had  the 
tetraiodide  of  caffeine  hydriodide. 

Properties. — When  dry  the  periodide  is  a  violet-blue 
amorphous  powder  melting  at  213°  C.  When  moist  it 
rapidly  loses  iodine  on  exposure  to  air.  It  is  permanent 
when  dry,  and  suffers  but  slight  loss  when  heated  to  100° 
C.  Two  grms.  heated  for  four  hours  at  that  temperature 
lost  only  0-027  g'"'"-  =  i"33  per  cent.  It  loses  but  very 
little  of  its  iodine  when  suspended  in  water,  giving  up 
enough  iodine  to  saturate  the  liquid.  The  presence  of 
potassium  iodide  in  the  water  favours  the  liberation  of 
iodine,  but  even  then  it  is  but  slight.  The  periodide  dis- 
solves readily  in  alcohol,  especially  when  heated,  with 
considerable  decomposition  into  the  free  base  and  iodine. 
It  is  more  soluble  in  methyl  alcohol  and  suffers  less  de- 
composition in  that  solvent.  It  can  be  obtained  from 
methyl  alcohol,  on  spontaneous  evaporation  of  the  sol- 
vent, in  the  form  of  beautiful  crystals,  with  a  metallic  dark 
bluish  lustre.  When  examined  under  the  microscope  the 
crystals  appear  to  consist  of  six-sided  prisms.  Ether, 
whether  cold  or  warm,  decomposes  it  but  slightly.  The 
periodide  is  insoluble  in  chloroform,  carbon  disulphide, 
and  benzene.  It  is  soluble  without  decomposition  in  hot 
ethyl  acetate,  from  which  it  separates  on  cooling  as  a  dark 
granular  crystalline  deposit,  which  melts  at  215°  C. 

Limits  of  Precipitation. — Like  most  alkaloids,  caffeine 
is  precipitated  by  Wagner's  reagent  even  from  very  dilute 
solutions  of  the  base.  Although  not  charadteristic,  it  is 
yet  as  delicate  a  test  for  caffeine  as  we  have.  The  limits 
of  precipitation,  under  the  influence  of  different  acids,  will 
appear  from  the  accompanying  table.  The  tests  apply  to 
I  c.c.  of  the  solution  mentioned,  acidulated  with  two  or 
three  drops  of  the  acid,  and  to  this  two  drops  of  Wagner's 
reagent  (twentieth  normal)  was  added. 
(To  be  continued). 


Sulphuric  acid. 

Hydrochloric  acid. 

Nitric  acid. 

Dilution. 

5  per  cent. 

5  per  cent. 

5  per  cent. 

:  250 

Very  heavy. 

Very  heavy. 

Very  heavy 

:  1000 

Very  heavy. 

Very  heavy. 

Very  heavy 

■  1500 

Heavy. 

Heavy. 

Heavy. 

.  3000 

Fair. 

Fair. 

Fair. 

5000 

Very  slight. 

Slight. 

Slight. 

8000 

Very  slight. 

Slight. 

Slight. 

zoooo 

None. 

Very  slight. 

Very  slight. 

Acetic  acid.       Oxalic  acid.     Tartaric  acid.    Citric  acid. 
5  and  50  per  cent.   5  per  cent.        10  per  cent.      10  per  cent. 


None. 


Heavy. 
Heavy. 
Slight. 
Faint. 


Slight. 

Very  slight. 

None. 


Faint. 
None. 


Chemical  News, 
Feb.  19,  1897.      < 


Determination  of  Atomic  Masses  by  the  Eiectrolytic  Method  91 


THE  ACTION  OF  BORON  ON  IRON  AND 

STEEL,     AND      ERRORS      IN     IRON     ANALYSIS 

ACCOUNTED    FOR    BY    THE    PRESENCE 

OF    THAT    ELEMENT. 

By  H.  N.  WARREN,  Principal,  Liverpool  Research  Laboratory. 

Some  five  or  six  years  ago  a  somewhat  lengthy  description 
was  published  in  the  Chemical  News  with  rasped  to  the 
adion  of  boron  upon  metallic  iron,  which  researches  at 
that  time  led  to  the  discovery  of  the  now  well-known 
compound  boroneisen. 

Quite  recently  some  rather  remarkable  notes  have 
appeared  in  scientific  literature  of  the  preparation  of  that 
compound  by  the  aid  of  eledlrical  furnaces  ;  it  is  there- 
fore the  author's  intention,  after  a  long  and  varied  expe- 
rience with  the  element,  to  deny  most  emphatically  that 
anything  like  such  a  temperature  as  the  eledric  arc  is 
required  in  order  to  form  a  boro-ferric  compound.  Even 
ordinary  ferric  borate,  obtained  by  precipitating  ferric 
chloride  by  means  of  a  soluble  borate,  may,  after  drying, 
be  readily  reduced,  at  a  red  heat,  to  an  amorphous — and 
at  the  same  time  pyrophoric — boride ;  or  may  be  obtained 
of  a  silvery  whiteness,  fusible  at  a  white  heat  and  con- 
taining from  6  per  cent  boron,  by  melting  the  above- 
mentioned  compound  under  a  layer  of  borax,  the 
compound  being  of  sufficient  hardness  to  cut  glass  and 
even  scratch  flint,  the  horon  being  set  free  in  the  ele- 
mentary condition  by  means  of  eledro  dissolution.  This, 
however,  is  by  no  means  the  only  way  of  impregnating 
iron  with  boron  ;  on  the  other  hand,  it  is  extremely  diffi- 
cult to  prevent  the  formation  of  a  boride,  when  a  mixture 
of  iron  oxide  and  carbon  is  exposed  to  a  temperature 
sufficient  to  melt  the  cast-iron  thus  produced,  provided  a 
fusible  borate  is  used  as  a  flux.  Again,  borax  being  such 
a  desirable  fluxing  agent  for  metallurgic  redudions,  this 
compound  is  generally  made  use  of  in  smelting  small 
quantities  of  iron  ores,  for  the  purpose  of  further  ex- 
amination of  the  iron  thus  obtained.  This  readtion  is, 
however,  perfectly  useless,  provided  a  fluxable  borate  has 
been  employed,  as  one  hundred  samples  thus  reduced 
by  the  author  all  contained  more  or  less  boron,  averaging 
up  to  2  per  cent,  while  at  the  same  time  the  iron  in  most 
cases  appears  solely  as  white  cast,  the  carbon  existing  in 
the  combined  form  ;  also,  as  a  verification  test,  samples 
of  cast-iron  were  exposed  to  different  temperatures  in 
common  with  fusible  borates,  the  analyses  of  all  these 
samples  showing  a  deficiency  on  the  total  averaging  from 
i  to  2  per  cent. 

Liverpool  Research  Laboratory, 
18,  Albion  Street,  fiverton,  Liverpool. 


VOLUMETRIC    DETERMINATION 

OF     MOLYBDENUM     AND    VANADIUM.* 

By  CARL  FRIEDHEIM. 

In  concert  with  H.  Euler  I  have  elaborated  a  volumetric 
method  for  determining  molybdenum.  It  consists  in 
decomposing  the  molybdate  or  molybdenum  teroxide  in 
Bunsen's  apparatus  with  potassium  iodide  and  hydro- 
chloric acid,  absorbing  the  liberated  iodine  in  potassium 
iodide,  and  titrating  with  sodium  thiosulphate  in  the 
usual  manner. 

F.  A.  Gooch  and  Charlotte  Fairbanks  {Zeit.  Anorg. 
Chem.)  have  submitted  this  process  to  a  re-examination, 
with  the  result  that  satisfadlory  values  can  be  obtained 
only  under  conditions  which  they  have  ascertained  and 
communicated. 

Stridly  speaking,  it  might  be  sufficient  to  point  out 
that  (as  it  appears  from  the  figures  given  in  my  former 

*  Berichte  A.  Chem.  Gcstll, 


communication),  in  my  method  the  errors  fluduate  between 
—  Cog  and  4-0*36  (and  not  as  Gooch  and  Fairbank  state, 
between  -fo"05  and  1-13  per  cent),  whilst  the  authors 
just  named  obtain  errors  of  from  — 0*14  to  -fo*45,  in  order 
to  prove  that,  according  to  the  proposed  modification,  the 
results  obtained  are  not  better,  but  worse.  But  as  my 
method  admits  of  more  general  application,  and  on  this 
account  any  additional  difficulty  must  be  avoided  such  as 
would  be  involved  in  the  new  proposals,  I  must  examine 
more  closely  some  of  the  declarations  of  Gooch  and  Fair- 
banks. 

The  hydriodic  acid  liberated  on  treating  molybdenum 
teroxide  with  potassium  iodide  and  hydriodic  acid  is 
naturally — in  as  far  as  it  is  not  oxidised  by  the  molyb- 
denum teroxide — decomposed  by  the  oxygen  of  the  a  tmo- 
sphere,  which  naturally  must  signify  an  increased  elimina- 
tion of  iodine.  This  I  pointed  out  expressly  in  my  former 
communication,  in  which  it  is  stated: — "  We  have  found 
that  this  process  of  determination  can  be  carried  out — 
with  the  due  observation  of  certain  precautions — much 
more  rapidly  and  quite  as  accurately  in  Bunsen's  appa- 
ratus, and  therefore  by  distilling  the  substance  with 
potassium  iodide  and  hydrochloric  acid." 

But  if  we  heat  the  mixture  of  the  above  substances 
rapidly,  too  much  iodine  is  liberated  in  the  receiver ;  but 
if  we  work  in  such  a  manner  that  the  redudion  of  the 
substance  is  efFeded  before  hydriodic  acid  escapes,  we 
obtain  the  theoretical  quantity  of  iodine. 

Hence  the  following  modus  operandi  results  for  the 
execution  of  the  method  : — o'2  to  03  grm.  of  the  molyb- 
date are  mixed  in  the  decomposition  flask  of  Bunsen 
apparatus  with  o'5  to  0*75  grm.  of  potassium  iodide,  and 
so  much  hydrochloric  acid  of  sp.  gr.  i'i2  that  the  liquid 
may  fill  two-thirds  of  the  flask.  After  connedion  with 
the  escape  tube  and  its  introdudion  into  the  receiver,  the 
contents  of  the  flask  are  very  slowly  heated  so  as  to  reach 
ebullition,  when  the  escape  tube  is  filled  as  far  as  possible 
with  iodine  vapour  and  is  just  on  the  point  of  reflux. 
When  the  iodine  is  completely  expelled,  i.e.,  when  no 
more  violet  fumes  are  visible,  and  the  solution  takes  a 
light-green  colour,  the  distillation  is  at  once  broken  ofT, 
and  the  iodine  absorbed  by  potassium  iodide  in  the 
receiver  is  titrated  with  sodium  thiosulphate. 

When  Gooch  and  Fairbanks  repeat  these  diredions 
with  the  words  "  that  the  flask  is  two-thirds  filled,"  and 
continue  "  the  solution  is  not  raised  to  ebullition  until 
the  flask  is  entirely  filled  with  the  heavy  vapours  of  iodine, 
and  is  continued  until  iodine  is  no  longer  visible,  and  the 
liquid  has  taken  a  light-green  colour,"  they  have  evidently 
'  quite  overlooked  that  I  laid  particular  emphasis  on  the 
exclusion  of  air;  that  is,  on  the  non-contad  of  air  and 
hydriodic  acid. 

(To  be  continued). 


THE    DETERMINATION     OF    ATOMIC     MASSES 

OF     SILVER,     MERCURY,     AND     CADMIUM, 

BY     THE     ELECTROLYTIC     METHOD.* 

By  WILLETT  LEPLEY  HARDIN. 

(Continued  from  p.  79). 

Part  III. 
Determination  oj  the  Atomic  Mass  of  Cadmium. 
Nine    experimenters  have  determined  the  atomic  mass 
of  cadmium  by  many  different   methods,   but  the  large 
variations  in  the  results  given  by  different  chemists  leave 
the  true  value  of  this  constant  still  uncertain. 

Stromeyer  (Beizelius'  "  Lehrbuch,"  5th  Edition,  iii., 
i2ig)   gave  no  details  of  his  method  of  operation,  but 

*  Contribution  firom  the  Joha  Harrison  Laboratory  of  Chemistry 
No.  13.  From  the  author's  thesis  presented  to  the  Faculty  of  the 
University  of  Pennsylvania  for  the  degree  of  Ph.D. — From  the 
Journal  of  the  American  Chemical  Society,  xviii.,  p.  990. 


9^         Determtnaiion  of  Atomic  Masses  by  the  Electrolytic  Method. 


Chemical  Mbwb, 
Feb.  ig   1807. 


found  that  100  parts  of  cadmium  combined  with  14,352 
parts  of  oxygen.  On  the  basis  of  0=i6,  this  ratio  gives 
111-483  for  the  atomic  mass  of  cadmium.  This  result  is 
much  lower  than  those  obtained  by  other  experimenters, 
and  is  perhaps  only  of  historical  interest. 

In  a  series  of  nine  experiments,  Von  Hauer  {jfourn. 
Prakt.  Chetn.,  Ixxii.,  350)  determined  the  ratio  of  cadmium 
sulphate  to  cadmium  sulphide.  The  sulphate  used  was 
purified  by  repeated  re-crystallisations,  and  was  finally 
dried  at  a  temperature  of  200°.  After  weighing  the  sul- 
phate was  always  dried  a  second  time  and  re-weighed. 
The  two  weighings  never  differed  as  much  as  one  m.grm. 
The  sulphide  obtained  was  in  each  case  tested  for  sulphate 
The  redudlion  of  the  sulphate  to  sulphide  was  accom- 
plished by  heating  the  sulphate  in  a  current  of  dry 
hydrogen  sulphide  under  pressure.  The  mean  of  nine 
observations  computed  on  the  basis  of  0  =  16  and  8  =  32*06 
gives  111*93  ^o""  'h^  atomic  mass  of  cadmium.  Con- 
sidering the  large  quantity  of  material  used  each  time, 
and  the  precautions  taken  to  insure  accuracy,  there  seems 
to  be  little  objedtion  to  the  method. 

Dumas  (Ann.  Chim.  Phys.,  [3J,  Iv.,  158)  determined 
the  ratio  of  cadmium  chloride  to  metallic  silver  by  titrating 
a  solution  containing  a  weighed  quantity  of  cadmium 
chloride  with  a  silver  nitrate  solution  of  known  strength. 
The  cadmium  chloride  was  prepared  by  dissolving  metallic 
cadmium  in  boiling  hydrochloric  acid.  The  solution  was 
evaporated  to  dryness,  and  the  chloride  fused  for  six  hours 
in  a  current  of  hydrochloric  acid  gas.  The  mean  of  six 
determinations  gives  112*24  for  the  atomic  mass  of 
cadmium  (O-  16). 

Maximum  result,  Cd  =  1 12759 
Minimum       ,,       Cd  =  111*756 


Difference  =       1003 

This  large  variation  in  the  results  obtained  indicates 
the  presence  of  impurities  in  the  material  used.  In  the 
first  three  experiments  the  cadmium  was  not  purified  ;  the 
mean  of  these  three  is  Cd  =  112*476.  The  metal  used  in 
the  last  three  experiments  was  considered  by  Dumas  to 
be  absolutely  pure  ;  the  mean  of  the  last  three  results  is 
Cd  =  112*007.  From  the  degree  of  purity  of  the  cadmium 
chloride  used  in  the  different  experiments,  Dumas  was 
inclined  te  rejeift  the  higher  results,  and  concluded  that 
the  true  atomic  mass  of  cadmium  was  about  112. 

Lensen  {yourn.  Prakt.  Chem.,  Ixxix.,  281)  prepared 
pure  cadmium  oxalate  by  precipitating  a  solution  of 
cadmium  chloride,  purified  by  repeated  crystallisation, 
with  pure  oxalic  acid.  The  precipitate  was  washed  and 
carefully  dried  at  a  temperature  of  150°.  The  mean  of 
three  results  obtained  by  converting  a  weighed  portion 
of  the  oxalate  to  oxide  gives  112*06  for  the  atomic  mass 
of  cadmium  (0  =  i6),  The  small  quantity  of  material 
used  in  the  different  experiments  is  somewhat  objedtion- 
able. 

Huntington  {Proc.  Amer.  Acad.,  xvii.,  28)  under  the 
diredtion  of  Cooke,  determined  the  ratio  of  cadmium 
bromide  to  silver  bromide,  and  also  the  ratio  of  cadmium 
bromide  to  metallic  silver.  The  bromide  used  was  pre- 
pared by  dissolving  cadmium  carbonate,  which  had  been 
carefully  purified,  in  pure  hydrobromic  acid.  The  produdl 
obtained  was  dried  at  a  temperature  of  200°,  and  finally 
sublimed  in  a  porcelain  tube  in  a  current  of  dry  carbon 
dioxide.  In  the  first  series  of  experiments  the  silver 
bromide  corresponding  to  the  cadmium  bromide  used  was 
weighed.  The  mean  of  eight  determinations  computed 
from  the  total  quantity  of  material  used  and  silver 
bromide  obtained,  on  the  basis  of  Ag  =  107*93  and 
Br=79*95,  is  Cd  =  ii2  24.  In  the  second  series  of  experi- 
ments the  quantity  of  metallic  silver  required  to  precipi- 
tate a  known  quantity  of  cadmium  bromide  was  deter- 
mined. The  mean  of  eight  determinations  computed  as 
in  the  first  series  gives  112*245  for  the  atomic  mass  of 
cadmium.  The  separate  determinations  in  both  series 
agree  very  closely. 


Partridge  {Amer.  yourn.  Set.,  [3] ,  xi.,  377)  made  three 
series  of  determinations.  The  first  depended  upon  the 
conversion  of  cadmium  oxalate  into  oxide,  the  second,  on 
the  redudlion  of  the  sulphate  to  sulphide,  and  the  third, 
on  the  conversion  of  the  oxalate  into  sulphide.  The  cad- 
mium used  in  these  experiments  was  purified  by  distilling 
twice  in  vacuo.  Ten  observations  on  the  conversion  of 
the  oxalate  into  oxide,  computed  on  the  basis  of  0  =  16 
and  C  =  i2,  give  iii'8oi  as  a  mean  for  the  atomic  mass  of 
cadmium.  Re-calculated  by  Clarke  {Amer.  Chem.  yourn., 
xiii.,  34),  on  the  basis  of  0  =  i6  and  C=  12*005,  ^^^ 
atomic  mass  of  cadmium  becomes  iii'SiS.  The  mean 
of  ten  results  obtained  by  reducing  the  sulphate  to  sul- 
phide, computed  on  the  basis  of  0  =  i6  and  8=32,  gives 
111-797  for  the  atomic  mass  of  cadmium.  Re-calculated 
by  Clarke  on  the  basis  of  0  =  i6  and  8=32*074,  the  atomic 
mass  of  cadmium  is  iii'7ii.  In  the  third  series  the 
oxalate  of  cadmium  was  converted  into  sulphide  by 
heating  in  a  current  of  dry  hydrogen  sulphide.  The 
mean  of  ten  determinations,  computed  on  the  basis  of 
0  =  16  and  8  =  32,  gives  111*805  for  the  atomic  mass  of 
cadmium.  Re-calculated  by  Clarke  on  the  basis  of  0  =  l6 
and  8=32*074,  the  mean  becomes  111*589.  Partridge 
gives  111*8  for  the  atomic  mass  of  cadmium,  as  a  mean 
of  the  three  series.  If  the  higher  values  for  carbon  and 
sulphur  be  introduced  this  value  becomes  somewhat  lower. 

Jones  {Amer.  Chem.  yourn.,  xiv.,  261)  determined  the 
atomic  mass  of  cadmium  by  two  different  methods.  The 
first  was  based  on  the  conversion  of  the  metal  into  oxide, 
and  the  second  on  the  conversion  of  the  oxalate  into 
oxide.  The  cadmium  used  was  distilled  six  times  in 
vacuo.  The  last  distillate  was  tested  spedtroscopically, 
and  found  to  be  free  from  impurities.  In  the  first  series 
of  experiments  a  weighed  portion  of  the  pure  metal  was 
dissolved  in  pure  nitric  acid  in  a  porcelain  crucible.  The 
solution  was  evaporated  to  dryness,  and  the  resulting 
cadmium  nitrate  ignited  to  oxide.  The  final  decomposi- 
tion  was  accomplished  by  means  of  a  blast  lamp. 
Reducing  gases  were  carefully  excluded  from  the  crucible 
during  the  process  of  ignition.  The  weighings  were  all 
made  against  a  tared  crucible.  The  mean  often  observa- 
tions, computed  on  a  basis  of  0  =  i6,  gives  112*07  for  the 
atomic  mass  of  cadmium.  The  different  determinations 
agree  very  closely.  In  the  second  series  of  experiments 
cadmium  oxalate,  prepared  by  precipitating  pure  cadmium 
nitrate  with  pure  oxalic  acid,  was  converted  into  oxide. 
The  material  was  carefully  ignited  until  the  oxalate  was 
decomposed ;  it  was  then  treated  with  nitric  acid,  and 
again  ignited  in  a  manner  similar  to  that  described  in  the 
first  series.  The  mean  of  five  determinations  computed 
on  the  basis  of  0  =  i6  and  C  =  i2*oo3,  is  Cd  =  iii*032. 
From  all  the  observations  Jones  concludes  that  112*07 
represents  very  closely  the  atomic  mass  of  cadmium 
(0  =  i6). 

Lorimer  and  Smith  {Ztschr.  Anorg.  Chem.,  i.,  364) 
determined  the  ratio  of  the  atomic  mass  of  cadmium  to 
that  of  oxygen  by  dissolving  pure  cadmium  oxide  in 
potassium  cyanide  and  electrolysing  the  solution.  To 
obtain  pure  material,  the  commercial  cadmium  was  dis- 
solved in  nitric  acid,  and  the  solution  evaporated  to 
crystallisation.  The  crystals  of  cadmium  nitrate  were 
removed  from  the  liquid,  dissolved  in  pure  water,  and 
re-crystallised.  The  produdt  obtained  by  the  second 
re-crystallisation  was  dissolved  in  a  little  water  and 
treated  with  a  slight  excess  of  potassium  cyanide  in  a 
platinum  dish.  From  this  solution  the  metallic  cadmium 
was  thrown  out  by  means  of  the  ele&ric  current.  The 
nitrate  obtained  by  dissolving  the  eledrolytic  cadmium  in 
pure  nitric  acid  was  tested  spedroscopically  and  found  to 
be  free  from  impurities.  The  pure  cadmium  nitrate  was 
digested  with  ammonium  hydroxide  and  ammonium 
carbonate,  and  the  resulting  cadmium  carbonate  ignited 
to  oxide  in  a  platinum  crucible.  The  method  of  opera- 
tion was  very  simple,  a  weighed  portion  of  the  oxide  was 
dissolved  in  puie  potassium  cyanide,  the  solution  eledlro- 
ysed,  and  the  resulting  metallic  cadmium  weighed.    The 

I 


Chemical  >HWt>, 
Feb.  19,  1897. 


Use  of  very  small  Mirrors  wuh  Faraffin  Lamp  and  Scale, 


93 


mean    of    nine  observations    computed   on    the    basis   of 
0=  16  gives  II2"055  for  the  atomic  mass  of  cadmium. 

Bucher  (Thesis,  Johns  Hopkins  University,  1894)  made 
six  series  of  experiments.  The  cadmium  used  was  puri- 
fied by  nine  distillations  in  vacuo.  The  weighings  were 
all  reduced  to  a  vacuum  standard,  and  computed  on  the 
basis  of  0  =  16,  S  =  32"05g,  C  =  i2*oo3,  Cl  =  35"45, 
Br=79'95,  and  Ag=io7'93. 

In  the  first  series  cadmium  oxalate,  dried  for  fifiy 
hours  at  150°,  was  ignited  to  oxide.  The  mean  of  eight 
observations  gives  iii'Sg  for  the  atomic  mass  of  cadmium. 

In  the  second  series,  cadmium  oxalate  was  converted 
into  sulphide  by  heating  in  a  current  of  dry  hydrogen 
sulphide.  Ths  mean  of  four  determinations  is  Cd  = 
11215. 

In  the  third  series  a  weighed  quantity  of  cadmium 
chloride,  dried  at  a  temperature  of  300°  in  hydrochloric 
acid  gas,  was  precipitated  with  silver  nitrate,  and  the 
resulting  silver  chloiide  weighed.  The  mean  of  tweniy- 
one  determinations  isCd  =  H2'39.  The  separate  observa- 
tions in  this  series  agree  very  closely. 

The  fourth  series  was  similar  to  the  third,  except  that 
cadmium  bromide  was  used  instead  of  the  chloride. 
The  mean  of  five  determinations  isCd  =  ii2"38,  a  result 
almost  identical  with  that  obtained  from  the  chloride. 

In  the  fifth  series  a  weighed  portion  of  metallic  cadmium 
was  converted  into  sulphate,  which  was  dried  at  400°  and 
weighed.  The  excess  of  sulphuric  acid  which  remained 
with  the  sulphate  was  estimated  and  its  weight  dedudled. 
The  only  result  given  is  Cd  =  ii2-35. 

In  the  last  series  metallic  cadmium  was  converted  into 
oxide  by  dissolving  in  nitric  acid  and  igniting  the  resulting 
cadmium  nitrate.  The  mean  of  two  determinations  made 
by  igniting  the  material  in  a  porcelain  crucible  gives 
ii2'o8  for  the  atomic  mass  of  cadmium.  Three  similar 
determinations  made  with  a  platinum  crucible  gave  sis  a 
mean  Cd  =  iii'87.  From  a  series  of  experiments  on 
cadmium  oxide,  Bucher  concluded  that  a  corredion 
should  be  applied  to  the  last  and  also  the  first  series. 
By  making  this  corredlion,  the  results  in  these  two  scries 
would  be  very  close  to  those  obtained  from  the  chloride 
and  bromide. 

From  all  the  preceding  determinations  Clarke  gives 
II  1*93  as  the  most  probable  value  for  the  atomic  mass  of 
cadmium.  The  large  variation  in  the  results  of  different 
experimenters  has  not  been  fully  explained.  Some 
chemists  think  that  the  larger  values  are  due  to  a  higher 
degree  of  purity  in  the  metallic  cadmium  used,  and  hence 
regard  these  values  as  being  more  nearly  correrSt.  But  it 
must  be  remembered  that  the  reverse  is  true  in  the  experi- 
ments of  Dumas.  From  material  which  had  not  been 
purified,  Dumas  obtained  results  ranging  from  ii2'32  to 
ii2'76  for  the  atomic  mass  of  cadmium,  while  from 
material  which  he  considered  absolutely  pure,  the  results 
were  from  11176  to  ii2'i3. 

Preparation  of  Pure  Cadmium. 

The  metallic  cadmium  used  in  these  experiments  was 
purified  by  distillation  in  a  current  of  hydrogen  which  had 
been  passed  through  solutions  of  caustic  potash,  lead 
nitrate,  potassium  permanganate,  and  sulphuric  acid.  A 
hard  glass  combustion  tube  was  heated  to  redness,  and 
the  walls  of  the  tube  indented  at  two  points  with  a  three- 
cornered  file.  This  divided  the  tube  into  three  parts. 
Commercial  cadmium  was  placed  in  one  end  of  the  tube, 
and  connedion  made  with  the  hydrogen  generator. 
After  complete  removal  of  the  air,  the  tube  was  carefully 
heated  in  a  combustion  furnace  until  one-half  of  the 
metal  had  distilled  over  into  the  middle  portion  of  the 
tube.  The  metal  was  cooled  in  a  current  of  hydrogen. 
The  tube  was  then  broken  and  the  metal  removed.  The 
portions  in  the  first  and  last  sedtions  of  the  tube  were 
rejefted.  The  middle  portion  was  placed  in  a  second 
coiiibusiiun  tube,  similar  to  the  first,  and  the  distillation 
repeated.       After     three     distillations    the     metal    was 


examined   spedtroscopically   and   found  to    be  free  from 
impurities. 

(To  be  continued). 


PROCEEDINGS    OF    SOCIETIES. 

PHYSICAL     SOCIETY. 
Special  General  Meeting,  February  12th,  1897. 

The  Chair  was  taken  by  Captain  Abney,  who,  as  retiring 
President,  referred  to  some  of  the  changes  which  had 
occurred  in  the  Society  during  the  past  year. 

The  Annual  Subscription  had  been  raised,  but  a  satis- 
fadlory  number  of  new  Fellows  had  been  enrolled.  The 
Society  had  lost  two  by  death.  A  good  deal  of  work  had 
been  done  in  the  diredion  suggested  by  the  discoveries  of 
Rontgen. 

The  Treasurer,  Dr.  Atkinson,  then  presented  his 
Report  and  Balance-sheet  for  the  year  1896.  There  was 
evidence  of  improvement  in  the  financial  position,  but 
there  was  still  a  deficiency  to  be  met.  Profits  from  sales 
of  publications  had  been  small  ;  it  was  desirable  to  reduce 
the  price  of  the  volumes  of  colleded  papers  of  Joule  and 
Whe  itstone,  and  to  call  the  attention  of  physicists  to 
these  valuable  records  of  classical  wurk. 

Mr.  Walker  suggested  that  physical  laboratories, 
especially  those  in  London,  should  be  visited  by  Fellows 
of  the  Society,  with  a  view  to  comparing  notes  as  to  the 
construdlion  of  apparatus  ;  professors  of  colleges  and 
other  institutions  should  be  invited  to  appoint  visiting  days 
for  this  purpose. 

Votes  of  thanks  were  passed  to  the  retiring  President, 
Council,  and  Officers,  and  also  to  the  Council  of  the 
Chemical  Society  for  the  use  of  their  rooms  at  Burlington 
House. 

In  replying,  Capt.  Abney  said  that  the  coming  year 
would  probably  bring  about  further  improvements  in  the 
system  of  abstradting  and  indexing,  by  co-operation  with 
other  societies  at  home  and  abroad.  He  then  read  the 
list  of  Council  and  Officers  for  the  year  1897-8: — 

President—Sh&Uoid  Bidwell,  M.A.,  LL.B.,  F.R.S. 

Vice-Presidents,  who  have  filled  the  Office  of  President 
—Dr.  Gladstone,  Prof.  G.  C.  Foster,  Prof.  Adams,  The 
Lord  Kelvin,  Prof.  Clifton,  Prof.  Reinold,  Prof.  Ayrton, 
Prof.  Fitzgerald,  Prof.  Riicker,  Capt.  Abney. 

Vice-Presidents— Maj.-Gen.  E.  R.  Festing,  L.  Fletcher, 
Prof.  Perry,  G,  Johnstone  Stoney. 

Secretaries— r.  H.  Blakesley,  H.  M.  Elder. 

Foreign  Secretary  (new  office)— Prof.  S.  P.  Thompson. 

Treasurer — Dr.  Atkinson. 

Librarian — C.  Vernon  Boys. 

Other  Members  of  Council— Waltti  Bailey,  L.  Clark, 
A.  H.  Fison,  Prof.  Fleming,  R.  J.  Glazebrook,  Prof.  A. 
Gray,  G.  Griffith,  Prof.  Minchin,  Prof.  Ramsay,  J. 
Walker. 

The  newly-eleded  President,  Mr.  Shelford  Bidwell, 
then  took  the  Chair,  and  an  Ordinary  Meeting  was  held. 

Mr.  Blakesley  read  a  paper  by  Mr.  H.  H.  Hoffert, 
"  On  the  Use  of  very  small  Mirrors  with  Paraffin  Lamp 
and  Scale." 

For  the  mirrors  of  refledling  instruments  the  author 
prefers  small  redangular  strips  of  microscope  cover-glass, 
chosen  thin  and  plane.  These  are  first  silvered,  and  then 
cut  to  shape  by  a  splinter  of  diamond  embedded  in  wax. 
They  are  about  8  m.m.  long  by  i'5  m.m.  broad,  and  are 
suspended  so  that  their  longest  sides  are  vertical.  Red- 
angular  mirrors  suspended  in  this  way  are  lighter,  and 
have  less  inertia  than  round  mirrors  of  equal  aperture. 
A  paraffin-lamp  flame  placed  edgewise  to  the  mirror  gives 
b^ufiicient  illumination.  The  image  of  the  flame  is  focussed 
on   the  mrrror  by  a  lens  midway  between  them ;  it  is  a 


94 


Water  and  its  Purification . 


t  CftBMiCAL  News, 
I     Feb.  19,  1897. 


right  vertical  line,  and  thiis  conforms  to  the  shape  of  the 
mirror.  A  scale  is  fixed  upon  a  screen  between  the  lens 
and  lamp  ;  and  the  screen  has  a  circular  aperture  just 
below  the  centre  of  the  scale,  provided  with  a  vertical 
cross-wire.  The  relative  position  of  screen  and  lens  is 
adjusted  so  that  an  image  of  the  wire  is  formed  upon  the 
scale  after  reflexion  at  the  mirror. 

Mr.  Boys  said  he  had  frequently  used  small  mirrors 
construdted  as  described  by  the  author,  and  he  could  not 
see  what  was  new  in  the  method,  except  that  a  paraffin 
lamp  had  been  found  sufficiently  bright  for  the  purpose. 
It  is  desirable  to  diminish  inertia  by  choosing  extremely 
thin  glass.  Microscope  cover-glasses  are  generally  sup- 
plied in  squares  or  discs  very  fairly  equal  in  size;  if  they 
are  dealt  out  on  a  table,  like  a  pack  of  cards,  their  rela- 
tive thicknesses  can  be  judged  by  the  note  produced  as 
they  fall.  Flatness  can  be  estimated  nearly  enough  by 
balancing  them  one  by  one  upon  the  knuckle,  nearly  level 
with  the  eye,  and  observing  the  refledion  of  an  illuminated 
straight  edge,  such  as  a  window-bar.  All  rejected  glasses 
should  be  broken.  The  good  ones  can  be  further  examined 
by  a  telescope  and  artificial  star.  A  common  writing 
diamond  is  best  for  cutting  the  thin  plates.  Special  care 
must  be  taken  not  to  distort  the  mirror  in  fixing  to  the 
suspended  system.  If  liquid  shellac  is  used  in  the  attach- 
ment distortion  will  certainly  occur, — at  any  rate,  if  it  is 
applied  throughout  the  whole  length  of  the  mirror.  The 
best  way  is  to  make  the  attachment  at  a  mere  point, 
near  the  top  of  the  mirror,  using  a  speck  of  shellac 
as  viscous  as  possible,  and  heating,  if  necessary,  by 
radiation,  not  by  condudtion.  Mr.  Boys  thought  that  a 
refiedling  prism  near  the  mirror  might  be  used  in  certain 
cases  where  a  paraffin  lamp  with  its  inevitable  vertical 
flame  was  required  for  horizontal  proje(5lions.  For  general 
purposes  Mr.  Boys  prefers  some  sucFi  arrangement  as  the 
following: — If  the  source  of  light  is  a  point,  a  lens  is 
employed,  forming  an  image  of  the  source  upon  the 
mirror.  (If  the  source  of  light  is  a  surface,  this 
lens  is  evidently  superfluous).  The  cross-wire  is  stretched 
near  to  the  lens  on  the  side  towards  the  mirror.  It  is  now 
necessary  to  focus  the  cross-wire  upon  the  scale,  and  this 
is  best  done  by  a  plano-convex  fixed  lens  as  near  as  pos- 
sible to  the  mirror,  with  its  plane  face  towards  the  mirror. 
The  light  passes  twice  through  the  lens.  As  it  may  be 
necessary  to  change  the  plano-convex  lens  from  time  to 
time,  according  to  the  distance  of  the  scale,  Mr.  Boys 
attaches  it  with  a  little  vaseline  to  a  strip  of  plate  glass 
in  front  of  the  instrument.  One  advantage  of  such  an 
optical  system  is  that  it  allows  the  instrument  to  be  set 
up  in  the  same  position  with  respedt  to  the  scale  at  all 
times. 

Dr.  Thompson  pointed  out  that  Mr.  Hoifert  had  ob- 
tained his  results  using  only  one  lens,  by  properly  choosing 
the  position  of  the  cross-wire. 

A  vote  of  thanks  was  given  to  the  author,  and  the 
meeting  adjourned  until  February  26th. 


NOTICES  OF  BOOKS. 


Water  and  its  Purification  ;  a  Handbook  for  the  Use  of 
Local  Authorities,  Sanitary  Officers,  and  others  inte- 
rested in  Water  Supply.  By  Samuel  Rjdeal,  D.Sc, 
Fellow  of  University  College,  London,  F.I.C.  ; 
Examiner  in  Chemistry  to  Royal  College  of  Physicians  ; 
Public  Analyst  for  the  Lewisham  Distrift  Board  of 
Works ;  Water  Examiner  to  the  Guildford  Rural  Dis- 
tridl  Council ;  Author  of  "  Disinfedion  and  Disinfedt- 
ants."  With  numerous  Illustrations  and  Tables. 
London  :  Crosby  Lockwood  and  Son,  Stationers'  Hall 
Court.     Pp.  292.     1897. 

Writings  discussing    municipal  water   supply    resolve 
themselves  into  two  grand  categories.    The  one   deals 


with  the  outgoing  waters,  their  purification  or  disinfection, 
and  their  utilisation.  The  other  class,  of  which  the 
volume  before  us  is  an  excellent  specimen,  discusses  the 
incoming  waters,  their  suitability  for  domestic  and  indus- 
trial purposes,  and  their  improvement  whenever  pradti- 
cable. 

In  the  remarks  on  natural  waters  Dr.  Rideal  shows 
that  an  appeal  to  the  physical  charadters  of  a  water  is 
not  trustworthy,  and  may  even  be  dangerously  deceptive. 
He  rightly  urges  that  even  traces  of  the  poisonous  metals 
render  a  water  inadmissible  for  household  consumption. 
Lead,  the  most  insidious  and  dangerous  of  metallic 
impurities,  is,  unfortunately,  often  introduced  by  lead 
service-pipes.  Some  waters,  however,  have  the  dangerous 
property  of  rapidly  attacking  lead.  This  is  especially  the 
case  with  peaty  waters.  Cisterns  for  water-supply  are 
rightly  and  emphatically  condemned. 

It  is  an  unfortunate  circumstance  that  the  upland  areas, 
uncultivated  and  unpeopled,  are  not  sufficient  to  afford 
drainage  grounds  for  the  supply  of  adjacent  cities.  The 
instance  of  Manchester  is  most  instrudtive.  A  few  years 
ago  its  supply  from  a  series  of  reservoirs  construdted  in 
Longdendale  (not  Longerdale),  the  drainage  off  the  mill- 
stone grit,  and  the  uncultivated  moor-lands,  was  viewed 
as  sufficient  not  merely  for  the  present  but  the  future. 
But  recently  it  has  been  found  insufficient,  and  an  addi- 
tional supply  has  been  obtained  from  Thirlmere  in  Cum- 
berland. Contrary  to  our  fears  the  engineering  operations 
near  this  lake  have  not  interfered  with  the  beauty  of  the 
scenery. 

Dr.  Rideal  rightly  kolds  that  it  is  the  duty  of  the  State 
to  apportion  the  upland  water-sources  to  the  needs  of  the 
population. 

Mention  is  made  of  the  Holmfirth  catastrophe,  and  of 
the  still  more  appalling  disaster  at  Sheffield. 

The  London  County  Council  proposes  to  derive  the 
future  supply  of  the  metropolis  from  Wales,  taking  the 
head  waters  of  the  Usk,  Wye,  and  Towey,  and  conveying 
them  by  two  aquedudts  of  respedlively  150  and  175  miles 
in  length.  The  great  objedlion  to  this  scheme  would  be 
the  necessity  of  guarding  the  aquedudls  and  bridges  from 
possible  mischief  on  the  part  of  bodies  whom— as  wo  are 
not  a  political  organ — we  cannot  here  point  out.  The 
sujjgestion  that  the  purer  mountain  water  might  be 
"  exclusively  used  for  drinking  purposes,"  and  employing 
ordinary  waters  for  washing,  trade,  and  sanitary  purposes, 
would  certainly  lessen  the  demand  on  the  upland  areas, 
but  would  at  the  same  time  burden  the  consumer  with 
the  expense  of  a  duplicate  system  of  mains  and  service 
pipes. 

On  page  loi  we  find  the  standards  of  the  Thames 
Conservancy.  This  body  demands  that  discharges  into 
the  river  must  be  : — 

1.  Free  from  offensive  odour. 

2.  Free  from  suspended  matter. 

3.  Neither  acid  or  alkaline  to  test  papers. 

This  requirement  Dr.  Rideal  acutely  pronounces 
impossible,  since  natural  waters  are  almost  invariably 
acid  to  one  test  on  account  of  free  carbonic  acid,  and 
alkaline  to  another  owing  to  carbonates.  The  author 
suggests  that  limits  of  permissibility  should  be  given. 

4.  Not  more  than  60  grs.  per  gallon  of  total  solids. 

5.  Not  more  than  2  grs.  per  gallon  of  organic  carbon, 
and  075  grs.  per  gallon  of  organic  and  ammoniacal 
nitrogen. 

6.  Not  less  than  one  cubic  inch  of  free  oxygen  per 
gallon. 

Concerning  the  adtion  of  soft  waters  upon  leads  we 
find  two  conflidling  statements.  On  page  117  we  read 
"  that  its  (the  water  of  Loch  Katrine)  only  fault  is  that  it 
adls  rapidly  upon  lead,  of  which  we  shall  speak  further." 
But  on  page  137,  after  speaking  of  the  soft  water  of  the 
Varty  (Dublin),  the  author  writes  :  "  The  equally  soft 
water  of  Lock  Katrine  has  little  or  no  adtion  upon  this 
metal." 


Cbxuical  Nxwb,  I 
Feb.  ig,  1897.     ) 


Chemical  Notices  from  Foreign  Sources, 


95 


On  page  97  Dr.  Rideal  points  out  the  danger  of  allowing  ^ 
pigs  to  wade  in  streams,  and  consequently  to  introduce 
into  them  parasites. 

The  self-purification  of  rivers  is  exemplified  in  Dr.  P. 
Frankland's  paper  on  the  river  Dee  (p.  105). 

On  the  question  of  constant  v.  intermittent  water 
service  the  author  takes  the  right  view,  condemning  the 
latter  procedure,  which  has  justly  gone  out  of  use  in  most 
places  except  London. 

In  speaking  of  filters,  which  the  author  does  at  great 
length  and  with  thorough  fairness  and  accuracy,  he  shows 
that  all  domestic  filters,  except  the  Pasteur-Chamberland, 
are  of  very  doubtful  efficacy,  if  not  positively  harmful. 
The  Berkenfeld  filter  requires  to  be  boiled  either  once  or 
twice  every  twenty-four  hours. 

Referring  to  the  mains  and  service  pipes  for  the  distri- 
bution of  water  in  cities,  our  author  recommends  that  the 
pipes  should  be  laid  not  less  than  four  feet  below  the  sur- 
face, and  should  pass  within  about  three  feet  of  the  kitchen 
grate  before  branching  off  to  different  parts  of  the 
establishment. 

It  is  unfortunate  that  no  one  has  the  power  to  enforce 
these  standards  as  against  "Jerry." 

In  our  opinion  Dr.  Rideal  has  made  in  this  book  a 
valuable  contribution  to  our  sanitary  literature. 


CHEMICAL 


NOTICES    FROM 
SOURCES. 


FOREIGN 


Note.— All  degrees  of  temperature  ate  Centigrade  unless  otherwise 
expressed. 

Comptes  Rendus  Hebdomadairts  des  Seances,  de  V Academie 
des  Sciences.     Vol.  cxxiv.,  No.  3,  January  i8,  1897. 

Researches  on  Helium. — M.  Berthelot.— The  author 
has  succeeded  in  combining  helium,  both  with  the  ele- 
ments of  the  hydrogen  carbides,  and  with  those  of  carbon 
disulphide,  with  the  intervention  of  mercury  and  the  in- 
fluence of  the  eledtric  effluve,  all  precisely  under  the 
same  conditions  in  which  he  has  realised  the  combina- 
tion of  argon.  In  both  cases  these  syntheses  have  been 
checked  by  analysis  ;  that  is  to  say,  by  the  regeneration 
of  the  element  in  a  free  state. 

Remarks  on  the  Specific  Heats  of  Elementary 
Gases,  and  on  their  Atomic  Constitution.  —  M. 
Berthelot. — The  author  calls  attention  to  the  following 
values  of  specific  heat  at  constant  volumes,  referred  to 
an  identical  volume  of  the  elements,  such  as  that  occupied 
by  2.  grms.  of  hydrogen  : — 
Gas  with  a  monatomic  mol.     3*0 

Diatomic  gas      4'8  (not  split  up  at  present, 

and   66  split   up  above 

Tetratomic  gases il'4 

It  will  be  remarked  that  the  ratio  of  these  values,  measured 
near  the  ordinary  temperature  (between  0°  and  300°),  is 
not  remote  from  that  of  i  :  2  :  4 ;  that  is  to  say,  that  the 
specific  heats  of  the  simple  gases  at  a  constant  volume 
are  approximately  proportional  to  the  number  of  atoms 
contained  in  the  molecule.  Besides  the  four  groups  of 
gaseous  elements  just  distinguished,  there  are  others, 
such  as  contain  triatomic  elements,  e.g.,  ozone,  com- 
parable to  hyponitric  gas;  and  certain  hexatomic  ele- 
ments, sulphur  and  selenium.  But  their  specific  heat  is 
hitherto  unknown.  We  know  how  for  the  simplified 
notions  deduced  from  a  first  study  of  the  elementary 
gases  anciently  known,  e.g.,  hydrogen,  oxygen,  and  nitro- 
gen, there  are  being  substituted  more  profound  notions  on 
the  physico-chemical  constitution  of  the  elements. 

Classification  of  the  Chemical  Elements. — Lecoq 
de  Boisbaudran. — This  paper  will  be  inserted  at  some 
length. 


Certain  Salts  and  Derivatives  of  Dinitro-ortho- 
cresol. — P.  Cazeneuve. 

Law  of  the  Transparency  of  Gases  for  X  Rays. — 
L.  Benoist. — In  the  earliest  experiments  on  the  X  rays  it 
was  remarked  that  the  opacity  of  different  bodies 
for  the  rays  increased  in  general  with  their  density,  and 
it  was  thought  that  a  simple  relation  such  as  diredt  pro* 
portionality  might  exist  between  these  two  charaders. 
With  gaseous  bodies  the  case  is  different.  With  sul- 
phurous acid,  methyl  chloride,  and  air  the  absorption  pro- 
duced is  proportional  to  the  density  of  the  gas  employed. 
This  is  the  relation  which  Lenard  has  already  obtained  for 
the  kathodic  rays  before  Rontgen's  discovery.  As  the 
specific  absorbent  power  of  gases  resulting  from  the  fore- 
going measurements  gives  the  value  0*14,  aluminium 
gives  the  value  0*09  ;  the  deviation  is  not  great,  whence 
aluminium  would  almost  satisfy  a  general  law  of  propor- 
tionality  between  the  absorbent  power  and  the  density. 
On  the  contrary,  silver  gave  0*84 — a  number  six  times  too 
great. 

Speed  of  the  Redu(5tion  of  Chromic  Acid  by  Phos- 
phorous Acid. — G.  Viard. — This  paper  requires  the  for- 
mulae and  the  table  here  introduced. 

Ac^tion  of  Hydrogen  Sulphide  and  Selenide  upon 
Phosphonyl  Chloride. — A.  Besson. — If  we  dissolve  dry 
hydrogen  sulphide  at  0°  in  POCI3  and  leave  it  in  a  closed 
vessel,  in  a  few  hours  the  liquid  becomes  milky,  and  after 
twenty-four  hours  there  colleds  at  the  lower  part  of  the 
vessel  a  light  bulky  amorphous  precipitate,  whilst  the 
supernatant  liquid  becomes  limpid.  If  the  experiment  is 
prolonged,  there  is  a  slow  formation  of  crystalline  needles. 
Both  the  amorphous  precipitate  and  the  crystalline 
needles  have  the  same  composition,  P2O2S3  ;  that  is,  an 
oxy-sulphide.  Dry  hydrogen  selenide  has  no  perceptible 
adtion  upon  POCI3  in  the  cold,  but  at  100°  it  readts  slowly, 
forming  phosphonyl  selenide. 

A(5tion  of  Ethyloxalyl  Chloride  upon  Pseudo- 
cumene  and  Mesitylene. — E.  Bouveault. — These  two 
papers  are  not  suitable  for  abridgment. 

Decrease  of  the  Nitrogenous  Matter  in  the  Wheats 
of  the  Department  "  Du  Nord."— M.  Balland.— The 
nitrogenous  matter,  which  in  1848  varied  between  io'23 
and  i3'02  per  cent,  is  now  between  8-96  and  io'62  per 
cent. 


The  Reprodu(aion  of  Colour  by  Photographic 
Methods. — Sir  Henry  Trueman  Wood  is  announced  to 
read  a  paper  at  the  Society  of  Arts  on  this  subjed  on  the 
24th  inst.  Captain  Abney,  C.B.,  F.R.S.,  will  preside. 
Illustrations  will  be  shown  of  several  of  the  recently 
invented  processes  for  the  photographic  reprodudion  of 
colour. 

On  Chromium  and  Manganese  Phosphides. — A. 
Granger. — The  analysis  of  these  phosphides  is  delicate, 
on  account  of  the  difficulty  ot  separating  phosphoric  acid 
from  chromium  and  manganese  oxides.  The  author 
reduced  the  substances  to  a  fine  powder,  treated  them 
with  melting  potassa,  raising  the  temperature  gradually 
to  dull  redness,  and  keeping  the  mass  in  tranquil  fusion 
for  li  hours.  The  mass,  when  cold,  is  dissolved  in 
boiling  water,  acidified  with  nitric  acid  in  the  case  of 
chrome,  or  with  hydrochloric  acid  in  the  case  of  man- 
ganese. The  chromic  solution  is  then  treated  with  ammo- 
nium molybdate  to  precipitate  phosphoric  acid.  In  the 
filtrate  the  chlorate  is  reduced  to  the  state  of  a  salt  of 
chrome  which  is  precipitated  in  the  state  of  sesquioxide, 
carrying  molybdenum  down  with  it.  The  precipitate, 
dissolved  and  re-precipitated,  yields  an  oxide  sufficiently 
free  from  foreign  salts.  The  manganic  solution,  eva- 
porated to  dryness  with  hydrochloric  acid  in  excess,  is 
neutralised  with  ammonia,  and  ammonium  sulphide  is 
added.  We  evaporate  to  dryness,  and  add  a  further 
quantity  of  the  latter  reagent  ;  re-dissolved  in  water,  and 
filtered,  the  precipitate  contains  all  the  manganese,  and 
in  the  fil'rate  the  phosphoric  acid  is  determined  as  usual. 


96 


Meetings  for  the  Week, 


Chemical  News, 
Feb   19,  1897. 


MEETINGS    FOR    THE    WEEK. 

M    ONDAT,  22nd.— Society  of  Arts,  8.    (Cantor  Leftures).    "Industrial 
Uses  of  Cellulose,"  by  C.  F.  Cross,  F.C.S. 
Tuesday,  23rd.— Royal   Institution,  3.     "  Animal    Elefiricity,"  by 

Prof  A.  D.  Waller,  F.R.S. 
Wednesday,  24th.— Society  of  Arts,  8.   "  ReproducSion  of  Colour  by 
Photographic  Methods,"  by  Sir  Henry  True- 
man  Wood. 
Thursday,  25th.— Royal  Institution,  3.      "  The  Problems  of  Araic 
Geology,"  by  J.  W.  Gregory,  D.Sc,  F.R.S. 

Society  of  Arts,  8.    "  The  Mechanical  Production 

of  Cold,"  by  Prof.  James  A.  Ewing,  M.A.,  F.R.S. 
Friday,  26th.— Royal  Institution,  9.      "  Palestine   Exploration,"  by 
Lieut.  Col.  C.  R.  Conder,  R.E. 

Physical,  5.      "Photography  of  Ripples,"   by  J.   H. 

Vincent. 
Saturday,   27th.— Royal    Institution,  3.      "  The    Growth    of    the 
Mediterranean  Route  to  the  East,"  by  Walter 
Frewen  Loid. 


TO    CORRESPONDENTS. 

.4.G.  i4.— You  had  better  write  to  the  Secretaries  of  the  various 
societies  to  which  you  wish  to  belong.  They  will  send  full  particulars 
of  qualifications  required. 


Analytical  and  Manufa(5luring  Chemist  wanted. 
One  with  a  good  knowledge  of  the  Manufacture  of  Small 
Chemicals  preferred.— Please  apply,  in  strift  confidence,  giving  full 
information  as  to  age,  experience,  and  salary  required,  to  "  Manu- 
fadlurer,"  Chemical  News  Office,  6  &  7,  Creed  Lane,  Ludgate  Hill, 
London,  E.G. 

hemist  wanted,  Chemical  Works  in  London. 

— His  duties  would  be  principally  in  the  Lsboratory,  but  it 
would  be  essential  that  applicants  should  have  had  pra<5tical  experi- 
ence as  Works  Manager.— Reply,  stating  age,  past  experience,  and 
salary  required,  to  C.C.C,  care  of  Clarke,  Son,  and  Piatt,  85,  Grace- 
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Works'  Chemist,  A.I.C.,  late  with  large 
London  manufafturers,  well  up  in  Plant  and  Building  Con- 
struction, experience  in  management  of  men,  and  in  conduction  of 
Technical  Research  work,  good  Commercial  Analyst,  seeks  Appoint- 
ment.   Moderate  Salary.— Address,  "  Plant,"  Chemical  News  Office, 

6  &  7,  Creed  Lane,  Ludgate  Hill,  London,  E.G. 

Recently  Published,  with  Illustrations,  in  Demy  8vo.,  cloth. 

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^^p'eb.'a^is^T''}     Removal  of  Oxide  from  Melted  Copper  and  Copper  Alloys, 


97 


THE    CHEMICAL    NEWS 


Vol.  LXXV.,  No.  1944. 


ON  THE 

REMOVAL   OF   OXIDE  FROM    MELTED   COPPER 

AND    COPPER    ALLOYS. 

By  SERGIUS  KERN,  M.E.,  St.  Petersburg. 

The  following  is  perhaps  not  new  to  many  metallurgists, 
but  the  modus  operandi  of  the  application  of  phosphorus 
for  cleaning  copper  alloys,  just  before  casting  them  into 
ingots  or  mouldings,  must  be  new  to  many. 

In  order  to  reduce  the  oxides  and  to  obtain  dense  and 
solid  castings,  for  several  years  the  Obouchoff  Works 
here  have  successfully  used  our  plan,  which  is  as 
follows : — 

In  order  to  safely  throw  the  phosphorus  into  the  pots 
of  melted  copper,  just  before  drawing  them  out  of  the 
furnace,  the  phosphorus  is  submitted  to  the  following 
treatment :  —  Phosphorus  is  cut  into  pieces,  weighing 
about  3  ounces  each,  and  placed  in  a  concentrated 
solution  of  copper  sulphate,  where  it  is  kept  for  further 
use.  From  time  to  time  fresh  copper  sulphate  is  added, 
and  pieces  of  phosphorus  also,  after  taking  out  for 
foundry  uses  pieces  of  phosphorus  already  covered  with 
precipitated  copper. 

In  this  manner  it  is  easy  to  handle  phosphorus,  which 
also  when  thrown  into  pots  does  not  take  fire  at  once, 
but  safely  reaches  the  melted  metal  to  adt  in  the  desired 
manner. 

About  two  pieces  are  usually  sufficient  for  i  cwt.  of 
metal  in  the  pot. 

The  addition  of  phosphorus  in  the  mentioned  manner 
to  copper  plays  the  part  of  ferromanganese  to  steel. 

February  13, 1897. 


concludes  that  their  observations  were  pradtically  only 
corredt  so  far  as  they  agreed  with  those  of  Schonbein. 
The  author  has  also  investigated  the  aiftion  of  precipitated 
mercuric  oxide  upon  iodine  water,  and  find  that  hypo- 
iodous  acid  is  formed.  The  filtered  (colourless)  solution 
possesses  only  the  feeblest  possible  bleaching  properties, 
but  the  addition  of  a  little  alkali  transforms  it  at 
once  into  as  strong  a  bleaching  solution  as  Schonbein's, 
and  which  it  now  exadlly  resembles.  By  the  methods 
mentioned  above  it  is  found  that  from  40  to  45  per  cent, 
out  of  a  possible  50  per  cent,  of  the  iodine  used  exists  in 
the  solution  as  hypoiodous  acid.  By  using  iodine  water 
and  a  little  suspended  iodine,  a  stronger  solution  is  ob- 
tained, which  very  soon  decomposes,  turning  brown, 
owing  to  the  liberation  of  iodine.  The  hypoiodous  acid 
probably  decomposes  as  follows  : — 

3HOI  =  2HI  +  HIO3. 
and  the  hydriodic  acid  and  iodic  acid  immediately  decom- 
pose each  other,  with  liberation  of  iodine.  The  author 
suggests  a  possible  explanation  of  the  feeble  bleaching 
power  of  the  free  acid  in  the  instability  of  the  hydriodic 
acid  which  will  be  left,  compared  with  the  alkaline 
iodides. 

A  solution  containing  hypoiodous  acid  also  appears  to 
be  formed  by  the  adtion  of  various  silver  salts  upon  iodine 
water,  the  best  results  being  obtained  with  silver  nitrate 
and  silver  carbonate.  These  liquids  bleach  much  more 
rapidly  than  the  one  described  above,  probably  because  of 
the  silver  which  is  present ;  but  they  are  much  less  rapid 
in  their  bleaching  adtion  than  the  alkaline  hypoiodites.  In 
other  respedts  they  resemble  Schonbein's  solutions,  being, 
however,  much  less  stable,  this  again  being  probably  due 
to  the  presence  of  silver  in  the  solution.  The  liquid  ob- 
tained by  adding  a  few  drops  of  nitrate  of  silver  to 
aqueous  iodine  loses  go  per  cent  of  its  bleaching  power 
in  five  minutes. 


HYPOIODOUS    ACID    AND    HYPOIODITES.* 
By  R.  L.  TAYLOR,  F.C.S. 

The  author  confirms  and  extends  the  observations  of 
Schonbein,  using,  as  he  did,  an  aqueous  solution  of  iodine. 
When  a  little  alkali  is  added  there  is  pradtically  no  iodate 
formed,  from  90  to  95  per  cent  of  the  iodine  undergoing 
the  readtion  represented  by  the  equation — 

2KOH  +  Ia  =  KI+KOI-j-HaO. 
This  is  proved  by  the  bleaching  adlion  upon  a  standard 
Bolution  of  indigo,  and  also  by  Schwicker's   method  of 
decomposing  the  hypoiodite  by  a  bicarbonate  or  by  car- 
bonic  acid. 

The  solution  bleaches  indigo  much  more  rapidly  than 
chlorine  or  hypochlorites,  but  does  not  bleach  litmus.  It 
gives  a  precipitate  with  cobalt  nitrate  which  blackens  on 
standing,  and  an  immediate  brown  precipitate  with  man- 
ganous  salts  and  lead  salts.  Stronger  solutions  are 
obtained  by  using  iodine  water  containing  a  little  sus- 
pended iodine.  All  the  solutions  are  decomposed  com- 
pletely by  boiling  for  three  or  four  minutes.  The  author 
concludes  that  the  readtion  represented  above,  as  Walker 
and  Ray  have  also  recently  stated,  is  a  balanced  one. 
He  has  repeated  Lunge  and  Schoch's  experiments,  who 
obtained,  by  the  adlion  of  iodine  upon  lime  in  presence  of 
comparatively  little  water,  a  bleaching  liquid  which  stood 
being  boiled  for  hours  without  being  decomposed.     He 

*  Summary  of  a  Paper  read  at  the  Manchester  Literary  and  Philo 
■ophical  Society,  February  gtb,  1897. 


OPENING    UP    OF    SILICATES. 
By  P.  JANNASCH. 

For  this  purpose  the  author  uses  pure  lead  silicate,  and 
finds  it  satisfadtory.  He  proceeded  from  Bong's  pro- 
posal to  use  lead  oxide  for  this  purpose,  supported  upon 
the  favourable  experiments  which  he  made  in  concert 
with  J.  Locke  in  determining  the  water  in  topaz.  Jannasch 
proposes  to  mix  the  silicate  (freed  from  organic  matter,  if 
necessary  by  ignition)  with  from  ten  to  twelve  parts  of 
lead  carbonate,  and  heat  it  in  a  platinum  crucible,  52  to 
53  m.m.  in  height,  and  45  ra.m.  wide  at  top,  for  from 
^fteen  to  twenty  minutes  at  first,  with  a  flame  of  about 
an  inch  in  height.  It  is  then  heated  to  fusion,  but  the 
crucible  must  not  be  red-hot  for  more  than  one-third  of 
its  height.  The  fusion  is  continued  for  ten  to  fifteen 
minutes.  Care  must  be  taken  that  the  flame  does  not 
smoke  in  order  to  avoid  any  redudtive  adtion.  The  crucible 
is  taken  diredtly  from  the  flame  and  plunged  into  cold 
distilled  water.  The  melt  is  removed  from  the  crucible 
by  gentle  tapping  and  squeezing,  and  decomposed  with 
nitric  acid,  and  finally  evaporated  repeatedly  to  dust- 
dryness  with  concentrated  nitric  acid,  and  the  residue  is 
taken  up  with  10  c.c.  of  concentrated  nitric  acid,  diluted 
with  75  to  100  c.c.  of  water,  heated  on  the  water-bath  for 
fifteen  minutes,  filtered  and  washed. 

The  filtrate  is  mixed  with  abundance  of  hydrochloric 
acid ;  after  settling  the  lead  chloride  is  sucked  off  and 
washed  with  hydrochloric  acid  (i  vol.  concentrated  acid 
+  I  vol.  water).  The  filtrate  is  evaporated  down  (to 
expel  nitric  acid)  with  30  c.c.  hydrochloric  acid  (i  :  4) 
and  as  much  water.  The  residue  of  the  lead  chloride  is 
filtered  off  and  quickly  washed  with  cold  water.  The 
traces  of  lead  left  in  the  filtrate  are  precipitated  with  sul- 
phuretted hydrogen.  The  hydrogen  sulphide  is  then 
entirely  removed  from  the  filtrate. — Zeit.  Anorg.  Chemie, 


98 


A  ction  of  Wagner* s  Reagent  upon  Caffeine. 


I  CbbmicalNbws, 

1      Feb.  26,  1897. 


A    SENSITIVE    SIMPLE     REACTION     FOR 

NITROUS     ACID. 

By  Prof.  Dr.  E.  RIEGLER. 

We  introduce  into  a  small  test-tube  about  2  or  3  centi- 
grms.  of  crystallised  naphthionic  acid,  and  from  5  to  6 
c.c.  of  the  liquid  to  be  examined  for  nitrous  acid,  shake 
up  well,  add  2  or  3  drops  of  concentrated  hydrochloric 
acid,  shake  up  thoroughly  for  a  minute,  and  allow  from 
20  to  30  drops  of  ammonia  to  flow  slowly  into  the  test- 
tube  whilst  held  in  a  slanting  position  ;  when  there 
appears  at  the  surface  of  contaA  of  the  liquids  a  rose- 
coloured  ring,  even  if  only  traces  of  nitrous  acid  are  pre- 
sent. If  we  shake  up  the  entire  liquid  it  becomes  rose- 
coloured  or  deep  red,  according  to  the  quantity  of  the 
nitrous  acid. 

As  very  dilute  solutions  of  naphthionic  acid  have  a 
violet-blue  fluorescence,  it  is  advantageous  to  examine 
the  colour  by  transmitted  light. 

The  rea&ion  consists  herein,  that  the  naphthionic  acid 
is  converted  by  the  nitrous  acid  into  diazo-naphthalin 
sulphonic  acid,  which  forms  with  another  mol.  of  naph- 
thionic acid,  and  with  ammonia  a  colouring  matter  which 
determines  the  rose  colouration. 

In  rain  and  drinking  waters  the  nitrous  acid  can  be 
very  finely  shown  by  means  of  this  rea&ion.  The 
detedlion  of  nitrites  in  saliva  is  extremely  instructive.  To 
this  end  we  dilute  the  saliva  with  five  times  its  volume 
of  pure  distilled  water,  filter,  and  treat  5  or  6  c.c.  of  the 
filtrate  as  above  diredted. 

Traces  of  nitrous  acid  may  in  like  manner  be  dete&able 
in  urine. — Zeit.  Analyt.  Chemie. 


WORKING     UP    URANIUM     RESIDUES. 
By  A.  GOWALOWSKI. 

In  this  paper  I  formerly  described  a  method  for  working 
up  uraninm  phosphate  residues.  Supported  upon  Laugier's 
observations  I  used  ammonium  carbonate  for  dissolving 
hydrated  uranium  phosphate,  but  I  have  now  abandoned 
this  method  in  favour  of  sodium  carbonate  (ammonia 
soda),  which  is  both  cheaper  and  has  a  greater  solvent 
power.  By  introducing  the  uranic  precipitate  into  a 
strong  solution  of  ammonia  soda,  I  dissolve  the  uranium 
phosphate,  filter,  and  add  rather  more  ferric  chloride  than 
is  necessary  to  take  up  all  the  phosphoric  acid,  and  filter 
again,  when  iron  phosphate  and  ferric  hydrate  remain, 
which  are  washed  with  water.  I  treat  the  entire  filtrate 
in  small  portions  with  magnesia  mixture  as  long  as  there 
appears  a  turbidity  of  ammonio-magnesium  phosphate, 
whereby  any  residues  of  phosphoric  acid  are  separated. 
From  the  solution  precipitate  uranium  oxide  with  sodium 
carbonate  ;  filter  after  standing  for  twenty-four  hours,  and 
dissolve  either  at  once  in  acetic  acid  or  acidify  previously 
with  hydrochloric  acid,  boil  to  expel  carbonic  acid,  pre- 
cipitate with  ammonia,  colledt  the  ammonia-uranic  oxide 
on  the  filter,  wash,  and  dissolve  in  acetic  acid  or  in  nitric 
or  hydrochloric  acid,— Zeit.  Analyt.  Chemie. 


Isomerism  of  Stru(!\ure  and  of  Rotatory  Power. — 
Ph.  A.  Guye  and  J.  Guechgorine. — It  results  from  these 
researches  that  we  know  at  present  three  series  of  propylic 
isomers  and  three  series  of  butylic  isomers  among  the 
derivatives  of  adtive  amylic  alcohol.  If  we  take  account 
of  the  decreasing  charader  of  the  rotatory  powers  in  each 
of  these  series,  we  conclude  that  in  all  these  series  the 
propylic  group  behaves  as  heavier  than  the  isopropyl 
group,  and  that  the  isobutyl  group  behaves  as  heavier 
than  normal  butyl,  which  in  turn  adls  as  heavier  than 
secondary  butyl. — Comptes  Rendus,  cxxiv.,  No.  5. 


ON    THE    ACTION     OF    WAGNER'S     REAGENT 

UPON    CAFFEINE,    AND 

A   NEW    METHOD   FOR   THE   ESTIMATION 

OF    CAFFEINE.' 

By  M.GOMBERG. 
(Concluded  from  p.  go). 

Bitimation  of  Caffeine. 
All  the  methods  for  the  estimation  of  caffeine  depend 
upon  the  extraction  of  the  alkaloid  by  an  immiscible  sol- 
vent from  either  a  dry  residue  or  from  its  solution  in 
water.  But  Spencer  (Journ.  Anal.  Chem.,  iv.,  390,  i8go) 
has  recently  shown  how  difficult  it  is  to  remove  the  alka- 
loid from  its  solution  in  water.  According  to  him,  it  is 
necessary  to  shake  out  the  liquid  at  least  seven  times  with 
chloroform,  in  order  to  remove  caffeine  quantitatively.  It 
is  usually  stated  that  caffeine  does  not  form  any  stable 
salts  in  a  watery  solution,  and  consequently  it  can  be 
shaken  out  with  immiscible  solvents  from  either  alkaline 
or  acid  solutions.  But  this  is  only  relatively  true,  as  will 
appear  from  the  following  illustrations.  1*0085  grms.  of 
caffeine  were  dissolved  in  60  c.c.  of  sulphuric  acid  (i :  10), 
and  this  solution  was  repeatedly  shaken  out  with  chloro- 
form, 25  c.c.  at  a  time. 

10  consecutive  portions  of  chloro- 
form gave  a  total  of 0'35i4  grm.  caffeine. 

3  additional  portions  of  chloro- 
form made  a  total  of 0*4^59     ft  M 

3    more    additional    portions    of 

chloroform  made  a  total  of     ..     0*5034     „  „ 

The  extreme  delicacy  of  the  test  for  caffeine  by  means 
of  Wagner's  reagent  has  suggested  the  possibility  of 
applying  this  reagent  for  the  quantitative  estimation  of 
the  alkaloid.  Its  successful  application  necessitates,  of 
course,  a  solution  of  the  alkaloid  free  from  other  sub- 
stances that  are  precipitated  by,  or  absorb  iodine, — a  con- 
dition requisite  in  the  estimation  of  any  base  by  means  of 
Wagner's  reagent.  This  method  gives  very  satisfactory 
results,  as  nearly  theoretical  as  could  be  expedted.  I  am 
indebted  for  the  analytical  data  of  the  subjoined  table  to 
Mr.  James  W.  Knox,  holder  of  the  Stearns'  Fellowship  in 
the  School  of  Pharmacy.  The  method  of  procedure  em- 
ployed by  us  was  prai^ically  the  same  as  that  used  by 
Kippenberger.  Definite  volumes  of  acidulated  solutions 
of  caffeine  were  precipitated  with  a  known  volume  of 
iodine  in  potassium  iodide.  After  complete  precipitation 
an  aliquot  portion  of  the  supernatant  liquid  was  obtained, 
either  by  decantation  or  filtration,  and  the  excess  of 
iodine  was  estimated  by  titrating  against  a  tenth  normal 
solution  of  sodium  thiosulphate.  The  precipitation  is 
best  performed  in  a  tall  test-tube  on  foot,  and  the  solution 
for  titration  is  removed  dire(5tly  by  immersing  the  end  of 
the  burette  into  the  liquid  and  applying  sudion  at  the 
upper  end.  When  it  is  desirable  to  filter  off  an  aliquot 
portion,  a  filter  of  glass-wool  and  asbestos  gives  very  satis- 
fadtory  results. 

We  have  tested  the  method  on  solutions  of  caffeine 
acidulated  with  sulphuric  acid,  the  solutions  being  of  dif- 
ferent strengths,  namely,  containing  0*25  per  cent  of 
caffeine,  0*50  per  cent,  0*75  per  cent,  and  I'oo  per  cent 
respeiaively.  We  have  varied  in  different  series  of  experi- 
ments the  amounts  of  Wagner's  reagent,  employing  just 
the  theoretical  quantities,  a  small  and  large  excess  above 
that,  as  well  as  quantities  below  those  required  by  the 
theory.  Columns  I.,  II.,  III.,  and  IV.,  give  the  results 
obtained  by  allowing  the  solutions  to  stand  for  an  hour 
before  decanting  an  aliquot  portion  for  titration ;  column 
V.  shows  the  results  obtained  when  the  liquid  for  titra- 
tion was  filtered  off  within  five  minutes  after  the  addition 
of  Wagner's  reagent.  The  results  are  calculated  on 
the     basis    that     the     periodide    has     the     composition 

*  From  the  Journal  of  the  American  Chemical  Society,  xviii.,  No.  4. 


OBBMICAL  NBWBiI 

Feb.  t6,  1897.     f 


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C8H10N4O2.  HI.  I4.     The  amount  of  alkaloid  is  calculated 
from  the  amount  of  iodine  used  up,  by  the  formula — 

4I  :  C8H10N4O2  : :  506  :  194  ; 
i.e.,  one  part  of  iodine  represents  03834  part  of  caffeine. 
Or,  I  c.c.  tenth  normal  iodine =0*00485  grm.  caffeine. 

The  results  presented  below  show  that  the  estimation 
of  caffeine  by  this  method  is  very  exadt.  The  best  results 
are  obtained  when  iodine  is  in  considerable  excess,  as  is 
evident  from  the  figures  obtained  where  one  and  one-third 
and  twice  the  theoretical  quantities  of  Wagner's  reagent 
were  used.  All  the  results  in  the  table  were  obtained  on 
solutions  of  caffeine  acidulated  with  sulphuric  acid,  the 
acidulation  being  tolerably  strong,  about  i  c.c.  of  the  con- 
centrated  acid  to  50  c.c.  of  the  liquid.  Experiments  upon 
the  influence  of  the  acid  indicate  that  a  large  excess  of 
sulphuric  acid  interferes  to  some  extent  with  the  readtion. 
The  amount  of  recovered  caffeine  fails  as  low  as  95  per 
cent  of  the  quantity  taken,  when  4  c.c.  of  the  concen- 
trated acid  to  50  c.c.  of  the  liquid  are  used.  The  results 
are  also  not  very  uniform  and  concordant.  The  fadl  that 
the  precipitation  of  caffeine  by  Wagner's  reagent  is  more 
delicate  in  presence  of  hydrochloric  acid  than  any  other 
acid  would  make  it  advisable  to  employ  that  acid  in 
quantitative  estimation  of  the  base  by  iodine. 

This  method  could  easily  be  employed  for  the  estima- 
tion of  the  alkaloid  in  caffeine-bearing  drugs.  Of  course, 
it  is  necessary  to  have  the  final  solution  of  the  alkaloid 
in  water  as  free  as  possible  from  other  substances  that 
may  be  precipitated  by  Wagner's  reagent.  The  estima- 
tion of  caffeine  by  this  method  is  likely  to  give  higher  re- 
sults than  have  hitherto  been  obtained.  The  following 
procedure  is  recommended  :* — The  drug  is  thoroughly 
digested  with  water  for  some  time,  by  the  aid  of  heat, 
cooled,  and  made  up  to  a  definite  volume,  and  filtered. 
An  aliquot  portion  of  the  filtrate  is  treated  with  lead 
acetate,  the  precipitate  allowed  to  settle  and  filtered. 
The  whole  of  the  filtrate,  or  a  given  portion  of  it,  is  treated 
with  hydrogen  sulphide  to  remove  the  lead,  and  filtered. 
This  filtrate,  after  boiling  off  the  hydrogen  sulphide,  is 
divided  into  two  equal  portions,  and  each  treated  with  a 
definite  volume  of  the  standard  iodine  solution, — the  first 
portion  without  the  addition  of  any  mineral  acid,  the 
second  with  the  addition  of  hydrochloric  or  sulphuric  acid. 
After  five  to  ten  minutes'  standing  the  excess  of  iodine  is 
estimated  in  each  of  the  two  solutions,  as  described 
above.  The  first  portion,  containing  no  other  but  some 
acetic  acid,  serves  to  indicate  whether  the  filtrate  from 
the  lead  sulphide  contains  any  other  materials  besides 
caffeine  that  are  likely  to  be  precipitated  by  Wagner's 
reagent, — for  caffeine  itself  is  not  precipitated  by  it  even 
in  presence  of  tolerably  strong  acetic  acid.  If  any  absorp- 
tion of  iodine  be  found  in  the  first  portion,  then  that 
quantity  is  to  be  subtradled  from  the  amount  of  iodine 
taken  up  by  the  second  portion ;  the  difference  represents 
the  iodine  used  up  in  the  formation  of  the  periodide  of 
caffeine.  The  amount  thus  used  up  multiplied  by  03834 
gives  the  amount  of  caffeine  in  that  particular  portion  of 
the  liquid. 

LONDON     WATER    SUPPLY. 
Report  on  the  Composition  and  Quality  of  Daily 
Samples    of  the  Water   Supplied  to    London 
FOR  the  Month  Ending  January  31ST,  1897. 

By  WILLIAM  CROOKES,  F.R.S., 

and 

PROFESSOR  DEWAR,  F.R.S. 

To  Major-General  A.  De  Courcv  Scott,  R.E., 
Water  Examiner,  Metropolis  Water  Act,  1871. 

London,  February  nth,  1897. 
Sir, — We    submit    herewith,    at    the    request    of   the 
Diretflors,  the  results  of  our  analyses  of  the  182  samples 
•  These  direAions  aie   in   part  given  by  Spencer,  1890  (Joum. 
Anal.  Chem.,  iv.,  390). 


100 


Report  of  Committee  on  A  tomk  Weights. 


j  Cbbmical  Nbws, 
\     Feb.  26,  X897. 


of  water  colledted  by  us  during  the  past  month,  at  the 
several  places  and  on  the  several  days  indicated,  from  the 
mains  of  the  London  Water  Companies  taking  their 
supply  from  the  Thames  and  Lea. 

In  Table  I.  we  have  recorded  the  analyses  in  detail  of 
samples,  one  taken  daily,  from  Jan.  ist  to  Jan.  31st 
inclusive.  The  purity  of  the  water,  in  respedt  to  organic 
matter,  has  been  determined  by  the  Oxygen  and  Com- 
bustion processes;  and  the  results  of  our  analyses  by 
these  methods  are  stated  in  Columns  XIV.  to  XVIII. 

We  have  recorded  in  Table  II.  the  tint  of  the  several 
samples  of  water,  as  determined  by  the  colour-meter 
described  in  a  previous  report. 

In  Table  III.  we  have  recorded  the  oxygen  required  to 
oxidise  the  organic  matter  in  all  the  samples  submitted 
to  analysis. 

Of  the  182  samples  examined  all  were  found  to  be  clear, 
bright,  and  well  filtered. 

The  rainfall  at  Oxford  during  the  month  still  shows  a 
small  deficiency,  the  average  fall  for  the  last  thirty  years 
is  2*i6  inches,  the  aftual  fall  in  January  was  i"85  inches, 
making  a  deficiency  of  o'3i  inch  ;  it  has  been  pretty  fairly 
distributed  through  the  month,  the  greatest  fall  being  0*58 
inch  on  the  8th. 

Our  ba^eriological  examinations  have  been,  and  will 
in  future  be,  conduced  on  a  much  larger  scale  ;  this  month 
105  samples  were  examined,  with  the  following  results  : — 

Colonies 
per  c.c. 

Thames  water,  unfiltered 6409 

Thames  water,  from  the  clear  water  wells  of 
the  five  Thames-derived  supplies.,    highest 

Ditto        ditto  lowest 

Ditto        ditto  ..     (45  samples)     mean 

New  River  water,  unfiltered 

New  River  water,  from  the  Company's  clear 
water  well 

River  Lea  water,  unfiltered       1460 

River  Lea  water  from  the  East  London  Com- 
pany's clear  water  well ao 

With  regard  to  the  above  results,  it  is  our  duty  to  say 
that  one  very  exceptional  result  was  also  recorded  during 
the  month,  viz.,  on  the  14th,  when  one  of  the  wells  was 
found  to  contain,  in  our  judgment,  too  great  a  number  of 
microbes,  having  regard  to  the  usual  high  quality  of  the 
filtered  supply.  A  serious  warning  of  the  abnormal  bac- 
teriological condition  of  the  water  was  immediately  com- 
municated to  the  Engineer  of  the  Company,  and  the  next 
sample  of  water,  taken  within  48  hours,  had  resumed  its 
normal  condition. 

We  are,  Sir, 

Your  obedient  Servants, 

William  Crookes. 
James  Dewar. 


75 

4 

30 

1420 

37 


THIRD    ANNUAL     REPORT    OF    COMMITTEE 

ON    ATOMIC    WEIGHTS. 

RESULTS     PUBLISHED     DURING    1895.* 

By  F.  W.  CLARKE. 

(Continued  from  p.  90). 

Tellurium.  —  The  determinations  of  atomic  weight  by 
Staudenmeier  {Ztschr.  Anorg.  Chem.,  x.,  189;  calcula- 
tions based  upon  0  =  i6  and  H  =  i'0032)  all  start  out  from 
telluric  acid,  H2Te04-2H20,  which  had  been  purified  by 
repeated  crystallisation.  Two  essentially  different 
methods  were  adopted.  First,  telluric  acid  was  dehy- 
drated, and  reduced  to  TeOa  by  heating.  Secondly, 
telluric  acid  was  reduced  by  heating  in  hydrogen  to 
metallic  tellurium,  finely  divided  silver  being  mixed  with 
the  acid  to  retain  the  tellurium  by  preventing  volatilisa- 
tion. In  four  experiments.  TeOa  was  reduced  to  Te  in 
*  Read  at  the  Cleveland  Meeting,  December  31,  1895.  From  the 
Journal  of  the  American  Chemical  Society,  xviii.,  No.  3. 


the  same  manner.      The  weights  and  results  may   be 
classified  as  follows  for  the  convenience  of  comparison  :^ 

TeOa  :  Te. 


TeO,. 

Loss  on  reduA 

ion.  Atomic  weight  of  Te 

o'giyi 

0-1839 

127-6 

1-9721 

0-3951 

127-7 

2-4115 

0-4835 

127-6 

I-OI72 

0-2041 

127-5 

Telluric  Acid  : 

TeOj. 

Telluric  acid. 

Loss. 

Atomic  weight  of  Te 

1-7218 

0*5260 

127-2 

2-8402 

0-8676 

127-1 

4-0998 

1-2528 

127-1 

3-0916 

0-9450 

12705 

I'ii38 

0-3405 

127-0 

4*9843 

1-5236 

127-05 

4-6716 

1-4278 

127'X 

Telluric  Acid 

Te. 

Telluric  acid 

Loss. 

Atomic  weight  of  Te 

1-2299 

0-5471 

1273 

I-OI75 

0-4526 

127-3 

2-5946 

I -1549 

127*2 

There  is  a  good  discussion  in  the  paper  as  to  the  pos- 
sible cause  of  error  in  these  determinations,  and  also  con- 
cerning the  place  of  tellurium  in  the  periodic  system. 
Staudenmeier  upholds  the  homogeneity  of  tellurium  as  an 
element,  as  against  the  supposition  that  it  is  a  mixture. 

Some  years  ago  Brauner,  in  an  elaborate  paper  upon 
tellurium,  sought  to  show  that  the  ordinary  element  was 
a  mixture  of  true  tellurium  with  a  higher  homologue  of 
atomic  weight  214.  He  now  (Jourrt.  Chem.  Soc,  Ixvii., 
549)  concludes  that  this  is  very  improbable,  and  suggests 
that  tellurium  may  contain  a  homologue  of  argon,  of 
atomic  weight  130.  For  this  supposition  no  evidence  is 
given  apart  from  the  abnormality  of  the  atomic  weight, 
which  should  fall  below  that  of  iodine. 

Yttrium. — The  atomic  weight  of  this  metal  has  been 
re-determined  by  Jones  {Am.  Chem.  yo«r».,  xvii.,  154; 
calculations  based  upon  O  =  16  and  H  =  1*0032), 
who  started  out  with  material  purified  by  Rowland's  pro- 
cess; that  is,  by  precipitation  with  potassium  ferro- 
cyanide.  First,  oxide  was  converted  into  sulphate;  and 
secondly,  sulphate  was  transformed  to  oxide  by  calcination. 
The  weights  and  results  were  as  follows : — 

First  Method. 


Y,0,. 

Y,(SO.)a. 

Atomic  weight  of  Y. 

0-2415 

0-4984 

88-89 

0*4112 

0*8485 

8892 

0*2238 

0-4617 

88-97 

0-3334 

0-6879 

88*94 

0-3408 

0-7033 

88*90 

0-3418 

0-7049 

89*05 

0*2810 

0-5798 

88*94 

0*3718 

0-7803 

88-8g 

0*4379 

09032 

8g*o2 

0*4798 

0-9901 

88-gi 

Mean.. 

..     88*94 

Second  Method. 

Y,(SOJ,. 

Y,o,. 

Atomic  weight  of  Y 

0-5906 

0-2862 

88*91 

0-4918 

0-2383 

88*8g 

0-5579 

0-2705 

89*03 

0-6430 

0*3117 

88*99 

0-6953 

0-3369 

88*89 

1-4192 

0-6880 

88*99 

0-8307 

0-4027 

88-99 

07980 

0-3869 

89-02 

0-8538 

0-4139 

88-99 

1-1890 

0-5763 

88-96 

Mean.. 


88-97 


Chbuical  News, 
Feb.  26,  1897. 


Determination  of  Atomic  Masses  by  the  Electrolytic  Methods        101 


These  determinations  are  probably  the  best  hitherto 
made,  although  they  have  been  briefly  criticised  by  Dela- 
fontaine  (Chem.  News,  Ixxi,,  243),  who  prefers  the  lower 
value  obtained  by  himself,  Y=87"3.  Delafontaine  re- 
affirms the  existence  of  phillipium,  and  regards  gado- 
linium as  identical  with  decipium.  Jones  (Chem.  News, 
Ixxi.,  305),  in  a  brief  rejoinder,  defends  his  own  work,  and 
urges  that  Delafontaine  has  failed  to  show  wherein  it  is 
defective. 

The  Cerite  Earths, — Papers  upon  this  subjefthave  been 
published  by  Schiitzenberger  and  by  Brauner,  In  his 
first  communication,  Schiitzenberger  {Compt.  Rend,,  cxx., 
663)  deals  with  cerium,  which  had  been  freed  from 
lanthanum  and  "  didymium "  by  fusion  of  the  mixed 
nitrates  with  saltpetre.  The  yellowish  white  cerium 
oxide  was  converted  into  cerium  sulphate,  which  was 
dried  at  440°.  In  this  salt,  with  special  precautions,  the 
sulphuric  acid  was  estimated  by  precipitation  with  barium 
chloride.  One  hundred  parts  of  cerium  sulphate  gave 
I23'30  of  barium  sulphate.  Hence,  Ce  =  i39"45,  according 
to  Schiitzenberger's  calculations.    Re-computing  with — 

0  =  16,  S=32'07,  and  Ba=  137*43, 
Ce  =  139-96. 

In  a  second  paper  {Compt.  Rend.,  cxx.,  962)  Schiitzen- 
berger describes  the  results  obtained  by  the  fradionation  of 
cerium  sulphate.  Preparations  were  thus  secured  giving 
oxides  of  various  colours,  such  as  canary-yellow,  yellowish 
rose,  reddish,  and  brownish  red.  These,  by  the  synthesis 
of  the  sulphates,  the  barium  sulphate  method,  &c.,  gave 
varying  values  for  cerium,  ranging  from  I35'7  up  to  i43*3. 
Schiitzenberger  concludes  that  the  cerium  sesquioxide 
from  cerite  contains  small  quantities  of  another  earth  of 
lower  atomic  weight.  In  a  third  paper  (Compt,  Rend., 
cxx.,  1143)  he  continues  the  investigation  with  the  other 
cerite  earths.  For  the  didymiums  he  finds  a  range  in 
atomic  weight  from  i37*5  to  i43'5  approximately. 

Brauner's  paper  (Chem.  News,  Ixxi.,  2S3)  is  partly  a 
reclamation  of  priority  over  Schiitzenberger,  and  partly  a 
preliminary  statement  of  new  results.  In  his  earlier  work 
he  found  that  cerium  oxide  was  a  mixture  of  two  earths  ; 
one  white,  the  other  flesh  colour  with  a  tinge  of  orange, 
and  atomic  weights  for  the  contained  metal  of  140*2  and 
14572  respectively.  In  his  later  researches  Brauner 
fra&ionates  his  material  by  several  methods.  One  con- 
stituent obtained  from  cerium  oxide  is  a  dark  salmon- 
coloured  earth,  the  oxide  of  a  metal  which  he  calls  "  meta- 
cerium."  The  other  constituent  he  calls  cerium.  Pure 
cerium  oxalate  by  Gibbs's  permanganate  method  gave 
29*506  and  29*503  per  cent  of  cerium  sesquioxide  with 
4^'934*per  cent  of  cerium  dioxide,  Hence,  Ce  =  139*91, 
or,  with  a  slight  correction,  Ce  =  i40'oi.  This  is  not  far 
from  Schiitzenberger's  value. 

(To  be  continued). 


THE    DETERMINATION     OF    ATOMIC     MASSES 

OF    SILVER,     MERCURY,    AND    CADMIUM, 

BY    THE    ELECTROLYTIC    METHOD.* 

By  WILLETT  LEPLEY  HARDIN. 

(Concluded  from  p.  93). 

Part  III.  {continued). 

First  Series. 

Experiments  on  Cadmium  Chloride. 

Dumas  and  Bucher  have  both  determined  the  ratio  of 

cadmium  to  chlorine  in  cadmium  chloride.    The  results 

given  for  the  atomic  mass  of  cadmium  by  the  latter  ex- 

♦  Contribution  from  the  John  Harrison  Laboratory  of  Chemistry, 
No.  13.  From  the  author's  thesis  presented  to  the  Faculty  of  the 
University  of  Pennsylvania  for  the  degree  of  Ph.D.— From  the 
Journal  oj  the  American  Chemical  Society,  xviii.,  p.  ggo. 


perimenter  are  almost  four-tenths  of  a  unit  higher  than 
those  given  by  the  former. 

Preparation  of  Cadmium  Chloride, 
Hydrochloric  acid  was  purifled  by  first  passing  chlorine 
through  the  commercial  C.  P.  acid  to  remove  any  sul- 
phur dioxide ;  the  excess  of  chlorine  was  removed  by  a 
current  of  carbon  dioxide.  The  acid  was  then  distilled 
from  calcium  chloride  and  the  hydrochloric  acid  gas  col- 
ledled  in  pure  water.  Pure  metallic  cadmium  was  then 
dissolved  in  the  acid  and  the  solution  evaporated  to  crys- 
tallisation. The  crystals  of  cadmium  chloride  were  re- 
moved from  the  liquid  and  thoroughly  dried.  The 
material  was  then  placed  in  a  hard  glass  combustion-tube, 
similar  to  that  used  in  the  distillation  of  metallic  cadmium, 
and  carefully  sublimed  in  a  current  of  dry  carbon  dioxide. 
The  first  and  last  portions  of  the  sublimate  were  rejedted. 
The  middle  portion,  which  consisted  of  pearly  leaflets, 
was  placed  in  a  weighing  tube  and  kept  in  a  desiccator. 
As  only  a  small  quantity  of  the  material  could  be  sub- 
limed at  a  time,  the  different  analyses  were  made  from 
different  sublimations. 

Mode  of  Procedure. 
A  weighed  portion  of  the  cadmium  chloride  was  dis- 
solved in  a  little  water  in  a  platinum  dish,  a  slight  excess 
of  potassium  cyanide  was  added  and,  after  diluting  to 
200  c.c.  with  pure  water,  the  solution  was  electrolysed. 
Before  interrupting  the  current,  the  liquid  was  syphoned 
from  a  dish  in  a  manner  already  outlined  in  the  experi- 
ments on  silver.  The  metallic  deposit  was  washed 
several  times  with  boiling  water  and  carefully  dried.  The 
strength  of  the  current  and  time  of  aClion  were  as  fol- 
lows : — 

Time  of  aftion.  Strength  of  current. 

1 2  hours,.     ..    N.Dioo=o*i   ampere. 
4      „     ..     ..     N.Dioo=o'i5        „ 

4 N.Dioo=o*3o        „ 

The  cadmium  was  thrown  down  as  a  dense  white 
deposit.  Ten  results  on  cadmium  chloride  reduced  to  a 
vacuum  standard  on  the  basis  of — 

3*3     =  density  of  cadmium  chloride, 
8*55  =  ,,         metallic  cadmium, 

21*4     =  ,,         platinum  dish, 

8'5     =  II         weights, 

and  computed  for  the  formula  CdClj,  assuming  35*45  to 
be  the  atomic  mass  of  chlorine,  are  as  follows : — 


I 
2 
3 
4 
5 
6 

7 
8 

9 
10 


Weight 

of  CdCla. 

Grms. 

0*43140 
0*49165 
0*71752 
0*72188 
0*77264 
081224 
0*90022 
1*02072 
1  *26322 
1*52344 

Mean  .. 

Maximum 

Minimum 


Weight 
ofCd. 
Grm. 

0*26422 
0*30112 
0*43942 
0*44208 
0*47319 
0*49742 

0*55 135 

0*62505 

0*77365 

0*93314 

=  112*038 
.  =  112*078 
.      =   112*002 


Atomic  mass 
of  cadmium. 


1 12*054 
112*052 
112*028 
112*021 
112-036 
112*023 
112*041 
112*002 
1X2*041 
112*078 


Difference  ,.     =      0-076 
Probable  error   =  ^0*005 
From  the  total  quantity  of  material  used  and  metal 
obtained,  we    have    112040    for    the   atomic    mass  of 
cadmium. 

Second  Series. 
Preparation  of  Cadmium  Bromide. 
The  bromine  used  in  this   series  was  purified  as  out- 
lined in   the   experiments  on  mercuric  bromide.      The 


io^ 


Determination  of  Atomic  Masses  by  the  Electtolytic  Method.    {^^F^b^eM*?'"' 


cadmium  bromide  was  prepared  by  allowing  bromine  water 
to  aa  on  metallic  cadmium  for  several  days  at  the  ordinary 
temperature.  When  the  adlion  was  complete,  the  solu- 
tion was  filtered  and  evaporated  to  crystallisation.  The 
crystals  of  cadmium  bromide  were  removed  from  the 
liquid  and  thoroughly  dried.  The  material  was  then 
placed  in  a  hard  glass  combustion-tube  and  carefully  sub- 
limed in  a  current  of  dry  carbon  dioxide.  The  first  and  last 
portions  of  the  sublimate  were  rejeifled.  The  middle  por- 
tion was  removed  from  the  tube,  placed  in  a  weighing 
bottle  and  kept  in  a  desiccator.  The  produdl  obtained  in 
this  way  consisted  of  a  crystalline  pearly  leaflet  which 
dissolved  immediately  in  water  without  leaving  a  residue. 

Mode  of  Procedure, 
The  method  of  operation  was  the  same  as  for  cadmium 
chloride.  A  weighed  portion  of  the  material  was  dis- 
solved in  a  little  water  in  a  platinum  dish.  A  slight  ex- 
cess of  potassium  cyanide  was  then  added,  and  after 
diluting  to  200  c.c.  the  solution  was  eledtrolysed  and  the 
resulting  metal  weighed.  The  strength  of  current  and 
time  of  aftion  were  the  same  as  for  cadmium  chloride. 

Ten  observations  on  cadmium  bromide  reduced  to  a 
vacuum  standard  on  a  basis  of — 

4'8     =  density  of  cadmium  bromide, 
8*55  =  II         metallic  cadmium, 

21 '4     =  ,,  platinum  dish, 

8'5     =  I,  weights, 

and  computed  for  the  formula  CdBrj,  assuming  79*95  to 
be  the  atomic  mass  of  bromine,  are  as  follows : — 


Atomic  mass 

Weight  of  CdBr,. 

Weight  of  Cd. 

of  cadmium. 

Grm. 

Grm. 

I 

o'57745 

o*237go 

112*031 

2 

076412 

0-31484 

112-052 

3 

0-91835 

0-37842 

112-067 

4 

1-01460 

041808 

112-068 

5 

1-15074 

0*47414 

112-053 

b 

I -24751 

0-51392 

ll2-oig 

7 

1-25951 

0-51905 

122*087 

8 

1*51805 

0-62556 

112*076 

9 

1-63543 

0-67378 

112*034 

10 

2-15342 

0-88722 

112*041 

Mean    .. 

..      =112053 

Maximum 

..      =  112*087 

Minimum 

..     =  ii2*oig 

Difference    ..      =      o*o68 
Probable  error    =  ^^0*005 

From  the  total  quantity  of  material  used  and  the  meta' 
obtained,  Cd  =  112*053. 

Third  Series. 

In  these  experiments  an  attempt  was  made  to  deter- 
mine the  ratio  of  the  atomic  mass  of  cadmium  to  that  of 
silver  by  allowing  the  same  eledlric  current  to  pass  suc- 
cessively through  solutions  of  the  two  metals  and  weighing 
the  resulting  deposits.  The  arrangement  of  apparatus 
and  the  details  of  the  method  were  described  under  the 
mercury-silver  series.  The  results  were  not  as  satisfac- 
tory as  the  corresponding  results  obtained  for  mercury. 
A  large  number  of  determinations  were  made  with  cur- 
rents of  different  strength  and  solutions  of  different  con- 
centration, but  the  results  were,  in  most  cases,  far  below 
those  obtained  in  the  first  two  series.  A  current  which 
deposited  about  twelve-hundredths  of  a  grm.  of  silver  per 
hour  seemed  to  give  the  best  results.  From  all  the  ob- 
servations, five  results  were  seleded  which  differed  only 
about  one-tenth  of  a  unit  from  those  of  the  first  two 
series.  Results  selected  in  this  way  are  entitled  to  but 
little  weight,  and  perhaps  should  not  be  used  in  deter- 
mining the  general  mean  of  all  the  observations. 

Computed  on  the  basis  of  107*92  for  the  atomic  mass 
of  silver,  the  only  admissible  results  are  as  follows  : — 


Weight  of 
Grm. 

Weight  of 
Cd. 
Grm. 

Atomic  mass  of 
Cadmium. 

I 

2 

3 
4 
5 

0-24335 
0-21262 

0-24515 
0-24331 
0-42520 

0-12624 
0-11032 
0-12720 
0*12616 
0-22058 

1 1 1-928 
iii*ggi 
111-952 
iii-gi6 
iii-g7i 

Mean  .. 
Maximum   . 
Minimum    . 

=    III 
=    111 
=    III 

952 
991 
gi6 

Difference  . 

=        0 

07s 

This  method  was  discussed  under  mercury.  The  prob- 
able sources  of  error  pointed  out  there  apply  equally  well 
in  the  case  of  cadmium.  Until  the  large  variations  can 
be  accounted  for  and  the  difficulties  overcome,  the  method 
must  be  regarded  as  unsatisfadlory. 

Summary. 

Inasmuch  as  but  one  method  of  analysis  has  been  used 
throughout  this  work,  it  is  useless  to  discuss  it  here.  The 
advantages  and  objections  pointed  out  under  silver  apply 
also  to  cadmium. 

In  summing  up  the  work  on  cadmium,  equal  weight 
must  be  given  to  the  first  two  series.  The  last  series 
must  be  considered  alone,  and  all  that  need  be  said  of  it 
is,  that  the  results  obtained  for  the  atomic  mass  of  cad- 
mium never  exceeded  112.  In  the  corresponding  series 
on  mercury,  the  variations  were  in  both  diredtions  from 
200. 

The  general  mean  of  the  first  two  series  calculated  from 
the  separate  observations  is — 

Atomic  mass  of  Cd. 

First  series =   112*038 

Second  series     ..     ..     =  112053 


General  mean 


=   112*0455 


From  the  total  quantity  of  material  used  and  metal 
obtained  we  have — 

Atomic  mass  of  Cd. 

First  series =   112-040 

Second  series     ..     ..     =  112*053 


General  mean 


=  112-0465 


Combining  this  with  the  first  general  mean  we  have 
112*046  as  the  most  probable  result  of  all  the  work,  for 
the  atomic  mass  of  cadmium.  This  result  is  lower  than 
those  obtained  by  Huntington  and  Bucher,  but  agrees 
very  closely  with  the  results  obtained  by  von  Hauer, 
Dumas,  Lensen,  Jones,  and  Lorimer  and  Smith. 

I  wish  here  to  express  my  sense  of  gratitude  to 
Professor  Edgar  F.  Smith,  at  whose  suggestion  this  work 
was  undertaken  and  under  whose  personal  supervision  it 
was  carried  out. 


Radio-photography  of  the  Soft  Parts  of  Man  and 
of  the  Lower  Animals. — MM.  Remy  and  Contremoulin. 
We  have  the  honour  of  presenting  to  the  Academy  a  new 
result  of  our  researches  on  the  application  of  the  X  rays 
to  anatomical  studies.  By  the  aid  of  chemical  prepara- 
tions on  the  bodies  of  men  and  frogs,  we  have  been  able 
to  place  the  muscles,  the  ligaments,  and  the  tendons  in 
such  a  state  that  they  have  yielded  radio-photographic 
images.  The  muscle  projedted  shows  a  dark  tint,  but 
within  the  limits  thus  indicated  we  perceive  dark  traits 
which  pertain  to  the  muscular  bundles.  The  muscle  is 
thus  masked  by  bundles  of  longitudinal  striae  very  dis- 
tiniftly  limited.  In  the  frog,  prepared  by  the  same  means, 
the  muscles  are  fully  visible.  In  this  animal  we  have 
obtained  an  image  of  the  crystalline  lens  and  of  the 
coatings  of  the  eye. — Comptes  Rendus,  cxxiv.,  No.  5. 


CHBMICAL  NbWB.I 

Feb.  26, 1897.     I 


Electric  Shadows  and  Luminescence, 


103 


ELECTRIC    SHADOWS   AND    LUMINESCENCE.* 
By  Prof.  SILVANUS  P.  THOMPSON,  D.Sc,  F.R.8.,  M.R.I. 

The  early  days  of  the  year  1896  were  marked  by  the 
announcement  telegraphed  from  Vienna  to  the  eifedt  that 
Professor  Rontgen,  a  man  whose  name,  though  little 
known  outside  the  world  of  science,  was  well  known  and 
highly  esteemed  by  those  who  were  mitiates  in  physics, 
had  discovered  the  existence  of  rays  of  a  new  and  extra- 
ordinary kind.  Taking  a  Crookes  tube,  excited  of  course 
by  a  proper  eleftric  spark,  and  covering  it  up  within  a 
case  of  black  cardboard,  he  found  it  to  produce  in  the 
surrounding  space  some  entirely  unexpedled  effedts. 
Black  cardboard  is  impervious  not  only  to  ordinary  light 
and  to  radiant  heat,  but  also  to  all  those  other  known 
kinds  of  invisible  light  beyond  the  violet  end  of  the 
spedrum,  known  as  adlinic  waves,  which  are  such  aftive 
agents  in  the  produdtion  both  of  fluorescence  and  of 
photographic  actions.  Yet  the  invisible  emanations  of 
the  Crookes  tube,  which  passed  freely  through  the  opaque 
cardboard,  were  found  by  Rontgen  to  be  capable  of 
revealing  their  presence  in  two  ways.  In  the  first  place 
he  had  seen  them  to  projedt  shadows  upon  a  luminescent 
screen  of  paper  coated  with  the  highly  fluorescent  sub- 
stance called  platino-cyanide  of  barium,  and  in  the  second 
place  he  had  been  able  to  photograph  these  shadows  by 
letting  them  fall  upon  an  ordinary  photographic  plate. 
The  discovery  was  singular.  It  revealed  the  existence 
of  a  remarkable  and  hitherto  unexpected  species  of  radia- 
tion. It  added  another  to  the  many  puzzling  phenomena 
attendant  upon  the  discharge  of  eledtricity  in  vacuo. 
It  proved  that  something  which  in  the  ordinary  sense  in 
which  those  terms  are  used  is  neither  light  nor  elec- 
tricity was  generated  in  the  Crookes  tube,  and  passed 
from  it  through  substances  opaque  alike  to  both. 

But  that  which  took  the  imagination  of  the  multitude 
by  storm,  and  aroused  an  interest  the  intensity  the  like  of 
which  has  not  been  known  to  be  aroused  by  any  other 
scientific  discovery  in  our  times,  was  not  the  fadt  that 
Professor  R5ntgen  had  seen  luminescent  shadows  from  a 
Crookes  tube,  or  had  obtained  a  photograph  of  those 
shadows  ;  it  was  the  entirely  subsidiary  and  comparatively 
unimportant  point  that  to  these  mysterious  radiations 
flesh  is  more  transparent  than  bone. 

Let  me  begin  by  showing  you  as  a  first  experiment  that 
same  fadt  which  Rontgen  announced  of  the  produdtion  of 
luminescent  shadows  by  these  invisible  rays.  Before  you 
there  stands  a  Crookes  tube,  of  the  most  modern  kind.f 
for  this  particular  purpose.  We  have  here  an  indudtion 
coilj  capable  of  giving  6-inch  sparks,  with  which  we  can 
Bend  eledtric  discharges  through  the  tube,  illuminating  it 
with  its  charadteristic  golden-green  glow.  I  now  cover 
over  the  tube  and  exclude  all  ordinary  light,  not  with  a 
box  of  black  cardboard  but  with  a  black  velvet  cloth. 
And  now  in  the  darkness  I  am  able  to  show  you  how  on 
a  sheet  of  paper  covered  with  the  highly  fluorescent 
platino-cyanide  of  barium — the  well-known  substance 
which  Rontgen  himself  was  using  —  the  shadows  of 
objedts  placed  between.  See  how  this  sheet  shines  in 
the  light  of  the  tube  transmuting  the  invisible  radiations 
into  visible  light.  I  hold  my  purse  behind  the  screen — 
you  see  the  shadow  of  the  metal  clasp,  and  of  the  metal 
contents  (two  coins  and  a  ring),  but  you  see  not  the 
shadow  of  the  leather  purse  itself,  for  leather  is  trans- 
parent to  these  rays  while  metal  is  opaque.  I  hold  my 
hand  behind  and  you  see — or  at  least  those  of  you  who 
are  within  a  few  yards  of  me — the  shadow  of  my  hand, 
or  rather  of  the  bones  of  my  hand,  surrounded  by  a  fainter 
shadow  of  the  almost  transparent  flesh. 

*  A  LeAure  de  ivered  at  the  Royal  Institution  oi  Great  Britain 
Friday,  May  8,  i8g6. 

t  A  Crookes  "  focus "  tube  (Jackson  pattern),  conatruAed  by 
Messrs.  Newton  and  Co  ,  of  Fleet  Street,  London. 

t  An  Apps  coil  capable  of  giving  sparks  25  centimetres  in  length, 
but  on  this  occasion  excited  with  only  j  cells,  giving  sparks  about  6 
inches  in  length. 


Now  the  second  fa^  that  Rontgen  announced  was  that 
these  same  rays  which  escape  through  the  opaque  cover- 
ing and  excite  fluorescence  are  also  capable  of  taking 
photographic  impressions  of  the  shadows.  There  is 
nothing  whatever  new  about  this  part  of  the  subjedt:  it 
is  the  old  photograph  ;  there  is  no  '•  new  photography." 
Here  is  a  common  camera  back,  and  here  inside  it  is  a 
photographic  dry-plate — quite  a  common  dry-plate,  such 
as  has  been  known  for  ten  years.  This  plate  is  covered 
with  a  black  card,  so  that  it  may  not  become  fogged  by 
the  light  of  the  room  when  I  draw  the  slide.  All  I  have 
to  do  is  to  lay  it  upon  the  table  below  the  Crookes  tube 
so  as  to  cast  the  shadow  upon  it,  and  after  due  exposure 
develop  the  plate  in  the  ordinary  well-understood  way. 
Now  it  may  be  interesting  to  see  the  proof  of  the  fadt  that 
bone  is  less  transparent  than  flesh.  So,  with  your  per- 
mission, I  will  ask  my  little  daughter  to  have  her  hand 
photographed.     (Experiment  made). 

At  the  time  of  Rontgen's  announcement,  the  exposure 
required  with  the  Crookes  tubes  that  were  then  in  exist- 
ence was  from  twenty  minutes  to,  I  think,  two  or  three 
hours.  Very  shortly  improvements  were  made  ;  and  with 
these  modern  tubes  one  minute  is  quite  sufficient  for  an 
exposure.  Indeed,  one  minute  is  too  much  for  many 
objedts.  I  have  not  previously  tried  this  particular  tube, 
though  I  judge  by  its  appearance  that  it  is  in  good  con- 
dition. As  soon  as  the  exposure  of  one  minute  is  over 
we  will  have  the  plate  taken  into  the  dark  room  and 
developed  in  the  ordinary  way ;  and  when  it  is  developed 
we  will  have  it  brought  back  into  this  room  and  put  into 
the  lantern,  that  you  may  see  what  has  been  done. 

Now,  while  we  are  taking  photographs,  I  may  as  well 
take  a  second  to  illustrate  another  point.  Rontgen 
investigated  in  the  most  careful  and  elaborate  way  the 
relative  transparency  of  different  materials  for  these 
mysterious  rays.  He  noticed  that  wood,  and  many  sub- 
stances which  are  opaque  to  ordinary  light,  are  trans- 
parent to  these  rays  ;  whilst,  on  the  contrary,  several  sub- 
stances that  are  transparent  to  light,  such  as  calc-spar 
and  heavy  glass,  are  very  opaque  toward  them.  Many 
experimenters  have  examined  this  question  of  relative 
transparency.  I  devoted  a  day  or  two  to  the  study  of 
gems,  and  found  that  imitation  rubies  made  of  red  glass 
are  much  more  opaque  than  real  rubies,  and  that  paste 
diamonds  are  much  more  opaque  than  real  diamonds. 
Real  diamonds  and  rubies  are  indeed  very  transparent,  and 
scarcely  cast  any  shadows  on  the  luminescent  screen, 
though  I  have  found  diamond  to  be  more  opaque  than  an 
equal  thickness  of  black  carbon.  There  are  laid  upon 
this  piece  of  card  two  rubies,  one  being  only  a  glass  ruby. 
There  is  also  a  row  of  four  small  diamonds.  I  will  leave 
you  to  find  out  whether  they  are  false  or  real.  And  then 
there  are  three  larger  diamonds,  one  of  which  is  uncut 
and  is  a  genuine  South  African  stone.  I  lay  them  down 
upon  a  photographic  plate  and  expose  them  to  the 
Rontgen  rays  so  that  we  may  test  their  relative  trans- 
parency. (The  two  photographs  thus  taken  were  pro- 
jedled  upon  the  screen  at  the  close  of  the  ledture.) 

Amongst  the  things  which  Rontgen  told  us  was  the 
fadl  that  different  kinds  of  glass  are  unequally  transparent ; 
that  lead-glass,  for  instance,  is  much  more  opaque  than 
soda-glass,  or  potash-glass,  or,  indeed,  any  glass  which 
does  not  contain  a  heavy  metal  like  lead.  He  found  that 
pradically  the  transparency  was  governed  by  the  density ; 
that  the  heavy  or  the  dense  substances  were  the  more 
opaque.  There  is  now  some  reason  to  corredl  that  state- 
ment, though  in  the  main  as  a  first  approximation  it  is 
perfedtly  true.  Professor  Dewar  has  shown  that  you 
must  take  into  account,  not  the  density  in  gross,  but  the 
atomic  weight.  Taking  any  homologous  series,  for 
example,  such  as  a  number  of  sulphides,  or  oxides,  or 
chlorides,  that  one  which  contains  the  atomically 
heavier  metal  will  be  the  more  opaque.  Again,  the 
bromide  of  sodium  is  more  opaque  than  the  chloride  of 
the  same  metal,  and  the  iodide  is  more  opaque  than  the 
bromide.    But  as   the  correspondence  between  relative 


I04 


Electric  Shadows  and  Luminescence, 


1  Chemical  News, 
1      Feb.  26, 1897. 


opacity  and  molecular  or  atomic  weight  breaks  down 
when  we  try  to  pass  from  one  series  of  compounds  to  a 
different  series,  there  is  some  reason  to  carry  the  matter 
to  a  further  degree  of  approximation.  We  must  go 
beyond  the  suggestion  of  atomic  weight.  The  nearest 
approach  to  a  law  that  I  have  been  able  to  get  at  yet,  on 
comparing  tables  of  statistics,  is  that  the  transparency  is 
proportional  to  the  specific  heat.  For  homologous  series 
this  is,  of  course,  the  same  as  saying  that  the  trans- 
parency is  inversely  proportion  to  the  molecular  weight. 

Rontgen  found  all  the  heavy  metals  to  be  remarkably 
opaque,  while  light  metals  like  sodium  and  aluminium, 
and  even  zinc,  are  remarkable  for  their  transparency. 
Aluminium,  which  is  opaque  to  every  known  kind  of 
light,  is  transparent,  even  in  sheets  half  an  inch  thick,  to 
these  rays.  Lithium,  the  lightest  of  solid  metals,  and 
with  an  atomic  weight  7  as  against  aluminium  27,  is  so 
transparent  that  I  have  not  been  able  yet  even  to  see  its 
shadow.  Of  all  liquids  water  is  the  most  transparent, 
and  it  has  the  highest  specific  heat  of  all  of  them. 

Rontgen  further  found  these  rays  to  be  incapable  either 
of  refradion  by  lens  or  prism,*  or  of  reflection  by  any 
polished  mirror.  Refle(5tion  there  is  in  one  sense,  that  of 
diffuse  refieiftion,  such  as  white  paper  exercises  on  common 
light.  No  lens  can  concentrate  these  rays  ;  they  are  also 
apparently  incapable  of  being  polarised.  One  difficulty 
in  experimenting  on  these  strange  properties  is  that  air 
itself  adts  as  a  turbid  medium,  reflecting  back  diffusely,  as 
a  smoky  cloud  would  do  for  ordinary  light,  a  portion  of 
the  rays. 

Finding  that  these  radiations  differed  in  so  many 
ways  from  ordinary  light,  and  while  resembling 
and  even  surpassing  ultra-violet  rays  in  their  strong 
adtinic  properties,  yet  differed  entirely  from  them  in 
respe^  of  the  properties  of  refradtion,  reflection,  and 
polarisation,  he  named  them  "  X  rays."  To  judge  by  his 
own  writing,  he  appeared  to  wish  that  they  might  prove 
to  be  longitudinal  vibrations  in  the  ether,  the  possibility 
of  the  existence  of  which  has  been  a  subjedt  of  specula- 
tion on  the  part  of  some  of  the  most  learned  of  mathe- 
matical physicists.  Others  have  suggested  that  these  X 
rays  are  transverse  vibrations  of  a  much  higher  frequency 
and  shorter  wave-length  than  any  known  kind  of  ultra- 
violet light.  Others,  again,  see  in  them  evidence  that 
radiant  matter  {i.e.,  kathodic  streams  of  particles)  can 
traverse  the  glass  of  a  Crookes  tube,  and  regard  them  as 
material  in  their  nature.  Lastly,  it  has  been  suggested 
that  they  may  be  neither  waves  nor  streams  of  matter,  but 
vortex  motions  in  the  ether. 

To  follow  out  the  bearings  of  these  speculations,  as 
well  as  to  trace  the  development  of  discovery,  let  us  go 
back  a  little  and  consider  what  was  the  starting-point  of 
Rdntgen's  research.  He  was  using  a  Crookes  tube.  It 
is  one  of  the  difficulties  of  my  task  to-night  that  I  have 
to  speak  in  the  presence  of  him  who  is  the  master  of  us 
all  in  this  subjedt  of  eledlric  discharges  in  the  vacuum 
tube.  But  to  understand  the  discoveries  of  Crookes  let 
us  first  witness  a  few  experimental  illustrations  of  the 
phenomena  of  eledtric  discharges  in  vacuum  tubes.  Many 
of  them  have  been  known  for  half  a  century.  We  all 
know  of  the  researches  made  in  England  by  Gassiot,  and 
by  Varley  and  others,  and  the  tubes  of  Geissler  of  Bonn 
are  a  household  word.  But  there  is  one  set  of  researches 
which  deserves  to  be  known  far  better  than  it  is,  that 
made  by  Dr.  W.  H.  Th.  Meyer,  of  Frankfort,  whose  pam- 
phletf  I  hold  in  my  hand.  In  it  he  depidts  a  number  of 
tubes  in  various  stages  of  exhaustion,  including  one  in 


*  Perrin,  in  Paris,  and  Winkelmann,  in  Jena,  have  independently 
found  what  they  believe  to  be  evidence  of  refraftion  through  an 
aluminium  prism.  Both  observers  detedted  a  slight  deviation,  but 
in  a  diredtion  toward  the  refradling  angle,  showing  aluminium  to 
have  for  these  rays  a  refradtive  index,  slightly  less  with  respedt  to 
air  than  unity. 

i  "  Beohachliingen  iiber  das  geschichtete  eledtrische  Licht,  sowie 
iiber  den  merkwiirdigen  Einfluss  des  Magneten  auf  dasselbe;"  von 
Dr.  W.  H.  Theodor  Meyer.    Berlio,  1838. 


that  highest  stage  of  exhaustion  which  one  is  prone  to 
think  of  modern  origin. 

In  order  to  illustrate  the  successive  phenomena  which 
are  produced  when  eledtric  discharges  are  sent  through  a 
tube  during  progressively  increasing  exhaustion,  there  is 
here  exhibited  a  set  of  identical  tubes.  Each  is  a  simple 
straight  tube,  having  sealed  in  at  each  end  an  eledtrode 
terminating  in  a  short  piece  of  aluminium  wire.  The 
eledtrode  by  which  the  eledtric  current  enters  is  known  as 
the  anode,  that  by  which  it  leaves  the  tube  as  the  kathode. 
The  only  difference  between  these  eight  tubes  lies  in  the 
degree  of  rarefadlion  of  the  interior  air.  The  first  one 
contains  air  at  the  ordinary  pressure.  As  its  eledtrodes 
are  about  12  inches  apart  I  am  unable  with  the  Apps 
indudtion  coil  (excited  to  throw  an  8-inch  spark)  to  send 
a  spark  through  it.  From  the  second  tube  about  four- 
fifths  of  the  air  has  been  abstradted,  and  here  we  obtain  a 
forked  brush-like  spark  between  the  eledtrodes.  The 
third  tube  has  been  exhausted  to  about  one-twentieth 
part,  and  shows  as  the  discharge  a  single  thin  red  linear 
spark  like  a  flexible  luminous  thread.  When,  as  in  the 
fourth  tube,  the  exhaustion  is  carried  so  far  as  to  leave 
but  one  fortieth,  the  red  line  is  found  to  have  widened  out 
into  a  luminous  band  which  extends  from  pole  to  pole, 
while  a  violet  mantle  makes  its  appearance  at  each  end 
and  spreads  over  both  of  the  eledtrodes.  On  carrying  the 
exhaustion  to  the  stage  shown  by  the  fifth  tube,  where 
only  about  i-5ooth  of  the  original  air  is  left  behind,  we 
note  that  the  luminous  column  has  broken  up  transversely 
into  flickering  striae,  that  the  violet  mantle  round  the 
kathode  has  become  more  distindt,  and  is  separated  by  a 
dark  interval  from  the  luminous  red  column,  while  a 
second  and  very  narrow  dark  space  appears  to  separate 
the  violet  mantle  from  the  surface  of  the  kathode.  In  the 
sixth  tube  the  exhaustion  has  been  carried  to  about 
i-io,oooth.  The  flickering  striae  have  changed  shape  and 
colour,  being  paler.  The  light  at  the  anode  has  dwindled 
to  a  small  bright  patch.  The  violet  glow  surrounding  the 
kathode  has  expanded  to  fill  the  whole  of  that  end  of  the 
tube ;  the  dark  space  has  become  more  distindt,  and 
within  it  the  kathode  now  shows  on  its  surface  an  inner 
mantle  of  dull  red  light.  There  is  a  slight  tendency  for 
the  glass  to  show  a  greenish  fluorescence  near  the  kathode 
end.  In  the  seventh  tube  the  luminous  column  has  sub- 
sided into  a  few  greyish  white  nebulous  patches,  the  dark 
space  round  the  kathode  has  greatly  expanded,  and 
the  glass  of  the  tube  has  now  begun  to  show  a  yellow- 
green  fluorescence.  The  exhaustion  has  been  pushed  so 
that  only  about  i-5o,oooth  or  less  of  the  original  air  is 
present.  In  the  eighth  and  last  tube  only  one  or  two 
millionths  of  the  original  air  have  been  left,  with  the 
result  that  the  tube  now  offers  an  enormously  increased 
resistance  to  the  passage  of  the  discharge.  All  the  in- 
ternal flickering  nebulosities  have  vanished  ;  the  tube 
looks  as  though  there  were  no  residual  air  within.  But 
now  the  glass  itself  shines  with  a  fine  yellow'green 
fluorescence  which  is  particularly  bright  in  the  region 
around  the  kathode.  Were  the  exhaustion  to  be  carried 
much  further  the  spark  from  this  indudtion  coil  would  no 
longer  pass,  so  high  would  the  resistance  become.  All 
these  successive  stages  up  to  the  last  can  be  shown  in 
one  and  the  same  tube  attached  to  a  modern  rapid  air< 
pump.  But  for  the  proper  production  of  the  high  vacua 
of  the  last  stages,  where  eledtric  shadows  are  alone  pro- 
duced, nothing  short  of  a  mercurial  pump,  either  in  the 
form  invented  by  Sprengel  or  in  that  used  by  Geissler 
(or  one  of  the  recent  modifications)  will  suffice. 

The  phenomenon  of  fluorescence  of  the  glass,  which 
manifests  itself  when  the  exhaustion  has  become  suffi- 
ciently high,  was  known  in  a  general  way  as  far  back  as 
1869  or  1870.  The  tube  next  to  be  shown  is  a  modern 
reprodudlion  of  a  tube  used  at  that  time  by  Hittorf,  of 
Miinster.  It  differs  from  the  tubes  last  shown  by  having 
a  bend  in  it.  Hittorf  observed  that  when  such  a  tube  is 
exhausted  sufficiently  highly  to  give  at  the  kathode  the 
characteristic  greenish  yellow  fluorescence,  this  greenish 


I^BBIilCiL  NBWt,  1 

Feb.  26, 1897.     f 


Electric  Shadows  and  Luminescence, 


105 


yellow  fluorescence  refused  to  go  round  the  bend.  It 
might  appear  at  one  end  or  the  other,  according  to  the 
direiftion  in  which  the  discharge  was  being  sent,  but 
would  not  go  round  the  bend.  The  effedt  was  as  if  the 
discharge  went  in  straight  lines  from  the  bit  of  wire 
that  served  as  kathode  to  the  walls  of  the  tube.  Indeed 
shadow  effecas  were  observed  by  him,  and  by  Wright, 
of  Yale,  and  afterwards  independently  by  Crookes,  who 
greatly  extended  our  knowledge  of  the  fadls.  We  may 
take  this  fadt,  that  the  fluorescence  caused  by  the  kathode 
will  not  go  round  a  corner,  as  the  starting-point  of  the 
memorable  researches  of  Crookes  on  radiant  matter  a 
score  of  years  ago. 

Before  you  are  several  tubes  which  illustrate  the  re- 
searches made  by  Crookes.  The  first  is  a  simple  glass  bulb 
into  which  are  sealed  the  two  ele^rodes, — the  anode,  by 
which  the  current  enters,  terminating  in  a  bit  of  stout  alumi- 
nium wire ;  the  other,  by  which  the  current  leaves,  called 
the  kathode,  terminating  in  a  small  flat  aluminium  disk. 
The  glass  bulb  was  itself  highly  exhausted — how  highly 
we  shall  presently  see.  From  the  flat  front  surface  of  the 
kathode,  when  sparks  are  sent  through  the  bulb,  a  sort 
of  back-discharge  takes  place  in  a  diredtion  normal  to 
the  surface.  This  discharge,  which  only  occurs  at  a  very 
high  degree  of  exhaustion,  possesses  several  properties 
which  distinguish  it  from  all  other  kinds  of  discharge.  It 
is  propagated  in  straight  lines,  causes  a  brilliant  lumines- 
cence wherever  it  strikes  against  the  glass  walls  of  the 
tubes,  casting  shadows  of  intervening  objeds,  it  heats  the 
surface  on  which  it  impinges,  and  strikes  them  with  a 
distindt  mechanical  force.  Singular  to  relate,  it  is  also 
capable  of  being  defledled  by  a  magnet  as  though  it  were 
a  flexible  condudtor  carrying  the  current.  Struck  by  the 
singularity  of  these  kathode  rays  or  kathode  discharges, 
which  formed  the  subjedt  of  several  beautiful  researches, 


fadtion,  the  diredtion  of  these  kathode  rays  was  found  to 
be  independent  of  the  position  of  the  anode.  He  found 
kathode  rays  to  be  produced  even  when  no  internal 
ele&rodes  were  inserted,  and  when,  instead,  external 
patches  of  tinfoil  were  attached  to  the  glass.  Their  me- 
chanical adtion  he  studied  by  causing  them  to  impinge 
upon  the  vanes  of  a  pivoted  fly,  which  was  thereby  set 
into  rotation.  In  a  later  experiment  he  caused  the  fly  of 
a  *'  molecule  mill  "  to  be  set  into  rotation,  not  by  the  im- 
padt  of  the  kathodic  discharge,  but  by  the  kinetic  energy 
of  the  particles  returning  back  toward  the  anode  after 
they  had  impinged  against  the  walls  of  the  tube  and  lost 
their  negative  eledtric  charges.  A  mere  resume  of 
Crookes's  work  in  those  years  beginning  about  i86g  or 
1870,  and  extending  not  only  for  ten  years  adtively,  but 
going  on  at  intervals  until  a  year  or  two  ago,  would  of 
itself  fill  a  whole  course  of  ledtures.  Into  the  controversy 
which  has  arisen  between  Crookes  and  the  English 
physicists  on  the  one  hand,  and  the  German  physicists  on 
the  other,  there  is  no  need  to  enter.  SufSce  it  to  say 
that  while  the  German  physicists  mostly  rejedl  Crookes's 
hypothesis  of  radiant  matter,  and  regard  all  these  various 
phenomena  as  the  result  of  mere  wave-motions  within 
the  tube,  the  British  physicists,  including  Lord  Kelvin 
and  Sir  George  Stokes,  accept  Crookes's  view  of  the 
material  nature  of  the  kathode  rays.  Who,  indeed,  that 
has  seen  the  molecule  mill  at  work  can  doubt  that, 
whether  vibrations  are  present  or  not  (and  doubtless  there 
are  vibrations  present),  there  are  adtually  streams  of 
moving  particles  as  an  essential  feature  of  the  kathodic 
discharge  ?  For  the  moment  the  vidtory  undoubtedly 
rests  with  the  views  of  Crookes. 

But  of  all  these  phenomena  the  one  which  concerns  us 
most  is  that  of  the  produdtion  of  eledtrical  shadows. 
Eredting  in  the  path  of  the  kathode  rays  an  obstacle  cut 


Fig.  I. 


Crookes  advanced  the  hypothesis  that  they  consisted  of 
flights  of  negatively  eledlrified  particles  or  *'  radiant 
matter."  The  particles  he  sometimes  spoke  of  as  mole- 
cules, sometimes  as  dissociated  atoms,  or,  as  we  should 
now  say,  ions.  He  studied  the  wanderings  of  these  flying 
particles  by  inserting  within  the  bulb  at  different  points 
auxiliary  eledtrodes.  He  found  the  interior  of  the  bulb  to 
be  positively  eledlrified  in  all  parts  except  within  the  dark 
space  which  surrounds  the  kathode,  that  is  to  say,  except 
within  the  range  of  the  adlual  kathode  discharge.  The 
kathode  discharge  itself  was  found  to  be  possessed,  to  an 
extent  exceeding  any  other  known  agency,  of  the  power  of 
exciting  fluorescence  and  phosphorescence  in  minerals  and 
gems.  The  kathode  rays  were  themselves  discernible  as 
they  crossed  the  interior  of  the  tube.  In  such  a  bulb  the 
kathode  rays  would  form  a  blue  streak  impinging  straight 
upon  the  anode.  The  kathode  used  in  the  next  Crookes 
tube  is  of  a  concave  shape.  Crookes  found  that,  since 
the  kathode  rays  left  the  surface  normally,  the  result  of 
curving  the  kathode  was  to  focus  the  rays  toward  the 
centre  of  curvature.  By  so  focussing  the  rays  upon  a  bit 
of  platinum  foil,  it  was  found  possible  to  fuse  and  even 
melt  the  metal. 
Unlike  the  discharges  obtained  at  lower  stages  of  rare- 


Fia.  2. 


out  in  sheet  metal, — a  cross  of  thin  aluminium  is  the 
favourite  objedt, — a  shadow  of  it  is  observed  to  be  cast 
upon  the  wall  of  the  tube  behind  it ;  the  glass  phosphor- 
escing brilliantly  except  where  shielded  from  the  impadl 
of  the  kathode  rays,  so  that  the  shadow  comes  out  dark 
against  a  luminous  background.  Common  soda-glass 
gives  this  greenish  golden  tint,  while  lead-glass  exhibits 
a  blue  phosphorescence.  Not  glass  alone,  but  diamonds, 
rubies,  emeralds,  calc-spar,  and  other  earthy  materials, 
such  as  alumina,  and  notably  yttria,  produce  the  most 
brilliant  efledts  under  the  kathode  discharge,  some  of  them 
only  fluorescing  transiently,  others  with  a  persistent 
phosphorescence.  As  a  sample  is  shown  a  tube  in  which 
a  sea-shell,  slightly  calcined  to  remove  organic  matter,  is 
made  to  emit  a  brilliant  luminescence  under  the  impadt  of 
rays  from  a  kathode  placed  above  it.  The  shell  itself 
casts  a  shadow  against  the  lower  part  of  the  tube.  Some 
of  the  shadow  effedls  are  very  mysterious,  and  have 
recently  claimed  much  of  my  attention.  The  size  of  the 
kathodic  shadows  is  affedled  by  the  eledtrical  state  of  the 
objedl.  Eledtrifying  it  positively  makes  its  shadow  shrink 
to  smaller  dimensions.  Eledtrifying  it  negatively  causes 
a  singular  enlargement  of  the  shadow.  There  seems  to 
be  no  difference  between  the  shadow  of  a  metallic  body 


io6 


Animal  and  Vegetable  Fats  and  Otis. 


/  C^bhiCal  NbW», 
•     Feb.  26,  1897. 


^nd  that  of  a  non-metallic  body  of  the  same  size.  All 
bodies  cast  shadows,  however  thin.  Even  a  film  of  glass 
I- 10,000th  of  an  Inch  thick — so  thin  that  it  showed 
iridescence  like  a  soap-bubble — was  found  by  Crookes  to 
cast  its  shadow. 

Another  point  noticed  by  Crookes  was  that  if  the  ex- 
haustion is  carried  very  far,  and  the  tube  is  stimulated  by 
a  sufficiently  strong  electromotive  force,  the  phosphores- 
cence may  occur  at  points  not  in  the  line  of  discharge, 
but  round  a  corner.  Not  that  the  kathode  rays  turn  the 
corner,  however.  Apparently  some  of  the  more  quickly 
moving,  or  perhaps  more  highly  charged  particles, — atoms, 
molecules,  or  ions,  those,  in  fadt,  described  by  Crookes 
as  "  loose  and  erratic," — would  manage  to  get  round  the 
corners  and  produce  effe(Ss  of  a  more  or  less  diredtly 
kathodic  kind  in  places  where  they  could  not  have  pene- 
trated by  any  motion  in  a  straight  line. 

Here  (Fig.  i)  is  a  tube — a  variation  on  one  of  Hittorf's. 
having  two  branches  that  cross  one  another  at  right 
angles.  There  are  two  small  disks  of  aluminium  in  the 
bulbous  ends  to  serve  as  eledrodes.  When  either  of  these 
is  made  the  kathode,  the  whole  limb  in  which  it  is  situated 
fluoresces  brilliantly  of  a  golden-green  tint,  particularly 
at  the  distant  end.  But  the  other  limb  remains  dark,  save 
for  a  little  nebulous  blue  patch,  near  the  anode,  due  to 
residual  gas.  Another  tube  (Fig.  a)  is  made  as  a  zigzag, 
and  here  again  only  the  end  branch  shines.  On  reversing 
the  current  the  luminescence  shifts  to  the  other  end. 
But  when  the  tube  is  more  highly  exhausted,  the  phos- 
phorescence is  observed  not  only  in  the  end  branch  where 
the  kathode  is,  but  also  slightly  at  the  end  wall  of  each 
branch  of  the  zigzag.  Apparently  the  residual  gas  will 
ai5t  partly  as  its  own  kathode,  and  throw  off  something 
which  causes  the  glass  beyond  to  phosphoresce. 
(To  be  continued). 


NOTICES  OF  BOOKS. 


Chemistry  for  Engineers  and  Manufacturers.     A  Pra&ical 
Text-book.     By  Bertram   Blount,    F.I.C.,   F.C.S., 
Assoc.   Inst.   C.E.,  and  A.  G.  Bloxam,  F.I.C,  F.C.S. 
With  Illustrations.      Vol.  II.,  Chemistry  of  Manufac- 
turing Processes.      London :  Charles   Griffin   and    Co. 
(Ltd.).     1896.     8vo.,  pp.  484. 
This  volume  is  devoted  to  notices  of  the  sulphuric  acid 
manufadlure;  of  alkali  and  its  by-produdts  ;  of  destrudtive 
distillation,  including  the  gas-manufadture  ;  of  artificial 
manures,  petroleum,  lime,  and  cement ;  of  the  clay  in- 
dustries, and  glass,  sugar,  and  starch  ;  of  brewing  and 
distilling ;  oils,  resins,  and  varnishes,  soaps  and  candles, 
textiles   and  bleaching    colouring-matters,    dyeing    and 
printing  ;  of  paper  and  pasteboard,  pigments  and  paints, 
leather  glue  and  size,  explosives  and  matches  ;  and  of  the 
minor  chemical  manufa^ures. 

The  reader  will  be  surprised  at  finding  all  these  arts 
and  manufadlures— some  of  capital  importance — treated 
in  the  compass  of  437  pages  ;  but  the  authors  explain  in 
their  Preface  that  they  seek  to  expound  those  dominant 
principles  which,  they  allege,  "  are  too  often  hidden  be- 
neath masses  of  mere  detail,  and  are  consequently  apt 
to  be  overlooked  by  the  specialist  in  any  one  branch,  to 
his  detriment,  in  that  he  frequently  fails  to  apply  to  his 
own  work  principles  which  are  matters  of  common  know- 
ledge elsewhere." 

It  is  to  be  regretted  that  no  instances  are  given  of  this 
overlooking  which  so  frequently  happens.  According  to 
our  own  observation  the  specialist  eagerly,  and  even 
anxiously,  looks  about  for  principles  which  may  throw 
light  upon  his  own  department. 

The  bibliography  seems  to  us  somewhat  deficient ;  not 
a  few  important  works  on  different  departments  have  been 
overlooked. 


We  regret  to  find  that  the  authors  have  omitted  the 
opportunity  to  deal  a  blow  in  passing  at  the  recent  stulti- 
fication of  the  Methylated  Spirit  Adt.  If  the  Excise 
wished  to  render  methylated  spirit  absolutely  undrinkable, 
they  might  have  demanded  the  addition  to  the  spirit  of  a 
few  drops  of  Dippel's  animal  oil,  which  is  successfully 
used  in  Germany,  and  which  does  not  interfere  with 
industrial  uses. 

The  addition  of  dyes  and  mordants  to  sugar — an  in- 
creasing evil — should  be  carefully  looked  into. 

Mention  is  made  of  a  fraudulent  custom  in  the  pigment- 
trade,  pale  chrome-yellows  being  called  and  sold  as  pure 
when  let  down  with  lead  sulphate.  Hard  waters  for  the 
use  of  the  dyer  and  tissue-printer  are  rightly  objeAed  to ; 
if  a  hard  water  is  required  for  any  special  process,  it  is 
better  to  add  a  salt  of  lime  to  a  pure-water  supply. 

The  manufadture  of  artificial  silk  is  considered  as 
hitherto  not  a  commercial  success. 

In  the  matter  of  the  vinegar  manufadture,  it  may  be 
asked  why  sugar  at  its  present  prices  is  not  used  in  pre- 
ference to  malt,  save  for  domestic  manufadture  ?  No 
mention  is  made  here  of  date  vinegar,  which  is  coming 
into  use. 

This  work  will  be  found  useful  to  manufacturers  who, 
without  being  chemical  specialists,  wish  to  have  a  general 
insight  into  chemical  manufactures. 


A  Practical  Treatise  on  Animal  and  Vegetable  Fats  and 
Oils,   both   Fixed   and    Volatile ;    their    Physical   and 
Chemical  Properties  and  Uses,  the  Manner  of  Extradting 
and    Refining  them,  and  Pradtical   Rules   for  Testing 
them  —  as   the    Manufadture   of   Artificial    Butter,   of 
Lubricants,   &c.      With    Lists    of    American   Patents 
relating  to  the  Extradtion,  Rendering,  Refining,  Decom- 
posing, and  Bleaching  of  Fats  and  Oils.     By  William 
T.  Brannt,  Editor  of  the  "  Techno-chemical  Receipt- 
Book,"  "  Petroleum,"  &c.      Second  Edition,  Revised 
and   in   great   part   Re-written.     Illustrated   with   302 
Engravings.      In    Two  Volumes.       Vol.   I.,   pp.  528; 
Vol.  II.,  pp.  728.     Philadelphia :  H.  C.  Baird  and  Co. 
London :    Sampson   Low,   Marston,    and   Co.   (Ltd.). 
1896. 
Wb  have  here  an  encyclopaedia  of  the  animal  and  vege- 
table fats  and  oils  from  a  botanical,  chemical,  industrial, 
and  commercial  point   of  view.      The   analysis   of  oils, 
whether  for  identification  or  for  the  detedtion  of  frauds, 
presents  great  difficulties.     Numerous  processes,  physical 
and  chemical,  have  been  applied,  not  without  success. 
But  the  properties  of  oils  are  apt  to  be  modified  by  age, 
by  climate,  by  the  soils  of  their  native  countries,  so  that, 
especially  in  forensic  cases,  it  becomes  very  difficult  for 
the  expert  to  give  an  apodidtic  decision  as  to  the  genuine 
or  fraudulent  character  of  any  sample  in  question.     We 
have  here  a  most  elaborate  table  of  the  colour  readtion, 
with  a  mixture  of  sulphuric  and  nitric  acids,  with  potash 
and  soda  lye,  with  zinc  chloride,  with  hydrochloric  acid 
and  sugar.     Next  come  the  well-known  elaidin  test,  the 
thermal  test  of  Maumen^,  and  Fehling  test,  depending  on 
the  heat  liberated  on  mixing  fatty  oils  with  sulphuric  acid 
at  density  1*840;  Tomlinson's   cohesion   figures,  which 
require  the  outlay  of  much  time  before  trustworthy  results 
can  be  reached. 

Among  quantitative  methods  there  rank  the  determina- 
tion of  the  ester  number,  of  the  acid  number,  the  acid 
number  +  the  ester  number  being  the  Kottstorfer  saponi- 
fication number;  the  determination  of  the  fatty  acids 
insoluble  in  water  (Hehner's  number) ;  determination  of 
the  volatile  fatty  acids  (Reichert's  number) ;  the  iodine 
absorption  (Hiibl's  number).  The  determination  of  oxy- 
fatty  acids  gives  the  acetyl  number  of  Benedikt-Ulzer. 

In  determining  the  purity  of  an  oil,  the  author 
examines  firstly  the  argonoleptic  and  generally  the  phy- 
sical properties.  He  then  applies  the  qualitative  chemical 
methods,     and,    lastly,     the    quantitative    procedures. 


Cbkuical  Niwb,  I 
Feb.  36, 1897.     I 


Chemical  Notices  Jrom  Foreign  Sources, 


107 


among  which  Hiibl's  iodine  number  is  most  generally 
determined. 

A  table  shows  the  approximate  relative  commercial 
value,  and  hence  gives  a  key  to  the  oils  likely  to  be  used 
for  fraudulent  purposes. 

No  small  trouble  is  occasioned  in  commerce  by  the 
circumstance  that  the  seeds  of  the  three  species  of 
Brasiica,  which  yield  respedlively  colra,  rape,  and  rubsen 
oils,  cannot  be  decisively  distinguished  from  each  other, 
either  by  measurement  or  by  the  aid  of  the  microscope. 

The  presence  of  any  oil  of  this  group — the  products  of 
the  Cruet f era— m&y  be  detedled  by  boiling  the  oil  with 
white-lead  plaster  {Emplastrum  plutnbi).  The  oil  is  turned 
brown  or  black  by  the  formation  of  lead  sulphide. 

Sesame  oil  or  gingelly  oil  is  used  as  a  table  oil,  and  is 
esteemed  fully  equal  to  the  best  olive  oils.  It  is  a  curious 
(si£t  that,  though  the  seed  is  chiefly  grown  in  India,  yet 
the  oils  pressed  in  Europe  are  considered  superior  to  those 
pressed  at  home. 

Olive  oil,  in  consequence  of  its  high  price,  is  especially 
open  to  fraud.  Its  eledtric  condu^ivity  is  much  lower 
than  that  of  any  other  vegetable  oil.  Accordingly 
Palmieri  has  devised  an  apparatus — the  diaxometer — 
which  utilises  this  peculiarity.  This  instrument,  how- 
ever, is  expensive,  and  not  easy  of  manipulation.  More- 
over, leaving  sophistication  out  of  the  question,  olive  oils 
are  subject  to  spontaneous  alterations  which  render  the 
test  untrustworthy. 

The  spedtroscopic  examination  of  olive  oil  is  likewise 
not  trustworthy.  The  absorption  bands  observed  in  olive 
oil  are  not  due  to  the  oil  itself,  but  to  chlorophyll,  and  do 
not  occur  at  all  in  bleached  oils. 

M.  Brull6,  Diredtor  of  the  Agricultural  Station  at  Nice, 
has  devised  two  methods  of  testing  the  purity  of  olive 
oils,  showing  the  kind  and  quantity  of  other  oils  used  for 
their  sophistication. 

These  two  tests  we  shall  give  in  extenso  on  a  future 
occasion.  We  must  remember  that  dishonest  merchants 
and  manufafturers  now  consult  experts  who  are  them- 
selves unscrupulous,  or  who  are  carefully  kept  in  ignorance 
of  the  purposes  for  which  their  advice  is  required. 

We  shall  return  to  this  most  valuable  work  at  the 
earliest  opportunity. 


CORRESPONDENCE. 

HOW  SOON  SHALL  THE  STUDENT  BEGIN 
THE    STUDY    OF    QUALITATIVE    ANALYSIS  ? 

To  the  Editor  of  the  Chemical  News. 
Sir,— Mr.  Beebe's  article  in  your  last  issue  is  an  interest- 
ing one,  and  will  I  hope  bring  some  comment.  I  should 
think,  however,  that  few  teachers  would  agree  with  him, 
for  surely  qualitative  analysis  is  an  application  of  the 
science  and  not  the  science  itself.  The  great  diiSculty 
is  to  induce  pupils  to  think,  and  though  one  may  be  care- 
ful to  point  out  that  qualitative  analysis  is  really  a 
chemical  Euclid,  I  have  found  but  few  pupils  who  will 
work  through  their  analyses  according  to  the  syllogistic 
method  of  the  great  geometer.  The  attention  given  to 
schemes  of  analysis,  and  the  importance  given  to  the 
testing  of  powders  until  recently  by  the  Science  and  Art 
Department  have  done  much  to  take  away  the  educational 
value  of  chemistry  as  a  school  subject. 

As  regards  danger  in  making  the  common  gases,  these 
will  have  to  be  made  some  time,  and  if  it  is  pointed  out 
to  a  pupil  why  there  is  danger,  and  how  to  guard  against 
it,  no  mishap  is  likely  to  occur,  even  should  that 
"  dangerous  gas  "  hydrogen  be  the  subjedt  of  the  lesson. 
— I  am,  &c., 

....  C.  J.  Woodward. 

Municipal  Technical  Schools, 

Birmingham,  Feb.  aoth,  1897. 


CHEMICAL 


NOTICES   FROM 
SOURCES. 


FOREIGN 


NoTB. — All  degrees  of  temperature  are  Centigrade  unlets  otherwise 

expressed. 

Comptes  Rendus  Hebdomadaires  des  Seances,  deV Academic 
des  Sciences.     Vol.  cxxiv.,  No.  4,  January  25,   1897. 

A  medal  was  presented  to  M.  Faye  on  the  occasion  of 
the  50th  anniversary  of  his  nomination  as  a  Member  of 
the  Academy  of  Sciences.  M.  Faye  made  a  suitable 
reply. 

Fluorescence  of  Vitrified  Matters  under  the  A(5tion 
of  Rontgen's  Rays.  —  M.  jBagiquet.  —  The  following 
phenomena  have,  I  believe,  not  been  hitherto  signalised. 
The  substances  mentioned  below  become  luminous  under 
the  influence  of  the  X  rays,  in  the  following  decreasing 
order: — Baked  enamels ;  crown  glass ;  flint-glass ;  ordinary 
glass,  and  especially  the  kind  known  as  crystal ;  sheet-glass 
from  the  works  of  Saint-Gobain  ;  porcelain  enamelled 
faience;  enamel  powder  before  baking;  and  even  cut 
diamond.  We  know,  also,  that  most  of  these  substances 
are  fluorescent  in  the  violet  and  the  ultra-violet  rays.  It 
is  therefore  possible  to  form  with  these  substances 
fluorescent  screens  which  enable  us  to  repeat  radioscopic 
experiments  with  this  advantage,  that  the  vitrified  sub- 
stances  just  mentioned  may  be  worked  optically.  The 
images  obtained  are  more  definite,  though  less  brilliant, 
than  are  those  with  crystals  cemented  upon  card  hitherto 
employed.  We  utilise  also  successfully  these  substances 
for  shortening  the  exposure  in  radiographic  experiments, 
and  we  have  not  to  fear  the  granular  spots  produced  by 
the  crystals  above  mentioned.  Does  this  fluorescence  of 
glass  not  explain  the  disputed  fadl  that  persons  affeded 
with  cataradt  see  the  X  rays  ?  In  fadt,  if  we  place  our- 
selves  in  the  field  of  emission  of  a  Crookestube,  furnished 
with  thick  spedlacles  with  convex  glasses,  we  experience 
the  sensation  of  a  light  like  that  of  phosphorus.  This 
sensation  is  the  result  of  the  fluorescence  of  the  glass, 
which  forms  before  the  eyes  a  luminous  mist  easily  recog- 
nised by  persons  surrounding  the  patient.  Besides  the 
scientific  applications  there  are  an  entire  series  of  very 
beautiful  experiments,  which  I  am  about  classifying  with 
a  view  to  early  publication. 

Adtion  of  Carbon  Dioxide  and  Monoxide  upon 
Aluminium.  —  MM.  QuntJ!  and  Masson.  —  This  paper 
will  be  inserted  in  full. 

Spedlra  of  the  Non-metals  in  Fused  Salts  — 
Silicon.  —  A.  de  Gramont.  —  This  paper  will  be  inserted 
in  full. 

On  Chromium  and  Manganese  Phosphides. — A. 
Granger. — Already  inserted. 

Influence  of  Temperature  on  Rotatory  Power. — 
Ph.  A.  Guye  and  Mile.  E.  Aston. — In  all  we  know  at  least 
fifty  adtive  liquids  whose  rotatory  power  decreases  with 
the  elevation  of  temperature  in  the  entire  interval  of  the 
experiments. 

On  Two  Isomeric  Trietbylene-dipbenyl  Hydra- 
zines, a  and  /3. — In  presence  of  hyposulphites  the  adlion 
of  aldehyd  or  phenylhydrazine  yields  the  isomer  a 
almost  pure.  In  neutral  solutions  aldehyd  adting  upon 
phenylhydrazine  phosphate  produces  chiefly  the 
isomer  ^. 

On  a  High  Homologue  of  Urea.  —  Oechsner  de 
Koninck. — It  seems  very  admissible  that  in  proportion  as 
the  oxidising  power  of  the  system  is  weakened,  the 
number  of  the  atoms  of  carbon  of  the  quaternary  com- 
pounds eliminated  by  the  kidneys  increases  progressively. 


Contribution  to  the  Study  of  the  Adtion  of  Zinc 
upon  Red  Wines. — L.  A.  Lovat. — Zinc  denaturates  red 
wines  and  renders  them  poisonous.  Hence  the  use  of  this 
metal  should  be  severely  forbidden  in  the  cock  for  casks, 
vats,  &c. — Comptes  Rendus,  cxxiv.,  No.  5. 


108 


Meetings  for  the  Week, 


rCHBUICAt  NBWS, 

I     Feb.  a6,  X897. 


NOTES    AND    QUERIES. 

%♦  Our  Notes  and  Queries  column  was  opened  for  the  purpose  of 
giving  and  obtaining  information  likely  to  be  of  use  to  our  readers 
generally.  We  cannot  undertake  to  let  this  column  be  the  means 
of  transmitting  merely  private  information,  or  such  trade  notices 
as  should  legitimately  come  in  the  advertisement  columns. 

Waterproofing  Canvas. — I  should  like  to  know  a  good  receipt 
for  chemically  rendering  canvas,  &c.,  waterproof,  ours  being  a  very 
old  and  almost  obsolete  method.— Weekly  Reader, 


MEETINGS    FOR    THE    WEEK. 


Monday,  March  ist.— Society  of  Arts,  8.  (Cantor  Leftures).  "In- 
dustrial Uses  of  Cellulose,"  by  C.  F.  Cross, 
F.C.S. 

Society  of  Chemical  Industry,  8.     "  Relation 

of  Colour  to  Quality  in  Malt,"  by  J.  W.  Lovi- 
bond.  "  Hehner's  Bromine  Tests  for  Oils," 
by  J.  H.B.  Jenkins.  "Analysis  of  Super- 
phosphates," by  J.  H.  Coste. 
Tuesday,  2nd.— Royal  Institution,  3.  "Animal  Eleftricity,"  by 
Prof.  A.  D.  Waller,  F.R.S. 

Society  of  Arts,  8.    "  Gesso,"  by  Matthew  Webb. 

Wednesday,  3rd.— Society  of  Arts,  8.  "  English  Orchards,"  by  Geo. 

Gordon. 

Society  of  Public  Analysts,  8.     "  The  Composi- 

tion of  Milk  and  Milk  Produfts,"  by  H.  Droop 
Richmond.  "Estimation  of  Milk  Sugar  in 
Milk  "and  "Detection  of  Mixtures  of  Diluted 
Condensed  or  Sterilised  Milk  with  Fresh 
Milk,"  by  H.  Droop  Richmond  and  L.  K. 
Boseley.  "  Constitution  of  Milk,"  by  H.  Droop 
Richmond.  "  Copper  in  Peas,"  by  R.  Bodmer 
and  C.  G.  Moor,  M.A.  "  Coffee  Palace  Coffee 
Infusions,"  by  E.  G.  Clayton. 
Thursday,  4th.— Royal  Institution,  3.    "  Greek  History  and  Extant 

Monuments,"  by  Prof.  Percy  Gardner,  F.S.A. 
— -  Society  of  Arts,  8.  ■    "  The  Mechanical  ProduAion 

of  Cold,"  by  Prof.  James  A.  Ewing,  M.A.,  F.R.S. 

-  Chemical,  8.  Ballot  for  Election  of  Fellows.  "Some 

Hydrocarbons  from  American  Petroleum  —  I. 
Normal  and  Iso-Pentane,"  by  Sydney  Young, 
F.R.S.,  and  G.  L.  Thomas,  B.Sc.  "  The  Vapour 
Pressures,  Specific  Volumes,  and  Critical  Con- 
stants of  Normal  Pentane,  with  a  Note  on  the 
Critical  Point,"  by  Sydney  Young,  F.R.S.  "On 
the  Freezing-point  Curves  of  Alloys  containing 
Zinc,"  by  C.  T.  Heycock,  F.R.S.,  and  F.  H. 
Neville.  "  The  Oxides  of  Cobalt  and  the  Co- 
baltites,"  by  A.  H.  McConnell  and  E.  S.  Hanes. 

Friday,  5th.— Royal  Institution,  9.  "  Some  Curiosities  of  Vision," 
by  Shelford  Bidwell,  F.R.S. 

Saturday,  6th.— Royal  Institution,  3.  "  Eleftricity  and  Electrical 
Vibrations,"  by  Right  Hon.  Lord  Rayleigb,  M.A., 
F.R.S. 


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CHBUICAL  N  BW8, 

March  5,  1807.     I 


Determination  of  Sulphur  in  Irons, 


109 


THE    CHEMICAL     NEWS. 


Vol.  LXXV.,  No.  1945. 


THE     AGE     OF     COPPER     IN     CHALDEA. 
By  M.  BERTHELOT. 


The  discoveries  made  some  years  ago  by  M.  de  Sarzee, 
at  Tello  in  Chaldea,  have  brought  to  our  knowledge  monu- 
ments of  a  high  antiquity,  extending  back  to  the  origin 
of  civilisation,  5000  or  6000  years  ago.  They  have  fur- 
nished weapons,  ornaments,  and  tools  which  throw  a  new 
light  on  the  origin  of  the  industry  of  metals.  Such  are 
the  objedts  deposited  at  the  Louvre,  which  our  colleague, 
M.  Heuzey,  has  kindly  referred  to  my  examination.  We 
find  here  the  first  and  most  ancient  monuments  belonging 
to  the  age  of  copper.  . 

I.  I  have  analysed  a  colossal  lance  or  blade  showing 
various  designs  and  inscriptions,  with  the  name  of  a  king 
of  Kish  which  goes  back  to  an  epoch  anterior  to  Our- 
Nina,  i.  e.,  about  4000  years  before  our  era.  This  lance 
has  not  been  devoted  to  pradical  service,  but  has  a 
hieratic  charader,  having  been  consecrated  to  some  deity. 
It  is  formed  of  a  red  metal,  being  strongly  attacked  in 
some  parts  and  changed  into  a  greenish  paste. 

The  filings  of  the  metal  consist  of  copper  approximately 
pure,  and  I  have  found  in  it  no  tin,  zinc,  arsenic,  or  anti- 
mony in  any  appreciable  amount. 

The  oxidised  portion  consists  of  hydrated  copper  oxy- 
chloride  (atacamite)  free  from  carbonate.  There  was 
found  in  it  neither  arsenic,  antimony,  tin,  or  zinc,  but  a 
trace  of  lead.  This  substance,  after  drying  in  the  stove, 
contained  CI  =  ig'S, 

This  oxychloride  results  from  the  adion  of  the  brackish 
waters  of  the  soil  in  the  midst  of  which  the  blade  has 
been  lying  for  so  many  centuries.  When  once  the  objed 
is  brought  in  contadl  with  the  air,  tlie  presence  of  the 
alkaline  chlorides  and  atacamite  threaten  a  total  dis- 
aggregation in  consequence  of  its  progressive  conversion 
into  super-copper  oxide.  This  aggregation  results  from 
a  certain  series  of  readtions,  set  up  by  a  small  quantity  of 
sodium  chloride  with  the  intermediation  of  atacamite, 
which  I  have  defined  by  diredt  experiment  (Annales  de 
Chimie  et  Physique,  Series  7,  vol.  iv.,  p.  552).  Most  of 
the  statues  of  copper  found  in  the  same  excavations  are 
undergoing  this  same  decomposition  at  the  Museum. 
They  are  wrongly  labelled  "  Objects  of  Bronze,"  as  they 
consist  of  pure  copper. 

2.  Hatchet  with  a  socket  formed  of  red  metal.  Broken 
fragments  coated  with  a  greenish  patina.  A  similar  in- 
strument is  represented  in  the  hands  of  Chaldean 
personages  on  the  monuments  from  the  epoch  of  Our- 
Nina  to  that  of  Goudea,  that  is,  from  the  year  4000  to 
the  year  3000  before  our  era. 

The  fragments  which  I  have  analysed  consist  essentially 
of  metallic  copper  associated  with  a  little  cupric  oxide. 
No  tin,  lead,  zinc,  arsenic,  or  antimony.  The  hatchet 
has  therefore  not  been  formed  of  bronze,  but  of  copper 
sensibly  pure. 

3.  Entire  hatchet,  red,  with  a  sharp  edge,  horizontal 
and  socketed.  It  has  been  found  with  its  handle  below 
the  ancient  construdlion  of  the  king  Our-Nina.  M. 
Heuzey  regards  it  as  perhaps  the  most  ancient  relic  met 
with  in  these  excavations.  The  metal  is  hard,  of  pure 
copper,  free  from  tin,  lead,  or  zinc,  but  contains  traces  of 
arsenic  and  phosphorus.  It  seems  to  have  been  hardened 
by  the  concourse  of  these  latter  elements.  But  we  do 
not  possess  the  ores  which  have  served  in  the  manufadture 
of  the  Chaldean  objedts,  and  we  cannot  assert,  as  is  the 
case  of  the  specimens  from  Sinai,  that  the  presence  of 
arsenic  is  due  to  the  addition  of  some  substance  foreign 


to  the  copper  ore  properly  so  called.  In  any  case  I  must 
here  repeat  that  we  have  to  do  with  copper,  and  not 
bronze,  as  the  Chaldean  tools,  &c.,  contain  no  tin. 

4.  Egg-shaped  article,  of  a  metallic  aspedt,  weighing 
121  grms.,  found  along  with  the  Chaldean  remains.  The 
filings  consisted  of  iron  partially  oxidised,  without  arsenic, 
zinc,  or  alumina. 

5.  Ingot  and  filings  (ancient)  of  a  white  metal, 
found  with  the  Chaldean  remains  in  an  urn  of  coarse 
pottery.  The  filings  of  the  ingot  contain  : — Silver,  gyi\ 
copper,  a  small  quantity  ;  notable  patina  ;  no  lead. 

6.  Leaf  of  yellow  gold,  of  Chaldean  or  Assyrian 
origin.  This  gold  contains  neither  copper,  lead,  nor  iron 
in  sensible  proportion.  It  contains  a  considerable  quan- 
tity of  silver,  which  the  minimal  weight  of  the  sample  at 
my  disposal  did  not  permit  me  to  determine  with  pre- 
cision. In  this  and  other  cases  it  is  always  the  antique 
alloy  of  gold  and  silver  known  under  the  name  of  asem. 
The  manner  of  purifying  native  gold  was  not  well  under- 
stood  in  Egypt  and  Chaldea  in, those  remote  ages. 

The  existence  of  successive  degrees  in  the  use  of  the 
purification  of  the  metals,  both  common  and  precious, 
appears  from  these  analyses.  In  particular,  the  use  of 
pure  copper  for  arms  and  tools  was  common  in  Chaldea 
about  the  year  4000  B.C.  It  preceded  the  use  of  bronze, 
t.  e.,  copper  alloyed  with  tin,  which  is  found  in  later 
articles  both  in  Egypt  and  Chaldea.  We  may  even  add 
that  the  form  of  hatchets  with  handles,  the  processes  of 
moulding  and  manufadture,  and  even  the  practical  uses  to 
which  the  tools  were  destined,  have  been  the  same  both 
for  the  pure  hatchets  of  copper  in  Chaldea  and  for  the 
prehistoric   hatchets   of    Europe    and   Siberia. — Comptes 


Rendus,  cxxiv.,  p.  328. 


CARBIDE     OF     CALCIUM. 

In  consequence  of  the  growing  importance  of  carbide  of 
calcium,  and  the  fadt  that  the  mere  contadt  of  moisture 
with  this  material  causes  a  dangerous  evolution  of  the 
highly  inflammable  gas  known  as  Acetylene,  the  Home 
Secretary  has  caused  inquiries  to  be  made  into  the  sub- 
jedt,  with  the  result  that  an  Order  in  Council  has  to-day 
been  made  under  the  14th  Sedtion  of  the  "  Petroleum 
Adt,  1871,"  bringing  carbide  of  calcium  within  the  opera- 
tion of  that  Adt. 

Accordingly,  from  the  date  on  which  such  Order  comes 
into  force,  viz.,  ist  April,  1897,  >^  ^'''  ^^  unlawful  to  keep 
carbide  of  calcium  except  in  virtue   of  a  license  to 
obtained  from  the  Local  Authority  under  the 
Adt." 

Any  Local  Authority  to  whom  application  maybe  made 
for  a  license  to  keep  carbide  of  calcium  can,  if  it  so  de- 
sires, obtain,  on  application  to  the  Home  Office,  a 
Memorandum  showing  the  charadler  of  the  risks  to  be 
guarded  against,  and  containing  suggestions  as  to  the 
nature  of  the  precautions  likely  to  be  most  effedtual  for 
securing  safety. 
Whitehall,  26th  February,  1897. 


be 
Petroleum 


DETERMINATION    OF    SULPHUR    IN    IRONS. 
By  OTTO  HERTINQ. 

In  the  laboratories  of  many  iron  works  it  is  customary  to  . 
be  content  with  Wiborgh's  method  (colorimetric),  as  the 
determination  by  the  bromine  method  is  tedious,  and  very 
unpleasant  where  the  ventilation  arrangements  are  impar- 
fed.  I  will  by  no  means  deny  the  value  of  the  colori- 
metric method,  but  wish  to  point  out  that  the  results  are 
frequently  very  inaccurate,  owing  to  imperfedtly  con- 
struded  apparatus  or  to  escapes  at  the  joints.  The  latter 


no 


Report  of  Committee  on  A  tomic  Weights. 


i  CHKItlCAL  NbW 

I    March  s,  1897. 


we  may  best  deted  by  means  of  nitro-prusside  papers. 
A  disadvantage  in  Wiborgh's  method  which  cannot  be 
overlooked  is,  that  we  are  compelled  to  use  a  very  small 
quantity  of  material  (0*2  to  at  most  o*8  grm.)  of  borings, 
which  is  far  too  small  a  quantity.  The  most  expeditious 
quantitative  method  which  yields  perfedlly  satisfadory 
results,  is,  in  my  opinion,  the  following,  which  E.  F. 
Wood  (of  the  Homestead  Steel  Works)  publishes  briefly 
in  Blair's  "Analysis  of  Iron"  p.  71 : — 5  or  10  grms.  of 
borings  are  treated  with  hydrochloric  acid ;  the  hydrogen 
sulphide  evolved  is  condudled  into  an  ammoniacal  cad- 
mium salt  (acetate  or  chloride) ;  the  cadmium  sulphide  is 
colleAed  on  a  small  filter,  shaken  out  with  cold  water  in 
an  Erlenmeyer  flask,  mixed  with  «/20  solution  of  iodine 
in  excess,  which  is  then  titrated  back  with  a  corresponding 
solution  of  thiosulphate.  The  entire  operation  can  be 
completed  in  one  hour. 

About  two  years  ago  Prof,  de  Koninck  proposed  to  de- 
termine sulphur  in  irons,  adding  a  small  quantity  of 
stannous  chloride  to  the  hydrochloric  solution  to  prevent 
the  formation  of  ferric  chloride.  I  am  now  of  De 
Koninck's  opinion,  that  the  oxygen  of  the  air  in  i  litre 
does  not  readl  so  quickly  upon  hydrogen  sulphide  as  to 
occasion  a  separation  of  sulphur  which  might  thus  escape 
determination.  Hence  it  is  not  necessary  to  expel  the  air 
of  the  flask  by  the  introdudlion  of  a  current  of  hydrogen 
or  carbon  dioxide.— CAemJ^^r  Zeitung,  Feb.  6. 


THIRD    ANNUAL     REPORT    OF    COMMITTEE 

ON     ATOMIC     WEIGHTS. 

RESULTS     PUBLISHED     DURING    1895.* 

By  F.  W.  CLARKE. 

(Concluded  from  p.  loi). 

Helium  and  Argon. — The  true  atomic  weights  of  these 
remarkable  gases  are  still  in  doubt,  and  so  far  can  only 
be  inferred  from  their  speciflc  gravities.  For  argon,  the 
discoverers,  Rayleigh  and  Ramsay  (P/»7.  Trans.,  clxxxvu, 
220 — 223)  give  various  determinations  of  density,  ranging 
H  =  i)  from  19*48  to  20-6.  The  value  I9'9  they  regard 
as  approximately  corredt. 

For  helium,  Ramsay  {yourn.  Chem.  Soc,  iii.,  684)  gives 
the  density  218,  while  Langlet  {Ztschr.  Anorg.  Chem., 
x.,  289)  finds  the  somewhat  lower  value  2  00. 

From  one  set  of  physical  data  both  gases  appear  to  be 
monatomic,  but  from  other  considerations  they  are  sup- 
posably  diatomic.  Upon  this  question,  controversy  has 
been  most  adtive,  and  no  final  settlement  has  yet  been 
reached.  If  diatomic,  argon  and  helium  have  approxi- 
mately the  atomic  weights  2  and  20  respedively ;  if  mon- 
atomic, these  values  must  be  doubled.  In  either  case 
helium  is  an  element  lying  between  hydrogen  and 
lithium  ;  but  argon  is  most  difficult  to  classify.  With 
the  atomic  weight  20,  argon  fills  in  the  eighth  column  of 
the  periodic  system,  between  fluorine  and  sodium  ;  but  if 
it  is  40,  the  position  of  the  gas  is  anomalous.  A  slightly 
lower  value  would  place  it  between  chlorine  and  potas- 
sium, and  again  in  the  eighth  column  of  Mendeleeff's 
table,  but  for  the  number  40  no  opening  can  be  found. 

It  must  be  noted  that  neither  gas,  so  far,  has  been 
proved  to  be  absolutely  homogeneous  ;  and  it  is  quite 
possible  that  both  may  contain  admixtures  of  other  things. 
This  consideration  has  been  repeatedly  urged  by  various 
writers.  If  argon  is  monatomic,  a  small  impurity  of 
greater  density,  say  of  a  unknown  element  falling  between 
bromine  and  rubidium,  would  account  for  the  abnormality 
of  its  atomic  weight,  and  tend  towards  the  reduction  of 
the  latter.  If  the  element  is  diatomic,  its  classification  is 
easy  enough  on  the  basis  of  existing  data.  Its  resemblance 


♦  Read  at  the  Cleveland  Meeting,  December  31, 1895. 
Journal  of  the  American  Chemical  Society,  xviii.,  No.  3. 


From  the 


H  =  1. 

Aluminum 26*91 

Antimony 119*52 

Argon ? 

Arsenic      74"52 

Barium       136-40 

Bismuth 206*54 

Boron 10*86 

Bromine 79"34 

Cadmium iii'oS 

Caesium      131*89 

Calcium 3978 

Carbon       11*92 

Cerium       ..      ..      ..  1391 

Chlorine 35°  18 

Chromium 5i'74 

Cobalt        58*49 

Columbium        ..     ..  93*3 

Copper        63*12 

Erbium       165*0 

Fluorine 1889 

Gadolinium       ..      ..  154*9 

Gallium     68*5 

Germanium      ..      ..  71*75 

Glucinum 901 

Gold 19574 

Helium      ? 

Hydrogen 1*00 

Indium       112*8 

Iodine        125*89 

Iridium       191-66 

Iron 55'6o 

Lanthanum       ..      ..  137*6 

Lead 205*36 

Lithium      697 

Magnesium       ..     ..  24-11 

Manganese        ..     ..  54*57 

Mercury 198*5 

Molybdenum     .,      ..  9526 

Neodymium       ..      ..  139*4 

Nickel        58*24 

Nitrogen i3*94 

Osmium 189*55 

Oxygen      15879 

Palladium 105*56 

Phosphorus       . .      . .  30  79 

Platinum i93'4i 

Potassium 38*82 

Praseodymium..      ..  i42'4 

Rhodium 10223 

Rubidium 84*78 

Ruthenium        ..      ..  100*91 

Samarium 148*9 

Scandium 437 

Selenium 78*4 

Silicon        28*18 

Silver 107*11 

Sodium      2288 

Strontium 8695 

Sulphur      3183 

Tantalum i8i*2 

Tellurium 126*1? 

Terbium 1588 

Thallium 20260 

Thorium 230*87 

Thulium 169-4 

Tin 118-15 

Titanium 47  79 

Tungsten 183*44 

Uranium 237*77 

Vanadium          ..      ..  50*99 

Ytterbium 171*7 

Yttrium      88*28 

Zinc 64*91 

Zirconium 89*9 


O  =  16. 

27*11 

i2o*43 

? 

75  09 
13743 
20811 

10*95 

7995 

111-93 

132  89 

40*08 

12*01 

140*2 

35*45 

52  14 

58-93 

94-0 

63-60 

166-3 

1903 

156*1 

69*0 

723 

908 
197-24 

? 

1008 

"37 
126*85 
193*12 
56*02 
1386 
206-92 

703 
24-29 

5499 

200*O 
95-98 

140*5 
5869 
1404 

190-99 
16*00 

10636 
31  02 

194*89 

39*" 
143-5 
103  01 

85-43 
IOI-68 
150*0 
44*0 
790 
28  40 
107*92 
23-05 
87-61 
32-07 
182*6 
1270  ? 
160*0 
204*15 
232*63 
170-7 
119*05 

48-15 
184-84 

239-59 

51*38 
173*0 

88*95 

65*41 

90 -6 


CHbhical  I<bws, 
March  5,  1897.    1 


Electric  Shadows  and  Luminescence* 


lit 


to  nitrogen,  as  regards  density,  boiling-point,  difficulty  of 
liquefa&ion,  &c.,  lead  me  personally  to  favour  the  lower 
figure  for  its  atomic  weight,  and  the  same  considerations 
may  apply  to  helium  also.  Until  further  evidence  is 
furnished,  therefdre,  I  shall  assume  the  values  2  and  20 
as  approximately  true  for  the  atomic  weight  of  helium 
and  argon. 

Carbon. — Wanklyn  (Chem.  News,  Ixxii.,  164  ;  see  also 
Phil.  Mag.,  August,  1895  »  ^'so  the  reports  of  this  com- 
mittee for  1893  and  1894),  on  the  basis  of  his  investiga- 
tions into  the  composition  of  hydrocarbons,  reiterates  his 
belief  that  the  atomic  weight  of  carbon  is  not  12  but  6. 
This  question  is  one  which  falls  rather  outside  the  scope 
of  this  report  and  needs  no  further  discussion  here.  If 
Wanklyn's  contention  is  sustained,  the  value  assigned  to 
carbon  in  the  table  accompanying  this  paper  should  be 
divided  by  two. 

In  the  accompanying  table  of  atomic  weights,  the  values 
are  given  according  to  both  standards,  H=3i  and  0  =  i6. 
Many  of  the  figures  are  the  results  of  new  and  complete 
re-calculation  from  all  available  data,  made  in  the  pre- 
paration of  a  new  edition  of  my  "  Re-calculation  of  the 
Atomic  Weights." 


ELECTRIC    SHADOWS  AND    LUMINESCENCE.* 

By  Prof.  SILVANUS  P.  THOMPSON,  D.Sc,  F.R.8.,  M.R.I. 

(Continued  from  p,  106), 

And  now  let  me  remark  that  not  one  of  all  the  tubes 
shown  since  the  first  one  is  capable  of  showing  a  shadow 
upon  the  fluorescent  screen  outside,  or  of  taking  a  photo- 
graph through  a  sheet  of  aluminium.  Even  the  brilliant  tube 
which  showed  so  excellently  the  shadow  of  the  cross,  fails 
to  show  any  result  after  hours  of  vain  waiting.  It  yields 
no  rays  that  will  penetrate  aluminium.  For  experiments 
with  Rontgen  rays  it  is  absolutely  necessary  that  the 
process  of  exhaustion  should  be  carried  beyond  the 
stage  that  suffices  for  the  produdtion  of  kathode  shadows  ; 
it  must  be  pushed  to  about  that  limit  which  Crookes  him- 
self described  as  his  unit  for  the  degreee  of  vacuum, 
namely,  one-millionth  of  an  atmosphere.  I  do  not  say 
that  with  long  exposures  photographs  cannot  be  taken 
when  the  degree  of  exhaustion  is  lower.  Something  de- 
pends, too,  upon  the  degree  to  which  the  eledlric  discharge 
is  stimulated,  and  something  also  depends  upon  the  shape 
and  structure  of  the  tube  and  upon  the  size  and  shape  of 
the  kathode.  But  on  none  of  these  things  does  the 
emission  of  X-rays  depend  so  much  as  upon  the  degree 
of  vacuum.  The  highly  exhausted  vacuum  is  the  one  real 
essential. 

So  soon  as  Crookes's  researches  upon  eledtric  shadows 
had  become  known,  eledtricians  set  to  work  to  try  to  pro- 
duce eleiftric  shadows  in  ordinary  air  without  any  vacuum. 
One  of  the  ablest  of  experimenters.  Prof.  W.  Holtz,  was 
successful,  using  as  a  source  of  eledtric  discharge  the 
eledlrified  wind  which  is  given  off  by  a  metal  point 
attached  to  the  pole  of  an  influence  machine.  If  in  a 
perfectly  dark  room  such  a  point  is  placed  opposite  and  at 
a  few  inches  from  a  wooden  disc  covered  with  white  silk 
and  connected  at  its  back  or  edges  to  the  other  pole  of  the 
machine,  it  will  be  observed  to  show  a  pale  luminosity 
over  a  circular  patch  where  it  is  struck  by  the  eledtric 
wind.  If  then  the  objedl  is  brought  between  the  disc  and 
the  point  a  shadow  will  be  observed  to  be  cast  upon  the 
white  surface.  Non-condudlors  do  not  cast  shadows  as 
well  as  condudtors  do.  A  piece  of  thin  mica  scarcely 
casts  a  shadow  at  all  until  it  is  moistened.  Double 
shadows  can  be  got  by  using  two  disks  covered  with  silk 
facing  one  another ;  any  condudting  objedt  introduced 
between  them  casts  a  shadow  on  both.    If  such  a  shadow 


•  A  Ledture  delivered  at  the  Royal   Institution  of  Great  Britain. 
Friday,  May  8,  i8g6. 


from  an  eledlrified  point  is  cast  downward  upon  a  sheet  of 
ebonite  or  pitch,  the  parts  not  shaded  are  found  after- 
wards to  remain  eledlrified,  and  can  be  discovered  by 
scattering  over  them  Lichtenberg's  mixed  powders  of  red- 
lead  and  lycopodium,  thus  perpetuating  the  shadow. 

But  now  it  is  possible  to  produce  eledlric  shadows  in 
another  way,  photograpically,  as  has  been  known  for 
some  years  {Proc.  Phys.  Soc.  Land.,  xi.,  353,  1892),  from 
metal  objedls  such  as  coins,  by  simply  laying  them  down 
upon  a  photographic  dry-plate  (a  gelatino-bromide  plate) 
and  sending  an  eledlric  spark  (from  an  indudlion-coil) 
into  them. 

Fig.  3  shows  the  arrangement  adopted  by  the  Rev.  F. 
J.  Smith,  who  is  kind  enough  to  exhibit  in  the  library  to- 
night some  scores  of  his  beautiful  "  indudloscript  "  photo- 
graphs. Upon  the  screen  I  throw  a  few  samples,  in- 
eluding  a  print  of  one  of  the  Jubilee  coins  (Fig.  4). 
These  curious  photographs  are  produed  simply  by  the 
chemical  adlion  of  the  eledlric  discharges  which  stream 
off  from  all  the  projedling  portions,  and  so  roughly  repro- 
duce an  image  of  the  coin.  Since  Rdntgen's  discovery 
many  persons  have  announced  their  supposed  discovery 
of  the  produdlion  of  eledlric  shadow-pidlures  without  the 
aid  of  a  Crookes  tube.  What  they  have  really  observed 
is,  however,  totally  different.  They  have  not  been  pro- 
ducing X-rays  at  all,  but  have  merely  re-discovered  these 
indudloscript  shadows. 

Between  the  researches  of  Crookes,  however,  and  those 
of  Rontgen,  there  came  in  a  very  remarkable  body  of 
researches  in  Germany.  I  have  but  to  name  Goldstein, 
Puluj,  Hertz,  Wiedemann,  and  Lenard  (See  Note), 
amongst  the  workers,  to  show  what  interest  has  been 
concentrated  on  the  subjedl.  Hertz,  whose  loss  Science 
has  not  ceased  to  lament,  observed  that  a  part  at  least  of 
the  kathode  rays  were  capable  of  passing  through  thin 
aluminium  sheet,  a  property  which  confirmed  him  in  his 
previous  doubt  as  to  the  material  nature  of  the  kathodic 
discharge.  His  pupil,  Philipp  Lenard,  now  Prof.  Lenard, 
of  Aachen,  took  up  the  point.  He  fitted  up  a  tube  with  a 
small  window  of  aluminium  foil  opposite  the  kathode,  its 
form  being  that  shown  in  Fig.  5.  The  kathode  was  a  flat 
disk  on  the  end  of  a  glass  covered  wire  stem.  The  anode 
was  a  cylindrical  tube  of  brass  surrounding  the  kathode. 
Upon  the  further  end  of  the  tube  a  brass  cap  was  fixed 
by  means  of  vacuum-tight  cement.  Over  a  small  orifice 
in  this  brass  cap  was  set  the  aluminium  window  of  foil 
only  i-4ooth  m.m.  thick.  By  this  means  he  was  able  to 
do  what  had  previously  been  supposed  impossible — bring 
the  kathode  rays  out  into  the  open  air.  Or,  at  least,  that 
is  what  he  appears  to  have  considered  that  he  was  doing. 
Certainly  he  succeeded  in  bringing  out  from  the  vacuum 
tube  rays  that,  if  not  adlual  prolongations  of  the  kathode 
rays,  were  closely  identified  with  them.  He  examined 
their  properties  both  in  the  open  air  and  in  gases  contained 
in  a  second  chamber  beyond  the  window,  and  found  them 
to  be  capable  of  producing  photographic  impressions  on 
sensitive  plates.  He  further  examined  the  question 
whether  they  can  be  defledled  by  a  magnet.  Fig.  6,  which 
is  copied  from  Lenard's  paper,  shows  the  results.  The 
row  of  spots  on  the  left  side  shows  the  photographic  efifedl 
under  various  different  conditions  of  experiment  when  there 
was  no  magnet  present.  The  spots  in  the  right-hand  row 
show  the  effedls  obtained  when  a  magnet  was  present. 
For  example,  in  the  third  row  from  the  top  it  is  seen  that 
the  bundle  of  rays  when  subjedled  to  the  influence  of  the 
magnet  is  partially  dispersed,  the  spot  being  enlarged 
sideways  and  having  a  kind  of  nebulous  tail.  This  proves 
that  through  the  aluminium  window  there  came  some 
rays  which  were  defledled  by  a  magnet,  and  some  rays 
also  which  were  not  defledled  by  a  magnet.  The  question 
naturally  arises  whether  the  rays  which  Lenard  had  thus 
succeeded  in  bringing  out  into  the  open  air  are  the 
same  thing  as  the  rays  with  which  Crookes  had  been 
working  with  inside  the  vacuum.  To  that  question  the 
final  answer  cannot  yet  be  given.  Certainly  some  of  the 
Lenard  rays  resemble  the  interior  kathode  rays ;  but  some 


112 


Electric  Shadows  and  Luminescence, 


(  Chemical  News, 
l     March  5,  1897. 


differ  in  the  crucial  respea  of  defiedtability  by  the 
magnet.  The  higher  the  degree  of  vacuum,  the  less  are 
the  rays  defledted. 

Note. 

Goldstein,  in  his  "  Researches  on  the  Refledion  of 
Eledtric  (t. «.,  Kathode)  Rays,"  in  Wiedemann's  Annalen 
(xv.,  246,  1882),  came  very  near  to  the  discovery  of  the 
Rontgen  rays.  After  pointing  out  that  Hittorf  had  held 
the  opinion  that  the  kathode  rays  end  at  the  place  where 


Dry  pZcUe 


FLate- of  Copjur 


Fig.  3. 

they  strike  upon  a  solid  wall,  and  that  they  are  unable  to 
proceed  in  any  direction  at  all  from  thence,  Goldstein 
dire(5ls  attention  to  the  circumstance  that  fluorescent 
patches  are  sometimes  seen  at  the  end  of  crooked  tubes, 
where  they  could  not  have  been  caused  by  the  dired 
impaft  of  kathode  discharges.  He  discusses  the  question 
whether  this  is  due  to  reflexion  or  to  a  defledlion  caused 
by  the  spot  where  impadl  first  took  place  having  become 
eleiftrified  negatively,  and  therefore  afting  as  a  secondary 
kathode.  The  latter  hypothesis  is  rendered  untenable  by 
his  observation  that  if  the  spot  of  first  impadt  is  made  an. 
anode  the  efFed  still  occurs.  He  then  shows  that  the 
phenomena  are  inconsistent  with  a  specular  refle(5tion,  but 


Fig.  4. 

are  explained  by  supposing  that  there  is  a  diffuse  reflec- 
tion. He  then  sums  up  as  follows: — "A  bundle  of 
kathode  rays  does  not  end,  at  least  under  those  circum- 
stances under  which  it  excites  phosphorescence,  at  the 
place  where  it  strikes  upon  a  solid  wall,  but  from  the  place 
of  impadt  on  the  wall  there  proceed  eledtric  rays  in  every 
diredtion  in  the  gaseous  space.  These  rays  may  be  con- 
sidered as  refledled.  Any  solid  wall  of  any  property 
whatever  may  serve  as  a  refledting  surface.  It  is  imma- 
terial whether  or  not  it  is  capable  of  phosphorescence,  or 
whether  it  consists  of  an   insulator  or  of  a  condudior. 


The  refledtion  is  diffuse,  no  matter  whether  the  surface  is 
dull  or  most  highly  polished.  An  anode  refledts  the 
kathode  rays  sensibly  as  well  as  a  neutral  condudtor  or  an 
insulator.  The  refledled  rays  have,  like  the  diredl  kathode 
rays,  the  property  to  excite  phosphorescence  at  their 
ends.  They  are  subjedl  to  defledlion,  and  their  ends  are 
deviated  in  the  same  sense  as  the  ends  of  kathode  rays, 
which  would  extend  from  the  reflecting  surface  toward  the 
place  hit  by  the  refledled  rays." 

Puluj,  "  Radiant  Eledlrode  Matter,  and  the  so-called 
Fourth  State."  Published  in  vol.  i.  of  "  Physical  Me- 
moirs," by  the  Physical  Society  of  London,  1889.  These 
are  translated  from  papers  published  in  1883  in  the 
Memoirs  of  the  Imperial  Academy  oj  Sciences  at  Vienna. 


Fig.  5. 


H.  Hertz.  "  Researches  on  the  Glow  -  Discharge," 
Wied.  Ann.,  xix,,  782,  1883.  Hertz  regards  the  kathode 
rays  as  a  property  of  the  ether,  not  as  consisting  of 
moving  particles.  He  flnds  the  kathode  rays  to  consist 
of  a  heterogeneous  variety  of  kinds  which  differ  from  one 
another  in  their  properties  of  causing  phosphorescence,  of 
being  absorbed,  and  of  being  defledled  by  the  magnet. 


2. 


iSr. 


Fig.  6. 


"  On  the  Transmission  of  the  Kathode  Rays  through 
Thin  Layers  of  Metal"  (xlv.,  28,  1892),  Hertz  finds  that 
glass  fluoresces  in  kathode  rays,  even  if  covered  with  gold- 
leaf  or  thin  films  of  various  metals,  though  not  if  covered 
with  thin  mica.  Aluminium  was  found  best,  and  allowed 
fluorescence  to  occur  even  when  a  sheet  of  aluminium- 
leaf  was  used  so  thick  as  to  be  opaque  to  light.  A 
diaphragm  of  thin  aluminium-leaf  on  a  metal  frame 
placed  inside  a  Crookes  tube  at  20  cm.  from  the  kathode, 
permitted  enough  rays  to  pass  to  give  a  tolerably  bright 
and  even  fluorescence  over  the  whole  of  the  further  end 
of  the  tube.    These  rays,  after  passing  through  the  leaf 


Crbmical  NBW8,  I 
March  5,  1897.    I 


Oxalates  of  Zirconium, 


113 


of  metal,  still  showed  redilinear  propagation  (with  some 
diiTusion),  and  had  not  lost  the  property  of  being  defiedted 
by  the  magnet. 

E.  Wiedemann's  papers,  which  are  of  special  im- 
portance, have  mostly  appeared  in  Wiedemann's  Annalen. 
The  following  are  the  chief  of  them.  Some  of  the  later 
have  been  written  in  collaboration  with  Prof.  H.  Ebert. 

"  On  the  Phosphorescent  Light  excited  by  Eledtric  Dis- 
charges" {Wied.  Ann.,  ix.,  157,  1880). 

"  On  Eiedtric  Discharges  in  Gases  "  (xx.,  756,  1881). 

•'  On  Fluorescence  and  Phosphorescence,"  Pt.  i  (xxxiv., 
446,  1888). 

'•  On  the  Mechanism  of  Luminosity "  (xxxvii.,  177, 
1889). 

"  On  Kathodo-  and  Photo-Luminescence  of  Glasses  " 
(xxxviii.,  488,  1889). 

"  On  Eledlric  Discharges  in  Gases  and  Flames  "  (xxxv., 
209,  220,  234,  237,  255,  1888). 

"On  Eledtric  Discharges"  (xxxvi.,  643,  1889). 

"  On  the  Apparent  Repulsion  of  Parallel  Kathode  Rays  " 
(xlvi.,  158,  1892). 

"  On  Eledric  Discharges  ;  Excitation  of  Eledtric  Oscil- 
lations and  the  Relation  of  Discharge-tubes  to  the  same  " 
(xlviii.,  549,  and  xlix.,  i,  1893). 

"  Researches  on  Eledlrodynamic  Screening-a(5tion  and 
Eledtric  Shadows"  (xlix.,  32,  1893). 

"  Luminous  Phenomena  in  Eledlrode-less  Rarefied 
Spaces  under  the  Influence  of  Rapidly-alternating  Elec- 
tric Fields"  (I.,  I,  221,  1893). 

With  J.  B.  Messerschmitt,  "On  Fluorescence  and 
Phosphorescence,  Pt.  II.,  Validity  of  Talbot's  Law" 
(xxxiv.,  463,  1888). 

With  H,  Ebert,  "On  the  Transparency  of  Kathode 
Deposits,"  Sitzber.  d,  Phys.-Med.  Soc.  zu  Erlangen,  Dec. 
14,  1891. 

Lenard's  Papers  are: — 

"  Note  on  a  Phosphoroscope,  with  Spark  Illumination  " 
{Wied.  Ann.,  xxxiv.,  918,  1888). 

With  M.  Wolf,  "Luminescence  of  Pyrogallic  Acid" 
(xxxiv.,  918,  1888). 

With  V.  Klatt,  "  On  the  Phosphorescence  of  Copper, 
Bismuth,  and  Manganese  in  the  Sulphides  of  Alkaline 
Earths"  (xxxviii.,  90,  i88g). 

"  On  Kathode  Rays  in  Gases  at  Atmospheric  Pressure, 
and  in  the  most  Extreme  Vacuum  "  (li.,  225,  1894). 

"  On  the  Magnetic  Deflexion  of  the  Kathode  Rays  "  (Hi., 
22,  1894). 

"  On  the  Absorption  of  the  Kathode  Rays"  (Ivi.,  255, 
1895). 

(To  be  continued). 


THE    OXALATES    OF    ZIRCONIUM. 
By  F.  P.  VENABLE  and  CHARLES  BASKERVILLE. 

The  text-books  of  chemistry  make  either  very  little  or  no 
reference  to  the  oxalates  of  zirconium.  Beyond  an  occa- 
sional reference  to  the  oxalate  or  basic  oxalate  gotten  by 
precipitating  with  oxalic  acid  or  an  oxalate,  we  can  find 
little  mention  of  these  compounds.  Behrens,  in  his  micro- 
chemical  work,  speaks  of  an  oxalate  prepared  as  colour- 
less pyramids  by  precipitating  a  solution  of  zirconium 
sulphate  with  potassium  binoxalate,  but  no  analyses  are 
given,  and  the  crystals  could  scarcely  have  been  the  pure 
oxalate.  Paykull  ("  Ofv.  af.  Vet.  Ak.  Forhandl.,"  ref.  in 
Ber.  d.  Chem,  Ges.,  xii.,  1719)  speaks  of  double  oxalates 
being  prepared  with  the  alkaline  oxalates  (i  :  2)  and  his 
failure  to  prepare  the  neutral  oxalate.  His  methods,  and 
indeed  full  results,  are  unknown  to  us,  as  we  did  not  have 
access  to  the  original  paper. 

We  may  summarise  the  work  which  follows  in  the  suc- 
ceeding pages  by  saying  that  we  found  it  possible  to  pre- 
pare the   basic  oxalates    by  precipitation.      This   was 


usually  in  the  form  of  Zr(C204)2.Zr(OH)4,  though  other 
ratios  were  gotten.  The  neutral  oxalate  we  did  not  suc- 
ceed in  preparing,  but  instead  the  tendency  seems  to  be 
toward  the  formation  of  the  acid  oxalate, — 

Zr(C204)2.H2C204'8H30. 
This  tendency  toward  the  formation  of  acid  salts  was 
shown  also  in  the  double  oxalates.    Two  of  these  were 
prepared.     For  sodium, — 

Zr(C204)2.3NaC204.H3C204.5H20, 

and  for  potassium  the  salt — 

[Zr(C204)2]2.(K2C204)2.H2C204.8H20. 

The  oxalate  with  ammonium  as  a  constituent  was  not  so 
easy  of  preparation  in  a  pure  state.  The  compound 
secured  was  Zr(C204)2.2(NH4)2C204.  The  experiments 
and  analyses  are  given  in  detail. 

Zirconium  Oxalates. 

The  Oxalate  Gotten  by  Precipitation.— On  the  addition 
of  a  saturated  solution  of  oxalic  acid  to  a  slightly  acid 
solution  of  zirconium  chloride  until  no  further  precipita- 
tion occurred,  a  gelatinous  precipitate  formed  which  had 
very  nearly  the  composition  Zr(C204)2  2Zr(0H)4.  Ana- 
lysis I.  gave  Zr  46-39,  and  C2O4  30-89,  instead  of  the 
theoretical  4640  and  30-93  respedively.  The  filtrate 
from  this  was  turbid,  and  on  standing  yielded  another 
precipitate  which  had  nearly  the  composition 
2Zr(C204)2.3Zr(0H)4. 

These  basic  oxalates  are  very  difficultly  soluble  in 
acids,  and  of  extremely  fine  subdivision,  settling  slowly 
and  passing  through  even  the  best  filters.  It  does  not 
seem  probable  that  they  could  be  secured  of  very  constant 
composition.  Probably  basic  oxalates  with  many  different 
ratios  between  the  oxalate  and  the  hydroxide  might  be 
secured.  On  drying  at  100°,  or  even  a  little  lower,  the 
oxalic  acid  is  gradually  volatilised  and  lost.  This  is  true 
of  all  the  oxalates  and  double  oxalates  prepared,  so  that 
the  only  mode  of  drying  these  preparations  was  between 
filter-paper. 

The  Acid  Oxalate  prepared  by  Crystallisation. — In  pre- 
paring this  oxalate,  zirconium  hydroxide  was  dissolved  in 
oxalic  acid.  The  hydroxide  is  quite  soluble  in  oxalic  acid, 
and  a  concentrated  solution  is  readily  obtained.  A  con- 
siderable excess  of  the  acid  is  required  to  hold  the  oxalate 
thus  formed  in  solution.  If  this  solution  be  acidified  by 
means  of  hydrochloric  acid  a  very  fine  precipitate  is  ob- 
tained, settling  very  slowly,  easily  passing  through  the 
best  filter-papers,  and  insoluble  even  in  a  considerable 
excess  of  the  acid,  but  soluble  in  concentrated  suljhuric 
acid.  This  precipitate  was  not  analysed,  nor  were  the 
exadt  conditions  of  its  formation  determined,  as  its  exam- 
ination did  not  promise  results  of  sufficient  importance 
to  justify  overcoming  the  difficulties  in  the  way. 

On  evaporating  the  acid  solution  of  the  oxalate  the 
excess  of  oxalic  acid  first  crystallises  out.  In  the  various 
preparations  made,  the  first  one  or  two  crops  of  long 
crystals  were  found  to  be  nearly  pure  oxalic  acid,  and 
were  rejedted.  Then  the  form  of  the  crystals  changed  to 
small  granular  or  prismatic  masses,  and  with  each  suc- 
ceeding crop  of  crystals  the  percentage  of  zirconium  in- 
creased, reaching  speedily  an  approximately  constant 
ratio.  No  difference  in  the  form  of  the  crystals  in  these 
different  crops  could  be  deteded  on  superficial  examina- 
tion, and  hence  it  was  impossible  to  distinguish  between 
the  zirconium  oxalate  and  the  oxalic  acid  almost  free  of 
zirconium,  except  by  analysis.  In  no  case  was  the 
normal  oxalate  secured.  The  analyses  showed  a  tendency 
toward  the  formation  of  an  acid  oxalate  and  to  mixtures 
of  this  with  the  normal  oxalate.  These  mixtures  were 
gotten  in  the  later  crystallisations,  but  the  last  crystallisa- 
tion, when  nearly  the  whole  would  solidify  into  a  crystal- 
line mass,  showed  decreased  percentages  of  zirconium. 
It  is  possible  that  larger  amounts  than  we  had  at  our  dis- 
posal would  enable  one  so  to  fra(aion  the  crystallisation 
as  to  secure  a  pure  oxalate.    It  is,  however,  questionable 


114 


Oxalates  of  Zirconium. 


Chemical  Nbws, 

March  5,  18Q7. 


whether  the  normal  oxalate  can  exist  in  solution  without 
admixture  with  some  oxalic  acid. 

Four  series  of  crystallisations  were  made,  and  in  two 
cases  fairly  abundant  crops  of  crystals  corresponding  to 
the  acid  oxalate  were  obtained.  In  each  series  enough  of 
the  zirconium  hydroxide  was  taken  to  form  about  20  grms. 
of  the  oxalate. 

First  series.       Second  series. 
Sixth  fraflion.      Fifth  fraction. 

II.  III.  ^rCCjOtVHjCaO,. 

Zr         ..      ..     25*44  25*28  25'53 

Ca04    ..     ..     74*55  7472  74*47 

These  are  calculated  upon  the  water-free  basis.  The 
crystals  contained  29*34  ^nd  29*27  per  cent  of  water 
respeaively,  where  the  salt  Zr(C204j2H2C204.8H30  con- 
tains 28  90  per  cent.  Other  crops  of  crystals  contained 
percentages  of  zirconium  not  varying  greatly  from  these 
given  above  as  28*14,  27-62,  24*9,  23*83.  The  percentage 
of  zirconium  in  the  normal  oxalate  is  33*96. 

Zirconium  Sodium  Oxalate. 

The  addition  of  sodium  oxalate  to  a  slightly  acid  solution 
of  zirconium  chloride  gives  a  gelatinous  white  precipitate. 
Most  of  this  dissolves  in  an  excess  of  the  oxalate.  The 
undissolved  portion  settles  to  the  bottom,  and  after  pro- 
longed standing  a  second  layer  of  a  more  powdery  appear- 
ance forms.  This  can  also  be  gotten  by  concentration  of 
the  filtrate  from  the  first  precipitate.  Analysis  showed 
that  the  first  gelatinous  precipitate  was  chiefly  Zr(0H)4. 
The  second  precipitate  was  a  double  oxalate  of  zirconium 
and  sodium,  but  was  either  of  inconstant  composition 
(varying  ratios  of  sodium  to  the  zirconium),  or  was  de- 
composed by  the  washing. 

The  analyses,  calculated  on  the  dry  basis,  gave : — 


Zr 
Na 
C2O4 


IV. 
53'" 

9*i6 
3806 


V. 

4686 

410 

39"64 


VI. 

41*98 

1*07 

4295 


If  the  solution  made  with  the  excess  of  sodium  oxalate 
was  diluted  considerably  with  water,  a  gelatinous  precipi- 
tate was  formed,  very  fine  and  insoluble.  Precipitates 
were  also  formed  by  the  addition  of  hydrochloric  acid. 
This  mode  of  forming  the  double  oxalate  was  abandoned, 
and  the  following  method  was  adopted  with  greater  suc- 
cess. Zirconium  hydroxide  was  dissolved  in  an  excess  of 
oxalic  acid,  and  to  this  a  concentrated  solution  of  sodium 
hydroxide  was  added,  bringing  it  nearly  to  neutralisation. 
When  the  solution  was  concentrated,  an  abundant  crop 
of  crystals  was  obtained  on  cooling,  a  good  deal  of  heat 
being  evolved  in  the  mixing.  Further  evaporation  yielded 
other  crops  of  crystals.  These  were  washed,  dried  be- 
tween filter-paper,  and  analysed.  The  results  are  given 
in  the  following  table  : — 


VII. 


VIII. 


IX. 


Calculated. 


Na       ..      ..      18*14  I7'46  1775  18*19 

Zr       ..      ..      12-59         i2*66         1278         ii'93 
C2O4  ..      ..     69*27         66-89         6947         6988 

These  results  show  a  somewhat  wide  variation  from 
those  calculated.  This  probably  arises  from  the  faiftthat 
the  fradlions  were  not  composed  of  the  crystals  of  a  single 
kind  of  oxalate,  but  had  other  oxalates  mixed  with  them 
in  small  amounts.  Examined  under  a  magnifying  glass 
they  seemed  to  be  homogeneous,  but  the  different  crops 
could  not  be  distinguished  from  one  another.  They  were 
all  small,  hard  prismatic  crystals,  somewhat  diiBcultly 
soluble  in  water.  One  set  of  crystals,  the  analysis  of  which 
is  reported  under  Vll.  in  the  above  table,  was  re-dis- 
solved in  water  and  re-crystallised.  On  analysis  it  yielded 
the  following  results: — 

VII.  XI. 


Na 18*14 

Zr 1259 


C2O. 


69*27 


i8  19 
12-71 
69-10 


These  were  calculated  upon  a  water-free  basis.  The 
crystals  from  the  various  crops  mentioned  above  did  not 
contain  a  very  constant  amount  of  water,  but  ranged  from 
913  to  11*06.  The  calculated  amount  of  water  in 
Zr(C204)2.3Na2C204.H2C204.5H20  is  10*62.  It  would 
seem,  therefore,  that  the  tendency,  when  this  method  of 
formation  is  adopted,  is  toward  the  formation  of  crystals 
containing  free  oxalic  acid  and  with  the  sodium  and  zir- 
conium oxalates  bearing  a  ratio  of  three  to  one. 

Zirconium  Potassium  Oxalate. 

The  curdy  precipitate  gotten  by  precipitating  zirconium 
chloride  with  normal  potassium  oxalate  is  insoluble  in  an 
excess  of  either  of  the  substances.  The  precipitate  first 
obtained  is  an  impure  zirconium  hydroxide,  containing 
only  small  amounts  of  oxalic  acid.  The  supernatant 
liquid,  on  concentration,  yields  needle-like  crystals  of 
potassium  oxalate,  carrying  only  traces  of  zirconium. 
After  the  separation  of  a  good  deal  of  this  potassium 
oxalate,  further  concentration  yielded  a  gelatinous  sub- 
stance having  the  composition  (XII.)  :  Zr,  3934;  K,  5*06; 
C2O4,  43*05  ;  which  seems  to  be  a  basic  zirconium  oxalate, 
mixed  or  united  with  a  small  proportion  of  potassium 
oxalate.  If  the  potassium  be  calculated  as  potassium 
oxalate  and  subtracted,  the  composition  of  the  remainder 
would  be  approximately  Zr(0H)4.Zr(C204)2. 

On  adding  potassium  binoxalate  to  a  solution  of  zir- 
conium chloride  a  white  curdy  precipitate  was  obtained 
which  was  not  completely  soluble  in  excess  of  the 
binoxalate.  The  somewhat  turbid  solution  was  filtered 
and  evaporated.  Large  crystals  resembling  those  of 
oxalic  acid  formed.  These  were  separated,  and  on  ana- 
lysis proved  to  be  oxalic  acid.  At  the  same  time  a 
number  of  small  crystals  were  formed,  which  were 
mechanically  separated,  washed,  and  dried.  These  were 
analysed,  and  are  reported  under  XIII.  A  further  crop 
was  gotten  from  the  mother-liquor,  and  the  analysts  is 
given  under  XIV. 

XIII.  XIV. 


Zr 19-59 

K 1618 

C2O4 64*23 


17*99 
1391 
68*09 


The  curdy  precipitate  which  first  formed  was  also 
examined,  and  found  to  have  the  composition 
Zr{C204)2.2Zr(OH)4. 

The  addition  of  a  solution  of  potassium  tetroxalate  to 
zirconium  chloride  gave  a  gelatinous  precipitate  of  zirco- 
nium oxalate  (basic),  carrymg  a  little  potassium  oxalate. 
Subtrading  the  potassium  oxalate,  the  percentages  (XVI.) 
Zr  39-09,  and  C2O4  38*63,  are  left,  which  are  not  very 
different  from  the  figures  gotten  for  the  precipitate  from 
potassium  oxalate  (neutral). 

This  curdy  gelatinous  precipitate  was  dissolved  in 
excess  of  tetroxalate,  and  the  solution  placed  over 
sulphuric  acid  to  crystallise,  and  yielded  crystals  having 
the  composition  (XVII.):  Zr  20-85,  ^  1672,  and  C2O4 
62'3i.  As  will  be  seen,  these  are  not  far  from  the  i  :  2 
zirconium  potassium  oxalate,  with  excess  of  oxalic  acid. 

When  potassium  hydroxide  was  added  to  a  solution  of 
zirconium  oxalate  in  oxalic  acid  until  nearly  neutral,  and 
then  set  aside  for  crystallisation,  various  crops  of  crystals 
were  gotten,  as  in  the  case  of  the  double  sodium  oxalates. 
These  crops  of  crystals  were  similar  in  appearance  to  the 
sodium  crystals.  They  were  analysed  and  showed  fairly 
constant  composition. 

XVIII.  XIX.         XX.  XXI.  (KjCaOjj.kjCjO, 

Zr..     18*08  19*25  I9'83  i8*47  ^8*95 

K  ..     16-41  i6'35  14*84  14*46  i6*34 

C2O4  66-51  64*40  65*33  67*07  64*71 

The  three  previous  analyses  may  also  be  referred  to 
here  as  having  approximately  the  same  composition.  (See 
Analyses  XIII.,  XIV.,  XVII.).  These  are  calculated  as 
water-free.     In   the  Analyses  XVIII.  and  XIX.  the  per- 


ChSmical  Nbws,  > 
i  March  s,  1897.     ' 


Photography  of  Rtpples^ 


»I5 


centages  of  water  were  iTgg  and  i2"38.  These  would 
correspond  to  the  formula  — 

(Zr(C204)2)2.(K2C2O4)2.H2C2O4.8H2O. 

In  this  case,  as  in  the  zirconium  oxalates  and  the  sodium 
oxalates,  the  crystals  seem  to  form  only  along  with  free 
oxalic  acid,  giving  acid  salts. 

Zirconium  Ammonium  Oxalates. 
The  addition  of  a  solution  of  ammonium  oxalate  to  the 
slightly  acid  solution  of  zirconium  chloride  gave  a  heavy 
gelatinous  precipitate  which  was  soluble  in  excess  of 
ammonium  oxalate,  and  proved  to  be  zirconium  hydroxide 
with  more  or  less  zirconium  oxalate  and  small  amounts 
of  ammonia.  The  filtrate  from  this  precipitate  was 
evaporated  slowly  and  a  fine  crystalline  powder  obtained. 
This  contained  (XXII.)  Zt  42*17  -per  cent,  and  C2O4 
39'86  per  cent.  This  is  in  fair  agreement  with— 
Zr(C203)2.Zr(OH)4. 

When  ammonium  oxalate  is  added  until  the  first  gela- 
tinous precipitate  is  re-dissolved,  and  then  evaporated  to 
crystallisation,  different  crops  of  crystals  can  be  gotten 
containing  various  amounts  of  ammonia.  These  did  not 
seem  to  have  any  regular  composition  in  our  experiments, 
and  were  looked  upon  as  basic  zirconium  oxalates  with 
varying  amounts  of  ammonium  oxalate  present.  Thus 
for  one  of  these  the  figures  (XVIII.)  Zr  3i'48,  NH3  7'i4, 
and  C2O4  6i'38  were  gotten. 

Abandoning  this  method,  and  using  the  one  adopted  in 
the  cases  of  the  sodium  and  potassium  double  oxalates,  a 
more  favourable  result  was  obtained.  Zirconium  hydroxide 
was  dissolved  in  excess  of  oxalic  acid,  and  then  this  was 
nearly  neutralised  by  means  of  ammonium  hydroxide. 
Analyses  of  these  crops  of  crystals  follow  : — 


Zr  . 
NH3 
C2O4 


XXIV. 

1655 
1446 
69-99 


XXV. 

2(NH4)aCa04 

1666 

13-35 
6999 

17-58 
I3"28 
68*94 

While  these  do  not  show  that  the  crystals  had  been 
thoroughly  purified,  the  results  indicate  that  the  composi- 
tion is  one  zirconium  oxalate  to  two  ammonium  oxalate. 
On  re-crystallising  one  of  these  crops  of  crystals,  zirco- 
nium hydroxide  was  observed  to  separate  when  the 
solution  was  heated  (to  evaporate  to  crystallisation),  and 
the  crystals  which  were  obtained  consisted  of  ammonium 
oxalate  alone. 

In  general  it  may  be  stated  that  the  zirconium  oxalate 
fails  to  show  any  decided  tendency  to  enter  into  clearly- 
defined  combinations  with  the  alkaline  oxalates,  exhibiting 
rather  a  power  of  crystallising  along  with  them  in  mix- 
tures of  any  proportions.  It  can  only  be  said  at  best  that 
under  the  conditions  of  our  experiments  certain  ratios 
seem  to  be  preferred,  and  appeared  more  persistently.  In 
all  cases  the  crystals  formed  from  oxalic  acid  solutions, 
and  this  free  oxalic  acid  crystallised  with  them,  giving 
acid  oxalates. — yourn.  Amer.  Chem.  Soc,  xix.,  p.  12. 


Royal  Institution.  —  A  General  Monthly  Meeting  of 
the  Members  of  the  Royal  Institution  was  held  on 
March  ist,  Sir  James  Crichton-Browne,  M.D.,  F.R.S., 
Treasurer  and  Vice-President,  presiding.  The  following 
were  elefted  Members  : — F.  J.  Beaumont,  Major  C.  T. 
Blewitt,  R.A.,  J.  F.  L.  Brunner,  James  Cadett,  J.  C. 
Carter,  John  Cohen,  Mrs.  Thomas  Collier,  J.  G.  Craggs, 
T.  Donaldson,  Henry  Edmunds,  Mrs.  Henry  Edmunds, 
G.  S.  Elliot,  W.  A.  Frost,  F.R.C.S.,  W.  T.  Garnett,  J. P., 
H.  A.  Harben,  Dr.  F.  Hewitt.  F.  W.  Hildyard,  Mrs. 
George  King,  H.  Leitner,  the  Rev,  J.  D.  Parker,  E.  .M. 
Preston,  J.  M.  Richards,  Colonel  G.  Sartorius,  F.  H. 
Schwann,  Dr.  W.  R.  Smith,  H.  A.  Stern,  C.  J.  Stewart, 
G.  L.  Stewart,  Mrs.  A.  D.  Waller,  and  Mrs.  J.  Lawsun 
Walton. 


PROCEEDINGS    OF    SOCIETIES. 

PHYSICAL    SOCIETY. 
Ordinary  Meeting,  February  26th,  1897. 

Mr.  Shelford  Bidwell,  President,  in  the  Chair. 

Mr.  J.  H.  Vincent  read  a  paper  on  the  "  Photography  of 
Hippies:' 

If  mercury  is  used  as  the  medium,  all  waves  less  than 
1*3  cm.  long  come  under  Lord  Kelvin's  definition  of  a 
ripple ;  that  is  to  say,  they  are  waves  whose  lengths  are 
less  than  such  as  are  propagated  \yith  minimum  velocity. 
Vibrations  in  mercury  of  about  200  per  second  and  up- 
wards generate  waves  whose  propagation  is  controlled 
almost  entirely  by  surface  tension,  and  these  waves  are 
therefore  classed  as  "  capillary  ripples."  Their  speed  of 
propagation  is  of  the  order  of  about  one  foot  per  second. 
They  are  invisible,  owing  to  their  high  frequency,  not  in 
consequence  of  the  velocity  of  their  propagation.  It  is 
usual  to  examine  them  by  some  stereoscopic  method. 

Mr.  Vincent  obtains  photographs  of  the  disturbed  mer- 
cury surface  by  the  sudden  illumination  of  an  eledric 
spark.  The  spark  is  about  half  a  centimetre  in  length, 
and  it  lasts  about  one  two-hundred-thousandth  part  of  a 
second.  Its  brightness  is  increased  by  an  auxiliary  spark- 
gap.  The  optical  arrangement  consists  of  two  lenses, 
one  in  the  path  of  the  incident  light,  and  another  to  con- 
verge the  reflecfted  light  from  the  mercury  surface  into  a 
photographic  camera.  Ripples  are  set  up  in  the  mercury 
by  a  stylus  attached  to  a  tuning  fork.  For  this  purpose 
it  is  generally  sufficient  to  give  a  slight  blow  to  the 
prongs  ;  but  when  continuous  vibration  is  required  the 
tuning-fork  can  be  connedted  by  a  thread  to  an  eledlrically 
driven  fork,  as  suggested  by  Mr.  Watson. 

The  first  photograph  shows  a  series  of  circular  waves, 
set  up  by  a  single  stylus  attached  to  a  fork  vibrating  180 
times  a  second.  Fixed  points  at  known  distance,  just 
above  the  mercury  surface,  enable  the  wave-lengths  to  be 
deduced  from  the  photographs ;  and,  as  the  frequency  is 
known,  the  surface  tension  may  be  easily  calculated. 

In  a  second  photograph,  two  styluses  are  attached  to 
the  same  prong.  Dark  lines  are  seen  to  radiate  from  the 
region  between  the  centres  of  oscillation;  these  are  the 
lines  of  minimum  disturbance — hypberolas,  of  which  the 
centres  of  disturba,r;ice  are  the  foci.  This  photograph 
illustrates  "  interference  "  similarly  to  the  optical  method 
of  Young  and  Fresnel. 

A  third  photograph  shows  the  formation  of  elliptical 
curves  of  disturbance,  being  the  loci  of  the  intersedlion  of 
two  series  of  circles,  corresponding  one  to  each  of  the  two 
centres  of  vibration.  Unlike  the  system  of  hyperbolas, 
these  ellipses  are  not  at  rest,  but  travel  outward  from  the 
sources.  In  order  to  render  these  ellipses  stationary,  it 
would  be  necessary  to  change  one  of  the  sources  into  a 
sink,  towards  which  the  circular  waves  might  converge  ; 
the  photograph  would  then  correspond  to  the  optical 
device  of  M.  Meslin,  who  obtains  interference  fringes 
by  means  of  a  screen  placed  between  two  point  centres, 
one  a  source,  and  the  other  a  sink. 

The  phenomena  of  interference  and  diffradtion  are  well 
shown  in  a  photograph  of  a  point  source  and  a  refledling 
line.  The  refiedtor  here  is  one  side  of  a  triangular  piece 
of  microscope  cover-glass.  The  interference  lines  are  due 
to  the  mutual  adtion  of  incident  and  refiedled  rays;  they 
are  analogous  to  Lloyd's  single-mirror  fringes.  Other 
photographs  exhibit  analogues  of  "  spherical  aberration  " 
and  •'  forced  vibration." 

Mr.  Vincent  acknowledged  his  indebtedness  to  Mr. 
Boys  for  the  recommendation  of  attempting  the  photo- 
graphy of  capillary  ripples. 

Mr.  Boys  congratulated  the  author  upon  the  way  in 
which  the  experimental  difficulties  had  been  overcome. 
The  results  would  bear  a  good  deal  of  close  examination, 
and  they  would  be  found  to  present  analogues  of  the 


ii6 


Animal  and  Vegetable  Fats  and  Otis. 


greatest  service  in  demonstrating  the  phenomena  of 
acoustics  and  optics.  Such  photographs  were  far  better 
than  geometrical  piftures  drawn  by  instruments.  For 
example,  in  the  photograph  illustrating  the  regions  of 
minimum  disturbance  by  lines  radiating  from  a  two-point 
source,  it  was  easy  to  make  out  the  positions  where  the 
two  series  of  waves  were  half  a  period  behind  one 
another.  The  crests  and  troughs  appeared  as  a  set  of 
dark  and  light  concentric  alternating  circles,  broken  up 
into  short  arcs  by  radiating  lines — the  loci  of  minimum 
disturbance  ;  all  the  crests  on  one  side  of  any  particular 
radiating  line  were  seen  to  correspond  to  troughs  on  the 
other  side,  so  that  the  field  of  disturbance  was  mapped 
out  as  in  acoustics.  One  set  of  phenomena  yet  awaited 
illustration  by  this  photographic  method,  and  that  was 
"  diffradion  "  from  a  grating.  It  might  be  possible  to 
use  as  an  exciter  a  comb  with  chisel-shaped  points.  He 
did  not  think  it  would  be  possible  to  go  quite  so  far  as  to 
reproduce  analogues  of  spedlral  analysis.  Since  wave- 
length varies  with  surface  tension,  it  was  possible  to  vary 
the  wave-length  by  dropping  a  little  ox-gall  or  soap  solu- 
tion upon  the  mercury  surface. 

Mr.  Blakesley  asked  why  no  refle<5tion8  occurred  from 
the  sides  of  the  mercury  retainer. 

Mr.  Boys  said  the  waves  were  lost  at  the  edges  of  the 
meniscus.  The  mercury  was  kept  in  position  by  an  an- 
nular ring  of  thin  glass. 

Mr.  Appleyard  suggested  that  the  analogue  of  refrac- 
tion might  be  obtained  by  an  alteration  of  the  surface- 
tension  over  a  small  area  by  amalgamation  or  other 
means. 

Mr.  Vincent  thought  this  could  be  done,  but  that  it 
would  be  very  difficult. 

The  President  proposed  a  vote  of  thanks  to  the  author. 

Mr.  Elder  then  read  a  paper  by  Mr.  Beckit  Burnie 
on  "  The  Thermo-electric  Properties  of  some  Liquid 
Metals." 

The  investigation  was  made  with  a  view  to  determining 
the  effeca  of  melting  upon  the  thermo-eledric  properties 
of  certain  metals.  The  metal  to  be  tested  is  contained  in 
a  W-shaped  glass  tube,  of  which  one  limb  can  be  cooled 
and  the  other  heated.  Thus  one  limb  can  contain  molten, 
and  the  other  solid,  metal.  Copper  wires  are  plunged 
one  into  each  limb,  and  through  these  connexion  is  made 
with  a  galvanometer.  The  thermal  junctions,  therefore, 
are  copper-hot  metal  and  copper-cold  metal.  The  teni- 
perature  is  deduced  from  a  separate  thermal  couple,  cali- 
brated by  a  mercurial  thermometer.  Curves  are  drawn 
co-ordinating  temperature  and  eledlromotive  force.  It  is 
found  that  their  slope  depends  upon  the  rate  of  cooling 
or  heating  of  the  metals  ;  this  is  particularly  the  case 
with  bismuth.  The  effedl  is  attributed  to  the  variation  in 
crystalline  strufture  of  the  metal  under  test  at  different 
rates  of  solidification.  With  tin  the  change  is  less  marked, 
and  with  lead  it  is  unnoticeable.  At  or  about  the  melting- 
points  there  is  considerable  change  of  slope  in  the  curves. 
Here,  again,  the  effedt  is  smallest  for  lead  ;  somewhat 
greater  with  tin;  and  remarkably  large  with  bismuth,  the 
latter  changing  from  an  exceedingly  adtive  thermo- 
eledtric  metal  to  one  resembling  lead.  A  great  change 
occurs  also  with  mercury  at  the  melting-point,  indicating 
a  difference  in  the  Peltier  effedt  between  solid  and  molten 
metals. 

A  vote  of  thanks  to  Mr.  Beckit  Burnie  was  proposed  by 
the  President,  and  the  meeting  adjourned  until 
March  12th. 


EDINBURGH     UNIVERSITY     CHEMICAL 

SOCIETY. 

Fifth  Ordinary  Meeting,  February  8th,  1897. 

Dr.  J.  E.  Mackenzie  in  the  Chair. 

Mr.  W.  W.Taylor,  M.A.,  B.Sc,  read  a  paper  on  the 
"  Electrolytic  Dissociation  of  Water." 


I  Chemical  News, 
I     March  5,  1897. 

The  author  began  by  describing  the  main  principles  of 
the  theory  of  eledrolytic  dissociation. 

The  work  of  Kohlrausch  in  determining  the  aftual  con- 
dudtivity  of  pure  water  was  described  in  detail. 

The  method  adopted  by  Wijs  for  arriving  at  the  disso- 
ciation grade  from  tlie  hydrolysis  of  methyl  acetate;  that 
of  Arrhenius  and  others  from  the  balance  between  aniline 
acetate  and  water  ;  and,  lastly,  the  numbers  got  by 
Ostwald  and  Nernst  from  the  eleiSromotive  force  of  a  gas 
battery  consisting  of  hydrogen  eledtrodes  in  acid  and 
alkali,  were  all  treated  of  and  carefully  explained. 


Sixth  Ordinary  Meeting,  February  22nd,  1897. 
Mr.  W.  W.  Taylor  in  the  Chair. 

Dr.  Marshall  gave  a  ledlure  on  "  Electrolysis." 

A  historical  sketch  of  the  subjeft  from  the  end  of  last 
century  till  the  present  time  was  first  given  ;  the  inven- 
tion of  the  eledric  pile  by  Volta,  the  decomposition  of 
water  by  Nicholson  and  Carlisle,  Davy's  discoveries,  and 
those  of  Berzelius,  Faraday's  laws,  and  the  work  of 
Daniell  and  Hittorf ;  finally,  the  theory  proposed  by 
Arrhenius. 

The  uses  of  eledtrolysis  in  chemical  analysis  were  then 
considered,  various  examples  being  taken  to  illustrate  this 
in  reference  to  quantitative  ele<5lrolysis. 

A  brief  mention  was  then  made  of  the  uses  of  eledlro- 
lysis  in  eledrotyping,  eledtro-metallurgy,  and  the  purifica- 
tion of  such  metals  as  copper. 

A  seledlion  was  made  both  from  inorganic  and  organic 
substances  to  show  how  certain  syntheses  could  be  con- 
du(5ted  by  eledtrolytic  means. 


NOTICES  OF  BOOKS. 


A  Practical  Treatise  on  Animal  and  Vegetable  Fats  and 

Oils.     By  W.  T.  Brannt.     (Second  Notice).     Vol.  II. 

Philadelphia :  H.  C.  Baird  and  Co.    London  :  Sampson 

Low,  Marston,  and  Co.,  Ltd.  i8g6. 
We  find  here  firstly  the  conclusion  of  the  account  of  the 
non-volatile  or  fatty  oils.  The  efficacy  of  boiling  as 
applied  to  linseed  oil  is  traced  to  the  expulsion  of  muci- 
lage. It  is  remarkable  that  in  some  parts  of  Russia  and 
Germany  cold-drawn  linseed  oil  is  used  as  a  table-oil  and 
in  cookery. 

The  produdtion  of  sunflower  oil  for  industrial  uses  in 
Russia  is  steadily  increasing. 

Nut-oil,  expressed  from  the  walnut,  dries  better  even 
than  linseed  oil,  and  is  preferred  for  artistic  uses.  Sperm 
oil  has  an  advantage  over  most  oils,  as  its  sophistication 
is  exceedingly  difficult.  The  nature  of  ambergris  is  still 
a  disputed  question  ;  some  authorities  considering  it  as 
a  pathological  secretion  of  the  urinary  bladder,  whilst 
others  regard  it  as  merely  the  indurated  faeces  of  the 
animal. 

The  remarkable  penetrative  power  of  doeglic  oil  was 
put  on  record  as  early  as  1250.  The  credit  of  first  obtain- 
ing cod-liver  oil,  colourless,  not  in  virtue  of  any  artificial 
bleaching,  but  of  the  total  freedom  from  putrefaction, 
seems  to  belong  to  Peter  Moller.  Eulachon  oil  is  preferred 
by  some  physicians  as  being  more  digestible  than  cod- 
liver  oil. 

Fish-waste  is  a  most  valuable  source  of  artificial 
manure,  and  is  capable  of  much  extension.  It  is  con- 
duced chiefly  in  the  Lofoten  Isles,  at  Newfoundland,  and 
on  the  coasts  of  the  United  States. 

Borneo  tallow,  obtained  from  trees  of  the  genus  Hopea, 
is  a  lubricating  agent  far  preferable  even  to  olive  oil. 
The  cultivation  of  the  tree  deserves  attention. 

Cacao-butter,  one  of  the  produdls  of  Theobroma  cacao. 


CBBUICAL  NBWBi  I 
March  5.  1897.     I 


Chemistry  of  Dairying. 


117 


and  not  of  Cocas  mucifera  or  of  Elais  guineensis,  has  an 
exceptional  power  of  resisting  rancidity,  but  it  is  scan- 
dalously sophisttcated  with  produCls  which  have  no  such 
properties.  The  original  home  of  the  cocoa-nut  (better, 
to  avoid  confusion,  cocos  nut)  is  corredlly  stated  as  being 
the  Malay  and  the  South  Sea  Archipelago. 

It  is  satisfadtory  to  find  that  the  leading  manufadurers 
and  merchants  are  discouraging  the  term  "  refined  lard  " 
as  applied  to  adulterated  produds. 

On  the  subjedt  of  butters,  as  judged  by  Hehner's  test, 
our  author  holds  that  samples  with  88  per  cent  of  inso- 
luble fatty  acids  may  be  pronounced  "  pure,"  those  with 
a  higher  percentage"  suspicious,"  and  with  over  8973  per 
cent  "adulterated."  We  regret  to  find  "  titer  "  used  in 
place  of  "  standard." 

Among  the  waxes,  next  to  bees-wax,  Chinese  wax 
{ceryl  cerotate)  is  said  to  possess  "  ten  times  the  illumi- 
nating power  of  ordinary  candles." 

Waste  fats  include  a  variety  of  industrial  produds,  one 
of  the  most  important  being  the  Yorkshire  grease 
recovered  from  the  waste  waters  of  fulling  mills.  Its 
removal  from  the  town  sewage,  and  ultimately  from  the 
streams,  is  a  necessary  preliminary  to  the  purification  of 
the  latter. 

The  bleaching  of  fixed  oils  and  fats  is  explained  very 
carefully.  The  chemical  procedures  were  first  introduced 
by  Berthollet,  though  chlorine,  which  he  proposed,  has 
since  been  superseded  by  hydrogen  peroxide,  and  in  some 
cases  by  chromates  mixed  with  hydrochloric  acid.  Animal 
charcoal  is  not  well  adapted  for  bleaching  oils. 

The  successful  application  of  feeble  elecSlric  currents 
for  bleaching  oils  seems  to  be  due  to  L.  Levat,  of  Aix. 
Acids  could  not  be  entirely  removed  in  this  manner  from 
inferior  lubricating  oils. 

Artificial  butter  was  first  produced  by  Mege-Mourier, 
under  the  auspices  of  Napoleon  III.  It  is  somewhat 
remarkable  that  whilst  the  Governments  of  France  and 
Germany  have  encouraged  the  manufafture  and  sale  of 
margarine,  of  course,  under  the  proper  regulations  to 
prevent  fraud,  in  the  United  States  it  has  been  opposed 
and  persecuted  in  every  pradicable  way.  Eminent 
chemists,  physiologists,  and  physicians,  after  long  and 
careful  courses  of  experiment,  have  decided  that  margarine 
has  no  unwholesome  properties,  and  that  it  is  less  disposed 
to  turn  rancid  than  normal  cow-butter. 

Into  the  essential  or  volatile  oils,  their  preparation  and 
their  distin(Stive  charaders,  space  does  not  allow  us  to 
enter. 

We  can  strongly  recommend  this  work  to  the  vast  and 
varied  industries  with  which  it  is  concerned. 


The  Chemistry  of  Dairying  ;  An  Outline  of  the  Chemical 
and  Applied  Changes  which  takes  place  in  Milk  and  in 
the    Manufadure    of    Butter    and    Cheese;     and    the 
Rational  Feeding  of  Dairy  Stock.     By  Harry  Snyder, 
B.S.,  Professor  of  Agricultural  Chemistry,  University 
of  Minnesota,  and   Chemist  of  the   Minnesota  Experi- 
ment Station.     Easton,  Pennsylvania  :  Chemical  Pub- 
lishing Co.     1897. 
The  appearance  of  this  book  is  explained  and  justified 
by   the  change   which,  within   the   last   few   years,  has 
occurred  in  dairying.     From  a  mere  rule-of-thumb  trade 
to  an  industry  which,  to  be  successful,  must  be  conducted 
on  scientific  principles,   or,  at  least,  in  accordance  with 
fadls  scientifically  determined. 

In  the  chapter  on  the  "  General  Composition  of  Milk," 
the  reader  is  reminded  that  milk-fat  and  butter  are  not 
identical.  Milk-fat  is  the  pure  dry  fat,  free  from  water, 
casein,  or  salt,  all  of  which  are  present  in  butter  to  the 
extent  of  about  17  per  cent. 

For  testing  milk  the  Babcock  method  is  recommended 

as   trustworthy  for  whole  milk,  but  as  less  reliable  for 

butter-milk  and  skim-milk.     Milk  when  partially  frozen 

is  not  in  a  condition  to  be  sampled. 

The  use  of  pure  cultures,  or  as  they  are   here   called 


"  starters,"  seems  to  be  attracting  attention  in  America 
for  the  ripening  of  cream. 

The  results  of  the  lactometer  are  shown  as  liable  to 
error  on  account  of  the  complex  composition  of  milk. 
Cream  itself  is  variable,  as  it  may  contain  as  much  as  60 
per  cent  of  fat.  The  higher  the  temperature  reached  in 
churning,  washing,  and  working,  the  less  is  the  proportion 
of  water  retained  in  the  butter. 

We  find  here  no  mention  of  the  vegetable  matters 
which  in  cheese-making  may  be  used  as  substitutes  for 
rennet. 

It  will  be  remarked  here  that  in  America  a  difference 
seems  to  be  made  between  oleo-margarine  and  butterin, 
the  former  being  harder  and  less  fusible.  With  us  this 
difference  does  not  obtain,  oleomargarine  being  the  name 
recognised  by  the  law.  It  may  here  be  noted  that  the 
butter  now  obtained  from  the  milk  of  the  cocoa-nut  is 
more  digestible  than  cow-butter. 

This  very  useful  manual  is  addressed  not  to  experts, 
but  to  young  men  preparing  themselves  for  the  position 
of  the  dairy-farmer. 


Engineering  Chemistry  ;  A  Manual  of  Quantitative 
Chemical  Analysis  for  the  Use  of  Students,  Chemists, 
and  Engineers.  By  Thomas  B.  Stillman,  M.Sc, 
Ph.D.,  Professor  of  Analytical  Chemistry  in  the 
Stevens  Institute  of  Technology.  With  154  illustra- 
tions. Easton,  Pennsylvania :  Chemical  Publishing 
Company. 

The  Publishing  Company  of  Pennsylvania  is  decidedly 
earning  a  high  and  well-merited  regulation  for  the  produc- 
tion of  works  on  technical  chemistry.  The  title  of  the  volume 
might  with  advantage  be  somewhat  modified.  Perhaps  we 
might  suggest  "Manualof  Quantitative  Analysis, especially 
arranged  for  the  Use  of  Engineers."  But  there  is  one 
sedtion  which  could  not  be  legitimately  placed  under 
such  a  caption.  We  refer,  of  course,  to  the  copious  and 
ably-written  instrudtions  for  the  sanitary  analysis  of 
water,  a  subjedt  belonging  to  the  medical  pradtitioner,  or 
the  chemist  truly  so-called,  rather  than  to  the  engineer. 
Here,  however,  we  find  no  mention  of  the  "tintometer" 
which  is  generally  found  preferable  to  the  various  calori- 
meters. Much  of  the  matter  on  soaps  can  scarcely  be 
called  engineering  chemistry. 

On  the  other  hand,  something  might  have  been  usefully 
added  to  the  remarks  on  filters.  The  Pasteur  filter, 
which  is  generally  found  the  best— at  least  for  work  on 
a  domestic  scale — does  not  seem  to  be  mentioned. 

The  reader  will  be  fully  aware  that  the  weights  used  in 
the  United  States  of  America  are  identical  with  the 
British  standards.  But  this  agreement  unfortunately 
does  not  extend  to  the  measures  for  liquids.  The 
American  gallon  is  about  equal  to  the  old  English  wine 
gallon.  The  obstinacy  with  which  America,  like  France 
and  Germany,  clings  to  Baume's  hydrometer  is  painful. 
If  there  is  any  occult  reason  why  commercial  men  should 
not  or  cannot  use  the  diredt  specific  gravity  scale,  why 
not  use  Twaddle,  which  exists  only  in  one  type,  and 
which  is  easily  and  simply  re-calculated  into  diredt 
specific  gravity  ? 

Engineers  will  find  this  book  a  most  useful  and  trust- 
worthy guide. 

Report  on  the  Teaching  of  Chemistry  by  a  Special  Sub- 
Committee  appointed  by  the  Technical  Education  Board 
of  the  London  County  Council,  November  23rd,  1896. 
We  hope  that  in  our  endeavours  to  realise  a  worthy 
standard  of  education  in  this  country,  we  shall  not 
remind  the  world  of  the  too  many  cooks  who  spoiled  the 
broth.  We  can  scarcely  enumerate  the  various  public 
and  semi-public  bodies  who  have  their  fingers  in  John 
Bull's  pie.  Some  boards  and  committees  concerned  are, 
if  we  consider  their  origin,  little  likely  to  play  a  very 
salutary  part.   But  some  of  the  gentlemen  whose  opinions 


Ii8 


Bread  and  Panification, 


IOhbmical  Nbws, 
\     March  5,  1807. 


are  here  put  on  record  are  fully  qualified  to  speak  on 
higher  education,  and  deserve  a  respedtful  hearing. 
Thus,  Mr.  D.  Howard,  Dr.  Armstrong,  and  Dr.  Tildendo 
not  consider  that  examination  seledls  the  best  students. 
"  The  best  thing  to  be  done  in  London  to  promote  this 
higher  instrudtion  is  to  extend  the  system  of  senior 
scholarships."  These  scholarships  should  on  no  account 
be  awarded  as  the  results  of  an  examination,  but  as  the 
personal  recommendation  of  the  professors  upon  whom 
the  responsibility  must  be  thrown  of  nominating  only 
students  of  promise.  Such  scholars  after  about  two  years 
of  special  training  in  research  should  be  able  to  work  by 
themselves."  "  A  person  who  is  studying  for  the  B.Sc. 
degree  is  handicapped  as  far  as  pradtical  work  is  con- 
cerned, as  he  has  to  cram  for  his  examinations.  The 
boys  cannot  be  picked  out  by  mere  examination,  but  by 
careful  observation  of  their  work,  bcholarships  gained 
by  examination  have  done  higher  education  a  good  deal 
of  injury." 

In  short,  a  careful  survey  of  the  opinions  expressed  by 
the  authorities  here  quoted  shows  more  than  ever  that  the 
blind  reliance  on  examinations  as  a  test  of  merit  is  nearing 
its  end.  "  The  seledion  should  rather  be  determined  by 
the  recommendation  of  the  head  master  of  the  school 
from  which  a  pupil  may  proceed,  based  on  the  work  of 
the  candidate  throughout  his  whole  school  career. 

This  is  substantially  the  system  which  has  worked  so 
successfully  in  Germany. 

The  conclusions  drawn  from  the  evidence  submitted 
are: — 

1.  That  chemistry  is  a  valuable  subjedl  for  school 
teaching. 

2.  That  it  should  be  preceded  by  elementary  courses 
of  physics, 

3.  That  the  work  should  be  always  largely  pradtical. 

4.  That  no  attempt  should  be  made  to  impart  in 
schools  any  knowledge  of  the  application  of  chemistry 
for  commercial  purposes. 

5.  That  in  seledling  candidates  for  the  higher  science 
training  a  written  examination  is  insufficient  and  inad> 
visable. 

This  report  is  worth  the  most  careful  attention  of  all 
who  are  or  aim  at  becoming  authorities  on  national 
instruction. 


Selection  of  Procedures  for  the  Analysis  of  Fuels,  Iron 

Ores,  Castings,  Steels,  and  Irons.    (Recueil  de  Procedes 

de    Dosage    pour    I'Analyse    des    Combustibles,    des 

Minerals  de  Fer,  des  Pontes,  des  Aciers,  et  des  Fers). 

By  G.  Arth,  (Professeur  de   Chimie  Industrielle  a  la 

Faculte  des  Sciences  de  Nancy.     Paris :  G.  Carre  and 

C.  Naud.    8vo.,  pp.  313.     1897. 

The  present  development  of  the  iron   and  steel  manu- 

fadtures,  and  the  extension  of  the  industrial  applications, 

has  naturally  led  to  the  appearance  of  such  works  as  that 

before  us. 

The  author  tells  us  in  this  preface  that  he  does  not  offer 
a  treatise  on  analysis,  but  merely  a  seledion  of  the  pro- 
cedures in  use  in  the  principal  siderurgical  establishments 
and  of  other  methods  which  it  may  be  useful  to  know. 
He  remarks  that  industrial  analyses  are  of  two  different 
kinds.  On  the  one  hand  easy  and  rapid  methods  for 
daily  use,  and  on  the  other  difficult  procedures  for  estab- 
lishing the  composition  of  substances  taken  as  types,  or 
for  checking  doubtful  results  or  such  as  have  been  the 
subjedt  of  dispute. 

No  fewer  than  60  pages  are  here  devoted  to  the  assay 
and  analysis  of  fuels.  The  exa(Sl  difference  between 
assay  and  analysis  is  scarcely  as  clear  as  it  might  be 
desirable.  "  Assay "  may  mean  either  a  qualitative 
operation,  or  perhaps  the  determination  of  some  leading 
ingredient.  He  determines  phosphorus  in  the  ashes  of 
the  fuel  by  means  of  the  molybdenum  method. 

He  determines  the  calorific  power  of  a  fuel  by  calori- 
metric  methods,  using  the  bombs  of  Hempel,  of  Mahler, 


and  Berthelot.  A  whole  page  plate  shows  the  installation 
of  the  bomb  at  the  Chemical  Institute  of  Nancy,  whilst  a 
table  exemplifies  the  calculation. 

There  is  also  an  account  of  the  determination  of  calori- 
metric  power  by  evaporation,  and  experiments  in  the 
boilers  of  industrial  establishments.  Three  steam  units 
may  be  employed,  those  of  Rankine,  Brix,  and  Hartig, 
equal  respedively  to  537,  540"6,  and  552*2  cal.  Then 
follows  an  account  of  the  values  of  gaseous  fuels  ;  to  wit, 
the  gases  of  gazogens,  of  blast  furnaces,  the  gaseous 
mixtures  of  the  Dawson  system.  A  chapter  is  also 
devoted  to  gas  analysis,  i.e.,  gases  not  employed  as  fuels 
but  still  summed  up  under  the  head  assay  and  analyses 
of  combustibles. 

The  second  part  is  occupied  with  the  "  assay  and 
analysis  of  ores,"  mainly,  of  course,  those  of  iron.  The 
analysis  of  titaniferous  irons  is,  however,  explained  at 
some  length  according  to  the  indication  of  Posti.  It  is 
remarked  that  the  presence  of  titanic  acid  introduces 
several  causes  of  error  in  determinations  executed  in  the 
ordinary  manner.  It  is  also  stated  that  oxygenated  water 
is  an  excellent  reagent  for  detecting  the  presence  of 
titanic  acid,  as  in  acid  solutions  containing  this  titanic 
acid  it  produces  a  fine  orange-yellow. 

A  third  part  of  the  work  discusses  the  analysis  of 
metallic  produtfts,  iron  castings,  and  steels.  There  is 
also  the  procedure  of  T.  Parry  and  J.  J.  Morgan  for  the 
analysis  of  titanium,  and  the  determination  of  phosphoric 
acid  in  basic  slags. 

Bread  and  Panification  ;  Chemistry  and  Technology  of 
Baking  and  Grinding.  ("  Le  Pain  et  la  Panification 
Chimie  et  Technologie  de  la  Boulangerie  et  de  la 
Meunerie").  By  LfioN  Boutroux,  Professeur  de  Chemie 
Doyen  de  la  Facult6  des  Sciences  de  Besan^on. 
Paris  :  J.B.  Bailliere  et  Fils.  Pp.358.  1897. 
France  has  long  been  distinguished  for  its  eminence  in 
the  art  of  baking  and  all  the  collateral  branches. 

Hence,  an  author  who  combines  the  traditional  skill 
of  his  country  with  a  full  insight  into  the  results  of 
of  modern  Science  is  well  worthy  of  our  careful  attention. 
Professor  Boutroux,  moreover,  has  not  confined  his 
studies  to  French  authorities,  but  has  utilised  the  treatises 
of  Birnbaum  and  Jago,  so  that  he  is  able  to  lay  before  his 
readers  the  full  results  of  the  experience  of  the  day. 

From  an  analysis  here  given  of  wheats  as  produced  in 
different  countries  we  find  the  highest  rank  in  percentage 
of  gluten  and  albumen  belongs  to  a  Polish  wheat,  namely, 
21*5  per  cent,  whilst  the  second  place  falls  to  Egyptian 
wheat  with  2o"6  per  cent.  If  we  contrast  these  figures 
with  the  white  provincial  wheat  of  9*8,  we  shall  not  con- 
clude that  temperature  and  latitude  are  main  fadlors  in 
the  growth  of  superior  wheats.  In  a  dry  season,  how- 
ever, the  nitrogen  is  much  higher  than  in  medium  and 
moist  years. 

The  different  parts  of  the  grain  are  by  no  means  chemi- 
cally identical,  and  vary  in  consequence  in  their  physio- 
logical adlivity.  The  "  entire  flour  "  so  much  valued  in 
Britain  owes  its  laxative  properties — annoying  and  even 
dangerous  to  some  persons  if  beneficial  to  others — to  the 
soluble  matter  of  its  coatings. 

The  use  of  rollers  in  milling  was  first  applied  in  Hun- 
gary about  1874,  and  established  itself  in  Western  Europe 
since  1878. 

The  theory  of  panary  fermentation  is  thus  summed  up. 
It  consists  essentially  in  an  alcoholic  fermentation  by 
means  of  yeast  and  of  the  sugar  pre-existing  in  the  flour. 
According  to  Bibra's  analyses  of  bread  the  composition 
and  even  the  reactions  difl^er  greatly.  Some  white  breads, 
e.g.,  those  of  St.  Petersburg,  are  neutral.  The  rye  bread 
of  Niiremburg  and  of  Stockholm  is  acid  ;  so  is  also  the 
notorious  pumpernickel  of  Westphalia,  a  whole-meal 
bread  containing  a  little  extra  bran.  A  still  inferior  bread, 
Keilchen,  is  made  in  some  parts  of  Saxony  and  Silesia. 
The  frauds  committed  by,  or  ascribed  to,  bakers  are 


Crruical  Nbws,  I 
March  s,  1897.     I 


Chemical  Notices  from  Foreign  Sources. 


119 


classified  as — (i)  The  use  of  an  excess  of  water  ;  (2)  the 
use  of  damaged  flours  ;  (3)  the  addition  of  alien  flours  ; 
and  lastly  (4),  tha  addition  of  saline  waters  other  than 
sodium  chloride. 

This  book  will  prove  very  valuable  to  public  analysts, 
medical  officers  of  health,  and  pharmacists. 

Conspectus  of  Chemical  Analysis.     Part   I.— Qualitative 
Analysis.     ("  Precis  d'Analyse  Chimique."      Premiere 
Partie. — Analyse  Qualitative).      By  E.  Fink,  Chef  des 
Travaux  Pratiques  d'Analyse  a  I'Ecole  de  Physique  et 
de  Chimie   Industrielle   a  la   Ville   de  Paris.     Paris: 
Georges  Carres.     1896. 
This  little  manual  describes,  in  the  first  place,  the  re- 
actions in  the  dry  way,  and  then  the  reagents  employed 
in  the  solid  and  in  the  liquid  state.     The  author  then 
proceeds  to  the  assay,  and  in  the  dry  way,  including  the 
use  of  the  spedtroscope.     Next  follows  a  classification  of 
the  metals  from  an  analytical  point  of  view,  in  which  we 
perceive   that   not   a    few    of    the   rarer  substances    are 
omitted.     Next  we   come  to  the  readlions   of  the  acids, 
classified  as  the  sulphuric,  the  hydrochloric,  the   nitric, 
the  oxalic,  the  succinic,  and  acetic  groups. 

What  may  be  called  an  Appendix  treats  of  the  prepara- 
tion of  the  substances  to  be  analysed,  the  systematic 
procedure  for  the  detection  of  bases  and  acids,  and  the 
arrangement  of  the  results. 


CORRESPONDENCE 


HOW    SOON    SHALL    STUDENTS    BEGIN    THE 

STUDY     OF     QUALITATIVE     ANALYSIS? 

A  Rejoinder. 

To  the  Editor  of  the  Chemical  News. 
Sir, — We   perused   Mr.    Beebe's    article   on   the    above 
question  with  interest,  but  we  are  quite  unable  to  agree 
with  the  conclusions  he  draws. 

Mr.  Beebe  has  three  objedtionsto  the  student  beginning 
his  laboratory  course  with  the  study  of  the  preparation 
and  properties  of  simple  gases,  &c.  We  take  these  ob- 
jections in  order. 

1.  "  The  experiments  are  dangerous."  Quite  true,  if  the 
manipulation  is  careless ;  but  is  not  a  careless  student 
just  as  likely  in  qualitative  analysis  to  send  half  a  test- 
tube  of  hot  acid  into  his  neighbour's  face,  as  to  blow  him 
up  with  a  flask  of  impure  hydrogen  when  preparing  that 
gas  ?  And  if  a  spirit  of  recklessness  is  abroad  in  the 
laboratory,  whose  fault  is  it?  Mr.  Beebe  mentions  hy- 
drogen and  phosphorus  especially,  in  this  connexion.  If 
the  former  be  prepared  in  &  small  flask,  and  not  a  WoulfFs 
bottle,  the  danger  is  lessened.  All  experiments,  too,  can 
be  performed  with  small  quantities  of  the  gas  ;  and  the 
combustion  of  hydrogen,  to  show  the  produdion  of  water, 
is  of  course  left  till  late  in  the  lesson,  when  the  flasks  are 
free  from  air.  Students  should  be  warned  of  any  dangerous 
practice. 

Phosphorus  need  not  be  burned  in  oxygen,  since  carbon 
and  sulphur  could  be  used,  but  small  fragments  may  very 
well  be  given  out  by  the  demonstrator  as  required,  and  the 
experiment  performed. 

Here,  in  an  organised  science  school,  we  have  classes 
of  boys  and  girls,  from  eleven  to  fourteen  years  of  age, 
working  two  lessons  a  week,  and  no  accident  whatever 
has  occurred  under  the  new  Science  Syllabus  for  the  past 
two  years. 

But,  assuming  that  such  a  course  is  dangerous,  we  fail 
to  see  that  practice  in  warming  liquids  in  test-tubes,  or  in 
flltering  off  precipitates,  trains  a  student  to  handle  the 
evolution  flask  or  the  deflagrating  spoon.  An  hour's  drill 
in  the  fitting  up  and  corre(5t  use  of  apparatus  would  ac- 
complish far  more  in  this  respedt. 

2.  Unconnectedness.  By  this  term  Mr.  Beebe  would 
apparently  have  us  understand  that  opportunities  for 
revision  are  wanting   in  the  course  he  condemns.     His 


ideal  seems  to  be  after  a  "  This-is-the-house-that-Jack- 
built"  principle.  A  series  of  lessons  dealing  with  non- 
metallic  elements  can  be  made  to  follow  one  another  in 
logical  sequence,  and  when  twelve  have  been  covered  it 
is  a  good  plan  to  repeat  them.  But  the  constant  repe- 
tition,  such  as  is  obtained  in  qualitative  analysis,  soon 
produces  mechanical  work,  and  has  then  little  educational 
value. 

3.  Interest.  This  can  certainly  be  well  maintained  by 
the  course  Mr.  Beebe  criticises.  Variety  is  always  inte- 
resting, and  the  preparation  of  simple  gases,  supplemented 
by  easy  quantitative  experiments,  gives  far  more  scope  in 
this  direction  than  does  qualitative  analysis.  Our  young 
students  give  unmistakable  proofs  that  they  find  their 
work  here  interesting. 

Again,  Mr.  Beebe  says  that  the  student  should  have  a 
good  knowledge  of  the  preparation  and  properties  of  non- 
metallic  elements  before— or  at  any  rate  while— he  is  en- 
gaged in  qualitative  analysis.  Our  experience  is  that 
this  knowlege  is  very  slowly  gained  from  "  leCtures,"  no 
matter  how  ably  "  illustrated  by  experiments  "  they  may 
be.  What  things  of  mystery  our  chemical  ledtures  were 
to  us  as  youngsters  twenty  years  ago  !  But  direCtly  a 
student  begins  to  do  the  experiments  for  himself,  and 
record  his  own  observations  and  inferences  in  his  note- 
book, the  assimilation  of  this  knowledge  proceeds  apace. 

Finally,  is  there  nothing  to  be  said  as  to  the  relative 
educational  value  of  the  two  systems  ?  We  would  train 
our  pupils  to  be  deft  in  manipulation,  keen  to  observe  and 
discriminate,  and  accurate  in  drawing  an  inference. 

The  use  of  test-tubes  and  reagent  bottles,  the  colours 
and  appearances  of  precipitates,  do  not  carry  us  far 
towards  such  a  goal,  while  the  "  inferences  "  are  mainly 
matters  of  memory.  That  which  by  constant  repetition 
is  performed  mechanically  ceases  to  have  any  value  as  a 
mental  exercise,  and  young  students  soon  acquire  a  very 
mechanical  way  of  "  getting  out"  salts. 

But,  on  the  other  hand,  in  determining  the  properties 
of  a  common  gas,  the  pupil's  attention  is  kept  on  the  qui 
Vive  all  the  lesson  ;  he  has  fresh  observations  to  chronicle 
and  new  inferences  to  draw  continually,  while  the  arrange- 
ment and  fitting  up  of  his  varied  apparatus  cultivates  his 
manipulative  powers.  Nor  must  the  quantitative  side  be 
forgotten.  A  lad  of  twelve,  who  has  worked  with  us  six 
months,  with  one  pradlice  lesson  weekly,  has  just  found 
experimentally  that  145  m.grms.  of  mercuric  oxide,  when 
heated  in  a  combustion-tube,  give  off  6'2  c.c.  of  oxygen, 
and  leave  a  residue  of  mercury  weighing  133  m.grms. 
Such  an  exercise  has  done  more  for  his  education  than 
the  qualitative  analysis  of  half-a-dozen  simple  salts. — 
I  am,  &c., 

H.  WiGLEY,  6. A.,  F.C.S. 
Winsford. 

CHEMICAL    NOTICES    FROM    FOREIGN 
SOURCES. 

Comptes  Rendus  Hebdomadaires  des  Seances,  dePAcademie 
des  Sciences.     Vol.  cxxiv.,  No.  5,  February  i,  1897. 

Constitution  of  the  Combination  of  Antipyrine 
with  the  Phtnols.— G.  Patein. — The  author  infers  that 
—  I.  Monomethylphenyl  pyrazolone  does  not  combine 
either  with  phenols  or  acid  phenols.  2.  Of  the  two 
atoms  of  nitrogen  in  antipyrine,  the  nitrogen  i,  being 
entirely  in  the  same  relations  in  the  mols.  of  dimethyl 
pyrazolone  and  of  monomethyl  pyrazolone,  antipyrine 
fixes  the  phenols  by  means  of  nitrogen  2.  3.  The  exist- 
ence of  the  combinations  of  antipyrine  and  the  phenols 
cannot  be  reconciled  wieh  the  supposition  of  E.  von 
Meyer,  according  to  which  antipyrine  might  be  considered 
as  a  sort  of  betaine. 

Determination  of  Lipase. — MM.  Hanriot  and  Camus. 

Separation  of  Glycerin  in  Wines  by  Elimination 
in  Watery  Vapours. —  MM.  F.  Bordas  and  Sigoda 
Raczkonski. 


120 


Meetings  for  the  Week, 


(CHBMICAL  ftEWS, 

1     March  5,  1897. 


NOTES    AND    QUERIES. 

%*  Our  Notes  and  Queries  column  was  opened  for  the  purpose  of 
giving  and  obtaining  information  likely  to  be  of  use  to  our  readers 
generally.  We  cannot  undertake  to  let  this  column  be  the  means 
of  transmitting  merely  private  information,  or  such  trade  notices 
as  should  legitimately  come  in  the  advertisement  columns. 

Purifying  Mercury. — I  shall  be  obliged  if  any  correspondent  can 
tell  me  how  to  purify  a  quantity  of  mercury  I  have  got.  Some  zinc 
has  been  dissolved  in  it.  I  have  no  apparatus  tor  distilling  the  mer- 
cury properly,  so  that  method  is  impracticable.  At  present  the  mer- 
cury  adheres  to  glass,  and  so  is  useless  for  a  large  number  of  experi- 
ments.— J.  MacGregor. 


MEETINGS    FOR    THE    WEEK. 

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Estimation  of  Sulphur  in  Irony  Steel,  and  Sulphides  of  Iron.        121 


THE    CHEMICAL     NEWS. 

Vol.  LXXV.,  No.  1946. 

VOLUMETRIC    ESTIMATION    OF    SULPHUR 

IN   IRON,  STEEL,   AND   SULPHIDES   OF    IRON. 

By  G.  G.  BOUCHER. 

There  is  only  one  volumetric  process,  I  believe,  for  the  esti- 
mation of  sulphur  in  iron  and  steel  in  general  use,  viz.,  the 
iodine  method.  It  is  fairly  accurate  and  quick,  but  has  one 
great  disadvantage — the  solutions  do  not  keep  well.  If 
kept  for  any  length  of  time  they  lose  their  strength, 
especially  if  exposed  to  sunlight,  and  consequently  have 
to  be  frequently  re-standardised.  It  occurred  to  me  that 
if  it  were  possible  to  obtain  a  process  where  only  one 
solution  is  used,  and  that  one  a  solution  which  would 
keep  its  strength  for  any  length  of  time,  it  would  be  a 
distindt  advantage. 

This  I  found  could  easily  be  done ;  and  the  following 
process  will,  with  care,  be  found  to  give  very  good  results, 
which  will  compare  well  with  those  given  by  the  iodine 
method. 

The  apparatus  used  in  this  method  is  the  same  as  that 
used  in  the  iodine  process. 

From  10  to  15,  or  even  20,  grms.  of  iron  or  steel  are 
weighed  out  into  a  flask,  which  is  then  connedled  to  the 
U-tube.  Fifteen  c.c.  of  a  solution  (strength  5E)  of  NaHO 
are  run  into  the  U-tube,  and  then  sufficient  HCl  (strength 
5E)  run  into  the  flask  to  dissolve  the  iron.  The  flask 
and  contents  are  gently  heated,  and  when  the  metal  has 
completely  dissolved  the  solution  is  heated  to  boiling. 
The  U-tube  is  now  disconne(5ted,  and  the  contents  run 
slowly  into  an  acid  solution  of  Fe2Cl6.  H2S  is  liberated, 
and  a  portion  of  the  iron  is  reduced.  The  reduced  iron 
is  then  estimated  by  a  standard  solution  of  K2Cr207,  and 
it  will  be  evident  from  the  formulae  below  that  each  c.c. 
of  K2Cra07  used  will  be  equivalent  to  a  certain  quantity 
of  sulphur. 

(i).  Fe2Cl6  +  H2S  =  2FeCl2+2HCl+S. 
(2).  6FeCla+K2Cr207+i4HCl  = 

=  3Fe2Cl6-|-2KCl  +  Cr2Cl6+7H20. 

By  dissolving  3"o65  grms.  of  K2Cr207  in  1000  c.c.  of 
distilled  water,  a  solution  is  obtained  i  c.c.  of  which  is 
equivalent  to  o'ooi  grm.  sulphur.  A  solution  of  twice 
this  strength  is  used  for  the  estimation  of  small  quantities, 
but  when  the  sulphur  is  believed  to  be  above  o"i5  percent, 
it  is  advisable  to  use  a  stronger  solution,  and  the  standard 
solution  used  in  the  analysis  of  iron  ores  is  used,  i  c.c.= 
0'0057i  grm.  of  sulphur. 

The  ferric  chloride  solution  used  is  made  by  adding  a 
solution  of  ferric  chloride,  containing  o'l  grm.  of  iron  in 
I  c.c,  to  50  c.c.  of  hot  HCl  (strength  5E).  The  amount 
of  ferric  chloride  required  should  be  calculated,  as  it  is 
not  advisable  to  have  a  large  excess  ;  about  0'5  or  i  c.c. 
is  usually  found  sufficient. 

The  bichromate  solution  can  be  standardised  by  pure 
iron  wire  or  ferrous  ammonium  sulphate,  but  a  better 
method  is  to  dissolve  about  15  grms.  of  iron  or  steel,  in 
which  the  sulphur  has  already  been  determined  gravi- 
metrically,  and  treat  the  metal  as  described  above.  The 
amount  of  bichromate  required  to  oxidise  the  reduced 
iron,  divided  by  the  amount  of  sulphur  known  to  be  pre- 
sent in  the  15  grms.  weighed  out  will  give  the  value  of 
each  c.c.  in  sulphur. 

Sulphur  in  Sulphides  of  Iron. 
If  the  sulphide  is  soluble  in  HCl,  0*5  grm.  is  weighed 
out  into  a  300  c.c.  flask,  dissolved  in  about  40  c.c.  HCl 
(strength  5E),  and  treated  in  the  same  way  as  iron.    If 


the  sulphide  is  insoluble  in  HCl,o'5  grm.  is  weighed  out 
into  a  porcelain  crucible  and  mixed  with  an  excess  of  pure 
iron  (6  grms.).  The  crucible  is  then  filled  up  with  ground 
charcoal,  covered  with  a  lid,  and  heated  to  redness  in  a 
muffie  with  a  closed  door  for  ten  or  fifteen  minutes.  The 
crucible  is  then  taken  out,  allowed  to  cool,  the  contents 
emptied  into  a  300  c.c.  flask  and  treated  as  soluble 
sulphide. 

It  is  advisable  to  make  a  blank  experiment,  using  the 
same  quantity  of  iron,  &c.,  required  by  this  method.  The 
iron  is  sure  to  contain  a  little  sulphur,  which  would  make 
the  results  appear  higher  than  they  should  be.  Below  I 
give  some  analyses  by  this  method. 


Bessemer  Iron, 

Gravimetric  method. 

KjCr,0,  method 

S  per  cent. 

S  per  cent. 

Sample  i 

..     ..     0-04I 

0*038 

..       2 

.  „     ..     0-015 

0*017 

..       3 

.        . .       0'020 

0023 

.,       4 

.        . .       0-028 

Mottled  Iron. 

0*030 

Sample  i 

.     ..     0*312 

0320 

11       2 

..     0*411 

0*399 

..       3 

.     . .     0*295 

0*296 

..       4 

.     . .     0*384 

0*387 

Sulphides  of  Iron  (Insoluble). 

Sample  i 

..     ..     48*61 

49*25 

2 

. .     . .     30*68 

30*97 

..       3 

.     ..     3256 

32*14 

..       4 

..     ..     sro 

51*10 

..       5 

.     . .       0*707 

0773 

The  process  is  a  quick  one ;  an  analysis  of  iron,  steel, 
or  sulphide  for  sulphur  can  be  made  comfortably  in  about 
half  or  three-quarters  of  an  hour.  When  the  percentage 
of  sulphur  is  very  low  considerable  care  is  required  at 
the  finish  of  the  process ;  the  indicator  should  show  no 
sign  of  any  blue  colour  for  the  space  of  one  minute. 

I  tried  this  method  on  a  sample  of  copper  sulphide  with 
the  objedl  of  seeing  whether  it  would  be  possible  to  deter- 
mine the  sulphur  volumetrically.  I  expeded  that  some 
of  the  sulphur  would  be  detained  by  the  copper,  but 
thought  the  experiment  worth  trying.  The  copper  sul- 
phide was  first  heated  with  pure  iron  in  a  muffle,  and 
afterwards  treated  just  as  sulphide  of  iron.  The  results 
I  give  below : — 

Copper  Sulphide. 


Gravimetric  process. 
S  per  cent. 

Experiment  I..     ..     24*0 
„         2..     ..     24*0 


Volumetric  process. 
S  per  cent. 

22*30 
2274 


The  idea  of  heating  the  iron  sulphide  with  pure  iron  in 
a  muffle  is  not  mine;  it  is  a  process  devised  by  F.  P. 
Tread  well,  and  can  be  found  in  the  journal  of  the  Chemical 
Society,  vol.  Ix. 

Laboratory,  North  Lonsdale  Iron  Works, 
Ulverston. 


ESTIMATION    OF    BORIC    ACID    IN    FOODS. 

By  L.  DE  KONINGH. 

The  estimation  of  boric  acid,  at  one  time  very  trouble- 
some, has  become  quite  an  easy  matter  since  the  discovery 
that  it  may  be  accurately  titrated  in  presence  of  glycerol 
with  phenolphthalein  as  indicator.  To  apply  the  process 
to  articles  of  food  (and  I  will  confine  myself  for  the  pre- 
sent to  milk  and  uncooked  eggs)  some  few  precautions 
must,  however,  be  taken. 
Boric  acid  is  seldom  used  alone,  but  mostly  in  admixture 


122 


Electric  Shadows  and  Luminescence, 


(  Crbuical  News, 
(   March  I2, 1897. 


with  borax,  a  mixture  of  three  parts  of  the  acid  with  one 
part  of  ground  borax,  constituting  the  article  known  as 
glacialine.  In  pradlice  it  is,  however,  in  my  opinion,  not 
necessary  to  make  a  distindtion  between  the  acid  and  its 
sodium  salt,  as  both  are  no  doubt  equally  harmless  in 
small  quantities;  but  if  the  amount  of  either  reaches 
I  per  cent  or  more  the  time  has  come  for  a  protest. 

When  testing  uncooked  eggs  (the  entire  contents  beaten 
up]  for  boric  acid,  I  take  5  grms.  of  the  sample,  add  one 
drop  of  sodium  hydroxide  (i  :  i),  dry,  and  finally  incine- 
rate. The  char  is  then  powdered,  boiled  with  water,  and 
the  residual  black  mass  again  burnt.  The  ash  is  also 
boiled  with  water,  and  the  two  solutions  are  united.  The 
liquid  is  now  faintly  coloured  by  methyl  orange,  and  tenth- 
normal sulphuric  acid  is  added  until  a  faint  pink  is  ob- 
tained. The  solution  is  now  boiled  for  a  minute  to  expel 
carbon  dioxide,  cooled,  mixed  with  one-half  of  its  bulk  of 
glycerol,  and  titrated  with  tenth-normal  sodium  hydroxide, 
with  phenolphthalein  as  indicator.  Although  it  is  now 
admitted  that  in  presence  of  glycerol  the  amount  of  acid 
may  be  calculated  from  the  number  of  c.c.  of  sodium 
hydroxide  used,  I  prefer  to  check  my  sodium  hydroxide 
with  pure  crystallised  boric  acid,  using  about  the  same 
quantity  as  present  in  the  sample,  and  mixing  this  up 
with  exadtly  the  same  amount  of  glycerol  and  water. 
Working  in  this  manner  the  estimation  of  boric  acid  is, 
as  regards  accuracy,  second  to  none. 

It  must,  however,  be  remembered  that  eggs  contain  a 
small  quantity  of  alkaline  phosphates,  and  that  phosphoric 
acid  behaves  somewhat  like  the  boric  acid.  A  method  of 
removing  this  acid  has  already  been  proposed  and  is  based 
on  the  insolubility  of  calcium  phosphate  and  the  compara- 
tively large  solubility  of  the  borate.  I  find,  however, 
that  in  uncooked  eggs  there  is  just  enough  phosphoric 
acid  to  account  for  3  cc.  tenthnormal  sodium  hydroxide, 
when  working  on  5  grms.  of  sample,  so  I  now  propose  to 
dedudt  3  c.c.  of  sodium  hydroxide  from  the  number  of  c.c. 
taken  by  the  sample.  I  scarcely  need  point  out  the  neces- 
sity of  proving  the  acid  by  the  alcohol  test.  As  a  rule  the 
presence  may  be  ascertained  by  simply  stirring  some  of 
the  sample  with  a  drop  of  sulphuric  acid  and  a  little  spirits 
of  wine  and  then  setting  fire  to  it. 

When  dealing  with  milk  I  allow  i  c.c.  of  sodium 
hydroxide  for  every  10  grms.  of  the  sample.  If  the 
amount  of  acid  is,  as  usual,  very  small,  no  particular 
accuracy  can  be  claimed  for  the  process ;  but  if  present 
in  larger,  and  consequently  harmful,  quantity,  the  results 
are  all  that  may  be  desired. — journal  of  the  American 
Chemical  Society,  xix.,  No.  i,  p.  55. 


ELECTRIC    SHADOWS  AND    LUMINESCENCE.* 

By  Prof.  SILVANUS  P.  THOMPSON,  D.Sc,  F.R.8.,  M.R.I. 
(Continued  from  p.  113). 

Having  touched  all  too  briefly  upon  the  researches  of 
Lenard,  it  remains  for  me  to  speak  of  those  of  Wiede- 
mann, of  Erlangen,  who  for  many  years  has  made  a  study 
both  of  the  phenomena  of  ele(5lric  discharge  and  of  those 
of  fluorescence  and  phosphorescence.  In  a  research 
made  in  the  year  1895  he  attained  some  results  of  singular 
interest.  He  had  been  making  eledtric  discharges,  in 
collaboration  with  Prof.  Ebert,  by  a  special  apparatus  for 
producing  eledtric  oscillations  of  high  frequency.  This 
apparatus,  in  the  modified  form  given  to  it  by  Ebert 
{Wiedemann's  Annalen,  liii.,  p.  144,  1894),  stands  on  the 
table  before  you.  It  is  an  apparatus  ol  the  same  class  as 
that  described  here  some  years  ago  by  Oliver  Lodge,  for 
producing  Hertzian  waves.  An  oscillating  spark  is  pro- 
duced between  two  polished  balls  set  between  two  con- 
densers, A  and   B,   each   made   of  plates  of  sheet  zinc 

*  A  Ledlure  delivered  at  the  Royal  Institution  of  Great  Britain, 
Friday,  May  8, 1896. 


(Fig.  7)  a  few  m.m.  apart.  Their  external  circuit  is 
however,  led  into  the  primary  of  a  small  indudtion-coil, 
the  secondary  of  which  goes  to  a  third  condenser,  c. 
When  sparks  from  the  Apps  coil  are  sent  to  the  spark-gap, 
the  oscillations  of  the  two  primary  condensers  set  up 
secondary  oscillations  in  the  third  condenser,  to  which  a 


Fig.  7. 

vacuum  tube  can  be  conneded.  If,  now,  by  adjusting  the 
distances  between  the  plates  of  condensers,  we  tune  the 
primary  and  secondary  circuits  together,  the  eledric  oscil- 
lations that  result  will  persist  much  longer  than  if  the 
circuits  are  not  so  tuned.     Though  each  oscillation  may 


Fig.  8. 


last  less  than  the  loo-millionth  of  a  second,  there  will  be 
at  each  spark  some  20,000  or  30,000  oscillations  before 
they  have  died  out.  Wiedemann  and  Ebert  have  found 
that  these  persistent  oscillations  are  specially  adapted  to 


Fig.  9. 

excite  luminescence.  To  illustrate  the  point  I  seledl  here 
an  old  Geissler  tube  with  a  comparatively  poor  vacuum. 
When  stimulated  by  ordinary  sparks  diredlly  from  the 
Apps  coil  through  the  platinum  ele^rodea  at  its  ends,  it 


CRBMICAL  NbWS,  I 

March  12, 1897.  f 


Electric  Shadows  and  Luminescence, 


123 


f^- 


'^M 


Fig.  10. 


shows  the  usual  features  of  Geissler  tubes:  there  is  a 
luminous  column  extending  through  the  central  bulb  with 
stratifications  along  its  length,  while  around  the  kathode 
is  the  usual  violet  glow.  The  glass  shows  no  fluorescence. 
I  now  charge  the  conne<5lions,  uniting  the  wires  from 
Eber's  apparatus,  not  to  the  terminal  eledrodes  of  the 
tube,  but  to  two  patches  of  tin-foil  stuck  upon  the  outside 
of  the  central  bulb.  Under  these  conditions  the  eledtric 
oscillations  illuminate  the  central  bulb  with  a  glow  quite 
different  from  that  previously  seen.  Beneath  each  patch 
of  foil  you  can  discern  the  bluish  kathode  discharge,  and 
the  glass  now  shines  with  charaiSleristic  apple-green 
fluorescence.  By  moving  one  plate  of  one  of  the  con- 
densers in  or  out,  I  alter  the  conditions  of  resonance  in 


the  circuit,  and  when  the  tuning  is  best  the  fluorescence 
is  at  its  brightest.  Now  Wiedemann  observed  (Zeitschr. 
fur  Elektrochemie,  July,  1895,  p.  159)  that  the  light  so 
generated  is  capable  of  exercising  a  photographic  aftion, 
and  of  other  effeds,  but  is  incapable  either  of  passing 
through  a  thin  plate  of  fluor-spar  or  of  being  defleded  by 
a  magnet.  These  rays  differed,  therefore,  both  from 
ultra-violet  light  and  from  kathode  rays  ;  hence  Wiede- 
mann  pronounced  then  to  consist  of  a  new  species  which 
he  named  "  Entladungsstrahlen,"  or  discharge-rays.  It 
is  again  a  matter  for  research  to  determine  whether 
Wiedemann's  rays  are  the  same  as  Lenard's,  or  as  Ront- 
gen's  rays.  Wiedemann's  coadjutor  Ebert  went  on  with 
the    research,   and  produced  on   this   principle  a  little 


Table  I. 

Change 

Cause 

Cause 

Nature 

Restore 

Capable 

Capable 

Cause 

Penetrate 

photo- 

combina- 

Defleaed 

Discharge 

Affeft 

of 

thermo- 

of 

of 

Kind  of  rays. 

lumi- 

alumi- 

graphic 

tion  of  H 

by 

elearifl- 

spark 

eleftric 

lumi- 

being 

refrac- 

nescence 

.  nium. 

aftion. 

and  CI. 

magnet. 

cation. 

length. 

discharge. 

nescence. 

polarised. 

tion,  &c 

Ultraviolet  light 

Yes 

— 

Yes 

Yes 

No 

If  - 

Yes 

— 

Yes 

Yes 

Yes 

Infra-red  light  .. 

No 

No 

— 

No 

No 

No 

— 

— 

No 

Yes 

Yes 

Hertzian  waves  . 

No 

No 

— 

No 

No 

Charge 
vio- 

Yes 

— 

No 

Yes 

Yes 

Kathode  rays    . . 

Yes 

If  thin 

Yes 



Yes       • 





__ 





lently 

Lenard  rays 

Yes 

Yes 

Yes 

— 

Partly 

Yes 

Yes 

Yee 

— 

— 

— 

Wiedemann  rays 

Yes 

Yes 

Yes 

— 

No 

— 

— 

— 

Yes 

— 

— 

Rontgen  rays    . . 

Yes 

Yes 

Yes 

— 

No 

Yes 

Yes 

Yes 

Yes 

No 

No 

Becquerel  rays.. 

— 

Yes 

Yes 

— 

No 

Yes 

— 

— 

— 

Yes 

— 

Eledric  effluve.. 

Yes 

No 

Yes 

Yes 

? 

— 

— 

— 

Yes 

No 

No 

124 


Electric  Shadows  and  Luminescence. 


<  CRBklCAL  NbwS, 

(    March  iz,  1897. 


"  luminescence  lamp  "  having  two  external  rings  of  foil 
as  electrodes  ;  and  within  the  vacuum  bulb  a  small  pastille 
of  phosphorescent  stuff,  which,  when  excited  by  the  oscilla- 
tions of  the  tuned  circuits,  glows  with  a  small  bright  light. 
Ebert  claims  that  its  efficiency  is  many  times  greater  than 
that  of  the  ordinary  glow  lamp. 

Returning  now  to  Rontgen's  researches,  we  will  take  a 
glance  at  the  kind  of  tube  (Fig.  8)  which  he  was  em- 
ploying when  he  made  his  discovery  of  the  X-rays.  Its 
general  resemblance  to  previous  tubes*  is  self-evident. 
The  anode  was  a  piece  of  aluminium  tube  through  which 
passed  the  glass-covered  kathode  wire,  with  a  small  flat 
aluminium  plate  on  its  extremity.  From  this  flat  plate 
kathode  rays  shot  forward  against  the  bulging  end  of  the 
tube,  and,  without  any  aluminium  window  rays  which 
were  capable  of  exciting  fluorescence,  found  their  way 
through  the  glass  walls.  Lenard  had  so  boxed  up  his 
tube  with  brass  cap  and  metal  case,  that  if  anything  in 
the  way  of  rays  struggled  through  the  glass  walls  of  his 
tube  he  might  not  notice  it.  Possibly  he  never  looked 
for  it.  Rontgen  made  the  fortunate  observation  that  when 
his  tube  was  closely  covered  with  opaque  black  card  it 
still  could  cause  fluorescence  on  a  screen  covered  with 
platino-cyanide  of  barium  on  which  shadows  were  cast. 
From  seeing  the  shadows  thus  to  securing  their  imprint 
permanently  on  a  photographic  plate  was  but  s  small 
step,  and  the  discovery  that  they  could  pass  freely  through 
a  sheet  of  the  metal  aluminium  was  the  natural  result  of 
an  inquiry  as  to  the  transparency  of  different  materials. 
Aluminium  is  to  these  rays  much  more  transparent  than 
ordinary  glass.  No  lens  can  focus  them,  nor  mirror 
refle(5t  them,  and,  unlike  the  kathode  rays  within  the  tube, 
they  are  not  defledled  by  the  magnet. 

The  criterion  which  we  have  at  present  as  to  whether 
any  rays  from  any  other  source  are  or  are  not  the  same  as 
the  X-rays  is  that  they  shall  be  able  to  fulfil  the  following 
fourfold  test : — They  must  be  capable  of  exciting  lumi- 
nescence ;  they  must  be  capable  of  impressing  an  image 
on  a  photographic  plate  ;  they  must  be  capable  of  passing 
through  aluminium  ;  and  they  must  be  incapable  of  being 
defledted  by  a  magnet.  In  addition  they  must — so  far  as 
present  evidence  goes — be  incapable  of  being  either  re- 
fradted  or  polarised.  Any  rays  that  will  fulfil  these  tests 
must  for  the  present  be  considered  identical  with  X-rays. 

Now  it  has  been  suggested  that  the  X-rays  are  the 
same  as  ultra-violet  light.  This  is  certainly  not  so,  for 
ultra-violet  light,  as  known  to  us  by  the  researches  of 
Stokes,  Tyndall,  Becquerel,  and  Cornu,  will  not  go  through 
aluminium  and  is  not  defledled  by  a  magnet,  though  it 
will  excite  luminescence  and  take  photographs.  Further- 
more, ultra-violet  light  can  be  refra(5ted  and  polarised. 

It  has  also  been  suggested  that  the  X-rays  are  merely 
invisible  heat-rays.  But  this  is  certainly  untrue  also, 
because  although  Abney  has  succeeded  in  taking  photo- 
graphs by  heat-rays,  they  will  not  go  through  aluminium, 
are  not  deiletfted  by  the  magnet,  and  instead  of  exciting 
phosphorescence  they  destroy  it,  as  Goethe  found  out 
nearly  a  hundred  years  ago. 

Neither  are  they  Hertzian  waves  of  longer  period  than 
the  heat  waves. 

So  far  as  is  at  present  known  there  is  no  other  way  of 
producing  the  X-rays  than  that  of  employing  the  highly 
exhausted  vacuum  tube.  They  are  not  found  in  the  light 
of  ordinary  eledlric  sparks  in  air.  They  are  not  discover- 
able amongst  the  rays  emitted  by  ordinary  Geissler  tubes 
with  a  low  exhaustion.  They  are  not  found  in  sunlight  or 
any  artificial  light.  The  arc  light,  though  it  yields  rays 
that  will  give  photographic  shadows  through  a  thin  pine- 
wood  board,  yields  no  rays  that  will  pass  through 
aluminium.  The  only  other  rays  that  seem  to  come 
within  reasonable  possibility  of  being  X  rays  are  the 
Lenard  rays,  some  of  which  are  probably  identical  with 
Rontgen's ;  the  Wiedemann  rays,  which  are,  so  far  as  yet 

» 

*  It  is,  in  faA,  identical  with  the  form  described  by  Hertz  in  1883 
See  Wiedemann's  Annalen,  xix..  p.  810. 


investigated,  entirely  similar;  and  the  Becquerel  rays,  to 
which  some  allusion  will  presently  be  made.  It  will, 
however,  be  convenient  here  to  present  a  synoptic  table 
(see  Table  I.)  of  the  various  kinds  of  rays  and  their 
respedtive  physical  properties. 

One  other  physical  property  of  the  X-rays  has  been  dis- 
covered since  the  publication  of  Rontgen's  research.  It 
was  discovered  simultaneously  in  Cambridge  (by  Prof. 
J.  J.  Thomson),  in  Paris,  in  Bologna,  and  in  St.  Peters- 
burg, that  these  X-rays  will  cause  the  diseledlrification  of 
an  eledtrified  body,  no  matter  whether  it  is  positively  or 
negatively  charged.*  That  ultra-violet  light  can  dis- 
eledtrify  bodies  that  have  been  negatively  charged  was 
previously  known  from  the  researches  of  Hertz,  and  of 
Elster  and  Geitel.  This  fresh  discovery  that  X-rays  will 
also  discharge  a  positive  eledtrification  sets  up  a  new 
physical  test.  Let  me  show  you  a  simple  piece  of  appa- 
ratus which  I  have  found  very  convenient  for  the  purpose 
of  demonstrating  this  discovery.  It  is  an  aluminium-leaf 
eledtroscope  (Fig.  g)  entirely  shielded  from  all  external 
eleiSlrostatic  influences  by  being  enclosed  in  transparent 
metallic  gauze.  It  is  so  well  shielded  that  even  when  the 
cap  is  removed  it  cannot  be  charged  in  the  ordinary  in- 
dudtive  way,  but  must  be  eledtrified  by  diredi  conduAion. 
The  aluminium-leaves  hang  at  the  side  of  a  fixed  central 
plate  as  in  Exner's  electroscope.  The  containing  vessel 
is  of  thin  Bohemian  glass.  On  exciting  the  instrument 
positively  from  a  rod  of  rubbed  glass,  or  negatively  from 
a  rod  of  rubbed  celluloid,  the  leaves  diverge.  In  either 
case,  as  soon  as  the  X-rays  are  caused  to  shine  upon  the 
instrument,  the  leaves  fall. 

It  occurred  to  me  that  by  the  aid  of  this  property  of 
diseledlrification  it  might  be  possible  to  produce  eledtric 
shadows  without  having  resort  to  any  photography.  You 
are  aware  that  if  the  surface  or  any  part  of  the  surface 
of  a  body  is  eledlrified,  the  fadl  that  it  is  eledtrified  can  be 
ascertained  by  dusting  over  it  mixed  powders  of  red-lead 
and  sulphur  (or  red-lead  and  lycopodium).  With  the  aid 
of  Mr.  Miles  Walker,  who  has  worked  with  me  all  through 
this  matter,  I  have  succeeded  in  producing,  on  this  plan, 
well  defined  shadows  which  will  now  be  demonstrated  to 
you.  A  clean  sheet  of  ebonite,  freed  from  all  traces  of 
previous  eledtrification  by  being  passed  through  a  spirit 
flame,  is  laid  on  a  properly  prepared  metal  table.  On  it 
stands  a  small  tray  of  thin  aluminium,  supported  on  four 
insulating  legs.  In  this  tray  is  placed  the  objedt  whose 
shadow  is  to  be  cast, — for  example,  a  pair  of  scissors  or 
an  objedl  cut  out  in  sheet  lead.  Over  this  again  is  placed 
a  leaden  cover  with  an  opening  above  the  tray,  the  leaden 
cover  being  designed  to  cut  off  eledlrostatic  influences 
which  might  interfere.  The  tray  is  then  eledtrified  by  a 
small  influence  machine,  and  while  it  is  so  eledtrified 
X-rays  are  sent  downwards  from  a  Crookes  tube  placed 
above.  They  pass  down  through  the  aluminium  tray  and 
carry  its  eledtrification  to  the  ebonite  sheet,  which  there- 
fore becomes  eledtrified  all  over  except  in  the  parts  which 
are  shielded  by  the  scissors  or  other  metallic  objedt.  The 
sheet  of  ebonite  is  then  removed  from  the  leaden  enclosure, 
the  aluminium  tray  lifted  off,  and  the  mixed  powders  are 
dusted  over,  adhering  to  the  surface  of  the  ebonite  and 
revealing  the  otherwise  invisible  eledtric  shadow.  Fig.  10 
is  a  shadow  taken  in  this  way.  It  is  but  right  to  mention 
that  Prof.  Righi,  of  Bologna,  has  independently  obtained 
eledtric  dust  shadows  in  a  very  similar  way  since  these 
experiments  of  mine  were  begun. 

(To  be  continued). 


Annmoniacal  Silver  Chlorides.— R.  Jary.— In  the 
case  of  ammoniacal  chlorides  the  dissociation  in  a  space 
occupied  by  water  ensues  in  the  same  manner  as  in  a 
\!iCu\im.—Comptes  Rendus,  cxxiv..  No.  6. 

♦  It  is  of  great  interest  to  note  that  this  identical  property  had 
been  observed  by  Lenard  a  year  previously  as  an  effedl  of  his  rays. 
He  found  they  would  discharge  an  eledtroscope  enclosed  in  a  metal 
chamber,  with  an  aluminium  sheet  in  front,  whether  positively 
or  negatively  charged,  aad  at  a  distance  of  30  centimetres  from 
bis  tube. 


C<IBMICAL  NbWS, 

March  12,  1897. 


}      Volumetric  Determinatton  of  Molybdenum  and  Vanadium,  125 


VOLUMETRIC    DETERMINATION 

OF     MOLYBDENUM     AND    VANADIUM.* 

By  CARL  FRIEDHEIM. 

(Concluded  from  p.  gi). 

Hence  they  {i.e.,  Gooch  and  Fairbanks)  recommend  to 
effei5t  the  whole  operation  in  a  current  of  carbon  dioxide 
free  from  atmospheric  air,  for  which,  instead  of  the  simple 
and  convenient  Bunsen  apparatus,  a  more  complicated 
distillatory  apparatus  is  requisite,  which,  on  account  of 
its  greater  capacity,  must  give  greater  errors  except  we 
work  with  carbon  dioxide.  That  better  results  cannot  be 
obtained  has  been  already  mentioned. 

A  further  reason  which  Gooch  and  Fairbanks  advance 
for  the  necessity  of  their  proposed  alteration  of  my 
method  cannot  hold  good.  They  consider  it  necessary 
that  the  solution  to  be  decomposed  during  the  operation 
should  be  evaporated  down  from  a  given  initial  volume 
to  a  fixed  final  volume,  interrupting  the  process  as  soon 
as  the  latter  is  reached.  They  were  led  to  this  modus 
operandi  "  because  it  is  not  sufficient  to  indicate  that  the 
ebullition  must  be  interrupted  when  the  liquid  has  taken 
a  clear  green  colour,  and  when  a  vapour  of  the  colour  of 
iodine  ceases  to  pass  over,  for  the  green  colour  of  the 
solution  is  formed  very  slowly,  and  we  (Gooch  and  Fair- 
banks) were  able  to  show  iodine  in  the  residue  long  after 
the  green  colour  had  been  perfectly  developed." 

The  latter  phenomenon  certainly  takes  place,  but  has 
nothing  whatever  to  do  with  the  redudlion  of  the  molj'b- 
denum  teroxide,  but  must  be  referred  to  the  fadl  that  if 
the  contents  of  the  flask  are  brought  in  contad  with  the 
air  the  hydriodic  acid  is  at  once  oxidised.  The  longer 
such  a  solution  is  left  in  contadl  with  carbon  disulphide 
with  access  of  air  the  more  intensely  it  is  coloured,  which 
does  not  ensue  if  air  is  excluded. 

The  appearance  of  the  green  tinge  and  the  disappear- 
ance of  the  iodine  colouration  shows  sharply  the  end  of 
the  readtion,  as  it  is  manifest  from  results  already  pub- 
lished, even  for  substances  whose  proportion  of  molyb- 
denum is  unknown,  and  gives  a  more  trustworthy  basis 
than  boiling  down  the  solution  to  a  certain  volume,  which 
is  suitable  only  for  the  weights  used  by  Gooch  and  Fair- 
banks, and  cannot  be  at  once  transferred  to  substances 
whose  proportion  of  molybdenum  is  unknown. 

In  the  same  connexion  we  must  notice  another  proposal 
made  by  the  same  authors.  It  is  well  known  that  vana- 
dium pentoxide  can  be  quantitatively  reduced  to  tetroxide 
by  potassium  bromide  and  hydrochloric  acid,  and  that  an 
excellent  volumetric  method  for  determining  vanadium 
can  be  secured  (Holverscheidt's  method)  by  receiving  the 
liberated  halogen  in  potassium  iodide,  and  titrating  the 
iodine  set  at  liberty.  In  concert  with  Euler  I  have 
showed  that  on  boiling  vanadium  pentoxide  with  potas- 
sium iodide  and  hydrochloric  acid,  the  redudlion  can  like- 
wise be  carried  almost  quantitatively  as  far  as  vanadium 
tetroxide,  whilst  vanadium  teroxide  is  formed  quantita- 
tively on  the  addition  of  syrupy  phosphoric  acid.  Of 
course,  we  have  not  utilised  this  result  for  a  volumetric 
investigation  of  pure  vanadates,  for  which  there  was  no 
need,  since  the  potassium  bromide  method  is  simpler, 
more  convenient,  and  more  trustworthy.  Ph.  E.  Browning 
(Zeit.  Anorg.  Chemie)  now  proposes  to  modify  this  method 
of  reduction  so  that  the  redudion  of  the  vanadates  is 
effedled  under  certain  conditions  in  open  vessels  with 
potassium  iodate  and  sulphuric  acid  ;  the  solution,  after 
the  iodine  has  been  expelled  by  boiling  is  neutralised 
with  alkaline  hydroxide  mixed  with  tartaric  acid  and 
bicarbonate,  and  the  vanadium  tetroxide  existing  in 
solution  is  determined  with  a  standard  solution  of  iodine, 
titrating  back  with  arsenious  acid. 

As  an  advantage  over  the  convenient  method  of  distil- 
lation,   it  is    alleged  that  the  complicated  distillatory 


*  Berichte  d.  D.  Chem.  Qestll. 


apparatus  is  superfluous.  To  this  it  may  be  replied  that 
the  manipulation  of  the  compendious  Bunsen  apparatus 
18  the  most  convenient  conceivable,  that  the  supercession 
of  a  smooth  titration  with  thiosulphate  by  titration  with 
two  standard  solutions,  in  one  case  with  a  blue  liquid, 
does  not  mean  any  progress,  and  that,  finally,  in 
Browning's  method,  the  determination  of  the  bases  (e.g., 
lead  and  barium)  in  the  residue  of  the  distillation  is  ren- 
dered impossible  and  much  more  difificult. 

Exadly  the  same  objedtions  must  be  urged  against  the 
modification  of  my  method  for  the  determination  of 
molybdenum  as  proposed  by  Gooch  and  Fairbanks,  which 
consists  in  decomposing  the  molybdate  in  an  open  method 
and  titrating  it  on  Browning's  principle. 

In  a  subsequent  memoir  (Zeit.  Anorg.  Chemie)  A.  v  • 
banks  proposes  to  determine  the  phosphorus  in  the  yellow 
ammonium  phospho-molybdate  indiredly,  the  molybde- 
num in  the  compound  being  ascertained  according  to  the 
Gooch-Fairbanks-Browning  method.  The  authors  here 
overlook  to  mention  that  I  have  already  recommended 
the  volumetric  determination  of  the  molybdenum  in 
phospho-molybdates,  and  the  method  which  I  have 
described,  and  that  I  connedled  with  it  Hundeshagen's 
method  for  titrating  the  total  method  by  alkali  hydroxide, 
therefore  determining  the  phosphoric  acid  as  difference. 
This  method  is,  however,  of  interest  only  for  the  general 
examination  of  the  so-called  white  phospho-molybdates; 
for  the  determination  of  the  phosphorus  in  the  yellow 
compound  the  gravimetric  method  of  Hundeshagen- 
Pemberton  is  far  simpler  and  more  convenient  than  that 
proposed  by  Fairbanks. 


PROCEEDINGS    OF    SOCIETIES. 

CHEMICAL  SOCIETY. 
Ordinary  Meeting,  January  21st,  1897. 

Mr.  A.  G.Vernon  Harcourt,  President,  in  the  Chair. 

Messrs.  Charles  A.  Hill,  Arthur  Marshall,  and  William 
H.  Sodeau  were  formally  admitted  Fellows  of  the  Society. 

Certificates  were  read  for  the  first  time  in  favour  of 
Messrs.  William  Arbuckle,  34,  Moore  Street,  Cadogan 
Square,  S.W. ;  Masumi  Chikashige,  B.Sc,  Kumamoto, 
Japan  ;  Alfred  Foster  Cholerton,  Lyndum  House,  Lincoln 
Street,  Leicester  ;  Clarence  Hamilton  Creasey,  78,  Bagge- 
holme  Road,  Lincoln;  James  Crowther,  B.Sc,  West 
Field,  Lightcliffe,  Halifax ;  William  Alfred  Davis,  108, 
Gordon  Road,  Peckham,  S.E.,  Ernest  Goulding,  18, 
Mercer's  Road,  Holloway,  N;  Charles  Heppenstall, 
Ferrybank,  Arklow,  Co.  Wicklow ;  Harold  Johnson,  5. 
Boulevard  Clovis,  Bruxelles  ;  William  Robert  Lang,  B.Sc., 
5,  Crown  Gardens,  Glasgow  ;  Barker  North,  3,  Manor 
Terrace,  Felixstowe  ;  Herbert  Spindler  Pullar,  Rosebank, 
Perth,  N.B  ;  William  Ralston,  B.Sc,  337,  Cathcart  Road, 
Lrlasgow;John  Stewart  Remington,  Dromore,  Milverton, 
Leamington  ;  Leonard  Sumner,  B  Sc,  Butt  Hill,  Prest- 
wich,  near  Manchester;  Andrew  Turnbull,  Ph.D.,  Dal- 
dowie,  Broomhouse,  near  Glasgow. 

The  certificates  of  the  following  candidates,  recom- 
mended  by  the  Council,  under  Bye-law  I.,  par.  3,  were  also 

Thomas  Hannibal  Aquino,  Gadag,  Dharwar  Distrid, 
India;  Alfred  Rutter,  Broken  Hill,  N.S.W.  ;  Rustomii 
Navroji  Unwalla,  Bhaunagar,  Kathiawar,  India. 

The  following  is  the  text  of  the  letter  which  has  been 
received  from  Professor  Stanislao  Cannizzaro,  acknow- 
ledging the  address  presented  to  him  by  the  Society  on 
the  occasion  of  his  jubilee. 

To  the  Council  and  Fellows  of  the  Chemical  Society 

of  London. 
Gentlemen,— I  beg  to  offer  to  your  Society  the  report 
of  the  celebration  of  my  seventieth  birthday,  togethti 


I2( 


A  ctton  of  Diastase  on  Starch. 


CbbmicalNbws, 

March  12, 18Q7. 


with  the  volume  containing  some  of  my  writings  which 
were  reprinted  on  that  occasion,  and  a  copy  in  bronze  of 
the  gold  medal  which  was  presented  to  me. 

At  the  same  time,  I  beg  to  convey  to  my  colleagues 
the  expression  of  my  heartfelt  gratitude  for  their  very 
flattering  address,  which  I  have  received  with  the  greatest 
satisfadiion. 

The  Chemical  Society  won  my  devotion,  when,  in  1862, 
they  added  my  name  to  the  restridled  roll  of  their  foreign 
members  ;  and  again  in  1872  when  they  honoured  me  by 
intrusting  to  me  the  delivery  of  the  Faraday  Ledture. 

A  further  proof  of  their  high  consideration  is  now 
offered  to  me  in  this  address,  in  which  I  find  my  labours 
for  Science  appreciated  and  valued  in  so  very  high  a 
degree  by  authority  so  competent :  I  feel  I  am  indebted 
for  this  favourable  estimate  of  my  merits  to  the  extreme 
kindness  which  my  English  colleagues  have  always 
shown  to  me,  and  for  which  I  now  desire  to  express  my 
profound  gratitude. 

Great  is  the  pleasure  which  this  fresh  manifestation  of 
their  affedlionate  esteem  has  afforded  me,  thus  assuring 
me  that  their  estimate  of  me  has  in  no  way  lessened. 
Your  ever  true  and  affe(5lionate  colleague, 

Stanislao  Cannizzaro. 

December,  1896. 

Of  the  following  papers  those  marked  *  were  read : — 

•i.  "  Observations  on  the  Properties  of  some  Highly 
Purified  Substances."    By  W.  A.  Shenstone. 

1.  The  author  has  compared  the  behaviour  of  oxygen 
under  the  influence  of  the  silent  discharge  of  ele(5tricity 
when  saturated  with  water  vapour,  and  when  carefully 
dried.  The  results  show  that,  contrary  to  the  statement 
of  previous  investigators,  oxygen  is  most  freely  convened 
into  ozone  when  wet,  and  that  well  dried  oxygen  yields 
only  a  very  minute  percentage  of  ozone.  The_  results 
obtained  also  shows  that  the  ozone  in  ozonised  oxygen 
is  far  more  stable  in  the  presence  of  water  vapour  than 
in  its  absence.  That  is  to  say,  the  change  by  which 
ozone  is  converted  into  oxygen  is  very  greatly  retarded 
by  the  presence  of  moisture. 

2.  Chlorine  prepared  by  the  eleftrolyis  of  silver  chloride, 
and  also  carefully  purified  bromine  and  iodine,  have  been 
dried  by  very  thorough  treatment  with  prepared  phos- 
phoric oxide,  and  then  presented  to  the  aiftion  of  mercury 
prepared  for  the  purpose  by  several  di8tin(ft  methods  and 
thoroughly  dried.  In  every  case  the  metal  and  the 
halogen  interadled  instantly  and  rapidly. 

3.  Highly  purified  chlorine,  when  submitted  to  the 
silent  discharge  of  ele(5tricity,  does  not  undergo  condensa- 
tion. 

4.  The  abnormal  expansion  of  chlorine  which  has  been 
described  by  several  observers  appears  to  depend  upon 
the  presence  of  impurities  in  the  chlorine. 

Incidentally,  a  new  vacuum  tap  and  other  novel  appa- 
ratus are  described  in  this  paper. 
Discussion. 

The  President,  Mr.  H.  B.  Baker,  and  Professor 
TiLDEN  expressed  their  admiration  of  the  skill  and 
resource  which  Mr.  Shenstone  had  brought  to  bear  in 
investigating  a  difficult  problem. 

Dr.  Thorpe  stated  that  he  had  witnessed  Dr.  Budde's 
experiments  at  Bonn,  which  were  conduded  with  great 
care,  and  he  had  watched  the  expansion  of  chlorine  under 
the  influence  of  the  violet  and  ultra-violet  rays.  The 
chlorine  had  been  prepared  by  the  oxidation  of  hydro- 
chloric acid,  and  was  believed  to  be  pure.  Some  sub- 
sequent observers  had  confirmed  Dr.  Budde's  results,  but 
others  had  failed  to  do  so — as  was  now  the  case  with 
Mr.  Shenstone,  whose  painstaking  enquiry,  he  hoped, 
might  be  the  means  of  finally  settling  the  question. 

Dr.  Thorne  stated  that  he  had  observed  on  a  large 
scale  the  instability  of  ozone  when  in  contact  with  an 
alkali. 

Mr.  Shenstone,  in  reply,  stated  that  he  did  not  doubt 
the  correctness  of  Dr.  Budde's  observations  with  chlorine  > 


prepared  and  purified  as  he  had  described.  He  con 
sidered,  however,  that  such  chlorine  could  not  be  regarded 
as  highly  purified,  and  that  moisture  was  almost  certainly 
present. 

*2.  '•  The  Action  of  Diastase  on  Starch."  By  Arthur 
R.  Ling  and  Julian  L.  Baker. 

The  authors  show  that  maltose  when  heated  with 
Fehling's  solution,  under  the  conditions  prescribed  by 
Wein,  reduces  rojg  grms.  of  copper  per  grm.  of  sugar. 
The  table  of  Wein,  therefore,  gives  results  which  are  4-5 
per  cent  too  low,  a  result  also  arrived  at  by  Brown, 
Morris,  and  Millar. 

They  have  examined  in  detail  the  produdts  of  the 
limited  adlion  of  diastase  on  starch  at  70°,  and  have 
separated  maltose  and  the  following  unfermentable  sub- 
stances, which  were  purified  to  such  an  extent  as  to  free 
them  from  all  extraneous  matter. 

Maltodextrin  o,  CagHezOsi,  identical  with  Brown  and 
Morris's  maltodextrin,  but  having  the  properties 
[o]d  =  i8o  :  R  =  32-8i. 

Maltodextrin  p,  C24H4202I,  identical  with  Prior's 
"  achroodextrin  III.,"  and  having  the  properties 
[o]d  =  17i6  and  R  =  43. 

A  substance,  C12H22O11,  isomeric  with  maltose,  and 
obtained  from  the  unfermentable  residue  of  that  particular 
fradion  previously  called  isomaltose  by  Lintner.  It  had 
the  constants  [a]D  =  i56  and  R  =  62'5,  and  may  consist 
of  the  simple"  dextrin,"  C12H20O10+H2O,  the  existence 
of  which  the  authors'  previous  work  foreshadowed. 
Inasmuch  as  it  gave  a  small  amount  of  crystalline 
osazone,  it  perhaps  contained  maltose. 

When  the  three  substances  above  named  are  treated 
with  an  excess  of  diastase  at  60°  for  a  few  hours,  the 
approximate  reducing  powers  of  the  products  are  R=90  ; 
Qi'S  ;  94i  respedively. 

There  are  now  ample  data  to  conclude  that  starch, 
when  hydrolysed  by  diastase,  is  converted  into  a  series 
of  maltodextrins  of  gradually  decreasing  molecular 
weight  and  optical  rotatory  power,  and  of  increasing 
reducing  power.  These  appear  to  have  the  optical  and 
reducing  properties  of  mixtures  of  the  original  starch  and 
maltose. 

Discussion. 

Dr.  G.  H.  Morris  regretted  that  Messrs.  Ling  and 
Baker  had  given  no  particulars  of  the  substances  they 
described  beyond  the  constants  [ajo  and  R.  He  had 
therefore  no  means  of  judging  whether  the  substances 
agreed  with  the  maltodextrin  described  by  Mr.  H.  T. 
Brown  and  himself,  nor  was  it  possible  to  follow  the 
authors'  line  of  work.  The  constants  given  for  malto- 
dextrin o  agreed  fairly  with  the  law  of  definite  relation  as 
formulated  by  Mr.  Brown  and  himself;  but  the  malto- 
dextrin /3  (Prior's  achroodextrin  III.)  did  not,  and  the 
purity  of  this  substance  is  therefore  doubtful.  He  wished 
to  learn  more  about  the  unfermentable  residue  of  isomal- 
tose, which  the  authors  appeared  to  regard  as  one  of  the 
end-produdls  of  the  action  of  diastase  on  starch.  He  did 
not  think  it  necessary  to  enunciate  a  new  theory  of 
starch  conversion  whilst  there  was  still  so  much  dispute 
as  to  fads. 

Mr.  Ling,  in  reply  to  Mr.  Chapman,  said  he  saw  no 
reason  for  assuming  the  presence  of  a  "  stable"  dextrin 
among  the  produds  of  starch  hydrolysis  ;  ultimately 
maltose  was  the  sole  produd.  In  reply  to  Dr.  Morris,  he 
said  that  much  more  information  would  be  found  in  the 
paper  than  it  had  been  possible  to  give  an  account  of  in 
the  brief  time  at  his  disposal.  It  would  be  seen  that  the 
formulae  of  the  maltodextrins  could  not  be  calculated 
from  the  percentages  of  apparent  maltose  which  they 
yielded. 

•3.  "  The  Solution  Density  and  Cuptic-Reducing  Power 
of  Dextrose,  Lavulose,  and  Invert-Sugar.^^  By  Horace 
T,  Browne,  F.R.S.,  G.  Harris  Morris,  Ph.D.,  and  J. 
H.  Millar. 

The  authors  have  extended  the  methods  deacribed  in 


Chbuical  News,  i 
March  12,  1897.    ] 


Derivatives  of  Maclurin. 


127 


their  previous  paper  {Proc,  1896,  xii.,  241)  to  the  exami- 
nation of  the  solution  density  and  cupric-redudtion  of 
dextrose,  laevulose,  and  invert-sugar.  They  find  that  the 
solution  densities  of  the  two  former  differ  considerably 
with  the  same  concentration  of  the  solution,  but  that  the 
volume  occupied  in  solution  by  a  unit  of  weight  of  each 
is  less  at  lower  than  at  higher  concentrations,  conse- 
quently the  divisor  to  be  applied  to  the  specific  gravity 
decreases  with  the  concentration.  The  solution  density 
of  invert-sugar  was  calculated  from  those  of  dextrose  and 
laevulose,  and  the  results  so  obtained  were  confirmed  at 
vaiious  points  by  direift  experiments. 

They  also  find  that  the  cupric-reducing  powers  of  the 
three  sugars,  when  determined  under  their  standard  con- 
ditions, are,  for  dextrose,  /c=ii7  to  105  ;  for  lasvulose, 
ic=i07'5  to  loi ;  and  for  invert  sugar,  ic  =  iii  to  103. 
The  higher  numbers  are  obtained  when  a  small  amount 
of  cuprous  oxide  is  precipitated,  and  the  lower  when 
redudtion  is  carried  nearly  to  the  maximum.  When  the 
experimental  numbers  are  expressed  in  the  form  of  a 
curve,  it  is  found  that  at  the  one  end,  taking  the  cupric- 
redudlion  of  dextrose  at  100,  laevulose  is  represented  by 
91-3,  and  invert-sugar  by  94*2  ;  at  the  other  end  of  the 
curve  the  ratio  is  100,  94'6,  and  975  ;  whilst  at  an  inter- 
mediate point,  which  corresponds  to  the  amount  of  cuprous 
oxide  usually  reduced,  the  relation  is,  dextrose  100, 
laevulose  92-3,  and  invert-sugar  9615. 

4.  "Derivatives  0/  Maclurin.^^  Part  II.  By  A.  G. 
Perkin. 

From  maclurin  which  yields  a  pentabenzoyl  derivative 
(Konig  and  Kostanechi,  Ber.,  1894,  xxvii.,  1996),  a  pent- 
acetyl  compound  has  not  yet  been  obtained,  for  by 
acetylisation  in  the  ordinary  way  only  sticky  produdls 
result,  and  when  excess  of  sodium  acetate  is  employed 
(Ciamician  and  Silber,  Ber.,  1894,  xxvii.,  1628),  there  is 
formed  a  peculiar  substance  having  the  composition  of 
pentaceiyl  maclurin  less  i  molecule  of  water.  Judging 
from  the  stability  of  maclurin-azo-benzene, 

C,3H806(N2-C6H5)2. 
described  in  a  previous  communication  (Bedford  and 
Perkin,  Trans.,  1895,  Ixvii.,  933),  when  compared  with 
that  of  maclurin  itself,  it  appeared  probable  that  this  on 
acetylisation  might  behave  normally,  which  was  found 
to  be  the  case. 

Triacetylmaclurin-azobenzene, 

Ci3H506(C2H30)3(N2-C6H5)2, 
orange-yellow  needles,  m.p.  240 — 243°,  is  insoluble  in 
cold  alkaline  solutions,  but  decomposed  by  them  on 
boiling.  Suspended  in  acetic  acid  and  treated  with  sul- 
phuric acid,  a  quantitative  yield  of  maclurin-azobenzene 
is  produced.  Phloroglucin-azobene  similarly  yields  a 
monacetyl  derivative,  C6H303(C2H30)iN2C6H5)2,  orange- 
red  needles,  m.p.  222 — 223°,  also  quantitatively  decom- 
posed by  sulphuric  acid  into  the  azo-compound.  These 
substances  furnished  no  higher  acetyl  derivatives,  two 
hydroxyls  present  in  the  original  molecules  of  maclurin 
and  phloroglucinol  having  assumed  in  their  diazobenzene 
compounds  the  ketonic  condition.  This  method  is  being 
applied  for  the  estimation  of  hydroxyl  groups  in  certain 
analogous  substances,  particularly  catechin  and  cyano- 
maclurin,  which  combine  readily  with  diazobenzene,  but 
do  not  give  normal  produdts  on  acetylisation  by  the  usual 
method. 

Mention  is  made  of  a  second  produdi  closely  resembling 
luteolin  trimethyl  ether,  and  formed  at  the  same  time, 
during  the  methylation  of  luteolin.  This,  though  isolated 
many  months  since,  was  not  mentioned  at  the  time,  be- 
lieving that  the  work  then  published  was  sufficient  to 
establish  priority  for  the  further  study  of  this  readtion. 
The  author  wishes  to  reserve  this  to  himself  for  further 
examination. 

5.  '•  Halogen-substituted  Acidic  Thiocarbimides  and 
their  Derivatives  ;  a  Contribution  to  the  Chemistry  of  the 
Thiohydantdins:^     By  AuausTUS  Edward  Dixon,  M.D. 


Continuing  his  previous  work  on  the  acidylthio- 
carbimides  IJ^rans.,  1895,  Ixvii.,  1040;  1896,  Ixix.,  855; 
ibid  ,  1593,  &c.),  the  author  endeavoured  to  prepare 
halogen  substitution  derivatives  of  certain  members  of  the 
faity  acid  class,  in  the  hope  that,  by  combination  with 
organic  bases,  glycolylthioureas  would  be  obtained  of 
known  sirudlure,  whose  relations  to  the  thiohydantoins 
produced  by  other  methods  would  serve  to  decide  the  con- 
stitution of  the  latter. 

The  derivatives  in  question  were  obtained  by  heating  a 
mixture  of  sand  and  lead  thiocyanate  with  the  ohalogen- 
ised  acid  chloride  (or  bromide),  dissolved  in  anhydrous 
toluene;  as  a  rule,  the  yield  amounted  to  only  about 
60  per  cent  of  the  theoretical.  On  bringing  the  produdks 
into  contadt  with  primary  or  (secondary)  amines,  inter- 
adtion  occurred  spontaneously,  with  elimination  of  the 
halogen,  and  formation  of  the  corresponding  substituted 
thiohydantoin,  for  instance — 

CH  'S 

CH2Cl-CO-NCS-f-ToNH2=HCl-h  |     ^       \c:NTo. 

co-nh/ 

By  prolonged  boiling  with  hydrochloric  acid,  the  latter 
compound  is  hydrolysed,  ammonia  being  formed,  together 
with  a  substance  (melting  at  119 — 120°)  identical  with  the 
"  orihotolylthiocarbimidoglycolide"  obtained  by  Voltzkow 
{Ber.,  1880,  xiii.,  1580)  from  EtOH,ToNCS  and 
CH2CICOOH.  Since  the  nitrogenised  organic  group, 
introduced  by  the  base  in  the  formation  of  the  thiohydan- 
toin, does  not  form  an  integral  portion  of  its  ring,  whilst, 
on  the  other  hand,  the  nitrogen  withdrawn  by  hydrolysis 
holds  no  organic  radicle  in  combination,  it  follows  that 
the  ring  must  exchange  its  NH  for  oxygen,  thereby  be- 
coming— 

CHj'Sv 
I  >C:NTo; 

coo/ 

thus,  by  an  entirely  different  method,  the  formula  is  cor- 
roborated, which  Evers  assigns  to  the  corresponding 
phenyl  derivative  (Ber.,  1888,  xxi.,  975).  From  ortho- 
tolylthiourea  and  ethylic  chloracetate,  a  thiohydantoin 
was  obtained,  agreeing  in  properties  with  that  produced 
from  the  thiocarbimide  ;  on  hydrolysis,  it  afforded  the 
same  glycolide,  m.  p.  119 — 120°. 

On  the  other  hand,  thiourea,  when  treated  with  a  sub- 
stituted chloracetamide  (e.g.,  chloracetanilide)  yielded 
(P.  Meyer,  Ber.,  1877,  x.,  1965)  thiohydantoin,  together 
with  a  substitution  derivative;  the  phenylthiohydantoin 
so  obtained  was  apparently  identical  with  that  produced 
from  phenylthiourea  and  ethylic  chloracetate.  The 
essential  interadion  he  explained  substantially  as  fol- 
lows : — 

CHjCl  HSv  CH2*S    V 

I  -J-  >C:NH  =  HCl-{-  I  >C:NH, 

CO-NHPh      NH2/  CO-NPh/ 

and  the  fadt  that  ammonia  and  phenylthiocarbimido- 
glycolide  were  formed  on  hydrolysis,  appeared  to  agree 
satisfadlorily  with  the  above  view  of  its  constitution,  as 
well  as  to  fix  that  of  the  glycolide, — 

CH2-S    V  CHj-S    V 

>C:NH-|-H20  =  NH3-t-  |  >C0. 

CONPh/  CO-NPh/ 

It  would  seem,  however,  from  Meyer's  paper,  that  the 
particular  phenylthiohydantoin  obtained  from  chlor- 
acetanilide was  not  used  in  preparing  the  related  phenyl- 
thiocarbimidoglycolide ;  it  was  conceivable,  therefore, 
that  the  former  might,  though  melting  at  the  same  tem- 
perature, be  really  isomeric  with  that  produced  by  the 
other  methods.  This  could  be  ascertained  by  examining 
the  produdls  of  hydrolysis,  for  the  withdrawal  from  the 
ring  of  its  nitrogenised  group  would  afford  aniline,  to- 
gether with  "  thiocarbimidoglycolide," — 
CHj'Sv 

I  >C:NH; 

CO'O  / 


128 


Halogen-Substituted  A  cidic  Thiocarbimides* 


I  CtlBMieAL  NBltrS) 

I   March  12, 1897. 


whilst,  even  if  the  phenyl  group  should  be  retained,  and 
ammonia  formed  instead,  the  produ(5t — 

I         >co 

CO-NPh/ 

would  still  be  an  isomeride  of  the  true  phenyl  thio- 
carbimidoglycolide, — 

I  >C:NPh. 

CO-0  / 

But,  on  experiment,  the  produdls  of  hydrolysis,  and  hence 
the  thiohydantoin  itself,  were  found  to  be  identical  with 
those  obtained  in  other  ways.  Finally,  the  compound 
was  decomposed  by  carbon  disulphide  at  180°,  phenyl- 
thiocarbimide  being  obtained,  together  with  rhodanic 
acid,  but  not  a  trace  of  thiocyanic  acid ;  and  hence  the 
interadlion  follows  the  course — 


CHjS  V  CH/S 

I  >C:NPh  +  CS2=  I 

conh/  CO-NH 


/ 


PhNCS. 


The  author  therefore  regards  the  known  monosubstituted 
thiohydantoins  in  which  the  radicle  is  attached  to  nitro- 
gen, as  constituted  on  the  type— 
CHa-S 


CONH 


C:NR 


CONHPh    NHa'' 


and  suggests  that  the  formation  of  the  phenylic  member 
from  thiourea  and  chloracetanilide  may  be  due  to  a 
secondary  a^ion,  for  thiohydantoin  is  also  produced, 
together  with  aniline, — 

CHaCl  HS  V 

+        NC:NH  =  PhNH2+ 

CHa'S  V 

+  1  >C:NH  +  HC1; 

conh/ 

and  from  these,  by  mutual  interaction,  ammonia  and 
phenylthiohydantoin  might  result.  Ammonia  was,  in 
fadt,  expelled,  when  aniline  and  thiohydantoin  were 
heated  together  with  alcohol ;  and  a  substance  produced, 
which  appeared,  judging  from  its  melting-point,  to  be  its 
phenylic  derivative,  but  the  quantity  obtained  was  insuf- 
ficient for  analysis. 

The  following  compounds  are  described  : — 

Orthotolylthiohydantohi, — 

CHa'S  V 

I  >C:NC7H7. 

CO-NH/ 

From    chloracetylthiocarbimide    and    orthotoluidine ; 

white  prisms,  melting  at  144 — 145°  (corr.).  When  boiled 
with  baryta-water  it  yields  thioglycolic  acid  ;  by  boiling, 
dilute  hydrochloric  acid,  it  is  slowly  decomposed  into 
ammonia  and  •'  orthotolylthiocarbimidoglycolide," — 

CHa'Sv 

I  >C:NC7H7. 

CO-0  / 
The  same  thiohydantoin   is  produced   from   orthotolyl- 
thiourea  and  ethylic  monochloracetate  ;  its  hydrochloride 
melts  at  212-5—213-5°  (uncorr.). 
Methylphenylthiohydanto'in, — 

CHa■S^. 

I         \C-N(CH3)C6H5. 
CO-N  ^ 

From  the  thiocarbimide  and  methylaniline ;  flattened 

needles,  melting  at  129—130°  (corr.),  and  decomposed  by 
boiling  with  caustic  alkali  or  baryta-water,  into  ammonia, 
methylaniline,  and  thioglycollic  acid.  It  is  also  ob- 
tained by  heating  aa-methylphenylthiourea,  in  alcohol, 
with  ethylic  monochloracetate ;  the  hydrochloride  melts 
at  I93-I94"'' 


Benzylphenylthiohydanto'in, — 

CHa'Sv 

>CNPh-CHa-Ph. 


CO 


-N^ 


— From  benzylaniline  ;  it  melts  at  118—119°,  and  is  de- 
composed by  prolonged  boiling  with  hydrochloric  acid, 
into  benzylaniline,  and  a  substance  melting  at  about 
123—124°,  probably  "  thiocarbimidoglycolide." 

Allylphenylthiohydantoin. —  From  allylphenylthiocarb- 
amide  and  monochloracetamide  an  oil  was  obtained  ;  it 
appears  to  be  a  mixture  of  the  two  forms — 


CHa-S    V  CHaS    . 

I  >C:NPh  and    |  >:NA1I. 


CO-NAIK  CONPh' 

a  Bromopropionylthiocarbimide,  CHj-CHBr-CO  NCS, 
when  treated  with  orthotoluidine,  affords  wf<A_y/o>'</iofo/y/- 
thiohydanto'in, — 

CH3'CH-S    \^ 

I  >C:NC7H7. 

CO-NH/ 

Crystalline  powder,  melting  at  72—73°,  and  decomposed 
by  boiling  dilute  alkali,  with  formation  of  o-thioladic  acid, 
CH3-CH(SH)-C02H. 
Dithethylphenylthiohydanto'in, — 

CH3-CHa-SK 

I         >C-N(CH3)PH. 

co-n/^ 

—From  the  above  thiocarbimide  and  methylaniline ; 
vitreous  plates,  melting  at  129—130°. 

a-BromobutyrylthiocarbimideyCH^'CHz  C^^t'CO-UCS' 
by  combination  with  aniline,  yielded  ethylphenylthio' 
hydantoin, — 

CH3-CHa*CH-S    v 

I  >C:NC6H5. 

CO-NH/ 

White  needles,  m.  p.  148 — 149°  (corr.). 

Ethylorthotolylthiohydantotn. — A  sandy  white  powder, 
melting  at  95—96°,  to  a  turbid  liquid,  clearing  at  98°; 
the  hydrochloride  forms  white  needles,  m.  p.  224 — 225° 
(corr.).  When  boiled  with  alkali,  then  acidified  and 
mixed  with  ferric  chloride,  followed  by  ammonia,  a 
purplish  colouration  is  produced,  due,  probably,  to  the 
presence  of  o-thiobutyric  acid. 

For  greater  convenience  and  precision  in  naming 
"  thiohydantoins  "  of  the  above  types,  and  the  corre- 
sponding derivatives  of — 

.NH-CHa 
CS<  I      , 

^NH-CO 

together  with  the  related  "  thiohydantoic  "  acids,  the 
author  proposes  a  modification  of  the  nomenclature  at 
present  employed. 

6.  •'  The  Amyl  (Secondary  butyUmethyl)  Derivatives  of 
Glyceric,  Diacetylglyceric,  and  Dibenzoylglyceric  Acids, 
Active  and  Inactive.''  By  Percy  Frankland,  Ph.D., 
B.Sc,  F.R.S.,  and  Thomas  Slater  Price,  B.Sc. 

The  authors  describe  the  preparation  and  properties  of 
amyl  (laevo-a(5tive)  glycerate  (dextro-adive),  amyl  (in- 
adive)  glycerate  (dextro  -  a<5tive),  amyl  (laevo-adtive) 
glycerate  (inadive),  as  well  as  of  the  corresponding 
diacetyl  and  dibenzoylglycerates.  The  Interest  attaching 
to  these  bodies  depends,  firstly,  on  those  compounds  with 
the  inadtive  amyl  and  adive  acid  radicle  filling  gaps  in 
the  series  of  adive  glycerates,  diacetylglycerates,  and 
dibenzoylglycerates  already  prepared,  and  described  by 
one  of  the  authors.  The  position  of  the  maximum  rota- 
tion in  these  series  becomes  thus  more  precisely  localised. 
Secondly,  the  influence  of  one  asymmetric  carbon  atom 
on  another  in  the  same  molecule  can  be  ascertained,  and 
the  principle  of  the  superposition  of  the  optical  effeds  of 
the  asymmetric  carbon  atoms  is  put  to  the  test  and  found 


CRBIllCAL  MBWSi  1 

March  I2, 1897.    ' 


Wide  Dissemination  of  some  of  the  Rarer  Elements. 


129 


to  hold  good.  Thus  the  authors  show  how  the  optical 
properties  of  the  eight  possible  adtive  amylglycerates  can 
be  calculated  from  a  knowledge  of  the  optical  properties 
of  two  particular  ones,  and  similarly  in  the  case  of  the 
eight  adtive  amyl  diacetylglycerates,  and  the  eight  active 
amyl  dibenzoylglycerates. 

In  the  series  of  the  dibenzoylglycerates,  of  which  now 
the  methyl,  ethyl,  propyl,  and  amyl  terms  are  known,  the 
rotation  diminishes  from  the  methyl  to  the  amyl  com- 
pound,  and  there  is  every  probability  that  in  this  series 
the  rotation  will  be  found  to  pass  through  a  minimum. 

The  influence  of  temperature  on  the  rotation  of  all  the 
compounds  described  has  been  also  investigated,  with  the 
result  that,  as  before,  the  rotation  of  the  glycerates  was 
found  to  be  but  little  sensitive  to  temperature,  the  rota- 
tion of  the  diacetylglycerates  much  more  sensitive,  and 
that  of  the  dibenzoylglycerates  still  more  sensitive  to 
temperature.  Again,  as  before,  it  was  found  that  the 
negative  rotation  of  the  diacetylglycerates  increased, 
whilst  the  positive  rotation  of  the  dibenzoylglycerates 
diminished  with  rise  of  temperature.  It  was,  however, 
further  found  that  the  compounds  in  which  the  amyl 
alone  was  adtive,  viz.,  amyl  (laevo-active)  glycerate 
(inadive),  amyl  (Isevo-aftive)  diacetylglycerate  (inadlive), 
and  amyl  (Isevo-aftive)  dibenzoylglycerate  (inadlive),  had 
their  rotation  pradtically  unaffedled  by  temperature,  the 
sensitiveness  to  temperature  being  thus  confined  to  the 
rotation  dependent  on  the  asymmetric  carbon  atom 
belonging  to  the  glyceric  acid  part  of  the  molecule. 

7.  "  The  Refraction  Constants  of  Crystallised  Salts.' 
By  Alfred  E.  Tutton. 

This  communication  is  in  reply  to  certain  criticisms  of 
Pope  [Trans.,  1896,  Ixix.,  1530)  concerning  the  author's 
work  on  the  refradlion  constants  of  the  sulphates  and 
double  sulphates  containing  potassium,  rubidium,  and 
csesium  {Trans.,  1896,  Ixix.,  502).  It  is  first  shown  that 
the  claim  of  Pope  to  originality,  in  showing  that  the  mole- 
cular refradions  of  solid  salts  are  the  sums  of  the  atomic 
or  equivalent  refradlions  of  the  components,  is  unfounded, 
and  that  the  whole  of  the  conclusions  published  in  the 
author's  memoir,  with  regard  to  this  subject,  in  connec- 
tion with  the  entire  twenty-two  double  sulphates  investi- 
gated, were  based  upon  the  assumption  of  this  rule.  The 
second  point  is  with  regard  to  the  criticism  that  the  mean 
molecular  refradlions  of  the  salts  given  were  not  the  mean 
of  the  three  values  corresponding  to  all  three  refradlive 
indices  of  the  biaxial  crystals  in  each  case,  but  the  mean 
of  the  two  extreme  values ;  and  with  regard  to  the  re- 
calculated results  presented  by  Pope  taking  the  inter- 
mediate value  into  account,  which  Pope  appears  to  show 
exhibit  far  greater  accordance  than  the  author's  values. 
The  author  points  out  that  the  course  pursued  was  taken 
after  careful  consideration,  with  full  knowledge  of  the 
problem,  and  for  the  sufficient  reason  that  the  whole  of 
the  salts  in  question  were  so  extremely  feebly  doubly  re- 
fradtive,  and  the  extreme  values  consequently  so  close 
together,  that  he  judged  that  the  difference  between  the 
results  of  the  two  processes  would  be  within  the  range  of 
experimental  error.  He  then  shows  that  grave  errors 
occur  in  Pope's  re-calculations  ;  there  are  numerous 
errors  in  Table  III.,  two  of  them  being  whole  numbers, 
one  of  which  amounts  to  a  fifth  of  the  total  value,  and 
Table  IV.,  is  entirely  wrong  in  consequence.  When  the 
errors  are  corredted,  the  latter  table,  in  which  the  two 
whole-number  errors  also  appear,  assumes  quite  a  different 
aspedt,  the  results  of  the  two  modes  of  calculation  become 
nearly  identical,  the  differences  between  them  being  then 
well  within  the  range  of  the  experimental  error,  and  amply 
justify  the  author's  course.  The  author  finally  shows 
that  the  two  cases,  rubidium  sulphate  and  caesium  sul- 
phate, quoted  by  Pope  as  adverse  to  the  author's  state- 
ment that "  the  matter  in  a  crystal  has,  for  refradlion 
purposes,  the  same  average  effeA  as  the  same  matter 
uncrystallised,"  lead  to  diametrically  opposite  conclu- 
sions ;  and,  moreover,  that  such  conclusions   are  of  no 


value,  as  the  differences  in  question  between  the  values 
for  solution  and  for  the  crystallised  condition  are  well 
within  the  range  of  experimental  error. 

8.  "  The  Re/raction  Constants  of  Crystallint  Salts.'' 
A  Corredlion.     By  William  Jackson  Pope. 

The  author  regrets  to  find,  notwithstanding  that  the 
numbers  used  in  his  paper  {Trans.,  1896,  Ixix.,  1530)  were 
several  times  checked,  an  error  of  a  unit  in  two  numbers 
in  Table  III.  which  vitiates  the  first  line  of  Table  IV. 
{loc.  cit.,  p.  1537)  ;  the  first,  third,  seventh,  and  ninth 
numbers  in  the  line  in  question  should  be  5*11,  5*26,  I4'5t 
and  15*00,  and  in  the  fourth  column  of  Table  III.  the 
numbers  4*25  and  13*51  should  each  be  increased  by 
unity.  The  comparison  made  in  the  six  lines  following 
Table  IV.  is  consequently  unjustifiable. 

The  error,  although  to  be  regretted,  in  no  way  affeiAs 
the  general  argument,  but, if  left  uncorredted,  tells  unfairly 
against  the  method  of  calculation  used  by  Tutton. 

9.  "  On  the  Wide  Dissemination  of  some  of  the  Rarer 
Elements  and  the  Mode  of  their  Association  in  Common 
Ores  and  Minerals."  By  W.  N.  Hartley,  F.R.S.,  and 
HUQH  Ramaqe. 

By  means  of  spedlrographic  analysis  the  authors  have 
examined  about  170  specimens  of  ores  and  minerals, 
comprising  oxides,  carbonates,  and  sulphides.  Half  a 
grm.  of  each  substance,  finely  powdered,  was  heated  in 
the  oxyhydrogen  flame.  The  following  elements  and 
their  compounds  yield  spedlra  under  these  conditions 
which  are  easily  observed. 

(a)  In  very  small  quantity — 

Na,  Ca,  Pb,  Ni,  K,  Se,  Bi,  Cu,  Ba,  Cr,  Kb,  Ga,  Mn, 
Ag,  In,  Fe,  Cs,  Tl,  Co. 

(6)  In  small  quantity — 

Li,  Au,  Cd,  Sb,  and  Sn. 

(c)  In  such  quantity  as  to  indicate  that  the  substance 
is  a  principal  constituent  of  the  mineral — 

Be,  B,  Di,  Te,  Rh  ?,  Mg,  Al,  S,  Pd  ?,  Zn,  Ce,  Se,  Ru  ?. 

Some  of  the  metallic  elements  in  the  list  (c)  under 
special  conditions  yield  oxyhydrogen  flame  spedlra,  which 
are  easily  observed  even  in  small  quantity.  Other  ele- 
ments than  the  above  have  not  been  sought  for  in  this 
research. 

In  almost  every  case  the  locality  from  which  the  speci- 
mens of  ores  and  minerals  came  is  recorded,  and  the  re- 
sults of  the  spedtrographic  analysis  have  been  tabulated. 
Several  novel  and  interesting  fadts  are  disclosed,  which 
may  be  stated  very  briefly  as  follows  : — 

Clay  Iron-stones  and  Black-band  Ores.  —  Fifty-one 
specimens  examined.  All  contain  sodium,  potassium, 
copper,  calcium,  and  manganese  ;  47  contain  silver;  32, 
lead;  21,  gallium;  13,  nickel;  12,  chromium;  i,  stron- 
tium ;  and  i,  thallium.  Probably  all  contain  rubidium, 
but  it  is  difficult  to  recognise  owing  to  the  multitude  of 
iron  lines.     Three  specimens  undoubtedly  contain  it. 

Brown  Hcematites. — Six  specimens  examined.  All  con- 
tain sodium,  potassium,  copper,  calcium,  and  manganese  ; 
5  contain  silver;  5,  lead ;  and  5,  nickel;  3,  chromium ; 
2,  gallium  ;  2,  thallium ;  and  i,  indium.  Probably  all 
contain  rubidium  ;  in  one  it  is  undoubtedly  present. 

Limonites. — Five  specimens  examined.  All  contain 
sodium,  potassium,  silver,  manganese,  and  apparently 
rubidium;  4  contain  calcium;  4,  lead;  3,  copper;  3, 
nickel;  i,  gallium;  i,  thallium  ;  and  i,  chromium. 

Red  Hcematites. — Eighteen  specimens  examined.  All 
contain  sodium  and  potassium;  17  contain  copper ;  14, 
manganese;  13,  silver;  12,  lead ;  12,  calcium;  3  contain 
gallium  ;  3,  indium  ;  3,  nickel ;  2,  chromium  ;  i,  rubidium ; 
and  I,  thallium. 

Magnetites. — Seven  specimens  examined.  All  contain 
sodium,  potassium,  copper,  silver,  calcium,  gallium,  lead, 
and  manganese.  Four  appear  to  contain  rubidium  ;  2, 
Bickel ;  and  i  contains  indium. 

Siderities. — Five  specimens  examined.  All  contain 
sodium,  potassium,  copper,  silver,  calcium,  indium,  and 


130 


The  late  Georges  VtUe. 


I  Cheu:cal  News, 
i    Mareh  12.  13^7, 


manganese;    3   contain  lead;    i  contains  rubidium;  i, 
gallium;  i,  cobalt;  i,  nickel;  and  i,  bismuth. 

Aluminous  Minerals,  such  as  Bauxites. — Seventeen 
specimens.  All  contain  sodium,  potassium,  copper,  cal- 
cium, and  iron  ;  16  contain  gallium;  15,  chromium  ;  13, 
nickel ;  12,  manganese ;  g,  silver  ;  3,  lead  ;  and  2, 
rubidium. 

Manganese  Ores  and  Minerals. — Eleven  specimens  ex- 
amiiicd.  All  contain  sodium,  potassium,  copper,  calcium, 
and  iron  ;  10  contain  silver  ;  5,  rubidium,  and  5,  nickel; 
4,  gallium  ;  4,  lead  ;  and  4,  strontium ;  2,  barium ;  i, 
indium;  and  i,  cobalt. 

Blendes  —Fourteen  specimens  examined.  All  contain 
sodium,  copper,  silver,  and  iron  ;  13,  potassium  ;  12,  gal- 
lium; 12,  lead;  10,  silver;  10,  manganese;  g,  indium  ; 
7,  cadmium;  4,  thallium;  2,  nickel;  and  i,  chromium. 
The  zinc  was  observed  in  only  8  specimens,  the  spedtrum 
being  hidden  by  other  lines. 

Nickel  and  Cobalt  Ores. — Nine  specimens  examined. 
All  contain  sodium,  potassium,  copper,  calcium,  iron,  and 
nickel;  6  contain  cobalt;  6,  lead;  4,  chromium;  3,  silver; 
I,  barium;  and  i,  strontium. 

Tin  Ores. — Five  specimens  examined.     All  contain  so-  I 
dium,  indium,  and  iron  ;  4  contain  potassium  ;  3,  copper ; 
3,  calcium  ;  3,  lead  ;  2,  silver;  and  2,  manganese. 

Galenas. — Eight  specimens.  All  contain  sodium, 
potassium,  copper,  silver,  and  iron  ;  4  contain  manganese  ; 
and  3,  calcium. 

Pyrites.— Th'iTieen  specimens.  All  contain  sodium, 
potassium,  copper,  silver,  calcium,  and  iron;  11  contain 
lead;  10,  manganese  ;  5,  indium;  5,  thallium  ;  5,  nickel ; 
and  I,  gallium. 

Out  of  168  ores  and  minerals  examined,  gallium  occurs 
in  68 ;  indium  in  30  ;  and  thallium  in  17.  Rubidium  oc- 
curs probably  in  70,  but  unquestionably  in  13.  All  the 
carbonates  of  iron  and  all  the  tin  ores,  without  exception, 
contain  indium.  With  one  single  exception,  all  the 
bauxites  contain  gallium. 

Silver,  copper,  calcium,  potassium,  and  sodium  are  very 
widely  disseminated  through  all  ores  and  minerals. 

The  authors  draw  dedudions  as  to  the  formation  of 
beds  and  lodes  of  ore  from  the  following  fadls,  which  they 
claim  to  have  established  :— First,  that  certain  groups  of 
ores  and  minerals  are  pervaded  by  small  quantities  of  the 
same  metals  as  common  impurities.  Secondly,  the  rare 
metals,  more  particularly  rubidium,  gallium,  indium,  and 
thallium,  are  associated  with  the  same  groups  of  minerals, 
and  also  with  allied  groups. 

It  is  easy  to  trace  the  association  of  similarly  consti- 
tuted compounds  to  their  connexion  with  elements 
related  to  each  other,  as  determined  by  the  periodic 
system  of  classification.  These  compounds  have  certain 
properties  in  common,  distindlive  of  the  groups  of  elements 
and  compounds  to  which  they  belong  ;  hence  in  a  given 
course  of  chemical  changes,  similar  compounds  are 
formed  and  thrown  together  by  precipitation  or  otherwise. 
All  the  minerals  mentioned  have  undoubtedly  had  an 
aqueous  origin. 

The  presence  of  the  alkali  metals  in  all  the  specimens, 
but  in  variable  proportions,  has  a  special  significance. 

In  the  analysis  of  many  different  precipitates,  obtained 
both  in  neutral  and  even  strongly  acid  solutions,  the 
alkali  metals  have  been  found  in  combination  with  the 
precipitated  substance.  It  has  long  been  known  that 
manganese,  aluminium,  and  iron  in  the  state  of 
hydroxides,  combine  with  more  or  less  of  the  alkalis, 
but  in  a  great  measure  such  combinations  have  been  dis- 
regarded. 

Anniversary  Meeting. 

The  Anniversary  Meeting  will  be  held  on  Wednesday, 
March  31st,  at  3  o'clock  in  the  afternoon. 
Anniversary  Dinner. 

It  has  been  arranged  that  the  Fellows  of  the  Society 
and  their  friends  shall  dine  together  at  the  Criterion 
Restaurant  on  Wednesday,  March  3i8t,  at  6.30  for  7  p.m. 


OBITUARY. 


THE     LATE    GEORGES    VILLE. 

It  is  our  very  painful  duty  to  put  on  record  the  death  of 
our  valued  friend  Georges  Ville,  who  closed  his  most  useful 
and  honourable  career  on  February  22nd.  The  deceased 
held  the  Chair  of  Vegetable  Physiology  in  the  Museum 
of  the  Jardin  des  Plantes.  His  life  has  been  essentially 
devoted  to  a  pradical  study  of  the  vital  conditions  of 
plants,  and  especially  of  our  food-plants. 

Professor  Ville  pointed  out  the  necessity  of  keeping 
cultivated  lands  adequately  supplied  with  those  constitu- 
ents of  plant-food  which  are  most  readily  exhausted  by 
the  crops.  As  such,  in  addition  to  phosphoric  acid, 
potassium  salt,  and  nitrogen,  he  laid  great  weight  on 
lime  in  the  form  of  gypsum.  This  recommendation,  we 
need  scarcely  say,  though  borne  out  by  his  experiments, 
is  not  ratified  by  British  pradice.  To  keep  cattle  for  the 
produAion  of  manure — as  is  done  by  too  many  farmers  in 
this  country — he  humorously  compared  to  the  condud  of 
a  supposed  iron  manufadurer  who  should  plant  and  keep 
up  forests  to  supply  his  work  with  fuel.  He  shows  that 
all  the  elements  of  plant-food  can  be  obtained  at  less  cost 
from  mineral  sources.  But  it  is  a  gross  misunderstanding 
to  say  that  Prof.  Ville  denounced  the  use  of  animal 
manures. 

He  introduced  in  France  the  method  of  trial-plots  of 
arable  land,  thus  making  the  plant  analyse  the  soil  for 
itself.  The  process  which  he  names  sideration  is  simply 
ploughing  in  crops  which  are  of  no  value  in  themselves, 
but  which  serve  to  enrich  the  soil  especially  by  fixing 
atmospheric  nitrogen  in  states  suitable  for  the  nourish- 
ment of  succeeding  crops. 

His  published  works,  some  of  which  have  been  trans- 
lated into  English,  are  of  great  but  unequal  value.  His 
ledtures  on  agriculture,  delivered  in  Belgium  as  well  as  in 
France,  cannot  fail  to  rouse  up  the  agricultural  mind, 
though  they  carry  ideas  which  in  England  would  be  quite 
out  of  place.  But  he  has  done  an  incalculable  service  to 
France,  and  to  the  civilised  world  in  general,  by  exposing 
the  worn-out  fallacy  that  organic  matter  by  passing 
through  the  bodies  of  horses  or  of  oxen  acquires  some 
novel  and  mysterious  virtue  which  it  had  not  before. 

Ville's  chref  works  are  :  —  "  Artificial  Manures  " 
(Longmans  and  Co.),  and  "The  Perplexed  Farmer,  how 
is  he  to  meet  Alien  Competition  ?  "  (Longmans  and  Co., 
i8gi). 


NOTICES  OF  BOOKS. 


London 


Directory   of  Paper  Makers,  January,    i8gy, 

Marchant,  Singer,  and  Co. 
The  paper  industry  does  not  meet  with  an  amount  of 
attention  from  the  outside  public  at  all  commensurate 
with  its  importance. 

The  work  before  us  confines  itself  8tri(5lly  to  the  con- 
ventional funiflions  of  a  diredlory  without  entering  at  all 
upon  the  prospers,  the  difficulties,  and  possible  dangers 
of  the  trade.  The  manufadlure  of  filter-papers  occupies 
the  attention  of  eight  firms,  but  we  fear  we  must  say  that 
none  of  these  takes  a  standing  equal  to  that  of  Munktell 
and  Co.,  of  Sweden,  and  Schleicher  and  Schiill,  of 
Germany. 

A  circumstance  which  we  much  regret  is  that  the 
trade  is  so  scantily  developed  in  Ireland.  There  the  air 
is  less  polluted  with  smoke  than  in  most  parts  of  England 
and  even  of  Scotland  ;  the  water  supply  is  more  abundant 
in  quantity,  and  we  think  we  may  say  superior  in  purity 
to  that  on  our  side  of  St.  George's  Channel.  Ireland  has, 
in  short,  the  greatest  natural  facilities  for  the  develop- 
ment of  the  paper  manufafture. 


Chkuical  Nbws, 
March  12, 1897. 


Chemical  Notices  from  Foreign  Sources, 


13' 


CORRESPONDENCE. 

RELATION     BETWEEN     ROTATION 

AND    REDUCING     POWERS     OF    HYDROLYSED 

STARCH     SOLUTIONS. 

To  the  Editor  of  the  Chemical  News. 
SiR.^I   have  not  yet  read  the   full  paper  of  Browne, 
Morris,  and   Millar,   a  notice  of   which  appears  in  the 
Chemical  News  (Ixxv.,  p.  42). 

The  fadt  that  a  constant  relation  exists  between  cupric 
reducing  and  rotatory  powers  in  hydrolysed  starch  solu- 
tions was  pointed  out  by  me,  in  a  paper  read  before  the 
A.A.A.S.  at  the  Boston  meeting,  in  1880,  and  published 
in  full  in  the  Proceedings  for  that  year,  and  in  the 
yournal  of  the  American  Chemical  Society  (vol.  ii,,  1880, 
pp.  395 — 402).  There  is  also  an  abstraft  of  my  paper  in 
the  Berichte  der  Deutschen  Chemischen  Gesellscha/t 
(xiv.,  1584). 

From  the  results  of  my  investigations,  it  would  be 
only  a  logical  conclusion  to  infer  that  similar  relations 
exist  among  hydrolytic  starch  produdls  in  general.  In 
the  materials  examined  by  me,  the  produdls  of  hydrolysis 
were  chiefly  dextrose  and  dextrine.  In  the  researches 
made  by  the  authors  above  mentioned,  maltose  and  dex- 
trine were  the  chief  hydrolytic  produfts. 

In  my  paper  the  data  of  the  examination  of  a  large 
number  of  samples  of  commercial  starch  glucoses  are 
found,  with  formulae  for  calculating  the  percentage  of 
reducing  sugars  for  varying  specific  gravities.  The  cal- 
culated reducing  powers  obtained  by  these  formulae  were 
found  to  agree  remarkably  well  with  the  adtual  reducing 
data  secured  with  Fehling  solution.  With  the  improved 
modern  optical  and  chemical  methods  it  is  quite  certain 
that  a  formula  could  be  construdted  for  the  hydrolytic 
produdls  of  starch  obtained  with  sulphuric  acid,  which 
would  give  diredtiy,  from  the  optical  observation  of  the 
solutions,  pradically  corre(^  figures  for  reducing  powers. 
— I  am,  &c., 

H.  W.  Wiley,  Chief  of  Division. 

United  States  Department  of  Agriculture, 

Division  of  Chemistry,  Washington,  D.C., 
February  24, 1897. 


CHEMICAL 


NOTICES    FROM 
SOURCES. 


FOKtlCiN 


Note.— All  degrees  of  temperature  are  Centigrade  unless  otherwise 
expressed. 

Comptes  Rendus  Hebdomadaires  des  Seances,  del'Academie 
des  Sciences,     Vol.  cxxiv,,  No.  6,  February  8,  1897. 

M.  Leidier,  of  Marseille,  addressed  to  the  Academy  a 
memoir  on  an  automatic  lightning  rod  for  telegraphic  and 
telephonic  lines. 

New  Researches  on  the  Determination  of  Pyro- 
phoric  Acid. — M.  Berthelot  and  G.  Andre. — Fadls  to 
serve  towards  the  "  History  of  Metaphosphoric  Acid," 
by  M.  Berthelot  and  G.  Andre. 

Redutftion  of  Nitrates  in  Arable  Soil. — P.  P.  Dehe- 
rain. — These  three  papers  will  be  inserted  in  full. 

Certain  Coloured  Rea(5^ions. — E.  Pineura. — These 
colourations  are  obtained  with  /3-naphthol-sulphuric  acid 
prepared  by  dissolving  0-02  grm.  of  j3-naphthol  in  i  c.c. 
ofsulphuricacidofsp.gr.  i'83;  we  add  from  10  to  15 
drops  of  this  reagent  to  about  0*5  grm.  of  the  substance 
to  be  charadterised  ;  if  the  latter  is  in  solution  it  is  gently 
evaporated  to  dryness.  Tartaric  acid  gives  at  first  a  blue 
colour,  which,  if  we  continue  to  heat,  gradually  passes  to 
a  very  decided  green  tint ;  if,  when  the  matter  is  cold, 
we  add  15  to  20  times  its  volume  of  water  we  obtain  a 


permanent  yellowish  red.  Citric  acid  gives  an  intense 
blue,  which  does  not  turn  green  with  prolonged  applica- 
tion of  heat.  The  addition  of  15  to  20  times  its  volume 
of  water  gives  a  colourless  solution,  or  one  very  fainly 
yellowish.  A  small  quantity  of  tartaric  acid  mixed  with 
the  citric  acid  brings  up  the  green  tint  which  pure  citric 
acid  never  produces;  10  to  12  percent  of  tartaric  acid 
then  produces  a  dark  greenish  blue.  Pure  malic  acid 
gives  at  once  a  yellowish  green  colour,  which  becomes 
bright  yellow  on  prolonging  the  heat.  The  addition  of 
water  turns  the  colour  to  a  bright  orange.  These  readlions 
are  charadteristic  and  easy  to  observe ;  it  is  merely  neces- 
sary to  heat  carefully,  and  to  withdraw  the  capsule  from 
the  fire  as  soon  as  any  colour  is  observed.  If  it  ceases  to 
increase  in  intensity,  we  heat  afresh  if  requisite.  Other 
organic  substances  produce  similar  colours,  but  less  defi- 
nite and  charadteristic.  /3-naphthoI  sulphuric  acid  also 
serves  to  distinguish  the  alkaline  nitrites  ;  10  drops  of  this 
reagent,  added  to  0*05  grm.  sodium  nitrite,  dissolved  in  a 
few  drops  of  water,  give  rise  to  a  very  intense  redness, 
which  is  not  altered  on  the  addition  of  water.  Alkaline 
nitrates  may  be  distinguished  in  an  analogous  manner  by 
means  of  a  solution  of  o'lo  grm.  resorcin  in  i  c.c.  of  sul- 
phuric acid  at  176.  The  adlion  of  this  reagent  upon 
0*05  grm.  potassium  or  sodium  nitrate  determines  the 
appearance  of  a  red-brown,  which  soon  becomes  a  very 
intense  violet,  and  which  passes  to  orange  on  the  addition 
of  water. 

New  Method  of  Preparing  the  Primary  Amines. — 
Marcel  Delepine. — It  becomes  easy  to  have  a  pure  pri- 
mary amine,  if  we  can  combine  the  corresponding  mineral 
ether  with  hexamethylamine. 

Sanitation  of  the  Match  Trade.  —  M.  Magitot. — 
The  author's  conclusions  are: — i.  The  sanitation  of  the 
manufadture  of  matches  with  white  phosphorus  is  a  pro- 
blem simple  and  easy  of  solution.  2.  The  method  of 
sanitation  consists  of  two  orders  of  means  based  on  two 
fadiorsof  injury,  which  are  (a)  phosphorism,  (6)  necrosis. 
3.  To  phosphorism  we  oppose  the  ventilation  of  the  work 
by  artificial  means,  powerful  enough  to  withdraw  the 
poisonous  emanations  from  the  workers.  To  necrosis  we 
oppose  the  principle  of  seledlion  ;  that  of  recruitment  and 
maintenance  from  the  hands  of  persons  entirely  free 
from  any  injury  of  the  mouth  or  the  jaws  which  might 
furnish  an  opening  for  the  chemical  mischief.  4.  The 
problem  of  sanitation  is  entirely  comprised  in  the  two 
terms — ventilation  and  seledlion. 

Determination  of  Potassium  Bitartrate  in  Winss. 
— Henri  Gautier. — This  paper  will  be  inserted  in  full. 

Indigenous  Essence  of  Basil  (Ocymum  basilicum). 
— MM.  Dupont  and  Guerlain. — The  produdt  which  ac 
companies  linalol  in  oil  of  basil  is  estragol  (para-methoxy- 
allylbenzene). 

Argon  and  Nitrogen  in  the  Blood. — P.  Regnard  and 
Th.  Schlcesing. — The  authors  were  obliged  to  operate  on 
about  10  litres  of  blood.  The  blood,  on  leaving  the  veins, 
could  not  be  allowed  to  come  in  contadt  with  the  air  for 
a  single  instant.  Whilst  adhering  to  fadls  positively  ob- 
served, the  authors  conclude  that  argon  exists  in  solution 
in  the  blood. 

No.  7,  February  15,  1897. 
The  Age  of  Copper  in  Chaldea.— M.   Berthelot. — 
Already  inserted. 

A  Safety  Receiver  adapted  for  containing  Liquefied 
Gases. — J.  Fournier. — This  paper  requires  the  accom- 
panying figures. 

Influence  of  the  X-Rays  on  the  Striking  Distance 
of  the  Eledlric  Spark.— M.  Guggenheimer.— The  author 
has  succeeded  in  establishing  that : — i.  At  equal  dis- 
tances and  at  equal  potential  differences  the  augmentation 
of  the  striking  distance  of  the  passive  spark  depends  on 
the  intensity  of  the  X-rays  encountering  the  micrometer. 
2.    At  an  equal  diifersnce   of  potential  (by  the  micro< 


132 


Meetings /or  the  Week, 


r  Crshical  nbws, 
1    March  i2, 1897. 


meter)  and  at  an  equal  intensity  of  the  X-rays  the 
augmentation  of  the  striking  distance  of  the  passive 
spark  depends  on  the  distance  of  the  micrometer  from  the 
emissive  wall  of  the  tube.  3.  The  interposition  of  a 
fluorescent  screen  of  barium  platinocyanide,  of  a  plate  of 
glass,  or  of  quartz  does  not  appreciably  change  the 
radiation. 

False  Equilibria  of  Hydrogen  Selenide. — H.  Pela- 
ron. — A  mathematical  paper  v/ith  a  diagram,  not  suitable 
for  insertion. 

Adtion  of  Cuprous  Oxide  upon  Solutions  of  Silver 
Nitrate.  —  Paul  Sabatier.  —  Not  susceptible  of  useful 
abstradtion. 

On  certain  Derivatives  of  Salicylic  Aldehyd. — 
Paul  Rivals. — A  thermo-chemical  paper.  The  heat  of 
molecular  combustion  is  =  15897  cal.  at  constant 
volumes  and  15903  cal.  at  a  constant  pressure. 


NOTES    AND    QUERIES. 

♦»♦  Our  Notes  and  Queries  column  was  opened  for  the  purpose  of 
giving  and  obtaining  information  likely  to  be  of  use  to  our  readers 
generally.  We  cannot  undertake  to  let  this  column  be  the  means 
of  transmitting  merely  private  information,  or  such  trade  notices 
as  should  legitimately  come  in  the  advertisement  columns. 

Dental  Alloy*.— Are  there  any  books  on  the  alloys  used  in  den- 
tistry ?  If  80,  who  are  the  publishers  ?— Jack. 

MEETINGS    FOR    THE    WEEK. 

Monday,  15th.— Society  of  Arts,  8.     (Cantor  Leftures).     "Alloys," 

by  Prof.  W.  Chandler  Roberts  Austen,  F.R.S. 
Tuesday,  16th.— Royal  Institution,  3.     "  Animal   Eleftricity,"  by 
Prof.  A.  D.  Waller,  F.R.S. 

Society  of  Arts,  8.     •'  The  Progress  of  the  British 

Colonies  of  Australasia  during  the  Sixty  Years  of 
Hei  Majesty's  Reign,"  by  James  Bonwick. 
WxDNBBDAV,  i^th.— Society  of  Arts,  8.      "  Music  in  England  at  the 

Queen's  Accession,"  by  J.  Spencer  Curwen. 
Thursdav,  iSth.— Chemical,  8.  "  On  the  Atomic  W«ight  of  Car- 
bon," by  Alexander  Scott,  M.A.,  D.Sc.  "  On 
a  New  Series  of  Miacosulphates  of  the  Vitriol 
Group,"  by  Alexander  Scott,  M.A.,  D.Sc. 
"  The  Aftion  of  Alkyl  Haloids  on  Aldoximes 
and  Ketoximes,"  by  Wyndham  R.  Dunstan, 
F.R.S.,  and  Ernest  Goulding. 

Royal  Institution,  3.    "  Greek  History  and  Extant 

Monuments,"  by  Prof.  Percy  Gardner,  F.S.A. 
Friday,  19th.— Royal  Institution,    9.      "Greek    and    Latin   Palao- 

graphy,"  by  Sir  Edward  Maunde  Thompson. 
Saturday,  20th.— Royal  Institution,  3.    "  Eleftricity  and  Electrical 
Vibrations,"  by  Right  Hon.  Lord  Rayleigh,  M.A., 
F.R.S. 

ACETONE — Answering  all  requirements. 

.A.OHD  J^CIETIO— Purest  and  sweet. 

BODB-A-dC-Cryst.  and  powder. 

__  OZETDESiIO— Cryst.  made  in  earthenware. 
(3.  /X  T.T.Tn— From  best  Chinese  galls,  pure. 

SJLIjIG'Z'XjIO— By  Kolbe's  process. 

rj|i_^3<q-2<3"XO— For  Pharmacy  and  the  Arts. 

LIQUID  CHLORINE 

(Compressed  in  steel  cylinders). 

FORMALIN    (W"  CH2O)— Antiseptic  and  Preservative. 

POTASS.  PERMANGANATE— Cryst.,  large  and  small, 

SULPHOCYANIDE   OF   AMMONIUM. 

BARIUM. 

THORIUM,  ZIRCONIUM,  and  CERIUM  SALTS. 

T A RTA R   E M  ET I  C-Cryst.  and  Powder. 

PUMICE.     TRIPOLI   AND   METAL  POWDERS. 

ALL  CHEMICALS   FOR  ANALYSIS   AND  THE  ARTS. 

Wholesale  Agents— 

A.  &  Mr  ZIMMERMANN, 

9  &  10,  ST.  MARY-AT-HILL,  LONDON,  E.G. 


An  Associate  of  the  Institute  of  Chemistry* 

^*-  who  has  had  four  years'  experience  with  Consultant  Analyst 
and  four  years  at  Works,  desires  engagement.  Food  and  Agricultural 
work  specialities.  Unexceptional  references. — Address,  H.  I.,  271 
Wellington  Square,  London,  S.W. 

A  nalytical  Chemist,  A.I.C.,  who  has  had  expe- 

■^  •^  rience  in  well-known  Laboratory  and  Cement  Works,  seeks 
employment  in  Works  or  Laboratory. — Address,  "  Works,''  Chemi- 
cal News  Office,  6  &  7,  Creed  Lane,  Ludgate  Hill,  London,  E.C. 

Analytical   Chemist    (Ph.D.)   seeks   Engage- 

^*-  ment ;  Belgian  (26);  studied  in  Germany  and  Switzerland; 
three  and  a  half  years'  experience  with  Agricultural  Laboratory  ; 
now  engaged  at  Aniline  Colour  manufadtories.  Thorough  knowledge 
of  English,  French,  German,  and  Dutch. — Address,  "A.B.K.,"  care  of 
Street  and  Co.,  30,  Cornhill,  E.C. 

A  ssistant  wanted,  at  the  end  of  March,  in  a 

^  ^  London  Analytical  Laboratory.  Hours,  10  to  5  ;  Sat.,  10  to  I. 
Annual  holiday,  14  days.  Applicants  must  be  experienced  in  the 
quantitative  analysis  of  water,  food,  drugs,  and  commercial  substances 
generally.  F.LC.  or  A.LC.  preferred.  Salary,  paid  monthly,  jf  100 
to  £125  a  year,  according  to  qualifications. — Apply  to  A.Z.,  Chemical 
News  Office,  6  &  7,  Creed  Lane,  Ludgate  Hill,  London,  E.C. 

\A7"orks'    Chemist,    A.I.C,    late    with    large 

'  •  London  manufacturers,  well  up  in  Plant  and  Building  Con- 
stru(5tion,  experience  in  management  of  men,  and  in  conduSion  of 
Technical  Research  work,  good  Commercial  Analyst,  seeks  Appoint- 
ment. Moderate  Salary.— Address,  "  Plant,"  Chemical  News  Office, 
6  &7,  Creed  Lane,  Ludgate  Hill,  London,  E.C. 

'^XT'anted,   in   London    Smelting  Works,    an 

*  *  Assistant  Chemist.  Must  be  well  up  in  Leady  and  Cuprous 
material. — Write  C.N.  gzg,  Deacon's  Advertising  Offices,  Leadenhall 
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-■■  Manure  Works.  —  Apply,  by  letter  only,  to  Mr.  Vincent 
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pOR  SALE.— Complete  set   of  "Journal   of 

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NOTICE  IS  HEREBY  GIVEN, 
That  the  Board  will   meet  at  the   Board  Room,  117,  High   Street, 
Poplar,  on  Tuesday,  the  i6th  day  of  March  inst.,  at  6.30  o'clock  in 
the  evening  precisely,  to  receive 

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PERMANGANATE  OF  POTASH,  AT  PER  Lb. 

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Cbbmioal  Nbws,  I 
March  19, 1897.    J 


Estimatton  of  Zinc  Oxide, 


133 


THE    CHEMICAL    NEWS 


Vol.  LXXVm  No.  1947. 


A  NOTE    ON  THE    ESTIMATION    OF  ZINC 
OXIDE. 

By  B.  ASTON,  B.Sc.  (Lond.),  and  L.  NEWTON, 
University  College,  London. 

Fbesenius  States  that  zinc  oxide,  when  mixed  with  sul- 
phur, and  heated  gradually  to  redness  in  a  current  of 
hydrogen  gas,  is  quantitatively  transformed  into  zinc  sul- 
phide. 

We  attempted  in  this  way  to  determine  the  purity  of 
zinc  oxide  prepared  in  the  following  manner  from  pure 
zinc,  and  have  met  with  an  anomaly  which,  we  think, 
deserves  to  be  placed  on  record.  A  preliminary  analysis  of 
the  zinc  was  first  made,  by  dissolving  a  weighed  quantity 
in  nitric  acid,  evaporating  to  dryness,  igniting,  and  then 
weighing  the  zinc  oxide  obtained. 

i'io6  grms.  of  zinc  gave  1*38075  grms.  of  zinc  oxide. 
Percentage  of  zinc  in  the  ZnO — Found,  80*29 ;  Calculated, 
80*24. 

50  grms.  of  zinc,  thus  shown  to  be  almost  pure,  were 
dissolved  in  pure  nitric  acid,  and  the  solution  evaporated 
to  dryness.  The  residue  was  taken  up  with  water,  and 
the  solution  filtered.  To  the  filtrate  a  few  drops  of  ammo- 
nium sulphide  were  added,  the  liquid  was  allowed  to  stand 
for  some  hours  with  repeated  shaking,  and  then  filtered. 

The  filtrate  was  evaporated  to  dryness  on  a  water-bath, 
then  dried  in  an  air-bath  at  150°  C,  and  finally  ignited,  first 
in  the  blowpipe,  and  then  for  three  hours  in  a  muffle 
furnace. 

Two  weighed  specimens  of  oxide  thus  prepared  were 
mixed  with  sulphur  and  gradually  heated  to  redness  in  a 
current  of  hydrogen  gas. 

After  cooling  down  in  the  gas  the  crucibles  were 
weighed. 

This  process  was  repeated  in  the  one  case  sixteen,  in 
the  other  twenty-two  times,  but  in  neither  did  the  quan- 
tity of  zinc  sulphide  exceed  96  per  cent  of  the  theoretical, 
though  it  had  increased  generally  by  a  small  amount  at 
each  weighing. 

These  results  might  conceivably  be  due  to  impurities 
in  the  zinc  oxide  used,  andTwe  therefore  tried  another 
method  of  estimation,  viz.,  as  sulphate,  in  order  to  see 
whether  the  same  result  would  be  obtained. 

A  weighed  quantity  of  the  oxide  was  dissolved  in  dilute 
sulphuric  acid  in  a  weighed  platinum  crucible  and  evapor- 
ated to  dryness  ;  the  greater  part  of  the  acid  was  driven 
off  by  heating  in  an  asbestos  oven  to  about  340°  C. 

The  crucible  was  placed  in  a  sulphur  bath  for  about  two 
hours,  then  removed  and  weighed.  It  was  replaced  in  the 
bath  for  an  equal  period  of  time,  and  then  re-weighed 
(Baubigny,  Comptes  Rendus,  vol.  xcvii.,  p.  854).  The 
weight  had  not  changed,  and  the  result  of  the  experiment 
was  that — 

0*5742  grm.  of  ZnO  gave  1*14065  grms.  of  ZnS04; 

hence  the  percentage  of  zinc  in  the  zinc  oxide  was  80*19 
instead  of  80*24,  the  theoretical  quantity. 

Our  zinc  oxide,  therefore,  was  pure,  and,  so  it  would 
seem,  that  the  change  from  oxide  prepared  from  zinc 
nitrate,  to  sulphide  by  heating  with  sulphur  in  a  current 
of  hydrogen,  cannot  be  made  the  basis  of  a  quantitative 
method. 

At  this  point  it  may  be  advisable  to  give  some  of  the 
numbers  experimentally  obtained. 


(z).  0*3555  g"ii*  of  zinc  oxide  gave— 

ist  weighing 0*3735  grm.  ZnS. 

0*3905 


6th 
loth 
nth 


0*3985 
0-3985 


At  this  stage  ZnS  and  sulphur  were  ground  together  in 
an  agate  mortar,  so  as  to  make  sure  of  an  intimate 
mixture. 

14th  weighing 0*4065  grm.  ZnS. 

i6th        , 0*4070    „        „ 

At  this  point  the  quantity  of  ZnS  obtained  was  95*59 
per  cent  of  the  theoretical. 

(2).  In  this  case  the  zinc  oxide  and  sulphur  were  in 
each  case  ground  together  in  an  agate  mortar,  and  then 
introduced  into  the  crucible. 

0*4685  grm.  of  zinc  oxide  gave — 

isi  weighing 0*5055  grm.  ZnS. 

"th        „         05275    „        „ 

i3tn        ••         05280    „        „ 

15th        M         0*53275  „        „ 

i6tn        .1         o'53a5    „        » 

aand       „        05374    „       „ 

At  this  point  the  experiment  was  arbitrarily  stopped. 
The  quantity  of  zinc  sulphide  obtained  was  95*88  per  cent 
of  the  theoretical.  The  compound  formed  appears  in 
each  case  to  correspond  roughly  to  a  formula  3ZnS.2ZnO. 
Two  points  may  be  noted  about  these  numbers : — 

1.  After  the  first  heating  with  sulphur,  the  weight  of 
sulphide  produced  is  more  than  85  per  cent  of  the  theo- 
retical, being  in  the  first  case  87*7  per  cent  and  in  the 
second  90*10  per  cent ;  any  further  increase  is  only  by 
very  small  quantities,  and  cannot  be  due  to  impurities  in 
the  sulphur,  which  left  no  residue  on  ignition. 

2.  Two  weighings  may  give  exadlly  the  same  number ; 
that  is  to  say,  a  constant  point  is  reached,  and  yet  on  re- 
peating the  process  an  increase  is  obtained.  Thus  it  is 
impossible  to  find  a  point  at  which  the  change  from  oxide 
to  sulphide  definitely  stops. 

It  was  thought  advisable  to  see  whether,  under  the 
same  circumstances,  zinc  oxide  prepared  from  compounds 
other  than  the  nitrate  would  be  quantitatively  changed 
into  sulphide. 

Experiments  were  therefore  tried  with — 

(i)  Zinc  oxide  prepared  from  zinc  sulphide  by  ignition. 

(2)  „  „  „       carbonate        „ 

(3)  II  II  II       sulphate  „ 

(i).  The  zinc  sulphide  used  was  prepared  by  dissolving 
some  of  our  pure  zinc  oxide  in  acetic  acid,  and  passing 
into  the  solution  a  current  of  sulphuretted  hydrogen  gas. 

The  precipitate  was  coUei^ed,  washed,  and  then  dried 
in  a  current  of  hydrogen  gas. 

That  this  sulphide  was  pure  is  shown  by  the  following 
analyses  : — 

(a)  0*1582  grm.  ZnS  gave  on  ignition  0*1322  grm.  ZnO. 

(b)  0*11075        „  „  0*0925        „ 

Percentage  of  Zn     Percentage  of  Zn  in  ZaS 
found.  calculated  by  theory. 


(a) 
(b) 


67*052 


67*010 
67*010 


0*11585  grm.  of  zinc  oxide  thus  prepared  was  heated 
with  sulphur  in  the  usual  manner,  and  gave  0*13860  grm. 
ZnS. 

Percentage  of  Zn  Percentage  of  Zn  in  ZnO 

found.  calculated  by  theory. 

80*16  80*24 

(2).  Zinc  Oxide  prepared  from  Zinc  Carbonate. 
Some  zinc  oxide  was  dissolved  in  acetic  acid,  and  pre- 
cipitated with  pure  ammonium  carbonate  solution. 


134 


Electric  Shadows  and  Luminescence, 


I  Cbbmical  Nbws, 
March  ig,  1897. 


The  precipitate  was  colledled,  washed  with  boiling 
water,  and  then  ignited  until  its  weight  remained  constant. 
0'2245  grm.  of  zinc  oxide  thus  prepared  was  mixed  with 
sulphur  and  treated  in  the  usual  manner,  giving  02685 
grm.  of  zinc  sulphide. 


Percentage  of  Za 
found, 

8o'i4 


Percentage  of  Za  in  ZnO 
by  theory. 

8o'24 


(3).  Zinc  Oxide  prepared  from  Zinc  Sulphate. 
The   zinc  oxide  used  in    this    case   was    prepared   by 
igniting  to  a  constant  weight  the  sulphate  previously  ob- 
tained in  the  estimation  of  zinc  oxide  as  sulphate. 

o"i40  grm.  of  zinc  oxide  gave  o'i68  grm.  of  zinc  sul- 
phide. 

Percentage  of  Za  Percentage  of  Zn  in  ZnO 

found.  calculated. 

80*41  80*24 

It  must  be  pointed  out  that  in  this  case  the  final  point 
was  only  reached  after  three  ignitions  with  sulphur.  But 
after  the  first  ignition  the  quantity  of  zinc  sulphide 
formed  was  already  98*4  per  cent,  and  therefore  the  case 
is  hardly  comparable  to  that  of  the  oxide  prepared  from 
the  nitrate. 

Thus,  zinc  oxide  prepared  by  ignition  of  the  nitrate  is 
not  quantitatively  transformed  into  sulphide  by  heating 
with  sulphur  in  a  current  of  hydrogen  gas,  as  are  speci- 
mens of  oxide  prepared  in  other  ways. 

University  College,  London, 
March,  1897. 


THE    DETERMINATION     OF    TITANIC    ACID. 
By  J.  JAS.  MORGAN. 

In  determining  titanic  acid  in  iron  ores  by  the  usual 
methods,  part  of  it  is  found  with  the  insoluble  residue 
and  part  in  the  acid  solution.  Arnold,  in  his  "  Steel 
Works  Analysis,"  describes  a  method  based  upon  the 
principle  that,  in  the  presence  of  excess  of  phosphate  of 
iron,  titanic  acid  forms  an  insoluble  phospho-titanate  of 
iron,  and  is  found  with  the  insoluble  residue,  and,  in  the 
absence  of  suf&cient  phosphate  of  iron  to  fix  the  titanium 
in  this  form,  brings  about  the  desideratum  by  the  addition 
of  ammonium  phosphate.  The  method  on  the  whole  is 
very  satisfadtory,  the  only  drawback  being  the  method  of 
precipitating  the  titanium,  which  is  effected  by  boiling 
the  largely  diluted  solution  (measuring  1000  c.c.)  until  the 
volume  is  reduced  to  250  c.c.  This  occupies  considerable 
time,  while  the  precipitate  not  unfrequently  adheres  so 
tenaciously  to  the  beaker  as  to  render  the  complete 
removal  a  very  difficult  matter.  The  writer,  therefore, 
prefers  Blair's  method  of  precipitation,  and  carries  out 
an  estimation  as  follows  (a  combination  of  Arnold's  and 
Blair's  methods) : — 

To  the  weighed  portion  of  the  dry  ore  add  i  grm.  of 
ammonium  phosphate  dissolved  in  a  little  water,  and 
effedt  solution  by  digesting  with  hydrochloric  acid,  and, 
when  solution  is  complete,  evaporate  to  dryness  and  well 
bake.  Dissolve  the  dry  mass  in  hydrochloric  acid,  dilute, 
coUedt  the  insoluble  residue  (containing  the  whole  of  the 
titanic  acid  as  phospho-titanate  of  iron)  on  a  filter-paper, 
and  wash  with  hot  dilute  hydrochloric  acid  and  cold  water 
until  free  from  iron  salts.  Dry  the  filter-paper  and  contents, 
ignite  the  contents  in  a  platinum  crucible,  and  mix  with 
about  ten  times  its  weight  of  potassium  carbonate.  Fuse, 
extradt  the  fusion  in  a  little  hot  water,  filter  off  the  inso- 
luble, and  well  but  carefully  wash  with  hot  water.  Then 
dry  filter  and  contents,  place  in  a  platinum  crucible, 
ignite,  mix  with  about  6  grms.  of  acid  potassium  sulphate, 
and  fuse  at  a  low  red  heat  for  half  an  hour.  Extradt  the 
cold  fusion  in  10  c.c.  of  hydrochloric  acid  and  30  c.c.  of 


sulphurous  acid,  filter,  and  wash  with  hot  water.  Dilute 
the  filtrate,  add  20  grms.  of  sodium  acetate  dissolved  in 
water,  then  one-sixth  the  volume  of  acetic  acid,  and  boil 
for  a  few  minutes.  Allow  the  resulting  precipitate  to 
settle,  colledt  on  a  filter,  and  wash  with  water  containing 
acetic  acid.     Dry,  ignite,  and  weigh  as  TiOa. 

With  pig  irons  the  weighed  portion,  after  the  addition 
of  the  ammonium  phosphate,*  is  dissolved  in  nitric  acid, 
sp.  gr.  i'20,  the  solution  taken  to  dryness,  and  baked.  The 
dry  mass,  dissolved  in  hydrochloric  acid,  again  taken  to 
dryness,  re-dissolved  in  hydrochloric  acid,  and,  after  di- 
luting the  solution,  the  silica,  &c.,  filtered  off;  the 
remainder  of  the  operation  being  then  similar  to  the 
above. 


A     RECLAMATION. 


We  have  received  a  communication  from  Prof.  Dr.  C. 
Riffenbach,  bearing  date  "  Cairo,  February  18,  1897." 
The  author  mentions  that  we  insert  in  the  Chemical 
News  of  February  12th  a  reprint  of  a  paper  by  M. 
Gomberg,  of  Michigan,  which  appeared  in  the  journal  of 
the  American  Chemical  Society,  and  which  touches  his 
region. 

Prof.  Riffenbach  informs  us  that  he  published  this 
research  by  Gomberg  in  the  Zeitschrift  fur  Analyt. 
Chemie,  1896,  p.  466,  as  a  Supplement,  and  requires  us  to 
notice  his  research.  To  this  end  he,  simultaneously  with 
this  letter,  sends  a  special  reprint  of  the  paper.f 


ELECTRIC    SHADOWS  AND    LUMINESCENCE.^ 

By  Prof.  SILVANUS  P.  THOMPSON,  D.Sc,  F.R.S.,  M.R.I. 
(Concluded  from  p.  124). 

This  will  be  a  convenient  place  to  mention  a  new  effedt 
of  X-rays  which  I  have  recently  observed,  and  which  is 
set  down  in  the  table.  When  X-rays  fall  upon  a  metal 
objedl  eledlrified  by  an  influence  machine,  they  produce 
some  curious  changes  in  the  nature  of  the  discharge  into 
the  air.  If  the  body  is  already  discharging  itself  from 
some  edge  or  corner  in  an  aigrette  or  brush  discharge 
(visible  in  darkness  only)  the  size  and  form  of  the  aigrette 
is  much  altered.  Under  some  circumstances  not  yet  in- 
vestigated, the  incidence  of  X-rays  causes  the  aigrette 
to  disappear ;  under,  others,  the  X-rays  provoke  its  ap- 
pearance. 

Since  the  publication  of  Rontgen's  research  the  most 
notable  advance  that  has  been  made  has  been  in  the  direc- 
tion of  improving  the  tubes.  Rontgen  himself  has 
mostly  employed  a  pear-shaped  tube  with  a  flat  circular 
kathode  near  the  top,  producing  a  beautiful  fluorescence 
of  the  lower  part  of  the  tube.  He  carefully  verified  the 
circumstance  that  the  X-rays  originate  at  that  portion  of 
the  glass  surface  which  receives  the  impadt  of  the 
kathodic  discharge.  They  appear  in  fadl  to  be  generated 
at  the  place  where  the  kathode  discharge  first  impinges 
upon  the  surface  of  any  solid  body.  It  is  not  necessary 
that  the  substance  which  is  to  adt  as  emitter  of  the  X-rays 
should  become  fluorescent.  On  the  contrary,  it  appears 
that  the  best  radiators  are  substances  that  do  not 
fluoresce,  namely  the  metals.  I  have  found  zinc,  mag- 
nesium, aluminium,  copper,  iron,  and  platinum  to  answer 
— the  last  two  best.§  Mr.  Porter,  of  University  College, 
and  Mr.  Jackson,  of  King's  College,  have  independently 
found  out  the  merits  of  platinum  foil,  the  former  using 


*  With  phosphoric  irons  the  addition  of  ammonium  phosphate  is 
not  necessary,  unless  the  titanium  present  is  considerabl  e. 

+  At  the  present  date  this  reprint  has  not  reached  us. — Ed.  C.N. 

t  A  Lecture  delivered  at  the  Royal  Institution  of  Great  Britain, 
Friday,  May  8,  1896. 

§  (The  author  has  since  found  metallic  uranium  to  surpass  all 
other  metals). 


March  19, 1897.   / 

an  old  Crookes  tube  designed  for  showing  the  heating 
effedt  of  the  kathode  discharge  when  concentrated  by  a 
concave  kathode.  On  the  table  are  some  of  the  experi- 
mental forma  (see  Philosophical  Magazine,  August,  1896, 
p.  162)  of  tubes  I  have  used.  The  best  results  are  found 
when  the  kathodic  discharge  is  diredted  against  an  interior 
piece  of  metal — preferably  platinum — which  I  term  the 
antikathode  (Comptes  Rendtis,  cxxii.,  p.  807),  set  obliquely 
opposite  the  kathode,  and  which  serves  as  a  radiatmg  sur- 
face from  which  the  X-rays  are  emitted  in  all  dirediions. 
When  experimenting  with  various  forms  of  tube,  I  have 
spent  much  time  in  watching,  by  aid  of  a  fluorescent 
screen,  their  emissive  adtivity  during  the  progress  of  ex- 
haustion. As  already  mentioned,  X-rays  are  not  emitted 
until  the  stage  of  minimum  internal  resistance  has  been 
passed.  As  the  exhaustion  advances,  while  resistance 
rises  and  spark  length  increases,  there  is  noticed,  by  aid  of 
the  screen,  a  luminosity  in  the  bulb,  which,  faint  at  first, 
seems  to  come  both  from  the  front  face  of  the  bit  of 
platinum  that  serves  as  antikathode,  and  from  the  back 
face  ;  an  oblique  dark  line  (Fig.  11),  corresponding  to  the 
plane  of  the  antikathode,  being  observed  in  the  screen  to 
separate  the  two  luminous  regions.  On  slightly  increasing 
the  exhaustion  the  emission  of  X.rays  from  the  back  of 
the  antikathode  ceases,  while  that  from  the  front  greatly 
increases  (Fig.  12),  and  is  quite  bright  right  up  to  the 
angle  delimitedby  the  plane  of  the  antikathode.  There  is 
something  mysterious,  needing  careful  investigation,  in  this 
lateral  emission  of  X-rays  under  the  impadof  the  kathode 
discharge. 

Of  all  the  many  forms  of  tube  yet  produced  none  has 
been  found  to  surpass  the  particular  pattern  devised  by 
Mr.  Sydney  Jackson  (Fig.  13),  and  known  as  the  "  focus 
tube."  It  was  with  such  a  tube  that  I  showed  you  at  the 
outset  the  fundamental  experiments  of  Rontgen.  A  con- 
cave polished  kathode  of  aluminium  concentrates  the 
kathodic  discharge  upon  a  small  oblique  sheet  of  platinum, 
which,  while  adting  as  antikathode,  serves  at  the  same 
time  as  anode.  Not  only  does  the  concentration  of  the 
kathodic  discharge  upon  the  metal  cause  it  to  emit  X-rays 
much  more  vigorously,  but  it  also  has  the  efTect  of  causing 
them  to  be  emitted  from  a  comparatively  small  and  definite 
source,  with  the  result  that  the  shadows  cast  by  opaque 
objedts  are  darker.  (Photographs  were  then  thrown  upon 
the  screen,  those  taken  with  "  focus"  tubes  showing  re- 
markable definition  of  detail.  Some  of  these  were  by 
Mr.  J.  W.  Giffen  ;  others,  showing  diseased  bones,  &c,, 
taken  by  the  ledlurer,  and  some  by  Mr.  Campbell- Swinton 
and  by  Mr.  Sydney  Rowland,  were  also  projedted). 

The  objedtion  has  been  taken  that  in  these  shadow 
photographs  it  is  impossible  to  distinguish  the  parts  that 
are  behind  from  those  that  are  in  front.  In  a  sense  that 
is  80.  But  I  venture  to  say  that  the  objedlion  not  only 
can  be  got  over,  but  has  been  got  over.  I  cannot  show 
the  proof  of  my  assertion  upon  the  screen,  because  I  can- 
not put  upon  the  screen  a  stereoscopic  view.  But  here  in 
my  hand  is  the  Rontgen  stereograph  of  a  dead  tame  rabbit. 
Two  views  were  taken,  in  which  the  X-rays  were  thrown 
in  two  different  diredtions  at  an  angle  to  one  another. 
When  these  two  views  are  stereoscopically  combined,  you 
observe  the  rabbit's  body  with  the  lungs  and  liver  inside 
in  their  relative  positions.  The  soft  organs,  which  cast 
faint  shadows  almost  indistinguishable  amid  the  detail  of 
ribs  and  other  tissues,  now  detach  themselves  into  different 
planes,  and  are  recognisable  distindtly.  I  now  send  up 
for  projedtion  in  the  lantern  the  two  photographs  that  were 
taken  at  the  beginning  of  my  discourse,  and  which  have  in 
the  meantime  been  developed. 

Turning  back  to  the  phenomena  of   luminescence,* 

•  This  very  convenient  term  was  suggested  some  six  years  ago  by 
Wiedemann,  to  denote  the  many  phenomena  known  variously  as 
fluorescence  or  phosphoreseence.  It  refers  to  all  those  cases  in 
which  light  is  produced,  whether  under  the  stimulus  of  eleftric  dis- 
charge, of  heat,  of  prior  exposure  to  illumination,  or  of  chemical 
aftion,  and  the  like,  in  which  the  light  is  emitted  at  a  lower  temper- 
ature than  that  which  would  be  necessary  if  it  were  to  be  emitted  by 
means  of  incandescence. 


Electric  Shadows  and  Luminescence, 


^35 


permit  me  to  draw  your  attention  to  the  accompanying 
table  of  the  different  kinds  of  luminescence  with  which 
the  physicist  has  to  deal. 

Table  II. 

Phenomenon.  Substance  in  which  it  occurs. 

1.  Chemi-luminescence       ..  Phosphorus     oxidising     in 

moist  air ;  decaying  wood ; 
decaying  fish ;  glowworm ; 
firefly ;  marine  organisms, 
&c. 

2.  Photo-luminescence       ..   Fluor-spar ;  uranium-glass  ; 

(a)  transient   =    Fluor-      quinine ;  scheelite ;    plat- 

escence.  inocyanides    of    various 

bases  ;  eosin,  and  many 
coal-tar  produdts. 

(b)  persistent  =  Phosphot-  Bologna-stone;      Canton's 

escence.  phosphorus  and  other  sul- 

phides of  alkaline  earths  ; 
some  diamonds,  &c. 

3.  Thermo-luminescence    ..   Scheelite;  fluor-spar. 

4.  Tribo-luminescence..     ..   Diamonds;    sugar;    uranyl 

nitrate ;  pentadacylpara- 
tolylketone. 

5.  Eledtroluminescence      ..   Many  rarefied  gases;  many 

(a)  Effluvio-luminescence.  of  the  fluorescent  and 
phosphorescent  bodies. 

{b)  Kathodo-luminescence  Rubies,  glass,  diamonds, 
many  gems  and  minerals. 

6.  Crystallo-luminescence  ..   Arsenious  acid. 

7.  Lyo-luminescence    ..     ..  Sub-chlorides    of     alkali- 

metals, 

8.  X-luminescence       ..     ..  Platino-cyanides,  scheelite, 

&c. 

You  will  note  the  names  given  to  discriminate  from  one 
another  the  various  sorts  of  luminescence.  Chemi- 
luminescence  denotes  that  due  to  chemical  adtion,  as 
when  phosphorus  oxidises,  or  when  the  glowworm  emits 
its  cold  light.  Then  there  is  the  photo-luminescence  of 
the  bodies  which  shine  when  they  are  shone  upon.  There 
is  the  thermo  luminescence  of  the  bodies  which  shine 
when  heated.  There  is  tribo-luminescence  caused  by 
certain  substances  when  they  are  rubbed.  There  is  the 
kathodo-luminescence  of  the  objedts  placed  in  a  Crookes 
tube.  There  is  the  crystallo-luminescence  of  certain 
materials  when  they  become  solid  ;  and  the  lyo-lumines- 
cence of  certain  other  materials  when  they  are  dissolved. 
Lastly,  there  is  the  X-luminescence  set  up  by  the  X-rays. 

Pausing  on  photo  luminescence,  here  is  an  experiment 
to  illustrate  the  difference  between  its  two  varieties,  phos- 
phorescence and  fluorescence.  Light  from  an  arc  lamp, 
filtered  from  all  rays  except  violet  and  ultra-violet,  is 
thrown  upon  a  disc  to  which  rapid  rotation  is  given  by  an 
eledtric  motor.  The  disc  is  painted  with  two  rings,  one 
of  sulphide  of  calcium,  the  other  of  tungstate  of  calcium. 
Though  the  light  falls  only  on  one  patch,  you  note  that 
the  sulphide  shows  a  continuous  ring  of  blue  light,  for 
the  emission  of  light  persists  after  the  stuff  has  passed 
out  of  the  illuminating  rays.  The  tungstate,  on  the  other 
hand,  shows  only  a  short  trail  of  light,  the  rest  of  the  ring 
being  non-luminous,  since  tungstate  has  but  little  per- 
sistence, The  light  has  in  fadl  died  out  before  the  stuff 
has  passed  a  quarter  of  an  inch  from  the  illuminating 
beam.  This  is  a  sort  of  phosphoroscope  designed  to 
show  how  long  different  materials  will  emit  light  after 
they  have  been  shone  upon.  Those  which  show  only  a 
temporary  luminescence  are  called  fluorescent,  while  those 
with  persistent  luminescence  are  called  phosphorescent. 
For  many  years  it  has  been  known  that  some  diamonds 
are  phosphorescent.  Three  such  are  here  shown,*  which, 
after  exposure  of  one  minute  to  the  arc  light,  shine  in  the 
dark  like  glowworms.  The  most  highly  phosphorescent 
material  yet  produced  is  an  artificial  preparation  of  sul- 

*  Kindly  lent  by  Dr.  T.  H.  Gladstone,  F.R.S. 


136 


Electric  Shadows  and  Luminescence, 


(Chbhical  News, 
March  19, 1897. 


Fio.  II. 


Fio.  12. 


Fio.  13. 


phide  of  calcium  tnanufadlured  by  Mr.  Home.  The 
specimen  exhibited  has  a  candle-power  of  about  ^^  candle 
per  square  inch  after  exposure  for  a  few  seconds  to  diredl 
sunlight ;  but  the  brilliancy  rapidly  dies  away,  though 
there  is  a  visible  luminescence  for  many  days.  This  sub- 
stance is  also  brightly  luminescent  in  a  Crookes  tube,  and 
less  brightly  under  the  influence  of  X-rays. 

Many  substances,  notably  fluor-spar,  have  the  property 
of  thermo-luminescence,  that  is,  they  shine  in  the  dark 
when  warmed.  Powdered  fluor-spar  dropped  upon  a  hot 
shovel  emits  bright  light.  If,  however,  the  spar  is  heated 
to  a  temperature  considerably  below  red  heat  for  some 
hours,  it  apparently  comes  to  an  end  of  its  store  of 
luminous  energy,  and  ceases  to  shine.  Such  a  specimen, 
even  after  being  kept  for  some  months,  refuses  to  shine  a 
second  time  when  again  heated.  It  has,  however,  long 
been  known  that  the  property  of  luminescing  when 
warmed  can  be  restored  to  the  spar  by  passing  a  few 
eledtric  sparks  over  it,  or  by  exposing  it  to  the  silent  dis- 
charge  or  aigrette.  Wiedemann  having  found  that  the 
kathode  rays  produce  a  similar  effedt,  it  occurred  to  me 
to  try  to  find  out  whether  any  of  these  X-rays  also  would 
revivify  thermo-luminescence.  I  have  found  that  on  ex- 
posure for  twenty  minutes  to  X-rays,  a  sample  of  fluor- 
spar which  had  lost  its  thermo-luminescent  property  by 


Fio.  14. 

prolonged  heating  was  partially  though  not  completely 
revivified. 

I  referred  earlier  to  the  rays  recently  discovered  by  M. 
H.  Becquerel.  In  February  last  M.  Becquerel,  and  inde- 
pendently I  myself  (see  Philosophical  Magazine,  July, 
i8g6),  made  the  observation  that  uranium  salts  emit  some 
rays  which  very  closely  resemble  the  X-rays,  since  they 
will  pass  through  aluminium  and  produce  photographic 
adtion.  It  remains  to  be  seen  whether  these  rays  are 
identical  with  those  of  Rontgen. 

Finally,  let  me  briefly  exhibit  two  results  of  my  own 
work.  There  is  now  shown  (Fig.  14)  the  photographic 
shadow  of  two  half-hoop  ruby  rings.  One  of  them  is  of 
real  rubies,  the  other  of  imitation  stones.  By  artificial 
light  it  is  difficult  to  distinguish  one  from  the  other,  but 
when  viewed  by  the  X-rays  there  is  no  mistaking  the 
false  for  the  true.  The  real  rubies  are  highly  transparent, 
those  of  glass  are  pradlically  opaque. 

After  gaining  much  experience  in  judging  by  photo- 
graphy of  the  relative  transparency  of  materials,  I  made 
a  careful  research  (Phil,  Mag.,  August,  1896)  to  discover 
whether  these  rays  can  be  polarised.  At  first  I  used 
tourmalines  of  various  thicknesses  and  colours.  More 
recently  I  have  tried  a  number  of  other  dichroic  sub- 
stances, —  andalusite,  sulphate  of  nickel,  of  nickel  and 


CSBMICAL  NBWB, 

March  ig,  1897. 


Some  Apparatus  for  Steam-disttllation, 


21 


ammonium,  sulphate  of  cobalt,  and  the  like.  The  method 
used  for  all  was  the  following : — A  slice  of  the  crystal 
was  broken  into  three  parts.  One  part  was  laid  down, 
and  upon  it  were  superposed  the  other  two  in  such  a  way 
tliat  in  one  the  crystallographic  axis  was  parallel,  in  the 
other  perpendicular,  to  the  crystallographic  axis  in  the 
first  piece.  If  there  were  any  polarisation  the  double 
thickness  where  crossed  in  struiJlure  would  be  moie 
opaque  than  the  double  thickness  where  the  struduie  was 
parallel.  Not  the  slightest  trace  of  polarisation  could  I 
observe  in  any  case.  Of  numerous  other  observers  who 
have  sought  to  find  polarisation,  none  has  yet  produced  a 
single  uncontestable  case  of  polarisation. 

At  the  present  moment  interest  centres  around  the  use 
of  luminescent  screens  for  observing  the  Rontgen 
shadows,  and  in  this  diredtion  some  advances  have  been 
claimed  of  late.  It  should,  however,  not  be  forgotten 
that  Rontgen's  original  discovery  was  made  with  a  screen 
covered  with  platino-cyanide  of  barium.  Here  is  a  piece 
of  card  covered  with  patches  of  several  different  kinds  of 
luminescent  stuffs,  several  platino-cyanides,  several  sul- 
phides, and  some  samples  of  tungstate  of  calcium.  Of 
these  materials  the  brightest  in  luminescence  is  the 
hydrated  platino-cyanide  of  potassium  employed  by  Mr. 
Sydney  Jackson  ;  the  next  brightest  is  a  French  sample 
of  platino-cyanide  of  barium;  platino-cyanide  of  stron- 
tium coming  third. 

Using  a  focus  tube  of  Mr.  Jackson's  improved  pattern, 
enclosed  in  a  box  with  a  cardboard  front,  and  taking  a 
platino-cyanide  screen,  I  am  able  in  conclusion  to  demon- 
strate to  all  those  of  my  audience  who  are  within  a  few 
feet  of  the  apparatus,  the  fadts  that  have  so  startled  the 
world.  You  can  see  the  bones  of  my  hand  and  of  my 
wrist.  You  can  see  light  between  the  two  bones  of  my 
forearm;  while  metal  objeds,  keys,  coins,  scissors,  &c., 
enclosed  in  boxes,  embedded  in  wood  blocks,  or  locked  up 
in  leather  bags,  are  plainly  visible  to  the  eye. 

Whatever  these  remarkable  rays  are,  whether  they  are 
vortices  in  the  ether,  or  longitudinal  vibrations,  or  radiant 
matter  that  has  penetrated  the  tube,  or,  lastly,  whether 
they  consist  simply  of  ultra-violet  light,  their  discovery 
affords  us  one  more  illustration  of  the  fa(5t  that  there  is 
no  finality  in  science.  The  universe  around  us  is  not  only 
not  empty,  is  not  only  not  dark,  but  is,  on  the  contrary, 
absolutely  full  and  palpitating  with  light :  though  there 
be  light  which  our  eyes  may  never  see,  and  sounds  which 
our  ears  may  never  hear.  But  science  has  not  yet  pro- 
nounced its  last  word  on  the  hearing  of  that  which  is 
inaudible  and  the  seeing  of  that  which  is  invisible. 


PROCEEDINGS    OF    SOCIETIES. 

CHEMICAL  SOCIETY. 
Ordinary  Meeting,  February  4th,  1897. 

Mr.  A.  G.Vernon  Harcourt,  President,  in  the  Chair. 

Mr.  H.  L.  Bowman  was  formally  admitted  a  Fellow  of 
the  Society. 

Certificates  were  read  for  the  first  time  in  favour  of 
Messrs.  John  Owen  Alexander,  11,  Avenue  Road,  South 
Norwood  Park,  S.E. ;  John  B.  Ashworth,  16,  Ducie  Street, 
Prince's  Park,  Liverpool ;  John  Barclay,  B.Sc,  Avenue 
Cottage,  near  Bromsgrove,  Worcestershire  ;  Frank 
Bastow,  B.Sc,  i,  Braithwaite,  Keighley  ;  William  Dillon, 
7,  Laurel  Place,  Chapel  Lane,  Armley,  Lancashire;  E. 
G.  Guest,  M.A.,  The  Grammar  School,  Kirkham,  Lanca- 
shire; T.  Hartley,  Gatwell  Street,  Bruton,  Somerset; 
John  Holmes,  Crewe  Villa,  Putney  Bridge  Road,  S.W. ; 
O.  C.  Johnson,  52,  Thayer  Street,  Ann  Arbor,  Michigan, 
U.S.A.  ;  H.  King,  B.Sc,  4,  North  Street,  Scarborough; 
H.  M.  Lloyd,  28,  Vidloria  Street,  Merthyr;  R.  N.  Lyne, 


Government  Offices,  Zanzibar ;  C.  H.  Parker,  Manor 
House,  Tettenhall,  Wolverhampton;  S.  Pollitt,  B.Sc, 
19,  Paulton  Square,  Chelsea,  S.W. ;  M.  Wildermann, 
Ph.D.,  Davy-Faraday  La'^oratory,  Albemarle  Street,  W. 

Of  the  following  papeis  those  marked  *  were  read  : — 

*io.  ''Observations  upon  the  Oxidation  of  Nitrogen 
Gas.^'     By  Lord  Ravleigh,  F.R.S. 

On  the  basis  of  Davy's  assertion  that  the  dissolved 
nitrogen  of  water  is  oxidised  during  ele(5trolysis,  various 
attempts  were  made  ;  but  they  led  to  no  useful  result, 
even  leaving  it  doubtful  whether  Davy's  fatfts  are  corre<a. 

The  influence  of  pressure  upon  the  oxidation  of  nitrogen 
by  the  eledlric  flame  was  next  examined.  It  appeared 
that,  while  in  a  small  vessel  the  effetft  of  increased  pres- 
sure was  favourable,  but  little  advantage  resulted  when 
the  vessel  was  large  enough  to  give  the  maximum  effed 
at  a  given  pressure.  The  pressures  compared  were  two 
atmospheres,  one  atmosphere,  and  half  an  atmosphere. 

The  remainder  of  the  paper  is  devoted  to  a  detailed 
description  of  a  large  scale  apparatus  (shown  working)  in 
which  21  litres  of  mixed  gases  enter  into  combination  per 
hour,  at  an  expenditure  of  about  i  horse-power. 

Discussion. 

Professor  Armstrong,  referring  to  Lord  Rayleigh's  re- 
mark as  to  the  importance  of  the  platinum  eleftrodes 
being  red-hot,  enquired  whether  there  was  any  evidence 
that  the  platinum  played  a  special  part  in  the  process. 

Professor  Ramsay  suggested,  as  an  explanation  of  the 
better  results  obtained  when  a  large  vessel  was  employed, 
that  nitric  oxide  was  the  first  produdt,  and  that  this  sub- 
sequently combined  with  oxygen  to  form  the  peroxide. 

The  President  considered  it  probable  that  some  of  the 
oxide  of  nitrogen  first  formed  was  subsequently  decom- 
posed by  the  heat  of  the  flame  itself,  and  that  the  large 
vessel,  by  presenting  a  large  surface  of  alkaline  liquid, 
favoured  the  rapid  absorption  of  the  oxide  of  nitrogen, 
and  thus  less  was  decomposed  than  would  be  the  case  in 
a  smaller  vessel,  where  the  rate  of  absorption  was  smaller. 
He  enquired  with  what  proportion  of  nitrogen  to  oxygen 
combustion  occurred  most  rapidly. 

Professor  M'Leod  remarked  that  he  had  made  an  ex- 
periment in  the  manner  originally  suggested  by  Cavendish, 
and  had  found  that  nitrite  as  well  as  nitrate  was  formed. 

Lord  Rayleigh,  in  reply,  said  that  the  larger  vessel 
apparently  led  to  better  results  by  increasing  the  facilities 
for  absorption.  He  did  not  consider  that  the  platinum 
played  any  special  part  in  the  process.  The  adtion  seemed 
most  rapid  when  the  proportion  of  air  to  oxygen  was  as 
about  5  to  6,  which  corresponds  with  two  of  nitrogen  to 
three  of  oxygen.  He  believed  that  both  nitrite  and 
nitrate  were  formed.  The  apparatus  shown  was  suitable 
for  the  preliminary  concentration,  but  not  for  the  final 
purification  of  argon. 

•11.  •'  On  some  Apparatus  for  Steam-distillation."  By 
F.  E.  Matthews,  Ph.D. 

In  this  paper  several  forms  of  apparatus  for  automati- 
cally steam-distilling  substances  are  described. 

Some  solids  of  high  melting-point  may  be  separated  by 
boiling  the  substance  mixed  with  water  in  a  flask  fitted 
with  a  reflux  condenser  ;  the  solid  substance  adheres  to  the 
inside  of  the  condenser,  whence  it  can  be  removed  from 
time  to  time. 

For  liquids  heavier  than  water,  the  flask  in  which  the 
mixture  is  boiled  is  connected  with  ihe  side  tube  of  an  or- 
dinary distilling-flask ;  this  disiilling-flask,  filled  with 
water  up  to  the  side-tube,  serves  as  the  receiver.  Into 
the  neck  of  the  receiver,  and  passing  below  the  surface  of 
the  water,  a  bent  Liebig's  condenser  is  fitted  which  has 
the  peculiarity  of  having  a  hole  made  in  it  a  short  distance 
above  the  level  of  the  water  in  the  receiver.  On  boiling 
the  mixture  in  the  flask,  the  vapours  pass  up  the  side- 
tube  of  the  receiver  into  the  upper  portion  of  its  neck  and 
thence  through  the  hole  in  the  receiver,  when  condensa- 
tion takes  place.      The  condensed  liquids  run  down  the 


138 


Wechsler*s  Method  /or  the  Separation  of  Fatty  A  ctds. 


Cbbmical  Nbws, 

March  19, 1S97. 


condenser  to  the  water-level  in  the  receiver,  where  a  drop 
of  the  heavy  fluid  sufficiently  large  to  sink  is  formed  from 
time  to  time.  The  condensed  liquids  displace  their  own 
volume  of  water,  which  flows  from  the  receiver  through 
the  side-tube  back  again  to  the  boiling-flask.  In  all  cases 
in  which  vapour  is  passing  in  one  diredion  in  a  tube,  and 
water  in  the  other,  the  advantage  of  perforating  the  tube 
near  its  lower  end  is  pointed  out. 

For  liquids  lighter  than  water,  the  apparatus  consists 
of  the  boiling-flask,  which  is  an  ordinary  distilling-flask  ; 
this  is  conneded  by  the  upper  opening  to  an  upright  tube 
furnished  with  a  J-piece.  The  top  of  the  upright  tube  is 
connedted  to  the  condenser,  the  lower  end  dips  two  or 
three  inches  into  a  Woulfe's  bottle,  containing  water  in 
sufficient  quantity,  which  serves  as  the  receiver.  Through 
another  neck  of  the  Woulfe's  bottle,  a  second  tube  passes 
from  the  bottom  of  the  bottle  and  is  connected  to  the  side- 
tube  of  the  boiling-flask.  The  mixed  vapours  pass  from 
the  boiling-flask  into  the  upright  T-tube,  thence  into  the 
condenser;  there  becoming  condensed,  they  fall  down 
into  the  J-tube,  producing  a  column  of  liquid  which  forces 
water  from  the  bottom  of  the  receiver  back  into  the 
boiling-flask  through  its  side-tube. 

A  modification  of  this  apparatus  dispenses  with  the 
necessity  of  having  an  indiarubber  connection  exposed  to 
the  hot  vapour.  In  this  modification  the  boiling-flask  is 
an  ordinary  plain  flask.  This  is  connedted  to  the  con- 
denser by  a  side-tube  blown  on  to  the  upright  tube.  The 
water  returns  to  the  boiling-flask  through  another  T-tube, 
blown  on  to  the  side-tube  of  the  upright  tube.  For  con- 
veniently emptying  the  receiver  without  dismantling  the 
apparatus,  a  separating  funnel  with  two  necks  may  re- 
place the  Woulfe's  bottle  of  the  previous  apparatus. 

Many  liquids  bump  badly  when  boiled  with  water  ;  this 
can  generally  be  got  over  by  introducing  a  zinc-platinum 
couple  into  the  boiling- flask.  The  temperature  of  the 
water  in  the  boiling-flask  may  be  raised  by  dissolving 
suitable  substances,  such  as  sulphuric  acid  or  calcic 
chloride,  in  it,  or  liquids  of  higher  boiling-point  may  be 
used. 

*12.  "  Researches  in  the  Stilbene  Series."    I.    By  John 

J.   SUDBOROUGH,  Ph.D. 

The  author  has  obtained  benzil  as  one  of  the  products 
of  the  a(5tion  of  zinc  dust  and  acetic  acid  on  benzoin  ;  if 
the  a(5tion  is  continued  the  benzil  disappears  and  the  chief 
produdt  is  deoxybenzoin.  The  formation  of  an  oxidation 
produdt  of  benzoin  by  the  action  on  it  of  zinc  dust  and 
acetic  acid  appeared  so  remarkable  that  the  author  has 
studied  the  a(5tion  of  acetic  acid  alone  on  benzoin,  and  he 
finds  that  small  quantities  of  benzil  are  formed  if  benzoin 
is  heated  with  six  times  its  weight  of  glacial  acetic  acid 
on  the  water-bath  for  eight  — nine  hours. 

By  the  adtion  of  phosphorus  pentachloride  on  deoxy- 
benzoin a  solid  chlorstilbene  has  been  obtained,  which 
differs  from  Zinin's  oily  compound.  It  melts  at  45°, 
yields  a  dibromide  and  a  dichloride,  also  with  nitrous 
fumes  two  compounds  probably  represented  by  the  for- 
mula PhCHNOaCClNOa-Ph  (m.  p.  128°)  and 
Ph'C{N02):C(N02)-Ph  (yellow  prisms,  m.  p.  104—105°). 

An  oily  compound  can  be  obtained  by  the  adtion  of 
phosphorus  pentachloride  on  deoxybenzoin  at  low  tem- 
peratures. The  oil  contains  the  same  amount  of  chlorine 
as  solid  chlorstilbene. 

Methyldeoxybenzoin  and  ethyldeoxybenzoin  on  treat- 
ment with  phosphorus  pentachloride  can  be  made  to  yield 
both  oily  and  crystalline  compounds,  analysis  of  which 
points  to  their  being  methyl-  and  ethyl-chlorstilbenes. 
Solid  methylchlorstilbene  melts  at  124°,  and  the  corre- 
sponding ethyl  compound  at  60°.  The  dichlorides  and 
dibromides  are  also  described.  The  question  as  to  the 
nature  of  the  oily  compounds  has  not  been  settled;  the 
author  describes  a  method  by  which  he  proposes  to  deter- 
mine whether  they  are  merely  slightly  impure  forms  of 
the  solid  compound,  true  stereo-isomerides,  or  strudturally 
isomeric  with  the  solid  compounds. 


*I2,  "  Diortho-substituted  Benzoic  Acids.  III.  Hydro- 
lysis of  Substituted  Benzatnides."  By  John  J.  Sud- 
BOROUGH,  Ph.D.,  Percy  G.  Jackson,  and  Lorenzo  L. 
Lloyd. 

In  order  to  determine  whether  diortho-substituted 
benzamides  exhibit  the  same  remarkable  degree  of 
stability  towards  hydrolysing  agents  as  characSterises  the 
diortho-benzoyl  chlorides  {Trans.,  1895,  Ixvii.,  587)  and 
ethereal  salts,  the  authors  have  investigated  the  following 
compounds : — 

Ortho-,  meta-,  and  para-brombenzamide ;  2:4-,  2:6-, 
and  3  :  5-dibrombenzamide  ;  2:4:6-  and  3:4:  5-tribrom- 
benzamide ;  2  :  4  :  6-trichlorbenzamide  ;  2 : 4  :  6-trimethyl- 
benzamide  (mesitylformamide)  and  mesitylacetamide, 
CeHaMes'CHz'CONHa.  Of  the  three  mono-substituted 
brombenzamides  the  ortho-compound  proves  to  be  some- 
what more  stable  in  the  presence  of  boiling  (30  per  cent) 
sulphuric  acid  than  the  meta-  and  para-compounds.  This 
agrees  with  the  properties  of  the  corresponding  methylic 
monobrombenzoates  and  of  the  monobrombenzoyl 
chlorides. 

Of  the  three  dibromamides  the  2:6-  or  di-ortho- 
substituted  compound  proves  to  be  the  one  most  difficult 
to  hydrolyse  by  means  of  75  per  cent  sulphuric  acid,  and 
again  of  the  two  tribromamides  the  2:4:6-  or  symmetri- 
cally substituted  amide  is  much  more  stable  than  the 
isomeric  3:4:  5-tribrombenzamide.  2:4:  6-trichlor- 
benzamide although  not  hydrolysed  so  readily  as  2:4- 
and  3  :  5-dibrom-  and  3  :  4  : 5-tribrombenzamide  is  less 
stable  than  the  corresponding  2:4:  6-tribrom-compound. 

The  methyl  derivatives  could  not  be  investigated  as  re- 
gards their  hydrolysis  with  75  per  cent  sulphuric  acid,  as 
they  are  charred  and  decomposed  by  this  means.  To- 
wards 30  per  cent  sulphuric  acid  the  mesitylformamide  is 
much  more  stable  than  the  corresponding  acetamide. 

In  the  course  of  this  investigation  the  following  new 
compounds  have  been  obtained: — 3  :5-Dibrombenzamide, 
m.  p.  187°;  2 : 4 :6-tribrombenzonitrile,  m.  p.  127°; 
2  :  4  :  6-tribrombenzamide,  m.  p.  193 — 194°;  3:4:  5-tri- 
brombenzamide, m.  p.  199°;  2 : 4 :  6-trichlorbenzonitrile, 
*"•  P*  75° »  2:4:  6-trichlorbenzamide,  m.  p.  177" ;  mesityl* 
formamide,  m.  p.  105° ;  mesitylacetamide,  m.  p.  210°. 

*i4.  "  Conversion  of  Camphoroxime  into  Methylcam* 
phorimine  and  Camphenylnitramine."  By  M.  O.  Forstbr, 
Ph.D. 

Further  investigation  of  the  base  obtained  on  heating 
camphoroxime  in  sealed  tubes  with  methylic  iodide  has 
proved  it  to  be  the  methyl-derivative  of  Tiemann's  cam- 
phorimine  ;  it  therefore  has  the  formula^- 
,CHa 


C8H14 


C:N-Me 


and  not,  as  appeared  probable  from  the  preliminary  ex- 
amination (Proc,  1895,  xi.,  145),  the  formula  CizHigN. 
This  is  shown  by  its  behaviour  towards  concentrated 
hydrochloric  acid  at  200°,  giving  rise  to  camphor  and 
methylamine. 

Methylcantphorimine  hydrochloride  and  methiodide  melt 
at  270°  and  231 — 232°  respedtively  ;  the  perbromide  has 
also  been  prepared. 

The  adlion  of  dilute  nitric  acid  on  camphoroxime,  if 
interrupted  after  a  few  minutes,  gives  rise  to  camphenyl- 
nitramine,  which  is  also  formed  when  a  solution  of  the 
oxime  in  chloroform  is  treated  with  nitrogen  peroxide. 

An  acid  solution  of  potassium  permanganate  converts 
camphoroxime  into  an  unstable  nitroso-derivative,  which 
separates  from  the  liquid  as  a  sticky,  green  mass ;  when 
preserved  in  the  desiccator  the  substance  deliquesces, 
and  loses  its  green  colour,  the  yellow  residue  yielding 
camphor  when  distilled  in  an  atmosphere  of  steam. 

15.  "  Note  on  Wechsler's  Method  for  the  Separation  of 
Fatty  Acids."    By  Arthur  W.  Crossley. 

Wechsler  {Monatsh.,  1893,  xiv.,  462)  has  described  a 
method  for  the  separation  of  fatty  acids,  the  principle  of 
which  method  is  contained  in  the  following  statement. 


Chemical  News,  i 
March  19, 1897.    ( 


Formation  of  Dtthionic  A  cid^ 


If  to  a  mixture  of  two  fatty  acids  four-fifths  of  the 
caustic  soda  necessary  to  neutralise  them  be  added,  and 
the  whole  steam-distilled,  the  distillate  contains  the  pure 
higher-boiling  acid.  From  the  residue  of  the  distillation 
a  further  three-fifths  of  the  acids  are  set  free  by  addition 
of  sulphuric  acid,  and  the  whole  distilled  in  steam. 
Finally,  the  remaining  fifth  of  the  acid  is  set  free,  and  in 
this  case  the  distillate  contains  the  lower-boiling  acid  in 
a  pure  condition. 

The  purity  of  the  acids  contained  in  the  various  distil- 
lates was  proved  by  converting  them  into  silver  salts  and 
subsequent  analysis  of  these  salts. 

After  trying  this  method  of  separation,  with  very  un- 
satisfactory results,  on  a  mixture  of  fatty  acids  obtained 
in  a  research  on  which  Professor  Perkin  and  the  author 
have  been  engaged  for  some  time  past,  it  was  thought  ad- 
visable to  test  some  of  Wechsler's  experimental  data. 

Accordingly,  Wechsler's  experiments  have  been  care- 
fully repeated  and  results  obtained  which  do  not  agree 
with  that  author's. 

As  Wechsler  always  worked  with  equimolecular  propor- 
tions of  fatty  acids,  the  results  of  some  experiments  are 
recorded  in  which  varying  proportions  of  fatty  acids  were 
employed.  In  every  case  the  results  were  unsatisfa(5tory, 
(or  even  when  using  three  molecules  of  the  lower  to  one 
of  the  higher  boiling  acid,  the  former  was  not  obtained 
pure  in  the  last  distillate,  and  the  first  distillate  contained 
a  decided  mixture  of  the  two  acids. 

It  is  therefore  to  be  concluded  that  Wechsler's  method 
does  not  give  such  good  results  as  the  author  suggests, 
nor  can  it  in  any  way  be  looked  upon  as  a  satisfadory 
method  for  separating  mixtures  of  fatty  acids. 

16.  '*  On  the  Crystalline  Structure  of  Gold  and  Platinum 
Nuggets  and  Gold  Ingots."  By  A.  Liversidge,  LL.D,, 
F.R.S. 

In  view  of  the  theory  that  gold  nuggets  are  built  up  of 
concentric  layers  deposited  round  a  central  nucleus,  the 
author  has  examined  a  large  number  of  specimens  from 
various  sources.  The  nuggets  were  ground  down,  or 
sliced  through,  to  obtain  seiflions,  which  were  polished 
and  etched  by  suitable  solvents.  They  all  possessed  a 
well-marked  crystalline  strucfture,  and  usually  enclose 
foreign  substances.  The  crystalline  strudture  is  not  in- 
compatible with  an  aqueous  origin  ;  and  the  author  sug- 
gests that  the  gold  has  been  slowly  deposited  from  solu- 
tion, either  at  ordiinary  or  at  high  temperatures  ;  the 
nuggets  being  more  or  less  rolled  masses  of  gold  which 
have  been  set  free  from  disintegrated  veins. 

17.  "  On  the  presence  of  Gold  in  Natural  Saline  Deposit^ 
and  Marine  Plants."    By  A.  Liversidge,  LL.D.,  F.R.S. 

The  author  gives  a  preliminary  account  of  the  results 
of  the  examination  for  gold  of  rock  salt,  sylvine,  and  other 
similar  saline  deposits,  bittern,  sea-weed,  kelp,  oyster- 
shells,  &c.  The  process  of  determination  used  was  to 
add  from  0*5  to  5  grms.  of  ferrous  sulphate  to  the  unfiltered 
solution  of  100  to  1000  grms.  of  the  salt  in  water.  The 
resulting  precipitate  was  then  scorified  with  lead  and 
cupelled.  The  natural  salts  contained  from  i  to  2  grains 
of  gold  per  ton,  whilst  kelp  and  bittern  furnished  in  some 
cases  as  much  as  from  14  to  20  grains. 


Ordinary  Meeting,  February  i8th,  1897. 

Mr.  A.  G.  Vernon  Harcourt,  President,  in  the  Chair. 

Mr.  E.  Haynes  Jeffers  was  formally  admitted  a  Fellow  of 
the  Society. 

Certificates  were  read  for  the  first  time  in  favour  of 
Messrs.  Herbert  William  Leyland  Barlow,  M.A.,  M.B., 
Holly  Bank,  Urmston,  Manchester;  Frederick  Filmer  de 
Morgan,  Andely  Lodge,  Caeran  Park,  Newport,  Mon- 
mouthshire ;  Louis  Charles  Oeverell,  Onslow  House, 
Worthing;  William  James  George  Lasseter,  B.A.,  10, 


139   ; 

Stanley  Road,  Oxford  ;  Harry  Edward  William  Phillips, 
B.A.,  47,  Chalfont  Road,  Oxford ;  William  Herbert 
Waite,  B.A.,  Park  Road,  Halifax;  Charles  Thomas 
Foster  Watts,  7,  Cambrian  Crescent,  Chester;  John 
Welsh,  I2A,  Seller  Street,  Chester. 

The  certificate  of  the  following  candidate,  recommended 
by  the  Council  under  Bye-law  I.  {3),  was  also  read  : — 

Frederic  Hewlett  Burton-Brown,  Simla,  India. 

It  was  announced  that  the  following  changes  in  the 
Officers  and  Council  were  proposed  by  the  Council : — 

As  President — Professor  James  Dewar,  M.A.,  LL.D., 
F.R.S.,  vice  Mr.  A.  G.  Vernon  Harcourt,  M.A.,  D.C.L., 
LL.D.,  F.R.S.  As  Vice-Presidents  —  Proiessor  W. 
Ramsay,  Ph.D.,  F.R.S.,  and  Professor  J.  Emerson 
Reynolds,  M.A.,  F.R.S.,  vice  Professor  James  Dewar, 
M.A.,  LL.D.,  F.R.S.,  and  Mr.  Horace  T.  Brown,  F.R.S. 
As  Ordinary  Members  of  Council— Messrs.  C.  T.  Heycock, 
M.A.,  F.R.S.  ;  Rudolph  Messel,  Ph.D.  ;  Tom  Kirke  Rose, 
D.Sc.  ;  and  Alexander  Scott,  M.A.,  D.Sc,  vice  Messrs. 
Bernard  Dyer,  D.Sc;  G.Harris  Morris,  Ph.D.;  W.  A. 
Shenstone ;  and  T.  Stevenson,  M.D. 

It  was  also  announced  that  the  Council  had  awarded 
the  LongstafT  Medal  to  Prof.  William  Ramsay,  F.R.S., 
for  the  discovery  of  helium,  and  his  share  in  the  investi- 
gation of  argon. 

Messrs.  H.  Brereton  Baker,  F.  D.  Chattaway,  and 
John  Shields  were  appointed  to  audit  the  Society's 
accounts. 

Of  the  following  papers  those  marked  *  were  read. 

*i8.  "  The  Formation  of  Dithionic  Acid  in  the  Oxida- 
tion of  Sulphurous  Acid  by  Potassium  Permanganate." 
By  T.  S.  Dymond  and  F.  Hughes. 

When  a  solution  of  sulphurous  acid  is  titrated  with  a 
solution  of  potassium  permanganate,  decolorisation  of 
the  permanganate  ceases  when  only  89  per  cent  of  the 
quantity  required  to  oxidise  the  sulphurous  acid  to  sul- 
phuric acid  has  been  used.  This  is  due  to  the  formation 
of  dithionic  acid  in  addition  to  sulphuric  acid.  The  pro- 
portion of  dithionic  acid  produced  is  constant,  and  is  not 
influenced  by  either  the  dilution  or  the  temperature,  or 
the  acidity  of  the  solution.  Its  produdtion,  therefore, 
appears  to  be  an  essential  part  of  the  readlion,  and  to  be 
due  to  the  weak  oxidising  adlion  of  the  permanganate  in 
a  final  stage  of  its  redudtion.  The  sulphuric  and 
dithionic  acids  produced  are  in  the  proportion  required 
by  the  supposition  that  manganese  heptoxide  is  first  re- 
duced to  the  red  oxide  with  produdtion  of  sulphuric  acid, 
and  further  reduced  to  the  monoxide  with  produdtion  of 
dithionic  acid.  When,  however,  sulphurous  acid  is 
treated  with  the  red  oxide,  sulphuric  acid  is  the  only 
produdl. 

Discussion. 

The  President  said  that  he  had  worked,  a  number  of 
years  ago,  upon  the  readtion  between  solutions  of  potas- 
sium permanganate  and  sulphurous  acid,  before  sodium 
thiosulphate  had  come  into  use  for  estimating  iodine.  In 
making  determinations  without  excluding  air  from  the 
water,  he  had  found  that  the  quantity  of  permanganate 
used  was  far  less  than  the  amount  necessary  for  the  com- 
plete oxidation  of  the  sulphurous  acid.  He  found  that 
the  sulphurous  acid  was  oxidised  by  the  atmospheric 
oxygen  dissolved  in  the  water,  and  so  progressively  as 
the  water  gradually  dissolved  the  oxygen  in  the  air  lying 
over  it.  As  the  result  of  a  number  of  experiments,  he 
proved  that  the  diminution  in  the  quantity  of  perman- 
ganate required  increased  with  the  dilution  of  the  sul- 
phurous acid,  and  also  that  if  the  water  was  boiled  until 
air-free  the  quantity  of  permanganate  used  was  larger ; 
but  he  had  not  obtained  such  constant  results  as  Messrs. 
Dymond  and  Hughes.  He  had  tried  the  experiment  of 
adding  a  small  quantity  of  manganous  sulphate  to  the 
dilute  solution,  and  had  found  that  this  salt  also  was  able 
to  determine  the  oxidation  of  sulphurous  acid  by  atmo- 
spheric oxygen.     He  thought  the  author's  experimenta 


140 


Mechanical  Cause  of  Homogeneity  of  Structure  and  Symmetry,  {^MaJ'chig.'SffJ'' 


extremely  interesting  in  showing  the  constant  produdiion 
of  dithionic  acid. 

Dr.  Scott  thought  it  would  be  worth  while  to  try  the 
effedt  of  manganic  sulphate  in  oxidising  sulphurous  acid. 

Prof.  DuNSTAN  suggested  that  it  would  be  interesting 
to  determine  whether  the  formation  of  dithionic  acid  oc- 
curred at  the  positive  ele(5trode  during  the  eledirolysis  of 
a  solution  of  sulphurous  acid,  since  it  seemed  possible 
that  the  dithionic  acid  might  be  formed  by  the  oxidation 
of  sulphurous  acid  in  much  the  same  way  as  persulphuric 
acid  was  formed  by  the  oxidation  of  sulphuric  acid.  He 
understood  that  in  the  remarkable  adion  of  manganous 
sulphate  described  by  the  President  this  salt  undergoes 
no  change. 

(To  be  continued). 


PHYSICAL     SOCIETY. 
Ordinary  Meeting,  March  12th,  1897. 

Mr.  Shelford  Bidwell,  President,  in  the  Chair. 

Mr.  William  Barlow  read  a  paper  on  "  A  Mechanical 
Cause  of  Homogeneity  of  Structure  and  Symmetry, 
Geometrically  Investigated,  with  Special  Application  to 
Crystals  and  to  Chemical  Combination."  Illustrated  by 
Models. 

The  author  has  previously  established  that  every  homo- 
geneous strudlure  displays  one  or  other  of  the  thirty-two 
kinds  of  crystalline  symmetry.  He  now  shows  that 
homogeneous  struftures  possessing  most,  if  not  all,  of 
these  kinds  of  symmetry  may  be  produced  mechanically, 
as  the  equilibrium  arrangements  of  assemblages  of 
mutually  -  repellent  particles;  and,  also,  that  these 
mechanical  systems  of  particles  exhibit  charadleristics 
entirely  analogous  to  certain  crystalline  and  other  pro- 
perties of  matter.  The  fundamental  concept  may  be  sum- 
marised thus  : — A  number  of  different  kinds  of  mutually- 
repellent  particles  dispersed  through  space,  the  amount 
of  this  repulsion  being  some  inverse  fundtion  of  the  dis- 
tance between  the  particles  concerned ;  the  particles  are 
destitute  of  polarity,  and  the  difference  in  kind  consists 
in  a  difference  in  the  degree  of  mutual  repulsion  which 
two  particles  exercise,  according  to  the  kinds  taken.  It 
is  further  premised  that  the  assemblage  is  agitated,  so  as 
to  render  unstable  all  but  the  final  equilibrium  arrange- 
ment ;  and  a  means  is  provided  for  linking  the  particles 
symmetrically,  and  unlinking  them,  under  certain  circum- 
stances, so  as  to  modify  the  repulsion  between  the 
particles  affedled.  The  data  thus  summarised  may  be 
regarded  as  merely  provisional,  because  the  making  of  the 
equilibrium  arrangement  one  in  which  "  closest  packing  " 
prevails,  is  the  objedt  primarily  aimed  at ;  and  these  con- 
cepts are  mere  devices  for  attaining  this  end.  By  the 
employment  of  particles  of  different  kinds,  a  large  amount 
of  variety  is  provided  for.  The  first  step  taken  is  to  de- 
duce the  law  of  '•  closest  packing,"  which  runs  thus  : — 
Every  assemblage  of  mutually-repellent  particles  will  con- 
tinually approximate  to,  or  strive  after,  that  relative 
arrangement  of  the  particles  composing  it,  in  which  it 
has  come,  at  every  part,  to  occupy  a  minimum  of  space 
under  a  given  general  pressure,  or  average  repulsion,  be- 
tween the  particles.  This  law  aifts  on  all  assemblages  of 
the  nature  defined,  however  numerous  the  kinds  of 
particles  composing  them  ;  but  for  its  effedls  to  be  trace- 
able, a  very  limited  number  of  kinds  must  be  present. 
Passing  from  assemblages  consisting  of  a  single  kind  of 
particle,  the  author  takes  a  very  simple  case  of  two  kinds 
of  particles  confined  to  a  plane,  and  shows  what  type  of 
symmetry  will  be  produced  when  equilibrium  is  realised. 
Very  simple  cases  of  particles  in  space  are  then  taken, 
and  it  is  shown  that  a  large  number  of  different  kinds  of 
symmetry  are  displayed  by  the  equilibrium  arrangements 


produced  when  there  is  variety  in  the  relations  between 
the  repulsions.  To  illustrate  "  close  packing,"  stacks  of 
balls  of  various  sizes  are  employed  ;  but  it  is  pointed  out 
that  the  conditions  of  statical  equilibrium  of  the  particles 
are  not  always  adequately  expressed  in  this  way  ; 
although  every  case  of  the  latter  kind  can  be  represented 
approximately  by  a  case  of  the  former  kind,  possessed  of 
the  same  order  of  symmetry.  Very  slight  variation  in  the 
relations  between  the  repulsions  alters  the  form  of  the 
equilibrium  arrangement ;  sometimes  merely  changing 
the  angle  without  affefting  the  type;  sometimes,  when  it 
passes  some  critical  point,  bringing  about  an  alteration 
iii  type.  Changes  of  the  first  kind  resemble  the  change 
in  crystal  form  caused  by  variation  of  temperature  ;  whilst 
those  of  the  latter  kind,  especially  when  associated  with 
re-arrangement  of  the  particles,  are  analogous  to  poly- 
morphism. In  many  cases  the  arrangement  of  the 
particles  is  such  that  some  may  be  removed  without 
affedling  the  distribution  of  the  remainder,  and  without 
destroying  the  "close  packing,"  If,  therefore,  other 
particles,  exercising  a  slightly  less  repulsion,  be  sub- 
stituted for  the  removed,  inoperative,  particles,  the  only 
resulting  change  consists  in  a  diminution  of  the  pressure 
on  the  particles  surrounding  them.  A  species  of  isomor- 
phism is  in  this  way  realised. 

When  the  particles  of  an  assemblage  are  partially  con- 
nedled  by  hypothetic  linking  in  a  symmetiical  manner, 
similar  groups  are  formed  ;  but,  in  order  that  the  forma- 
tion of  such  groups  may  not  be  arbitrary,  the  partitioning 
which  is  produced  must  have  as  complete  symmetry  as 
that  of  the  partioned  strudure.  In  consequence  of  this, 
some  kinds  of  groups  are  not  diredlly  obtainable  by  sym- 
metrical  partitioning  of  a  homogeneous  strudure  ;  but  it 
is  always  conceivable  that  they  may  be  included  in  the 
larger  groups  of  some  more  complex  constellation,  and 
that  they  may  be  subsequently  separated  to  form  an 
assemblage  by  themselves.  Consequently,  very  intricate 
results  may  be  reached  by  successive  steps.  Symmetrical 
intermixture,  linking,  and  unlinking,  succeeding  one 
another  until  complicated  groups  are  built  up,  for  the  pro- 
dudlion  of  which  such  an  agency  as  "close  packing" 
appears  at  first  sight  inadequate.  Having  called  attention 
to  a  large  number  of  arrangements,  some  capable  and 
some  incapable  of  symmetrical  partitioning  intogroups  of  a 
single  kind,  some  linked  and  some  unlinked,  the  author  con- 
tends to.have  established  the  following  two  propositions : — 
(i)  The  nature  of  the  symmetry  displayed  by  a  homo- 
geneous assemblage  of  mutually-repellent  particles  of  dif- 
ferent kinds  in  equilibrium,  depends  on  the  relations  sub- 
sisting between  the  repulsions  exercised  by  these  particles. 
(2)  The  assemblages  belonging  to  all  of  the  thirty-two 
classes  of  crystalline  symmetry  result  from  the  funda- 
mental law  of  "  close  packing,"  when  the  relations  be- 
tween the  different  repulsions  take  the  widest  possible 
range  of  variety.  Links  which  restrain  the  adion  of  the 
repulsion  can  be  present  between  some  of  the  particles 
in  some  cases.  The  author  refers  to  crystal  '•  twinning," 
and  points  out  that  the  adlion  of  dimorphism  is  competent 
to  produce  analogous  *'  twinning  "  of  symmetrical 
assemblages  of  linked  particles.  A  number  of  other  pro- 
perties of  linked  assemblages  analogous  to  those  of  crys- 
tals are  also  described.  In  the  domain  of  chemistry  the 
author  cites  the  continually  accumulating  experimental 
evidence  of  the  existence  of  geometrical  arrangement  in 
the  molecule,  both  that  established  stereochemically  and 
that  derived  from  the  study  of  isomerism,  as  revealing  a 
state  of  things  precisely  such  as  is  arrived  at  by  the  law 
of  '•  closest  packing  "  in  assemblages  afterwards  broken 
up  into  similar  groups  of  particles.  Attention  is  called  to 
many  groupings  of  the  latter  order  fulfilling  very  exadlly 
the  conditions  of  disubstitution  in  the  case  of  many  car- 
bon compounds.  While  he  does  not  regard  his  work  as 
throwing  any  light  on  the  nature  of  change  of  state,  or 
change  of  bulk,  the  author  observes  that  the  distribution 
in  precise  proportions  of  the  constituents  that  must  ob- 


Chbmical  Mbws, 
March  ig,  i8g7. 


Compounds  of  Nitrogen  and  Argon, 


141 


viously  accompany  or  precede  a  chemical  combination, 
may  fairly  be  claimed  as  a  resemblance  to  the  regular 
intermixture  brought  about  according  to  the  law  of 
••  closest  packing,"  He  further  suggests  that  the  reason 
why  some  bodies  do  not  readily  interadt  may  be  due  to 
the  "  close  packing  "  of  one  or  both. 

Prof.  Herschel  said  he  was  f  articularly  pleased  with 
the  models.  He  thought  it  probable  that  a  very  wide 
application  would  be  found  for  the  author's  results.  There 
was  no  doubt  much  to  be  learnt  from  models  built  up  of 
spheres  of  two  or  more  sizes,  but  it  would  be  necessary 
to  learn  a  great  deal  more  about  these  symmetrical  ar- 
rangements  before  they  could  be  applied  with  any  degree 
of  certainty. 

Mr.  Fletcher  said  it  was  impossible  to  criticise  the 
paper  without  long  and  careful  study.  From  certain 
hypotheses  the  author  had  deduced  a  law  of  •'  closest 
packing  "  that  seemed  adequate  to  explain  many  results 
observed  by  chemists  and  crystallographers ;  at  the  same 
time  admitting  that  the  law  might  be  presumed  from 
other  reasoning.  By  his  models  he  had  tried  to  present  a 
pidture  not  of  the  forms  of  atoms  or  molecules,  but 
merely  analogical  representations  of  the  probable  struc- 
ture of  particles.  Hitherto  the  research  had  been  confined 
to  determining  the  possible  arrangements  of  particles  all 
of  one  kind,  but  here  were  examples  of  packed  spheres  of 
various  sizes.  It  was  not  quite  clear  how,  in  an  ele- 
mentary substance,  there  could  be  such  a  strudlure, 
although  there  certainly  were  cases  of  polymorphism 
awaiting  explanation,  as  for  instance  with  sulphur.  The 
paper,  with  its  188  pages  of  MS.,  represented  a  vast 
amount  of  clear  thinking,  and  many  years  of  admirable 
work. 

Prof.  Adams  called  the  attention  of  Fellows  of  the 
Physical  Society  to  the  Museum  at  King's  College,  where 
were  the  original  models  as  made  and  used  by  the  early 
investigators  of  this  branch  of  Physics. 

Prof.  MiERS  (communicated,  too  late  for  reading) — The 
principle  of  "close  packing"  was  not  new,  but  Mr. 
Barlow  was  the  first  to  extend  it  to  explain  solution, 
diffusion,  and  stereochemical  problems.  His  remarks  on 
the  growth  of  curved  crystals,  vicinal  faces,  and  pseudo- 
symmetrical  crystals  were  open  to  criticism.  With  regard 
to  vicinal  faces,  however,  lencite  seemed  to  be  a  mineral 
in  accord  with  his  hypothesis.  The  author  regarded  a 
crystal  as  consisting  of  mutually  repellent  particles  of 
different  sorts :  this  seemed  a  very  right  way  of  attacking 
the  problem  of  crystal  strudlure,  and  would  explain  some 
recent  observations  of  Rinne  on  crystals  consisting  of 
water  particles  and  silicate  particles.  Further,  Mr. 
Barlow  had  considered  the  way  in  which  an  assemblage 
might  be  broken  up  by  the  loosening  of  the  ties,  and  the 
change  of  partners,  among  individual  members.  That  is 
to  say,  he  had  considered  crystallisation  and  solution, 
features  quite  ignored  by  ordinary  theories.  His  view  of 
crystal  strudture  failed  to  explain  why  crystals  should 
have  faces,  and  gave  no  hint  as  to  the  controlling  forces 
which  keep  mutually-repellent  particles  together.  Never- 
theless it  suggested,  among  other  striking  analogies,  those 
bearing  on  the  relationship  between  crystal  structure  and 
chemical  constitution,  and  the  irregularities  of  crystals, 
such  as  were  commonly  negledted  in  accepted  theories. 
Mr.  Barlow  had  opened  up  a  very  promising  line  of 
inquiry. 

Mr.  Barlow,  in  replying,  said  he  greatly  appreciated 
the  interest  shown  in  his  work. 

The  President  then  proposed  a  vote  of  thanks  to  the 
author,  and  the  meeting  was  adjourned  until  March  26th. 
At  the  invitation  of  Dr.  S.  P.  Thompson,  the  Society 
will  on  that  occasion  meet  at  the  Technical  College, 
Leonard  Street,  Finsbury. 


EDINBURGH     UNIVERSITY    CHEMICAL 

SOCIETY. 

Last  Ordinary  Meeting  of  the  Session,  March  8th,  1897. 

Mr.  C.  Saintsbury  in  the  Chair. 

Dr.  J.  E.  Mackenzie  read  a  paper  '*  On  the  Compounds  of 
Nitrogen  and  Hydrogen." 

Five  such  compounds  are  at  present  known: — NH3, 
ammonia;  N2H4,  hydrazine;  N3H,  azoimide;  N4H4, 
ammonium  nitride  ;  and  N5H5,  hydrazine  nitride. 

Ammonia  does  not  call  for  description  here.  The 
other  substances  are  of  comparatively  recent  discovery, 
the  chemist  to  whom  we  owe  most  of  our  knowledge  of 
them  being  Theodor  Curtius.  In  1883  he  commenced  a 
series  of  researches  on  amido- acids.  In  the  course  of 
these  he  obtained  the  hydrochloride  of  ethyl  amido- 
acetate,  a  beautiful  crystalline  substance,  which,  on 
being  diazotised,  yielded  ethyl  diazo-acetate  {Ber,,  xvi., 
2230)  :— 
HCl-HaNCHaCOOCaHs  +  NO2H  = 

=  NatCHCOOCaHj  +  2H2O  +  HCI. 

By  similar  treatment  other  amido-acid  esters  yielded 
diazo  esters  {your.  Prak.  Chemie,  [2],  xxxviii.,  404), 
these  being  oils,  slightly  soluble  in  water,  miscible  with 
the  ordinary  organic  solvents,  having  a  charadteristic 
odour  and  being  volatile.  The  diazo-acetic  ester,  on 
treatment  with  dilute  caustic  soda,  gave  the  sodium  salt, 
which,  on  being  acidified  with  dilute  sulphuric  acid,  split 
off  nitrogen  and  formed  glycollic  acid, — 

2N2CH-C00Na  -f-  H2SO4  +  2H2O  = 

=  2N2  -f  2CH2(OH)COOH  +  2Na2S04. 

On  the  other  hand,  if  concentrated  caustic  soda  were 
used,  a  polymer,  triazo-acetic  acid,  was  formed,  which,  by 
the  adlion  of  acids,  broke  up  into  hydrazine  and  oxalic 
acid, — 

(N2CH)3(COOH)3  +  6H,0  =  3N2H4  +  3(COOH)2. 

Thus,  in  1887,  the  sulphate  of  hydrazine  was  obtained. 
Other  salts  were  also  formed,  and  from  them  Curtius  sepa- 
rated hydrazine  hydrate,  N2H4,H20,  by  distilling  with 
strong  bases  such  as  CaO  or  NaHO.  The  hydrate  is  a 
colourless,  fuming  liquid,  b.p.  iig°.  It  destroys  cork  and 
rubber,  and  is  a  powerful  reducing  agent  and  poison. 

In  1895  Lobry  de  Bruyn  isolated  free  hydrazine : — 
(a)  by  mixing  anhydrous  solutions  of  hydrazine  hydro- 
chloride and  sodium  methylate,  separating  the  sodium 
chloride  and  fradtionating  the  resulting  solution  under 
reduced  pressure,— 

N2H4-HC1  -I-  NaOCzHa  =  NaCl  +  CH3OH  -|-  NaH4; 

(6)  by  dehydrating  the  hydrate  by  means  of  barium  oxide 
and  distilling  under  reduced  pressure. 

Hydrazine  melts  at  -f-  1-4°  and  boils  at  113*5°,  under 
761  m.m.,  or  at  56°  under  71  m.m.  pressure  of  mercury. 
It  is  one  of  the  strongest  reducing  agents.  In  chlorine 
it  takes  fire  spontaneously,  HCI  and  N  being  formed. 
With  sulphur  it  readts  in  cold,  with  produdtion  of  SHj 
and  N.  It  displaces  ammonia  from  solutions  of  ammo- 
nium salts.  With  acids  it  forms  two  series  of  salts,  e.g., 
N2H4.HCI  and  N2H4,2HCI.  Its  condensations  with 
aldehyds  and  ketones  are  very  important. 

Other  methods  of  preparing  hydrazine  are  those  of 
Pechmann  (Ber.,  xxviii.,  1847  and  2374),  Thiele  and 
Duden  {Ber.,  xxvii.,  3498).  That  of  the  latter  is  the 
simplest.  By  the  adtion  of  sulphurous  acid  on  potassium 
nitrite,  potassium  dinitroso-sulphonate  is  formed,  which 
on  redudtion  by  sodium  amalgam  eventually  affords 
hydrazine, — 

^^>N-N0  +  6H  =  ^^°|>N-NH2-|-H20-|-K0H  = 

=  H2N-NHa  +  K2S04. 


142 


Chemical  Notices  from  Foreign  Sources. 


I  Cbbmical  Nbws, 
I    March  ig,  1897. 


In  1890  Curtius  published  his  first  paper  on  "  Azo- 
imide,  N3H  "  {Ber.,  xxiii.,  3023).  By  means  of  hydrazine 
benzoyl-glycollic  ester  is  converted  into  benzoyl  hydra- 
zide, — 

C6H5CO-OCH2-COOC2H5  +  2N2H4=C6H5CONH-NH2+ 
+NH2-NHCH2COOH  +  C2H50H, 

which  on  diazotising  yields  benzoyl  azbimide, — 

C6H5-CONH-NH2  +  NOOH  =  C6H5-CON3+2H20. 

This  decomposes  when  boiled  with  caustic  soda, — 

C6H5CON3+2NaOH  =  C6H5COONa  +  N3Na+H20, 

forming  sodium  nitride,  from  which  azoimide  is  set  free 
by  the  adtion  of  acids, — 

NgNa  +  H2SO4  =  N3H  +  NaHS04. 

By  careful  fraiftionation  a  solution  of  gi  per  cent  N3H 
was  obtained,  which  was  dehydrated  by  calcium  chloride. 
Azoimide  is  a  colourless  liquid  with  an  unbearable  odour, 
boils  at  37°,  and  is  miscible  with  water  and  alcohol.  It 
is  frightfully  explosive  ;  5  c.grms.  exploded  in  a  barometer 
tube  shattering  the  glass  to  a  powder  and  spreading  the 
mercuiry  as  a  fine  dust. 

Angeli's  method  of  obtaining  azoimide  is  probably  the 
simplest.  On  mixing  solutions  of  hydrazine  sulphate  and 
silver  nitrite,  silver  nitride  separates, — 

N2H4,H2S04  +  AgNOz  =  N3Ag  +  2H2O  +  H2SO4. 

Thiele's  method,  starting  from  amido-guanidine,  and 
Wislicenus's  from  sodamide,  are  also  important. 

The  metallic  salts  of  azoimide  resemble  those  of  hydro- 
chloric acid  very  much,  except  that  they  are  explosive. 
Ammonium  nitride,  N3NH4,  is  the  most  perfedt  explosive 
known;  i  kilo,  is  calculated  to  liberate  1148  litres  of  gas 
at  0°  and  760  mm.  {Bull.  Soc.  Chim.  Paris,  xi.,  744). 

Hydrazine  nitride,  N3N2H5,  is  formed  by  mixing  hydra- 
zine hydrate  and  ammonium  nitride  or  free  azoimide.  It 
is  a  crystalline  substance,  which  behaves  like  gun-cotton, 
burning  quietly  on  exposure  to  fiame,  but  exploding  on 
detonation  or  sudden  heating. 


NOTICES  OF  BOOKS. 


A  Handbook  for  Brewers  ;  being  a  Pradlical  Guide  to  the 
Art  of  Brewing  and  Malting,  embracing  the  Conclusions 
of  Modern  Research  which  bear  upon  the  Practice  of 
Brewing.      By   Herbert   Edwards   Wright,    M.A., 
Author  of  a  '•  Handbook  for  Young  Brewers."    Second 
Edition,  thoroughly  Revised.     London  :  Crosby  Lock- 
wood  and  Son,  7,  Stationers'  Hall  Court,  Ludgate  Hill. 
1897.     Small  8vo.,  pp.  516. 
This  work  is  of  an  extremely  comprehensive  charaiSter. 
It  is   concerned   not  merely  with   the   chemistry  of  the 
brewing  process,  but  also  with  the  mechanical  construdlion 
of  brewery   plant  in   the    widest    sense    of    the    term. 
Micro-biology   and  the  use   of  the   microscope  are  very 
carefully  considered.     We  cannot,  however,  agree  with 
the  author's  rather  unfavourable  estimate  of  immersion 
lenses.   Several  little  precautionary  hints  are  given  which 
prove  the  author  to  be  a  pradical  microscopist. 

The   controversies   between   Liebig,   Pasteur,   Traube, 
and  Brefeld  are  fairly  expounded. 

The  commercial  phase  of  the  brewer's  business  is  next 
expounded. 

As  regards  the  theoretical  considerations,  Mr.  Wright 
ventures  on  the  opinion  that  "  the  final  limit  of  subdivision 
has  probably  never  been  reached."  The  *'  pleomorphic 
craze"  of  A.  G,  Salamon  and  others  meets  with  little 
countenance.  But  such  questions  have  a  very  subordi- 
nate interest  for  the  brewer,  or  indeed  for  any  technical 
chemist. 
We  are  glad  to  find  the  admission  that  Demerara  sugar 


(when  genuine)  is  perhaps  the  best  and  purest  sugar  in 
the  world  (p.  148).  On  the  opposite  page  it  is  mentioned 
that  sugars  having  a  large  bold  crystal  are  not  beloved  by 
the  trade,  as  they  oppose  certain  difficulties  to  the  mys- 
terious process  known  as  handling — which,  by  the  way, 
avenges  itself  on  the  men  by  whom  it  is  effedted. 

An  entire  and  ably  written  chapter  is  devoted  to  water 
and  its  impurities.  It  is  admitted  that  soluble  mineral 
matter  may  be  tolerated  by  the  brewer  to  an  extent  larger 
than  would  be  tolerated  in  a  drinking  or  culinary  water, 
or  in  that  employed  in  the  tindtorial  art.  The  injurious 
adtion  of  salts  of  magnesium  in  appreciable  quantities, 
we  submit,  can  scarcely  be  contested.  Nitrites  in  a 
brewing  water  he  objedls  to  on  the  authority  of  Emile 
Laurent. 

The  author  lays  little  weight  upon  Prof.  Frankland's 
previous  sewage  pollution.  He  attaches  more  weight 
than  does  Prof.  Wanklyn  to  the  possible  presence  of 
phosphoric  acid  in  waters,  and  he  considers  that  waters 
which  after  boiling  and  filtration — we  would  add  by  the 
Chamber  land- Pasteur  process  —  develop  organisms  with 
the  Heisch  test,  probably  contain  organic  matter  of  an 
albuminous  charadter,  and  should  be  used  (if  at  all)  with 
great  caution. 

The  author  quotes  the  conclusion  of  Jorgensen,  that 
for  brewing  purposes  it  is  only  necessary  to  know  whether 
the  water  contains  organisms  capable  of  developing  in 
wort  or  beer. 

Mr.  Wright  reminds  his  readers  that  the  presence  of 
free  carbonic  acid  in  waters  is  by  no  means  a  proof  of 
purity. 

In  speaking  of  materials  used  as  partial  substitute  for 
malt,  the  author  mentions  that  beet-sugar  is  far  inferior 
to  cane-sugar  for  brewing  purposes. 

This  book  will  be  found  most  useful  not  merely  to 
brewers,  whether  learners  or  pradtitioners,  but  to  technolo- 
gists in  general. 


CORRESPONDENCE. 


LOST     PLATINUM. 

To  the  Editor  of  the  Chemical  News, 
Sir, — Three  platinum  basins  have  recently  disappeared 
from  this  laboratory,  and,  as  it  is  just  possible  that  some 
amongst  your  numerous  readers  may  have  been  buying 
second  hand  platinum  basins,  I  append  the  following  par- 
ticulars, in  the  hope — perhaps  somewhat  remote — that  the 
platinum  may  be  recovered  and  the  thief  brought  to 
book :  Basin  marked  A  (scratched  on  the  side),  weight 
2i"877grm8. ;  basin  scratched  B,  weight  22'4i2  grms.  ; 
basin  scratched  X,  weight  59747  grms. — I  am,  &c., 

S.  Archd.  Vasey. 
Liaboratory,  423,  Strand,  W.C, 
March  17,  1897. 


CHEMICAL 


NOTICES    FROM 
SOURCES. 


FOREIGN 


Note.— All  degrees  of  temperature  are  Centigrade  unless  otherwise 

expressed. 

Comptes  Rendus  Hebdomadaires  des  Seances,  del'Academie 
des  Sciences.    Vol.  cxxiv.,  No.  8,  February  22,  1897. 

M.  VioUe  has  been  eledted  a  Member  of  the  Academy 
in  the  Sedtion  of  Physics,  vice  M.  Fizeau,  deceased. 

M.  de  Heen,  of  Liege,  addresses  to  the  Academy  two 
notes,  entitled  '*  Existence  of  Anodic  Rays  analogous  to 


Crkuical  News,  i 
March  ig,  1897.  J 


Chemical  Notices  from  Foreign  Sources. 


143 


the  Cathodic  Rays,"  and  "  Photography  of  the  EleAric 
Radiations  of  the  Sun  and  of  the  Solar  Atmosphere." 

M.  Breton  demanded  the  opening  of  two  sealed  papers 
recently  deposited  by  him,  and  relating,  the  one  to  "  the 
use  of  alternating  simple  currents,  diphasic  and  triphasic, 
for  the  produdion  of  X-rays;"  and  the  other  to  "  a  radio- 
graphic phial  for  the  refrigeration  of  the  anticathode  by  a 
current  of  cold  water." 

M.  de  Sanderval  addressed  a  paper,  accompanying 
photographs  obtained  through  metallic  plates  of  different 
natures. 

M.  A.  Graby,  of  Malange,  sent  the  description  of  a 
new  photographic  procedure,  rendering  it  possible  to 
obiain  positives  in  the  colours  without  the  produdtion  of 
a  proof. 

New  Method  for  producing  Transparent  Crystals. 
— Ch.  de  Wateville.— If  during  its  growth  we  give  to  a 
crystal  a  movement  of  rotation  on  itself  it  assumes  a 
transparency  and  a  lustre  analogous  to  those  of  precious 
stones  seen  cut  and  polished  whatever  may  be  the  axis  of 
the  crystal  near  which  the  rotation  is  effedled.  The 
movement  appears  not  to  lose  any  influence  upon  the 
relative  development  of  the  faces  unless  it  is  very  rapid 
and  the  solution  is  very  concentrated.  If  we  operate, 
e.g.,  upon  a  solution  of  alum  saturated  above  50°  (and 
with  the  speed  of  several  rotations  per  second),  we  pro- 
gressively disappear  the  faces  of  the  dodecahedron,  and 
those  of  the  cube  which  the  crystal  presents  at  the  outset 
of  the  operation  ;  those  of  the  odahedron  of  the  max- 
imum density  alone  remaining.  The  author  has  obtained 
especially  satisfadtory  results  with  potassium  and  ammo- 
nium alums,  copper  sulphate,  and  sodium  chlorate. 

On  Persulphuryl  Chloride. — A.  Besson. — This  me- 
moir will  be  inserted  in  extenso. 

Anethol  and  its  Homologues. — Ch.  Mouet  and  A. 
Chauvet.  —  The  author  describes  a  new  synthesis  of 
anethol,  simpler  they  consider  than  than  the  procedure  of 
Perkin.  They  have  thus  obtained  two  homologues  of 
anethol  (para-butenyl  anisol  and  para-isopentenyl  anisol). 

Soluble  Oxidising  Ferment  of  the  Cassage  of 
Wines.  —  P.  Gazeneuve.  —  Not  suitable  for  useful 
abstradion. 

Deted^ion  of  Coal-tar  Colours  in  White  Wines 
and  the  Difference  between  the  Colours  and  those  of 
Caramel. — Alb.  d'Aguilar  and  W.  da  Silva. — This  memoir 
will  be  inserted  in  full. 

Revue  Universelle  des  Mines  et  de  la  Metallurgie. 
Series  3,  Vol.  xxxvii..  No.  i. 
This  issue  contains  no  chemical  matter. 

No.  2. 
Ores  of  Manganese  in  Russia  (Chemiker  Zeitung). — 
It  appears  that  in  1896  the  Russian  output  of  manganese 
ores  was  248,000  tons,  that  of  the  rest  of  the  world  be  ng 
only  66,821  tons. 

Bulletin  de  la  Societe  d' Encouragement  pour  F Industrie 
Nationale.     Series  5,  Vol.  ii.,  No.  i. 

Review  of  the  Progress  effeded  in  the  Industry  o^ 
Essences  and  Perfumes.  —  A.  Haller.  —  The  author 
claims  the  produdion  of  perfumes  as  an  art  evidently 
French.  Only  the  English  produds  approach  them  in 
fineness,  but  they  possess  neither  the  distindion  nor  the 
delicacy  of  French  perfumery.  France,  both  on  its 
southern  coasts  and  in  Algeria,  possesses  great  natural 
advantages  for  this  manufadure;  but  he  recommends 
that  the  aid  of  chemical  science  should  be  carefully  and 
eagerly  sought  for.  He  raises  the  question  whether  the 
French  madder  produdion  might  not  have  been  saved  by 
such  means,  pointing  out  that,  in  spite  of  artificial 
indigo,  the  yield  of  India  has  since  1886  been  increased 


from  33.320  chests  yearly  to  40,510.  The  firm  Schimmel 
and  Co.,  of  Leipzig,  employs  at  present  nine  chemists. 
The  English  lavender  (of  Mitcham)  cannot  be  estimated 
solely  according  to  its  percentage  of  linalyle  acetate,  and 
it  is  yet  preferred  to  common  essences  of  lavender  which 
contain  from  30  to  40  per  cent.  We  cannot  help  expressing 
our  deep  regret  that  a  part  of  the  precious  Mitcham  soil 
has  been  allowed  to  fall  into  the  hands  of  "Jerry." 
Whether  the  oil  of  lavender  obtained  at  Sandy  (Bedford- 
shire) is  equal  to  the  Mitcham  growth  we  are  not  yet  able 
to  decide.  English  essence  of  peppermint  (Mitcham)  is 
always  in  demand  on  account  of  the  fineness  of  its  odour, 
the  cause  of  which  chemical  research  has  not  yet  been 
able  to  deted. 


MISCELLANEOUS. 

The  Chemiker  Zeitung. — The  issue  of  February  20th 
gives  a  plan  and  a  full  description  of  the  Pharmaceutical 
Institute  and  Laboratory  for  Applied  Chemistry  in  con- 
nedion  with  the  University  of  Munich.  This  journal  is 
also  discussing  the  possible  influence  of  the  deposit  of 
"  sealed  papers  "  describing  the  details  of  an  invention 
may  have  upon  a  patent  subsequently  obtained. 

Adion  of  Nitrogen  Oxides  upon  Ferrous  Chloride 
and  Bromide. — V.  Thomas. — The  compounds  obtained 
are  inalterable  in  dry  air,  and  undergo  no  loss  of  weight 
in  a  vacuum.  In  most  cases  they  are  capable  of  being 
split  up  into  chloride  (or  bromide)  and  nitrogen  peroxide. 
— Comptes  Rendus,  cxxiv..  No.  8. 

A(!\ion  of  Dilute  Nitric  Acid  upon  Nitrates  in 
Presence  of  Ether.  —  M.  Tanret.  —  On  agitating  water 
containing  nitric  acid  with  aqueous  ether,  the  acid  is  dis- 
tributed by  the  water  and  the  ether  so  that  the  quantities 
dissolved  by  an  equal  volume  of  each  liquid  bear  a  con- 
stant relation  to  each  other.  This  relation  has  been 
called  by  MM.  Berthelot  and  Jungfleisch  the  coefficient  of 
distribution;  it  is  independent  of  the  relative  volume  of 
the  two  liquids,  but  varies  with  their  temperature  and 
concentration. — Comptes  Rendus,  cxxiv..  No.  g. 

Discharge  of  the  Rontgen  Rays :  Part  Played  by 
the  Surfaces  Struck. — Jean  Perrin. — The  gas  effed  is 
readily  explained  if  we  admit  that  the  X  rays  at  every 
point  of  their  track  liberate  equal  quantities  of  posi- 
tive and  negative  eledricity,  movable  along  tubes  of 
force  which  contain  them.  Similarly  the  metallic  effed 
is  readily  explained  by  supposing  that  on  the  contad  of  a 
condudor,  and  in  a  manner  variable  with  nature,  the  ion- 
isation  of  the  gas  is  very  intense.  I  propose  to  call  this 
phenomenon  the  superficial  ionisation  of  the  gas  on  con- 
tad  wiih  the  condudor. — Comptes  Rendus,  cxxiv..  No.  9. 

The  Chemical  Laboratory  of  Wiesbaden.  —  The 
Chemical  Laboratory  of  Prof.  Dr.  R.  Fresenius  has  been 
attended  by  fifty-eight  Students  during  the  Winter  Session 
of  1896-97.  Of  these,  forty-three  were  from  Germany, 
four  from  England,  two  from  Switzerland,  two  from 
Sweden  and  Norway,  two  from  the  United  States  of 
North  America,  one  from  Austria,  one  from  Roumania, 
one  from  Russia,  one  from  Spain,  and  one  from  Brazil. 
There  were  three  Assistant  Demonstrators  in  the  several 
teaching  departments,  and  twenty  Assistants  in  the 
Versuchsstationen  (private  laboratories).  Besides  the 
Diredor,  Geh.  Hofrath  Prof.  Dr.  R.  Fresenius,  there  are 
engaged,  as  Teachers  in  the  Establishment,  Prof.  Dr.  H. 
Fresenius,  Dr.  W.  Fresenius,  Dr.  E.  Hintz,  Dr.  med.  G. 
Frank,  Dr.  W.  Lenz.Dr.  L.Griinhut,  and  ArchitedBrahm. 
The  next  Summer  Term  begins  on  the  26th  of  April. 
Throughout  the  Winter  Session,  besides  various  scientific 
researches,  a  great  number  of  analy.ses  have  been  under- 
taken in  the  different  departments  of  the  Laboratory  for 
manufadurers  of  all  kinds,  in  judicial  cases,  and  in  many 
branches  of  trade,  mining,  agriculture,  and  hygiene. 


144 


Meetings  for  the  Week, 


{Chemical  mbws, 
March  19, 1897. 


NOTES    AND    QUERIES. 

*«*  Our  Notes  and  Queries  column  was  opened  for  the  purpose  of 
giving  and  obtaining  information  likely  to  be  of  use  to  oui  readers 
generally.  We  cannot  undertake  to  let  this  column  be  the  means 
of  transmitting  merely  private  information,  or  such  trade  notices 
as  should  legitimately  come  in  the  advertisement  columns. 

Dental  Alloys.— (Reply  to  "Jack"). — Consult  "Hunter's  Me- 
chanical Dentistry"  (Longmans  and  Co.,  3s.  6d.).  Supplied  by  Elliot 
Stock,  62,  Paternoster  Row,  E.C.,  for  3s.  id.— G.  A.  Kbyworth, 
Hastings. 


MEETINGS    FOR    THE    WEEK. 

Monday,  22nd.— Society  of  Arts,  4.30.   (Cantor  Leftures).    "Alloys," 

by  Prof.  W.  Chandler  Roberts-Austen,  F.R.S. 
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Esttmation  of  Thoria. 


145 


THE    CHEMICAL    NEWS 

Vol.  LXXV.,  No.  1948. 


ESTIMATION    OF    THORIA. 

CHEMICAL   ANALYSIS    OF    MONAZITE    SAND.* 

By  CHARLES  GLASER. 

Since  the  introdudlion  of  the  Auer-Welsbach  light,  the 
commercial  importance  of  monazite  sand  has  grown 
greatly,  and  chemists  are  now  asked  to  determine  the 
percentage  of  true  monazite,  and  especially  that  of  thoria, 
in  samples  of  the  sand.  This  has  heretofore  been  accom- 
plished indiredly  ;  the  quantities  of  iron,  titanium,  and 
silica  were  determined,  and  the  remainder  of  the  material 
calculated  as  monazite.  A  sample  treated  in  this  manner 
gave  the  following  results: — 

Iron  oxide 3'5o  per  cent 

Titanic  acid 467        „ 

Silica 6-40       „ 

Monazite,  by  difference    ..     ..  85*43       ,, 


The  sample  contained  i8'38  per  cent  phosphoric  acid, 
which  calculated  as  cerium  phosphate  (fadtor3-32)  equals 
61*10  per  cent. 

From  analyses  printed  in  Dana's  "  Mineralogy,"  it  was 
inferred  that  after  elimination  of  rutile  and  silica,  the 
remainder  would  be  found  to  consist  chiefly  of  phosphates 
of  the  cerium  group,  but  this  is  not  true. 

For  the  determination  of  the  acftual  composition  of  the 
monazite  sand  in  question,  it  was  decided  to  attempt  an 
estimation  of  each  of  its  components,  by  means  of 
methods  to  be  found  in  the  available  literature.  As  chief 
sources  of  information,  Graham-Otto's  "  Chemistry  " 
and  Crookes's  "  Seledt  Methods  in  Chemical  Analysis  " 
were  used  ;  due  regard  was  also  given  to  the  work  which 
has  appeared  in  the  chemical  journals  of  recent  years.  I 
was  not  able,  however,  to  make  an  exhaustive  examina 
tion  of  the  literature. 

It  became  evident  that  no  reliable  method  could  be 
worked  out  until  examination  had  been  made  of  all  the 
work  which  had  been  done  in  the  field,  and  it  seemed 
necessary  to  investigate  the  whole  question.  In  the  fol- 
lowing statements  of  preliminary  experiments  a  large  por- 
tion of  analytical  data  has  been  omitted,  because  other- 
wise this  paper  would  have  been  bulky.  Only  the  out- 
lines of  a  general  plan  of  procedure  will  therefore  be 
given. 

So  far  as  possible,  it  was  my  intention  to  examine  all 
the  methods  proposed  for  estimation  of  thoria,  but  in  one 
notable  instance  this  could  not  be  done.  In  the  American 
Chemical  jfournal  (vol.  xvi.)  L.  M.  Dennis  and  F.  L. 
Kortright  describe  a  method  for  estimation  of  thoria  by 
means  of  potassium  hydronitride,  KN3.  An  attempt  to 
work  by  the  method  proved  a  failure  in  my  hands,  partly 
because  of  a  mishap  while  preparing  the  reagent,  only 
enough  of  which  was  saved  for  a  single  qualitative  reac- 
tion ;  but  chiefly  because  Mr.  Dennis  declined,  when 
requested,  to  give  me  further  information.  He  replied 
that  he  was  not  then  at  liberty  to  detail  his  experience, 
"  as  the  potassium  hydronitride  process  is  more  than  an 
analytical  one.  It  is  a  commercial  process  for  the  pre- 
paration of  pure  thoria,  which  is,  I  think,  unequalled  by 
any  of  the  methods  employed  by  the  Welsbach  chemists, 
Shapleigh  included.  Some  of  them  have  tried  to  use  the 
method  and  have  failed.    I  think  I  know  why  they  failed. 

*  From  the  Journal  of  the  American  Chemical  Society,  vol.  xviii., 
No.  9. 


But  I  do  not  think  it  quite  fair  for  them  to  ask  me  to  heln 
them  out  of  their  difficulties.  *^ 

Although  the  publication  was  made  in  a  scientific 
journal,  it  seems  to  have  been  but  a  partial  statement. 
For  which  reason  criticism  is  invited  and  the  value  of  the 
work  IS  thrown  somewhat  in  doubt.  No  further  attempt 
was  made  to  follow  it  out. 

By  means  of  fusion  with  alkali  carbonates,  an  attempt 
was  made  to  separate  monazite  sand  into  two  parts 
According  to  Wohler,  all  titanic  acid  ought  to  become 
soluble  provided  the  fusion  is  made  at  a  suffi- 
ciently  high  temperature.  Therefore  a  blowpipe  was 
used.  In  later  work  I  employed  the  highest  temperatures 
afforded  by  a  muffle,  and  for  as  many  as  two  hours.  But 
at  no  time  was  more  than  a  fradtion  of  the  titanic  acid 
rendered  soluble  in  water.  Moreover,  Wohler's  direcftions 
to  pour  the  fusion  upon  an  iron  plate,  and  afterwards  to 
powder  it,  are  not  praiflicable  because  of  loss  likely  to 
ensue.  It  was  found  best  to  let  the  fusion  soak  in  water 
over  night,  sometimes  even  for  several  days,  or  until  per- 
fedt  disintegration  resulted.  But  such  a  procedure  may 
have  decreased  the  solubility  of  titanic  acid  in  water. 
Phosphoric  acid  and  alumina  (and  also  silica  to  a  large 
extent)  were  completely  dissolved  out  of  the  fused  mass. 
The  portion  insoluble  in  water  was  rendered  soluble  by 
the  well-known  treatment  with  strong  sulphuric  acid,  and 
also  by  fusion  with  acid  potassium  sulphate.  The  solu- 
tion thus  obtained,  after  being  freed  from  silica,  was 
boiled  to  separate  titanic  acid,  from  four  to  seven  hours 
during  the  first  experiment.  Later,  after  addition  of 
sodium  sulphite,  this  was  accompanied  by  saturating  with 
hydrogen  sulphide,  first  in  the  hot  and  then  in  the  cooled 
solution.     This  method  is  preferable  to  the  first. 

After  separation  of  titanic  acid  and  the  metals  of  the 
fifth  group,  various  methods  were  tried  for  separation  of 
thoria  from  the  other  earths.  It  was  found  that  the  solu- 
tion must  not  be  strongly  acid  when  treated  with  ammo- 
nium oxalate  for  precipitation  of  thoria  and  the  metals  of 
the  cerium  group,  or  traces  of  thoria  will  remain  in  solu- 
tion.  It  is  best  to  nearly  neutralise  with  ammonia,  and 
to  precipitate  in  boiling  solution. 

During  the  earlier  experiments  some  difficulty  was 
found  in  keeping  in  solution  all  of  the  zirconia,  which  is 
accomplished  only  by  a  large  excess  of  the  reagent,  while 
yttria  and  glucina  readily  form  soluble  double  salts. 
Under  these  conditions  oxalates  of  the  cerium  metals  pre-* 
cipitate  immediately,  while  thorium  oxalate  separates 
upon  cooling.  Attempts  to  separate  thorium  oxalate 
from  oxalates  of  the  metals  of  the  cerium  group  by  filtra- 
tion of  the  hot  solution  gave  unsatisfadlory  results.  The 
oxalates  will  pass  through  the  filter  for  a  long  time. 
Bumping  of  the  liquid  made  it  imprafticable  to  keep  it 
boiling  until  the  entire  precipitate  became  crystalline. 
But  if  large  quantities  of  thoria  are  to  be  separated  from 
small  ones  of  the  other  oxalates  the  method  works  well. 

After  the  insoluble  oxalates  were  separated  by  filtra- 
tion  and  were  washed  v/ith  water,  they  were  converted 
into  oxides  by  heating,  and  were  re-dissolved  as  sulphates. 
In  this  strongly  concentrated  solution,  made  nearly 
neutral  by  ammonia,  an  attempt  was  made  to  separate 
thoria  from  the  other  metals  by  boiling  with  sodium 
hyposulphite.  In  no  instance  was  a  complete  separation 
effedted,  but  such  portions  as  were  obtained  proved  to  be 
quite  pure.  The  single  exception  was  that  in  which  the 
whole  of  the  cerium  was  precipitated,  for  reasons  not 
ascertained.  Attempts  were  made  to  free  thoria  from 
most  of  the  cerium  by  fradlional  precipitation  with  weak 
ammonia,  but  no  considerable  advantage  was  gained 
thereby,  since  repeatedly  the  second  fraftion  showed 
traces  of  thorium. 

To  determine  the  solubility  or  insolubility  of  the  dif- 
ferent substances  left  in  the  insoluble  residue  from 
fusions,  such  residue  was  treated  with  dilute  hydrochloric 
acid,  both  cold  and  hot.  The  solution  was  found  to 
contain  all  the  iron  and  titanium,  the  larger  part  of  the 
ilica,  and  about  one-half  of  the  earths  present ;  these 


146 


Estimation  of  Thoria. 


\  Chemical  Nbvs, 
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147 


consisted  of  relatively  large  portions  of  zirconia  and 
glucina.  Thoria  seems  not  to  enter  into  solution,  but  is 
left  with  the  remainder  of  the  earths. 

An  attempt  was  made  to  separate  thorium  oxalate  from 
the  mixed  precipitatedoxalates,  by  boiling  with  ammonium 
oxalate.  Such  boiling,  filtering,  and  crystallising  yielded 
oxalates,  which,  after  ignition,  corresponded  to  2*29  per 
cent  of  oxides.  The  earths  were,  however,  of  a  deep 
orange  colour,  and  contained  both  cerium  and  zirconia. 
The  latter  was  present  because  an  insufficient  quantity 
of  ammonium  oxalate  had  been  used  in  the  first  precipita- 
tion. In  the  oxalates  of  the  cerium  metals  found  in- 
soluble in  the  above  treatment,  the  presence  of  thoria 
could  be  distinctly  proven  by  means  of  sodium  hypo- 
sulphite, for  which  reason  the  work  proved  unsatisfaftory. 

To  facilitate  a  comparison  of  the  more  important  reac- 
tions of  the  elements  herein  studied,  the  accompanying 
table  has  been  prepared  partly  from  their  known  behaviour, 
and  partly  from  the  results  obtained  during  this  investi- 
gation. 

With  the  view  of  obtaining  further  knowledge  of  the 
behaviour  of  thoria,  fragments  of  Welsbach  mantles  were 
subjedled  to  analysis.  They  weighed  o*659i  grm.,  which 
after  ignition  fell  to  0*6552  grm.  Prolonged  treatment 
with  boiling  sulphuric  acid  left  a  residue  of  o'oSSj  grm., 
which  became  soluble  in  water  after  fusion  with  acid 
potassium  sulphate.  The  solutions  thus  obtained  were 
examined  by  the  same  method,  but  separately,  as  fol- 
lows :— After  neutralising  with  ammonia  the  greater  part 
of  the  free  acid,  the  solutions  were  heated  to  boiling  and 
hot  solution  of  ammonium  oxalate  was  added. 

In  solution  I.  a  precipitate  appeared,  but  dissolved 
rapidly  upon  addition  of  more  of  the  reagent. 

In  solution  II.  a  slight  turbidity  appealed,  there  was  no 
precipitate,  and  it  soon  became  perfedly  clear. 

Upon  cooling,  solution  I.  yielded  a  moderate  quantity 
of  a  crystalline  deposit,  while  solution  II.  gave  a  copious 
one.  Both  precipitates  were  collefted  on  one  filter, 
washed,  ignited,  and  weighed.  They  yielded  0-1124  grm. 
of  thoria. 

The  filtrate  from  I.  gave  a  copious  precipitate  with 
ammonia,  while  that  from  II.  gave  only  a  slight  one  ;  both 
of  these  were  washed  on  one  filter,  re-dissolved  in  dilute 
hydrochloric  acid,  and  again  precipitated  by  ammonia. 
An  excess  of  ammonium  carbonate  entirely  dissolved  the 
precipitate.  Potassium  hydroxide  gave  a  precipitate  not 
soluble  in  an  excess  of  the  precipitant,  indicating  zirconia, 
the  weight  of  which  was  o'SsSo  grm.  An  attempt  to 
purify  it  from  occluded  alkali,  by  again  precipitating  with 
ammonia,  failed  through  an  accident,  in  which  part  of 
the  mnterial  was  lost.  Calculating  by  difference,  the 
weight  of  zirconia  ought  to  have  been  0*5428  grm.  Both 
precipitates  were  pure  white. 

Therefore,  this  analysis  afforded  the  following  com- 
position of  the  mantles :— Thoria,  1715  per  cent ;  zirconia, 
82  85  per  cent. 

The  separation  of  the  two  earths  was  effedled  without 
difficulty,  and  the  thoria  was  used  in  the  following  experi- 
ments : — 

o'0487  grm.  was  weighed,  dissolved,  and  mixed  with  the 
solution  of  cerium  metals  from  a  previous  experiment. 
The  solution  was  nearly  neutralised  with  ammonia, 
heated  to  boiling,  a  hot  solution  of  ammonium  oxalate 
added,  and  the  mixture  allowed  to  cool.  The  precipitate 
was  caught  on  a  filter  and  washed  with  cold  water,  ex- 
tradled  in  boiling  ammonium  oxalate  solution,  caught  on 
a  filter,  and  washed  hot ;  the  filtrate  was  allowed  to  cool 
(precipitate  i).  The  residue  was  macerated  in  a  hot  so- 
lution of  ammonium  acetate,  filtered  (residue  A),  and 
filtrate  examined  for  thoria,  as  follows  : — Hydrochloric 
acid  was  added  to  separate  thoria  as  oxalate,  which  fell 
in  part  only,  and  the  remainder  was  obtained  by  sodium 
hydroxide  (precipitate  2).  Both  these  precipitates  afforded 
but  a  part  of  the  thoria  originally  weighed,  the  greater 
part  being  held  yet  with  the  cerium  metals.  The  method 
had  failed. 


The  residue  (A)  upon  the  filter  was  reduced  to  oxide 
and  dissolved  as  sulphate.  After  neutralising  with  am- 
monia, the  liquid  was  heated  to  boiling,  and  there  was 
added  an  excess  of  ammonium  oxalate  with  some  ammo- 
nium acetate  ;  after  filtering,  the  filtrate  was  treated  with 
sodium  hydroxide  (precipitates). 

The  precipitates,  thus  obtained  in  three  fradlions,  were 
ignited  and  found  to  weigh  0*0774  grm.,  showing  that  the 
thoria  was  very  impure.  The  greyish  mass  was  fused 
with  acid  potassium  sulphate,  and  unfortunately  a  small 
fradlion  of  the  fused  mass  was  lost.  However,  from  the 
saved  portion  a  pure  thoria,  weighing  0*0402  grm.,  was 
obtained. 

In  the  next  experiment,  0*0343  gr™'  of  thoria  and 
0*1004  grm.  of  impure  cerium  oxide  were  dissolved  as 
sulphates,  and  treated  with  ammonium  oxalate  and 
acetate,  as  for  precipitate  3,  next  above.  By  precipitating 
the  filtrate  with  ammonia  there  was  obtained  0*0360  grm. 
of  impure  thoria,  which  after  purification  weighed  0*0344 
grm.     Cerium  oxide  recovered  weighed  0*0935  g^m. 

I  desire  to  call  attention  to  what  has  been  observed 
frequently  during  these  experiments.  If  thorium  oxalate, 
held  in  solution  by  ammonium  acetate,  b&  precipitated  by 
ammonia,  the  earth  so  obtained,  when  washed  with  the 
greatest  care  and  re-dissolved  in  a  mineral  acid,  cannot 
from  an  almost  neutral  solution  be  again  completely  pre- 
cipitated by  ammonium  oxalate;  even  if  the  earth  had 
been  ignited  after  re-solution.  It  will  also  be  found  that  a 
considerable  increase  has  occurred  in  its  solubility  in 
liquidscontaining  much  potastium  or  ammonium  sulphate. 
When  enough  thoria  has  been  c jllefled,  it  is  my  intention 
to  further  examine  this  peculiar  behaviour. 

(To  be  continued). 


LONDON     WATER    SUPPLY. 
Report  on  the  Composition  and  Quality  of  Daily 
Samples   of  the  Water  Supplied  to   London 
FOR  THE  Month  Ending  February  28th,  1897. 

By  WILLIAM  CROOKES,  F.R.S.. 

and 

PROFESSOR  DEWAR,  F.R.S. 

To  Major-General  A.  De  Courcy  Scott,  R.E., 
Water  Examiner,  Metropolis  Water  Act,  1871. 

London,  March  loth,  1897. 
Sir, — We  submit  herewith,  at  the  request  of  the 
Diredors,  the  results  of  our  analyses  of  the  168  samples 
of  water  colleded  by  us  during  the  past  month,  at  the 
several  places  and  on  the  several  days  indicated,  from  the 
mains  of  the  London  Water  Companies  taking  their 
supply  from  the  Thames  and  Lea. 

In  Table  I.  we  have  recorded  the  analyses  in  detail  of 
samples,  one  taken  daily,  from  Feb.  ist  to  Feb.  28th 
inclusive.  The  purity  of  the  water,  in  respedl  to  organic 
matter,  has  been  determined  by  the  Oxygen  and  Com- 
bustion processes;  and  the  results  of  our  analyses  by 
these  methods  are  stated  in  Columns  XIV.  to  XVIII. 

We  have  recorded  in  Table  II.  the  tint  of  the  several 
samples  of  water,  as  determined  by  the  colour-meter 
described  in  a  previous  report. 

In  Table  III.  we  have  recorded  the  oxygen  required  to 
oxidise  the  organic  matter  in  all  the  samples  submitted 
to  analysis. 

Of  the  168  samples  examined  one  was  recorded  as 
"  clear  but  dull,"  the  remainder  being  clear,  bright,  and 
well  filtered. 

The  rainfall  at  Oxford  during  February  was  2*41  inches. 
The  average  for  thirty  years  being  1*76  inches,  we  have 
had  an  excess  of  065  inch  ;  1*48  inches  fell  on  the  first 
five  days  of  the  month. 

Our  badleriological  examination  of  the  London  watera 
give  the  following  results  — 


148 


Revision  of  the  Atomic  Weight  of  Magnesium. 


f  Chbuical  Nbwb, 
1    March  26, 1807. 


Microbes 
per  c.c. 
Thames    water,    unfiltered    (average    of    20 

samples) 95^° 

Thames  water,  from  the  clear  water  wells  of 
five  Thames-derived  supplies  (average  of  99 

samples) 22 

Ditto        ditto  highest        89 

Ditto        ditto  lowest  3 

New  River,  unfiltered  (average  of  19  samples)     1589 
New  River,  from  the  Company's  clear  water 

well  (average  of  20  samples) 20 

River  Lea,  unfiltered  (average  of  19  samples)     1177 
River  Lea,  from  the  East  London  Water  Com- 
pany's clear  water  well  (average  of  19  sam- 
ples)             40 

The  quality  of  the  London  waters  during  February  has 
been  uniformly  good,  with  one  exception.  Since  the 
beginning  of  this  year  we  have  much  enlarged  the  scope 
of  our  enquiries,  and  have  examined  badteriologically  the 
clear  water  well  at  the  Hampton  Works  of  the  Grand 
Jundlion  Water  Company,  as  well  as  that  at  the  Kew 
Works  of  the  same  Company.  On  some  occasions  during 
the  month  the  Hampton  water  has  given  high  results ; 
these  were  at  once  communicated  to  the  Engineer  of  the 
Companyi  and  the  matter  is  receiving  serious  attention. 
We  are,  Sir, 

Your  obedient  Servants, 

William  Crookes. 
James  Dewar. 


A    REVISION    OF    THE    ATOMIC    WEIGHT    OF 
MAGNESIUM.' 

By  THEODORE  WILLIAM  RICHARDS 

and 

HARRY  GEORGE  PARKER. 

Although  numerous  determinations  of  the  atomic  weight 
of  magnesium  have  been  made,  the  results  obtained  show 
such  very  wide  variations  among  themselves  that  the  value 
in  use  at  present  cannot  be  accepted  with  any  certainty. 
It  will  not  be  necessary  to  review  in  detail  all  the  work 
published,  as  most  of  it  was  done  more  than  forty  years 
ago,  before  quantitative  methods  had  attained  their  present 
exadness  ;  but  the  following  table  of  methods  used  and 
results  obtained  will  assist  in  a  clear  comprehension  of  the 
situation. 

Previous  Work  on  the  Atomic  Weight  of  Magnesium.] 
Synthesis  of  sulphate  by  the  adlion   ot  sulphuric 
acid  on  the  oxide. 
Berzelius,  1826.   "  Lehrbuch,"  5th  edition,  iii., 

1227.  25-3 

Svanberg  and  Nordenfeldt,  1848.     Erdmann's 

yourn,  Prakt.  Chem.,  1848,  xlv.,  473.  24*7 

Bahr,  1852.     Erdmann's  yourn,  Prakt.  Chem., 

1852,  Ivi.,  3x0.  24-8 

Marignac,  1884.     Ann.  Chim.  Phys.,  1884,  (5)i 

i.,  289,  321.  24-37 

Conversion  of  sulphate  into  oxide. 

Jacquelain,  1851.  Ann.  Chim.  Phys.,  (3),  kkxu., 

195-  34-5 

Determination  of  sulphuric  acid  in  sulphate. 

Gay-Lussac,  1820.      Ann.  Chim.  Phys.,  xiii., 

308.  24-6 

Scheerer,  1846,  Pugg.  Ann.,  1846,  Ixix.,  535.        24*5 
Scheerer,  1847,  Later  Correiftion.    Pogg.  Ann  , 

1847,  '""  .  407-  24-5  ? 

Jacquelain,  1851.   Ann.  Chim.  Phys.,  1851,  (3), 

xxxii.,  195.  24*2 

♦  Contributions  from  the  Chemical  Laboratory  of  Harvard  Coilege. 
From  ihe  trocee^.ings  of  the  American  Academy  0/  Ar  sand  Sciences, 
vol.  xxxii.,  No.  2. 

t  We  are  indebted  to  Mr.  F.  W.  Clarke  for  most  of  the  above 
references. 


Conversion  of  oxalate  into  oxide. 

Svanberg  ^nd  Nordenfeldt,  1848.     Erdmann's 

yourn.  Prakt.  Chem.,  1848,  xlv.,  473.  247 

Determination  of  chlorine  in  magnesic  chloride. 
Dumas,  1859.    Ann.  Chim.  Phys.,  1859,  (3),  Iv., 

129,  187.  24-6 

Conversion  of  carbonate  into  the  oxide. 

Marchand   and   Scheerer,    1850.      Erdmann's 

yourn,  Prakt.  Chem.,  1850,  1.,  385.  24*0 

Scheerer,    1859,   Later   Correction.      Liebig's 

Ann.,  1859,  ex.,  236.  24*0 

Conversion  of  metal  into  oxide. 

Burton  and  Vorce,  1890.     Am.  Chem.  yourn., 

1890,  xii.,  219.  24*29 

It  will  be  seen  that,  with  the  exception  of  the  results 
obtained  by  the  precipitation  of  the  sulphuric  acid  with 
barium  chloride  and  the  precipitation  of  the  chlorine  with 
argentic  nitrate,  all  the  methods  employed  involve  the  use 
of  magnesic  oxide.  The  fadl  that  all  such  results  are 
untrustworthy  was  shown  by  T.  W.  Richards  and  E.  F. 
Rogers  {Proc.  Amer.  Acad.,  xxviii.,  200J  in  their  work  upon 
the  occlusion  of  gases  by  the  oxides  of  certain  metals  when 
obtained  by  the  ignition  of  various  salts.  The  error  from 
this  source  is  so  large  that  it  seems  hopeless  to  apply  a 
corre<5tion  to  previous  work  upon  the  atomic  weight  of 
magnesium,  as  the  amount  of  gas  occluded  depends  in  a 
large  degree  upon  the  method  and  thoroughness  of 
ignition. 

Concerning  the  results  obtained  by  the  precipitation  of 
the  sulphuric  acid  in  magnesic  sulphate,  it  is  only  neces- 
sary to  point  out  the  error  due  to  the  occlusion  of  various 
soluble  substances  present  in  the  solution  from  which  the 
precipitation  was  made.  This  error  was  recognised  by 
Scheerer,  after  publishing  his  results,  and  an  approximate 
correction  was  made  ;  but  such  a  corredion  does  not  merit 
much  confidence,  as  will  be  seen. 

In  the  work  of  Dumas  it  is  evident  that  some  magnesic 
oxychloride  was  formed,  and  he  does  not  appear  at  all 
confident  of  the  accuracy  of  his  results.  From  the  experi- 
ence of  the  writers  it  does  not  seem  likely  that  the  method 
which  he  used  would  give  magnesic  chloride  free  from 
the  oxide. 

Preliminary  Experiments. 

Because  considerable  experience  had  been  gained  in  a 
previous  research  {Proc.  Amer.  Acad.  Arts  Sci.,  xxxi.,  p. 
by)  upon  the  occlusion  by  baric  sulphate  of  salts  present 
in  a  solution  from  which  this  insoluble  salt  was  precipi- 
tated, it  was  thought  that  Gay-Lussac's  and  Scheerer's 
method  of  precipitating  magnesic  sulphate  with  baric 
chloride  might  now  be  used  with  advantage,  applying 
subsequently  the  necessary  correcflions  for  occluded  sub- 
stances.  It  had  previously  been  found  that  the  concen- 
tration of  the  solution  and  the  method  of  pouring  had  a 
great  deal  to  do  with  the  amount  of  occlusion  ;  and  hence 
it  seemed  likely  that  by  working  in  a  very  dilute  solution 
and  pouring  the  magnesic  sulphate  into  the  baric  chloride 
with  extreme  slowness,  the  occlusion  of  baric  chloride 
might  be  large,  but  that  the  precipitate  might  be  free  from 
magnesium.  Several  experiments  were  made  to  ascertain 
the  corredness  of  this  supposition,  but  in  each  case  it  was 
found  that,  notwithstanding  the  precautions  adopted,  a 
very  notable  quantity  of  magnesium  was  occluded  in  the 
baric  sulphate.  It  had  been  the  custom  in  working  upon 
this  precipitation  to  fuse  the  weighed  baric  sulphate  with 
sodic  carbonate,  to  extrad  the  sodic  chloride  thus  formed, 
and  to  determine  the  chlorine  with  argentic  nitrate  and 
calculate  as  baric  chloride,  subtradting  this  amount  from 
the  total  weight  of  baric  sulphate  found.  This  method 
gave  very  satisfadlory  results,  but  of  course  it  could  not 
be  applied  when  the  baric  sulphate  was  mixed  with 
magnesic  chloride  and  sulphate  as  well  as  baric  chloride, 
for  then  no  one  could  discover  the  proportion  in  which 
each  salt  was  present  with  sufficient  accuracy  for  work 
upon  atomic  weights. 


Crbmical  Nbws,  I 
March  26,  1897.   I 


Revision  of  the  A  tomic  Weight  of  Magnesium^ 


149 


The  possibility  of  obtaining  satisfatSlory  results  by  the 
determination  of  the  chlorine  in  magnesic  chloride  was 
now  considered.  The  great  disadvantage  of  this  method, 
as  is  well  known,  is  the  extreme  difficulty  of  obtaining 
pure  anhydrous  magnesic  chloride.  The  usual  method  of 
igniting  the  double  chloride  of  ammonium  and  magnesium 
was  tried  a  number  of  times,  but  it  was  found  that  a 
quantity  of  the  oxychloride  was  always  formed.  As  indi- 
cators do  not  give  a  sharp  reaction  in  the  presence  of 
magnesic  salts,  the  hydrochloric  acid  driven  off  cannot  be 
added  afterwards  by  titrating  back  to  the  neutral  point 
with  a  weak  acid  solution,  and  it  is  therefore  necessary  to 
obtain  in  the  first  place  magnesic  chloride  containing  its 
full  complement  of  acid. 

The  method  was  then  modified  by  condudling  the 
ignition  of  the  double  salt  in  a  tightly  covered  platinum 
crucible  in  a  stream  of  hydrochloric  acid  instead  of  air. 
That  a  considerable  quantity  of  oxychloride  was  usually 
formed,  even  under  these  conditions,  was  easily  ascer- 
tained by  dissolving  the  resulting  produdt  in  water,  when 
the  oxychloride  remained  as  an  insoluble  residue.  In  two 
or  three  cases,  however,  the  amount  of  oxychloride  formed 
was  comparatively  small ;  hence  it  was  hoped  that,  if  the 
right  conditions  could  be  found,  the  chloride  might  be  ob- 
tained in  a  pure  state.  Another  series  of  experiments 
with  a  modified   apparatus   was   therefore    undertaken. 


result  the  hard  glass  tube  was  ground  with  a  long  tapering 
joint  diredtly  into  the  wider  desiccating  or  cooling  tube 
used  to  contain  the  weighing  bottle.  This  desiccating- 
tube  had  a  sort  of  bulb  or  *'  pocket  "  blown  upon  one  side 
of  it,  to  receive  the  stopper  of  the  weighing-bottle,  thus 
allowing  the  boat  to  be  pushed  past  the  stopper  dire(5ily 
from  the  ignition-tube  into  the  bottle.  Afterwards  the 
stopper  could  be  rolled  into  place  with  a  rod  provided  for 
the  purpose.  The  arrangement  was  used  with  great  suc- 
cess in  a  recent  determination  of  the  atomic  weight  of 
zinc  (Richards  and  Rogers,  Pvoc.  Amer.  Acad.,  xxxi.,  158, 
174),  to  which  it  was  equally  applicable.  A  reference  to 
the  annexed  sketch  (Fig.  i)  will  make  the  apparatus  more 
comprehensible. 

The  desiccating  apparatus  for  the  hydrochloric  acid  gas 
consisted  of  two  towers,  composed  of  a  number  of  glass 
bulbs  filled  with  beads,  upon  which  strong  sulphuric  acid  was 
allowed  to  trickle  from  small  reservoirs  at  the  top  into 
suitable  receptacles  at  the  bottom.  This  apparatus  was 
construfled  wholly  of  glass,  with  glass  gridirons  for 
flexibility,  and  ground  or  sealed  glass  connedtions.  Joints 
were  made  tight  with  syrupy  phosphoric  acid  (Morley). 
The  hydrochloric  acid,  after  being  evolved  by  allowing 
strong  sulphuric  acid  to  run  into  a  flask  containing  a 
strong  solution  of  hydrochloric  acid,  was  passed  through 
a  wash-bottle  containing  sulphuric  acid,  thence  through 


Fig.  I.— Bottling  Apparatus,  Horizontal  Section. 
B,  stopper  of  bottle.    C  C,  hard  glass  tube.    D,  platinum  boat  containing  fused  magnesic  chloride. 


A,  weighing-bottle 

The  expulsion  of  the  ammonic  chloride  was  conduced  in 
a  combustion-tube  and  the  number  of  drying-tubes  was 
increased,  so  that  the  hydrochloric  acid  gas  might  be  as 
free  as  possible  from  water.  The  heat  was  applied  very 
gradually,  in  order  that  the  double  chloride  might  be 
almost  anhydrous  before  the  sublimation  of  the  ammonic 
chloride  began.  This  method  gave  better  results.  It  was 
observed  that  in  two  or  three  experiments,  where  the  con- 
ditions had  been  unusually  favourable,  the  resulting 
chloride  gave  a  clear  solution ;  and  it  seemed  therefore 
probable  that,  if  an  apparatus  could  be  devised  to  deliver 
a  rapid  stream  of  hydrochloric  acid  gas  entirely  free  from 
aqueous  vapour,  the  method  might  be  successful. 

Assuming  that  these  conditions  might  be  fulfilled, 
another  difficulty  remained  to  be  overcome ;  for  everi  if 
the  magnesic  chloride  could  be  obtained  in  the  combustion 
tube  free  from  water  and  oxychloride,  the  problem  still 
remained  to  weigh  the  salt  without  foreign  admixture.  If 
the  boat  were  allowed  to  remain  in  the  tube  until  cool, 
and  then  removed  to  a  weighing-bottle,  the  salt  must  ab- 
sorb a  very  notable  quantity  of  moisture  from  the  air  in 
the  operation,  however  quickly  this  operation  might  be 
performed.  The  boat  cannot  be  transferred  to  another 
tube  and  re-heated,  as  the  moisture  present  readts  upon 
the  chloride,  forming  some  oxychloride  and  liberating 
hydrochloric  acid.  If  it  is  taken  from  the  combustion- 
tube  while  hot  and  allowed  to  cool  in  a  weighing  bottle, 
the  same  effeft  is  produced.  Dumas  had  met  with  the 
same  difficulties  in  his  work  with  this  method,  and  he 
endeavoured  to  compromise  matters  by  removing  the  boat 
from  the  combustion  -  tube  when  it  had  only  partly 
cooled.  As  his  subsequent  results  proved,  however,  the 
moisture  from  the  air  reaped  upon  the  chloride,  forming 
some  oxychloride,  which  interfered  seriously  with  the 
accuracy  of  his  work.  To  obviate  this  difficulty  the  form 
of  apparatus  used  by  one  of  us  (Richards,  Proc.  Amer. 
Acad.,  XXX.,  383)  in  drying  strontic  bromide  was  altered 
80  that  the  boat  could  be  transferred  diredlly  from  the 
ignition-tube  to  the  weighing-bottle  without  an  instant^s 
exposure  to  the  outside  air.    In  order  tc  accomplish  this 


the  towers  just  described,  afterwards  through  a  tube  con- 
taining phosphoric  pentoxide,  and  finally  into  the  com- 
bustion tube.  The  apparatus  was  so  arranged  that  the 
current  of  air  from  an  aspirator  could  be  passed  through 
another  set  of  towers,  a  duplicate  of  those  used  for  drying 
the  acid  gas.  By  means  of  stopcocks  either  dry  hydro- 
chloric acid  gas  or  dry  air  could  be  passed  through  the 
tube  containing  the  weighing  tube  and  boat. 

With  the  help  of  this  contrivance  it  was  found  possible 
to  drive  off  the  ammonic  chloride  in  a  current  of  dry 
hydrochloric  acid,  to  drive  off  the  excess  of  acid  from  the 
fused  magnesic  chloride  by  means  of  a  current  of  perfedly 
dry  air,  and  to  shut  up  the  pure  salt  in  a  weighing-bottle 
without  the  least  possible  means  of  access  of  a  trace  of 
aqueous  vapour.  The  details  of  the  method  will  be 
described  later;  magnesic  chloride  prepared  after  this 
fashion  gives  a  perfe&Iy  clear  solution  in  water.  Since 
this  problem  was  solved,  attention  was  now  turned  to  the 
preparation  of  materials  for  the  atomic  weight  determina- 
tions. 

(To  be  continued). 


Industrial  Transformation  of  Olei'c  Acid  into 
StearolaAone  and  Monooxystearic  Acid. — M.  David. 
— The  author  can  form  at  will  stereoladlone  and  oxystearic 
acid,  or,  if  the  liquid  is  exposed  to  cold,  all  the  oxystearic 
acid  may  be  converted  into  stearoIacSone. — Comptes  Rend., 
cxxiv.,  No.  g. 

Procedure  for  the  Determination  or  Bxtradtion  of 
Gold  from  Auriferous  Ores. — E.  Serrent.— The  author 
introduces  into  the  mass  of  ground  ore,  in  proportions 
calculated  according  to  the  supposed  percentage  of  gold, 
a  mixture  of  sodium  chloride  and  nitrate  with  sulphuric 
acid.  When  the  readtion  is  completed  the  gold  chloride 
is  dissolved  out  by  the  addition  of  water  and  the  gold  is 
precipitated  by  ferrous  sulphate.— Cow^f«  Rend,,  cxxiv., 
No.  9.  ,  .         , 

.tjinoa  liiiw  -Sks— ^ss  Jc 


I    o 


Sodamide. 


I  Crbmical  News, 

I     March  26,  1807. 


PROCEEDINGS    OF    SOCIETIES. 

CHEMICAL  SOCIETY. 
Ordinary  Meeting,  February  iZth,  1897. 

Mr.  A.  G.  Vernom  Harcourt,  Piesident,  in  the  Chair. 

(Concluded  from  p.  140). 

•19.  '^  On  the  Production  of  Pyridine  Derivatives  from 
Ethylic  i3-amido-crotonate.  By  J.  Norman  Collie, 
Ph.D.,  F.R.S. 

Amongst  compounds  from  which  pyridine  derivatives 
can  be  obtained,  ethylic  acetoacetate  stands  out  promi- 
nently. The  author  has  already  called  attention  to  the 
fa(5t  that,  when  ethylic  |3-amido-crotonate  is  distilled, 
various  pyridine  compounds  are  formed.  When  the 
hydrochloride  of  ethylic  j8-amido  crotonate  is  heated  to  a 
temperature  of  about  120°,  it  at  once  condenses  according 
to  the  equation — 

2C6HiiN02HCl  =  CioHi3N03+NH4CI  +  C2H50H  +  HCl. 

This  compound,  C10H13NO3,  is  the  ethylic  ether  of  an 
oxylutidine  ;  it  melts  at  138—139°.  If  in  its  produ(5lion 
the  hydrochloride  of  ethylic  /S-amidocrotonate  be  heated 
with  one  molecular  quantity  of  ethylic  j8-amidocro- 
tonate, — 

C6HixN02HCl  +  C6HiiN02  =  CioHi3N03  +  NH4Cl  + 

+  C2H5OH, 

an  isomeric  ether  is  obtained,  tn.  p.  166 — 1§7°.  The  acids 
obtained  from  these  two  ethers  melt  respedtively  at 
300 — 304°  and  190 — 191°,  and  both  acids  decompose  at 
their  melting-point,  lose  carbon  dioxide,  and  give  pseudo- 
lutidostyril. 

NH  NH 

,'C     CO  COOCaHs'CHaC     CO 


CH3 

II        I 
COGCaHs-C      CH 

\^ 
C 

I 

CH3 
Ether,  m.  p.  139" 
Acid,  m.  p.  300". 
A. 


HC     CH 

V 

I 

CH3 
Ether,  m.  p.  167'*, 
Acid,  tn.  p.  190°. 

B. 


Ether  A,  when  boiled  with  soda,  only  hydrolyses  with 
considerable  difficulty.  It  does  not  reaft  with  acetyl 
chloride,  hydroxylamine,  or  nitrous  acids ;  strong  sul- 
phuric acid  dissolves  it  on  warming,  but  the  substance  is 
precipitated  unchanged  when  the  mixture  is  poured  into 
water.  With  bromine,  a  mono-substituted  derivative  is 
produced,  CloHizNOjBr,  m.  p.  158—159°.  With  phos- 
phorus pentachloiide  a  chloro-lutidins  derivative  results, 
C10H12NO2CI,  which  is  an  oil,  b.-p.  288 — 290".  After 
prolonged  treatment  with  tin  and  hydrochloric  acid,  the 
chlorine  is  removed  and  replaced  by  hydrogen,  and  an 
a  7'-dimethyl-|(3  ethylic  carboxylate  of  pyridine,  b.-p.  246 
—  248°,  is  obtained. 

The  acid  obtained  by  the  hydrolysis  of  ether  A  is  very 
insoluble  in  water,  but  can  best  be  re-crystallised  from 
that  solvent ;  various  attempts  were  made  to  convert  this 
acid  into  the  isomeric  acid  obtained  from  ether  B,  but 
without  result. 

Ether  B,  which  is  isomeric  with  ether  A,  is  hydrolysed 
at  once  when  added  to  soda  solution  and  warmed.  It 
gives  a  compound  wiih  phenylhydrazine,  and  when  boiled 
with  strong  hydrochloric  acid  is  decomposed  ;  it  is  much 
less  stable  than  ether  A. 

With  bromine  it  gives  a  di-substituted  produfl  at  once, 
CioHiiN03Br2.  This  compound,  when  treated  with  soda, 
gives  the  sodium  salt  of  a  dibrcmo-acid,  which  acid  melts 
at  227—228°  with  complete  decomposition.    Eiher  B  gives 


on  hydrolysis  an  acid,  m.  p,  190 — 191°,  which  can  easily 
be  crystallised  from  hot  water  ;  when  melted  it  decom- 
poses quantitatively  into  carbon  dioxide  and  pseudo- 
lutidostyril  in  exadly  the  same  manner  as  the  isomeric 
acid,  m.  p,  300— 304°.     Pseudolutidostyrii, — 

C5H3(CH3)2NO, 

which  is  a  dimethylpyridine  derivative,  was  first  obtained 
by  Hantzsch  {Ber.,  1884,  ''vii.,  2904),  by  the  adtion  of 
heat  on  a  trimethylpyridine  derivative.  It  was  found  on 
heating  pseudolutidostyrii  with  zinc  dust,  that,  although 
some  dimethylpyridine  (lutidine)  was  formed,  the  chief 
produdt  of  the  reaAion  was  a  trimethylpyridine  (col- 
lidine). 

Pseudolutidostyrii,  when  aifled  on  by  phosphorus 
pentachloride,  gives  a-7-dimethyl-a-chloropyridine,  b.-p. 
212 — 214°,  and  this  compound  when  passed  over  heated 
zinc  dust  yields  dimethylpyridine  alone. 

Discussion. 

Dr.  Forster  drew  attention  to  the  apparent  similarity 
between  the  reaftions  of  the  pyridine  derivatives  described 
by  Dr.  Colle  and  certain  of  the  nitrogen  derivatives  of 
camphor  when  Tiemann's  formula  was  employed, 

Dr.  Kipping  was  of  opinion  that  there  was  no  essential 
difference  between  Tiemann's  for  camphor  and  that  pro- 
posed by  Bredt.  He  thought  that  the  possibility  of  the 
occurrence  of  tautomerism  or  stereoisomerism  in  the  com- 
pounds described  by  Dr.  Collie  should  be  kept  in  view. 

Dr.  Collie,  in  reply,  said  he  had  not  gone  completely 
into  the  details  of  the  various  readions  he  had  made  use 
of  in  preparing  these  substances,  and  he  thought  that 
when  the  full  paper  was  read  it  would  be  seen  that  the 
substances  were  aftually  different  in  constitution,  and  not 
merely  tautomeric  or  stereoisomeric. 

•20.  "  Sodamide  and  some  of  its  Substitution  DerivU' 
tives."     By  A.  W.  Titherley,  M.Sc,  Ph.D. 

Sodamide  in  its  readions  with  organic  haloid  compounds 
invariably  gives  rise  to  complex  decompositions  without 
appreciable  replacement  of  the  halogen  by  NHj.  The 
hydrogen  of  the  sodamide,  and  not  the  sodium,  readts, 
giving  hydrochloric  acid,  which  with  the  amide  yields 
ammonia,  whilst  the  group  NaN=  remains  more  or  less 
intaft,  being  found  afterwards  as  sodium  cyanide  and 
sodium  cyanamide.  Charring  invariably  occurs,  even 
when  the  readlion  is  condudled  with  care. 

Sodamide  on  treatment  with  organic  substances 
possessing  a  weak  acid  tendency,  such  as  oximes  and 
hydrazines,  readily  reads,  giving  ammonia  and  sodium 
derivatives.  In  benzene  solution  these  are  obtained 
usually  as  fine  crystalline  precipitates,  which  may  some- 
times be  crystallised  from  boiling  benzene.  Sodium 
acetoxime,  sodium  hydrazobenzene,  sodium  phenyl- 
hydrazine,  and  others,  have  been  thus  obtained. 

A  series  of  substitution  derivatives  of  sodamide  formed 
by  the  replacement  of  one  or  both  hydrogen  atoms  in 
NaNH2  have  also  been  prepared  by  the  interaction  of 
sodamide  with  (i)  Aromatic  amines ;  (2)  Amides,  ac- 
cording to  the  general  equations  : — 

(rt)  NaNH2-fR-NH2  =  NaNH-R-}-NH3; 

(6)  NaNH2+RCONH2  =  NaNH•CO•R-^NH3. 

In  the  former  case  the  readtion  is  condudted  with  the 
substances  in  the  free  state  in  an  atmosphere  of  coal-gas, 
and  in  the  latter  in  benzene  solution. 

Potassium  ethylamide,  KNHC2H5,  is  formed  by  the 
careful  adtion  of  ethylamine  gas  upon  gently  heated 
potassium.  On  heating,  it  readily  decomposes  into 
potassium  cyanide,  charcoal,  and  hydrogen.  Sodium 
phenylamide,  NaNH-CgHs,  sodium  diphenylamide 
NaN(C6H5)2,  sodium  ^-tolylamide,  sodium  /3-naphthyl. 
amide,  &c.,  are  all  very  readily  prepared  by  the  above 
general  readtion.  They  form  white,  greenish-yellow,  or 
brown,  amorphous  solids  with  conchoidal  fradture,  or 
light  yellowish  powders,  which  are  blackened  and  decom- 


Supposed  Condensation  of  Benzyl  with  Uthyl  A  Icohoh 


Chemical  Nbwb,  i 
March  26,  1897.    ) 

posed  quickly  in  the  air,  darkening  especially  when 
moistened  with  benzene. 

When  sodamide  readls  with  organic  amides  (best  in 
boiling  benzene  solution)  ammonia  is  rapidly  evolved,  and 
the  substituted  sodamides  are  obtained  as  fine,  white, 
crystalline  solids,  those  of  larger  molecular  weight  being 
appreciably  soluble  in  benzene. 

Sodium  formamide,  NaNH-CO-H,  sodium  acetamide, 
NaNHC0CH3,  sodium  propionamide,  and  sodium  benz- 
amide  have  been  thus  prepared — the  latter  apparently 
identical  with  the  compound  obtained  by  Curtius  from  the 
aAion  of  sodium  upon  benzamide  by  long-continued 
boiling  in  xylol  solution. 

The  latter  class  of  substituted  sodamides  are  soluble 
without  decomposition  in  alcohol,  and  their  solutions,  on 
treatment  with  alcoholic  silver  nitrate,  throw  down  bright 
orange-red  precipitates  of  the  silver  compounds,  which 
are  very  unstable.  From  the  colour  of  these  silver  de- 
rivatives, and  the  difficulty  with  which  they  and  the 
sodium  compounds  appear  to  rea<5l  with  alkyl  iodides,  &c., 
the  author  concludes  that  the  silver  and  sodium  atoms, 
respedtively,  are  diredliy  attached  to  nitrogen,  and  that 
therefore  the  above  derivatives  are  to  be  represented  as 
possessing  the  ordinary  amide  and  not  the  imido-hydroxy 
formula;  the  amides  themselves  are  most  probably 
tautomeric  substances. 

•21.  "  Rnbidamide."  By  A.  W.  Titherlev,  M.Sc, 
Ph.D. 

Metallic  rubidium  behaves  like  the  other  alkali  metals 
towards  ammonia,  displacing  one  atom  of  hydrogen  and 
forming  rubidamide,  RhNHj.  Though  not  so  energetic 
as  in  the  case  of  lithium,  the  adtion  is  very  rapid  and 
commences  in  the  cold.  On  heating  in  a  silver  boat  to 
between  200 — 300°,  oily  drops  of  the  amide  quickly  form 
and  flow  to  a  liquid  in  which  the  metal  floats  and  partly 
dissolves  to  a  deep  blue  solution,  at  once  decolourised 
and  converted  into  rubidamide  by  the  adlion  of  ammonia. 
Rubidamide  crystallises  in  plates  melting  at  285—287°, 
higher  than  sodamide  and  potassamide,  but  lower  than 
lithamide.  At  400°  it  distils  undecomposed  in  a  current 
of  ammonia.  With  water  it  is  violently  decomposed, 
giving  ammonia  and  rubidium  hydrate.  Alcohol  also 
decomposes  it,  and  its  behaviour  with  organic  substances 
is  very  similar  to  that  of  sodamide  or  potassamide. 

*22.  "  On  the  Spectrographic  Analysis  of  some  Con^mer- 
cial  Samples  of  Metals,  of  Chemical  Preparations,  and  of 
Minerals  from  Stassfurt  Potash  Beds.''  By  W.  N. 
Hartley,  F.R.S.,  and  Hugh  Ramage. 

In  continuation  of  the  work  already  published  {Roy. 
Soc.  Proc,  1896,  Ix.,  393,  and  Proc.,  1897,  "•''•>  i^'' 
samples  were  examined  of  steel  made  at  Middlesbrough 
from  the  blast-furnace  metal  smelted  from  Cleveland  clay 
ironstone,  and  rolled  into  rails;  of  alumina  and  "red 
mud  "  separated  from  bauxite  at  the  British  Aluminium 
Co.'s  Works  at  Larne,  and  of  the  aluminium  prepared 
from  the  alumina  at  Foyers  and  of  various  commercial 
alums. 

It  is  shown  that  of  the  constituents  of  the  blast- 
furnace metal,  the  alkali  metals,  calcium,  copper,  silver, 
gallium,  manganese,  and  lead  are  present  also  in  the 
steel,  but  the  chromium  and  nickel  have  been  removed. 

Of  the  constituents  of  bauxite,  traces  of  sodium, 
potassium,  calcium,  copper,  silver,  gallium,  iron,  man- 
ganese, and  lead  are  found  in  the  metallic  aluminium. 
These  elements  are  also  present  in  larger  quantities  in 
the  "  red  mud,"  and  in  addition  nickel  and  chromium  are 
present. 

The  Alums. — Examined  diredly,  by  healing  0*5  grm.  of 
the  dried  sample  in  the  oxyhydrogen  flame,  sodium, 
potassium,  rubidium,  calcium,  and  thallium  are  found  as 
common  constituents,  and  copper,  gallium,  iron,  and 
nickel  as  occasional  constituents.  More  interesting 
results  were  obtained  by  examining  the  precipitates  pro- 
duced by  potassium  ferrocyanide  in  solutions,  containing 
50  grms.  of  the  alum  strongly  acidified  with  hydrochloric 


151 


acid.  These  precipitates  contained  the  elements  sodium, 
potassium,  rubidium,  caesium,  copper,  silver,  calcium, 
gallium,  thallium,  nickel,  manganese,  besides  iron,  which 
was  also  present  in  the  acid  radical.  The  rubidium, 
caesium,  gallium,  and  thallium  lines  are  strong  in  some 
of  the  spedra,  and  the  results  indicate  that  these  ele- 
ments are  almost  wholly  precipitated  by  this  process.  A 
sample  of  "  aluminoferric "  from  Messrs.  Spence  and 
Sons,  Manchester,  contained  all  the  elements  found  in 
the  alums,  but  in  much  larger  quantities.  Of  these  ele 
ments  the  pyrites  furnishes  the  thallium  and  also  a  trace 
of  indium  found  in  a  by-produ<S  of  the  manufadlure  of 
alum,  whilst  the  other  elements  were  traced  to  the 
aluminous  minerals,  bauxite  and  shale.  The  shale  was 
richer  in  alkalis  and  gallium  than  the  bauxite,  but  a 
sample  of  French  bauxite  was  richer  in  silver  and  lithium 
than  either  Irish  bauxite  or  shale. 

Samples  of  Stassfurt  minerals  were  examined  in  the 
course  of  the  investigation,  and  were  found  to  yield 
spedlra  containing  no  lines  of  rubidium,  caesium,  gallium, 
or  thallium.  These  salts  gave  only  weak  lines  of  a  few 
elements  besides  the  lines  of  the  principal  elements  com- 
posing them. 

It  is  pointed  out  in  the  paper  that  the  elements  found 
by  their  spedlra  adlually  exist  in  the  specimens,  as  there 
is  no  possibility  of  them  being  accidentally  introduced, 
and,  furthermore,  substances  have  been  examined  which 
have  given  no  trace  even  of  such  widely  distributed  ele- 
ments as  potassium  and  calcium,  and  in  which  the  D  lines 
are  very  weak. 

The  systematic  examination  of  railway  metal  by  such 
an  analytical  method  as  is  here  employed  might  lead  to 
results  of  pradlical  importance.  The  method  reveals  the 
presence  of  small  quantities  of  metals  such  as  copper, 
silver,  gallium,  and  lead,  which  have  not  been  con- 
sidered in  dealing  with  commercial  irons,  and  the  influ- 
ences of  which  upon  the  physical  properties  of  these  have 
not  been  studied. 

Discussion. 

Dr.  RiDEAL  suggested  that  the  calcium  present  in 
aluminium  and  its  compounds  might  be  derived  from  the 
vessels  employed  in  the  manufafture  as  well  as  from  the 
bauxite.  He  thought  it  probable  that  calcium  might  be 
present  as  metal  in  commercial  specimens  of  aluminium. 

23.  "Dissociation  Pressure  of  Alkylammonium  Hydro- 
sulphides."  By  James  Walker,  D.Sc,  Ph.D.,  and  John 
S.  LuMSDEN,  B.Sc,  Ph  D. 

The  dissociation  pressures  of  ammonium,  ethylammo* 
nium,  and  dimethylammonium  hydrosulphides  have  been 
determined,  as  well  at  the  dissociation  pressures  of  mix- 
tures of  these  substances  in  pairs.  The  values  obtained 
for  the  mixtures  fell  in  every  case  considerably  below  the 
values  calculated  from  the  dissociation  pressures  of  the 
components  by  the  law  of  mass  adlion.  The  ratios  of 
the  dissociation  pressures  of  these  substances,  whether 
simple  or  mixed,  are  independent  of  the  temperature,  a 
fa(5t  which  proves  their  heats  of  dissociation  to  be  equal. 

24.  "  Supposed  Condensation  of  Benxil  with  Ethyl 
Alcohol.  A  Correction."  By  Francis  Robert  Japp, 
F.R.S, 

The  author  finds  that  the  compound,  described  by  him 
in  a  paper  published  jointly  with  Miss  Owens  {Trans., 
1885,  xlvii.,  go),  as  formed  by  the  condensation  of  benzil 
with  ethyl  alcohol,  is  in  reality  identical  with  Japp  and 
Miller's  anhydracetonedibenzil,  C31H24O4  (m.  p.  194 — 
193°),  and  that  its  formation  was  due  to  the  presence  of 
acetone  in  the  "  methylated  spirit  "  (alcohol  "  denatured  " 
with  10  per  cent  of  crude  wood-spirit),  which  was  used 
instead  of  duty-paid  alcohol,  in  the  preparation  of  the 
compound.  The  formula,  C30H24O4,  ascribed  to  the  con- 
densation compound,  requires  analytical  figures  differing 
only  very  slightly  from  those  required  by  anhydracetone- 
dibenzil. 

At  the  time  the  paper  was  published,  the  authors 
believed  the  compound  to  be  identical  with  Limpricht 


152 


Identity  of  Laurent's  Amarone  with  Tetraphenylazine. 


and  Schwanert's  elhyldibenzoin,  C3oH2604,  which  Jena 
stated  that  he  had  prepared  by  the  adlion  of  alcoholic 
potash  on  benzil — the  reaction  employed  by  the  authors. 
On  the  strength  of  this  belief,  they  proposed  to  alter 
Limpricht  and  Schwanert's.formula  to  C30H24O4,  and  they 
further  cast  doubt  on  the  existence  of  an  acetyl  derivative 
which  these  investigators  had  prepared. 

The  author  regrets  the  publication  of  these  perfeftly 
baseless  criticisms  on  Limpricht  and  Schwanert's  work. 

The  author  is  indebted  to  Prof.  Alexander  Smith  for 
privately  informing  him  that  he  had  not  succeeded  in 
preparing  the  compound  from  benzil  and  alcohol,  and  thus 
calling  his  attention  to  the  matter. 

25.  "The  Viscosity  of  Mixtures  of  Miscible  Liquids." 
By  T.  E.  Thorpe,  F.R.S.,  and  J.  W.  Rodger. 

The  authors  having  measured  the  viscosity  of  a  large 
number  of  liquids,  mostly  carbon  compounds  and  of  very 
different  types,  at  various  temperatures  up  to  the  boiling- 
points  under  a  standard  atmosphere  (Phil.  Trans.,  1894, 
clxxxv.A,  379;  1897.  clxxxix.A),  ^^^e  made  observations 
on  mixtures  of  chemically  indifferent  and  miscible 
liquids,  with  the  view  of  throwing  light  on  the  relation  of 
the  viscosity  of  a  mixture  to  the  viscosity  of  its  consti- 
tuents. A  sufficiently  comprehensive  study  of  this 
question  would  afford  answers  to  many  questions  of  in- 
terest. Thus  it  would  settle  whether  viscosity  was 
related  to  the  number  of  molecules  per  unit  volume  or 
per  unit  surface,  and  would  indicate,  therefore,  how  vis- 
cosity observations — and  indeed  all  observations  which 
depend  upon  surface  effedls — should  be  treated.  It  would 
also  indicate  whether,  in  the  case  of  a  mixture  of  a  simple 
and  a  complex  liquid,  the  values  of  viscosity  gave  any 
indication  of  the  decomposition  of  molecular  aggregates, 
and  how  such  decomposition  was  related  to  dilution  and 
temperature. 

On  the  present  occasion  the  authors  communicate  the 
results  of  a  series  of  measurements  made  at  different 
temperatures  on  mixtures  of  carbon  tetrachloride  and 
benzene,  methyl  iodide  and  carbon  disulphide,  and  ether 
and  chloroform,  the  last  pair  of  which  they  studied  on 
account  of  the  relatively  considerable  evolution  of  heat 
which  accompanies  their  admixture.  The  methods  of 
observation  and  of  reduction  were  the  same  as  those  pre- 
viously employed,  and  the  apparatus  was  identical  with 
that  already  described  {loc.  cit,). 

In  no  case  could  the  density  of  the  mixture  be  calcu- 
lated by  the  ordinary  admixture  rule.  Carbon  tetrachloride 
and  benzene  contradl  on  mixing,  as  already  found  by  F. 
D.  Brown  {Trans.,  1881,  xxxix.,  207),  whereas  methyl 
iodide  and  carbon  disulphide  expand.  Ether  and  chloro- 
form contradl  considerably. 

As  regards  viscosity,  the  observations  afford  additional 
evidence  of  the  fa(Sl  indicated  by  Wijkander  and  sup- 
ported by  Linebarger,  that  the  viscosity  of  a  mixture  of 
miscible  and  chemically  indifferent  liquids  is  rarely,  if 
ever,  under  all  conditions,  a  linear  fundtion  of  the  compo- 
sition. It  seldom  happens  that  a  liquid  in  a  mixture 
preserves  the  particular  viscosity  it  possesses  in  the  un- 
mixed condition.  To  judge  from  the  instances  hitherto 
studied,  the  viscosity  of  the  mixture  is,  as  a  rule,  uni- 
formly lower  than  the  value  calculated  on  the  assumption 
that  each  constituent  exercises  an  influence  proportional 
to  its  amount,  although  many  examples  are  known  to  the 
contrary.  No  simple  relation  can  as  yet  be  traced  be- 
tween the  viscosity  of  a  mixture  and  that  of  its  con- 
stituents. 

In  the  case  of  a  mixture  of  ether  and  chloroform,  the 
viscosity  at  low  temperatures  is  greater  than  the  admixture 
rule  would  indicate;  but  as  the  temperature  is  raised,  or 
as  the  mixture  giving  the  maximum  contraction  is  diluted, 
the  viscosity  eventually  becomes  less  than  the  calculated 
value,  when  the  general  course  of  the  curve  showing  the 
relation  of  viscosity  to  composition  resembles  that  of  such 
mixtures  as  carbon  tetrachloride  and  benzene,  or  of 
methyl  iodide  and  carbon  disulphide.   The  phenomena  in 


I  Chbuical  Nbws, 
I   March  26, 1897. 


the  case  of  a  mixture  of  ether  and  chloroform  would  seem, 
to  begin  with,  to  be  analogous  to  those  of  a  mixture  of 
ethyl  alcohol  and  water,  but  the  condition  which  deter- 
mines  the  contradion  and  the  maximum  viscosity,  whether 
it  be  a  feeble  chemical  combination  or  a  molecular  aggre- 
gation of  a  purely  physical  charafter,  is  destroyed  by  heat 
or  dilution. 

26.  "  Magnesium  Nitride  as  a  Reagent."  By  H.  Lloyd 
Snaps,  D.Sc,  Ph.D. 

The  objedt  of  the  experiments  detailed  in  this  paper 
was  to  investigate  whether  magnesium  nitride  could  be 
utilised  to  introduce  nitrogen  in  the  place  of  oxygen, 
chlorine,  and  other  negative  elements  which  combine 
with  magnesium.  The  author  investigated  the  behaviour 
of  magnesium  nitride  towards  chloroform,  carbon  tri- 
chloride, and  benzaldehyde  respeftively,  in  the  hope  that 
the  reaaions  represented  by  the  following  equations 
would  occur: — 

(1)  2CHCl3-HVlg3N2  =  3MgCl2  +  2HCN; 

(2)  C2Cl6+Mg3N2  =  3MgCl2  +  C2N2; 

(3)  3C6H5-COH  +  Mg3N2  =  3MgO  +  (C6H5-CH)3N2. 
The  substancer  to  be  treated  with   magnesium  nitride 
were  sometimes  passed  in  the  form  of  vapour  over  the 
latter  compound,  and  sometimes  direftly  mixed  with  it, 
the  mixture  being  heated  in  a  sealed  tube. 

In  no  case  was  the  desired  nitrogenous  compound  ob- 
tained. The  chloroform  was  not  attacked  at  temperatures 
at  which  hydrocyanic  acid  could  exist  without  decompo- 
sition, but  at  higher  temperatures  an  energetic  readlion 
took  place,  and  the  observed  results  were  consonant 
with  the  reaiftion — 

2CHCl3-hMg3N2  =  3MgCl3-fCa+Na-fHa. 
Carbon  trichloride  and  benzaldehyde  were  likewise  un- 
affefted  at  temperatures  below  those  at  which  the  antici- 
pated produ(5ts  could  be  formed.  On  heating  with 
benzaldehyde  to  about  240°,  a  crystalline  produdt,  identical 
with  that  described  by  Laurent  as  amarone,  was  obtained. 
Both  were  subsequently  discovered  to  be  identical  with 
the  substance  named  tetraphenylazine  by  Japp  and 
Burton.     (See  also  the  following  paper). 

27.  "  The  Identity  of  Laurent's  Amarone  with  Tetra- 
phenylazine." By  H.  Lloyd  Snape,  D.Sc,  Ph.D.,  and 
Arthur  Brooke,  Ph.D. 

Amarone  being  required  to  compare  with  the  substance 
obtained,  as  described  in  the  preceding  paper,  by  the 
adion  of  magnesium  nitride  upon  benzaldehyde,  the 
authors  repeated  Laurent's  experiments. 

It  was  necessary,  in  the  first  instance,  to  prepare 
benzoylazotide.  This,  it  was  found,  could  be  more 
readily  prepared  than  by  the  methods  previously  given, 
by  the  acflion  of  ammonium  cyanide  upon  benzaldehyde. 
Laurent  had  stated  that  benzhydramide  was  produced  by 
the  long-continued  adiion  of  ammonium  cyanide  upon 
benzaldehyde,  but  this  was  probably  due  to  his  having 
employed  an  excess  of  the  former  reagent.  The  formula 
given  by  Laurent  to  benzhydramide  would  accord  with  its 
formation  by  treating  benzoylazotide  with  benzaldehyde, 
CeHjCO-H-f  Ci5Hi2N2  =  C22Hi8N30.  The  authors  pro- 
pose to  try  whether  such  areadion  can  actually  be  carried 
out.  The  vapours  of  ammonium  cyanide  were  conducted 
into  a  mixture  of  benzaldehyde  and  alcohol.  Crude 
benzoylazotide  slowly  separated  out,  and  was  washed  with 
alcohol  and  re-crystallised  from  benzene.  The  crystals 
softened  at  198°,  and  completely  melted,  with  attendant 
decomposition,  at  202°.  They  were  readily  soluble  in 
benzene  and  chloroform  ;  difficultly  soluble  in  alcohol  and 
carbon  disulphide,  scarcely  at  all  soluble  in  ether,  and  in- 
soluble in  water.  An  estimation  of  nitrogen  established 
their  identity  with  the  benzoylazotide  previously  obtained 
by  other  methods. 

To  prepare  amarone,  benzoylazotide  was  next  subjefled 
to  dry  distillation  under  a  pressure  of  21  m.m.  The  resi- 
due left,  after  hydrocyanic  acid  and  other  comparatively 


wHCMICAL  NBWS,  I 

March  26,  1897.    I 


Apiin  and  Apigenin* 


153 


volatile  vapours  had  been  removed,  was  crystallised  from 
alcohol  containing  a  small  quantity  of  hydrochloric  acid, 
and  washed  with  some  more  of  the  same  solution  to  ex- 
tract any  residual  lophine.  The  crystals  which  were  left 
melted  at  243  to  244°,  dissolved  in  concentrated  sulphuric 
acid  giving  the  charadleristic  red  solution,  and  behaved 
towards  other  solvents  precisely  in  the  same  manner  as 
the  crystalline  substance  previously  prepared  from  mag- 
nesium nitride  and  benzaldehyde. 

By  analysis  it  was  found  that  the  empirical  formula  of 
amarone  was  C14H10N,  not  CisHuN,  as  had  been 
stated  by  Laurent.  The  amarone  which  he  obtained  was 
evidently  not  pure,  its  melting-point  being  only  233°,  or 
about  10°  lower  than  that  of  the  purified  material. 

Moreover,  a  comparison  of  the  properties  of  pure  ama- 
rone showed  it  to  be  identical  with  the  substance  named 
by  Japp  and  Burton  tetraphenylazine,  C28H20N2.  The 
authors  were  kindly  supplied  by  Professor  Japp  with  some 
of  the  latter  compound,  prepared  by  him  from  benzoin, 
for  the  purpose  of  instituting  this  comparison.  It  was 
thus  established  that  amarone,  as  described  by  Laurent, 
was  adually  tetraphenylazine. 

It  seems  probable  to  the  authors  that  the  substance  ob- 
tained by  Curtius  and  Blumer  having  the  same  empirical 
formula,  Ci4HioN,  to  which  they  have  not  assigned  a 
strudural  formula,  will  likewise  prove  to  be  tetraphenyl- 
azine. The  properties  of  this  compound,  so  far  as  they 
have  been  described,  agree  with  this  supposition. 

28.  "  Studies  on  the  Interaction  of  Highly-purified 
Gases  in  presence  of  Catalytic  Agents."  Part  I.  By  Wm. 
French,  M.A. 

In  absence  of  light,  spongy  platinum  does  not  appear 
to  bring  about  combination  between  oxygen  and  hydrogen 
if  they  have  been  previously  carefully  dried  ;  and,  so  far, 
experiments  seem  to  show  that,  after  the  gases  have  been 
in  conta(£t  with  the  platinum,  added  moisture  does  not 
cause  an  explosion. 

29.  "  Contributions  to  the  Knowledge  of  the  ^-Kttonic 
Acids."     Part  III.     By  S.  Ruhemann,  Ph.D.,  M.A. 

The  author  arrives  at  the  conclusion,  from  the  further 
study  of  the  adtion  of  ethylic  chlorofumarate  and  ethylic 
a-chlorocrotonate  on  ethereal  salts  of  jB-ketonic  acids, 
that  the  substances  described  before  {,Trans.,  i8g6,  Ixix., 
530,  1383)  are  to  be  regarded  as  ketone-compounds,  and 
he  gives  the  corrections  necessitated  by  the  change  of 
view  concerning  the  constitution  of  the  various  products 
there  recorded.  He  further  shows  that  the  substance 
formed  from  ethylic  chlorofumarate  and  ethylic  aceto- 
methylacetate  is  to  be  looked  upon  as  ethylic  aceto- 
allylenedicarboxylate, — 

CH3'COC(COOC2H5):C:CHCOOC2H5. 

Aniline  adts  on  this  ethereal  salt  with  formation  of  an 
anile-compound  which  crystallises  in  yellow  plates  (m.p. 
180°). 

Ethylic  benzoylacetate  and  ethylicacetonedicarboxylate 
form,  with  ethylic  o-chlorocrotonate,  compounds  which 
are  to  be  represented  by  the  formulae — 

C6H5-C(OH):CCOOC2H5 

CHa-CHiC-COOCzHs 
Ethylic  benzoylbutylenedicarboxylate. 

COOCaH5CH2-CO'CH-COOC2H5 

CHs'CHiCOOCaHs 
Ethylic  malonylbutylenetricarboxylate. 

The  latter  substance,  under  the  influence  of  ammonia, 
yields  two  isomeric  diamides  of  the  ethereal  salt,  having 
the  formula  CHH16N2O5,  besides  a  diamide  of  the  cor- 
responding acid. 

30.  "  Contributions  to  the  Knowledge  of  the  fi-Ketonic 
Acids."  Part  IV.  By  S.  Ruhemann,  Ph.D.,  M. A.,  and 
A.  S.  Hemmy,  B.A.,  M.Sc. 


and — 


Ethylic  acetosuccinate  was  found  to  give  a  colour  re- 
adlion  with  ferric  chloride,  in  opposition  to  the  statement 
of  Conrad  {Annalen,  1877,  clxxxviii,,  218).  The  authors 
give  an  account  of  various  substances  formed  from  this 
ethereal  salt  under  the  influence  of  ammonia  and  of 
phenylhydrazine.  In  the  latter  case,  ethylic  methyl- 
phenylpyrazolone  acetate  is  formed,  which,  on  hydrolysis, 
yields  the  corresponding  acid.  The  bromo-derivaiive  of 
ethylic  acetosuccinate  was  prepared,  and  on  distillation 
in  a  vacuum  gave  ethylic  carbotetrinate  (cf.  Moscheles 
and  Cornelius,  Ber.,  1888,  xxi.,  2603). 

Ethylic  benzoylsuccinate,  obtained  according  to 
Perkin's  diredions  {Trans.,  1885,  xlvii.,  272)  was  found  to 
distil  without  decomposition  at  192 — 193°  at  10  m.m., 
and  to  be  decomposed  by  ammonia  with  formation  of 
succinamide. 

31.  "Oxidation  of  Phenylstyrenyloxytriazole."  By 
George  Young,  Ph.D. 

The  oxidation  by  alkaline  potassium  permanganate  of 
phenylstyrenyloxytriazole, — 

C6H5.CH :  CH(C6H5)-C2N30H, 

yields  phenyloxytriazole  carboxylic  acid — 

CeHs-CjNsCOHjCOaH. 

This  acid,  immediately  on  liberation,  loses  carbon  dt« 
oxide  and  forms  phenyloxytriazole, — 

CeHs-N-N^^ 

I        >COH. 
HC:N/ 

The  following  derivatives  of  the  carboxylic  acid  have 
been  prepared  :  —  Ethylic  phenylethoxytriazole  car- 
boxylate,  Ph-C2N3(OEt)C02Et,  white  needles,  m.  p.  82— 
83°.  Amide,  CeHj-CaNsCOCaHsJCONHa,  white  needles 
m.  p.  149—150°.     Silver  salt, — 

C6H5-C2N3(OC2H5)C02Ag-f-2H20. 
Phenylethoxytriazole  carboxylic  acid,  when  liberated, 
loses  carbon  dioxide  and  forms  phenylethoxytriazole, 
C6H5C2N3H-OC2H5,  needles,  m.  p.  60°.  This  compound 
has  also  been  formed  by  the  acftion  of  ethyl  iodide  on  the 
silver  derivative  of  phenyloxytriazole. 

32.  "  Apiin  and  Apigenin."  (Preliminary  notice).  By 
A.  G.  Perkin. 

Apiin,  a  constituent  of  parsley  (Apium  petroselinum), 
was  first  isolated  by  Braconnot  {Ann.,  1843,  xlviii.,  349), 
and  subsequently  examined  by  Planta  and  Wallace  {Ann., 
1850,  Ixxiv.,  262),  who  found  it  consisted  of  a  glucoside, 
Gerichten  {Ber.,  1876,  ix.,  1124,  in  a  more  detailed  inves- 
tigation, assigned  it  the  formula  C27H320i6,  and  consi- 
dered its  decomposition  by  dilute  acids  to  be  most 
probably  represented  by  the  equation — 

C27H320,6  +  H20  =  Ci5H,o05-|-2C6H,206, 
which  is  based  upon  the  yield  of  apigenin  thus  obtained. 
He  described  no  derivatives  of  apigenin,  but  states  that 
by  the  adlion  of  alkali  there  is  produced  phloroglucol  and 
ail  acid,  which  by  prolonged  treatment  is  decomposed 
with  formation  of  protocatechuic  acid,  ^-hydroxybenzoic 
acid,  formic  and  oxalic  acids. 

Having  suspedted,  from  a  description  of  its  properties, 
that  apigenin  was  a  yellow  colouring-matter,  and  this 
having  been  proved  to  be  the  case,  the  present  investiga- 
tion was  instituted.  It  is  wished  to  reserve  the  further 
study  of  the  readtions  of  this  interesting  substance. 

The  glucoside  apiin  is  somewhat  difficult  to  fully  de- 
compose by  dilute  acids,  the  apigenin  produced  after 
three  hours'  digestion  with  hydrochloric  acid  of  sp.  gr. 
1-04  yieldingC  =  64-3;  H=3-9o;  after  ten  hours,  C  =  65'8i, 
6574;  H  =  3-45,  4'oi ;  and  only  when  so  treated  for 
twenty-five  hours  are  numbers  obtained  indicating  the 
formula  C15H10O5,  evidently  the  corredl  one.  Calc, 
C  =  6666;  H  =  37o;  Found,  C  =  66-34,  66-37;  H^s'Sy, 
3-81.  Apigenin  contains  no  methoxy  groups,  and  does 
not  combine  with  mineral  acids ;  it,   however,  forms  a 


t54 


The  Chemical  Society  Election. 


f  CtlBMICAL  NBWS, 
\     March  26.  1807.1 


Bulphonic  acid  not  yet  thoroughly  examined.  Dibrom- 
apigenin  crystallises  in  almost  colourless  needles,  melting 
above  290°.  CisHsOjBra  requires  0  =  42*05;  H  =  i-87; 
Found,  6  =  4209;  H  =  2'23;  and  a  tribenzoyl  compound, 
Ci5H705(C7H50)3,  needles,  m,  p.  210— 212°,  has  also  been 
obtained.  Calc,  0  =  74-23  ;  H  =378.  Found,  0  =  7441; 
H=4"i7.  Apigenin  reads  with  diazobenzene,  forming 
Ci5H805(C6H5N2)2.  orange-red  needles,  m.  p.  290 — 292°. 
Calc,  0  =  6778;  H  =  374  ;  N  =  ii  71.  Found,  0  =  67-22; 
H  =  3-75;  N  =  ii-54,  11-56;  which  yields  a  monacetyl 
derivative  0i5H7O5(02H3O)(C6H5N2)2  ;  orange-red  leaf- 
lets, m.  p.  259— 260°.    Oalc,  0  =  6692;  H  =  3  84.    Found, 

0  =  6666;  H  =  4"05.  Experiments  on  the  further  acetyl- 
isation  of  this  substance  are  in  progress.  By  treatment 
with  strong  alkali  there  is  obtained  from  apigenin,  phloro- 
glucol,  an  acid,  m.  p.  208—209%  probably  /"-hydroxy- 
benzoic  acid,  a  trace  of  acetic  acid,  and  a  substance 
crystallising  in  colourless  needles,  m.  p.  107°,  which  bears 
some  resemblance  to  ^-hydroxyacetophenone.  Fuming 
nitric  acid  decomposes  apigenin,  the  principal  produdt 
being  an  acid  ;  yellow  needles ;  m.  p.  244 — 245"^.  The 
dyeing  properties  of  apigenin  will  be  described  in  the  full 
communication.  The  investigation  of  these  substances 
will  be  continued,  and  the  study  of  the  ethylation  and 
methylation  of  apigenin  is  also  in  progress. 

33.  "  Note  on  the  Constitution  of  the  so-called  '  Nitrogen 
Iodide.' "    By  J.  W.  Mallet,  F.R.S. 

Mr.  Ohattaway  concludes  his  paper  by  saying  that  "  at 
present  the  formula  NH3I2  seems  best  to  accord  with  the 
readions  of  the  compound  as  a  whole,  and  best  to  group 
all  the  known  fads  regarding  it."  Reference  to  a  short 
paper  by  my  sometime  student,  Mr.  W.  H.  Seamon,  pub- 
lished in  the  Ohemical  News,  1881,  xliv.,  188,  will  show 
that  a  very  different  substance — liquid,  and  non-explosive 
— gives  results  on  analysis  agreeing  well  with  this  formula. 
It  was  obtained  by  the  action  of  dry  gaseous  ammonia  on 
solid  iodine,  and  appears  to  be  identical  with  the  substance 
prepared  in  a  different  way  by  Guthrie,  of  which  brief 
mention  is  made  by  Mr.  Ohattaway  in  a  footnote. 

I  cannot  agree  with  him  that  in  the  explosive  compound 
the  ratio  of  N  :  I  is  always  i :  2.  Some  analytical  results 
of  my  own  (published  in  the  paper  on  this  subjed  in  the 
American  Chemical  journal,  1879,  i.,  4)  were  quite  incom- 
patible with  this  ratio,  and  agreed  nearly  with  the  ratio 

1  '.3.  In  view  of  the  fad  that  the  preparation  which  gave 
these  results  had  been  freely  washed  with  alcohol  and 
afterwards  with  ether,  I  cannot  think  it  probable  that  any 
considerable  formation  and  retention  of  iodoform  raised 
the  proportion  of  iodine. 

In  any  discussion  of  the  composition  of  the  explosive 
substance  in  question,  some  attention  ought  surely  to  be 
given  to  the  probable  analogy  with  nitrogen  trichloride, 
for  which  Gattermann  seems  to  have  fairly  well  established 
the  formula. 


NOTICES  OF  BOOKS. 


Our  Secret  Friends  and  Foes.  By  Percy  Faraday 
Frankland,  Ph.D.,  B.Sc,  F.R.S.,  F.C.S.,  &c..  Pro- 
fessor of  Ohemistry  in  Mason  OoUege,  Birmingham. 
Third  Edition,  Revised  and  Enlarged.  London  and 
Brighton  :  Society  for  Promoting  Ohristian  Knowledge. 
New  York :  E.  and  J.  B.  Young  and  Oo.  1897.  Post 
8vo.     Pp.  238. 

The  study  and  application  of  baderiology  during  the 
past  few  years  has  made  such  rapid  strides,  in  so  many 
diredions,  that  we  are  always  glad  to  see  new  and  en- 
larged editions  of  such  well-known  works  as  those  given 
to  us  by  Prof.  Percy  Frankland. 

This  latest  addition  to  baderiological  literature  sets 
orth  in  a  clear,  and  not  too  technical  manner,  the  funda- 
mental ideas  which  govern  the  study  of  the  science.    The 


early  chapters  deal  with  the  micro-organisms  in  air  and 
in  water.  Chapters  IV.  and  V.  are  devoted  respedively 
to  useful  and  malignant  micro-organisms,  and  it  is 
important  for  it  to  be  as  widely  known  as  possible  that 
many  microbes  are  absolutely  essential  to  our  existence. 
There  is  a  widely-spread  belief  among  the  general  public 
that  all  microbes  are  harmful ;  and  great  expense,  and  a 
good  deal  of  trouble,  is  incurred  in  reducing  the  number 
of  baderia  in  water  used  not  only  for  drinking  pur- 
poses, but  even  for  watering  roads,  putting  out  fires, 
&c.  It  should  be  borne  in  mind  that  many  of  these 
microbes  ad  in  a  certain  sense  as  policemen  ;  the  microbes 
of  anthrax,  typhoid,  and  such  like,  cannot  live  in  water 
"  contaminated  "  with  a  certain  number  of  harmless  mi- 
crobes. What  risk  then  is  run,  if  perchance  a  few  of 
these  malignant  organisms  find  their  way  into  an  almost 
sterile  water-supply  where  there  are  not  enough  "  police" 
microbes  to  hold  them  in  check! 

The  new  chapter,  number  VIII.,  is  one  of  great  interest 
and  importance,  entitled  *'  Recent  Applications  of  Baderi- 
ology," several  recent  discoveries  of  prevention  and  cure  of 
disease,  snake-bite  poisoning,  &c.,  being  herein  described. 
Is  it  necessary  to  add  that,  owing  to  the  adion  of  our 
legislators,  most  of  this  excellent  and  valuable  work  is 
being  done  abroad  ? 

Some  curious  results  of  experiments  on  the  "  manuring  " 
of  land  by  appropriate  microbes  are  described,  and  an 
excellent  cut  is  added  showing  the  difference  between 
two  similarvetches,  Vicia  villosa,  one  inoculated  with  pure 
cuhivations  of  Pisum  sativum,  nodulebaderia,  and  the 
other  uninoculated  ;  the  difference  is  very  striking. 

At  the  end  of  the  book  is  a  table  giving  the  number  of 
microbes  per  c.c.  in  London  waters  during  the  years  1886, 
1887,  and  1888,  wherein  we  see  that,  so  short  a  time 
ago  as  ten  years,  the  colonies  were  counted  by  hundreds, 
and  even  thousands,  whereas  the  average  number  during 
last  year,  1896,  was  twenty-five. 


CORRESPONDENCE. 


THE    CHEMICAL    SOCIETY    ELECTION. 

To  the  Editor  of  the  Chemical  News. 
Sir, — In  view  of  the  insidious  attempt  that  is  being  made 
to  reverse  the  recommendations  of  the  Council  —  an 
attempt  absolutely  without  precedent  in  the  annals  of 
the  Society — I  would  ask  you  to  allow  me  to  bring  under 
the  notice  of  the  Fellows  generally  what  I  believe  to  be 
the  true  situation. 

Although  at  the  outset  it  was  an  attack  on  the  distin* 
guished  gentleman  who  has  been  nominated  President  by 
the  unanimous  vote  of  a  very  large  and  entirely  repre- 
sentative Council,  I  am  satisfied  that  the  rancorous  oppo- 
sition of  his  fellow  countrymen  is  now  put  quite  in  the 
background,  and  that  the  majority  of  those  whose  names 
have  been  given  in  as  nominating  another  have  been  led 
to  promise  their  votes  from  an  entirely  different  point  of 
view,  and  not  with  any  personal  motives. 

Mr.  Muir  and  his  immediate  following  are  no  doubt 
determined  haters  :  those  who  took  the  trouble  to  read  the 
letters  which  disfigured  the  columns  of  Nature  some 
couple  of  years  ago  will  be  aware  of  the  virulently 
personal,  most  ill-advised,  and  entirely  unprofessional 
attacks  which  were  made  on  Prof.  Dewar,  and  will  be 
able  to  rate  the  opposition  of  such  men  at  its  true  value. 

Some,  no  doubt,  have  been  influenced  by  the  sugges- 
tion that  the  work  done  within  recent  times  by  Prof. 
Ramsay  entitles  him  to  the  preference,  and  have  joined 
the  movement  out  of  sheer  good  nature.  To  these  it  may 
be  pointed  out  that,  although  of  a  less  sensational 
1  charader,  the  work  done  by  Prof.  Dewar  on  the  physical 
'  properties  of  metals  and  other  substances  at  very  low 


CHRMtCAL  NSWS,  I 

March  26,  1897.  I 


Chemical  Notices  from  Foreign  Sources, 


155 


temperatures  is  of  altogether  extraordinary  importance 
and  value  in  the  eyes  of  those  who  can  appreciate  it,  and 
not  inferior  in  interest  to  any  work  accomplished  during 
the  past  few  years.  Moreover,  it  has  not  been  initiated 
by  any  casual  observation,  but  is  the  final  outcome  of 
preparations  made  with  unwearied  perseverance  and 
most  remarkable  skill  during  a  long  series  of  years,  and 
of  work  carried  out  with  great  courage  and  at  most  serious 
personal  risk. 

When  I  ask  those  about  me  what  motives  have  in- 
spired their  conduct,  no  two  give  the  same  or  a  straight- 
forward answer.  But  as  I  extend  my  inquiries,  I  5nd  that 
wrongheadedness  and  narrowness,  combined  with  a  cer- 
tain amount  of  personal  vanity,  are  really  at  root  the 
cause  of  the  movement. 

Dr.  Collie,  Dr.  Kipping  and  their  friends  are,  in  fa6t,  of 
opinion  that  undue  preference  has  been  shown  to  senior 
members  of  the  Society.  How  the  juniors  have  suffered  at 
the  expense  of  the  seniors  I  am  totally  unable  to  discover — 
the  more  so  when  I  find  that  during  the  past  ten  years  the 
Society  has  borne  the  expense  of  publishing  papers  by  Dr. 
Kipping,  for  example,  covering  some  500  pages  of  the 
Society's  Transactions.  A  gentleman  who  has  received 
such  treatment  at  the  hands  of  the  Publishing  Committee 
and  the  Council  can  scarcely  have  any  grievous  cause  of 
complaint  against  his  seniors — but  if  he  have,  let  him 
state  it  fairly  and  openly, 

I  assert,  on  the  basis  of  considerably  over  twenty 
years'  experience,  that  no  Council  has  been  more  loyal  or 
careful  of  the  interests  of  all  se(5tions  of  the  Society  ; 
each  year  the  new  members  have  been  seledted  on  the 
ground  of  service  rendered  to  Chemical  Science  and  for 
no  other  reason,  and  men  such  as  Collie  and  Kipping 
have  been  given  a  voice  in  the  management  at  the  earliest 
possible  opportunity. 

One  of  my  late  students,  whose  name  figures  on  the 
list  of  objedlors,  to  whom  I  wrote  asking  his  reasons, 
replies  as  follows : — 

"  I  allowed  my  name  to  be  added  to  the  list  of 
Ramsay's  nominators  on  the  ground  that  this  is  the  only 
means  the  rank  and  file  of  the  Society  have  of  influencing 
the  ele(5tion  of  OfGcers,  and  as  a  protest  against  the 
present  mode  of  election.  The  present  system  amounts 
to  the  Council  eledting  President  and  also  eleding  itself. 

•'  I  imagine  that  the  fad  that  Dewar  is  unpopular  has 
been  seized  as  the  means  of  making  the  protest." 

It  is  clearly  a  case  in  which,  as  the  poet  has  well  put 
it:— 

"  The  dog  to  serve  some  private  ends 
Went  mad  and  bit  the  man." 

But  surely,  Sir,  Englishmen  have  a  reputation  for  fairne^^s. 
It  would  be  outrageous  to  attempt  to  damage  the  public 
reputation  of  a  man  who  is  deemed  good  enough  by  the 
managers  of  the  Royal  Institution  to  occupy  the  post  of 
Resident  Manager, — a  post  once  held  by  Faraday, — and 
with  whom  Lord  Rayleigh  is  prepared  to  work  as  a 
colleague  in  condudling  the  Davy-Faraday  laboratory. 
Young  gentlemen  like  Dr.  Lapworth,  but  six  months  ago 
a  student  in  my  laboratory,  Mr.  Marshall,  Mr.  Mills,  Mr. 
Evans, — all  recently  students  under  me, — my  junior  De- 
monstrator Mr.  Pope,  Mr.  Ling,  and  many  others  on  the 
list  personally  known  to  me,  can  neither  know  anything 
against  Professor  Dewar  nor  have  any  grievance  against 
the  Society  which  justifies  them  in  their  adlion,  and 
straightlaced  representatives  of  the  analytical  profession 
like  Mr.  Cassal  must  have  other  motives  than  mere  per- 
sonal ones  for  joining  in  such  a  crusade. 

Dr.  Collie  is  reported  to  have  stated  at  the  last  meeting 
of  the  Society  that  the  nomination  of  Prof.  Ramsay  had 
been  made  without  his  knowledge  or  permission.  I  ven- 
ture to  challenge  the  accuracy  of  this  statement;  if  I  am 
not  altogether  misinformed,  Prof.  Ramsay  has  known 
what  is  going  on  from  the  beginning,  and  is  pledged  to 
"  reform  "  the  Society,  I  believe,  by  abolishing  the  "  old 
buffers"  and  ensconcing  the  young  radicals  in  theirplaces. 

I  will  yield  to  no  one  in  the  desire  in  every  way  to  pro- 


mote the  interests  of  the  Chemical  Society  as  representa- 
tive of  the  interests  of  chemical  science  in  this  country. 
We  have  accomplished  much  during  the  past  twenty  years, 
and  may  do  much  more  in  the  future  ;  but  it  behoves  us 
to  work  together  fairly  and  honestly  if  we  are  to  continue 
to  exert  an  influence  for  good.  I  trust,  therefore,  that  all 
right-minded  Fellows  of  the  Society  will  unite  in  resisting 
the  ill-considered  attempt  that  is  being  made  both  to  preju- 
dice the  position  of  a  man  who  has  the  interests  of  the 
Society  most  warmly  at  heart,  and  to  introduce  changes 
which,  whether  desirable  or  not,  have  not  been  for  one 
moment  previously  brought  under  our  notice. — I  am,  &c., 

Henry  E.  Armstronc. 


CHEMICAL     NOTICES    FROM    FOREIGN 
SOURCES. 

Comptes  Rendus  Hebdomadaires  des  Seances,  deVAcademit 
des  Sciences.     Vol.  cxxiv.,  No.  g,  March  g,  1897. 

Researches  on  the  Uranic  Rays. — Henri  Becquerel. 
— Will  be  inserted  in  full. 

Discharge  of  the  Rontgen  Rays :  Part  Played  by 
the  Surfaces  Struck. — Jean  Perrin.— Already  inserted. 

Existence  of  Anodic  Rays  Analogous  to  the 
Kathodic  Rays  of  L6aard  and  Crookes. — P.  de  Haen. 
— This  paper  requires  the  accompanying  diagram. 

Determination  of  Atmospheric  Ozone  on  Mont 
Blanc. — Maurice  de  Thierry. — Will  be  inserted  in  full. 

A(5tion  of  Dilute  Nitric  Acid  upon  Nitrates  in 
Presence  of  Ether. — M.  Tanret. — Already  inserted. 

A(5tion  of  Aluminium  Chloride  upon  Camphoric 
Acid.— G.  Blanc. — Will  be  inserted  in  full. 

MEETINGS    FOR    ThITwEEK.  ^ 

MoNDAT,  agth.— Society  of  Arts,  4.30.   (Cantor  Leftures).   "Alloys," 

by  Prof.  W.  Chandler  Roberts-Austen,  F.R.S. 
Tuesday,  30th.— Royal  Institution,  3.     "  Animal   Eledtricity,"  by 
Prof.  A.  D.  Waller,  F.R.S. 

Society  of  Arts,  8.       *'  Lead- Work,"  by  W.   R. 

Lethaby. 
Wednbsdav,  31st.— Society  of  Arts,  8.     "Cycling— Historical  and 
Praftical,"  by  George  Lacy  Hiliier. 

Chemical,  3.    (Annual  General  Meeting).    Ballot 

for  Eledlion  of  OfiBcers  and  Council.    At  7  p.m., 
Anniversary  Dinner  at  the  Criterion  Restaurant. 
TiiUKSDAr,  April  ist.— Chemical,  8.    "  Oxidation  of  a-Y-dim«thyl  a'- 
cbloro-pyridine,"  by  H.  Aston  and  J.  Nor- 
man Collie,  Ph.D..  F.R.S.    "Composition 
of  Cooked  Fish,"  by  K.  I.  Williams. 
— —  Royal  Institution,  3.     "  The  Relation  of  Geology 

to  History,"  Bv  Prof.  W.  Boyd  Dawkins,  M.A., 
F.R.S.,  F.G.S'. 

Society  of  Arts,  4.30.     •'  A  Visit  to  Russian  Cen- 

tral Asia,"  by  M.  F.  O'Dwyer. 
Friday,  2nd.— Royal  Institution,  g.  "  Metallic  Alloys  and  the  fheory 

of  Solution,"  by  C.  T.  Heycock.  F.R.S. 
Saturday,  3rd.-^Royal  Institution,  j.     '*  EleAricity  and  Electrical 

Vibrations,"  by  Right  Hon.  Lord  Rayleigh,  M.A., 

F.R.S. 

CHEAP  SETS  OF  STANDARD  BOOKS. 

In  good  condition,  and  sent  Carriage  Free  in  Great  Britain. 
Philosophical    Magazine,    from    commencement,    1798   to    1885 

(exc.  I  vol.  and  7  .>os.),  185  vols,  half  calf,  <Stc.,  very  scarce,  £64, 
Watts'  Dii5ty.  of  Chemistry  and  the  Allied  Sciences;  complete  set, 

UNABRIDGED  EDITION,  Q  VOlS.  cloth,  1872-8I,  £l5,  tOr  £S  BS. 

Do  ,  New  Ed  ,  3  vols.  New,  i&88-g2  {Special oj^er),  £6  r4s  ,tor  £4  15s. 
Thorpe's  Di(ity.  of  Applied  Chemistry  (complete  set).    1895.    The 

companion  work  to  "  Watts."    3  vols..  New,  £7  ys.  for  £5  12s. 
Chemical  News,  Complete  Set,  186^—89,  60  vols.,  cloth,  £18  los. 
Proceedings  of  the  Royal  Society  of  London,  Complets  Set, 

from  1854  to  1889;  39  vois.,  8vo.  cloth.    Scarce.    £io  los. 
Philosophical   Trans.  Roy.   Soc.  Lond.    Consecutive  set,  from 

1S43  to  1889,  205  vols,  or  pts.,  cloth,  Sec,  £50  (pub.  ;^i8g9s.  6d.). 
Nature  ;  complete  set,  1869  to  1893  ;  4$  vols.,  cloth,  scarce,  £12. 
Chemistry  applied  to  Arts  and  ManufaAures  by  writers  of  eminence 

( SchorUmmer  and  others) ;  engravings,  8  vols.  (1880),  £4,  for  38/6. 
Gmelin's  Handbook  of  Chemistry  (Organic  and  Inorganic),  by 

Hy.  Watts,  complete  set,  19  vols,  cl.,  scarce,  £20.  for  £S  8s. 
Trans.  Roy.  Soc.  of  Edin.,  1788  to  i8go,  36  vols.,  4(0.,  ht.  calf,  £45 

WM.  F.  CLAY,  Bookseller,  Teviot  Place,  EDINBURGH. 


156 


Advertisements. 


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\    March  26,  1897. 


AGRICULTURAL  CHEMICAL  ANALYSIS. 

By  H.  W.  Wiley.  Vol.  I.,  SOILS,  15s.  Vol.  II., 
FERTILIZERS,  8s.  Vol.  III.,  AGRICULTURAL 
PRODUCTS,  15J. 

ENGINEERING  CHEMISTRY. 

By  J.  B.  Stillman.     Cloth,  r8s. 

THE  CHEMISTRY  OF  DAIRYING 

By  H.  Snyder.    Cloth,  6j. 

THE  CHEMISTRY  OF  POTTERY. 

By  Karl  Langenbeck.     Cloth,  6s. 

DEVELOPMENT  OF  THE  PERIODIC  LAW- 

By  F.  P.  Venable.     Cloth.  105. 

CHEMISTRY  FOR  BEGINNERS. 

By  Edward  Hart.     Cloth,  6s. 

Circulars  on  application. 

CHEMICAL  PUBLISHING  CO. 
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BECKER'S  STUDENT'S  BALANCE,  in  polished  mahogany 
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BREWER'S  Thermometers,  Hydrometers,  and  Saccharometers, 
and  for  Oil  Trades  and  manufafturing  purposes 


A  nalytical  Chemist,  at  present  employed,  ten 

^*^  years*  experience,  five  years  with  well-known  Public  Analyst, 
desires  opening  in  London  in  an  Analyst's  laboratory  or  in  a  Mann- 
fafturing  Chemist's  or  commercial  concern.  Highest  testimonials 
and  references.  Moderate  salary. — Address,  A.  J  ,  Chemical  News 
Office,  6  &  7,  Creed  Lane,  Ludgate  Hill,  London,  E.C. 

A   Manufadlurer's  Chemist  (A.I.C.),  who  has 

*^  just  completed  his  engagement  with  an  eminent  firm,  is  open 
to  appointment  as  Head  Chemist  or  Manager.  Experience  in 
laying  down  Plant,  Ereftion  of  Buildings,  and  management  of  men. 
Has  developed  and  carried  out  New  Processes.  Good  Analyst. — 
Address,  "  Progress,"  Chemical  News  Office,  6  &  7,  Creed  Lane, 
Ludgate  Hill,  London,  E.C. 

AGENCY.  —  A    Gentleman    with    extensive 

^  *■  commercial  experience  wishes  to  aft  as  Foreign  Representative 
for  a  first-class  firm.  Travels  through  Italy,  Egypt,  India,  Burmah, 
Straits  Settlements,  Australian  Colonies,  and  New  Zealand,  the 
Dutch  Indies,  China  and  Japan,  Chili,  Argentine  Republic,  and  Rio 
de  Janeiro. — Address,  in  stridt  confidence,  to  Export  897,  Messrs. 
Deacon's,  Leadenhall  Street. 

r^hemist  seeks    Engagement   as  Assistant  to 

^^  Analyst  or  as  Lefture  and  Laboratory  Demonstrator.  Age  21. 
Three  years'  laboratory  training. — Address,  F.  W.  M.,  29,  New  St., 
Chelmsford,  Easex. 


Situation  wanted  as  Chemist  in  Works  or 
Laboratory,  at  home  or  abroad.  Large  experience  in  the  ex- 
tradlion  of  Copper,  Gold,  Silver,  and  the  maoufafture  of  Potassium 
Cyanide.  First-class  references. — Address,  M.  M.,  Chemical  News 
Office,  6  &  7,  Creed  Lane,  Liidgate  Hill,  London,  E.C. 

■pxperienced  Swedish  Chemist,  good  Analyst, 

-•— '     desires   Engagement.  —  Please   address   "  Lugner,"  care  of 
Rudolf  Mosse,  Nuremberg,  Bavaria. 


r^erman  Technical  Chemist,  educated  in  Berlin, 

^•^  then  studied  during  18  months  the  machinery  department, 
conversant  with  the  English  and  French  languages,  desires  Engage- 
ment at  home  or  abroad  by  Odtober  next. — Please  address  "  D.  7879," 
care  of  Hudolf  Mosse,  Munich,  Bavaria; 

pOR  SALE.— Four  Wrought-Iron  Agitating 

-I-  Tanks,  about  5  ft.  6  in.  diameter  by  4  ft.  6  in.  deep,  with  pro- 
peller agitator,  and  g;ear.  One  ditto  6  ft.  diameter  by  4  ft.  deep.  Full 
particulars  and  drawings  on  application. — Johnson  and  Phillips,  Vic- 
toria Works,  Charlton,  Kent. 

SULPHIDE    OF    BARIUM, 

Warranted  80  per  cent,  supplied  very  cheap  in  large  quantities. 

NIEDERHEITMANN    &    STEINAU, 
Chemical  Works,  Florsheim,  Frankfort  on  the  Main. 


ACETONE Answering  all  requirements. 

J^CJXID  _A.CETIO-P"fest  and  sweet. 

BOI^^A-CIG-Cryst.  and  powder. 

— —  CITDRIC— Cryst.  made  in  earthenware. 

__  Q.  ^  T.T.Tr^— From  best  Chinese  galls,  pure. 

SjA-XjICJ'2'XjIO— By  Kolbe's  process. 

rj-t^^-2sf-jsj-X(^—FotPhSirm3Lcy&ndih6Atts- 

LIQUID  CHLORINE 

(Compressed  in  steel  cylinders). 

FORMALIN    (W«  CH2O)— Antiseptic  and  Preservative, 

POTASS.  PERM ANGANATE-Cryst.,  large  and  small. 

SULPHOCYANIDE    OF   AMMONIUM. 
BARIUM. 

THORIUM,  ZIRCONIUM,  and  CERIUM  SALTS. 

TARTAR    EMETIC-Cryst.  and  Powder. 

PUMICE.     TRIPOLI    AND   METAL   POWDERS. 

ALL  CHEMICALS    FOR   ANALYSIS    AND   THE   ARTS. 

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Chbuical  MBWB,  I 
April  2, 1897.     / 


Estimatton  of  Thoria, 


THE    CHEMICAL    NEWS 


Vol.  LXXV.,  No.  1949. 


ON   THE 

DETECTION     OF    THE     COLOURING-MATTERS 
OF    COAL    IN     WHITE    WINES, 

AND   ON 

DISTINGUISHING    THESE    PIGMENTS   FROM 

THE    COLOURS    OF    CARAMEL. 

By    ALB.    D'AGUIAR    and    W.    da    SILVA. 

The  recognition  of  the  coal-tar  colours,  and  their  dis- 
tindlion  from  caramel  in  liqueurs,  has  already  been 
undertaken  by  Rocques,  Saglor,  Roeser,  and  other  che- 
mists. Quite  recently  Cruz  Nagelh&es  has  sought  to 
demonstrate  that  the  methods  in  common  use  for  the 
dete(5tion  of  coal-tar  colours  in  old  white  wines  may 
prove  defedive,  and  lead  us  to  confound  caramel  with  the 
yellow  or  orange-yellow  colours  of  coal. 

We  request  permission  to  present  on  this  question  our 
experiments  conduced  in  the  Municipal  Laboratory  of 
Oporto. 

We  shall  confine  ourselves  to  reporting  the  results  ob- 
tained by  the  use  of  amylic  alcohol  on  wines  rendered 
alkaline  by  the  addition  of  ammonia,  with  dyeing  experi- 
ments on  silk  by  immersion  in  amylic  alcohol. 

We  have  experimented  with  the  following  colours : — 
I,  binitro-naphthol;  2,  chrysoidine;  3,  Bismarck  brown  ; 
4,  orange  II.;  5,  tropeoline ;  6,  Biebrich  red;  7,  azo- 
flavine ;  8,  helianihine ;  9,  methyl-orange;  10,  amido- 
azo-benzene;  11.,  naphthol  yellow  S  ;  12,  caramel.  These 
colours  were  respectively  dissolved  each  in  alcohol  of  sp. 
gr.  20°,  and  the  solutions  were  mixed  with  400  c.c.  of 
white  wine  from  Ermida,  grown  in  the  north  of  Portugal. 
The  caramel  was  added  to  the  wine  in  the  proportion  of 
5  c.c.  to  400  c.c,  and  was  obtained  with  500  grms.  of 
pure  sugar,  heated  to  215°,  and  lastly  dissolved  in  800 
c.c.  of  water.  The  intensities  of  colour  were  compared 
with  Ermida  wine,  seen  in  a  stratum  at  the  depth  of 
12  cm. 

We  made  three  series  of  experiments. 

The  colours  of  caramel  give,  by  the  usual  treatment 
with  amylic  alcohol,  results  very  doubtful  and  sometimes 
negative.  On  the  contrary,  the  coal-tar  yellows  present 
a  group  of  very  distindt  colours,  which  are  very  charadter- 
istic  if  they  are  used  in  the  fraudulent  wine-trade. — 
Chemiker  Zeitumg. 


157 


ESTIMATION    OF    THORIA. 

CHEMICAL   ANALYSIS   OF    MONAZITE    SAND.* 

By  CHARLES   GLASER. 

(Concluded  from  p.  147). 

Systematic  Method  of  Analysis. 
From  the  analytical  data  given,  the  following  method  has 
been  deduced. 

It  is  essential  that  the  mineral  be  divided  to  the 
greatest  possible  degree.  Prolonged  powdering  in  an 
agate  mortar  is  indispensable.  Solution  is  effedted 
either  by  prolonged  heating  with  strong  sulphuric  acid,  or 
by  fusion  with  acid  potassium    sulphate.      In   the  latter 

♦  From  the  Journal  0/  the  American  Chemical  Society,  vol.  xviii., 
No,  9. 


case,  the  cooled  mass  is  warmed  with  so  much  sulphuric 
acid  that  the  produdl,  after  cooling,  may  be  poured  from 
the  crucible.  The  first  method  takes  more  time  than  the 
second,  but  it  introduces  less  of  the  objecftionable  potas- 
slum  salts.  It  is  advisable  to  fuse  only  those  portions 
which  are  insoluble  in  sulphuric  acid. 

For  estimation  of  silica  the  sulphuric  acid  treatment  is 
preferable,  in  which  case  it  is  best  to  evaporate  once  on 
a  sand-bath  to  dryness,  to  render  silica  insoluble,  and 
then  to  add  fresh  sulphuric  acid.  The  resulting  mixture 
should  be  added  slowly  to  ice  cold  water,  which  dissolves 
the  mass  excepting  silica  and  tantalic  acid,  with  possibly 
traces  of  titanic  acid,  thoria,  and  zirconia.  After 
filtering,  the  residue  should  be  ignited  and  weighed. 
Silica  is  eliminated  by  repeated  treatment  with  hydro- 
fluoric acid.  Any  residue  remaining  should  be  moistened 
with  sulphuric  acid,  to  convert  the  fluorides  of  the  earths 
into  sulphates,  which,  after  ignition  at  a  high  tempera- 
ture, are  weighed  as  oxides,  and  silica  determined  by  the 
loss  in  weight.  The  residue  of  tantalic  acid,  with  possibly 
traces  of  the  bodies  mentioned  above,  is  treated  with 
sulphuric  acid  and  hydrofluoric  acid.  Tantalic  acid 
remains  insoluble,  and  may  be  filtered  off  and  weighed. 
The  matter  soluble  may  be  added  to  the  main  solution. 

The  original  solution  is  saturated  with  hydrogen  sul- 
phide,  first  at  boiling  and  then  at  the  ordinary  tempera- 
ture.  Titanic  acid  is  precipitated,  together  with  metals 
of  the  fifth  group.  That  sodium  sulphite  assists  in  the 
precipitation  of  titanic  acid  has  not  been  verified  in  my 
work. 

When  completely  settled,  the  liquid  is  filtered  and  the 
filtrate  boiled  to  expel  hydrogen  sulphide.  Any  free  acid 
may  be  nearly  neutralised  with  ammonia ;  to  the  boiling 
liquid  is  added  an  excess  of  a  boiling  solution  of  ammo- 
nium oxalate,  as  much  as  100  c.c.  of  the  cold  saturated 
solution  for  2  grms.  of  monazite  sand.  The  excess 
necessarily  must  be  large.  The  mixture  is  then  permitted 
to  cool,  best  for  an  entire  night.  The  solution  will  con- 
tain phosphoric  acid,  the  oxides  of  iron,  manganese, 
aluminum,  glucinum,  yttrium,  zirconium,  and  calcium. 
In  the  precipitate  will  be  found  thoria  and  the  oxides  of 
the  cerium  group. 

If  the  bodies  in  solution  are  to  be  estimated,  add  am- 
monia  to  precipitate  the  metals  as  phosphates.  Filter 
and  wash  thoroughly,  preserve  the  filtrate  for  estimation 
of  phosphoric  acid  and  alumina.  Ignite  the  precipitate 
and  fuse  it  with  mixed  carbonates  of  potassium  and 
sodium.  The  fused  mass  is  exhausted  with  hot  water, 
filtered,  and  the  residue  well  washed  with  hot  water. 
The  filtrate  is  added  to  that  containing  phosphoric  acid 
and  alumina. 

The  remaining  oxides  and  carbonates  are  dissolved  in 
sulphuric  acid  and  precipitated  with  ammonia.  Lime  is 
estimated  in  the  filtrate  therefrom. 

When  an  attempt  is  now  made  to  dissolve  the  precipi- 
tated hydroxides  on  the  filter  by  dilute  hydrochloric  acid, 
it  sometimes  occurs  that  zirconia  in  part  remains. 
Therefore  it  is  best,  after  this  operation,  to  incinerate  the 
filter.  Then  neutralise  the  solution  with  ammonia  as 
far  as  pradicable.  Pour  this  slowly,  with  constant 
stirring,  into  a  mixture  of  ammonium  carbonate  and  am- 
monium  sulphide,  prepared  as  follows :— To  a  solution 
of  ammonium  carbonate  more  than  enough  to  neutralise 
the  free  hydrochloric  acid  above  indicated,  and  to  hold  in 
solution  the  earths  to  be  dealt  with,  add  enough  of  am- 
monium sulphide  (usually  a  few  c.c.)  to  precipitate  the 
metals  of  the  fourth  group.  The  latter  will  be  precipi- 
tated, while  zirconia,  yttria,  and  glucinum  remain  in 
solution.  Iron  and  manganese  may  be  determined  by  the 
usual  methods, 

If  the  carbonate  solution  be  boiled  for  one  hour  the 
earths  are  completely  precipitated.  They  may  be  caught 
on  a  filter  and  dissolved  in  hydrochloric  acid  ;  or  the 
carbonate  solution  may  be  treated  diredlly  with  that  acid, 
carbon  dioxide  expelled  by  boiling,  the  solution  cooled 


158 


Revision  0/  the  Atomic  Weight  of  Magnesium, 


{Cbbmical  NbW8, 
April  2, 1897, 


and  treated  with  an  excess  of  sodium  hydroxide.  Zir- 
conium and  yttria  are  completely  precipitated,  while 
glucina  remains  dissolved ;  to  precipitate  this,  boil  the 
solution  one  hour. 

To  separate  zirconia  from  yttria,  dissolve  the  hydroxides 
in  hydrochloric  acid,  warm,  then  saturate  the  solution 
with  sodium  sulphate.  When  cold,  zirconia  separates  in 
the  well-known  manner.  From  the  filtrate  ammonia 
separates  yttria. 

As  the  earths  are  apt  to  occlude  alkali  salts,  it  is  best 
to  dissolve  and  again  precipitate  them  (with  ammonia) 
before  they  are  ignited  and  weighed. 

Separation  of  the  precipitated  oxalates  of  thoria  and  of 
the  cerium  group  is  accomplished  as  follows  : — The 
oxalates  are  reduced  to  oxides  by  ignition,  then  converted 
into  sulphates,  the  greater  part  of  the  free  acid  neutral- 
ised with  ammonia,  the  solution  boiled,  and  boiling  am- 
monium oxalate  added  in  excess.  After  a  short  time  (as 
soon  as  oxalates  of  the  cerium  metals  have  formed,  but 
before  the  liquid  has  cooled),  a  few  c.c.  of  solution  of 
ammonium  acetate  are  added.  When  cold,  the  entire 
cerium  group  is  precipitated  as  oxalates,  while  thoria  re- 
mains in  solution.  After  prolonged  standing,  best  over 
night,  the  insoluble  oxalates  are  removed  by  filtration  ; 
in  the  filtrate,  precipitate  thoria  with  ammonia  in  excess, 
filter,  ignite,  and  weigh. 

Separation  of  cerium  from  lanthanum  and  didymium 
is  easily  accomplished  by  the  well-known  method.  Pass 
a  current  of  chlorine  through  the  liquid  containing  the 
hydroxides,  which  have  been  freshly  precipitated  by  a 
fixed  alkali. 

Separation  of  lanthanum  from  didymium  was  not 
attempted. 

An  analysis  of  the  monazite  sand  used  in  my  work, 
made  as  indicated  in  the  foregoing  notes,  gave  results 
as  follows : — 

Titanic  acid . .  4-67 

Silica 6*40 

Phosphorus  pentoxide       18*38 

Lead      trace 

Alumina       1-62 

Lime      1-20 

Cerium  oxide  (CeO) 32*93 

Lanthanum  and  didymium  oxides  ..      ..  7*93 

Thoria 1*43 

Ferric  oxide 7*83 

Zirconia  and  yttria 13*98 

Glucina ..      ..  125 

Tantalic  acid       066 

Not  determined  .. 1*72 


Titanic  acid  and  silica  was  determined  in  a  separate 
portion. 

The  determination  of  tantalic  acid  was  only  approxi- 
mate, since  a  part  of  it  is  dissolved  by  fusion  with  acid 
potassium  sulphate,  and  thus  escapes  weighing.  As 
several  such  fusions  were  made,  it  is  probable  that  the 
greater  part  of  the  matter  "  not  determined  "  ought  to  be 
reckoned  as  tantalic  acid.  The  quantity  stated  was  an 
average  of  three  determinations  (mmus  or  plus  0*05)  from 
the  residue  of  repeated  fusions. 

Through  the  courtesy  of  Mr,  H.  B.  C.  Nitze,  of  the 
Geological  Survey  of  North  Carolina,  I  have  received  a 
number  of  samples  of  monazite  sand  mined  at  various 
localities  in  that  state.  Two  of  these  had  been  prepared 
by  a  new  process,  and  were  found  to  be  pradically  free 
from  rutile  and  garnets.  They  were  excellent  material 
for  my  methods  of  analysis,  and  they  gave  results  as  fol- 
lows : — 


Analysis  of  of  a  Coarse  Monazite  Sand  from  Shelby, 
North  Carolina. 

Silica 3-20 

Titanic  acid 0*61 

Cerium  metals  as  CeO      63*80 

Phosphorus  pentoxide       28*16 

Thoria 2*32 

Zirconia,  glucina,  yttria 1-52 

Manganese trace 

No  iron,  alumina,  or  lime o'oo 


The  colour  of  this  sand  was  honey-yellow. 


9961 


Analysis  of  a  Fine  Monazite  Sand  from  Bellewood, 
North  Carolina. 

Silica 1*45 

Titanic  acid 1*40 

Cerium  metals  as  CeO      59*09 

Phosphorus  pentoxide       26*05 

Thoria i-ig 

Zirconia,  glucina,  yttria 2*68 

Tantalic  acid ..      ..  6*39 

Iron  and  manganese  oxides      0*65 

Alumina        015 


The  colour  of  this  sand  was  honey-yellow. 


99*05 


A    REVISION    OF    THE    ATOMIC    WEIGHT    OF 
MAGNESIUM.' 

By  THEODORE  WILLIAM  RICHARDS 

and 

HARRY  GEORGE  PARKER. 

(Continued  from  p.  149). 


Preparation  of  Materials. 
The  sample  of  ammonic  magnesic  chloride  which  will  be 
hereafter  referred  to  as  sample  No.  1,  was  prepared  as 
follows: — About  500  grms.  of  ordinary  "  C.  P,"  magnesic 
chloride  were  saturated  with  hydrogen  sulphide,  a  small 
amount  of  ammonia  was  added,  and  the  whole  was 
allowed  to  stand  in  a  warm  place  for  several  days.  To 
the  supernatant  liquid  after  decantation  a  small  quantity 
of  very  pure  ammonic  oxalate  was  added.  The  magnesic 
chloride  thus  almost  wholly  freed  from  calcium  was  again 
decanted  ;  and  after  more  ammonic  oxalate  had  been 
added,  the  whole  was  allowed  to  stand,  and  the  clear 
liquid  was  yet  once  more  decanted.  The  solution  was 
then  evaporated  to  dryness,  and  the  resulting  cake  dried 
in  an  oven  and  ignited  in  a  platinum  dish.  The  mixture 
of  magnesic  oxide  and  oxychloride  thus  formed  was 
washed  with  the  aid  of  a  filter  pump  for  about  sixty  hours. 
At  the  end  of  this  time,  although  the  wash  water  con- 
tained no  sodium,  the  insoluble  precipitate  was  not  free 
from  that  metal.  The  precipitate  was  therefore  dissolved 
in  hydrochloric  acid,  previously  distilled  in  platinum  for 
the  purpose,  and  the  solution  was  filtered.  In  order  to 
eliminate  the  sodium,  a  portion  of  the  magnesium  was 
precipitated  by  passing  into  the  solution  a  current  of  am- 
monia gas.  The  precipitate  formed  by  this  very  wasteful 
process  was  washed  for  several  days,  at  the  end  of  which 
time  it  was  found  to  be  free  from  any  appreciable  traces 
of  sodium  and  potassium,  when  tested  with  the  spedlro- 
scope. 

Ammonic  chloride  was  now  prepared  by  mixing  streams 
of  ammonia  and  hydrochloric  acid  gas.     This  gave  am- 


*  Contributions  from  the  Chemical  Laboratory  of  Harvard  College, 
From  the  Proceedings  of  the  American  Academy  0/ Arts  and  Sciences. 
vol.  xxxii.,  No.  3. 


Cbbmical  Nbws,I 
April  2, 1897.      I 


Some  Hydrocarbons  from  American  Petroleum, 


159 


monic  chloride  mixed  probably  to  a  certain  extent  with 
various  amines,  but  free  from  inorganic  salts.  As  the 
amines  must  be  driven  off  later,  it  was  not  thought  worth 
while  to  take  the  trouble  of  removing  them  at  this  stage 
of  the  work. 

The  solution  of  ammonic  chloride  thus  prepared  was 
added  to  the  solution  of  magnesic  chloride  obtained  by 
dissolving  the  oxychloride  in  hydrochloric  acid  in  propor- 
tions corresponding  to  formula  Mg.Cl2(NH4)Cl,  and  the 
mixture  was  carefully  evaporated  to  dryness  and  gently 
heated  in  an  oven.  It  is,  of  course,  unnecessary  to  say 
that  all  the  latter  part  of  this  purification  was  done  as 
far  as  possible  in  platinum.  The  solid  cake  was  powdered 
in  an  agate  mortar,  and  placed  in  a  glass-stoppered 
bottle  which  was  kept  in  a  closed  jar.  The  double 
chloride  thus  prepared  was  then  tested  with  the  spedro- 
scope,  but  no  impurities  could  be  discovered ;  and  its 
solution  in  water  was  perfedly  clear.  Tests  were  made 
with  ammonic  oxalate  and  baric  chloride,  but  in  neither 
case  was  a  precipitate  formed  on  long  standing. 

The  second  sample  of  magnesic  chloride  was  treated  in 
a  similar  way  up  to  the  point  where  it  was  necessary  to 
get  rid  of  sodium  and  potassium.  The  solution  was 
evaporated  to  dryness  in  a  platinum  dish  with  the  aid  of 
an  alcohol  lamp,  and  the  resulting  cake  was  gently 
ignited  and  then  washed  for  a  long  time,  nothing  but 
platinum  being  allowed  to  come  in  contadt  with  the 
material  from  this  time  forth,  and  all  the  heating  being 
done  by  means  of  alcohol  lamps  to  avoid  the  danger  of 
contamination  of  sulphur  from  illuminating  gas.  The 
oxychloride  thus  formed  was  then  dissolved  in  pure 
hydrochloric  acid  and  filtered.  By  evaporating  down 
again  the  magnesium  was  again  rendered  insoluble.  This 
process  was  repeated  again  and  again,  until  there  was  no 
trace  of  sodium  or  potassium  remaining. 

The  ammonic  chloride  necessary  for  the  preparation 
of  the  double  salt  from  this  second  sample  of  magnesic 
chloride  was  prepared  by  digesting  ammonic  chloride 
with  nitric  acid  to  destroy  the  amines  (Kriiss,  Liebig's 
Annul.,  ccxxxviii.,  51).  It  was  then  dried,  sublimed 
several  times,  re-crystallised  five  or  six  times  from  its 
aqueous  solution,  and  again  sublimed  in  a  current  of  air 
which  had  been  passed  through  wash  bottles  containing 
respedively  a  concentrated  solution  of  potash  and  sul- 
phuric acid.  After  having  been  sublimed  in  this  manner 
about  ten  or  twelve  times,  it  was  dissolved  in  re-distilled 
water  and  added  to  the  sample  of  magnesic  chloride.  The 
whole  was  then  filtered,  evaporated  to  dryness,  partly 
dehydrated,  broken  up  and  placed  in  a  glass  stoppered 
bottle.  The  usual  tests  were  made  as  to  its  purity,  but 
no  traces  of  foreign  matter  were  discovered. 

The  third  sample  of  magnesic  chloride,  which  was  used 
for  the  final  experiment  in  the  last  series,  was  at  first 
treated  in  about  the  same  way  as  the  others.  The  pre- 
cautions taken  were  somewhat  greater,  and  the  fradional 
precipitation  with  ammonic  oxalate  was  continued  long 
after  the  last  traces  of  calcium  discoverable  by  the  spectro- 
scope had  disappeared  from  the  precipitates  of  magnesic 
oxalate.  The  ammonic  magnesic  chloride,  already  very 
pure,  prepared  from  this  sample,  was  then  crystallised 
eight  or  ten  times,  the  last  six  or  eight  re-crystallisations 
being  conduced  in  platinum.  From  over  a  kilogrm.  of 
magnesic  chloride  used  in  the  beginning,  the  portion 
finally  separated  out  consisted  only  of  a  few  grms.  This 
sample  showed  no  traces  of  the  sodium  line  when  tested 
with  the  spe(5troscope ;  indeed,  several  other  samples,  ob- 
tained from  the  mother  liquors  of  the  purest  sample,  gave 
equally  satisfaftory  negative  spedlroscopic  results.  Since 
the  magnesic  chloride  had  contained  in  the  first  place  a 
very  noticeable  amount  of  sodic  chloride,  the  fadt  of  the 
complete  elimination  of  the  impurity  seemed  a  satisfac- 
tory indication  of  the  elimination  of  other  foreign 
materials.  The  double  chloride  was  dried  over  an  alcohol 
lamp,  and  treated  in  the  same  manner  as  the  other 

samples. 

(To  be  continued). 


PROCEEDINGS    OF    SOCIETIES. 

CHEMICAL  SOCIETY. 
Ordinary  Meeting,  March  4th,  1897. 

Mr.  A.  G.  Vernon  Harcourt,  President,  in  the  Chair. 

Certificates  were  read  for  the  first  time  in  favour  of 
Messrs.  Alaric  Vincent  Colpoys  Fenby,  B.Sc,  Hutton 
Grammar  School,  Preston  ;  R.  Glode  Guyer,  20,  Queen's 
Road,  St.  John's  Wood,  N.W. ;  Tom  Mitchell,  Cemetery 
House,  Shaw,  near  Oldham  ;  Robert  Howson  Pickard, 
B.Sc,  Southfield,  Priory  Road,  Edgbaston,  Birmingham. 

Mr.  Cassal  asked  whether  the  officers  had  withdrawn 
the  certificate  of  a  candidate  from  the  list  to  be  balloted 
for  that  evening. 

Professor  Thomson  stated  that  the  certificate  of  one 
of  the  candidates  had  been  postponed  pending  further 
information. 

Dr.  Armstrong  remarked  that  such  adion  had  been 
taken  by  the  officers  on  former  occasions,  and  was  within 
their  discretion. 

The  following  were  duly  elecSed  Fellows  of  the  Society  : 
— Messrs.  John  Owen  Alexander;  Thomas  Hannibal 
Aquino ;  William  Arbuckle ;  John  B.  Ashworth  ;  John 
Barclay,  B.Sc. ;  Frank  Bastow  ;  Jyoti  Bhushan  Bhaduri, 
M.A.  ;  James  Herbert  Brown ;  F.  Hewlett  Burton- 
Brown,  M.A. ;  Alfred  Cartmell ;  Masumi  Chikashige, 
B.bc.  ;  Alfred  Foster  Cholerton ;  Clarence  Hamilton 
Creasey  ;  James  Crowther,  B.Sc. ;  William  Alfred  Davis  ; 
William  Diamond ;  John  Wallis  Dodgson,  B.Sc. ;  Law- 
rence Dufty ;  William  Buckland  Edwards ;  Joseph  Lake 
Gibbons ;  Alexander  W.  Gilbody,  M.Sc,  Ph.D. ;  Harold 
Walter  Gough,  B.A. ;  Ernest  Goulding;  Edward  Graham 
Guest,  M.A. ;  Vaughan  Harley,  M.D  ;  Ernald  G.  Justinian 
Hartley,  B.A. ;  Thomas  Hartley ;  Charles  Heppenstall ; 
John  Holmes ;  Fred  Ibbotson,  B.Sc. ;  William  Rose 
Innes,  B.Sc,  Ph.D. ;  David  Smiles  Jerdan,  M.A.,  B.Sc  ; 
Harold  Johnson ;  Otis  C.  Johnson ;  Herbert  King ; 
William  Robert  Lang,  B.Sc ;  Theophilus  Henry  Lee  ; 
Charles  Henry  Martin  ;  Barker  North  ;  Charles  Henry 
Parker;  Samuel  Pollitt,  B.Sc;  Herbert  Swindler  PuUar  ; 
William  Ralston,  B.Sc. ;  John  Stewart  Remington ; 
Edward  Rosling;  Alfred  Rutter;  Frank  Southerden ; 
William  James  Stainer,  B.A. ;  Henry  Potter  Stevens, 
B.A. ;  Leonard  Sumner,  B.Sc;  Harry  Thompson;  An- 
drew Turnbull,  Ph.D;  Basil  William  Turner;  Rustomji 
Navroji  Umwalla;  Samuel  Matthew  Walford;  J.Wallace 
Walker,  M.A.,  Ph.D.  ;  and  Meyer  Wilderman,  Ph.D. 

In  accordance  with  the  Bye-law,  the  lists  of  the  names 
of  the  Fellows  recommended  for  ele(5tion  as  official  and 
ordinary  Members  of  Council  were  read  from  the  Chair. 

Of  the  following  papers  those  marked  *  were  read : — 

•34.  "  Some  Hydrocarbons  from  American  Petroleum, 
I.  Normal  and  Iso-pentane."  By  Sydney  Young,  D.Sc, 
F.R.S.,  and  G.  L.  Thomas,  B.Sc. 

The  two  pentanes  were  separated  by  fradlional  distilla- 
tion from  the  "pentane"  supplied  by  Merck  of  Darmstadt. 
This  substance,  which  is  obtained  by  the  distillation  of 
American  petroleum,  is  a  complex  mixture  of  butanes, 
pentanes,  and  hexanes,  with  some  benzene  and  a  little 
hexanaphthene.  A  combination  of  a  dephlegmator  with 
a  constant  (or  rather  "  regulated  ")  temperature  still-head 
was  employed ;  the  apparatus  is  fully  described  in  the 
paper. 

Some  of  the  constants  of  isopentane  were  determined 
so  as  to  compare  them  with  those  of  the  two  specimens 
prepared  synthetically  ;  the  agreement  was  found  to  be 
very  satisfacftory.  The  boiling-points  under  normal 
pressure  are  :— Isopentane,  27-95  ;  normal  pentane,  36-3. 
The  specific  gravities  at  0°  are:— Isopentane,  0*63930 ; 
normal  pentane,  0*64539. 


i6o 


Freezing-point  Curves  of  Alloys  containing  Zmc. 


'  Uheuical  Nbws, 
\      April  2,  1897. 


*35.  '^The  Vapour  Pressures,  Specific  Volumes,  and 
Critical  Constants  of  Normal  Pentane ;  with  a  Note  on 
the  Critical  Point."    By  Sydney  Young,  D.Sc,  F.R.S. 

The  critical  temperature  of  normal  pentane  is  i97"2, 
the  critical  pressure  is  25,100  m.m.,  and  the  critical 
volume  of  a  grm.  4*303  c.c.  The  vapour  pressures  and 
specific  volumes  were  determined  from  low  temperatures 
to  the  critical  point,  and  the  observations  were  taken  as 
near  to  the  critical  point  as  possible  {igj'i^),  in  order  to 
obtain  more  complete  experimental  evidence  regarding 
the  condition  of  a  substance  at  and  very  near  that  point. 

The  ratios  of  the  absolute  temperatures  (boiling-points) 
and  volumes  to!|the  critical  constants,  also  the  ratio  of  the 
a<5tual  to  the  'theoretical  density  at  the  critical  point 
(3765),  lead  to  the  conclusion  that,  at  the  critical  tem- 
perature and  in  the  liquid  state,  the  molecules  are  simple, 
like  those  of  the  gas. 

Discussion. 

The  President  said  that  for  many  years  he  had  been 
interested  in  the  isopentane  derived  from  American  petro- 
leum, having  proposed  that  its  flame  should  be  used, 
under  specified  conditions,  as  a  standard  of  light.  He 
had  purified  it  by  shaking  with  sulphuric  acid,  and  after- 
wards with  soda.  He  had  no  doubt  it  was  an  improve- 
ment to  use  nitric  acid,  as  Dr.  Young  had  done.  He  had 
used  a  dephlegmator  very  similar  to  that  described,  but 
had  never  succeeded  by  fra(^ionaI  distillation  in  obtaining 
a  substance  of  such  a  constant  boiling-point  as  that  ob- 
tained by  Dr.  Young.  He  was  much  interested  to  hear 
this  proof  by  Dr.  Young  of  the  identity  of  isopentane 
with  that  which  is  obtained  from  amyl  iodide,  as  experi- 
ments on  the  illuminating  power  did  not  quite  settle  this 
question. 

Dr.  Armstrong  thought  that  it  was  not  quite  certain 
that  the  isopentane  used  by  Dr.  Young  was  a  single  thing, 
and  it  was  probably  very  difficult  to  obtain  satisfactory 
proof  of  purity.  In  the  case  of  the  specimen  derived 
from  amyl  alcohol,  he  considered  it  likely  that  this  was  a 
mixture  of  two  hydrocarbons,  as  it  did  not  appear  that 
the  amyl  alcohol  of  fusel  oil  had  first  been  separated  into 
its  two  constituents. 

Dr.  Craw  said  that  Dr.  Young  seemed  to  have  shown 
that  the  critical  temperature  could  be  determined  accu- 
rately for  the  class  of  compounds  on  which  he  had 
worked ;  but  he  asked  whether  the  critical  temperature  is 
capable  of  being  determined  with  the  same  accuracy  for 
all  classes  of  compounds. 

Mr.  Groves  agreed  with  Dr.  Armstrong  as  to  the 
necessity  of  taking  special  precautions  in  purifying 
materials  and  of  not  trusting  to  those  supplied  by  manu- 
fa(%urers. 

Dr.  Thorpe  said  he  had  had  some  experience  in  the 
preparation  of  isopentane.  He  had  obtained  it  from  amyl 
alcohols  of  very  different  origin.  The  question  was 
whether  the  isopentane  derived  from  fusel  oils  of  very 
different  origin  would  give  the  same  hydrocarbon.  He 
had  found  that  all  the  specimens  of  isopentane  gave  prac- 
tically the  same  boiling-point  and  density  numbers  as 
those  obtained  by  Dr.  Young.  Nevertheless,  Mr.  Rodger 
and  he  had  found  that  the  viscosities  of  isopentane 
derived  from  different  sources  varied  considerably,  and  it 
was  significant  that  their  specific  volumes  and  specific 
gravities  agreed  closely  with  those  recorded  by  Dr.  Young. 
In  the  case  of  other  liquids  differently  prepared  and  puri- 
fied, the  same  viscosity  numbers  were  obtained :  for 
example.  Prof.  Dunstan  had  provided  him  with  a  sample 
of  pure  ether,  and  Dr.  Perkin  also  provided  him  with  a 
sample,  and  the  viscosities  of  the  two  were  in  perfedt 
agreement.  Similarly,  he  had  compared  two  samples  of 
benzene  of  different  origin,  and  here  also  the  two  samples 
gave  the  same  viscosity  number.  On  this  account  he 
was  inclined  to  question  the  homogeneity  of  isopentane 
prepared  from  amyl  alcohol. 

Dr.  Young,  in  reply  said  he  had  spent  many  months  in 
purifying  the  materials,  and  was   satisfied  that  they  were 


pure.  He  was,  indeed,  surprised  that  doubt  should  be 
cast  upon  the  matter. 

In  the  fradionation  of  the  pentane  and  isopentane,  he 
started  with  considerable  quantities  of  materials,  about 
1500  grms.,  and  he  obtained  about  no  grms.  of  pure  sub- 
stance. The  liquid  was  fradionated  about  twenty  times, 
and  the  loss  was  nearly  20  grms.  in  each  fradtionation. 
There  were  only,  as  far  as  he  knew,  three  isomeric  pen- 
tanes,  and,  as  they  had  distindtly  different  boiling-points, 
he  did  not  see  that  there  could  be  any  mistake  as  to  their 
identity.  The  critical  temperatures  and  pressures  are 
very  delicate  tests  of  the  purity  of  the  substance.  With 
slightly  impure  ether,  the  difference  in  critical  pressure  is 
very  considerable. 

With  regard  to  the  fradtionation  of  pentane  and  iso- 
pentane, the  ordinary  methods  of  fradtional  distillation 
would  not  answer.  With  the  ordinary  still-head,  the  loss 
by  evaporation  was  greater  than  the  gain  by  distillation, 
but  the  regulated  still-head  he  had  used  gave  most  satis- 
fadtory  results.  He  had  no  hesitation  in  saying  that,  with 
all  substances  which  do  not  undergo  decomposition  when 
heated,  the  critical  point  can  be  determined  within  one- 
tenth  of  a  degree. 

•36.  "  On  the  Freezing-point  Curves  of  Alloys  containing 
Zinc."    By  C.  T.  Heycock,  F.R.S,,  and  F.  H.  Neville. 

The  paper  is  divided  into  two  sedtions,  the  first  dealing 
with  cases  where  the  freezing-point  of  zinc  is  depressed 
by  the  addition  of  another  metal,  the  second  with  the 
cases  where  it  is  raised  by  such  an  addition. 

In  Sedlion  I,  complete  binary  alloys  of  the  following 
pairs  of  metals,  zinc-cadmium,  zinc-aluminium,  zinc-tin, 
and  zinc-bismuth,  are  given.  In  the  first  three  cases  the 
metals  appear  to  be  miscible  with  each  other  in  all  pro- 
portions ;  but  for  zinc-bismuth  the  freezing-point  curve 
shows  the  horizontal  line  of  identical  freezing-points 
charadteristic  of  the  state  when  the  alloy  has  separated 
into  two  conjugate  liquids. 

Taking  the  freezing-point  of  zinc  as  419°,  the  authors 
find  for  the  temperatures  of  freezing  and  the  composition 
of  the  eutedtic  mixtures  the  following: — 


Alloy. 
Zn— Cd 
Zn— Al 
Zn— Sn 
Zn— Bi 


They  do  not  consider  that  there  is  any  indication  of 
these  metals  combining  chemically  to  form  definite  com- 
pounds when  they  are  melted  together. 

Dilute  solutions  of  the  following  metals  in  zinc  were 
also  examined: — Lead,  thallium,  antimony,  magnesium. 

The  authors  find  that,  with  the  exception  of  aluminium 
and  cadmium,  all  the  above-mentioned  metals,  when  added 
in  small  quantities  to  molten  zinc,  cause  the  same  atomic 
fall ;  that  is,  an  alloy  containing  i  atomic  weight  in  solu- 
tion in  99  atomic  weights  of  zinc  has  a  freezing-point 
lower  by  5'i°  than  that  of  pure  zinc.  Cadmium  causes  a 
somewhat  smaller  and  aluminium  a  decidedly  smaller 
depression.  The  atomic  depression  of  5*1°,  when  used 
with  van't  Hoff's  equation  for  the  latent  heat,  gives  28*3 
calories  for  the  latent  heat  of  fusion  of  zinc,  instead  of 
Person's  value  of  28'i3. 

In  Sedlion  II.  dilute  solutions  of  copper  and  of  gold  in 
zinc  are  considered,  and  also  a  complete  freezing-point 
curve  for  all  alloys  of  zinc  and  silver. 

When  small  quantities  of  any  one  of  these  three  metals 
are  added  to  molten  zinc  the  effedl  is  the  same :  the 
freezing-point  is  raised,  and  the  whole  mass  of  metal 
appears  to  solidify  at  a  temperature  above  the  freezing- 
point  of  pure  zinc.  The  rise  in  the  freezing-point,  more- 
over, is  proportional  to  the  amount  of  the  second  metal 
present.  But  when  as  much  as  2  atomic  per  cents  of 
silver  or  of  copper,  or  3*3  of  gold,  have  been  added,  the 
phenomenon  alters,  apparently  abruptly.    There  are  now 


F,.P, 

Atomic  p.c.  of 

zinc 

264-5 

74 

281 

ZI 

198 

84 

254-5 

91-8 

Cbbhical  Nbws,  t 

April  2.  1897.       1 


New  Synthesis  m  the  Sugar  Group, 


161 


two  freezing-points,  a  higher  one  which  is  very  fugitive, 
and  which  is  followed  by  the  precipitation  of  much  solid, 
and  a  lower  one  which  is  very  constant,  and  which  is  in- 
dependent of  the  amount  of  the  added  metal  so  long  as 
the  above-mentioned  minimum  is  present.  In  the  zinc- 
silver  curve  singularities  are  also  found  near  70  and  60 
atomic  per  cents  of  zinc,  indicating  the  existence  of  more 
or  less  stable  compounds  ;  but  the  formula  of  these  com- 
pounds is  uncertain.  Near  37-5  atomic  per  cents  of  zinc 
there  is  another  well-marked  angle  and  a  series  of  eutedic 
second  freezing-points,  the  phenomenon  being  possibly 
due  to  the  separations  of  the  alloy  into  conjugate  liquids. 

The  authors  also  describe  briefly  some  of  the  physical 
properties  of  the  zinc-silver  alloys,  which  appear  to  change 
in  charadler  at  the  angles  of  the  curve. 

The  composition  of  the  silver-zinc  alloys  at  each 
freezing-point  was  determined  by  extrading  a  portion  in 
the  liquid  state,  and  estimating  the  percentage  of  silver 
by  a  volumetric  analysis. 

Discussion. 

Mr.  Newlands  asked  whether  the  formulae  of  the 
compounds  which  were  supposed  to  exist  at  certain 
points,— viz.,  AgZn,  AgZnz,  and  AgZns,— represented 
atoms  of  the  metals,  or  only  that  the  metals  were  present 
in  that  proportion. 

Mr.  Groves  asked  whether  there  was  any  connexion 
between  the  colour  of  the  silver-zinc  alloy  and  any  of  the 
points  on  the  curve. 

Mr.  Jenkins  asked  whether  the  colour  of  the  alloy  was 
in  any  way  due  to  the  effedt  of  mechanical  stress  during 
sudden  cooling. 

Dr.  Craw  asked  whether  the  atoms  in  the  alloy  were 
in  the  monatomic  state,  and  whether  the  alloy  might  be 
compared  with  a  solution. 

Mr.  Neville,  in  reply,  said  the  formulae  were  only 
empirical.  They  were  disposed  to  think  that  the  dissolved 
metal  was  in  a  monatomic  state.  The  colour  of  the  alloy 
did  not  seem  to  have  any  connedtion  with  the  points  on 
the  curve,  and,  although  great  mechanical  stress  occurred 
in  its  produdion,  this  did  not  seem  to  afford  an  explana- 
tion of  the  colour. 

*37.  "  The  Oxides  of  Cobalt  and  the  Cobaltites."  By 
Arthur  H.  McConnell  and  Edgar  S.  Hanes, 

The  authors  describe  a  method  for  the  preparation  of 
alkali  cobaltites,  and  show  that  cobalt  forms  an  oxide, 
C0O2,  and  an  acid,  H2C0O3,  which  have  hitherto  been 
looked  upon  as  hypothetical,  and  a  series  of  alkali  salts 
on  the  type  of  potassium  cobaltite,  KzOCoOa.  The  con- 
clusions the  authors  arrive  at  are  as  follows  : — 

1.  That  Durrant  (Proc,  1896,  xii.,  96,  244)  has  not  pro- 
duced sufficient  evidence  for  the  existeiice  of  either  cobaltic 
acid  or  cobalt  percarbonate. 

2.  That  cobaltous  acid  corresponds  with  cobalt  dioxide, 
and  forms  alkali  salts  fairly  stable  in  solution,  which  solu- 
tions have  an  unmistakable  green  colour. 

3.  That  cobalt  forms  a  series  of  compounds  with  other 
metals  in  which  the  cobalt  is  part  of  the  acid  radicle. 

4.  That  cobaltous  acid  and  cobaltites  are  stridlly 
analogous  to  manganous  acid  and  manganites,  thus 
showing  that  the  properties  of  cobalt  are  closely  allied  to 
those  of  the  other  elements  associated  with  it  in  the 
periodic  classification.  Manganese  is  readily  oxidised  to 
the  peroxide  Mn02,  but  cobalt  much  less  readily  yields 
the  corresponding  peroxide  CoOj. 

5.  In  view  of  the  fadl  that  cobalt  dioxide  does  un- 
doubtedly exist  in  a  number  of  compounds,  the  authors 
suggest  that  the  oxides  of  cobalt  should  be  re-named,  to 
bring  them  into  line  with  the  corresponding  oxides  of 
manganese. 

6.  It  is  highly  improbable  that  the  formation  of  this 
green  solution  will  prove  to  be  of  any  use  for  the 
separation  of  cobalt  from  nickel,  either  quantitatively  or 
qualitatively. 


*38.  "i4  New  Synthesis  in  the  Sugar  Qroup."  By 
Henry  J.  Horstman  Fenton,  M.A. 

In  previous  communications  it  has  been  shown  that  the 
acid  (dihydroxymaleic  acid)  obtained  by  oxidation  of 
tartaric  acid  in  presence  of  iron  decomposes,  on  heating 
with  water,  almost  quantitatively  into  glycollic  aldehyde 
and  carbon  dioxide.  Also,  that  this  aldehyde,  when 
heated  in  a  vacuum,  undergoes  condensation,  yielding  a 
sweet-tasting,  solid  gum,  which  has  the  formula  CeHiaOe. 

The  present  paper  describes  an  investigation  which 
has  been  made  upon  the  properties  of  this  condensation 
produdt. 

It  is  easily  soluble  in  water,  and  its  solution  quickly 
reduces  Fehling's  solution  and  ammoniacal  silver  nitrate. 
It  gives  various  colour  readtions  charaderistic  of  "  sugars," 
and,  after  purification  with  alcohol,  yields,  with  phenyl- 
hydrazine,  a  normal  hexosazone,  Ci8Ha2N404,  melting  at 
168—170°.  Heated  with  water  to  140°,  it  yields  furfural. 
It  is  optically  inadlive,  and  appears  to  be  incapable  of  fer- 
mentation by  yeast. 

The  purified  "  sugar,"  when  further  heated  in  a  vacuum 
to  100—106°,  loses  water  and  becomes  hard  and  brittle. 
After  two  to  four  hours'  heating  it  has  the  composition 
C12H22O11,  and  after  twenty-four  hours'  heating  the  com- 
position nearly  approximates  to  CeHioOs. 

The  conditions  under  which  tartaric  acid  may  be  con- 
verted into  dihydroxymaleic  acid  by  atmospheric  oxygen 
exhibit  close  analogies  with  some  of  the  essential  con- 
ditions of  vegetable  growth  ;  and  it  is  suggested  that  the 
diredt  produdlion  of  a  "sugar"  in  the  manner  above 
indicated  may  possibly  help  to  throw  light  upon  the 
natural  formation  of  carbohydrates. 

39.  "  The  Dinitrosamines  of  Ethylene  Aniline,  the 
Ethylene  Toluidines  and  their  Derivatives.^'  By  Francis 
E.  Francis,  Ph.D.,  B.Sc. 

The  dinitrosamine  of  ethylene  aniline  gives  ^-dinitroso- 
ethylene  aniline  hydrochloride  on  treatment  with  a  mixture 
of  glacial  acetic  and  hydrochloric  acids,  and  the  resulting 
tetramine  yields  quinone  on  oxidation,  showing  that  it  is 
a  ^-diamine,  ethylene-/-phenylene  diamine.  The  di- 
nitrosamines of  ethylene-o-toluidine  and  ethylene-w- 
toluidine  yield  di-nitroso  compounds,  which  on  redudlion 
pass  into  corresponding  tetramines,  whereas  the  di- 
nitrosamine of  ethylene-^-toluidine  is  decomposed.  This 
clearly  shows  that  in  the  substances  investigated  the 
nitroso-group  can  only  pass  under  the  treatment  described 
to  the  ^-position  in  the  benzene  nucleus. 

40.  "  Contribution  to  the  Knowledge  of  the  fi-Ketonic 
Acids."  Part  V.  By  S.  Ruhemann,  M.A.,  Ph.D.,  and 
A.  S.  Hemmv,  B.A.,  M.Sc. 

Whilst  studying  the  interadlion  between  the  sodium 
derivative  of  ethylic  oxalacetate  and  ethylic  chloro- 
fumarate,  the  authors  observed  the  formation  of  two 
isomerides  of  the  formula  C14H16O8.  One  of  them, 
melting  with  decomposition  at  200°,  forms  blue  salts  with 
alkalis  which,  by  an  excess  of  the  reagent,  become 
colourless.  The  other,  which  melts  at  123°,  does  not 
yield  coloured  salts,  but  gives  a  dark  red  colouration 
with  ferric  chloride.  The  authors  arrive  at  the  view  that 
in  the  formation  of  these  compounds,  ethylic  oxalacetate 
alone  takes  part,  and  they  represent  the  constitution  of 
the  substance  decomposing  at  200°  by  the  formula — 


COOC2H5-C: 


rC-COOCaHs 

0CC0H:CC00CaH5 

EthylicaDhydro-oxalaconitate, 

the  Other  by  the  s>  mbol — 

COOEfC-O'COOEt 

I!         II 
HCCOC-COOEt 

Etbylicpyronctricarboxylate, 


l62 


Synthesis  of  Citric  Acid. 


dHEuiCAL  News 

April  a,  1807. 


41.  "  Enantiotnorphic  Forms  of  Ethylpropylpiperido- 
nium  Iodide."    By  Clare  de  Brereton  Evans. 

It  has  been  found  that  ethylpropylpiperidonium  iodide 
(CsHioEtPrNI)  maybe  obtained  from  its  solution  in  ab- 
solute alcohol,  in  right-handed  and  left-handed  crystals. 
The  enantiomorphism,  however,  is  of  a  purely  crystallo- 
genic  order,  due  to  the  arrangement  of  the  molecules  in 
the  crystal,  and  not  to  the  position  of  the  atoms  in  space. 
This  is  proved  by  the  optical  inadlivity  of  the  substance 
in  solution,  as  well  as  by  the  fadt  that  either  variety  may 
be  converted  into  the  other  by  re  crystallisation,  the  be- 
haviour being  like  that  observed  in  the  case  of  sodium 
chlorate  and  bromate,  &c.,  &c. 

42.  '*  Further  Note  on  Ketopinic  Acid  —  Pinophanic 
Acid."     By  W.  S.  Gilles  and  F.  F.  Renwick. 

The  further  investigation  of  the  acid  obtained  by 
oxidising  the  solid  hydrochloride  from  pinene  with  the 
strongest  nitric  acid  {Trans.,  1896,  Ixix.,  1397)  has  brought 
to  light  a  variety  of  interesting  points. 

Although  bromine  alone  does  not  attack  it,  ketopinic 
acid  is  readily  brominated  if  a  small  quantity  of  phos- 
phorus be  present ;  the  produd  has  the  formula — 

CioHijOaBr.  (0=46-18;  46-06;  H=4-96,5-oo;  Br=3070' 
Calc.  0  =  45-98;  H=4-98;  Br  =  30-66). 

Monobromoketopinic  acid  melts  at  181°;  it  is  readily 
soluble  in  ether,  acetone,  acetic  acid,  and  ethylic  acetate, 
but  sparingly  so  in  benzene,  chloroform,  and  hot  water. 
When  heated  with  aniline  or  quinoline,  it  is  re-converted 
into  ketopinic  acid. 

The  hydroxime  of  ketopinic  acid  is  merely  hydrolysed 
when  boiled  with  50  per  cent  sulphuric  acid,  being  re- 
converted into  ketopinic  acid. 

When  cautiously  fused  with  caustic  soda,  or  even  when 
boiled  with  an  alcoholic  solution   of    sodium  ethylate, 
ketopinic  acid  is  converted  into  a  dibasic  acid,  pinophanic 
acid,  of  the  formula — 
C10H16O4 (0  =  60-14,60-13;  H  =  7-86,8-02;  Ag  in  silver  salt 

=  51-87,  52-03.     Calc.  C  =  6o-oo;  H  =  8-oo;  Ag  =  52-i7). 

Pinophanic  acid  melts  at  203° ;  it  is  insoluble  in  benzene, 
light  petroleum,  and  chloroform,  moderately  soluble  in 
hot  water  and  hot  ethylic  acetate,  and  readily  soluble  in 
alcohol,  acetone,  and  ether.  Like  ketopinic  acid,  it  does 
not  combine  with  bromine. 

Although  but  slowly  attacked,  ketopinic  acid  is  oxidised 
by  prolonged  digestion  with  neutral  potassium  perman- 
ganate solution.  The  produdt  appears  to  be  identical  in 
composition  with  Kipping's  camphotricarboxylic  acid  and 
Marsh  and  Gardner's  camphoic  acid,  but  more  closely 
resembles  the  latter. 

These  acids  are  now  being  fully  investigated. 

43.  'M  Synthesis  of  Citric  Acid."  By  W.  T.  Laurencei 
B.A.,  Ph.D. 

Ethylic  citrate  was  obtained  synthetically  by  the  con- 
densation  of  ethylic   bromacetate   with   ethylic   oxalyl- 
acetate  in   the  presence   of  zinc,  as    indicated    by  the 
following  equations  : — 
(i)  C00Et-CH2Br+C00Et:CH2-C0-C00Et-|-Zn  = 

=  COOEfCH2-C(OZnBr)(CH2-COOEt)-COOEt. 
(2)C00EfCH2-C(0ZnBr)(CH2-C00Et)-C00Et-l-H20  = 
=  COOEt-CH2-C(OH)(CHa-COOEt)-COOEt-J-Zno-f 
-J-HBR. 
The  yield  of  ethylic  citrate  is  very  poor,  owing  to  other 
readlions  proceeding  simultaneously.  To  further  con- 
firm the  formation  of  ethylic  citrate,  it  was  converted 
into  the  calcium  salt  of  citric  acid,  and  a  substance  ob- 
tained showing  the  charadteristic  properties  of  calcium 
citrate.  The  same  salt  was  also  obtained  by  heating  the 
zinc  compound  formed  in  equation  No.  i  with  alcoholic 
jotash  and  precipitating  the  calcium  citrate  from  the  hot 
solution. 

The  results  were  all  confirmed  by  analysis.  The  above 
synthesis  of  citric  acid  seems  to  be  of  interest  as  being 


more   diredt   and   simple   than  the   synthesis  from  sym- 
dichloracetone  or  from  ethyl-^-cyanacetoacetate. 


Ordinary  Meeting,  March  18th,  1897. 

Mr.  A.  G.  Vernon  Harcourt,  President,  in  the  Chair. 

Messrs.  H.  P.  Stevens,  J.  W.  Walker,  W.  Arbuckle, 
N.  T.  N.  Wilsmore,  M.  Wildermann,  W.  J.  Pope,  A.  W. 
Crossley,  H.  R.  Le  Sueur,  J.  H.  Miller,  R.  D.  Littlefield, 

F.  H,  Neville,  W.  M.  Heller,  G.  McGowan,  C.  M.  Cross- 
man,  J.  Holmes,  and  F.  Southerden  were  formally 
admitted  Fellows  of  the  Society. 

Certificates  were  read  for  the  first  time  in  favour  of 
Messrs.  Alfred  Hunter  Boylau,  EUerslie,  Richmond  Road, 
Ealing,  W. ;  Henry  Norris  Davidge,  37,  Duke  Street, 
Grosvenor  Square,  W. ;  Charles  Henry  Field,  The  Elms', 
Green  Street  Green,  Orpington  ;  Thomas  Girtin,  B.A  , 
125A,  Highbury  New  Park,  N. ;  James  Jones,  117,  Old 
Christchurch  Road,  Bournemouth  ;  Charles  MacCulloch, 
395,  Collins  Street,  Melbourne ;  George  Fowlie  Merson, 
65,  Northumberland  Street,  Newcastle  ;  Thomas  Tickle, 
4,  Packenham  street,  W.C. 

In  accordance  with  the  By-laws,  the  following  com- 
munication was  read  from  the  Chair  : — 

We,  the  undersigned,  beg  to  propose  Prof.  William 
Ramsay,  Ph.D.,  F.R.S.,  as  President  of  the  Chemical 
Society  in  succession  to  Mr.  A.  Vernon  Harcourt,  M.A., 
M.D.,  D.C.L.,  F.R.S.:— 

Baly,  E.  C.  C. ;  Baker,  C.  F. ;  Burgess,  Herbert  E. ; 
Blount,  Bertram  ;  Blundstone,  Edward,  R. ;  Berncastle, 
Richard  ;  Cassal,  Charles  E.  ;  Chattaway,  F.  D. ;  Chap- 
man, Alfred  C. ;  Collie,  J.  Norman  ;  Chorley,  John  C. ; 
Coste,  J.  H. ;  Crossley,  Arthur;  Dufton,  S.  T. ;  Ekins, 
Arthur  E. ;  Edwards.  W.  Buckland  ;  Evans,  R.  C.  T  ; 
Elborne,  William;  Earle,  Alfred;  Elford,  P.;  Forster, 
M.  0. ;  Graham,  Edward  ;  Grimwood,  R.  ;  Harley, 
Vaughan  ;  Harvey,  Sydney  ;  Baker,  Julian  L. ;  Floris,  R. 
B. ;  Jackman,  E.  J.;  Jones,  Cecil;  Johnson,  David; 
Kipping,  Stanley  F.  ;  Kellas,  Alex.  M. ;  Kingzett,  C.  T.; 
Ling,  A. ;  Lapworth,  A. ;  Livingston,  W.  T. ;  Littlefield, 
R.  D. ;  Routledge,  R. ;  Lamb,  Edmund;  Moody,  Gerald 
T. ;  Bodmer,  R. ;  Moor,  C.  G.  ;  Millar,  J.  H.;  McCrae, 
J.;  Macdonald,  G. ;  Mills,  Charles;  McGowan,  Geo.; 
Pope,  W.  J. ;  Parry,  Ernest  J. ;  Pidon,  Harold  ;  Plimpton, 
R.  T.  ;  Richmond,  H.  Droop ;  Simpson,  Arthur  M. ; 
Stevens,  H.  P.;  Travers,  M.  W. ;  Le  Sueur,  H.  R.  ; 
Wade,  John  ;  Wagner,  W.  G. ;  Wilsmore,  N.  T.  M. ; 
Walker,  J.  Wallace;  Sworn,  Sydney  A.;  Cornish, 
Vaughan ;"  Sykes,  Walter  J. ;  Waterhouse,  Robert ; 
Chattaway,  William ;  Priest,  Martin ;  Marsh,  J.  E ; 
Muspratt,  Edmund  K. ;  Mitchell,  C.  A.;  Muspratt, 
Sydney  K.;  Adams,  Arthur  ;  Marshall,  Arthur;  Wilson, 
John;  Bone,  W,  A.;  Fisher,  E.  H.  ;  Chapman,  Arthur 
J. ;  Wheelwright,  E.  W. ;  Lewis,  W.  H. ;  Sudborough, 
J.  J. ;  Veley,  V.  H. ;  Walker,  James ;  Colman,  Harold 

G.  ;  Christopher,  George  ;  Macnair,  D.  S. ;  Bell, 
Chichester  A.  ;  Wertheimer,  J.  ;  Hodgkin,  John  ; 
Archbutt,  Leonard  ;  Muir,  M.  M.  Pattison  ;  Shaw,  G. 
E. ;  Taylor,  R.  L. ;  Colwell,  J.  Kear ;  Cribb,  Cecil  H.  ; 
Butterfield,  W.  J.  Atkinson;  Hanes,  Edgar  S. ;  Suther- 
land, D.  A.;  Teed,  Frank  L. ;  Fulcher,  L.  W.  ;  Heller, 
W.  M. ;  Sandford,  P.  Gerald  ;  Snape,  H.  Lloyd  ;  Knight, 
J.  B.;  Cooper,  A.  J.;  Adams,  P.  T. ;  Adams,  M.  A. ; 
Eiloart,  A.  ;  Corfield,  W.  H. ;  Muter,  J.;  Muter,  A.  H. 
M.;  Dodd,  W.  H.  ;  Koningh,  L.  de  ;  Mawer,  W.  F. ; 
Lascelles,  P.  B. ;  Bruce,  James  ;  Turpin,  G.  S. 

Professor  Collie  stated  that  the  nomination  of  Professor 
Ramsay  had  been  made  without  his  knowledge  or  his 
permission. 

Of  the  following  papers  those  marked  *  were  read  : — 


Chbmical  Nbw8»  I 
April  2,  1897.     I 


Synthesis  of  Camphoronic  A  ctd. 


163 


•44.  •'  On  the  Atothic  Weight  of  Carbon."  By 
Alexander  Scott,  M,A.,  D.Sc. 

The  objedt  of  this  paper  is  to  call  attention  to  the  un- 
satisfadlory  nature  of  the  experimental  evidence  on  which 
the  determinations  of  the  atomic  weight  of  carbon  rest. 
The  two  methods  on  which  reliance  is  chiefly  placed  are 
shown  to  be  only  in  agreement  because  a  source  of  error 
which  afTeds  both  a<fts  in  opposite  diredlions.  This  is 
due  to  an  erroneous  determination  of  Dumas  and  Stas,  in 
1840,  of  the  expansion  produced  in  potash  solutions  by 
the  absorption  of  caibon  dioxide.  All  later  workers  at 
this  problem  seem  to  have  accepted  their  conclusions 
without  further  verification.  The  seriousness  of  this 
source  of  error  is  apparent  when  we  consider  that  over  40 
m.grms.  is  the  corredlion  for  the  weight  in  vacuo  of  the 
carbon  dioxide  in  one  experiment  alone.  The  correction 
per  grm.  of  carbon  dioxide  is  shown  to  be  0"56  to  o'57  c.c, 
instead  of  o'i5  c.c,  as  taken  by  Dumas  and  Stas.  The 
probable  efifedt  of  the  gases  "  occluded  "  in  the  copper 
oxide  is  next  considered,  and,  as  far  as  possible,  allowed 
for.  It  is  sliown  by  many  determinations  that  the  experi- 
ments of  Richards  give  the  quantity  as  much  too  great, 
the  mean  result  of  his  best  experiments  being  0088  per 
cent  by  weight  of  nitrogen  in  copper  oxide  made  from  the 
nitrate,  whilst  the  experiments  here  described  give  as  a 
mean  only  about  0*007  per  cent. 

Other  sources  of  error  and  the  best  methods  of  making 
more  accurate  determinations  are  next  considered.  The 
re-calculated  values  are  12*008  from  the  combustion  of 
the  various  forms  of  carbon,  and  12  "050  from  the  conver- 
sion of  the  monoxide  into  the  dioxide. 

Discussion. 
In  reply  to  questions  from  Mr.  Groves,  Mr.  Blount, 
Mr.  Heycock,  and  the  President,  Mr.  Scott  stated  that 
150  grms.  of  the  oxalate  furnished  about  4  grms.  of  car- 
bon. In  the  case  of  the  potash  solution,  it  was  the  ex- 
pansion of  the  liquid  which  had  to  be  correded  for.  The 
rate  of  absorption  of  carbon  dioxide  by  potash  solution  at 
any  given  time  was  affedled  by  the  amount  of  carbon  di- 
oxide which  had  been  already  absorbed.  Carbon  mon- 
oxide was  completely  absorbed  by  potash  after  some 
time. 

•45.  "  On  a  New  Series  of  Mixed  Sulphates  of  the 
Vitriol  Group."     By  Alexander  Scott,  M.A.,  D.Sc. 

This  paper  describes  a  new  series  of  mixed  sulphates 
of  the  form  (M,N)"S04.H20.  The  most  interesting  is 
the  ferrous  cupric  sulphate,  the  colour  of  which  is  reddish 
brown  ;  it  dissolves  in  water,  giving  a  blue  green  solution. 

The  composition  of  this  salt  on  analysis  corresponds  to 
the  formula  (CuFe)S04,HaO,  or  (Fe5Cu2)(S04)7,7H20. 
These  salts  are  made  by  adding  about  an  equal  bulk  of 
strong  sulphuric  acid  to  solutions  of  the  mixed  sulphates. 

Discussion. 
Mr.  Spiller,  referring  to  investigations  he  had  con- 
duced on  some  double  sulphates  of  this  group,  crystal- 
lised from  water,  the  results  of  which  were  communicated 
to  the  British  Association  ten  years  ago,  said  that  he  was 
led  to  the  conclusion  that  the  amount  of  water  of  crystal- 
lisation in  such  mixed  sulphates  was  the  mean  of  that 
present  in  their  constituent  salts. 

•46.  'M  Synthesis  of  Camphoronic  Acid."  By  William 
Henry  Perkin,  jun.,  F.R.S.,  and  Jocelyn  Field  Thorpe, 
Ph.D. 

In  a  previous  communication  {Proc,  1896,  xii.,  155)  ex- 
periments were  described  dealing  with  the  adion  of 
metallic  zinc  on  mixtures  of  bromo-ethylic  salts  and 
ketones  or  ketonic  acids  ;  notably  on  mixtures  of  ethylic 
aceto-acetate  and  ethylic  a-brom-iso-butyrate,  and  of 
ethylic  dimethylacetoacetate  and  ethylic  bromoacetate, 
and  it  was  shown  that  the  same  hydroxy-ethylic  salt, 
namely,  ethylic-/3-hydroxy-a-a-j8-trimethyl  glutarate  was 
in  each  case  produced  thus : — 


MejtCBr     CO-CHa  Mej-.C-C         CHaBr 

I      4-1        I  and  I    I      +  I 

EtOOC         CHsCOOEt  EtOOC  CH3     COOEt 

give— 

Me2:C-C(0H)CH2 

11  I 

EtOOC  CH3     COOEt 

This  ethylic- P-hydroxyaa-P  trimethylglutarate  (b.  p. 
165°,  30  m.m.),  as  previously  stated,  splits  up,  on  hydro- 
lysis with  alcoholic  potash,  into  acetic  and  isobutyric 
acids.  When,  however,  it  is  boiled  with  dilute  hydro- 
chloric acid,  it  does  not  behave  in  this  way,  but  yields 
considerable  quantities  of  the  corresponding  ^-hydroxy- 
a-a  /3-trimethylglutaric  acid, — 

COOH-C{CH3)2-C(OH)-(CH3)CH2COOH, 
which  is  a  crystalline  body,  separating  from  a  mixture  of 
light  petroleum  and  ethylic  acetate  in   glistening  prisms 
melting  at  128°. 

In  the  previous  communication,  an  acid  melting  at 
148°,  obtained  by  the  adion  of  alcoholic  potassium  cyanide 
on  ethylic-)8-brom-a  a-^-trimethyl  glutarate,  was  described 
as  a  trimethylglutaric  acid  :  we  now  wish  to  corred  this 
statement.  Alcoholic  potassium  cyanide  is  apparently 
without  adion  upon  the  bromethylic  salt  at  the  tempera- 
ture of  the  boiling  water-bath,  and,  on  hydrolysing  the 
produd  with  alcoholic  potassium  hydroxide,  the  un- 
saturated acid,  a-a-P-trimethylglutaconic  acid, — 

COOH-CH:C(CH3)-C(CH3)2COOH, 
melting  at  148°,  is  produced,  and  not  the  trimethyl- 
glutaric acid  as  was  at  first  supposed.  This  acid  is 
remarkably  stable,  and  is  not  affeded  by  boiling  with 
sodium  amalgam.  When,  however,  its  boiling  solution 
in  alcohol  is  treated  with  sodium,  the  unsaturated  acid  is 
gradually  reduced  to  a-a-fi-trimethylglutaric  acid, 
COOHCH2CH^CH3)-C(CH3)2-COOH,  which  crystal- 
lises from  dilute  hydrochloric  acid  in  prismatic  needles 
melting  at  109°;  the  anhydride  of  this  acid  melts  at  38% 
and  yields,  on  treatment  with  aniline,  an  anilic  add 
forming  lustrous  plates  from  dilute  alcohol  melting  at 
155°.  Although  the  melting-points  of  the  acid  and  of  the 
anil  are  very  similar  to  those  of  the  trimethylglutaiic 
acid  which  Balbiano  obtained  from  camphoric  acid,  it 
does  not  appear  that  the  acids  are  identical,  and  it  is 
probable  that  Balbiano's  acid  is  the  isomeric  a-/3-|3-tri- 
methylglutaric  acid, — 

COOHCH(CH3)-C(CH3)2CH2-COOH, 

as  this  chemist  suggests. 

On  treating  ethylic  |8-hydroxy-o  a-/3-trimethylglutarate 
with  phosphorus  pentachloride,  the  chlorethylic  salt, 
namely,  fS-chlor-aa  $-trintethyl  glutarate, — 

COOC2H5C(CH3)2-C(Cl)-(CH3)-CH2-COOC2H5, 
is  obtained  as  a  colourless  mobile  liquid  which  boils  at 
139°  (20  m.m.).  When  this  substance  or  the  corre- 
sponding bromo-derivative  is  heated  with  alcoholic  potas- 
sium cyanide  in  a  closed  tube  at  160°  ethylic-fi  cyano-a-a- 
trimethyl  glutarate, — 

COOEfC(Me2)C-(CN)(Me)-CH2-COOEt, 
is  obtained  after  twelve  hours  as  an  oily  liquid  boiling  at 
180—185°  (25  m.m.).  It  is  difficult  to  isolate  in  the  pure 
condition  owing  to  the  presence  of  varying  quantities  of 
the  ethylic  salt  of  trimethylglutaconic  acid,  a  substance 
which  boils  at  about  the  same  temperature  as  the  nitrite 

(175°.  30  ni-n^  )• 

This  nitrile  was  hydrolysed  by  boiling  with  dilu  e 
hydrochloric  acid,  and  after  filtering  from  the  trimethyl- 
glutaconic acid,  which  separated  on  cooling,  the  filtrate 
yielded  on  neutralisation  with  ammonia  and  addition  of 
barium  chloride  no  precipitate,  but  on  boiling,  a  quantity 
of  a  sparingly  soluble  barium  salt  separated.  This  salt 
was  colleded,  well  washed,  and  decomposed  by  boiling 
with  the  calculated  quantity  of  sulphuric  acid  ;  the  filtrate 
from  the  barium  sulphate  was  then  evaporated  to  a  small 


164 


Liquid  Coherers  and  Mobile  Conductors. 


f  Chemical  News, 
\      April  2,  1897. 


bulk,  when  on  cooling  a  crystalline  acid  separated, 
which  melted  at  157°  with  decomposition,  and  on  analysis 
gave  the  following  numbers: — 

0'i258  grm.  gave  0*2276  grm.  CO2  and  0*0746  grm. 
HaO.  Calc.  for  (C9H14O6):  H  =  6-40;  0  =  49-50.  Found: 
H  =  6*58;  C  =  49'34.  a-a-fi-Triniethyltricarballylic  acid, 
C00H-CH2C(C00H)(Me)C(Me2)C00H. 

That  this  acid  is  identical  with  camphoronic  acid  is, 
in  our  opinion,  proved  by  the  following  considerations  : — 

(i).  The  synthetical  acid  gives  the  same  results  on 
analysis,  and  melts  at  the  same  temperature  as  cam- 
phoronic acid. 

(2)  When  equal  quantities  of  the  synthetical  acid  and 
camphoronic  acid  are  intimately  mixed,  the  mixture  melts 
at  exactly  the  same  temperature,  i.e.,  157°,  with  decom- 
position. 

(3)  It  gives,  when  dissolved  in  a  slight  excess  of  am- 
monia, no  precipitate  with  barium  chloride  until  the  liquid 
is  warmed,  and  then  the  insoluble  barium  salt  separates 
exa(Stly  as  in  the  case  of  camphoronic  acid. 

(4)  When  heated  with  acetyl  chloride,  both  the  acids 
are  converted  into  an  anhydro-acid,  which  melts  in  both 
cases  at  135—136°. 

The  anhydrocamphoronic  acid  from  the  synthetical  acid 
gave  on  analysis  the  following  results  :  —  Found, 
0  =  54*03;  H  =  6-ii.  CgHijOs  Calc.  C=54'oo;  H  =  6*oo 
per  cent. 

In  a  previous  communication  {Proc,  1896,  xii.,  192),* 
one  of  us  had  occasion  to  express  the  opinion  that  Tie- 
mann's  formula  for  camphoronic  acid, — 

COOHCH(CH3)-C(CH3)2CH-(COOH)2, 
which  contains  the  group  -CH(C00H)2  must  be  incor- 
red,  on  account  of  the  fadt  that  camphoronic  acid,  when 
heated  with  water  at  230°,  is  not  decomposed  with 
elimination  of  CO2.  The  experiments  which  we  have 
briefly  described  in  this  communication  appear  to  us  to 
prove  that  camphoronic  acid  has  the  constitution  first 
proposed  by  Bredt  (Ber.,  1893,  xxvi.,  3048),  namely,  that 
of  an  aaj8-iriniethyltricarballylic  acid, — 

COOH-C(CH3)2-CCH3(COOH)-CH2COOH. 

(To  be  continued). 


PHYSICAL     SOCIETY. 
Ordinary  Meeting,  March  26th,  1897. 

Mr.  Shblford  Bidwell,  President,  in  the  Chair. 

At  the  invitation  of  Dr.  S.  P.  Thompson,  the  meeting 
was  held  at  the  Technical  College,  Leonard  Street, 
Finsbury. 

Mr.  RoLLO  Appleyard  read  a  paper  on  "  Liquid 
Coherers  and  Mobile  Conductors,"  and  showed  the  fol- 
lowing experiments : — 

(i.)  A  glass  tube,  containing  mercury  and  paraffin  oil, 
is  shaken  up  until  the  mercury  divides  into  small 
spheroids.  The  resistance  of  the  chain  of  spheroids 
under  these  conditions  is  several  megohms.  Coherence 
can  be  brought  about  by  a  dired  current,  a  spark,  or  by  a 
Hertz  oscillator.  The  coherence  is  visible,  the  spheroids 
forming  into  large  globules.  At  the  same  time,  the 
resistance  falls  to  a  fraftion  of  an  ohm.  (2.)  An  unstable 
emulsion  is  formed  by  shaking  water  and  paraffin  oil  to- 
gether, in  a  glass  tube,  called  by  the  author  a  "rain" 
tube.  The  oil  may  be  coloured  with  alkanet  root.  By 
electrification,  the  water  suspended  in  the  oil  is  suddenly 
precipitated  in  a  shower  through  the  oil,  precisely  as  rain 
is  precipitated  in  the  air,  after  thunder.  (3.)  A  mixture 
of  paraffin  oil  and  water  is  poured  into  a  photographic 


♦  The  formula  given  here  from  Bredt's  constitution  of  camphoronic 
acid  is  a  misprint,  it  should  be — 

COOHC(CH,),-C(CH,)(COOH)— CH,-COOH. 


dish,  just  covering  the  bottom,  and  a  little  mercury  is 
poured  in.  Any  two  separate  globules  of  mercury  in  the 
dish  are  then  conneiSled  by  wires  to  a  battery  of  about 
200  volts,  through  a  reversing-key.  A  momentary  tap  of 
the  key  causes  instantaneous  deformation  of  the  mercury, 
especially  of  the  globule  connected  to  the  negative  pole. 
If  the  current  is  kept  on,  the  negative  globule  sends  forth 
a  long  tentacle  of  mercury  across  the  dish  to  the  positive 
globule.  The  tentacle  may  break  into  spheroids.  Inter- 
mediate globules  send  forth  "  fingers"  towards  the  posi- 
tive terminal-globule,  and,  by  continued  application  of  the 
current,  the  "  fingers  "  link  intermediate  globules, — illus- 
trating the  nature  of  liquid  coherence.  By  using  the 
current-reverser  as  a  telegraphic  transmitting-key,  the 
motions,  to  right  or  left,  of  the  "finger"  of  any  stray 
globule,  may  be  interpreted  to  form  the  letters  of  the 
Morse  code.  By  a  succession  of  taps  of  the  key  in  one 
diredlion  or  the  other,  a  globule  can  be  made  to  "cater- 
pillar" along  the  dish. 

Prof.  Ramsay  said  he  had  once  attempted  to  facilitate 
churning  by  the  application  of  8  or  g  volts  to  some  milk. 
He  thought  the  cream  came  a  little  faster,  but  it  turned 
sour  very  quickly. 

Prof.  Fitzgerald  thought  that  the  effeds  observed  in 
experiment  3  were  the  result  of  current,  and  not  of  eledro- 
static  changes ;  and  he  would  like  to  know  the  value  of 
the  adlual  current  used.  There  was  no  doubt  that  the 
motions  were  due  to  variations  in  capillarity. 

Mr.  Shelford  Bidwell  asked  how  the  mercury  was 
formed  into  spheroids  in  the  tube  in  experiment  i. 

Mr.  Appleyard,  in  replying  to  Prof.  Fitzgerald,  said  it 
was  not  easy  to  define  the  circuit,  as  the  terminal-globules 
were  rather  capricious,  but  he  would  try  and  measure  the 
current  in  some  particular  case.  The  mercury-tube  in 
experiment  i  was  shaken  in  a  horizontal  plane ;  the 
operation  took  about  ten  minutes.  Equal  volumes  of 
mercury  and  oil  was  a  good  proportion.  One  quarter  of 
the  length  of  the  tube  should  be  left  as  an  air-space. 

Prof.  Dalby  then  exhibited  five  pieces  of  apparatus:  — 
(i.)  A  Kinematic  Slide.  (2.)  An  Inertia  Apparatus  with 
trifilar  suspension,  (3,)  A  Wilberforce  Spring.  (4.)  An 
Ewing's  Reading-telescope.  (5.)  A  Kinematic  Hook- 
gauge.  Models  I,  2,  4  and  5  illustrated  the  various 
degrees  of  freedom  of  bodies  restrained  at  different  num- 
bers of  points.  It  was  shown  with  3  that  in  extending  a 
spiral  spring  there  results  a  certain  amount  of  twisting. 
If  a  mass  is  hung  at  the  lower  end  of  the  spiral  in  such  a 
way  that,  when  suddenly  released  after  extension  of  the 
spring,  the  time  of  oscillation  of  the  mass  in  the  horizon- 
tal plane  (rotation)  is  the  same  as  the  time  of  vertical 
oscillation,  then  the  tendency  to  twist  results  in  a  change 
of  energy  which  alternates  between  the  rotary  and  linear 
forms. 

Mr.  Boys  drew  attention  to  the  conditions  of  restraint, 
and  suggested  a  criterion  for  determining  whether  a  piece 
of  mechanism  was  designed  for  minimum  strain  on  the 
strudure  :  a  thin  wedge  slipped  under  any  one  point  of 
contadt  should  not  disturb  the  other  points  of  restraint. 

Prof.  Fitzgerald  pointed  out  the  effedl  of  symmetry 
upon  the  motion  of  the  spring  of  5.  The  spiral  hap- 
pened  to  be  an  unsymmetrical  form  ;  the  change  of  phase 
from  vertical  to  rotary  oscillation  was  therefore  rapid.  In 
the  case  of  the  vibration  of  a  symmetrical  stretched  cord 
the  change  of  phase  would  be  very  slow. 

Dr.  Thompson  exhibited  two  Kinematic  Models  de- 
pending upon  the  principle  that  any  simple  harmonic 
motion  may  be  considered  as  the  resultant  of  two  oppo- 
sitely direded  motions.  The  first  illustrates  the  synthesis 
of  two  opposite  circular  motions  of  equal  period  and 
magnitude  to  form  a  straight  line  motion  ;  the  second 
shows  the  combination  of  two  simple  harmonic  motions 
of  equal  period  and  amplitude  in  any  difference  of  phase, 
to  form  a  circular  motion.  In  each  case  the  motion  is 
communicated  to  a  stylus  by  a  link-gear,  operated  by  two 
wheels  rotating  in  opposite  diredions.     In  the  first  appa- 


Chemical  Nbwb, 
April  2,  1897. 


Principles  and  Practice  of  Agricultural  Analysis. 


165 


ratus  the  wheels  are  pivoted  about  their  centres,  and  the 
link-gear  is  pinned  to  one  point  on  the  flat  surface  of  each 
wheel,  near  the  circumference  ;  in  the  second  apparatus 
the  wheels  rotate  as  eccentrics  at  180°  to  one  another,  and 
the  motion  to  the  link-gear  is  communicated  by  thrust- 
rods,  held  by  springs  against  the  peripheries  of  the 
corresponding  wheels. 

Dr.  Thompson  further  exhibited  a  device  for  proje(5ling, 
by  lantern,  the  rotating  magnet  and  copper  disc  of  Arago, 
The  curious  rotations  and  lateral  movements  of  iron- 
filings,  in  a  revolving  magnetic  field,  were  similarly  pro- 
jedted  on  a  screen.  He  also  showed  some  experiments 
with  a  heat-indicating  paint,  made  from  a  double  iodide 
of  copper  and  mercury,  discovered  twenty  years  ago  by  a 
German  physicist.  At  ordinary  temperatures  the  paint  is 
red,  but  at  97°  it  turns  black.  If  paper  is  covered  with 
this  substance,  and  then  warmed  at  a  stove,  the  change 
is  effeded  in  a  few  seconds.  Various  designs  can  be 
wrought  upon  the  back  of  the  paper  in  dead-black  or  gold, 
so  that  when  warmed  they  appear  in  red  or  black  on  the 
front,  according  to  their  respedive  absorptive  powers.  Or 
local  cooling  by  the  hand  will  yield  a  silhouette.  If  the 
paper  is  allowed  to  cool,  the  silhouette  vanishes,  but  it 
appears  again  when  the  paper  is  re-heated.  It  has  thus 
a  kind  of  thermal  "  memory."  A  yellow  double  iodide  of 
silver  and  mercury  is  even  more  sensitive.  It  changes 
from  yellow  to  dark  red  at  45°  C. 

Lastly,  Dr.  Thompson  exhibited  a  Kinematic  Model  of 
Hertz-wave  Transmission.  A  row  of  lead  bullets  is  sus 
pended  from  strings,  so  that  the  bullets  hang  clear  of  one 
another  by  about  an  inch,  in  a  right  line.  The  strings 
are  meshed,  and  herein  the  model  differs  from  the  well- 
known  wave-models  used  in  acoustics.  If  the  attempt  is 
made  to  send  an  acoustic  form  of  wave  through  the 
system,  by  giving  an  impulse  to  the  first  bullet  in  the 
plane  of  the  other  pendulums,  it  fails  immediately,  owing 
to  the  slackening  of  parts  of  the  meshes.  Thus  only 
transverse  vibrations  can  be  transmitted.  To  illustrate 
the  propagation  of  a  Hertz-wave,  a  heavy  pendulum, 
oscillating  in  a  plane  at  right  angles  to  the  line  of  bullets, 
atone  end,  represents  the  Hertz  "  oscillator."  A  metal 
ring,  mounted  horizontally  on  a  trifilar  suspension,  and 
properly  "  tuned,"  represents,  at  the  distant  end,  the 
Hertz  "resonator."  Waves,  formed  by  the  transverse 
vibrations  of  successive  bullets,  are  then  propagated  from 
end  to  end. 

Prof.  Fitzgerald  said  the  model  was  specially  inte- 
resting as  illustrating  the  difference  in  velocities  of  pro- 
pagation of  a  given  wave,  and  of  the  energy  corresponding 
to  it.  The  model  did  not  accurately  compare  with  ether, 
because  in  ether  the  rate  at  which  the  energy  is  propa- 
gated is  the  same  as  that  of  the  wave.  The  difference  of 
the  two  rates,  for  any  medium,  depended  upon  the 
"dispersion"  of  the  medium.  By  slight  alteration  of  the 
pendular-suspensions  this  dispersion  might  be  made 
different  at  different  parts  of  the  model,  and  would  then 
correspond  to  certain  known  cases  of  "  anomalous  "  dis- 
persion. Or  again,  it  might  be  made  to  illustrate  the 
theory  of  Helmholtz  with  regard  to  the  vibrations  of  the 
molecules  of  glass;  according  to  which,  the  vibration  of 
the  molecules  alters  the  vibrations  of  the  waves,  so  that 
dispersion  occurs,  and  the  energy  is  not  propagated  at  the 
same  rate  as  the  waves  themselves.  It  was  shown  by 
Michaelson  that  it  was  possible  to  have  a  medium  in 
which  the  energy  is  propagated  in  one  diredion  and  the 
wave  in  another.  This  was  attained,  in  a  magnetic 
model,  by  Ewing.  The  mesh  apparatus  indicated  how  a 
model  could  be  made  which  should  give  our  "  harmonics" 
and  "  over-tones  "  very  different  from  one  another ;  where 
different  wave-lengths  would  be  propagated  with  different 
velocities,  and  the  over-tones  would  correspond  to  the 
differences.  Further,  it  indicated  a  mechanism  for  pro- 
ducing any  desired  8pe(5lrum,  such,  for  instance,  as  that 
of  hydrogen.  A  somewhat  similar  model  had  been  de- 
signed by  Glazebrook  for  illustrating  the  absorption-bands 
of  a  medium  when  the  rate  of  vibration  was  the  same  as 


the  free  period  of  the  vibrations  of  each  of  the  molecules, 
which  is  the  theory  of  Helmholtz,  but  it  was  not  such  a 
simple  model.  The  experiment  of  red  paper  changing  to 
black  was  interesting  as  illustrating  a  red  spedlrum  varying 
with  temperature. 

Mr.  Shelford  Bidwell  proposed  a  vote  of  thanks  to 
all  the  exhibitors,  and  the  Society  adjourned  until 
April  gth. 


NOTICES  OF  BOOKS. 


Principles  and  Practice  of  Agricultural  Analysis :  a 
Manual  for  the  Examination  of  Sjils,  Fertilisers,  and 
Agricultural  Produds.  For  the  Use  of  Analysts, 
Teachers,  and  Students  of  Agricultural  Chemistry. 
Vol.  III.  —  Agricultural  Prodticts.  By  Harry  W. 
Wiley,  Chemist  to  the  U.S.  Department  of  Agricul- 
ture. Easton,  Pennsylvania:  Chemical  Publishing  Co. 
1897.     Pp.  644. 

This  volume  opens  with  a  carefully  compiled  dissertation 
on  sampling,  drying,  incineration,  and  extradion — 
subjedls  in  which  it  is  possible,  even  for  experienced 
praditioners,  to  go  astray,  with  grievous  inconvenience 
and  injury  to  their  professional  reputation. 

As  regards  the  scope  of  the  work,  we  note  that  whilst 
hops  are  included,  opium  with  of  course  morphia  are  left 
outside  the  pale.  Nor  are  organic  matters,  odoriferous 
and  tindlorial,  admitted,  except  as  regards  the  pigments 
of  wines.  The  importance  and  the  delicacy  of  the  pro- 
cedures for  desiccation  and  incineration  are  certainly  not 
exaggerated.  The  apparatus  for  dyeing  samples  m  vacuo 
or  in  currents  of  inert  gases,  though  somewhat  compli- 
cated, will  be  found  of  great  utility. 

Part  II.  is  devoted  to  sugars  and  starches.  In  consi- 
dering the  areometric  method  for  the  determination  of 
sugars,  we  regret  to  find  the  total  omission  of  Twaddle's 
instrument  and  scale  in  favour  of  Baume. 

Part  III.  treats  of  the  separation  and  determination  of 
carbohydrates  in  agricultural  produdls,  crude  and  manu- 
fadured;  and  Part  IV.  deals  with  fats  and  oils.  Here 
the  usual  analytical  methods  are  expounded.  It  is  truth- 
fully admitted  that  the  spedroscope  is  of  little  pradical 
utility  in  oil  analysis. 

In  the  fifth,  sixth,  and  seventh  parts,  we  find  an  ac- 
count respedively  of  the  separation  and  determination  of 
nitrogenous  bodies,  of  dairy  produce,  and  of  miscellaneous 
agricultural  produds.  Here  the  defeds  of  ensilage  are 
admitted.  The  writer  condemns  as  fraudulent  the  sale 
of  horse  flesh  as  beef  and  pork,  but  he  rightly  holds  that 
it  is  unobjedionable  if  sold  under  its  own  name. 

The  author's  orthography  is  apt  to  set  the  teeth  of  us 
Britishers  on  edge,  and  raises  the  question  why,  if 
Americans  have  gone  so  far  in  the  "  fonetic  "  diredion, 
they  do  not  fully  adopt  the  code  of  the  spelling  re- 
formers ? 

Concerning  the  value  of  Mr.  Wiley's  work  as  a  whole, 
there  can  be  no  difference  of  opinion. 


Chapters  on  the  Aims  and  Practice  of  Teaching.  Edited 
by  Frederick  Spencer,  M.A.,  Ph.D.,  Professor  of  the 
French  Language  of  Literature  at  the  University  Col- 
lege of  North  Wales;  formerly  Chief  Master  on  the 
Modern  Side  at  the  Leys  Schools,  Cambridge.  Cam- 
bridge :  University  Press.     1897.     8vo.,  pp.  284. 

Much  of  this  book  deals  with  subjeds  on  which  our 
opinion  is  little  more  valuable  than  that  of  the  "  man  in 
the  street."  At  the  same  time,  whilst  admitting  the 
wealth  of  thought  which  is  here  put  forth,  we  must  pre- 
sume to  express  our  regret  at  the  predominating 
"  verbalism  "  of  some   of  the   writers.     Too   often  they 


1 66 


The  Chemical  Society  Election. 


ICbbmical  Nbws, 

\       April  2,  1897. 


seem  to  forget  the  glaring  {&&.&  that  so  long  as  boys  are 
compared  by  the  figure  which  they  make  in  classical  sub' 
jedts  the  gravest  mistakes  are  committed.  Every  one 
knows  that  Justus  Liebig  and  Charles  Darwin  were  in  their 
school-days  set  down  as  hopeless  dunces.  But  when 
released  from  verbalism  they  became,  each  in  his  depart- 
ment, great  creative  spirits,  of  more  value  to  the  world 
than  generations  of  grammarians.  Yet  one  of  the 
writers  here  before  us  "  has  no  hesitation  in  saying  that, 
on  the  average,  boys  trained  on  the  classical  side  of  our 
public  schools  make  better  men  of  science  and  medicine 
than  the  boys  who  come  to  the  University  from  the 
modern  side ;  for  the  classics  develop  the  power  of  sus- 
tained and  orderly  thinking!  "  Our  conclusion  is,  that 
the  power  of  sustained  and  close  observation,  as  required 
by  the  chemist  and  the  biologist,  is  checked  by  classical 
studies.  The  writer  seems  to  detedl  objedtions  to  the 
study  of  physiology  which  strike  us  as  singular.  The 
••honest  boy"  discussed  on  p.  275  must  be  a  morbid,  and 
we  believe  a  rare,  phenomenon. 

The  objedlions  urged  against  zoology,  as  tending  •'  to 
become  uncleanly,"  cannot  apply  to  its  widest,  most  inte- 
resting, and  at  the  same  time  most  utilitarian  department 
— entomology. 

The  writers  of  these  "  Chapters  "  merit  full  recognition 
as  being  unfriendly  to  the  modern  educational  idol, 
examinationism.  Hence  we  must  conscientiously  and 
warmly  recommend  it  to  the  heads  of  colleges. 


CORRESPONDENCE. 


Th$  University  of  Nebraska.    Calendar,  1896-1897. 

The  University  of  Nebraska  is  in  some  respe(5ts  excep 
tional  in  its  constitution.  Unlike  the  German  universities, 
but  like  those  of  Britain,  it  has  what  we  may  venture  to 
call  a  faculty  of  music.  Unlike  all  the  European  seats 
of  learning,  it  includes  painting,  sculpture  and  archi- 
tedlure,  and  elocution  and  oratory  in  its  scope.  In  other 
words,  according  to  Seiflion  5211  of  its  Rules,  it  comprises 
a  college  of  literature,  science,  and  art;  secondly,  an  indus- 
trial college,  embracing  agriculture,  pradlical  science,  civil 
engineering,  and  the  mechanical  arts  ;  third,  a  college  of 
law  ;  fourthly,  a  college  of  medicine  ;  fifthly,  a  college  of 
the  fine  arts. 

Sedtion  5221  ena(Sts  that  no  person  shall — because  of 
age,  sex,  colour,  or  nationality — be  excluded  from  the 
privileges  of  this  institution.  This  sweeping  proviso 
might,  we  submit,  be  amended  by  fixing  a  junior  limit  of 
age  for  matriculation.  For  "colour"  we  would,  had  we 
the  right  to  interfere,  substitute  "  race." 

There  is  here,  as  it  appears  to  us,  too  great  a  tendency 
to  commit  different  duties  to  one  and  the  same  person. 
Thus  we  find  a  professor  of  entomology,  ornithology,  and 
taxidermy.  Taxidermy  is  generally  the  duty  of  the 
curator  or  ••custos."  We  perceive  that  there  are  at  the 
Nebraska  University  a  chemical  laboratory,  a  philoso- 
phical laboratory,  and  a  physical  laboratory,  as  well  as  a 
botanical  and  an  eledrical.  It  must  be  at  times  difficult 
to  define  the  scopes  and  duties  of  the  different  labora- 
tories. 

The  '•sugar  school"  confines  its  attention  to  pradtical 
study  of  the  beet  sugars. 

A  branch  of  study,  concerning  which  we  feel  in  some 
doubt,  is  known  as  "  civics,"  and,  considered  in  con- 
jundion  with  political  economy,  "  eledtives  "  may  mean 
optional  courses  of  study. 

There  is  also  a  department  for  military  studies,  doubt- 
less for  tallies  and  strategy. 


New  Process  of  Sterilisation  by  Heat  under  Pres- 
sure.— W.  Kiihn. — The  author's  experiments  show  that 
when  the  conditions  of  heating  prevent  all  loss  of  gas  and 
of  aromatic  and  volatile  principles  the  liquid  is  unchanged 
in  its  argonoleptic properties. — Compt.Rend,,  cxxiv.,  No.  g. 


THE    CHEMICAL    SOCIETY    ELECTION. 

To  the  Editor  of  the  Chemical  News, 

Sir, — At  the  Chemical  Society  meeting,  March  18,  1897, 
I  made  the  statement  that  the  nomination  of  Professor 
W.  Ramsay  as  a  candidate  for  the  Presidentship  of  the 
Chemical  Society  was  made  without  his  knowledge  or 
consent.  To  the  best  of  my  belief,  and  so  far  as  I  have 
any  means  of  judging,  that  was  an  accurate  statement. 
I  have  seen  a  letter  in  the  Chemical  News  from  Prof. 
Armstrong  in  which  he  "ventures  to  doubt  the  accuracy 
of  that  statement."  I  wish  to  state  distindly  that  he  has 
no  ground  whatever  for  his  doubt.  When  I  made  my 
statement  I  was  sure  of  my  fads  and  I  am  so  still. — I  am, 
&c., 

J.  Norman  Collie. 

16,  Campden  Grove,  Kensington,  W., 
April  1, 1897. 


THE   NEW  SCIENTIFIC   CLUB. 

To  the  Editor  of  the  Chemical  News. 
Sir, — My  attention  has  been  called  to  the  fadt  that  my 
name  appears  on  a  circular,  signed  "  Robert  Ingram," 
relating  to  the  proposed  formation  of  a  new  Scientific 
Club.  I  wish  to  say  that  the  use  of  my  name  in  this  con- 
nexion is  entirely  unauthorised.  I  have  no  intention  of 
joining  any  Club  promoted  by  Mr.  Robert  Ingram. — I  am, 
&c., 

T.  E.  Thorpe. 
March  25, 1897. 

TEACHING    OF    CHEMISTRY. 

To  the  Editor  of  the  Chemical  News, 
Sir, — The  importance  of  this  subjedl  is  the  only  apology 
I  offer  for  reopening  the  discussion.     Its  importance  to 
the  rising  generation  of  chemists,  manufacturers,  &c.,  is 
obvious. 

Mr.  Beebe  adduces  three  reasons  why  the  novice,  at 
the  outset  of  his  career,  should  not  devote  his  time  to 
the  preparation  of  gases,  salts,  and  such  like.  I  will  take 
them  in  order : — 

1.  That  they  are  dangerous. — Mr.  Wigley,  who,  judging 
from  his  letter,  must  have  had  a  lengthened  experience  as 
a  teacher  of  chemistry,  says  "that  there  is  more  danger 
in  acid  from  a  test-tube  being  boiled  over  a  neighbour's 
face  than  in  making  hydrogen."  I  agree  with  him  ;  for, 
as  far  as  my  experience  goes,  I  have  never  seen  any  one 
hurt  in  the  preparation  of  the  latter,  whereas  several  in- 
stances have  come  under  my  notice  in  which  boiling 
acid  or  other  liquid  has  been  shot  out  into  a  fellow 
student's  face. 

2.  Failure  in  connecting  the  various  etiperiments.  —  I 
think  the  boot  is  on  the  other  foot.  There  is  a  great 
similarity  between  a  good  many  of  the  experiments 
leading  from  one  thing  to  another.  Take  as  an  example 
KC103,NH4N03,NH4N02,H2C204,  and  many  other  sub- 
btances  which,  when  heated,  split  up  into  simpler  bodies, 
whereas  in  precipitating  a  substance  a  more  complex 
compound  is  often  produced. 

3.  Does  not  awaken  and  hold  students^  interests  like 
Qualitative  Analysis.  —  My  answer  to  this  is,  if  the 
student  is  guided  aright  he  very  soon  acquires  sufficient 
powers  of  observation  to  find  them  interesting,  and  he 
gets  a  thorough  grounding  in  the  fundamental  truths  of 
chemistry  whereby  he  may  become  a  sterling  and 
intelligent  chemist.  Such  has  been  my  experience  of 
students. 

Mr.  Beebe  remarks  that  ledlure  experiments  are  unne* 


Chkuical  Nxws,  I 
April  2, 1897.  it  f 


Chemical  Notices  from  Foreign  Sources, 


167 


cessarily  complex,  and  students'  ideas  confused  and  hazy. 
Does  not  this  statement  controvert  his  own  objeAion  to 
the  students  performing  his  own  experiments  ? 

To  commence  a  beginner's  course  of  chemistry  with 
qualitative  analysis  is  tantamount  to  teaching  a  boy  who 
is  intended  to  become  a  musician  the  art  of  turning  the 
handle  of  a  barrel  organ.  A  novice  is  incapable  of 
intelligently  understanding  what  he  does  in  qualitative 
analysis,  or  why  he  does  it.  I  agree  with  Mr.  Beebe  that 
the  first  lessons  should  be  as  simple  as  possible.  But 
which  is  the  easier  for  the  young  student  to  under- 
stand  (I  take  the  simplest  instance  in  each  case), 
AgN03  +  HCl  =  AgCl  +  HN03  or  HgO  =  Hg  +  0?  I  say 
most  decidedly  the  latter. 

I  regret  to  find  that  Mr.  Beebe  thinks  a  man  is  a  "  real 
chemist "  when  he  can  work  through  an  arbitrary  analy- 
tical table  and  discover  what  a  simple  salt  is.  I  have 
met  with  men  capable  of  telling  most  ordinary  substances 
simply  by  looking  at  them,  and  who  had  no  idea  of  the 
readlion  that  occurs  when  carbon  is  burnt.  These  I  pre- 
sume must  be  more  "  real  chemists  "  still, — I  am,  &c., 
C.  SoRDES  Ellis,  A.I.C,  F.C.S., 

The  Technical  School,  Late  Demonstrator  to  the  Pharm. 

Radcliffe,  Lancashire,  Soc.  of  Great  Britain. 

March  19, 1S97, 


CHEMICAL 


NOTICES   FROM 
SOURCES. 


FOREIGN 


Note.— All  degrees  of  temperature  are  Centigrade  unless  otherwise 
expressed, 

Comptes  Rendus  Hebdomadaires  des  Seances,  deVAcademit 
des  Sciences.    Vol.  cxxiv.,  No.  10,  March  8,  1897, 

Researches  on  the  Earths  contained  in  Monazitic 
Sands.  —  MM.  Schiitzenberger  and  Boudouard.  —  The 
authors  have  separated:  —  i.  A  cerium  of  an  atomic 
weight  bordering  upon  138  or  somewhat  lower,  the  solu- 
tion of  which  is  not  precipitated  by  copper  oxide.  2.  A 
cerium  of  an  atomic  weight  close  upon  148,  the  sulphate 
of  which  is  precipitable  by  copper  oxide  and  also  by 
sodium  sulphate.  3.  A  cerium  of  an  atomic  weight  close 
upon  157,  its  sulphate  being  precipitable  by  copper  oxide, 
but  not  by  sodium  sulphate.  The  solutions  of  this  sul- 
phate are  charadlerised  by  the  gummy  aspecSt  which  they 
take  during  concentration.  These  three  earths  yield 
yellow  eerie  salts  decomposable  by  heat  into  white  cerous 
salts.  Hydrogen  peroxide  with  soda  precipitates  them 
with  an  orange-red  colour.  Ammonium  oxalate  precipi- 
tates all  these,  and  the  precipitates  are  not  soluble  in  a 
cold  excess  of  the  reagent.  No  difference  between  the 
three  earths  is  dete(5ted  on  spedlroscopic  examination. 
The  portion  soluble  in  neutral  ammonium  oxalate,  and 
not  precipitable  by  sodium  sulphate,  does  not  display  the 
coloured  readions  of  cerium.  It  belongs  to  the  thorium 
group.  The  experiments  indicate  that  we  have  not  to  do 
with  a  homogeneous  produdl. 

Apparatus  employed  for  Collecting  Air  at  Great 
Heights  in  the  Ascent  of  the  Aerophile  on  February 
18,1897.  Analysis  of  the  Air  colle(5\ed. — L.  Cailletet, 
— In  100  vols,  of  air  deprived  of  carbonic  acid,  and  taken 
at  the  height  of  15,500  metres,  there  was  found — 

Oxygen        2079  vols. 

Nitrogen      78*27     „ 

Argon 0-94     „ 

The  ratio  of  argon  to  the  total  of  nitrogen  plus  argon 
=  0*01185. 

Adtion  of  Phosphorus  upon  Gold.  —  A.  Granger.  — 
The  author,  after  referring  to  the  experiments  of  Schrot- 
ter,  Hautefeuille,  and  Perry,  states  that  he  has  obtained 
a  gold  phosphide,  AU3P4,  of  a  grey  colour    and  very 


brittle.  It  is  easily  destroyed  if  heated  in  contact  with 
air,  and  is  readily  attacked  by  chlorine  and  aqua  regia. 

Determination  of  Antimony  as  Peroxide.  —  H. 
Baubigny. — This  paper  will  be  inserted  in  full. 

Action  of  Free  Bases  upon  Salts. — Albert  Colson. — 
The  decomposition  of  ammoniacal  salts  is  a  phenomenon 
of  heterogeneous  dissociation,  comparable  to  the  decom- 
position of  lead  chloride  by  sulphuric  acid. 

A  New  Derivative  of  Phenylisindazol  obtained  by 
the  A(5tion  of  Salicylic  Aldehyd  upon  Phenyl- 
hydrazin. — H.  Causse. — The  produdt  of  the  readlion  of 
salicylic  aldehyd  upon  phenylhydrazin  has  been  hitherto 
regarded  as  a  hydrazone  with  the  melting-point  at  142°, 
The  produdt  which  we  have  obtained  has  a  composition 
agreeing  with  the  formula  C12H10N2.  When  pure  and 
dry  it  forms  stable,  colourless  needles,  which  turn  green 
on  exposure  to  light,  and  melt  without  decomposition  at 
142°.  Ferric  chloride  occasions  no  change  of  colour,  and 
Fehling's  liquid  effeds  no  redudion. 

Action  of  Tannin  upon  some  Alkaloids. — CEchsner 
de  Coninck.  —  The  author  takes  0*0834  g^m.  pure  dry 
tannin  and  4*610  grms.  pure  tannin.  On  mixing  the  two 
substances  no  precipitation  is  occasioned,  though  the 
tannin  becomes  moist  and  is  gradually  dissolved.  The 
liquid  is  placed  above  sulphuric  acid,  when  in  about  three 
days  it  deposits  a  viscid  mass,  insoluble  in  cold  water. 
The  author  introduces,  into  a  very  strong  aqueous  solu- 
tion of  pyridine,  a  little  pure  tannin,  when  there  is  no 
precipitation,  but  the  tannin  rapidly  forms  a  viscid  mass. 
A  solution  of  tannin  serves  for  the  ready  distinction  of 
pyridine  and  piperidine. 

Employment  of  Cryoscopy  in  the  Analysis  of 
Milk. — MM.  Bordas  and  Ganin. — The  authors  maintain 
that  it  is  impossible  to  admit  the  constant  congelation 
point  of  milk. 

MISCELLANEOUS. 

Chemical  Society. — Anniversary  Meeting. — At  the 
General  Meeting  held  at  the  Society's  Rooms,  Wednesday, 
March  31st,  1897,  Professor  Dewar,  F.R.S.,  was  eledled 
President.  The  meeting  was  the  fullest  on  record,  between 
300  and  400  Fellows  being  present. 


MEETINGS    FOR    THE    WEEK. 

Monday,  5th,— Society  of  Arts,  4  30.    (Cantor  Leftures).    "  Alloys," 
by  Prof.  W.  Chandler  Roberts-Austen,  F.R.S. 

Society  of  Chemical  Industry,  8.    Eleftion  of  OfBcers 

and  Five  Memb-rs  of   Committee.      "  Chemical 
Stability  of  Nitro-compound  Explosives,"  by  O. 
Guttmann,  K.LC. 
Tuesday,  6th. — Royal  Institution,   3.       "  Animal     Eledlricity,"  by 
Prof.  A.  D.  Waller,  F.R.S. 

Society  of  Arts,  8.      "  Recent  Travels  in  Rhodesia 

and  British  Bechuanaland,"  by  C   E.  Fripp. 
Wednesday,  7th.— Society  ot  Arts,  8       "Dairy  Produce  and  Milk 

Supply,"  by  M,  J,  Dunstan,  F.R.S. E. 
Thursday.  8th.— Royal  Institution,  3.       "  The  Relation  of  Geology 
to  History,"  Bv  Prof.  W.  Boyd  Dawkins,  M..\., 
F.R.S.,  F.3.S. 
Friday,  gth. — Royal  Institution,  9.      "  The  Limits  of  .\udition,"  by 
Lord  Rayleigh,  F.R.S. 

Physical,  5.     "  A  Nickel  Stress  Telephone,"  by  T.  A, 

Garrett,  M.A.,  and  W.  Lucas,  M.A.      "On   Alter- 
nating Currents   in  Concentric  Condu(5lors,"  by  W. 
A.  Price,  M.A.      "  Effeft  of  Capacity  on  Stationary 
EleArical  Waves  in  Wires,"  by  W.  B.  Morton,  M.A. 
Saturday,  10th. — Royal  Institution,  j.    "  Electricity  and  Electrical 
Vibrations,"  by  Right  Hon.  Lord  Rayleigh,  M.A., 
F.R.S. 


TO    CORRESPONDENTS. 

D.  W .  Birch. — Write  to  the  author  of  the  paper,  care  of  the  Secre- 
tary of  the  Academy  of  Sciences,  53  Quai  des  Grands- Augustins, 
Paris. 

H.l.  Foifen— Consult  "  The  Praftical  Methods  of  Organic  Che- 
mistry," by  L.  Gattermann.    Published  by  Macmillan  &  Co.,  189G. 


i68 


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Chbmical  Nbws,  I 
April  9, 1897.      I 


Gases  enclosed  in  Crystalltne  Rocks  and  Minerals. 


169 


THE    CHEMICAL     NEWS 


Vol.  LXXV.,  No.  1950. 


ON  THE   GASES  ENCLOSED   IN    CRYSTALLINE 

ROCKS  AND    MINERALS.* 

By    W.    A.    TILDEN,    D.Sc,   F.R.S. 

It  has  long  been  knownf  that  many  crystallised  minerals 
contain  gas  enclosed  in  cavities  in  which  drops  of  liquid 
are  also  frequently  visible.  The  liquid  often  consists  of 
Waaler,  occasionally  of  hydrocarbons,  and  not  unfrequently 
of  carbon  dioxide,  the  latter  being  recognisable  by  the 
peculiarities  of  its  behaviour  under  the  application  of  heat. 
The  liquid  supposed  to  be  carbon  dioxide  has  been  found 
in  some  cases  to  pass  from  the  liquid  to  the  gaseous 
state,  and  therefore  to  disappear,  and  to  return  from  gas 
to  liquid  at  temperatures  lower  by  two  or  three  degrees 
than  the  critical  point  of  carbon  dioxide.  This  seems  to 
indicate  the  presence  of  some  incondensable  gas,  and  as 
H.  Davy  found  nitrogen  in  the  fluid  cavities  of  quartz,  it 
seemed  probable  that  the  alteration  of  the  critical-point 
was  due  to  that  gas. 

My  attention  was  drawn  to  this  subjeft  by  the  observa- 
tion that  Peterhead  granite,  when  heated  in  a  vacuum, 
gives  off  several  times  its  volume  of  gas,  consisting,  to  the 
extent  of  three-fourths  of  its  volume,  of  hydrogen  (Roy. 
Soc.  Proc,  vol.  lix.,  p.  218).  < 

Since  this  observation,  I  find  that  the  presence  of  hy- 
drogen in  crystalline  rocks  has  been  recognised  by  other 
observers,  notably  by  A.  W.  Wright  (Amer.  J.  Set.,  vol. 
xii.,  p.  171).  In  the  course  of  a  study  of  the  gases  from 
meteorites,  Wright  obtained  from  a  certain  "  trap  "  rock, 
the  origin  and  oharader  of  which  is  not  stated,  at  a  low 
red  heat,  "  about  three-fourths  of  its  volume  of  mixed 
gases,  which  were  found  to  contain  about  13  per  cent  of 
carbon  dioxide,  the  residue  being  chiefly  hydrogen. 
Another  specimen  of  trap  containing  small  nodules  of 
anorthite  was  examined  at  the  request  of  Mr.  G.  W. 
Hames,  who  had  observed  gas  cavities  in  a  thin  sedlion 
of  the  mineral  prepared  for  microscopic  examination. 
This  gave  off  somewhat  more  than  its  own  volume  of  gas, 
which  was  found  to  contain  some  24  per  cent  of  carbon 
dioxide." 

Professor  Dewar  and  Mr.  Ansdell  have  also  examined 
one  or  two  rocks  in  the  course  of  their  researches  on 
meteorites  (Roy.  Inst.  Proc,  1886).  They  found  that  both 
gneiss  and  felspar,  containing  graphite,  yield  gas,  which, 
upon  analysis,  was  found  to  have  the  composition  stated 
below  : — 


Occluded  gas 
in  volumes     CO,, 
of  the  rock. 


CO. 


H,. 


CH«. 


Gneiss     ..     532        82-38      2-38      13-61      0-47       1-20 
Felspar  ..     1*27        9472      o'8i        221      o'6i       i"40 

Dewar  and  Ansdell  remark  that  "  the  small  quantity  of 
marsh  gas,  no  doubt,  comes  from  the  disseminated 
graphite,  but  the  presence  of  the  hydrogen  is  more  diffi- 
cult to  explain,  and  requires  further  investigation." 

I  have  lately  been  following  up  this  question,  and  have 
obtained  results  which  present  some  points  of  considerable 
interest.  For  materials  I  have  been  indebted  chiefly  to 
my  colleague,  Professor  Judd,  who  has  also  supplied  in- 

•  A  Paper  read  before  the  Royal  Society,  March,  1897. 

t  The  chief  literature  of  this  subjeft  is  contained  in  the  following 
papers  :— Brewster,  R.  S.  Edin.  Trans.,  1824,  vol.  x.,  p.  i ;  Edin.  J. 
Science,  vol.  vi.,  p.  115;  Simmler,  Pogg.  Ann.,  vol.  cv.,  p.  460; 
Sorby  and  Butler,  Roy.  Soc.  Proc,  vol.  xvii.,  p.  291 ;  Vogelsang  and 
Geissler,  Pogg.  Ann.,  vol.  cxxxvii.,  pp,  56  and  257  ;  Hartley,  C.  S, 
Trans.,  1876,  vol.  i.,  p.  137,  and  vol.  ii.,  p.  237. 


formation  as  to  the  probable  geological  age  of  the  speci- 
mens of  rocks  and  minerals  tested.  All  that  I  have  ex- 
amined yield  permanent  gas  when  heated  in  a  vacuum. 
This  gas  varies  in  amount  from  a  volume  about  equal  to 
that  of  the  rock  or  mineral  to  about  eighteen  times  that 
volume.  It  usually  consists  of  hydrogen  in  much  larger 
proportion  than  that  found  by  the  observers  just  quoted, 
together  with  carbon  dioxide  and  smaller  quantities  of 
carbon  monoxide  and  hydrocarbons.  Every  specimen  has 
been  examined  by  the  spectroscope  for  helium,  but  in  no 
case  could  D3  be  recognised,  or  any  other  line  which 
would  lead  to  a  suspicion  of  the  presence  of  this  sub- 
stance. The  gas  is  very  frequently,  but  not  always, 
accompanied  by  water  in  notable  quantities. 

The  gas  is  apparently  wholly  enclosed  in  cavities  which 
are  visible  in  thin  secftions  of  the  rock  when  viewed  under 
the  microscope,  but  as  they  are  extremely  minute,  very 
little  gas  is  lost  when  the  rock  is  reduced  to  coarse  powder, 
and  as  a  result  of  experiment  in  one  or  two  cases,  I  find 
that  pradlically  the  same  amount  of  gas  is  evolved  on 
heating  the  rock  whether  it  is  used  in  small  lumps  or  in 
powder.  In  the  first  series  of  experiments  undertaken 
with  the  objedt  of  a  rapid  survey  of  the  materials,  the 
gases  were  not  completely  analysed.  They  were  colledted, 
measured,  the  carbon  dioxide  removed  by  potash,  and  the 
residue  examined  by  the  speftroscope.  When  ignited  in 
the  air  it  always  burned  with  a  pale  flame  resembling 
that  of  hydrogen. 

The  accompanying  table  gives  the  results  of  these  ex- 
periments. 

A  seledion  of  these  was  then  subje(5ted  to  more  careful 
and  exadt  analysis.  For  this  purpose  fresh  masses  of  the 
rock  were  taken,  and  the  gas  extradled  in  the  usual  way. 
The  following  are  the  results  : — 

COg.  CO.      CH4.    Nj.      H,. 

Granite  from  Skye     ..      ,.  23-60  6*45     3-02  5'i3  6i'68 

Gabbro  from  Lizard  . .      ..     5*50  2'i6     2*03  i"9o  88"42 

Pyroxene  gneiss,  Ceylon  ..  7772  8'o6    0*56  i'i6  1249 

Gneiss  from  Seringapatam.  31*62  5*36    0*51  o'56  6i*93 

Basalt  from  Antrim   ..     ..  32'o8  20*08  10*00  i*6i  3615 

To  account  for  the  large  proportion  of  hydrogen  and 
carbonic  oxide  in  these  gases,  it  is  only  necessary  to 
suppose  that  the  rock  enclosing  them  was  crystallised  in 
an  atmosphere  rich  in  carbon  dioxide  and  steam  which 
had  been,  or  were  at  the  same  time,  in  contadl  with  some 
easily  oxidisable  substance,  at  a  moderately  high  tem- 
perature. Of  the  substances  capable  of  so  adling,  carbon, 
a  metal,  or  a  protoxide  of  a  metal,  present  themselves  as 
the  most  probable. 

The  redudtion  of  carbon  dioxide  or  of  water  vapour  by 
carbon  gives  rise  to  the  formation  of  carbon  monoxide, 
and  if  carbon  had  been  the  agent  the  proportion  of  this 
gas  in  the  mixture  must  have  been  greater  than  is  found 
to  be  the  case.  It  is,  of  course,  well  known  that  carbon 
dioxide  and  water  vapour  are  both  dissociated  at 
moderately  high  temperatures,  but  the  greater  part  of  the 
liberated  oxygen  re-combines  at  lower  temperatures, 
though  a  small  portion  may  remain  free  in  the  presence 
of  a  large  quantity  of  an  indifferent  gas  or  vapour.  No  free 
oxygen  has  been  found  in  any  of  the  gases  analysed. 

Direft  experiments  made  with  ferrous  oxide  (obtained  by 
gently  heating  pure  chalybite)  and  with  magnetic  oxide 
of  iron,  show  that  while  the  former,  at  a  red-heat,  decom- 
poses both  steam  and  carbon  dioxide  quite  freely, 
liberating  hydrogen  and  carbon  monoxide,  and  becoming 
itself  oxidised  into  magnetic  oxide;  the  latter  has  no 
a(5tion  at  all  upon  either  steam  or  carbon  dioxide. 
Magnetic  oxide  of  iron  is  the  final  produdof  the  adtion  of 
steam  or  of  carbon  dioxide  at  a  high  temperature  upon 
metallic  iron  : — 

3Fe-f4H20  =  Fe304-f-4Ha. 
3Fe+4COa=Fe304-F4CO. 

Now,  metallic  iron  has  been  detected  in  basalts  and 
some  other  rocks  by  Andrews  (Brit.  Assoc.  Rep.,  1852, 


170 


Determination' of  Atmospheric  Ozone  on  Mont  Blanc. 


'  Chemical  News, 
1      April  9,  1897. 


Name  of  rock  or  mineral. 


Localitv. 


Charad^er. 


Granite  i     

,.      2 

Salen,  Mull..     . 

Gabbro L.  Coruisk,  Skye 

Basalt Antrim 


Rocks  of  Tertiary  Age. 
Skye Plutonic,  acid 


basic. 


Rocks  of  Palceozoic  Age. 

Quartzite Durness  (Sutherland)  .     ..     Aqueous,  altered 

Gabbro.. Lizard Plutonic, basic. . 

Granite        Peterhead ,,        acid.. 

„  Cornwall      „  ,1     . . 

Rocks  of  Unknown  Age  {mostly  Archaan). 

Granite        Near  Dublin       Plutonic,  acid  .. 

,,  Ardshiel       ,,  ,,     .. 

Greisen        Altenburg  (Saxony)  ....             ,,        altered 

Granulite Central  India ,,  ,, 

Quartz  schist      Cas.  Wellan  (Co.  Down). .  Metamorphic  .. 

Fuchsite  schist Baroda „ 

Corundum  rock Pipra,  S.  Rewab,  India     ..                 ., 

Pyroxene  gneiss Dombra  (Ceylon)       ....                 ,, 

Gneiss  with  corundum      Seringapatam     ,, 

„        „     garnets  and  graphite  ..  Dolosweila  (Ceylon)..      ..                 ,, 

,,     Himalayas  (Nanga  Parbm)                ,, 

Recent  Lava. 
Vesuvius,  1760 — 


Minerals. 


Graphite      Ceylon         ..     .. 

Quartz  matrix  of  same     — 

Beryl Irish      

Tinstone      Straits  Settlements 


Compos 

tion 

Volume  of  gas 

per  volume 

of  rock, 

in  100  vol 

umes. 

COj. 

H„,&c 

1-6 

11-5 

88-5 

^•8 

31-0 

69"0 

I '3 

347 

b5-3 

35 

2 1 -6 

78-4 

8-0 

32*0 

68-0 

2-2 

14-3 

857 

6-4 

trace 

1000 

26 

248 

75-2 

4-3 

8-8 

91*2 

5"o 

9-4 

go-6 

6-9 

79-5 

20-5 

1-8 

136 

86-4 

2-6 

487 

5f3 

2-8 

23  0 

77-0 

4-2 

20-8 

792 

3-5 

26  0 

740 

73 

84-4 

15& 

17-8 

180 

820 

4'5 

iro 

890 

72 

II-5 

88-5 

0*65 


720 


28-0 


7-5 

48-0 

52*0 

1-2 

44"5 

555 

&-7 

60 

94-0 

1-3 

45  "4 

54*6 

Sedlions,  p.  34),  and  by  some  other  observers  (e.g.,  G.  W. 
Hawes,  Amer.  y.  Set.,  1877,  Ser.  3,  vol.  xiii.,  p.  33),  and 
I  have  verified  this  observation  in  the  case  of  the  gabbro 
of  Loch  Coruisk.  But  it  must  be  remembered  that  both 
the  reactions  indicated  in  the  equations  just  given  are 
reversible,  and  therefore  the  presence  of  metallic  iron 
along  with  the  magnetic  oxide  in  such  rocks  cannot  be  taken 
by  itself  as  final  proof  that  the  oxide  and  the  associated 
gases,  hydrogen  and  carbonic  oxide,  are  the  produdls  of 
the  adion  of  steam  and  carbon  dioxide  upon  metallic  iron. 
The  presence  of  marsh  gas  in  these  rocks  and  the  produc- 
tion of  large  quantities  of  hydrocarbonous  gases,  as  well 
as  liquid  petroleum,  in  many  parts  of  the  earth's  surface, 
tend  to  support  the  view,  which  is  apparently  gaining 
ground,  that  in  the  interior  of  the  earth's  crust  there  are 
large  masses,  not  only  of  metal  but  of  compounds  of 
metals,  such  as  iron  and  manganese,  with  carbon. 
Assuming  the  existence  of  such  material,  it  is  easy  to 
conceive  how,  by  the  adlion  of  water  at  an  elevated  tem- 
perature, it  may  give  rise  to  metallic  oxides  and  mixtures 
of  hydrogen  with  parafSnoid  and  other  hydrocarbons. 
This  view  was  put  forward  some  years  ago  by  Mendeleefl" 
("  Principles  of  Chemistry,"  Translation  by  Kamensky 
and  Greenaway,  vol.  i.,  364—365),  and  it  has  lately  re- 
ceived further  support  from  the  results  of  the  study  of 
metallic  carbides,  which  we  owe  especially  to  Moissan 
{Roy.  Soc.  Proc,  vol.  Ix.,  1896,  pp.  156 — 160). 


Determination  of  Phosphate  in  Thomas  Slags.— 
According  to  Dr.  O.  Bottcher  (Chemiker  Zeitung),  the 
citrate  method  cannot  be  universally  accepted  for  the  de- 
termination in  ground  Thomas  slags  of  phosphate  soluble 
in  citric  acid  until  further  comparative  analyses  have  been 
carried  out. 


DETERMINATfON     OF    ATMOSPHERIC     OZONE 

ON     MONT    BLANC. 

By    MAURICE    de    THIERRY. 

Thanks  to  the  kind  support  of  M.  Janssen  I  have  been 
able  to  commence,  in  1894,  a  series  of  researches  on 
Mont  Blanc,  and  continue  them  in  1895  and  1896.  The 
bad  weather,  which  has  not  ceased  to  prevail  en  these 
heights  during  last  summer,  has  hindered  me  from  com- 
pletely executing  the  programme  which  I  had  drawn  up; 
still  the  interest  which  the  first  part  of  my  researches 
seemed  to  present  encourages  me  to  present  them  to  the 
Academy. 

In  September,  1894,  I  was  struck  with  the  rapidity 
with  which  slips  of  amidised  ozonoscopic  paper 
(Schcenbein's  paper),  and  red  litmus  paper  saturated  with 
potassium  iodide  (Houzeau's  paper),  exposed  to  the  air 
on  the  platform  of  the  Observatory  on  the  summit  of 
Mont  Blanc,  at  the  altitude  of  4812  metres,  took  respe<5t- 
ively  deep  violet  and  blue  colourations.  Paper  steeped 
in  thallous  oxide  was  equally  and  rapidly  blackened  with 
formation  of  thallic  oxide  (Bceettgen  readtion).  It  was 
the  same  with  plates  of  silver  which  I  had  prepared  by 
reducing  a  solution  of  silver  nitrate  with  ladose. 

These  first  observations  were  already  interesting  when 
— on  Tuesday,  August  13th,  at  noon— I,  along  with  my 
two  guides,  was  attacked  by  a  tempest  of  snow  (altitude 
of  42,000  metres),  accompanied  by  numerous  peals  of 
thunder,  and  the  fall  of  hailstones  perfedtly  spherical  and 
of  the  size  of  large  peas. 

A  violent  N.W.  wind  was  blowing ;  Naudin's  air 
hygrometer  marked  115°,  and  the  thermometer,  which 
before  the  storm  was  at  0°,  fell  rapidly  to  —15.  A  number 
of    hailstones,   collected    on    a  sheet  of   iodo-amidised 


Chbuical  NbW8,1 
April  g,  1897.      I 


Action  of  Permanganate  of  Potash,  &c.j  on  Bacteria^ 


171 


ozonoscopic  paper,  made  immediately  circular  violet 
spots,  larger  than  the  diameter  of  the  hailstones,  the 
centre  of  the  spots  occupied  by  the  hailstones  being  paler 
than  the  circumference.  The  violence  of  the  storm  did 
not  allow  me  to  examine  closely  if  these  spots  were 
formed  by  an  atmosphere  of  ozone  surrounding  the  hail- 
stone when  it  fell,  or  by  hydrogen  peroxide  (which  might 
give  the  same  adlion)  derived  from  the  melting  of  the  hail. 
I  must  add  that  the  snows  (recent  or  old)  taken  on  ad- 
joining heights  have  never  given  the  charaderistic 
readions  of  hydrogen  peroxide.  The  water  from  melted 
snow  has  always  given  the  charaderistic  readion  of  am- 
monia with  Nessler's  test. 

The  author  resolved  to  determine  quantitatively  the 
atmospheric  ozone  on  Mont  Blanc.  He  finds  that  at 
Chamounix  (1050  metres)  the  atmospheric  ozone  is  3*5 
m.grms.,  and  on  the  Grand  Mulets  (3020  metres)  9*4 
m.grms.  per  1000  cubic  metres  of  air, — that  is  to  say, 
nearly  four  times  greater  than  at  Paris.  The  quantity  of 
ozone  therefore  increases  with  the  altitude. 

The  author  is  engaged  with  the  analysis  of  air  which 
he  has  brought  with  him  from  the  Grand  Mulets.  He  is 
also  studying  the  possible  presence  of  nitrous  acid  in 
certain  strata  of  air. — Comptes  Rendus,  cxxiv.,  No.  9. 


EXPERIMENTS    ON    THE    ACTION     OF 

PERMANGANATE    OF    POTASH     AND    ACETIC 

ACID    ON    THE    BACTERIA    IN    RAW 

THAMES    WATER. 

By  HENRY  CROOKES,  A.R.S.M,,  M.I.E.E. 

A  FEW  months  ago  I  carried  out  a  series  of  experi- 
ments  on  the  adion  of  certain  germicides  on  the  baderia 
in  raw  Thames  water,  my  primary  objed  being  to  deter- 
mine the  influence  of  time,  and  quantity  of  material 
employed.  After  a  number  of  tentative  and  preliminary 
experiments,  to  get  an  idea  of  the  most  suitable  quantities 
and  strengths,  I  at  length  decided  to  work  with  a  constant 
volume  of  250  cc.  of  raw  water,  adding  to  it  a  standard 
solution  of  KMn04  of  20  grains  per  gallon.  The  method 
of  procedure  was  as  follows  : — 

In  the  first  series  of  experiments  10  c.c.  of  the  standard 
KMn04  were  added  to  three  different  bottles,  each  con- 
taining 250  c.c.  of  unfiltered  water;  these  were  marked 
B,  C,  D,  while  A  was  the  raw  water  untreated. 

B  was  allowed  to  stand  for  15  minutes,  when  0*5  c.c. 
was  mixed  with  10  c.c.  of  nutrient  gelatin  peptone,  poured 
into  a  sterile  Pietri  dish,  and  when  cool  placed  in  the 
incubator,  and  kept  at  20°  to  20*5°  for  48  hours. 

C  was  allowed  to  stand  for  30  minutes,  and  D  for 
60  minutes,  both  these  (as  well  as  A)  being  then  treated  in 
exadly  the  same  manner  as  B.  Aft-^r  48  hours  the 
colonies  were  counted  under  the  microscope,  and  the 
following  results  obtained : — 

Colonies 
Series  I.  per  c.c. 

A.  Unfiltered  water  untreated 3876 

B.  250  c.c.  of  same  water  +  10  c.c.  standard 

KMn04,  after  15  minutes       332 

C.  250  c.c.  of  same  water  -f-  10  c.c.  standard 

KMn04,  after  30  minutes       240 

D.  250  c.c.  of  same  water  +  10  c.c,  standard 

KMn04,  after  60  minutes       36 

These  figures  show  a  very  rapid  diminution  in  the 
number  of  baderia,  even  with  so  weak  a  solution  of 
KMn04  as  20  grains  per  gallon. 

My  next  experiments  were  to  determine  the  germicidal 
power  of  varying  quantities  of  KMnO^  (always  the  same 
standard  strength)  in  a  constant  time.  Four  bottles  were 
taken,  as  before,  A  being  untreated ;  to  B  were  added 
5  C.C,  to  C  10  c.c,  and  to  D  20  c.c.  of  KMn04;  these 


were  all  allowed  to  stand  for  15  minutes,  then  treated  as 
before,  and  incubated  for  48  hours.  At  the  end  of  that 
time  the  following  number  of  colonies  per  cc.  were 
found  : — 

Colonies 
Series  II.  per  c.c. 

A,  Unfiltered  water  untreated 3850 

B,  250  c.c.  of  same  water  +  5  c.c,  standard 

KMn04,  after  15  minutes       260 

C,  250  cc.  of  same  water  +  10  c.c.  standard 

KMn04,  after  15  minutes       ..      ••     ..       190 

D,  250  cc.  of  same  water  +  20  c.c.  standard 

KMn04,  after  15  minutes       40 

From  these  figures  it  would  appear  that  there  is  very 
little  difference  in  the  adion  of  a  small  quantity  of 
KMn04  for  a  long  time,  and  a  much  larger  quantity  for 
a  shorter  time. 

Another  setofexperimentsconduded  in  exadlythe  same 
manner,  save  that  the  standard  KMn04  was  made  slightly 
acid  with  acetic  acid,  gave  the  following  results : — 

Colonies 
Series  III.  per  c.e. 

A.  Unfiltered  water,  untreated 2040 

B.  250  c.c.  of  same  water  +  10  c.c.  standard 

KMn04,  after  15  minutes       

C.  250  c.c.  of  same  water  +  10  c.c.  standard 

KMn04,  after  30  minutes       .,     ..     ., 

D.  250  cc.  of  same  water  +  10  c.c.  standard 

KMn04,  after  60  minutes       53 

ColoDiss 
Series  IV.  per  c.c. 

A.  Unfiltered  water,  untreated 2400 

B.  250  c.c.  of  same  water  +  5  c.c.  standard 

KMn04,  after  15  minutes       589 

C.  250  c.c.  of  same  water  +  10  c.c.  standard 

KMn04,  after  15  minutes       141 

D.  250  c.c.  01  same  water  +  20  cc,  standard 

KMn04,  after  15  minutes       90 

Finally,  another  set  was  done,  in  all  respeds  similar, 
but  that  the  standard  KMn04  was  made  alkaline  with 
caustic  soda,  the  results  being  as  follows  :— > 

Colonies 
Series  V.  per  c.c. 

A.  Unfiltered  water  untieated 3080 

B.  250  c.c  of  same  water  +  10  c.c.  of  standard 

KMn04,  alter  15  minutes       , 

C.  250  cc.  of  same  water  +  10  c.c,  of  standard 
KMn04,  after  30  minutes       120 

250  c.c,  01  same  water  -f-  10  c.c.  of  standard 
KMn04,  after  60  minutes       ..     .. 


116 


90 


268 


D. 


..      ..         87 

Colonies 
Series  VI.  per  c.c, 

A.  Unfiltered  water  untreated 12400 

B.  250  c.c,  of  same  water  +  5  cc.  of  standard 

KMn04,  after  15  minutes       3720 

C.  250  c.c.  of  same  water  +  10  c.c  of  standard 

KMn04,  after  15  minutes       ..      .,      ..     2170 

D.  250  c.c.  of  same  water  +  20 c.c  of  standard 

KMn04,  after  15  minutes       ..     .,     .,       434 

These  six  seiies  of  experiments,  when  calculated  as 
percentages  of  microbes  present  at  each  stage,  appear  as 
follows,  and  can  be  easily  compared: — 


Neut 

ral. 

Aci 

d. 

Alkaline, 

Series 

I. 

11. 

111. 

IV. 

V. 

VI. 

A. 

lOO'O 

lOO'O 

1000 

100 'O 

lOO'O 

lOO'O 

B. 

8-5 

67 

57 

24'5 

87 

30*0 

C, 

61 

4"9 

4 '4 

6-0 

3-9 

^TH 

D. 

0-9 

I'O 

27 

37 

2-8 

3*5 

We  see  at  once  that  the  strongest  and  most  rapid  adion 
takes  place  when  the  permanganate  solution  is  neutral, 
the  most  noticeable  difference  being  the  remarkable  loss 
of  power  of  5  c.c,  of  both  acid  and  alkaline  permanganate 
(Series  IV.  and  VI.}  when  ading  for  fifteen  minutes  (B). 


172 


Revision  0/  the  Atomic  Weight  of  Magnesium, 


I     April  9, 1897. 


I  next  turned  my  attention  to  the  adlion  of  acetic  acid 
alone  on  unfiltered  water ;  the  methods  of  procedure  and 
incubation  were  the  same  as  in  the  previous  experiments, 
the  first  being  with  a  varying  quantity  of  a  i  per  cent 
solution  standing  for  15  minutes.  After  48  hours  in  the 
incubator  the  following  results  were  obtained  :— 

Colonies 
Sbries  VII.  per  c.c. 

A.  Unfiltered  water  untreated 5890 

B.  250  c.c.  of  same  water  +  i  c.c.  of  i   per 

cent  acid,  after  15  minutes 3684 

C.  250  c.c.  of  same  water  +  5  c.c.  of  i  per 

cent  acid,  after  15  minutes 3262 

D.  250  c.c.  of  same  water  +  10  c.c.  of  i  per 

cent  acid,  after  15  minutes    ..     ••     ..     2846 

These  figures  show  a  slight  and  regular  diminution  in 
the  number  of  badteria ;  but  the  acid  was  evidently  too 
weak,  so  a  stronger  solution — viz.,  10  per  cent — was  pre- 
pared and  the  experiments  repeated  with  the  following 

results : — 

Colonies 
Series  VIII.  per  c.c. 

A.  Unfiltered  water  untreated 824 

B.  250  c.c.  of  same  water  +  1  c.c.  of  10  per 

cent  acid,  after  15  minutes 600 

C.  250  c.c.  of  same  water  +  5  c.c.  of  10  per 

cent  acid,  after  15  minutes 456 

D.  250  c.c.  of  same  water  +  10  c.c.  of  10  per 

cent  acid,  after  15  minutes 238 

These  showed  a  stronger  aftion,  but  nothing  striking, 
so  a  further  lot  was  done  with  a  50  per  cent  solution  of 
acetic  acid,  with  the  following  remarkable  results  :  — 

Colonies 
Series  IX.  per  c.c. 

A.  Unfiltered  water  untreated 1976 

B.  250  c.c.  of  same  water  +  i  c.c.  of  50  per 

cent  acid,  after  15  minutes 750 

C.  250  c.c.  of  same  water  +  5  c.c.  of  50  per 

cent  acid,  after  15  minutes 30 

D.  250  c.c.  of  same  water  +  10  c.c.  of  50  per 

cent  acid,  after  15  minutes o 

A  50  per  cent  solution  of  acetic  acid  proving  unnecessa- 
rily strong,  two  more  trials  were  made  with  the  10  per  cent 
solution,  keeping  the  quantities  constant,  viz  ,  5  c.c.  and 
10  c.c,  and  varying  the  time  10,  30,  and  60  minutes. 

Colonies 
Series  X.  per  c.c. 

A.  Unfiltered  water,  untreated 9792 

B.  250  c.c.  of  same  water  +  5  c.c.  of  10  per 

cent  acid,  after  10  minutes 4096 

C.  250  c.c.  of  same  water  +  5  c.c.  of  10  per 

cent  acid,  after  30  minutes 2176 

D.  250  c.c.  of  same  water  +  5  c.c.  of  lo  per 

cent  acid,  after  60  minutes 1280 

Colonies 
Series  XI.  per  c.c. 

A.  Unfiltered  water,  untreated        2090 

B.  250  c.c.  of  same  water  +  10  c.c.  of  10  per 

cent  acid,  after  10  minutes 508 

C.  250  c.c.  of  same  water  +  10  c.c.  of  10  per 

cent  acid,  after  30  minutes 380 

D.  250  c.c.  of  same  water  +  10  c.c.  of  10  per 

cent  acid,  after  60  minutes 280 

By  converting  the  results  of  Series  IX.,  X.,  and  XI. 
into  percentages  as  before,  we  get  the  following  table  : — 
Series  IX.  Series  X.  Series  XI. 

A.  lOO'O  loo'o  loo'o 

B.  37-9  41*8  24-3 

C.  I'5  22"2  l8'I 

D.  o'o  13*0  134 

From  these  figures  we  see  that  time  is  a  stronger  fadtor 
in  the  decrease  in  the  number  of  microbes  than  an  in- 


crease in  the  quantity  of  the  acid  used.  Thus,  in  Series 
X.  and  XL,  while  after  ten  minutes  standing  (B)  the  differ- 
ence is  very  marked,  after  sixty  minutes  (D)  there  is 
pradically  nothing  to  choose  between  them. 

Further  experiments  are  being  carried  on,  and  I  hope  to 
be  able  to  publish  the  results  in  due  course. 


A    REVISION 


OF    THE    ATOMIC 

MAGNESIUM.* 


WEIGHT    OF 


By  THEODORE  WILLIAM  RICHARDS 

and 

HARRY  GEORGE  PARKER. 

(Continued  from  p.  159). 


Purification  of  Silver. 
No  very  great  labour  was  expended  upon  the  purification 
of  the  first  quantity  of  silver,  as  the  chlorine  in  magnesic 
chloride  was  to  be  precipitated  with  an  undetermined 
excess  of  silver  nitrate.  Residues  were  therefore  worked 
up  by  dissolving  silver  (obtained  by  reduction  with  zinc) 
in  nitric  acid,  precipitating  the  metal  as  chloride,  and 
converting  the  chloride  into  metallic  silver  by  means  of 
invert  sugar.  The  reduced  silver,  after  having  been  fused 
into  buttons,  was  thoroughly  washed  and  dissolved  in 
nitric  acid.  The  solution  of  argentic  nitrate  thus  obtained 
was  diluted  very  much  with  water,  allowed  to  stand,  and 
filtered  just  previous  to  using. 

With  the  second  sample,  on  the  other  hand,  much 
greater  care  was  taken,  as  it  was  designed  in  this  case  to 
ascertain  the  diredt  ratio  between  silver  and  magnesic 
chloride.  The  material  came  partly  from  some  refined 
silver,  purchased  in  the  market,  and  partly  from  some 
pure  silver  residues  remaining  from  previous  work.  The 
silver  was  precipitated  from  a  solution  of  the  nitrate  with 
pure  hydrochloric  acid,  and  reduced  by  means  of  invert 
sugar  and  pure  sodic  hydrate,  the  sodic  hydrate  having 
been  previously  freed  from  heavy  metals  by  eledtrolysis. 
Both  the  chloride  and  reduced  silver  were  very  thoroughly 
washed,  the  silver  was  dissolved  in  pure  nitric  acid,  and 
the  process  was  repeated.  After  this  cycle  of  operations 
had  been  performed  four  or  five  times,  the  reduced  silver 
was  fused  on  a  cupel  of  sugar  charcoal  before  the  blow- 
pipe. The  resulting  button  was  scrubbed  with  sand,  and 
made  the  anode  of  a  weak  galvanic  circuit  in  a  solution 
of  argentic  nitrate  prepared  from  the  same  silver.  The 
cathode  was  a  piece  of  pure  silver  wire,  upon  which  the 
whole  of  the  silver  was  deposited  in  a  crystalline  mass. 
The  silver  crystals  were  then  removed  from  the  solution 
and  fused  in  a  vacuum  upon  a  boat  of  pure  lime  (Proc. 
Amer.  Acad.  Arts  Sci.,  xxx.,  379 ;  xxxi.,  173),  which  was 
contained  in  a  porcelain  tube.  Such  a  boat  may  be  made 
by  lining  a  porcelain  boat  with  a  mixture  of  three  parts 
of  pure  lime  and  one  part  of  pure  anhydrous  calcic 
nitrate,  and  igniting  the  mixture.  The  porcelain  boat  ia 
thus  covered  with  a  firm  coherent  layer  of  pure  calcic 
oxide.  In  order  to  prevent  the  possibility  of  a  trace  of 
organic  matter  distilling  off  from  the  rubber  stoppers 
usually  used  to  close  such  a  tube,  a  set  of  hollow  brass 
stoppers  were  made,  through  which  a  current  of  cold 
water  circulated.  This  latter  device  is  due  to  a  sugges- 
tion of  Professor  Hempel.  The  construiflion  of  this  piece 
of  apparatus  is  evident  from  the  diagram  (Fig.  2). 

Of  course,  the  button  after  fusion  showed  no  trace  of 
spirting  from  contained  oxygen.  It  was  scrubbed  with 
distilled  water  and  clean  sand,  and  divided  into  small 
pieces  by  means  of  a  clean  steel  chisel.  The  fragments 
were  alternately  boiled  in  strong  hydrochloric  acid  and 
digested  in  ammonia  water,  this  process  being  repeated 
ten  or  fifteen  times.     The  silver  was  finally  washed  with 


*  Contributions  from  the  Chemical  Laboratory  of  Harvard  College. 
From  the  Proceedings  of  the  American  Academy  of  Arts  and  Sciences, 
vol.  xxxii.,  No.  2, 


OHBMICAL  NBWfekl 

April  9,  1897.      I 


Revision  0/  the  A  tomic  Weight  of  Magnesium, 


173 


distilled  water  and  afterwards  kept  in  a  desiccator,  which 
was  opened  only  when  necessary  to  weigh  out  silver  for  a 
determination. 

A  portion  of  the  second  sample  was  treated  in  the  same 
way,  except  that  in  the  end  it  was  fused  on  sugar  char- 
coal before  the  blowpipe  and  cooled  in  the  reducing  flame. 
Particular  pains  were  taken  to  prevent  the  absorption  of 
oxygen,  and  the  button  did  not  show  the  slightest  trace 
of  having  contained  this  gas.  From  this  portion  wire  was 
prepared  of  various  thicknesses,  by  means  of  a  draw  plate ; 
and  the  weights  of  given  lengths  of  these  wires  were 
determined,  so  that  small  weights  could  be  made  with 
considerable  accuracy.  Of  course,  the  wire  was  treated 
in  the  same  fashion  as  the  rest  of  the  silver,  in  order  to 
remove  any  iron  which  might  be  present  on  the  surface. 

The  third  and  fourth  samples  of  silver  were  prepared 
in  the  same  manner  as  the  second,  the  starting-point 
being  the  pure  residues  left  from  the  analyses  made 
with  previous  samples.  No  qualitative  nor  quantitative 
difference  could  be  observed  between  any  of  these  pre- 
parations of  silver.  Fused  upon  sugar  charcoal,  they 
melted  to  a  clear  globule  free  from  any  film, — a  fad  which 
in  itself,  according  to  Stas,  is  an  excellent  test  of  the 
purity  of  silver, — and  all  gave  pradically  the  same  results 
in  later  determinations. 

All  water  used  was  re-distilled  with  potassic  perman- 


;^^^b: 


XXX.,  369  ;  xxxi.,  158).  We  are  indebted  to  the  Cyrus  M. 
Warren  Fund  of  Harvard  University  for  some  of  the 
platinum  ware  used  in  the  following  work. 

The  atomic  weights  used  in  this  investigation  were  as 
follows : — 


O 

CI 


Ag 


107-930 


. .     i6'ooo 
••     35 '456 

Method  of  Work. 
The  method  of  operating  may  be  inferred  from  the 
description  of  the  apparatus.  The  platinum  boat,  after 
having  been  weighed  within  its  weighing  bottle,  was  filled 
with  the  double  chloride  of  ammonium  and  magnesium 
and  placed  in  position  in  the  ignition-tube,  resting  upon 
a  sort  of  carriage  of  platinum  foil.  The  weighing  bottle 
was  placed  with  its  stopper  in  appropriate  position  in  the 
"  bottling  tube,"  as  previously  described.  A  current  of 
dry  hydrochloric  acid  gas  was  then  passed  through  the 
apparatus  and  the  ignition  tube  was  heated  by  a  suitable 
arrangement  of  burners.  At  first  the  residual  moisture 
was  driven  off  by  the  heat  and  carried  away  by  the  stream 
of  gas.  When  as  much  water  as  possible  was  expelled  in 
this  manner,  the  heat  was  slowly  increased,  so  that  the 
ammonic  chloride  commences  to  vaporise.  It  was  found 
that  the  sublimation  commenced  before  the  salt  was  freed 
from  the  last  traces  of  moisture,  but  an  effort  was  always 


fnp 


Fig.  2.— Apparatus  for  Fusing  Silver,  Vertical  Section. 

A  ia  conneAed  with  a  Sprengel  pump.    B  B,  hollow  brass  stoppers  in  porcelain  tube.    C,  boat  of  lime  containing  silver. 
D,  "  window  "  for  observation.    E  E  E  E,  rubber  packing  of  stopper.    F,  Fletcher  furnace. 


ganate,  some  of  it  being  condensed, in  a  platinum  con- 
denser, and  some  of  it  by  means  of  a  tube  of  pure  block 
tin,  which  was  carefully  tested  in  order  to  prove  the 
absence  of  an  impurity  of  lead.  Considerable  quantities 
upon  evaporation  in  platinum  left  a  scarcely  appreciable 
residue,  there  being  apparently  no  difference  between  the 
water  condensed  in  tin  and  that  in  platinum  (see  Proc. 
Amer.  Acad.  Arts  Sci.,  xxvi.,  249  ;  xxx.,  380).  The  water 
was  prepared  as  short  a  time  as  possible  before  being 
used,  and  was  carefully  kept  in  a  suitable  bottle  fitted 
with  a  syphon,  air  being  admitted  to  the  bottle  through 
a  filter  of  cotton-wool.  It  was  carefully  tested  for  chlorine 
by  means  of  the  nephelometer  from  time  to  time. 

The  sulphuric  acid  used  for  the  preliminary  drying  of 
the  gases  was  the  usual  "  chemically  pure  "  acid  of  the 
laboratory,  of  a  specific  gravity  of  about  1-83.  For  the 
final  drying  this  acid  was  boiled  down  in  platinum. 

Weighing. 
The  balance  used  was  a  long-armed  Becker,  sensitive 
to  about  one-thirtieth  of  a  milligrm.  with  the  largest  load 
that  it  was  required  to  carry  during  the  investigation, 
while  the  weights  were  a  good  set  of  gold  plated  ones, 
which  were  kept  in  the  balance  case  under  a  glass  cover. 
These  weights  were  very  carefully  compared  with  one 
another,  and  all  weighings  were,  of  course,  reduced  to  the 
vacuum  standard.  The  specific  gravity  of  magnesic 
chloride  used  for  this  computation  was  the  value  2-177 
determined  by  Playfair  and  Joule.  Weighing  was  done 
by  substitution,  the  objed  to  be  weighed  being  placed  on 
the  right-hand  pan  and  balanced  by  tare  weights  on  the 
left.  In  general,  the  precautions  used  in  the  recent  work 
done  in  this  laboratory  upon  copper,  barium,  strontium, 
and  zinc  were  adhered  to  with  great  care  (Richards,  Proc. 
Amer.  Acad.  Arts  Sci.,  xxvi.,  240;  xxviii.,  i;  xxix..  55  ; 


made,  by  the  very  gradual  increase  of  heat,  to  make  this 
proportion  of  water  as  small  as  possible  ;  and  it  is  probable 
that  the  salt  was  pradlically  anhydrous  some  time  before  the 
last  of  the  ammonic  chloride  was  sublimed.  When  no 
further  evolution  of  ammonic  chloride  could  be  observed, 
the  heat  was  increased  until  the  tube  and  boat  were 
heated  to  redness,  and  the  magnesic  chloride  had  fused 
into  a  clear,  colourless  limpid  liquid.  It  requires  a  very 
excellent  piece  of  combustion  tubing  to  stand  the  heat 
necessary  to  fuse  magnesic  chloride,  and  a  number  of 
tubes  were  spoiled  during  the  course  of  the  work.  In  the 
first  series  of  determinations  the  boat  was  allowed  to 
cool  while  the  current  of  hydrochloric  acid  gas  was  still 
passing.  The  tubes  containing  the  boat  and  weighing 
bottle  were  then  thoroughly  washed  out  with  a  current 
of  air  dried  in  an  apparatus  similar  to  that  used  for  drying 
the  hydrochloric  acid  gas,  as  previously  described.  After 
it  was  certain  that  all  of  the  acid  gas  had  been  displaced, 
and  while  the  current  of  air  was  passing  rapidly  to  prevent 
any  diffusion  of  moist  air  back  into  the  apparatus,  the 
bulbs  were  removed  from  the  farther  end  of  the  ignition- 
tube,  and  the  boat  was  pushed  into  the  bottle  in  the 
manner  already  described.  The  boat  itself  remained 
constant  in  weight  during  these  op-  rations,  showing  that 
the  magnesic  chloride  had  not  adt^d  upon  it. 

After  weighing,  the  boat  and  its  contents  were  placed 
in  a  large  glass-stoppered  Erlenmeyer  flask,  and  the  mag- 
nesic chloride  was  dissolved  in  pure  water.  The  chlorine 
was  precipitated  with  a  dilute  solution  of  argentic  nitrate 
(this  solution  contained  never  more  than  i  per  cent  of 
silver) ;  and  after  a  thorough  shaking  the  whole  was 
allowed  to  stand  in  the  dark  over  night.  The  argentic 
chloride  was  washed  by  decantation  a  number  of  times, 
with  vigorous  shaking,  and  was  finally  colleded  upon  a 
Gooch  crucible  in  the  usual  manner.     The  precipitate 


174 


Revision  of  the  Atomic  Weight  of  Magnesium. 


I  Chemical  News 

I       April  g,i8c7. 


was  dried  from  five  to  ten  hours  in  an  oven,  carefully 
proteded  from  dust  and  dirt,  and  v/eighed.  After 
weighing,  the  cake  of  precipitate,  together  with  some 
adherent  asbestos,  was  removed  to  a  tared  porcelain 
crucible  and  heated  until  it  began  to  fuse.  The  crucible 
was  again  weighed,  and  the  loss  of  weight,  if  any,  noted, 
and  subtradted  from  the  weight  of  the  Gooch  crucible  and 
contents.  The  filtrate,  containing  a  little  dissolved 
argentic  chloride,  was  evaporated  down  to  small  bulk  and 
filtered  through  a  very  small  filter  ;  and  the  weight  of  the 
precipitate  was  added  to  the  weight  of  the  first  portion. 
In  some  cases  the  small  amount  of  argentic  chloride  pre- 
sent was  determined  with  the  nephelometer  (see  Proc. 
Aiuer.  Acad.  Arts  Sci.,  xxx.,  385). 

The  wash  water  from  the  precipitate  colleded  on  the 
Gooch  crucible  was  also  run  through  a  small  filter  to 
make  sure  that  no  asbestos  had  been  carried  away  from 
the  crucible  in  the  process  of  washing  ;  and  this  correc- 
tion, when  appreciable,  was  applied  in  the  appropriate 
place. 

The  washing  and  filtration  were  both  performed  in  dim 
orange  light,  which  had  been  suitably  tested  as  to  its 
non-a(5tinic  properties.  Even  after  fusing  the  argentic 
chloride  was  almost  colourless,  showing  that  only  un- 
essential traces  had  deen  decomposed  by  the  light. 

The  result  of  the  first  series  of  five  experiments  is  given 
below.  These  determinations  were  consecutive,  except 
that  one  determination  met  with  an  accident  and  was  not 
completed. 

Series  I. 

No.  Sample  Sample  Weight 
of  of  MgCl.j    of  of 

expt.   used.  Ag  used.  MgCl^. 

I  I'.l.^'iSO  4'or952 
4-56369 
3-98528 

4*23297 
377670 


Weight 

of 

AgCl. 


Ratio.  Atomic 

MgClj  :  2AgCl=    weight 
100:  n. 


l"33550 
i"5i6oi 

i'324i3 
I '40664 
1-25487 


300-975 
301-033 
300-974 
300928 
300-963 


of  Mg, 
24-368 
24350 
24369 
24"384 
24'373 


Average..     ..     24*369 

A  careful  consideration  of  the  possible  constant  errors 
involved  in  the  foregoing  results  lead  to  the  belief  that 
the  figures  found  are  too  high  rather  than  too  low,  as  the 
presence  either  of  a  small  amount  of  water  or  of  oxy. 
chloride  in  the  magnesia  chloride  would  tend  in  this 
direiStion. 

Second  Series  of  Determinations. 

In  order  to  drive  all  the  subliming  ammonic  chloride  to 
the  further  end  of  the  combustion-tube  during  the  ignition, 
it  had  been  found  necessary  that  the  current  of  gas  should 
be  very  considerable  ;  and  hence  it  was  desirable  to  con- 
stru<fl  a  piece  of  apparatus  which  should  deliver  the 
various  gases  rapidly,  but  nevertheless  as  dry  as  it  is 
possible  to  obtain  them.  It  was  also  desirable  to  work 
with  larger  quantities  of  materials  than  could  be  handled 
in  the  former  apparatus.  For  these  reasons  another  piece 
of  apparatus  was  construdted  to  dry  the  hydrochloric  acid 
gas  ;  this  apparatus  contained  several  flasks  of  sulphuric 
acid,  three  very  efficient  towers  containing  the  same  acid, 
which  was  constantly  renewed,  and  a  long  tube  con- 
taining re-sublimed  phosphoric  pentoxide.  One  of  the 
towers  is  shown  (Fig.  3).  The  whole  apparatus  was 
fused  or  ground  together,  thus  wholly  avoiding  rubber  or 
xorit  connexions. 

in  the  following  determinations  the  boat  was  allowed 
to  cool  in  an  atmosphere  of  dry  nitrogen,  as  a  further 
precaution  against  a  possible  partial  decomposition  of  the 
sensitive  magnesic  chloride.  As  soon  as  the  salt  had 
been  fused,  a  current  of  dry  nitrogen  was  passed  into  the 
combustion-lube  and  the  hydrochloric  acid  generator  was 
disconneded.  The  nitrogen  was  prepared  by  passing 
mixed  air  and  ammonia  over  rolls  of  copper  gauze  heated 
to  redness,  the  excess  of  ammonia  being  removed  by 
passing  the  gases  through  wash  bottles  containing  dilute 
sulphuric  acid    and  the  nitrogen  was  dried  in  a  set  of 


towers  similar  to  those  used  for  drying  the  current  of  air. 
When  the  tube  was  cool,  the  current  of  dry  air  was  turned 
on,  and  the  tube  and  its  contents  washed  out  as  in  pre- 
vious experiments. 

As  there  were  no  especial  objeftions  against  the  use  of 
rubber  conneiflions  and  stoppers  in  the  part  of  the 
apparatus  used  for  drying  the  air,  several  large  towers 
were  employed,  each  filled  with  crushed  pumice  stone  and 
saturated  with  sulphuric  acid  previous  to  using.  Both  air 
and  nitrogen  were  finally  dried  by  re-sublimed  phosphoric 
pentoxide.  The  bottling  and  combustion-tubes  were  of 
the  same  construdtion  as  in  the  former  apparatus,  except 
that  they  were  larger. 

In  the  second  series  the  method  of  igniting  the  double 
salt  to  obtain  the  magnesic  chloride  was  the  same  as  in 
the  first;  but  the  method  of  estimating  the  amount  of 
chlorine  present  was  different.    From  the  approximate 


Fig.  3. — One  of  the  Towers  used  for  Drying 
Hydrochloric  Acid  (70  cm.  high). 

atomic  weight  of  magnesium  already  found,  a  calculation 
was  made  as  to  the  amount  of  silver  necessary  exadtly  to 
precipitate  the  chlorine  present  in  the  sample  of  magnesic 
chloride  taken.  This  amount  of  silver  was  weighed  out 
as  nearly  as  possible,  dissolved  in  nitric  acid  in  an  Erlen- 
meyer  flask,  provided  with  a  set  of  bulbs  to  catch  the 
spray  from  the  evolution  of  gas,  and  added  to  the  solution 
of  magnesic  chloride  contained  in  a  large  flask.  The 
flask  was  thoroughly  agitated  in  the  dark,  and  allowed  to 
stand  over  night.  Fifty  c.c.  were  then  withdrawn  by 
means  of  a  pipette,  and  tested  by  means  of  a  nephelo- 
meter, or  apparatus  for  determining  the  amount  of  pre- 
cipitate from  the  intensity  of  the  opalescence  produced  by 
it.  This  piece  of  apparatus  was  construdted  for  the  pur- 
pose, and  consisted  of  two  redtangular  glass  cells,  with  a 
mirror  enclosed  in  a  dark  case,  so  arranged  that  the 
column  of  liquid  contained  in  the  lower  part  of  the  cells 
could  be  viewed  horizontally  without  disturbance  from 


Chbhical  Mbws,  ) 
April  q,  1897.      ) 


Atomic  Weight  of  Japanese  Tellurium, 


175 


Furface  refledions.  A  dark  screen  was  placed  at  the 
further  end  of  the  cells,  and  the  whole  so  arranged  that 
light  could  come  to  the  eye  only  by  reflection  from  solid 
particles  which  might  be  suspended  in  the  column  of 
liquid  inspeded.  It  the  liquid  was  perfedlly  clear,  the 
field  of  vision  remained  black,  but  an  extremely  small 
amount  of  precipitate  produced  a  very  marked  change, 
and  the  intensity  of  opalescence  was  approximaiely  pro- 
portional to  the  amount  of  precipitate.  It  was  found 
perfedly  easy  and  certain,  by  this  method,  to  distinguish 
the  difference  between  0*002  and  0-003  of  a  milligrm.  of 
argentic  chloride  or  between  0*004  and  0005  of  a  milligrm., 
and  larger  amounts  in  proportion.  This  instrument  gave 
such  satisfadion  in  this  research  that  the  method  will  be 
worked  out  for  various  other  reaftions,  and  published 
later. 

The  method  of  using  this  apparatus  was  as  follows  : — 
25  c.c.  of  the  clear  supernatant  liquid  from  the  flask  con- 
taining the  well-shaken  argentic  chloride  and  magnesic 
nitrate  were  placed  in  each  cell,  5  c.c.  of  a  very  dilute 
solution  of  argentic  nitrate  being  added  to  one,  and  5  c.c. 
of  a  correspondingly  dilute  solution  of  ammonic  chloride 
to  the  other.  The  silver  solution  contained  i  m.grm. 
of  silver  to  the  c.c.  An  unequal  depth  of  cloudiness 
indicated  an  excess  of  either  silver  or  chlorine  in  the 
original  solution,  and  accordingly  the  amount  necessary 
for  neutralisation  was  run  into  the  large  flask  containing 
precipitate  and  solution  from  a  burette.  The  solution 
was  again  allowed  to  stand  in  the  dark  with  occasional 
shaking,  and  after  the  precipitate  had  entirely  subsided 
was  again  tested  as  before,  and  this  cycle  of  operations 
was  repeated  until  the  opalescences  matched  one  another.* 
It  will  be  observed  that,  if  water  is  added  to  the  cell 
giving  the  more  dense  opalescence  until  the  effedt  becomes 
equal  on  both  sides,  the  amount  of  dilution  will  give  a 
means  of  ascertaining  the  amount  of  precipitate  in  each 
cell.  The  appropriate  corredions  were  then  applied  to 
the  amount  of  silver  taken.  Due  allowance  was  made 
for  the  slightly  diminishing  volume  of  the  solution  in  the 
flask.  The  addition  of  i-ioth  of  a  m.grm.  of  silver  to  a 
litre  of  solution  produced  a  distinct  change  in  the  depth 
of  colour  observed.  After  the  matching  was  completed, 
repeated  trials  were  made  with  fresh  portions  of  the  solu- 
tion to  confirm  the  result ;  and  as  the  depth  of  opalescence 
as  seen  in  the  nephelometer  was  perfedly  flat,  without 
disturbing  efledions,  the  end  point  could  be  determined 
with  great  precision. 

Several  results  obtained  in  this  manner  are  given  in 
Series  II. 

Series  II. 

No.    Sample  Sample      Weight  Ratio,  Atomic 

of    of  MgClj  ofAg  of  Weight     MgCl2:2Ag     weight 

ezp.      used.     used.        MgCI,.         of  Ag.         ^loo-.n.        of  Mg. 

611  278284      6*30284       226*490        24*395 

I  I  2*29360      5*19560        226*526        24379 

812  2*36579      5*35989        226*558        24*366 


Average..     ..     24*380 

These  results,  however,  do  not  merit  great  confidence' 
for  the  apparatus,  which  had  become  somewhat  compli- 
cated, did  not  work  smoothly  at  first,  on  account  of  some 
minor  imperfedions  which  were  remedied  later.  Besides 
this,  careful  consideration  led  to  the  suspicion  that  the 
towers  used  for  drying  the  air  and  nitrogen  were  not 
eflicient  enough  to  remove  the  last  traces  of  water.  Of 
necessity  the  towers  had  to  be  charged  with  sulphuric 
acid  an  hour  or  two  before  their  final  use,  and  during  that 
time  a  large  part  of  the  acid  drained  out  of  the  pumice 
stone.  This  surmise  was  fully  confirmed  by  later  experi- 
ments; and  since  this  was  the  case,  the  second  series 
must  be  rejeded  in  the  final  estimate  of  the  atomic 
weight. 

(To  be  continued). 

For  details  of  this  method  see  Stas,  Mem,  Acad.  Belg.,  xliii., 
Part  II.,  and  Richards,  Proc,  Amer,  Acad.,  xxix.,  86;  xxx.,  385. 


THE    ATOMIC    WEIGHT    OF    JAPANESE 

TELLURIUM. 

By    MASUMI    CHIKASHIGE,    Rigakushi, 
College  of  Science,  Imperial  Univers  ty. 

The  atomic  weight  of  tellurium  has  been  determined  by 
Berzelius  (1833),  von  Hauer  (1857),  Wills  (1879),  Brauner 
(1883,  1889),  and  Staudenmaier  (1895),  Berzelius  gave  it 
as  128*3  (0=i6).  Staudenmaier  has  only  reduced  it  to 
127  6.  Brauner  had  also  obtained  this  number,  that  is, 
I27-64,  by  determining  the  quantity  of  bromine  in  the 
tetrabromide ;  but  in  other  ways,  which  he  could  not 
admit  to  be  inaccurate,  he  obtained  widely  varying  num- 
bers for  the  atomic  weight.  To  explain  these  variations, 
he  assumed  that  what  passes  for  the  element  tellurium  is 
a  mixture  or  compound.  The  number  125,  which  since 
1884  has  been  generally  accepted  as  the  atomic  weight 
of  tellurium,  was  suggested  by  Mendeleeff,  but  was 
adopted  on  the  grounds  of  Brauner's  determinations 
(partly  by  faulty  methods,  as  he  has  since  ascertained) 
published  in  1883  in  Russia.  A  paper  by  him,  on  the 
atomic  weight  of  tellurium,  which  appeared  last  year  in 
the  Journal  of  the  (London)  Chemical  Society,  supplies 
no  new  data.  It  throws  no  light  upon  the  causes  of  the 
varying  results  he  had  previously  obtained  by  different 
methods,  but  apparently  contains  the  admission  from 
him  at  last  that,  so  far  as  can  be  determined  by  known 
methods,  the  atomic  weight  of  tellurium  is  127*64 
(127*7  nt  vacuo). 

The  objedl  of  the  research  described  in  the  present 
communication  has  been,  not  to  add  one  more  to  the 
above-mentioned  determinations  of  the  atomic  weight  of 
tellurium,  by  some  modification  of  a  method  already  em- 
ployed or  by  some  new  method,  but  to  apply  Brauner's 
tetrabromide  method  to  tellurium  of  utterly  different 
origin  from  that  of  what  he  worked  upon.  European  and 
American  tellurium  occurs  in  association  with  heavy 
metals,  and  might,  therefore,  when  separated  from  those 
which  are  known,  still  retain  unknown  elements,  in  ac- 
I  cordance  with  Brauner's  conception.  But  in  Japan 
tellurium  is  found  in  native  sulphur,  as  was  discovered  by 
Divers,  Shimose,  and  Shimidzu,  in  1883  (Chem.  News; 
y.  Chem.  Soc),  There  occurs,  in  fad,  in  this  country,  a 
massive,  crystalline,  red  sulphur,  a  variety  of  the  selen- 
sulphur  (Stromeyer)  found  in  the  Lipari  Isles,  in  Naples 
(Phipson),  and  in  the  Hawaian  Islands  (Dana).  It  is 
semi-transparent,  and  indistinguishable  in  appearance 
from  native  sulphur,  except  by  its  beautiful  orange  colour, 
and  occurs  interspersed  with  simple  sulphur  in  the  same 
blocks.  I  take  from  the  Chemical  News  the  composition 
of  a  sample  analysed  by  Divers  and  Shimidzu  : — Tellu- 
rium, 0*17;  selenium,  o*o6 ;  arsenic,  o'oi  jer  cent; 
traces  only  of  molybdenum  and  earthy  matter,  and  sul- 
phur, by  difference,  99*75  per  cent.  It  is  accordingly 
much  more  a  tellurosulphur  than  a  selenosulphur. 

Concerning  this  tellurium,  it  need  not  be  contended 
that  it  is  more  truly  an  element  than  that  found  combined 
with  bismuth,  gold,  lead,  and  silver;  it  is  sufficient  to 
assert  the  high  improbability  that  it  should  contain  the 
same  unknown  elements  as  the  latter.  That  being  the 
case,  then  if  it  gives  the  same  result  by  Brauner's  tetra- 
bromide method  as  that  obtained  with  Hungarian  tellu- 
rium, the  likelihood  that  tellurium  with  atomic  weight 
127  6  is  an  element  is  greatly  increased,  if  not  raised  to  a 
certainty.  Such  was  the  view  taken  of  the  matter  by  my 
honoured  teacher.  Dr.  Edward  Divers,  F.R.S.,who  placed 
in  my  hands  about  14  grms.  of  tellurium,  which  had  been 
prepared  by  him  and  Mr.  Shimose  years  ago.  They  had 
obtained  this  tellurium  from  the  sediment  removed  from 
the  lead  chambers  of  a  sulphuric  acid  fadory,  by  a  method 
the  particulars  of  which  they  communicated  to  the 
Chemical  News  in  1883.  The  tellurium,  which  I  thus 
received,  had  already  been  carefully  freed  from  selenium 
and  distilled  in  hydrogen. 
Before  I  had  made  very  much  progress  in  preparing 


1^6 


Method  for  Determining  Melting -points. 


I  Chemical  News, 
I      April  9,  1897. 


for  the  determination  of  the  atomic  weight,  a  preparation 
which  has  taken  a  very  long  time,  Staudenm.aier's  memoir 
came  to  hand,  but  its  contents  did  not  deter  me  from 
finishing  my  investigation,  though  they  can  leave  no 
reasonable  doubt,  I  think,  that  the  atomic  weight  of  the 
element  is  leally  12^6. 

Long  as  the  work  has  occupied  me,  there  is  now  no 
occasion  to  describe  it  in  detail,  since  it  was  purposely 
the  closest  copy  I  could  make  of  Brauner's  operations,  so 
far  as  these  seemed  to  be  material  to  the  point.  The  tel- 
lurium, already  so  pure,  was  tested  for  impurities,  and  was 
again  distilled  in  hydrogen. 

Excellent  commercial  bromine  was  distilled  from 
potassium  bromide,  zinc  oxide,  and  water  (Stas).  It  was 
dehydrated  first  by  means  of  anhydrous  calcium  bromide 
left  in  it  for  some  days,  and  then  by  baryta,  from  which 
it  was  filtered  through  asbestos  in  vessels  closed  from  the 
air.  It  was  then  distilled  into  a  receiver  sealed  on  to  the 
distilling  flask. 

The  silver  was  first  precipitated  by  Stas's  well-known 
sulphite  method,  fused  under  borax  and  nitre,  then  kept 
for  a  time  in  fusing  potassium-sodium  carbonate,  washed 
with  water,  hydrochloric  acid,  and  ammonia,  melted  again 
in  a  lime  crucible,  and  granulated  in  distilled  water. 

The  distilled  water  of  the  laboratory  was  fradlionally 
re-distilled,  and  the  nitric  acid  was  treated  in  the  same 
way. 

The  balance  used  is  one  by  Sartorius  (his  first  quality), 
which  has  been  hitherto  only  sparingly  used  for  special 
cases.  The  weights  are  of  quartz  and  platinum,  from 
Gerhardt,  and  were  found  by  me  to  have  been  closely 
adjusted.  S 

The  tellurium  bromide  was  prepared  by  adding  the  tel- 
lurium to  the  bromine,  in  a  tube,  exaaiy  as  described  by 
Brauner.  In  such  a  tube  he  direftly  sublimed  it,  but  I 
had  to  transfer  it  to  another  longer  tube.  The  procedure 
was  to  slide  into  this  tube,  nearly  to  the  bottom,  an  open 
tube  loosely  fitting  it,  down  this  to  drop  the  powdery 
crude  tetrabromide,  and  then  withdraw  it,  leaving  the 
walls  of  the  sublimation  tube  unsoiled.  This  tube,  at 
once  closed  by  a  cork,  was  then  contracted  about  25  cm. 
from  its  closed  end,  and  again  about  12  cm.  further  off, 
where  it  was  cut  off  from  the  corked  end,  and  the 
narrowed  mouth  attached  by  caoutchouc  tubing  to  the 
drying  tube  conneded  with  a  Sprengel  pump.  The  tube 
was  placed  in  the  furnace  with  its  first  contradion  just 
outside ;  the  bromide  before  sublimation  occupied  the 
hinder  third  of  the  tube  within  the  furnace.  Sublimation 
was  in  all  other  respedts  effedted  just  as  described  by 
Brauner,  a  little  dibromide  being  sublimed  off  at  200° 
into  the  outer  part  of  the  tube,  and  the  tetrabromide 
sublimed  at  a  temperature  kept  closely  at  300"  into  the 
anterior  part  of  the  tube  within  the  furnace.  Pradtically 
nothing  remained  unsublimed,  which  showed  that  the 
transference  of  the  undistilled  bromide  from  tube  to  tube 
had  been  effected  with  impunity,  this  compound  not  being 
noticeably  hygroscopic,  and  the  air,  at  the  time,  being 
cold  and  very  dry.  The  sublimation  furnace  was  an  exa<5t 
copy  of  Brauner's. 

The  tellurium  bromide  was  weighed  off  and  dissolved 
in  tartaric  acid  in  one  vessel,  added  to  the  silver  nitrate, 
shaken  for  hours  in  the  bottle,  with  a  conical,  polished, 
pointed  stopper  projeding  into  it,  and  then  finished  off 
volumetrically,  all  just  as  described  by  Brauner  (except 
that  the  final  titration  was  not  effedled  in  a  dark  room, 
but  in  feeble  daylight). 

I  made  only  the  three  det€rmina*ier^  here  given, 
negleding  a  trial  for  piactice,  with  good  result,  in  which 
high  accuracy  wai  not  sought  for.  The  following  are  the 
results  : — 

At.  wt. 

127-57 
I27'6i 
127-58 

The  details  of    Exp.   II.    are:— .Silver  weighed    off, 


Expt. 

Tellm.  brom. 

Silver. 

I. 

4'l8i2 

4-0348 

11. 

4'3059 

4-^547 

111. 

4-5929 

443 19 

4*1548  grms. ;  time  of  continuous  shaking  by  water-motor, 
4  hours;  precipitate,  thoroughly  pulverulent;  silver  solu- 
tion added,  0-4 c.c,  which  produced  no  turbidity;  potas- 
sium bromide  solution  required,  08  c.c.  =  0-54  c.c.  silver 
solution.  Since  there  had  been  taken  silver  in  excess, 
equivalent  to  0-14  c.c.  silver  solution,  and  therefore 
0-00014  grm.  silver,  the  adual  quantity  of  silver  required 
by  the  4*3059  grms.  bromide  had  been  4*1547  grms. 
Then  — 

79063  X4-I547X  100  o  .  u         • 

'^  ^  ^ — ^    ^^'  ^ =71*48  per  cent  bromme, 

107-938x4-3059 
and — 

^/i07-938x4*3059_yg.g63\  =  i27-6i  at.  wt.  tellm. 

V       41547  / 

In  Exp.  I.  the  silver  weighed  out  was  not  so  closely 
apportioned,  and  several  c.c.  of  the  volumetric  solution 
had  to  be  used  ;  otherwise  it  agreed  with  II.,  as  did  also 
III.  in  its  details. 

When  it  is  considered  that  Brauner  and  I  have  obtained 
by  the  same  method  identical  results,  although  he  worked 
with  tellurium  that  had  presented  itself  in  combination 
with  metals,  while  I  have  worked  with  that  occurring  in 
native  sulphur  of  high  purity,  except  for  the  presence  of 
this  tellurium  and  of  selenium,  so  far  as  can  be  ascer- 
tained by  tests  for  known  elements  ;  and  when  it  is  further 
considered  that  Staudenmaier's  results  are  the  same  as 
Brauner's,  though  obtained  by  a  wholly  different  method, 
no  reasonable  doubt  can  remain  that  the  atomic  weight  of 
tellurium  is  127  6. 

The  occurrence  of  tellurium  in  Japan  in  association 
with  selenium  in  native  sulphur  is  also  a  fad  of  great 
significance  in  settling  the  place  of  this  substance  in  a 
natural  classification  of  the  elements,  showing,  as  this 
does,  so  close  a  habitude  to  exist  between  it  and  sulphur 
and  selenium. — Journal  of  the  College  of  Science,  Impe- 
rial University,  Japan,  vol.  ix..  Part  II.,  p.  123. 


PROCEEDINGS    OF    SOCIETIES. 

CHEMICAL  SOCIETY. 
Ordinary  Meeting,  March  i8th,  1897. 

Mr.  A.  G.  Vbrnon  Harcourt,  President,  in  the  Chair. 

(Concluded  from  p.  164). 
47.  "  Note  on  a  Method  for  Determining  Melting-poiuts." 
By  Ernest  H.  CeoK,  D.Sc. 

So  many  methods  have  been  introduced  for  the  deter- 
mination of  melting-points  that  an  apology  is  perhaps 
necessary  for  describing  another ;  but  the  following 
method  has  been  found  to  work  so  well  in  this  laboratory, 
and  to  be  so  easy  of  manipulation,  that  the  author  ven- 
tures to  place  it  on  record. 

Notwithstanding,  however,  the  theoretical  simplicity  of 
taking  a  melting-point,  it  is  surprising  that  in  commercial 
work  considerable  differences  frequently  occur  between 
analysts  when  reporting  upon  such  a  substance,  for 
example,  as  paraffin  scale.  Probably  most,  if  not  all,  of 
these  differences  are  caused  by  the  different  methods  em- 
ployed. Thus  it  is  well  known  that  "  the  English  test," 
which  consists  in  allowing  the  wax  to  solidify  in  a  test- 
tube  in  which  the  thermometer  is  placed,  gives  results 
from  2j  to  3°  Fahr.  lower  than  the  "American  test,"  in 
which  the  wax  was  melted  in  an  open  dish.  Both  these 
methods  again  differ  slightly  from  the  capillary-tube  plan, 
and  in  this  process  a  different  result  is  obtained  when  an 
open  tube  is  used  than  when  it  is  closed.  There  are,  in 
fad,  many  precautions  which  are  necessary  to  be  observed 
if  concordant  resill's  are  to  be  obtained,  and  it  is  much 
to  be  desired  that  some  distind  and  definite  regulations 
should  be  made  with  reference  to  the  matter. 

The  apparatus  employed  is  a  beaker  filled  to  the  brim 


IHBMICAL  MbWS, 

April  9,  1897.      I 


The  French  Academy  of  Sciences. 


i>7 


with  water;  inside  this,  and  separated  from  it  on  all 
sides,  is  a  smaller  one.  The  smaller  beaker  is  partly 
filled  with  mercury  in  which  is  placed  a  thermometer.  A 
stirrer  is  used  to  keep  the  water  in  the  large  beaker  of 
uniform  temperature.  A  cardboard  or  other  disc  covers 
the  smaller  beaker  when  the  operation  is  in  progress. 
The  whole  is  heated  from  below  by  means  of  a  sand- 
bath.  When  the  melting-point  to  be  determined  is  under 
30°  it  is  better  to  replace  the  sand-bath  by  an  evaporating 
dish  containing  water. 

The  process  is  conduced  as  follows  :— The  material 
whose  melting-point  is  to  be  taken  is  placed  on  three  or 
four  small  pieces  of  thin  ferro-type  plate,  or  other  thin 
metallic  sheet,  or  on  the  cover  glasses  which  are  used  for 
microscope  slides.  If  ferro-type  or  other  metallic  slips 
are  used,  care  must  be  taken  to  remove  the  varnish  or 
other  coating,  in  order  that  good  metallic  contad  can  be 
had  with  the  mercury.  The  slips,  with  the  substance  on 
them,  are  now  placed  on  the  surface  of  the  mercury,  and 
the  heat  applied  until  the  substance  melts.  The  solidi- 
fying-point  is  obtained  by  raising  the  temperature  above 
the  melting-point,  and  allowing  the  beaker  to  cool,  noting 
the  thermometer  when  the  first  solidification  takes  place. 

For  temperatures  between  100  and  200°,  the  larger 
beaker  is  filled  with  paraffin  wax. 

The  following  precautions  have  been  found  to  be  neces 
sary: — (i)  The  temperature  must  be  made  to  rise  very 
slowly.  (2)  The  liquid  in  the  outer  beaker  must  be  fre- 
quently stirred.  (3)  Not  less  than  2'5  cm.  in  depth  of 
mercury  must  cover  the  inner  beaker.  (4)  Sufficient 
volume  of  water  must  be  allowed  between  the  two 
beakers.  The  minimum  distances  to  give  good  results 
are  i  inch  between  them  laterally  and  ij  inches  at  the 
bottom.  (5)  The  inner  beaker  must  be  immersed  a  suffi- 
cient depth  in  the  water.  This  point  is  of  great  import- 
ance, the  least  distance  between  the  top  of  the  mercury 
and  the  top  of  the  water  being  3  inches.  A  greater 
distance  is,  however,  to  be  preferred.  (6)  The  whole 
apparatus  should  be  protefted  from  draughts.  (7)  The 
disc  should  be  kept  on  the  smaller  beaker  during  the 
determination. 

The  following  examples  will  show  the  degree  of  accu- 
racy to  be  obtained  in  ordinary  working,  some  of  the 
results  being  obtained  by  students  who  have  never  taken 
a  melting-point  determination  before: — Paraffin  wax  (i), 
49-8,  49  7,  49"5,  498.  Paraffin  wax  (2),  46*2,  46*0,  46'o, 
46-0.  Paraffin  wax  (3),  46-5,  463,  46-5.  Ortho-mono 
nitro-phenol,  445,  447.     Urea,  i3i'o,  i3t'5,  13 1*2. 

48.  "  Velocity  of  Urea  Formation  in  Aqueous  Alcohol.^' 
By  James  Walker,  D.Sc,  and  Sydney  A.  Kay,  B.Sc. 

The  authors  have  investigated  the  rate  of  formation  of 
urea  from  ammonium  cyanate  in  pure  water,  and  in  mix- 
tures of  water  and  alcohol,  containing  10,  30,  50,  70,  and 
90  per  cent  by  volume  of  the  latter.  The  alcohol  adls  in 
two  ways :  first,  it  diminishes  the  degree  of  dissociation 
of  the  cyanate,  and  thus  retards  the  adtion  by  diminishing 
the  number  of  adtive  molecules ;  secondly,  it  increases 
the  rate  at  which  the  ions  produced  by  the  dissociation 
interad.  The  second  mode  of  adion  outweighs  the  first, 
so  that  there  is  on  the  whole  a  marked  acceleration  as  the 
water  of  the  solvent  is  replaced  by  alcohol.  If  the  re- 
verse transformation  of  urea  into  cyanate,  and  the  degree 
of  dissociation  of  the  latter  at  the  various  stages  of  the 
process,  are  taken  into  consideration,  the  requirements  of 
the  law  of  mass-adlion  are  stridtly  fulfilled. 

Methylic  alcohol,  acetone,  glycol,  glycerol,  and  cane- 
sugar  exert  a  similar  accelerating  effedt  when  part  of  the 
water  used  as  solvent  is  replaced  by  them. 

From  the  displacement  of  the  point  of  equilibrium  be 
tween  cyanate  and  urea  by  change  of  temperature,  it  is 
calculated  that  the  transformation  of  ammonium  ions  and 
cyanic  ions  into  urea  is  accompanied  by  a  heat  evolution 
of  about  5000  cals.  per  grm. -molecule. 

49.  ^^  Action  of  Alkyl  Haloids  on  Aldoximes  and 
Ketoximesy  By  Wyndham  R.  Dunstan,  F.R.S.,  and 
Ernest  Goulding. 


The  authors  find  that,  when  formaldoxime,  acetald<.xime, 
and  acetoxime  are  heated  in  alcoholic  solution  with  an 
alkyl  iodide  or  bromide,  they  are  converted  into  compounds 
of  alkyloximes  in  which  the  alkyl  group  is  united  to  nitro- 
gen R'CHN{R')0  and  R'2CNCH(R')0.  These  derivatives 
are  isomerides  of  the  little-known  ethers  of  the  oximes 
R'CH:NOR'  and  R'jCNOR',  and  are  to  be  regarded  as 
derivatives  of  the  tautomeric  or  isoximidoforms  of  the 
ordinary  aldoxime  or  ketoxime — 


R'CHNH 

\/ 
O 


and 


R'zCNH 

V     . 
O 

in  which  the  alkyl  replaces  the  hydrogen  of  the  amido- 
group.  Their  constitution  has  been  proved  by  their 
hydrolysis  into  ^-substituted  hydroxylamines,  NH(R')OH, 
and  the  corrresponding  aldehyde  or  ketone. 

Formaldoxime,  when  mixed  with  methyliodide,  either  in 
alcoholic  or  ethereal  solution,  is  converted  into  a  crystal- 
line salt  of  the  formula  (CHjNOHJaCHsI.  It  has  been 
previously  shown  (Dunstan  and  Bossi,  Proc,  1894,  x.,55) 
that  formaldoxime  forms  salts  with  monobasic  acids 
which  contain  3  mols.  of  the  oxime  (CHaNOHjgHCl, 
&c.  On  hydrolysis,  followed  by  redutflion,  i  molecule  of 
methylamine  hydrochloride  and  2  mols.  of  ammonium 
chloride  are  produced,  and  on  heating  near  its  melting- 
point  (io2*)  only  2  molecules  of  formaldoxime  distil  from 
it.  The  formula  of  the  compound  may  therefore  be 
written  (CH2NOH)2,CH2N(CH3)O.HI.  The  base  corre- 
sponding with  this  salt  could  not  be  separated.  Methyl 
bromide  heated  with  formaldoxime  furnishes  the  corre- 
spondinsi  hydrobromide. 

Acetaldoxime  combines  with  methyliodide,  forming  the 
hydriodide  of  a  base  which  has  so  far  only  been  obtained 
in  the  liquid  state  even  after  a  process  of  fradlional  preci- 
pitation of  an  alcoholic  solution  by  ether.  On  hydrolysis 
this  salt  furnishes  acetaldehyde  and  /3-methyl  hydroxyl- 
amine.  There  can  therefore  be  no  doubt  that  its  formula 
is  CHaCHNCCHgjO.HI.  Methyl  bromide  combines  in 
the  same  manner,  forming  the  corresponding  hydro- 
bromide.  Ethyl  iodide  forms  the  hydriodide  of  the  ethyl 
derivative,  CH3CHN(C2H5)O.HI.  Neither  of  the  salts 
has  been  crystallised,  and  the  corresponding  bases  are 
highly  unstable. 

Acetoxime.— By  heating  acetoxime  with  methyl  iodide 
a  red  liquid  is  obtained,  which,  on  concentration,  deposits 
red  crystals  with  a  fine  green  lustre.  The  mother-liquor 
furnished  the  little-known  methylamine  hydriodide — 

(CH3NH2.HI), 
m  glistening,  crystalline  plates  (from  alcohol  and  ether). 
This   is   a  very  stable  non-deliquescent  salt,  melting  at 
220°  with  partial  decomposition. 

The  red  crystals  were  proved  by  analysis  to  be  a 
methylacetoxime  periodide  of  the  formula — 

[(CH3)2CN(CH3)O.HI]2l. 

On  hydrolysis  it  breaks  up  into  acetone  and  j8-methyl- 
hydroxylamine. 

Many  attempts  were  made  to  isolate  the  hydriodide 
from  the  periodide,  and  also  to  prepare  other  salts  from 
this  compound,  including  the  base,  but  without  success, 
owing  to  the  great  instability  of  these  substances. 

The  hydrobromide  appears  to  be  formed  when  methyl 
bromide  is  heated  with  an  alcoholic  solution  of  acetoxime, 
but  this  salt  could  not  be  crystallised. 


THE    FRENCH    ACADEMY  OF   SCIENCES. 

The  following  communication  from  their  Correspondent 
in  Paris  appeared  in  The  Times  of  April  7th  :— 

M.  Berthelot  read  this  afternoon,  at  the  Academy  of 
Sciences,  the  following  letter  addressed  to  him  in  French 
by  Mr.  H.  Wilde,  President  of  the  Manchester  Literary 
and  Philosophical  Society,  announcing  to  the  Academy 
the  gift  of  ;£'550o  to  be  set  apart  for  an  annual  prize  of 


178 


The  Chemical  Society  Election. 


4000  frs.  I  send  you  the  original  letter,  without  under- 
taking,  considering  its  special  and  technical  character,  to 
translate  it. 

"  Diverses  considerations  m'engagent  adluellement  a 
me  mettre  en  communication  avec  I'Academie  dans  le  but 
de  stimuler  de  nouvelles  investigations  dans  les  sciences 
physico-chimiques,  et  de  faire  disparaitre  quelques-uns 
des  obstacles  qui  entravent  leurs  progres.  L'un  de  ces 
obstacles  qui  appelle  la  serieuse  attention  des  penseurs 
philosophes  est  I'invasion  d'une  autorite  dogmatique  dans 
une  science  scolastique,  pour  soutenir  des  erreurs  demon- 
trees  et  des  methodes  erronees  d'observation  et  d'experi- 
ence.  II  sera  sufEsant  pour  Tobjet  que  j'ai  adtuellement 
en  vue  de  citer  le  systeme  periodique  des  elements  chi- 
miques  comme  un  exemple  de  I'abus  d'autorite  dans  une 
branche  de  la  science  ou  vous  occupez  un  rang  si  distin- 
gue. J'ai  a  vous  exprimer  mes  regrets  que  vos  vues  au 
sujet  de  la  pretendue  loi  periodique  ne  soient  venues  que 
recemment  a  ma  connaissance ;  sans  cela  je  m'y  serais 
r^fere  dans  mes  travaux  gen^raux  sur  les  relations  nume- 
riques  des  poids  atomiques.  Quoique  vous  ayez  clairement 
indique,  monsieur,  dans  vos  '  Origines  de  I'AIchimie,'  les 
sophismes  et  les  contradidtions  inherents  a  ce  systeme, 
et  que  vous  ayez  egalement  montre  que  la  prediction  de 
I'existence  et  des  proprietes  des  elements  inconnus  n'a 
aucune  relation  necessaire  avec  la  pretendue  loi  periodique, 
cependant  ce  systeme  a  depuis  ete  impose  aux  personnes 
qui  s'occupent  de  science  par  les  societes  scientifiques  et 
les  corps  enseignants  comme  une  verit6  naturelle  d'une 
autorite  indiscutable. 

"  Je  n'ai  pas  besoin  de  vous  rappeler  que  I'etat  aduel 
de  la  chimie  theorique  en  raison  de  la  connaissance 
formelle  de  ce  dogme  est  reellement  deplorable.  Les 
savants  qui  aspirent  a  se  distinguer  dans  la  chimie  et 
dans  la  physique  estiment  qu'il  est  necessaire  de  donner 
des  preuves  de  leur  croyance  personnelle,  en  tachant  de 
montrer  la  correlation  de  leurs  propres  travaux  sur  des 
points  particuliers  avec  le  systeme  periodique,  et  ils 
cvitent  toute  reference  aux  proportions  multiples  des  poids 
atomiques,  comme  a  une  dangereuse  heresie.  Beaucoup 
de  ces  neophytes,  de  meme  que  certains  auteurs  de 
manuels,  ne  peuvent  se  faire  une  idee,  ou  ignorent  ia 
signification  de  I'idde  de  la  p6riodicite  telle  qu'elie  est 
cefinie  par  DeChancourtois,  Newlands  et  Mendeleief 
dans  leurs  memoires  respedlifs.  Ils  appliquent  I'expression 
impropre  de  loi  periodique  it  la  progression  de  proprie-^s 
anterieurement  connues  observables  dans  les  families 
naturelles  des  Elements,  a  la  correlation  avec  les  poids 
a:omiques  de  proprietes  physiques  et  chimiques  6tablies 
depuis  longtemps,  a  la  progression  bien  connue  des 
proprietes  physiques  dans  les  series  homologues  des 
composes  organiques.  Par  suite,  le  danger  pour  les 
progres  future  de  la  chimie  theorique  est  que,  lorsque 
I'idee  illusoire  d'une  spiro-periodicite  des  proprietes 
analogues  des  elements  sera  universellement  abandonnee, 
ie  nom  impropre  de  loi  periodique  est  expose  a  prendre 
dans  la  science  un  caraftere  parasite  de  la  meme  facon 
que  cette  autre  expression  impropre,  '  esprit  lunatique,' 
avec  ses  d^riv^s,  subsiste  encore  dans  la  civilisation 
moderne  comme  une  survivance  de  la  physiologic  mentale 
barbare  des  ages  passes. 

"  Heureusement  pour  I'avenir  de  la  philosophic  chimique 
que  I'esprit  dc  Dumas  vit  encore  dans  les  esprits  de  la 
plupart  des  chimistes  fran^ais,  qui  ne  reconnaissent 
autune  autre  autorite  que  la  v^rite  de  la  nature  telle 
qu'elie  se  presente  a  I'entendement,  et  qu'ils  sont  par 
la  exempts  de  I'illusion  de  la  pretendue  loi  periodique 
En  renonnaissance  des  nombreux  profits  que  j'ai  retires 
de  la  science  fran9aise,  tant  pure  qu'appliquee,  j'ai 
I'honncur  d'offrir  a  I'Academie  la  somme  de  £5500 
(137500  ^•)  PO""^  ^"^®  placee  en  rente  fran9aise,  et 
rint^ret  provenant  de  sette  somme  devra  etre  applique 
a  la  fondation  d'une  prix  de  4000  f.  a  decerner  tous  les 
ans  a  I'auteur  d'une  decouverte  ou  d'un  ouvrage  quel- 
conque  en  astronomic,  physique,  chimie,  raineralogie, 


{Chbhical  Nbws, 
April  9,  1897, 

geologie,  et  mdcanique,  qui,  au  jugement  de  I'Academie, 
sera  juge  le  plus  meritant.     L'attrihution  de  ce  prix  sera 
internationale  et  pourra  6tre  retrospedtive. 
"  Alderley  Edge,  Cheshire,  15  Mars,  1897," 

The  gift  has  given  great  satisfadtion  at  the  Academy, 
and  is  as  much  to  the  honour  of  the  donor  as  to  that  of 
the  distinguished  secretary  of  that  Academy,  whose  work 
is  referred  to  in  such  terms  of  gratitude. 


CORRESPONDENCE. 


THE    CHEMICAL    SOCIETY    ELECTION. 

To  the  Editor  of  the  Chemical  News. 
Sir, — In  view  of  the  misleading  reference  recently  made 
in  the  press  to  an  unfortunate  incident  in  the  celebrated 
Edison-Swan  patent  adion,  and  as  this  incident  has,  I 
believe,  been  twisted  into  an  argument  against  voting 
for  Professor  Dewar  in  the  ill-considered  contest  to  which 
he  has  just  been  exposed,  I  would  request,  Sir,  that  you  will 
give  publication  to  the  answers  I  have  received  from 
several  very  eminent  gentlemen  who  were  engaged  in  the 
case,  whose  opinion  on  the  incident  I  ventured  to  solicit 
in  the  interests  of  truth  and  fairness.  I  would  beg  that  you 
will  also  give  publication  to  a  letter  on  the  same  subjedl 
which  Mr.  Crookes  has  received  from  the  Right  Hon. 
Lord  Davey.  I  need  scarcely  add  that  the  full  authority 
of  the  writers  has  been  secured  for  the  publication  of  the 
correspondence. — I  am,  &c., 

Henry  E.  Armstrong. 

86,  Brook  Street,  W., 

March  31, 1897. 

Dear  Professor  Crookes, 

I  was  away  from  home  yesterday,  and  am  truly 
sorry  that  I  did  not  get  your  letter  in  time  to  reply  to  it 
last  night.  I  am  afraid  this  letter  will  be  of  no  use 
to  you. 

The  incident  in  question  occurred  during  my  cross- 
examination  of  Professor  Dewar.  My  recolledlion  of  it 
is  sufficiently  clear  to  enable  me  to  say  that  1  did  not 
think  that  Professor  Dewar  intended  to  mislead  either  his 
Court  or  myself.  I  feel  sure  that  the  misunderstanding 
was  due  to  imperfed  appreciation,  by  the  learned  Judge 
and  by  myself,  of  the  nature  and  objedt  of  the  experiment 
which  Professor  Dewar  was  explaining.  You  may  show 
this  letter  to  Professor  Dewar  himself  or  anybody  else. 
Yours  very  truly, 

Davey. 

Wm.  Crookes,  Esq.,  &c.,  &c. 

57,  Onslow  Square,  S.W., 

March  27tb,  1897. 

Dear  Professor  Armstrong, 

You  have  my  full  authority  for  saying  that  the 
remark  made  by  Mr.  Justice  Kay  about  Professor  Dewar's 
evidence  in  the  Edison  case  was  quite  without  cause.  It 
arose,  I  think,  from  a  misunderstanding  on  the  part  of  the 
Judge  as  to  the  meaning  of  the  evidence. 

The  further  evidence  fully  substantiated  the  position 
taken  by  Dewar  in  the  matter,  and  the  Court  of  Appeal 
reversed  Kay's  decision. 

Yours  very  sincerely, 

J.  Fletcher  Moulton. 

2,  Pump  Court,  Temple,  E.G., 

31  March,  1897. 

Dear  Professor  Armstrong, 

I  am  in  receipt  of  your  letter  of  the  zgth  with 
enclosures. 

The  attack  upon  Professor  Dewar  is  most  unfair  and 
unjustifiable.     I  am  intimately  acquainted  With  every- 


Chrmical  Nbws,  I 
April  9, 1897.     I 


Chemical  Notices  from  Foreign  Sources, 


179 


thing  that  happened  in  the  case  before  Mr.  Justice  Kay 
which  is  referred  to.  No  experiment  of  any  kind  was 
performed  which  could  be  in  any  way  charadlerised  as  an 
attempt  to  mislead.  The  late  Lord  Justice,  then  Mr. 
Justice  Kay,  was  mistaken,  and  did  not  understand  the 
nature  of  the  experiment  to  which  he  was  referring.  His 
decision  was  reversed  in  the  Court  of  Appeal,  and  I  say, 
without  the  slightest  hesitation,  that  everything  which 
Professor  Dewar  did  upon  that  occasion  was  perfe(5tly 
straightforward  and  justifiable.  Make  any  use  you  like 
of  this  letter. 

Yours  faithfully, 

Richard  Webster. 

Holmwood,  Wimbledon  Common,  S.W., 

31  March. 

My  Dear  Armstrong, 

With  regard  to  the  incident  in  the  Edison  and 
Swan  case  some  years  ago,  I  thought  strongly  at  the 
time,  and  I  still  think,  that  Dewar's  answers  did  not  tend 
to  mislead  the  Court,  and  that  he  certainly  did  not  mean 
to  mislead. 

I  followed  Dewar  in  the  box,  but  I  do  not  remember 
that  I  confirmed  the  particular  experiment  in  question.  I 
considered  the  experiment  as  of  little  consequence  in  the 
case. 

Yours  very  truly, 

J.   HOPKINSON. 

Atheneeum  Club, 

April  2nd,  1897. 

Dear  Armstrong, 

In  reply  to  your  enquiry  re  Edison  and  Swan  v. 
Holland  we  have  to  say  that,  being  on  the  opposite  side 
to  Prof.  Dewar,  no  one  could  have  been  more  likely  than 
ourselves  to  take  an  adverse  view  of  the  experiment  which 
formed  the  subjedt  of  Mr.  Justice  Kay's  remarks. 

We,  however,  were  both  of  opinion  that  the  experiment 
brought  forward  by  Prof.  Dewar  was  perfedly  bond  fide,  and 
that  there  was  nothing  in  his  description  of  it  to  justify  the 
adverse  remarks  of  the  Judge,  and  certainly  nothing  to 
justify  the  conclusion  that  the  Judge  seemed  to  draw 
from  it. 

We  need  scarcely  add  that  there  was  nothing  whatever 
in  the  incident  which  refleded  upon  the  honesty  and  truth- 
fulness  of  the  conclusion  which  Prof.  Dewar  drew  from  his 
experiment.  The  garbled  version  which  appeared  in  one 
or  two  journals  has  no  doubt  misled  the  public,  both 
scientific  and  otherwise,  as  to  the  severe  comments  made 
by  Mr.  Justice  Kay  upon  Prof.  Dewar's  experiment.  The 
misunierstanding  was  completely  cleared  up  by  the  evi- 
dence oi  subsequent  witnesses  and  by  experiments  tried 
before  Prof.  Stokes  on  behalf  of  the  Court. 
We  are 

Yours  very  truly, 

E.  Frankland. 
William  Crookes. 


THE    CHEMICAL    SOCIETY    ELECTION. 

To  the  Editor  of  the  Chemical  News. 
Sir, — As  I  had  written  privately  to  Professor  Armstrong, 
assuring  him  that  Dr.  Collie's  statement  that  my 
nomination  to  the  Presidentship  of  the  Chemical  Society 
was  made  without  my  knowledge  or  consent,  I  had  hoped 
that  his  honourable  feelings  would  have  led  him  to  retra(5t 
publicly  his  statement  challenging  Dr.  Collie's  veracity. 
As  my  hopes  are  disappointed,  I  have  no  choice  but  to 
ask  you  to  publish  this  letter,  and  to  state  that  Dr.  Collie's 
remarks  at  the  meeting  of  the  Chemical  Society,  as 
reported  in  the  Proceedings  on  the  iSth  March,  were 
literally  true.— I  am,  &c., 

William  Ramsay. 

University  College,  London,  W.C.» 
April  3,  1S97. 


CHEMICAL    NOTICES    FROM    FOREIGN 
SOURCES. 

NoTB.— All  degrees  of  temperature  are  Centigrade  unless  otherwiie 

expressed. 

Comptes  Rendus  Hebdomadaires  des  Seances,  deVAcademie 
des  Sciences.     Vol.  cxxiv.,  No.  ir,  March  15,  1897. 

New  Apparatus  for  the  Application  of  Spedlral 
Analysis  to  the  Recognition  of  Gases. — M.  Bertheiot. 
— The  experiments  described  throw  a  clear  light  on  the 
nature  of  the  nitrogenous  principles  which  are  formed 
under  the  influence  of  the  eiHuve  adting  upon  organic 
compounds.  What  brightens  the  interest  is  analogy  of 
this  order  of  reactions  with  those  exerted  between  the 
nitrogen  of  the  atmosphere  and  the  immediate  principles 
of  plants. 

Adtion  of  High  Temperatures  upon  Antimony  Per- 
oxide.— H.  Baubigny. — Experiment  proves  that  antimonic 
acid,  Sb205,  is  stable  at  357°;  it  begins  to  decompose  at 
440°,  though  very  slowly,  and  even  at  nascent  redness  the 
decomposition  is  very  slow.  It  is  not  until  about  750° — 
800°  that  the  antimonic  acid  is  quickly  transformed  into 
antimony  peroxide,  Sb204,  which  is  stable  at  this  temper- 
ature. But  if  it  is  further  heated  the  hypoantimonic  acid 
is  decomposed  in  turn,  perhaps  at  the  temperature  of 
melting  silver,  but  assuredly  a  little  above,  and  certainly 
below  the  fusion-point  of  gold,  at  which  its  decomposition 
into  oxygen  and  volatile  antimonious  acid  becomes  fairly 
rapid.  Antimony  peroxide  cannot  therefore  be  considered 
as  a  fixed  body,  since  it  is  decomposed  by  the  mere  a(5tion 
of  heat. 

A(5tion  of  Tannin  and  other  Organic  Derivatives 
upon  certain  Compound  Alkaloids  and  Ureas. — 
Oechsner  de  Coninck. — The  author  has  experimented  with 
pure  tannin,  a  mixture  of  tannin  and  pipendine,  gallic 
acid,  pyrogallol,  pyrocatechine,  hydroquinone,  and  the 
compound  ureas. 

Certain  Derivatives  of  Anethol. — Georges  Darzens. 
— The  substitution  of  chlorine  for  hydrogen  in  the  lateral 
chain  does  not  modify  the  odour  of  anethol.  Carbon 
tetrachloride  has  the  property  of  dissolving  almost  all 
organic  bodies. 

Fixation  of  Iodine  by  Wheat  and  Rice  Starches. — 
G.  Rouvier. 

Solubility  of  the  Red  Pigment  of  the  Grape  and 
the  Sterilisation  of  the  Musts  of  Fruit. — A.  Rosen- 
stiehl. — The  exclusion  of  the  air  is  necessary  for  preserving 
the  red  colour  of  the  grape  and  of  otiier  fruits.  Musts 
preserved  from  contadt  with  the  air  retain  the  agreeable 
laste  of  fresli  grapes.  The  red  colouring  matter  of  the 
irkins  of  the  grape  and  of  other  fruits  is  soluble  in  the  un- 
fermenied  juice.  The  aiftion  of  the  air  renders  the 
colouring  matter  insoluble.  It  is  one  of  the  causes  of  the 
boiled  taste.  We  may  make  preserves  of  musts,  pos- 
sessing the  colour,  the  flavour,  and  the  aroma  of  the  fresh 
fruit. 

No.  12,  March  22,  2897. 

Note  on  an  £le(5tric  Commutator  whieh  can  be 
Managed  from  a  Distance. — C.  Gros. 

On  Autoradioscopy. — Foveau  de  Courmelle. 

Researches  on  the  Monazite  Sands. — G.  Urbain  and 
E.  Badischowsky. — Will  be  inserted  in  full. 

A  Read\ion  of  Carbon  Monoxide. — A.  Mermet. — 
Will  be  inserted  in  full. 

On  Isolauronic  Acid.— G.  Blanc. — The  author  has  in 
a  former  paper  described  certain  derivatives  of  isolauron- 
olic  acid,  especially  the  aldehyd  CgHi40. 

New  Method  of  Staining  Acetylene.  —  Georges 
Claude  and  Albert  Hass. — The  authors  describe  an  ex- 
periment which  consists  in  maintaining  indefinitely  in 
acetone  at  a  pressure  of  3  atmospheres  a  platinum  wire 
heated  to  bright  redness  by  the  eledric  current. 


i8o 


Royal  Institution, 


(Chemical  Nbws, 
April  9,  1897. 


MISCELLANEOUS. 

Carbohydrates  remaining  in  Beer.  —  P.  Petit.  —  As 
regards  inversion  of  acids,  the  dextrine  of  beer  behaves 
in  a  manner  quite  different  from  ordinary  dextrines,  and 
its  manner  of  inversion  approximates  rather  to  that  of 
melitriose. — Comptrs  Rendus'  cxxiv.,  No.  10. 

Royal  Institution.— The  following  are  the  Ledture 
arrangements  after  Easter: — Dr.  Tempest  Anderson,  four 
ledures  on  "Volcanoes"  (the  Tyndall  Ledures) ;  Dr. 
Ernest  H.  Starling,  three  leftures  on  "  The  Heart  and  its 
Work";  the  Rev.  Canon  Ainger,  four  ledtures  on  "  Some 
Leaders  in  the  Poetic  Revival  of  1760-1820— Covirper, 
Burns,  Wordsworth,  Scott";  Professor  Dewar,  three 
ledures  on  "Liquid  Air  as  an  Agent  of  Research  ";  the 
Reverend  J.  P.  Mahaffy,  three  ledlures  on  '*  The 
Greek  Theatre  according  to  Recent  Discoveries  "  ; 
Mr.  J.  A.  Fuller  Maitland,  four  ledlures  on  "  Music  in 
England  during  the  Reign  of  Queen  Vidloria"  (with 
musical  illustrations).  The  Friday  Evening  Meetings 
will  be  resumed  on  April  30th,  when  a  discourse  will  be 
given  by  Professor  J.  J.  Thomson  on  "  Cathode  Rays"  ; 
succeeding  discourses  will  probably  be  given  by  "Anthony 
Hope,"  Professor  Harold  Dixon,  the  Right  Hon.  Lord 
Kelvin,  Professor  H.  Moissan,  Mr.  W.  H.  Preece,  Mr. 
William  Crookes,  and  other  gentlemen. 


WILLIAM     F.     CLAY, 

CHEMICAL  BOOKSELLER  AND  PUBLISHER 

^.18,  Teviot  Place,  Edinburgh. 

SPECIALITIES. 

SECOND-HAND  CHEMICAL  UnUlWl  (English  and  Foreign). 

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Edited  by  Prof.  Ed.  Hart,  assisted  by  eminent  spe- 
cialists. (W.  F.  Clay,  Sole  Agent).  Prospeftus  free. 
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Cbbmical  Mbws,  I 
April  ij,  1897.     f 


Researches  on  Monaztttc  Sands, 


181 


THE    CHEMICAL     NEWS. 


Vol.  LXXV.,  No.  1951. 


ECONOMIC  PREPARATION  OF  HYDROXYLAMINE 
SULPHATE. 


By 


Prof.    EDWARD     DIVERS,    M.D.,    F.R.S.,    and 
TAMEMASA  HAGA,  F.C.S.,  Rigakuhakushi, 
Late  Asst.  Prof.  College  of  Science,  Imperial  University. 


In  1887  Raschig  made  known  that  hydroxylamine  can  be 
got  from  a  nitrite  by  sulphonation  followed  by  hydrolysis, 
and  took  out  patents  for  its  manufaaure  in  this  way.  As 
to  what  extent  these  patents  may  have  since  been  worked, 
and  with  what  success,  we  have  no  information  ;  but  we 
cannot  believe  that  this  process  has  been  advantageously 
carried  out  without  great  modification  of  the  diredlions 
given.  The  one  we  are  about  to  describe  is  very  pro- 
dudlive  and  economical  for  the  preparation  of  hydroxyl- 
amine sulphate,  a  non-deliquescent  salt,  readily  forming 
large  crystals,  and  soluble  in  three-quarters  of  its  weight 
of  water  at  20°. 

Commercial  sodium  nitrite  of  95  per  cent  purity  does 
not  contain  more  than  i  per  cent  of  objedlionable  matters, 
such  as  chloride  and  nitrate,  and  is  therefore  pure  enough. 
A  concentrated  solution  of  this  salt  {2  mols.)  and  of 
sodium  carbonate  (i  mol.),  pretty  closely  adjusted  in  their 
proportions,  is  treated  with  sulphur  dioxide  till  just  acid, 
while  it  is  kept  well  agitated  at  2—3°  below  zero  by  im- 
mersion in  ice  and  brine.  At  this  temperature  the  con- 
version of  the  nitrite  into  oximidosulphonateis  apparently 
perfedt.  Gently  warmed  with  a  few  drops  of  sulphuric 
acid  the  oximidosulphonate  rapidly  hydrolyses,  with 
marked  rise  of  temperature,  into  oxyamidosulphonate  and 
acid  sulphate.  The  solution  of  these  salts  is  kept  at 
go— 95°  for  two  days,  by  the  end  of  which  time  all  oxy- 
amidosulphonate will  have  hydrolysed  into  hydroxylamine 
sulphate  and  sodium  acid  sulphate,  while  so  small  a  quan- 
tity of  ammonium  salt  is  produced  as  can  only  be  deteded 
in  the  very  last  mother-liquors  of  crystallisation  by 
chloroplatinic  acid  (potassium  hydroxide  being  an  unsuit- 
able reagent  in  presence  of  hydroxylamine).  At  80—85° 
five  days  are  necessary,  but  then  pradically  no  ammonia 
is  formed.  At  70°,  three  weeks  at  least  are  necessary, 
while  at  the  common  temperature  much  oxyamido- 
sulphonic  acid  remains  after  several  month's,  even  when 
much  sulphuric  acid  has  been  added.  On  the  other  hand, 
the  solution  kept  boiling  needs  seven  or  eight  hours 
usually  to  deprive  it  of  all  sulphonate  ;  but  the  boiling 
has  disastrous  effedts  on  the  hydroxlamine,  destroying  at 
least  one-third  of  it,  by  converting  it  (through  amido- 
sulphonic  acid  ?)  into  ammonia,  and  wasting  another 
third  as  a  pradtically  inseparable  mixture  of  its  sulphate 
with  ammonium  sulphate. 

To  be  assured  of  the  disappearance  of  all  sulphonate 
it  is  well  to  add  barium  chloride  in  excess  to  a  little  of  the 
solution,  and  filter,  and  then  boil  the  filtrate  with  potas- 
sium chlorate,  which  will  change  any  sulphonate  into 
sulphate.  Sulphonation  complete,  the  solution  is  -neu- 
tralised with  sodium  carbonate,  using  methyl  orange  as 
indicator,  and  evaporated  till  it  weighs  only  loj  to  11  times 
as  much  as  the  sodium  nitrite  taken.  Left  to  cool  where 
its  temperature  will  fall  to  0°  or  lower,  nearly  all  its 
sodium  sulphate  will  crystallise  out.  The  mother-liquor, 
evaporated  sufficiently  and  cooled  to  the  common  tem- 
perature, yields  much  hydroxylamine  sulphate,  the 
mother-liquor  from  which,  very  slightly  diluted  and 
cooled  below  0°,  gives  again  a  little  sodium  sulphate, 
and  can  be  worked  for  more  hydroxylamine  sulphate,  as 
before. 


The  crude  hydroxylamine  sulphate  weighs  about  9  parts 
for  every  10  parts  of  sodium  nitrite  taken.  It  needs  to  be 
re-crystallised,  but  the  mother-liquors  can  be  closely 
worked  up.  On  the  other  hand,  the  sodium  sulphate  re- 
crystallised,  or  even  washed  with  ice-water,  will  give 
up  I  part  more  of  hydroxylamine  sulphate ;  so  that 
sodium  nitrite  will  yield,  on  the  small  scale,  nearly  its  own 
weight  of  pure  hydroxylamine  sulphate.  No  doubt,  on 
the  large  scale,  the  theoretical  yield  of  118*84  per  cent 
could  be  more  nearly  approached. 

Potassium  nitrite  is  not  well  fitted  for  the  preparation 
of  hydroxylamine,  because  of  the  difficulty  experienced 
in  closely  separating  its  sulphate  from  that  of  potassium. 
After  several  re-crystallisations  the  hydroxylamine  salt 
contains  i'8  per  cent  of  potassium  sulphate.  The  addi- 
tion  of  aluminium  sulphate  is  not  an  improvement,  for 
then  the  hydroxylamine  sulphate,  separated  as  far  as 
pradticable  from  the  potassium  alum,  leaves  behind  on 
ignition  as  much  as  5*7  per  cent  residue. — journal  of  the 
College  of  Science,  Imperial  University,  Japan,  vol.  ix.. 
Part  II.,  p.  291. 


RESEARCHES    ON     MONAZITIC    SANDS. 
By  G.  URBAIN  and  E.  BUDISCHOVSKY. 

We  have  undertaken  this  enquiry  to  find  if  it  is  legitimate 
to  admit  the  existence  in  the  monazitic  sands  of  a  new 
earth  ;  the  atomic  weight  would  be  approximately  =  100. 

In  very  precise  and  minute  researches  on  the  fradiona- 
tion  earths  of  the  yttrium  series  obtained  from  the 
monazitic  sands,  P.  Schiitzenberger  and  O.  Boudouard 
have  succeeded  in  isolating  portions  which  cannot  be 
split  up,  presenting  a  charader  of  great  stability,  and 
having  an  atomic  weight  close  upon  102. 

More  recently  Drossbach  {Berichte,  xxx.,  2452),  on 
studying  a  monazite,  arrived  at  similar  conclusions. 

In  contradidion  with  these  results,  Mr.  Crookes 
(Chemical  News,  No.  193 1,  p.  259),  having  examined  a 
specimen  of  the  yttrium  earths  derived  from  the  mona- 
zitic sands,  and  known  as  lucium,  concludes  from  the 
specflrum  analysis — notwithstanding  the  hesitations  of 
Schiitzenberger  and  Boudouard — that  these  oxides  ought 
to  be  regarded  as  impure  yttrium. 

The  hypothetical  element  supposed  to  be  contained  in 
the  portion  of  the  yttrium  earths  precipitable  by  sodium 
hyposulphite,  we  shall  confine  ourselves  in  this  paper  to 
a  description  of  the  experiments  which  we  have  made  on 
the  portions  of  the  earth  precipitated  by  this  reagent,  as 
Mr.  Crookes  has  demonstrated  that  it  is  a  very  general 
agent  of  fractionation,  and  that  it  perfedly  precipitates 
yttrium. 

The  sands  which  'we  studied  are  the  same  as  those 
which  have  been  the  subjedt  of  the  beautiful  researches 
of  Schiitzenberger  and  Boudouard.  We  repeated  the 
treatment  of  the  earths  with  potassium  sulphate  until  the 
concentrated  solutions — on  examination  with  the  micro- 
scope in  a  concentrated  solution  and  in  a  stratum  of  20  to 
30  cm.  in  depth — no  longer  displayed  the  absorption- 
spedlrum  of  didymium.  The  absorption-spedtrum  of  the 
solution  free  from  didymium  is  the  following : — 

Wave-lengths. 

A  weakening 656—649 

A  still  weaker  band      . .      . .  583 — 670 

A  narrow  weak  band    ..      ..  541      — 

A  broad  band 535 — 517 

Very  faint       535 — 526 

Very  strong  maximum..     ..  —     522 

A  very  faint  band 493 — 484 

This  spedlrum,  which  is  of  little  intensity,  coincides  very 
closely  with  the  spedtrum  described  for  erbium. 
One  of  us  having  observed  that  the  acetylacetonates 


l82 


Determination  of  Ztnc  by  Potassium  Ferrocyanide. 


•  Crbmical  Nbws, 
t    April  15,  1897. 


of  the  rare  earths  are  soluble  in  most  of  the  organic 
solvents  and  easily  admit  of  fradlionations,  it  seemed  in- 
teresting to  apply  this  method  to  those  earths,  to  trace  if 
we  should  reach  results  different  from  those  of  the  authors 
cited. 

We  followed  very  closely  the  course  of  the  fradlion- 
ations by  the  determination  of  the  atomic  weights. 

The  method  which  we  employed  for  this  does  not  differ 
sensibly  from  that  of  Schiitzenberger  and  Boudouard. 
Thanks  to  the  advice  of  Friedel  we  fixed  upon  a  method 
of  operating  which  seems  to  us  out  of  the  reach  of  criti- 
cism. The  salts  we  converted  into  nitrates ;  the 
solution  of  the  nitrates  is  mixed  with  sulphuric  acid,  and 
the  sulphates  are  evaporated  to  dryness  to  expel  the  chief 
part  of  the  free  acid.  The  solid  sulphates  are  introduced 
into  small  tubes,  which  are  heated  in  the  vapour  of  mer- 
cury, by  means  of  a  bottle  of  mercury  fitted  with  a  reflux 
pipe  and  three  muffles  supported  vertically.  We  cause 
the  sulphates  to  pass  successively  into  the  different 
muffles,  weighing  them  from  time  to  time  until  we  obtain 
a  weight  constant  to  about  \  m.grm.  The  sulphates  are 
then  transformed  into  oxides,  by  heating  them  in  a  double 
platinum  crucible  in  the  Fourguignon  furnace  until  the 
weight  is  constant.  The  atomic  weight  is  easily  deduced 
from  the  transformation  of  the  sulphates  into  oxides. 
We  have  satisfied  ourselves  that  on  heating  the  oxides 
successively  in  a  current  of  oxygen,  and  in  a  current  of 
hydrogen,  they  do  not  undergo  a  perceptible  variation  of 
weight. 

We  prepare  the  acetylacetates  as  follows  : — 

The  nitrates  in  a  very  dilute  aqueous  solution  (5  grms. 
per  litre)  are  precipitated  with  ammonia.  We  wash  by 
decantation,  and  add  the  quantity  of  acetylacetone  theo- 
retically sufiScient  to  transform  the  hydrates  into  crystal- 
line acetylacetonates.  We  filter  ;  the  crystals  are 
fractionated  at  first  in  alcohol  and  then  in  benzene. 
These  two  reagents  dissolve  the  acetylacetonates  freely 
in  heat,  and  on  cooling  re-deposit  them  in  needles. 

In  alcohol  the  substances  of  low  atomic  weight  are 
concentrated  in  the  first  crystals  ;  after  six  fradtionations 
the  mother-liquors  and  the  crystals  have  sensibly  the  same 
atomic  weights. 

Colledting  the  portions  of  adjacent  atomic  weights  we 
made  a  series  of  fractionations  in  benzene. 

These  results  are  interesting  to  compare  with  those 
obtained  by  Schiitzenberger  and  Boudouard.  —  Complet 
Rendus,  cxxiv.,  p.  618. 


THE  VOLUMETRIC    DETERMINATION 

OF    ZINC    BY    POTASSIUM     FERROCYANIDE. 

By  L.  L.  DE  KONINCK  and  EUG.  PROST. 

The  volumetric  determination  of  zinc,  since  the  publica- 
tion of  the  Schaffner  process  in  1856,  has  formed  the 
subjedt  of  numerous  researches. 

Of  all  the  methods  proposed,  two  only  seem  admissible 
in  current  pradlice. 

On  the  European  continent  the  process  of  Schaffner 
seems  to  be  almost  exclusively  in  use.  It  consists  in  the 
use  of  sodium  sulphide.  In  America  the  Galletti  pro- 
cedure, as  modified  by  Fahlberg,  meets  with  great  favour. 
It  depends  on  the  precipitation  of  zinc  by  potassium 
ferrocyanide  in  an  acid  solution  (Chem.  News,  Ixvii.,  5). 
The  ferrocyanide  p  ocess  appears  to  have  been  less  care- 
fully studied  than  that  of  bchaffner.  It  is  applied  in 
three  modifications :— i.  In  an  acid  solution,  as  originally 
proposed  by  Galletti.  2.  In  a  simple  ammoniacal  solution 
(A.  Renard).  3.  In  a  tartaric-ammoniacal  solution.  The 
authors  confine  their  attention  to  the  original  procedure  of 
Galletti.  They  examine  the  influence  of  time,  and  find  that 
an  excess  of  ferrocyanide  corresponding  to  20  per  cent  is 
sufficient  to  produce  the  transformation  in  fifteen  minutes. 


j  The  order  in  which  the  solutions  are  mixed  is  without 
influence  upon  the  result.  Ammonium  chloride  promotes 
the  precipitation.  Ammonium  nitrate  has  no  adtion.  To 
obtain  very  exadt  results  the  solutions  must  have  a  con- 
stant  degree  of  acidity. 

If  the  solution  of  zinc  is  treated  with  hydrogen  sul- 
phide,  in  order  to  throw  down  copper,  cadmium,  &c.,  it  is 
necessary  to  re-oxidise  the  salts  of  iron  by  nitric  acid  or 
bromine. 

The  presence  of  bromine  has  no  influence.  The  effedts 
of  nitric  acid  may  be  annulled  by  means  of  sodium  sul- 
phite. Manganese,  if  present,  must  be  completely 
eliminated  before  titration. 

All  metals  capable  of  readting  with  ferrocyanide  under 
the  circumstances  of  the  experiment  must  also  be 
eliminated. 

To  the  ammoniacal  solution  finally  obtained,  con- 
taining a  quantity  of  ammoniacal  compounds  more  or 
less  constant,  are  added  a  few  drops  of  sodium  sulphite ; 
the  liquid  is  then  neutralised  with  hydrochloric  acid,  and 
then  acidulated  with  a  constant  quantity  of  the  same  acid. 

To  this  solution  is  then  added  a  measured  volume  of  so- 
lution of  ferrocyanide,  constituting  an  excess  of  20  to  25 
p.  c.  on  the  quantity  necessary  for  the  exadt  precipitation. 
After  digestion  for  at  least  ten  to  fifteen  minutes,  the 
quantity  of  zinc  corresponding  to  the  excess  of  the  re- 
agent is  ascertained  by  titrating  back  by  means  of  a 
neutral  or  very  slightly  acid  solution  of  ZnCIj. 

Solutions  to  be  used, 

A.  A  zinc  solution  containing  per  litre  10  grms.  of  the 
metal,  and  very  slightly  acid.  To  obtain  this  we  dissolve 
10  or  20  grms.  of  pure  zinc  in  a  minimum  of  hydrochloric 
acid,  in  a  flask  graduated  to  i  or  2  litres  with  the  acid  of 
moderate  heat. 

When  the  solution  is  complete  the  liquid  is  brought 
approximately  to  half  the  final  volume,  and  the  excess  of 
acid  neutralised  by  means  of  a  solution  of  potassium  car- 
bonate until  the  appearance  of  a  slight  precipitate,  which 
is  made  to  disappear  by  adding  hydrochloric  acid  drop  by 
drop.  The  liquid  is  brought  to  the  ordinary  temperature, 
and  the  flask  filled  exadtly  up  to  the  mark  with  distilled 
water. 

B.  A  solution  of  potassium  ferrocyanide.  When,  as  is 
frequently  the  case  in  technical  assay,  the  quantity  of 
zinc  present  is  approximately  known,  we  take  2  c.c.  of 
ferrocyanide  per  supposed  centigrm.  of  zinc,  and  have 
thus  the  excess  of  25  per  cent  which  we  recommend  to 
be  employed. 

C.  The  indicator  is  a  solution  of  i  per  cent  uranium 
nitrate  in  an  aqueous  solution. 

Assay  of  Ores. 

We  treat  a  portion  of  the  ore  of  2*5  grms.,  dried  at  100° 
with  aqua  regia  if  it  is  a  blende,  or  with  fuming  hydro- 
chloric acid  if  it  is  a  calamine.  When  the  attack  is 
complete  we  evaporate  to  dryness  to  render  the  silica  in- 
soluble, take  up  the  residue  from  the  evaporation  in  5  c.c. 
of  hydrochloric  acid  and  a  little  water,  and  then,  after 
heating  for  some  time  to  ensure  the  solution  of  the  basic 
salts  produced  by  evaporation,  we  add  50  to  60  c.c.  of 
water  and  heat  to  70°.  We  then  submit  the  liquid  to  the 
adtion  of  a  moderate  current  of  hydrogen  sulphide ; 
during  the  passage  of  this  gas  we  add,  in  several  por- 
tions, 100  c.c.  of  water,  to  facilitate  the  subsidence  of 
the  lead  and  the  cadmium  which  would  not  be  precipi- 
tated  in  a  solution  too  strongly  acid.  On  the  other  hand, 
we  must  not  prolong  the  passage  of  the  hydrogen  sulphide 
beyond  the  necessary  time,  nor  must  we  dilute  too  strongly 
for  fear  of  precipitating  zinc. 

The  precipitate  of  the  sulphides  is  coUedled  on  a  filter 
along  with  the  silica,  if  there  is  no  reason  for  colledling 
this  separately.  It  is  acidified  with  5  per  cent  of  hydro- 
chloric acid  charged  with  hydrogen  sulphide. 

The  washing  is  complete  when  the  last  drops  of  the 


CUBMICAL  NBW8,  I 
April  15,  1897.     / 


Revision  of  the  A  tomic  Weight  of  Magnesium, 


183 


precipitate,  rendered  alkaline  with  ammonia,  no  longer 
give  the  slightest  precipitate  with  a  drop  of  sodium 
sulphide. 

The  filtrate  is  heated  at  ebullition  until  the  hydrogen 
sulphide  is  expelled;  it  is  mixed  with  10  c.c.  of  fuming 
hydrochloric  acid  and  from  10  to  25  c.c.  of  saturated 
bromine  water  (according  to  the  proportion  of  iron),  so  as 
to  reoxidise  the  ferrous  salts  and  assist  the  precipitation 
of  manganese.  It  is  then  passed  drop  by  drop,  whilst 
constantly  stirring,  into  a  flask  marked  at  500  c.c,  con- 
taining 100  c.c.  of  concentrated  ammonia  and  10  c.c.  of 
solution  of  ammonium  bicarbonate  more  or  less  saturated 
in  the  cold  (about  20  to  25  per  cent).  It  is  allowed  to 
cool,  water  is  added  up  to  the  mark,  stirring  so  as  to 
render  the  mixture  homogeneous,  left  for  a  short  time 
to  deposit  the  precipitate,  and  filtered  with  a  dry  filter. 

The  method  described  is  that  applicable  to  the  prepara- 
tion of  the  solution  for  the  most  complex  ores.  In  the 
absence  of  metals  precipitable  by  hydrogen  sulphide  the 
treatment  with  that  reagent  is  omitted,  and  the  re-oxidation 
of  the  iron  salts  is  unnecessary,  since  they  have  not  been 
reduced. 

The  use  of  bromine  is  needed  only  if  the  ore  is  man- 
ganiferous. 

If  the  ore  contains  metals  requiring  treatment  with 
hydrogen  sulphide,  but  no  manganese,  the  re-oxidation  of 
the  ferrous  salts  may,  if  preferred,  be  effeaed  by  boiling 
nitric  acid. 

We  take  100  c.c.  of  the  ammoniacal  filtrate  prepared 
as  above  direded,  add  a  few  drops  of  sulphite,  and  pour 
in  gradually  hydrochloric  acid  (sp.  gr.  1-075)  until  a  small 
morsel  of  litmus-paper  thrown  into  the  liquid  shows,  in 
passing  to  redness,  that  the  point  of  neutralisation  has 
been  reached  (about  30  c.c),  and  we  then  add  further 
10  c.c.  of  the  same  acid. 

(To  be  continued). 


Series  III. 

No.  Sample 

Sam 

pie  Weight 

Weight 

Ratio. 

Atomic 

of  of  MgCl 

t    of 

of 

of 

Mg0l2:2Ag= 

weight 

rxpt.    used. 

Ag  used.  MgCIj. 

Ag. 

100:  n. 

of  Mg. 

9         I 

2 

i"g9276 

4*5i5S4 

226-597 

24-349 

10         I 

2 

178870 

4-05256 

226-565 

24-363 

II         I 

2 

2-12832 

4-82174 

226-551 

24-369 

12         2 

2 

2-51483 

5-69714 

226542 

24-373 

13         2 

3 

2-40672 

5"45294 

226571 

24-360 

14         2 

3 

1-95005 

4-41747 
Average 

226531 

24-377 

24365 

Fourth  and  Final  Series  of  Determinations. 
The  apparatus  was  now  put  in  the  best  possible  order, 
and  the  phosphorous  pentoxide  tubes  were  re-charged,  in 
order  to  make  ready  for  a  series  of  determinations  in 
which  the  very  highest  exa<ftness  was  to  be  aimed  at. 
The  purest  samples  of  material  were  used,  and  all  other 
precautions,  learned  from  previous  work,  were  taken  to 
insure  accuracy.  The  following  determinations  were 
consecutive,  with  the  exception  oi  one  between  Nos.  15 
and  16,  which  was  spoiled  by  a  slight  accident. 

Series  IV. 

Weight  Ratio.  Atomic 

of  Weight     MgClgtzAg       weight 

MgCl,.    of  Ag.    =100 :«.    of  Mg. 

2-03402  4-60855  226-573  24-360 

1-91048  4-32841  226-562  24364 

2-09932  4-75635  226566  24-362 

1-82041  4-12447  226568  24-362 

1-92065  4-35151  226565  24-363 

i'iii72  2-51876   226564   24-363 


A    REVISION    OF    THE    ATOMIC    WEIGHT    OF 
MAGNESIUM.* 

By  THEODORE  WILLIAM  RICHARDS 

and 

HARRY  GEORGE  PARKER. 

(Concluded  from  p.  173). 

Third  Series  of  Determinations. 
In  order  to  remedy  the  most  serious  defed  of  the  second 
series,  the  arrangement  for  drying  the  air  and  nitrogen 
was  much  enlarged  and  improved.  By  pouring  sulphuric 
acid  into  the  safety  funnels,  at  the  top  of  the  many  towers, 
from  time  to  time,  during  the  passage  of  the  gas,  the 
glass  beads  were  kept  thoroughly  saturated  during  the 
whole  process.  The  sulphuric  acid  having  reached  the 
bottom  of  the  column,  drained  out  of  the  tubes  provided 
for  that  purpose  into  beakers  below.  It  will  be  seen  that 
by  this  means  the  efficiency  of  the  apparatus  was  far 
greater  than  in  the  previous  form.  As  a  test,  a  very  rapid 
stream  of  wet  air  from  a  water  blast  was  passed  through 
the  apparatus  and  then  through  a  weighed  phosphorus 
pentoxide  bulb  for  nearly  two  hours,  without  the  slightest 
appreciable  increase  of  weight  of  the  pentoxide  bulb.  The 
same  test  was  applied  to  the  apparatus  for  drying  the 
hydrochloric  acid  gas,  with  the  same  result. 

With  the  help  of  this  important  addition  to  the  appa- 
ratus, another  series  of  determinations  was  now  made. 
The  somewhat  lower  result  of  this  series  is  undoubtedly 
due  to  the  more  perfedt  desiccation  of  the  gases  ;  the 
agreement  of  the  individual  results  is  still  not  quite  per- 
feft,  but  the  series  is  undoubtedly  far  more  reliable  than 
the  second. 

*  Contributions  from  the  Chemical  Labor.itory  ot  Harvard  College. 
From  the  FroceeUtngs  0/  the  American  Academy  of  Arts  and  Sciences, 
vol.  xxxii.,  No.  2. 


No.  Sample  Sample 

o  of  MgCljj  of  Ag 

exp.  used,  used, 

15  2  3 

16  2  3 

17  2  3 

18  2  2 

19  2  2 

20  3  4 


Average 24-362 


Extreme  difference..       0-004 

These  results  agree  with  one  another  as  well  as  could 
possibly  be  expedled,  for  the  difference  between  the 
extremes  in  the  last  series  corresponds  to  a  difference  of 
only  one-tenth  ol  a  milligrm.  in  the  weight  of  the  magnesic 
chloride.  Since  two  wholly  distindt  samples  of  this  salt 
and  three  wholly  distindt  samples  of  silver  were  used  in 
this  teries,  we  may  conclude  that  all  ordinary  accidental 
errors  had  been  eliminated  ;  and  in  a  critical  discussion 
of  the  result  we  may  limit  ourselves  to  the  consideration 
of  the  possible  constant  errors  of  the  process. 

The  most  serious  objedlion  to  the  method  is,  of  course, 
the  possible  retention  of  water,  of  magnesic  oxychloride, 
or  of  amnionic  chloride  by  the  magnesic  salt. 

With  regard  to  the  first  two  difficulties,  it  need  only 
be  said  that  the  gases  used  for  drying  the  magnesic 
chloride  were  as  dry  as  present  possibilities  permit  them 
to  be  made.  The  phosphorus  pentoxide  in  the  last  drying 
tube  showed  no  trace  of  liquefadlion  at  the  close  of  the 
research,  but  seemed  to  be  as  light  and  powdery  as  at 
first,  in  spite  of  the  fadt  that  several  hundred  litres  of  gas 
had  been  passed  over  it.  Any  trace  of  oxygen,  as  well  as 
of  aqueous  vapour,  was  excluded  from  the  hot  salt ;  for 
the  hydrochloric  acid  gas  was  replaced  by  nitrogen,  and 
this  was  driven  out  in  its  turn  by  dry  air  only  after  the 
tube  had  cooled.  A  means  of  proving  absolutely  that  no 
water  remained  does  not  exist;  but  it  is  extremely  hard 
to  see  how  water  could  have  gained  access  to  the  care- 
fully guarded  magnesic  chloride. 

The  fadl  that  every  sample  of  magnesic  chloride  used  in 
the  last  series  gave  an  absolutely  clear  and  transparent 
solution  in  water  is  additional  evidence  of  much  weight; 
for  a  very  small  trace  of  oxychloride  would  have  shown 
itself  in  opalescence.  As  a  proof  of  this  it  may  be  stated 
that  in  experiment  No.  12  of  Series  III.  there  was  a  per- 
ceptible cloudiness  upon  the  solution  of  the  magnesic 
chloride  in  water,  owing  to  a  known  access  of  a  trace  of 
aqueous  vapour,  caused  by  a  momentary  stoppage  of  ths 


184 


Atomic  Weights  of  Nitrogen  and  Arsenic. 


(ChbmicAl  NbWb, 
I     April  15,  1897. 


current  of  nitrogen.  This  result  is,  however,  scarcely  at 
all  different  from  the  others. 

With  regard  to  the  possible  retention  of  ammonic 
chloride  by  the  magnesium  salt,  it  maybe  said:— First, 
that  none  could  be  detedled  by  means  of  a  Nessler  solu- 
tion; and,  secondly,  that  even  if  a  small  amount  had 
been  retained,  it  would  have  made  but  a  very  slight  dif- 
ference in  the  final  result. 

Our  result  is  essentially  the  same,  no  matter  whether 
the  chlorine  is  weighed  as  argentic  chloride  (Series  I.),  or 
the  amount  of  silver  necessary  to  precipitate  it  is  found 
(Series  III.  and  IV.).  This  fadl  is  satisfadtory  evidence 
that  the  silver  and  chlorine  were  both  pure,  as  well  as  that 
no  magnesic  chloride  was  occluded  by  the  argentic  chloride. 
Thus  :— 

From  the  ratio  2AgCl  :  MgClj  (Series  I.),  Mg  =  24-369. 
„  „  2Ag  :  MgCl2  (Series  III.),  Mg  =  24-365. 
„        „        2Ag      :  MgCl2  (Series  IV.),  Mg  =  24-362. 

Upon  comparing  these  figures  with  the  older  ones,  they 
are  seen  to  agree  surprisingly  with  Marignac's  value  ob- 
tained from  work  upon  magnesic  oxide  and  sulphate 
(Mg  =  24*37).  Burton  and  Vorce's  syntheses  of  magnesic 
oxide  gave  a  lower  value  for  magnesium  (24-28) ;  but  if 
these  were  corredted  for  a  probable  amount  of  gases  in 
the  magnesic  oxide,  the  result  would  probably  be  close  to 
the  present  one.  The  analytical  chemist  should  not  for- 
get that  the  value  24-36  is  ij  per  cent  higher  than  the 
round  number  24,  which  has  been  so  commonly  accepted. 

For  reasons  which  must  be  manifest  to  any  careful 
reader  of  the  foregoing  paper,  we  accept  the  value  given 
by  the  fourth  and  last  of  our  series  as  representing  the 
most  probable  atomic  weight  of  magnesium.  It  remains 
only  to  state  this  result  in  terms  of  the  usual  unfortunately 
varying  standards  of  reference  used  by  the  scientific 
world. 

If  0  =  i6-ooo,  Mg  =  24-362 
If  0=15-96,  Mg  =  24-301 
If  0  =  15-88,     Mg  =  24-I79 


THE   ATOMIC   WEIGHTS    OF    NITROGEN    AND 

ARSENIC* 

By  JOSEPH  GILLINGHAM  HIBBS. 

The  atomic  weight  of  the  metal  molybdenum  had  been 
determined  by  expelling  molybdic  acid  from  sodium 
molybdate  with  hydrochloric  acid  gas,  then  weighmg  the 
residual  sodium  chloride. 

Having  found  that  nitric  acid  and  arsenic  acid  were 
driven  from  their  alkali  salts  with  eas6,  leaving  a  chloride 
that  was  absolutely  pure,  and  believing  that  the  atomic 
masses  of  nitrogen  and  arsenic  determined  in  this  manner 
would  afford  a  valuable  contribution  to  the  literature 
relating  to  these  constants,  a  carefully  condudted  series 
of  experiments  was  made  with  two  nitrates  and  one 
arsenate.  The  results  are  given  in  detail  in  the  following 
lines : — 

The  Atomic  Weight  of  Nitrogen. 

In  the  past,  determinations  of  the  atomic  weight  of 
nitrogen  have  been  made  from  the  density  of  the  gas 
itself,  from  the  ratio  between  ammonium  chloride  and 
silver,  and  from  the  decomposition  of  certain  nitrates. 
The  first  method  in  particular  has  been  frequently  applied. 
Thomson,  Dulong,  Berzelius,  and  Lavoisier  brought  to 
light  many  new  fads  relating  to  the  atomic  weight  of 
nitrogen  ;  unfortunately,  however,  they  have  been  affefted 
by  complications  that  have  introduced  inaccuracies. 

*  Contribution  from  the  John  Harrison  Laboratory  of  Chemistry. 
From  the  author's  thesis  presented  to  the  faculty  ot  the  University 
of  Pennsylvania  for  the  degree  of  Doftor  of  Philosophy,  1896.  From 
the  Journal  of  the  American  Chemical  Society,  vol.  xviii..  No.  12. 


Dumas  and  Boussingault  [Comptes  Rendus,  1841,  xii., 
1005)  found  the  mean  density  of  nitrogen  to  be  0-972; 
for  hydrogen  they  found  9  mean  density  of  00693,  which 
would  give  nitrogen  an  atomic  weight  of  14-026.  Reg- 
nault  obtained  a  more  concordant  series  of  results,  the 
mean  being  0-97137,  and  a  density  for  hydrogen  of 
0-0692,  which  makes  the  atomic  weight  of  nitrogen  equal 
to  14-0244. 

Clarke  gives  in  detail  his  computation  of  the  means  of 
the  results  obtained  by  Penny,  Stas,  and  Marignac. 
Their  work  on  the  determination  of  the  atomic  weight  of 
this  particular  element  was  mainly  on  the  ratio  of  ammo- 
nium chloride  and  silver,  and  the  decomposition  of  cer- 
tain nitrates.  A  great  degree  of  accuracy  was  main- 
tained throughout  the  entire  investigation ;  but  the 
amount  of  work  required  to  obtain  a  single  result  neces- 
sarily lays  the  method  open  to  a  serious  error  of 
manipulation. 

In  this  connexion  a  paragraph  from  Clarke's  "  A  Re- 
calculation of  the  Atomic  Weights  "  may  be  cited  : — 
"  The  general  method  of  working  upon  these  ratios  is  due 
to  Penny.  Applied  to  the  ratio  between  the  chloride  and 
nitrate  of  potassium,  it  is  as  follows  : — A  weighed  quan- 
tity of  the  chloride  is  introduced  into  a  flask  which  is 
placed  upon  its  side  and  connedled  with  a  receiver.  An 
excess  of  pure  nitric  acid  is  added,  and  the  transformation 
is  gradually  brought  about  by  the  aid  of  heat,  the  nitrate 
being  brought  into  a  weighable  foim.  The  liquid  in  the 
receiver  is  also  evaporated,  and  the  trace  of  solid  matter 
which  has  been  mechanically  carried  over  is  recovered 
and  also  taken  into  account." 

The  method  indicated  in  this  study,  and  adlually  applied 
with  the  results  appended,  is  decidedly  less  objedtionable. 
In  this  method  there  is  no  distillation,  no  precipitate;  in 
fa(5t,  nothing  that  could  involve  serious  error. 

Clarke  summarises  the  results  of  Penny,  Stas,  and 
Marignac  as  follows: — 

1.  From  specific  gravity  of  N       ..     ..     N  =  14-0244 

2.  ,,  ammonium  chloride       ..      ..  N  =  14-0336 

3.  „  ratio  number  four N  =  140330 

4.  ,,  silver  nitrate N  =  13  9840 

5.  „  potassium  nitrate N  =  13-9774 

6.  „  sodium  nitrate N  =  13  9906 


Mean  of  results  for  N . . 


N  =  14-0210 


If  oxygen  is  16,  this  becomes  14-0291.  Stas  found  the 
atomic  weight  of  nitrogen  to  be  14-044.  Dumas  found  14 
by  experiments  on  the  combustion  of  ammonia  and 
cyanogen  (0=i6).  Pelouze  found  14-014  by  bringing  a 
known  weight  of  silver  nitrate  in  contadt  with  a  known 
and  slightly  excessive  weight  of  ammonium  chloride, 
which  excess  was  titrated.  Anderson  found  13-95  ''y  ^^^ 
decomposition  of  the  nitrate  of  lead,  with  just  enough 
heat  for  decomposition  (the  same  method  that  was  used 
by  Berzelius).  Marignac  found  14-02  by  dissolving  a 
known  weight  of  silver  in  nitric  acid  and  then  melting  and 
weighing  the  nitrate  found. 

A. — Atomic  Weight  of  Nitrogen  by  Action  of  Hydrogen 
Chloride  upon  Potassium  Nitrate. 

The  purest  salt  obtainable  was  dissolved  in  water, 
filtered,  and  re-crystallised  six  times,  a  solution  of  which 
was  tested  for  chlorides,  sulphates,  &c.,  but  no  impurity 
was  found.  One  more  crystallisation  was  made  and  the 
best  crystals  were  seledted.  These  were  washed  with 
distilled  water  and  dried  at  210°  C.  for  three  hours, 
powdered,  and  again  dried,  and  finally  placed  in  a 
weighing  bottle.  This  compound  was  dried  before  each 
experiment.  It  was  also  allowed  to  stand  in  a  balance 
case  one  hour  before  weighing.  The  same  degree  of 
care  was  exercised  in  the  preparation  of  the  boat  for 
weighing. 

The  weighing  bottle  was  placed  on  the  scale  pan  and 


Chbmical  News, 
April  15,  1897. 


Atomic  Weights  of  Nitrogen  and  Arsenic, 


185 


No, 


Potassium 

nitrate 

taken. 

Grm. 

0*11084 

0-14864 

0"2I056 

0*23248 

0*24271 


Potassium 
chloride, 
obtained. 

Grm. 
0*08173 
0*00960 

015525 
0*17214 
0*17894 


CorreAion  for 
potassium 
nitrate, 
Grm. 
0*00006 
0*00007 
0*00011 
0*00012 
0*00013 


Correftion  for 
potassium 
chloride. 

Grm. 
0*00004 
000005 
0*00008 
0*00009 
0*00009 


Table  A. 

Correftion  for 
weight  of 
potassium 
nitrate. 
Grm. 
0*11090 
0*14871 
0*21067 
0*23360 
0*24284 


Correftion  for 
weight  of 
potassium 
chloride. 

Grm. 
0*08177 
0*10965 

o*i5533 
0*17223 
o- 17903 


Molecular 

weight  of        Atomic  weight 
potassium  nitrate    of  nitrogen 


Atomic  weight  of  nitrogen  =  14*0118  i  0*000472. 


obtained. 

0*101121 
0*101120 
0*101123 
0*I0II21 
0*101124 


obtained. 

14*011 
14010 
14013 
14*011 
14*014 


No. 

I. 
2. 

3- 

4* 
5* 


Potassium 
nitrate  taken, 
Grm. 
0*01550 
0*20967 
0*26217 
o*666io 
093676 


Sodium  chloride  Correftion  for 


obtained. 

Grm. 
0*01064 
0*14419 
0*18029 

0*46805 
0*64422 


sodium  nitrate. 
Grm. 

0*00009 
0*00012 
0*00035 
0*00042 


Table  B. 

Correftion  for     CorrecStion  for    Corredlion  for 
sodium  chloride,  sodium  nitrate,  sodium  chloride. 


Grm. 

0*00007 
0*00009 
0*00024 
0*00034 


Grm. 
0*01550 
0*20976 
0*26229 
0*66645 
0*93718 


Grm. 
o*oio66 
0*14426 
0*18038 
0*45829 
0*64456 


Molecular  weight   Atomic  weight 
of  sodium  nitrate,     of  nitrogen. 


85061 
85*061 
85*064 
85*064 
85-058 


14*011 
i4*oii 
14*014 
14*014 
14*008 


Atomic  weight  of  nitrogen  =  i4'oii6  -^  0*000741. 


Sodium 
No.     pyroarsenate 
taken. 
Grm. 

o  02176 

0  04711 
005792 
0*40780 
0*50440 
077497 
082853 
i*ig;68 

1  67464 
3*22485 


Sodium 
chloride 
obtained. 

Grm. 
0*01439 
0-03114 
0*03828 
0*26970 
0*33028 
0*51222 
0-54762 
0*78690 
1*10681 
2*13168 


Correftion  for 

sodium 
pyroarsenate. 
Grm. 
0*00001 
0*00002 
0*00003 
O*OO02I 

000026 
0*00041 
0-00044 
0-00056 
0-ooo8l 
0*00152 


Table 

Corredlion  for 
sodium 
chloride. 

Grm. 
0*00000 
OOOOOI 
0*00002 
0*00011 
0*00017 
000027 
0*00029 
0*00041 
0*00051 
0*00099 


Atomic  weight  of  arsenic 


Correftion  for 
sodium 

pyroarsenate. 
Grm. 
0-02177 
0*04713 
005795 
0*40801 
0*50466 
077538 
0-82897 
I-19124 

I '67545 
3*22637 

=  74 '9158  ± 


Correftion  for 
sodium 
chloride. 
Grm. 
001439 
0-03115 
0*03830 
0-26981 

033045 
0-51249 

0-54791 
0*78731 
I-IO732 
2*13267 

0*00222. 


Molecular  weight  Atomic  weight 
of  sodium  of 

pyroarsenate.  arsenic. 


354*008 

354*042 

354-054 
354*002 

354033 
354-034 
354-034 
354-053 
354*057 
354*002 


74*904 
74921 
74-927 
74-901 
74-916 
74*917 
74917 
74-926 
74928 
74-901 


allowed  to  stand  several  minutes  in  order  to  regain  its 
normal  temperature.  After  weighing  it  was  quickly 
opened  and  a  portion  of  the  salt  removed  to  the  boat,  and 
again  closed  and  allowed  to  stand  in  the  balance  case  for 
several  hours  before  re-weighing.  The  boat  was  then 
introduced  into  the  combustion  tube  and  the  gas  passed 
over  it.  The  charafteristic  adtion  took  place,  The  only 
difference  in  the  method  of  procedure  adopted  here  and  that 
described  in  the  first  sedtion  of  this  paper,  was  a  longer 
time  being  given  to  complete  the  adtion,  using  a  lower 
temperature,  in  order  to  do  away  with  all  possibility  of 
fusion  of  the  salt.  It  was  then  carefully  removed  to  a 
vacuum  desiccator  and  allowed  to  stand  over  night  before 
weighing.  It  may  be  said  also  that  experiments  were 
only  condudted  on  clear  days  to  insure  the  non-entrance 
of  moisture. 

With  potassium  nitrate,  no  great  variation  of  amount 
was  taken. 

Five  determinations  were  made  in  this  case  (Table  A). 

The  atomic  values  used  in  these  calculations  were 
taken  from  "  Table  of  Atomic  Masses,"  revised  by  F.  W. 
Clarke,  in  Odtober,  1891. 

The  figures  deduced  from  these  values  are,  of  course, 
subjedt  to  any  change  made  by  later  revision  of  atomic 
weights.  It  is  not  so  much  the  exadl  figure  to  which 
attention  is  called,  as  to  the  constancy  of  result  brought 
forward  by  this  method.     The  values  used  were : — 

Oxygen 16*00 

Potassium 39*ii 

Chlorine        35'45 

Specific  gravity  potassium  nitrate 2-1 

Specific  gravity  potassium  chloride        ..     ..  1*99 


B. — Atomic  Weight  of  Nitrogen  by  Action  of  Hydrogen 

Chloride  upon  Sodium  Nitrate. 
The  same  degree  of  care  and  method  of  procedure  were 
here  observed  as  in  Division  A.     The  results  are  given  in 
Table  B. 

Atomic  values  used  were  : — 

Oxygen 16*00 

Sodium 2305 

Chlorine        35  45 

Specific  gravity  sodium  chloride 2-16 

Specific  gravity  sodium  nitrate       2*26 

When  these  results  are  compared  with  those  obtained 
by  Penny  and  Stas  by  treatment  of  potassium  chloride 
with  nitric  acid,  and  the  treatment  of  potassium  nitrate 
with  hydrochloric  acid  (likewise  for  sodium),  a  close  com- 
parison can  be  made. 

Penny.         Hydrogen  chloride  method. 
For  potassium  nitrate     13-9774  140118 

For  sodium  nitrate  . .     13-9906  140116 

Showing  a  difference  of — 

0*0344  'or  potassium  salt, 
o*o2i'j  for  sodium  salt. 

When  a  mean  of  the  above  results  is  taken,  the  atomic 
weight  of  nitrogen  equals — 

13*9996  for  potassium  salt, 
14*0011  for  sodium  salt. 

Taking  now  a  mean  of  these  values,  the  atomic  weight 
of  nitrogen  would  be  14*0003. 


i86 


Ferrocyanides  of  Zinc  and  Manganese. 


Chbmical  Nbws, 
April  15,  1897. 


C. — The  Atomic  Weight  of  Arsenic. 

The  atomic  weight  of  arsenic  has  been  obtained  from 
the  [chloride  (ASCI3),  the  bromide  (AsBrs),  and  the  tri- 
oxide  (AS2O3). 

Pelouze,  in  1845  {Comptes  Rendus,  x.,  1047),  and  Dumas, 
in  1859,  determined  it  by  the  titration  with  known  quan- 
tities of  pure  silver  in  the  analysis  of  arsenic  trichloride. 
The  mean  of  their  results,  as  computed  by  Clarke,  gives 
the  atomic  weight  of  arsenic  74*829.  Wallace  {Phil, 
Mag.,  (4),  xviii.,  279)  makes  the  same  titration  with  silver 
in  the  analysis  of  arsenic  tribromide.  His  value  is 
74*046.  Kessler  made  a  set  of  determinations  by  esti- 
mating the  amount  of  potassium  bichromate  required  to 
oxidise  100  parts  of  arsenic  trioxide  to  arsenic  pentoxide. 
He  obtained  a  mean  value  of  75*002. 

A  mean  of  these  results  gives  the  following  : — 

From  ASCI3  74*829 

,,     AsBr3  74*046 

,,     AS2O3  75002 

General  mean 74'9i8 

Ifoxygen  =  i6  then  the  atomic  weight  of  arsenic  will 
equal  75*090. 

Berzelius,  in  1826,  heated  sulphur  and  arsenic  trioxide 
together  in  such  away  that  sulphur  dioxide  alone  escaped  ; 
this  method  gave  74*840  as  the  atomic  weight  of  arsenic. 
But  one  experiment  was  made,  so  that  it  does  not  possess 
much  value.  In  the  above  method  there  seems  to  be  a 
wide  variation  in  the  results  obtained,  the  difference  be- 
tween the  extreme  values  is  but  little  less  than  one  unit. 

By  the  hydrogen  chloride  method,  we  have  but  the 
weighing  of  the  material  used  in  the  determination — 
which  must  necessarily  enter  every  estimation  or  analysis 
— and  a  single  weighing  after  the  aiflion  of  the  acid  gas. 
As  in  the  case  of  nitrogen,  the  method  seems  to  be  as 
short  and  concise  as  possible. 

The  methods  and  modus  operandi  were  exadtly  the 
same  as  those  used  in  the  determination  of  the  atomic 
weight  of  nitrogen. 

The  sodium  chloride  obtained  was  perfedlly  white  in 
colour.  In  no  instance  was  it  fused.  After  weighing 
the  salt  residue  it  showed  no  traces  of  arsenic,  and  was 
readily  soluble  in  cold  water  without  residue.  The  same 
conditions  of  atmosphere  were  observed. 

As  the  specific  gravity  of  sodium  pyroarsenate  could  not 
be  obtained,  it  was  determined  by  means  of  the  specific 
gravity  bottle,  against  chloroform,  and  was  found  to  be 
2*205,  while  the  specific  gravity  of  sodium  chloride  was 
taken  as  2*16.    The  atomic  values  used  were  *. — 

Oxygen 16*00 

Sodium 23*05 

Chlorine 35'4S 

The  results  here  obtained,  besides  being  to  a  great 
degree  constant,  compare  favourably  with  those  obtained 
by  Pelouze  (74  829)  and  Kessler  (75*002). 

A  coincidence  may  here  be  shown  by  the  fa(ft  that  the 
mean  of  these  values  gives  74*9155,  while  the  hydrogen 
chloride  method  gives  74*9158. 

In  order  to  give  the  method  a  thorough  trial,  the 
amounts  taken  cover  a  wide  range.  The  smallest  amount 
used  was  0*02176  grm.  of  sodium  pyroarsenate,  and  the 
largest  3*22485  grms.  It  will  also  be  noticed  that  the 
variation  in  result  is  but  0*027  for  ten  determinations 
(Table  C). 

1 


NOTES  d>f  THE 

FERROCYANIDES  OF  ZINC  AND   MANGANESE. 
By  EDMUND  H.  MILLER. 

Th^  composition  of  the  ferrocyanides  of  zinc  and  man- 
gan  Be,  formed  when  salts  of  these  metals  are  precipitated 


by  potassium  ferrocyanide,  is  given  by  Prescott  and 
Johnson  ("  Qualitative  Analysis,"  pp.  67  and  57)  as 
Zn2Fe(CN)6  and  Mn2Fe(CN)6,  while  the  books  on  volu- 
metric analysis,  such  as  Sutton's  and  Beringer's,  ignore 
the  composition  of  this  precipitate. 

The  prevailing  idea  is  that  in  the  titration  of  zinc  by 
potassium  ferrocyanide,  a  normal  zinc  ferrocyanide  is 
formed.  This  I  believe  to  be  incorredt,  for  if  the  reaction 
is — 

K4Fe(CN)6+2ZnCl2  =  Zn2Fe(CN)6+4KCl, 

a  solution  of  potassium  ferrocyanide,  i  c.c.  of  which  is 
equivalent  to  10  m.grms.  of  zinc,  would  contain  32*32 
grms.  of  K4Fe(CN)6*3H20  to  the  litre,  not  43  2  (Sutton, 
"Volumetric  Analysis,"  p.  329;  Beringer,  "Assaying," 
p.  219)  to  45  grms.  (Furman,  "  Assaying,"  p.  205),  as  has 
been  found  by  experiment.  Using  44  grms.  per  litre  as 
a  basis  for  calculation,  the  rea(5tion  becomes — 

2K4Fe(CN)6+3ZnCl2=Zn3K2(Fe(CN)6)2+6KCl. 

This  readtion  is  not  merely  one  that  may  possibly  be 
true,  but  according  to  Wyrouboff  (/4hh.  Chim.  Phys.,  [5], 
viii.,  485),  the  precipitate  formed  iby  the  adtion  of  potas- 
sium ferrocyanide  on  a  zinc  salt,  whichever  is  in  excess, 
is  3Zn2Fe(CN)6.K4F3(CN)6.i2n20,  white,  while  the 
normal  salt,  Zn2Fe(CN)6.4H20,  is  formed  only  by  the 
action  of  hydroferrocyanic  acid  on  a  zinc  salt. 

This  statement  agrees  both  with  the  preceding  readlion 
and  with  the  results  obtained  in  standardising  potassium 
ferrocyanide  solution. 

The  manganese  precipitate  with  potassium  ferrocyanide, 
as  obtained  in  titration,  is  given  by  Stone  (yourn,  Amer. 
Chem.  Soc.,xvii.,473)  as  Mn3Fe2(CN)i2.  This  is  a  ferri-, 
not  a  ferrocyanide,  thus  making  necessary  a  change  of 
quantivalence.  Mr.  Stone  also  states  that  an  amount  of 
potassium  ferrocyanide  which  will  precipitate  4  atoms  of 
zinc  will  only  precipitate  3  of  manganese,  thus  basing  his 
calculation  on  the  formation  of  normal  zinc  ferrocyanide. 

Wyrouboff  {Ann,  Chivi.  Phys.,  [5],  viii.,  474)  gives  the 
precipitate  obtained  from  potassium  ferrocyanide  and 
manganese  salt,  whichever  is  in  excess,  as — 

5Mn2Fe(CN)6.4K4Fe(CN)6.4H20,  rose  white; 

while    the    normal    salt    Mn2Fe(CN)6.7H20,   cream,    is 
formed  as  in  the  case  of  zinc  by  hydroferrocyanic  acid. 

The  solution  used  by  Mr.  Stone  had  the  following 
strength : — 

I  c.c.  =  o*oo5o6  grm,  zinc. 

I  c.c.  =  0*00384  grm.  manganese. 

If  the  ratio  were  exadlly  four  zinc  to  three  manganese, 
using  the  most  recent  atomic  weights,  the  strength  of  this 
solution  against  manganese  would  be  i  c.c.  =  0*00382 
grm. ;  while,  according  to  Wyrouboff,  ioMn  =  9K4Fe(CN}6 
and  6Zn  =  4K4Fe(CN)6,  or  ioMn  =  i3*5  Zn,  or  iMn  =  i-35 
Zn,  and  the  strength  against  manganese  would  be  r  c.c. 
=  0*003774  grm. 

These  figures  show  but  little  difference  between  the  two 
ratios,  and,  while  Mr.  Stone's  experimental  results  are 
undoubtedly  accurate,  his  theory  based  on  the  formation 
of  Zn2Fe(CN)6  and  Mn3Fe2(CN)i2  is  not  satisfadtorily 
proved. 

This  article  is  only  a  preliminary  note  regarding  the 
composition  of  the  ferrocyanides  as  they  are  being  inves- 
tigated in  this  laboratory. 

In  connection  with  the  ferrocyanide  of  zinc  I  have  found 
a  very  strong  solution  of  hydrochloroplatinic  acid, 
H2PtCl6)  acidified  with  hydrochloric  acid,  a  most  satis- 
fadory  indicator  for  the  titration  of  zinc  by  potassium 
ferrocyanide,  when  performed  in  a  hot  solution.  This 
indicator  is  used  in  the  same  way  as  uranium  acetate,  and 
is  less  affeded  by  a  varying  amount  of  hydrochloric  acid. 
The  end  readion  is  a  bright  emerald-green,  which  takes  a 
few  seconds  to  develop.  It  will  not  work  with  a  cold 
solution.  —  Journal  of  the  American  Chemical  Society, 
xviii.,  No.  12, 


Chsuical  Nbws.I 
April  IS,  1897.    f 


Nickel  Stress  Telephone. 


187 


PROCEEDINGS    OF    SOCIETIES. 

PHYSICAL    SOCIETY. 
Ordinary  Meeting,  April  gth,  1897. 

Mr.  Shelford  Bidwell,  President,  in  the  Chair. 

Mr.  T.  a.  Garrett  read  a  Paper  on  •'  A  Nickel  Stress 
Telephone." 

In  conjundlion  with  Mr.  W.  Lucas,  the  author  has 
experimented  upon  telephones  with  nickel  magnets.  A 
magnetised  nickel  rod  is  wound  with  insulated  wire,  and 
is  then  fixed  vertically  by  a  clamp  at  its  lower  end.  A 
wooden  diaphragm  is  rigidly  attached  to  the  top  of  the 
rod,  in  a  horizontal  plane.  The  rod  just  passes  through 
the  middle  of  the  diaphragm,  where  it  is  fixed  with 
sealing-wax.  The  diaphragm  is  entirely  supported  by  the 
nickel  rod.  On  speaking  against  the  top  of  the  diaphragm, 
variations  of  longitudinal  pressure,  and  consequently  of 
magnetisation,  are  produced  in  the  nickel ;  and  correspond- 
ing undulatory  currents  are  induced  in  the  surrounding 
coil.  The  nickel  wire  is  sometimes  magnetised  by  stroking 
it  with  a  magnet,  and  sometimes  by  passing  a  current 
through  the  coil.  A  diaphragm  of  pine  wood  gives  better 
results  than  a  metallic  plate.  The  instrument  does  not 
work  well  as  a  "  receiver  " ;  an  ordinary  telephone  is  used 
for  this  latter  purpose.  The  results  obtained  with  a  weakly 
magnetised  nickel  rod  are  much  better  than  those  with  a 
strongly  magnetised  steel  rod,  indicating  that  the  undu- 
latory currents  are  due  rather  to  magnetic  variations 
arising  from  changes  of  stress  than  to  the  relative  motions 
of  the  magnet  and  coil. 

Dr.  S.  P.  Thompson  said  that  some  years  ago  he  had 
worked  with  a  somewhat  similar  apparatus,  using  it  as  a 
"  receiver,"  with  wires  of  nickel,  cobalt,  and  iron.  Cobalt 
gave  the  best  results  ;  the  metallic  strips  in  his  experi- 
ments dipped  into  the  solenoids  without  contact  with 
them.  This  arrangement  did  not  work  well  as  a  "  trans- 
mitter," even  when  a  battery  was  included  in  the  circuit. 
In  some  cases  the  rods  were  cut  into  short  lengths  sepa- 
rated by  brass. 

Mr.  Boys  asked  how  the  nickel  "stress"  instrument 
compared  in  clearness  and  loudness  with  an  ordinary 
telephone. 

Mr.  Shelford  Bidwell  had  tried  a  nickel  telephone 
with  a  mica  diaphragm  ;  depending  not  upon  mechanical 
stress,  but  magnetic  strain.     It  did  not  work  well. 

Dr.  Chree  thought  the  "stress"  telephone  might 
possibly  be  improved  by  choosing  the  right  strength  of 
magnetic  field. 

Mr.  Appleyard  said  the  arrangement  was  interesting 
historically,  because  it  was,  mechanically,  almost  identical 
with  the  original  instrument  used  by  Philip  Reis  as  a 
"  receiver."  The  authors  had  succeeded  in  getting  it  to 
work  as  a  "  transmitter."  Their  success  was  probably 
due  to  the  rapidity  with  which  the  magnetisation  of 
nickel  responded  to  very  small  changes  of  stress  or 
current.  The  Post-Office  eleflricians  had  tried  to  intro- 
duce nickel  cores  into  relays,  on  account  of  its  magnetic 
sensitiveness  ;  the  results,  he  believed,  had  not  been  very 
satisfactory. 

Mr.  T.  A.  Garrett,  in  replying,  said  the  "  stress " 
telephone  gave  better  articulation  than  an  ordinary 
•'  watch  "  telephone,  but  the  sounds  were  feebler.  There 
seemed  to  be  a  field-strength  proper  to  the  instrument  ; 
he  had  noticed  that  the  articulation  was  clearer  with  three 
cells  than  with  six. 

Mr.  W.  A.  Price  then  read  a  Paper  on  "Alternating 
Currents  in  Concentric  Conductors." 

This  is  a  mathematical  investigation  of  a  proposed  new 
form  of  submarine  cable.     Tlie  case  is  considered  of  two  I 
concentric  condudors,  interrupted  alternately  at  different  I 


points  throughout  the  whole  length.  In  the  mathematical 
treatment  the  cable  is  supposed  to  be  laid  in  a  circular 
path,  and  successive  charges  of  eledricity  are  supposed 
to  be  applied  at  some  point  at  the  extremity  of  a  diameter 
of  the  circle.  Expressions  are  given  for  the  amplitude  of 
the  periodic  charges  arriving  at  a  point  diametrically  op- 
posite to  the  first;  and  for  the  redudion  in  amplitude, 
throughout  the  whole  length  of  the  cable,  of  an  applied 
E.M.F.  The  theory  indicates  that  under  no  circumstances 
can  the  "speed"  of  a  cable  of  the  proposed  form  be 
greater  than  the  "speed"  of  a  cable  of  ordinary  type. 
The  author  has  experimented  upon  an  artificial  cable 
conneded  up  to  represent  the  proposed  form.  The 
"  definition"  of  signals  is  considerably  better  than  that 
obtained  through  an  artificial  cable  of  analogous 
"weight"  and  "length"  connedled  up  in  the  ordinary 
way.  Within  certain  limits  the  "  definition  "  continues 
to  improve  as  the  number  of  seiftions,  or  subdivisions,  of 
the  cable  is  increased. 

Mr.  Blakesley  said  he  was  sorry  the  result  did  not 
indicate  a  successful  type  of  cable.  He  would  have  been 
inclined  to  predidl  that  the  amplitude  would  have  de- 
creased with  the  number  of  sedtions.  If  a  number  of 
condensers  were  joined  in  series,  and  one  end  was  sub- 
jedled  to  a  periodic  E.M.F. ,  the  amplitude  would  fall  off 
inversely  as  the  square  of  the  distance. 

Mr.  Price  then  exhibited  a  galvanometer  support. 
The  instrument  is  suspended  from  two  indiarubber 
cords  attached  at  the  top  and  bottom  to  cross-bars  of 
metal,  thus  forming  a  redlangle.  The  cross-bars  are 
provided  with  knife-edges  in  such  a  way  as  to  compensate 
for  unequal  stretching  of  the  indiarubber.  Weights  can 
be  added,  if  necessary,  to  the  support,  so  as  to  increase 
its  inertia. 

Mr.  H.  Garrett  read  a  Paper,  communicated  by  Prof. 
W.  B.  Morton,  on  "  The  Effect  of  Capacity  on  Stationary 
Electrical  Waves  in  Wires." 

The  author  investigates  the  effed  produced  when  a  con- 
denser is  inserted  at  a  point  in  the  secondary  circuit  of 
the  apparatus  used  by  Blondlot  for  obtaining  stationary 
eledrical  waves  in  wires.  The  positions  of  successive 
nodes  are  determined  in  the  usual  way,  by  a  bridge,  with 
a  vacuum-tube  indicator.  When  two  opposite  points  of 
the  parallel  secondary  wires  are  joined  to  the  plates  of  a 
small  air-condenser,  the  nodes  approach  the  condenser  on 
either  side.  The  amount  of  the  displacement  of  the 
nodes — that  is  to  say,  the  extent  of  the  shortening  of  the 
apparent  half  wave-length — depends  upon  the  position  of 
the  capacity  along  the  wires.  The  efifedt  is  nil  when  the 
condenser  is  at  a  node,  and  a  maximum  when  it  is  mid- 
way between  two  nodes.  The  state  of  affairs  at  a  point 
of  the  circuit  is  obtained  by  summation  of  a  series  of 
separate  disturbances  due  to  the  different  direcfl  and  re- 
flecfled  trains.  In  obtaining  a  formula  for  the  conditions 
of  resonance,  with  which  to  compare  the  observations,  the 
author  adopts  a  method  from  Heaviside.  It  connedts  the 
frequency  of  oscillation  with  the  position  and  capacity  of 
the  condenser. 

Mr.  Shelford  Bidwell  proposed  a  vote  of  thanks  to 
all  the  authors,  and  the  meeting  was  adjourned  until 
May  14th. 


Adion  of  Nickel  upon  Ethylene.— Paul  Sabatier  and 
J.  B.  Senderens.— The  authors  have  caused  ethylene  to 
a(ft  upon  nickel  obtained  by  reducing  the  oxide  with  hydro- 
gen. After  cooling  in  a  current  of  hydrogen  the  metal  is 
exposed  to  ethylene  which  has  been  care/ully  dried  and 
purified.  There  is  no  effedl  in  the  cold,  but  about  300° 
and  more  readily  at  a  higher  temperature  the  nickel  gradu- 
ally sprouts,  yielding  a  very  voluminous  black  matter. 
This  matter  is  carbon  in  which  nickel  is  distributed. — 
Comptvs  Rendus,  cxxiv.,  No.  12. 


i88 


A  Manual  of  Chemistry, 


I  Chemical  News, 
\    April  15,  1897. 


NOTICES  OF  BOOKS. 


A  Detailed  Course  of  Qualitative  Chemical  Analysis  of 
Inorganic  Substances.     With  Explanatory  Notes.     By 
Arthur  A.  Noyes,  Ph.D.,  Assistant  Professor  of  Che- 
mistry in  the   Massachusetts  Institute  of  Technology 
(Boston).     Third  Revised  and  Enlarged  Edition.     New 
York:  The  Macmillan  Company.      1897.     89  pp.,  8vo. 
An  Introductory  Course  of  Quantitative  Analysis.     With 
Explanatory  Notes  and  Stoichiometrical  Problems.    By 
Henry    P.   Talbot,   Ph.D  ,    Associate    Professor    of 
Analytical  Chemistry  in  the  Massachusetts  Institute  of 
Technology   (Boston).      New  York:    The   Macmillan 
Company.     1897.     ^25  pp.,  Svo. 
Those  who  follow  the  fashion  of  deprecating  the  rapid 
multiplication  of  chemical  text-books  do  not  fully  com- 
prehend the  conditions  which  impel  the  authors  to  issue 
them. 

Teachers  finding  themselves  expected  to  give  instruAion 
in  elementary  chemistry  to  large  classes  of  young  men 
having  no  previous  experience  in  manipulation,  and  finding 
it  impossible  to  give  to  each  member  of  the  class  that 
personal  assistance  and  supervision  which  is  well  nigh 
indispensable  to  success,  are  compelled  to  plan  courses  of 
laboratory  work  adapted  to  the  circumstances,  and  to 
prepare,  in  manuscript,  diredlions  embracing  such  minute 
details  that  the  students  cannot  possibly  go  astray. 
These  manuscript  notes  grow  from  year  to  year  with  the 
needs  of  successive  classes,  and  gain  in  value  by  the 
experience  of  the  teacher,  until  after  a  few  years  the 
instruftor  finds  it  more  economical  of  the  time  of 
the  student  to  print  these  notes  than  to  communicate  the 
statements  orally.  Moreover,  each  Institution  establishes 
courses  having  different  ultimate  aims,  one  being  intended 
to  qualify  the  students  for  the  pursuit  of  mining,  another 
for  engineering,  a  third  for  the  vocation  of  geologist  or 
of  naturalist,  and,  in  consequence,  the  charadter  of  the 
chemical  work  required  is  modified  to  suit  each  case. 
This  does  not  imply  that  the  fundamental  fadls  of 
chemistry  differ  in  the  several  courses  of  instrudlion,  but 
that  the  topics  treated  are  seleded  to  lead  the  students  in 
the  diredtion  of  the  goals. 

Again,  the  amount  of  time  that  can  be  devoted  to 
chemical  instrudtion  is  sometimes  greatly  abbreviated,  so 
that  the  instructor  finds  indispensable  the  utmost  conden- 
sation, consistent  with  perspicuity.  Hence  standard 
treatises  on  analytical  chemistry,  such  as  those  of 
Fresenius,  are  relegated  to  the  position  of  books  of  \ 
reference,  and  the  students  are  supplied  with  specially 
adapted  guides. 

We  do  not  claim,  but  we  surmise,  that  the  books  under 
review  have  arisen  in  some  such  way,  and  this,  instead  of 
being  a  disadvantage,  is  one  of  the  causes  of  their 
excellence. 

Professor  Noyes's  little  work  has  evidently  found  a 
larger  circle  of  friends  than  the  few  students  in  his  own 
classes,  for  it  has  reached  a  third  edition.  A  charadter- 
istic  feature  of  the  book  is  the  separation  of  the  methods 
of  procedure  from  the  notes  upon  them,  the  former  con- 
sisting of  very  detailed  diredlions  for  carrying  out  the 
processes,  and  the  notes  serving  to  explain  the  philosophy 
of  the  same.  The  sedlion  on  the  detedlion  of  metals  is 
followed  by  one  on  the  detedlion  of  acids,  and  a  third  on 
analysis  by  the  dry  method.  These  are  succeeded  by 
instrudlions  for  the  preparation  of  the  solutions,  and  an 
appendix  on  the  preparation  of  reagents. 

Professor  Talbot's  treatise  is  intended  for  beginners 
who  have  completed  a  course  in  qualitative  analysis,  and 
follows  the  same  method  as  that  of  Professor  Noyes. 
The  author  remarks  that  his  book  should  be  supplemented 
by  reference  to  the  works  of  Fresenius,  Mohr,  and 
Sutton.  Instead  of  seledling  simple  salts  for  analysis  as 
preliminary  pradice,  Dr.  Talbot  uses  approximately  pure 
samples  of  appropriate  minerals  or  industrial  produAs : 


this  advances  the  student  more  rapidly  without  greatly 
increasing  the  difficulties.  Part  IV.,  Stoichiometry,  is  a 
valuable  feature. 

Both  Prof.  Noyes  and  Prof.  Talbot  are  to  be  congratu- 
lated on  the  handsome  paper  and  typography  which  is 
furnished  by  Macmillan  and  Co.,  the  publishers.— H.  C.B. 


Laboratory  Manual.  A  Short  Course  of  Practical 
Chemistry.  By  Alfred  C.  Beebe.  Chicago :  A. 
Flanagan. 

The  work  before  us  is  a  favourable  specimen  of  those 
elementary  treatises  on  chemistry  in  which  the  English 
press  has  been  so  prolific,  and  which  are  now  also 
appearing  in  America.  The  author  lays  some  emphasis 
upon  a  readlion  for  the  recognition  of  potassium,  which 
has  been  proposed  by  Koninck  and  approved  of  by  W. 
Crookes.  It  has  the  advantages  of  being  cheaper  than 
platinum  chloride,  and  more  manageable  than  tartaric 
acid.  Otherwise,  whilst  considering  the  instrudlions 
conveyed  in  this  book  sound  and  purposive,  we  fail  to  find 
them  superior  to  those  met  with  in  similar  manuals. 


Les  Nouveautes  Chimiques  par  1897.  Nouveaux  Appareils 
de  Laboratoires,  Methodes  Nouvelles  de  Researches 
apliques  a  la  Science  et  a  Vlndustrie.  Camille 
PouLENC,  Sc.D.  Paris  :  J.  B.  Bailliere  et  Fils.  1897. 
This  work  has  been  compiled  in  order  to  give  chemists 
and  physicists  an  account  of  recent  discoveries  fuller  and 
more  accurate  than  the  notices  which  we  encounter  in 
the  literary  and  the  political  press.  The  first  chapter  is 
taken  up  with  general  applications  of  chemistry  and 
physics,  such  as  Dr.  Joly's  meldometer  for  the  rapid  and 
accurate  determination  of  the  fusion-points  of  bodies 
which  melt  at  high  temperatures;  the  pyrometric  tele- 
scope of  Mesure  and  Nouel ;  the  new  self-corredling  air- 
thermometer  of  F.  G.  Miiller;  the  short  thermometers  of 
Dr.  Raikow  ;  McTrae's  thermo-element  for  determining 
high  temperatues ;  the  Wiborgh  thermophore,  for  deter- 
mination of  elevated  temperatures  ;  the  double  differential 
thermoscope  of  Loesen  ;  Dunnington's  new  gas-regulator; 
various  apparatus  for  the  produdlion  of  acetylene  ;  M. 
Griinberg's  proposed  appliance  for  the  rapid  deter- 
mination of  the  specific  gravity  of  ores  ;  the  universal 
densimeter  of  Courtonne  ;  the  densimeter  of  Pieri ;  the 
compensating  densimeter  of  Galaine  ;  Vandevyn's  new 
areometer. 

An  important  sedlion  of  the  book  is  devoted  to 
badleriology.  The  description  of  the  novelties  here  are 
well  and  abundantly  illustrated.  Many — we  might  say 
most— of  the  paragraphs  here  inserted  seem  to  have  been 
gleaned  from  the  Chemiker  Zeitnng  and  its  Supplement  the 
Chemiiches  Repertorium. 

We  hope  that  the  "  Nouveautes  Chimiques  "  will  be 
continued  yearly,  as  it  is  calculated  to  prove  highly  ser- 
viceable  to  men  of  Science. 


A  Manual  of  Chemistry,  Theoretical  and  Practical.    Based 
on  Watts's  Edition  of  "  Fownes's  Manual."     By  W.  A. 
TiLDEN,  D.Sc,  F.R.S.,  Professor  of  Chemistry  in  the 
Royal  College  of  Science.  London  :  J.  and  A.  Churchill. 
1897.     Crown  8vo.,  pp-  599. 
This  work  is  somewhat  complicated  in  its  origin.     The 
last  traces  of  the  work  of  Fownes,  we  are  told,  have  dis- 
appeared under  the  hands  of  the  successive  editors  in 
accordance  with  the  development  of  chemical   science, 
and  the  final  result  is  a  most  satisfadlory  specimen  of  the 
intermediate  type  of  chemical  handbook. 

A  preliminary  chapter  has  been  added,  giving  in  broad 
outline  the  leading  points  in  the  history  of  chemistry 
from  the  time  of  Boyle  downwards.  The  author  expresses 


;bbmical  News,  ) 
April  15,  1807.     f 


Practical  Work  in  Physics. 


189 


the  veiy  corredl  opinion  that  such  historical  survey  will 
prove  useful  to  the  student. 

Dr.  Tilden,  whilst  accepting  the  periodic  system,  does 
not  regard  it  as  the  be-all  and  end-all  of  classification, 
It  is  pointed  out  as  a  singular  fad  that  the  discoverers  of 
oxygen,  Scheele  and  Priestley,  remained  phlogistians  to 
the  end  of  their  lives. 

After  the  list  of  the  elements  we  find  the  term  "  metal- 
loids "used,  not  as  it  is  done  in  France,  for  the  non- 
metals,  but  as  a  sub-class  of  the  latter. 

In  speaking  of  the  composition  of  the  atmosphere,  we 
find  an  expression  which  may  be  misunderstood.  The 
writer  means,  of  course,  that  ozone  and  hydrogen  per- 
oxide may  replace  each  other,  but  a  junior  reader  might 
carry  away  the  impression  that  ozone  is  a  synonym  for 
hydrogen  peroxide. 

Dr.  Tilden  greatly  underrates  the  confusion  arising 
from  the  different  hydrometer  scales,  which  are  far  more 
than  two  or  three. 

The  periodic  law  is  here  ascribed  to  Newlands,  Lothar 
Meyer  and  Mendeleeff  receiving  the  credit  of  having 
elaborated  the  original  idea.  The  relations  among  the 
atomic  weights  of  the  elements,  as  connedted  with  their 
attributes,  are  explained  by  the  diagram  devised  by  Dr. 
Emerson  Reynolds,  and  subsequently  modified  by  Mr. 
Crookes.  Dr.  Tilden  does  not  enter  upon  a  variety  of 
other  schemes  for  the  classification  of  the  metals,  such  as 
those  of  Chancourtois. 

The  sedtion  on  the  glass  manufadlure  gives  the  compo- 
sition of  Bohemian  plate-glass  and  English  flint-glass, 
but  overlooks  the  Jena  glass,  which  is  now  rapidly  and 
deservedly  rising  in  favour. 

'  According  to  the  recent  researches  of  Prof.  Berthelot, 
pure  copper  (commercially  so  called)  was  used  for  tools 
and  weapons  before  the  introdudlion  of  bronze. 

In  speaking  of  the  Bessemer  process,  it  might  have 
been  added  that  the  slag  from  the  basic  process  (Thomas 
slag)  is  an  excellent  phosphatic  manure,  equal — and  in 
some  cases  even  preferable — to  superphosphate. 

Tin  has  occasioned  some  trouble  in  chemical  classifica- 
tion. In  common  life  it  ranks  as  a  metal,  and  is,  indeed, 
one  of  the  bodies  upon  which  the  concept  of  a  "  metal  " 
was  primarily  founded.  We  sometimes,  however,  find  it 
placed  as  a  non-metal  or  a  semi-metal.  Dr.  Tilden  asso- 
ciates it  with  thorium,  zirconium,  and  cerium. 

It  is  impossible  for  us  to  notice  all  the  numerous 
passages  in  this  work  which  justify,  and  indeed  call  for, 
favourable  comment.     The  index  is  excellent. 


The  Organised  Science  Series.     First  Stage. — Inorganic 
Chemistry,      By  G.   H.   Baily,   D.Sc.  (Lond.),  Ph.D. 
(Heidelberg),  Ledturer  in  the  Vidtoria  University,  and 
also  Assistant  Examiner  in  the   Science   and  Art  De- 
partment.     Edited  by  William  Briggs,  M.A.,  F.C.S., 
F.R.A.S. ,     Principal     of    University     Correspondence 
College.      London :  W.   B.    Clive,   University   Corre- 
spondence College  Press.    Warehouse,  13,  Booksellers' 
Row,  Strand,  W.C.     8vo.,  pp.  210. 
The   title-page   of  this   little  book   might  justify   a  few 
questions.   What,  for  instance,  is  "  Organised  Science  "  ? 
The   definition   of  Science   is  "  organised   knowledge "  ; 
what,  then,  is  "  organised  science  "  ?     Or  is  it  the  series 
only   which   is  organised,  rather  than  any  other  series  ? 
Again,   it   may   be   asked,    what   are   the   charaderistic 
features  of  University  Correspondence  College,  an  organ- 
isation which  seems  to  do  its  own  printing  and  publishing  ? 
Again,  we  find  mention  of  a  "  University  College  Tutorial 
Series,"  which  has  the  same  general  editor.     How   are 
two  series  connedled  together,  if  at  all  ?    There  is  further 
a   weekly    journal,    the     University    Correspondent    and 
University  Correspondence  College  Magasine.      There  is, 
if  it  has  not  experienced  the  "  happy  despatch,"  a  journal 
bearing  the  ominous  name,  the  Competition,  but  issued, 
as  far  as  we  are  aware,  under  different  auspices.     Have 


we  not  here  the  old  unhappy  game  of  too  many  cooks 
spoiling  the  broth  ? 

It  will  be  perceived  that  the  "  University  Correspond- 
ence College  "  prepares  students  for  examinations  at  the 
London  University.  The  various  chapters  are  fitted  with 
sets  of  questions,  and,  in  addition,  there  are  answers  to 
the  questions  and  to  the  "chemical  calculations." 

The  instrudlions  given  are  satisfadtory,  but  the  question 
still  arises  Cui  bono  ? 


Abstract  of  Chemical  Analysis.  Second  Part. — Quanti- 
tative Analysis.  By  E.  Fink,  Head  of  Pradlical  Opera- 
tions in  Analysis  at  the  Municipal  School  of  Industrial 
Physics  and  Chemistry  of  the  City  of  Paris.  ("Precis 
d'Analyse  Chimique."  Deuxieme  Partie.  —  Analyse 
Quantitative.  Par  E.  Fink,  Chef  des  Travaux  Pratiques 
d'Analyse  a  I'Ecole  Municipale  de  Physique  et  de 
Chimie  Industrielles  a  la  ViUe  de  Paris).  Paris : 
Georges  Carre  and  C.  Naud.     i8g6. 

This  book  differs  little  from  the  generality  of  works  on 
the  same  subjedl  and  of  the  same  extent.  The  balance 
proposed  by  Dr.  Curie  is  described  and  figured.  The 
weights  are  of  course  arranged  on  the  ultra-decimal  prin- 
ciple, with  the  exclusion  of  all  pieces  which  are  not  sub- 
multiples  of  the  preceding  weight.  The  bases  are  classified 
as  belonging  to  the  group  of  arsenic,  copper,  iron,  barium, 
and  potassium. 

The  analytical  methods  are  divided  into  the  gravimetric, 
eledlrolytic,  volumetric,  and  colorimetric.  The  instru- 
ments employed  in  the  last  method  are  those  of  Duboscq 
and  Salleron.  The  tintometer  is  not  mentioned.  Quan- 
titative spedtroscopic  analysis  also  is  overlooked. 


Practical  Work  in  Physics.  For  Use  in  Schools  and 
Colleges.  By  W.  G.  Woolcombe,  M.A.  (Oxon),  B.Sc. 
(London),  Senior  Science  Master  in  King  Edward's 
High  School,  Birmingham.  Part  III.  ~  Light  and 
Sound.  Oxford  :  Clarendon  Press.  London  :  Frowde 
(Oxford  University  Press  Warehouse),  Amen  Corner, 
E.  C.     Crown  8vo.,  pp.  95. 

The  Preface  informs  us  that  an  essential  feature  of  the 
work  before  us  is  to  furnish,  at  a  trifling  cost,  a  fairly 
complete  experimental  course  in  the  subjedts  covered.  As 
regards  the  trifling  cost  we  have  to  consider,  in  the  first 
place,  the  book  itself;  and  in  the  second,  the  inexpensive 
charadler  of  the  apparatus  required.  The  subjedts  here 
considered  "  do  not  appeal  so  much  to  the  student's 
power  of  observation  as  to  that  of  his  judgment."  Here 
therefore  the  author,  in  his  estimate  of  the  educational 
value  of  physics,  differs  from  those  authorities  who  con- 
sider that  its  value  consists  mainly  in  its  training  and 
stimulating  the  student's  faculties  of  observation.  Who 
is  in  the  right  we  do  not  undertake  to  decide.  It  will  be 
perceived  that  sound  is  not  on  all  fours  with  light,  heat, 
and  eledtricity.  These  agencies  are  all  molecular,  whilst 
sound  is  plainly  molar.  So  that,  in  spite  of  the  fadt  that 
the  study  of  sound  first  made  us  familiar  with  vibratory 
motions,  we  are  at  a  loss  as  to  whether  acoustics  ought 
to  rank  with  optics. 


Quantitative  Estimation  of  Urine;  New  System  of  Rapid 
Analysis,   for   Medical   Men   and   Pharmacists.     By   J. 

Barker  Smith,  L.R.C.P.  (Lond.).    London  :  Bailliere, 

Tindall,  and  Cox.  1897.  ^P*  37- 
The  author  of  this  pamphlet  has  had  a  long  experience 
in  the  analysis  of  urine,  and  has  naturally  evolved,  so  to 
say,  several  new  and  rapid  methods.  Time  is,  of  course, 
a  gieat  fadlor  in  carrying  on  work  of  this  charadler,  and 
the  general  pradiitioner  will  doubtless  appreciate  the  im- 
provements and  modifications  herein  described. 

The  tests  applied   to  urine  may  be  arranged  in  two 
main  divisions : — 


1 90 


Teaching  of  Chemistry. 


I  Chemical  Mbws, 
i     April  15.  18C7. 


I.  Tests  of  a  sample  of  urine  rendered  alkaline,  these 
being  used  for  the  estimation  oi  acidity,  urea,  sugar, 
total  urates,  phosphates,  ammonia,  &'C. 
II.  Tests  associated  with  the  estimation  of  normal  or 

acid  urine : — albumen,  biliary  salts,  peptone,  &'C, 
The  general  procedure  {a)  is  fully  set  forth  and  ex- 
plained; this  is  followed  by  two  sedtions  {b  and  c),  fully 
describing  the  special  methods  used,  all  the  details  being 
minutely  gone  into  ;  possible  errors  and  misinterpretations 
of  results  are  pointed  out,  and  many  examples  of 
adtual  periodic  examinations  are  given. 

Accompanying  this  pamphlet  is  a  small,  conveniently 
arranged  pocket  set  of  tables,  and  general  instrudtions 
for  the  rapid  thermometric  method  of  the  quantitative 
analysis  of  urine ;  the  complete  apparatus  required 
(besides  these  tables)  comprises  only  a  measure,  phial, 
and  thermometer,  so  that  with  the  few  reagents  required 
only  a  small  box  is  needed. 


CORRESPONDENCE. 


THE  NEW  SCIENTIFIC   CLUB. 

To  the  Editor  of  the  Chemical  News. 
Sir,— My  attention  has  been  drawn  to  the  fa<5t  that  my 
name  appears  on  a  circular  signed  by  Mr.  Robert  Ingram 
proposing  to  found  a  Club  for  scientific  men.  I  write  to 
ask  you  to  give  publicity  to  the  faift  that  I  know  nothing 
of  the  proposed  Club,  and  have  not  sanctioned  the  use  of 
my  name  in  any  way. — I  am,  &c., 

W.  Ramsay. 

12,  Arundel  Gardens,  W., 
April  9,  1897. 

CHEMICAL    SOCIETY    ELECTION. 

To  the  Editor  of  the  Chemical  News. 
Sir, — Your  readers  might  be  led  to  infer  from  Professor 
Ramsay's  letter  of  April  3rd  that  I  had  not  replied  to 
the  communication  he  addressed  to  me  :  this  would  be  a 
mistake. 

Professor  Ramsay  well  knows  that  I  made  a  full  reply, 
in  which  I  challenged  him  to  put  aside  all  verbal  quibbles  ; 
and  that  it  is  I  who  am  without  an  answer.  He  has  but 
to  say  that  he  wishes  that  the  letter  he  wrote  to  me, 
dated  27th  March,  and  my  answer  to  it,  dated  30th  March, 
shall  be  published, — I  will  then  forthwith  place  both  in 
your  hands  for  communication  to  your  readers. — I  am,  &c., 

Henry  E.  Armstrong. 


TEACHING    OF    CHEMISTRY. 

To  the  Editor  of  the  Chemical  News. 
Sir, — I  have  read  the  letters  of  Mr.  Woodward  and  Mr. 
Wigley  with  great  interest,  but  cannot  see  in  either  suffi- 
cient reason  to  change  my  original  position.  Both  the 
above-named  gentlemen  think  I  over-estimate  the  danger 
beginners  incur  when  handling  the  simple  gases.  I  can 
only  say  that  I  know  of  a  number  of  serious  explosions 
of  these  gases  that  I  believe  would  have  been  avoided  had 
their  preparation  been  deferred  till  later  in  the  course. 
Of  course  I  cannot  speak  of  English  schools,  but  in  the 
American  schools  with  which  I  am  familiar  this  danger 
is  greatly  increased  by  giving  too  many  pupils  to  one 
teacher.  In  my  opinion  this  overcrowding  of  classes  is 
the  most  serious  shortcoming  in  our  American  schools 
to-day,  but  it  only  aggravates  the  danger  which  is  already 
present.  In  regard  to  the  danger  of  explosions  from 
careless  handling  of  acids  that  is  present  in  either  quali- 


tative analysis  or  the  preparation  of  the  non-metallic 
elements,  and  so  cannot  count  against  either  subjeft, 
Mr.  Wigley  thinks  qualitative  analysis  would  not  prepare 
the  student  to  work  with  gases.  I  think  work  with 
chemicals  and  apparatus  in  any  branch  of  the  subjed 
will  materially  aid  work  in  other  lines. 

Both  Mr.  Woodward  and  Mr.  Wigley  seem  to  place 
small  value  on  the  educational  e^ed  of  qualitative 
analysis.  To  my  mind  one  of  the  most  important  objeds 
of  laboratory  work  is  to  teach  the  student  to  think 
logically  and  to  observe  accurately.  Both  of  these  ob- 
jedts  are  as  well  accomplished  by  qualitative  analysis  as 
by  the  preparation  of  the  simple  gases.  Whether  quali- 
tative analysis  becomes  routine  or  not  depends  entirely 
upon  the  ability  of  the  teacher.  Surely  a  subjedt  that 
has  claimed  the  attention  of  some  of  the  ablest  chemists 
who  have  ever  lived  ought  to  contain  enough  intellectual 
matter  to  prevent  the  subjedl  from  becoming  stale  and 
profitless  to  the  beginner.  With  the  rare  elements  to 
study — which  I  should  not  advise  at  this  stage  of  the 
work — I  think  there  is  no  need  for  purely  mechanical 
work. 

To  Mr.  Woodward's  criticism  that  the  students  wonH 
reason,  I  may  say  I  think  we  are  all  more  or  less  lazy  in 
that  respedt.  The  remedy  I  suggest  is  the  one  Nature 
uses  for  more  advanced  scholars,  namely,  to  stimulate 
interest  by  withholding  results  from  the  experimenter.  I 
strongly  approve  of  text-books  in  which  the  students  are 
never  given  a  result  when  it  can  reasonably  be  withheld. 

I  may  state  my  position  by  saying  that  I  do  not  advise 
the  abandonment  of  work  with  the  simple  gases  and  the 
other  non-metallic  elements,  but  I  suggest  that  it  is  not 
suitable  for  the  first  work  in  the  chemical  laboratory.  I 
should  recommend  some  such  chen\ical  course  as  the  fol- 
lowing : — Recitations,  with  strid  and  searching  ques- 
tioning daily,  upon  the  non-metallic  elements  and  such 
work  as  is  usually  included  in  that  branch  of  the  subjedt 
in  a  short  text-book.  These  recitations  should  be 
thoroughly  illustrated  by  experiments  performed  by  the 
teacher,  which  are  recorded  by  the  pupils.  Then  the 
essential  principles  of  qualitative  analysis  should  be 
taught  by  laboratory  work.  Finally,  a  review  of  the 
non-metallic  elements,  in  which  the  student  does  the 
adlual  work  himself.  Here  quantitative  analysis  could 
be  brought  in  to  great  advantage,  I  think.  I  am  not  pre- 
pared to  say  that  it  ought  not  to  be  brought  in  sooner, 
for  I  think  it  is  too  little  used ;  but  I  think  some  know- 
ledge of  chemical  manipulation  had  best  precede  it. 
Qualitative  analysis  can  be  made  quantitative  also  with 
great  ease.  After  this  review  of  the  non-metallic  ele- 
ments, the  subjedt  is  ready  to  be  expanded  along  any  line 
the  teacher  may  see  fit  to  follow. 

The  delay  in  answering  the  letters  of  Mr.  Woodward 
and  of  Mr.  Wigley,  and  the  fadt  that  I  answer  both  gentle- 
men in  one  and  the  same  letter,  I  hope  will  be  pardoned 
on  account  of  my  distance  from  London. — I  am,  &c., 

Alfred  C.  Beebe. 

Savanna,  Ills.,  U.S.A. 


CHEMICAL     NOTICES    FROM    FOREIGN 
SOURCES. 

Note. — All  degrees  of  temperature  are  Centigrade  unlessotherwise 
expressed. 

Comptes  Rendus  Hebdomadaires  des  Seances,  deVAcademie 
des  Sciences.     Vol.  cxxiv.,  No.  13,  March  29,  1897. 

The  President  announced  the  presence  of  Dr.  Nansen 
at  the  session,  whom  he  cordially  welcomed  on  behalf  of 
the  Academy. 

Transformations  of  the  Sugars,  and  on  Levulic 
Acid.— MM.  Berthelot  and  Andie. — In  virtue  of  its  gene- 


Chruical  News,  I 
April  15, 1897.    J 


Chemical  Notices  from  Foreign  Sources. 


191 


ration  by  means  of  aldehydic  groups,  the  molecule  of 
glucose  behaves  as  being  eminently  moveable,  capable  of 
being  split  up  at  the  ordinary  temperature  in  various 
different  diredtions  :  its  constituent  atoms  of  hydrogen  and 
oxygen  oscillate  among  numerous  centres  of  carbon.  In 
all  cases  it  is  a  question  of  purely  chemical  agents.  We 
have  never  ceased  to  think  that  it  must  be  the  same  in 
the  produdlion  of  alcohol;  the  living  cell  which  there 
intervenes  not  being  the  true  specific  agent  of  the  readion, 
but  having  the  funiSlion  of  secreting  such  a  specific  agent. 
To  this  opinion  adhere  the  majority  of  the  physiologists 
who  occupy  themselves  with  the  study  of  infedious  mala- 
dies. 

On  the  Fatty  Matters  Found  in  the  Egyptian 
Tombs  of  Abydos. — C.  Friedel. — The  author  has  ex- 
amined certain  antique  objeds  found  at  Abydos  by  M. 
Amelineau  and  considered  to  be  anterior  to  the  first 
dynasty.  The  fatty  matter  consisted  chiefly  of  palmitic 
and  stearic  acids,  and  was  doubtless  the  tallow  of  beef  or 
of  mutton.  It  is  interesting  to  find  that  the  fatty  acids, 
such  as  the  stearic  and  palmitic  acid,  and  even  the  gly- 
cerides  of  these  acids,  have  been  capable  of  preservation 
for  thousands  of  years.  Among  the  substances  found  in 
small  vases  was  pulverised  lead  sulphide  mixed  with  a 
quantity  of  fatter  matter ;  evidently  a  cosmetic  used  as 
antimony  sulphide  is  still  employed  in  the  East. 

Transformationof  theDiatnond  into  Graphite  inthe 
Crookes  Tube.— H.  Moissan. — Mr.  Crookes  has  demon- 
strated in  his  fine  researches  on  the  phenomenon  whicli 
he  has  named  molecular  bombardment  that  on  placing 
diamonds  in  one  of  his  tubes  they  quickly  lose  their  lustre 
and  are  coated  with  a  black  layer.  Having  been  present 
in  his  laboratory  at  this  curious  experiment  I  asked  him 
for  some  of  the  diamonds  which  had  been  thus  bombarded 
that  I  might  study  the  variety  of  carbon  produced  under  these 
conditions.  Mr.  Crookes  having  kindly  sent  me  a  diamond 
the  surface  of  which  had  been  completely  blackened  by 
this  bombardment,  I  heated  it  to  60°  in  an  oxidising  mix- 
ture of  potassium  chlorate  and  fuming  nitric  acid  prepared 
from  sulphuric  acid  exadly  monohydrated  and  potassium 
nitrate  fused  and  quite  free  from  moisture.  The  adlion  on 
the  black  layer  is  very  slow.  There  is  produced  graphitic 
oxide,  which  at  an  increased  temperature  yields  pyro- 
graphitic  acid  which  is  easily  destroyed  by  nitric  acid. 
Hence  the  variety  of  carbon  which  coated  the  diamond 
was  graphite.  This  transformation  of  the  diamond  into 
graphite  must  be  very  high.  Mr.  Crookes  had  already 
proved  the  platinum-iridium  can  be  fused  in  his  tubes,  but 
the  temperature  obtained  in  the  bombardment  is  much 
higher,  since  the  transformation  of  diamond  into  graphite 
requires  the  high  temperature  of  the  eledlric  arc.  The 
higher  the  temperature  to  which  graphite  is  raised  the 
greater  is  its  resistance  to  oxidation.  The  temperature 
reached  is  probably  about  3600°. 

Mutual  Ad\ions  of  Eled^rodes  and  of  Cathodic 
Rays  in  Rarefied  Gases. — H.  Deslandres. — The  author 
concludes  that  when  we  have  in  the  vicinity  of  a  cathode 
a  conductive  or  insulated  body  which  is  taken  as  an 
anode  or  is  insulated,  everything  ensues  as  if  the  cathodic 
rays  were  attraded.  The  mutual  adion  of  the  rays  and 
the  cathodes  takes  place  only  when  the  rays  interpenetrate 
each  other. 

Stannic  Chlorobromides. — A.  Besson. — Theory  leads 
us  to  foresee  the  existence  of  the  chlorobromides  of  the 
type  SnX4,  SnClgBr,  SnCljBra,  SnCIBrg.  The  compound 
SnC'sBr  forms  the  main  part  of  the  fradlion  which  distils 
at  50 — 55°  under  the  pressure  of  3  cm.  The  chloro- 
bromide,  SnCIgBra,  is  separated  from  the  fraction  passing 
over  between  60°  and  70°.  The  compound  SnClBr3  distils 
over  the  same  pressure  at  about  73°. 

Conditions  of  the  Diredl  Combination  of  Sulphur 
and  Hydrogen. — H.Pelabon. — Hydrogen  may  still  com- 
bine with  sulphur  as  long  as  the  temperature  is  not  below 
215°.     Between  215°  and  350°  the  combination  is   still 


limited.    The  diredl  combination  of  the  two  substances 

is  effe(5ted  the  more  rapidly  the  higher  is  the  temperature. 
The  maximum  quantity  of  hydrogen  sulphide  formed  at 
a  given  temperature  increases  regularly  with  temperature. 
Above  440°  we  reach  the  same  limit,  whether  we  set  out 
from  sulphur  and  hydrogen  or  from  pure  hydrogen  sul- 
phides. If  we  substitute  for  pure  hydrogen  a  mixture  of 
hydrogen  and  nitrogen,  the  maximum  quantity  of  hydrogen 
sulphide  formed  after  heating  for  a  given  time  is  less  than 
with  pure  hydrogen ;  all  circumstances  being  equal  the 
difference  is  less  the  higher  the  temperature. 

Action  of  Bromine  and  Hydrobromic  Acid  upon 
Ethyl  Acetate. — Boleslas  Epstein. —  A  critique  of  the 
results  of  M.  Crafts  published  in  the  Comptes  Rendus, 
vol.  Ivi.,  p.  707,  1863. 


MISCELLANEOUS. 


Royal  Institution.  —  A  General  Monthly  Meeting  of 
the  Members  of  the  Royal  Institution  was  held  on 
April  5th,  Sir  James  Crichton-Browne,  M.D.,  F.R.S., 
Treasurer  and  Vice-President,  presiding.  The  following 
were  eleded  Members:— Mr.  J.  H.  Colls,  Mr.  H.  E.  Dia- 
mond, Mrs.  J.  Dundas  Grant,  Mr.  Douglas  Hall,  Mr.  W. 
Hunter,  and  Mr.  F.  M.  Mackenzie,  M.R.C.S.  The  special 
thanks  of  the  Members  were  returned  to  Sir  William  J. 
Farrer  for  a  donation  of  £50  to  the  Fund  for  the  Promo- 
tion of  Experimental  Research  at  Low  Temperatures. 

Gravimetric  "Estimation  of  Sugar. — G.  Ambuhl 
{Chetn.  Zeit.,  1897,  "'''•.  ^S?)- — The  author  recommends 
that  the  cuprous  oxide  produced  in  the  Fehling-AUihn 
process  should  be  dried  for  one  hour  at  98*5°  C,  and 
weighed  as  such,  instead  of  being  reduced  to  the  metallic 
state.  He  presents  an  elaborate  table,  showing  the  results 
of  the  method  when  applied  to  forty-six  samples  of  wine, 
honey,  and  diabetic  urine.  In  the  case  of  wines,  the 
figures  are  pradically  identical  with  those  obtained  by 
weighingthe  metal,  being  usually  a  trifle  higher(maximum 
-}-o"09;  average  -f  0*034  per  cent).  With  honey,  the 
excess  averages  0-23  per  cent  on  amounts  of  sugar 
varying  from  57  to  69  per  cent ;  and  with  urine  containing 
4*25  to  6'i6  per  cent  of  sugar,  the  mean  difference  be- 
tween the  two  processes  is  ojio  per  cent,  but  in  this 
instance  the  suboxide  was  manifestly  contaminated  with 
organic  substances,  which  suffer  decomposition  on 
ignition. — The  Analyst, 


NOTES    AND    QUERIES, 


*^*  Our  Notes  and  Queries  column  was  opened  for  the  purpose  of 
giving  and  obtaining  information  likely  to  be  of  use  to  our  readers 
generally.  We  cannot  undertake  to  let  this  column  be  the  means 
of  transmitting;  merely  private  information,  or  such  trade  notices 
as  should  legitimately  come  in  the  advertisement  columns. 

Qun  Paper. — Will  some  correspondent  inform  me  the  way  to 
make  gun  paper,  by  the  quire  at  a  time.  I  find  when  trying  to  make 
more  than  a  single  sheet  the  whole  quire  adheres  and  becomes  one 
solid  cake  or  block. — F.  F. 

Pemberton's  Molybdate  Method  for  Phosphoric  Acid. — 
Will  some  correspondent  kindly  inform  me  where  I  can  find  any 
description  of  a  modification  of  Pemberton's  molybdate  method  for 
phosphoric  acid,  being  the  use  of  glue  to  make  the  yellow  precipitate 
sink  so  as  to  enable  one  to  better  see  the  end  rea(5lion.  The  method 
is  used,  I  believe,  in  the  State  Agricultural  Laboratories  in  Switzer- 
land,-R.  C.  W. 


Crrata. — No.  1910,  p.  II,  col.  I,  line  19  from  bottom,  for  "go°"  read 
"  o°."  No.  1950,  p.  179,  col.  2,  line  5  from  bottom, /o;-  "  Staining  " 
retid  "  Storing."  ■■  '  ' 


ig2 


Advertisements, 


i  CaSHICAL  Nbws, 
1     April  15, 1897. 


AGRICULTURAL  CHEMICAL  ANALYSIS. 

By  H.  W.  Wiley.  Vol.  I..  SOILS,  155.  Vol.  II., 
FERTILIZERS.  85.  Vol.  III.,  AGRICULTURAL 
PRODUCTS,  15J. 

ENGINEERING  CHEMISTRY. 

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By  H.  Snyder.     Cloth,  6s. 

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Chbuical  Mbws, 
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)        Occurrence  0/  Raffinose  in  A  merican  Sugar  Beets, 


193 


THE    CHEMICAL     NEWS 


Vol.  LXXV,,  No.  1952. 


METHOD    OF    SEPARATION    OF 

NICKEL   FROM   COBALT,   NICKEL  FROM    IRON, 

AND    COBALT    FROM    ALUMINIUM. 

By    E.   PINERUA, 
Laboratory  of    the  University  of   Valladolid,   Spain. 

On  account  of  the  very  close  resemblance  between  nickel 
and  cobalt  their  separation  offers  many  difficulties,  and 
calls  for  special  methods.  The  process  generally  em- 
ployed, viz.,  the  potassic  nitrite  method,  is  very  tedious, 
and  above  all  requires  certain  conditions  as  to  the  pro- 
portion of  cobalt  present  (Fleitmann,  Z.  fur.  Anal. 
Chem.,  xiv.,  76,  1875). 

Liebig's  method,  by  means  of  cyanide  of  potassium, 
bromine,  and  an  alkali,  is  very  delicate. 

That  of  Langier,  which  consists  in  precipitating  the 
nickel  and  cobalt  as  oxalates,  and  dissolving  these  in  am- 
monia, and  exposing  this  solution  to  the  adtion  of  the  air, 
has  been  abandoned. 

Gautre's  modification  {Z.  fur  Anal.  Chem.,  v.,  75,  1866) 
of  the  cyanide  of  potassium  and  mercuric  oxide  process, 
is  again  not  very  exadt. 

The  latest  method,  that  of  Knorre  and  Ilinski  {Z.  fur. 
Ange.  Chem.,  vi.,  264,  1893),  based  on  the  precipitation  of 
cobalt  by  nitroso-jS-naphthol,  which  does  not  precipitate 
the  nickel,  is  good  ;  but  we  think  the  simplest  and  most 
rapid  is  that  which  we  have  recently  employed  at  this 
laboratory,  founded  on  the  insolubility  of  chloride  of  nickel 
in  a  solution  of  ordinary  ether  saturated  with  hydrochloric 
acid  gas  at  a  low  temperature. 

The  adtion  of  hydrochloric  acid  gas  on  the  metallic 
oxides  and  their  salts  has  been  studied  by  Debray,  E. 
Pechard,  Ditte,  Engel,  Hanriot,  Rothe,  Smith  and  Ober- 
holtzer,  Smith  and  Hibbs,  Smith  and  Meyer,  Jannasch 
and  Schmith,  Bird  Moyer,  F.  A.  Gooch,  F.  S.  Havens, 
and  many  other  chemists  ;  but  we  believe  that,  up  to  the 
present,  no  method  of  separation  of  the  above  named 
metals  has  been  published,  based,  as  ours  is,  on  the  inso- 
lubility of  the  chlorides  of  nickel  and  aluminium,  and 
the  great  solubility  of  cobalt  and  iron,  in  the  solution 
previously  mentioned. 

The  hydrated  chlorides  (o'3  grm.  to  0*4  grm.)  of  the 
metals,  nickel  and  cobalt,  nickel  and  iron,  cobalt  and 
aluminium,  are  dissolved  in  the  smallest  possible  quantity 
of  water,  and  to  the  solution  is  added  10  or  12  cm.  of 
fuming  hydrochloric  acid  and  10  cm.  of  ordinary  ether 
(D  15  c  =  0*725),  or,  better  still,  anhydrous  ether.  This 
must  be  well  shaken,  and  through  the  resulting  homo- 
geneous liquid  a  current  of  hydrochloric  acid  gas  is  passed 
continuously  until  complete  saturation,  at  the  temperature 
of  melting  ice,  with  which  the  beaker  or  test-tube  should 
be  surrounded.*  During  this  operation  the  nickel  is  pre- 
cipitated in  the  state  of  heavy,  cvy^iaWine,  yellow  chloride, 
and  the  cobalt  remains  in  solution  with  an  intense  blue 
colour  (Engel's  acid  chloride).  In  the  presence  of  iron, 
which  under  these  conditions  would  give  a  bright  yellow 
solution,  the  colour  becomes  green. 

•  Our  hydrochloric  acid  gas  was  obtained  by  the  reaftion  in  the 
cold  of  concentrated  sulphuric  acid  and  chloride  of  ammonium. 
The  apparatus  employed  consists  of  a  litre  flask,  with  three  large 
openings  at  the  top,  and  one  draw-off  tube  at  the  side  near  the 
bottom.  One  of  the  three  necks  allows  the  gas  to  pass  by  means  of 
stoppered  tube;  another  serves  for  the  introdu(5tion  of  small  lumps 
of  the  aramoniacal  salt  ;  and  in  the  third  is  inserted  a  Welter  safety 
tube,  by  which  means  small  quantities  of  sulphuric  acid  are  added. 
The  lower  side  tube  is  used  for  emptying  the  apparatus  when 
necessary. 


Most  of  the  commercial  chlorides  of  nickel  and  cobalt, 
soi-disant  pure,  are  really  very  impure.  By  using  our 
process  for  precipitating  the  nickel,  on  the  commercial 
chlorides  of  cobalt,  the  resultant  liquid  is  of  a  bluish 
green  instead  of  a  pure  blue  colour,  indicating  the  pre- 
sence of  iron. 

The  precipitated  chloride  of  nickel  is  yellow,  but  some- 
times the  remaining  liquid  is  of  a  light  yellowish  green 
colour,  indicating  the  presence  of  iron  and  cobalt. 

We  have  noticed,  by  using  different  solvents,  pheno- 
mena which  by  their  importance  demand  studying  with 
very  great  attention.  We  are  led  to  believe,  as  are  the  che- 
mists Kriiss  and  Schmidt,  Remler,  Winckler,  de  Koninck, 
and  others,  that  nickel  and  cobalt  are  not  adtually  known 
in  a  state  of  purity,  and  that  they  probably  contain  other 
elements  still  unknown. 

The  precipitate  of  chloride  of  nickel  is  washed  by 
decantation,  with  ether  saturated  with  hydrochloric  acid 
gas,  at  a  low  temperature,  colledted  on  a  filter,  and 
thoroughly  washed  again  on  the  filter;  it  can  then  be 
weighed  and  the  nickel  estimated  in  the  ordinary  manner 
(such  as  sulphate,  for  example)  with  very  accurate 
results. 

The  same  method  of  procedure  can  be  utilised  for  the 
separation  of  aluminium  and  cobalt ;  the  former  metal  is 
completely  precipitated  in  the  state  of  insoluble  chloride, 
as  it  is  when  in  the  presence  of  iron,  using  the  analogous 
method  of  Hanriot  and  Rothe,  as  modified  by  F.  A. 
Gooch  and  F.  S.  Havens.* 

The  cobalt  remains  like  the  iron  in  solution ;  and  the 
insoluble  chloride  of  aluminium,  washed  with  ether  satu- 
rated  with  hydrochloric  acid  gas,  can  be  estimated  with 
great  accuracy. 

To  effedl  the  separation  of  nickel  from  iron,  it  is  neces- 
sary to  wash  the  chloride  of  nickel  many  times  with  ether 
to  eliminate  the  chloride  of  iron  which  is  re-dissolved, 
and  the  operation  must  be  repeated  several  times. 


THE    OCCURRENCE    OF    RAFFINOSE    IN 

AMERICAN   SUGAR   BEETS. 

By  W.  E.  STONE  and  W.  H.   BAIRD. 

Raffinose,  as  a  distinft  kind  of  sugar,  belongs  to  the 
comparatively  little  met  with  class  of  tri-saccharides  with 
the  formula  C18H32O16.  It  has  been  shown  that  the 
sugars  found  in  different  plants,  such  as  Eucalyptus, 
cotton-seed,  barley,  wheat,  and  finally  in  molasses  and 
refinery  produdts  of  the  sugar  beet,  and  called  variously 
melitose,  gossypose,  and  raffinose,  are  all  identical  with 
each  other. 

In  the  residual  and  secondary  produdts  resulting  in  the 
manufadture  of  beet  sugar,  raffinose  has  long  caused 
serious  and  unexplainable  errors,  inasmuch  as  it  crystal- 
lises with  cane  sugar,  modifying  its  form  and  increasing 
the  specific  rotation.  It  was  at  first  thought  that  raffinose 
was  not  originally  present  in  the  beet  juices,  but  it  has 
been  since  shown  that  such  is  not  the  case. 

The  special  processes  of  making  beet  sugar  from  beet 
juices,  as  carried  on  at  the  Norfolk  (U.S.A.)  Works,  are 
fully  described;  an  important  point  to  note  is  that, owing 
to  the  behaviour  of  raffinose  during  the  process  of  manu- 
fadture  of  beet  sugar,  it  gradually  becomes  more  and  more 
concentrated  in  the  molasses  and  secondary  produdts  of 
the  fadlory,  and  it  has  been  noted  that  if  the  amount  of 
raffinose  present  reaches  8  to  12  per  cent,  or  even  less,  it 
not  only  destroys  the  accuracy  of  all  polarimetric  deter- 
minations, but  seriously  retards  the  crystallisation  of  the 
sucrose  itself. 


*  "  Method  for  the  Separation  of  Aluminium  from  Iron,"  by  F.  A. 
Gooch  and  F.  S.  Havens.  Contributions  from  the  Kent  Chemical 
Laboratory  of  Yale  University.  American  Journal  of  Science,  vol.  ii.. 
Fourth  Series,  December,  1896;  Chemical  News,  vol.  Uxiv.,  p.  29^, 


194 


Determination  of  Sulphur  in  Cast-iron, 


{Chemical  News, 
l     April  23,  1897. 


Repeated  attempts,  during  1895  and  1896,  were  made  to 
detecft  raffinose  by  Tollens's  method  of  producing  mucic 
acid,  but  were  met  with  failure,  and  the  results  herein 
given  well  illustrate  the  untrustworthiness  of  the  mucic 
acid  test  when  applied  to  complex  mixtures  of  salts  and 
organic  matters,  such  as  molasses.  Numerous  methods 
have  been  proposed  for  the  isolation  of  raffinose,  and  the 
authors  proceed  to  describe  several  of  them,  such  as  those 
used  and  described  by  Kodyl  and  Scheibler,  and  they 
finally  found  a  combination  of  several  of  these  which 
proved  successful.  This  method  is  described  at  length, 
and  from  the  results  obtained  the  authors  feel  justified  in 
concluding  that  raffinose  occurs  in  the  juices  of  the  Ameri- 
can sugar  beet  in  appreciable  quantities.  Certain  peculi- 
arities of  crystallisation  of  mixtures  of  sucrose  and  raffinose 
are  pointed  out,  the  authors  finding,  when  examining  the 
crystals  under  the  microscope,  that  frequently  solutions 
containing  apparently  but  a  very  small  amount  of  raffinose 
would  completely  crystallise  into  forms  which  could 
scarcely  be  distinguished  from  pure  raffinose.  This  modifi- 
cation of  the  crystalline  form  of  sucrose  would  seem  to 
afford  a  ready  means  of  deteding  the  presence  of  small 
amounts  of  raffinose  when  mixed  with  sucrose. — Abridged 
from  the  journal  of  the  American  Chemical  Society,  xix., 
No.  2. 


THE    DETERMINATION     OF    SULPHUR    IN 

CAST-IRON. 

By  FRANCIS  C.  PHILLIPS. 

In  a  Paper  read  before  the  American  Chemical  Society 
in  August,  1895  {yourn.  Amer.  Chew.  Soc,  xvii.,  891),  I 
have  detailed  some  experiments  made  in  the  determina- 
tion of  sulphur  in  white  cast-iron  by  the  evolution  method, 
and  have  attempted  to  show  that  the  loss  of  sulphur  in 
its  determination  in  such  iron  may  be  due  to  the  formation 
of  organic  sulphur  compounds  not  oxidisable  to  sulphuric 
acid  by  the  usual  means. 

By  passing  the  gases  evolved  during  the  solution  of 
the  iron  in  hydrochloric  acid  through  a  heated  porcelain 
tube,  it  was  found  that  the  volatile  organic  sulphur  com- 
pounds may  be  decomposed  and  nearly  all  the  sulphur 
recovered  byconversion  into  hydrogen  sulphide,  oxidation 
and  precipitation  as  barium  sulphate. 

In  judging  of  the  corredlness  of  an  analytical  method 
it  has  been  necessary,  in  the  case  of  the  majority  of  the 
constituents  of  iron,  to  depend  upon  a  single  criterion; 
that  method  is  regarded  as  most  accurate  which,  being 
correct  in  its  details,  yields  the  highest  percentage  of  the 
constituent  sought  to  be  determined.  For  it  is  hardly 
possible  to  add  to  pure  iron  a  known  percentage  of 
sulphur,  phosphorus,  or  carbon,  and  test  the  method  by  a 
determination  of  the  added  constituent.  For  the  deter- 
mination of  sulphur  in  iron  it  has  been  common  to  regard 
the  method  of  oxidation  and  solution  of  the  iron  by  nitric 
acid,  followed  by  precipitation  of  the  sulphur  in  form  of 
barium  sulphate,  as  the  most  accurate,  inasmuch  that  it 
yields  results  somewhat  higher  than  those  obtained  by 
other  modes  of  procedure. 

It  does  not  seem  probable  that  an  appreciable  error 
could  occur  in  the  use  of  this  method,  unless,  in  the 
simultaneous  oxidation  of  the  carbon  and  sulphur  of  the 
iron,  an  organic  sulphur  compound  should  be  formed. 

It  has  seemed  to  be  of  interest,  however,  to  apply  a 
method  for  the  determination  of  sulphur  by  which  all  the 
constituents  of  the  metal  could  be  completely  oxidised  in 
a  dry  state  and  at  a  high  temperature,  in  order  to  avoid 
as  effedlually  as  possible  the  chances  of  loss  due  to  the 
conversion  of  sulphur  into  a  volatile  compound  not 
oxidisable  by  ordinary  means  to  sulphuric  acid. 

In  searching  for  a  method  which  should  answer  these 
requirements,  it  seemed  possible  that  by  heating  the  iron 
in  the  form  of  fine  powder,  in  presence  of  a  mixture  of 
alkaline  carbonate  and  nitrate,  the    sulphur    might  be 


oxidised  diredtly  and  completely  to  the  condition  of  a 
sulphate  without  affording  an  opportunity  for  the  escape 
of  a  trace  of  sulpiuir  in  some  intermediate  volatile  or 
soluble  compound.  Accordingly  an  experiment  was  tried 
in  the  following  way  : — 

An  iron  containing  its  carbon  in  the  combined  form  was 
melted  in  a  crucible,  and  poured  while  fused  into  water. 
The  granulated  metal  was  crushed  in  a  steel  mortar  to  an 
extremely  fine  powder.  The  powder  so  obtained  was 
sifted  through  bolting  sheeting. 

Two  and  one-half  grms.  of  the  sifted  iron  were  mixed 
with  10  grms.  of  a  mixture  of  equal  parts  of  sodium 
nitrate  and  carbonate  in  a  platinum  crucible.  The  cru- 
cible was  covered  and  heated  over  a  Bunsen  burner.  At 
a  red  heat  a  sudden  and  rather  violent  readion  occurred, 
and,  having  been  begun,  was  easily  maintained  with  very 
little  aid  from  the  burner  flame.  The  readlion  appeared 
to  be  complete  in  a  few  minutes.  After  heating  for  a  half 
hour  the  crucible  was  cooled,  and  its  contents  softened  in 
water.  A  residue  of  a  reddish  brown  powder,  consisting 
of  ferric  oxide  with  a  little  ferrous  oxide,  was  obtained. 
This  residue  was  found  to  contain  no  sulphuric  acid,  and, 
on  digesting  with  hydrochloric  acid,  dissolved  without 
effervescence,  showing  that  none  of  the  particles  of  the 
original  iron  had  remained  unoxidised.  From  the  results 
of  this  experiment,  and  others  which  need  not  be  detailed 
here,  it  seemed  to  be  possible  to  oxidise  finely  divided 
iron  so  completely  by  heating  with  sodium  carbonate  and 
nitrate,  that  its  sulphur  might  be  converted  quantitatively 
into  sulphuric  acid. 

The  mixture  of  sodium  carbonate  and  nitrate,  although 
tending  to  oxidise  finely  divided  iron,  seems  to  exert  a 
less  powerful  adlion  upon  the  carbon  contained  in  the 
iron,  and  this  carbon  may  appear  as  a  black  residue  after 
the  fused  mass  has  been  softened  and  extraded  by  water 
and  the  ferric  oxide  dissolved  in  hydrochloric  acid. 

It  seems  to  be  important  for  the  success  of  the  method 
that  in  the  oxidation  of  the  iron  the  carbon  should  also 
be  nearly  or  completely  oxidised,  for  if  the  carbon  re- 
mained unburned  a  portion  of  the  sulphur  might  escape 
oxidation.  In  general  it  may  be  said  that  the  order  of 
oxidation  of  these  three  elements  by  the  method  used  is 
as  follows: — i,  iron;  2,  carbon;  3,  sulphur;  the  iron 
being  the  most  easily  oxidised,  and  the  sulphur  the  most 
difficult  to  oxidise.  This  order  is  not  exadly  what  we 
should  anticipate  ;  but  it  is  to  be  remembered  that  unless 
the  iron  grains  are  fine  enough  to  be  penetrated  by 
oxygen,  and  changed  completely  into  a  soft  powder  of 
ferric  oxide,  the  sulphur  and  carbon  have  no  opportunity 
to  oxidise  at  all.  If  the  iron  could  be  used  as  an  impal- 
pable powder  the  order  of  oxidation  would  probably  be 
different.  The  marked  resistance  of  the  carbon  to  oxida- 
tion has  been  frequently  observed,  even  when  using 
more  sodium  nitrate  in  the  fusion  than  is  theoretically 
enough  to  completely  oxidise  both  iron  and  carbon,  sup- 
posing that  the  sodium  nitrate  is  reduced  only  to  nitrite 
in  the  process. 

Experiments  of  a  similar  kind  were  tried  with  ferro- 
manganese.  A  metal  containing  about  80  per  cent  of 
manganese  was  used.  By  crushing  in  a  steel  mortar  this 
iron  was  very  easily  reduced  to  a  powder  fine  enough  to 
pass  through  bolting  sheeting.  On  heating  the  powder 
with  the  mixture  of  sodium  nitrate  and  carbonate  a  most 
violent  readlion  occurred,  the  metal  burning  with  a  long 
flame,  extending  several  inches  above  the  crucible.  In 
order  to  control  the  readlion  it  was  found  necessary  to 
melt  one-half  of  the  fusion  mixture  to  be  used  in  the 
crucible,  and  then  add  slowly  the  other  half,  previously 
mixed  with  the  powdered  metal,  while  stirring  constantly. 
In  this  way  the  readlion  could  be  easily  controlled.  On 
sofening  the  fused  mass  in  water  it  was  found  that  the 
iron  had  been  peroxidised  and  the  manganese  changed  to 
binoxide.  No  trace  of  sodium  manganate  was  ever 
formed,  the  solution  in  water  being  after  filtration  inva- 
riably colourless.  No  carbon  was  found  in  the  residue. 
The  oxidation  of  the  carbon  is  much  more  easily  efTedted 


CRBUICAL  NBWS,  I 
April  23,  1897.     I 


Determination  of  Sutphur  in  Cast'iron, 


195 


in  the  case  of  iron  containing  a  high  percentage  of  man- 
ganese. In  a)I  the  trials  made  the  silicon  of  the  iron  was 
oxidised,  but  it  was  found  that  when  the  fused  mass  is 
softened  in  water  very  little  silica  enters  into  solution  as 
an  alkaline  silicate,  the  greater  portion  remaining  insoluble 
and  in  a  fiocculent  form. 

Experiments  were  then  tried  with  a  grey  iron.  This 
form  of  iron  could  not  be  crushed  to  a  fine  powder,  and 
an  experiment  was  made  in  reducing  it  from  small 
drillings  by  means  of  a  chilled  iron  rubber  and  plate,  such 
as  is  ordinarily  used  for  grinding  ores.  Several  grey  irons 
were  tried  in  this  way.  Some  could  not  be  powdered  by 
the  method  just  mentioned,  the  grains  tending  to  flatten 
instead  of  being  crushed.  Others  were  readily  reduced, 
but  the  powder  was  not  in  any  case  fine  enough  for  sifting 
through  bolting  sheeting.  It  was  found,  in  the  case  of  a 
grey  iron  reduced  to  powder  by  the  method  of  grinding, 
that  on  fusion  with  the  mixture  of  sodium  nitrate  and 
carbonate,  used  in  the  precedingexperiments,  the  graphitic 
carbon  of  this  iron  was  more  readily  burnt  than  the  com- 
bined carbon  of  white  iron. 

As  it  had  proved  to  be  a  somewhat  difficult  matter  to 
oxidise  completely  the  carbon  of  the  iron  in  the  various 
experiments  made  with  the  fusion  method,  notably  in  the 
case  of  white  iron,  some  trials  were  made  in  the  use  of 
sodium  peroxide.  This  proved  to  be  a  more  efficient 
oxidising  agent  for  iron  and  its  contained  carbon  than 
sodium  nitrate.  For  these  trials  a  mixture  was  used 
consisting  of  forty-five  parts  each  of  sodium  peroxide 
and  sodium  nitrate,  together  with  ten  parts  of  sodium 
carbonate. 

White  iron  was  oxidised  and  its  carbon  burnt  during 
a  fusion  lasting  less  than  ten  minutes. 

On  heating  ferromanganese  with  this  mixture  the  iron 
was  found  to  be  completely  oxidised.  The  carbon  was 
burnt,  and  the  manganese  was  oxidised  and  converted 
into  sodium  manganate,  yielding  a  deep  green  solution 
when  the  fused  mass  was  digested  in  water. 

An  admixture  of  sodium  carbonate  to  sodium  peroxide 
tends  in  all  cases  to  diminish  its  aftion  upon  finely- 
divided  iron  at  a  high  temperature,  and  renders  the 
process  more  easily  controlled.  It  seemed  to  be  possible 
to  base  a  method  for  the  quantitative  determination  of 
sulphur  in  certain  kinds  of  cast  iron  upon  the  readlions 
described  above. 

An  indispensable  condition  of  success  in  the  use  of  the 
method  is  found  in  the  extreme  fineness  of  the  iron.  In 
the  case  of  white  irons  the  fineness  of  the  powder  has 
been  secured  by  crushing  in  a  steel  mortar  until  the 
powder  passed  through  a  sieve  of  bolting  sheeting  or 
bolting  cloth.* 

Some  grey  irons  cannot  be  crushed  or  ground.  To  these 
the  method  is  not  applicable.  For  grey  irons,  however, 
the  evolution  method  answers  all  requirements. 

The  following  details  are  given  of  the  method  finally 
employed : — 

I.  White  Iron,— A.ho\it  li  grms.  of  the  finely- powdered 
and  sifted  metal  was  intimately  mixed  with  8  grms.  of  the 
sodium  peroxide  mixture  above  mentioned,  or  with  4  grms. 
each  of  sodium  carbonate  and  nitrate.  The  somewhat  vio- 
lent readlion  set  up  on  the  application  of  strong  heat  to  the 
platinum  crucible  was  completed  in  a  few  minutes.  The 
crucible  was  heated  for  about  twenty  minutes  in  all. 
After  cooling,  the  contents  were  softened  in  water,  the 
solution  decanted,  and  the  residue  ground,  while  wet,  in 
a  mortar.  The  solution  and  residue  were  then  digested 
in  a  beaker  on  the  water-bath  for  one  hour  after  addition 
of  2  c.c.  of  strong  bromine  water.     The  liquid  was  then 

*  Two  different  materials  are  sold  which  are  suitable  for  the  sifting. 
One  is  called  bolting  cloth,  the  other  bolting  sheeting.  The  bolting 
cloth  used  in  these  experiments  contained  about  eighty-five  meshes 
to  the  linear  inch,  while  in  the  bolting  sheeting  about  one  hundred 
and  thirty-five  were  counted.  The  material  having  the  smaller 
number  of  meshes  is  made  ot  coarser  threads,  however,  and  yields, 
on  account  of  the  smaller  openings,  a  finer  powder.  Bolting  cloth  is, 
on  this  account,  better  suited  to  the  preparation  of  a  sample  of  white 
Jron  lor  a  determination  of  sulphur  by  the  method  described. 


Character  01 
iron  used. 

White  iron  A 
crushed  in 
mortar  and 
sifted  through 
bolting  sheet- 
ing. 


Fusion  mixture 
employed. 

Contained  equal 
parts  of  sodium 
carbonate  and 
nitrate. 


P.c.  of  sul- 
phur found 
by  fusion. 


White  iron  B 
crushed  and 
sifted. 


Ferromanga- 
nese crushed 
and  sifted. 


Means     .. 

Contained — 
45  parts  NaNOs 
45  parts  Na203 
10  parts  Na2C03. 


Means     .. 

Contained  equal 
parts  of  sodium 
nitrate  and  car- 
bonate. 


Means 


o'log 


0151 

O*022 
0027 

o-oiS 
o-oi8 
o'oiS 
o-oig 
o'oi6 

0'020 


P.c.  of  sul- 
phur found 

by  the 

method  of 

oxidation  by 

nitric  acid. 

O'lOI 

0*098 
0*096 
0099 

O'lOO 
0'102 
0102 

o"io4 


0100 

0'i43 
0-149 
0-143 
0-147 


0-145 

0012 
0-013 
0-012 
o-oio 


Grey      iron 

Contained   equal 

0-034 

0*027 

drillings  pow- 

parts of  sodium 

0-030 

0030 

dered  by  rub- 

nitrate and  car- 

0036 

0-026 

ber  and  plate. 

bonate. 

0-034 

0  028 

Not  sifted. 

0-033 

0-028 

0-034 

0022 

M 

, 

Means    ..     .. 

0-033 

0*027 

filtered,  acidulated  with  hydrochloric  acid,  evaporated  to 
dryness  to  separate  the  small  portion  of  silica  which  had 
entered  in  solution,  and  filtered.  The  sulphuric  acid  was 
determined  in  the  filtrate  in  the  usual  manner.  The 
barium  sulphate  obtained  was  always  white.  If  the 
fusion  mixture  contains  sodium  carbonate  and  nitrate, 
but  no  sodium  peroxide,  the  crucible  must  be  heated  for  a 
longer  time,  but  a  portion  of  the  carbon  of  the  iron  may 
still  remain  unoxidised. 

2.  Ferromanganese. ~ln  this  case  it  is  better  to  use  a 
mixture  of  equal  parts  of  sodium  nitrate  and  carbonate, 
omitting  the  sodium  peroxide. 

Ten  grms.  of  the  mixture  were  divided  into  two  por- 
tions,  one  of  which  was  fused  in  a  crucible.  The  other 
portion,  mixed  with  2  or  2i  grms.  of  the  finely-powdered 
iron,  was  then  slowly  added.  Although  too  violent  com- 
bustion of  the  iron  is  to  be  avoided,  it  seems  to  be 
important,  for  the  success  of  the  method,  that  a  readlion 
of  decided  intensity  should  occur  during  the  fusion. 

Sodium  nitrate  possesses  an  advantage  over  sodium 
peroxide  in  its  greater  purity,  the  former  compound  being 
readily  obtainable  with  pradtically  insignificant  traces  of 
sulphur. 

Natural  gas  was  the  fuel  used  for  the  Bunsen  burner  id 
heating  the  charges.  This  gas  was  found,  by  repeated 
experiments,  not  to  contain  a  sufficient  quantity  of  bulphu* 


lg6 


Application  of  todtc  Actd  to  the  Analysis  of  Iodides. 


Chemical  NbWb, 
1     April  23, 1897. 


to  afFedt  the  purity  of  the  sodium  carbonate  when  heated 
in  a  platinum  crucible  in  the  same  manner  as  in  the  case 
of  the  determinations  described. 

The  usual  occurrence  of  sulphur  compounds  in  coal- 
gas  would  preclude  its  use  in  the  application  of  the 
method. 

From  the  experiments,  the  results  of  which  are  stated 
in  the  accompanying  table,  there  seems  to  be  some  reason 
to  suppose  that  not  quite  all  the  sulphur  of  the  iron  is 
converted  into  barium  sulphate  when  the  metal  is  oxidised 
and  dissolved  by  nitric  acid.  That  it  has  been  completely 
recovered  by  the  process  of  fusion  cannot  be  positively 
asserted.* 

The  method  I  have  described  is  not  proposed  as  a 
substitute  for  any  existing  method.  The  purpose  of  the 
present  work  was  merely  to  ascertain  as  far  as  possible 
whether,  by  a  process  of  diredt  oxidation  of  the  iron  in  a 
dry  state,  a  larger  proportion  of  the  sulphur  could  be 
recovered  in  weighable  form  than  by  the  usual  method  of 
oxidation  and  solution  in  nitric  acid. 

My  thanks  are  especially  due  to  Mr.  F.  B.  Smith  for 
great  care  and  attention  to  detail  in  condui5ting  the  experi- 
ments 1  have  detailed.— yowrna/  of  the  American  Chemical 
Society,  xviii.,  1079. 


THE  APPLICATION    OF   IODIC   ACID    TO    THE 

ANALYSIS    OF     lODIDES.f 

By  F.  A.  GOOCH  and  C.  F.  WALKER. 

It  has  long  been  understood  that  iodic  acid  is  easily  and 
completely  reduced  by  an  excess  of  hydriodic  acid  with 
the  liberation  of  iodine  according  to  the  equation — 
HI03-|-5HI  =  6I+3H20. 

To  apply  this  readtion  to  the  quantitative  estimation  of 
iodic  acid,  it  is  only  necessary  to  add  to  the  free  iodic 
acid  or  soluble  iodate  an  excess  of  a  soluble  iodide,  to 
acidify — best  with  dilute  sulphuric  acid, — and  to  titrate 
the  iodine  thus  set  free  with  sodium  thiosulphate,  one- 
sixth  of  the  iodine  found  being  credited  to  the  iodic  acid. 

It  has  been  shown  recently  by  Riegler  {Zeit.  Anal. 
Chemie,  xxxv.,  305)  that  this  reaiStion  may  be  also  applied 
to  the  quantitative  estimation  of  iodides,  the  iodine  set 
free  upon  the  addition  of  a  known  excess  of  iodic  acid  to 
the  iodide  solution  being  removed  by  petroleum  ether, 
and  the  residual  iodic  acid  titrated  diredly  with  sodium 
thiosulphate. 

The  present  investigation  was  undertaken  to  define 
more  particularly  the  limit  of  applicability  of  the  readtion 
and  to  establish,  if  possible,  a  direft  method  for  the  quan- 
titative estimation  of  iodides,  dependent  upon  the  adlion 
of  iodic  acid  or  an  iodate  in  the  presence  of  free  sulphuric 
acid,  neutralisation  of  the  solution  by  means  of  an  acid 
carbonate,  and  titration  of  the  free  iodine  by  arsenious 
acid — five-sixths  of  the  iodine  thus  found  being  credited 
to  the  iodide  to  be  estimated.  It  has  been  found  that  by 
fulfilling  certain  necessary  conditions,  the  proposed 
method  is  entirely  successful,  so  far  as  concerns  the  esti- 
mation  of  iodine  in  iodide  solutions  free  from  large 
amounts  of  chlorides  as  bromides. 

In  a  system  containing  a  considerable  quantity  of  free 
iodine  with  variable  amounts  of  the  other  reagents  men- 
tioned, as  well  as  possible  impurities,  it  is  conceivable 
that  secondary  readions  may  occur,  depending  largely  on 
conditions  of  mass,  time,  and  temperature,  and  of  a  sort 
likely  to  alter  the  amount  of  recoverable  iodine,  or  to 

»  The  method  of  preparation  of  a  sample  for  analysis  in  the  case 
of  the  more  brittle  forms  of  iron,  by  crushing  in  a  steel  mortar  and 
sifting,  is  suggested  in  Regnault's  "  Elements  of  Chemistry," 
translated  from  the  French  by  Betton,  1867,  ii.,  112. 

+  Contributions  from  the  Kent  Chemical  Laboratory  of  Yale 
University.  From  the  American  Journal  of  Science,  Fourth  Series, 
vol.  iii.,  No.  16. 


exert  an  excessive  oxidising  influence  on  the  arsenious 
acid  finally  titrated.  It  has  been  established  by  Schdn- 
bein,  Lunge  and  Schoch,  and  others,  that  iodme  forms 
compounds  with  the  alkalis  of  the  type  R — O — I,  and 
Phelps  (Am.  Journ.  Sci.,  ii.,  70,  1896)  has  recently  found 
that  the  formation  of  some  such  compound,  accompanying 
:  the  iodate  naturally  expedted,  is  distindlly  recognisable 
when  iodine  and  barium  hydroxide  interadl  at  ordinary 
temperatures.  It  has  been  shown,  also,  in  a  former  paper 
from  this  laboratory  (Roberts,  Am,  jfourn.  Sci.,  xlviii., 
157)  that  free  iodine  or  an  iodide  interads  very  easily  with 
iodic  acid  in  the  presence  of  dilute  hydrochloric  acid  with 
the  formation  of  iodine  monochluride,  according  to  the 
equations — 

HI03-H2l2-|-5HCl=3H20  +  5lCl. 

HI03-f2KI  +  5HCl  =  3H20-l-2KCl-t-3lCI. 
Moreover,  organic  compounds  containing  the  groups 
—  1  =  0    and     —  IZq)    i"    which    iodine    seems    to    be 

analogous  to  nitrogen,  result  in  great  variety  from  the 
oxidation  of  halogen  substitution  produdts.  It  would 
seem,  therefore,  that  the  formation  of  inorganic  redudtion 
produdts  of  iodic  acid  under  the  conditions  likely  to  ob- 
tain in  this  analytical  process  might  be  by  no  means 
beyond  the  bounds  of  possibility. 

A  few  simple  qualitative  tests  to  determine  the  possi- 
bility of  interadtion  between  small  quantities  of  iodine  and 
iodic  acid  alone  met  with  negative  results.  Thus,  a  single 
drop  of  a  decinormal  solution  of  iodine,  made  as  usual  in 
potassium  iodide,  gave  when  added  to  10  c.m.^  of  deci- 
normal iodic  acid  a  distindtive  colour  to  chloroform.  Similar 
results  were  obtained  when  the  iodine  was  employed  in 
aqueous  solution  in  which  there  was  no  alkaline  iodide. 
A  few  drops  of  an  aqueous  solution  of  iodine  treated  (in 
either  order)  with  10  c.m.ii  of  a  saturated  solution  of 
potassium  bicarbonate  and  10  c.m.^  of  decinormal  iodic 
acid  gave  the  same  distindtive  colour  to  chloroform  as 
came  from  the  same  amount  of  iodine  in  the  absence  of 
the  iodic  acid.  So  it  appears  that  if  in  the  system  under 
consideration,  readtions  do  occur  between  iodic  acid  and 
iodine  to  alter  the  amount  of  iodine  recoverable,  such 
adtion  is  not  appreciable  between  small  amounts  of  these 
materials.  This,  however,  does  not  preclude  the  possi- 
bility of  perceptible  changes  under  the  mass  adtion  of  a 
large  amount  of  iodine. 

The  readtions  of  hydrochloric  acid,  and  probably  of 
hydrobromic  acid,  in  the  presence  of  varying  amounts  of 
iodic  acid,  iodine,  and  iodide,  as  well  as  the  readtion  of 
the  alkaline  carbonate  upon  such  mixtures,  are  doubtless 
complex,  more  or  less  reversible,  and  dependent  upon 
proportion  and  dilution.  The  tendency  of  the  former  re- 
adtions is  toward  the  redudtion  of  the  molecule  of  iodic 
acid,  and  the  formation  of  the  chloride  or  bromide  of 
iodine.  Thus,  Miss  Roberts  (loc.  cit.)  demonstrated  that 
a  solution  of  hydrochloric  acid,  so  dilute  that  by  itself 
it  is  without  eifedt  on  iodic  acid,  adts  upon  a  mixture  of 
iodic  acid  with  either  free  iodine  or  an  iodide  to  form 
iodine  monochloride.  The  adtion  of  the  acid  carbonate 
upon  the  iodine  chloride  or  bromide  may  produce  a  salt 
of  the  oxy-acids  and  free  iodine. 

The  pradlical  effedts,  under  the  conditions  of  analysis, 
of  the  readtion  between  iodine,  iodic  acid,  and  the 
halogen  acids  in  presence  of  sulphuric  acid,  and  of  reac- 
tions which  may  occur  upon  neutralisation  by  an  acid 
carbonate,  were  studied  in  detail  in  a  number  of  experi- 
ments. 

The  preliminary  experiments  of  Table  I.  were  made  to 
bring  out  the  effedt  of  neutralising  with  the  acid  carbonate 
and  subsequently  titrating  with  an  alkaline  arsenite  a 
solution  containing  sulphuric  acid  and  a  considerable 
amount  of  free  iodine.  The  danger  of  mechanical  loss  of 
iodine  during  the  effervescence  accompanying  neutralisa- 
tion, as  well  as  by  spontaneous  volatilisation  from  the 
surface  during  the  process  of  titration,  was  minimised  by 
eiTedling  the  neutralisation  in  the  trapped  Drexel  washing 


CMsmcAt  Nbwb,  ) 
April  23, 1897.     1 

Application  of  h 

')dic  Acic 

Table  I. 

Effect  of  the  Carbonate. 

[5  cm.' 

H2S04(i 

3).    Total  volume  of  liquid 

25oc.m.».] 

I( 

in  KI)  taken. 

KHCOgin  excess. 

I  found. 

Error. 

Grm. 

C.m.a. 

Grm. 

Grm. 

I. 

0-0713 

Very  small 

0-0707 

0-0006  — 

2. 

0*0715 

Very  small 

0-0710 

0-0005  - 

3. 

0-0713 

10 

0-0710 

0*0003  — 

4- 

0*0710 

10 

0-0706 

0-0004  — 

5- 

0-0723 

10 

0-0717 

0'OOo6  - 

6. 

0-0713 

20 

0-0709 

0-0004  — 

7- 

0-0713 

20 

0-0709 

0-0004  - 

8. 

0-3565 

Very  small 

03560 

0-0005  ~ 

9' 

0-3568 

Very  small 

0-3561 

0-0007  — 

10. 

0-3567 

10 

03563 

0-0004  — 

II. 

0-3596 

lO 

0-3588 

0*0008  - 

12. 

0-3565 

ID 

0-3565 

O'OOOO 

13. 

0-3572 

20 

0-3560 

0-00I2  — 

14. 

03567 

20 

0-3569 

0-0002  + 

bottle,  to  be  described  later,  and  making  the  titration  in 
the  same  tall  washing  cylinder  without  transfer.  To 
varying  amounts  of  a  recently  standardised  decinormal 
solution  of  iodine  were  added  successively  5  cm.'  of 
dilute  sulphuric  acid  and  varying  amounts  of  potassium 
bicarbonate  in  excess  of  that  necessary  to  neutralise  the 
free  acid,  decinormal  arsenious  acid  in  slight  excess  of  the 


iodine,  5  cm.*  of  starch  emulsion,  and  decinormal  iodine 
to  colouration,  the  total  volume  of  the  liquid  being  not 
greater  than  250  cm.*.  The  results  show  plainly  that 
while  the  loss,  mechanical  or  otherwise,  in  the  treatment 
of  reasonably  large  amounts  of  fairly  concentrated  iodine 
is  perceptible,  it  is  still  well  within  permissible  limits 
(amounting  to  a  little  less  than  0-0005  grm.  in  the  mean), 
and  obviously  independent  of  the  excess  of  the  carbonate 
in  the  solution,  and  of  the  amount  of  free  iodine  present. 
In  the  experiments  of  Table  II.  the  proposed  process  of 
analysis  was  tested  upon  potassium  iodide  taken  by  itself 
in  varying  amounts  of  a  ^^g  normal  solution  and  carefully 
standardised  by  the  method  formerly  elaborated  in  this 
laboratory  (Gooch  and  Browning,  Am.  yotirn.Sci.,x\xix., 
188).  The  apparatus  employed  was  a  Drexel  washing 
bottle  of  500  cm.*  or  1000  cm.*  capacity,  according  to 
requirements,  with  stopcock  and  thistle-tube  fused  to  the 
inlet-tube  and  a  Will  and  Varrentrapp  absorption-trap 
sealed  to   the  outlet,  as  shown   in    the   accompanying 


to  the  Analysts  of  Iodide.  197 

figure.  The  iodide  for  the  test  was  drawn  from  a  burette 
into  the  bottle  and  carefully  washed  down,  and  potassium 
iodate  in  excess  of  the  amount  theoretically  necessary 
(namely,  5  c.m.»  of  a  0-5  per  cent  solution  for  every  por- 
tion  of  20  c.m.»  of  the  iodide  solution),  was  added,  and 
the  volume  of  the  liquid  was  adjusted  to  the  volume  at 
which  it  was  desired  that  the  iodic  and  hydriodic  acids 
should  readt.  The  stopper  with  the  thistle-tube  and  trap 
was  now  placed  on  the  bottle  and  the  trap  was  half-filled 
by  means  of  a  pipette  with  a  5  per  cent  solution  of  potas- 
sium iodide.  Five  cm.  of  dilute  (i  13)  sulphuric  acid 
were  added  through  the  thistle  tube  and  washed  down; 
the  stopcock  was  closed,  and  the  solution  gently  agitated, 
if  necessary,  to  insure  a  complete  separation  of  iodine. 
Potassium  bicarbonate  in  saturated  solution  to  an  amount 
about  ID  cm.  in  excess  of  that  required  to  neutralise 
5  c.m.»  of  dilute  (1:3)  sulphuric  acid,  was  poured  into 
the  thistle-tube,  and  allowed  to  flow  into  the  bottle  slowly 
enough  to  avoid  a  too  violent  evolution  of  gas.  The 
stopcock  was  closed,  and  the  solution  agitated  by  giving 
to  the  bottle  a  rotary  motion,  at  the  same  time  keeping 
the  bottom  pressed  down  upon  the  work  table,  to  prevent 
a  possible  splashing  of  the  iodide  out  of  the  trap  into  the 
yet  acid  solution.  When  the  neutralisation  of  the  solution 
had  been  completed,  the  bottle  was  shaken  until  the  last 
trace  of  violet  vapour  was  absorbed  in  the  liquid.  The 
greater  part  of  the  solution  in  the  trap  was  then  run  back 
into  the  bottle,  the  stopper  removed,  and  the  tube  and 
trap  carefully  washed  ;  the  washings  being  added  to  the 
bulk  of  the  solution.  Decinormal  arsenious  acid  was 
introduced  from  a  burette  to  the  bleaching  point,  5  cm.' 
of  starch  emulsion  were  added,  and  the  solution  was 
titrated  back  with  decinormal  iodine  (usually  only  a  few 
drops)  to  colouration. 

Table  II. 


Effect  of  Dilution. 

Approximate 

Volume 

KI  taken. 

KI  found. 

Error,     volume  upon 
addition  of  H,SO 

H^SO,  (I 
4.    used. 

Grm. 

Grm. 

Grm.            Cm. 3. 

Cm. 3. 

I. 

0-0772 

0-0768 

0-0004—           150 

5 

2. 

0-0772 

0-0765 

0-0007—           150 

5 

3- 

0*1544 

0-1546 

00002 -J-          150 

5 

4- 

0-1544 

0*1541 

0*0003  -           150 

5 

5- 

0-3087 

0*3090 

0*0003+           150 

5 

6. 

0-3087 

0*3088 

0-0001+           150 

5 

7- 

03859 

0*3864 

00005+           150 

5 

8. 

0-3859 

0*3860 

0*0001 -i-          150 

5 

9- 

0*0772 

0-0754 

0-0018-          300 

5 

10. 

0-0772 

0-0757 

0*0015—          300 

5 

II. 

0-1543 

01532 

o'ooil-          300 

5 

12. 

0-1544 

0-1524 

0-0020—          300 

5 

13 

0*0772 

0-0744 

0-0028—          500 

5 

14. 

0-0772 

0-0737 

0-0035  —          500 

5 

15. 

0-1544 

0-1521 

0-0023  —          500 

5 

16. 

0-I544 

O-1512 

0*0032—          500 

5 

17- 

03859 

0-3827 

0-0032-          500 

5 

18. 

0-3859 

0-3831 

0*0028-          500 

5 

19. 

0-0772 

0-0744 

00028-          500 

10 

20. 

0-0772 

0-0757 

0-0015—          500 

10 

21. 

0*3859 

0-3828 

0-0031-          500 

10 

22. 

0*3859 

0-3827 

0-0032—          500 

10 

Blank  tests  made  upon  a  solution  obtained  by  mixing 
the  maximum  amount  of  the  iodate  with  5  cm.»  of  dilute 
sulphuric  acid  (i :  3),  neutralising  as  usual  with  potassium 
bicarbonate,  adding  the  iodide  from  the  trap  and  5  cm.* 
of  starch  emulsion,  showed  that  a  single  drop  of  iodine 
was  invariably  sufficient  to  bring  out  the  starch  blue. 
Occasionally  it  was  found  that  the  mixture,  particularly 
when  chlorides  or  bromides  were  present,  of  itself 
developed  a  trace  of  colour,  but  by  no  means  a  reading 
tint.     A  corre<5tion  of  the  one  drop  of  iodine  necessary  to 


igS 


Sodium  Peroxide  as  a  Third  Group  Reagent. 


bring  out  the  colour  readlion  in  the  blanks  was  applied 
uniformly  in  the  analytical  process. 

The  number  of  centimetres  of  decinormal  arsenious 
acid  required  to  bleach  the  free  iodine,  multiplied  by 
0-01383  (log.  2T40822)  gives  the  number  of  grms.  of 
potassium  iodide  taken  for  analysis,  being  equivalent  to 
five-sixths  of  the  iodine  liberated  in  the  solution. 

From  these  results  it  appears  that  the  degree  of  dilu- 
tion of  the  solution  at  the  time  when  the  mixed  iodide 
and  iodate  are  acidified  has  an  important  influence  on 
the  completeness  of  the  readtion.  Thus,  the  mean  error 
of  the  determinations  in  which  the  volume  at  the  time  of 
the  leadion  did  not  exceed  150  c.m.»  was  pradically 
nothing,  while  the  errors  at  volumes  of  300  c.m.^  and 
500  cm. 3  amounted  to  o'ooi6  grm.  and  o'ooaS  grm. 
respedively.  It  is  obvious  that  the  doubling  of  the 
amount  of  sulphuric  acid  used  in  acidifying  does  not  in- 
crease the  amount  of  iodine  liberated  at  the  highest  dilu- 
tion. The  plain  inference  is  that  the  interadtion  between 
the  iodide  and  iodate  should  be  brought  about  in  a  volume 
of  liquid  not  much  exceeding  150  cm.  3. 

In  the  following  series  of  experiments,  recorded  in 
Table  III.,  the  efifeft  of  the  introduction  of  a  chloride  or 
bromide  into  the  iodide  (before  the  iodate  is  added)  was 
studied.  The  volume  of  the  liquid  at  the  time  of  acidifying 
was  fixed  at  150  cm. 3,  approximately,  and  5  c.m.^  of  the 
dilute  sulphuric  acid  (1:3)  were  used.  Tiie  mode  of  pro- 
cedure was  otherwise  similar  to  that  of  tlie  foregoing 
series. 

Table  III. 
Effect  of  Chloride  and  Bromidt: 


CrbhicalNbws, 

April  23,  i8g7. 


KI  taken. 
Grm. 

0-0772 
0*0772 
0-0771 
00773 

0-1544 
0-1544 
00772 
0-0773 
00772 
0*0772 
0-1544 
0-1543 


KI  found. 
Grm. 

0-0795 
0-0784 
0-0823 
UO819 
0-1588 
0*1590 
0*0802 
0*0853 
0*0873 
0*0861 
0*1646 
0*1626 


Error. 
Grm. 

0.0023 -|- 
o•OOI2+ 
0*0052 -f 
0-0046  + 
00044  + 
0*0046  + 
0*0030  + 
0*0080  + 
0*0101  + 
0*0089  + 
0*0102  + 
0*0083  + 


NaCl  taken.  KBr  taken. 

Grm.  Grin. 

02  — 

0-2  — 

0*5  — 

05  — 

05 

05  — 

—  02 

—  0*2 

—  0-5 

0-5 

—  0-5 

—  o'5 


The  influence  of  sodium  chloride  and  potassium 
bromide  in  increasing  the  amount  of  iodine  liberated 
is  plain.  The  increase  comes  without  doubt  from  the 
iodate,  and  is  doubtless  due  to  the  formation  of  iodine 
chloride  or  bromide,  during  the  acidifying,  by  the  inter- 
adion  of  the  free  iodine,  the  iodic  acid,  and  the  hydro- 
chloric or  hydrobromic  acid,  according  to  the  reactions 
previously  discussed.  It  is  plain,  therefore,  that  the 
value  of  the  process  in  the  determination  of  iotline  in  an 
iodide  is  restrided  of  necessity  to  those  cases  in  which  it 
is  known  that  chlorides  or  bromides  are  not  present  to 
any  considerable  extent.  For  determining  the  standard 
of  a  solution  of  nearly  pure  potassium  iodide,'empIoyed  in 
so  many  laboratory  processes,  it  should  find  useful 
application. 

In  Table  IV.  are  comprised  a  number  of  experiments 
made  exadly  like  those  which  seemed  to  give  the  best 
results  in  the  series  of  Table  II.  The  iodide  and  an  ex- 
cess of  iodate  (5  c.m.^*  of  the  0-5  per  cent  solution  to 
every  20  c.in.^  of  N/40  iodide)  were  made  to  interad  in  a 
volume  of  about  150  cm.",  5  cm.^  of  sulphuric  acid 
(i :  3)  were  used  to  bring  about  the  readion,  10  c.ni.^  of 
potassium  bicarbonate  were  added  after  the  neutralisation 
of  the  sulphuric  acid  was  complete,  and  the  fiee  iodine 
was  estimated  by  titrating  decinormal  arsenious  acid,  the 
manipulation  being  like  that  previously  described  in 
detail. 

The  average  result  of  a  series  of  several  determinations 
in  which  a  great  excess  (0*1  grm.)  of  potassium  iodate 
was  used,  proved  to  be  pradicaliy  identical  with  that  of  a 


I. 
2. 
3- 
4- 
5- 
6. 

7- 
8. 

9- 
10. 
II. 
12. 

13- 
14. 

15- 
.16. 

17. 
18. 
19. 
20. 
21. 
22. 

23- 
24. 

25- 


Analysis  0/ 

KI  taken. 
Grm. 

0*0814 
0*0814 
00814 
0*0815 
0*0814 
0*0814 
0*0814 
0*1628 
0*1628 
0*1628 
0*1628 
0*1628 
0*1628 
0*1628 
0*2442 
0*2442 
0-2442 
0-3256 
03256 
0*3256 
0*3256 
0*3256 
0*4071 
0-4071 
0*4071 


Table  IV. 

Pure  Potassium  Iodide. 


KI  found. 
Grm. 

00816 
0*0813 
0*0805 
00809 
0-0808 
o*o8o6 
0-0812 
0*1624 
0-1617 
0-1621 
0-1619 
0-1624 
01621 
01626 
0*2451 
0*2442 
0*2439 
0*3258 
0*3256 
03258 
0*3272 
0*3256 
0*4076 
0-4080 
0*4073 


Error. 
Grm. 

O*0002  + 

0*0001  — 
o*ooog- 
o*ooo6  — 
0*0006  — 
o-ooo8  — 

00002  — 
0*0004  — 

O*O0II  — 

0-0007  — 
o'ooog  — 
0*0004  — 
0*0007  — 
0*0002  — 
0*0009  + 
00000 

00003  — 

0*0002  + 

o-oooo 
0*0002  + 
0*0016  + 
0*0000 
0*0005  + 
0*0009+ 
0*0002+ 


similar  series  in  which  only  a  small  excess  of  the  iodate 
was  employed,  so  that  it  appears  to  be  unnecessary  in 
any  pradical  work  to  restridt  the  amount  of  iodate  below 
the  amount  necessary  to  decompose  the  maximum  quan- 
tity of  potassium  iodide  which  we  have  handled,  namely, 
0-4  grm. 

It  appears  that  for  the  estimation  of  iodine  in  a  soluble 
iodide  free  from  notable  amounts  of  chlorides  or  bromides, 
this  method,  depending  as  it  does  upon  a  single  standard 
solution,  is  simple,  fairly  accurate,  and  rapid. 


SODIUM    PEROXIDE    AS    A   THIRD    GROUP 

REAGENT. 
By    S.    W.    PARR. 

Sodium  peroxide  as  a  reagent  has  properties  of  a  very 
unusual  and  striking  charadter.  These  properties  are  no 
less  valuable  than  peculiar,  and  indicate  for  this  substance 
a  prominent  place  in  analytical  work.  The  immediate 
objedl  of  this  paper  is  to  note  the  advantages  and  adapt- 
ability of  sodium  peroxide  to  qualitative  analysis.  By 
this  means  its  numerous  charadleristics  can  be  best  illus- 
trated. The  specific  data  indicating  its  use  in  certain 
lines  of  quantitative  analytical  work  will  be  given  later. 
The  methods  herein  set  forth  have  been  employed  in  this 
laboratory  during  the  past  year  by  large  classes  in  quali- 
tative analysis.  This  pradical  test  of  the  processes  in- 
volved has  abundantly  demonstrated  their  value. 

In  the  ordinary  procedure  for  the  separation  of  the 
metals  the  greatest  difficulty  arises  in  the  third  or  iron 
group.  These  complications  may  be  briefly  enumerated 
as  follows : — 

(a).  The  separation  of  zinc  in  the  presence  of 
chromium. 

(b).  The  unsatisfadtory  separation  of  cobalt  and  nickel 
from  the  other  members  of  the  group  by  the  adlion  of 
dilute  hydrochloric  acid  on  their  sulphides. 

(c).  The  variations  arising  from  the  presence  of  phos- 
phates, &c. 

It  is  not  necessary  to  enlarge  upon  these  difficulties. 
The  one  most  commonly  ignored  in  methods  is  usually 


Chkmical  .News, 
April  23.  »8y7. 


Sodium  Feroxide  as  a  Third  Group  Reagent. 


199 


outlined,  and  yet  a  very  serious  obstacle  is  the  one 
designated  under  (a).  Zinc  and  chromium  enter  into  a 
combination  which,  to  a  very  large  extent,  resists  the 
adtion  of  ammonia  and  ammonium  salts.  The  use  of 
barium  carbonate  to  obviate  this  difficulty  is  cumbersome. 
By  use  of  sodium  peroxide  we  may  oxidise  the  chromic 
compounds  present  to  sodium  chromate,  and  thus  com- 
pletely eliminate  it  as  a  fadtor  in  any  precipitation 
likely  to  be  employed,  excepting  of  course  such  as  would 
involve  a  redudlion  and  return  to  the  condition  of  a 
chromic  salt. 

The  method  of  procedure  is  as  follows  : — The  solution 
should  be  slightly  acid.  A  small  porcelain  spoonful  of 
the  peroxide  is  slowly  sifted  in  with  constant  stirring. 
The  solution  is  then  heated  to  complete  the  decomposi- 
tion of  the  peroxide,  and  finally  boiled  for  some  minutes 
after  the  oxygen  seems  to  be  all  driven  off.  The  com- 
pleteness of  the  oxidation  may  be  easily  tested  by  filtering 
from  any  insoluble  constituents,  acidifying,  boiling,  and 
making  ammoniacal.  A  precipitate  may  be  aluminum  or 
unoxidised  chromium.  Filter  and  wash  free  from  all  so- 
dium chromate,  re-dissolve  in  a  little  nitric  acid,  and  treat 
as  before  with  a  small  amount  of  sodium  peroxide.  A 
yellow  colouration  is  due  to  the  chromium  which  escaped 
oxidation  by  the  first  treatment.  However,  if  properly 
conduded,  the  first  operation  should  be  complete.  Simi- 
larly, the  insoluble  residue  on  the  filter,  if  suspeded  of 
being  a  zinc-chromium  compound,  may  be  washed  free, 
from  chromate,  dissolved  in  dilute  nitric  acid,  and  treated 
again  with  the  peroxide.  The  only  condition  so  far 
governing  the  completeness  of  the  transformation  to  the 
chromate  form  is  the  necessity  of  starting  the  oxidation  with 
the  chromium  entirely  in  solution.  Precipitated  chromium 
hydroxide  will  undergo  this  transformation,  but  less 
readily,  and  especially  if  the  precipitate  is  the  double  one 
of  zinc  and  chromium.  Hence  the  advisability  of  begin- 
ning the  oxidation  with  the  solution  containing  some  free 
acid,  preferably  nitric.  The  quantity  of  free  acid  is  im- 
material, less  than  i  c.c.  being  sufficient.  It  should  be 
noted,  however,  that  the  amount  of  sodium  peroxide 
should  cause  the  solution  to  pass  quite  beyond  the  neutral 
condition,  since  the  oxidation  is  only  partial  while  in  the 
acid  state.  It  might  be  expedted  that  the  moment  the 
addition  of  sodium  peroxide  passed  the  neutral  point  the 
precipitation  of  chromium  would  commence,  and  the 
completeness  of  the  oxidation  be  lessened  inconsequence, 
but  I  have  not  found  this  to  be  the  case.  The  oxidising 
adtion  of  the  peroxide  is  so  pronounced  that  it  precedes 
the  precipitating  aftion,  hence  the  reason  for  using  the 
dry  sodium  peroxide.  A  cold  saturated  solution  of  the 
peroxide  will  operate  but  incompletely.  Hydrogen  per- 
oxide will  also  adl  similarly,  but  even  less  completely  than 
the  solution  of  sodium  peroxide.  For  obvious  reasons 
also  the  operation  is  performed  on  the  solution  before 
heating,  and  it  is  better  to  shake  the  powder  in  gradually 
than  to  drop  the  reagent  in  at  once. 

We  are  ready  now  to  note  the  effedl  of  such  treatment 
as  above  indicated,  upon  the  other  members  of  this  group, 
assuming  that  any  or  all  may  be  present,  including  cobalt 
and  nickel.     The  results  are  as  follows  : — 

(a).  Aluminum  compounds  are  in  solution  in  the  form 
of  sodium  aluminate,  not  different  from  the  ordinary  result 
from  using  sodium  hydroxide  in  excess.  It  is  assumed, 
of  course,  that  the  sodium  peroxide  has  exceeded  the  free 
acid  in  sufficient  amount  to  provide  sodium  hydroxide  in 
excess. 

[b).  Zinc  is  similarly  in  solution  as  zincate. 

\c).  Iron  precipitates  as  a  very  dense,  reddish  brown 
precipitate,  the  exadt  composition  of  which  is  being  made 
a  matter  of  investigation.  The  precipitation  is  complete, 
no  re-solution  being  effedted  upon  boiling.  The  filtration 
is  performed  with  great  facility.  The  precipitate  is  almost 
insoluble  in  concentrated  nitric  acid;  soluble  in  dilute 
acids  on  heating.  If  phosphates  are  present  none  are 
precipitated  with  the  iron,  but  all  pass  through  and  are  . 
found  in  the  filtrate. 


(d).  Manganese  behaves  exaiftly  as  iron,  precipitating 
presumably  as  the  hynrated  dioxide,  MnOaArHzO,  having 
all  the  properties  of  that  compound  as  to  colour,  solu- 
bilities, &c.  Similarly  also  phosphates  are  not  precipi- 
tated.  It  should  also  be  noted  that  from  this  precipitate 
can  most  readily  be  obtained  the  delicate  test  for  the 
presence  of  manganese  by  formation  of  permanganic  acid 
by  means  of  nitric  acid  and  lead  peroxide  or  Pb304. 

{e).  Cobalt  precipitates  also  a  black  hydrated  cobaltic 
oxide  with  solubilities  the  same  as  in  the  case  of  iron  and 
manganese.  No  phosphate  is  precipitated  with  the 
cobalt.  The  precipitate,  in  conjundlion  with  dilute  acid 
and  potassium  iodide,  liljerates  free  iodine,  imparting  an 
intense  blue  to  starch  solution.  This  latter  property, 
however,  is  common  to  the  precipitates  of  iron  and  man- 
ganese under  [c)  and  {d). 

if).  Nickel  precipitates,  as  the  ordinary  green  nickelous 
hydroxide,  Ni(0H)2,  easily  soluble  in  acid,  either  concen- 
trated or  dilute.  As  to  phosphates,  in  the  case  of  nickel, 
if  present  in  large  amounts,  small  quantities  are  found  in 
the  precipitated  nickel.  A  re-solution  and  re-precipitation 
with  sodium  peroxide,  however,  eliminates  all  the  phos- 
phate from  the  precipitate.  The  behaviour  of  nickel  in 
thus  precipitating  as  the  nickelous  compound  indicates 
for  its  higher  form  of  oxidation  a  less  degree  of  stability 
than  exists  in  the  case  of  cobalt.  This  property  suggests 
the  readiest  and  most  delicate  method  for  the  detedlion 
of  nickel,  even  in  the  presence  of  the  three  precipitates 
enumerated  above,  thus: — Boiling  this  precipitate  of 
nickel  with  bromine  water  converts  it  at  once  into  the 
black  nickelic  hydroxide,  which  has  the  property  of  de- 
composing potassium  iodide  with  water  alone,  no  acid 
being  required,  as  in  the  case  of  iron,  manganese,  and 
cobalt.  It  is  necessary,  of  course,  to  boil  off  the  free 
bromine,  which  is  readily  accomplished.  The  adlion  upon 
a  potassium  iodide  starch  solution  is  very  marked. 

The  above  fadts  suggest  a  method  for  the  iron  group 
which  is  indicated  by  the  accompanying  table.  It  is  given 
here  to  illustrate  the  adaptability  of  some  of  the  well- 
known  but  more  positive  and  satisfadtory  tests  for  the 
several  metals. 

In  the  presence  of  phosphates  the  method  so  far  em- 
ployed has  been  as  follows:  —  Upon  dissolving  the 
precipitate  from  the  ammonium  sulphide  in  concentrated 
nitric  acid,  a  very  little  of  the  solution  is  tested  for  phos- 
phoric acid  in  the  usual  manner.  If  present,  granulated 
tin  is  added  and  the  boiling  continued.  Filter  from  the 
insoluble  tin  phosphate,  make  ammoniacal,  re-precipitate 
with  ammonium  sulphide,  and  proceed  as  with  phosphoric 
acid  absent.  Any  method  not  involving  the  use  of  tin, 
and  depending  upon  the  non-formation  of  the  phosphates 
of  iron,  manganese,  and  nickel,  is  as  yet  unsatisfadtory. 
Having  removed  the  barium  and  strontium  with  sulphuric 
acid  before  the  precipitation  with  ammonium  sulphide, 
the  oxidation  and  precipitation  by  means  of  sodium  per- 
oxide may  be  performed  as  usual  ;  but  before  filtering, 
the  solution  is  made  acid  with  acetic  acid,  and  boiled  °a 
little  further  and  filtered.  The  filtrate  now  may  contain, 
besides  the  aluminum,  zinc,  and  chromium,  the  nickel 
which  is  readily  soluble  in  acetic  acid,  and  the  calcium 
and  magnesium  which  has  been  brought  along  by  means 
of  the  phosphoric  acid.  A  little  of  the  cobalt,  however, 
dissolves  with  the  acetic  acid,  and  a  solvent  has  not  been 
found  thus  far  for  the  calcium  phosphate  and  nickel 
hydroxide  that  will  not  dissolve  traces  of  the  other  three 
metals  of  the  precipitate. 

One  other  application  to  qualitative  analysis  may  be 
mentioned  as  having  proved  valuable.  In  testing  for 
acids  a  ready  method  for  distinguishing  between  carbon 
dioxide  and  sulphur  dioxide,  when  both  are  present,  is 
found  in  the  use  of  a  solution  of  sodium  peroxide.  Con- 
dudted  into  this  solution,  the  above  gases  form  sodium 
carbonate  and  sodium  sulphate  respedtively.  With  lime- 
water  the  solution  will  give  a  copious  precipitate  if  the 
carbonate  has  been  formed,  and  with  an  acidulated  solu- 
tion  of  barium  chloride  the  sulphate  test  is  obtained. 


200 


Hydrolysis  of  Acid  Amides, 


t  Cheuical  New», 
I     April  23,  1897. 


The  precipitate  obtained  in  the  ordinary  method  by  means 
of  ammonium  hydroxide  and  ammonium  sulphide 
contains,  as  hydroxides  and  sulphides,  iron,  man- 
ganese, cobalt,  nickel,  aluminum,  zinc,  and  chromium, 
and  is  brought  into  solution  by  means  of  10  to  15  c.c. 
of  concentrated  nitric  acid  with  heat.  Nearly  neu- 
tralise with  sodium  hydroxide,  then  siit  in  slowly  with 
stirring  sodium  peroxide  in  excess.     Boil. 

Precipitate    A     contains  Solution   A   contains   al' 

iron,     manganese,     cobalt,  the    aluminum,    zinc,    and 

and  nickel.  chromium.       The     yellow 

(a).  Test  for  iron  by  dis-  colour      is       evidence      of 

solving  a  small  portion  of  chromium.      Acidify     with 

the    precipitate     in    dilute  hydrochloric  acid,  boil,  and 

hydrochloric  acid  and  add-  add  ammonium  hydroxide, 

ing  potassium  thiocyanate.  Precipitate  B  consists  of 

The   blood-red   colouration  aluminum    hydroxide,    and 

is  due  to  ferric  thiocyanate.  any    chromium    hydroxide 

(6).  For  manganese,  to  5  that  may  have  escaped  ox- 

c.c.    of   water    add   5   c.c.  idation.     Dissolve  in  nitric 

concentrated  nitric  acid  and  acid,  and  repeat  the  preci- 

5  to  10  grms.  Pb304.      Stir  pitation   with   sodium  per- 

into   the   warm   mixture   a  oxide,  or  apply  the  blowpipe 

little  of  the  precipitate  and  and  cobalt   test  for  alumi- 

let  stand.   A  purple  solution  num. 

is  permanganic  acid.  Solution  B  contains  zinc 

(c).  In  absence  of  iron  or  and  chromium, 

manganese,  stir  a  little  of  (a).    Test     for     zinc    by 

the   precipitate   into  dilute  adding  to  a  portion  a  few 

hydrochloric  acid,  and  add  drops   of    potassium   ferro- 

solution  of  potassium  iodide  cyanide.      A   heavy   white 

and  starch.     In  presence  of  precipitate  indicates  zinc, 

iron  and  manganese  use  the  (6).  If  further  verification 

bead  test.  of    chromium     is    needed, 

{d).    Boil    some    of    the  make  the  solution  acid  with 

precipitate     with     bromine  hydrochloric  acid,  and  boil 

water  till  all  bromine  is  ex-  with  a  little  alcohol  added, 

pelled,  add  water  and  solu-  The  chromium  reverts  to  the 

tion    of    potassium    iodide  green  chromic  chloride, 
and  starch,  Ni(0H)3-l-KI  = 
Ni(0H)2  +  KOH  +  I,  im- 
parting   the    blue    to    the 
solution. 

Many  other  features  incidental  to  the  properties  above 
outlined  have  developed,  mainly  of  interest  in  quanti- 
tative methods.  It  is  hoped  that  the  data  will  be  of 
sufficient  value  to  warrant  further  notice. — jfournal  of  the 
American  Chemical  Society,  xix.,  p.  347. 


LONDON     WATER    SUPPLY. 
Report  on  the  Composition  and  Quality  of  Daily 
Samples   of  the  Water  Supplied  to   London 
FOR  THE  Month  Ending  March  31ST,  1897. 

By  WILLIAM  CROOKES,  F.R.S., 

and 

PROFESSOR  DEWAR,  F.R.S. 

To  Major-General  A.  De  Courcy  Scott,  R.E., 
Water  Examiner,  Metropolis  Water  Act,  1871. 

London,  April  loth,  1897. 
Sir, — We  submit  herewith,  at  the  request  of  the 
Directors,  the  results  of  our  analyses  of  the  189  samples 
of  water  coUeded  by  us  during  the  past  month,  at  the 
several  places  and  on  the  several  days  indicated,  from  the 
mains  of  the  London  Water  Companies  taking  their 
supply  from  the  Thames  and  Lea. 

In  Table  I.  we  have  recorded  the  analyses  in  detail  of 
samples,  one  taken  daily,  from  March  ist  to  March  31st 
inclusive.  The  purity  of  the  water,  in  resped  to  organic 
matter,  has  been  determined  by  the  Oxygen  and  Com- 
bustion processes;  and  the  results  of  our  analyses  by 
these  methods  are  stated  in  Columns  XIV.  to  XVIII. 


We  have  recorded  in  Table  II.  the  tint  of  the  several 
samples  of  water,  as  determined  by  the  colour-meter 
described  in  a  previous  report. 

In  Table  III.  we  have  recorded  the  oxygen  required  to 
oxidise  the  organic  matter  in  all  the  samples  submitted 
to  analysis. 

Of  the  189  samples  examined  one  was  recorded  as 
"  turbid,"  the  remainder  being  clear,  bright,  and  well 
filtered. 

There  has  been  a  large  excess  of  rain  recorded  at  Oxford 
during  the  month,  the  adtual  fall  being  2-61  inches;  as  the 
average  fall  for  thirty  years  is  only  1-50  inches,  we  have 
had  an  excess  of  I'li  inches. 

Our  baderiological  examination  of  the  London  waters 
gives  the  following  results: — 

Microbes 
,  per  c.c. 

Ihames    water,    unfiltered    (average    of    27 

samples) gigy 

Thames  water,  from  the  clear  water  wells  of 
five  Thames-derived  supplies  (average  of  159 

samples) 33 

Ditto        ditto  highest      372 

Ditto        ditto  lowest  2 

New  River,  unfiltered  (average  of  27  samples)     1160 
New  River,  from  the  Company's  clear  water 

well  (average  of  27  samples)  ." 30 

River  Lea,  unfiltered  (average  of  27  samples)     io8o 
River  Lea,  from  the  East  London  Water  Com- 
pany's clear  water  well  (average  of  27  sam- 
ples)             22 

Last  month  we  drew  attention  to  the  abnormal  badterial 
contents  of  some  samples  taken  from  the  wells  of  the 
Grand  Jundtion  Water  Works  at  Hampton,  conneded  with 
the  supply  of  the  country  district.  The  Engineer  has  now 
informed  us  that  the  Company  in  May  last  authorised 
extensive  additions  and  alterations  to  their  filtering  plant 
af  Hampton  ;  these  are  in  course  of  construdtion.  The 
Board,  however,  having  had  our  recent  communications 
on  the  subjeia  brought  to  their  notice,  have  now  author- 
ised the  Engineer  to  carry  out  more  extensive  alterations 
than  had  been  previously  contemplated.  We  have  had  a 
consultation  with  the  Engineer,  at  which  he  submitted 
the  general  jplans  of  the  proposed  new  filtering  plant, 
which  in  our  opinion  will  meet  the  difficulty. 

Since  the  beginning  of  the  month  the  water  from  the 
Hampton  Works  has  steadily  improved,  and  for  the  last 
ten  days  it  has  been  in  a  satisfadlory  condition. 

At  this  season  of  the  year  there  is  always  a  considerable 
amount  of  fish  spawn  in  the  river,  clogging  up  the  filters, 
and  rendering  very  frequent  cleaning  necessary.  This, 
added  to  the  recent  heavy  rainfall,  has  put  a  severe 
strain  on  the  filtration  plant  of  the  different  Companies. 
The  results,  however,  show  that  they  have  been  well  able 
to  cope  with  the  difficulties. 

We  are,  Sir, 

Your  obedient  Servants, 

William  Crookes. 
James  Dewar. 


THE   HYDROLYSIS  OF  ACID  AMIDES. 
By  IRA  REMSEN. 

A  NUMBER  of  years  ago,  with  the  assistance  of  advanced 
workers  in  this  laboratory,  I  carried  out  a  series  of  invest!- 
gations  on  the  oxidation  of  substitution-produds  of  aro- 
matic hydrocarbons,  the  results  of  which  went  to  show 
that,  when  the  oxidising  agent  is  chromic  acid,  an  oxid- 
isable  residue,  situated  in  the  ortho  position  with  reference 
to  an  atom  or  group  that  is  not  oxidisable,  is  almost  com- 
pletely proteded  from  oxidation,  whilst  similar  groups  in 
the  meta  or  para  position  are  easily  oxidised.  Later,  ex- 
periments were  tried  on  the  redudion  of  nitro  compounds 
of  different  strudlure,  but,  although  results  of  some  value 


SbBMlCAL  NBWft, 
April  23,  1897.     I 


Edinburgh  University  Graduation  Ceremonial. 


201 


were  thus  obtained,  these  have  not  been  published,  as  I 
have  hoped  that  the  method  of  making  the  measurements 
might  be  improved.  Still  later,  my  attention  was  drawn 
to  the  marked  difference  between  benzoic  sulphinide 
(saccharin)  and  parasulphaminebenzoic  acid  (Remsen  and 
Burton,  Am.  Chem,  jfourn.,  xi.,  p.  403)  towards  boiling 
dilute  acids.  The  former  is  easily  converted  into  the  cor- 
responding acid  ammonium  salt,  while  the  latter  remains 
unchanged. 

About  a  year  ago  I  requested  Mr.  E.  £.  Read,  of  this 
laboratory,  to  make  some  experiments  on  the  relative  ease 
with  which  the  three  nitrobenzamides  are  converted  into 
their  ammonium  salts  by  dilute  acids.  Mr.  Read  has  since 
devoted  himself  with  much  skill  and  energy  to  this  work, 
and  the  results  reached  are  most  interesting.  A  method 
has  been  devised  by  which  it  is  possible  to  measure  with 
a  considerable  degree  of  accuracy  the  rate  of  the  hydro- 
lysis. The  experiments  thus  far  completed  have  been 
carried  out  with  hydrochloric  acid  of  three  concentrations 
and  with  sulphuric  acid  of  three  concentrations.  The  de- 
tails of  the  experiments  will  be  communicated  later,  and 
it  will  then  be  seen  that  the  curves  showing  the  rate  of 
change  are  remarkably  regular.  A  striking  difference  is 
shown  in  the  adtion  of  the  three  nitrobenzamides.  The 
following  results  obtained  with  half  normal  hydrochloric 
acid  may  serve  as  an  example: — 

Time  Per  cent  of  Per  cent  of  Per  cent  of 

in  hours.      o-amide  changed,  m-amide  changed.  />-amide  changed. 

i  —  2I-I  24*4 

1  —  42"8  48*2 
li  —  50-1  63-4 

2  —  6S'0  71 -2 

3  3'3  80-5  84-5 

4  3  9  88-9  91-9 

5  —  92*6  94*6 

6  6'2  94*2  96*9 

7  —  _  _ 

8  8-6  _  _ 

The  orthoamide  is  seen  to  resist  the  adion  of  the  hydro- 
lysing  agent  to  a  very  marked  degree,  so  that  it  was  diffi- 
cult to  measure  the  amount  of  the  change  if  the  heating 
was  not  continued  for  at  least  three  hours.  On  the  other 
hand,  the  meta  and  para  amides  yield  readily,  the  para 
somewhat  more  so  than  the  meta. 

It  seems  highly  probable  that  other  aromatic  acid  amides 
that  contain  an  atom  or  group  in  the  ortho  position  to  the 
group  CONH2  will  condudt  themselves  in  a  similar  way. 
These  phenomena  are  suggestive  of  those  studied  in  this 
laboratory  many  years  ago,  to  which  reference  has  already 
been  made.  Apparently  the  single  nitro  group  in  the 
ortho  position  with  reference  to  the  carbamide  group, 
CONH2,  protects  this  from  the  adlion  of  dilute  acids,  as 
the  nitro  group  in  the  ortho  position  to  methyl  protedls 
this  from  oxidation  by  chromic  acid,  as  shown  in  my 
earlier  experiments.  There  is  also  some  analogy  between 
these  protedion  phenomena  and  those  recently  studied  by 
Vidor  Meyer  and  his  students — an  analogy  which  Meyer 
does  not  appear  to  have  recognised. 

The  objed  of  this  note  is  to  inform  chemists  that  we 
are  in  possession  of  a  method  that  makes  measurements 
of  the  kind  given  above  comparatively  easy,  and  that  we 
propose  to  apply  the  method  to  the  study  of  as  large  a 
number  of  cases  as  possible,  with  the  objed  of  deter- 
mining— 

1.  Whether  the  influence  of  ortho  groups  upon  the  hy- 
drolysis of  acid  amides  is  always  the  same  ;  and 

2.  How  various  atoms  and  groups  differ  in  their  effed 
upon  the  rate  of  hydrolysis. 

This  work  will  require  some  time,  and  it  seems  best  to 
postpone  the  publication  of  the  results  until  the  investi- 
gation is  completed. 

(The  substance  of  this  note  was  communicated  by  me 
to  the  National  Academy  of  Sciences,  at  the  New  York 


meeting  held  November  i8,   i8g6).— American  Chemical 
journal,  April,  1897. 


WHO   SHALL   BE   HEN-WIFE. 

"  Na  ye  maun  gan  wi'  me  the  noo,  Wullie  "  (his  name 
was  Charles),  said  Henrietta,  as  she  flung  a  brawny  arm 
round  the  lad's  neck;  ."sure  my  friend  Jemmie's  as 
Scotch  as  they  make  'em." 

"  Na,  na,  lass;  I  maun  gan  wi'  Wilhelmina,  an'  my 
name's  no  Wullie,— hang  it  I— and  ye  need  na  gar  me  a 
crick  in  my— what  do  you  call  it  in  this  lingo  ?— craig. 
Your  fren'  Jemmie's  a  fause  loon  ;  didna  she  deceive  the 
kirk  and  get  the  mickle  rebuke  o'  the  meeneester?" 

"  Then  ye '11  no  mair  keep  company  wi'  me  (hang  this 
jargon!)"  said  Henrietta,  who  was  English,  and  found 
Kailyardish  trying. 

Said  Charles,  "I  care  no  for  ye,  an  I  ne'er  lo'ed  ye  nor 
e'r  any  but  the  Scots  lassie  Wilhelmina. 

"  You're  a  rude  little  boy,"  said  she. 

"  Stay  y're  havers,  and  no  clack  like  siccan,"  said  the 
Chem.  Soc.affiided  by  the  genius  temporum,  and  involun- 
tarily speaking  the  lingo. 

"An'  why  shall  we  no  have  a  bit  clavers  ?  Sair,  I  ken 
I'm  as  winsome  as  Jemmie,"  said  Wilhelmina,  as  she 
tried  to  pull  Wullie  to  her  side. 

"  Bide  a  wee,"  said  a  voice.     It  was  Jemmie's. 

There  was  a  confused  struggle;  Wullie  squealed  and 
kicked,  the  Chem.  Soc.  awoke  with  a  start,  and  found 
Jemmie  installed  as  hen-wife,  and  the  kailyard  resuming 
its  normal  gentlemanly  demeanour. 

Ian  McCrockett. 


EDINBURGH     UNIVERSITY    GRADUATION 
CEREMONIAL. 

Professor  Sir  Ludovic  Grant,  Bart.,  Dean  of  the 
Faculty  of  Law,  introduced  Professor  James  Dewar, 
F.R.S.,  Royal  Institution,  London,  to  receive  the  degree 
of  LL.  D. 

The  University  recalls  with  pride  that  the  distinguished 
physicist  and  experimentalist  who  now  stands  before  us 
received  his  earliest  training  in  science  and  first  impulse 
towards  research  within  her  precinds.  For  Professor 
Dewar  was  a  pupil  of  Professor  Tait's,  and  thereafter 
aded  as  assistant  to  Professor,  now  Lord,  Lyon  Playfair, 
when  he  held  the  Chair  of  Chemistry  in  Edinburgh. 
Since  that  period  Professor  Dewar  has  been  called  to 
many  offices  which  are  the  prerogative  of  the  highest 
scientific  eminence.  He  was  a  member  of  the  Govern- 
ment  Committee  on  Explosives,  and  of  the  Royal  Com- 
mission  on  the  Metropolitan  Wafer  Supply,  and  is  now 
President  of  the  Chemical  Society,  Jacksonian  Professor 
of  Natural  Experimental  Philosophy  in  the  University  of 
Cambridge,  and  Fullerian  Professor  of  Chemistry  in  the 
Royal  Institution.  But  a  bare  recital  of  his  appointments 
conveys  no  adequate  idea  of  Professor  Dewar's  services 
to  science.  Despite  the  duties  of  official  life,  he  has 
devoted  himself  untiringly  to  experimental  research,  and 
his  investigations  have  been  produdive  of  the  most 
remarkable  results,  and  constitute  his  chief  claim  to 
academic  recognition.  In  particular  may  be  mentioned 
the  discoveries  he  has  made  regarding  the  liquefadion  of 
gases,  and  the  properties  of  matter  at  a  very  low  tempera- 
tijre.  In  many  instances  his  experiments  demanded  the 
highest  courage,  no  less  than  perseverance  and  skill,  for 
they  were  fraught  with  extreme  personal  danger.  His 
Alma  Mater  rejoices  to  follow  the  example  already  set  by 
the  Universities  of  St.  Andrews  and  Glasgow,  by  con- 
ferring  upon  her  distinguished  alumnus  the  honorary 
degree  of  Dodor  of  Laws.  (Applause).  —  Scotsman, 
April  12,  1897. 


202 


Chemical  Notices  from  Foreign  Sources. 


ICtlBtllCAL  N«WS, 

I      April  23,  1807. 


NOTICES  OF  BOOKS. 


An  Outline  of  the  Theory  of  Solution  and  its  Results. 
For  Chemists  and  Elediicians,  By  J.  Livingston  R. 
Morgan,  Ph.D.  (Leipzig),  Instrudor  in  Quantitative 
Analysis,  Polytechnic  Institute,  Brooklyn  (New  York). 
New  York  :  John  Wiley  and  Sons.  London  :  Chapman 
and  Hall,  Limited.     1897.     63  pp.,  i2mo. 

This  little  book  should  be  in  the  hands  of  every  student 
of  chemistry  who  cares  to  make  himself  acquainted  with 
recent  developments  in   chemical  philosopny,  and  every  j 
student  who  does  not  care  should  be  required  to  pass  an 
intelligent  examination  on  its  sixty-three  pages. 

The  author  has  compiled  a  very  clear,  condensed,  and 
up-to  date  account  of  the  modern  theory  of  solution  and 
its  influence  on  chemical  philosophy;  he  shows  its 
development  logically  and  historically  as  based  on  eledro- 
lytic  dissociation,  from  the  laws  governing  the  behaviour 
of  gases.  The  results  obtained  by  van't  Hoff,  Arrhenius, 
and  Ostwald  (to  whom  the  book  is  dedicated)  are  ! 
admirably  stated,  and  without  being  overloaded  with  j 
mathematical  expressions.  Students  of  analytical  j 
chemistry  who  have  not  the  time  to  digest  the  .arger 
treatises  of  Ostwald  and  Le  Blanc,  will  find  thi'  little 
work  valuable  in  removing  the  empiric  charader  01  their 
studies  and  processes ;  the  laboratory  worker  will  learn 
why  an  excess  of  a  precipitant  is  efficacious,  and  why 
certain  salts  are  added  to  water  used  in  making  precipi- 
tates, and  why  indicators  in  volumetric  analysis  adt  as 
they  do. 

The  theory  of  solution  is  daily  becoming  more  and 
more  important  for  theoretical  and  pradical  chemistry, 
as  well  as  for  eledlricity,  and  Dr.  Morgan  has  supplied  an 
excellent  introdudion  to  the  larger  treatises. 

One  typographical  error  cannot  be  overlooked  :  Helm- 
holtz  appears  twice  as  "  Helmholst,"  but  the  book  is 
neatly  printed. 

H.  C.  B. 


CHEMICAL 


NOTICES    FROM 
SOURCES. 


FOREIGN 


Note.— All  degrees  of  temperature  are  Centigrade  unlessotherwise 
expressed. 

Comptes  Rendus  Hebdomadaires  des  Seances,  de  V Academic 
des  Sciences.  Vol.  cxxiv.,  No.  14,  April  5,  1897. 
Preparation  of  Iron  Carbide  by  the  DirecJt  Union 
of  the  Metal  and  of  Carbon. — Henri  Moissan. — If  we 
heat  pure  iron  and  the  carbon  of  sugar  to  the  high  temper- 
ature of  the  eledric  furnace,  and  then  allow  the  regulus 
to  cool  slowly,  we  find  in  the  metal  merely  a  small  trace 
of  combined  carbon.  We  thus  obtain  a  grey  casting  which 
solidifies  towards  1150°.  If  the  metal  is  run  into  a  mould 
at  the  temperature  of  1300°  to  1400°  it  contains  on  cooling 
graphite  and  a  larger  quantity  of  combined  carbon  ;  this 
is  white  cast  metal.  Lastly,  if  we  cool  abruptly  in  water 
iron  saturated  with  carbon  at  3000°,  there  is  produced  an 
abundant  crystallisation  in  the  metal,  and  we  may 
separate  from  it  a  pure  definite  crystalline  carbide,  CFe3, 
This  carbide  is  identical  with  that  of  steel.  All  these 
fads  are  explained  simply  on  admitting  that  iron  carbide, 
like  ozone  and  silver  oxide,  may  be  formed  at  a  very  high 
temperature  and  then  be  decomposed  progressively  on  a 
redudion  of  temperature.  We  find  a  notable  quantity  in 
steel,  the  melting-point  of  which  is  high,  rather  less  in 
white  cast  metal,  and  very  little  in  grey  castings.  In  all 
our  experiments  we  have  observed  the  formation  of  the 
carbide  only  in  the  liquid  metal. 


Nomination,  —  The  Academy  proceeded  to  the 
nomination  of  a  member  in  the  Sedion  of  Astronomy, 
vice  M.  Tisserand,  deceased.  M.  Radau  obtained  the 
absolute  majority  of  the  votes,  and  was  accordingly  pro- 
claimed eleded. 

A  letter  was  read  from  H.  Wilde,  F.R.S.,  President  of 
the  Manchester  Literary  and  Philosophical  Society, 
addressed  to  M.  Berthelot,  criticising  as  improper  the 
expression  the  "  Periodic  Law,"  and  offering  to  the 
Academy  the  sum  of  £5500  (  =  137,500  frcs.)  to  be 
invested  in  French  securities  and  the  interest  applied  to 
the  foundation  of  an  annual  prize  of  4000  frcs.  to  be 
awarded  to  the  author  of  any  discovery  or  research  in 
astronomy,  physics,  chemistry,  mineralogy,  geology,  and 
mechanics,  which  in  the  judgment  of  the  Academy  shall 
be  considered  the  most  meritorious.  The  award  of  this 
prize  will  be  international,  and  maybe  retrospedive.  (See 
Chemical  News,  vol.  Ixxv.,  p.  177). 

Partial  Polarisation  of  the  Radiations  emitted  by 
some  Sources  of  Light  under  the  Influence  of  the 
Magnetic  Field. — N.  Egoroff  and  N.  Georgiensky, — 
Some  months  ago  Dr.  Leeman,  of  the  University  of 
Leyden,  made  remarkable  experiments  on  the  influence 
of  a  fairly  strong  magnetic  field  on  the  emission  of  flames 
in  a  Bunsen  Burner  (sodium  and  lithium).  He  demon- 
strated that  the  perturbation  undergone  by  the  ions  under 
the  influence  of  the  magnetic  focus  produce  new  periods 
and  luminous  vibrations  (expansion  of  the  spedral  rays 
of  sodium  and  lithium).  Subsequently  Dr.  Leeman,  led 
by  the  theoretic  views  of  Prof.  Lorentz,  has  demonstrated 
the  peculiar  polarisation  of  these  new  vibrations. 

New  Cadmium  Lamp  for  the  Produ(5\ion  of  Inter- 
ference Fringes. — Maurice  Hamy.— The  resistance  of 
the  lamp  when  in  adion  is  equal  to  that  of  one-fifth  m.m. 
of  air.  A  decided  rise  of  temperature  above  350°  increases 
this  resistance,  so  that  the  discharge  no  longer  takes 
place  in  the  apparatus.  Besides  the  four  radiations — red, 
green,  blue,  indigo— the  spedroscope  has  enabled  me  to 
identify  all  the  known  visible  rays  of  cadmium  in  the 
light  given  out  by  the  lamp  ;  and  besides  a  faint  ray  in 
the  red  (\  632),  the  rays  of  sodium,  a  fine  ray  in  the  green 
(A  515),  invisible  in  the  spedrum  of  the  spark,  striking 
into  the  air  between  the  eledrodes  of  cadmium. 

Researches  on  Nickel  Steels.  Meteorological 
Properties.— Ch.  E.  Guillaume. — A  mechanical  paper. 

Nature  of  various  kinds  of  Radiations  produced 
by  Bodies  under  the  Influence  of  Light. — G.  Le  Bon. 
— This  paper  will  be  inserted  as  early  as  possible. 

New  Oxide  of  Phosphorus.— A.  Besson. — The  com- 
position of  this  phosphorous  oxide  is  shown  by  the  for- 
mula P2O. 

Metastannyl  Chloride.— R.  Engel.— This  paper  will 
be  inserted  in  full. 

Adion  of  High  Temperatures  upon  Copper,  Bis- 
muth, Silver,  Tin,  Nickel,  and  Cobalt  Sulphides. — 
A.  Mourlot. — We  can  completely  desulphurise  the  bismuth 
and  copper  sulphides,  but  the  desulphuration  of  bismuth 
is  by  far  the  more  difficult.  Silver  sulphide  on  exposure 
to  the  highest  temperatures  yields  a  volatile  produd  still 
retaining  traces  of  sulphur.  Cobalt  and  nickel  yield  sul- 
phides relatively  stable,  CoS  and  Ni2S.  Tin  sulphide 
undergoes  a  partial  volatilisation  and  furnishes  a  crystal- 
line regulus  of  protosulphide,  a  new  example  of  a  sulphide 
stable  at  a  high  temperature. 

Combinations  of  Gaseous  Ammonia  and  Methyl- 
amine  with  the  Haloid  Compounds  of  Lithium. — 
J.  Bonnefoir. — A  thermo-chemical  paper. 

Adion  of  Tannin  and  of  Gallic  Acid  upon  certain 
Alkaloids. — Oeschner  de  Coninck. — The  author  examines 
the  adion  of  dry  pulverulent  tannin  upon  pure  nicotine 
and  nicotine  in  aqueous  solution.  The  result  was  nega- 
tive, as  also  in  the  case  of  alcoholic  and  ethereal  solution. 


Chbuical  Nbws,  I 
April  23,  1897.     ) 


Meetings  for  the  Week, 


201 


Preparation  of  Sodium  Carbide  and  Mono.sodic 
Ethylene. —  Camille  Matignon. —  The  author  describes 
the  modus  operandi  which  he  has  adopted. 

Observations  Concerning  the  Freezing  Tempera- 
ture of  Milk. — J.  Winter, — A  controversial  paper  in 
reply  to  MM.  Bordas  and  Genin. 

Non-identity  of  the  Lipases  of  Different  Origins. — 
M.  Hanriot. — The  blood  of  the  eel  contains  the  same 
lipase  as  the  blood  of  the  horse,  but  in  a  much  greater 
quantity. 

Certain  Properties  of  the  Ferment  of  Fradture  of 
Wines. — P.  Cazeneuve. — The  author  enquires  into  the 
aiStion  of  sulphurous  acid,  which  in  a  small  proportion 
destroys  the  adlion  of  an  oxidase,  and  thus  prevents  the 
•'  fradlure  "  of  wines. 

Novel  Method  of  obtainingthe  Perfume  of  Flowers. 
— Jacques  Passy. — The  author  uses  water  in  place  of  the 
fats  used  in  the  process  of  enfleurage. 


Bulletin  de  la  Societe  d' Encouragement  pour  I' Industrie 
Nationale.     Series  5,  Vol.  ii.,  No.  2. 

Economical  Treatment  of  the  By-produ(I\s  of  Dis- 
tillation of  Starchy  Produ(J\s. — A  report  presented  on 
behalf  of  the  Committee  of  Chemical  Arts  by  M.  de  Luynes 
on  the  procedures  adopted  by  MM.  Bonaid  and  Boulet, 
who,  when  treating  the  distillery  residues  by  the  procedure 
described  and  figured  in  this  paper,  utilise  them  for  the 
production  of  oils  and  matters  suitable  for  cattle-foods. 


Revue  Universelle  des  Mines  et  de  la  Metallurgie, 
Series  3,  Vol.  xxxvii..  No.  3. 

This  issue  contains  no  chemical  matter. 


MISCELLANEOUS. 

Tuberculin  O  and  R. — Prof.  Koch  has  succeeded  in 
the  produdtion  of  two  new  prcp.Trations  which  he  names 
as  above,  both  of  which  possess  an  immunising  adion 
against  the  bacilli  of  tuberculosis.  The  preparation  is 
injedted  beneath  the  skin  at  first  in  small  quantities,  and 
the  dose  is  then  gradually  increased. 

Test  for  Formaldehyd. — L.  Kentmann  {Fharm.  Gen. 
Anz.,  1896,  viii.,  356). — If  the  suspedled  liquid  is  floated 
on  an  equal  volume  of  a  solution  of  01  grm.  of  morphine 
hydrochloride  in  i  c.c.  of  strong  sulphuric  acid,  a  red 
violet  colour  is  produced  within  a  few  minutes,  provided 
the  formalin  exceeds  one  part  per  6000. — The  Analyst. 


MEETINGS    FOR    THE    WEEK. 


Tuesday,  27th.— Royal  Institution,  3.     "  Volcanoes,"  by  Dr.  Tem- 
pest Anderson,  B.Sc. 

Society  of  Arts,  8.    "  Delft  Ware,"  by  Dr.  J.  W.  L. 

Glaisher,  F.R  S. 
Wednesday,  28th.— Society  of  Arts,  8.     "  Asbestos  and  Asbestic— 
with  some  Account  of  the  Recent  Discovery  of 
the  latter  at  Danville,  in  Lower  Canada,"  by 
Robert  H,  Jones. 
Thursday.  29th.— Royal  Institution,  3.     "  Liquid  Air  as  an  Agent  of 
Ressarch,"  by  Prof.  Dewar,  F.R  S.,  &c.      (The 
Rev.  Canon  Ainger  being  unable  through  illness 
to  begin  his  ledtures  on  tnis  day), 

Chemical,  8.      "  Monochlordiparaconic   Acid    and 

some   Condensations,"  by  H.   C   Myers,  Ph.D. 
"  Decomposition   of  Iron    Pyrites,''   by    W.   A. 
Caldecott,  B.A. 
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RESEARCHES    ON     THE    EARTHS 
CONTAINED     IN     THE     MONAZITE     SANDS. 

By  MM.  SCHUTZENBERGER  and  BOUDOUARD. 

Crystalline  cerium  sulphate  obtained  by  the  treatment 
of  monazite  sands  has  yielded  us,  on  analysis,  figures 
which  lead  for  the  corresponding  metal  to  an  atomic 
weight  decidedly  higher  than  that  resulting  from  the 
analysis  of  the  cerium  sulphate  obtained  from  cerite 
(i40'5  to  141  in  place  of  139  to  i39'5  for  the  formula  06203). 
As  this  result  shows  the  probable  presence  of  a  strange 
earth  bordering  on  cerium,  we  have  sought  to  isolate  the 
latter,  which  we  have  efifefted  in  the  following  manner  : — 

1.  The  monazite  sands,  reduced  to  powder,  are  treated 
with  sulphuric  acid  in  heat.  The  excess  of  the  sulphuric 
acid  is  evaporated,  and  the  residue  is  treated  with  water. 

2.  The  solution  is  saturated  with  potassium  sulphate, 
which  precipitates  the  earths  of  the  cerium  group  in  the 
state  of  double  cerium  sulphates,  insoluble  in  water 
charged  with  potassium  sulphates.  The  precipitate  is 
washed  with  a  saturated  solution  of  potassium  sulphate, 
then  suspended  in  water,  and  decomposed  in  heat  by  an 
excess  of  caustic  soda.  The  hydrated  oxides,  precipitated 
and  washed,  are  dissolved  in  nitric  acid  and  re-precipitated 
with  ammonia,  washed,  re-dissolved  in  nitric  acid,  and 
finally  precipitated  by  oxalic  acid. 

3.  The  oxalates,  washed  and  dried,  are  converted  into 
nitrates  by  nitric  acid.  The  nitrates  are  dried  and  melted 
at  325°,  with  8  parts  of  saltpetre  (Debray's  process), 
unto  tranquil  fusion.  Theceriumoxide(binoxide),  insoluble, 
is  separated  from  solution  of  saltpetre  water  and  the 
nitrates  of  didymium  and  lanthanum.  After  washing,  it 
is  transformed  into  sulphate  by  the  aftion  of  sulphuric 
acid  ;  the  dissolved  sulphate  is  precipitated  with  oxalic 
acid  ;  the  washed  oxalate  is  converted  into  nitrate,  which 
is  dried  and  melted  a  second  time  at  320°,  with  8  parts  of 
saltpetre.  This  second  treatment  serves  to  eliminate 
small  quantities  of  didymium  entangled  in  the  first  fusion. 
We  thus  obtain  a  light  yellow  oxide,  finely  divided,  which 
is  first  converted  by  sulphuric  acid  into  yellow  cerium 
sulphate,  and  then  into  cerous  sulphate,  (S04)3Ce2,  by  a 
moderate  ignition  of  cerium  sulphate,  (S04)2Ce. 

4.  The  white  cerous  sulphate  is  dissolved  in  water  in 
the  cold,  and  the  solution  is  heated  in  a  capsule  on  the 
water-bath.  During  the  evaporation  of  the  liquid,  being 
kept  between  75°  and  80°,  an  abundant  crystallisation 
separates  out.  When  the  deposit  of  crystals  formed  in 
heat  ceases  to  appear,  the  mother-liquor  is  decanted  off. 

The  crystals  separated  are  dehydrated,  dissolved  in  cold 
water,  and  the  solution  is  again  concentrated  by  heat, 
with  separation  of  crystals  and  of  a  mother-liquor. 

The  same  operation  is  repeated  several  times,  and  the 
mother-liquors  obtained  from  the  successive  crystallisa- 
tions are  added  to  the  first. 

We  thus  obtain  (i)  a  sulphate  crystallised  in  brilliant 
colourless  prisms,  containing  i3'5  per  cent  of  crystalline 
water,  entirely  eliminated  at  about  300°,  which  we 
designate  as  A;   (2),  a  mother-liquor,  B. 

The  crystals  A,  dehydrated  and  dis^lved  in  water, 
were  precipitated  with  a  large  excess  of  a  solution  of 
neutral  ammonium  oxalate.  The  liquor  heated  for  some 
hours  on  the  water-bath  is  filtered  when  quite  cold,  and 
the  cerium  oxalate  is  washed  with  a  solution  of  ammo- 
nium oxalate  until  the  filtrate  is  no  longer  rendered  turbid 
on  the  addition  of  nitric  acid.    The  operation  seems  to 


eliminate  the  traces  of  thorium  which  may  have  become 
mixed  with  the  cerium. 

The  cerium  oxalate  is  afresh  converted  into  sulphate. 
The  analysis  of  this  sulphate,  after  desiccation  at  440°, 
gave — (i)  for  27196  of  sulphuric  anhydride,  i'649r  of  cal- 
cined rose-coloured  oxide  ;  calculating  this  oxide  as  CeOz 
we  have,  for  the  atomic  weight  of  the  metal,  Ce  =  i40'5; 
(2)  for  2'6oi7  of  anhydrous  sulphate  we  found  31904 
barium  sulphate,  whence  we  deduce  Ce  =  i4i"05. 

The  determination  of  the  sulphuric  acid  by  barium 
chloride  requires  certain  precautions,  which  have  been  in- 
dicated by  one  of  us  in  a  former  paper  on  cerium. 

The  augmentation  of  the  atomic  weight  of  the  cerium 
of  monazite  cfinnot,  therefore,  be  due  to  the  presence  of 
thorium  which  would  have  been  removed  by  the  treatment 
with  ammonium  oxalate.  Still,  for  greater  security,  we 
applied  to  the  dilute  solution  of  this  sulphate  the  method 
indicated  by  Lecoq  de  Boisbaudran,  by  heating  it  gently 
for  a  long  time  with  an  excess  of  copper  oxide  precipitated 
and  dehydrated  at  100°.  The  cupric  oxide  precipitates  the 
thorium,  but  not  the  cerium.  Very  little  copper  passed 
into  solution,  and  the  filtrate  had  a  greenish  colour.  When 
freed  from  copper  by  hydrogen  sulphide,  and  concentrated 
on  the  water-bath,  this  liquid  yields  crystals,  like  the 
former  in  appearance,  but  differing  in  composition  : — 

1.  Hydrated  sulphate,  39288;  anhydrous  sulphate  ob- 
tained, 3'40i2;  water,  per  cent,  3'47. 

2.  Anhydrous  sulphate  employed,  2*3075  ;  oxide  (white) 
obtained  by  calcination,  3'928,  whence  Ce=i38'6,  con- 
sidering the  oxide  as  dioxide. 

3.  Anhydrous  sulphate  employed,  2'3667 ;  barium  sul- 
phate obtained,  2'932o,  whence  Ce  =  i38'i. 

4.  Anhydrous  sulphate  employed,  2.7475 ;  barium  sul- 
phate obtained,  3"4045,  whence  Ce  =  i38"i. 

5.  Anhydrous  sulphate  employed,  2'4i76;  barium  sul- 
phate obtained,  2*2940,  whence  06  =  137-7. 

In  all  the  analyses  effected  with  similar  produ(5ts,  puri- 
fied with  copper  oxide,  the  determination  by  calcination 
of  the  sulphate  gives  for  the  atomic  weight  of  the  cerium 
a  value  a  little  higher  than  that  resulting  from  a  deter- 
mination of  the  sulphuric  acid. 

This  is  the  inverse  of  that  always  observed  on  analysing 
cerium  sulphates  which  have  not  undergone  the  purifica- 
tion with  copper  oxide.  The  atomic  weight  deduced  from 
the  calcination  of  the  sulphate,  and  calculating  the 
residual  oxide  as  dioxide,  is  sensibly  below  that  deduced 
from  the  contamination  of  the  sulphuric  acid. 

Examination  of  the  Mother-liquors,  B. — These  mother- 
liquors,  diluted  with  water,  are  diredtly  treated  with  an 
excess  of  copper  oxide  precipitated  and  dehydrated  at 
100°  whilst  in  the  water. 

A  notable  quantity  of  copper  is  dissolved,  and  the 
excess  of  this  oxide  is  found  mixed  with  a  large  proportion 
of  a  precipitated  white  hydrate.  The  deposit  is  washed, 
and  added  to  the  precipitate  formed  by  the  A  crystals 
under  the  influence  of  cupric  oxide. 

The  filtrate,  freed  from  copper  by  means  of  hydrogen 
sulphide,  yielded  crystals  of  cerous  sulphate  similar  to  the 
foregoing,  that  is  to  say  to  about  Ce  =  138*0. 

Examination  of  the  Precipitate  yielded  by  Copper  Oxide-, 
— This  is  stirred  up  in  water  and  dissolved  in  a  slight 
excess  of  sulphuric  acid.  The  lukewarm  solution  is  freed 
from  copper  by  means  of  hydrogen  sulphide.  It  still 
presents  very  distinctly  the  charaders  of  the  cerium  salts. 
On  treatment  with  soda  it  gives,  after  the  addition  of  an 
oxygenated  water,  an  orange-yellow  precipitate.  On  the 
other  hand,  it  reveals  the  presence  of  large  proportions  of 
thorium  or  of  analogous  bodies ;  it  is  thus  that,  when 
concentrated  on  the  water-bath,  it  yields  an  abundant 
white  flocculent  deposit  formed  of  felted  needles,  which, 
on  analysis,  lead  to  atomic  weights  bordering  on  that  of 
thorium. 

In  order  to  separate  the  cerium  from  the  thorium,  we 
saturated  the  liquid  with  sodium  sulphate.  After  some 
time  there  is  formed  a  scanty  precipitate  of  double  sul- 
phate,  which   was    separated    after  twelve    hours,   and 


206 


Behaviour  of  Bacteria  with  Chemical  Reagents^ 


>  Chemical  Nbws, 
1    April  30,  X897. 


washed  with  a  solution  of  sodium   sulphate   saturated  in 
the  cold. 

This  double  sulphate,  decomposed  in  heat  with  caustic 
soda,  gave  an  oxide  which  when  converted  into  sulphate 
offers  the  charaders  of  cerium  sulphate.  Its  analysis 
gave  :— 

1.  Anhydrous  sulphate  employed,  2*3014;  barium  sul- 
phate obtained,  27570,  whence  Ce  =  147*8. 

2.  Anhydrous  sulphate  employed,  3*3074;  calcined 
oxide  obtained,  2*0074,  whence  Ce=  141*6. 

3.  Hydrated  sulphate,  3*6582  ;  anhydrous  sulphate  ob- 
tained, 3"i6ii ;  water  per  cent,  I3'5. 

4.  Anhydrous  sulphate  employed,  i'7673;  calcined  oxide 
obtained,  10730,  whence  Ce=  141*1. 

The  solution  of  this  sulphate  crystallises  during  the 
evaporation  in  crystalline  crusts,  adhering  to  the  bottom 
of  the  capsule,  and  which  appear  homogeneous  to  the 
desiccation  of  the  last  drop  of  the  liquid.  From  these 
results  we  may  calculate  that  the  oxide  obtained  by  the 
calcination  of  the  sulphate  has  a  composition  close  upon 
2Ce203*Ce204. 

Examination  of  the  Saturated  Solution  of  Sodium  Sul- 
phate separated  from  the  foregoing  Precipitate.  —  The 
earth  withdrawn  from  this  liquid  by  means  of  caustic 
soda,  washed,  dissolved  in  nitric  acid,  precipitated  anew 
with  ammonia,  and  washed,  still  shows  the  presence  of 
cerium  compounds.  Its  solutions  give  with  soda  a  white 
precipitate,  which  becomes  reddish  yellow  on  the  addition 
of  oxygenated  water. 

We  succeed  in  separating  the  eerie  part  which  occasions 
these  coloured  readions,by  treating  the  neutral  solution  of 
the  sulphate  in  the  cold  with  an  excess  of  neutral  ammo- 
nium sulphate.  The  greater  part  of  the  precipitate  dis- 
solves ;  the  insoluble  portion,  when  filtered  and  washed, 
calcined,  and  again  transformed  into  sulphate,  gives  a 
salt  very  soluble  in  water  and  does  not  deposit  crystals 
during  evaporation.  The  liquid  thickens  on  concentra- 
tion, forming  on  the  surface  films  like  those  of  a  solution 
of  gum.  On  evaporation  we  obtain  a  colourless  mass, 
amorphous  and  transparent,  which  if  kept  for  some  time 
in  a  stove  at  100°  becomes  opaque  and  crystalline. 

The  analysis  of  the  crystals  which  give  the  coloured 
readlions  of  cerium  furnished  the  following  numbers: — 

1.  Anhydrous  sulphate  employed,  2*566  ;  barium  sul- 
phate obtained,  2*975,  whence  Ce=  157*45. 

2.  Anhydrous  sulphate  employed,  2*6684;  calcined  oxide 
obtained,  1*6320,  whence  Ce  =  144*3,  calculating  the 
calcined  oxide  as  bioxide.  From  these  results  we  may 
attribute  to  this  oxide  the  formula  already  found,  that  of 
an  intermediate  oxide. 

The  earths  bordering  on  cerium  oxide,  with  a  nigh 
molecular  weight,  give,  on  the  calcination  of  their  sul- 
phate, not  a  bioxide,  but  an  intermediate  oxide. 

This  explains  the  disagreement  constantly  observed  be- 
tween the  results  of  the  determination  of  the  sulphuric 
acid,  and  on  the  calcination  of  the  sulphate  whenever  it 
has  not  been  purified  with  copper  oxide. 

In  fine,  we  have  separated : — 

1.  A  cerium  with  an  atomic  weight  near  138,  and 
rather  lower,  the  solution  of  which  does  not  precipitate 
copper  oxide. 

2.  A  cerium  of  an  atomic  weight  near  148,  the  sulphate 
of  which  is  precipitable  by  copper  oxide,  and  also  by  so- 
dium sulphate. 

3.  A  cerium  of  an  atomic  weight  near  157,  the  sulphate 
of  which  is  precipitable  by  copper  oxide,  but  not  by  so- 
dium sulphate.  The  solutions  are  charaderised  by  taking 
a  gummy  aspedl  during  concentration. 

These  three  earths  give  yellow  eerie  salts,  decomposable 
by  heat  into  white  cerium  salts.  Oxygenated  water  with 
soda  precipitates  them  of  an  orange-red.  Ammonium 
oxalate  precipitates  them,  all  three,  and  the  precipitates 
are  not  soluble  in  excess.  Spedtroscopic  examination 
(sparks  with  chloride)  does  not  show  any  difference 
between  the  three  salts. 

The  part  soluble  in  neutral  ammonium  oxalate,  and  not 


precipitated  by  sodium  sulphate,  does  not  present  the 
coloured  readlions  of  cerium,  but  belongs  to  the  thorium 
group.  The  experiments  hitherto  effedled  have  led  us  to 
a  homogeneous  produdl. — Comptes  Rendiis,  cxxiv.,  p.  481. 


THE    BEHAVIOUR    OF     BACTERIA    WITH 
CHEMICAL   REAGENTS. 

By  TH.  PAUL  and  B.  KRONIG. 

From  the  authors'  experiments  with  the  spores  of 
splenic  fever  and  those  of  Staphylococcus  pyogenes  it 
results  that — 

1.  With  the  exception  of  platinum,  the  salts  of  gold, 
silver,  and  mercury  have  a  specific  toxic  adtion. 

2.  The  disinfedlive  adion  of  the  metallic  salts  depends 
not  aloneon  the  concentration  of  the  metal  in  solution,  but 
also  on  the  specific  properties  of  the  salts  and  the  solvent. 
Behring's  view  that  the  disinfedive  value  of  the  mercury 
solutions  depends  alone  on  the  percentage  of  soluble 
mercury  cannot  be  rightly  admitted. 

3.  Solutions  of  metallic  salts  in  which  the  metal  is  an 
ingredient  of  a  complex  ion,  and  the  concentration  of  its 
ion  is  hence  very  trifling,  exert  merely  a  very  slight  anti- 
septic adion. 

4.  The  effedt  of  a  metallic  salt  depends  not  merely  on 
the  specific  adlion  of  the  metallic  ion,  but  also  on  that  of 
the  anion. 

5.  The  haloid  compounds  of  Hg  (including  the  cyanides 
and  sulphocyanides)  disinfedt  according  to  their  degree 
of  dissociation. 

6.  The  disinfedlive  adlion  of  aqueous  mercuric  chloride 
is  lowered  by  the  addition  of  metallic  chlorides. 

7.  The  strong  acids  adl  at  concentrations  of  i  litre 
and  upwards,  not  only  corresponding  to  the  concentra- 
tion of  their  hydrogen  ions,  but  also  by  means  of  the 
specific  properties  of  the  anion.  The  strong  acids,  even 
if  more  dilute,  and  the  weak  organic  acids  seem  to  adl  in 
the  proportion  of  their  degree  of  dissociation. 

8.  The  bases  KOH,  NaOH,  and  LiOH,  when  disso- 
ciated, disinfedl  almost  equally;  NH4(0H),  when  much 
less  dissociated,  disinfedls  very  little. 

g.  The  oxidising  agents,  NHO3,  H2Cr207,  HCIO3, 
HMn04,  adl  according  to  their  position  in  the  series  laid 
down  according  to  their  eledlric  behaviour.  Chlorine  does 
not  rank  in  this  series,  but  has  a  very  powerful  specific 
adlion. 

10.  The  disinfedlive  adlion  of  the  halogens,  CI,  Br,  I, 
decreases,  like  their  general  chemical  behaviour,  with  the 
increase  of  atomic  weight. 

11.  The  statements  Scheurlein  that  solutions  of  phenol 
disinfedl  better  on  the  addition  of  salts  was  verified. 

12.  The  known  fadl  that  substances  dissolved  in  alcohol 
and  ether  are  almost  without  adlion  on  the  spores  of 
splenic  fever  was  confirmed  by  the  author's  observations. 

13.  Aqueous  alcohol  of  known  percentage  heightens  the 
disinfedive  adlion  of  HgCl2  and  AgNOs-  —  Chemiker 
Zeitung.  

Determination  of  Organic  Matter  in  Potable  Water. 
— Dr.  E.  Fricke.— It  is  an  unpleasant  property  of  centi- 
normal  oxalic  acid  that  it  gradually  loses  its  efficiency.  A 
recent  solution  of  oxalic  acid  of  which  10  c.c.  are  just 
faintly  reddened  by  an  equal  volume  of  permanganate, 
after  being  kept  for  eight  days  required  only  9*5  c.c.  for 
adjustment,  and  after  four  weeks  its  value  had  fallen  to  8 
c.c.  permanganate.  The  appearance  of  flocculent  matter 
showed  that  the  oxalic  acid  is  decomposed  by  fungi.  As 
it  is  very  inconvenient  to  prepare  a  new  standard  solution 
every  day  or  two  I  tried  adding  to  the  oxalic  solution 
1  grm.  boric  acid  per  litre,  and  I  find  that  after  ten  weeks 
it  has  remained  unchanged.  The  boric  acid  has  no  adlion 
upon  the  permanganate. — Chem.  Zeitung,  No.  26,  1897. 


Crbmical  News,  | 

April  30,  1897.     I 


The  Ironstone  or  the  Weald, 


207 


THE     IRONSTONE     OF     THE     WEALD. 
By  Dr.  T.   L.   PHIPSON. 

Of  the  various  ironstones  examined  of  late  years  in  this 
laboratory,  none  are  more  interesting  than  that  of  the 
Weald.  This  particular  portion  of  the  Earth's  crust, 
which  lies  just  below  the  green  sand  of  the  chalk  forma- 
tions, is  rarely  met  with  on  the  surface  of  the  globe.  It 
presents  the  charaders  of  a  fresh-water  formation,  and 
has  been  found  to  contain  the  remains  of  some  gigantic 
reptiles.  There  exist  a  few  small  patches  of  it  in  the 
South  of  England.  The  fresh-water  Paludina  shells  are 
one  of  its  charadleristics. 

I  have  made  a  careful  examination  of  the  ironstone  of 
this  formation,  and  have  found  that  it  consists  of  a 
yellowish  white  or  grey  carbonate  of  iron,  generally 
coated  with  hydrated  peroxide  in  the  form  of  brown 
haematite,  which  in  its  turn  passes  into  reddish  orange  or 
yellow  ochraceous  stones  containing  much  silica. 

The  carbonate  of  iron  of  the  coal  measures  is  also, 
evidently,  of  fresh-water  origin  ;  for,  among  the  ores  of 
this  kind  forwarded  to  me  from  South  Staffordshire,  I 
have  met  with  a  beautiful  little  specimen  of  a  fresh-water 
mollusc  (Unio)  presenting  exadly  the  composition  of  these 
spathic  ironstones. 

But  whilst  the  carbonate  of  iron  of  the  coal  strata  con- 
tains a  notable  amount  of  phosphates  and  sulphates,  that 
of  the  Weald  is  remarkably  pure  in  this  respedl. 

The  Weald  ironstone  has  given  me  from  34  to  42  per 
cent  of  metallic  iron  ;  14  to  46  per  cent  of  silica  (which  is 
the  chief  impurity),  and  about  2  to  3  per  cent  of  oxide  of 
manganese,  with  similar  quantities  of  magnesia  and 
alumina,  and  a  little  lime,  but  only  faint  traces  of  sul- 
phates and  phosphates. 

These  spathic  ironstones  seem  to  have  been  formed 
from  ancient  chalybeate  springs,  such  as  are  rather  fre- 
quent at  the  present  day,  especially  in  Germany,  where 
the  process  is  stiil  in  adion,  the  iron  being  dissolved  from 
the  rocks  through  which  issue  constantly  vast  streams  of 
carbonic  acid.  Near  Neubau,  in  Waldeck,  for  instance,  I 
have  seen  bubbles  of  carbonic  acid  varying  in  size  from 
that  of  a  walnut  to  that  of  a  man's  head,  bursting  on  the 
surface  of  springs,  incessantly,  day  and  night ;  and  this 
volcanic  adion  has  been  continuous  there  as  long  as  man 
can  remember. 

The  almost  complete  absence  of  phosphorus  and  sul- 
phur in  the  ironstone  of  the  Weald  is  rather  remarkable, 
since  spathic  ironstone  is  generally  different  in  this 
respedl.  In  olden  times,  when  forests  abounded  in  the 
South  of  England,  this  ore  was  smelted  and  made  good 
iron.  I  have  heard  it  stated  that  the  old  iron-railings  of 
St.  Paul's  Cathedral  were  obtained  from  this  source  ;  and 
among  the  samples  forwarded  to  me  for  analysis,  and 
picked  up  on  the  surface  of  the  ground,  I  have  met  with 
pieces  of  slag  that  appear  to  be  Catalan  slag. 

Casa  Mia  Laboratory,  Putney,  S.W, 
April  27,  1897. 


MODIFICATION     OF     THE     THALLEOQUIN 

TEST     FOR     QUININE. 

By  F.  S.  HYDE. 

It  is  extremely  important  for  the  success  of  this  test  that 
the  reagents  employed  should  be  dilute.  Some  authorities 
give  the  quantity  of  each  reagent  necessary,  without 
stating  the  proper  dilution,  thereby  causing  much  incon- 
venience. 

The  light  green  colouration  produced  on  porcelain  by 
contadl  of  the  quinine  salt  with  weak  bromine  or  chlorine 
water  and  ammonia,  is  not  nearly  so  striking  as  the 
brilliant  emerald-green  colour  obtained  by  using  dilute 
solutions  in  a  test-tube. 


Usually  the  analyst  deals  with  unknown  quantities,  or 
mere  traces,  but  for  experiment  it  will  be  found  convenient 
to  use  from  3  to  5  m.grms.  of  the  quinine  salt  for  each 
test.  (With  larger  amounts  there  is  a  tendency  to  form 
bulky  precipitates). 

For  example,  place  3  to  5  m.grms.  (0*003  to  0*005  grm.) 
quinine  sulphate  in  a  test-tube,  and  add  about  5  c.c.  dis- 
tilled water.  Acidulate  with  one  drop  (not  more)  of  dilute 
sulphuric  acid  (i  :  4),  which  immediately  dissolves  the 
quinine  sulphate  with  a  blue  fluorescence.  An  excess  of 
the  acid  should  be  avoided. 

At  this  point  various  authorities  recommend  the 
addition  of  weak  bromine  or  chlorine  water;  but  the 
writer  has  found  that  if  a  clear,  filtered  solution  of  cal- 
cium hypochlorite  (bleaching  powder)  be  substituted  for 
the  bromine  or  chlorine  water,  the  results  will  be  more 
satisfactory  so  far  as  certainty  and  brilliancy  of  the  test 
are  concerned. 

The  points  to  be  observed  are  as  follows  : — After  acidu- 
lation  with  one  drop  of  sulphuric  acid  (i  :  4)  the 
hypochlorite  solution  is  added  through  a  small  filter  to 
the  quinine  solution  in  the  test-tube,  until  the  blue 
fluorescence  just  disappears,  and  the  solution  acquires  a 
faint  golden  tmt ;  then  add  a  few  drops  of  dilute  ammonia 
(i  :  3),  when  a  clear  emerald-green  colour  should  appear. 
(Thalleoquin  test). 

The  tint  thus  produced  seems  to  be  more  brilliant  than 
that  obtained  through  the  agency  of  bromine  water. 

On  the  addition  of  a  slight  excess  of  dilute  sulphuric 
acid  to  this  green  solution,  a  bloodred  tint  will  be  pro- 
duced, which  may  be  considered  confirmatory.  This  is 
not  always  the  case,  however,  when  bromine  water  has 
been  used  in  the  preliminary  operation. 

Potassium  or  sodium  hypobromite  is  not  applicable,  on 
account  of  the  strong  alkali,  which  tends  to  precipitate 
the  white  quinine  base,  and  thus  interfere  with  the  bril- 
liancyof  thetcst.  Chlorinated  soda  (Labarraque's  solution) 
likewise  gives  uncertain  results,  the  tints  varying  from 
yellowish  green  to  violet. — journal  of  the  American 
Chemical  Society,  xix.,  p.  331. 


THE    ACTION     OF     ACID     VAPOURS     ON 

METALLIC    SULPHIDES.* 
By  JEROME  KELLEY,  Jun.,    and  EDGAR  F.  SMITH. 

Experiments  made  in  this  laboratory  on  the  adion  of 
the  vapours  of  hydrochloric  acid  upon  the  sulphide  of 
arsenic  proved  that  the  latter  is  wholly  volatilised.  The 
purpose  of  the  present  communication  is  to  record  further 
observations  along  analogous  lines.  Thus,  when  washed 
and  dried  arsenic  trisulphide  is  exposed  to  the  adion  of 
hydrobromic  acid  gas,  it  volatilises  completely.  Indeed, 
the  adlion  commences  in  the  cold  with  the  formation  of  a 
liquid  that  passes  out  of  the  containing  vessel  upon  the 
application  of  a  very  gentle  heat.  In  evidence  of  this, 
two  quantitative  experiments  may  be  given  : — 


Arsenic  sulphide  taken. 
Grm. 

0-2945 
0-4632 


Arsenic  sulphide  expelled. 
Grm. 

0-2941 
0-4628 


Antimony  trisulphide,  like  that  of  arsenic,  is  volatilised 
by  hydrochloric  acid  gas.  It  was  quite  probable  that  a 
like  deportment  would  be  observed  if  hydrobromic  acid 
gas  should  be  substituted.  This  was  found  to  be  the  case. 
When  the  gas  came  in  contact  with  the  sulphide  it  became 
liquid  and  volatilised  as  soon  as  a  gentle  heat  was  played 
upon  the  boat  in  which  the  sulphide  was  contained. 

*  Contribution  from  the  John  Harrison  Laboratory  of  Chemistry. 
From  the  Journal  of  the  American  Chemical  Society,  xviii.,  No.  12. 


208 


Estimation  of  Molybdenum  lodometrically. 


(CBBHICAL  NBWSt 
April  30,  1897. 


Antimony  sulphide  taken. 
Grm. 

0*1473 

0*0938 


Antimony  sulphide  expelled. 
Grm. 

0*1469 
00935 


Upon  substituting  stannic  sulphide  for  antimony  sul- 
phide,  an  experience  similar  to  that  observed  with  anti- 
mony and  arsenic  sulphides  followed.  There  was  a  com- 
plete volatilisation  with  but  a  trifling  residue,  which 
proved  to  be  carbon  from  filter-paper  that  had  adhered  to 
the  metallic  sulphide. 


Stannic  sulphide  taken. 
Grm. 

0'i88o 

0-5527 
0-4174 


Stannic  sulphide  expelled. 
Grm. 

o-i88o 
0-5521 
0-4169 


The  oxides  of  arsenic,  antimony,  and  tin  (at  least  in 
the  stannic  form)  can  be  volatilised  in  a  current  of  hydro- 
chloric acid  gas.  This  is  also  true  of  the  sulphides  of 
arsenic  and  antimony,  but  how  the  two  sulphides  of  tin 
would  adl  under  like  conditions  was  not  known. 

Experiments  recently  made  demonstrate  the  perfedt 
volatility  of  stannic  sulphide  in  this  way.  With  stannous 
sulphide  it  was  found  that  by  the  continued  adion  of  the 
gas  in  the  cold  theie  followed  a  complete  conversion  into 
chloride  without  any  volatilisation.  That  the  residue  was 
the  chloride  was  evident  from  its  adtion  upon  a  mercuric 
salt  solution.  The  figures  obtained  in  the  several  trials 
were : — 


Stannous  chloride  found. 
Grm. 

0*3544 
0-4893 


Stannous  chloride  theory. 
Grm. 

0-3523 
0-4903 


Several  attempts  were  made  to  separate  stannous  and 
stannic  sulphides  by  this  procedure.  The  results  were 
unsatisfadory.  In  order  to  drive  out  the  stannic  salt 
completely  it  is  necessary  to  heat  the  mixture,  and  this 
caused  a  partial  volatilisation  of  the  stannous  chloride,  so 
that  quantitative  results  could  not  be  obtained. 

Comparatively  few  metallic  sulphides  have  been  studied 
in  the  direftion  indicated  in  the  preceding  lines,  so  that  it 
is  probable  that  a  wider  application  of  the  method  will 
disclose  interesting  behaviours,  and  that  probably  new 
separations  can  be  brought  about  ir  this  way.  The  adion 
of  the  vapours  of  haloid  acids  has  also  been  tried  on  natural 
sulphides  with  a  fair  degree  of  success. 


THE    ESTIMATION     OF     MOLYBDENUM 

lODOMETRICALLY.* 

By  F.  A.  GOOCH. 


In  a  former  paper  from  this  laboratory  (Gooch  and  Fair- 
banks, Am.yourn.  Set.,  IV.,  ii.,  157,  1896)  several  modes 
of  applying  hydriodic  acid  to  the  redudion  of  molybdic 
acid  were  studied.  It  was  found,  first,  that  the  digestion 
process  of  Mauro  and  Danesi  (Zeit.  Anal.  Chemie,  xx., 
507)  is  of  very  limited  applicability,  owing  to  the  fadl  that 
the  readion  of  redudlion  is  reversible.  Secondly,  it 
appeared  that  the  use  of  the  same  readlion  by  Friedheim 
and  Euier  {Ber.  d.  D.  Chetn.  Gesell.,  xxviii.,  2066)  in  a 
distillation  process,  so  arranged  that  the  iodine  set  free 
in  the  redudion  might  be  caught  in  the  distillate  and 
titrated  to  serve  as  the  measure  of  the  reducing  aftion, 
was  not  sufficiently  regular  because  of  inattention  to 
minor  details.  It  was  shown  that  by  taking  care  to  adjust 
the    conditions    constant    results    might    be    obtained. 

♦Contributions  from  the  Kent  Chemical  Laboratory  of  Yale 
University.  From  the  American  Journal  of  Science,  Fourth  Series, 
vol.  in.,  March,  1897. 


Thirdly,  the  fad  was  developed  that  by  simply  boiling  the 
solution  under  well-defined  conditions  in  an  ordinary 
Erlenmeyer  flask,  partly  closed  by  a  simple  trap,  the 
redudion  of  the  molybdic  acid  proceeded  regularly,  and 
that  the  addition  of  standard  iodine  to  the  solution  made 
alkaline  with  sodium  bicarbonate  served  to  restore  the 
original  condition  of  oxidation  of  the  molybdic  acid.  The 
results  of  this  treatment  were  shown  to  be  accurate. 

In  a  recent  paper  {Ber.  d.  D.  Chem.  GeselL,xxix.,  2981) 
Friedheim  has  seen  fit  to  make  our  modifications  of  the 
distillation  process  the  subjed  of  attack.  Friedheim's 
comments  upon  the  third  method  discussed— as  v/ell  as 
upon  a  subsequent  application  of  the  process  ("  An  lodo- 
metric  Method  for  the  Determination  of  Phosphorus  in 
Iron,"  by  Charlotte  Fairbanks)— are  evidently  prompted 
wholly  by  personal  opinion  and  demand  no  further  at- 
tentioii.  With  reference  to  Friedheim's  denial  of  the 
necessity  of  modification  in  the  Friedheim  and  Euler 
treatment  the  case  is  different. 

The  process  of  Friedheim  and  Euler  consists,  it  will  be 
remembered,  in  treating  the  soluble  molybdate,  or  the 
solution  of  molybdic  acid  in  sodium  hydroxide,  with 
potassium  iodide  and  hydrochloric  acid  in  a  Bunsen 
apparatus,  boiling  until  the  solution  is  of  a  clear  green 
colour,  coUeding  the  iodine  distilled  in  potassium 
iodide,  and  titrating  it  with  sodium  thiosulphate.  We 
found  that  the  development  of  the  green  colour 
was  not  a  sufficient  criterion  of  the  exad  redudion 
of  the  molybdic  acid  to  the  condition  of  the  pentoxide 
and  of  the  removal  of  the  iodine  which  should  be  theoreti- 
cally set  free.  To  accomplish  that  end  we  found  it  safer 
and  more  convenient  to  start  the  distillation  with  a  definite 
volume  (40  c.m.»)  of  liquid  and  boil  until  a  definite 
volume  (25  cm. 3)  was  reached,  care  being  taken  with 
regard  to  the  strength  of  acid  and  the  excess  of  potassium 
iodide  employed.  Experience  showed  unmistakably  that 
in  order  to  avoid  the  decomposing  adion  of  the  air  upon 
the  hot  vaporous  hydriodic  acid  in  the  retort,  it  was 
necessary  to  go  beyond  the  measures  advised  by  Fried- 
heim and  Euler  (namely,  to  warm  the  retort  and  its  con- 
tents slowly,  heating  to  boiling  only  when  the  conneding 
tube  was  well  filled  with  iodine  vapour,  and  the  tendency 
toward  back-sudion  of  the  liquid  in  the  receiver  began  to 
appear),  and  to  condud  the  operation  in  a  simple  little 
apparatus  (the  retort  holding  about  100  c.m.^)  put  to- 
gether entirely  with  sealed  and  ground  joints,  as  snown 
in  the  figure  of  the  former  paper,  so  arranged  that  a  cur- 
rent of  purified  carbon  dioxide  could  be  passed  through 
retort  and  receiver  during  the  distillation.  With  this 
apparatus  we  were  able  to  determine  with  accuracy  the 
point  of  concentration  at  which  the  free  iodine  left  the 
liquid,  the  molybdic  acid  having  been  converted  to  the 
condition  of  the  pentoxide.  It  was  found  that  if  depend- 
ence is  placed  upon  the  occurrence  of  the  so-called  clear 
green  colour  of  the  liquid  to  determine  the  end  of  the 
distillation,  it  may  frequently  happen  that  free  iodine  re- 
mains in  the  residue.  This  takes  place,  it  will  be 
observed,  in  the  atmosphere  of  carbon  dioxide,  so  that 
the  presence  of  the  free  iodine  can  by  no  possibility  be 
attributed  to  the  adion  of  atmospheric  air  upon  the 
hydriodic  acid  remaining  after  the  distillation  is  complete. 
On  the  other  hand,  it  appeared  that,  if  the  distillation  is 
pushed  too  far,  the  molybdenum  pentoxide  may  be  still 
further  reduced,  with  consequent  evolution  of  more  thai> 
the  expeded  amount  of  iodine.  The  attainment  of  an 
exad  degree  of  redudion  with  the  expulsion  of  the  corre- 
sponding amount  of  iodine  becomes,  therefore,  a  matter 
of  chance  unless  further  precautions  are  taken.  We 
found  in  our  experiments  that  if  amounts  less  than  0-3 
grm.  of  the  molybdic  acid  are  introduced  in  soluble  form 
into  the  100  c.m.^  retort  with  a  not  too  great  excess  of 
potassium  iodide,  and  the  40  c.m.^  of  liquid  so  constituted 
that  20  cm. 3  of  it  shall  be  water  and  20  c.m.^  the 
strongest  hydrochloric  acid,  the  redudion  proceeds  with 
a  fair  degree  of  regularity  in  the  manner  expeded.  We 
found   it   important  to   restrid  the  excess  of  potassium 


Chbmicai.  Nbws, 

April  30,  1897. 


Determination  of  Potash  and  Phosphoric  Acid  tn  Fodders.  209 


iodide  so  that  it  shall  never  exceed  the  theoretical  require- 
ment by  more  than  o"5  grm. 

Our  determinations  with  the  pure  molybdenum  trioxide 
showed  errors  varying  from  o'ooio  grm.  +  to  0*0007 
grm.  —  ;  the  variations  from  theory  in  the  experiments 
with  ammonium  molybdate  ranged  from  o'ooii  grm.  +  to 
0001 1  grm.  — .  If  these  results  are  compared  with  those 
given  by  Friedheim  and  Euler,  the  advantage  is  a  little 
in  favour  of  the  latter  ;  but  a  scrutiny  of  the  figures  given 
by  Friedheim  and  Euler  developes  the  fadt  that  the 
apparent  accuracy  of  their  work  is  founded  upon  mis- 
calculations. This  fadt  was  known  to  us  at  the  time  of 
our  former  writing,  but  we  did  not  consider  it  essential 
then  to  make  the  matter  public.  The  recent  attack  of 
Friedheim  makes  that  course  now  necessary. 

Herewith  is  reproduced  a  table  of  results  obtained  by 
Friedheim  and  Euler  in  the  test  of  their  method  upon 
ammonium  molybdate,  shown  by  analysis  to  contain  81*49 
per  cent  of  molybdenum  trioxide.  The  figures  which  are 
incorredt  are  enclosed  in  brackets  : — 


Original  Figures  of  Friedheim  and  Euler. 


Molybdate 
taken. 
Grm. 

0*2674 
0*4418 
0*4075 
0*3281 
0*4340 
0*4098 
0-4305 


NajSjOg 
used. 
C.m.s. 

30*8 
50-8 
[40*7]* 
37*33 
49'43 
46-63 
49*o8 


I  c.m.»  = 
o  00709 
M0O3. 

I  1  cm.*  = 
[  0*007086 
I     M0O3. 

*  Probably  467 


M0O3 
found. 
Grm. 

0*2184 
03601 

0-3317 
0-2644 
0-3502 
0-3304 
0-3478 


Per  cent  of 

M0O3  referred 

to  molybdate 

taken. 

[81*71] 
81-51 
81-40 

r8i*85n 

81-69 

81-67 1 

L8i*78J 


Appended  is  a  re-calculation  of  the  percentage  of  the 
trioxide  found,  with  columns  showing  the  percentage 
error  and  the  error  stated  in  fra(5tions  of  a  grm.  Changes 
from  the  figures  of  Friedheim  and  Euler  are  in  modern- 
faced  type. 


Re-calculation 

of  the  Results 

0/ Friedheim  and  Euler. 

CorreAed  per  cent        Error  in  per  cent 
of  MoOg  found,             of  M0O3  found 
referred  to  the        compared  with  M0O3 
molybdate.                        taken. 

Error  of  MoO,. 
Grm. 

81-68 
81*51 

0*23  + 
o-03-f- 

0*0005  + 
O-oooi-f- 

81*40 
80*58 

0-12- 
1-12  — 

0-0004  — 
0*0030  — 

80-69 
80-62 
80-79 

0-99- 
1-05- 
0-86- 

00035  — 
0*0035  - 
0-0030  — 

These  figures  of  their  own  (properly  calculated)  are  suf- 
ficient to  show  the  inadequacy  of  the  method  of  Fried- 
heim and  Euler.  We  ourselves  were  occasionally  able  to 
get  results  from  the  method  of  Friedheim  and  Euler  tjuite 
as  good  as  these ;  it  must  be  said,  however,  that  most  of 
our  results  obtained  by  their  unmodified  method  have 
been  even  worse  than  their  own. 

In  another  series  of  six  determinations,  in  which 
molybdenum  trioxide  was  the  starting  point,  Friedheim 
and  Euler  were  more  successful,  the  errors  varying  from 
0*0006  grm.  +  to  0*0006  grm.  -.  Thus,  Friedheim 
and  Euler  establish  by  their  own  results  the  fa(5t  that  the 
hitting  of  the  right  point  at  which  to  stop  their  process  of 
boiling  is  a  matter  of  chance.  In  spite  of  the  probability 
that  some  of  the  iodine  which  they  found  in  the  receiver 
was  liberated  by  atmospheric  adion,  the  fadl  remains  that 
their  results  are  in  many  cases  very  low.  That  is,  they 
did  not  boil  long  enough. 

The  difficulty  appears  again  in  the  modification  of 
their  method  which  Friedheim  and  Euler  apply  to  the 
determination  of  molybdenum  trioxide  associated  with 
vanadium  pentoxide  (Ber.  d.  D.  Chem.  GeselL,  xxviii., 
2072),  namely,  the  distillation  with  phosphoric  acid  and 


potassium  iodide  of  the  residue  left  after  reducing  the 
vanadium  pentoxide  by  hydrochloric  acid  and  potassium 
bromide,  according  to  the  method  of  Holverscheit.  We 
reproduce  the  part  of  their  table  which  refers  to  the 
determination  of  the  molybdenum,  adding,  however, 
columns  containing  the  errors  and  corrected  percentages. 


Per  cent 

Per  cent 

MoOg 

MoO, 

MoOj 

Error. 

MoOg. 

taken. 

found. 

F.  andE. 

Grm. 

Re-calculated 

0-15037 

0-15005 

99-79 

0*00032- 

99-79 

0*16895 

0*16879 

99*90 

0-00016  — 

99-90 

0-17758 

0-17729 

99-84 

0-00029- 

99-84 

024975 

0-24962 

99-95 

0*00013  — 

99-95 

0*33x51 

0-33607 

[99-87] 

0*00456 -f- 

101*38 

Four  of  the  five  determinations  are  accurate,  but  the 
fadt  that  all  figures  are  carried  out  to  the  fifth  decimal 
place  does  not  keep  three  good  sized  figures  out  of  the 
error  column  for  the  fifth  determination. 

It  is  hardly  necessary,  in  the  light  of  a  comparison  of 
the  results  of  Friedheim  and  Euler  with  ours,  to  discuss 
further  the  unreliability  of  the  unmodified  process.  The 
necessity  of  a  proper  control  of  the  volume,  strength  of 
acid  and  excess  of  potassium  iodide,  as  well  as  proper 
protedion  from  atmospheric  oxidation,  is  real. 

On  a  former  occasion  the  unpleasant  necessity  presented 
itself  (Gooch  and  Browning,  Am.  yourn.  Sci.,  xlv.,334)  of 
pointing  out  the  fad  that  certain  unfounded  criticisms  on 
the  part  of  Friedheim  and  Meyer  were  based  upon  an 
unfortunate  use  by  them  of  impure  reagents ;  the  difficulty 
in  the  present  case,  for  Friedheim  and  Euler,  seems  to 
reside  in  the  arithmetical  process. 


DETERMINATION     OF     POTASH 

AND     PHOSPHORIC     ACID     IN     FODDERS. 

By  H.   W.  WILEY. 

In  the  comparative  analyses  of  soils  during  the  past 
three  years  we  have  grown  a  great  number  of  pot  cultures 
and  determined  the  mineral  plant-foods  in  the  resulting 
crops.  The  following  modified  potash  method,  devised 
by  Mr.  K.  P.  McElroy,  while  not  sacrificing  accuracy,  has 
made  it  possible  for  one  analyst  to  determine  the  potash, 
often  in  duplicate,  in  more  than  ten  samples  a  day.  Since 
the  quantity  of  the  crop  harvested  from  a  poor  soil  is  often 
small,  it  is  desirable  that  the  phosphoric  acid  and  potash 
be  determined  in  the  same  sample. 

The  method  in  use  for  the  determination  of  potash  in 
feeding  stuffs,  in  the  laboratory  of  the  United  States 
Department  of  Agriculture  is  a  simple  modification  of 
the  ordinary  Lindo-Gladding  method,  as  prescribed  by 
the  Association  of  Official  Agricultural  Chemists.  It  is 
as  follows  : — 

Burn  8  grms.  of  the  substance  over  a  low  flame  to  a 
proximate  whiteness.  Burning  after  addition  of  sulphuric 
acid  does  not  give  more  potash  than  burning  alone,  and  it 
is  more  troublesome.  Transfer  the  ash  to  a  200  c.c.  ilask, 
using  about  50  c.c.  of  water;  add  5  c.c.  of  strong  hydro- 
chloric acid,  and  place  on  the  steam-bath  for  an  nour,  or 
boil  from  five  to  ten  minutes.  Add  a  little  iron  chloride 
to  precipitate  all  phosphoric  acid  as  ferric  phosphate,  then 
10  c.c.  of  strong  ammonia,  and  then  from  5  to  10  c.c.  of 
ammonium  carbonate  solution  {200  grms.  per  litre  of  the 
commercial  salt).  Replace  on  the  steam-bath  and  heat 
for  an  hour,  and  allow  to  stand  over  night.  Complete  the 
volume  to  the  200  c.c.  mark  with  water,  and  shake  three 
times  at  intervals  of  five  or  ten  minutes.  Grease  the 
inside  of  the  neck  of  the  flask,  and  pour  its  contents  on 
a  dry  folded  filter.  When  all  is  transferred  to  the  filter 
and  run  through,  wash  down  the  neck  of  the  flask  with  a 
little  water,  put  the  funnel  into  the  flask,  and  stand  aside 
till  the  filter  dries.     The  roll  up  the  filter,  and  push  down 


210 


Chemical  Society. — Anniversary  Meeting. 


Chemical  Nbws, 

April  30,  1807, 


nto  the  flask.  Add  dilute  nitric  acid,  digest,  make  volume 
up  to  the  mark,  and  use  an  aliquot  part  for  the  determma- 
tion  of  phosphoric  acid. 

Transfer  50  c.c.  of  the  filtrate  containing  the  pota^h, 
equivalent  to  2  grms.  of  material,  to  a  platinum  dish, 
cover,  and  heat  on  the  steam-bath  till  evolution  of  gas 
ceases.  Remove  the  cover,  and  rinse  it  and  the  sides  of 
the  dish  with  a  stream  from  the  wash-bottle.  Evaporate 
to  dryness,  and  heat  in  an  air-bath  till  all  water  is  removed 
in  order  to  avoid  loss  by  decrepitation  in  the  subsequent 
ignition.  Heat  over  a  low  gas  flame  till  the  bulk  of  the 
ammonium  chloride  is  removed,  cool,  and  add  i  c.c.  of 
sulphuric  acid  {1:1);  then  heat  on  a  hot  plate  till  fuming 
begins,  then  over  a  flame  till  all  the  sulphuric  acid  is 
driven  off  and  the  residue  in  the  dish  is  white.  Every 
portion  of  the  dish  should  reach  a  lov/  but  distind  red 
heat,  the  bottom  first  and  then  the  sides.  The  reason  for 
the  preliminary  driving  off  of  the  bulk  of  the  ammonia  as 
sal-ammoniac  is  that  ammonium  sulphate  melts  and 
sputters,  involving  danger  of  loss.  Cool  the  dish,  and 
add  one  or  two  drops  of  strong  hydrochloric  acid,  then 
from  50  to  75  c.c.  of  water,  washing  down  the  sides  of 
the  dish  with  a  jet  from  the  wash-bottle.  Add  platinum 
chloride  solution  in  amount  equivalent  to  150  m.m.  of 
metallic  platinum  for  materials  not  containing  over  4  per 
cent  of  potash.  Very  few  reach  this  limit.  Evaporate  on 
the  water-bath  as  usual,  and  take  up  with  alcohol  of  80 
(volume)  per  cent.  Filter  through  a  Gooch  crucible, 
keeping  the  insoluble  material  in  the  dish  as  far  as  pos- 
sible. Wash  with  four  more  portions  of  alcohol,  decanting 
through  the  crucible  each  time.  Finally  rinse  down  the 
sides  of  the  crucible  with  a  stream  of  alcohol  from  a 
wash-bottle.  Cover  the  residue  in  the  dish  with  the  half- 
saturated  solution  of  ammonium  chloride  prescribed  in 
the  official  method  for  the  determination  of  potash,  and 
stir  thoroughly.  Decant  through  the  Gooch  crucible,  and 
treat  with  five  or  more  portions  of  sal-ammoniac  solution, 
decanting  through  the  crucible  each  time.  Finally  wash 
into  the  crucible  with  80  per  cent  alcohol.  When  the 
transfer  is  complete,  rinse  the  sides  of  the  crucible 
thoroughly,  and  finally  fill  it  twice  with  alcohol,  of  course 
constantlv  filtering  with  a  vacuum.  Dry  for  an  hour  at 
100"  and  weigh. 

Pour  about  150  c.c.  of  boiling  water  through  the 
weighed  Gooch  crucible.  If  the  platinum  potassium 
chloride  is  not  wholly  dissolved,  again  bring  the  filtrate 
to  a  boil  and  pour  through  once  more.  Store  this  filtrate 
finally  in  a  large  flask,  containing  aluminium  clippings, 
to  reduce  the  platinum.  Bring  a  fresh  portion  of  water 
{150  c.c.)  to  a  boil,  and  pour  through  the  Gooch  crucible. 
Remove  the  crucible  from  the  vacuum  apparatus,  wipe, 
and  dry  in  an  air-bath,  with  good  ventilation,  for  two 
hours,  at  110°.  Weigh  once  more.  The  loss  in  weight 
is  the  double  chloride.  The  second  portion  of  hot  water 
is  used  to  dissolve  the  double  salt  in  the  next  crucible 
operated  upon,  after  being  once  more  brought  to  a  boil. 
— journal  of  the  American  Chemical  Society,  xix. ,  p.  320. 


PROCEEDINGS    OF    SOCIETIES. 

CHEMICAL  SOCIETY. 
Extra  Meeting,  March  2^th,  1897. 

Mr.  A.  G.  Vernon  Harcourt,  President,  in  the  Chair. 

Professor  P.  Frankland,  Ph.D.,  B.Sc,  F.R.S., delivered 
the  Pasteur  Memorial  Ledlure. 

It  was  pointed  out  that,  although  the  name  of  Pasteur 
was  associated  with  the  progress  of  so  many  branches  of 
science,  it  appeared  that  his  remarkable  success  in  such 
varied  fields  of  investigation  was  in  large  measure  due  to 
the  chemical  discipline  under  which  he  had  grown  up, 


and  in   his  having   almost  for   the   first  time   extended 
the      experimental      methods      and      close      reasoning 
of  the  chemist  to  other  sciences,  in  which   previous  in- 
vestigators had  been   mostly  occupied  with  matters  of  a 
superficial    charadler.      Reference    was    then    made    to 
Pasteur's   birth,   on   December  27,  ,1822,  his   early   life 
and  entrance  as  a  student  into  the  Ecole  Normale,  to  his 
being  retained  as  an  assistant  there  by  Balard,  and  to  his 
interest  being  awakened  in  the  study  of  crystallography 
by  Delafosse.     His  classical  researches  on  the  tartrates 
and  malates  were  then  described,  and  the  principal  results 
discussed  from  a  pradlical  and  theoretical  point  of  view. 
It   was    shown    of  what  enormous    importance   for  the 
development  of  chemical  theory  had  been  the  introdudion 
by  Pasteur  of  the  conception  of  molecular  symmetry  and 
dissymmetry,  whilst  the  wide  applicability  of  his  methods 
of  investigating  stereoisomeric  compounds  was  indicated 
in  outline.     The  manner  in  which  he  was  next  led  to  in- 
vestigate fermentation    phenomena  was  then  described, 
his  conflid  with  Liebig  was  touched  upon,  and  his  over- 
throw of  the  so-called  "chemical  fermentation  theory" 
detailed.     Reference  was  then  made  to  his  participation 
in    the   spontaneous  generation  controversy,  and  to  his 
viftories  over  Pouchet,  Joly,   Musset,  and  Bastian,  the 
last    champions   of  the    dodrine    of    abiogenesis.      The 
pradlical  aspeds  of  Pasteur's, fermentation  studies  were 
briefly  considered,  the  famous  "Etudes  surlabiere";  "  sur 
le  vin,"  and  "sur  la  vinaigre,"  as  well  as  process  known 
as  pasteurisation.    Thedired  influence  of  these  fermenta- 
tion studies  on  medicine,  surgery,  and  public  health  was 
pointed   out,  and  the  manner  in  which   they  had  led   to 
the  magnificent  work  of  Lister  on  the  antiseptic  treatment 
of  wounds  was  indicated.     Pasteur's  investigation  of  the 
destrudive  silkworm  diseases,  pebrlne  and  flacherie,  was 
then  dealt  with,  and  his  gradual  attradion  into  the  field 
of  pathological  research  traced.     His  studies  on  anthrax, 
his  recognition  of  the  bacillus  of  malignant  oedema,  and 
his  discovery  of  the  Staphylococcus  pyogenes  and  of  the 
Streptococcus  pyogenes  were  referred  to.    Then  the  manner 
in  which    he   came   upon  the    possibility  of   attenuating 
viruses  and  preparing  vaccines  were  described  ;  the  ledure 
concluded  with  an  account  of  the  methods  of  protedive 
inoculation  devised  by  Pasteur,  first  for  fowl-cholera,  then 
for  anthrax,  for  swine-measles,  and  his  final   triumph  in 
successfully  elaborating  a  curative  treatment  for  rabies. 

Lord  Lister,  P.R.S.,  proposed,  and  Sir  Henry  Roscoe 
seconded,  a  vote  of  thanks  to  Professor  Percy  Frank- 
land,  which  was  carried  unanimously. 


Anniversary  Meeting,  March  z'^st,  1897. 
Mr.  A.  G.  Vernon  Harcourt,  President,  in  the  Chair. 

Professor  Collie.  F.R.S.,  and  Dr.  Wynne,  F.R.S.,  were 
appointed  scrutators,  and  a  ballot  was  opened  for  the 
eledion  of  Officers  and  Council  for  the  ensuing  year,  the 
ballot  being  closed  at  the  conclusion  of  the  President's 
Address. 

The  Longstaff  Medal  was  then  presented  to  Professor 
Ramsay  for  the  discovery  of  helium,  and  for  his  share  in 
the  investigation  of  argon.  The  President  referred  to 
the  circumstances  under  which  the  first  announcement  of 
the  discovery  was  made,  and  expressed  the  pleasure  he 
felt  in  presenting  him  with  the  Medal. 

The  President  began  his  Address  by  thanking  the 
Fellows,  and  more  especially  the  Officers  and  Council, 
for  the  kindness  with  which  they  had  aided  him  during 
his  year  of  office,  and  expressed  his  pleasure  at  the  pro- 
gress of  the  Society  during  the  past  year.  He  referred  to 
the  arrangements  made  for  the  reading  of  papers,  and 
suggested  means  by  which  the  discussions  might  be  made 
more  useful. 

The  publication  of  the  Jubilee  volume,  largely  drawn 


CBauiCAi.  >Bw&,  I 
April  30,  1897.    I 


Chemical  Society. — Anniversary  Meeting. 


211 


up  by  Dr.  Armstrong,  was  mentioned,  and  the  services 
rendered  by  Mr.  Warington  in  its  preparation  were 
acknowledged.  The  Hofmann  Memorial  Ledlures  had 
also  been  issued.  Lothar  Meyer  and  Pasteur  Memorial 
Lectures  had  been  delivered  in  the  year,  and  arrange- 
ments had  been  made  for  the  Kekule  Ledture.  Reference 
was  also  made  to  the  work  of  the  Council  through  the 
year,  to  the  death  of  Sir  William  Grove,  an  original 
member  of  the  Society,  and  to  the  munificent  donation  of 
one  thousand  guineas  by  Mr.  J.  J.  Tustin. 

The  remainder  of  the  Address  was  devoted  to  the  con- 
sideration of  the  question  whether  the  changes  which 
matter  undergoes  are  different  in  their  nature. 

The  numerical  strength  of  the  Society  was  as  follows  : — 

Number  of  Fellows,  March  31st,  1896 2019 

since  eledled 130 

reinstated  by  Council    ....  7 

2156 
Removed  on  account  of  non-payment  of  two 

annual  subscriptions 25 

Withdrawn 29 

Deaths 23 

—         77 

Number  of  Fellows,  March  31st,  1897 2079 

Foreign  Members 27 

The  following  have  died  : — I.  M.  T.  Anderson  ;  John 
Curragh  ;  Captain  Marshall  Hall;  G.  Harley,  F.R.S. ; 
James  Hart;  John  Hughes;  W.  Lapraik,  Ph.D.  ;  J.  B.  L. 
Mackay;  A.  H.  Mason;  H.  A.  Nott ;  Baron  F.  von 
Mueller,  F.R.S.  ;  W.  J.  Palmer;  Sir  J.  Prestwich, 
F.R.S.  ;  Edward  Rawlms  ;  G.  F.  Schacht  ;  James 
Scorgie  ;  T.  Shimidzu;  T.J.Smith;  Charles  Tomlinson, 
F.R.S.;  W.  H.  Walenn;  Richard  Weaver;  W.  H. 
Wood;  T.  G.  Wormley,  M.D. 

The  number  of  communications  made  to  the  Society 
during  the  year  was  173. 

One  hundred  and  seventeen  papers  and  three  Memorial 
Ledures  were  published  in  the  Transactions  for  1896, 
occupying  1702  pages,  whereas  in  the  preceding  year  116 
papers  were  published,  occupying  1172  pages. 

The  following  were  the  statistics  relating  to  the 
Abstrads: — 

Part  I. 

Pages.        No.  of  abstradls. 
Organic  Chemistry      716  1201 

Part  II. 

General  and  Physical  Chemistry  319 

Inorganic  Chemistry 287 

Mineralogical  Chemistry    ..      ..  267 
Physiological  Chemistry     ..      ..  lg2 
Chemistry  of  Vegetable  Physio- 
logy and  Agriculture       ..      ..  153 
Analytical  Chemistry 430 


Total  in  Part  II.       ..     . 
Total  in  Parts  I.  and  II. 


684 
1400 


1638 
2839 


Eight  hundred  and  fifteen  volumes  had  been  borrowed 
from,  and  163  books,  310  volumes  of  periodicals,  and  24 
pamphlets  added  to  the  Library. 

Professor  Odling,  F.R.S.,  proposed  a  vote  of  thanks 
to  the  President,  coupled  with  the  request  that  he  would 
allow  his  Address  to  be  printed  in  the  Transactions. 

Dr.  Frankland,  F.R.S.,  seconded  the  motion,  which 
was  carried  by  acclamation. 

The  President  having  returned  thanks, 

Dr.  Thorpe,  F.R.S.,  the  treasurer,  gave  an  account  of 
the  balance  sheet,  which  he  laid  before  the  Society,  duly 
audited. 


The  receipts  had  been  : — By  admission  fees  and  sub- 
scriptions, ^4134 ;  by  sale  of  Journal  and  advertise- 
ments, ;£^702  14s.  gd. ;  and  by  dividends  on  invested  capital, 
;^4i5  los.  6d.  Tne  expenses  had  been  : — On  account 
ot  the  Journal,  ;£"3o89  8s.  id.  ;  on  account  of  the 
Proceedings,  ;^237  i8s.  id. ;  on  account  of  the  General 
Index,  ;^464  3s.  gd.  ;  on  account  of  the  Library, 
^355  2S.  od.  ;  on  account  of  the  Jubilee,  ;^336  12s.  id.; 
House  expenses,  3^199  17s.  4d. ;  the  total  expenditure 
being  ;i^5385  4s.  7d.  Grants  amounting  to  ;£'3o8  had  been 
made  to  the  Fellows  from  the  Research  Fund  during  the 
year. 

Sir  F.  Abel,  F.R.S.,  proposed  that  the  thanks  of  the 
Fellows  be  tendered  to  the  Treasurer  for  his  services 
during  the  past  year;  this  motion  was  seconded  by  Mr. 
Phipson  Beale,  Q.C,  and  carried. 

The  Treasurer,  in  responding,  proposed  a  vote  of 
thanks  to  the  auditors. 

Mr.  J.  H.  M.  Page  seconded  the  motion,  which  was 
unanimously  adopted,  and  acknowledged  by  Mr.  H.  B. 
Baker. 

Dr.  W.  J.  Russell,  F.R.S.,  proposed  a  vote  of  thanks 
to  the  Officers  and  Council. 

Professor  TiLDEN,  F.R.S.,  seconded  the  motion,  which 
was  unanimously  adopted. 

Dr.  Dyer  responded  on  behalf  of  the  Council. 

Professor  H.  B.  Dixon,  F.R.S.,  proposed  a  vote  of 
thanks  to  tne  Editor,  Sub -Editor,  Abstractors,  and 
Indexers,  which  was  seconded  by  Mr.  Friswell,  and 
carried. 

Mr.  Groves,  F.R.S.,  responded. 

The  scrutators  having  presented  their  report  to  the 
President,  he  declared  that  the  following  had  been  duly 
eledled  : — 

President — James  Dewar,  M.A.,  LL.D.,  F.R.S. 

Vice-Presidents  who  have  filltd  the  office  of  President — 
SirF.  A.  Abel,  Bart.,  K.C.B.,  D.C.L.,  F.R.S.;  H.  E. 
Armstrong.  Ph.D.,  LL.D.,  F.R.S.;  A.  Crum  Brown, 
D.Sc,  M.D.,  F.R.S.;  W.  Crookes,  F.R.S.;  E.  Frank- 
land,  D.C.L.,  F.R.S.;  Sir  J.  H.Gilbert,  Ph.D.,  F.R.S.; 
J.  H.  Gladstone,  Ph.D.,  F.R.S.;  A.  Vernon  Harcourt, 
D.C.L.,  F.R.S. ;  H.  Miiller,  Ph.D.,  F.R.S.;  W.  Odling, 
M.B.,  F.R.S.;  W.  H.  Perkin,  LL.D.,  Ph.D.,  F.R.S.; 
Lord  Playfair,  Ph.D.,  K.C.B.,  F.R.S.  ;  Sir  H.  E.  Roscoe, 
LL.D.,  F.R.S.;  W.  T.  Russell,  Ph.D.,  F.R.S.;  A.  W. 
Williamson,  LL.D.,  F'.R.S. 

Vice-Presidents — Francis  Robert   Japp,    M.A.,    Ph.D., 
LL.D.,     F.R.S,  ;     Ludwig     Mond,     F.R.S.  ;      William 
Ramsay,  Pn.D.,  F.R.S.;    J.  Emerson   Reynolds,   D.Sc, 
F.R.S.;    W.    Chandler   Roberts-Austen,    C  B.,   F.R.S.;, 
William  A.  Tilden,  F.R.S. 

Secretaries — J.  Millar  Thomson;  Wyndham  R.  Dunstan, 
M.A.,  F.R.S. 

Foreign  Secretary — Raphael  Meldola,  F.R.S. 

Treasurer— T .  E.  Thorpe,  LL.D.,  F.R.S. 

Other  Members  of  Council — P.  Phillips  Bedson,  D.Sc.  ; 
Bennet  Hooper  Brough  ;  Otto  Hehner;  C.  T.  Heycock, 
M.A.,  F.R.S.  ;  Herbert  McLeod,  F.R.S.  ;  Rudolph 
Messel,  Ph.D  ;  H.  Forster  Morley,  M.A.  ;  James  Wyllie 
Rodger;  T.  Kirke  Rose,  D  Sc. ;  Alexander  Scott,  M. A., 
D.Sc. ;  Arthur  Smithells,  B.Sc. ;  Sydney  Young,  D.Sc, 
F.R.S. 

The  question  having  been  raised  as  to  whether  the 
number  of  votes  cast  for  each  candidate  for  the  Presidency 
should  be  declared,  the  President  stated  that  this  had 
not  been  the  custom,  but  he  would  take  the  sense  of  the 
meeting  on  the  point.  A  majority  being  in  favour  of  a 
declaration  of  the  numbers,  the  President  conferred  with 
the  scrutators  and  then  stated  that  there  was  a  difficulty 
in  announcing  the  numbers,  owing  to  a  question  having 
arisen  in  reference  to  the  validity  of  certain  voting  papers, 
in  which  the  instrudlion  to  erase  the  printed  name  had 
not  been  complied  with. 

Inasmuch  as  the  rejedtion  of  these  irregular  papers 
would  only  increase  the  majority  and  not  affedl  the  result 


212 


Compostiton  or  Cooked  Fish. 


I  Chemical  News, 
1     April  30,  1897. 


of  the  eledlion,  and  as  it  now  appeared  that  the  announce- 
.ment  of  the  numbers  would  involve  re-counting  the 
votes,  the  President  suggested  that  the  Fellows  should 
be  content  with  the  scrutators'  report.  The  ruling  of  the 
President  as  to  the  validity  of  the  irregular  papers  having 
been  requested,  he  stated  that,  in  his  opinion,  they  were 
invalid. 

Questions  having  been  asked  as  to  the  by-laws 
governing  the  eledion,  the  President  stated  that  the 
eletflion  had  been  conduced  in  strid  accordance  with  the 
by-laws,  and  he  therefore  declared  the  ele(5lion  valid. 

In  the  evening,  at  7  p.m.,  the  Fellows  and  their  friends 
dined  together  at  the  Criterion  Restaurant,  Mr.  A.  G. 
Vernon  Harcourt,  the  retiring  President,  in  the  Chair. 

The  following  toasts  were  proposed  : — 

By  the  Chairman  :  i.  Her  Most  Gracious  Majesty  the 
Queen.  2.  Their  Royal  Highnesses  the  Prince  and 
Princess  of  Wales  and  the  others  members  of  the  Royal 
Family. 

By  the  Right  Hon.  Lord  Lister,  President  of  the  Royal 
Society  :  3.   Prosperity  to  the  Chemical  Society. 

By  William  Crookes,  £5^.,  F.R.S. :  4.  The  Learned 
and  Scientific  Societies,  coupled  with  the  name  of  Sir 
John  Evans,  K.C.B.,  Treasurer  of  the  Royal  Society. 

By  Dr.  J.  H.  Gladstone,  F.R.S.  ;  5.  The  Guests, 
coupled  with  the  name  of  Professor  Michael  Foster, 
Secretary  of  the  Royal  Society. 

By  Dr.  W.  J.  Russell,  F.R.S. :  6.  The  retiring 
President. 

By  Dr.  Armstrong,  F.R.S. :  7.  The  Secretaries, 
coupled  with  the  name  of  Professor  J.  M.  Thomson. 


Ordinary  Meeting,  April  ist,  1897. 

Prof.  Dewar,  F.R.S.,  President,  in  the  Chair. 

Messrs.  William  Douglas,  Ernest  Goulding,  T.  H.  Lee, 
and  W.  A.  Davis  were  formally  admitted  Fellows  of  the 
Society. 

Certificates  were  read  for  the  first  time  in  favour  of 
Messrs.  William  Barlow,  Hillfield,  Muswell  Hill,  N.; 
James  Brierley,  12,  Biunswick  Square,  Southampton ; 
Alexander  Duckham,  Grooms  Hill,  Greenwich  Park,  S.E. ; 
Harold  William  Harrie,  298,  Amhurst  Road,  Stoke  New- 
ington,  N.;  Sydney  Hill,  11,  Salisbury  Street,  Hull; 
Willie  Lee  Mallinson,  Gawthorp  Green,  Kirkheaton ; 
Edmund  Howd  Miller,  M.A.,  Ph.D.,  Columbia  University, 
U.S.A. ;  Joseph  Previte  Kennedy  Orton,  BA.,  Ph.D.,  20, 
Loughborough  Road,  Biixton,  S.W. ;  Charles  Alfred 
West,  105,  Sydney  Street,  Chelsea,  S.W. ;  Paul  Thomas 
White,  Horton  Field,  West  Drayton. 

Mr.  Cassal  asked  whether  the  President  would  take 
steps  to  carry  into  efFeft  the  wishes  of  a  majority  at  the 
Anniversary  Meeting,  that  a  recount  of  the  ballot  papers 
should  be  made,  and  the  votes  recorded  for  the  two 
nominees  for  the  Presidency  announced  to  the  Fellows. 
Mr.  Vernon  Harcourt  said  that,  although  a  majority 
at  the  Anniversary  Meeting  had  declared  themselves  in 
favour  of  the  announcement  of  the  numbers,  it  had  not 
been  found  possible  to  make  any  exad  announcement 
without  going  through  the  voting  papers  again,  and  he 
had  hoped  that,  having  regard  to  all  the  circumstances, 
it  would  be  generally  felt  best  to  accept  the  result  of  the 
eledlion  as  it  had  been  recorded  by  the  Scrutators,  espe- 
cially as  a  succindl  and  accurate  account  of  what  had 
happened  at  the  Anniversary  Meeting  had  been  included 
in  the  minutes. 

The  President  said  he  considered  the  subjeft  closed, 
but  promised  to  bring  the  question  before  the  Council. 
He  could  not  see  that  any  good  would  result  from  a  re- 
count of  the  voting  papers  for  the  mere  purpose  of 
delaring  the    exadl  numerical  majority  by    which    the 


President  had  been  eleded.     He   hoped  that  long  before 
the  Council  met  the  matter  would  be  forgotten. 

Of  the  following  papers  those  marked  *  were  read  : — 

*50.  "  The  Hydrolysis  of  Perthiocyanic  Acid."  By  F. 
D.  Chattaway,  M.A.,  and  H.  P.  Stevens,  B.A. 

When  potassium  thiocyanate  is  treated  with  sulphuric 
acid,  many  different  substances  are  produced ;  thiocyanic 
acid,  however,  is  always  first  liberated,  and  then  readls  in 
various  ways  determined  by  the  conditions  of  the  ex- 
periment. 

The  best  known  readlion,  usually  represented  as  a 
simple  hydrolysis  of  thiocyanic  acid,  is  that  by  which 
carbon  oxysulphide  is  commonly  prepared.  Other  adtions, 
however,  go  on,  and  the  carbon  oxysulphide  is  invariably 
mixed  with  carbon  dioxide,  sulphur  dioxide,  hydrocyanic 
acid,  and  carbon  bisulphide. 

The  authors  have  observed  that,  in  addition  to  these,  a 
considerable  amount  of  thiourea  is  produced.  This  thio- 
urea has  been  found  to  be  a  decomposition  produft  of 
perthiocyanic  acid,  which  is  always  formed  in  consider- 
able quantity  when  acids  adl  upon  thiocyanates,  and  the 
paper  deals  mainly  with  the  hydrolysis  of  this  acid. 

Perthiocyanic  acid  is  easily  hydrolysed,  either  by  heating 
with  water  under  pressure,  or  by  heating  with  strong  sul- 
phuric acid,  thiourea,  carbon  oxysulphide,  and  sulphur 
being  formed. — 

H2N2C2S3  -f-  H2O  =  CS(NH2)2  +  COS  +  S. 
As  the  adlion  only  takes  place  at  a  comparatively  high 
temperature,  one  or  other  of  these  produdls  is  invariably 
decomposed.  When  perthiocyanic  acid  is  heated  with 
water  to  about  200°  in  closed  tubes,  this  aftion  may  be 
considered  to  take  place  first ;  but  at  the  high  temperature 
the  thiourea  is  transformed  completely  into  ammonium 
thiocyanate,  while  the  carbon  oxysulphide  reads  with 
water,  giving  carbon  dioxide  and  hydrogen  sulphide,  so 
that  the  final  adion  is — 

H2N2C2S3  -f  2H2O  =  NH4NCS  +  CO2  +  H2S  4-  S. 

When  perthiocyanic  acid  is  heated  with  60  per  cent 
sulphuric  acid,  a  similar  hydrolysis  must  also  take  place  ; 
a  certain  amount  of  the  thiourea,  however,  escapes  trans- 
formation, but  the  sulphur  and  carbon  oxysulphide  are 
oxidised  by  the  sulphuric  acid,  sulphur  dioxide  and  carbon 
dioxide  being  produced. 

The  thiourea  found  among  the  produdts  of  the  a&ion  of 
strong  sulphuric  acid  on  potassium  thiocyanate,  is,  with- 
out doubt,  formed  in  this  way  by  the  adlion  of  the  strong 
acid  on  the  perthiocyanic  acid  first  produced. 

Discussion. 
In  reply  to  questions  from  Mr.  Groves  and  the 
President,  Mr.  Stevens  stated  that  they  had  not  been 
able  to  analyse  the  liquid  supposed  to  be  hydrogen  disul- 
phide,  but  they  were  satisfied  as  to  its  identity  from  a 
comparison  of  its  properties  with  those  of  hydrogen  disul- 
phide  specially  prepared  for  the  purpose. 

•51.  ''The  Composition  of  Cooked  Fish."  By  Katharine 
I.  Williams. 

Twenty-two  species  of  fresh  fish  and  five  species  of 
preserved  fish  and  oysters  were  examined  after  cooking. 

Determinations  were  made  of  the  following  con- 
siituents  : — Water  ;  carbon  and  hydrogen  ;  nitrogen  (total) 
by  Ruffle's  method ;  nitrogen  by  soda-lim«  combustion  ; 
ash  ;  sulphur  ;  phosphorus  ;  fat ;  proteids  ;  carbohydrates 
convertible  into  glucose ;  nitrates  extraded  by  dilute  al- 
cohol ;  heats  of  combustion.  The  results  are  recorded 
in  a  series  of  tables. 

Discussion. 

In  reply  to  questions  from  Mr.  Groves,  Mr.  Hehner,. 
Mr.  Sutherland,  Mr.  Cassal,  and  Prof.  Dunstan,  Miss 
Williams  stated  that  the  fish,  in  each  case,  had  been 
analysed  in  the  condition  in  which  it  would  be  eaten. 
Details  of  the  mode  in  which  the  fish  had  been  prepared 
were  given  in  the  paper.     The  common  opinion  that  fish 


wBBWICAL  ^B^VS,  I 

April  30, 1897.     I 


Carbohydrates  of  Wheats  Maize,  Floury  and  Bread. 


213 


contained  much  phosphorus  seemed  to  be  erroneous. 
Little  or  none  of  the  phosphorus  would  be  removed  in 
cooking. 

*52.  "  On  the  Oxidation  Products  of  ay-Dimethyl- 
a'-Chloropyridine."  By  Emily  Aston,  B.Sc,  and  J. 
Norman  Collie,  Ph.D.,  F.R.S. 

The  present  communication  is  an  account  of  the  con- 
tiuuation  of  some  work  of  one  of  the  authors  with  A.  P. 
Sedgwick  {Trans.,  1895,  Ixvii.,  399).  The  substance 
a-y-dimethyl-a'-chloropyridine  was  obtained  by  the  action 
of  phosphorus  pentachloride  on  pseudolutidostyril.  When 
oxidised  with  potassium  permanganate,  two  isomeric  acids 
are  obtained,  each  having  the  formula — 

C5H2(CH3)(COOH)NCl. 

One  (m.  p.  98°)  is  much  more  soluble  in  water  than  the 
other  and  crystallises  with  i  mol.  of  water;  it  produces 
with  ferrous  sulphate  an  orange-brown  colouration.  When 
strongly  heated,  it  decomposes  with  much  charring  and 
evolution  of  carbon  dioxide  and  some  hydrogen  chloride ; 
the  residue  furnished  a-chloro-T'-methylpyridine, — 

C5H3(CH3)NC1,  b.p.  194°. 

Prolonged  treatment  with  tin  and  hydrochloric  acid  gave 
■y-methylpicolinic  acid,  and  this  substance  when  distilled 
yielded  picoline  or  ^-methylpyridine. 

This  acid  (m.  p.  98°)  is,  therefore,  a-chloro-7-methyl- 
a'-pyridine  carboxylic  acid. 


'\CH 


cciy' 


The  second  acid  obtained  by  the  adion  of  potassium 
permanganate  on  ay-dimethyl-a'-chloropyridine  is  much 
less  soluble  in  water.  It  melts  at  214°,  and  on  heating 
completely  decomposes  without  forming  chloropicoline. 
With  ferrous  sulphate  it  furnished  a  precipitate  instead 
of  a  colouration.  Tin  and  hydrochloric  acid  only  reduced 
it  very  slowly,  and  it  was  found  to  be  impossible  to  sepa- 
rate the  chlorine  free  acid  from  the  unchanged  compound. 
A  small  quantity  of  free  o-picoline  was,  however,  obtained 
by  distilling  the  impure  reduced  acid,  thus  proving  that 
this  acid  (m.  p.  214°)  was  thea-chloro-a-methyl-a'-pyridine 
carboxylic  acid. 

COOH— C/^^^  ^  C(CH3)\j^ 

Attempts  were  made  to  obtain  the  dicarboxylic  acid 
from  both  the  acids  by  oxidising  with  potassium  perman- 
ganate, but  without  success. 


NOTICES  OF  BOOKS. 


The  Carbohydrates  of  Wheat,  Maize,  Flour,  and  Bread  ' 
and  the  Action  oj  Enzymic  Ferments  upon  Starches  of 
Different  Origin.     By  W.  E.  Stone,  Ph.D.,  Professor 
of  Chemistry,  Purdue  University.    Washington  :  Govern- 
ment Printing  Office.     1896. 
The  investigations    described  in    this   report  constitute 
part  of   the  enquiries  being    carried  on   to   enable   the 
Secretary  of  Agriculture  to  investigate  and  report  on  the 
nutritive  value  of  various  articles  of  food. 

It  has  long  been  customary  to  estimate  the  quantity  of 
carbohydrates  in  grains  and  flours  by  difference,  that 
portion  of  the  material  not  found  to  be  of  the  nature  of 
fat,  ash,  moisture,  fibre,  or  of  nitrogenous  charadler,  being 
regarded  as  of  carbohydrate  nature.  The  investigations 
here  recorded  have  been  made  with  the  objedt  of  discri- 
minating between  the  various  carbohydrates  known  to  be 
present  in  cereals,  and  to  trace  the  effe<a  of  the  separation 
of  the  grain  into  its  parts,  as  occurs  in  milling.  The 
different  kinds  and  qualities  of  wheat,  maize,  and  flour 
examined,  as  well  as  the  methods  employed,  are  then 
fully  gone  into,  and  it  is  important  to  note  that  each  con- 


stituent has  been  actually  determined,  and  that  no  result 
has  been  obtained  by  "  difference,"  each  carbohydrate, 
with  the  exception  of  cellulose,  having  been  brought  to 
the  form  of  reducing  sugar,  in  which  state  it  was  titrated 
with  Fehling's  solution. 

Both  classes  of  wheat  examined  were  found  to  contain 
small  amounts  of  sucrose,  ranging  from  o'5  per  cent  up- 
wards; the  principal  carbohydrate  present  is  starch, 
which  reached  30  per  cent.  This  proportion  was  consi- 
derably increased  by  milling,  which,  by  eliminating  a  good 
deal  of  the  fibre,  brought  the  amount  of  starch  up  to  35, 
and  even  45  per  cent. 

Breads  made  from  these  flours  were  then  examined, 
and,  contrary  to  expectation,  it  was  found  that  the  adtion 
of  bread-making  and  baking  does  not  change  the  nature 
or  condition  of  the  carbohydrates  of  wheat  and  maize  to 
any  great  extent ;  in  the  case  of  wheat  flour  with  one  appa- 
rently abnormal  exception,  not  more  than  10  per  cent  of 
the  total  starch  originally  present  was  changed  in  any 
way. 

The  attention  of  investigators  has  of  late  been  direded 
to  the  adtion  of  enzyms  on  carbohydrates.  Recent  re- 
searches show  that  different  yeasts  produce  certain 
specific  enzyms,  each  with  an  ability  to  convert  some 
particular  class  of  carbohydrate,  such  as  ladlose,  maltose, 
or  sucrose  ;  for  instance,  ordinary  yeast  inverts  the  two 
latter,  but  not  the  former,  while  others  will  produce 
enzyms  converting  either  sucrose  or  ladose,  but  not 
maltose.  The  susceptibility  of  starches  to  the  more 
important  enzyms,  viz,,  those  occurring  in  grains,  or 
more  especially  diastase,  those  occurring  in  saliva,  parti- 
larly  ptyalin,  and  those  occurring  in  the  pancreatic 
secretion,  were  the  subiedl  of  the  next  studies.  In 
addition,  a  few  experiments  were  made  with  a  new 
diastatic  enzym  developed  by  the  fungus  Eurotium  oryza, 
discovered  by  Mr.  Jokichi  Takamine,  and  known  com- 
mercially as  "Taka-koji"  or  "  Taka-diastase."  The 
results  have  a  pradtical  bearing  on  the  comparative 
digestibility  of  different  starches.  The  adtion  of  diastase 
on  starch  is  increased  by  minimal  amounts  of  acids,  and, 
on  the  other  hand,  it  is  checked  or  altogether  stopped  by 
greater  amounts  of  acids,  and  the  smallest  amounts  of 
alkalis,  or  alkaline  salts. 

The  ability  of  diastase  to  convert  large  amounts  of  starch 
into  soluble  compounds  is  remarkable ;  some  authors 
estimate  it  at  as  much  as  200,000  times  its  own  weight. 
There  has  been  much  discussion  as  to  the  nature  and 
number  of  the  intermediate  produds  of  the  decomposi- 
tion of  starch  ;  but  it  is  now  considered  probable  that 
they  consist  of  the  various  forms  of  dextrin,  which  gra- 
dually become  changed  to  maltose  and  isomaltose. 
Under  precisely  similar  conditions  the  adtion  of  different 
enzyms  on  different  starches  varies  considerably,  some 
starches  requiring  eighty  times  as  long  as  others  for 
complete  saccharification,  but  they  all  preserve  the  same 
relative  order  with  regard  to  the  commoner  enzymic  fer- 
ments ;  with  taka-diastase,  potato-starch  was  completely 
converted  in  seven  minutes,  this  being  much  quicker 
than  with  any  of  the  others ;  and  it  is  reasonable  to 
assume  that  the  relative  degree  of  susceptibility  exhibited 
by  starches  in  the  experiments  described  would  still  hold 
good  when  subjedted  to  the  same  enzyms  in  the  process 
of  digestion  ;  in  fadt,  we  understand  that  "  taka-diastase" 
is  being  largely  and  increasingly  used  in  cases  of  dyspepsia 
with  excellent  results. 


Commercial  Fertilisers  and  Chemicals,  Inspected,  Analysed, 

and  Admitted  for  Sale,  in  the  State  of  Georgia,  up  to 

September  ist,  1896.     By  Dr.  George  F.  Payne,  State 

Chemist.     Atlanta,  Georgia  :  G.   W.  Harrison,  State 

Printer. 

This  book  is  chiefly  devoted  to  a  recital  and  exposition 

of  the   State   laws    of  Georgia   regulating    the    sale    of 

manures.    These  laws  certainly  do  not  err  on  the  side  of 

undue  lenity.     All  manures   have   to   be  sold  under  aa 


214 


A  Reclamation. 


I  Chemical  News, 
1      April  30.  1807. 


analysis,  setting  forth  the  moisture  at  212°  F.,  the  inso- 
luble phosphoric  acid,  the  available  phosphoric  acid,  the 
ammonia  adlual  and  potential,  and,  lastly,  the  potash. 

The  fadt  that  the  purchaser  waives  the  inspedion  and 
official  analysis  "  shall  be  no  protedlion  to  any  person 
selling  or  offering  fertilisers  for  sale."  In  addition  to  the 
labels  attached  to  the  packages,  there  are  to  be  fixed  on 
each  box,  barrel,  &c.,  leaden  tags  numbered  progressively. 
Any  tags  left  in  possession  of  the  manufadlurer  or  mer- 
chant at  the  close  of  the  season  shall  not  be  used  for 
another  season,  nor  shall  they  be  redeemable  by  the 
Department  of  Agriculture.  The  analysis  of  the  State 
chemist  is  to  be  held  by  an  official  known  as  the 
"  ordinary." 

The  analysis  given  by  the  State  chemist  or  his  substi- 
tute is  held  to  be  conclusive  evidence  against  a  charge 
of  " partial  or  total  failure  of  consideration."  Hence  it 
seems  that  if  the  dealer's  analysis  is  fully  confirmed  by 
the  State  chemist,  the  dealer  is  not,  as  a  matter  of  course, 
entitled  to  his  money.  This,  however,  is  still  more  equi- 
table than  our  English  pratftice.  With  us  a  purchaser  of 
manures  may  ignore  for  a  year  or  more  all  applications 
for  payment,  and  at  last,  when  he  finds  that  his  creditor 
is  in  earnest,  may  still  be  allowed  to  plead  defedive 
quality — a  plea  which,  if  well  founded,  should  have  been 
urged  in  answer  to  the  first  application  for  payment. 


Agricultural  journal,  published  by  the  Department  of  Agri- 
culture, Cape  of  Good  Hope.  January  14,  1897.  Cape 
Town  :  Townhend,  Taylor,  and  Snashall. 
This  issue  is  very  rich  in  useful  observations.  Across 
the  Free  State  border  there  are  several  farms  being  visited 
by  rinderpest,  whilst  the  colonial  area  is  still  entirely  free. 
Inoculation  with  garlic  in  the  dewlap  has  proved  useless, 
as  has  also  drenching  with  petroleum  and  carbolic  acid. 

In  the  Richmond  distridl  droves  of  wild  ostriches  have 
made  their  appearance,  and  are  doing  damage. 

The  vapour  of  carbon  bisulphide  is  strongly  recom- 
mended for  dealing  with  destrudtive  insedls,  care  being  of 
course  taken  to  keep  lighted  candles  and  matches  at  a 
distance. 

In  South  Africa,  as  far  as  it  is  known,  there  are  no  soils 
rich  in  potash. 

Dr.  R.  Morloth  strongly  recommends  basic  slags  fur 
suppying  the  needful  phosphate  on  the  Cape  Flats  and 
the  whole  of  the  Western  province. 


The  Law  and  Practice  of  Letters  Patent  for  Inventions. 
By  Lewis  Edmunds,  D.Sc,  Q.C,  of  the  Inner  Temple 
and  of  the  Oxford  Circuit.  Second  Edition,  by  T.  M. 
Stevens,  D.C.L.,  of  Gray's  Inn  and  of  the  South- 
Eastern  Circuit,  Barrister-at-Law.  London  :  Stevens 
and  Sons,  Limited.     1897.     8vo.,  pp.  943. 

A  WORK  of  this  kind  presents  to  the  authors  unusual  diffi- 
culties, on  account  of  the  complicated  nature  of  the  sub- 
ject matter  which  lies  on  the  borderland  between  law  and 
technology,  whether  the  invention  relates  to  physics, 
chemistry,  or  mechanics. 

A  further  complication  is  that  such  works  are  rightly 
expe<5ted  to  deal  with  Patent  Law  and  Pradice  as  at  pre- 
sent existing,  whilst  the  inventor  not  improbably  and  not 
unreasonably  demands  to  see  where  such  law  and  pradice 
might  be  improved  to  the  encouragement  of  our  national 
industries.  The  Patent  Law  Amendment  Ads  of  1852 
and  1883  have  involved  important  alterations,  both  in  law 
and  pradice,  which  the  authors  have  set  forth  fully  and 
clearly. 

One  of  the  great  defeds  of  our  patent  system  is  that  it 
is  not  imperial.  To  obtain  the  protedion  of  an  invention 
for  the  whole  of  Her  Majesty's  dominions  costs,  if  we 
remember  rightly,  about  ;£'iioo.  Now,  what  we  want  is 
a  system  of  imperial  patents,  obtainable  on  equal  terms, 


and  with  equal  advantages,  in  London,  Calcutta,  Cape 
Town,  Sydney,  or  other  suitable  central  cities. 

Another  defed  in  our  patent  arrangements  is  the  very 
"  one-sided  reciprocity  "  with  alien  countries  which  we 
have  agreed  to.  Thus  a  German  or  a  French  subjed  can 
obtain  and  uphold  a  British  patent  just  as  easily  as  a 
British  subjed.  But  if  the  latter  applies  in  Berlin  for 
the  protedion  of  an  invention,  his  application,  after  pro- 
longed correspondence,  may  be  refused. 

In  most  countries  a  patent  is  granted  to  any  applicant 
inter  alia  on  the  condition  that  it  is  adually  and  continu- 
ously worked  on  a  commercial  scale  in  the  country  or 
countries  in  which  it  is  patented.  In  Britain  no  such 
stipulation  prevails,  and  an  article  made  under  any 
existing  and  unexpired  British  patent  may  be  imported 
from  abroad. 

A  deficiency  in  the  British  patent  system  is  that  it  pro- 
teds  the  so-called  invention  and  sale  of  quack  medicines, 
foods,  cosmetics,  &c.,  in  which  the  inventor  claims  to 
have  some  exclusive  right  or  secret.  Here  we  might 
advantageously  copy  the  German  patent  law,  which 
refuses  patents  for  medicines,  &c.  But  we  might  justly 
and  wisely  go  a  step  further,  and  cut  off  the  stratagem  by 
which  a  German  quack  evades  the  law,  i.e.,  by  refusing 
protedion  to  methods  for  manufaduring  "  nostrums  "  or 
secret  and  "  proprietary  "  articles  whatever. 

The  work  before  us  will  be  found  invaluable  to 
patentees,  counsel,  solicitors,  patent  agents,  and  all 
persons  who  have  to  take  into  consideration  the  value  of 
an  invention.  We  do  not  hope  that  it  may  be  of  service 
to  the  pseudo-inventors — "  sifters  "  as  they  are  called  in 
the  manufaduring  distrids — who  are  always  trying  how 
near  they  can  sail  to  some  valuable  novelty. 


CORRESPONDENCE. 


A    RECLAMATION. 

To  the  Editor  of  the  Chemical  News. 
Sir, — My  attention  has  been  called  to  "  A  Reclamation  " 
in  the  Chemical  News  of  March  19th  (vol.  Ixxv.,  p,  134). 
This  note  conveys  an  erroneous  impression.  The  author 
of  it,  who  is  apparently  Kippenberger  (not  Riffenbach)  is 
made  to  say  that  "  he  published  this  research  by  Gomberg 
in  the  Zeitschriftfur  Analytische  Chetnie,  1896,  p.  466,  as 
a  supplement." 

On  reference  to  this  article  I  find  that  Kippenberger,  in 
a  "  Nachtrag"  to  the  article  cited  refers  to  the  article  of 
Gomberg  and  comments  on  it  at  some  length,  but  nowhere 
charges  that  Gomberg  did  anything  improper.  Anyone 
reading  the  note  in  the  Chemical  News  would,  I  think, 
conclude  that  Gomberg  stole  the  article,  and  that  the 
Journal  of  the  American  Chemical  Society  had  no  right  to 
publish  it.  This,  I  think,  does  injustice  both  to  Gomberg 
and  to  the  Society,  and  I  wish  to  corred  this  false  im- 
pression.— I  am,  &c., 

Edward  Hart, 
Editor  of  the  Journal  of  the 
American  Chemical  Society. 

Easton,  Pa.,  April  6,  1897. 


Physiological  and  Pathological  A<I\ion  of  the  X 
Rays.— M.  Sorel.— The  X  ray  exerts  a  powerful  adion 
upon  the  cell  and  its  contents,  and  its  prolonged  appli- 
cation would  be  imprudent,  at  least  in  certain  subjeds, 
near  the  important  organs  such  as  the  stomach,  the  heart, 
the  lungs,  and  the  eyes.  In  a  great  number  of  cases  the 
body  of  a  dead  animal  is  always  much  more  opaque  to 
the  X  rays  than  the  body  of  a  similar  animal  immediately 
after  death  and  still  vfSLrm.—Compt.  Rend.,  cxxiv.,No.  15. 


Chemical  News,  i 
April  30, 1897.    ) 


CHEMICAL 


Chemical  Notices  from  Foreign  Sources, 


21 


NOTICES  FROM 
SOURCES. 


FOREIGN 


Note. — All  degrees  of  temperature  are  Centigrade  unless  otherwise 
expressed, 

Comptes  Rendus  Hebdomadaires  des  Seances,  deVAcademie 
des  Sciences.     Vol.  cxxiv.,  No.  15,  April  12,  1897. 

Law  of  the  Discharge  of  Eledlirised  Uratiium  into 
the  Air. — Henri  Becquerel. — The  author  gives  in  this 
paper  the  law  of  the  loss  of  elecStricity  by  uranium  as  a 
funcftion  of  time  and  of  the  potential  of  the  eledrised 
bodies.  Salts  of  uranium  which  he  has  preserved  for 
more  than  a  year  proteded  from  any  known  radiation 
continue  to  emit,  with  an  intensity  scarcely  decreased, 
radiations  which  produce  photographic  impressions 
through  opaque  bodies. 

Photography  of  Konig's  Flames. — M.  Maraze. — This 
paper  requires,  or  rather  consists  of,  eight  photographic 
proofs. 

Experiments  made  with  a  New  Kathodic  Apparatus 
generating  X  Rays,  and  with  several  Vessels  sealed 
on  the  same  Gaseous  Circuit. — Foveau  de  Courmelles 
and  G.  Segny. — On  observing  the  luminous,  fluorescent, 
and  kathodic  effedts  produced  we  find  that  the  internal 
pressure  in  an  exhausted  tube  is  not  equal  at  all  points;  that 
towards  the  extremity  the  vacuum  is  much  more  complete 
than  at  the  other  extremity  of  the  same  gaseous  circuit, 
and  that  the  molecules  which  are  able  to  remain  in  such 
highly  rarefied  media  are  driven  with  extreme  violence 
towards  the  most  extreme  point  of  the  circuit  of  the  appa- 
ratus. The  authors  signalise  the  rapidity  and  definiteness 
of  the  results  obtained  with  the  vacuum  tube. 

Formation  Heats  of  Formic  Aldehyd.— Marcel  Dele- 
pine. — A  thermochemical  memoir.  The  formation  heat 
of  gaseous  formic  aldehyd  from  its  elements  is  -t-25'4 
cals.,  and  of  dissolved  aldehyd  is  +40'4  cals. 

Formation  of  Ammonium  Cyanide  and  its  Manu- 
fadlure. — Denis  Lance. — Ammonia  gas  passing  over  car- 
bon at  a  temperature  between  1000°  and  1100°  C.  always 
yields  ammonium  cyanide.  The  yield  of  cyanogen  is 
more  considerable  if  we  use  a  mixture  of  ammoniacal  gas, 
nitrogen,  and  hydrogen.  The  yield  reaches  its  maximum 
at  1100°  C,  and  when  the  gases  are  in  the  following  pro- 
portions : — NH5  =  i-26th  of  the  mixture  formed  by  N  and 
loH.  In  these  conditions  at  least  70  per  cent  of  the 
nitrogen  of  the  ammonium  cyanide  is  derived  from  the 
free  nitrogen  of  the  mixture,  i.e.,  from  the  nitrogen  of  the 
air. 


MISCELLANEOUS. 


The  Stas  Memorial. — Invitations  have  been  sent  by 
the  Organising  Committee  to  all  subscribers  to  attend 
the  Inauguration  of  the  Monument  eredled  to  Stas.  The 
ceremony  will  take  place  on  May  nth,  at  4  p.m.,  in  the 
garden  of  the  Palace  of  the  Academies,  Brussels. 

Iron  and  Steel  Institute. — The  Annual  Meeting  of 
the  Institute  will  be  held  at  the  Institution  of  Civil 
Engineers,  Great  George  Street,  Westminster,  on  Tuesday 
and  Wednesday,  the  nth  and  12th  days  of  May,  1897, 
commencing  each  day  at  10.30  o'clock  a.m.  The  fol- 
lowing is  a  list  of  Papers  that  are  expecSed  to  be  read  and 
discussed : — 

'•  On  the  Permeability  of  Steel-making  Crucibles,"  by 
Professor  J.  O.  Arnold  and  F.  K.  Knowles. 

*'  On  the  Pradice  of  the  Combined  Open-hearth 
Process  of  Bertrand  and  Thiel,"  by  E.  Bertrand. 


"  On  the  Agricultural  Value  of  Sulphate  of  Ammonia 
from  Blast-furnaces,"  by  F.  J.  R.  CaruUa. 

"On  the  Specific  Heat  of  Iron,"  by  Professor  W.  N. 
Hartley,  F.R.S. 

"  On  Charging  Open-hearth  Furnaces  by  Machinery," 
by  Jeremiah  Head. 

"  On  the  '  Weardale  '  Re-heating  Furnace,"  by  H.  W. 
Hollis. 

"  On  the  EfTed  of  Phosphorus  on  Cold  Shortness,"  by 
Baron  Hanns  Juptncr  von  Jonstorff. 

"  On  the  Determination  of  Hardening  and  Carbide 
Carbon,"  by  Baron  Hanns  Juptner  von  Jonstorff. 

"On  Malleable  Cast  Iron,"  by  G.  P.  Royston. 

"  On  Carbon  Changes  connedted  with  Malleable  Cast 
Iron,"  by  G.  P.  Royston. 

"  On  Microscope  Accessories  for  Metallographers,"  by 
J.  E.  Stead,  Member  of  Council. 

"  On  Central  Blast  Cupolas,"  by  T.  D.  West. 

Silver  Hydride.  —  Edwin  J.  Bartlett  and  W.  F.  Rice 
{Am  .Chern.  y.,  xix.,  49-52). — Silver  hydride,  AgH,  was 
prepared  by  precipitating  a  dilute  solution  of  silver  nitrate 
with  dilute  hypophosphorous  acid  in  excess.  The  solu- 
tion becomes  wine-coloured  at  first,  changing  to  black, 
and  after  a  few  minutes  black  spongv  flakes  are  precipi- 
tated, which  are  filtered  at  once.  The  filtrate,  on  long 
standing  or  boiling,  deposits  metallic  silver.  Silver 
hydride  is  not  decomposed  by  water. — jfourn.  American 
Chemical  Society. 

Paraisobutylphenoxyacetic  Acid.  —  W.  P.  Bradley 
and  F.  Kniffen  {Am.  Chem.  jfourn.,  xix.,  70 — 76). — Para- 
isobutylphenoxyacetic acid  was  prepared  by  heating 
paraisobutylphenol  and  chloracetic  acid  dissolved  in 
sodium  hydroxide.  The  mixture  was  neutralised  with 
sulphuric  acid,  treated  with  an  excess  of  sodium  car- 
bonate, and  extracted  with  ether  to  remove  any  excess  of 
phenol.  The  resulting  liquid  was  then  evaporated  to  a 
small  bulk,  acidified,  and  the  acid  extraded  with  ether. 
The  compound  is  a  cream-white  solid,  melts  at  86'5°,  and 
crystallises  from  ligroin  in  radial  crystals.  The  barium 
and  magnesium  salts  crystallise  well.  The  amide,  pre- 
pared from  the  methyl  ester,  crystallises  from  ligroin  in 
white  plates,  which  melt  at  134°.  The  anilide,  meta- 
nitranilide,  ortho-  and  paratoluides,  and  hydrazide  are 
described.  A  tetranitro  derivative  of  the  anilide  was 
formed  by  the  adion  of  fuming  nitric  acid.  The  fad  that 
the  four  nitro-groups  are  divided  equally  between  the  two 
benzene  rings  was  proved  by  the  adion  of  potassium 
hydroxide,  which  decomposed  the  compound  into  the 
ortho-  and  paradinitraniline.— yow^M.  Amer.  Chem.  Soc. 


MEETINGS    FOR    THE    WEEK. 


Monday,  3rd. — Society  of  Arts,  4.30.     (Cantor  Leftures).    "Design 
in  Lettering,"  by  Lewis  Foreman  Day. 

Royal  Institution,  5.     General  Monthly  Meeting. 

Tuesday,  4th. — Royal  Institution,  3.     "  Volcanoes,"  by  Dr.  Tem- 
pest Anderson,  B.Sc. 

Society  of  Arts,  4.30.    "  The  Ar(5lic  and  Antardlic," 

by  Aubyn  Trevor-Battye. 
Wednesday,  5th.— Society  of  Arts,  8.    "The  Railway  to  India,"  by 
C.  K.  D.  Black. 

Thursday.  6th.— Royal  Institution,  3.    "  Liquid  Air  as  an  Agent  of 
Research,"  by  Prof.  Dewar,  F.R.S. ,  &c. 

Chemical,  8.      Ballot  for  the  Eledtion  of  Fellows. 

"A  Bunsen  Burner  for  Acetylene,"  by  A.  E. 
Munby,  M.A.  "  Readlions  between  Lead  and 
the  Oxides  of  Sulphur,"  by  H.  C.  Jenkins  and  E. 
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Chemical  Nbws,  | 
May  7,  1897.      1 


Electrical  Conduciiviiy  of  Aluminium. 


217 


THE    CHEMICAL     NEWS 


Vol.  LXXV.,  No.  1954. 


RECENT     DETERMINATIONS    OF    THE 

ELECTRICAL  CONDUCTIVITY  OF  ALUMINIUM. 

By  JOSEPH  W.  RICHARDS  and  JOHN  A.  THOMSON. 

Many  and  various  values  have  been  determined  for  the 
ele<5trical  condudivity  of  this  metal.  The  causes  have 
been  as  follows  : — 

(i).  The  impurity  of  the  metal  used.  Until  1886,  the 
best  commercial  aluminium  rarely  surpassed  gS  per  cent 
in  purity,  and  it  was  not  until  1889  that  commercial  metal 
of  99  per  cent  was  put  on  the  market.  As  will  be  shown 
later,  the  effedt,  even  within  these  narrow  limits,  is  to 
change  the  condudlivity  nearly  10  per  cent. 

(2).  The  reference  of  the  condudivity  to  copper  or 
silver  as  standards.  In  such  cases,  the  exadt  purity  of  the 
copper  or  silver  and  the  physical  condition  of  these 
•metals,  whether  hard  or  soft,  must  be  known  in  order  to 
give  the  comparison  its  proper  value ;  but  these  were  in 
most  cases  either  unknown  or  negleded.  Even  at  the 
present  time,  the  absolute  condutStivity  of  pure  soft  copper 
or  silver  cannot  be  said  to  be  fixed  closer  than  within  i 
per  cent,  so  that  figures  for  condudlivity  of  aluminium, 
given  only  with  reference  to  copper  or  silver,  cannot,  at 
best,  have  an  accurate  significance. 

(3).  Lack  of  an  accurate  standard  of  absolute  resistance. 
The  adoption  of  standard  units  of  resistance,  by  inter- 
national concert,  and  the  consequent  multiplication  of 
registered  copies,  has  made  it  an  easy  matter  to  use  in 
experiments  certified  instruments  of  accurately  known 
resistance,  and  thus  to  dispense  with  self-construdled 
units  of  comparison  in  favour  of  more  accurate  standards. 

{4).  Imperfedt  methods  of  measurement.  Of  late  years, 
several  ingenious  arrangements  have  been  devised  for 
■eliminating  from  the  calculations  of  experiments  the 
resistance  of  connedlions,  always  an  uncertain  quantity, 
and  more  refined  instruments  for  measuring  and  balancing 
eledtric  currents  have  been  construdled,  thus  permitting 
of  increased  accuracy  in  results. 

In  the  following  experiments  the  specimens  tested  were 
kindly  furnished  by  the  Pittsburgh  Redudtion  Company, 
and  were  all  analysed  by  Mr.  Handy,  of  the  Pittsburgh 
Testing  Laboratory,  so  that  their  composition  was  accu- 
rately known.  The  condudlivity  is  given  in  absolute 
measurement,  so  that  no  reference  to  any  other  metal  as 
a  standard  can  affetft  the  results.  This  was  rendered 
possible  by  the  use  of  a  certified  standard  resistance  coil 
of  I  "  International  "  ohm,  whose  possible  error  is  not 
over  0-02  per  cent,  and  by  the  use  of  the  Carey  Foster 
method  of  comparison.  The  metal  was  in  wire,  of  50-foot 
lengths,  the  diameter  of  which  was  measured  by  a  micro- 
meter and  checked  by  weighing  and  determining  the 
specific  gravity.  The  wires  were  wound  on  wooden 
bobbins  and  immersed  in  oil,  the  temperature  of  which 


was  given  by  a  thermometer.  The  galvanometer  used 
was  a  refiediing  instrument,  sufiS.iently  delicate  for  all 
purposes.  Ttie  standard  coil  was  immersed  in  water, 
and  the  room  was  kept  at  a  constant  temperature.  The 
bridge  wire  used  was  carefully  calibrated,  and  all  readings 
were  taken  several  times.  Two  separate  wires  were 
tested  in  case  of  Experiment  i,  the  result  given  being 
the  mean  of  two  results,  which  differed  only  one-hundredth 
of  I  per  cent  from  each  other. 

For  the  redudion"  from  the  working  temperature  to  0° 
C.  an  experiment  was  made  with  wire  No.  i,  which 
showed  that  between  27°  C.  and  0°  C.  its  temperature 
coefficient  was  o'O0392  per  degree.  This  coefficient  was 
used  for  the  nearly  pure  wires,  while  for  4  and  5  a  slightly 
lower  coefficient,  determined  by  Mr.  Scott,  was  used.  It 
appears  that  the  purer  the  metal  the  greater  its  tempera- 
ture coefficient. 

Condudtivity  tests  of  a  similar  set  of  wires  were  made 
by  Mr.  C.  F.  Scott,  eledlrician  of  the  Westinghouse 
Eiedric  Company,  Pittsburgh.  They  were  made  by  com- 
parison with  pure  copper,  with  a  Wheatstone  bridge. 
These  results  can  only  be  compared  with  ours  by 
assuming  a  certain  value  for  the  condudlivity  of  copper, 
and  even  then  we  cannot  say  how  nearly  the  copper  used 
by  Mr.  Scott  would  approach  that  standard.  Sir  W. 
Thompson's  value  for  the  specific  resistance  of  copper  is 
1580,  Dewar's  1562.  In  the  following  table  we  reduce 
our  results  to  each  of  these  standards,  and  add  Scott's 
results  for  comparison  : — 


I. 

I. 

Relativi 

Soft  .. 
Hard  .     . 

'  Conductivity  [Copper 

Richards  and  Thomson. 
Using  for  copper  the 

resistances 
(1580)                  (1562). 

=  100). 

C.  F.  Scott. 

Aftual  resistance  of 

copper  employed 

not  known. 

.      65-0 
•      64-4 

64-2 
637 

63-1 

2. 

2. 

Soft  ..      . 
Hard  ,      . 

.      62-3 
.     6ri 

616 
60-5 

62-2 

3- 

Hard  .      . 

•     55'5 

54-9 

56*2 

4- 

Hard  .     . 

.     56'o 

55"4 

5S'5 

5- 
5- 

Soft  ..      . 
Hard  .     . 

•  52-9 

•  52-5 

52-3 
5i'9 

55  "0 

Temperature  Coefficient  for  1°  C. 

C.  F.  Scott.                  Richaras  and  Thomson. 
(Between  15=  and  80°  C).      (Between  0°  and  27^  C). 

I. 
2. 
3- 
4- 
5- 

..       .. 

0*00385 
000385 
0*00360 
0*00361 
0*00359 

0*00392 

In  connedlion  with  the  results  of  Mr.  Scott  and  our- 
selves, we  may  mention  for  comparison  those  of 
Charpentier-Page,who  used  what  he  calls  ^Mr«  aluminium, 
which  may  safely  be  assumed  to  be  the  No.  i  grade  of 
European  aluminium,  averaging  99  per  cent  pure.  He 
finds  as  follows  : — 


Analysis. 

/  luminium. 

Iron. 

Copptr. 

Silicon, 

Sodium. 

I. 

99  66 

010 

O'OO 

o-i6 

0*008 

2. 

99-58 

0-25 

O'OO 

o*i6 

0-052 

3- 

9877 

0*20 

0-57 

0-45 

0*012 

4' 

97*i6 

0-25 

2-26 

0*30 

0-032 

5- 

94*39 

0-25 

"^•07 

0-24 

0*052 

I -50 


Resistance  at  0°  C.  of  a  wire 

I  metre  long  by  i  m.m, 

(iiameter,  in  ohms. 

Hard. 

^  ^31245 
0-03290 
.  0*03627 
0*03  5  yo 
0-03583 


Specific  resistance  ato°C., 

I.e.,  resistance  of  i  c  c.  in 

absolute  (C.G.S.)  units 

of  resistance. 


Hard. 

24537 
2584*0 
2848*0 
?8i9-6 
3011-4 


Annealed. 
2432-2 
2535'0 


2l8 


Expertmtnts  with  Cathode  Rays. 


1       May  7.  1897. 


Soft  .. 
Hard.. 


Specific  resistance 
(Calculated.to  0°  C). 

. .      2659 
2684 


Compared  with  copper. 


(1580). 
Per  cent. 


(1562). 
Per  cent. 


59*4 
58-9 


58-8 
58-2 


It  should  be  noticed  that  these  results  fall  exadlly  be- 
tween our  Nos.  2  and  3,  also  just  where  its  composition 
would  most  probably  lie.  The  results  also  agree  closely 
with  ours  in  showing  almost  exa(flly  i  per  cent  greater 
condudivity  for  the  annealed  than  for  the  hard-drawn 
wire. 

Dewar  and  Fleming  have  also  recently  found  as  the 
specific  resistance  of  "  Swiss  aluminium  about  99  per  cent 
pure  "  the  value  2563  at  0°  C,  which  is  609  per  cent  of 
that  of  copper,  according  to  their  own  measurements. 
This  also  fits  in  well  with  our  determinations,  but  the 
comparison  would  have  been  much  more  satisfadtory  if 
the  exadl  composition  of  their  metal  had  been  determined. 

C.  K.  McGee  determined,  in  1890,  the  cohdudivity  of 
aluminium  analysing  98*52  per  cent  pure  to  be;54-8  per 
cent  that  of  copper  when  unannealed.  This  metal  was 
nearly  identical  with  our  No.  3  in  composition,  and  the 
results  are  the  same  within  i  per  cent. 

The  conclusions  we  would  draw  from  these  experiments 
and  comparisons  are  that — 

The  condudtivity  of  hard  drawn  commercial  aluminium 
is  strongly  affeded  by  impurities,  being,  approximately, — ' 

(Copper  =  ioo). 

98'5  per  cent  pure  aluminium 55-0 

99"o         ,.  .. 590 

99"5         ..  ..  6i-o 

9975       11  >»  ......     630— 64-0 

loo"o        „  ,,  probably     ..     66-o — 67*0 

Annealed  wire  has  a  condudivity  very  nearly  1  per  cent 
greater  than  the  unannealed. — jfournal  of  the  Franklin 
Institute,  March,  1897. 


STANDARD   IODINE  SOLUTION  FOR  SULPHUR 

DETERMINATIONS.' 

By    EDWARD    K.    LANDIS. 

The  following  calculation  shows  an  easy  method  of  pre- 
paring Payne's  iodine  solution,  with  the  least  amount  of 
calculation. 

Reactions. 

K2Mn208  +  ioFeS04-f8H2S04  =  5Fe^(S04)3-f-K2S04-^ 
2MnS04-l-8H20.  

K2Mn208-f-ioKI  =  ioI+6K20-i-2MnO. 

H2S-h2l  =  2HI  +  S, 

2  atoms  1  =  2  atoms  Fe  =  i  atom  S. 

32  grms.  S  =  112  grms.  Fe. 

I  grm.  S  =  3'5  grms.  Fe.  '  r.  :,:>  11:  u  >  r  : 

When  5  grms.  are  taken  for  analysis,  o'ot  per  cent  = 
0*0005  g<^"^M  ^^^  ^h's  multiplied  by  iooO(=  o'5  grm.  in  a 
litre. 

Let  X  =  value  of  i  c.c.  K2Mn203  in  Fe  ta  grms. 

175 
X 

3-5 

Therefore  1*75  divided  by  the  value  ©f  one  c.c.  potas- 
sium permanganate  in  iron  in  grms.  gives  the  number  of 
c.c.  of  potassium  permanganate  to  be  added  to  the  potas- 
sium iodide  and  sulphuric  acid  and  diluted  to  one  litre, 
to  form  iodine  solution  of  such  strength  that  one  c.c.  will 
be  equal  to  001  per  cent  sulphur  when  using  five  grms. 
of  sample. — yourn.  American  Chem.  Soc,  xix.,  No.  3. 


o  '5  3  "5 

Then-i=  0-5  x -^ 


SOME     EXPERIMENTS     WITH 
RAYS.' 
By  A.  C.  C.  SWINTON. 


CATHODE 


The  extensive  employment  of  the  focus  form  of  Crookes 
tubes  as  the  most  efficient  known  means  of  generating 
X  rays,  has  rendered  advisable  the  more  complete  in- 
vestigation of  the  cathode  ray  discharge  in  tubes  of  this 
description. 

Hitherto,  the  usual  method  of  investigating  the  charac- 
teristics of  a  cathode  ray  discharge  apart  from  its 
mechanical  properties,  and  beyond  what  is  visible  to  the 
unassisted  eye,  has  been  by  allowing  the  rays  to  fall  upon 
a  screen  of  some  brightly  fluorescent  material,  such  as 
glasses  of  various  descriptions,  or  screens  covered  with 
fluorescent  salts.  With  ail  of  these  the  maximum 
amount  of  fluorescence  appears  to  be  produced  by  such 
comparatively  weak  cathode  rays,  that  in  some  cases  the 
special  effeds  produced  by  the  more  powerful  rays  seem 
to  be  more  or  less  entirely  masked,  while  the  well- 
known  phenomenon  of  the  fatigue  of  fluorescent  sub- 
stances, when  exposed  to  the  more  adive  rays,  conduces 
to  the  same  result.  , ,       '  '    •     ,    '. 

\  ■:  •  ■■  '  ■'  ■  '  ■    ■  .1  ;■>■  ;..:('•>  s'-ij  V'  •  • 

Surface  Lurhine'scewe  of'  Carbon^  when  exposed  to 
■■■■'''■  Cathode  Rays, 

I  have  found  in  some  cases  that  by  replacing  the  usual 
screen,  made  of  or  covered  with  fluorescent  material,  by 
one  of  ordinary  eledric  light  carbon,  much  appears  which 
was  previously  invisible.  When  a  concentrated  stream 
of  powerful  cathode  rays  are  focussed  upon  a  surface  of 
carbon  in  this  manner,  a  very  brilliant  and  distindly 
defined  luminescent  spot  appears  on  the  surface  of  the 
carbon  at  the  point  of  impad  of  the  rays,  the  remainder 
of  the  carbon  remaining  black.  This  luminescent  spot 
seems  to  have  a  very  close  relation  to  the  fluorescent 
spots  on  glass  and  on  other  fluorescent  materials  under 
similar  influence.  The  effed  is  evidently  a  purely  surface 
effed,  as  when  the  cathode  stream  is  rapidly  defleded  by 
means  of  a  magnet  the  luminescent  spot  on  the  carbon 
moves  with  no  perceptible  lag.  Further,  though,  as  is 
also  the  case  with  glass,  the  whole  of  the  carbon  becomes 
gradually  heated  to  a  considerable  extent  if  much  power 
be  employed  for  a  long  period  of  time,  these  luminescent 
spots  are  instantaneously  produced  on  carbon  of  very 
considerable  brilliancy  with  but  a  comparatively  low 
power.  Again,  just  as  glass  is  known  to  become  fatigued 
under  the  influence  of  cathode  rays,  so  that  after  a  time  it 
refuses  to  fluoresce  so  brightly  as  before,  so  carbon  is 
similarly  fatigued,  though  only  after  having  been  very 
strongly  aded  upon.  Carbon,  like  glass,  also  recovers 
its  property  of  giving  a  surface  luminescence  to  some 
extent,  though  it  does  not  seem  to  entirely  recover,  at  any 
rate,  at  all  rapidly. 

That  the  rays  which  firoduce  the  luminescence  of  the 
carbon  are  the  same  rays  that  cause  fluorescence  of  the 
glass  can  be  proved  by  defleding  the  rays  from  the  carbon 
on  to  the  glass  by  means  of  a  magnet. 

As  it  is  exceedingly  difficult,  if  not  impossible,  to  ob- 
tain  carbon  plates  which  do  not  contain  hydrocarbons 
and  other  volatile  matter  which  are  rapidly  given  off^  and 
reduce  the  vacuum  very  quickly  when  the  carbon  becomes 
at  all  heated,  it  is  necessary  to  keep  the  tube  conneded 
to  the  mercury  pump,  so  that  the  vacuum  can  be  restored 
after  each  experiment.  This  arrangement  was  followed 
in  all  the  experiments  described  below,  except  where  spe- 
cific mention  is  made  to  the  contrary. 

Apparent  Form  of  the  Cathode  Ray  Dischargeiin  a 

Focus  Tube. 
As  is  well  known,  in  tubes  of  the  ordinary  focus  type 
with  a  single  spherical  concave  cathode,  the  rays  coming 

•  A  Paper  rtad  before  the  Royal  Society,  March  11,  1897. 


B    MICAL  ftBWS,  • 

May  7, 1897.      I 


Experiments  with  Cathode  Rays, 


219 


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220 


Experiments  with  Cathode  Rays. 


(  Chemical  News, 
\       May7,  i8p7. 


off  normally  to  the  cathode  surface  appear  to  converge  in 
more  or  less  of  a  cone  to  a  focus,  and,  if  the  vacuum  be 
not  too  high,  to  diverge  again  immediately  in  another 
cone  upon  the  other  side  of  the  focus.  At  higher  vacua 
the  rays,  after  passing  the  focus,  do  not  appear  to  diverge 
again  at  once,  but  seem  to  form  themselves  into  a  descrip- 
tion of  thread  which  conneifls  the  convergent  and  divergent 
cones,  and  is  longer  or  shorter  according  as  the  vacuum 
is  higher  or  lower.  The  angle  of  the  divergent  cone  ap- 
pears, however,  to  be  always  proportional  to  that  of  the 
convergent  cone.  The  focus,  or  perhaps  more  corredly 
the  point  at  which  this  thread  commences,  seems  always 
to  be  more  distant  from  the  cathode  than  the  centre  of 
curvature  of  the  latter,  but  the  variation  in  this  respedt 
seems  to  be  less  and  less  the  higher  the  exhaustion.  This 
is  no  doubt  due  to  the  mutual  lepulsion  of  the  rays,  and 
accords  with  the  assumption  that  the  rays  consist  ot 
charged  particles,  which  travel  more  and  more  rapidly  the 
higher  the  exhaustion.  Probably  for  the  same  reason 
cathodes  that  are  only  slightly  concave  focus  further  in 
proportion  beyond  their  centres  of  curvature  than  do 
deeply  concave  cathodes  for  the  same  vacuum. 

Apparent  Hollowness  of  the  Divergent  Cone  of  Rays. 
When  the  divergent  cone  is  thrown  upon  a  thin  plati- 
num disc,  as  in  the  ordinary  focus  tube,  and  sufficient 
eledlric  power — say,  from  a  lo-inch  Rumhkorff  coil — is 
employed,  the  platinum  quickly  attains  to  a  red  heat. 
With  platinum,  either  the  whole  disc  becomes  uniformly 
heated,  or  in  the  event  of  the  diameter  of  the  cone  of 
rays  where  it  strikes  the  platinum  being  small,  compared 
with  the  area  of  the  platinum,  that  poition  of  the  plati- 
num covered  by  the  base  of  the  cor  e  becomes  uniformly 
heated  to  a  higher  temperature  than  the  remainder.  This 
is  as  much  as  can  usually  be  seen  with  platinum,  though 
rather  moie  is  sometimes  visible  with  aluminium  ;  but  if, 
instead  of  either  metal,  the  disc  is  made  of  ordinary 
eledlric  light  carbon,  I  have  found  that  the  luminescent 
portion  of  the  carbon,  instead  of  comprising  the  whole 
disc,  or  consisting  of  a  uniformly  heated  circle,  will  in 
some  cases  take  the  shape  of  a  brilliantly  luminescent 
and  apparently  white  hot  ring,  with  a  well  defined  dark, 
and  seemingly  quite  cold,  interior.  As  the  dimensions  of 
the  cone  of  rays  are  increased  or  decreased  by  decreasing 
or  increasingthe  vacuum,  the  luminescent  ring  will  be  found 
to  increase  or  decrease  correspondingly  in  diameter,  at  the 
same  time  being  brighter  when  small  than  when  large. 
Further,  when  the  ring  is  very  small  it  will  usually  have 
a  very  brightly  luminescent  central  spot,  with  a  dark  inter- 
vening portion  between  this  spot  and  the  ring,  and  when 
the  vacuum  is  further  increased  the  ring  will  gradually 
close  in  upon  the  spot  until  only  the  latter  remains. 

Figs.  I,  2,  3,  and  4  show  diagrammatically  these  hollow 
effeifts,  as  produced  by  spherical  aluminium  cathodes, 
1*125  ^^'  diameter  and  0708  in.  radius  of  curvature,  for 
four  degrees  of  vacuum,  i  being  the  lowest  and  4  the 
highest  exhaustion.  The  upper  portion  of  each  of  these 
figures  represents  the  general  appearance  of  the  cathode 
discharge  between  the  spherical  concave  aluminium 
cathode  c  at  the  top,  and  the  carbon  anti-cathode  b  at 
the  bottom,  as  accurately  as  it  is  possible  to  represent 
evanescent  coloured  appearances  in  monochrome.  The 
other  appearances,  due  to  the  dark  space  and  fluores^:eiice 
of  the  glass,  are  omitted  for  the  sake  of  simplicity.  Be- 
neath each  of  the  elevational  views  of  the  cathode 
discharge  will  be  found  a  plan  view  of  the  carbon  anti- 
cathode,  showing  for  each  condition  of  vacuum  the  effedt 
of  the  cathode  discharge  upon  the  carbon  anti-cathode,  in 
forming  a  brightly  luminescent  hollow  ring,  gradually 
decreasing  in  diameter  as  the  vacuum  is  increased,  until  it 
centres  on  a  point,  as  already  mentioned. 

It  may  further  be  remarked  that  the  diameter  of  the 
luminescent  ring  may  be  increased  or  diminished,  or 
finally  reduced  to  a  point,  without  altering  the  degree  of 
vacuum,  by  moving  the  anti-cathode  away  from  or  to- 
wards or  finally  into  the  focus  of  the  cathode  stream,  the 


appearance  of  the  ring  in  each  of  these  cases  being  prac- 
tically similar  to  those  shown  in  the  figures  for  a  uniform 
distance  with  varying  vacuum.  When  the  anti-cathode 
surface  is  not  at  right  angles  to  the  line  of  the  discharge, 
the  ring,  in  place  of  being  circular,  takes  the  proper  form 
of  a  conic  sedlion.  The  holding  of  a  magnet  near  the 
tube  distorts  the  ring  from  a  circular  shape  and  moves  its 
position  on  the  carbon. 

From  these  experiments  it  appears  that  the  diverging 
cone  of  cathode  rays  ads  as  though  it  were  not  of  uni- 
form density  throughout  its  sedion,  but,  at  any  rate,  in 
some  instances  as  if  it  were  completely  hollow.  This 
fad  does  not  appear  to  have  previously  been  noted. 


Apparent  Hollowness  of  the  Convergent  Cone  of  Rays. 

The  apparent  hollowness  of  the  divergent  cathode  ray 
being  thus  established,  it  was  thought  desirable  to  ascer- 
tain whether  the  same  condition  of  affairs  exists  in  the 
converging  beam  of  rays  between  the  cathode  and  the 
focus.  Owing  to  the  well-known  difficulty  of  getting  any 
discharge  to  pass  when  the  distance  between  the  eledrodes 
is  less  than  the  thickness  of  the  dark  space,  and  to  the 
disturbing  effed  which  the  anti-cathode  screen  is  found  to 
have  when  brought  within  the  focus  of  the  cathode,  espe- 
cially with  high  vacua,  this  question  was  found  much 
more  difficult  to  decide  than  that  of  the  hollowness  of  the 
divergent  cone.  However,  that  the  convergent  cone  also 
ads  under  certain  circumstances  as  though  it  were 
almost  completely  hollow,  and  ads  generally  as  if  it  had 
a  considerable  tendency  towards  hollowness  at  low  vacua,, 
was  also  finally  fully  determined.  The  lower  portions  of 
figs.  5,  6,  and  7  show  the  bright  ring  appearance  upon  the 
carbon  anti-cathode  at  two  different  degrees  of  exhaustion, 
B  being  higher  vacua  than  b',  and  with  the  anti-cathode 
at  the  three  different  distances  from  the  cathode  within 
the  focus  of  the  latter,  as  shown  in  the  upper  part  of  each 
figure.  As  will  be  observed  in  this  case,  the  degree  of 
vacuum  is  found  not  to  appreciably  affed  the  dimensions 
of  the  figure,  though  it  should  be  stated  that  the  vacua  in 
each  case  were  comparatively  low,  as  vacua  as  high  as 
those  employed  when  the  anti-cathode  was  outside  the 
focus  gave  no  results  at  all.  As  will  be  seen,  however, 
the  diameter  of  the  luminescent  ring  is  arfeded  by  the- 
degree  of  proximity  of  the  anti-cathode  to  the  cathode, 
being  larger  when  the  distance  is  small  than  when  it  is 
great ;  while  in  every  case  there  is  a  decided  tendency  to- 
wards hollowness,  though  usually  with  some  slight  internal 
luminescence  ana  with  a  bright  central  spot,  while  in  one 
case,  when  the  anti  cathode  was  very  close  to  the  cathode 
and  the  vacuum  was  comparatively  high,  the  ring  is  seen 
completely  hollow,  and  there  is  no  central  spot. 

A  convenient  form  of  tube  for  showing  the  apparent 
hollowness  of  both  the  divergent  and  convergent  cone  of 
cathode  rays  is  shown  in  fig.  8,  where  the  anti-cathode 
disc  b,  made  of  eledric  light  carbon,  is  supported  upon  a 
small  carrier  which  slides  upon  the  bottom  of  the  tube, 
and  is  conneded  to  the  anode  terminal,  D,  by  means  of 
two  aluminium  wires,  each  of  which  have  a  ring  at  their 
extremity  through  which  they  respedively  pass.  As  the 
carbon,  under  the  adion  of  the  cathode  rays,  gives  off 
hydrocarbon  vapour,  it  is  necessary,  as  already  mentioned,, 
to  try  all  these  experimfuis  with  the  tube  conneded  to- 
the  mercury  pump  ;  but  with  this  connedion  made  through 
a  slightly  flexible  mercury  joint  it  is  possible,  by  inclining 
and  gently  tapping  the  tube,  to  bring  the  anti-cathode  to 
any  desired  position  either  near  or  far  away  from  the 
cathode.  For  experiments  upon  the  divergent  cone,  it  is. 
not  necessary  that  the  anti-cathode  screen  should  be  con- 
neded to  the  anode  terminal,  and,  consequently,  the- 
sliding  aluminium  wires  inside  the  tube  are  not  required. 
They  are,  however,  necessary  when  observations  are  to  be- 
made  on  the  convergent  cone  between  the  cathode  and 
the  focus,  as  the  anti-cathode  screen  when  placed  within 
the  focus  must  be  conneded  to  the  anode,  or  it  appears  to 


Chemical  Nbws, 

May  7,  1897. 


Use  of  A  lumtnum  for  Condensers. 


22i 


get  negatively  charged,  and   adts  itself  as   an  additional 
cathode,  throwing  cathode  rays  in  all  direAions. 

It  may  here  be  mentioned  that  the  fatigue  of  the  carbon 
already  alluded  to  renders  necessary  some  precautions  in 
carrying  out  the  above-mentioned  experiments,  as  other- 
wise the  observer  may  be  misled  into  thinking  that  a  beam 
of  cathode  rays  is  effectively  hollow  when  this  is  not  the 
case,  owing  to  the  centre  of  the  carbon  covered  by  the 
beam  having  been  fatigued  by  some  previous  experiments. 
By  taking  the  precaution,  however,  of  deflefting  the 
cathode  beam  by  means  of  a  magnet  on  to  various  por- 
tions of  the  carbon  screen,  such  errors  may  be  avoided. 
It  should  also  be  noted  that  these  hollow  effedls  appear 
only  to  be  obtained  with  fairly  short  focus  cathodes,  such 
as  are  usually  employed  in  X-ray  focus  tubes,  that  is  to 
say,  with  cathodes  whose  diameter  is  large  as  compared 
with  their  radius  of  curvature,  so  that  the  rays  converge 
and  diverge  rapidly  to  and  from  the  focus.  With  com- 
paratively flat,  long,  focus  cathodes,  the  cones  do  not 
show  any  signs  of  being  hollow,  and  produce  a  uniformly 
luminescent  spot  upon  the  carbon  of  larger  or  smaller 
diameter,  according  to  the  conditions  of  vacuum  and  the 
position  of  the  screen. 

For  instance,  while  cathodes  1*125  inches  diameter  and 
0708  inch  radius  of  curvature  gave  in  the  manner 
described  distindly  hollow  convergent  and  divergent 
cones,  a  cathode  i  inch  diameter  and  i"5  inches  radius  of 
curvature  gave  convergent  and  divergent  cones  that  ap- 
peared to  be  uniformly  solid  under  all  conditions. 
(To  be  continued). 


THE  QUALITATIVE  SEPARATION  OF  ARSENIC, 
ANTIMONY,  AND  TIN.* 

By    S.    G.    RAWSON,    D.Sc,    F.I.C., 
Ledturer  in  Chemistry,  Technical  College,  Huddersfield. 

To  any  originality  in  the  process  which  I  propose  describing 
I  can  lay  no  claim,  the  principles  involved  depending 
upon  a  combination  of  certain  well-known  methods.  The 
suggested  separation  of  these  metals  is  based  primarily 
upon  the  use  of  oxalic  acid  as  originally  published  by 
Clarke  in  his  paper  (Chemical  News,  xxi.,  p.  124)  upon 
the  quantitative  estimation  of  these  metals,  a  process 
which  to  me  never  seems  to  have  come  into  the  promi- 
nence which  it  so  thoroughly  deserves.  I  have  but  little 
faith  in  the  methods  now  employed,  especially  in  those 
for  the  separation  of  antimony  and  tin.  The  former 
metal  is  frequently  evolved  either  as  the  hydride  or  depo- 
sited as  a  black  stain  upon  platinum ;  the  tin  being 
thrown  down  upon  zinc;  this  deposit  is  then  scraped  off, 
dissolved  in  acid,  and  the  solution  treated  with  mercuric 
chloride.  That  other  people  share  in  my  disbelief  in  this 
method  is  shown  by  the  fa<5t  that,  in  so  far  as  my  know- 
ledge goes,  I  have  never  heard  in  any  examination  of 
more  than  two  of  those  bodies  being  given  for  qualitative 
determination  in  one  and  the  same  substance.  Even 
under  these  favourable  conditions,  it  is  seldom  that  the 
mixture  contains  only  a  small  percentage  of  one  of  the 
constituents ;  the  amounts  more  usually  approximate  to 
equality,  the  difficulties  of  separation  being  thereby  much 
reduced.  The  method  I  would  suggest  is  as  follows : — 
The  sulphides  of  the  metals  are  washed  upon  the  filter- 
paper,  and  the  whole  or  part  of  the  residue  is  placed  in  a 
test-tube  and  boiled  with  2  or  3  c.c.  of  concentrated 
hydrochloric  acid,  to  which  a  drop  or  two  of  nitric  acid  is 
added,  and  again  boiled.  A  yellow  residue  after  the 
treatment  with  hydrochloric  acid  gives  a  preliminary  clue 
as  to  the  presence  of  arsenic,  this  sulphide  being  slightly, 
if  at  all,  attacked  by  the  acid.  A  saturated  solution  of 
oxalic  acid  is  added  in  quantity  sufficient  to  fill  two-thirds 

*  A  Paper  read  before  the  Society  of  Chemical  Industry  (Yorkihire 
Section),  January  25th,  1897. 


of  the  test-tube  ;  the  whole  is  boiled,  and  crystals  of 
oxalic  acid  are  added  until  a  hot  concentrated  solution  of 
oxalic  acid  is  obtained.  A  stream  of  sulphuretted  hydro- 
gen is  passed,  the  whole  of  the  arsenic  and  antimony 
being  precipitated  as  sulphides,  which  are  filtered  off,  the 
tin  remaining  in  solution.  To  the  filtrate  ammonia  is 
added  until  distindtly  alkaline.  If  a  precipitate  should 
then  appear,  which  will  not  be  the  case  unless  a  large 
amount  of  tin  be  present,  add  ammonium  sulphide  drop 
by  drop  until  the  precipitate  re-dissolves  :  this  it  will  do 
very  readily.  Acidulate  with  acetic  acid;  a  heavy  white 
precipitate,  turning  brown,  indicates  tin  as  a  mixture  of 
oxide  and  sulphide.  It  may  be  here  noted  that  the 
treatment  of  ordinary  ammonium  sulphide  with  acetic 
acid  produces  a  precipitate  of  sulphur,  but  the  appearance 
of  the  precipitates  formed  in  the  two  cases  is  quite  dis- 
tindt  and  cannot  be  mistaken.  Turning  again  to  the 
residual  sulphides  of  arsenic  and  antimony,  these  may  be 
treated  either  with  ammonium  carbonate  in  the  well-known 
way,  or,  and  preferably  I  think,  as  follows : — Dissolve  in 
hydrochloric  acid  with  two  or  three  drops  of  nitric  acid, 
boil,  and  place  the  solution  in  a  Marsh  apparatus.  The 
evolved  hydrides  are  then  passed  through  a  solution  of 
silver  nitrate,  and  the  antimonide  of  silver  formed  filtered 
off.  To  the  filtrate  add  a  few  drops  of  silver  nitrate,  and 
then  very  cautiously  ammonium  hydrate  until  the  yellow 
precipitate  of  silver  arsenite  appears.  The  silver  anti- 
monide precipitate  is  washed,  boiled  with  tartaric  acid 
and  filtered,  a  little  hydrochloric  acid  is  added,  and 
sulphuretted  hydrogen  passed  through  the  filtrate,  orange- 
red  antimony  sulphide  being  thrown  down.  To  both  of 
these  precipitates  the  ordinary  reduction  and  sublimation 
tests  can  be  applied.  The  above  method  gives  thoroughly 
good  results,  and  with  amounts  of  the  respedtive  sulphides 
varying  within  wide  limits,  and  does  not  require  that 
tinkering  with  bits  of  platinum  foil  and  of  zinc  which  is 
both  unreliable  and  unpleasant. 


THE   USE  OF  ALUMINUM   FOR  CONDENSERS.* 
By  T.  H.  NORTON. 

In  connexion  with  the  extended  use  of  aluminum  in  this 
laboratory  for  various  forms  of  apparatus,  water-baths, 
air-baths,  Bunsen  burners,  hot  water  filtering  funnels,  &c., 
it  seemed  desirable  to  study  the  availability  of  the  metal 
for  condensation  processes. 

For  this  purpose  a  condenser  was  construdled  as  fol- 
lows : — The  outer  jacket  was  of  glass  ;  the  inner  tube  was 
of  aluminum  and  possessed  the  following  dimensions — 
length  122  cm.,  external  diameter  i  cm.,  inner  diameter 
8i  m.m.,  weight  per  metre  29  grms.  At  a  distance  of 
15  cm.  from  the  end,  the  tube  was  bent  at  right  angles. 
This  permitted  of  connexion  with  a  distilling  flask,  with- 
out allowing  the  condensing  vapours  to  come  in  contadl 
with  any  substance  but  aluminum.  It  might  be  men- 
tioned here  that  in  order  to  bend  an  aluminum  tube  of 
these  dimensions  satisfadtorily,  it  is  necessary  to  fill  it 
with  molten  lead,  and  further,  that  several  distillations 
with  water  are  requisite  in  order  to  remove  completely 
slight  traces  of  lead  adherent  to  the  surface  of  the 
aluminum,  after  this  operation. 

The  method  of  testing  the  condenser  was  to  distil  a 
measured  quantity  of  a  liquid  from  the  glass  flask,  used 
as  a  still,  coUedt  the  distillate  in  glass,  evaporate  it  from 
weighed  platinum  dishes,  and  note  the  weight  of  the 
ignited  residue,  thus  ascertaining  whether  there  was  any 
appreciable  attack  on  the  aluminum.  Nothing  was 
attempted  beyond  the  ordinary  precautions  for  preventing 
dust  from  contaminating  the  distillates. 

*  Contributions  from  the  Chemical  Laboratory  of  the  University  of 
Cincinnati.  Prom  thu  Journal  of  the  American  Chemical  Soculy, 
xix.,  No.  2. 


222 


Sou  terments  important  in  Agriculture. 


UHBIIiC*t.NBWt| 

May  7, 1897. 


The  liquids  first  employed  were  organic.  In  each  case 
500  c.c.  were  distilled,  and  the  weights  of  the  residue  left 
on  evaporating  the  distillate  noted.  The  following  results 
were  obtained : — 

Liquid.  Residue  from  500  c.c. 

Ethyl  alcohol  (specific  gravity  0*809)..     ••  o'ooi     grm. 

Benzene    ..     ..     ••     o-ooi6    „ 

Nitrobenzene 0*0004     ,, 

Chloroform ..  0*0002     ,, 

Ethyl  ether      0*0000 

Acetone o'oooi     ,, 

In  all  these  cases  it  was  evident  that  very  rapid  distil- 
lation could  be  carried  on  with  an  exceedingly  short  tube, 
on  account  of  the  high  conductive  power  of  the  aluminum. 
The  residues  obtained  showed  that  there  was  pradtically 
no  attack  upon  the  aluminum. 

The  deportment  of  the  metal  towards  steam  was  next 
studied,  and  here  it  was  deemed  wise  to  establish  in  all 
cases  comparative  experiments  with  glass  and  block  tin. 
The  glass  condenser  tube  used  for  this  purpose  was  84 
cm.  long  and  had  an  inner  diameter  of  16  m.m. ;  the  tin 
condenser  tube  was  305  cm.  long  and  had  an  inner 
diameter  of  21  m.m.  With  the  exception  of  differences 
in  the  superficial  surface  for  condensation,  other  condi- 
tions were  essentially  identical.  Three  series  of  distilla- 
tions were  carried  on  with  the  three  following  samples  of 
water : — 

A.  Hydrant  water  (Ohio  river  water),  containing  much 

impurity. 

B.  Hydrant  water  (Ohio  river  water),  containing  less 

impurity. 

C.  Distilled  water. 

In  all  cases  500  c.c.  were  employed.  The  following 
residues  were  obtained  : — 

Aluminum.  Block  tin.  Glass. 

A 0*0112            0*006  o*oii8  grm. 

B 0*0032            0*0028  0*0091     ,, 

C 0*0035             0*005  o*oo8       ,. 

A  check  determination  on  the  amount  of  dust  colleding 
in  the  platinum  dish  during  the  time  for  evaporation, 
showed  it  to  be  0*0002  grm.  after  ignition. 

These  results  would  show  that  as  far  as  purity  of  the 
produiJt  is  concerned,  aluminum  possesses  about  the  same 
advantages  over  glass  as  tin,  in  connexion  with  the  dis- 
tillation of  water.  In  lightness  and  conduftivity  it  ex- 
hibits marked  superiority  to  the  tin. 

For  use  with  neutral  organic  liquids  it  is  well  adapted, 
more  especially  in  the  distillation  of  low  boiling  sub- 
stances, such  as  ether.  Here,  also,  the  high  thermal 
conductivity,  as  well  as  the  absence  of  brittleness,  are 
fadtors  in  its  favour  as  compared  with  glass. 

Mr.  R.  W.  Hochstetter  rendered  valuable  assistance  in 
the  determination  of  the  above  data. 


SOIL     FERMENTS     IMPORTANT 
AGRICULTURE.' 


IN 


By     HARVliY     W.     WILEY, 

Chief  of  tl]e  Division  of  Chemistry,  Department  of  Agriculture, 

Washington,  D.C. 


Introductory. — Soil  ferments  important  in  agriculture  are 
those  which  help  to  make  the  soil  from  original  rocks  and 
those  which  are  adlive  in  preparing  the  food  of  plants  for 
absorption  and  assimilation.  The  old  idea  that  the  soil  is 
an  inert  mass  of  mineral  matter  has  given  way  to  the  new 
conception  of  the  soil  as  a  living  organism.  The  parts  of 
the  soil  which  are  not  endowed  with  life  at  the  present 

*  Abstract  of  a  LeClure  delivered  before  the  Chemical  Section  of 
the  Franklin  Icstitute,  February  16th,  1897. 


time  have  their  highest  significance  as  the  environment  of 
the  living  organisms  which  they  contain,  and  which  they 
may  help  to  nourish.  The  plant  which  forms  the  growing 
crop  receives  its  nourishment  through  the  media  of  the 
air  and  soil ;  but  this  nourishment  must  undergo  a  process 
of  digestion,  similar  to  that  suffered  by  the  food  which 
nourishes  animals,  before  it  becomes  available  as  plant- 
food.  Indeed,  the  purely  mineral,  inorganic  foods  of 
plants  are  probably  not  always  absorbed  as  such,  and 
must  undergo  a  decomposition  before  they  are  assimi- 
lated. A  striking  instance  of  this  is  shown  in  the  case  of 
silica,  an  important  plant-food  and  a  type  of  inert  mineral 
matter.  Silica  is  highly  insoluble,  and  apparently  the 
least  suited  of  the  mineral  constituents  of  the  earth  to 
enter  the  vital  organism  of  the  plant.  Yet  not  only  do  we 
find  it  in  the  tissues  of  the  mature  plant,  but  also,  strange 
to  say,  in  the  greatest  abundance  in  those  parts  of  the 
plant  organism — viz.,  the  leaves — most  remote  from  the 
sources  of  supply.  It  is  evident  from  this  that  the 
highly  insoluble  silica  of  the  soil  must  undergo  a  com- 
plete solution  in  order  to  be  carried  by  the  juices  of  the 
plant  through  the  network  of  cellular  tissues,  to  be  finally 
re-deposited  in  the  leaf. 

The  part  which  soil  ferments  have  played  in  the  forma- 
tion of  arable  soil  from  the  original  rocks  is  not  thoroughly 
appreciated.  The  naked  rocks  of  high  mountams  com- 
prise mineralogical  types  of  the  most  varied  nature,  viz., 
granite,  porphyry,  gneiss,  mica  schist,  volcanic  rocks  and 
limestones  of  all  varieties,  and  all  these  have  been  found 
to  be  covered  with  a  nitrifying  ferment  which  is  doubtless 
extremely  aiftive  in  producing  incipient  decay.  At  the 
high  altitudes  in  which  these  observations  have  been 
made,  the  activity  of  badleria  is  necessarily  limited  by  the 
low  temperature  to  which  they  are  subjeAed  during  the 
greater  part  of  the  year.  During  the  winter  season  their 
life  is  suspended,  but  is  not  extinguished,  since  they  have 
been  found  living  and  ready  to  resume  all  their  aiftivity 
after  an  indefinite  sleep,  perhaps  of  thousands  of  years, 
on  the  ice  of  the  glaciers,  where  the  temperature  never 
rises  above  the  freezing-point.  When  the  aiftivity  of 
these  ferments  in  the  most  unfavourable  conditions  is 
recognised,  it  is  easily  seen  how  much  more  adlive  they 
become  when  brought  down  to  lower  levels,  where  they 
are  nourished  by  the  favouring  conditions  which  exist, 
especially  during  the  summer,  in  cultivated  soils.  In 
fadt,  the  importance  of  the  adlion  of  these  bodies  on  the 
mineral  particles  of  which  the  soil  is  largely  composed 
has  never  been  fully  recognised,  and  there  is  no  doubt 
whatever  of  the  great  significance  of  their  decomposing 
adion  in  the  liberation  of  plant-food  locked  up  in  unde- 
composed  mineral  strudures.  In  this  case  the  acftivity  of 
the  bafteria  is  not  limited  to  the  surface  of  rock  masses, 
but  permeates  every  particle  of  soil,  and  thus  becomes 
effecSive  over  a  vastly  extended  surface. 

When  the  extreme  minuteness  of  these  organisms,  and 
of  the  phenomena  which  they  produce,  is  considered, 
there  may  be  a  tendency  to  despise  their  importance ;  but 
by  reason  of  the  fad  that  their  adtivity  is  never  ceasing, 
and  of  the  widest  application,  it  must  be  placed  among 
the  geologic  causes  to  which  the  crust  of  the  earth  owes 
a  part  of  its  adual  physiognomy,  and  to  which  the  forma- 
tion of  the  deposits  of  the  comminuted  elements  consti- 
tuting arable  soil  is  due. 

But  the  adion  of  these  ferments  has  not  stopped  with 
the  aid  they  have  given  to  soil  formation.  It  is  highly 
probable  that  they  assist  in  a  most  marked  manner  in  the 
final  dissolution  of  the  soil  particles,  and  the  setting  free 
of  the  plant-foods  which  they  contain.  It  is  quite  certain 
that  in  the  primary  decay  of  bare  rocks,  especially  at 
high  altitudes,  the  nitrifying  organism  plays  a  highly  im- 
portant part,  preparing  the  surface  of  the  rock  for  the  first 
growth  of  lichens  and  other  low  vegetable  organisms, 
from  which  the  first  traces  of  humus  are  formed.  The 
discovery  that  the  nitrifying  organism  can  subsist  upon  a 
purely  mineral  food  is  one  of  the  chief  supports  of  the 
idea  that  they  were  especially  adive  in  the  very  beginning 


Chcmical  >Bwm,l 
May  7, 1897.     f 


Soil  Ferments  important  in  Agriculture, 


223- 


of  soil  formation.  It  has  been  shown  that  these  badteria 
can  be  developed  by  absorbing  from  the  ambient  atmo- 
sphere traces  of  ammonia  and  other  bodies  which  may  be 
present  in  the  air.  There  is  thus  discovered  in  the  very 
first  produds  of  the  attrition  of  rocks  the  charaAeristic 
element  of  vegetable  soil,  viz.,  humus,  the  proportion  of 
which  increases  rapidly  with  the  processes  of  disintegra- 
tion, until  finally  the  decaying  mass  is  capable  of 
sustaining  chlorophyll-containing  plants.  Not  only  upon 
the  surface  of  exposed  rocks  have  these  organisms  been 
discovered,  but  they  are  found  to  extend  also  to  a  consider- 
able distance  in  the  anterior.  They  not  only  play  an 
important  part  by  diredt  a(5lion  upon  the  mineral  matters 
which  the  rocks  contain,  but  later  on,  through  the  produc- 
tion of  nitric  acid,  greatly  favour  the  final  solution  of  the 
soil  particles. 

Kinds  of  Organisms  in  the  Soil. — The  nitrifying  or- 
ganisms in  the  soil  exist  in  common  with  hundreds  of 
others,  many  of  which  are  doubtless  acftive  upou  the  soil 
particles.  The  organisms  to  which  particular  attention  is 
called  in  this  address,  in  addition  to  those  which  help  to 
dissolve  the  soil  particles  already  mentioned,  are  those 
which  are  adlive  in  preparing  organic  foods  for  absorption 
and  assimilation  by  plants,  and  those  which  ad  upon  free 
atmospheric  nitrogen  and  bring  it  into  a  shape  suited  to 
plant>nutrition. 

In  general  these  are  called  the  nitrifying  ferments,  and 
their  adion  is  uniformly  favourable  to  vegetable  growth. 
Attention  should  also  be  given  to  another  class  of  organ- 
isms found  in  the  soil,  whose  adivity  is  inimical  to  plant 
growth  or  hurtful  in  some  other  way.  This  class  comprises 
the  denitrifying  organisms,  and  those  of  a  pathogenic 
nature  which  may  exist  in  the  soil,  and  by  their  adivity 
cause  disease  in  man  and  beast. 

The  Nitrifying  Ferments.  —  The  micro-organisms  of 
niost  importance  to  agriculture,  and  those  to  which  atten- 
tion is  particularly  called  in  this  article,  are  the  baderia 
which  ad  upon  nitrogenous  matters  and  oxidise  them  to 
nitric  acid,  or  which  exert  a  reducing  efFed  on  nitric  acid, 
bringing  it  to  lower  forms  of  oxidation,  or  even  to  free 
nitrogen.  These  organisms  belong  to  many  different 
species,  and  ad  in  very  many  different  ways.  The 
general  group  to  which  they  belong  is  known  as  nitro- 
'baderia.  The  classification  of  these  organisms  by  genera 
and  species  would  prove  of  little  interest  to  the  readers 
of  this  article.  In  general  it  may  be  said  that  there  are 
three  distind  genera,  comprising,  in  the  first  place,  those 
organisms  which  form  ammonia  or  carbonate  of  ammonia 
from  organic  nitrogenous  compounds,  such  as  albumen  ; 
in  the  second  place,  the  organisms  which  transform 
carbonate  of  ammonia  into  nitrous  acid ;  and  in  the 
third  place,  those  which  transform  nitrous  into  nitric 
acid.  Each  genus  is  necessary  in  the  complete  trans- 
formation of  proteid  matter  into  nitric  acid,  in  which 
latter  form  alone  nitrogen  is  chiefiy  available  for  piant- 
•food. 

Production  of  Ammonia.  —  The  baderia  which  are 
-especially  adive  in  the  formation  of  ammonia  are  found 
constantly  in  surface  soils  and  in  the  air  and  rain-waters. 
'By  the  adivity  of  these  organisms  in  the  decomposition 
of  proteid  matter,  large  quantities  of  ammonium  car- 
bonate are  produced.  The  organic  carbon  which  is 
present  in  a  compound  is  aded  upon  during  the  oxidation 
•of  the  proteid,  and  carbon  dioxide  and  certain  organic 
acids  are  formed.  The  organic  sulphur  which  is  present 
18  converted  into  sulphuric  acid,  and  the  hydrogen  partly 
into  water  and  partly  into  ammonia.  This  oxidation  is 
accomplished  by  baderia,  and,  to  a  less  extent,  by 
moulds  and  yeasts.  The  table  shown  on  the  screen  con- 
tains the  names  of  the  common  soil  baderia  which 
ammonise  proteid  matters.  The  column  headed  "  per 
cent  "  shows  the  amount  of  proteid  matter  changed  into 
ammonia  by  the  several  organisms  in  twenty  days,  at  a 
temperature  of  30°.  Of  all  the  baderia  which  have  been 
studied,  the  species  mycoides  has  the  highest  ammonising 
power,  being  capable  of  changing  nearly  half  of  the  pro- 


teid into  ammoniacal  nitrogen  in  the  time  named.  Itf , 
soils  where  the  environment  does  not  permit  of  the  deve-'! 
lopment  of  the  nitrifying  ferments,  the  change  stops  with 
ammonia.  Such  conditions  are  found  in  the  vegetable 
soils  of  swamps,  which  are  extremely  acid.  In  such  soils 
ammonia  is  quite  freely  produced,  while  the  nitrous  aad 
nitric  organisms  are  absent. 

In  the  analysis  of  a  swamp  soil,  which  had  been  showa 
by  a  baderial  culture  to  contain  no  nitrifying  ferments, 
0*03698  per  cent  of  nitrogen  was  found  as  ammonia,  and 
only  a  trace  as  nitric  acid.  In  another  vegetable  soil, 
which  contained  nitrifying  organisms,  0*0336  per  cent  of 
ammoniacal  and  0*0474  per  cent  nitric  nitrogen  were 
present.  Of  the  moulds,  several  have  been  found 
capable  of  producing  considerable  quantities  of  ammo* 
nia.  Among  these  Cephalothecium  roseum  converted 
over  30  per  cent  of  proteid  into  ammoniacal  nitrogen  in 
five  days,  and  Aspergillus  terricola  was  only  a  little  less 
adive. 

The  yeasts  are  still  less  adive,  but  a  large  number  of 
them  produces  ammonia  in  small  quantities. 

In  general,  it  may  be  said  that  in  cultivated  soils  which 
have  a  neutral  or  alkaline  readion,  baderia  are  almost 
the  sole  ammonia  makers,  while  in  vegetable  soils  of  a 
marked  acid  readion,  as  in  swamps  and  forests,  the 
moulds  are  the  chief  producers  of  ammonia. 

In  the  oxidation  of  albumen  by  the  Bacillus  mycoides 
the  carbon  is  oxidised  to  carbon  dioxide,  the  sulphur  to 
sulphuric  acid,  and  the  hydrogen  to  water  and  to  am« 
monia. 

The  readion  may  be  expressed  by  the  formula — 

C72Hii2Ni8S022=29H20+  72CO2    +    SO3    -I- 18NH3 
Albumen.  Water.  Carbon  Sulphur       Ammonia, 

dioxide.        trioxide. 

The  Bacillus  mycoides,  under  certain  conditions,  can 
form  ammonia  also  from  nitrates.  In  the  absence  of 
oxygen  it  reduces  nitrates  to  ammonia  in  presence  of  an 
organic  substance  like  sugar.  In  this  adion  it  is  anaerobic, 
while  in  the  ordinary  process  of  converting  proteid  matter 
into  ammonia  the  adion  takes  place  in  the  absence  of 
oxygen.  This  is  a  curious  instance  of  a  reverse  adion 
produced  by  the  same  organism  in  a  different  environ- 
ment, showing,  as  it  does,  an  oxidising  adion  in  the 
presence  of  oxygen,  and  a  reducing  adion  in  its  absence. 
Some  idea  of  the  charader  of  the  Bacillus  mycoides,  and 
the  methods  of  its  culture,  can  be  gained  by  a  study  of 
the  photographs  which  will  now  be  projeded  upon  the 
screen. 

Production  of  Nitrous  Acid. — The  next  step  in  the 
process  of  nitrification  is  the  conversion  of  ammonia  or 
its  compounds  into  nitrous  acid.  With  a  moderate  store 
of  ammonia  the  oxidation  into  nitrous  acid  takes  place, 
as  a  rule,  without  any  of  the  nitrogen  being  lost  in  a  free 
state  or  being  volatilised  as  ammonia  compounds.  When, 
however,  there  is  a  large  excess  of  ammonium  carbonate, 
a  considerable  loss  ot  nitrogen  may  take  place.  The 
pradical  dedudion  to  be  drawn  from  this  fad  is  ap- 
parent. Nitrogenous  fertilisers  should  be  applied  only 
in  moderate  quantities,  so  as  not  to  increase  the  stock  of 
material  beyond  the  power  of  the  adive  ferments  to 
handle  it. 

The  nitrous  ferment  is  by  far  the  largest  and  most 
vigorous  of  the  nitrifying  organisms.  It  is  from  three  to 
(our  times  as  large  as  the  nitric  ferment,  and  under  a 
high  power  of  the  microscope  appears  as  minute  globules, 
slightly  oblate.  These  globules  are  multiplied  by  fission, 
and  the  divided  parts  develop  rapidly  to  perfed  organisms 
of  full  size.  In  most  cases  the  organisms  appear  as 
distind  globules,  but  many  are  congregated  into  masses 
where  the  distindive  cell  strudure  seems  to  be  lost.  (A 
photograph  of  the  nitrous  organism  was  shown  upon  the 
screen). 

Conversion  of  Nitrous  into  Nitric  Acid. — The  last  step 
iti  the  process  of  nitrification  consists  in  the  oxidation  of 
tiitrous  to  nitric  acid.    As  a  rule,  plants  absorb  nitro- 


224 


^  .  -    -:.i,        ■  >.-    ■    ■,-\    .^   '  r       ■■■ 

Recovery  of  Waste  PldtitiuTfiuhidrtde. 


{Chemical  News. 
May  7,  1897. 


genous  food  only  as  nitric  acid,  but  it  cannot  be  said  that 
the  nitrogen  may  not  be  used  by  the  plant  in  other  forms. 
Some  experiments  seem  to  show  that  ammonia  and  its 
compounds  and  humus  may  be  direftly  absorbed  by  plants, 
but  if  this  be  true  it  must  be  only  in  very  limited  quanti- 
ties. The  final  step,  therefore,  in  nitrification  is  necessary 
to  secure  this  valuable  food  in  its  most  highly  available 
state.  The  nitrifying  organisms  are  much  smaller  than 
their  nitrous  cousins,  and  of  the  same  general  shape,  but 
more  globular. 

It  must  not  be  supposed  that  these  steps  in  the  prepara- 
tion of  a  nitrogenous  food  are  performed  with  entire  dis- 
tindness.  The  impression  might  be  obtained  that  the 
ammoniacal  ferment  exerted  its  adtivity,  converting  the 
whole  of  the  nitrogenous  supply  into  ammonia,  and  that 
in  this  state  only  the  nitrous  ferment  would  become 
active  and  convert  the  whole  produd  into  nitrous  acid, 
which  finally,  under  the  influence  of  the  nitric  ferment, 
would  form  nitric  acid.  In  point  of  fad,  however,  in 
arable  soils  and  under  favourable  conditions,  the  steps  of 
nitrification  may  be  almost  synchronous.  In  the  case  of 
a  growing  crop,  a  chemical  examination  or  repeated 
chemical  examinations  might  find  only  traces  of  ammonia 
and  nitrous  and  nitric  acids.  As  each  particle  of  ammo- 
nia is  formed,  it  is  converted  without  delay  into  nitrous 
acid,  and  then  at  once  into  nitric  acid.  The  nitric  acid 
formed  is  absorbed  by  the  growing  plant,  and  thus  it 
might  seem  that  the  adivity  of  the  ferments  present  in 
the  soil  had  been  reduced  to  a  minimum,  when  in  point  of 
fad  they  were  exercising  their  fundions  with  maximum 
vigour.  The  separate  stages  of  nitrification  mentioned 
above  can  only  be  secured  in  the  laboratory  by  a  skilled 
baderioiogist  patiently  working  to  separate  the  different 
genera  of  nitrifying  organisms  until  he  procures  them  in 
an  absolutely  pure  form.  As  may  be  supposed,  this  is 
very  difficult  to  accomplish. 

(A  photograph  of  the  nitric  organism  was  shown  upon 
the  screen). 

(To  be  continued). 


RECOVERY  OF  WASTE  PLATINUM  CHLORIDE. 
By  H.  W.  WILEY. 


Aluminum  turnings,  freed  of  oil,  have  been  used  in  this 
laboratory  for  some  time  for  many  purposes.  Immediately 
after  the  publication  of  the  paper  of  Wislicenus  and  Kauf- 
mann  (Ber.  d.  Chetn.  Ges.,  xxviii.,  1323)  on  the  various 
applications  of  aluminum  amalgam  in  the  laboratory,  a 
large  quantity  of  these  turnings  was  procured  from  the 
Pittsburg  Redudion  Co.  Considerable  difficulty  was 
encountered  in  attempting  to  use  these  turnings  in  the 
manner  described  in  the  manner  cited  above.  Mr.  McElroy 
prepared  the  amalgam  by  washing  aluminum  clippings 
with  ether  to  remove  oil,  treating  with  dilute  caustic  soda 
till  free  evolution  of  gas  took  place,  and  then  washing 
with  water  to  remove  the  alkali.  The  solution  of  corro- 
sive sublimate  was  made  in  alcohol  (chosen  because  the 
most  convenient  solvent),  diluted  with  water,  and  poured 
over  the  aluminum.  When  the  evolution  of  gas  was  seen 
to  take  place  from  every  piece  of  aluminum  in  sight,  the 
mercuric  chloride  solution  was  decanted  and  the 
aluminum  washed  chloride-free  with  water.  The  treat- 
ment with  soda  and  mercuric  chloride  was  then  repeated. 
Finally,  the  turnings  were  washed  free  of  water  with 
strong  alcohol.  The  washed  amalgam  in  fresh  portions 
of"  absolute  "  alcohol  kept  up  a  steady  evolution  of  gas, 
long  after  the  time  all  water  should  have  been  removed. 
A  portion  was  removed  from  the  alcohol,  washed  with 
ether,  and  placed  in  petroleum  ether,  where  the  evolution 
of  gas  became  quite  strong.  The  containing  flask  was 
loosely  stoppered  and  stood  aside  over  night.  In  the 
morning  the  petroleum  ether  was  gone. 


A  fresh  portion  of  amalgam  from  2oogrms.  of  aluminum 
was  prepared  and  treated  as  before,  except  that  the 
washing  with  alcohol  was  more  thorough.  The  alcohol 
was  removed  with  ether,  and  the  amalgam  finally  washed 
with  kerosene.  It  was  then  covered  with  kerosene  and 
stood  aside.  In  about  half  an  hour  the  evolution  of  gas 
became  quite  violent  and  the  containing  bottle  hot.  On 
cooling  under  the  tap  the  generation  of  gas  slackened, 
but  on  standing  increased  again  as  the  mixture  warmed 
up. 

The  kerosene  was  such  as  is  used  for  lamps.  It  gave 
a  black  zone  of  lead  sulphide  when  treated  with  the  lead 
acetate  test.  It  is  very  likely  Lima  oil.  As  is  well 
known,  in  the  Frasch  process  of  purifying,  the  oil  is 
passed  through  copper  oxide,  which  it  converts  into 
copper  sulphide.  As  for  every  atom  of  sulphur  removed 
an  atom  of  oxygen  must  go  into  the  oil,  probably  the 
adion  of  the  aluminum  consisted  in  appropriating  this 
oxygen.  Neither  bright  sodium  or  sodium  amalgam  had 
any  special  adion  on  the  kerosene  used.  The  adion  of 
the  amalgam  on  strong  alcohol  has  been  confirmed  by 
Hillyer  (Am.  Chem.  yottnn.,xw'\u.,  621).  We  have  been, 
able  to  use  these  turnings,  amalgamated  with  mercuric 
chloride,  for  the  redudion  of  nitrates  to  ammonia  for 
analytical  and  other  purposes,  and  it  is  probable  that  a 
speedy  and  accurate  analytical  process  maybe  elaborated 
on  this  line.  We  have,  however,  found  the  most  success- 
ful use  of  the  turnings  in  the  recovery  of  platinum  waste. 
This  method  of  recovery  is  due  to  Mr.  K.  P.  McElroy, 
and  has  been  worked  out  by  him  in  detail,  and  has  been 
successfully  used  for  some  time  in  the  recovery  of 
platinum  chloride  waste  from  potash  analyses.  The 
method  is  as  follows  : — 

The  waste  platinum  from  potash  determinations  is  col- 
leded  and  to  the  hut  water  solution  of  platinum  potas- 
sium chloride  is  added  aluminum  in  the  form  of  clippings 
or  turnings.  In  a  few  minutes  a  platinum-aluminum 
couple  is  formed  and  redudion  goes  on  vigorously.  The 
addition  of  hydrochloric  acid  is  not  necessary,  but  is 
advisable  for  promoting  the  settling  of  the  platinum 
formed.  After  the  redudion  is  complete,  more  hydro- 
chloric acid  is  added  to  dissolve  the  excess  of  aluminum. 
When  this  is  done  the  platinum  will  be  found  to  settle, 
and  the  supernatant  liquid  will  be  clear.  The  supernatant 
liquid  contains  but  little  suspended  platinum,  but  it  i& 
passed  through  a  large  folded  filter.  If  it  does  not  come 
through  clear,  as  is  sometimes  the  case,  return  it  a  few 
times.  As  but  little  platinum  gets  on  the  filter,  the  same 
filter  is  used  over  and  over  again  for  successive  filtrationSv 
until  enough  platinum  accumulates  to  make  its  recovery 
worth  while.  When  the  clear  liquid  is  all  decanted,  add 
water  to  the  spongy  platinum,  shake,  allow  to  settle,  and 
decant.  Repeat  this  until  the  supernatant  liquid  is  free 
of  chloride.  The  spongy  platinum  is  then  covered  with 
strong  nitric  acid  and  heated  for  the  purpose  of  removing 
copper.  Aluminum  often  contains  a  little  copper,  which 
of  course  remains  with  the  platinum.  When  the  copper 
is  all  dissolved,  the  copper  nitrate  and  the  excess  of  nitric 
acid  are  removed  by  washing  with  water  by  decantation 
as  before,  till  the  supernatant  liquid  is  acid  free  when 
tested  with  Congo  paper.  The  resulting  platinum  black, 
is  dissolved  with  aqua  regia,  made  by  mixing  five  parts  of 
hydrochloric  acid  with  one  part  of  nitric,  added  in  amount 
sufficient  to  dissolve  all  of  the  platinum  present.  The 
solution  thus  obtained  is  transferred  to  a  porcelain  dish 
and  evaporated  on  a  steam-bath  till  a  portion  taken  out 
with  a  rod  solidifies  on  cooling.  The  residue  is  diluted 
with  water  and  hydrochloric  acid  and  re-evaporated.  If, 
on  adding  water  to  the  syrupy  mass  formed  by  this 
evaporation,  nitrous  vapours  are  evolved,  add  plenty  of 
water  and  re-evaporate.  Repeat  this  evaporation  with> 
water  till  the  nitrous  vapours  are  no  longer  evolved  on 
dilution.  Finally,  dilute  sufficiently  to  filter  and  add 
water  until  the  colour  of  a  platinum  chloride  solution  of 
known  content  is  matched. — journal  of  the  Americaru 
Chemical  Society,  xix.,  No.  3. 


Cbbmical  Mbws,  I 
•'May  7.1897..     I 


^'^y^^^'^'^:  m;.YThe  Electric  Furnace. 


22- 


NOTICES  OF  BOOKS. 


The  Electric  Furnace.  ("  Le  Four  Ele<flrique  ").  By 
Henri  Moissan,  Membre  de  I'Institut.  Paris :  G. 
Steinheil.     1897.     Pp-  S^S* 

(First  Notice). 

M.  Moissan  was  led,  he  tells  us,  to  the  invention  of  the 
eledlhc  furnace  by  the  necessity  of  having  an  extremely 
high  temperature  to  enable  him  to  carry  on  his  experi- 
ments on  the  crystallisation  of  carbon  from  its  solution 
in  molten  iron  ;  this  can  be  achieved  at  about  1000°,  but 
as  he  aimed  at  vt^orking  on  fairly  large  quantities  of 
material,  he  found  the  ordinary  methods  employed 
inadequate. 

The  book  is  divided  into  four  chapters.  The  first  deals  with 
the  different  patterns  of  furnaces  used,  and  their  application 
to  the  study  of  the  fusion  and  volatilisation  of  a  certain 
number  of  refradory  bodies.  Chapter  II.  comprises  the 
study  of  three  varieties  of  carbon,  viz.,  amorphous  csrbon, 
graphite,  and  diamond.  In  Chapter  III.  we  have  the 
preparation  of  several  simple  bodies  by  means  of  the 
eledric  furnace,  and  the  experiments  carried  out  on 
chromium,  manganese,  molybdenum,  tungsten,  uranium, 
vanadium,  zirconium,  titanium,  silicon,  and  aluminium  ; 
while  in  the  fourth  and  last  chapter  we  find  described  the 
research  on  a  new  series  of  binary  compounds,  such  as 
carbides,  silicides,  and  borides.  The  preparation  of 
carbide  of  calcium,  in  particular,  has  been  the  subjecft  of 
a  distinct  research,  and  is  described  in  detail. 

The  highest  temperatures  hitherto  attained  industrially 
range  between  1700°  and  1800".  The  invention  of  the 
oxy-hyrirogen  blowpipe  by  MM.  Sainte-Claire  Deville  and 
Debray  rendered  great  services  to  chemistry,  but  the 
highest  temperature  obtained  by  its  means  was  not  more 
than  2000°.  Other  workers,  before  M.  Moissan,  had  used 
the  intense  heat  developed  by  the  eledric  arc,  notably 
Despretz,  Siemens,  Huntingdon,  Cowles,  and  others;  but 
there  were  objedions  to  all  their  furnaces,  though  they 
were  suitable  to  the  purposes  for  which  they  were 
devised. 

The  author  of  this  work  insists  that  his  furnace  is  not 
an  industrial  one,  but  is  meant  solely  for  research ;  his 
primary  objed  being  to  concentrate  as  much  heat  as  pos- 
sible into  the  smallest  possible  space.  His  early  experi- 
ments were  carried  out  by  means  of  a  small  Gramme 
dynamo,  giving  a  current  of  35  to  40  amperes  at  a  pres- 
sure of  55  volts.  But  as  the  work  proceeded,  this  was 
found  to  be  insufficient,  and  by  the  courtesy  of  the 
diredtors  of  some  of  the  large  eledtric  lighting  companies, 
M.  Moissan  was  enabled  to  avail  himself  of  much  more 
powerful  currents  ;  on  a  few  occasions  using  as  much  as 
300  h.-p.  at  one  time. 

M.  Moissan's  first  furnace  was  made  of  quicklime,  and 
was  exhibited  at  the  Academic  des  Sciences  in  December, 
1892.  It  consisted  of  two  well-dressed  bricks  of  lime  ' 
placed  one  on  the  other,  the  lower  one  containing  a  small 
cavity  which  served  as  a  crucible,  with  two  grooves  from 
it  to  the  outside,  to  hold  the  eleftrodes.  The  upper  brick 
was  slightly  hollowed  out  over  the  cavity  in  the  lower 
one,  and  as  the  surface  is  soon  melted  it  becomes,  so  to 
say,  polished,  and  ads  as  a  refiedor,  increasing  the  heat 
in  the  cavity  below.  The  cavity  could  also  be  used  to 
hold  a  small  carbon  crucible  containing  the  substance  to 
be  melted.  The  great  point  of  difference  between  this 
furnace  and  all  previous  models  is  that,  in  this  new  one, 
the  material  under  treatment  does  not  come  in  contad 
with  the  eledric  arc — that  is  to  say,  with  the  vapour  of 
carbon.  Another  great  convenience  is  that  the  eledrodes 
are  movable,  thus  affording  great  facilities  for  striking 
and  regulating  the  arc.  The  dimensions  of  the  bricks 
first  used  were  as  follows : — The  upper,  18  cm.  x  15  cm. 
K  5  cm.  thick ;  the  lower,  18  cm.  x  15  cm.  x  8  cm. 
thick.  This  was  large  enough  for  working  with  a  current 
of  100  to  125  amperes  and  50  or  60  volts;  by  increasing 


the  length  to  22  cm.  or  25  cm.,  one  can  use  a  current  of 
450  amperes  and  75  volts. 

Very  great  care  had  to  be  exercised  in  the  manufadure 
of  the  eledrodes,  so  as  to,  as  far  as  possible,  avoid  all 
chance  of  impurities. 

To  demonstrate  the  facility  with  which  quicklime  can 
be  volatilised,  no  crucible  need  be  employed,  the  bricks 
themselves  supplying  the  material  for  the  experiment. 
As  soon  as  the  arc  is  established  there  is  a  strong  smell 
of  hydrocyanic  acid,  the  small  quantity  of  water  remaining 
in  the  eledrodes  forming,  with  the  carbon,  acetylene ; 
this  gas  in  the  presence  of  nitrogen,  under  the  powerful 
adion  of  the  arc,  accomplishing  tne  synthesis  of  hydro- 
cyanic acid,  as  discovered  by  Berthelot.  This,  however, 
does  not  continue  long.  The  regulation  of  the  arc  must 
be  carefully  attended  to,  as  the  furnace  is  cold  at  first,  but, 
on  warming,  the  carbons  can  be  separated  until  they  are 
2  cm.  or  2i  cm.  apart.  With  a  current  of  400  amperes 
and  80  volts,  the  flames  issuing  from  the  grooves  holding 
the  eledrodes  are  accompanied,  after  five  or  six  minutes, 
by  torrents  of  white  smoke,  produced  by  the  volatilisation 
of  the  lime,  and  this  can  easily  be  condensed  on  any  cold 
j  surface.  With  a  current  of  800  amperes  and  no  volts 
I  more  than  100  grms.  of  lime  can  be  volatilised  in  five 
j  minutes ;  this  bears  testimony  to  the  enormous  power  of 
the  furnace.  On  removing  the  cover  at  the  end  of  the 
experiment,  it  can  be  seen  that  the  lime  in  the  cavity  is 
adually  melted,  and  by  allowing  the  cover  to  cool 
gradually,  veritable  staladites  are  formed. 

For  some  experiments,  carbonate  of  lime  is  preferable 
for  making  the  body  of  the  furnace  ;  it  possesses  greater 
solidity  or  compadness  than  quicklime,  and  is  easily  ob- 
tained in  large  blocks. 

When  using  such  enormous  currents  as  1200  to  2000 
amperes  and  100  volts,  lime  bricks  are  speedily  put  hors 
de  combat,  and  proper  manipulation  becomes  out  of  the 
question  ;  in  such  a  case  the  cavity  in  the  brick  is  enlarged 
and  lined  with  alternate  plates  of  magnesia  and  carbon, 
the  magnesia  being  next  to  the  lime,  and  the  carbon  on 
the  inside.  By  such  an  arrangement  the  carbon  and  lime, 
which  would  otherwise  form  carbides  of  lime,  are  kept 
apart,  and  as  magnesia  is  not  reducible  by  carbon,  the 
furnace  remains  uninjured. 

Another  modification  of  the  eledric  furnace  consists  in 
inserting  a  pair  of  carbon  tubes  through  the  lower  brick 
in  such  a  manner  that  they  are  at  right  angles  to  the  elec- 
trodes and  about  i  cm.  below  the  arc  ;  by  their  means  the 
gases  inevitably  driven  off  by  the  intense  heat  of  the  arc  find  a 
ready  exit,  and  the  experiment  can  be  continued  for  several 
hours  instead  of  minutes.  The  tubes  and  the  eledrodes 
are  of  course  kept  from  contad  with  the  lime  or  chalk  by 
means  of  a  protedive  layer  of  magnesia,  and  it  is  noticed 
that  the  ends  of  the  carbon  tubes  exposed  to  this  extreme 
temperature  are  entirely  converted  into  graphite.  By 
inclining  the  tube  to  an  angle  of  30°  the  furnace  can  be 
employed  to  produce  the  most  refradory  metals  in  quan- 
tity ;  thus  in  an  hour  2  kilogrammes  of  chromium  v/ere 
reduced  from  oxide  and  run  into  an  ingot. 

A  further  modification,  or  rather  extension,  of  the  fur- 
nace consists  in  arranging  several  arcs  in  parallel ;  by  this 
means  a  greater  quantity  of  heat  can  be  obtained  and 
large  quantities  of  metals  produced  without  necessarily 
going  to  a  great  extreme  of  temperature ;  but,  if  required, 
a  large  and  continuous  stream  of  highly  refradory  metal 
can  be  obtained  at  a  melting-point  of  considerably  over 
3000°.  M.  VioUe  has  put  the  highest  attainable  temper- 
ature  at  3500°. 


jfournal  of  Agriculture,  published  by  the  Department  of 
Agriculture,  Cape  of  Good  Hope.  March  18,  1897.  Cape 
Town  :  Townshend,  Taylor,  and  Snashall. 

No.  6  of  this  journal  has  just  reached  us ;  it  contains 
several  interesting  articles  on  subjeds  conneded  with 
agricultural  and  farming  work,  fruit  growing,  forestry,  &c. 


226 


Chemtcal  Notices  Jrom  Foreign  Sources, 


CBBMICAL  NBWti 

May  7. 1897. 


Some  interesting  remarks  are  to  be  found  in  a  short 
-article  entitled  "  Bacteriology  and  the  Plague,"  in  which 
reference  is  made  also  to  the  work  of  certain  French 
savants  in  the  Transvaal  who  are  engaged  in  the  study  of 
the  rinderpest. 

The  great  difficulty  to  be  contended  with  in  serious  epi- 
demics of  this  kind,  is  to  provide  at  short  notice,  and  keep  up 
an  efficient  supply  of  anti-toxic  serum.  Its  preparation  is 
naturally  a  long  and  cautious  process,  as  each  individual 
animal  can  only  yield  at  intervals  a  limited  quantity  of 
serum  without  feeling  ill  efTedts.  Long  before  the  present 
epidemic,  the  baderiological  treatment  of  disease  had  been 
developed  by  the  Government  of  India  on  a  much  greater 
scale  than  that  attempted  by  any  European  Government. 
A  year  and  a  half  ago,  in  the  Presidency  of  Bengal  alone, 
-42,445  persons  were  inoculated  for  cholera,  without  a 
single  mishap,  or  injury  to  health. 


Traite  Elementaire  de  Chimie  a  I'Usage  des  Candidats  au 
Certificat  d'Aptitude  des  Sciences  Physiques,  et  Natu- 
relies  et  des  Candidats  aux  Baccalaureats  Scientifiques. 
Paris :  Georges  Carre  and  C.  Naud.     1896. 

Chimie  Minerale.  Par  A.  Haller,  Correspondant 
de  rinstitut,  Diredeur  de  I'lnstitut  Chimique  de  Nancy, 
and  P.  Th.  Muller,  Maitre  de  Conference  a  I'lnstitut 
Chimique  de  Nancy.     Pp.  336. 

Chimie  Organique.     (By  the  same  Authors). 

The  work  on  Mineral  Chemistry  is  a  good  and  useful  expo- 
sition of  chemical  principles  and  the  elementary  laws  of 
chemical  science.  There  is  a  catalogue  of  the  elements 
in  which  argon  and  helium  duly  figure,  but  neodymium 
■and  praseodymium  are  not  recognised  as  separate  ele- 
ments. The  laws  of  Dalton,  of  Gay-Lussac,  the  hypo- 
thesis of  Avogadro  and  Ampere,  are  fully  expounded  ;  also 
'the  determination  of  molecular  and  atomic  weights  are 
^given,  followed  by  an  outline  of  crystallography. 

The  principles  of  thermo-chemistry  are  introduced  after 
the  halogens. 

Oxygen,  sulphur,  selenium,  and  tellurium  are  made  to 
rank  as  the  second  family  of  the  "metalloids."  For  the 
recognition  of  ozone  the  authors  recommend  the  use  of 
thallium  paper  in  the  first  place,  but  Hurter's  reagent  is 
not  omitted.  Mineral  waters  are  here  divided  into  eight 
classes — the  acidulous,  the  alkaline,  the  sulphuretted,  the 
chlorides,  bromides,  and  iodides,  the  sulphate,  the  iron 
waters,  and  the  arsenical. 

The  descriptions  of  the  several  elements  are  followed 
by  a  sketch  of  the  periodic  classification,  here  ascribed 
solely  to  Mendeleefif.  An  abstract  of  qualitative  analysis 
xoncludes  the  work. 

The  authors  have  accomplished  their  task  ably  as  far  as 
its  limited  scope  would  permit. 

In  the  work  on  Organic  Chemistry,  the  authors,  in  their 
introdudory  remarks,  draw  the  accepted  distindion  between 
organic  compounds  and  organised  bodies.  They  classify 
organic  matter  as  containmg  two  elements  only,  such  as 
benzene,  or  three  elements,  huch  as  alcohol,  or  acetic  acid, 
or,  again,  four  elements,  as  is  the  case  with  urea  and 
indigo.  As  a  supplement  follow  artificial  compounds  into 
which  a  number  of  extraneous  elements  have  been  intro- 
duced. 

At  the  end  of  the  work  we  find  an  account  of  produdls 
of  unknown  constitution,  such  as  biliary  produds,  gela- 
tins, albumenoids,  syntonines,  peptones,  enzymes,  milk, 
blood,  blood-pigments,  &c.  We  do  not  find  any  special 
mention  of  the  "  toxines." 

Within  its  scope  this  work  fulfils  the  reasonable  expeft- 
ation  of  the  student. 


The  Principles  of  Mathematical  Chemistry.  The  Energetics 
of  Chemical  Phenomena.  By  Dr.  Georg  Helm,  Pro- 
fessor in  the  Royal  Technical  High  School,  Dresden. 
Authorised  Translation  from  the  German,  by  J, 
Livingston  R.  Morgan,  Ph.D.  (Leipzig),  Instrudlor  in 
The  Brooklyn  Polytechnic  Institute.  New  York  :  John 
Wiley  and  Sons.  London  :  Chapman  and  Hall,  Lim. 
1897.     Pp-  viii. — 228,  i2mo.,  cloth. 

Dr.  Helm's  well-known  "  Grundziige  der  mathematischen 
Chemie,"  published  in  1894,  is  now  offered  to  students  in 
an  English  dress. 

The  translation  follows  the  text  as  closely  as  possible, 
and  Dr.  Morgan  has  "  aimed  at  clearness  rather  than 
literary  style  ; "  yet  the  involved  sentences  peculiar  to 
German  only  occasionally  appear  through  the  translation. 

The  work  is  divided  into  four  parts.  Part  I.  dealing 
with  the  measurement  of  chemical  energy,  mechanical 
energy,  and  the  volume  energy  of  gases.  Part  II.  is 
devoted  to  entropy,  and  discusses  the  thermodynamics 
of  perfeA  gases,  the  entropy  of  gases  and  gas  mixtures, 
the  relations  between  heat  and  volume  energy,  as  well  as 
eleiftrical  energy.  Part  III.  treats  of  chemical  intensity, 
concluding  with  a  chapter  on  the  velocity  of  a  chemical 
rea(^ion.  Part  IV.  considers  the  degrees  of  freedom  of 
chemical  phenomena,  such  as  the  rule  and  equilibrium  of 
phases. 

Students  of  chemistry  who  have  the  habit  of  dealing 
with  subjedts  on  a  mathematical  basis  will  find  this 
volume  of  great  service,  throwing  much  light  on  the  recent 
developments  of  the  science.  It  is  not  a  book  for 
beginners,  but  one  which  advanced  classes  should  take  up 
with  great  profit.  The  author  frequently  refers  to 
Wilhelm  Ostwald's  writings,  to  which  Helm's  book  forms 
a  good  guide. 

The  labours  of  Willard  Gibbs  in  this  direction  are  more 
than  once  gracefully  acknowledged  by  the  author.  An 
index  closes  the  volume.  H.  C.  B. 


CHEMICAL 


NOTICES    FROM 
SOURCES. 


FOREIGN 


NoTB.— All  degrees  of  temperature  are  Centigrade  unless  otherwise 
expressed. 

Comptes  Rendus  Hebdomadaires  des  Seances,  dePAcademie 
des  Sciences.     Vol.  cxxiv..  No.  16,  April  20,  1897. 

Determination  of  the  Surface,  the  Bulk,  and  the 
Chemical  Composition  of  the  Human  Body. — Ch. 
Bouchard. — The  disassimilation  is  proportional  to  the 
weight  of  the  body,  or  rather  to  the  weight  of  fixed  albu- 
men, and  the  fundional  or  respiratory  consumption  is 
proportional  to  the  surface  of  the  body.  The  produdls 
of  nutrition,  i.e.,  the  chemical  produds  (urea,  carbonic 
acid,  and  water),  and  the  dynamic  produds  (calories) 
depend  on  the  quantity  of  fixed  albumen  and  the  intensity 
of  its  adivity. 

Details  of  the  Method  followed  in  precise 
Cryoscopic  Researches.— F.  N.  Raoult.— The  author 
has  succeeded  in  measuring  the  redudions  of  the  freezing 
point  with  an  approximation  of  o*o665°.  By  this  means 
he  has  made  a  methodical  study  of  the  influence  of  super- 
fusion  upon  the  congelation-point  of  aqueous  solution. 

On  the  Physiological  Atftion  of  the  X  Rays. — W. 
Crookes. — I  can  entirely  corroborate  the  observations  of 
the  learned  author  of  the  paper  just  read  (memoir  by  M. 
Sorel,  Comptes  Rendus,  Session  of  April  12,  p.  826).  I 
believe,  nevertheless,  that  the  X  rays  ad  upon  different 
persons  with  a  different  intensity.  In  particular,  I  have 
worked  for  a  long  time  with  tubes  producing  rays  of  this 
kind,  and  I  have  perhaps  been  exposed  to  their  adion  for 
a  longer  time  than  most  experimentalists,  but  without 


Chemical  Nkws,  i 
May  7. 1897.      1 


Royal  Institution, 


227 


undergoing  any  effeSs  either  upon  the  face  or  the  hands. 
On  the  other  hand,  I  have  observed  very  marked  physio- 
logical  effefts,  analogous  to  those  which  have  been  just 
spoken  of,  produced  upon  persons  who  had  been  exposed 
to  the  X  rays.  I  am  therefore  inclined  to  think  that  the 
very  energetic  acftion  sometimes  observed  with  these  rays 
depends,  up  to  a  certain  point,  oh  the  idiosyncrasy  of  the 
experimentalist. 

Comparison  of  the  Absorption  by  Crystallised 
Media,  of  Luminous  Rays,  and  X  Rays.— V.  AgafonofT. 

On  studying  my  proofs   I  was   surprised  to  find   that 

there  exists  a  general  opposition  between  the  absorption 
for  the  luminous  rays  and  for  the  Rontgen  rays.  The 
sulphates  very  transparent  for  the  ultra-violet  rays  are 
extremely  opaque  for  the  X  rays.  The  inverse  holds 
good  for  the  majority  of  crystalline  organic  compounds. 
The  nitrates  absorb  the  luminous  rays  more  than  the  sul- 
phates and  less  than  organic  bodies ;  the  X  rays,  on  the 
contrary,  less  than  the  sulphates  and  more  than  organic 
bodies. 

Black  Light.— M.  Perrigot.— Black  light  plays  no  part 
in  the  explanation  of  phenomena  conneded  with  fadts 
the  law  of  which  is  perfedly  known. 

Separation  of  Chlorine  and  Bromine.— H.  Baubigny 
and  P.  Rivals. 

Separation  of  Nickel  from  Cobalt  and  Iron,  and  of 
Cobalt  from  Aluminium.— E.  Piiierua. — (See  p.  193). 

On  Cholesterine,— Ch.  Cloez.— Cholesterine  can  com- 
bine with  a  single  atom  of  bromine  to  form  a  body, 
C26H440Br,  less  soluble  in  cold  carbon  disulphide  than 
is  cholesterine  itself  and  its  dibromide. 


MISCELLANEOUS. 


Royal  Institution.  —  The  Annual  Meeting  of  the 
Members  of  the  Royal  Institution  of  Great  Britain 
was  held  on  Saturday  afternoon,  May  ist,  at  the  house 
of  the  Institution  in  Albemarle  Street,  Sir  James 
Crichton-Browne,  M.D.,  F.R.S,  Treasurer  and  Vice- 
President,  presiding.  The  Annual  Report  of  the  Com- 
mittee of  Visitors  for  the  year  1896,  testifying  to  the 
continued  prosperity  and  efficient  management  of  the 
Institution,  was  read  and  adopted.  Fifty-eight  new 
Members  were  eledted  in  1896.  Sixty-four  Leisures  and 
nineteen  Evening  Discourses  were  delivered  in  1896. 
The  books  and  pamphlets  presented  in  1896  amounted  to 
about  274  volumes,  making,  with  621  volumes  (including 
periodicals  bound)  purchased  by  the  Managers,  a  total  of 
895  volumes  added  to  the  Library  in  the  year.  Thanks 
were  voted  to  the  President,  Treasurer,  and  the  Honorary 
Secretary,  to  the  Committees  of  Managers  and  Visitors, 
and  to  the  Professors,  for  their  valuable  services  to  the 
Institution  during  the  past  year.  The  following  gentle- 
men were  unanimously  elefted  as  Officers  for  the  ensuing 
year: — 

President  —  The  Duke  of  Northumberland,  K.G., 
D.C.L.,  LL.D. 

Treaiurer — Sir  James  Crichton-Browne,  M.D.,  LL.D., 
F.R.S. 

Secretary  —  Sir  Frederick  Bramwell,  Bart.,  D.C.L., 
LL.D.,  F.R.S.,  M.  Inst.  C.E. 

Managers  — ^\T  Frederick  Abel,  Bart.,  K.C.B.,  D.C.L., 
LL.D.,  F.R.S. ;  The  Right  Hon.  Arthur  James  Balfour, 
M.P.,  D.C.L.,  LL.D.,  F.R.S.;  John  Wolfe  Barry,  Esq., 
C.B.,  F.R.S.,  M.Inst.C.E. ;  William  Crookes,  Esq.,  F.R.S. ; 
Edward  Frankland,Esq.,  D.C.L.,  LL.D.,  F.R.S. ;  Charles 
Hawksley,  Esq.,  M.  Inst.  C.E. ;  Donald  William  Charles 
Hood,  M.D.,  F.R.C.P. ;  Vidtor  Horsley,  Esq.,  M.B., 
F.R.S.,F.R.C.S. ;  William  Huggins,  Esq.,  D.C.L.,LL  D., 


F.R.S.;  The   Right   Hon.   Lord   Lister, 
LL.D.,  Pres.  R.S. ;  Ludwig  Mond,  Esq 


M.D.,   D.C.L. 
Ph.D.,  F.R.S. 


LiLi.u.,  I'res.  K.a. ;  i^uawig  moiiu,  iio^.,  •.  »i.i^.,  *  .»»•>.».  ,. 
Arthur  William  Riicker,  Esq.,  M.A.,  D.Sc,  F.R.S. ;  Basil 
Woodd  Smith,  Esq.,  F.R.A.S.,  F.S.A.;  The  Hon.  Sir 
James  Stirling,  M.A.,  LL.D.;  Sir  Henry  Thompson,. 
KRCS     KRAS 

Visitors  —  Sir'  James  Blyth,  Bart. ;  William  Arthur 
Brailey,  M.D.,  M.R.C.S. ;  Edward  Dent.  Esq.;  John 
Ambrose  Fleming,  Esq.,  M.A.,  D.Sc,  F.R.S.  ;  Edward 
Kraftmeier,  Esq.;  Sir  Francis  Laking,  M.D.;  Hugh 
Leonard,  Esq.,  M.Inst.C.E.;  Sir  Philip  Magnus,  J. P. ;. 
T.  Lambert  Mears,  Esq.,  M.A.,  LL.D. ;  Lachlan  Mack- 
intosh  Rate,  Esq.,  M.A. ;  Thomas  Tyrer,  Esq.,  F.C.S., 
F.I.C. ;  Roger  William  Wallace,  Esq.,  Q.C. ;  John 
Westlake,  Esq.,  Q.C,  LL.D.;  His  Honour  Judge  Frede- 
rick Meadows  White,  Q.C.  ;  James  Wimshurst,  Esq. 

University  of  London. — The  following  Examiners  for 
the  year  1897-8  were  eledted  at  the  Meeting  of  the  Senate, 
held  April  28th,  1897  :— Mathematics  ^"'^  Natural  Philo- 
sophy-E.  W.  Hobson,  Sc.D.,  F.R.S.,  and  Joseph  Larmor,. 
D.Sc,  M.A.,  F.R.S.  Experimental  Philosophy — Prof.  G. 
F.  FitzGerald,  M.A.,  F.RS.,  and  Prof.  Silvanus  Thompson, 
D.Sc,  B.A.,  F.R.S.  Chemistry— Prof.  Wyndham  R. 
Dunstan,  M. A.,  F.R.S.,  and  Prof.  William  Ramsay,  Ph.D., 
F.R.S.  Geology  and  Physical  Geography— Prof.  T.  G. 
Bonney,  Sc.D.,  LL.D.,  M.A.,  F.R.S.,  and  Prof.  Charles 
Lapworth,  LLD.,  F.R.S.  Materia  Medica  and  Pharma- 
ceutical Chemistry— Sidney  Phillips,  xM.D.,  and  W.  Hale 
White,  M.D.  Forensic  Medicine— Prof.  J.  Dixon  Mann, 
M.D.,  and  Thomas  Stevenson,  M.D. 

Speed  of  Esterification,  as  compared  with  Theory. 
Robert  B.  Warder  {y.  Phys.  Chem.,  i.,  149).— The  author 
shows  that  the  rate  of  esterification  of  alcohol  and  the 
three  chloracetic  acids,  as  determined  by  Lichty  {Tech. 
Quart.,  viii.,  99),  does  not  conform  to  the  requirements  o£ 
the  laws  of  mass-acftion  in  the  form  applicable  to  a  rever- 
sible reaaion  of  the  second  order,  and  he  suggests  four 
possible  causes  of  the  deviations. — Journ.  Amer.  Chem. 
Soc. 

On  the  Volatility  of  Ferric  Chloride.  —  Henry  P. 
Talbot  [Am.  Chem.  J.,  xix.,  52-59).— The  experimental 
data  show  that  no  loss  of  ferric  chloride  occurs,  when  its 
solutions  (whether  neutral  or  acidified  with  hydrochloric 
acid)  are  evaporated  to  dryness  on  the  water-bath  or  upon 
the  hot  plate,  provided  in  the  latter  case  they  are  not  too 
strongly  overheated.  The  residues  so  obtained  were  sub- 
jedled  to  the  temperature  usually  employed  to  dehydrate 
silicic  acid  (130°  C.)  for  two  hours,  but  suffered  no  loss  of 
iron.  Prolonged  heating  of  these  residues  over  a  free 
flame  occasioned  but  a  slight  loss  (o"4  per  cent)  of  the 
iron  present.  Concentrated  acid  solutions  of  the  chloride, 
when  boiled  in  a  distilling  flask,  allowed  ferric  chloride  to 
pass  into  the  receiver  only  when  a  slight  separation  of  the 
solid  had  taken  place  on  the  side  of  the  flask,  which,  in 
the  acid  atmosphere,  was  volatilised  by  the  overheating 
of  the  glass.  When  ferric  chloride  solutions  are  evapor- 
ated with  exposure  to  the  air,  a  loss  of  chlorine  ensues, 
and  the  basic  ferric  salt  formed  prevents  loss  of  the  iron 
as  chloride.  The  presence  of  ammonium  chloride  with 
the  ferric  chloride  occasioned  no  loss  of  the  latter,  even 
at  130°  C.  The  residues,  when  heated  over  a  free  flame, 
suffered  a  loss  of  iron,  as  would  be  expedled.  The 
presence  of  aqua  regia  with  the  ferric  chloride  solution 
tends  to  occasion  a  slight  loss  of  iron  during  evaporation. 
The  maximum  loss  was  0'6  per  cent  of  the  iron  present, 
but  in  other  cases  very  little  or  no  loss  could  be  detedled. 
Vogel's  experiments  (N.  Ref.  Pharm.,  xviii.,  157)  were 
repeated,  and  it  was  found  that  a  slight  volatilisation  of 
iron  seems  to  take  place  from  an  ethereal  solution  at  t-he 
temperatures  of  the  laboratory,  but,  on  the  other  hand, 
the  presence  of  ether  or  its  vapour  does  not  promote  the 
volatilisation  of  the  ferric  chloride  from  its  boiling,  con-r 
centrated,  aqueous  solutions. —  jfourn.  Amer,  Chemical 
Soc. 


228 


Meetings /or  the  Week, 


Chemical  Mews, 
May  7,  1897. 


Pottery  and  Glass  Trades  Benevolent  Institution. 
— By  way  of  celebrating  the  Diamond  Jubilee  of  the 
reign  of  Queen  Viftoria,  and  of  benefitting  the  funds  of 
this  Institution,  entertainments  have  been  organised  by 
the  Board  of  Management.  On  Wednesday,  May  12th, 
there  will  be  a  Conversazione  and  Dance  at  the  Galleries 
of  the  Royal  Institute  of  Painters  in  Water  Colours, 
Prince's  Hall,  Piccadilly,  on  which  occasion  Sir  Henry 
Doulton  and  Miss  Doulton  will  receive  the  guests. 
On  Wednesday,  July  7th,  a  Dinner  will  be  held  in  the 
Prince's  Hall,  Hotel  Cecil,  Salisbury  Street,  Strand,  in 
aid  of  the  Diamond  Jubilee  Celebration  Fund,  when 
William  Woodall,  Esq.,  M.P.,  for  Hanley,  will  preside. 
The  Board  will  be  pleased  to  receive  subscriptions,  and 
the  names  of  ladies  or  gentlemen  who  will  kindly  con- 
sent to  ad  as  Stewards.  Tickets  and  further  information 
may  be  obtained  from  the  Secretary,  Mr.  A.  J.  Prickett, 
6,  Thavies  Inn,  Holborn  Circus,  E.C, 

The  Imperial  Hygienic  Laboratories  of  Japan. — 
Soon  after  Japan  had,  in  1869-70,  made  the  treaties  now 
in  force  with  foreign  countries,  medicines  were  imported 
in  large  quantities,  and,  in  order  to  proted  the  public 
againstquackery.theDepartment  of  Education  established 
a  sub-department  or  Medical  Bureau  to  examine  and 
report  on  the  quality  of  all  medicines  imported.  This 
department  has  gradually  grown,  and  so  increased  its 
scope  that  it  now  undertakes  the  analysis  and  examination 
of  all  kinds  and  sorts  of  substances.  During  the  year 
1895  the  total  number  of  bottles,  cans,  bags,  and  other 
packages  examined,  amounted  to  1,122,733,  of  which 
63,277  were  reported  to  be  unfit  for  use  :  these  figures 
give  an  idea  of  the  enormous  amount  of  work  done,  and 
it  is  interesting  to  note  that  for  some  years  past  the  work 
has  been  entirely  done  by  the  Japanese  themselves. 

Sixty-ninth  Meeting  of  the  German  Society  of 
Science  and  Arts  at  Brunswick,  Sept.  20th  to  25th, 
1897. — At  the  meeting  of  this  Society  in  September  next 
there  will  be  a  sitting  devoted  to  the  question  of  the 
constitution  of  camphor,  and  it  is  requested  that  any 
papers  or  notes  which  any  members  of  the  profession 
desire  to  contribute  may  be  sent  in  by  the  middle  of  May, 
so  that  they  can  be  included  in  the  official  programme 
which  is  to  be  issued  at  the  beginning  of  July.  It  is 
intended  to  devote  Wednesday,  the  22nd  of  September, 
to  a  general  meeting  of  all  who  are  interested  in  the 
subjecft  of  Photography  as  applied  to  scientific  investiga- 
tions ;  and  Prof.  H.  W.  Vogel,  of  Charlottenburg,  has 
promised  to  deliver  the  introdudory  address.  There  will 
also  be  an  exhibition  of  scientific  photographs  organised 
by  Prof.  Max  Miiller;  contributions  of  papers  and  photo- 
graphs are  requested  from  all  workers  on  the  subjed. 

MEETINGS    FOR    THE    WEEK. 

Monday,  loth.— Society  of  Arts,  8.      (Cantor  Leftures).    "  Design 

in  Lettering,"  by  Lewis  Foreman  Day. 
Tuesday,  iith.— Royal  Institution,  3.    "  Volcanoes,"  by  Dr.  Tem- 
pest Anderson,  B.Sc. 

Society  of  Arts,  8.    "  A  Half  Century  of  Line  En- 

graving, 1780. 1830,"  by  George  Clulow. 
Wednesday,  12th.— Society  of  Arts,  8.    "  Motor  Traffic— Technical 

Considerations,"  by  Sir  David  Salomons. 
THtJRSDAY,  13th,— Royal  Institution,  3.   "  Liquid  Air  as  an  Agent  of 

Research,"  by  Prof.  Dewar,  F.R.S.,  &c. 
Friday,  14th.— Royal  Institution,  9.    "  Explosion— Flames,"  by  Prof. 
Harold  Dixon,  F.R.S. 

Physical,  5.     "  Instrument  for  Comparing  Thermo- 

meters with  a  Standard,"  by  W.  Watson.  "  Experi- 
ment in  Surface  Tension,"  by  A.  S.  Ackerman. 
"  Effeft  of  Temperature  on  the  Magnetic  and  Elec- 
tric Properties  of  Iron,"  by  D.  K.  Morris.  "  Form- 
ation of  Mercury  Films  by  Eled):ric  Osmosis,"  by 
Rollo  Appleyard. 

Saturday,  15th.— Royal  Institution,  3.  "The  Greek  Theatre  according 
to  Recent  Discoveries,"  by  the  Rev.  I.  P.  Mahaffy, 

D.D. ^ 

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The  Fergusomte  Metals. 


229 


THE    CHEMICAL     NEWS 


Vol.  LXXV.,  No.  1955. 


ON    THE    FERGUSONITE    METALS. 

I.   On  Philippium. 

By  M.  MARC  DELAFONTAINE. 

After  long-continued  work  on  the  Gadolinite  and 
Samarskite  earths,  I  came  to  the  conclusion— published  in 
1878  and  1880 — that  the  yellow  oxide  erbia  discovered  by 
Mosander  in  1843  contained  two  yellow  earths,  which  I 
called  terbia  and  philippia.  Later  on  the  individuality  of 
the  latter  was  denied  by  two  English  chemists.  But  M. 
Marignac  mentioned  it  at  the  close  of  his  elaborate  paper 
on  the  Samarskite  Earths  (May,  1880),  and  Mr.W.  Crookes, 
who  first  rejected  it,  mentions  it  among  some  of  his  frac- 
tional products  of  yttria. 

The  lack  0/  time  and  insufficient  means  have  long  pre- 
vented my  completing  the  work,  by  which  I  expefted  to 
justify  my  conclusions.  The  investigation  of  the  Fer- 
gusonite  earths,  though  incomplete,  enable  me  to  show 
that  the  charaderistics  of  philippium  are  such  as  to  de- 
serve the  attention  of  those  who  are  discussing  the 
Periodic  Law  and  the  necessary  modifications  to  M. 
Mendeleeff 's  classification  of  elements. 

My  results  in  regard  to  the  other  Fergusonite  metals 
will  be  the  subjedl  of  a  second  paper,  now  nearly  finished. 

Occurrence. — Philippium  has  been  found  in  Gadolinites, 
Samarskite,  and  the  mineral  f-rom  Bluifton  (Slano  county, 
Texas),  described  and  analysed  as  Fergusonite  by  MM. 
Hidden  and  Mackintosh.  I  secured  several  pounds  of 
that  Fergusonite  from  Mr.  English,  mineralogist,  in  New 
York ;  it  has  proved  to  be  the  best  material  for  the  ex- 
•tra(^ion  of  philippium. 

Extraction. — 500  grms.  of  the  powdered  ore  were 
treated  at  a  time,  in  a  large  leaden  dish,  with  three  times 
their  weight  of  strong  hydrofluoric  acid.  The  reaAion  is 
attended  with  much  heat  and  a  great  effervescence, — 
hence  the  necessity  of  having  the  lead  vessel  not  more 
than  half  full  of  the  mixture.  When  the  bubbling  has 
subsided,  a  moderate  heat  is  applied  as  long  as  the  stirred 
mass  gives  off  bubbles.  An  equal  volume  of  water  is 
added  ;  the  acid  fluorides  dissolve,  and  the  earthy  fluorides 
remain  as  a  sediment,  coloured  green  by  uranium.  The 
supernatant  fluid  is  poured  out,  and  several  times  replaced 
by  water.  The  insoluble  fluorides  are  then  transferred 
into  a  large  platinum  dish,  and  decomposed  by  sulphuric 
acid.  The  solution  of  the  resulting  sulphates  containing 
uranium  in  the  uranous  form,  it  is  then  time  to  oxidise 
the  latter  with  some  hydrogen  peroxide,  or,  better,  some 
sodium  dioxide,  which  at  once  turns  the  liquid  yellow. 

Oxalic  acid  throws  down  the  earthy  oxalates  ;  iron  and 
uranium  remain  dissolved.  After  ignition  of  the  oxalates 
the  earths  are  left  as  a  moderately  dark  yellow  powder, 
completely  and  readily  soluble  in  nitric  acid.  The  mixed 
salts  show  an  absorption  spedtrum,  the  lack  of  intensity 
of  which  indicates  a  very  small  proportion  of  didymium, 
and  not  much  more  of  erbium.  The  pink  colour  of  the 
solution  is,  however,  much  stronger  than  we  might  expedl 
from  so  small  a  proportion  of  the  absorbing  nitrates. 
The  same  fadt  was  noticed  before  by  M.  Marignac  and 
myself  on  other  occasions. 

Philippium  may  be  separated  from  that  mixture  of 
nitrates  by  different  methods,  all  based  upon  the  fad  that 
its  basic  energy  is  less  than  that  of  its  congeners.  Frac- 
tional precipitations,  by  dilute  ammonia  or  by  potassium 
bioxalate,  have  been  resorted  to.  I  give  preference  to  the 
fractional  decomposition  of  the  nitrates  by  heat.     In  that 


way  philippium  is  separated  flrst,  then  a  pale- coloured 
earth  without  an  absorption  spedrum,  followed  by  the 
erbia  earths,  and  Anally  terbia  and  yttria. 

The  mass  of  nitrates  is  heated  in  a  flat-bottomed  dish  ; 
it  foams  much  for  a  while,  then  comes  to  a  quiet  fusion 
and  turns  red.  After  some  minutes  of  that  quiet  decom- 
position, the  dish  is  allowed  to  cool.  The  solid  residue 
is  a  beautiful  orange-red  glass,  which  water  dissolves  in 
part  only,  leaving  a  dark  yellow  gelatinous  basic  salt. 

The  same  process  is  repeated  on  the  parts  taken  up  by 
water  as  long  as  a  coloured  residue  is  left.  It  sometimes 
happens  that  the  glass-like  mass  re-dissolves  entirely  in 
water,  and  makes  an  opalescent  or  milky  yellowish  liquid 
with  a  decided  greenish  fluorescence.  That  may  be  cor- 
reded  by  the  addition  of  dilute  ammonia,  followed  oy  a 
digestion  of  several  hours  in  a  warm  place ;  I  And  it 
preferable  to  evaporate  the  whole  liquid  again,  and  de- 
compose it  at  a  somewhat  higher  temperature.  The 
subsalts  thus  obtained  were  sorted  according  to  their 
colour,  and  subjected  to  new  series  of  decompositions, 
until  a  bright  orange-yellow  basic  nitrate  was  obtained, 
which  dissolved  slowly  in  moderately  dilute  nitric  acid, 
and  thus  gave  a  deep  orange-red  transparent  solution. 
Sometimes  the  solution  is  entirely  colourless,  at  once. 

Characteristics.  —  There  are  two  series  of  philippium 
compounds — the  philippous  and  the  philippic  ones,  cor- 
responding to  a  white  and  to  an  orange  oxide.  The  salts 
of  the  first  series  are  colourless,  quite  stable,  and  gene- 
rally crystallise  well ;  they  correspond  to  the  lanthanum 
and  yttrium  salts.  Their  solutions  do  not  seem  to  give 
an  absorption-spedtrum ;  truly  they  sometimes  faintly 
show  the  erbium  lines  and  bands  under  a  thickness  of  5  or 
6  cm. ;  but  that  is  evidently  due  to  a  very  small  propor- 
tion of  erbium  metals,  which  it  is  very  hard  to  get  rid  of 
entirely. 

Potassium-philippous  sulphate  is  soluble  in  a  saturated 
solution  of  potassic  sulphate.  The  formiate  crystallises 
very  slowly  from  a  syrupy  solution,  in  fibro-radiated 
masses.  By  ignition,  the  oxalate  dried  at  130°  C.  yields 
about  51-5  per  cent  of  orange-coloured  oxide.  The  crys- 
tallised nitrate  is  colourless  ;  when  heated  it  melts,  and 
decomposes  into  a  reddish  glass,  not  entirely  soluble  in 
water,  but  very  apt  to  make  a  colloidal  solution  which 
passes  very  slowly  through  the  filter. 

Philippic  oxide  has  a  deep  orange-red  colour,  most  in- 
tense in  the  oxide  made  from  the  calcination  of  the  nitrate 
or  the  acetate.  Its  moist  hydrate  is  light  yellow.  When 
air-dried  it  is  in  small  and  somewhat  darker  lumps;  by 
calcination  it  turns  dark  red.  With  moderately  dilute 
cold  nitric  acid,  the  latter  makes  a  yellow  solution;  in 
strong  acid  it  dissoves  with  effervescence  and  heat,  and 
gives  the  colourless  philippous  nitrate.  With  hydrochloric 
acid,  philippic  oxide  evolves  chlorine,  and  gives  the  proto- 
salt.  Other  acids  dissolve  it  by  boiling  with  some 
alcohol. 

Equivalent. — Although  philippium  shows  a  very  close 
resemblance  to  yttrium  and  cerium,  the  constitution  of 
its  compounds  remains  to  be  established  by  crystallography 
or  otherwise. 

S03(  =  8o)  combines  with  about  96  of  philippous  oxide, 
which  makes  Pp  80,  or  120,  or  160,  according  to  whether 
the  oxide  is  PpO,  PP2O3,  or  even  PpOj. 

Relationship  to  Other  Elements.  —  Philippium  is  more 
closely  allied  to  cerium  and  terbium  than  to  any  other  of 
the  yttrium  and  cerium  metals.  It  is  to  yttrium  what 
cerium  is  to  lanthanum.  Its  equivalent,  the  colour  of  its 
subnitrates  and  that  of  the  philippic  salts,  the  solubility 
of  its  formiate,  separate  philippium  from  terbium.  These 
charatSleristics,  and  the  solubility  of  potassium-philippo 
sulphate  in  potassium  sulphate  solutions,  distinguish  it 
from  the  two  ceriums  of  M.  Brauner  and  M.  Schiitzen- 
berger.  A  heated  mixture  of  cerium  nitrate  with  that  of 
the  Fergusonite  earths  (left  after  the  removal  of  Pp)  does 
not  behave  at  all  like  the  original  nitrates  ;  the  residue  of 
cerium  subnitrates  does  not  resemble  the  corresponding 
compound  of  philippium.     Terbium  nitrate  melts  into  a 


230 


Soil  Ferments  important  in  Agriculture. 


I  Chbmical  Nbws, 
\     May  14,  1807. 


colourless  glass  which  after  partial  decomposition  is  n«t 
yellow,  and  leaves  no  yellow  residue  after  washing. 
Chicago,  April  24,  1897. 


ON    THE    SEPARATION     OF    THORIA    FROM 

ZIRCONIA. 

By  M.  MARC  DELAFONTAINE. 

Mr.  Glazer's  paper  on  the  Separation  of  Thoria  and 
Zirconia,  in  recent  numbers  of  the  Chemical  News, 
prompts  me  to  describe  here  the  method  which  I  have 
applied  for  years  to  similar  cases,  with  accurate  results. 
The  fusion  of  the  mineral  with  potassium  bisulphate  does 
not  work  well  in  the  case  of  mixtures  containing  titanic 
acid  with  zirconia.     I  proceed  as  follows : — 

The  powdered  mixture  (ore  or  oxides)  is  fused  in  a 
platinum  crucible  with  twice  its  weight  of  acid  potassium 
fluoride  (KHFI2).  The  zirconia  is  separated  as  potassium 
fluozirconate,  K2ZrFl6,  from  the  solidified  mass  by  means 
of  boiling  water  containing  a  few  drops  of  HFl. 

The  insoluble  fluorides  decomposed  by  sulphuric  acid, 
and  ignited  below  a  dull  red  heat,  will  leave  thorium, 
cerium,  and  other  earths,  as  sulphates.  Silica,  if  present, 
escapes  as  silicon  fluoride.  The  sulphates  are  dissolved 
in  water  and  precipitated  by  oxalic  acid,  the  oxalates 
being  treated  by  a  saturated  hot  solution  of  ammonium 
oxalate ;  the  thorium  salt  is  dissolved  and  cerium  left, 
The  ignited  oxalates  left  the  oxides  in  good  condition  for 
further  work.  Zirconia  is  thrown  down  from  its  fluo-salt 
by  ammonium  hydrate. 

Titanium,  if  present  in  the   original  mixture,  is  found 
as  fluotitanate  soluble  in  hot  water.     Hydrogen  peroxide 
would  separate  it  from  the  zirconia. 
Chicago,  April  24, 1897. 


SOIL    FERMENTS     IMPORTANT 
AGRICULTURE.* 


IN 


By    HARVEY    W.    WILEY, 

Chief  of  the  Division  of  Chemistry,  Oepartmect  of  Agriculture, 

Washington,  D.C. 

(Concluded  from  p.  224). 

Ferments  Oxidising  Free  Nitrogen. — In  the  preceding  para- 
graphs the  attention  of  the  reader  has  been  briefly  called  to 
the  adlion  of  those  species  of  ferments  which  attack  nitrogen 
in  some  of  its  forms  of  combination.  Since  nitrogenous 
food  is  the  most  expensive  form  of  nutriment  which 
the  plant  consumes,  it  is  a  matter  of  grave  importance 
to  agriculture  to  know  the  full  extent  of  the  supply  of 
this  costly  substance.  It  is  evident  that  the  continued 
adlion  of  nitrifying  ferments  finally  tends  to  exhaust  the 
stores  of  this  substance  which  have  been  provided  in  the 
soil.  The  quantities  of  oxidised  nitrogen  produced  by 
eledtric  discharges  in  the  air  and  by  other  meteorological 
phenomena,  and  which  are  brought  to  the  soil  in  rain 
waters,  are  of  considerable  magnitude,  but  lack  much  of 
supplying  the  ordinary  wastage  to  which  the  stores  of  soil 
nitrogen  are  subjedled.  Even  with  the  happiest  combi- 
nation of  circumstances,  it  is  not  difficult  to  see  in  what 
way  the  available  stores  of  nitrogen  could  be  diminished 
to  a  point  threatening  the  proper  sustenance  of  plants, 
and  thus  diminishing  the  necessary  supplies  of  human  food. 
The  examination  of  the  drainage  waters  which  come  from 
a  fertile  field  in  full  cultivation,  is  sufficient  to  convince 
the  most  sceptical  of  the  fadl  that  the  growing  crop  does 
not  by  any  means  absorb  all  of  the  produds  of  the  adlivity 
of  the  nitrifying  ferments.   Nitric  acid  and  its  compounds, 

*  Abstraft  of  a  Ledture  delivered  before  the  Chemical  Seftion  of 
the  Franklin  Institute,  February  i6th,  1897. 


I  the  nitrates,  are  exceedingly  soluble  in  water,  and  for  this 
'  reason  any  unappropriated  stores  of  them  in  the  soil  are 
easily  removed  by  heavy  downpours  of  rain.  Happily  the 
living  vegetable  organism  has  the  property  of  withholding 
nitric  acid  from  solution,  either  by  some  property  of  its 
tissues  or  more  probably  by  some  preliminary  combination 
which  the  nitric  acid  undergoes  in  the  plant  itself.  This 
is  easily  shown  by  a  simple  experiment.  If  fresh  and  still' 
living  plants  be  subjedled  to  the  solvent  adion  of  water, 
very  little  nitric  acid  will  be  found  to  pass  into  solution. 
If,  however,  the  plants  be  killed  before  the  experiment  is 
made,  by  being  exposed  for  some  time  in  an  atmosphere 
of  chloroform,  the  nitric  acid  which  they  contain  is  easily 
extracted  by  water. 

The  losses,  therefore,  which  an  arable  soil  sustains  in 
its  content  of  nitrogenous  matter  must  be  supplied  either 
by  the  addition  of  nitrogenous  fertilisers  or  by  some  adlion 
of  the  soil  whereby  the  nitrogen  which  pervades  it  may 
be  oxidised  and  fixed  in  a  form  suited  to  the  nourishment 
of  plants.  The  discussion  in  regard  to  the  possibility  of 
fixing  nitrogen  in  the  soil  has  been  carried  on  with  great 
vigour  during  the  last  two  decades.  The  proof,  however, 
is  now  overwhelming  that  such  fixation  does  take  place. 
It  would  not  be  proper  here  to  enter  into  a  discussion  of 
the  processes  by  which  this  fixation  is  determined,  and, 
in  fadt,  they  are  not  definitely  known.  One  thing,  how- 
ever, is  certain,  viz.,  that  it  is  accomplished  by  means  of 
micro-organisms  or  ferments  similar,  perhaps,  in  their 
nature  to  those  already  mentioned,  but  capable  of  ab- 
sorbing, assimilating,  and  oxidising  free  nitrogen. 

Methods  of  Oxidising  Free  Nitrogen. — At  the  present 
time  it  is  sufficiently  well  known  that  this  operation  takes 
place  in  two  ways.  In  the  first  place,  there  are  found  to 
exist  on  the  rootlets  of  certain  plants,  chiefly  of  the 
leguminous  family,  colonies  of  badleria  whose  fundtion  is 
known  by  the  eflfedts  which  they  produce.  In  such  plants 
in  a  state  of  maturity,  as  was  mentioned  above,  are  found 
larger  quantities  of  organic  nitrogen  than  could  possibly 
have  been  derived  from  the  soil  in  which  they  were  grown 
or  from  the  fertilisers  with  which  they  were  supplied. 
Cultural  experiments  in  sterilised  soils,  with  careful  ex- 
clusion of  all  sources  of  organic  nitrogen,  have  proved 
beyond  question  that  this  gain  in  nitrogen  is  found  only 
in  such  plants  as  are  infedted  by  the  organism  mentioned. 
The  logical  conclusion  is  therefore  inevitable  that  these 
organisms,  in  their  symbiotic  development  with  the  plant 
rootlets,  assimilate  and  oxidise  the  free  nitrogen  of  the 
air  and  present  it  to  the  plant  in  a  form  suited  to  absorp- 
tion. Attempts  have  been  made  to  inoculate  the  rootlets 
of  other  families  of  plants  with  these  organisms,  but  so 
far  without  any  pronounced  success.  There  are,  how- 
ever, certain  orders  of  low  vegetable  life,  such  as  crypto- 
gams, for  instance,  which  seem  to  share  to  a  certain 
degree  the  faculty  of  the  leguminous  plants  in  adting  as  a 
host  for  the  nitrifying  organisms  mentioned.  The  observa- 
tion above  recorded  becomes  a  sufficient  explanation  of 
the  fadl  that  the  fertility  of  fields  is  increased  by  the 
cultivation  of  leguminous  plants,  which  would  not  be 
possible  except  they  possess  some  such  property  as  that 
which  has  already  been  described. 

Another  order  of  organisms  has  also  been  discovered 
which  is  capable  of  oxidising  free  nitrogen  when  cultivated 
in  an  environment  from  which  organic  nitrogen  is  rigidly 
excluded.  It  seems  probable,  therefore,  even  in  soils 
which  bear  crops  not  capable  of  developing  nitrifying 
organisms  on  their  rootlets,  that  the  adtual  stores  of  avail- 
able nitrogen  may  be  increased.  This  fadl  explains  the 
observation  which  has  frequently  been  made  that  in  fields 
which  are  not  cultivated,  but  which  remain  in  grass,  there 
may  be  found  an  adtual  increase  in  the  total  amount  of 
nitrogen  which  is  available  for  plant  growth.  As  will  be  - 
seen  further  along,  the  soil  is  also  infested  with  an  or- 
ganism which  is  capable  of  destroying  nitric  acid  and 
returning  the  nitrogen  which  it  contains  to  the  air  in  a 
free  state.  It  seems  almost  certain  that  in  every  complete 
decomposition  of  a  nitrogenous   organism  a  part  of  the  - 


-CRBItlCAL  NBWSit 

May  14, 1897.     f 


Soil  Ferments  important  in  Agriculture. 


231 


nitrogen  which  it  contains  escapes  in  the  free  state.  Were 
it  not,  therefore,  for  the  fadt  that  this  free  nitrogen  can  be 
again  oxidised  and  made  available  for  plant  growth,  the 
total  stores  of  organic  nitrogen  in  existence  would  be 
gradually  diminished,  and  the  time  would  ultimately  come 
when  their  total  amount  would  not  be  sufficient  to  sustain 
a  plant  life  abundant  enough  to  supply  the  food  of  the 
animal  kingdom.  Thus  the  Earth  itself,  even  without 
becoming  too  cold  for  the  existence  of  the  life  which  is 
now  found  upon  it,  might  reach  a  state  when  plant  and 
animal  lite  would  become  practically  impossible  by  reason 
of  the  deficit  of  nitrogenous  foods. 

Much  less  is  known  concerning  the  charadter  and 
adlivity  of  the  organisms  that  oxidise  free  nitrogen  than 
of  those  which  feed  upon  organic  nitrogen.  It  cannot  be 
doubted,  however,  that  these  scarcely  known  ferments  are 
of  the  greatest  importance  to  agriculture,  and  the  further 
study  of  their  nature  and  the  proper  methods  of  increasing 
their  adivity  cannot  fail  to  result  in  the  greatest  advantage 
to  the  pradlical  farmer.  (Photographs  showing  the  occur- 
rence of  the  nitrifying  tubercules  of  leguminous  and  other 
plants  were  shown  upon  the  screen). 

Fertilising  Ferments. — Two  years  ago  I  used  the  fol- 
lowing words  in  a  Report  published  by  the  Department  of 
Agriculture : — 

"  When  a  soil  is  pradlically  free  from  albumenoid 
bodies,  and  contains  but  little  humus,  the  attempt  to 
develop  a  more  vigorous  nitrifying  ferment  would  be  of 
little  utility.  Even  in  a  soil  containing  a  considerable 
degree  of  humus,  it  may  be  found  that  its  nitrugen  con- 
tent has  been  so  far  reduced  as  to  leave  nothing  pradtically 
available  for  the  adivity  of  nitrification.  In  such  cases 
the  only  rational  method  of  procedure  is  in  the  application 
~of  fertilisers  containing  nitrogen.  In  other  cases,  where 
the  lack  of  fertility  is  due  to  the  extiniSlion  or  attenuation 
of  the  nitrifying  ferment,  remunerative  results  may  be 
obtained  by  some  process  of  seeding  similar  to  that 
described  above.  It  is  entirely  within  the  range  of  possi- 
bility that  there  may  be  developed  in  the  laboratory 
species  of  nitrifying  organisms  which  are  particularly 
adapted  for  aSion  on  different  nitrogenous  bodies.  For 
instance,  the  organism  which  is  found  most  effeiflive  in 
the  oxidation  of  albumenoid  matter  may  not  be  well 
suited  to  convert  amides  or  the  inert  nitrogen  of  humus 
into  nitric  acid.  We  have  already  seen  the  day  when  the 
butter-maker  sends  to  a  laboratory  for  a  ferment  best 
suited  to  the  ripening  of  his  cream.  It  may  not  be  long 
until  the  farmer  may  apply  to  his  laboratory  for  particular 
•nitrifying  ferments  to  be  applied  to  such  special  purposes 
as  are  mentioned  above.  Because  of  the  extreme  mi- 
nuteness of  these  organisms,  the  too  pradical  agronomist 
may  laugh  at  the  idea  of  producing  fertility  thereby ;  and 
this  idea,  indeed,  would  be  of  no  value  were  it  not  for  the 
wonderful  facility  of  propagation  which  an  organism  of 
this  kind  has  when  exposed  to  a  favourable  environment." 
It  is  true  that  the  pure  cultures  which  the  laboratory 
would  afford  would  be  of  little  avail  if  limited  to  their 
own  activity,  and  it  is  only  in  the  possibility  of  their 
almost  illimitable  development  that  their  fertilising  effecSts 
may  be  secured." 

It  is  of  interest  in  this  connedlion  to  recall  the  faiftthat 
a  few  months  ago  the  realisation  of  the  prophecy  above 
made  was  accomplished.  There  is  now  made,  and  offered 
for  sale  to  farmers,  a  nitrifying  ferment  called  nitragin, 
which  is  prepared  from  the  tubercules  of  certain  legu- 
minous plants.  It  is  found  that  this  material  is  of  use 
only  when  applied  to  crops  similar  to  those  from  which  it 
is  made,  while  it  does  not  acSt  upon  other  crops,  especially 
those  of  a  non-leguminous  nature.  For  instance,  if  the 
farmer  wish  to  fertilise  his  clover-field  with  a  nitrifying 
ferment  prepared  in  this  way,  he  must  get  one  which  is 
prepared  from  clover.  If  it  be  a  field  of  peas  or  beans, 
on  the  other  hand,  he  must  secure  a  ferment  prepared 
from  these  vegetables.  This  process  may  seem  ridiculous 
to  those  who  do  not  carefully  consider  all  of  its  aspedls  ; 
'hut  in  a  little  phial,  no  bigger  than  a  goose-quill,  can  be 


easily  contained  the  seeds  of  ferments  which,  by  proper 
multiplication,  will  produce  an  adtive  nitrification  over  a 
large  area.  In  the  preparation  of  the  ferment  it  is  best 
to  mix  it  with  fine,  moderately  moist  soil.  After  thorough 
mixing,  this  soil  is  then  sowed  over  the  land  as  one  would 
sow  wheat  or  oats.  By  the  process  of  fission  the 
organisms  which  are  thus  introduced  into  the  soil  rapidly 
multiply,  and  if  they  find  the  rootlets  of  plants  suitable 
to  their  environment  they  at  once  attach  themselves 
thereto,  where  new  tubercules,  similar  to  the  ones  you 
saw  upon  the  screen,  are  formed.  It  is  too  early  yet  to 
Speak  of  the  commercial  success  which  will  attend  this 
method  of  fertilisation,  but  there  is  no  doubt  of  the  faft 
that  when  a  field  which  contains  an  abundance  of  nitro- 
genous matter  becomes  practically  sterilised,  this  matter 
may  be  rendered  more  available  by  the  introduction  of 
proper  nitrifying  organisms,  and  it  is  also  certain  that 
when  those  crops,  such  as  the  Leguminosas,  which  are 
suited  to  the  development  of  the  colonies  of  tubercules 
upon  the  rootlets,  are  seeded  with  the  proper  organisms, 
the  number  of  tubercules  is  increased,  their  activity 
favoured,  and  the  assimilation  of  atmospheric  nitrogen 
hastened.  (Photographs  were  exhibited  upon  the  screen 
to  show  the  influence  of  inoculating  different  plants  with 
different  ferments  developed  on  radical  tubercules). 

Ferments  Inimical  to  Agriculture. — It  has  been  noticed 
by  many  observers  that  when  nitric  acid  is  subjected  to 
certain  fermentative  processes  it  becomes  decomposed  and 
gradually  disappears.  In  studying  the  causes  which  lead 
to  this  decomposition,  it  is  found  that  it  is  due  to  the 
action  of  a  micro-organism  or  ferment,  which,  by  reason 
of  the  result  of  its  fundtional  activity,  is  called  a  denitri- 
fying organism.  While  it  is  true  that  in  numbers  and 
activity  this  denitrifying  organism  does  not  equal  its  nitri- 
fying relation,  yet  it  is  a  matter  of  no  inconsiderable 
importance  to  know  fully  the  laws  which  govern  its 
existence.  As  in  the  case  of  the  baifteria  which  are  found 
in  ripening  cream,  where  some  produce  evil  and  some 
good  effects,  so  it  is  with  those  in  the  soil.  The  favouring 
organisms,  whose  fundtional  activity  prepares  nitrogen  in 
a  form  suited  for  plant  food,  are  accompanied  by  others, 
doubtless  nearly  related  to  them,  whose  fundtional  adivity 
tends  to  destroy  the  work  which  the  first  have  accom- 
plished. It  thus  happens  that  in  the  fermentation  of 
nitrogenous  bodies  there  is  danger  of  losing,  as  has 
already  been  said,  a  part  of  the  nitrogen,  which  may 
either  escape  as  gaseous  oxides  unsuited  for  the  sus- 
tenance of  plants,  or  even  as  free  nitrogen.  The  objedt, 
at  least  the  pradiical  objedt,  of  the  investigation  of  these 
denitrifying  organisms,  should  be  to  discover  some 
process  by  which  their  multiplication  could  be  prevented 
and  their  activity  diminished.  At  the  present  time  all 
that  is  known  is  that  in  ordinary  circumstances  these 
organisms  are  not  developed  in  sufficient  numbers  to 
prove  very  destructive.  It  has  already  been  mentioned, 
however,  that  in  case  of  a  very  great  excess  of  organic 
nitrogenous  matter  a  considerable  quantity  of  the  nitrogen 
therein  contained  may,  through  the  adtion  of  these  or- 
ganisms, be  lost.  The  pradtical  lesson  taught  here  is  to 
apply  nitrogenous  foods  in  a  moderate  manner  and  avoid 
every  unnecessary  excess. 

In  the  case  of  nitrifying  ferments,  it  has  been  seen 
that  nitric  acid  and  carbon  dioxide  are  some  of  the  final 
produdls  of  badlerial  adlivity.  In  the  denitrifying  process, 
on  the  other  hand,  free  hydrogen  and  free  nitrogen  are  the 
results  of  the  final  adlivity  of  the  micro-organisms.  In 
these  tubes  which  I  show  you,  which  are  partly  filled  with 
gas,  the  evolution  of  the  gaseous  material  has  been  secured 
by  introducing  into  the  sterilised  solution  containing  a 
nitrate,  a  denitrifying  ferment  obtained  from  a  soil  taken 
in  proximity  to  a  stable.  Expeiience  has  shown  that 
stable  manures  of  all  kinds  contain  these  denitrifying  fer- 
ments, and  that  these  are  capable  of  causing  considerable 
waste  of  nitrogen,  unless  care  is  taken  in  their  use.  The 
results  of  such  experiments  as  these  show  conclusively 
that  it  would  be  a  useless  extravagance  to  use  a  fertiliser 


232 


Study  of  Hyponitrous  A  cid. 


(  Cheuical  NbwSi 
I     May  14, 1897. 


containing  nitric  acid,  such  as  Chili  saltpetre,  in  connexion 
with  stable  manures. 

Pathogenic  Ferments. — There  are  also  other  forms  of 
ferments  in  the  soil  of  an  objedionable  nature  which  are 
not  related  to  the  nitrifying  organisms.  It  has  been  ob- 
served in  France  that,  in  localities  where  animals  are 
interred  which  have  died  of  charbon,  the  germs  of  this 
infe(5lious  malady  persist  in  the  soils  for  many  years,  and 
that,  especially  when  cereal  crops  are  cultivated  upon 
such  soils,  there  is  great  danger  of  contaminating  healthy 
cattle  with  the  same  disease.  In  one  case  it  was  observed 
that  many  sheep  which  were  pastured  in  a  field  in  which, 
two  years  before,  a  single  animal  which  had  died  of 
charbon  was  buried,  were  infeded  with  the  disease  and 
died.  In  like  manner,  it  is  entirely  probable  that  the 
germs  of  hog  cholera  may  be  preserved  in  the  soil  for 
many  years,  to  finally  again  be  brought  into  an  adlivity 
which  may  prove  most  disastrous  for  the  owners  of  swine. 
Every  effort  should  be  made  by  agronomists  to  avoid 
infedting  the  soil  by  carcasses  which  are  dead  from  any 
zymotic  disease.  Cremation  is  the  only  safe  method  of 
disposing  of  such  infedled  carcasses.  The  investigations 
of  scientists  have  shown  that  there  are  many  diseases  of 
an  infedlious  nature  due  to  these  germs,  and  that  these 
germs  may  preserve  their  vitality  in  the  soil.  Among 
others  may  be  mentioned  yellow  fever  and  tetanus,  and 
the  microbe  producing  the  bubonic  plague,  which 
retains  its  vitality  in  the  soil,  and  thus  escapes  entire 
eradication. 

Use  of  Sewage  as  Fertiliser. — For  the  reasons  given 
above,  the  agronomist,  who  also  has  at  heart  the  health 
and  welfare  of  man  and  beast,  can  hardly  look  with 
favour  upon  any  of  the  plans  which  have  been  proposed 
for  the  use  of  sewage  from  large  cities  for  irrigation  pur- 
poses. There  is  scarcely  a  time  in  any  large  city  when 
some  infedious  disease,  due  to  the  adlivity  of  germs,  does 
not  exist,  and  the  sewage  is  liable  at  all  times  to  be  con- 
taminated therewith.  In  view  of  the  fadi  that  the  vitality 
of  the  germs  mentioned  above  may  be  continued  for  a 
long  time  in  the  soil,  it  is  fair  to  conclude  that  it  is  of  the 
utmost  importance  to  avoid  the  contamination  of  the  soil, 
where  it  is  to  be  used  for  agricultural  purposes,  with  any 
of  the  dejeda  which  may  come  from  those  infedted  with 
any  zymotic  disease  whatever. 

Supplying  Lost  Nitrogen. — It  is  evident  that  if  no  pro- 
cess of  supplying  the  loss  of  nitrogen  existed,  the  soil 
would  soon  lose  its  power  of  furnishing  food  and  raiment 
for  man.  The  philosopher  who  studies  the  system  of 
Nature  sees  in  the  far  future  the  advent  of  a  time  when 
the  environment  of  man  on  the  Earth  will  be  too  harsh 
for  his  present  organisation.  The  slow  cooling  of  the 
Sun,  and  consequently  of  the  Earth,  is  the  principal  cause 
of  this  misfortune.  But  added  to  this  must  be  considered 
the  gradual  disappearance  of  carbon  dioxide  and  organic 
nitrogen,  two  of  the  essential  components  of  the  environ- 
ment   which    makes    plant-life    possible.      Diminishing 


diminished  by  long  ages  of  hopeless  labour,  and  witb. 
features  pinched  from  hunger  and  cold,  shall  have  been 
driven  to  the  equator  by  the  advancing  armies  of  ice,  his 
last  look  will  be  at  the  mocking  disc  of  the  Sun,  denying 
him  warmth,  and  his  last  mouthful  of  food  will  contain 
the  proteids  of  oatmeal. 

(The  ledure  was  fully  illustrated  with  experimental 
cultures  of  soil  microbes  and  by  means  of  lantern  slides). 
— journal  of  the  Franklin  Institute,  cxliii.,  p.  293. 


CONTRIBUTION    TO    THE    STUDY    OF 
HYPONITROUS    ACID.' 
By  A.  HAUTZSCH  and  A.  L.  KAUFMANN. 

In  taking  up  the  study  of  hyponitrous  acid,  discovered  by 
Maumene,  and  afterwards  worked  on  by  Divers,  Zorn, 
and  Van  der  Plaats,  we  had  two  considerations  in  view  •.- 
firstly,  the  relations  existing  between  hyponitrous  acid 
and  the  so-called  dinitrogenised  compounds,  expressed  by 
the  formula  HON  =  NOH,  and  by  the  name  dinitric  acidy 
proposed  by  Wislicenus;  and  secondly,  the  relations 
existing  between  this  acid  and  nitramide,  NH2.NO2,  dis- 
covered by  Thiele,  and  considered  by  him  to  be  astrudural 
isomer  of  hyponitrous  acid,  which  was  then  unknown  in 
the  free  state. 

We  have  perfedted  Zorn's  method  of  preparing  this 
acid,  in  such  a  manner  as  to  always  ensure  satisfadlory 
results,  and  finally  we  have  succeeded  in  obtaining  free 
nitrous  acid  in  the  solid  state.  Further,  we  have  prepared 
hyponitrite  of  ammonium,  which  was  up  till  recently, 
hardly  known,  and  have  isolated  in  the  solid  state  the 
benzylic  ether  of  hyponitrous  acid.  The  free  acid,  the 
salts,  and  its  ether  have  been  submitted  to  searching 
enquiry  as  to  their  chemical  and  physical  properties,  and 
compared  as  far  as  was  possible  with  the  nitramide 
isomer. 

Formation  of  Hyponitrites. 

In  the  series  of  the  intermediate  produdls  of  redtidlion, 
between  nitric  acid  and  ammonia,  hyponitrous  acid  will 
be  found  between  nitrous  acid  and  hydroxylamine : — 

HNO3,  HN02,(HN0)2,  N3HO,  NH3. 
It  follows,  then,  that  hyponitrous  acid  can  be  obtaitied 
either  by  the  redudtion  of  the  preceding  or  the  oxidation 
of  the  following  compound  in  the  series. 

a.  Methods  of  Reduction.  —  Sodium  amalgam,  either 
diredtly  (Divers,  Chemical  News,  xxiii.,  p.  206;  Zorn, 
Berichte  d.  Ch.  Ges.,  x.,  p.  1306)  or  indiredtly,  has  been 
principally  used  as  the  reducing  agent;  that  is  to  say,  by 
submitting  to  eledlrolysis  aqueous  solutions  of  nitrite  of 
soda,   with   the   mercury   as   the    negative   pole    (Zorn, 


Berichte,  xii.,  p.  1509)- 

,  .  „        However,  the  resulting  amounts  indicated  by  Zorn  have 

heat  and  light,  disappearing  carbon  dioxide  and  organic  \  never  been  obtained  by  the  different  chemists  who  have 
nitrogen,  are,  little  by  little,  making  the  struggle  for  studied  this  readlion  ;  but  Tanatar  (Berichte,  xxvi.,  p. 
existence  harder.  Tfii^  succeeded    in  obtaining  twice    as  much  as  Divers 

Nitrogen  is  lost  not  only  by  the  adlion  of  the  denitri- 
fying organisms,  but  also  by  the  solution  of  nitrates  and 
their  loss  in  drainao;e  waters.  From  the  sea  this  loss  is 
restored  in  part  by  fish  and  sea-weeds.  This  is  a  pradlical 
illustration  of  the  text,  •'  Cast  thy  bread  upon  the  waters, 
and  it  shall  return  after  many  days."  The  organisms  that 
oxidise  atmospheric  nitrogen  supply  another  part. 

Fortunately,  living  organisms  adapt  themselves  to 
changes  in  their  environment,  and  life,  therefore,  will  still 
be  possible  when  the  present  conditions  of  existence  shall 
have  disappeared. 

A  careful  study  of  the  causes  which  produce  a  waste  of 
nitrogen  and  those  which  restore  the  loss,  gives  the 
pleasing  assurance  that  the  present  kind  of  man  will  not 
die  of  nitrogen  hunger.  Some  of  the  best  producers  of 
proteids  flourish  at  high  latitudes. 

When  the  last  man  of  the  present  race,  with  a  stature 


163)  succeeded    in  obtaining  twice 
by  using  a  liquid  sodium  amalgam. 

The  assertions  of  some  writers  that  it  would  be  possible 
to  obtain  hyponitrite  of  soda  by  treating  nitrite  of  soda 
with  ferrous  hydrate  (Zorn,  Ibid.,  xv.,  pp.  1007  and  1288) 
or  by  melting  nitrite  of  soda  with  scrap  sheet-iron 
(Mencke,  Chem.  News,  xlix.,  p.  45)  have  not  been  con- 
firmed. Similarly,  we  have  not  been  able  to  prepare 
hyponitrites  by  the  redudion  of  nitrites  in  an  aqueous 
solution,  by  means  of  aluminium  amalgam,  as  described 
by   H.  Wislicenus  and  L.  Kaufmann   (Berichte,  xxviii., 

p.  1323). 

b.  Methods  of  Oxidation.— UyponitroMs  acid  can  be  pre- 
pared by  the  oxidation  of  hydroxylamine  and  its  derivatives. 
The  formation  of  hyponitrous  acid,  observed  by  Thum, 
by  the  adtion  of  hydroxylamine  on  some  metallic  oxides,. 

*  Moniteur  Scientifique,  vol.  xi..  p.  336,  May,  1897, 


Chemical  News,  ) 
May  14, 1897.     f 


Experiments  with  Cathode  Rays, 


233 


— mercuric  oxide,  cupric  oxide,  and  oxide  of  silver, — is 
based  on  the  direS  oxidation  of  hydroxylamine : — 

2NH2OH  +  2HgO  =  2Hg  +  H2O  +  NaOzHa. 
The  quantities  obtained  by  this  method  are  not  so  insig- 
nificant as  stated  by  Thum.  It  was  by  thus  treating, 
with  an  excess  of  mercuric  oxide,  an  alkaline  solution  of 
hydroxylamine,  prepared  from  5  grms.  of  sulphate  of  hy- 
droxylamine and  an  excess  of  caustic  potash,  that  we 
obtained— after  eliminating  the  mercury,  neutralising 
with  nitric  acid,  and  precipitating  with  nitrite  of  silver — 
o'5  grm.  of  hyponitrite  of  silver.  This  quantity  repre- 
sents  10  per  cent  of  the  weight  of  the  sulphate  of 
hydroxylamine,  and  about  5  per  cent  of  the  theoretical 
returns. 

The  splitting  up  of  benzo-sulphydroxamic  acid  (ob- 
tained by  the  adtion  of  hydroxylamine  on  sulpho-chlorated 
benzine)  by  alkalis,  into  benzo-sulphuric  acid  and  hypo- 
nitrous  acid,  lately  observed  by  Piloty  (Berichte,  xxix., 
p.  1560),  and  represented  by  the  equation — 

2C6H5SO2NHOH  +  2KOH  = 

=  2C6H7S02K  +  N2O2H2  +  2H2O, 

can  also  be  considered  as  an  oxidation  of  hydroxylamine. 
This  method  of  preparing  hyponitrous  acid  gives  fairly 
satisfadtory  results. 

The  aaion  of  nitrous  acid  on  hydroxylamine  also  gives 
rise  to  the  formation  of  hyponitrous  acid, — 

HONH2  +  ONOH  =  HON  +  NOH  -f-  H2O. 

According  toWislicenus  {Ibid.,  xxvi.,  p.  771)  this  readion 
might  be  considered  as  a  condensation.  Neither  the 
adtion  of  nitrite  of  soda  on  sulphate  of  hydroxylamine 
(Wislicenus)  or  that  of  nitrite  of  silver  on  chlorhydrate  of 
hydroxylamine  (Kratschmer,  These,  1895,  P-  9)  g've  satis- 
fadlory  results.  The  method  proposed  by  Tanatar 
{Berichte,  xxvi.,  p.  763)  —  reaaion  in  the  presence  of 
certain  bases — seems  to  be  the  one  giving  the  best  results. 

We  have  endeavoured  to  make  hyponitrite  of  soda,  and 
potash,  by  passing  a  current  of  dry  nitric  oxide  through  a 
liquid  sodic  or  potassic  amalgam.  But  the  result  was 
nil;  there  was  no  readtion.  Equally  unfruitful  were  the 
attempts  of  P.  Schatzmann  to  combine  protoxide  of  nitro- 
gen with  caustic  potash  under  pressure,  or  at  a  high  tem- 
perature. The  only  produdts  of  this  experiment  were 
ammonia  and  nitrite  of  potash,  but  no  hyponitrite  of 
potash. 

Preparation  of  Hyponitrite  of  Silver. 

As  in  our  experiments  we  had  need  of  large  quantities 
of  hyponitrite  of  silver,  which  serves  as  the  starting-point 
for  the  preparation  of  free  hyponitrous  acid,  we  endeavoured 
to  improve  the  then  best  known  among  the  methods  of 
preparing  hyponitrite  of  silver,  viz.,  that  based  on  the 
redudtion  of  nitrite  of  soda  by  sodium  amalgam.  We 
have  found  from  experience  that  the  return  is  considerably 
increased  —  i.  When  working  at  a  low  temperature ; 
2.  When  the  nitrite  of  silver  is  present  in  great  excess 
with  regard  to  the  nascent  hydrogen;  3.  When  the  re- 
a&ion  is  carried  on  in  alkaline  solution,  hyponitrous  acid 
being  unstable  except  in  strongly  alkaline  solutions. 
Influenced  by  these  fadls,  we  propose  the  following  method 
for  the  preparation  of  hyponitrite  of  silver: — 

To  a  properly  cooled  solution  of  20  grms.  of  pure 
nitrite  of  soda  add  10  grms.  of  caustic  soda  in  200  c.c.  of 
water;  a  liquid  amalgam,  obtained  by  dissolving  16  grms. 
of  sodium  in  2800  grms.  of  mercury  is  slowly  added,  drop 
by  drop.  During  the  operation,  which  should  last  about 
three-quarters  of  an  hour,  the  mixture  should  be  strongly 
and  continually  agitated.  After  having  separated  the 
mercury,  the  liquid,  cooled  to  0°,  is  heated  with  diluted 
nitric  acid  until  it  gives  but  a  very  slight  alkaline  readlion. 
To  eliminate  the  hydroxylamine,  which  is  always  formed 
in  this  redudtion,  mercuric  oxide  is  added,  the  mixture 
being  still  constantly  stirred,  until  the  last  portion  of  oxide 
added  no  longer  changes  colour.  The  liquid  is  rapidly 
filtered  with  a  filter-pump,  a  small  quantity  of  mercuric 


oxide  being  first  placed  in  the  filter.  The  filtrate  is  then 
neutralised  with  nitric  acid,  and  precipitated  with  nitrate 
of  silver.  The  yellow  precipitate  obtained  is  washed 
with  warm  water,  first  on  the  filter,  then  by  decantation  in 
an  Erlenmeyer  flask,  re-dissolved  in  very  dilute  nitric  acid, 
and  cooled  down  to  0°.  The  solution  is  then  rapidly  fil- 
tered and  precipitated  by  ammonia;  by  repeating  this 
we  obtain  perfedtly  pure  hyponitrite  of  silver.  This  can 
be  dried  either  over  a  water-bath  or  in  an  exsiccator  after 
being  washed  with  alcohol  and  ether. 

Analyses  of  the  substance  thus  obtained  have  given  the 
following  results: — 

I.  II. 

Grma.  Grms. 

Substance  used      ..     ..     o'zoig        0*3308 
Ag  by  titration       ..     ..     o'i573        0*2580 

Found.  Theory. 

I.  II. 

Ag  ..     yTQ^i*    7800°/.  AgNO  ..     78*26ji 

The  salt  prepared  as  described  above  possesses  all  the 
properties  of  hyponitrite  of  silver.  But,  contrary  to  the 
statement  of  Van  der  Plaats,  it  does  not  detonate  at  150°. 
In  spite  of  all  our  efforts  we  have  been  unable  to  explode 
it.  It  is  also  worthy  of  note  that  this  silver  salt  keeps  its 
yellow  colour  in  diffused  light;  but  in  diredt  sunlight  it 
quickly  assumes  a  yellowish  green  colour,  and  when 
moistened  the  surface  becomes  black. 

The  amount  of  hyponitrite  of  silver  obtained,  starting 
with  20  grms.  of  nitrite  of  soda,  is  from  2  to  3  grms.,  or  6 
to  7  per  cent  of  the  theoretical  quantity.  These  figures 
correspond  to  the  maximum  returns  indicated  by  Zorn, 
but  they  have  not  been  obtained  by  any  other  experi- 
menters who  have  used  Zorn's  method. 

It  is  best  not  to  attempt  the  redudlion  on  more  than  20 
grms.  of  nitrite  of  silver  at  a  time.  But  the  rough  produdts 
resulting  from  several  redudtions  can  all  be  purified 
together.  In  one  or  two  days  one  can  easily  prepare  20 
grms.  of  pure  hyponitrite  of  silver.  We  therefore  believe 
that  the  method  we  have  just  described  is  the  simplest  and 
the  least  expensive. 

(To  be  continued). 


SOME    EXPERIMENTS    WITH     CATHODE 
RAYS.* 

By  A.  C.  C.  SWINTON. 
(Continued  from  p.  221). 

The  Rays  cross  at  the  Focus  with  no  Rotation. 
In  order  to  investigate  the  cathode  rays  in  a  focus  tube 
still  further,  and  more  especially  in  order  to  discover 
whether  the  various  rays  from  the  cathode  cross  one 
another  at  the  focus,  or  diverge  again  without  crossing, 
and  also  in  order  to  discover  whether  there  is  any  twist  or 
rotation  of  the  rays,  similar  to  what  has  been  observed  in 
the  case  of  rays  focussed  by  magnetism,!  a  tube  was 
construdted  similar  to  that  used  in  the  previous  experi- 
ments,  with  a  carbon  anticathode  which  was  also  the 
anode,  fixed  at  the  opposite  side  of  the  focus  from  the 
cathode,  with  the  focus  about  equally  distant  between  it 
and  the  cathode.  The  peculiarity  of  this  tube  consisted 
in  the  fadl  that  a  sedtor  of  the  aluminium  cathode,  equal 
to  one-eighth  of  the  total  area  of  the  cathode,  had  been 
entirely  removed,  as  shown  at  c,  fig.  9.  It  was  expedled 
that  on  using  this  tube,  with  the  proper  degree  of  vacuum 
to  form  a  well-defined  ring  on  the  anti-cathode  screen, 
that  a  portion  of  the  ring,  corresponding  with  the  amount 
of  the  cathode  cut  away,  would  be  found  wanting;  and 
that  by  the  position  of  this  gap  in  the  ring  it  would  be 
possible  to  ascertain  whether  the  rays  crossed  at  the 
focus,   and    whether   there    was    any    rotation.      What 


*  A  Paper  read  before  the  Royal  Society,  March  11,  1897. 

i  See  experiments  by  K.  Birkeland,  Electrical  Review,  June  12, 1890. 


234 


Experiments  with  Cathode  Rays, 


j  Chemical  Nbws, 
(     May  14,  isg7. 


Cbkmical  mbwb,  I 
May  14, 1897.     I 


Experiments  with  Cathode  Rays, 


235 


V 


/\ 


\y 


as: 


aAually  was  observed  is  shown  for  three  different  con- 
ditions of  vacuum  in  fig.  g,  b  being  for  the  highest,  and 
b"  for  the  lowest  vacuum.  As  will  be  seen,  the  expedled 
gap  in  the  ring  was  obtained,  but  with  the  unexpedted 
addition  that  the  dimensions  of  this  gap,  instead  of  being 
only  one-eighth  of  the  circumference  of  the  ring,  was 
seven-eighths  of  the  circumference.  In  faft,  the  amount 
of  ring  shown  corresponded  not  with  the  seven-eighths 
of  the  remaining  cathode  surface,  but  with  the  one-eighth 
of  the  cathode  that  had  been  removed.    The  portion  of 


ring  that  did  appear  was  of  a  length  corresponding 
exaftly  to  the  arc  of  the  removed  sedor  of  the  cathode, 
according  to  its  greater  or  lesser  nearness  to  the  centre 
with  different  conditions  of  vacuum  ;  and  as  the  portion 
of  ring  was  in  each  case  exadtly  in  line  with  the  portion  of 
cathode  that  had  been  cut  away,  it  would  appear  that 
there  is  no  rotation  of  the  cathode  beam  as  a  whole,  that 
the  rays  do  cross  at  the  focus ;  and,  further,  that  when 
the  hollow  convergent  cone  is,  as  it  were,  split  in  this 
manner,  some  unexplained  adtion,  similar  in  tSe&  to  the 


236 


Separation  of  Chlorine  and  Bromine, 


{Chemical  NbwSt 
May  14,  1897. 


existence  of  a  circular  surface  tension,  causes  the  gap  to 
widen  out  and  the  remaining  portion  of  the  ring-shaped 
sedlion  of  the  cone  to  contradt  correspondingly,  without, 
however,  altering  its  diameter. 

In  order  to  further  investigate  the  matter  another  tube 
was  made,  as  shown  in  iig.  10,  in  which  the  concave 
cathode  was  complete ;  but  the  interior  of  the  tube  was 
furnished  with  a  small  movable  piece  of  aluminium,  a, 
which  by  shaking  could  be  moved  up  and  down  the  tube 
between  the  cathode,  c,  and  anti-cathode,  B,  and  which, 
while  not  quite  reaching  the  centre  of  the  tube,  would  fill 
up  very  nearly  one-quarter  of  the  circular  sedtional  area  of 
the  latter. 

With  this  arrangement  of  tube,  with  the  aluminium 
obstacle  placed  just  at  the  focus,  as  shown  in  fig.  11,  the 
point  of  the  obstacle  just  missing  the  cathode  rays,  a 
complete  ring  was  formed  on  the  carbon  anti-cathode. 
On  moving  the  obstacle  slightly  into  the  divergent  cone, 
exadtly  one-quarter  of  the  ring  on  the  anti-cathode  failed 
to  appear,  as  shown  in  fig.  12,  and  on  the  obstacle  being 
further  moved  in  the  same  diretftion  the  result  was  not 
altered,  as  shown  in  iig.  13. 

As  in  each  of  the  latter  two  cases  there  was  no  dis- 
placement of  the  gap  in  the  ring,  the  above  showed  that 
there  is  no  rotation  of  the  divergent  cathode  cone. 

Experiments  were  next  tried  with  the  aluminium  ob- 
stacle, moved  so  that  its  point  just  entered  the  converging 
cone  of  cathode  rays,  when  a  small  portion  of  the  ring 
was  cut  out  ;  but  on  the  opposite  side,  as  shown  in  fig.  14, 
this  confirming  the  previous  experiments,  which  showed 
that  the  rays  cross  one  another's  paths  at  the  focus  with- 
out rotation.  Upon  moving  the  aluminium  obstacle  a 
little  nearer  to  the  cathode,  so  that  its  point  entered  still 
further  into  the  convergent  cathode  beam,  one-half  of  the 
ring  disappeared,  as  in  fig.  15,  while  when  the  obstacle — 
which,  it  should  be  remembered,  blocked  only  one-quarter 
of  the  circular  area  of  the  tube — was  brought  close  up  to 
the  cathode,  only  about  one-quarter  of  the  ring  remained, 
as  in  fig.  16. 

Further  experiments  were  tried  with  the  aluminium 
obstacle  both  in  the  divergent  and  convergent  cones, 
but  with  the  tube  exhausted  to  different  degrees  of 
vacuum,  the  result  being  as  shown  in  figs.  17  and  18,  in 
which  in  each  case  u  shows  the  higheft  vacuum  and  b" 
the  lowest,  from  which  it  will  be  observed  that  when  the 
obstacle  was  in  the  divergent  cone  a  portion  of  the  ring 
was  cut  off  exadlly  proportional  to  the  angle  subtended 
by  the  sides  of  the  obstacle  ;  while  when  the  obstacle  was 
placed  in  the  convergent  cone,  a  much  larger  proportion 
of  the  ring  was  cut  off  in  each  case,  this  being  much 
more  marked  with  a  high  vacuum  when  the  diameter  of 
the  ring  was  small  than  with  a  low  vacuum  when  the 
diameter  of  the  ring  was  large. 

Convergent  and  Divergent  Cones  produced  by  Magnetic 
Focussing. 
In  order  to  discover  whether  the  apparent  hollowness 
of  the  convergent  and  divergent  cones  of  cathode  rays  as 
above  observed,  when  the  focussing  was  performed  by 
means  of  a  spherical  cathode,  was  in  any  way  due  to  the 
concave  form  of  the  cathode  or  to  the  fa(St  that  the  rays 
were  converging  or  diverging,  experiments  were  tried  with 
a  tube  having  a  fiat  aluminium  cathode,  the  rays  being 
caused  to  converge  to  a  focus  by  means  of  a  powerful 
eleftro-magnet  in  the  manner  described  by  the  writer  in 
his  paper  on  "The  Effeds  of  a  Strong  Magnetic  Field 
upon  Eledlric  Discharges  in  vacuo "  (Roy.  Soc.  Proc, 
1896,  vol.  Ix.,  p.  179). 

The  arrangement  is  shown  in  fig.  ig,  the  carbon  anti- 
cathode  screen,  b,  being  movable,  and  not  connedled  to 
the  anode  d,  which  was  contained  in  an  annex  to  the  tube. 
By  increasing  or  decreasing  the  power  of  an  eledtro- 
magnet,  m,  by  moving  it  nearer  to  or  further  away  from 
the  tube,  and  by  moving  the  anti-cathode  screen  up  and 
down  the  tube,  the  cathode  rays  could  be  focussed  on  the 
anti-cathode  screen  so  as  to  form  a  circle  of  any  desired 


size,  the  focus,  which  appears  to  be  exactly  on  the  pole 
of  the  magnet,  being,  of  course,  always  beyond  the  anti- 
cathode. 

In  order  similarly  to  investigate  a  divergent  cone  of 
cathode  rays  magnetically  produced,  a  circular  coil  of 
wire,  E,  was  employed  instead  of  the  magnet  in  the 
manner  recently  described  by  Professor  Fleming 
{Electrician,  January  i,  1897).  This  coil,  which  had  72 
turns  of  No.  18  S.W.G.  size  wire,  was  supplied  with  2a 
to  25  amperes  of  current  from  a  storage  battery.  It 
focussed  the  cathode  rays  at  a  point  exadtly  central  to  it» 
own  plane,  from  which  they  again  diverged  on  to  the  anti'- 
cathode  screen. 

With  convergent  and  divergent  cones  of  rays  produced 
magnetically  in  the  above  manner,  there  was  no  difficulty 
in  showing  that,  under  suitable  conditions,  these  cones 
adled  as  if  they  were  hollow,  giving  bright  rings  of  varying 
sizes,  sometimes  with  and  sometimes  without  bright 
central  spots,  upon  the  carbon  anti-cathode  screen  exadtly 
similar  in  appearance  to  those  obtained  with  the  concave: 
cathode. 

Further  observations  were  as  follows  : — 

In  some  instances,  two  concentric  hollow  rings  were 
observed,  especially  with  a  low  vacuum  when  the  magnet 
was  suddenly  turned  on  or  off.  The  rings  are  probably 
not  simultaneous,  but  successive,  but  this  cannot  be 
detected  with  the  unaided  eye. 

With  a  high  vacuum,  and  the  magnet  so  arranged  as 
to  focus  the  rays  accurately  upon  the  carbon,  a  small 
bright  spot  appears  at  first ;  as  the  vacuum  goes  down  this 
point  becomes  larger  and  fainter,  but  still  solid.  Suddenly 
it  becomes  hollow  and  brighter,  then,  as  the  vacuum  falls 
still  further,  the  ring  becomes  solid  again,  though  larger 
and  more  faint  than  before,  finally  it  disappears.  After 
this  stage  it  can  be  reproduced  momentarily,  without 
alteration  to  the  vacuum,  by  switching  the  magnet  on 
and  off  suddenly,  when  it  is  usually  hollow,  but  sometimes 
solid. 

(To  be  continued). 


SEPARATION    OF    CHLORINE    AND    BROMINE. 
By  H.  BAUBIGNY  and    P.  RIVALS. 

Determinations  of  chlorine,  bromine,  and  iodine  in 
mixtures  of  haloid  salts  have  been  always  considered  as 
operations  of  great  difficulty.  They  were,  in  fadt,  possible 
only  by  indiredt  methods,  generally  inaccurate  and  not 
admitting  of  any  control.  If  we  can  now  separate  with 
accuracy  iodine  from  the  two  other  elements,  the  pro- 
cedures given,  even  in  the  last  few  years,  for  determining 
chlorine  in  presence  of  bromine,  or  inversely,  are  still 
imperfedi.  This  fadl  has  led  us  to  our  present  researches. 
We  shall  consider  at  first  the  case  of  a  mixture  of 
chlorides  and  bromides,  where  the  problems  are  to  bring 
the  chlorine  and  the  bromine  to  the  state  of  alkaline  salts, 
or,  secondly,  to  the  state  of  silver  salts. 

Alkaline  Salts. — The  modern  methods  of  separating 
the  halogens  are  founded  in  general  upon  the  different 
properties  of  their  hydracids  in  presence  of  different 
oxidising  agents,  the  effedts  of  which  differ  also  with  the 
conditions  of  the  experiment.  As  oxidisers  we  have  em- 
ployed successively  lead  and  manganese  peroxides, 
oxygenated  water,  the  chromates,  permanganate,  ammo- 
nium persulphate,  the  arseniates,  &c.,  most  frequently  in 
presence  of  a  small  quantity  of  sulphuric  or  acetic  acid, 
or  of  a  salt  easily  decomposed,  such  as  ferric  or  aluminic 
sulphate.  But  in  any  case  we  must  meet  the  necessity 
of  having  a  solution  so  dilute  that  the  oxidation  may  be 
limited  to  one  of  the  hydracids.  Of  all  these  oxidising 
agents,  those  which  are  the  most  soluble  are  evidently 
the  most  perfedl,  or  at  least  the  most  regular,  in  their 
adtion ;  and  of  these,  permanganate  is  one  of  the  most 
energetic.  Peon  de  St.  Gilles  has  shown  that  if  we  treat 
a  mixture  of  alkaline  haloid  salts  in  a  neutral  or  alkaline 


Cbbmical  Nbws,  I 
May  14.  1897.      f 


The  Electnc  Furnace. 


237 


liquid  with  an  excess  of  permanganate,  all  the  iodine — and 
the  iodine  alone — is  oxidised,  so  that  the  iodide  is  entirely 
converted  into  iodate,  whilst  the  alkaline  chlorides  and 
bromides  are  not  aiTedled  even  at  100°.  But  if  the  per- 
manganate does  not  a.&  upon  potassium  or  sodium 
bromides,  nothing  proves  that  it  must  be  the  same  for 
those  of  all  metals.  Indeed,  we  have  found  that  if  the 
solution  of  neutral  copper  chloride  is  not  attacked  by 
permanganate  in  the  cold,  that  of  the  bromide  of  the  same 
metal  is  decomposed  with  liberation  of  bromine. 

The  phenomenon  of  oxidation  is  not  of  the  same  order 
as  for  the  alkaline  iodides,  but  it  permits  us  to  separate 
bromine  and  chlorine;  for  in  an  alkaline  chloride  or 
bromide  the  addition  of  neutral  copper  sulphate,  in  virtue 
of  the  law  of  distribution,  determines  the  formation  of 
copper  chloride  or  bromide.  If,  then,  we  further  add  a 
little  permanganate,  the  bromine,  if  present,  is  displaced. 
In  these  latter  conditions  it  is  easy  to  demonstrate  that 
the  readlion  is  quantitative. 

To  this  end,  having  prepared  standard  solutions  of  alkaline 
chloride  and  bromide,  we  operated  with  these  liquors,  at 
first  separately,  and  then  in  mixing  them  in  known  pro- 
portions. In  our  experiments  the  quantities  of  salts 
varied  from  o'lao  to  0*400  grm.,  and  for  these  weights  we 
have  taken  from  4  to  8  grms.  copper  sulphate,  and  from 
o'35o  to  0*400  grm.  permanganate.  We  commence  by 
dissolving  the  sulphate,  CuS04-|-5H20,  with  the  alkaline 
salt,  and  m  the  cold  liquid  the  crystals  of  permanganate. 
The  vessel  is  then  set  in  a  vacuum  at  the  ordinary  tem- 
perature (15 — 18°)  over  fragments  of  potassa.  The  next 
day  the  dry  residue,  if  taken  up  in  a  little  water,  gives 
off  no  odour.  We  then  complete  the  solution  by  adding 
enough  sulphurous  acid  to  reduce  MnOz  and  what 
remains  of  the  permanganate,  and  in  the  liquid  we  pre- 
cipitate the  chlorine  or  bromine  by  silver  nitrate,  very 
strong  in  nitric  acid  to  prevent  the  reducStion  of  a  little 
nitrate  by  the  excess  of  sulphurous  acid,  which  is 
destroyed  if  heated  in  presence  of  nitric  acid. 

We  colledt  the  bromide  or  chloride  until  the  liquid  is 
cold — for  silver  chloride  is  especially  soluble  in  boiling 
water,  even  if  neutral. 

The  following  are  some  of  the  results  obtained  : — 


AgBr  recovered. 
0*0005  grm. 
o*ooo6     „ 

AgCI  recovered. 
0586  grm. 
0-5858  „ 


Value  in  silver  salt  of  KBr  used. 
0*192  grm. 
0-384     M 

Value  in  silver  salt  of  the  NaCl  used. 
0*2922  grm. 
0*2917     „ 

On  the  subjedt  of  experiments  with  chloride,  we  must 
add  that  for  each  of  them  the  dry  residue  has  been  re- 
moistened  and  re-dried  twice  in  vacuo,  so  as  to  exaggerate 
the  decomposition  of  the  chlorides  if  such  were  capable  of 
being  produced  ;  the  adtion  may  therefore  be  regarded  as 
nul. 

Lastly,  for  mixtures  of  chlorides  and  bromides  experi- 
ment showed — 

Value  in  silver  salt — 


Per  NaCl  used. 
Grm. 


Per  KBr  used.    Salt  of  silver  recovered. 
Grm.  Grm. 


0*5844  0*192 

0*0731  0*576 

-Comptes  Rendus,  cxxiv.,  No.  16. 


0*5854 
0*0730 


Some  New^-Cetonic  Acids.— T.  Klobb.— The  alcoyl- 
phenacetylcyanacetic  ethers,  are  easily  saponified  in  the 
cold  by  alkalis,  but  if  warmed  they  quickly  give  oR 
ammonia.  By  this  means  nitrogen-free  acids  are  ob- 
tained, of  which  one  only — ethylphenacetylacetic  acid — 
had  up  to  now  been  prepared.  Several  others  have  been 
now  made,  and  their  properties  are  described  in  this 
paper. — Bull,  de  la  Soc.  Chitn.  de  Paris. 


NOTICES  OF  BOOKS. 


The  Electric  Furnace.  ("  Le  Four  Ele«5lrique ").  By 
Henri  Moissan,  Membre  de.  I'lnstitut.  Paris:  G. 
Steinheil.     1897.     Pp.  385. 

(Second  Notice). 
The  first  application  of  the  eleftric  furnace,  after  it  had 
passed  from  the  experimental  stage,  was  to  the  study  of  the 
crystallisation  of  the  metallic  oxides,  then  the  volatilisa- 
tion of  several  simple  bodies.  For  the  first  of  the  above- 
named  experiments  a  furnace  of  quicklime  was  used,  and 
when  working  on  small  quantities  of  material,  and  only 
using  about  four  horse-power,  the  carbons  were  purified 
by  being  first  submitted  to  the  adtion  of  chlorine  at  a  high 
temperature,  and  then  cooled  in  a  current  of  nitrogen. 
But  when  using  such  currents  as  were  furnished  by 
thirty  to  thirty-five  horse-power,  the  eledtrudes  had  to  be 
prepared  and  purified  with  the  minutest  care,  small 
amounts  of  impurities  exercising  great  infiuence  on  the 
results.  A  great  variety  of  substances  were  experimented 
on,  such  as  chalk,  lime,  strontia,  baryta,  magnesia, 
alumina,  &c.  It  is  impossible  to  operate  on  a  small  quan- 
tity of  alumina  in  contadl  with  lime,  as  a  liquid  aluminate 
of  lime  is  immediately  formed;  in  this  case  a  carbon 
crucible  is  used.  By  adding  a  very  small  quantity  of 
sesquioxide  of  chromium  to  the  alumina,  a  mass  of  small 
crystals  of  veritable  rubies  is  formed.  These,  however, 
are  not  so  fine  as  those  prepared  by  MM.  Fremy  and 
Verneuil.     The  author  has  not  followed  up  this  matter. 

The  oxides  of  the  iron  group  stable  at  high  tempera- 
tures form  masses  bristling  with  small  crystals. 

M.  Dufau  has,  by  using  the  eledtric  furnace,  noted  the 
existence  of  a  chromite  of  lime,  Cr203,CaO ;  a  tetra- 
chromite  of  barium,  4Cr203,BaO ;  a  cobaltite  of  magne- 
sium, Co03Mg;  and  a  nickelite  of  barium,  2Ni02,BaO. 

The  ordinary  metals  are  easily  volatilised  and  con- 
densed, as  well  as  even  such  refraiftory  ones  as  platinum 
and  uranium. 

The  experiments  to  try  and  volatilise  boron  were  not 
successful,  as  boride  of  carbon  was  immediately  formed ; 
this  is  easily  melted,  and  on  cooling  forms  definite 
crystals. 

An  early  conclusion  arrived  at  by  the  author  is,  that 
at  such  high  temperatures  as  those  obtained  by  means  of 
his  furnace,  the  bodies  hitherto  considered  as  most 
refradlory  are  easily  volatilised,  and  those  looked  upon  as 
being  the  most  stable  in  mineral  chemistry  are  destroyed 
either  by  dissociation  or  volatilisation.  There  remains 
only  a  series  of  new  compounds,  perfedly  crystallised  and 
of  exceptional  stability,  which  are  able  to  resist  the  adtion 
of  this  extreme  amount  of  heat.  These  are  borides, 
silicides,  and — above  all — the  metallic  carbides. 

Carbon  is,  of  all  the  simple  bodies,  the  one  which 
forms  the  most  curious  allotropic  varieties.  Its  contra- 
didory  properties,  its  different  specific  heats,  &c.,  have 
long  been  matters  for  earnest  thought  and  study.  The 
study  of  amorphous  carbon  ranges  over  a  wide  field,  and 
we  will  do  no  more  than  mention  the  fadl  en  passant. 
Graphite,  before  the  researches  of  M.  Berthelot,  included 
all  varieties  of  carbon  capable  of  leaving  a  mark  when 
rubbed  on  paper  ;  molybdenite  was  thus  easily  confounded 
with  graphite.  Berthelot  defined  graphite  as  "  every 
variety  of  carbon  capable  of  forming  by  oxidation  a 
graphitic  oxide."  This  property  definitely  established 
the  classification  of  the  varieties  of  carbon  into  three 
groups — diamond,  graphite,  and  amorphous  carbon.  M. 
Moissan  has,  in  his  researches,  shown  the  possibility  of 
bringing  all  kinds  of  carbon,  diamond  or  amorphous,  into 
the  graphitic  state.  The  discovery  of  graphite  in  a 
meteorite  from  the  Canon  Diablo  led  the  author  to  ex- 
amine other  meteorites,  to  find  out  if  they  also  contained 
carbon,  and,  if  so,  in  what  form.  In  some,  such  as  the 
meteoric  iron  from  Kendal  County,  Texas,  none  wa& 
found ;  that  from  Newstead,  in  Roxburghshire,  contained 


238 


Actiod  of  Enzyms  upon  Starches. 


I  Chkmical  Nbws> 
\     May  14, 1S97. 


amorphous  carbon  and  graphite;  deesite, from  Chili, con- 
tained a  small  quantity  of  graphite ;  and  of  three 
samples  of  iron  from  Ovifak,  all  contained  amorphous 
carbon,  two  contained  graphite,  but  none  contained 
-diamond,  either  black  or  transparent. 

A  few  of  the  graphites  which  can  be  prepared  in  the 
laboratory  are  here  passed  in  review.  Diamond  heated 
in  the  ele(^ric  arc  is  converted  into  graphite  ;  wood  char- 
coal, properly  purified,  is,  at  a  temperature  of  about  2200°, 
converted  into  graphite  in  ten  minutes.  There  are  many 
other  methods  for  producing  it  at  densities  varying  from 
2*io  to  2*25. 

The  study  of  the  solubility  of  carbon  in  metals  at  high 
temperatures  led  to  the  research  on  the  adtion  of  boron 
and  silicon  on  liquid  carbide  of  iron,  and  it  is  shown  that 
these  chemical  rea(5tions  are  as  clear  and  well-defined  as 
those  in  aqueous  solutions,  as  performed  in  the  laboratory 
at  ordinary  temperatures.  A  sample  of  cast-iron  was 
taken,  containing3'i8  per  cent  of  carbon  and  o'5  per  cent 
of  slag.  To  10  grms.  of  this  was  added  2*3  grms.  of 
boron.  After  heating,  it  was  allowed  to  cool,  when  the 
slag  on  the  surface  was  found  to  contain  all  the  original 
slag  and  most  of  the  boron,  while  the  carbon  in  the  iron 
was  reduced  to  0*27  per  cent,  the  boron  present  amounting 
to  8  or  g  per  cent. 

Silicon  has  a  similar  adion  of  replacing  a  part  of  the 
carbon,  the  carbon  expelled  being  found  on  cooling,  on 
the  top  of  the  metal  in  the  form  of  graphite. 

To  obtain  pressure  in  the  manufadure  of  graphite  in 
molten  iron,  recourse  was  had  to  the  plan  of  suddenly 
cooling  the  whole  mass  in  cold  water  ;  this  has  the  efTei^ 
of  strongly  compressing  the  carbon  dissolved  in  the  iron, 
and  after  cooling,  dissolving  the  iron,  &c.,  crystals  of 
graphite,  of  a  beautiful  shining  black  colour,  were  formed, 
bearing  a  close  resemblance  in  general  appearance  to 
specimens  of  graphite  found  in  the  blue  ground  from 
Kimberley;  its  density  is  2*16,  and  it  burns  in  oxygen  at 
about  660". 

All  the  samples  of  graphite  hitherto  examined  have 
been  found  to  contain  hydrogen.  This  might  be  due  to 
three  reasons :  u  may  be  a  physical  phenomenon,  or 
condensation  of  hydrogen  gas  in  the  graphite — as  might 
be  imagined  from  some  experiments  made  by  M.  Cailletet, 
who  noticed  that  hydrogen  was  absorbed  by  molten  iron  ; 
or,  again,  it  might  be  a  chemical  phenomenon  ;  an  experi- 
ment here  described,  however,  shows  that  hydrogen  is  not 
in  combination  with  the  graphite. 

Having  succeeded  in  making  crystallised  graphite,  it 
was  but  natural  that  M.  Moissan  should  next  attempt  the 
artificial  produ(5tion  of  diamonds.  Many  workers  have 
already  attempted  this  difficult  task,  but  their  results  have 
been  contradidory  and  uncertain.  The  author  fully 
recognised  that,  even  if  he  did  succeed,  the  diamonds  ob- 
tained would,  at  first  at  any  rate,  be  merely  microscopic. 
It  is  interesting  here  to  note  the  definition  of  •'  dia- 
mond "  ;  it  is  an  elementary  body,  of  maximum  hardness, 
3"5  density,  and  burns  in  oxygen  atsa  temperature  some- 
what above  700' ;  I  grm.  giving  3*666  grms.  of  carbonic 
acid.  The  principal  charadteristic  of  the  diamond  is  its 
great  hardness.  Numbers  of  bodies — carbides,  borides, 
silicides,  &c., — have  been  produced  by  means  of  the 
eledlric  furnace  which  will  scratch  ruby,  but  only  boride 
of  carbon  will  even  slowly  scratch  a  diamond. 

By  studying  the  occurrence  of  diamond,  and  the 
charadter  of  its  associates — zircon,  topaz,  titanic  iron,  &c., 
— which  are  found  in  the  same  matrix  and  under  similar 
conditions,  M.  Moissan  concluded  that  the  diamond  was 
formed  in  the  interior  of  the  earth  under  conditions  of 
great  heat  and  enormous  pressure.  To  imitate  this  he 
had  recourse,  as  before,  to  the  sudden  cooling  of  a  mass 
of  molten  iron  in  which  carbon  was  held  in  solution  ;  the 
exterior  being  suddenly  solidified  subjedted  the  still  liquid 
interior  to  very  great  pressure. 

It  was  not  without  a  certain  amount  of  apprehension 
that  this  experiment  was  performed  for  the  first  time  ; 
indeed,  it  seems  marvellous  that  the  adt  of  plunging  a 


crucible  containing  molten  iron  heated  to  a  temperature 
of  over  3000°  into  a  vessel  of  cold  water  did  not  result  in 
a  disastrous  explosion  ;  but  happily  it  is  not  so — the  ex- 
periment has  been  performed  over  300  times  without 
accident. 


CORRESPONDENCE. 


ACTION  OF   ENZYMS   UPON    STARCHES. 

To  the  Editor  of  the  Chemical  News. 
Sir, — I  have  read  with  much  pleasure  the  interesting 
review  in  your  issue  of  April  30th  on  Dr.  Stone's  report, 
especially  in  regard  to  the  adtion  of  enzyms  on  starches. 
I  notice  that  Taka-diastase  has  claimed  the  attention  of 
Dr.  Stone  to  such  an  extent  that,  although  this  special 
digestive  agent  had  not  been  long  before  his  notice  when 
he  made  his  report,  he  considered  it  to  be  of  sufHcient 
importance  to  call  for  special  mention  and  space.  I  am 
not  surprised  at  this  keen  interest  in  regard  to  a  prepara- 
tion possessing  diastasic  potency  to  the  extent  present  in 
Taka-diastase. 

As  I  have  experimented  with  this  diastasic  ferment  and 
considered  its  adtion  to  a  greater  extent  than  has  perhaps 
any  one  else  at  present  in  this  country,  I  venture  to  place 
before  your  readers  a  few  remarks  which  suggest  them- 
selves to  me  after  making  numerous  tests  on  different 
varieties  of  starch  and  comparisons  with  other  prepara- 
tions for  which  diastasic  power  is  claimed,  as  also  after 
having  had  frequent  discussions  with  medical  men  who 
have  used  Taka-diastase  pradtically  im  amylaceous  dys- 
pepsia— a  form  of  dyspepsia  which  is  said  to  constitute 
about  three-fourths  of  the  indigestion  due  to  deficiency  in 
the  quality  or  quantity  of  the  digestive  secretions  gene- 
rally. 

When  making  demonstrations  fn  this  connedtion  before 
some  members  of  the  British  Medical  Association  in  t^ie 
summer  of  1895,  I  was  impressed  by  the  interest  which 
was  manifested  in  the  treatment  of  mal-digestion  or  want 
of  due  assimilation  of  starchy  foods.  This  interest  is  of 
comparatively  recent  growth,  as  is  much  of  the  knowledge 
in  regard  to  the  causes  which  lead  to  the  produdlion  of  the 
condition  referred  to ;  in  fadt,  not  many  years  ago  there 
was  hardly  any  serious  attempt  at  differentiation  in  the 
diagnosis  or  treatment  of  what  is  called  "  indigestion." 
In  the  minds  of  many  persons  who  have  studied  the  ques- 
tions connedted  with  this  subjedt  there  still  exist  certain 
misconceptions  which  prevent  a  clear  understanding  of  the 
difficulties  that  present  themselves.  Dr.  R.  G.  Eccles 
states  that  "  one  of  the  gravest  mistakes  we  have  made  in 
the  past  has  been  in  supposing  that  the  stomach  only  had 
to  deal  with  proteids — that  within  it  only  albumen,  casein, 
gluten,  and  the  like  were  disposed  of.  The  fadt  is  that  the 
very  first  important  adt  performed  in  the  stomach  is  the 
digesting  of  starch.  All  gluten  reaches  it  enveloped  in  an 
insoluble  coating  like  the  sugar  or  gelatin  on  the  outside 
of  a  pill.  To  make  way  for  the  digestion  of  proteids  this 
must  be  rendered  soluble  and  removed.  To  do  so,  starch- 
digesting  has  to  be  the  first  task  of  the  stomach ;  following 
it  comes  proteid  digestion."  He  refers  to  the  belief  once 
entertained  almost  universally  that  conversion  of  the 
trifling  amount  of  starch  adled  on  during  the  process  of 
mastication  was  all  the  duty  saliva  performed,  and  then 
states  that  "  Ptyalin  was  never  intended  by  Nature  to  do 
its  work  in  the  mouth."  The  fadt  is  that,  under  normal 
conditions,  the  contents  of  the  stomach  may  not  contain 
any  free  hydrochloric  ecid  until  after  the  expiration  of  half- 
an-hour  to  an  hour  from  the  time  the  food  is  ingested. 

The  claim  made  for  Taka-diastase  is  that  it  will  convert 
one  hundred  times  its  own  weight  of  starch  into  assimi- 
lable material  in  ten  minutes,  and,  as  it  is  an  enzym  or 
unorganised  ferment  (the  adlion  of  which  might  theoretic- 
ally be  regarded  as  infinite),  it  might  be  considered  to 


Chemical  Nsws,  i 
May  14, 1897.     ) 


Chemical  Notices  jrom  Foreign  Sources, 


239 


proceed  indefinitely  if  the  produdls  of  its  conversion  were 
removed  as  formed.  But  Sir  William  Roberts  states  that 
diastase  is  no  exception  to  the  rule  in  physics,  that  energy 
in  performing  work  is  expended  and  finally  exhausted. 
Nevertheless  Taka-diastase  converts  over  1500  times  its 
own  weight  of  starch  in  three  hours. 

It  may  be  argued  that  as  digestion  of  starch  is  not  likely 
to  proceed  for  three  hours  in  the  stomach  it  is  not  neces- 
sary, in  considering  digestion,  to  estimate  the  power  of  a 
diastase  during  this  period  of  time;  but  we  have  to  bear 
in  mind  that,  as  digestion  proceeds,  the  pylorus  relaxes, 
allowing  the  passage  to  the  intestine  of  finely  divided  par- 
ticles and  of  such  ^uids  as  may  not  have  been  absorbed 
in  the  stomach ;  and  as  the  diastase  passing  with  such 
material  in  the  early  stage  of  digestion  may  still  be  adtive 
(as  a  matter  of  fadt  Taka-diastase  converts  starch  even  in 
a  slightly  acid  medium),  we  have  no  reason  to  conclude 
that  the  adlion  does  not,  under  such  circumstances,  pro- 
ceed in  the  intestines,  where  any  acid  may  be  expecSted  to 
be  gradually  neutralised  before  the  alkaline  condition 
asserts  itself. 

About  two  years  ago  I  witnessed  many  experiments 
performed  by  Mr.  Takamine  (assisted  by  Mr.  E.  V.  Hitch, 
of  Chicago)  in  regard  to  the  adtion  of  Taka-diastase  on 
different  varieties  of  starch,  as  also  in  comparison  with 
other  diastases.  The  tests  were  almost  entirely  confined 
to  the  adlion  of  the  diastase  from  the  commencement  of 
the  process  to  the  end  of  from  twenty  to  thirty  minutes 
only  (that  being  considered  a  satisfaftory  period  in  which 
to  make  the  tests  ),  during  which  time  Taka-diastase  was 
found  to  be  considerably  more  adtive  than  any  of  the 
numerous  preparations  with  which  comparison  was  made 
and  for  which  diastasic  potency  was  claimed.  Here  I 
would  remark  in  regard  to  tests  of  diastase  in  vitro  that 
there  is  no  reason  to  consider  that  conversion  to  the 
achromic  point,  although  useful  as  a  means  of  comparison, 
must  occur  before  absorption  takes  place  in  normal  di- 
gestion. Sir  William  Roberts  states  that  "  the  dextrines, 
even  those  coloured  by  iodine,  are  highly  diffusible,"  and 
that  complete  conversion  would  require  that  the  material 
should  retrace  us  steps  to  some  extent  in  being  converted 
into  glycogen. — I  am,  &c., 

Thomas  Christie. 

Chepstow  Place,  W.,  May  10,  1897. 


BENDING     ALUMINIUM     TUBES. 

To  the  Editor  ef  the  Chemical  News. 
Sir,— In  the  paper  by  Mr.  T.  H.  Norton  on  •'  The  Use  of 
Aluminum  for  Condensers"  (Chemical  News,  vol.  Ixxv., 
p.  221)  it  is  suggested  that  to  bend  the  aluminium  tube 
it  should  be  filled  with  lead,  which  is  afterwards  melted 
out.  Would  not  resin  or  shellac  be  more  easily  manipu- 
lated, while  the  traces  left  in  the  tube  could  be  readily 
removed  by  alcohol  or  some  other  solvent  ?  The  cycle- 
makers,  in  bending  steel  tubes  up  to  i  in.  diameter, 
habitually  use  resin  for  filling  the  tube  previous  to 
bending. 

I  should  like  to  ask  why  American  writers  usually  speak 
of  "alumin?»»."  The  name  "aluminium"  has  had  a 
long  and  honourable  career,  and  it  seems  a  pity,  as  Curran 
would  have  said,  to  knock  out  one  of  its  i's.  The  oxide 
is,  and  has  always  been,  called  alumina  ;  but  no  one,  I  be- 
lieve, has  proposed  the  names  "  sodwrn  "  and  "  potassMwt" 
because  their  oxides  are  called  soda  and  potassa. — I 
am,  &c., 

E.  G.  Bryant. 

King's  School,  Pontefraft,  May  8, 1897, 


CUhMlCAL 


Death  of  Mr.  M.  Carey  Lea. — We  regret  to  hear  of 
the  death  of  Mr.  Carey  Lea,  at  Philadelphia.  The 
deceased  was  well  known  to  the  readers  of  the  Chemical 
News  in  connedtion  with  his  researches  on  the  allotropic 
forms  of  silver  and  the  photo-sensitive  compounds  of  this 
metal. 


NOTICES    FROM 
SOURCES. 


FOKELGN 


Note.— All  degrees  of  temperature  are  Centigrade  unless  otherwise- 
expressed. 

Bulletin  de  la  Societe  Chimique  de  Paris. 
Series  3,  vols.  xvii.  and  xviii.,  No.  7. 

Apparatus  for  the  Estimation  of  Free  Nitrogen  in 
Purified  Coal-gas. — G.  Arth. — The  author  has  arranged 
his  apparatus  in  such  a  manner  as  to  enable  him  tocoUedt 
and  measure  large  quantities  of  nitrogen  gas,  thereby 
considerably  reducing  the  efFedt  of  errors  of  observation. 
The  apparatus,  which  appears  to  give  excellent  results, 
may  be  briefly  described  as  a  kind  of  combination  of 
Crum's  nitrometer  with  Frankland's  gas  measuring 
apparatus,  but  cannot  be  properly  understood  without  the 
accompanying  diagram. 

NewFrat^tionation  Apparatus  for  Use  in  Industrial 
Laboratories. — A.  Tixier. — This  apparatus  is  an  im- 
provement on  previous  forms,  but  requires  the  accom- 
panying diagram. 

Cryoscopic  Measurements.  —  A.  Ponsot.  —  The 
author  has  made  a  number  of  experiments  to  determine 
the  congelation-point  of  solutions  of  cane-sugar  of  various 
strengths.  The  thermometer  used  was  an  extremely  delicate 
one,  each  principal  division  being  equal  to  0*5  m.m. ;  but 
by  very  fine  subdivision,  and  using  a  glass  magnifying 
fifty  times,  and  allowing  corredtions  lor  pressure  and 
calibration,  the  final  readings,  he  claims,  can  be  reduced 
to  i/2o,oooth  of  a  degree  Centigrade. 

Eihylisoamylamines. — Aug.  Durand. —  These  were 
obtained  by  the  adiion  of  iodide  of  ethyl  on  isoamylamine. 
By  mixing  them  carefully  in  certain  proportions  a  pasty 
mass  is  formed,  composed  of  the  iodides  of  the  primary, 
secondary,  and  tertiary  bases.  This  mass  is  dissolved  in 
water,  boiled,  and  a  solution  of  potash  added,  then  boiled 
again  ;  the  distillate  is  received  in  an  excess  of  dilute 
hydrochloric  acid.  From  this,  the  secondary  base — that 
is  to  say,  ethylisoamylamine — can  be  separated  in  the 
form  of  its  nitroso-derivative  by  adding  nitrite  of  soda 
dissolved  in  a  small  quantity  of  water.  This  is,  after 
purification,  treated  in  various  manners.  Several  of  its 
compounds  are  here  described,  such  as  chloroplatinate  of 
ethylisoamylamine,  chloroaurate  of  ethylisoamylamine, 
oxalate  of  ethylisoamylamine,  &c. 

Anethol  and  Homologues  of  Anethol. — Ch.  Moureu 
and  A.  Chauvet. — The  authors  have  succeeded,  with  great 
ease,  in  preparing  two  homologues  of  anethol,  viz.,  para- 
butenylanisol  and  paraisopentenylanisol. 

Yellow  Colouring-matter  derived  from  Dinitro- 
fiuorescine. — F.  Reverdin. — A  paste  is  made  of  loogrms. 
of  water  and  100  grms.  of  dinitruiluorescine ;  to  this  is 
added,  while  agitating,  75  c.c.  of  21  per  cent  ammonia. 
The  mixture  dissolves  at  once  with  an  increase  of  tem- 
perature ;  it  then  gradually  commences  to  thicken,  till 
after  a  few  hours  it  forms  a  solid  mass.  It  is  then 
triturated  with  125  c.c.  of  salt  water,  filtered ;  then, 
after  well  draining,  the  produdt — an  ammoniacal  salt  of 
the  colouring  material — is  converted  into  an  acid  by  weak 
hydrochloric  acid.  It  is  filtered,  dried,  and  then  digested 
for  some  hours  at  the  ordinary  temperature  with  10  parts 
of  acetone,  in  which  it  is  completely  insoluble,  but  which 
frees  it  from  several  impurities  and  by-produdts  which 
accompany  it.  After  filtering  and  drying  it  is  converted 
into  a  salt  of  soda  easily  soluble  in  water.  About  70 
grms.  of  this  salt  are  obtained.  The  first  filtrate  contains 
an  orange  colouring-matter,  which  no  longer  gives  the 
readlions  of  dinitrofluorescine,  but  which,  by  treating 
with  bromine,  gives  a  red  colouring-matter,  similar  to 
scarlet. 

Some  Derivatives  of  Furfurane. — P,  Freundler. — 
Several    derivatives    of    furfurane    have    not    yet    been 


240 


Meetings /or  the  Week, 


{Chemical  News, 
May  14,  1897. 


described,  in  spite  of  the  interest  there  would  be  in  com- 
paring them  with  the  corresponding  benzenic  derivatives. 
Among  these  ure  furfurane-amine  or  furane  amine.  The 
best  method  of  preparing  this  body  was  found  to  be  by 
the  nitrification  of  furfurane  and  the  redudion  of  the 
nitrified  derivative.  This  will  be  fully  described  in  a 
future  paper,  the  present  one  being  devoted  to  the  adion 
of  the  hypobromites  and  of  hydrazin  on  the  pyromucic 
derivatives. 

Distillation  of  very  Dilute  Mixtures  of  Ethylic 
Alcohol  and  Water.  Application  to  the  Estimation 
of  Alcoholic  Solutions  containing  only  i/soooth  to 
i/io,oooth  part. — M.  Nicloux  and  L.  Baudeur. — This 
paper  will  be  inserted  in  full. 


Revue  Universelle  des  Mines  et  de  la  Metallurgie. 
Series  3,  Vol.  xxxviii..  No.  i. 
This  issue  contains  no  chemical  matter. 


NOTES    AND    QUERIES. 

***  Our  Notes  and  Queries  column  was  opened  for  the  purpose  of 
giving  and  obtaining  information  likely  to  be  of  use  to  our  readers 
generally.  We  cannot  undertake  to  let  this  column  be  the  means 
of  transmitting  merely  private  information,  or  such  trade  notices 
as  should  legitimately  come  in  the  advertisement  columns. 
Wells'  Patent  Continuous  Cooling  Process.— Will  some  cor- 
respondent kindly  inform  me  who  are  the  proprietors  of  this  process. 
— Enquirer. 


MEETINGS    FOR    THE    WEEK. 

Monday,  17th.— Society  of  Arts,  8.      (Cantor  Ledlures).    "  Design 
in  Lettering,"  by  Lewis  Foreman  Day. 

Wednesday,  19th.— Society  of  Arts,  8.    "  London  Water  Supply,"  by 
Dr.  P.  F.  Frankland,  F.R.S. 

Thursday,  20th. — Chemical,  8.  "Theory  of  Osmotic  Pressure  and 
the  Hypothesis  of  Eleftrolytic  Dissociation  ;" 
"  Molecular  Rotation  of  Optically  Aftive  Salts ;" 
Heats  of  Neutralisation  of  Acids  and  Bases  in 
Dilute  Aqueous  Solution;"  by  Holland  Cromp- 
ton,  "  The  Platinum-Silver  Alloys— their  Solu- 
bility in  Nitric  Acidj"  by  John  SpiUer.  "A  Com- 
parative Crystallographical  Study  of  the  Normal 
Selenates  of  Potassium,  Rubidium,  and  Cs- 
Bium,"byA.  E.  Tutton. 
— —  Society  of  Arts,  4.30.  "  Kerman  and  Persian  Belu- 

chistan,  with  special  reference  to  the  Journeys  of 
Alexander  the  Great  and  Marco  Polo,"  by  Capt. 
P.  Molesworth  Sykes. 


•VSTJ^ISTTEX). 


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Estimation  of  Carbon  in  Ferro-chrome, 


241 


THE    CHEMICAL     NEWS 


Vol.  LXXV.,  No.  1956. 


ON   THE 

REACTIONS     BETWEEN     LEAD     AND     THE 
OXIDES    OF    SULPHUR* 

By  HENRY  C.  JENKINS  and  ERNEST  A.  SMITH, 
Royal  College  of  Science,  London. 

The  authors  of  this  paper  draw  attention  to  the  fad, 
previously  noticed  by  one  of  them,  that  when  molten  lead 
is  exposed  at  high  temperatures  to  the  adtion  of  a  current 
of  sulphur  dioxide,  both  lead  sulphide  and  lead  oxide  are 
found  in  the  produdt. 

The  paper  is  the  account  of  a  research  undertaken 
with  a  view  to  ascertain  the  precise  readion  which  takes 
place  under  these  conditions,  as  well  as  to  see  whether  it 
did  not  account  for  some  anomalies  that  are  met  with 
whenever  a  full  explanation  of  the  chemistry  of  lead 
smelting  in  the  reverberatory  furnace  has  been  attempted. 

Mr.  Hannay  had  sought  (Chemical  News,  vol.  Ixx., 
1894,  PP-  43  ^°  45)  ^°  explain  these  anomalies  by  the 
assumption  that  a  volatile  body,  PbSaOa,  had  been  formed. 
He  based  the  evidence  for  the  existence  of  this  body, 
that  could  not  be  isolated,  on  the  observation  that  in 
some  experiments  he  had  conducted,  by  passing  air  over 
heated  galena,  he  only  obtained  one-half  of  the  lead  in 
the  metallic  state  according  to  an  equation — 

2PbS  +  O2  =  Pb  +  PbSzOa. 

The  authors,  on  repeating  this  experiment  with  air  and 
with  oxygen,  find  that  the  amount  of  lead  that  is  volatilised 
in  such  an  operation  does  not  bear  any  definite  ratio  to 
the  total  amount  of  lead  present,  but  can  be  made  to 
vary  greatly,  and  is  entirely  dependent  upon  the  velocity 
of  the  current  of  air  employed.  They,  therefore,  submit 
that  there  is  now  no  evidence  of  any  such  readtion,  the 
ratio  found  by  Mr.  Hannay  being  the  result  of  some 
accidental  coincidence  of  experimental  conditions. 

In  continuing  the  research,  the  authors  found  that,  on 
heating  a  mixture  of  lead  sulphide  and  lead  sulphate  in  a 
vacuum,  a  readtion  occurred  having  sulphur  dioxide  as  one 
of  the  produdts  ;  they  also  found  that  the  amount  of  residual 
lead  sulphide  and  oxide  was  dependent  on  the  duration 
of  the  experiment  as  well  as  on  the  temperatures.  They 
then  proceeded  to  test  separately  the  pairs  of  bodies  sup- 
posed to  be  present,  with  a  view  to  discover  whether 
secondary  or  reversed  readtions  occurred.  On  heating  lead 
with  lead  sulphate,  they  always  obtained  lead  sulphide  in 
the  produdt,  in  amounts  varying  with  the  temperature  of 
the  experiment  and  the  length  of  time  that  it  occupied. 
On  heating  together  lead  and  sulphur  dioxide,  they 
found  that  at  moderately  elevated  temperatures — 300°  to 
400"  C. — lead  sulphide  and  sulphuric  anhydride  are  formed 
in  each  other's  presence,  and  that  this  leads  to  the  forma- 
tion first  of  lead  oxide  and  then  of  lead  sulphate.  The 
adtion  is   represented  more  or  less  completely  by  the 

-  equation — 

Pb  +  3SO2  =  PbS  +  2SO3, 
Pb  +  2SO3  =  PbS04  -f-  SO2, 

'  or  more  simply — 

2Pb  -f  2SO2  =  PbS  +  PbS04, 

the  main  condition  determining  the  relative  amounts  of 
the  produ(%s  being  the  temperature  at  whith  the  experi- 
.ment  is  performed  under  similar  conditions. 

One  of  the  authors  is  continuing  the  investigation  of 

♦  Abstraft  of  Paper  read  before  the  Chemical  Society,  May  6, 1897. 


the  exadtj  conditions   of  the    equilibrium,  as  well  as  its 
extension^to  other  metals. 

The  last  of  these  equations  occurring  in  the  presence 
of  excess  of  sulphur  dioxide  is  the  exa(^  inverse  of  one  of 
the  main  readtions  of  lead  smelting,  as  stated  by  Dr. 
Percy,  and  in  which  readlion  a  supply  of  air  is  required  to 
sweep  away  the  sulphur  dioxide  as  soon  as  it  is  liberated. 
The  authors  submit  that,  as  the  new  equations  quite 
account  for  the  anomalies  to  which  attention  has  been 
drawn,  there  is  now  no  reason  whatever  to  doubt  that  the 
readtions  given  by  Dr.  Percy, — 

Pb  -f  PbS04  =  2PbO  +  SO2,     . 
PbS  -f  PbS04  =  2Pb  +  2SO2, 
as  well  as — 

PbS  4-  2PbO  =  sPb  -J-  SO2, 

do  adtually  take  place,  and  form  the  basis  of  the  metal- 
lurgy of  lead. 


THE    ESTIMATION     OF    CARBON     IN 

FERRO-CHROME. 

By  H.  BREARLEY  and  R.  L.  LEFFLER,  F.C.S. 

When,  three  or  four  years  ago,  the  need  to  estimate  the 
percentage  of  carbon  in  a  sample  of  ferro-chrome  arose,  the 
method  usually  adopted  for  silica  spiegels,  and  such  alloys 
as  are  unadted  upon  by  copper  solutions, — viz.,  combustion 
of  the  powdered  sample  with  CuO,— was  resorted  to.  The 
results  obtained  were  low,  very  low.  In  a  neighbouring 
laboratory  it  was  customary  to  grind  the  ferro-chrome  and 
CuO  together,  burn,  re-grind,  and  burn  again.  Tfte 
tediousness  of  the  method,  together  with  the  errors  of 
weighing  and  re-weighing,  would  make  the  method  an 
unreliable  one  in  case  the  alloy  was  completely  decarbon- 
ised. But  with  such  heat  as  we  could  get,  from  an 
ordinary  Bunsen  combustion  furnace,  only  about  50  per 
cent  of  the  contained  carbon  could  be  extradted  after 
grinding  and  re-grinding  six  or  seven  times.  By  substi- 
tuting lead  chromate  for  copper  oxide,  and  prolonging  the 
heat  for  two  hours  or  so,  much  better  results  were  ob- 
tained. In  fadt,  by  re-grinding  and  re-burning  three  or 
four  times,  nearly  the  whole  of  the  carbon  was  eliminated. 
But  this  method  would  not  serve  when  samples  were 
regularly  received. 

As  many  periodicals  and  text-books  as  were  available 
were  searched  for  a  less  tedious  and  more  accurate  method. 
A  method  by  Fresenius  and  Hintz  (Chem.  News,  Ixi.,  65) 
— treatment  with  chlorine  gas  and  combustion  of  the 
carbonaceous  residue  —  stood  solitary.  Later,  Arnold 
("  Steel  Works  Anal.,"  p.  213)  published  a  method  which 
will  be  referred  to  later  on.  Enquiries  were  made  from 
works'  chemists  and  laboratory  instrudlors  as  to  their 
respedtive  modus  operandi,  but  all  either  declared  their 
lack  of  a  satisfadtory  method  or  preferred  to  say  nothing 
of  the  one  they  had.  The  following  experiments  repre- 
sent the  attempts  made,  at  intervals  during  the  last  few 
years,  to  find  an  accurate  method  giving  consistent  results 
with  as  little  trouble  as  possible. 

Throughout  the  ferro-chrome  used  had  been  ground  to 
a  fine  powder  in  the  agate  mortar.  Leffler  shows  below 
that  this  excessive  fineness  is  sometimes  unnecessary. 

Of  the  variable  results  obtained  by  simply  heating, 
those  were  highest  which  had  been  most  highly  heated. 
This  naturally  suggested  raising  the  temperature  beyond 
that  attainable  with  the  ordinary  furnace  arrangement. 
The  part  of  the  tube,  therefore,  containing  the  porcelain 
boat  was  made  hotter  by  means  of  a  bov/pipe  flame  urged 
by  a  foot-bellows.  The  results  were  higher,  more  con- 
sistent, and  more  readily  obtained. 

For  clearness  sake  the  method  had  better  be  briefly 
described  : — Half  to  i  grm.  finely-powdered  ferro-chrome 
mixed  with  10  grms.  lead  chromate,  which  had  been  pre- 
viously   fused    and   re-ground   to    a  powder:  place    in 


242 


Estimation  of  Carbon  in  F err o -chrome. 


Chbmical  News, 
May  21, 1807. 


porcelain  boat  and  burn  in  porcelain  combustion-tube 
packed  with  CuO,  &c.  In  principle  there  is  of  course 
nothing  new  in  this  method  ;  it  is  rather  in  the  matter  of 
accessories  and  manipulation  that  the  advantage  lies. 

When  the  tube  is  heated  by  the  blowpipe,  the  mixture 
in  the  boat  melts  and  evolves  carbon  dioxide,  sometimes 
so  vigorously  as  to  spirt  over  the  side  or  strike  the  roof 
of  the  tube.  Even  if  the  boat  be  withdrawn  before 
cooling,  the  tube  will  rarely  bear  re-heating.  A  few  tubes 
lost  this  way  led  to  the  adoption  of  glass  tubes.  No 
simple  tube  obtainable  wonld  stand  the  necessary  heat, 
and  many  varieties — including  Schott's  Jena  glass — were 
tried.  The  tubes  were  covered  with  asbestos  millboard, 
i-32nd  of  an  inch  or  so  thick.  This  plan  is  adopted  with 
porcelain  tubes  for  ordinary  combustions.  There  is  much 
less  danger  of  fracflure  on  account  of  sudden  heating,  and 
in  the  case  of  the  best  Bohemian  glass  tubes  finally 
seledled  it  preserved  them  from  bending  when  sustained 
at  an  almost  white  heat.  Over  the  part  which  had  been 
strongly  heated  the  surface  was  pitted  with  small  holes. 
In  places  the  asbestos  was  fused  into  the  glass.  If  the 
tube  was  otherwise  preserved  it  invariably  cracked  on  re- 
heating, on  account  of  this  asbestos,  so  that  either  the 
boat  had  to  be  changed  with  the  tube  at  red  heat,  or  a 
strip  of  paper  had  to  be  wound  round  the  tube  before 
laying  over  the  wetted  asbestos.  The  paper  burned,  of 
course,  but  left  a  protedlive  covering  of  ash. 

To  prevent  the  boat  sticking  to  the  inside  of  the  tube 
it  was  covered  with  a  thin  piece  of  millboard  and  a 
thicker  piece  lined  the  inside,  so  that  the  fusion  might  be 
removed  and  the  boat  preserved.     A  cover  shaped  so — 


1 

was  laid  on  the  top  to  prevent  the  spirting  melt  striking 
the  roof  of  the  tube.  It  is  made  to  bend  over  the  end  of 
the  boat,  so  that  it  may  not  easily  be  brushed  off  in 
passing  along  the  tube.  The  boat  with  its  fittings  is 
strongly  ignited  before  use. 

The  lead  chromate  and  sample  were  mixed  by  shaking 
together  in  a  weighing  tube.  The  long  shape  with  wide- 
stoppered  neck  is  most  convenient.  A  little  asbestos  on 
the  finger-tip  removes  the  last  traces  cleanly  and 
effedlively. 

When  the  blowpipe  has  raised  the  temperature  of  the 
tube  the  gas  bubbles  through  the  potash  bulb  more  and 
more  quickly,  until  the  bubbles  can  scarcely  be  distin- 
guished. When  only  half  a  grm.  of  the  sample  is  taken, 
this  can  be  fairly  well  controlled  by  judicious  heating; 
but  with  larger  amounts — say  from  i  to  ij  grms. — the 
evolution  of  gas  is  beyond  control.  On  unfortunate  occa- 
sions it  is  almost  vigorous  enough  to  shatter  the  bulb. 
After  the  storm  comes  the  calm.  The  contents  of  the 
boat  now  greedily  absorb  oxygen,  and  unless  the  sup- 
ply be  quickened  the  KHO  may  be  pulled  back ;  the 
soft  glass  tube  will  certainly  be  crushed  on  to  the  boat, 
wrapping  it  completely  round. 

The  most  satisfadiory  way  of  showing  that  the  method 
used  was  a  reliable  one  was  to  repeat  assays  with  varying 
weights  of  the  ferro-chrome. 

Two  pieces  of  apparatus,  shown  in  figs,  i  and  2,  were 
used  to  control  the  rush  of  evolved  gases.  Fig.  i  was 
used  most  largely,  because  it  was  to  hand  and  already 
fitted  up.  It  is  indeed  Stead's  "  Gas  Sampler,"  and  is 
fully  described  in  Mawson  and  Swan's  Catalogue.  One 
of  the  lower  laps  should  be  replaced  by  a  larger  one. 
Fig.  2  works  automatically. 

Let  the  tube  be  heated  by  the  furnace  in  the  ordinary 
way,  then  heat  the  locality  of  the  boat  with  the  blowpipe. 
The  readlion  runs  the  length  of  the  boat  like  a  train  of 
gunpowder.  The  "controller"  being  attached  as  shown, 
and  the  mercury  arranged  as  though  a  sample  of  gas  was 
being  taken,  j  and  k  are  opened.  With  the  hand  on  l, 
the  potash  bulb  is  watched.  As  the  bubbling  becomes 
more  and  more  rapid  the  o  is  shut  off,  the  tap  (l)  suit- 
ably turned,  and  the  rush  accommodated  in  G.  (A  plug 
of  asbestos  fibre  should  have  been  pushed  in  after  the 


boat,  to  prevent  a  cloud  of  lead  oxide  being  drawn  along 
the  tube  and  into  the  "  controller  ").  The  oxygen  is  re- 
passed, so  as  to  supply  the  vigorous  absorption  in  the  boat 
and  keep  a  gentle  stream  through  the  bulb.  When  the 
absorption  in  the  boat  is  finished,  the  gases  are  forced 
from  Q  by  turning  the  taps  and  raising  H.  The  connec- 
tions are  swept  out  by  opening  m; 

There  is  no  reason  why  a  porcelain  tube  should  not  be 
used  over  and  over  again  if  the  noted  precautions  are 
taken.  The  best  glass  tubes  only  serve  three  or  four 
times. 

The  operation  is  not  so  long  as  the  description  might' 
suggest.      With  samples    powdered  and  tubes   already 


OXYGEN 


FIG. 2 


packed,  four  samples  have  been  weighed,  mixed,  boated, 
and  burned  in  five  hours.  Such  arrangements,  partly 
existing  in  most  metallurgical  laboratories,  we  have  used 
for  nearly  two  years. 

We  are  induced  to  notice  fig.  2  as  an  alternative  to 
fig.  I,  in  the  hope  that  it  may  serve  some  other  purpose. 
Neither  are  needed  in  the  operations  to  be  described 
later.  It  is  necessary  to  note  that  the  combustion  tube,  &c., 
is  aspirated  .by  an  arrangement  indicated  at  a  (fully 
described  Chem.  News,  Ixxiv.,  225),  which  ensures  con- 
stant pressure.  The  two  bottles  and  tubes  figured  are  in 
principle  precisely  the  same.  The  small  mercury  cup,  k, 
prevents  any  back  rush  of  air,  and  serves  to  make  the 
final  adjustment  of  pressures.     The   furnace  is  heated. 


Chbmical  Nbws,  I 
May  21. 1897.     I 


Estimation  of  Carbon  in  Ferro-chrome. 


oxygen  passed,  and  aspirator  attached  as  usual.  By 
means  of  k,  or  its  in-dipping  tube,  the  aspiration  due  to 
the  fall  of  mercury  is  made,  so  that  gas,  from  the  com- 
bustion-tube, is  just  on  the  point  of  being  drawn  through 
■  H.  Any  increase  of  pressure  in  the  tube,  such  as  would 
be  caused  by  the  readion  in  the  boat,  causes  mercury  to 
flow  from  K,  and  provides  itself  with  room  in  the  upper 
bottle.  The  gases  are  re-passed  through  the  combustion- 
tube  by  admitting  oxygen  and  running  the  mercury  below 
the  level  of  h,  and  then  sweeping  the  whole  out  by 
passing  successively  oxygen  and  air. 

The  following  assays  were  made  with  lead  chromate, 

as  described  on  a  sample  marked  10,543,  which  contained 

'61  per  cent  of  chromium.    Those  marked  with  an  asterisk 

were  done  a  year  ago  when  the  sample  was  received. 

The  rest  were  done  for  this  paper. 


o'5    grm.  taken. 
075 

1-00  „ 

125 
1*50 


I. 

II. 

8-8o* 

8-86»  per  cent. 

8-84 

>i 

8-86  • 

8-83       „ 

890 

t» 

S-gi 

n 

When  copper  oxide  is  substituted  for  lead  chromate 
more  heat  is  needed ;  there  is  less  spirting,  and  not  so 
violent  a  readtion.  The  fusion  has  the  appearance  of  a 
piece  of  gas  coke.  The  general  phenomena  are  similar 
to  those  noticed  with  chromate. 

Results  on  same  sample  (10,543)  ^^^  • — 


075  grm. 
I '00 

1*25 


taken. 


8-8g  per  cent. 
8*89        „ 
8-8o 


Other  metallic  oxides  were  tried,  more  from  curiosity 
than  from  hope  of  finding  more  suitable  reagents  than 
copper  oxide  or  lead  chromate.  In  1859  a  patent  was 
taken  out  for  the  produAion  of  malleable  iron  by  heating 
with  zinc  oxide,  so  long  as  the  iron  contained  appreciable 
amounts  of  carbon  metallic  zinc,  distilled  over  but  stopped 
when  the  decarbonisation  was  complete.  With  this  re- 
commendation zinc  oxide  was  tried,  but  it  could  not  be 
made  to  decarbonise  the  ferro-chrome  within  reasonable 
time  at  such  temperature  as  could  be  obtained  with  our 
blowpipe. 

It  need  not  be  argued  that  it  would  be  an  advantage  if 
•the  combustion  could  be  completed  at  ordinary  furnace 
temperatures,  and  in  a  becoming  manner,  without  the  use 
of  any  rush  controlling  arrangement.  The  use  of  lead 
peroxide  makes  this  possible.  In  this  operation  the  boat 
need  not  be  covered  with  asbestos  on  the  inside.  The 
charged  boat  is  placed  in  the  cool  combustion-tube.  The 
taps  are  burned  separately  and  slowly,  so  as  to  gradually 
liberate  the  oxygen  from  the  PbOj.  The  mixture  fuses, 
and  there  is  the  same  need  to  quicken  the  oxygen  to 
supply  the  absorption  in  the  boat,  but  all  else  goes  on 
with  comparative  quietness  and  at  ordinary  temperatures. 
Some  results  on  10,543  with  10  grms.  PbOa  are : — 


075  grm. 

I -00 
1-25 


taken. 


8-87  per  cent. 
8-86        „ 
887        „ 


243 

I  have  only  a  mere  acquaintance  with  other  methods 
than  those  described.  Volatilisation  in  a  stream  of 
chlorine,  and  subsequent  combustion  of  the  carbonaceous 
residue,  does  not  seem  to  have  found  much  favour.  This 
may  be  partly  due  to  the  fa(5t  that  the  apparatus  for  such 
an  operation  is  not  in  frequent  use  in  steel  works'  labora- 
tories, and  whatever  virtue  the  method  may  have  is  more 
than  counterbalanced  by  the  inconvenience  of  putting 
things  out  of  joint  for  a  day  or  two. 

Professor  Arnold's  method  has  been  largely  worked  by 
Leffler,  who  also  kindly  furnishes  other  useful  information. 
The  method  recommended  by  Prof.  Arnold  consists  in 
placing  the  sample,  intimately  mixed  with  lead  chromate, 
in  a  glass  combustion  tube  between  asbestos  plugs,  and 
subjedling  to  prolonged  heating  in  a  stream  of  moist  oxy- 
gen. The  method  has  been  repeatedly  tried  in  asbestos- 
covered  tubes;  no  naked  tube  obtainable  would  stand  the 
ordinary  furnace  heat,  and,  unfortunately.  Prof,  Arnold 
limits  himself  to  "  very  hard  glass  "  tubes.  Samples  kept 
at  a  bright  red  heat  from  two  to  four  and  a  half  hours 
only  yielded  about  fifty  per  cent  of  the  total  carbon  ob- 
tainable. (Found,  444,  4'57,  477,  on  a  sample  containing 
869  per  cent  C).  But  if  the  temperature  of  this  arrange- 
ment was  raised  by  the  blowpipe,  an  additional  amount 
of  carbon,  bringing  the  results  up  to  the  known  per- 
centage,  was  obtained.  Occasionally  the  oxide  of  lead 
formed  adted  severely  on  the  glass.  A  current  of  moist 
oxygen  seemed  to  have  no  more  effeft  than  a  dry  one; 
and,  theoretically  at  least,  it  seems  to  be  a  disadvantage 
in  this  way.  The  oxide  of  lead  formed  by  the  readtion 
between  the  reduced  lead  and  oxygen  might  conceivably 
be — and  in  some  cases,  indeed,  was — carried  to  the  far 
end  of  the  tube.  These  traces,  if  dry,  may  absorb  no 
appreciable  amount  of  CO2 ;  but  the  hydrate  of  lead 
protoxide,  made  possible  by  the  deposited  moisture,  very 
readily  absorbs  that  gas. 

It  is  generally  stated  that  the  ferro-chrome  used  should 
be  in  the  finest  possible  state  of  division.  Grinding  in 
the  agate  mortar  is  a  painful  job,  and  the  ease  with  which 
some  of  the  reagents  mentioned  above  decomposed  the 
ferro-chrome  suggested  that  this  state  of  "impalpable 
flour "  was  sometimes  unnecessary.  A  sample  was 
therefore  prepared  in  three  states  of  division. 

1.  Passing  through  wire  sieve  of  30  meshes  to  the  inch 

but  not  through  60. 

2.  Through  60  but  not  90. 

3.  Through  a  go. 

The  sample  contained  8*69  per  cent  C. 


Sample  through— 

30  not  60 

60     ,,    90 


Per  cent  of  carbon  with— 


PbCrO^. 

3'76 
8-6o 


CuO. 
I '02 
8-68 


PbOg. 
7-58 

a  67 


This  method  we  prefer  no  less  on  account  of  accuracy 
than  convenience. 

Lead  protoxide  did  not  give  satisfaftory  results.  In  all 
cases  a  blank  combustion  had  to  be  made,  but  with 
protoxide  the  blank  was  very  large  and  very  variable. 
The  sample  used  was  made  from  the  peroxide,  but  gave  a 
much  larger  blank,  which  is  most  likely  due  to  its  well- 
known  property  of  absorbing  carbon  dioxide  from  the  air. 
"Very  much  the  same  things  may  be  said  of  the  fused 
variety  litharge;  although,  probably  a  coincidence,  two 
very  good  results  were  obtained. 


In  the  30,  with  PbCr04  and  CuO,  the  grains  of  the 
ferro-chrome  were  distinctly  visible  after  the  combustion  ; 
the  CuO,  too,  was  not  even  fritted.  With  this  compara- 
tive coarseness  of  sample,  the  readlion  was  noticeably  less 
violent.  It  was  not  considered  necessary  to  make  assays 
on  the  90  after  obtaining  such  accurate  results  as  are 
shown  with  60.  Of  course,  the  assays  with  PbCr04  and 
CuO  were  blasted,  and  all  of  them  carried  out  as  pre- 
viously mentioned.  The  following  are  examples  showing 
that  the  carbon  percentage  is  very  variable : — 

C.  Cu. 

5*82  89-46 

8*40  60  02 

9'20  6073 

9'39  6184 

lO'iS  60*25 

II'22  67*24 

The  Laboratory, 

Messrs.  Thos.  Firth  and  Sons,  Lim., 

Sheffield. 


Study  of  Hyponitrous  A  cid. 


_f44 

CONTRIBUTION     TO     THE     STUDY    OF 
HYPONITROUS    ACID.' 
By  A.  HAUTZSCH  and  A.  L.  KAUFMANN. 
(Continued  from  p.  233)* 

Free  Hyponitrous  Acid. 
HtPONiTROUs  acid  was  first  obtained  in  the  free  state 
in  aqueous  solution  by  Van  der  Plaats  [Berichte,  vol.  x., 
p.  1507).  It  has  also  been  studied  by  Thum  (Wiener, 
Monatsh.,  vol.  xiv.,  p.  294).  About  the  same  time  as 
we  did,  Tanatar  obtained  it  in  an  oily  state,  probably  still 
containing  water.  To  obtain  this  acid  in  the  solid  state 
it  is  necessary  to  proceed  as  follows : — A  current  of 
hydrochloric  acid  gas,  dried  with  the  greatest  care,  is 
passed  through  ether  absolutely  free  from  water.  To 
this  etherised  hydrochloric  acid,  perfedlly  dry  hyponitrite 
of  silver  is  added  little  by  little.  The  solution  must  be 
kept  cool,  and  special  precautions  must  be  taken  to  pre- 
vent the  access  of  moisture.  Hyponitrite  of  silver  is 
added  until  the  last  portion  added  no  longer  loses  its 
colour;  that  is  to  say,  until  the  etherised  solution  no 
longer  contains  any  free  hydrochloric  acid.  This  solution 
is  then  rapidly  filtered  on  a  dry  filter,  and  placed  in  an 
exsiccator  in  vacuo.  Moisture  and  acid  fumes  must  be 
guarded  against  with  the  utmost  care,  and  for  this  reason 
a  crucible  containing  solid  caustic  potash  should  be 
placed  in  the  exsiccator.  The  evaporation  of  the  ether 
can  be  accelerated  by  passing  through  the  etherised  solu- 
tion a  current  of  air  which  has  been  first  passed  through 
two  wash  bottles — the  first  containing  a  solution  of  caustic 
potash,  the  second  sulphuric  acid — and  then  through  a 
tube  containing  phosphoric  anhydride.  It  is  advisable  to 
keep  the  exsiccator  in  a  refrigerating  mixture ;  the  ether 
then  evaporates,  leaving  the  hyponitrous  acid  in  the  form 
of  white  scales. 

Hyponitrous  acid  is  very  explosive.  When  absolutely 
dry  it  decomposes  spontaneously ;  the  decomposition  is 
accelerated  by  the  presence  of  acid  fumes,  but  retarded 
by  cold.  Simply  touching  it  with  a  glass  rod  is  enough  to 
cause  its  decomposition.  Contadt  with  solid  caustic 
potash  is  sufficient  to  cause  sudden  decomposition  accom- 
panied by  ignition. 

Hyponitrous  acid  is  not  only  very  soluble  in  water,  but 
it  also  dissolves  with  great  readiness  in  alcohol,  ether, 
chloroform,  and  benzene. 

We  have  not  been  able  to  carry  out  the  analysis  of  this 
acid.  So  long  as  there  is  any  ether  present,  the  crystals 
can  be  preserved  for  some  time,  but  as  soon  as  they  be- 
come quite  dry,  they  detonate  even  at  6°  without  any 
apparent  cause. 

We  have,  however,  been  able  to  show,  by  qualitative 
readions,  that  the  substance  obtained  was  really  hypo- 
nitrous acid.  We  placed  some  of  the  crystals  on  a  plate 
of  porous  porcelain,  and  the  moment  they  became  dry 
they  were  slid  off  into  a  watch-glass  containing  iced 
water.  The  solution  gave,  on  the  addition  of  nitrate  of 
silver,  the  charaderistic  hyponitrite  of  silver.  The 
aqueous  residue  obtained  by  the  decomposition  of  the 
crystals  also  gives  the  same  readion. 

The  water  formed  by  the  decomposition  of  hyponitrous 
acid,  according  to  the  following  equation, — 

HON,NOH  =  HjO-f-NjO, 
dissolves  a  portion  of  the  acid,  and  thus   saves  it  from 
decomposition. 

In  aqueous  solution,  hyponitrous  acid  is  much  more 
stable  than  in  the  anhydrous  state.  Although,  as  will  be 
shown  further  on,  the  acid  does  decompose  rapidly 
enough  when  in  aqueous  solution  at  25°,  it  is  still  suffi- 
ciently stable  at  0°  to  enable  one  to  determine  its  mole- 
cular weight  by  the  cryoscopic  method. 

Dettrmination  of  the  Molecular  Weight.  —  For  this 
operation  we  used  pure  water,  whose  freezing-point  had 

*  Moniteur  Scientifique,  vol.  xi,.  p.  336,  May,  1897. 


f  Chemical  News, 
\     May  21,  1897. 


been  determined  in  Beckmann's  apparatus,  and  with  it 
we  prepared  a  one-sixth  normal  solution  of  hydrochloric 
acid,  by  passing  through  it  a  current  of  hydrochloric  acid 
gas  and  diluting  to  the  proper  point.  200  c.c.  of  this 
solution,  which  contained  o"i2i7  grm.  of  HCl,  lowered 
the  freezing-point  by  o'625°  (mean  of  five  experiments). 
Without  removing  the  Beckmann  apparatus  from  the 
freezing  mixture,  we  added  a  solution  of  hyponitrite  in 
excess.  The  one-sixth  normal  solution  thus  obtained 
(o'i035  grm.  in  20  c.c.  of  water)  produced  a  lowering  of 
the  freezing-point  of  only  o*i67°  (mean  of  three  observa- 
tions). The  lowering  of  the  congelation-point  produced 
by  equivalent  quantities  of  hydrochloric  acid  and  hypo- 
nitrous acid,  are  in  the  proportion  of  i  to  3*8.  As  at  this 
degree  of  dilution  (the  molecular  quantity  in  6000  litres 
of  water)  hydrochloric  acid  is  completely  dissociated, 
and  has  a  molecular  weight  of  18*4,  and  a  number  of 
ions  =  2  ;  the  substitution  of  H2N2O2  for  HCl  =  (2H-f-2Cl) 
ought  to  result  in  the  redudtion  of  the  number  of  mole- 
cules to  one  quarter.  This  is  only  possible  if  the  hypo- 
nitrous acid,  very  much  diluted  (molecular  quantity  in 
3000  litres  of  water),  does  not  appreciably  dissociate 
itself  into  its  ions  ;  that  is  to  say,  if  it  is  a  very  weak  acid, 
that  which  our  experiments  on  its  condudlivity  fully  con- 
firm. We  have  then  : — Molecular  weight :  found,  59  ; 
theory,  H2N2O2,  62.  This  result  proves  that,  under  the 
conditions  we  have  just  indicated,  hyponitrous  acid  does 
not  exist  in  the  state  of  a  simple  molecule — 

=:0 
H- 


N: 


Action  of  Alkalis.  —  If  hyponitrous  acid  closely 
resembles  carbonic  acid  by  its  ready  dissociability,  the 
analogy  between  these  two  acids  is  shown  in  a  still  more 
striking  manner  in  their  titration  by  means  of  alkaline 
solutions,  using  phenolphthalein  as  indicator.  Thus,  as 
Thum  as  already  shown,  the  titration  indicates  only  half 
the  amount  of  acid  present.  The  following  experiment 
leaves  no  doubt  on  the  subjedl: — 

To  20  c.c.  of  a  decinormal  solution  of  hydrochloric 
acid  hyponitrite  of  silver  was  added  in  excess.  The  hypo- 
nitrous acid  liberated  was  immediately  neutralised  at  0° 
by  a  titrated  solution  of  baryta,  using  phenolphthalein  as 

indicator. 

Theory. 

, -^ > 

BaNjOj. 

Solution  of  baryta  used,  5  c.c.  50     10  c.c.  9 

Monosodic  hyponitrite,  like  monosodic  carbonate,  is 
neutral  to  phenolphthalein.    Thus,  this  analogy  exists  :— 


BaH.NjjO,. 
3  c.c.  45 


N, 


-ONa 
-OH 


and       eo; 


-ONa 
*0H   • 


Further,  acid  hyponitrite  is  not  stable  in  aqueous  solu- 
tion. If,  in  a  solution  of  hyponitrous  acid  titrated  with 
an  alkaline  solution  until  the  red  colouration  of  phenol-- 
phthalein  shows,  we  cause  the  colour  to  disappear  by 
adding  a  drop  of  hydrochloric  acid,  and  let  it  stand,  the 
red  colouration  will  reappear.  The  acid  hyponitrite  of 
soda  decomposes  very  slowly  into  protoxide  of  nitrogen 
and  caustic  soda,  according  to  the  equation — 


N, 


-ONa 
•OH  ' 


>NaO-i-NaOH. 


We  can  follow  this  decomposition  by  determining  the  in- 
crease of  the  alkalinity  of  the  solution.  Thus,  for 
example,  in  one  experiment  43  per  cent  of  the  amount  of 
hyponitrous  acid  which  was  originally  present  in  the 
solution  in  the  state  of  an  acid  salt  was  decomposed 
after  eighteen  hours  at  the  ordinary  temperature. 

Reactions  of  Hyponitrous  ^ cid. —Contrary  to  the  asser- 
tion of  Van  der  Plaats,  solutions  of  hyponitrous  acid  do 
not  decompose  iodate  of  potassium,  liberating  iodine 
(Thum).  We  found  that  on  adding  to  a  freshly  prepared' 
solution  of  free  hyponitrous  acid  a  solution  of  potass  ic 


Cbbmical  News,  ] 
May  21, 1897.     I 


Experiments  with  Cathode  Rays, 


245 


iodide  and  starch,  slightly  acidulated  with  acetic  acid,  the 
blue  colour  does  not  appear  at  first,  but  after  the  lapse  of 
some  time  the  liquid  becomes  blue,  and  the  colour  con- 
tinues to  become  more  and  more  intense.  A  further 
remarkable  thing  is,  that  on  adding  hyponitrite  of  silver 
to  cold  concentrated  sulphuric  acid,  and  adding  a  little 
diphenylamine,  a  very  intense  blue  colouration  is  produced. 
With  a  solution  of  ferrous  sulphate  a  brown  ring  is  ob- 
tained. These  readtions  are  charaderistic  of  nitrous  and 
nitric  acids.  We  shall  refer  to  them  again  later  on,  when 
discussing  the  decomposition  of  hyponitrous  acid. 

Hyponitrite  of  Ammonia,  H4NOH,NHO.— This  salt 
was  hitherto  unknown.  Zorn  observed  that  the  solution 
obtained  by  the  reaction  of  hyponitrite  of  silver  on  a  solu- 
tion of  chloride  of  ammonium,  which  should  contain 
hyponitrite  of  ammonium,  decomposed  very  rapidly  at 
the  ordinary  temperature,  with  evolution  of  gas.  How- 
ever, it  is  possible  to  isolate  an  ammoniacal  salt  by 
passing  a  current  of  well-dried  ammonia  gas  through  an 
etheric  solution  of  hyponitrous  acid,  as  already  described. 
After  a  very  short  time  the  salt  is  precipitated  in  the  form 
of  a  white  mass.  It  is  filtered  rapidly,  washed  with  ether, 
and  dried  on  plates  of  porous  porcelain. 

Hyponitrite  of  ammonium  melts  about  64°  to  63°,  de- 
composing with  violence.  It  is  easily  soluble  in  water, 
giving  an  alkaline  readtion.  But  it  has  not  been  recovered 
either  from  its  aqueous  or  alcoholic  solutions,  even  when 
working  in  vacuo.  The  solutions  leave  no  residue  what- 
ever on  evaporation.  Jackson's  assertion  (Berichte,  vol. 
xxvii.,  R.,  p.  562)  that  hyponitrite  of  ammonium  could  be 
obtained  in  beautiful  crystals  by  the  readtion  of  hypo- 
nitrite of  silver  on  an  alcoholic  solution  of  sulphide  of 
ammonium  is  evidently  founded  on  an  error.  In  the 
solid  state  this  substance  decomposes  slowly  at  ordinary 
temperatures  into  ammonia,  water,  and  protoxide  of 
nitrogen,  and  therefore  cannot  be  brought  to  a  constant 
weight.  It  is  for  this  reason  that  exadt  analytical  results 
cannot  be  obtained.  The  ammonia  has  been  estimated 
by  decomposing  the  freshly-prepared  and  rapidly  weighed 
salt  (taking  no  note  of  the  loss  of  weight)  by  caustic 
potash,  absorbing  the  gas  in  a  normal  solution  of  sul- 
phuric acid,  and  titrating  the  excess  of  acid.  Three 
estimations  carried  out  on  three  portions  of  one  and  the 
same  sample  gave  the  following  results  : — 

Grm.  Per  cent. 

I.  0*0560  of  hyponitrite  of  ammonia  gave  20*34  ^^3. 

II.    0-0947  )>  "  >'  20-IO        „ 

III.  0-0631  „  „  ,,        1994     „ 


Theory  :— 

NH4HN2O2.. 
(NH^jaN^Oj.. 


25-52  per  cent 
35-42      >• 


We  did  not  continue  our  experiments  on  the  estima- 
tion of  the  protoxide  of  nitrogen  by  decomposing  the  salt 
in  the  eudiometer  with  concentrated  sulphuric  acid.  Our 
first  attempt  resulted  in  a  violent  explosion,  which  blew 
the  apparatus  all  to  pieces. 

The  spontaneous  decomposition  of  hyponitrite  of  am- 
monia was  studied  by  determining  the  loss  of  weight  that 
the  salt  sustained  when  left  in  the  exsiccator  in  vacuo. 
The  following  are  some  of  the  results  obtained : — 


Time. 
Honrs. 


87 
119 
167 


Weight. 
Grm. 

0-I057 
00214 
0-0169 
0-0136 


Loss  of  weight. 
Per  cent. 


7975 
84-0 

87-13 


This  decomposition  of  acid  hyponitrite  of  ammonia 
resembles  that  of  bicarbonate  of  ammonia,  only  the  latter 
is  more  stable.  We  have  not  succeeded  in  preparing  the 
neutral  hyponitrite  of  ammonia,  even  when  passing  a 
current  of  ammonia  through  hyponitrous  acid  for  a  con- 
siderable time.   Here,  again,  the  analogy  existing  between 


hyponitrous  acid  and  carbonic  acid  is  evident ;  for,  as  rs 

well  known,  the  neutral  carbonate  of  ammonia  is  rapidly 

transformed  into  acid  carbonate  when  exposed  to  the  air> 

(To  be  continued). 


SOME     EXPERIMENTS    WITH     CATHODE 
RAYS.' 
Br  A.  C.  C.  SWINTON. 
(Concluded  from  |p.  236). 

The  Convergent  Cone  at  Higher  Vacuo. 
As  has  been  mentioned,  the  carbon  anti-cathode  screen 
was  found  useless  for  investigating  the  convergent  cone 
o  'cathode  rays  at  anything  but  a  very  low  vacuum,  by 
the  reason  of  the  well-known  difficulty  in  getting  any 
discharge  to  pass  when  the  distance  between  the  eledtrodes 
is  less  than  the  thickness  of  the  dark  space,  and  for  the 
further  reason  that  if  the  anti-cathode  screen  was  not 
connedied  to  the  anode,  it  became  itself  negatively  charged 
and  adled  as  an  additional  cathode  when  brought  into  the 
space  between  the  cathode  and  the  focus. 


Under  these  circumstances  it  was  thought  that  possibly 
some  additional  information  might  be  obtained  with  regard 
to  the  form  of  the  convergent  cone  at  high  vacua,  by 
making  tlie  concave  cathode  itself  of  carbon.  A  tube  was 
therefore  construdled  having  a  concave  carbon  cathode, 
the  diameter  of  which  was  i  inch,  and  the  radius  of 
curvature  0-75  inch.  The  appearance  of  the  cathode  with 
this  tube  is  shown  for  a  fairly  high  vacuum  in  fig.  20,  in 
which  the  cathode  itself  is  shown  in  sedtion,  so  as  to  let 
the  form  of  the  discharge  be  better  seen.  As  will  be  ob- 
served under  this  condition  of  vacuum,  which  was  too 
high  to  show  any  divergent  cone,  the  cone  of  convergent 
rays  appears  to  be  contradled  in  diameter  at  its  base,  and 
to  come  off  from  the  central  portion  of  the  cathode  only, 
the  remaining  surface  of  the  cathode  being  apparently 
inadlive.  This  was  found  to  be  still  more  the  case  at 
higher  vacua,  as  will  be  seen  from  fig.  21,  which  shows  in 
a  similar  manner  the  form  of  the  cathode  discharge  in  a 
tube  exhausted  to  a  very  high  vacuum.  In  this  case,  as 
will  be  observed,  the  whole  of  the  cathode  rays  appear  to 
come  off  from  a  very  small  spot  in  the  centre  of  the 
cathode.  Further,  that  this  small  spot  is,  at  any  rate, 
the  source  of  most,  if  not  all,  adtivity,  was  evident  from 
the  faft  that  it  became  luminescent  exad^ly  in  the  same 
manner,  but  in  a  less  degree,  than  had  previously  been 


*  A  Paper  read  before  the  Royal  Society,  March  11,  1897. 


246 


Experitntnts  with  Cathode  Rays, 


(Chemical  News, 
\     May  21,  IC)97- 


observed  with  a  carbon  surface  upon  which  cathode  rays 
were  concentrated.  Whether  this  surface  luminescence 
of  the  cathode  carbon  at  the  point  where  the  cathode  rays 
leave  it  is  due  to  the  violent  tearing  away  of  particles  of 
carbon,  or  to  some  other  csnse,  it  is  difficult  to  say,  but 
the  fa<5t  that  at  high  vacua  the  cathode  rays  come  off 
entirely,  or  at  any  rate  almost  entirely,  from  only  a  very 
small  portion  of  the  centre  of  the  cathode,  explains  the 
observed  fadt  that  within  limits  large  cathodes  have  no 
advantage  over  small  cathodes  in  X-ray  tubes. 

During  the  carrying  out  of  the  above  experiments  with 
a  carbon  cathode,  very  bright  sparks  were  occasionally 
seen  coming  off  the  cathode  and  passing  through  the 
focus,  and  it  was  consequently  thought  that  possibly  by 
placing  two  concave  carbon  cathodes  facing  one  another, 
such  particles,  by  being  caused  to  rebound  backwards  and 


forwards  continuously  between  the  two,  might  render  the 
form  of  cathode  stream  visible  at  very  high  vacua  when 
the  stream  itself  becomes  otherwise  invisible. 

With  this  view  a  tube  was  made  as  shown  in  fig.  22,  in 
which  two  concave  carbon  cathodes,  c  c,  similar  to  those 
employed  in  the  last  experiment,  were  placed  exadly  op- 
posite one  another,  so  that  a  prolongation  of  the  focus  of 
either  one  would  pass  through  the  centre  of  the  other. 
The  anode,  D,  was  placed  in  an  annex,  as  shown  in  the 
illustration,  and  the  two  cathodes  were  connected  together 
by  means  of  a  wire  outside  the  tube.  At  a  very  high  ex- 
haustion this  tube  gave  very  beautiful  effeds,  and  showed 
clearly  the  form  of  the  cathode  discharge  at  a  degree  of 
exhaustion  when  it  is  usually  in  itself  quite  invisible. 
Immediately  on  the  current  being  turned  on  and  the  dis- 
charge passing,  a  straight  and  thin  stream  of  bright  golden 


Chemical  Mbws,  I 
May  21,  1897.     I 


London  Water  Supply, 


coloured  particles,  of  apparently  incandescent  carbon, 
passed  between  small  luminescent  spots  at  the  centres  of 
each  cathode,  as  shown  in  fig.  23.  This  did  not  last  for 
more  than  a  second,  when,  owing  no  doubt  to  the  rapid 
fall  of  vacuum,  the  appearance  changed  to  that  shown  in 
fig.  24,  and  the  incandescent  particles  of  carbon  could  be 
seen  passing  backwards  and  forwards  along  the  convergent 
and  divergent  cones  of  cathode  rays,  which,  at  the  lower 
vacuum,  proceeded  from  both  cathodes,  and  spluttering  in 
the  centre,  where  the  particles  going  in  opposite  directions 
collided.  This  appearance  lasted  for  some  seconds,  be- 
coming gradually  fainter  as  the  vacuum  fell.  By  re-ex- 
hausting the  tube  with  the  pump,  however,  the  original 
appearance  shown  in  fig.  23,  as  also  the  appearance  shown 
in  fig.  24,  could  be  produced  as  often  as  desired.  Appa- 
rently the  particles  of  carbon  become  heated  to  incan- 
descence either  by  the  adtion  of  the  cathode  rays  upon 
them  while  they  are  flying  through  space,  or  by  their 
fridion  in  passing  through  the  residual  gas,  and  possibly 
by  their  mutual  collisions,  for  in  the  stage  shown  in  fig. 
24,  when  the  cathodes  themselves  show  no  luminescence, 
the  dying  particles  appear  to  be  most  intensely  li^inescent 
when  in  the  centre  of  the  tube.  It  may  be  mentioned 
that  after  this  experiment  had  been  repeated  several 
times,  the  glass  of  the  tube  became  perceptibly  blackened, 
which,  taken  with  the  facSt  that  a  similar  tube  with  cathodes 
of  aluminium  showed  no  stream  of  bright  particles,  goes 
to  show  that  the  particles  consist  of  carbon  torn  off  the 
surfaces  of  the  cathodes. 

The  Production  0/ X-rays. 

The  tube,  fig.  22,  with  carbon  cathodes  was  found  to 
produce  feeble  X-rays,  which,  when  observed  with  a 
fluorescent  screen,  appeared  to  come  either  from  the 
-fluorescent  glass  of  the  bulb  or  from  the  travelling  parti- 
cles of  carbon. 

In  order  to  ascertain  whether  it  is  necessary  that  the 
cathode  rays  should  fall  on  solid  matter  in  order  to  pro- 
duce X-rays,  another  tube  was  construdled,  similar  in  all 
respeiSs  to  that  shown  in  fig.  22,  with  the  exception  that 
the  two  cathodes  were  made  of  aluminium. 

It  was  thought  that  with  this  tube  the  opposing  streams 
of  cathode  rays  might  possibly  produce  X-rays  at  the 
point  where  they  met.  This  does  not  however,  appear  to 
be  the  case,  as  though  this  tube,  when  exhausted  to  so 
high  an  extent  that  the  alternative  spark  in  air  leapt  fully 
8  inches,  gave  X-rays  in  considerable  quantity,  these  rays 
appeared  to  come  entirely  from  portions  of  the  glass  of 
the  tube  that  were  covered  with  green  fluorescence,  and 
not  at  any  rate  appreciably  from  the  central  point  between 
the  two  cathodes,  where  the  opposing  streams  of  cathode 
rays  would  meet  one  another. 

It  seems,  therefore,  that  X-rays  can  only  be  produced 
by  cathode  rays  when  these  strike  solid  matter. 

In  conclusion  I  wish  to  mention  how  much  I  owe  in 
carrying  out  these  experiments  to  the  assistance  of  Mr. 
J.  C.  M.  Stanton  and  Mr.  H.  Tyson  Wolff,  who  have 
made  and  exhausted  all  the  tubes,  and  to  whom  I  am  also 
indebted  for  many  valuable  suggestions. 


LONDON     WATER    SUPPLY. 
Report  on  the  Composition  and  Quality  of  Daily 
Samples   of  the  Water  Supplied  to   London 
FOR  the  Month  Ending  April  30TH,  1897. 

By  WILLIAM  CROOKES,  F.R.S., 

and 

PROFESSOR  DEWAR,  F.R.S. 

To  Major-General  A.  De  Courcy  Scott,  R.E., 
Water  Examiner,  Metropolis  Water  Act,  1871. 

London,  May  loth,  1897. 
Sir,— We    submit    herewith,    at    the    request    of   the 
Direaors,  the  results  of  our  analyses  of  the  168  samples 


247^ 

of  water  colledled  by  us  during  the  past  month,  at  the 
several  places  and  on  the  several  days  indicated,  from  the 
mains  of  the  London  Water  Companies  taking  their 
supply  from  the  Thames  and  Lea. 

In  Table  I.  we  have  recorded  the  analyses  in  detail  of 
samples,  one  taken  daily,  from  April  ist  to  April  30th 
inclusive.  The  purity  of  the  water,  in  respe(5l  to  organic 
matter,  has  been  determined  by  the  Oxygen  and  Com- 
bustion processes;  and  the  results  of  our  analyses  by 
these  methods  are  stated  in  Columns  XIV.  to  XVIII. 

We  have  recorded  in  Table  II.  the  tint  of  the  several 
samples  of  water,  as  determined  by  the  colour-meter 
described  in  a  previous  report. 

In  Table  III.  we  have  recorded  the  oxygen  required  to 
oxidise  the  organic  matter  in  all  the  samples  submitted 
to  analysis. 

Of  the  168  samples  examined  all  were  recorded  as  clear, 
bright,  and  well  Altered. 

The  rainfall  at  Oxford  during  the  month  was  1*95 
inches;  the  average  for  30  years  is  i'66  inches,  making 
an  excess  of  0*29  inch  ;  0*54  inch  fell  on  the  21st,  the  rest 
was  fairly  evenly  distributed  throughout  the  month.  We 
have  now  had  a  total  excess  of  2'02  inches  this  year  on  an 
adual  fall  of  8*82  inches,  or  nearly  25  per  cent. 

Our  badteriological  examinations  of  234  samples  give 
the  following  results: — 

Microbes 
per  c.c. 
Thames  water,  unfiltered  (mean  of  24  samples)     3277 
Thames  water,  from  the  clear  water  wells  of 
five  Thames-derived  supplies  (mean  of  118 

samples) 38 

Ditto        ditto  highest      335 

Ditto         ditto  lowest  i 

New  River,  unfiltered  (mean  of  23  samples)  ..       892 
New  River,  filtered  (mean  of  23  samples)       . .         13 
River  Lea,  unfiltered  (mean  of  23  samples)    ..       708 
River  Lea,  from   the  clear  water  well   of  the 
East  London  Water  Company  (mean  of  23 
samples)     ..      27 

These  figures  give  a  sufficient  proof  of  the  efficiency  of 
the  filtering  beds  and  the  excellent  quality  of  the  water 
supplied  to  the  Metropolis. 

We  are,  Sir, 

Your  obedient  Servants, 

William  Crookes. 
James  Dewar. 


THE  QUANTITATIVE  AND  QUALITATIVE 

SEPARATION    OF    BARIUM,    STRONTIUM,    AND 

CALCIUM.* 

By    S.    G.    RAWSON,    D.Sc,   F.I.C., 
LsAurer  in  Chemistry,  Technical  College,  Huddersfield. 

In  the  quantitative  or  qualitative  separation  of  barium, 
strontium,  and  calcium,  there  has  been  always  a  consider- 
able amount  of  difficulty  due  to  the  remarkable  properties 
of  strontium  which  in  so  many  respeiSs  lie  almost  midway 
between  those  of  barium  and  of  calcium.  Hence  though 
the  estimation  of  both  barium  and  calcium  when  present 
together,  or  of  strontium  when  alone,  presents  but  little 
trouble,  yet  if  the  whole  three  members  of  the  group  be 
taken  the  task  becomes  one  of  greatly-increased  difficulty, 
it  being  no  easy  matter  to  ensure  either  the  complete 
precipitation  or  the  entire  retention  in  solution,  according 
to  the  process  to  be  employed,  of  the  strontium.  To  attain 
one  or  other  of  these  ends  many  methods  have  been  pro- 
posed ;  among  these  I  may  mention  the  following : — 
FreseniuB  recommends  in  his  work  the  precipitation  of  the 


*  A  Paper  read  before  the  Society  of  Chemical  Industry  (Yorkshire 
SeAion),  January  25th,  1897.  From  the  Journal  0/  the  Society  of 
Chemical  Industry,  vol.  xvi..  Mo,  2. 


248 


Separation  of  Barium,  Strontium^  and  Calcium, 


(  Chemical  Nbws, 

I      May  21,  1897. 


barium  as  silicoiluoride  and  the  subsequent  separation  of 
the  strontium  and  calcium  by  means  of  prolonged  boiling 
with  an  enormous  excess  of  ammonium  sulphate.  The 
particulars  of  the  remaining  processes  are  taken  from  the 
yournal  of  the  Society  of  Chemical  Industry.  Fresenius 
and  Ruppert  (1892,  p.  776)  have  investigated  the  relative 
solubilities  of  strontium  and  calcium  chromates  in  dilute 
alcohol ;  though  of  value  qualitatively  they  consider  that 
quantitatively  the  method  is  lacking  in  accuracy. 
McElroy  and  Biglow  (1893,  p.  181)  suggest  the  use  of 
aqueous  acetone  upon  these  same  salts,  but  seemingly 
only  for  qualitative  purposes.  In  this  year  also  (1893, 
p.  627)  Fresenius  recommends  the  separation  of  calcium 
as  nitrate  from  the  other  nitrates  by  its  solubility  in 
ether-alcohol,  the  results  he  gives  being  very  accurate. 
Browning  {1894,  ?•  282)  carefully  examined  the  solubility 
of  strontium  nitrate  in  boiling  amyl  alcohol,  in  which  the 
salt  is  almost  insoluble;  the  corresponding  calcium 
nitrate  dissolves  readily,  but  to  effedt  a  complete  separa- 
tion a  second  treatment  is  necessary,  Dupasquier  (1895, 
p.  822)  points  out  that  calcium  is  converted  into  a  tartrate 
by  boiling  in  a  liquid  containing  a  soluble  tartrate  and 
sulphate,  while  barium  and  strontium  remain  as  sulphates. 
These  are  estimated  indiredlly  for  quantitative  purposes. 
Baubigny  (1895,  P-  ^0^5)  separates  the  strontium  as  sul- 
phate in  the  presence  of  potassium  sulphate,  but  the  pre- 
cipitation is  not  complete. 

This  bibliography,  though  not  complete,  includes  the 
most  important  of  the  plans  suggested.  It  will  be  noticed 
that  in  almost  all  of  them  there  arises  the  dii^culty  of  the 
slight  solubility  of  the  strontium  salts  in  the  solvents 
necessarily  employed.  Further,  it  rarely  happens  that 
the  same  method  can  be  used  both  quantitatively  and  quali- 
tatively. But  the  special  objecf^ions  to  these  methods  are 
due  to  the  fadt  that  either  out-of-the-way  reagents  are 
employed,  or  that  much  and  prolonged  boiling  is  neces- 
sary to  convert  the  given  salts  into  the  required  modifica- 
tions. Both  these  are  hindrances  in  the  way  of  quantita- 
tive analysis,  and  are  most  serious  detriments  to  qualita- 
tive work. 

The  principle  of  the  separation  upon  which  I  have 
worked  depends  entirely  upon  the  behaviourof  the  nitrates 
of  these  three  metals  towards  concentrated  nitric  acid. 
The  method  is  also  readily  applicable  to  qualitative 
analysis  ;  the  nitrates  of  barium  and  of  strontium  are  quite 
insoluble  in  this  acid,  whilst  calcium  nitrate  dissolves  very 
rapidly.  That  barium  nitrate  is  insoluble  appears  to  be 
accepted,  but  there  is  considerable  divergence  of  opinion  as 
regards  the  strontium  salt ;  thus,  Wurtz  {Am.y.  Sci.,  [2], 
XXV.,  377)  states  that  it  is  sparingly  soluble  in  concentrated 
nitric  acid,  whilst  Schultz  (Zeit.  Ch.,  [2],  v., 537)  considers 
it  to  be  insoluble.  The  experiments  by  which  I  sought  to 
settle  this  initial  contradidlion  were  as  follows: — The  nitric 
acid  used,  and  which  was  bought  as  pure,  was  re-distilled, 
the  water  also  being  similarly  treated.  In  the  case  of  both 
the  nitric  acid  and  of  the  water,  portions  upon  evaporation 
either  left  no  residue  or  one  which  it  was  not  possible  to 
weigh.  The  carbonate  was  obtained,  at  different  times, 
from  Germany,  and  as  being  perfedlly  pure.  I  may  here 
mention  that  it  is  most  difficult  to  procure  pure  strontium 
carbonate.  All  the  material  which  I  obtained  invariably 
contained  traces  of  calcium  in  amounts  varying  from  0*25 
per  cent  to  even  2  per  cent.  The  presence  of  this 
impurity  caused  me  great  inconvenience,  and  at  first 
much  loss  of  time.  In  order  to  purify  the  carbonate  a 
considerable  quantity  was  converted  into  nitrate  and 
thoroughly  stirred  with  nitric  acid,  filtered,  and  the 
residue  dissolved  in  water  and  precipitated  as  carbonate, 
washed,  and  dried.  In  the  spedroscope  no  trace  of  the 
calcium  lines  were  now  visible.  So  satisfadory  and  rapid 
is  this  method  that  I  would  recommend  it  strongly  as 
being  the  most  easy  and  the  most  safe  for  the  purification 
of  strontium  from  calcium  salts.  I  may  here  mention 
that  throughout  my  experiments  I  always  used  the  car- 
bonates of  the  metals  partly  because  of  the  much  greater 
convenience  and  certainty  in  weighing,  and  also  because 


the  carbonates  are  far  more  likely  to  be  required  for  esti- 
mation under  usual  conditions  than  the  nitrates,  and 
therefore  it  seemed  advisable  to  work  upon  the  more  com- 
monly occurring  body. 

The  pure  carbonate  was  treated  with  dilute  nitric  acid 
and  evaporated  to  dryness  upon  the  water-bath.  Pure 
concentrated  nitric  acid  (sp.  gr.  i'445)  ^^^  ^^^1^  added  and 
the  mixture  kept  well  stirred  for  many  hours,  in  some 
cases  three  days.  The  solution  was  then  filtered  through 
filter-paper  or  glass-wool,  and  the  filtrate  evaporated  to 
dryness,  taken  up  with  a  little  hydrochloric  acid,  and  again 
evaporated.  The  residue  gave,  in  the  spedlroscope,  no 
trace  of  the  strontium  lines,  but  consisted  of  small  traces 
of  sodium  and  iron  sulphates  derived  from  the  acids 
employed,  and  of  celluloid  matter  arising  from  the  filter- 
paper,  when  used.  Similar  experiments  were  repeated 
many  times,  varying  the  amounts  of  carbonate  and  of  nitric 
acid,  but  onlyuponone  occasion,  in  one  of  my  earlier  experi- 
ments, did  I  distinguish  the  strontium  lines.  I  had  treated 
some  3  grms.  of  the  carbonate  with  nitric  acid,  and 
upon  filtering  and  evaporating  to  dryness  the  residue 
clearly  contained  strontium.  This  was  due  to  the  solution 
of  traces  of  the  nitrate,  the  nitric  acid  having  become  diluted 
by  the  considerable  amount  of  water  formed  in  the  conver- 
sion of  the  carbonate  into  nitrate.  On  all  subsequent 
occasions  I  invariably  evaporated  the  nitrate  to  dryness 
upon  the  water-bath,  and  then  took  up  with  fresh  nitric 
acid.  Under  these  conditions  the  readtion  was  only  as 
between  the  nitrate  and  nitric  acid,  and  the  strontium 
lines  did  not  again  become  visible  in  the  filtrate.  Hence 
strontium  nitrate  is  insoluble  in  concentrated  nitric  acid. 
Diredl  experiments  upon  barium  nitrate  showed  this  salt 
to  be  also  insoluble,  whilst  calcium  nitrate  readily  dis- 
solved. As  regards  the  nitric  acid,  I  prefer  the  specific 
gravity  to  be  about  1*46  (corresponding  to  80  per  cent  of 
the  acid)  or  even  higher,  but  for  most  purposes  the 
ordinary  acid  of  specific  gravity  1*42  (containing  70  per 
cent  of  HNO3)  will  suffice. 

The  adtual  quantitative  estimation  of  these  elements 
carry  out  in  the  following  manner: — The  carbonates  are 
evaporated  with  nitric  acid,  either  in  a  beaker  or  in  a, 
porcelain  dish,  preferably  the  latter,  upon  the  water-bath 
until  the  mass  is  quite  dry.  Concentrated  nitric  acid  is 
added  in  excess,  and  the  mixture  kept  well  stirred.  The 
crystals  settle  out  after  each  stirring  very  rapidly,  and  the 
clear  supernatant  liquid  is  poured  through  a  double  filter- 
paper  which  has  been  moistened  previously  with  concen- 
trated nitric  acid.  The  residue  may  be  washed  either  with 
the  concentrated  acid  by  decantation,  a  method  to  which 
the  mass  from  its  crystalline  nature  readily  lends  itself,  or 
in  the  customary  way  upon  the  paper. 

The  filtrate  is  evaporated  either  to  dryness,  taken  up 
with  hydrochloric  acid,  and  the  calcium  precipitated  as 
oxalate,  or  evaporated  down  with  sulphuric  acid,  and  the 
residue  after  ignition  weighed  as  sulphate. 

The  remaining  nitrates  are  dissolved  in  water,  and  the 
solution  made  alkaline  with  ammonium  hydrate,  acidified 
with  acetic  acid,  and  the  barium  precipitated  as  chromate. 
The  filtrate  is  warmed  with  hydrochloric  acid  and  alcohol 
until  the  chromate  is  reduced,  the  chromium  precipitated 
as  hydrate  and  filtered  off.  The  filtrate  is  evaporated  to 
dryness  upon  the  water-bath  with  a  little  sulphuric  acid. 
The  residue  is  treated  with  dilute  alcohol  and  washed, 
and  the  residual  strontium  sulphate  weighed  as  such.  Two 
out  of  the  different  test  analyses  which  I  have  made  give 
the  following  results: — 


Barium  carbonate  . , 
Strontium  carbonate 
Calcium  carbonate.. 


Taken. 

0'2I27 

o"4583 
0-2773 


Found. 


0'2I30 
0-4576 
o"278a 


Taken.      Found. 

0-5393  0-5379 
0-2578  0-2584 
o*5473     0-5470 

For  the  qualitative  separation  the  above  process  may  be 
much  simplified.  The  carbonates,  after  treating  with  the 
minimum  amount  of  nitric  acid,  are  boiled  down  just  to 
dryness ;  then  treated  with  concentrated  nitric  acid,  the 


wRBHICAL  NBWSi  I 

May  21.  1897.      • 


Formation  of  Mercury  Films  by  an  Electrical  Process. 


249 


paper  having  been  first  moistened  with  this  acid,  filtered, 
and  the  residue  washed  by  decantation.  The  filtrate  is 
diluted  considerably  with  water  made  alkaline  with  am- 
monia, and  the  lime  thrown  down  as  oxalate.  The 
residue  is  dissolved  in  water  (the  filter-paper  will  not 
disintegrate  unless  boiling  cold  water  be  used),  made 
alkaline  with  ammonia,  acidulated  with  acetic  acid,  and 
the  barium  precipitated  as  chromate.  To  the  filtrate  is 
added  hydrochloric  acid,  and  it  is  boiled  with  a  little 
alcohol,  and  the  chromium  precipitated  as  hydrate,  which 
is  filtered  off.  To  the  filtrate  sulphuric  acid  is  added,  and 
the  solution  heated ;  if  necessary  alcohol  is  added,  the 
strontium  coming  down  as  sulphate.  The  separation  of 
the  chromium  as  hydrate  is  not  in  all  cases  necessary. 

The  process  can  be  carried  out  very  rapidly,  and, 
further,  is  a  complete  separation  of  these  three  metals, 
and  does  not  rest  upon  grounds  such  as  the  length  of  time 
allowed  for  boiling  or  standing,  or  the  greater  or  lesser 
concentration  of  solutions. 


PROCEEDINGS    OF    SOCIETIES. 

PHYSICAL     SOCIETY. 
Ordinary  Meeting,  May  i^th,  1897. 

Mr.  Shelford  Bidwell,  President,  in  the  Chair. 

Mr.  W.  Watson  described  '^  Att  Instrument  for  com- 
paring Thermometers  with  a  Standard." 

The  thermometers  to  be  compared  are  inserted  together 
in  an  enclosed  vapour-tube,  the  temperature  of  which  can 
be  maintained  very  constant  at  different  parts  of  the 
scale.  The  apparatus  is  an  adaptation  of  the  arrange- 
ment devised  by  Ramsay  and  Young  for  vapour  densities. 
It  consists  of  a  wide  vertical  glass  tube,  with  a  narrower 
tube  attached  at  the  top.  The  narrow  tube  bends  down- 
wards and  communicates  with  a  closed  vessel  of  consider- 
able volume.  A  portion  of  the  vertical  tube  is  surrounded 
by  a  condensing-jacket,  and  a  manometer  tube  is  inserted 
near  the  top.  The  objedt  of  the  large  vessel  is  to  diminish 
errors  arising  from  fortuitous  changes  of  pressure 
resulting  from  small  leakages  or  "bumping"  of  the 
boiling  liquid.  Eledtrical  heating  of  the  bulb  containing 
the  liquid  effedually  removes  the  "  bumping."  The  fol- 
lowing liquids,  used  consecutively,  give  a  range  of  tem- 
perature from  20°  C.  to  120''  C.  :  carbon  bisulphide 
(20°— 46'),  ethyl  alcohol  (80"),  chlorobenzine  (120°).  The 
apparatus,  when  once  started,  requires  very  little  atten- 
tion ;  from  results  submitted  by  the  author,  the  variations 
do  not  exceed  0-02°  C.  per  hour.  In  construdting  the 
various  parts,  the  difficulties  of  glass-blowing  are  reduced 
by  making  the  joints  of  indiarubber  stoppers,  attached  to 
the  glass  with  indiarubber  solution.  Each  joint  is 
jacketted  with  glycerin.  If  the  above  liquids  are  used  in 
the  vaporiser,  the  scales  of  the  thermometers  can  always 
be  read  within  the  tube  ;  it  is  only  with  water  that  the 
condensed  vapour  gives  trouble. 

Prof.  Ayrton  thought  the  apparatus  would  come  into 
extensive  use  ;  it  did  away  with  errors  arising  from  differ- 
ences of  length  of  thermometer  stems,  it  left  no  question 
as  to  the  equality  of  temperature  of  the  two  bulbs,  and 
there  was  no  probability  of  error  due  to  a  difference  of 
thermal  "  lag  "  in  any  two  thermometers. 

Mr.  Watson,  in  replying  to  a  question  of  Prof.  Perry's, 
said  the  iadl  of  using  indiarubber  joints  limited  the  avail- 
able range  of  temperature.  Working  with  blown  joints, 
Ramsay  and  Young  had  found  no  difficulty  in  their  vapour- 
density  experiments  at  higher  temperatures. 

Prof.  Carey  Foster  read  a  paper  by  Mr,  D.  K.  Morris, 
of  Zvirich,  on  "  The  Effect  of  Temperature  upon  the 
Magnetic  and  Electric  Properties  of  Iron." 

The  investigation  relates  to  the  measurement  of  the 


magnetic  permeability,  hysteresis,  and  eledtrical  resist- 
ance of  iron  simultaneously  at  different  temperatures. 
The  specimens  are  formed  into  annular  rings  made  from 
iron  strip.  The  strip  is  first  lapped  round  with  asbestos- 
paper  and  mica,  and  then  wound  upon  itself  to  the 
requisite  thickness.  A  platinum  wire  is  included  in  the 
mica  lappings,  for  thermometrical  purposes.  Upon  each 
annular  ring  are  the  following  windings  : — (i)  A  primary 
magnetising  coil.  (2)  A  secondary  coil  connefted  to  a 
ballistic  galvanometer.  {3)  An  eledrical  heating  coil. 
Further,  the  iron  strip  is  itself  connected  to  a  Wheat- 
stone's  bridge,  for  resistance  measurements.  The  coil 
can  be  heated  to  1050°  C.  At  the  higher  temperatures, 
the  surrounding  air  has  to  be  freed  from  oxygen;  this  is 
done  by  enclosing  the  coil  in  a  suitable  vessel  and  ex- 
hausting with  an  air-pump.  When  most  of  the  air  has 
thus  been  removed,  the  residual  oxygen  is  absorbed  by  an 
electrically  heated  iron  wire.  Curves  are  drawn  repre- 
senting the  changes  of  permeability  at  the  different  tem- 
peratures, and,  at  the  same  temperature,  the  corre- 
sponding hysteresis  loops  are  plotted.  The  hysteresis 
diminishes  with  temperature  ;  it  nearly  vanishes  at  about 
764°  C. 

At  the  suggestion  of  Prof.  Ayrton,  it  was  agreed  that 
the  discussion  on  this  paper  should  be  adjourned  until  the 
publication  of  the  results.  The  paper  will  therefore  be 
printed  without  delay. 

Mr.  RoLLO  Appleyard  read  a  paper  on  *'  The  Forma- 
tion of  Mercury  Films  by  an  Electrical  Process.^' 

If  a  sheet  of  damp  leather,  or  similar  permeable  sub- 
stance, is  used  as  a  separating  diaphragm  between  two 
bodies  of  mercury,  and  a  current  is  sent  through  it,  a 
film  of  mercury  is  deposited  upon  the  surface  connected 
to  the  positive  pole  ;  and  the  film  remains  on  the  dia- 
phragm after  removal  from  the  apparatus.  If  the  dia- 
phragm is  replaced  in  the  apparatus  and  subjedted  to  a 
current  in  the  reverse  direction,  the  film  vanishes  from 
that  surface,  and  a  second  film  appears  on  the  other  side  ; 
that  is  to  say,  the  film  is  always  on  the  side  of  the 
diaphragm  conneded  to  the  positive  pole  of  the  battery, 
and  there  is  no  film  on  the  negative  surface.  Different 
diaphragms  and  films  were  exhibited — of  filter-paper, 
asbestos-paper,  plaster  of  Paris,  &c.  A  current  of  about 
one-fiftieth  of  an  ampere,  or  more,  is  necessary.  A  sheet 
of  tin-foil,  included  between  folds  of  filter-paper,  becomes 
perforated  with  pin-holes  when  the  current  is  passed  be- 
tween the  outside  surfaces.  This  happens  whether  the 
outside  eledtrodes  are  mercury  or  metal  plates.  If  the 
top  eledtrode  should  be  tin-foil,  this  also  becomes  per- 
forated as  well  as  the  included  sheet.  A  further  experi- 
ment was  shown,  in  which  a  gold  coin  is  placed  upon 
the  folds  of  filter-paper;  the  current  produces  a  gold  dis- 
colouration which  penetrates  the  folds.  This,  it  was 
suggested  by  the  author,  may  help  to  account  for  the 
formation  of  metallic  lodes  and  veins  as  they  exist  in 
rocks;  and  they  may  partly  explain  the  "  indudtoscripts  " 
of  Mr.  F.  J.  Smith. 

Dr.  S.  P.  Thompson  said  he  did  not  know  of  any  other 
examples  of  an  anode  being  more  adtive — mechanically — 
than  the  kathode,  except  the  eledlric  arc.  He  was  sur- 
prised that  the  film  should  appear  on  the  positive  surface. 

Mr.  Shelford  Bidwell  thought  selenium  presented, 
in  some  of  its  adlions,  an  example  of  the  anode  being  thus 
adlive. 

Prof.  Ayrton  said  that  if  a  vessel  containing  a  sub- 
stratum of  mercury  amalgam  was  filled  up  with  water  in 
which  gold  crushings  were  washed,  the  gold  descended 
into  the  amalgam.  This,  however,  might  be  partly  due 
to  gravity,  and  partly  to  simple  eledlrolysis. 

Mr.  Appleyard  said  he  had  no  definite  views  as  to  the 
formation  of  the  films.  He  believed  it  to  be  a  secondary 
eftedl  of  eledlrolysis.  aided  by  eledlric  osmosis.  The  ex- 
periments of  Mr.  C.  K.  Falkenstein  upon  the  eledric 
tanning  of  leather,  and  the  early  results  of  M.  Perret, 
helped  the  idea  of  eledlric  osmosis;  they  were  not  suffi- 


2dO 


The  Electric  Furnace. 


f  Cbruical  Mbws, 
1     May  21, 1897. 


theory  without   further 
analysis  of  the  deposits 


•cient,  however,   to  justify   that 
research.     A  careful   chemical 
left  in  the  folds  of  filter-paper  would  be  the  best  guide. 

The   President   proposed  votes   of    thanks    to    the 
authors,  and  the  meeting  was  adjourned  until  May  28th. 


THE     ROYAL     SOCIETY. 

A  Conversazione  was  held  at  the  Royal  Society's  Rooms 
at  Burlington  House,  on  Wednesday,  the  19th  of  May. 
The  guests  and  Fellows  were  received  by  the  President, 
XfOrd  Lister. 

Among  the  exhibits  were  some  interesting  colour- 
photographs,  produced  by  the  Danzac-Chassagne  process, 
the  details  of  which  are  not  known,  but  the  prints  (silver) 
are  believed  to  be  treated  with  a  solution  containing 
.albumen  and  certain  metallic  chlorides,  and  afterwards 
with  colouring  materials— blue,  green,  and  red, 

Mr.  Campbell  Swinton  showed  a  good  colledlion  of  the 
various  latest  forms  of  X-ray  tubes. 

In  the  principal  Library,  Prof.  Roberts-Austen  showed 
his  apparatus  for  micro-photography,  and  some  slides 
showing  the  mode  of  existence  of  carbon  in  steel ;  also  a 
diamond  made  by  himself,  by  M.  Moissan's  method— the 
magnifications  vary  from  500  to  1000  diameters. 

Messrs.  C.  T.  Heycock  and  F.  H.  Neville  had  a  curious 
alloy  of  silver  and  einc,  which  would  have  warmed  the 
hearts  of  the  old-time  alchemists.  At  the  ordinary  tem- 
perature it  is  the  colour  of  silver,  but  when  warmed  up  to 
.300°  C.  and  suddenly  cooled  it  becomes  copper-coloured 
or  bright  red,  and  remains  so  ;  if  again  heated,  and  cooled 
slowly,  it  resumes  its  original  colour.  This  is  not  an 
effedl  of  oxidation,  as  the  phenomenon  occurs  equally 
well  in  hydrogen  gas  or  in  vacuo. 

Prof.  Oliver  Lodge  exhibited  an  apparatus,  demon- 
strating Zeeman's  discovery  of  the  broadening  of  spedrum 
lines  by  the  a«aion  of  a  magnetic  field  on  the  source  of 
light.  By  reason  of  reversals,  the  usual  appearance  of 
each  sodium  line  is  as  if  it  were  double;  the  magnetic 
field  makes  it  appear  triple,  or  even  quadruple. 

Perhaps  one  of  the  prettiest  exhibits  is  Prof.  Silvanus 
Thompson's  model  of  a  Hertz  wave  transmission,  showing 
the  manner  in  which  a  wave  can  be  transmitted  to  and 
received  by  a  resonator  in  tune  with  the  oscillator. 

At  10  p.m.  Prof.  Ayrton  gave  a  demonstration  with 
experiments  and  lantern  slides,  on  "  Some  Elearic  and 
Mechanical  Analogues";  and  at  11  p.m.  Prof.  Farmer 
showed  some  slides  from  micro-photographs  illustrating 
nuclear  division  in  animal  and  vegetable  cells. 


NOTICES  OF  BOOKS. 


The  Electric  Furnace.  ("  Le  Four  Eledtrique ").  By 
Henri  Moissan,  Membre  de  I'lnstitut.  Paris :  G. 
Steinheil.     1897.     Pp-  376. 

(Concluding  Notice). 
The  preparation  of  simple  bodies  by  means  of  the  Eledtric 
Furnace  forms,  as  we  mentioned  previously,  the  subjedl- 
matterof  Chapter  HL  The  high  temperature  now  reached 
renders  possible  many  chemical  changes  which  have 
hitherto  been  unattainable.  We  know,  for  instance,  the 
laws  of  decomposition  by  heat,  of  carbonate  of  lime ;  but 
until  now  carbonate  of  barium  has  been  considered  to  be 
undecomposable,  simply  on  account  of  the  limited  means 
at  our  disposal.  It  is  now  shown  that  carbonate  of 
barium,  like  chalk,  loses  its  carbonic  acid  at  a  very  high 
temperature,  and  is  converted  into  caustic  baryta.  Fur- 
ther, certain  oxides— such  as  silica,  the  alkaline  earths, 
oxides  of  uranium,  vanadium,  and  zirconium — have  now 


been  diredlly  reduced  by  carbon,  yielding  the  pure  metals 
themselves,  or  metallic  carbides. 

Some  of  these  highly  refraftory  substances,  though 
reducible  to  the  metallic  state,  have  not  yet  been  produced 
in  the  form  of  ingots,  but  persist  in  remaining  in  a  pow- 
dery state,  a  phenomenon  analogous  to  very  finely-divided 
mercury.  Calcium,  strontium,  and  barium  are  among 
these;  on  the  other  hand,  chromium,  molybdenum,  tita- 
nium, uranium,  &c.,  can  be  produced  in  ingot  form  without 
much  difficulty.  For  the  purpose  of  his  research  on 
chromium,  M.  Moissan  prepared  40  kilogrms.  of  the 
metal. 

The  details  of  the  manufadure,  the  precautions  taken 
in  so  doing,  and  the  analyses  of  the  samples  of  ten  of 
these  rare  and  interesting  metals  are  then  given. 

The  general  method  of  procedure  will  be  by  now  easily 
understood  ;  but  the  various  and  minute  details,  to  be 
followed  in  the  handling  of  such  large  currents,  and 
enormous  temperatures,  in  the  produdlion  of  these  che- 
mically speaking  simple  bodies,  afford  many  pages  of  most 
interesting  matter. 

Alumina  has  always  been  regarded  as  irreducible  ;  but 
if  a  perfedly  transparent  crystal  of  corundum  be  placed 
in  a  carbon  crucible,  in  a  carbon  tube,  and  exposed  to  the 
heating  effect  of  a  current  of  1200  amperes  and  80  volts, 
it  is  volatilised  in  a  few  minutes.  The  crubible,  com- 
pletely converted  into  graphite,  does  not  contain  a  trace 
of  ash,  but  the  surface  of  the  tube  on  either  side  is 
covered  with  a  deposit  of  crystals  of  graphite  and  metal- 
lic aluminium  in  spheres  up  to  2  or  3  m.m.  in  diameter. 
The  author  has  made  extensive  experiments  on  the  various 
impurities  in  commercial  aluminium,  experiments  of  con- 
siderable importance  to  the  manufadurers  of  this 
metal :  different  samples  of  aluminium,  made  by  different 
processes,  vary  considerably,  not  only  in  chemical  compo- 
sition but  also  in  mechanical  utility,  small  quantities  of 
impurities  having — as  is  well  known  to  metallurgists-^an 
enormous  influence  on  the  physical  properties  of  many 
metals.  Comparative  tests  were  made  with  several  ingots 
of  aluminium,  some  containing  a  small  proportion  of 
carbon  (different  analyses  have  given  0*104,  o*ro8,  and 
o'o8o  per  cent  of  carbon),  and  the  other  containing  no 
carbon.  The  effed  of  this  minute  amount  of  impurity 
was  very  striking;  the  breaking  strain  of  pure  aluminium 
was  ii'i  kilos,  per  square  m.m.  and  the  elongation  9  per 
cent,  while  the  other  samples  containing  carbon  had 
breaking  strains  of  only  65  to  8*6  kilos,  per  square  m.m. 
and  elongations  of  from  3  to  5  per  cent. 

Chapter  IV.  deals  with  the  large  class  of  new  com- 
pounds known  as  carbides,  borides,  and  silicides.  It 
would  not  be  corred  to  say  that  metallic  carbides  were 
unknown  before  the  invention  of  M.  Moissan's  furnace. 
It  was  known  that  certain  metals  would  dissolve  carbon 
in  variable  proportions,  generally  when  the  metal  was  in 
large  excess  ;  but  the  dired  preparation  of  crystallised 
carbides  was  impossible  with  the  furnaces  then  in  use. 
The  researches  of  M.  Moissan  have  enabled  him  to 
classify  the  different  simple  bodies;  the  carbides,  in  fad, 
from  being  looked  upon  as  ill-defined  compounds,  are  now 
shown  to  possess  new  properties,  so  well  defined  that 
they  serve  as  a  good  basis  for  the  classification  of 
the  elements  into  natural  groups.  The  property  of  de- 
composing cold  water  and  furnishing  absolutely  pure 
acetylene  gas  is  charaderistic  of  the  carbides  of  lime, 
barium,  and  strontium,  while  the  carbides  of  aluminium 
and  glucinum — under  similar  conditions — will  produce 
pure  methane ;  these  are  two  distind  and  new  readions 
of  great  importance. 

We  will  not,  however,  dwell  longer  on  this  subjed — it 
has  previously  been  published  at  some  length  in  these 
columns,  but  will  close  this  notice  by  expressing  our 
admiration  for  the  excellent  work  done  and  the  great 
amount  of  time  and  labour  M.  Moissan  has  devoted  to 
his  research. 


Chemical  News,  i 
May  21, 1897.     ) 


Chemical  Notices  Jrom  Foreign  Sources. 


251 


CHEMICAL    NOTICES    FROM    FOREIGN 
SOURCES. 

Note.— All  degree!  of  temperature  are  Centigrade  uoless  otherwise 
expressed. 

Bulletin  de  la  Sociite  (T Encouragement  pour  r Industrie 
Nationale.     Series  5,  Vol.  ii.,  No.  4. 

Analysis  of  the  Fourth  Report  of  "  The  Research 
Committee  on  Alloys"  of  the  Institution  of  Mechan- 
ical Engineers  of  London. — This  is  a  long  and  inter- 
esting review  of  Prof.  Roberts- /Vusten's  report  to  the 
Institution  of  Mechanical  Engineers  and  Engineering  on 
February  12,  1897,  but  it  is  not  suitable  for  abstradlion. 


'.Rtvue  Qenerale  des  Sciences  Puns  et  Appliques. 
Nos.  7  and  8. 

Neither  of  these  numbers  contain  any  original  matter 
of  chemical  interest. 


BulUtin  des  Travaux  de  la  Societe  de  Pharmacie  de 
Bordeaux.    April,  1897. 

Detedtion  of  Oil  of  Arachis  in  Olive  Oil.— Prof.  Ch. 
Blarez. — The  detection  of  oil  of  sesame,  cotton-seed  oil, 
&c.,  in  olive  oil  is  not  a  matter  of  any  great  difficulty,  but 
the  problem  of  detedling  the  presence  of  oil  of  arachis  is 
always  a  matter  of  delicacy.  The  author  considers  that 
M.  Renard's  method  of  detedting  this  adulterant  has  the 
fault  of  being  too  long  and  requiring  great  experience  on 
the  part  of  the  person  using  it,  and  he  proposes  a  new  and 
much  quicker  method,  based  on  the  property  its  potash 
soaps  possess,  of  being  almost  insoluble  in  strong,  cold 
alcohol,  in  presence  of  a  notable  excess  of  potash.  The 
originality  claimed  consists  in  the  special  procedure  fol- 
lowed and  the  use  of  very  simple  apparatus,  and  may  be 
briefly  described  as  follows : — i.  Pour  i  c.c.  of  the  oil 
under  examination  into  a  test-tube  15  cm.  long.  2.  Add 
15  c.c.  of  pure  go*  alcohol  containing  4  or  5  per  cent  of 
pure  potash.  3.  Fit  the  tube  with  a  vertical  condenser. 
4.  Heat  the  tube  carefully  for  about  twenty  minutes  ;  the 
oil  will  rapidly  saponify  and  disappear,  the  alcohol  re- 
turning into  the  tube.  5.  Remove  the  condenser,  cork 
the  tube  and  put  it  in  a  cool  place.  In  the  case  of  pure 
oil  of  arachis  the  contents  of  the  tube  became  solid  after 
the  lapse  of  twenty-four  hours.  With  pure  olive  oil  there 
is  no  sign  of  solidification  after  the  lapse  of  twenty-four, 
forty-eight,  or  even  seventy-two  hours ;  but  with  a  mix- 
ture of  the  two  there  is  always  a  flocculent  precipitate,  in 
which  can  be  distinguished  crystals  of  arachidate  of 
potash. 


MISCELLANEOUS. 


Royal  Institution.— The  Friday  Evening  Discourse 
at  the  Royal  Institution  next  week  (May  28th)  will  be 
delivered  by  Prof.  H.  Moissan  (Diredteur  Laboratoire  de 
Chimie  Minerale  a  I'Ecole  Superieure  de  Pharmacie, 
Membre  de  I'Academie  des  Sciences,  Paris),  who  will 
lecfture  in  French  on  "The  Isolation  of  Fluorine  "  (with 
experiments).  On  Friday,  June  4th,  Mr.  W.  H.  Preece, 
C.B.,  F.R.S.,  will  ledlure  on  "Signalling  through  Space 
without  Wires."  On  Friday,  June  nth,  Mr.  William 
Crookes,  F.R.S.,  will  deliver  the  last  of  the  Friday 
Evening  Discourses  for  the  year ;  his  subjedl  will  be 
"  Diamonds." 

The  General  Italian  Exhibition.  —  This  Exhibition 
will  be  held  in  Turin   in  1898.     A  special  se<5tion  will  be 


devoted  to  Eletftricity,  and  a  prize— called  the  "Galileo- 
Ferraris  Prize" — will  be  given  to  the  most  important 
application  of  eledtricity  to  industrial  purposes.  The 
amount  already  subscribed  towards  this  prize  reaches 
15,000  francs. 

The  Rose  Polytechnic  Institute  of  Terre  Haute, 
Indiana.— The  Calendar  of  this  Institute  now  before  us 
gives  a  complete  list  of  the  ledtures  and  courses  of 
instruction  included  in  its  curriculum.  It  is,  firstly,  an 
Engineering  College;  this  naturally  includes  scientific 
training  in  such  subjedts  as  Chemistry,  Eledlricity,  Mathe- 
matics, &c.  The  general  plan  of  instrudtion  is  based  on 
the  principle  that  laboratory  and  shop  work,  field  and  office 
pradtice,  should  all  go  hand-in-hand  with  theory  and 
book  work. 

The  Pennsylvania  State  College.  —  We  have  re- 
ceived the  Prospedlus  and  Syllabus  of  the  above-named 
College,  and  have  much  pleasure  in  noting  its  growing 
importance  and  the  extended  scope  of  its  teachings. 
Started  in  1859  as  the  ''Farmer's  High  School,"  for  the 
purpose  of  giving  a  purely  agricultural  education,  it  has 
been  so  enlarged  as  to  include  all  those  subjedts  which  lie 
at  the  foundation  of  modern  industrial  pursuits.  The 
several  courses  of  ledtures,  and  of  instrudlion  generally, 
are  grouped  into  seven  Schools, — such  as  the  School  of 
Natural  Science  (biology  and  chemistry),  the  School  of 
Mathematics  and  Physics,  the  Schools  of  Mines, 
Engineering,  and  so  on.  The  course  of  chemistry  lasts 
for  two  years,  and  includes  both  mineral  and  organic 
chemistry,  theoretical  and  pradtical.  Elediricity  is  of 
course  not  negledted,  with  its  many  modern  applications, 
while  another  peculiar  feature  of  the  College  is  its  military 
organisation. 

Disinfedtion  with  Formic  Aldehyd. — In  the  Sanitary 
Chronicles  of  the  parish  of  St.  Marylebone,  for  the  month 
ending  March  31st,  1897,  ^''-  Winter  Blyth  records  some 
interesting  and  valuable  work  done  in  connedlion  with  the 
disinfedting  properties  of  formic  aldehyd,  commercially 
known  when  dissolved  in  water  as  "  formalin  "  or  "  formol." 
The  antiseptic  powers  of  formic  aldehyd  are  extraordi- 
nary ;  I  part  in  10,000  suffices  to  preserve  milk,  soup,  and 
similar  articles,  for  a  considerable  time,  which  fadt 
naturally  suggested  that  it  might  have  true  disii>fedting 
powers.  The  aqueous  solution  called  formalin  does  not 
give  very  satisfadtory  results  when  exposed  in  open  dishes, 
as  it  has  the  peculiar  property  of  changing  into  a  white 
solid, — in  other  words,  polymerisation  takes  place,  CHOH 
changing  into  C3H3O3H3,  the  latter  substance  being  a  far 
less  efficient  disinfedtant.  Bouse  and  Boudet,  however, 
found  that  when  the  gas  is  dissolved  in  a  solution  of  cal- 
cium chloride,  and  afterwards  heated  under  pressure, 
pradtically  dry  formic  aldehyd  was  driven  off.  The  ordi- 
nary method  of  disinfedting  a  room  is  to  seal  and  plug  up 
every  crack  and  opening ;  then  open  a  bottle  of  compressed 
sulphurous  acid,  and  leave  the  room  undisturbed  for  about 
twelve  hours  or  more.  A  comparative  trial  was  made 
with  sulphurous  acid  and  formic  aldehyd,  in  two  rooms 
in  which  were  exposed,  on  bits  of  linen,  four  cultures  of 
diphtheria,  four  of  the  typhoid  bacillus,  four  of  tuber- 
culosis, and  four  of  anthrax  ;  there  were  also  samples  of 
coloured  paper  and  materials  placed  in  the  room,  to 
enable  the  officials  to  observe  the  effedl,  if  any,  on  colours. 
After  nineteen  hours  the  rooms  were  opened,  and  the 
infedled  pieces  of  linen  were  sent  to  Prof.  Macfadyen,  who 
reported  as  follows  : — 

Sulphur  gas.        Formic  aldehyd. 

I.  Diphtheria  bacillus.  No  growth.  No  growth. 
II.  Typhoid  bacillus.  Good  growth.  No  growth. 
III.  Anthrax  bacillus.        Good  growth.     No  growth. 

The  tubercle  samples  could  not  be  properly  reported  on, 
as  they  were  found  to  be  contaminated  with  other  micro- 
organisms. The  formic  aldehyd  room,  on  being  entered, 
smelled  strongly  of  the  gas,  but  beyond  making  the  eyes 
smart  there   was  not  much  inconvenience   for    a   short 


252 


Meetings /or  the  Week, 


f  Chemical  Nbws, 
(      May  21,  1897. 


while;  but  in  the  sulphur  gas  room  three  attempts,  in  as 
many  quarters  of  an  hour,  were  made  to  open  the 
windows,  and  in  each  case  Dr.  Blyth  was  compelled  to 
retire,  gasping  and  choking;  it  was  more  than  an  hour 
before  the  windows  could  be  opened.  As  for  the  colours, 
both  gases  showed  a  trivial  bleaching  in  the  case  of  silk 
when  very  carefully  compared,  but  in  the  dyed  papers  no 
alteration  whatever  could  be  discerned.  In  conclusion. 
Dr.  Blyth  considers  that  formic  aldehyd  gas  is  superior  to 
sulphurous  acid  gas  as  a  disinfedtant,  and  he  recommends 
its  adoption  by  the  Vestry. 

Sophistication  of  Foods. — We  learn  from  the  Chem. 
Zeitung  that  the  Sanitary  Department  of  San  Francisco 
is  publishing  a  black  list  of  the  manufadlurers  and  dealers 
in  adulterated  food,  with  the  names  and  addresses  of  the 
offenders  in  full. 

Memorial  to  Professors  Gauss  and  Weber.  —  We 
have  the  pleasure  of  calling  the  attention  of  our  readers 
to  the  projeA  for  erefting,  at  Gottingen,  a  monument  to 
the  late  Professors  Gauss  and  Weber.  A  sum  of  23,520 
marks  has  been  already  colledled  for  the  purpose. 
Further  subscriptions  will  still  be  welcomed,  as  the  design 
of  Prof.  Harza  (of  Berlin)  is  of  a  somewhat  expensive 
charadter.  The  work  will, be  completed  within  two  years. 
The  President  of  the  Committee  is  Prof.  Dr.  W.  Vogt, 
and  the  Treasurer  is  Siegfried  Bonfey. 


NOTES    AND    QUERIES, 

•***  Our  Notes  and  Queries  column  was  opened  for  the  purpose  of 
giving  and  obtaining  information  likely  to  be  of  use  to  our  readers 
geiierally.  We  cannot  undertake  to  let  this  column  be  the  means 
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Separations  with  Alkaline  Acetates. 


253 


THE    CHEMICAL     NEWS 


Vol.  LXXV.,  No.  1957- 


AN  ATTEMPT  TO  CAUSE   HELIUM   OR  ARGON 

TO  PASS  THROUGH  RED-HOT  PALLADIUM, 

PLATINUM,  OR  IRON.* 

«y  WILLIAM  RAMSAY,  F.R.S.,  and  MORRIS  W.  TRAVERS. 

To  chronicle  experiments  which  produce  no  result  is  a 
necessity,  although  not  entirely  an  agreeable  one.  What- 
ever the  reason  ot  the  passage  of  hydrogen  through  red- 
hot  iron,  and  through  moderately  heated  palladium,  and 
platinum— whether  it  be  due  to  the  solubility  of  the  gas 
in  the  metal,  or  to  the  formation  of  an  easily  decomposable 
compound — neither  argon  nor  helium  is  able  to  pass 
through  any  one  of  these  metals,  even  at  a  fairly  high 
temperature.  This  would  imply  their  inability  to  form 
any  compound,  however  unstable,  with  these  metals,  or  to 
-dissolve  in  them  at  a  red  heat.  Such  inaftivity  is  in 
accordance  with  their  general  behaviour,  and  is  still 
another  proof  of  their  inertness. 

The  experiment  was  made  in  the  following  manner  : — 
A  tube  of  hard,  infusible  glass  was  conneAed  at  one  end 
with  the  reservoir  of  the  gas  under  experiment,  helium  or 
argon.  Into  its  other  end  was  corked  a  tube  of  platinum, 
closed  with  a  palladium  cap,  or,  if  iron  was  the  metal 
under  experiment,  with  a  tube  of  thin  wrought  iron,  also 
closed  at  the  end  ;  the  closed  end  of  the  interior  tube  was 
placed  so  that  it  could  be  raised  to  a  bright  red  heat  by 
bringing  a  blowpipe  flame  to  bear  on  the  hard  glass  tube. 
The  open  end  of  the  metal  tube  was  cemented  to  a  glass 
tube,  attached  to  a  Topler  pump,  and  provided  with  a 
Plijcker's  vacuum  tube,  so  that  the  spedtrum  of  any  gas 
passing  through  the  metal  could  be  observed.  This 
afforded,  at  the  same  time,  a  most  delicate  test  of  the 
presence  of  the  gas  under  experiment.  The  metal  tube 
was  exhausted,  until  green  phosphorescence  appeared  in 
the  vacuum  tube,  and  the  gas,  helium  or  argon,  was  ad- 
mitted into  the  space  between  the  glass  and  the  metal 
tube,  at  atmospheric  pressure.  The  glass  tube  was  then 
heated  to  the  highest  temperature  attainable  with  a  blow- 
pipe— perhaps  900°  or  950°  C.  In  no  case,  whether  the 
metal  tube  consisted  of  palladium,  platinum,  or  iron,  was 
there  the  smallest  transpiration  of  gas,  even  after  half  an 
hour.  The  phosphorescent  vacuum  remained  in  all  ex- 
periments quite  unimpaired. 


■SEPARATIONS    WITH     ALKALINE     ACETATES. 

(Preliminary  Paper). 

By    HARRY    BREARLEY. 

It  has  been  previously  shown  (Chemical  News,  xxvii., 
14;  Ixxv.,  13)  that  the  separation  of  iron  from  manganese 
by  means  of  soda  or  ammonia  acetates  is  the  more  im- 
perfedt  the  larger  the  excess  of  acetate  used.  It  has  also 
been  shown  (Chemical  News,  xl.,  273  ;  Ixxiv.,  16)  that 
for  this  and  other  metals  the  effedt  of  excessive  acetate 
was  obviated  by  the  presence  of  free  acetic  acid. 

The  reaflion  between  ferric  chloride  and  soda  acetate 
has  been  written — 

eNaCzHoOa.sHjO  +  FcaCle  = 

=  N aCl  4-  Fe2(C2H302)6  +  3H2O  ; 


whence  it  follows  that  8  grms.  of  the  crystallised  soda 
acetate  (NaCaHjOj-sHaO)  would  be  needed  to  precipitate 
I  grm.  of  metallic  iron  existing  as  ferric  chloride.  But 
iron  solutions  are  never  precipitated  in  that  state.  Pure 
or  carbonated  alkali  is  added;  after  the  free  acid  is 
neutralised,  the  precipitated  hydrate  continues  to  be  dis- 
solved by  the  ferric  chloride  to  saturation  point.  When 
this  is  reached,  the  faint  excess,  taken  up  in  two  or  three 
drops  of  HCl,  marks  the  point,  commonly  called 
"neutralised,"  to  which  solutions  are  usually  taken 
before  adding  the  acetate.  Acetate  is  needed  only  to 
precipitate  that  portion  of  the  ferric  chloride  not  already 
precipitated  as  hydrate,  and  which  holds  the  precipitated 
hydrate  in  solution.  The  amount  theoretically  required 
will  bear  the  same  ratio  to  8  grms.  that  the  final  bears  to 
the  initial  quantity  of  FcaCle  when  i  grm.  of  metal  is 
operated  on.  It  may  be  of  interest  to  show  experimentally 
what  amount  of  acetate  is  necessary  to  precipitate  a  solu- 
tion containing  variable  quantities  of  ferric  chloride  and 
hydrate.  It  is  certain  that  many  an  imperfeiSt  separation 
may  be  redeemed  by  using  minimum  amounts  of  acetate  ; 
and  separations,  generally  considered  impossible,  effe&ed 
by  further  modification  in  the  same  direction. 

It  was  decided  to  answer  questions  similar  to  the  ones 
suggested  when  the  iron  solutions  contained— (a)  No  free 
acid  and  no  dissolved  hydrate  ;  {b)  half  the  total  soluble 
hydrate;  and,  (c),  total  soluble  hydrate,  i.e.,  as  much 
hydrate  as  the  solution  could  be  made  to  dissolve.  More  or 
less  completely,  the  same  series  was  gone  through  with 
varying  amounts  of  acetic  acid  and  with  soda  and  am- 
monia salts. 

The  iron  solution  chiefly  used  was  made  by  dissolving 
40  grms.  of  Swedish  bar  iron  in  290  c.c.  HCl  and  oxidising 
with  50  c.c.  HNO3.  There  was  prepared  also  a  solution 
ofironinHNOs  (i*2o),  and  a  solution  by  dissolving  in 
HCl,  oxidising  with  HNO3,  evaporating  to  dryness,  and 
re-dissolving  in  HCl.  The  two  latter  solutions  were 
intended  for  comparing  with  the  first  at  different  points, 
so  that  the  data  established  might  be  available  whichever 
method  should  be  used  for  preparing  the  iron  solution. 
All  three  are  recommended  in  one  or  other  of  the  modern 
text-books. 

The  amount  of  free  acid  was  determined  by  adding 
excess  of  normal  soda  carbonate  to  boiling  iron  solutions, 
filtering  off  aliquot  part,  and  determining  excess  of  alkali 
with  standard  acid  and  methyl-orange  (Sutton,  "Vol. 
Anal.,"  5th  ed.,  p.  89). 

Dissolved  Hydrate. 
For  determining  the  dissolved  hydrate,  iron  solution 
representing  ^  grm.  of  metal  was  placed  in  a  flask  and 
normal  soda  or  ammonia  carbonate  run  in  from  a  burette. 
Towards  the  end  the  alkali  was  added  very  slowly,  and 
plenty  of  time  allowed  for  the  precipitated  hydrate  to  dis- 
solve.  The  faint  permanent  precipitate  was  dissolved 
with  standard  HCl.  The  total  alkali  used,  less  that 
1  needed  for  neutralising  the  free  acid,  gives  the  quantity 


*  A  Paper  read  before  the  Royal  Society,  May  14,  1897. 


Table  I. 
With  Soda  Carbonate. 


Iron  solution. 


Required 


To  precipitate 


Aqua  regia..  j 

Hydrochloric  ( 
acid . .      ..( 

Nitric  acid . .  | 


Aqua  regia. . 
Hydrochloric 


Total 

hydrate. 

C.c. 

268 1 
26  8  j 
2681 

268  i 
26-81 
268  J 

With  Ammonia  Carbonate. 
37-84        14-2        2364        26-8 
33*93 


Totdl 
alkali. 
C.c. 

by 
free  acid. 

Dissolved 
hydrate. 

3774 
37-84 

14-2 
14-2 

23"54 
23-64 

3372 

10-35 

23"37 

.B3«2 

10-35 

23*47 

34*o 

lo-i 

24-0 

34-0 

lO'I 

24-0 

10-35     2358       268 


Ratio, 
total  to 

final 
Fe,CI,. 

8-35 

7  93 

957 


8-48 
8-32. 


254 


Separations  with  Alkaline  Acetates. 


Crbuicai.  News, 

May  28,  1SC7. 


Free  acetic  o 

^    TT  (Acetate 145  c.c. 

^*  -"'t  Temp,  turbidity    ..      ..  84°  C. 

„    „  ]  Acetate 73 

"•   "•(  Temp,  turbidity   ..      ..  74 

„     TT   I  Acetate 5* 

^-    "'I  Temp,  turbidity   ....  ? 


Table  II. 

Soda  acetate. 

5 

10 

20  c. 

150 

160 

175 

90 

94 

95 

75 

80 

90 

80 

82 

80 

6 

12 

16 

80—84 

80—84 

88 

Ammonia  acetate. 


0 

5 

10  c.c 

150 

155 

163 

86 

94 

90 

78 

80 

85 

80 

91 

92 

5* 

7 

10 

? 

80 

81 

needed  to  form  the  dissolved  hydrate.  These  solutions, 
on  standing,  become  gradually  turbid,  and  after  standing 
weeks  or  months  allow  the  precipitate  to  settle  somewhat, 
but  such  a  precipitate  cannot  be  separated  by  ordinary 
filtration.  Completely  "  neutralised  "  and  perfe(aiy  clear 
solutions  will  appear  slightly  turbid  by  refledled  light 
after  standing  over  night.  This  additional  precaution  was 
taken  in  determining  the  dissolved  hydrate.  Some  results 
are  arranged  in  Table  I. 

These  solutions  all  contained  alkaline  salts,  due  to  the 
neutralisation  of  the  free  acid.  On  this  account  they  do 
undoubtedly  require  less  alkali.  The  nitrate  is  less 
adtive  in  this  respedt  than  the  chloride,  and  this  may 
partly  explain  why  more  hydrate  is  dissolved  in  the  nitric 
than  the  aqua  regia  solution,  and  least  of  all  in  the  HCl 
solution.  When  ammonium  chloride  representing  10  c.c. 
strong  HCl  was  added  to  a  solution  the  alkali  required 
to  precipitate  the  dissolved  hydrate  fell  from  23*57  ^'^' 
to  2274,  and  with  nitrate  representing  10  c.c.  HNO3 
(i'42)  it  fell  to  22*87  c.c. 

Kessler  (Chem.  News,  xxvii.,  14)  states  : — "  When  a 
hydrochloric  acid  solution  of  perchloride  of  iron  is 
neutralised  by  means  of  soda  carbonate,  so  as  to  cause  a 
permanent  precipitate,  and  the  latter  is  cautiously  dis- 
solved by  the  addition  of  some  HCl,  a  liquid  is  obtained 
which  contains  fourteen  times  its  equivalent  of  ferric 
hydrate  in  solution,  yet  it  is  not  precipitated  by  boiling.* 
This  passage  seems  to  have  been  misread  by  Blair 
("  Chem.  Anal,  of  Iron,"  p.  108),  who  makes  out  that, 
theoretically,  half  a  grm.  of  soda  acetate  is  sufficient  to 
precipitate  i  grm.  of  iron,  as  though  fourteen  times  as 
much  iron  exists  as  dissolved  hydrate  as  exists  as  chloride. 
The  intended  meaning  seems  to  be  that  the  dissolved 
Fe2(HO)6  =  14  Fcj  (existing  as  FeaClg).  Read  this  way,  the 
two  results  are  broadly  confirmatory. 

Precipitating  the  Iron. 

The  precipitations  with  acetate  were  performed  in  flasks. 
One  grm.  of  iron  taken  in  all  cases,  and  made,  finally,  in 
the  cold,  up  to  480  c.c,  so  that  at  Isoiling-point  it  would 
measure  500  c.c.  approximately.  The  temperature  at 
which  the  heated  solution  became  turbid  was  observed. 
In  some  cases  after  a  faint  turbidity  the  formation  of  the 
precipitate  was  very  tardy,  and  is  represented  by  two 
observations :  e.g.,  76—80*  C,  20  c.c.  of  the  soda  acetate 
contains  i  grm.  NaC2H302'3H20  crystals.  The  ammonia 
acetate  was  made  by  neutralising  acetic  acid  (33  per  cent) 
with  ammonia.  One  and  a  half  c.c.  of  such  a  solution 
contained  as  much  acetic  acid  as  i  grm.  soda  acetate 
crystals,  so  that  they  were  made  of  equal  value  by 
making  1*5  c.c.  of  the  former  up  to  20  c.c.  The  solutions 
were  neutral  on  the  acid  side,  if  I  may  be  allowed  to  use 
such  contradictory  terms.f 

An  iron  solution  may  be  said  to  be  completely  precipi- 
tated when,  the  basic  acetate  having  settled,  the  super, 
natant  solution  is  colourless  and  free  from  iron.  This, 
agreeable  to  theory,  was  found  to  be  the  case  when- 


*  The  neutralised  solutions  I  obtained,  if  diluted  with  about  20o 
c.c.  of  water,  were  partly  precipitated  by  boiling. 

f  The  ammonia  acetate  was  made  two  months  before  using.  It 
was  then  neutral,  as  when  first  made.  It  has  been  stated  that  the 
solution  decomposes  on  keeping,  and  should  be  made  as  required.  I 
believe  this  is  not  a  general  pradtice,  and  this  point  is  specially  noted 
in  the  hope  that  it  may  elicit  further  information. 


having  no  free  acid  and  no  dissolved  hydrate,  8  grms.  of 
soda  acetate  crystals  were  added;  7^  grms.  left  a  faintly 
coloured  supernatant  solution.  If  this  faintly  coloured 
solution  is  passed  hot  through  an  asbestos  filter,  the  fil- 
trate is  colourless,  crystal  clear,  and  when  acidified  gives 
no  colouration  with  sulphocyanide.  A  similar  result  is 
obtainable  using  7!  grms.  It  is  this  property  of  an  as- 
bestos filter  which  it  is  more  particularly  desirable  to 
observe  ;  for  is  it  not  likely  that,  if  only  so  much  acetate 
is  added  as  will  leave  a  faintly  coloured  supernatant  solu- 
tion, an  associated  metal,  having  similar  properties^ 
may  remain  completely  in  solution  and  depend  for  its 
complete  separation  from  the  last  portion  of  iron  on  its 
deportment  to  the  asbestos  ?  A  very  considerable  quan- 
tity of  iron  may  be  removed  from  a  hot  solution  in  this 
way  ;  cold  solutions  pass  unaltered. 

No  great  labour  was  spent,  therefore,  in  determining 
how  much  acetate  was  needed  to  give  a  colourless  super- 
solution  after  the  settling  of  the  precipitated  acetate,  but 
rather  to  determining  with  how  little  acetate  an  iron-free 
filtrate  could  be  obtained.  There  is,  of  course,  no  absolutely 
unalterable  amount.  Something  depends  on  how  the  filter 
is  made,  how  long  the  solution  is  boiled,  what  amount  o£ 
alkaline  salts,  &c.  In  the  instances  tabulated  the  solu- 
tion was  heated  until  it  quite  boiled,  cheesed  until  the 
precipitate  settled,  and  filtered.  Where  soda  acetate  is- 
used  for  precipitating,  soda  salts  have  been  used  through- 
out, and  similarly  for  ammonia.  N.H.,  H.H.,  and  T.H. 
mean  that  the  iron  solution  contained  no  hydrate,  half  the 
total  hydrate,  and  the  total  hydrate  respectively.  The 
table  shows  the  minimum  acetate. 

The  solutions  marked  with  an  asterisk  became  turbid 
on  adding  the  acetate,  but  did  not  leave  a  clear  super- 
solution  unless  they  were  heated.  When  larger  amounts 
of  acetate  (10  c.c.)  were  added,  the  precipitate  settled,, 
without  heating,  leaving  a  perfe(5tly  colourless  super- 
solution. 

The  preparation  of  the  large  vols,  of  T.H.  solution 
enabled  me  to  confirm  the  figures  given  above  for  the 
amount  of  hydrate  soluble  in  ferric  chloride. 

A  dozen  or  so  precipitations  were  made  of  iron  solu> 
tions  to  which  ammonia  salts,  containing  respectively 
10  c.c.  HCl  and  loc.c.  HNO3,  had  been  added.  Their 
presence  favours  the  precipitation,  the  chloride  more 
decidedly  so  than  the  nitrate.  With  the  same  volume  of 
acetate  the  temperature  of  turbidity  falls  about  10°  C. 

Precipitating  from  more  dilute  solutions  did  not  seem 
to  make  much  difference.  The  tendency  was  to  give  more 
perfe(5t  separations,  but  this  may  be  due  to  the  longer 
digestion  of  the  larger  volume  between  precipitating  and 
boiling  points. 

The  present  objedl  is  to  find  with  what  amounts  of  ace- 
tate, dissolved  hydrate,  and  free  acetic  acid,  the  most 
effective  separations  may  be  made  of  those  metals  which 
are  at  all  separable  by  these  means.  Attention  is  specially 
to  be  paid  to  those  separations  which  are  of  value  to  the 
steel  works'  chemist,  and  hence  separations  from  iron 
claim  first  notice.  Qualitative  tests,  which  have  indi- 
cated at  least  the  partial  separation  of  ferric  oxide  and 
alumina,  for  instance,  lend  colour  to  the  hope  that  the 
completed  investigation  may  not  be  without  value. 

The  Laboratory,  Norfolk  Works,  Sheffield. 


■CRBMICALNbWSj) 


May  28, 1897. 


Study  of  Hyponitrous  A  cid. 


255 


CONTRIBUTION     TO    THE     STUDY    OF 
HYPONITROUS     ACID.' 

By  A.  HAUTZSCH  and  A.  L.  KAUFMANN. 
(Continued  from  p.  245). 

Hyponitrite  of  Benzyl,  C7H70N  =  NOC7H7. 
The  only  ether  of  hyponitrous  acid  yet  known,  hypo- 
nitrite  of  ethyl,  was  obtained  by  Zorn  in  the  form  of  a 
yellow  oil,  by  treating  iodide  of  ethyl  with  hyponitrite  of 
silver.  In  spite  of  the  explosibility  of  this  ether,  its 
vapour  density  has  been  determined.  It  corresponds  to 
the  formula  (C2H5)2N202.  The  benzylic  ether  which 
we  have  prepared  is  much  more  stable. 

Pure,  dry,  hyponitrite  of  silver  is  added  in  excess,  to  a 
well-cooled  etherised  solution  of  carefully  purified  iodide 
of  benzyl;  the  temperature,  which  will  tend  to  rise,  must 
be  kept  low.  When,  after  two  or  three  hours,  the  smell 
of  iodide  of  benzyl  has  disappeared,  it  is  filtered,  the 
ether  is  evaporated  off,  and  we  obtain  the  benzylic  ether 
in  a  pure  state  by  re-crystallisation  in  ligroin. 

I.  01883  gr""-  of  'he  substance  gave  0*4757  grm.  CO2 

and  o*i042  grm.  H2O. 
II.  0*1147  grm.  of  the  substance  gave  0*2905  grm.  CO2 
and  0*0639  g""™*  H2O. 
III.  o'i46o  grm.  of  the   substance   gave   14*5   c.c.  N  at 
17°  C.  and  760  m.m.  pressure. 


I. 

II. 

III.        Theory,  CjHjNO 

C. 

68*8q»/. 

69*07'/. 

-                  69*42'/. 

H. 

6*157'. 

6*i9°/o 

-    ,               .579°A 

N. 

— 

— 

ii'ssy.        11*57°/. 

The  molecular  weight  of  the  ether  has  been  determined 
cryoscopically  in  acetic  solution,  by  passing — as  recom- 
mended by  Beckmann — a  continuous  current  of  dry  air 
over  the  liquid. 

I.  o'i04i  grm.  of  the  substance,  dissolved  in  20  c.c.  of 
glacial  acetic  acid  (sp.  gr.  =  i"055),  lowered  the 
congealing  point  by  o*o8i°  (mean  of  six  observa- 
tions). 
II.  0*3086  grm.  of  the  substance,  dissolved  in  20  c.c.  of 
glacial  acetic  acid,  lowered  the  congealing  point  by 
0'25i°  (mean  of  seven  observations). 


236 


Molecular  Weight. 
Found.  Theory, 


II. 


242 


Hyponitrite  of  benzyl  is  bi-molecular,  as  is  free  hypo- 
nitrous  acid  and  Zorn's  ethylic  ether.  It  is  easily  soluble 
in  alcohol  and  ether,  but  only  slightly  so  in  ligroin.  The 
latter  precipitates  it  from  its  solution  in  alcohol  or  ether. 
It  melts  at  43°  to  45°  with  decomposition,  and  detonates 
when  rapidly  heated  to  60°.  Even  at  the  ordinary  tem- 
perature it  volatilises  easily.  In  an  experiment  made,  its 
loss  of  weight  was  7*5  per  cent  in  seventeen  hours. 

The  decomposition  of  hyponitrite  of  benzyl  when 
warmed  gives  rise  to  a  considerable  disengagement  of 
gas.  To  discover  the  nature  of  this  gas  we  dissolved  a 
weighed  quantity  of  the  ether,  in  methylic  alcohol, 
warmed  the  solution  to  50°  in  a  current  of  carbonic  acid, 
and  colledled  the  gas  in  a  nitrometer. 

0*1915  grm.  gave  17*7  c.c.  (at  18°  and  751  m.m. 
pressure)  of  nitrogen  (and  not  protoxide  of  nitrogen). 

Nitrogen  found  10*57  per  cent;  theory  11*57  per  cent. 
Assuming  that  the  nitrogen  is  liberated  nearly  quantita- 
tively, the  decomposition  of  hyponitrite  of  benzyl  is  no 
<loubt  according  to  the  following  equation  : — 

C6H5CH20N,NOCH2C6H5  = 

=  C6HSCH2OH -I- C6H5CHO -f  N2. 

*  MeniUur  Scientifique,  vol.  xi.,  p.  336,  May,  1897, 


This  experiment  confirms  Zorn's  observation  relative  to 
the  decomposition  of  the  ethylic  ether  of  hyponitrous 
acid. 

Decomposition  of  Hyponitrous  Acid. 

It  has  been  generally  admitted,  up  to  the  present,  that 
hyponitrous  acid  splits  up  quantitatively  into  protoxide  of 
nitrogen  and  water. 

The  fa<a  that  hyponitrous  acid  gives  a  blue  colour  to 
iodide  of  potassium  and  starch  acidulated  with  acetic 
acid,  then  the  brown  colouration  produced  by  the  addition 
of  ferrous  sulphate  and  the  blue  colouration  produced  by 
the  additon  of  a  phenylamine  to  a  sulphuric  solution  of 
hyponitrous  acid,  and,  again,  the  observations  made  on 
the  determination  of  the  condudtivity  of  this  acid,  which 
will  be  described  further  on, — all  these  fadls  go  to  prove 
that,  by  a  secondary  reacftion,  hyponitrous  acid  gives  birth 
to  nitrous  acid. 

Above  all  we  could  suppose  that,  by  the  inverse  of  the 
synthesis  of  hyponitrous  acid  achieved  by  Wislicenus, 
this  acid  would  split  up,  under  certain  conditions,  into 
nitrous  acid,  and  hydroxylamine  according  to  the 
equation  HON,NOH-f  H20  =  H0N0  +  NH20H. 

In  spite  of  all  our  efforts  we  have  not  been  able  to  prove 
the  presence  of  hydroxylamine  among  the  produds  of  de- 
composition of  hyponitrous  acid.  On  the  other  hand,  we 
have  shown  that  hyponitrous  acid  partially  splits  up  into 
nitrous  acid  and  ammonia,  according  to  the  equation — 

3N2O2H2  =  2N2O3  -f  2N  H3. 

This  decomposition  is  easily  explained  on  the  supposition 
that  the  acid,  HON,NOH,  becomes  first  changed  into  its 
tautomeric  demimolecular  form,  0,NH,  to  which  nitroso- 
benzine  corresponds  as  its  ether  ;  after  which  a  molecule 
of  this  aldehyd  of  nitrous  acid  becomes  oxidised,  after 
the  manner  of  true  aldehyds,  at  the  expense  of  another 
molecule,  which  is  thus  reduced  to  ammonia  : — 

H0N,N0H  =  2HN0 

3HN0  =  NH3-f-N205. 

As  a  secondary  readion,  the  molecule  of  ammonia  may 
be  oxidised  at  the  expense  of  the  half  molecule  of  nitrous 
anhydride  formed,  and  may  eventually  form  nitrogen, 
water,  and  nitrous  or  nitric  acid,  according  to  the 
equation  NH3  -|-  N203  =  N3  +  HjO  +  HNO3.  However, 
in  comparison  with  the  splitting  up  into  protoxide  of 
nitrogen  and  water,  the  decomposition  we  have  just  men- 
tioned takes  place  but  very  slowly  in  aqueous  solution. 
A  freshly  prepared  solution  of  hyponitrous  acid,  boiled  in 
a  flask  fitted  with  a  vertical  condenser,  became  completely 
neutral,  and  did  not  contain  a  trace  of  nitrous  acid.  But, 
on  the  contrary,  an  exadly  similar  solution  left  for  several 
hours  at  25°  before  being  boiled,  maintained  its  acid 
readion  to  the  end  of  the  operation,  and,  moreover,  con- 
tained  2  per  cent  of  free  acid.  When  neutralised  and 
evaporated  to  dryness,  it  showed  the  nitrite  readtions  very 
clearly. 

Another  portion  of  the  same  solution  was  similarly 
boiled,  and  then  evaporated  to  dryness  with  hydrochloric 
acid.  Ammonia  could  be  deteded  in  the  residue  by  means 
of  Nessler's  solution. 

In  another  experiment  a  freshly  prepared  solution  of 
hyponitrous  acid  was  divided  into  three  portions  ;  the  first 
portion  was  left  intad,  the  second  was  treated  with 
caustic  potash  in  excess,  while  to  the  third  a  few  drops  of 
hydrochloric  acid  were  added.  After  the  lapse  of  twenty- 
four  hours,  these  three  solutions  were  analysed.  In  the 
first,  which  had  been  hyponitrous  acid  alone,  we  proved  the 
presence  of  nitrous  acid  by  means  of  diphenylamine. 
the  complete  absence  of  ammonia,  and  the  presence  of 
unaltered  hyponitrous  acid.  The  second  contained  neither 
nitrous  acid  nor  ammonia,  but  there  was  still  some  hypo- 
nitrous acid  present.  The  third  contained  neither  nitrous 
acid,  ammonia,  nor  hyponitrous  acid,  but  nitric  acid.  These 
three  experiments  confirm  the  view  that  hyponitrous  acid 
is  most  stable  in  an  alkaline  solution,  and  least  stable  in 


256 


Colouring-matters  in  White  Wines  and  Liqueurs, 


(Chemical  News^ 
I    May  28, 1897, 


an  acid  solution.  The  stability  of  the  pure  acid  in  aqueous 
solution  is  midway  between  the  two. 

We  need  not  be  astonished  that  no  ammonia  is  formed 
in  these  last  three  experiments.  The  ammonia  which 
might  be  formed  in  very  small  quantities  in  tte  acidulated 
solution,  would  be  immediately  destroyed  by  the  adtion  of 
the  nitrous  acid  which  would  be  formed  simultaneously. 
We  can  only  detedl  the  presence  of  ammonia  by  the  very 
rapid  evaporation  of  strongly  acid  solutions  of  hypo- 
nitrous  acid. 

The  formation  of  nitrous  acid  during  the  decomposition 
of  hyponitrous  acid  explains  the  blue  colouration  obtained 
with  diphenylamine,  and  the  brown  colouration  with 
ferrous  sulphate,  This  reaction  equally  explains  the  fadl 
that  the  determination  of  the  rapidity  of  the  decomposi- 
tion of  hyponitrous  acid  into  protoxide  of  nitrogen  and 
water  has  not  been  found  possible. 

Before  recognising  this  secondary  readlion  we  quite 
expeded  that  the  relation  between  the  still  undecomposed 
acid  (a)  and  that  already  decomposed  into  protoxide  of 
nitrogen  and  water  (;r)  could  be  determined  at  any  or 
every  moment  by  the  diminution  of  the  acid  titration. 
By  the  equation — 

I     ,  a 

c  =  -  .  log 

t        ^  a-x 

we  could  have  measured  the  speed-constant  of  the  de- 
composition. With  this  idea  we  took,  at  stated  intervals- 
10  c.c.  samples  of  a  solution  of  hyponitrous  acid,  pre. 
pared  at  0°  and  kept  at  25°  in  an  Ostwald  thermostat. 
These  samples  were  titrated  with  a  i/i6th  normal  solution 
of  baryta,  using  phenolphthalein  as  indicator.  But  the 
values  of  c,  calculated  according  to  the  above  formula, 
were  not  even  approximately  constant,  and  moreover 
increased  as  the  experiment  went  on.  This  increase  in 
the  speed  of  decompositon  can  only  be  attributed  to  the 
gradual  acceleration  of  the  secondary  readlion,  which 
results  in  the  formation  of  nitrous  acid.  It  is  another 
example  of  accelerant  catalytic  aiSlion  of  the  ions  of 
hydrogen,  for  here  again  the  presence  of  nitrous  acid  has 
been  definitely  proved. 

The  fad  that  acid  considerably  accelerates  the  decom- 
position of  hyponitrous  acid  has  been  shown  in  a  special 
experiment,  by  determining  the  speed  of  decomposition 
in  the  presence  of  hydrochloric  acid.  The  initial  values 
of  c  were  in  this  case  much  greater  than  those  obtained 
with  an  aqueous  solution  of  pure  hyponitrous  acid.  But 
here  again  we  could  not  obtain  a  constant  by  the  diminu- 
tion of  the  titration  of  the  acid.  But  if  we  took  as 
abscissae  the  calculated  values  of 

,  =  l.log^--, 
t  a  —  x 

and  the  corresponding  intervals  of  time  as  ordinate!,  we 
obtained  a  regular  curve  which  showed  that  the  speed  of 
decomposition  increased  with  the  quantity  of  the  sub- 
stance decomposed.  We  propose  later  to  make  a  special 
study  of  this  phenomenon. 

(To  be  continued). 


A     NEW    AND     ACCURATE     METHOD     FOR 

THE    ESTIMATION     OF     POTASSIUM- 

By  H.  N.  WARREN,  Principal,  Liverpool  Research  Laboratory. 

The  solution  containing  the  alkalis  as  chlorides,  having 
been  previously  exhausted  of  the  accompanying  group 
metals,  is  heated  with  an  excess  of  platinic  chloride,  and 
the  whole  evaporated  to  very  small  bulk  in  a  platinum 
dish,  or  other  suitable  receptacle;  to  the  contents  are 
now  added  about  double  the  original  quantity  of  a  mix- 
ture composed  of  equal  parts  of  amylic  alcohol  and 
ether.    The  precipitate  is   by  these  means  immediately 


rendered  dense,  and  can  thus  be  washed  once  or  twice 
with  the  utmost  facility,  using  the  same  mixture.  The- 
yellow  precipitate  thus  obtained  is  next  transferred  to  a' 
small  glass  beaker,  and  heated  to  the  boiling  point  with' 
the  addition  of  about  5  c.c.  of  formic  acid.  The  solution 
thus  speedily  assumes  a  brownish  tint,  at  which  stage  a 
slight  excess  of  ammonia  is  introduced,  and  re-boiled,, 
when  the  whole  of  the  platinum  is  precipitated  in  the  form 
of  black  flocks,  which  may  be  readily  washed  and  dried, 
from  the  weight  of  which  the  percentage  of  potassium 
present  may  be  readily  calculated. 

With  a  little  pradice  the  operation  will  be  found  more 
expeditious,  more  accurate,  and  at  the  same  time  less 
troublesome,  than  the  general  methods  advised  for  the 
estimation  of  potassium. 

Liverpool  Research  Laboratory, 
z8,  Albion  Street,  Everton,  Liverpool, 


ON    THE    RECOGNITION     OF 

THE    YELLOW    OF    NAPHTHOL     S,    AND     OF 

ANALOGOUS     COLOURING  -  MATTERS     IN 

WHITE     WINES     AND     LIQUEURS. 

By  ALBERTO  D'AGUIAR  and  WENCESLAU  da  SILVA. 

The  yellow  of  naphthol  S,  like  diamond  brilliant  yellow 
S,  &c.,  are  scarcely  extradled  from  an  alkaline  solution 
by  means  of  solvents,  such  as  amylic  ether,  acetic  ether, 
sulphuric  ether.  Under  these  conditions  we  proceed  as 
follows : — 

A  portion  of  the  wine  is  strongly  acidified  with  sul- 
phuric acid,  and  shaken  up  with  amylic  ether,  which 
extradls  all  the  colouring-matter  derived  from  the  coal-tar 
and  a  part  of  the  natural  colouring-matter  of  the  wine. 
After  decantation  and  filtration  the  amylic  alcohol  is 
agitated  with  an  excess  of  ammonia,  and  allowed  to 
remain  at  rest  until  it  is  permanently  limpid.  The  natural 
colouring-matter  of  the  wine,  as  also  various  other 
matters,  are  precipitated  by  the  ammonia.  The  amylic 
alcohol  retains  in  solution  a  portion  of  the  coal-tar  colour 
sufficient  for  its  deteftion  by  dyeing-tests  or  by  reagents. 
The  amylic  solution  is  shaken  up  with  water  and  acidu- 
lated sulphuric  acid  ;  after  standing  it  is  evaporated,  in 
contadl  with  a  thread  of  silk,  with  a  few  drops  of  ammo- 
nia. The  silk  is  then  distindly  dyed,  and  the  residue  left 
by  the  amylic  alcohol  is  next  submitted  to  the  adtion  of 
sulphuric  and  hydrochloric  acids  and  ammonia,  to  allow 
of  a  study  of  the  changes  produced  by  these  reagents. 

We  have  made  these  experiments  on  wines  coloured 
with  naphtha  yellow  S,  brilliant  yellow  S,  diamond  yellow, 
turmeric  and  fustic,  as  well  as  on  natural  wine.  The  re- 
sults were  positive  with  the  first  three,  but  negative  with 
the  last  three,  notwithstanding  the  strong  colouration  of 
the  amyl-alcoholic  tinctures. 

Bellier's  procedure  also  gave  very  distindl  positive 
results  with  the  first  three  tests,  but  negative  with  the 
latter. 

These  experiments  have  been  repeated  on  Ermida  wine 
mixed  with  the  other  yellow  coal-tar  colours  mentioned 
in  a  former  paper.  The  results  have  been  also  positive. — 
Comptes  Rendus,  cxxiv.,  No.  18,  1897. 


Contribution  to  the  Study  of  Tinc5\orial  ReacJtions. 
— A.  Reychler. — After  describing  a  number  of  experiments 
and  verifications  of  the  conditions  existing,  the  author 
claims  that  he  has  not  disproved  the  theory  put  forward 
by  M.  Knecht;  but,  on  the  contrary,  he  has  confirmed 
the  ideas  held  on  the  constitution  and  a(aion  of  saline 
solutions  in  respedl  of  dyeing. — Bulletin  de  la  Societe 
Chimique  de  Paris. 


Some  Present  Possibilities  in  the  Analysis  of  Iron  and  Steel         257 


Chkmical  NkW8,  I 
May  28,  1807.      I 

SOME    PRESENT    POSSIBILITIES    IN    THE 

ANALYSIS  OF   IRON   AND   STEEL.* 

By  C.  B.  DUDLEY. 


To  the  analytical  chemist  there  are  few  substances  in 
nature  more  interesting  than  a  piece  of  pig-iron,  few  sub- 
stances which  have  received  more  study,  and  few  which 
present  chemical  problems  more  difficult  of  solution.  The 
amount  of  work  which  has  already  been  done  in  connexion 
with  this  very  common  but  very  complex  substance  is 
sotnething  enormous.  Indeed,  if  we  add  to  the  study 
which  has  already  been  put  on  pig-iron  itself,  the  work 
which  has  been  done  on  what  may  perhaps  fairly  be  called 
its  progenitors,  viz.,  the  ores,  the  fuel,  the  flux,  and  the 
refradtory  materials  used  in  its  produAion,  and  then  con- 
sider still  farther  the  labour  already  expended  in  the  ana- 
lysis of  what  we  may  call  the  progeny  of  pig-iron,  viz., 
castings,  wrought  iron,  malleable  iron,  and  the  numerous 
grades  and  kinds  of  steel  made  by  the  various  processes 
of  the  present  day,  we  shall  surely  be  safe  in  saying  that 
more  chemical  work  has  been  done  in  connexion  with 
pig-iron  than  with  any  other  substance  in  nature.  Is  it 
too  much  to  affirm  that  at  the  present  time  one-third, 
possibly  one-half,  of  all  the  chemical  work  done  in  the 
world  is  in  connedlion  with  the  iron  industry,  either  in  the 
solution  of  unworkedout  problems,  the  development  of 
new  methods  of  analysis,  or  in  the  routine  analyses 
affedling  the  interests  of  producer  and  consumer. 

But  the  amount  of  work  already  done  and  in  daily  pro- 
gress in  connexion  with  this  substance  is  not  all  that  may 
be  said  in  regard  to  it.   The  complexity  of  pig-iron  is  very 
great,  and  consequently  the  analytical  problems  presented 
are  far  from  being  easy  of  solution.     It  may  not  be  unin- 
teresting to  enumerate  some  of  the  substances  which  have 
■    already  been  found  in  pig-iron.   We  find,  besides  the  ele- 
ment iron,  carbon,  phosphorus,  silicon,  sulphur,  manga- 
nese, copper,  chromium,  tungsten,  titanium,  vanadium, 
nickel,  cobalt,  aluminum,  potassium,  sodium,  magnesium, 
calcium,  and  lithium.   It  is  fair  to  say  there  is  apparently 
well  grounded  belief  that  the  last  five  are  charadteristic 
of  intermingled  slag  rather  than  of  the  metal  itself.     It  is 
not  intended  that  it  should  be  understood  that  all  of  these 
substances  have  been  found  in  any  one  sample  of  pig-iron, 
but  that  all  these  substances  have  aftually  been  deteifted 
in  the  analysis  of  this  alloy.     Indeed  there  seems  no  rea- 
son why  any  element,  which  either  occurs  in  the  metallic 
condition  in  nature,  or  which  is  reducible  to  that  condition 
by  carbon,  and  which  is  not  volatile  at  the  temperature  of 
the  blast  furnace,  may  not  occur  in  pig-iron,  provided  of 
course  it  will  alloy  with  the  metal.   Quite  a  large  number 
of  other  substances  besides  those  mentioned  above  have 
adtually  been  alloyed  with  some  form  of  iron  or  steel. 
Among  these  may  be  mentioned  zinc,  tin,  lead,  antimony, 
bismuth,  molybdenum,  silver,  platinum,  rhodium,  iridium, 
palladium,  and  gold.      Nor  is  this  all  that  may  confront 
the  analyst  who  devotes  himself  to  the  chemistry  of  iron 
and  stfcel.      Not  less  than  three  elements  which  usually 
exist  in  nature  in  the  gaseous  form  occur  in  these  metals, 
and  are  believed  to  have  important  influences  on  their 
physical  properties.      These  are  oxygen,  hydrogen,  and 
nitrogen  ;  while  the  numerous  analyses  show  the  presence 
of  carbon  monoxide  in  both  cast-iron,  wrought  iron,  and 
steel.     It  seems  quite  evident  that  the  chemist  who  hopes 
to  successfully  cope  with  the  problems  which  are  involved 
in  even  the  ultimate  analysis  of  iron  and  steel  in  their 
various  forms,  must  be  well  equipped  with  a  liberal  share 
of  the  methods  and  processes  known  to  mineral  chemis- 
try ;  and,  on  the  other  hand,  if  he  attempt  the  proximate 
analysis  of  these  substances,  or  the  separation  and  deter- 
mination of  the  various  compounds  of  the  elements  pre- 
sent, with  iron  or  with  each  other,  he  will  at  least  be 


brought  on  the  border-ground  of  organic  chemistry. 
Some  of  the  carbon  compounds  which  are  charadleristic 
of  the  brilliant  work  of  the  present  President  of  the 
French  Chemical  Society,  are  known  to  occur  in  or  have 
already  been  isolated  from  pig-iron. 

It  would  lead  us  too  far  from  our  present  purpose  to 
do  anything  more  than  enumerate  the  largest  number  of 
the  elements  given  above.  Suffice  it  to  say  that  in  what 
follows,  we  shall  confine  ourselves  to  the  five  first  men- 
tioned, viz.,  carbon,  phosphorus,  silicon,  sulphur,  and 
manganese.  And  the  question  which  we  shall  ask  our- 
selves is,  what  is  the  present  condition  of  a  portion  of  the 
analytical  methods  for  the  determination  of  these  sub- 
stances, considering  these  methods  both  in  regard  to 
their  accuracy  and  speed  ?  One  word  of  precaution.  It 
would  be  manifestly  impossible  to  comment  on  all  the 
methods  in  use  for  determining  these  constituents.  To 
enumerate  them  alone  would  weary  your  patience.  We 
shall  confine  ourselves,  therefore,  principally  to  methods 
which  may  be,  or  are,  used  when  the  diverse  interests  of 
producer  and  consumer  are  involved. 

Beginning,  then,  with  total  carbon  in  pig-iron,  wrought 
iron,  and  steel,  we  deem  it  safe  to  say  that  the  method 
by  combustion  in  oxygen  gas,  as  at  present  known  and 
worked   in   many  laboratories,    leaves  very  little   to   be 
desired,  so  far  as  accuracy  is  concerned,  and  is  sufficiently 
rapid  for  most  commercial  uses.     The  modification  intro- 
duced some  years  ago,  of  using  a  solution  of  the  double 
chloride   of  copper  and  ammonium,   instead   of   simple 
chloride  of  copper,*  to  release  the  carbon  from  the  iron, 
took  away  from  the  combustion  method  one  of  its  greatest 
difficulties,  viz.,  the  long  time  required  to  dissolve  the 
metal.  This  modification,  as  many  will  doubtless  remem- 
ber, reduced  the  time  required  for  solution  from  two  or 
three   days  to  an  hour  or  less.      Indeed,  at  the  present 
time,  if  a  good  stirring  machine  is  used,  it  is  quite  pos- 
sible to  dissolve  3  grms.  of  fairly  fine  borings  of  pig-iron, 
wrought  iron,  or  steel,  in  200  c.c.  of  the  proper  solvent  in 
from  ten  to  forty  minutes.     Still  further,  the  studies  of 
the     Committee    on    International     Standards    for    the 
Analysis  of   Iron   and    Steel   have   further  modified  the 
method,  and  it  is  believed  rendered  it  much  more  accu- 
rate.    Among  these  modifications  may  be  mentioned  the 
use  of  an  acid  instead  of  a  neutral  or  basic  solution  of 
the  double  salt  to  dissolve  the  metal.     This  point  was 
thoroughly  worked  out  by  Blair  (Trans.  Am.  Inst.  Mining 
1  ^ng-f  xix.,  614).     Following  this  came  the  work  done  in 
the  laboratory  of  the   Pennsylvania  Railroad  Company, 
demonstrating  the  unreliability  of  the  use  of  the  double 
chloride  of  copper  and  ammonium  as  a  solvent,  owing, 
as  appeared  later,  to  the  probable  presence  in  all  ammo- 
nia and  its  salts  obtainable  in  the  market,  even  those 
marked  '•  C.  P.,"  of  some  carbonaceous  material,  possibly 
pyridine  {Trans.  Am.  Inst.  Mining  Eng.,  xx.,  242)  derived 
from  the  gas  liquor  used  in  making  the  ammonia.     The 
substitution  of  the  potassium  for  the  ammonium  salt  has 
apparently  completely  overcome  this  difficulty,  and  this, 
with  the  use  of  oxygen  gas  instead  of  lead  chromate,  in 
which  to  burn  the  carbon,  and  some  modifications  of  the 
absorbing  and  purifying  train  (yourn.  Amer,  Chem.  Soc, 
XV.,  448),   have   seemingly   placed   the   dry  combustion 
method  for  determining  carbon  in  the  front  rank  of  suc- 
cessful and  accurate  analytical  processes.     The  principal 
known  source  of  error  in  the  method  at  the  present  time 
appears  to  be  in  connexion  with  the  weighing.     The  pot- 
ash   bulbs    and   small   calcium  chloride   tube    used    in 


Presidential  Address  delivered  at  the  Troy  Meeting  of  the  Ameri- 
can Chemical  Society,  December  29, 1896.  From  the  Journal  of  the 
Atturtcan  Chemical  Society,  xix..  No.  a 


*  It  is  di£Scult  to  say  positively  who  first  suggested  this  modifica- 
tion. The  first  mention  in  literature  that  we  are  able  to  find  is  in 
the  Transactions  of  the  American  Institute  of  Mintng  Engineers, 
•v.,  157,  by  J.  B.  Pearse.  But  a  private  communication  from  Andrew 
S.  McCreath,  states  that  he  made  the  suggestion  while  working 
under  Pearse,  and  that  Professor  Richter,  in  the  "  Leoben  Jahrbuch," 
had  previously  suggested  the  use  of  potassium  or  sodium  chloride 
with  copper  chloride,  which  led  him  to  try  the  ammonium  salt. 
McCreath's  description  of  the  method,  as  used  by  himseli,  is  pub- 
lished in  the  Transactions  of  the  American  Institute  of  Mining 
Engineers,  v.,  575. 


258       Some  Present  Possibilities  in  the  Analysis  of  Irom  and  Steel. 


I  Chbuicai.  Nbws, 
I      May  28,  1897. 


absorbing  the  carbon  dioxide  weigh  altogether  some  50  to  1  cent  of  carbon,  but  we  have  seen  very  large  numbers  of 


60  grms.,  and  present  considerable  surface.  If  now,  be 
tween  the  weighing  before  the  combustion  and  the 
weighing  after  the  combustion,  the  interval  being  an  hour 
or  a  little  more,  there  is  considerable  change  in  the  hygro- 
scopic condition  of  the  atmosphere,  an  error  of  coi  per 
cent  may  be  easily  introduced.  If  we  may  trust  our 
experience,  it  is  difficult  to  make  closely  agreeing  dupli- 
cate combustions  in  showery  weather.  Blair  suggests  a 
method  of  overcoming  this  difficulty,  consisting  in  having 
a  second  potash  bulb  and  calcium  chloride  tube  of — as 
nearly  as  possible — the  same  size  on  the  opposite  end  of 
the  balance  when  weighing. 

In  regard  to  the  accuracy  of  the  method  as  at  present 
understood,  it  may  be  said  that  undoubtedly  the  best  test 
of  the  accuracy  of  a  method  is  the  recovery  of  a  known 
amount  of  any   substance   added  to  the   material  to  be 
analysed.     This  procedure  being  manifestly  impossible  in 
the  case  of  iron  and  steel,  we  are  compelled  to  judge  of 
the  accuracy  of  the  combustion  method,  as  applied  to 
these  metals,   in   some    other  way.     For  this   purpose, 
however,  we  have  at  hand  the  results  obtained  by  different 
chemists,  using  different  methods,  but  working  on  the 
same  samples.     In  the  course  of  the  work  done  by  the 
Committee  on  International  Standards  for  the  Analysis  of 
Iron  and  Steel,  the  carbon  in  four  samples  of  steel  was 
determined.     First,   by    using   acid   double    chloride    of 
copper  and  potassium  as  solvent,  and  burning  in  oxygen 
gas  ;  Second,  by  using  the  same  solvent,  and  burning  in 
chromic  acid  solution  ;  and  Third,  by  treating  the  borings 
direA  with  bisulphate  of  potash  and  heat,  conduifling  the 
carbon  monoxide   and  sulphur  dioxide   formed  over  hot 
solid   chromic   acid,  which  oxidised  both   gases  and  re- 
tained the  sulphur  trioxide  formed,  and  finally  measuring 
the  volumes  of  the  resulting  carbon  dioxide  in  an  eudio- 
meter   tube.     Each    method    was    used   by   a   different 
chemist.     The  results  obtained  are  as  follows,  the  letters 
at  the  side  representing  the  four  samples  of  steel,  the 
figures   at   the   top   representing  the   chemists,   and  the 
figures  in  the  columns  the  percentages  of  carbon  in  the 
steel  samples : — 


A     .. 

••     i455(«) 

I  •440(a) 

I  •450(6) 

B     .. 

..     0-815 

0800 

0-815 

C     .. 

. .     0-450 

0-450 

0-448 

D     .. 

..     0-152 

0-185 

0-168 

(a)  Proc.  Eng.  of  Western  Peniia.,  ix.,  [9],  35. 
(6)  Ztscht.  anorg.  Chetn.,  iv.,  [3]  und  [4],  505. 


The  agreement  of  the  results  on  the  first  three  samples 
is  quite  marked.  The  discrepancy  on  the  fourth  sample 
has  not  been  explained.  The  matter  is  discussed  in  con- 
siderable detail  in  reference  (a),  but  we  think  it  safe  to 
conclude  that,  so  far  as  method  goes,  the  determination  of 
total  carbon  in  pig-  or  cast-iron,  wrought  iron,  and  steel, 
is  reasonably  accurate. 

The  speed  of  the  combustion  method  as  at  present 
worked  in  good  laboratories  is  quite  remarkable,  com- 
pared with  the  possibilities  twenty-five  years  ago.  A 
sufficient  supply  of  sample  borings  being  at  hand,  one 
operator  using  two  furnaces  may  readily  make  from  four- 
teen to  sixteen  combustions  in  a  day  of  eight  hours;  it 
being  understood  that  the  bulbs  are  weighed  with  oxygen 
gas  in  them  instead  of  air,  and  that  the  last  weight  of 
each  combustion,  except  the  last  one  at  night,  is  taken  as 
the  first  weight  of  the  succeeding  one.  It  is,  of  course, 
assumed  that  when  turning  out  the  amount  of  work  above 
described,  the  furnaces  and  apparatus  are  all  in  good 
order,  and  everything  working  well.  Accidents,  an 
occasional  overhauling  of  the  apparatus,  blank  combus- 
tions from  time  to  time  for  testing  purposes,  and  once  in 
a  while  an  obstinate  steel  that  refuses  to  dissolve  in  time 
or  gives  trouble  in  filtration,  will  tend  to  diminish  output. 
The  results  obtained  with  this  rapid  work  show,  when 
duplicates  are  made,  occasional  discrepancies,  as  high  as 
three  hundredths  of  a  per  cent  in  a  steel  containing  i  per 


duplicates,  made  as  above  described  which  did  not  dis- 
agree one  one-hundredth. 

Again,  when  work  is  not  so  plentiful  as  to  admit  of  the 
procedure  described  above,  the  method  still  permits  satis- 
factory speed.  Starting  with  a  fresh  sample  of  borings 
and  everything  in  good  order,  but  cold,  it  is  not  difficult 
to  get  two  closely-agreeing  determinations  on  the  same 
sample  in  two  hours  and  a  half.  Of  course,  in  investiga- 
tion or  referee  work,  more  time  would  undoubtedly  be 
used,  especially  if  the  interests  involved  are  very  great. 
But  we  have  many  times  been  astonished  in  our  own 
^  laboratory  at  the  close  agreement  between  the  results  ob- 
tained in  the  rapid  manner  described  above,  and  the 
duplicate  analysis  made  on  the  same  sample  for  confirma- 
tory purposes,  but  using  much  more  time  and  pains. 

Turning  now  to  the  determination  of  combined  carbon 
and  graphite,  we  do  not  find  the  state  of  affairs  so  satis- 
factory.     As  is  well  known,  these  two  constituents  are 
usually  found  by  first  determining  total  carbon,  then  dis- 
solving  another   portion  of  the  sample  in   hydrochloric 
acid,  filtering,  and  washing  with  caustic  potash,  alcohol, 
and  ether,  and  then  burning  the  residue ;  coiledting  and 
weighing  the  carbon  dioxide  formed,  as  in  an  ordinary 
combustion.     The  result  is  called  graphite,  and  the  com- 
bined carbon  is  the  difference  between  the  total  carbon 
and  the  graphite.    But,  as  Shimer  {Trans.  Am.  Inst.  Min. 
Eng.,  XXV.,  395)  has  so  well  shown,  what  we  adtually  get 
by  this  procedure  is  not  necessarily  the  graphite  and  the 
total  combined  carbon  in  the  sample,  but  only  the  com- 
bined  carbon  which   exists   in   the  metal   as   a  carbide 
soluble  in  hydrochloric  acid.     If  the  sample  contains  car- 
bides not  soluble  in  that  acid,  nor  in  the  materials  used 
in  washing,  the  carbon  of  these  carbides  appears  with, 
and  is  counted  as,  graphite.    Shimer  shows  that  titanium, 
and   possibly  vanadium   carbide,  are  apparently  not  in- 
frequently thus  counted.     The  use  of  sulphuric  instead  of 
hydrochloric  acid  leads  to  the  same  error,  while  the  em- 
ployment of  nitric  acid  as  solvent,  apparently  gives  the 
graphite  much  more  definitely,  but  leaves  us  in  doubt  as  to 
whether  the  combined  carbon  is  really  the  combined  carbon 
which  we  want,  in  order  to  have  light  on  the  quality  of 
the  metal  we  are  dealing  with.      It  is  obvious  that  the 
difficulty  here  is  in  our  lack  of  knowledge  as  to  what  car- 
bides adtually  exist  in  pig-  and  cast-iron,  and  if  there  are 
several  of  them,  which  one  or  ones  do  we  adtually  want 
to  know  the  carbon  content  of.     If  we  knew  positively 
that  the  combined  carbon  wanted  was  that  which  exists 
in  the  metal  as  carbides  of  iron  and  manganese,  and  that 
these  carbides  were  soluble  in  hydrochloric  or  sulphuric 
acid,  while  all  other  carbides  present  were  not  soluble  in 
these  acids,  obviously  we  should  use  these  acids  when  deter- 
mining combined  carbon.     On  the  other  hand,  if  we  want 
to  know  only  graphite,  and  care  little  about  the  combined 
carbon,  apparently  nitric  acid  is  the  solvent  to  use.     It  is 
clear  that  much  more  work  is  needed  on  this  subjedt — a 
state  of  affairs  which,  as  we  progress,  we  shall  find  is 
charadleristic  of  other  constituents  of  the  metals  we  are 
considering. 

(To  be  continued). 


Researches  on  the  Composition  of  Wheats  and  on 
their  Analysis. — Aime  Girard. — The  exclusion  from 
human  consumption  of  30/100  of  the  mass  of  wheat  known 
as  "  low  produce  "  and  refuse  milling,  places  at  the  dis- 
posal of  agriculture  a  very  rich  residue  for  the  food  of 
cattle.  These  produdls  are  very  rich  in  fatty  matter,  but 
their  woody  nature  presents  a  certain  resistance  to  the 
adtion  of  solvents.  To  facilitate  this  aftion,  I  advised, 
some  years  ago,  to  moisten  these  produdts  with  hydro- 
chloric acid  at  5  per  cent,  and  to  dry  them  afterwards,  so 
as  to  transform  the  cellules  and  the  vessels  into  pulveru- 
lent  hydrocellulose,  which  is  easily  penetrated  by  benzene 
or  ether. — Comptes  Rendus,  cxxiv..  No.  18. 


Crbmical  Mbws,  I 
May  sS,  1897.     I 


CorydaLine. 


259 


PROCEEDINGS    OF    SOCIETIES. 

CHEMICAL  SOCIETY. 
Ordinary  Meeting,  April  2gth,  1897. 

Professor  Dewar,  F.R.S.,  President,  in  the  Chair. 

Messrs.  Arthur  Croft  Hill,  Edward  G.  Guest,  and 
Horatio  Ballantyne  were  formally  admitted  Fellows  of 
the  Society. 

Certificates  were  read  for  the  first  time  in  favour  of 
Messrs.  Gerald  Noel  Brown,  8, The  Esplanade,  Plymouth; 
George  Lawson  Johnston,  Kingswood,  Sydenham  Hill, 
S.E. ;  William  Taverner,  i,  Stapenhill  Road,  Burton-on- 
Trent. 

The  President  announced  thatthe  Council  had  ordered 
a  re-count  of  the  balloting  papers  handed  in  at  the  Anni- 
versary Meeting.  The  re-count  would  be  conduded  by 
the  two  Scrutators  appointed  by  the  Society  at  the  Anni- 
versary Meeting,  in  the  presence  of  the  Secretaries. 

Mr,  Cassal  enquired  whether  the  adtual  numbers 
would  be  announced. 

The  President  replied  that  he  assumed  that  they 
would. 

Of  the  following  papers  those  marked  *  were  read  : — 
•53.    "On    the   Explosion   of  Chlorine   Peroxide   with 
Carbonic  Oxide."     By  H.  B.  Dixon,  M.A.,  F.R.S.,  and 
E.  J.  Russell,  B.Sc, 

To  test  the  question  whether  dried  carbonic  oxide  is 
more  readily  attacked  by  "  nascent  "  than  by  ordinary 
oxygen,  the  authors  have  fired  a  dried  mixture  of  chlorine 
peroxide  and  carbonic  oxide.  They  find  that  the  car- 
bonic oxide  is  not  completely  burnt  in  the  flame  although 
the  oxygen  is  in  excess  ;  and  the  drier  the  mixture  the  less 
carbonic  oxide  appears  to  be  burnt.  The  results  do  not 
favour  the  view  that  "  nascent  "  oxygen  attacks  carbonic 
oxide  more  readily  than  ordinary  oxygen. 

Discussion. 

Dr.  Scott  thought  it  desirable  to  try  the  effeft  of  some 
compound,  such  as  chloride  monoxide,  which  contained 
only  one  atom  of  oxygen,  before  concluding  that  "  nascent " 
oxygen  was  inoperative. 

Professor  Armstrong  referred  to  the  difficulty  of  ascer- 
taining whether  a  gas  was  completely  free  from  water. 

The  President  thought  that  the  ultra-violet  spedrum 
of  water  vapour,  which  he  and  Professor  Liveing  and  Dr. 
Huggins  had  simultaneously  discovered,  would  be  found 
to  be  a  very  delicate  test  of  its  presence  in  flames  or  ex- 
plosive mixtures. 

Mr.  CkooKES  agreed  with  the  President  as  to  the 
delicacy  of  this  test. 

•54.  "  On  the  Decomposition  of  Iron  Pyrites."  By  W. 
A.  Caldecott,  B.A. 

In  "Watts'  Didlionary  "  (1892  edition,  vol.  iii.,  p.  64) 
it  is  stated  that  ferrous  sulphide  '•  is  formed  by  the  reduc- 
tion of  Fe203  on  ferric  salts  by  decomposing  organic 
matter  in  the  presence  of  sulphates,"  also  that  "  finely- 
divided  yellow  pyrites  (FeSa)  oxidises  in  air  forming 
chiefly  FeS04."  T.  K.  Rose  ("  The  Metallurgy  of  Gold," 
1896,  page  343)  states  that  "  FeSj  is  oxidised  by  air  and 
water,  FeS04  and  free  H2SO4  being  formed." 

In  the  treatment  of  auriferous  pyritic  Witwatersrand 
conglomerate,  a  large  percentage  of  the  ore  is  reduced  by 
wet  crushing  in  the  battery  to  an  impalpable  powder. 
This  fine  material  constitutes  "  slimes,"  and  is  carried  in 
suspension  by  water  into  extensive  dams,  where  it  settles. 
The  slimes  leaving  the  battery  are  free  from  ferrous  sul- 
phide, but  this  compound  may  be  detedled  in  them  a  few 
days  after  deposition  in  the  dams.  The  settled  slimes 
form  a  clayey  mass,  pradlically  impermeable  to  air  and 
water,  and  consequently  subsequent  oxidation  of  the 
ferrous  sulphate  proceeds  extremely  slowly. 


When  iron  pyrites  are  crushed  to  an  impalpable  powder 
in  an  iron  mortar  ferrous  sulphide  is  formed. 

It  thus  appears  that  ferrous  sulphide  and  not  ferrous 
sulphate  may  be  the  first  produdt  of  the  decomposition  of' 
iron  pyrites. 

Owing  to  the  almost  total  absence  of  acidity  in  slimes 
deposited  as  above,  even  when  containing  oSg  per  cent 
ferrous  sulphide,  it  is  probable  that  under  these  conditions 
FeS2  undergoes  dissociation,  and  the  sulphur  is  separated 
as  such ;  the  author  is  engaged  in  further  investigating 
this  subjedt. 

•55.  "  Monochlordiparaconic  Acid  and  some  Condensa- 
tions."    By  Henry  C.  Myers,  Ph.D. 

An  attempt  to  prepare  methylparaconic  acid  by  the  re- 
du(5tion  of  the  trichlor-acid  furnished  the  dichlor-acid, 
which  on  treatment  with  barium  hydroxide  suffered  con- 
densation, forming  the  acid  CgHgC102,  which  has  been 
called  monochlordiparaconic  acid;  its  constitution  is 
under  investigation.  This  acid  loses  its  chlorine  on 
treatment  with  nascent  hydrogen,  producing  a  compound 
having  in  all  probability  the  formula  C9H12O2,  but  it  is  so 
unstable  that  its  investigation  is  very  difficult.  These 
condensations  are  being  further  investigated. 

56.  "  Corydaline."  Part  V.  By  James  J.  Dobbie, 
M.A.,  D.Sc,  and  Fred  Marsden,  M.Sc,  Ph.D. 

When  corydaline  is  heated  on  the  water-bath  with  very 
dilute  nitric  acid  (about  i :  20),  a  difficultly  soluble  nitrate, 
C22H2gN04-HN03,  is  first  formed. 

On  further  heating,  the  solution  becomes  dark  red  in 
colour,  and  soon  ceases  to  give  any  precipitate  on  testing 
with  ammonia.  If  at  this  stage  the  solution  be  allowed 
to  cool,  groups  of  bright  yellow  prismatic  crystals  separate 
out  on  the  sides  of  the  vessel.  The  crystals  consist  of 
the  nitrate  of  a  base — dehydrocorydaline — differing  from 
corydaline  by  four  atoms  of  hydrogen  (cf.  Trans.,  1897, 
Ixxii.,  i.,  175).  The  free  base  is  very  soluble  in  water  and 
alcohol,  and  is  difficult  to  obtain  in  crystals.  The  nitrate, 
C22H25N04-HN03 ;  the  chloride,  C22H25N04-HC1;  the 
platinochloride,  (C22H25N04-HCl)2PtCl4;  and  the  chloro- 
form compound,  C22H25N04*CHCl3,  are  described.  The 
solutions  of  dehydrocorydaline  and  its  salts  have  an 
intense  yellow  colour,  and  give  a  vivid  green  colour  with 
blue  litmus.  Reducing  agents  re-convert  dehydrocory- 
daline into  optically  inadlive  corydaline. 

If  concentration  of  the  acid  solution  be  continued  be- 
yond the  point  at  which  dehydrocorydaline  is  formed 
until  platinum  chloride  no  longer  gives  a  precipitate, 
yellow  coloured  crystals  of  an  acid  melting  at  218°  separate 
out  on  cooling.  This,  acid,  to  which,  for  convenience  of 
reference,  the  name  corydic  is  temporarily  given,  is  readily 
soluble  in  hot  water  and  in  alcohol,  but  insoluble  in  ether. 
Its  aqueous  solution  has  an  intense  yellow  colour,  and 
does  not  give  precipitates  with  any  of  the  metals  in 
aqueous  solution. 

A  silver  salt,  CisHisNOfiAga,  is  obtained  by  precipi- 
tating an  alcoholic  solution  of  the  potassium  salt  of  the 
acid  with  an  alcoholic  solution  of  silver  nitrate.  Corydic 
acid  contains  two  methoxy-groups  and  is  dibasic.  Its 
formula  is  Ci4H9N(OCH3)2(COOH2),iH20.  When 
heated  with  hydrogen  iodide  it  yields,  a  highly  insoluble 
phenolic  acid,  Ci4H9N(OH)2(CO  OH)2-2H20,  which 
separates  from  a  large  quantity  of  hot  water  in  brilliant 
yellow  spangles.  The  lead  salt  of  this  derivative,  dried  at 
130°,  has  the  composition  CieHnNOePb. 

When  corydic  acid  is  boiled  with  a  solution  of  potas- 
sium permanganate,  it  yields  a  mixture  of  at  least  four 

(I).'  An  acid,  Ci2H6N(OCH3)2(C03H)3,  which  crystal- 
lises from  hot  water  in  small  white  acicular  crystals 
melting  at  228*.  This  acid,  which  is  the  chief  produdt  of 
the  oxidation,  contains  two  methoxy-groups.  A  silver 
salt,  having  the  composition  Ci7Hi2N08Ag3,  has  been 
prepared.  (2).  A  hemipinic  acid,  yielding  an  ethylimide 
which  melts  at  228°,  and  differs  therefore  from  the  hemi- 
pinic acid  previously  described  as  occurring  amongst  the 


26o 


X  Ray  Photographs  with  Solid  Alloys, 


(Cheuical  Kews, 
May  2t,  Ibg7. 


produdts  of  oxidation  of  corydaline  with  potassium  per- 
manganate. It  is  thus  established  that  corydah'ne  con- 
tains two  benzene  nuclei,  and  the  formation  of  corydic 
acid  from  the  alkaloid  is  easily  explained  on  the  assump- 
tion that  one  of  the  rings  is  oxidised.  (3).  A  nitrogenous 
acid  melting  at  208°  which  contains  no  methoxy-groups 
and  gives  a  faint  brownish  yellow  colour  with  ferrous  sul- 
phate  solution,  and  evolves  a  strong  odour  of  pyridine 
when  heated  with  lime.  This  acid  has  the  formula 
CgH7N06'H20,  and  is  apparently  a  methylpyridine  tri- 
carboxylic acid.  It  is  not  identical  with  any  of  the  known 
acids  of  this  composition.  It  forms  a  silver  salt, 
C9H4N06Ag3,  and  gives  precipitates  with  lead,  barium, 
and  copper.  (4).  A  nitrogenous  acid  melting  at  243°, 
which  gives  a  yellowish  red  colour  with  ferrous  sulphate 
and  contains  methoxyl. 

Oxalic  acid  and  the  nitrogenous  acid  melting  at  208° 
were  obtained  from  the  mother-liquors  of  corydic  acid. 


Ordinary  Meeting,  May  6th,  1897. 

Professor  Dewar,  F.R.S.,  President,  in  the  Chair. 

Certificates  were  read  for  the  first  time  in  favour  of 
Messrs.  William  Ackroyd,  9,  Grandsmere  Place.  Halifax  ; 
William  Malam  Brothers,  Beechwood  House,  Prestwich, 
near  Manchester ;  William  Cranfield,  5,  Second  Avenue, 
Halifax  ;  A.  F.  Bilderbeck  Gomez,  24A,  Alfred  Place 
West,  South  Kensington ;  Frederick  Roscoe  Grundy, 
B.Sc,  20,  Derby  Road,  Douglas,  Isle  of  Man;  Edward 
Halliwell,  Alexandra  Crescent,  Dewsbury  ;  Harold 
Harman,  Brewers  Sugar  Co.,  Greenock ;  William 
Robertson  Pollock,  Kirkland,  Bonhill,  Dumbarton. 

The  President  stated  that,  in  accordance  with  the 
instrudlions  of  the  Council,  the  two  Scrutators,  in  the 
presence  of  the  Secretaries,  had  re-counted  the  votes  re- 
corded for  the  Presidency  at  the  Anniversary  Meeting. 
The  Scrutators'  report  will  be  presented  to  the  Council  in 
due  course,  but  he  thought  he  might  now  venture  to  say 
that  he  learned  from  the  Senior  Secretary  that  the  votes 
accepted  by  the  Scrutators  were  166  for  the  Council's 
nominee,  and  152  against. 

The  following  were  duly  eledled  Fellows  of  the 
Society:— Messrs.  Herbert  W.  L.  Barlow,  M.A.,  M.B.; 
William  Barlow;  Alfred  Hunter  Boylan;  James  Brierley; 
Henry  Norris  Davidge  ;  Louis  Charles  Deverell  ; 
Alexander  Duckham  ;  Alaric  Vincent  C  Fenby,  B.Sc. ; 
Charles  Henry  Field  ;  Thomas  Girtin,  B.A,  ;  R.  Glode 
Guyer;  Harold  William  Harrie  ;  Sydney  Hill;  W.  J.  G. 
Lasseter,  M.A.  ;  Charles  Macculloch  ;  Willie  Lee 
Mallinson ;  George  Fowlie  Merson  ;  Edmund  Howd 
Miller,  M.A.,  Ph  D. ;  Tom  Mitchell ;  Frederick  Filmer 
de  Morgan;  Joseph  Previte  K.  Orton,  B.A.,  Ph.D.; 
Harry  E.  W.  Phillips,  B.A. ;  Robert  Howson  Pickard, 
B.Sc;  Thomas  Tickle;  William  Herbert  Waite,  B.A.  ; 
Charles  Thomas  Foster  Watts;  John  Welsh;  Charles 
Alfred  West ;  Paul  Thomas  White. 

Of  the  following  papers  those  marked  *  were  read  : — 

•57.  "A  Bunsen  Burner  for  Acetylene."  By  A.  E. 
MUNBY,  M.A. 

The  cheap  produdion  of  calcium  carbide  has  placed  a 
powerful  illuminant  within  the  reach  of  those  who 
possess  no  gas  supply,  but  so  far  little  has  been  heard  of 
the  use  of  acetylene  as  a  heating  agent.  Our  laboratory 
is,  as  far  as  we  know,  the  first  to  make  use  of  the  gas  for 
this  purpose.  We  employ  a  Bunsen  burner  of  special 
dimensions,  the  tube  being  5  m.m.  in  internal  diameter. 
A  slightly  wider  tube  may  be  used,  provided  the  mouth 
be  curved  inwards,  so  that  the  adual  exit  does  not  exceed 
the  diameter  mentioned  ;  if  larger,  the  flame  tends  to 
strike  down.  The  gas  jet  is  very  small,  being  only 
capable  of  delivering  about  i  cubic  foot  of  acetylene  per 
hour  under  6  inches  water  pressure,  such  a  rate  of  con- 


sumption giving  an  ordinary  working  flame.  The  air- 
holes and  collar  are  arranged  as  in  an  ordinary  Bunsen, 
the  exad  size  of  the  former  not  being  of  much  importance 
provided  they  be  large  enough  to  admit  the  air  required. 
The  burner  is  protedted  with  a  cap,  when  not  in  use,  as 
its  efficiency  depends  upon  the  jet  maintaining  its  dimen- 
sions. A  generator  capable  of  giving  gas  under  7  inches 
water  pressure  with  the  full  number  of  burners  in  use  is 
required.  Under  this  pressure  a  large,  perfedly  blue 
flame  is  obtained,  which  may  be  turned  down  to  what 
may  be  termed  a  quarter  Bunsen  flame,  equivalent  to 
burning  the  gas  under  3  to  4  inches  water  pressure.  This 
is  the  smallest  pressure  with  which  the  burner  will  give 
anon-luminous  flame;  when  turned  lower,  the  zone  of 
partial  combustion  appears,  since  the  draught  is  then 
insufficient. 

The  heating  effedt  of  the  flame  is  of  course  very  great, 
enabling  one  to  dispense  with  the  blowpipe  for  some  ope- 
rations, such  as  small  fusions.  From  a  few  experiments 
on  heating  equal  quantities  of  water  under  like  conditions 
with  coal-gas  and  acetylene,  it  would  seem  that  in  prac- 
tice, for  equal  volumes  burnt,  the  latter  has  nearly  twice 
the  heating  power  of  the  former. 

The  use  of  the  gas  should  do  much  to  stimulate  research 
in  country  places  and  on  private  estates. 

*58.  "  The  Reactions  between  Lead  and  the  Oxides  of 
Sulphur."  By  Henry  C.  Jenkins  and  Ernest  A. 
Smith.     (This  paper  appeared  in  our  last  issue,  p.  241), 

Discussion. 

Professor  Roberts-Austen  said  that  he  was  much 
gratified  by  the  fad  that  the  accuracy  of  the  time- 
honoured  equations  given  by  his  distinguished  predecessor. 
Dr.  Percy,  as  representing  the  metallurgy  of  lead,  had 
been  abundantly  justified  by  work  done  in  the  Metal- 
lurgical Laboratory  of  the  Royal  College  of  Science.  He 
could  testify  to  the  extreme  care  which  Messrs.  Jenkins 
and  Smith  had  given  to  the  work,  and  the  reversible  re- 
adions  they  had  discovered  were  not  only  very  interesting, 
but  of  much  industrial  importance.  In  justice  to  Mr. 
Hannay,  it  might  be  conceded  that  the  singular  nature  of 
the  readions  discovered  by  the  authors  of  the  paper 
justified  Mr.  Hannay  in  questioning  the  accuracy  of  the 
old  equations,  and  it  was  satisfadory  that  the  difficulty 
had  now  been  solved. 

The  President,  Mr.  Groves,  and  Prof.  Armstrong 
thought  the  authors'  experiments  showed  that  it  was  un- 
necessary to  suppose  that  any  new  compound  of  lead  and 
sulphur  was  concerned  in  the  metallurgical  process. 

•59.  "X  Ray  Photographs  of  Solid  Alloys."  By  C.  T. 
Heycock,  F.R.S.,  and  F.  H.  Neville. 

In  a  previous  communication  {Trans.,  1889,  Iv.,  666) 
we  discussed  the  behaviour  of  gold  in  sodium  and  the 
state  of  the  gold  in  the  solid  alloy.  We  have  lately 
examined  alloys  of  gold  and  sodium  by  cutting  thin  sec- 
tions from  cylinders  of  the  alloy  of  various  concentrations, 
placing  these  on  a  photographic  plate,  and  photographing 
them  by  means  of  the  X  rays. 

On  account  of  the  much  greater  transparency  of  sodium 
to  these  rays  as  compared  with  gold,  the  individual  crystals 
of  the  alloy  are  clearly  shown.  The  plates  were  about 
12  m.m.  thick,  and  the  alloy  had  been  allowed  to  cool  and 
solidify  very  slowly.  Pure  sodium  shows  no  crystalline 
strudure,  but  an  alloy  containing  3  per  cent  of  gold  shows 
a  mass  of  transparent  sodium  crystals,  with  dark  spaces 
between  the  crystals  where  the  gold  has  concentrated 
during  the  process  of  solidification. 

A  10  per  cent  alloy  of  gold  shows  the  same  phenomena^ 
but  the  crystals  of  sodium  are  narrower,  and  the  dark 
spaces  occupy  a  larger  area. 

The  appearance  of  the  sodium  crystals  strongly  recalls 
the  fern-like  pattern  seen  when  ammonia  chloride  is 
crystallised  on  a  microscopic  plate,  doubtless  due  to  the 
fad  that  sodium,  like  so  many  other  metals,  crystallises 
in  the  regular  system.     An  eutedic  alloy  of  gold  and  so- 


Chemical  Nbws,  i 

May  28.  1897.      f 


Text-book  on  Tea-planting  and  Manufacture. 


261 


dium  (23*1  per  cent  gold),  shows,  as  one  would  expeA, 
scarcely  any  strudlure,  because  the  crystals  of  gold  and 
sodium  separate  out  simultaneously,  and  are  too  minute  to 
be  detedted  by  such  a  method. 

A  solution  obtained  by  saturating  sodium  with  gold  at 
a  temperature  considerably  above  the  melting  point  of 
sodium  shows  a  net-work  of  black,  opaque  needles, 
which  are  no  doubt  crystals  of  gold  which  have  separated 
and  grown  to  a  considerable  size  as  the  liquid  cooled. 

No  sodium  crystals  are  here  visible,  as  the  groundwork 
•  consisted  of  the  eutedlic  alloy.  We  have  been  able  to 
demonstrate  the  internal  structure  of  a  solid  alloy,  and  to 
show  that  the  process  of  solidification  is  strictly  com- 
parable to  that  of  a  saline  solution,  the  details  being 
perfedliy  visible  to  the  naked  eye. 

We  have  already  examined  some  aluminium  alloys  by 
this  method,  and  hope  to  present  a  complete  account  of 
the  work  to  the  Society,  The  method  will  probably  be 
applicable  in  all  cases  where  there  is  a  considerable  dif- 
ference in  transparency  between  the  metals  of  an  alloy. 

Discussion. 

Prof.  Roberts-Austen  said  that  the  use  of  Rontgen 
rays  for  revealiugthe  structure  of  certain  alloys  possessed 
advantages  when  it  was  desirable  to  view  the  alloys  as 
transparent,  as  distinguished  from  the  strudlure  shown  by 
a  seiftion  in  a  single  plane.  The  strudlure  of  alloys  as 
revealed  by  microphotography  had  now  attained  great 
perfedtion,  notably  in  the  hands  of  M.  Osmond  in  France, 
and  it  was  a  subje(5l  to  which  Professor  Austen  had 
recently  given  much  attention  ;  but  the  X  rays  might  be 
very  useful  in  the  case  of  alloys  containing  one  trans- 
parent metal.  When  Rontgen's  great  discovery  was  first 
published,  Prof.  Austen  had  examined  the  relative  trans- 
parency of  certain  metals,  and  endeavoured  to  detedt  the 
difference  between  hard  and  soft  steel,  but  the  sedlions  of 
steel  employed  were  too  thick,  and  the  experiments  were 
abandoned. 

It  had  been  shown  by  Osmond  and  by  Charpy  that 
euteflic  alloys  have  a  pearly  structure,  and  Prof.  Austen 
thought  that  the  gold-sodium  euteftic  shown  on  the 
screen  by  Mr.  Heycock  also  had  the  pearly  strudure.  As 
a  good  example  of  the  distribution  produced  by  freezing. 
Prof.  Austen  stated  that  if  a  triple  alloy  of  copper,  anti- 
mony, and  lead  was  cast  as  a  rod  and  fracSlured  trans- 
versely, a  purple  ring  of  the  "regulus  of  Venus  "  (the 
copper  antimony  alloy)  surrounded  the  grey  alloyed  lead 
which  was  driven  to  the  centre,  so  that  there  was  a  grey 
rod  inside  a  purple  tube.  He  hoped  that  Messrs.  Heycock 
and  Neville,  who  were  so  greatly  extending  our  knowledge 
of  alloys,  would  continue  their  investigations. 

The  President  remarked  that  this  was  an  important 
and  interesting  communication,  as  illustrating  the  service 
the  Rontgen  rays  might  be  to  the  chemist.  Soon  after 
the  announcement  of  the  original  discovery,  he  made  ex- 
periments on  the  transparency  of  the  elements  to  the  new 
rays,  and  took  a  number  of  photographs.  In  a  verbal 
communication  to  the  Royal  Society,  he  had  announced 
that  opacity  of  elements  to  the  rays  increased  in  the  same 
series  with  their  atomic  weight.  He  thought  the  rays 
might  sometimes  be  of  use  in  settling  doubtful  cases  of 
atomic  weight.  For  example,  if  liquid  or  solid  argon  were 
found  to  be  less  transparent  than  oxygen  or  nitrogen  in  a 
similar  condition,  it  might  be  safely  concluded  that  its 
atomic  weight  is  higher  than  that  of  either  of  the  other 
constituents  of  air. 

Research  Fund. 

A  meeting  of  the  Research  Fund  Committee  will  be  held 
in  June.  Applications  for  grants,  accompanied  by  full 
particulars,  should  be  sent  to  the  Secretaries  before 
June  8th. 

List  of  Fellows. 

A  new  list  of  Officers  and  Fellows  of  the  Chemical 
Society  being  in  course  of  preparation,  it  is  requested  that 
Fellows  will  send  any  alteration  of  address,  without  delay, 
to  the  Assistant  Secretary,  Burlington  House,  London,  W. 


NOTICES  OF  BOOKS. 


Tea :  a  Text-book  on  Tea-planting  and  Manufacture, 
Comprising  Chapters  on  the  History  and  Development 
of  the  Industry,  the  Cultivation  of  the  Tea-plant, 
the  Preparation  of  the  Leaf  for  the  Market,  the  Botany 
and  Chemistry  of  Tea,  &c. ;  with  some  Account  of  the 
Laws  affeding  Labour  in  Tea-gardens  in  Assam  and 
elsewhere.  By  David  Crole  (late  of  the  Jokai  Tea 
Company,  &c.).  Illustrated.  London  :  Crosby  Lock- 
wood  and  Son,  Stationers'  Hall  Court,  Ludgate  Hill. 
1897.     8vo.,  pp.  242. 

We  have  here  an  encyclopedic  monograph  on  tea,  almost 
from  every  conceivable  point  of  view.  The  planter,  the 
merchant,  the  general  consumer  may  all  very  well  be  inte- 
rested in  a  natural  produdt  which  is  here  truthfully  pro- 
nounced as  the  great  "rival  of  alcohol"  among  the 
British  race,  and  which  unfortunately  shares  its  deleterious 
adtion  on  public  health.  The  "tea-dinner"  is  a  powerful 
agent  in  sapping  our  national  health  and  vitality,  by  the 
simple  process  of  rendering  animal  foods  of  various  kinds 
indigestible,  and  by  the  equally  unsatisfadtory  trick  of  sub- 
stituting "  bread  and  butter  "  for  more  nourishing  viands. 
But  our  author,  whilst  fully  admitting  the  perils  of  tea- 
drinking  in  excess,  as  indulged  in  by  Samuel  Johnson, 
lays  down  three  conditions  under  which  the  Indian  herb 
may  be  consumed  not  merely  with  safety,  but  even  with 
benefit.  He  tells  us  not  to  use  water  which  has  been 
boiling  before.  "  Put  cold  water  in  the  kettle,  and  diredlly 
it  comes  to  a  boil  use  it  for  making  the  tea,  and  also  for 
previously  heating  the  tea-pot  and  cups." 

"  Infuse  for  about  four  minutes,  and  five  at  the  outside, 
and  then  drain  the  liquor  into  another  vessel,  so  that  no 
tea-leaves  remain  soaking  in  the  liquor. 

"  It  is  best,  from  every  point  of  view,  to  use  only  Indian 
or  Ceylon  tea." 

These  rules  substantially  agree  with  the  pradlice  of 
experienced  tea-brokers,  but  unfortunately  they  disagree 
with  many  laundresses  and  other  poor  women,  who  allow 
a  minute  dose  of  tea  to  simmer  on  the  hob  until  not  only 
all  the  tea  but  all  the  tannin  have  been  extradted.  Mr. 
Crole  refers  to  the  very  extensive  use  of  non  narcotic 
beverages, — tea,  mate,  coffee,  cocoa,  &c,, — and  suggests 
that  they  are  in  some  unknown  method  utilised  in  the 
human  economy.  To  solve  this  and  similar  questions 
would  doubtless  be  a  worthier  expenditure  of  brain-power 
than  preparing  for  examinations. 

In  Assam  the  greater  part  of  the  tea  crop  grows  in  the 
rich  soil  of  the  valleys.  A  bush  to  do  its  best  requires 
about  16  square  feet  of  well-cultivated  soil  around  it.  The 
tea-plant  requires  a  very  rich  soil,  a  tropical  rainfall  such 
as,  e.g.,  10  inches  daily,  and  a  very  hot  sun. 

The  author  thinks  that  not  only  British  colonies,  but 
Russia,  are  preferring  Assam  tea  to  those  imported  over- 
land from  China.  Without  this  increasing  demand  the 
tea-trade  of  India  and  Ceylon  will  be  swamped  by  over- 
produdtion.  The  author  suggests  that  it  would  be  a  wise 
policy  if  the  tea-growers  would  seek  to  open  out  new 
markets.  At  present  they  are  chiefly  following  out  the 
suicidal  policy  of  opening  up  fresh  lands.  One  of  the 
perils  of  the  planter  must  be  sought  in  the  inroads  of 
stray  beasts,  buffaloes,  and  —  what  is  much  worse  — 
elephants,  unless  the  prepared  lands  are  fenced  in  with 
barbed  wires. 

Among  the  animal  parasites  which  work  havoc  in  a 
plantation  is  the  "  red  spider,"  not  unknown  in  our  con- 
servatories at  home. 

The  mosquito  blight  is  a  scourge  incorredtly  named,  but 
fatally  destrudlive.  The  only  remedy  known  is  to  burn 
down,  root  and  branch,  all  the  bushes  aifedted.  Mr.  Crole 
recommends  the  most  jealous  inspedlion,  lest  the  enemy 
should,  like  the  coffee-bug  of  Ceylon,  suddenly  over- 
whelm all  the  plantations.    The  number  of  possible  anti- 


262 


Respiratory  Proteids. 


I  Chemical  News, 
1     May  28,  1897. 


dotes,  and  the  season  and  manner  of  their  application, 
require  careful  study.  Copper  sulphate  has  been  tried  for 
"  mosquito  blight,"  but  not  with  sufficient  perseverance 
to  admit  of  a  decisive  judgment.  We  hope  that  some 
experimentalist  will  appear  more  successful  than  Dr.  Koch 
has  proved  against  the  Rinderpest. 

In  "Appendix  B"  we  find  a  list  of  blight,  microbia, 
and  their  supposed  remedies  and  their  enemies, — proved 
oj  hoped  for, — which  will  prove  suggestive  reading. 

The  aspirant  after  laurels,  in  this  most  useful  or  rather 
necessary  warfare,  must  bear  in  mind  that  what  will 
destroy  an  animal  may  be  absolutely  harmless  to  a  para- 
sitical plant,  and  vice  versa. 

The  operations  of  withering  and  drying  the  tea-leaf 
have  given  scope  to  no  little  skill,  and  the  results,  those 
especially  of  the  Gibbs  machine,  leave  little  if  anything 
to  be  desired. 

Mr.  Crole  remarks  it  as  an  inconsistency  that,  after  the 
utmost  care  has  been  used  in  every  detail  of  the  tea- 
manufadlure,  it  is  stamped  into  the  boxes  with  the  boot- 
shod  feet  of  the  people  engaged  in  the  warehouses  in 
London. 

Mr.  Crole's  work  must  commend  itself  to  the  favour- 
able notice  of  a  vast  and  influential  portion  of  the 
British  public. 


Respiratory  Proteids,  Researches  in  Biological  Chemistry. 
By  A.  B.  Griffiths,  Ph.D.,  F.R.S.  (Edin.),  F.C.S., 
Ledurer  on  Chemistry  at  the  Brixton  School  of  Phar- 
macy, Member  of  the  Chemical  Societies  of  Paris  and 
St.  Petersburg,  Author  of  "  Physiology  of  the  Inverte- 
brata,"  "A  Manual  of  Baderiology,"  "  Researches  on 
Micro-organisms,"  &c.       London  :  L.  Reeve  and  Co. 
1897.     Pp-  ^26. 
The  purpose  of  the  present  work  is  to  expound  recent 
researches  in   biological   chemistry,  giving  details  of  the 
jespiratory  proteids  in  the  blood  of  animals.     The  author 
concludes  that  the  blood  of  the  earthworm  is  chemically 
comparable   to    that,   e.g.,   of   the   dog.     The   blood   of 
jnseds  (e.g.,  the  house-fly)  contains  haemoglobin.     The 
•blood  of  the  Lepidopterais  principally  green.  Lepidoptera 
are   free   from   respiratory    pigments,    but    have   still    a 
respiratory  fundion.     According  to  Regnault,  Reiset,  and 
Munk,  insedls,  in  proportion  to  their  weight,  take  up  as 
much  oxygen  as  the  highest  vertebrates.      Poulton  has 
shown  that  larval  blood  coagulates  much   more  rapidly 
than  pupal  blood. 

The  blood  of  three  species  of  arachnids  has  been 
analysed,  and  found  in  every  case  to  contain  copper  in 
the  form  of  haemocyanin.  The  blood  of  most  gasteropods 
and  cephalopods  also  contain  hasmocyanin. 

The  spedra  of  certain  respiratory  pigments  {e.  g., 
echizochrome,  oxychlorocruentin,  oxyhasmoglobin,  haemo- 
globin, myohaematin,  alkaline  haematoporphyrin,  and 
acid  haematoporphyrin)  are  shown  in  a  diagram ;  the 
serum  shows  two  bands  in  the  green,  but  turns  to  a  violet- 
red  if  allowed  to  remain  in  contadt  with  the  clot. 
Chlorocruorin,  a  green  colouring-matter  found  in  the  blood 
of  Saballa,  is  a  respiratory  pigment. 

Haemocyanin,  the  chief  oxygen  carrier  in  the  blood  of 
the  higher  invertebrates,  may  be  conveniently  studied  in 
the  blood  of  the  lobster,  the  crab,  and  the  sepia,  which 
contain  it  to  the  extent  of  about  0*30  per  cent. 
Haemogonin  gives  a  characteristic  rose-colour  with  Millon's 
reagent.  Pinnaglobine  contains  mariganese.  The  author 
points  out  that  the  respiratory  produds  of  animals 
(Mn  =  55,  Fe  =  56,  Cu  =  63)  do  not  differ  much  from  each 
other,  and  asks  if  these  weights  have  any  important 
meaning.  "  What  bearing  has  Prout's  hypothesis  or 
Crookes's  theory  of  the  genesis  of  the  elements  on  the 
subjedl  ?  Why  should  the  methods  present  in  respiratory 
proteids  have  pradlically  the  same  atomic  weight,  and  be 
located  about  a  quarter  of  the  distance  from  the  lowest 
weight  (H  =  i)  to  the  highest  weight  (U  =  24o)?  Has  the 
subjeft   any  bearing  on   the  dodlrine    of   evolution,  the 


theory  of  natural  selection,  and  the  adtion  of  the  en- 
vironment ?  " 

These  are  questions  which  merit  and  will  doubtless 
repay  a  careful  study. 

The  Appendix  contains  much  interesting  matter  con- 
cerning pelagine,  pupine,  cupine  (containing  lithium), 
carminic  acid,  lepidotic  and  lepidopteric  acids. 

To  all  students  of  biological  chemistry  this  little  book 
will  prove  deserving  of  close  study. 


The   School  of  Mines,  Laramie,   Wyoming.     Petroleum 
Series.     Bulletin  No.  2,  January,  1897. 

This  Report  comprises  an  account  of  the  geology  of  the 
Popo  Agie,  Lander,  and  Shoshons  Oil-fields,  by  W.  C. 
Knight,  Professor  of  Geology;  and  an  analysis  of  the 
petroleum  of  the  same  distrifts,  by  E.  E.  Slosson,  Pro- 
fessor of  Chemistry. 

Prof.  Slosson  remarks  that  the  higher  the  specific 
gravity  of  an  oil,  the  higher  will  be  the  flashing,  burning, 
boiling,  and  freezing  points,  the  darker  also  the  colour, 
and  the  greater  the  viscosity.  The  specific  gravities  in 
this  report  have  been  taken  at  15°  C.  by  the  Westphal 
balance  or  the  flask.  Viscidities  have  been  taken  by 
means  of  Engler's  viscosometer.  The  Popo  Agie  oil  is 
0-90000,  being  lighter  than  samples  taken  in  1897  and 
1887. 

The  flashing-point  of  the  crude  oil  is  32°  C,  and  the 
ignition-point  58°  C.  It  is  still  fluid  at  - 10°  C.  Its 
calorific  power,  as  determined  by  the  bomb-calorimeter, 
is  io'437  calories  per  grm.  =  i4'57iooo  foot-pounds  of 
energy  per  lb.  of  oil.  It  is  not  fluorescent,  and  on  distil- 
lation light  oils  and  non-condensible  gases  are  given  off 
at  300°  —  32°,  and  paraffin  appears  in  the  heavier  dis- 
tillates. 

In  its  crude  state  Popo  Agie  oil  is  inferior  to  the  Salt- 
creek  oil,  on  account  of  the  presence  of  light  oils,  tar,  and 
sulphur  compounds. 

AH  the  produds  of  the  distillation  of  the  Popo  Agie 
petroleum  can  be  capable  of  utilisation.  The  gases  can 
be  used  for  firing,  and  the  coke,  which  is  very  hard  and 
porous,  is  fit  for  metallurgical  uses.  The  residues  from 
filtration  can  be  worked  up  into  paraffin  or  vaseline. 


Report  of  the  Senior  Analyst  of  the  Department  of  Agri- 
culture of  the  Cape  of  Good  Hope,  for  the  Year  1896. 
Cape  Town  :  W.  A.  Richards  and  Sons.     1897. 

The  number  of  articles  analytically  examined  and  reported 
on  during  this  year  is  lower  than  in  the  year  immediately 
preceding,  but  is  nevertheless  very  satisfadtory  when  com- 
pared with  the  work  of  former  years,  being  almost  double 
that  of  the  previous  highest. 

Among  the  foods  analysed  under  the  Adulteration  Adl, 
we  note  that  that  21  per  cent  were  found  to  be  adulterated 
in  1896,  as  compared  with  18  per  cent  and  30  per  cent 
during  1895  and  1894  respectively.  These  figures  show 
the  great  necessity  existing  for  proper  control  over  the 
quality  of  foods  offered  for  sale  ;  milk  and  coffee  were 
the  greatest  sinners  (or,  perhaps,  sinned  against)  in  this 
respecSt. 

As  usual,  a  number  of  samples  of  water  have  been 
submitted  for  analysis  to  ascertain  their  suitability  for 
drinking  purposes,  but  no  very  definite  results  are  here  re- 
corded. "  In  my  last  three  annual  reports,"  we  read,  •'  refer- 
ence was  made  to  the  bad  quality  of  practically  all  the 
water  obtained  from  wells  at  Rondebosch  and  Claremont. 
Each  year  brought  its  evidence  in  the  diredtion  of  pollu- 
tion, and  1896  has  not  been  exceptional  in  this  respedt. 
Again  have  samples  of  well  water  from  Rondebosch  been 
submitted  for  analysis,  and  again  have  these  waters  been 
found  to  be  polluted  and  unfit  for  use."  This  points  to  a 
serious  lack  of  control ;  if  no  steps  can  be  taken  in  four 


Chbuical  News,  i 
May  28, 1897.     t 


Chemical  Notices  from  Foreign  Sources, 


263 


years  to  remedy  such  a  state  of  things,  is  it  to  be 
wondered  at,  that  the  death-rate  from  typhoid  and  fevers 
is  so  high  in  South  Africa  ? 

A  most  important  matter  in  a  large  agricultural  country 
like  Cape  Colony  is  the  analysis  of  soils,  and  the  recom- 
mendation of  the  most  suitable  fertilisers  to  be  added. 
Eighty-nine  of  such  analyses  have  been  made  over  a 
widely  extended  area. 


CORRESPONDENCE. 


PERMEABILITY   TO   X  RAYS. 

To  the  Editor  of  the  Chefiiical  News. 
Sir, — In  an  article  on  the  "  Permeability  of  Various  Ele- 
ments to  the  Rontgen  Rays  "  published  in  the  Chem.  News 
of  December  i8th,  1896  (vol.  Ixxiv.,  p.  291),  I  mentioned  an 
experiment  with  sodium  fluoride,  chloride,  bromide,  and 
iodide,  with  a  view  to  seeing  how  the  permeability  of  the 
halogens  varied  with  atomic  weight.  Unfortunately  the 
coil  used  gave  such  a  small  spark  that  the  sodium  fluoride 
alone  showed  any  permeability.  Since  then  I  have  obtained 
a  larger  coil  and  have  been  able  to  repeat  the  experiment. 
Instead  of  sodium  iodide,  however,  I  took  the  equivalent 
quantity  of  iodine.  It  was  quite  evident  that  fluorioe  is 
much  more  permeable  than  chlorine,  which  latter  is  more 
permeable  than  bromine  or  iodine,  these  two  being  nearly 
alike.  Amorphous  phosphorus  and  sulphur  tested  at  the 
same  time  were  somewhat  more  permeable  than  sodium 
chloride  containing  the  same  weight  of  chlorine,  hut  con- 
siderably more  permeable  than  sodium  fluoride.  On  the 
same  plate  I  had  the  radiograph  of  a  crystal  of  beryl, 
12  m.m.  thick,  and  of  a  crystal  of  zircon  of  half  the  thick- 
ness. The  latter  was  pradtically  opaque,  the  former  very 
perceptibly  permeable.  (Beryllium  has  a  low  atomic 
weight  and  zirconium  a  high  atomic  weight  ;  garnet  and 
zircon  are,  I  think,  the  only  gems  containing  elements  of 
high  atomic  weight,  and  they  are  the  only  impermeable 
ones).  I  have  now  tested  the  impermeability  of  all  the 
elements  whose  atomic  weight  is  not  above  40,  and  of  a 
very  considerable  number  of  those  with  high  atomic 
weight. 

All  the  elements  with  high  atomic  weight  below  that  of 
phosphorus  are  a  great  deal  more  permeable  than  those 
of  atomic  weight  higher  than  potassium,  those  elements 
with  atomic  weight  between  30  and  40  filling  in  the 
transition  space  somewhat  imperfecftly. 

The  atomic  weight  of  boron  differs  from  that  of  alu- 
minium by  just  the  same  amount  that  fluorine  does  from 
chlorine,  but  the  permeabilities  do  not  differ  nearly  so 
much  in  the  former  case  as  in  the  latter.  There  is  always 
a  great  difference  between  the  permeability  of  an  element 
with  atomic  weight  below  30  and  a  similar  element  whose 
atomic  weight  is  above  30. — I  am,  &c., 

John  Waddell. 

Royal  Military  College, 
KingstOD,  Canada. 


ESTIMATION   OF  CARBON  IN  FERRO-CHROME. 

To  the  Editor  of  the  Chemical  News. 
Sir, — In  your  last  issue  appears  the  record  of  a  very 
valuable  series  of  experiments  carried  out  by  Messrs. 
Brearley  and  Leffler  on  the  ••  Estimation  of  Carbon  in 
Ferro-chrome."  The  authors,  however,  assert  that  my 
method  is  only  capable  of  yielding  about  4^  of  the  9  per 
cent  of  carbon  present  in  such  alloys.  Such  a  statement 
should  only  have  been  made  on  the  surest  grounds.  As  a 
matter  of  fadt  the  method  when  properly  carried  out  yields 
on  an  average  8  to  9  per  cent  of  carbon  as  the  contents  of 
rich  ferro-chromes,  and  that  without  the  violent  readtions 
described  by  the  authors. 


They  also  say  "  no  naked  tube  obtainable  would  standi 
the  ordinary  furnace  heat."  It  is  true  that  such  tubes  are 
not  easy  to  obtain,  but  they  are  nevertheless  obtainable. 

It  would  be  interesting  to  know  the  type  of  furnace 
used  by  the  authors,  also  the  diameter  of  the  main  gas- 
pipe.  With  a  2  inch  gas  main,  a  Hoffman  furnace  in 
which  the  openings  of  the  clay  burners  have  been 
enlarged,  and  with  the  gas  at  night  pressure,  a  blowpipe 
is  not  necessary  for  the  combustion  of  0*5  grm.  of  ferro- 
chrome  flour  with  10  grms.  of  chromate  of  lead.  With  a 
poor  furnace,  or  a  limited  gas  supply,  the  results  are  as 
described  by  Messrs.  Brearley  and  Leffler.  With  refer- 
ence to  the  authors'  statements  about  moist  and  dry 
oxygen,  it  is  evident  that  they  do  not  quite  grasp  the 
meaning  of  these  terms.  It  is  also  clear  from  their 
remarks  that  they  have  never  used  dry  oxygen  in  which 
bright  steel  drillings  are  unoxidised  at  a  full  red  heat. 
My  instrudions  had  reference  to  almost  chemically  dry 
oxygen  issuing  from  a  tube  closely  packed  with  minute 
granules  of  potash-pumice,  previously  well  dried.  To 
restore  the  necessary  humidity  to  the  gas  it  was  passed 
over  "  some  loose  fragments  of  slightly  moistened 
asbestos." 

It  is  obviously  impossible  that  gas  taking  up  moisture 
from  shreds  of  damp  asbestos  placed  at  the  cool  inlet  end 
of  the  tube  could  deposit  water  at  the  hotter  exit  end. 
Moreover,  I  never  obtain  a  deposit  of  '•  oxide  of  lead  "  in 
the  position  just  named,  for  the  simple  reason  that  be- 
tween the  ferro-chrome  and  the  exit  there  are  three  plugs 
of  asbestos  and  a  6-inch  column  of  closely  packed  small 
fragments  of  copper  oxide. — I  am,  &c., 

J.  O.  Arnold. 

The  Technical  School,  Sheffield, 
May  24,  1897, 


CHEMICAL    NOTICES    FROM    FOREIGN 
SOURCES. 


Note.— All  degrees  of  temperature  are  Centigrade  unless  otherwiBtf 
expressed. 

Bulletin  dt  la  Societe  Chimiqtie  de  Paris. 
Series  3,  vols.  xvii.  and  xviii..  No.  8. 

Study  of  the  Hydration  of  Meta-phosphoric  Acid. 
— MM.  Berthelot  and  Andre.— The  authors  show  that 
sodic  meta-phosphates  prepared— (i)  By  heating  mono- 
sodic  phosphate  to  280= ;  (2)  by  melting  this  salt  at  a  red 
heat— behave  very  differently  in  dilute  solutions.  The 
acid  titration  of  the  first  salt,  done  immediately  after  its 
solution,  and  again  after  the  lapse  of  a  variable  number  of 
days,  indicates  the  presence  of  a  considerable  quantity  of 
a  mixture  of  ortho-  and  pyro-phosphoric  acids,  while  an 
acetic  magnesia  mixture  produces,  when  warmed,  an 
abundant  precipitate  of  ammonia  -  magnesic  pyro- 
phosphate,  representing  80  per  cent  of  the  total  phos- 
phorus present.  The  acid  titration  of  the  second  salt,  on 
the  contrary,  indicates  that,  under  the  same  conditions, 
the  formation  of  ortho-  and  pyrophosphoric  acids  is  much 
slower ;  the  precipitate  only  representing  50  per  cent  of 
the  total  phosphorus.  The  free  acids  prepared  by  mean» 
of  these  salts  confirm  these  results. 

Remarks  on  the  subje(5l  of  Colour  Reacflions  of 
Quinine. — E.  Blaise. — The  Vogel  readlion  is  independent 
of  ferrocyanide  of  potassium  ;  it  suffices  to  treat  the 
quinine  salt  with  bromine-water  and  dilute  ammonia  ta 
obtain  the  red  colour ;  this  becomes  green  if  strong  am- 
monia be  used. 

Law  of  Thermic  Constants. — D.  Tommasi. — A 
large  nunber  of  measurements  of  the  heat  of  combination 
have  been  made  since  1882  confirming  the  views  then 
put  forth  by  M.  Tommasi.  Many  obje(ftions  were  at  first 
raised,  but  these  have  been  finally  swept  on  one  side  and 
satisfied. 


264 


Meetings  for  the  Week, 


(Chbuical  ^Bws, 
1      May  28,  1897, 


Cause  of  Oxidation  of  Imitation  Gold  Foil. — Leo 
Vignon. — Not  suitable  for  abstradtion. 

Research  on  the  Coal-tar  Colours  in  White  Wines, 
and  the  Difference  between  these  Colouring 
Materials  and  those  of  Caramel. — A.  D'Aguiar  and 
"W.  da  Silva. — It  has  been  suggested  that  the  methods 
used  to  deteft  coal-tar  colours  in  matured  wines  is  at  fault, 
and  causes  confusion  of  caramel  with  aniline,  yellow  and 
orange.  The  authors  give  the  results  of  three  series  of 
experiments  made  by  them  with  eleven  aniline  colours, 
one  caramel,  and  one  natural  wine.  They  conclude  that 
caramel,  treated  in  the  ordinary  manner  by  amylic  alcohol 
made  alkaline  with  ammonia,  gives  results  always  very 
doubtful  and  sometimes  negative.  The  yellow  aniline 
colours,  on  the  contrary,  give  very  clear  results.  Experi- 
ments with  amylic  alcohol  in  barytic  solution,  and  acetic 
ether  in  barytic  and  ammoniacal  solution,  gave  no  better 
results  with  regard  to  caramel.  Further  experiments  were 
made  with  subacetate  of  lead,  acetate  of  mercury  and 
potash,  and  acetate  of  mercury  and  magnesia,  and  the 
authors  finally  conclude  that  the  methods  commonly  in 
use  may  be  in  every  way  relied  on. 

Estimation  of  Small  Quantities  of  Glycerin. — M. 
Nicloux. — The  estimation  of  glycerin,  based  on  the  re- 
adlion  of  bichromate  of  potash  and  sulphuric  acid,  has 
been  studied  by  many  chemists.  The  author  traverses  the 
statement  of  MM.  Bordas  and  Raczkowski  that  the  re- 
adion  can  be  formulated  by  the  following  equation  : — 

8SO4H2  +  3K2Cr207  +  {CH20H)2CH.0H  =  HCOOH  + 
+2CO2  +  11H2O  +  2Cr2{S0^)i+K2S0^+K2Cr20y+ 
+2K2SO4. 

The  mistake,  he  says,  cannot  be  accounted  for  by  a 
printer's  error,  as  on  one  side  of  the  equation  we  have  3 
molecules  of  bichromate,  and  on  the  other  only  i  molecule 
of  bichromate  and  sulphate  of  potassium. 

Notice  to  Authors.  —  The  Secretary  begs  that 
the  authors  of  any  papers  (French  or  foreign)  sent 
in  to  the  Society  will  also  send  an  abstra(^.  This  is 
rendered  necessary  by  the  large  number  of  communica- 
tions received,  and  the  fa<fl  that  the  salient  points  may 
be  unintentionally  overlooked  by  reason  of  the  abstradlor 
not  being  so  well  versed  in  the  particular  subjedl  as  the 
author  must  be.  It  has  been  decided  that  such  abstradls, 
when  signed  by  the  author,  will  be  printed  at  the  earliest 
opportunity,  if  not  more  than  one  page  in  length,  and  if 
sent  in  not  later  than  a  fortnight  after  the  publication  of 
the  original. 


MISCELLANEOUS. 


Atomic  Models  (Patent  No.  1999,  1897). — A  patent 
has  recently  been  granted  to  Mr.  Frederick  George 
Edwards,  of  London,  by  which  the  Government  afford 
protedlion  to  his  idea  that  all  atoms  can  be  represented 
by  varying  numbers  of  tetrahedrons.  The  germ  of  the 
idea  appears  to  be  that  as  there  about  seventy  elements 
known  to  chemists,  and  that  tetraiiedrons  can  be  grouped 
together  in  as  many  as  seventy  ways,  the  latter  can 
illustrate  the  former.  This  is  the  idea;  the  pradtice,  the 
inventor  shows,  is  not  so  simple.  For  instance,  he  says  : 
— "  Regular  tetrahedrons  do  not  fit  exadtly,  but  each 
tetrahedron  is  so  nearly  regular  that  it  may  be  supposed 
each  of  the  elements  were  {sic)  created  from  regular  tetra- 
hedrons in  a  plastic  condition."  This  strikes  us  as  a 
beautiful  example  of  inventing  fadls  to  fit  a  theory.  We 
are  glad  to  find  that  Mr.  Edwards  has  not  patented  atoms 
per  se,  but  merely  the  form  he  thinks  they  take,  together 
with  a  few  names  of  elements,  hitherto  undiscovered,  but 
prediifted  by  him.  These  are  : — Icosagon,  atomic  weight 
10;  ;ir-odine,  atomic  weight  215;  and  zadmium,  atomic 
weight  245.      It  will  be  interesting  to  watch  the  adion 


for  infringement  of  patent  which  will  result  if  any  chemist 
engaged  in  research  should  have  the  temerity,  or  the  mis- 
fortune to  discover  either  of  these  predidted  elements.  A 
lithographed  diagram  at  the  end  gives  the  shape  of  thirty- 
two  elements,  with  atomic  weights  made  to  fit ;  we  are 
sorry  to  have  to  record  the  fadl  that  many  of  these  atomic 
weights  are  wrong,  but  then  so  probably  are  the  shapes. 


NOTES    AND    QUERIES. 

*^*  Our  Notes  and  Queries  column  was  opened  for  the  purpose  of 
giving  and  obtaining  information  likely  to  be  of  use  to  our  readers 
generally.  We  cannot  undertake  to  let  this  column  be  the  means 
of  transmitting  merely  private  information,  or  such  trade  notices 
as  should  legitimately  come  in  the  advertisement  columns. 

Pile  Oil. — Can  any  correspondent  inform  us  who  are  the  manufac- 
turers or  proprietors  of  a  drug  or  preparation  known  as  "  Pile  Oil." — 
A.  O. 


MEETINGS    FOR    THE    WEEK. 

Tuesday,  June  ist. — Royal  Institution,  3.     "  The  Heart  and    its 
Work,"by  Dr.  Ernest  H.  Starling. 

Thursday,  2nd. — Chemical,  8.  "Thermo-Chemistry  of  Carbohydrate 
Hydrolysis,"  "  Thermal  Phenomena  attending 
the  Change  in  Rotatory  Power  of  Freshly  Pre- 
pared Solutions  of  certain  Carbohydrates,  with 
some  Remarks  on  the  Cause  of  Multirotation,'* 
by  Horace  T.  Brown,  F.R.S.,  and  Spencer  Pick- 
ering. F.R.S.  "Optical  Inversion  of  Cam- 
phor," "  Derivatives  of  Camphoric  Acid — Part 
II.  Optically  Inafiive  Derivatives,"  "  Racemism 
and  Pseudoracemism,"  by  F.  S.  Kipping,  Ph.D., 
D.Sc  ,  and  W.  T.  Pope.  "  On  Some  New  Gold 
Salts  of  the  Solanaceous  Alkaloids,"  by  H.  A.  D. 
Jowett,  D.Sc. 

Royal  Institution,  3.    "  William  Godwin  and  Mary 

WoUstonecraft,''  by  Churton  Collins,  M.A. 

Friday,  4th. — Royal  Institution,  9.  "  Signalling  through  Space  With- 
out Wires,"  by  W.  H.  Preece,  F.R.S. 

Saturday, 5th. — Royal  Institution,  3.  "Music  in  England  during  the 
Reign  of  Queen  Vidtoria,"  by  J .  A.  Fuller  Mait- 
land,  M.A. 


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OBBVICAL  NbW8,  I 

June  4,  1S97.     I 


A  Tropical  Food. 


265 


THE    CHEMICAL    NEWS 


Vol.  LXXV.,  No.  1958. 


ON   THE 

INTERVENTION     OF     MANGANESE     IN     THE 

OXIDATIONS    INDUCED     BY    LACCASE. 

By  GABRIEL  BERTRAND, 

As  I  have  already  had  occasion  to  remark,  the  soluble 
oxidising  ferment  of  the  lac-tree  laccase  yields,  on  incine- 
ration, an  ash  relatively  rich  in  manganese  oxide. 

On  combining  the  use  of  the  colorimeter  with  Hoppe- 
Seyler's  readtion,  which  consists  in  converting  the  man- 
ganese into  permanganic  acid  by  lead  binoxide  and  nitric 
acid,  I  have  found  that  i  grm.  of  laccase  extracted  from 
Armamase  lac  contains— 

Water  of  hydration    . .     . .     0*072 

Ash        0-046 

Manganese o'ooij 

cthtt  is  to  say,  a  proportion  of  manganese  close  upon  2'5 
per  cent  of  the  weight  of  the  ash. 

I  have  since  submitted  an  aqueous  solution  of  this 
laccase  to  a  fraftionated  precipitation  by  alcohol,  and  I 
have  thus  obtained  two  novel  ferments,  one  of  which  is 
more  aiftive  and  the  other  less  active  than  the  original 
laccase.  But  on  comparing  these  samples  with  each 
other,  I  observed  that  their  oxidising  power  varied  in  the 
same  diredtion  as  their  proportion  ol  manganese. 

Thus  the  volume  of  oxygen  fixed  in  ninety  minutes  by 
50  c.c.  of  solution  of  hydroquinone  at  2  per  cent,  in 
presence  of  0*260  grm.  of  the  produft  supposed  to  be  dry, 
has  been: — 

Sample  No.  1 ig'i  c.c. 

„        No.  2 15-5    „ 

„        No.  3 10-6    ,. 

whilst  the  determinations  of  manganese  gave  respedtively — 

No.  I      0*159  per  cent 

No.  3     0*126      „ 

No.  3     0098      ,, 

Is  this  a  simple  coincidence,  or  is  the  adivity  of  the 
soluble  ferment  due  to  the  presence  of  the  manganese  ? 
It  seemed  important  to  establish  this  point. 

To  this  end  I  first  sought  to  eliminate  all  the  man- 
ganese of  the  laccase  at  my  disposal.  But  the  problem 
being  doubtless  too  delicate,  I  have  not  yet  been  able  to 
solve  it  in  a  satisfadtory  manner.  In  some  cases  the 
elimination  of  the  metal  was  too  incomplete,  and  in  others 
the  reagent  modified  at  the  same  time  the  organic 
matter. 

Fortunately  I  had  another  method.  It  is  known  that 
laccase,  or  at  least  substances  closely  allied  to  it,  are 
found  in  the  generality  of  green  plants.  I  have  therefore 
extracted  laccase  from  a  series  of  different  species, 
varying  a  little  the  method  of  operation,  and  probably  by 
reason  of  a  special  composition  of  the  cellular  juice, 
I  succeeded  in  obtaining  from  lucerne  a  produd 
very  poor  in  manganese,  and  having  little  adlivity 
under  these  conditions,  but  which  resumes  its 
adlivity  on  the  addition  of  a  minimum  quantity  of  a 
salt  of  manganese.  The  produdt  is  prepared  as  fol- 
lows:—  Several  kilos,  of  ordinary  lucerne  {Medicago 
sativa),  gathered  at  the  beginning  of  the  flowering  season, 
were  at  first  bruised  and  submitted  to  the  press.  The 
juice,  saturated  with  chloroform,  was  left  to  coagulate  in 
the  dark.     After  twenty- four  hours  the  juice  was  filtered. 


2i  vols,  of  alcohol  were  added  to  the  precipitate,  drained, 
and  taken  up  in  a  little  water.  It  gave  on  filtration  a  limpid 
liquid  of  a  pale  yellow,  from  which  an  excess  of  alcohol 
(about  5  vols.)  separated  fiocks  nearly  white,  easy  to  col- 
led, and  which  rapidly  dried  in  vacuo. 

This  specimen  of  laccase,  extracted  from  lucerne,  con- 
tained then — 

Water  of  hydration  (determined  at  no")  12*4  "fm 

Organic  matters ..     42*4 

Ash 45*2 

And  a  very  small  proportion  of  manganese,  less 
than  i-50,oooth. 
On  dissolving  it,  in  the  proportion  of  o'loo  grm.  in  50 
c.c.  of  solution  of  hydroquinone,  we  observe,  even  after 
twenty-four  hours  of  continuous  agitation  in  contadt  with 
air,  merely  a  red  colour.  If,  on  the  contrary,  we  add  to 
the  same  solution  i  m.grm.  of  manganese  («.  §■.,  in  the 
state  of  sulphate),  in  about  two  hours  there  appear  in  the 
first  crystals  of  quinhydrone  evident  signs  of  oxidation. 

The  experiment  may  also  be  condudted  quantitatively. 
We  then  operate  according  to  the  method  already 
described,  and  measure  the  oxygen  absorbed.  We  thus 
find  for  the  proportions  above  given,  and  a  uniform 
agitation  of  six  hours,  at  the  ordinary  temperature 
(about  15")  :— 

1.  With  manganese  alone  (check  experiment)  0*3  c.c. 

2.  With  laccase  alone  (from  lucerne),  0*2  c.c. 

3.  For  laccase  with  manganese,  6*3  c.c. 

Manganese  cannot  be  replaced  in  a  useful  manner  by 
any  other  metal,  not  even  iron.  I  have  tried  with  the 
proportion  of  i  m.grm.  of  metal,  taken  as  sulphites : — 
Iron,  aluminium,  cerium,  zinc,  copper,  calcium,  magne- 
sium, and  potassium.  In  no  case  did  the  volume  of 
oxygen  absorbed  exceed  a  few  tenths  of  a  c.c. 

These  fadts  show  the  physiological  importance  of  man- 
ganese, and  definQ^  its  role  in  vegetables. — Comptes  Rendus, 
cxxiv.,  p.  1032. 


A  TROPICAL  FOOD. 
By  JOHN  B.  COPPOCK,  F.C.S.,  Harris  Institute,  Preston. 


In  many  parts  of  the  island  of  Cuba  the  fruit  of  the  banana 
tree  or  its  allies  is  used  as  the  "  staff  of  life  "  by  the 
natives,  and  upon  it  their  strength  is  preserved  unimpaired. 
A  sample  of  a  fiour  made  from  Musa  paradisiaca,  one  of 
the  banana  tribe,  yielded  upon  analysis — 

Water 10*62 

Albumenoids        3*55 

Fat 1*15 

Carbohydrates     8i'67 

Fibre      1*15 

Phosphoric  acid 0*26 

Salts  other  than  phosphates     ..  1*60 


We  may  therefore  conclude  it  to  be  a  starchy  food. 
The  nutritive  value  from  a  nitrogen  point  of  view  is  small, 
but  now  it  is  beginning  to  be  recognised  that  the  nitro- 
genous tissues  of  the  body  have  less  mobility  than  hitherto 
assumed,  we  may  consider  whether  nitrogen  ought  to 
occupy  the  pre-eminent  position  to  which  it  gets  assigned, 
but  rather  that  less  value  should  be  attached  to  it  and 
more  to  the  carbohydrates,  which  are  great  sources  of 
energy. 

Now  one  of  the  most  striking  features  of  this  natural 
produdt  is  the  solubility  of  the  carbohydrate  portion  ;  with 
only  warm  water  the  whole  of  it  forms  quickly  a  thin 
mucilage  which  is  apparently  very  digestible. 

The  extreme  solubility  of  this  fiour  is  further  emphasized 
by  the  fadt  that  it  has  long  been  used  in  the  island  of  Cuba 


266 


Dissemination  of  Micro-Orgamsms. 


Chkmical  News, 
June  4,  1807. 


as  a  food  or  gruel  for  infants  just  leaving  off  breast  feeding, 
despite  its  being  essentially  a  starchy  substance. 

The  phosphoric  acid  in  it  is  fairly  large  ;  hence  its  value 
is  enhanced  when  v/e  consider  the  important  part  played 
by  phosphorus  in  the  economy. 

A  microscopic  investigation  of  the  strudture  of  the  starch 
grains  led  to  these  conclusions.  The  granules  are  elon- 
gated, fairly  elliptical  in  shape  ;  the  layers  of  the  grain  are 
concentric,  but  only  faintly  visible;  the  granules  vary  much 
in  size,  but  the  large  ones  show  a  well-defined  hilum. 

The  flour  has  the  appearance  of  finely  ground  oatmeal, 
but  possesses  a  distindl  odour  of  an  agreeable  nature. 

A  few  words  on  the  botanical  characters.  The  banana 
and  the  tree  giving  this  produdl  belong  to  the  natural  order 
Musacea.  This  order  is  very  prolific  in  the  production  of 
fruit ;  it  produces  45  times  more  fruit  per  acre  than  the 
produftive  potato  and  131  times  more  than  wheat.  Of 
course  this  adlion  makes  it  very  exhausting  to  the  soil : 
the  soil  does  not  seem  to  be  replenished  by  artificial 
manures,  but  the  tree  is  removed  to  fresh  soil  every  few 
years. 

M.  sapientum  is  the  ordinary  banana,  the  variety  giving 
this  flour  being  M.  paradisiaca.  They  are  closely  related, 
the  two  being  distinguished  by  the  sweetness,  larger  size, 
and  succulent  nature  of  the  banana. 

The  young  shoots  of  some  species  are  also  eaten  after 
being  boiled  for  food. 


THE  DISSEMINATION   OF    MICRO-ORGANISMS, 

AND  THE   BEST  METHODS  OF  DESTROYING 

GERM  EMANATIONS  FROM  SEWER  GAS.* 

By  CHAS.  R.  C.  TICHBORNE,  F.C.S.,  F.I.C.,  Dep.  Pub.  Health, 
R.C.S.I.,  &c. 

There  are  two  charadlersof  germ  contagion,  which  may 
perhaps  be  best  illustrated  in  the  diseases  of  scarlatina 
and  enteric  fever. 

In  the  scarlatina  we  know  that  the  disease  is  largely 
conveyed  by  the  desquamation. 

In  enteric  fever  the  germs  which  are  carried  by  sewer 
gas  are  supposed,  with  considerable  force  of  evidence,  to 
be  a  fertile  source  of  spreading  the  disease. 

In  scarlatina  we  assume  that  the  "  Raft  Theory,"  as 
Tyndall  called  it,  plays  an  important  part,  whilst  in  the 
latter  we  must  assume  that  the  contagion  is  often  carried 
with  the  vapours  which  emanate  from  the  drains. 

In  my  present  communication  I  do  not  propose  to  deal 
at  any  length  with  the  gubjed  of  the  transmission  of 
germs  by  the  raft  theory.  It  is  fairly  understood  by  most 
*  physicists  and  badleriologists — but  I  may  as  well  concisely 
describe  it  as  most  scientists  understand  it.  We  assume 
that  the  ordinary  atmosphere,  let  us  say  at  the  sea-level, 
is  largely  contaminated  with  a  visible  and  ponderable 
matter,  which  we  term  atmospheric  dust.  This  atmo- 
spheric dust  is  found  largely  present  in  our  homes,  and 
also  in  the  streets  of  populous  towns.  It  consists  of 
ponderable  atoms,  which,  at  an  altitude  of  a  few  feet, 
almost  entirely  consists  of  organic  matter.  This  fad  was 
conclusively  demonstrated  by  Tyndall's  beautiful  experi- 
ments, in  producing  what  he  called  "optical  vacuums," 
by  the  combustion  of  the  organic  matter.  The  coarser 
particles  of  this  atmospheric  dust  adl  as  kinds  of  floating 
rafts,  and  carry  on  their  surface  the  finer  strudures  of 
life.  In  the  case  of  such  a  disease  as  scarlatina,  we  can 
easily  see  how  this  raft  theory  plays  an  important  part  in 
the  dissemination  of  the  desquamation. 

Even  the  smallest  germs  that  our  microscopes  have  yet 
revealed  have  a  certain  weight.  This  fad  is  shown  by 
the  absence  of  germs  at  high  altitudes,  such  as  Mont 

*  A  Paper  read  before  the  State  Medicine"  Seftion  of  the  Joint 
Medical  Association, 


Blanc,  or  in  the  very  still  atmospheres,  such  as  is  found' 
in  the  vaults  of  St,  Michau's  church.  I  demonstrated 
this  as  far  back  as  1870,  in  an  "  afternoon  ledure," 
delivered  at  the  Royal  Dublin  Society.  I  showed  that 
flasks  placed  all  night  in  the  vaults  of  St.  Michau's 
church  were,  when  sealed  next  morning,  optically  empty, 
or  free  from  atmospheric  dust,  and  were  therefore  free 
from  germs.  We  get  in  these  vaults  exadlly  the  same 
result  that  we  should  find  on  the  top  of  Mont  Blanc. 

I  believe  this  sterility  of  the  vaults  of  St.  Michau's 
church  has  been  the  subjedt  of  one  if  not  more  papers  read 
before  this  Academy.  I  am  sure  it  had  escaped  the 
authors'  observation  that  the  ground  had  been  already 
"  prospered." 

It  is  worthy  of  note  that  the  greater  part  of  pradlicab 
badleriology  is  now  worked  out  by  an  observation,  which' 
I  think  originated  with  Tyndall, — that  cotton-wool  is  a 
perfed  filter,  as  regards  this  atmospheric  dust,  and  that 
it  not  only  aded  upon  the  coarser  particles,  but  separated' 
the  finer  micro-organisms. 

I  may  be  excused  for  still  further  referring  to  my  own  re- 
searches in  this  diredlion,  mention  of  which  will  be  found  in 
the  later  editions  of  Parkes'  "Hygiene,"  by  DeChaumont, 
I  was  able  to  demonstrate  that  even  the  dust  at  the  top  of 
Nelson's  pillar  contained  over  29  per  cent  of  organic 
matter,  and  that  it  was  capable  of  setting  up  ladlic  fer- 
mentation in  a  neutral  solution  of  sugar  of  milk,  (Here 
is  a  solution  of  sugar  of  milk,  which,  although  sterilised, 
when  left  in  an  ordinary  room  containing  atmospheric 
dust  has  fermented,  and  become  solid  from  the  formation 
of  calcium  ladate). 

The  composition  at  every  yard  that  we  rise  from 
the  ground  becomes  freer  from  the  ponderous  earthy 
constituents,  but  richer  in  germs.  Of  course 
we  at  last  come  to  an  altitude  where  even  the  micro- 
organism becomes  scarce,  and  to  such  regions  as  the  high 
altitudes  of  Switzerland,  where  the  germ  is  unknown. 
Even  on  the  Mer  de  Glace  the  germs  may  be  said  to  be 
absent. 

So  much  for  the  raft  theory,  which  will  account  for  the 
dissemrnation  of  any  germs,  provided  they  have  arrived 
at  the  dry  condition  or  can  be  attached  to  a  dry  particle. 
What  can  be  more  easy  to  conceive  than  the  spreading  of 
scarlatina  by  a  process  such  as  this  ?  It  is  almost  self- 
evident. 

But  there  is  another  mode  by  which  preventible  disease 
is  disseminated,  which  has  never  to  my  mind  presented 
such  a  lucid  explanation  as  regards  its  propagation.  I 
refer  to  the  theory  which  supposes  that  a  certain  germ — 
let  us  say  like  that  accompanying  enteric  fever,  cholera, 
or  such  disease,  or  the  poison  of  yellow  fever  —  are 
capable  of  a<5ting  as  a  poison  when  evolved  in  sewer  gas. 
We  have  an  organism  which,  when  carried  in  water  or 
brought  mechanically  to  a  receptive  surface,  is  capable  of 
producing  disease,  and  yet  we  also  find  that  it  is  capable 
of  rising  in  such  a  vapour  as  sewer  gas.  I  use  the  term 
"vapour,"  not  in  the  vulgar  sense,  which  assumes  a  non- 
permanent  gas  capable  of  condensation,  but  in  the  sense 
that  means  anything  flying  or  escaping  ofT.  In  this  sense 
atmospheric  dust  is  volatile. 

Two  special  diseases  are  supposed  to  arise  from  the  air 
of  sewers  or  faecal  emanations,  typhoid  fever  and 
diarrhoea  ;  yet  if  these  diseases  are  caused  by  bacilli,  how 
are  they  volatilised,  for,  however  minute,  these  bacilli  are 
still  organic  structures  ?  Although  a  germ  is  so  small  that 
our  finest  balance  will  not  weigh  it,  and,  although  it  may 
only  be  0*005  of  a  m.m.  in  length,  we  might  as  reason- 
ably conceive  that  the  coarser  microscopic  life — such  as 
Rotatoria  or  Entomostraca,  which  we  can  almost  see  with 
our  eye — would  be  volatilised  as  a  vapour,  as  to  conceive 
that  pathogenic  microbes  would  be  so  transmitted. 

Prof,  Frankland  has  shown  that  liquid  sewage  matter  is 
not  likely  to  be  scattered  into  the  air,  except  by  gas  gene- 
rated in  it.  He  experimented  with  lithia,  a  chemical 
substance,  not  volatile,  but  which  could  be  easily  detedted, 
and  might  be  said  to  represent  micro-organisms.     He 


''CRByicAL  News,  I 
June  4,  1897.      I 


Dissemination  of  Micro-Organisms, 


267 


found  that  no  ordinary  agitation  of  the  sewer  water 
would  produce  indications  of  lithia  in  the  air,  but  that 
dire(5tly  gas  began  to  be  generated  in  the  sewage  by 
decomposition  the  bursting  of  the  gas-bubbles  carried  lithia 
into  the  air  {Proc.  Roy.  Soc,  1877). 

Now  I  think  here  is  the  clue  to  the  dissemination  of 
microbes,  but  not  exaftly  in  the  diredtion  which  he  indi- 
cated. Such  a  condition  of  sewage,  i.e.,  in  adtive 
fermentation,  is  hardly  conceivable  in  a  general  sense  in 
the  better  construdled  drains  found  connedted  with  houses 
of  a  good  class, — the  houses,  in  fadt,  where  typhoid  seems 
to  luxuriate.  We  must  suppose,  however,  in  a  system  of 
town  sewage,  certain  spots  in  the  mains  where,  from  the 
Frankland  cause,  the  microbes  are  scattered  into  the  air 
during  fermentation, — or,  let  us  say,  violent  concussions 
breaking  the  sewage  into  spray, — and  then  comes  the 
question.  How  are  they  disseminated  through  the  whole 
area  of  the  air  space  of  the  system  of  drains?  I  can 
easily  conceive  that  they  are  there  carried  by  a  condensed 
vapour  exadtly  represented  by  ordinary  dew.  At  certain 
hours  of  the  night,  just  as  we  see  the  rising  vapour 
settling  as  dew  in  a  valley,  I  believe  that  the  temperature 
of  the  water-laden  vapour  of  the  sewer  is  lowered  by 
being  met  with  the  layer  of  cold  night  air  through  the 
open  traps,  which  determine  a  dew-point  in  the  sewers 
themselves.  I  find  from  adlual  experiment  that  the  tem- 
perature of  the  sewer  water  as  it  flows  from  the  large 
sewers,  or  the  temperature  of  the  gas  in  the  mains,  is 
generally  2  or  3  degrees  above  the  temperature  of  the 
night  air.  The  gas  mains  bear  a  somewhat  similar  posi- 
tion underground  to  the  sewers  themselves,  and  give  a 
very  good  idea  of  this  variation  of  temperature.  A  varia- 
tion of  as  much  as  10°  to  15°  may  be  observed. 

Even  a  sudden  rise  in  the  barometer  will  just  determine 
the  deposition  of  the  liquid  portions  of  the  gas  in  the  mains, 
and  in  the  same  manner  will  also  determine,  even  more 
energetically,  a  dew  line  in  the  sewers.  Each  particle  of 
dew  becomes  a  raft  which  will  carry  microbes  upon  its 
surface,  perhaps  for  miles,  as  long  as  this  "dew  "  condi- 
tion lasts,  and,  as  the  sun's  warmth  dissipates  the  morning 
dew,  the  water  raft  disappears,  leaving  the  microbes  sus- 
pended in  mid  air;  or,  suppose  the  sewer  dew  is  carried 
into  a  warm  shaft  connedled  with  a  dwelling-house,  is  not 
the  assumption  apparent  that  again  we  have  the  water- 
rafts  converted  into  permanent  gas,  whilst  the  now  dry 
germs  float  about  seeking  whom  they  may  devour  ? 

I  will  just  conclude  by  a  few  remarks  upon  sewage  dis- 
infedlion  from  this  point  of  view. 

The  disinfedtants  employed  in  sewage  purification  can 
hardly  be  viewed  as  adlual  germicides.  The  modes  in 
which  they  are  necessarily  used  create  such  an  amount  of 
dilution  that  they  can  only  be  viewed  as  retarders  of  the 
development  of  microbes.  It  is  no  doubt  chiefly  from 
this  reason  that  they  are  not  more  extensively  used  in 
sewage  purification.  The  return  in  results,  as  regards  the 
prevention  of  diseases,  is  not  commensurate  with  the  great 
expense  of  oxidisers  such  as  permanganates  and  hypo- 
chlorites. They  are  not  in  favour,  because  without  they 
are  used  in  overwhelming  quantities  they  are  worse  than 
useless.  They  destroy  myriads  of  microbes,  but  they 
allow  myriads  to  escape,  and  to  these  they  only  seem 
to  add  fuel  to  the  fire.  It  is  true  that  at  the  pumping 
stations  in  London  manganate  of  soda  is  used,  or  was 
used ;  but  in  that  case  it  is  merely  employed  as  a 
deodoriser  at  the  end  of  the  process,  and  whilst  the  super- 
natant fluid  is  poured  into  the  river. 

From  the  reason  of  cheapness,  crude  carbolic  acid 
(which  may  be  considered  to  owe  its  virtue  to  phenol, 
cresylic  acid,  and  a  little  naphthalene)  is  extensively  used. 
Although  not  a  very  decided  germicide,  phenol  still  holds 
an  important  place  as  one  of  the  most  valuable  retarders 
of  germ  development.  Naphthalene  is  still  more  power- 
ful, and  may  be  looked  upon  as  a  germicide  proper ; 
although  very  cheap,  it  has  one  obiedtion,  namely,  its 
insolubility.  I  have  here  a  fluid  which  I  have  used  with 
some  success  for  years,  in  controlling  or  instantly  stopping 


germ  development,  for  which  there  are  many  occasions 
where  the  use  of  mercuric  chloride  is  inadmissible.  It 
consists  of— 

Crystallised  phenol  ..     ..     i  part, 

Camphor 3  parts, 

Naphthalene J  part, 

Coloured  with  rosaniline  carbolate. 

It  will  be  observed  that,  though  these  are  all  solids,  they 
form  a  liquid  on  rubbing  together.  One  drop  of  this 
liquid  will  instantly  arrest  any  tube  of  microbe  culture  in 
gelatin  at  any  point,  and  may  be  used  with  advantage  to 
place  on  record  comparative  experiments  with  microbe 
cultures. 

In  such  experiments  I  have  found  it  advantageous  to 
use  a  little  stiffer  nutrient  gelatin  than  that  given  in 
Crookshank.  I  increase  the  formula  there  given  from 
100  grms.  of  gelatin  to  120  grms.  {vide  "  Manual  of 
Badleriology,"  3rd  edit.,  p.  83). 

Now  it  is  a  similar  preparation  to  the  above  which  I 
should  propose  for  sewage  purification,  with  one  modifi- 
cation which  I  consider  invaluable.  Crude  carbolic  acid 
(phenol)  is  comparatively  cheap,  and  naphthalene  may  be 
viewed  as  a  waste  produdt  in  the  process  of  coal-tar  dis- 
tillation. For  the  camphor  I  would  substitute  terebene, 
which  may  be  looked  upon  almost  as  a  liquid  camphor. 
Where  the  sewers  of  a  large  city  are  being  provided 
for,  and  where  money  is  a  question  of  importance,  the 
light  oils  of  tar  may  be  substituted. 

Now  I  will  describe  the  scientific  theory  by  which  I 
believe  this  can  be  made  a  trap  for  typhoid  or  germs  of  a 
like  nature  in  sewer  gas. 

The  principle  involved  consists  in  adding  some  liquid 
body  which  shall  bring  the  specific  gravity  of  the  anti- 
septic below  that  of  the  sewer  matter.  When  such  a 
body  is  used  the  antiseptic  forms  at  once  a  fine  pellicle  on 
the  surface  of  the  sewage,  and  all  fluids  that  are 
volatilised  or  mechanically  eliminated  by  the  escape  of 
gas  must  pass  through  the  germicide  layer. 

If  carbolic  acid  or  the  crude  phenol  produdts  are  used 
by  themselves,  we  find  in  pradtice  that  they  immediately 
sink  to  the  bottom  of  the  flowing  sewage  which  passes  along 
over  the  top  in  a  continuous  stream  of  untouched  pollu- 
tion. The  crude  produdt  obtained  from  the  distillation  of 
coal-tar  is  specially  suited  to  this  purpose.  When  coal- 
tar  is  distilled,  in  the  first  instance,  it  is  divided  into  two 
divisions ;  one  is  called  "  light  coal-tar  oil,"  the  other 
"  heavy  coal-tar  oil."  The  first  are  all  the  produdts  which 
come  over  as  long  as  they  will  float  on  water,  and  they 
are  specially  rich  in  the  benzene,  naphthalene,  and  terebene 
series,  all  of  which  are  powerful  germicides.  By  substi- 
tuting these  oils  for  terebene,  we  get  an  antiseptic  fluid 
which  immediately  spreads  on  the  surface  of  the  sewage, 
locking  in  the  deleterious  vapours,  and  at  the  same  time 
passing  downwards  the  heavier  antiseptics,  such  as  the 
phenol,  by  the  simple  adt  of  solution. 

This  can  be  illustrated  by  the  following  simple  experi- 
ment : — If  we  pass,  by  a  pipette,  a  layer  of  carbolic  acid 
into  a  shallow  dish  of  water,  and  after  standing  some  time 
draw  off  some  of  the  supernatant  water,  we  shall  find,  on 
testing  it  with  a  little  bromine  water,  that  it  contains  no 
carbolic  acid.  If  in  a  second  experiment  we  use  such  a 
mixture  as  I  have  specified,  which  has  a  gravity  of  0-850 
to  0*950,  we  shall  find,  on  introducing  it  into  the  water 
with  the  pipette,  that  it  immediately  rises  to  the  surface, 
and  if  we  at  once  remove  some  of  the  water  from  the 
interior,  it  gives,  on  testing  with  bromine  water,  a  copious 
precipitate,  showing  that  the  carbolic  acid  has  permeated 
at  once  through  the  water,  which  represents  the  sewage. 
We  should  find,  on  further  examination,  that  the  powerful 
antiseptic  naphthalene  had  been  carried  with  it. 

I  have  endeavoured,  in  the  above  experiments,  to  show 
why,  in  many  cases,  the  use  of  carbolic  acid  has  been  a 
pradlical  failure  as  a  sewage  purifier,  and  to  indicate  that, 
as  regards  dealing  with  such  contagions  as  are  diffused 
through  sewer  gas,  a  principle  should  be  adopted  in  the 


268 


Study  of  Hyponitrous  A  cid. 


I  Chbmical  News, 
I      June  4, 1897. 


use  of  antiseptics.  This  principle  has  not,  so  far  as  I 
know,  been  openly  enunciated,  namely,  that  we  must  dis- 
infedt  from  the  surface  of  the  flowing  sewage,  and  not 
from  the  bottom. 


CONTRIBUTION     TO    THE    STUDY    OF 
HYPONITROUS    ACID.* 
By  A.  HAUT2SCH  and  A.  L.  KAUFMANN. 
(Concluded  from  p.  256). 

Conductivity  of  Hyponitrous  Acid. 
Perfectly  pure  hyponitrite  of  silver  is  added  in  excess 
to  a  1/32  normal  solution  of  hydrochloric  acid  at  0°.  The 
1/32  normal  solution  of  hyponitrous  acid  thus  obtained  is 
filtered  at  0°,  and  this  filtrate  is  used  for  the  determina- 
tion of  the  condudivity. 

I.  Molecular  amount  in  64  litres.    Temperature  0*. 
H^   =  2-98  /i*  *=  3 '65  h*  =  4'i4 


fi*  =  3-06 

M*    =  378 

/*••=  4-24 

M*    =  3*40 

M^    =   3-87 

^11—    ^.jg 

M*   =  3*46 

Ai»    =  3'92 

/«>»=     4-32 

II.  Solution  prepared  exactly  the  same  as  No.  I.,  but 

kept  at  0°  for  fifteen  hours. 
/I*   =  rg6  n^  =  2*07  fi*  =  2'i8 

/*•   =  I'qS  h'  =  2*09  /*'•=  219 

ft.*    =    2'00  >i'    =a   2'H  |i'>=s    2'22 

fi*    s=    2'02  n*    =  •2*14  yi4»«=    2-25 

The  result  obtained  was  similar  to  that  of  the  first 
experiment.  The  initial  value  was  smaller,  but  it 
gradually  increased. 

III.  The  solution  used   for  the   first  experiment  was 

examined  again  after  standing  for  fifteen  hours 
ato°. 

M*   =  21-65  M'  =  23'S6 

H*  =  21*92  fi»  =  23*68 

/t*    =3    21*94  fi''    =    22*8o 

ft*   =  21*83  fi*   =  23-68 

These  experiments  show  that  the  condudlivity  of  hypo- 
nitrous acid  increases  with  the  duration  of  the  current. 
Under  the  a(5lion  of  an  alternating  current,  hyponitrous 
acid  ought  to  give  rise  to  produds  which  would  be  better 
condudors  than  hyponitrous  acid  itself.  As  a  matter  of 
fadt  solutions  thus  treated  give,  with  sulphuric  acid, 
iodide  of  potassium,  and  starch,  an  intense  blue  colour. 
Thus  we  see  that  the  decomposition  previously  described 
is  effeaed  by  the  action  of  an  alternate  current  at  0°. 

Experiment  III.  shows  clearly  that  nitrous  acid  once 
formed  accelerates  the  decomposition  of  hyponitrous  acid 
ia  a  similar  manner.  As  probable  equivalent  of  the  con- 
duAivity  of  hyponitrous  acid,  we  must  take  into  account 
what  was  observed  in  the  first  place.  Its  value  should 
therefore  be,  assuming  v  to  be  equal  to  64,  fi  =  003. 

The  determination  of  the  condudivity  of  very  weak 
solutions,  and  the  calculation  of  the  constants  of  dissocia- 
tion, have  naturally  been  impossible  to  effedl  with  a  body 
which  is  such  a  bad  conduftor  and  so  unstable  as  hypo- 
nitrous acid.  But  contrary  to  the  general  opinion,  hypo- 
nitrous acid  is  a  very  weak  acid.  It  is,  in  fai^,  very 
similar  in  that  respe(5l  to  carbonic  acid,  whose  condudivity 
is,  according  to  Knox,  K=o*ooooooo8. 

Conductivity  of  Hyponitrite  of  Soda. 
Having  proved  by  previous  experiments  that  the  acid 
hyponitrite  of  soda,  NaHHaOj,  was  a  very  unstable  com- 
pound, we  endeavoured  to  determine  the  conduftivity  of 
the  neutral  salt.    This  latter  salt  could  not  be  prepared 

♦  Monitiur  Stitntifique,  vol.  xi.,  p.  336,  May,  1897, 


by  the  dired  adtion  of  hyponitrite  of  silver  in  excess  on  a- 
solution  of  chloride  of  sodium,  on  account  of  these  bodies 
adting  very  slowly  and  incompletely  on  one  another.    We  • 
obtained  it  by  mixing  equal  quantities  of  hyponitrous  acid  ' 
and  caustic  soda.     The  hyponitrous  acid  was  prepared  in 
the  ordinary  way,  by  the  action  of  hyponitrite  of  silver  on  ■ 
a  normal  solution  of  hydrochloric  acid  ;  the  caustic  soda 
was  prepared  according  to  Hautzsch  and   Gerilowski's 
method.     The  two  solutions,  mixed  at  0°,  were  diluted  so 
as  to  contain  a  i/32nd  normal  quantity  of  hyponitrite  o£^ 
soda. 

I.  V  =  64. 
fH  =  III-66 
Hz  =  110*76 
M3  =  109-56 

II.  »  =  126. 
Hi  =  139-06 
/ia  =  137*06 


1x4  =  109*56 
/i5  =  110*26 


H6  =  109-26 
fij  =  109*16 


Ma  =  135 '4 
M4  =  I34'42 


MS  =  I34'I2 
H6  =   I32"92 


III.  V  =  256. 

At  first  ju  =  148*04,  after  13  minutes  fx  =  141*14,  after 
15  hours  fi  =  126-34,  a^'er  7  minutes  fi  =  143*04, 
and  after  16  minutes  ju  =  139*64. 

The  three  series  of  experiments  show  that  the  values 
of  the  molecular  conductivity  diminish  from  one  experi- 
ment to  another.  This  can  be  accounted  for  in  two 
different  ways.  We  can  imagine  that  the  fixation  of  the 
carbonic  acid  in  the  air,  by  the  strongly  alkaline  hypo- 
nitrite of  silver,  would  have  the  effedt  of  decreasing  the 
condudtivity  of  the  latter.  The  fadts  observed  in  the  de- 
termination of  the  conducing  power  of  carbonate  of  soda 
show  that  this  supposition  is  probable.  But  we  may  also 
suppose  that,  under  the  influence  of  the  eledtric  current, 
hyponitrite  of  soda,  strongly  hydrolysed,  gives  rise  to  pro- 
duds  of  decomposition  of  very  bad  condudtivity. 

In  spite  of  these  difficulties  it  is  easy  to  see  that  the 
condudtivity  diminishes  considerably  on  dilution.  The 
most  probable  value  is  that  first  observed.  With  v  =  64, 
and  t  =  0°,  fi  =  00  112.  In  any  case,  however,  this  high 
number  shows  a  noticeable  splitting  up  of  the  disodic  salt, 
easily  shown  by  phenolphthalein. 

Comparison  of  Nitr amide  with  Hyponitrous  Acid. 

The  chemical  properties  being  known,  the  comparison' 
has  been  completed  by  the  determination  of  the  molecular 
weight  and  the  condudting  capacity  of  the  nitramide. 

The  determination  of  the  molecular  weight  of  the 
nitramide  gave  the  same  value  as  that  we  found  for  hypo- 
nitrous acid. 

Molecular  weight :  found,  61 ;  theory  HaNaOa,  62. 

Conductivity  of  Nitramide. 

I.  w  =  32;  temperature  =  0°. 

Five  series  of  experiments  were  made,  each  comprising^ 
four  determinations.  The  following  figures  show  th» 
average  of  each  series  : — 

1.  /i  =  1*97. 

2.  H  =  1*95. 

3-  M  =  i'93. 

4-  M  =   i'93. 
5.     u  =   1*96. 

II.  ».  =  64 ;  temperature  =  o". 
Means  of  two  series  of  experiments  : — 

1.  H  =  ^'^9- 

2.  ft  =  ^'^9- 

These  results  show  that,  contrary  to  the  opinion 
expressed  by  Thiele  {Zeitsch.  f.  Physik.,  xvii.,  p.  185)^, 
nitramide  is  a  very  weak  acid,  the  same  as  hyponitrous 
acid. 

The  low  condudtivity  makes  the  determination  of  the 
constant  of  dissociation  impossible.  But  at  any  rate  th& 
values  for  nitramide  (/*  =  00  2)  are  lower  than  in  the  casfr 


^7u''D'e4^89'!'''}    ^o^e  Present  PossibUittes  in  the  Analysis  of  Iron  and  Steel, 


269 


of  hyponitrouB  acid  (/*  =  00  3).  The  acidity  of  the  former 
is  therefore  slightly  more  pronounced  than  that  of  the 
latter ;  but  unlike  hyponitrous  acid,  the  condudtivity  of 
nitramide  is  not  modified  under  the  influence  of  an  alter- 
nate current.  Nitramide  in  the  free  state  is  thus  consider- 
ably more  stable  than  hyponitrous  acid. 

The  interchangeabilityof  these  two  substances,  one  into 
the  other,  by  inter-molecular  transposition,  appeared  to 
be  very  probable,  in  view  of  their  isomerism,  and  the 
analogy  of  their  proportions  which  exists;  but  the 
numerous  experiments  undertaken  with  a  view  to  cause 
this  transformation  have  up  to  now  given  only  negative 
results. 


SOME    PRESENT     POSSIBILITIES    IN    THE 
ANALYSIS  OF   IRON   AND   STEEL.* 

By  C.  B.  DUDLEY. 
(Continued  from  p.  258). 

Much  might  be  said  in  regard  to  the  colour  test  for  de- 
termining carbon  in  steel.  It  is  difficult  to  over-estimate 
the  value  and  importance  of  this  method,  especially  in  the 
daily  operation  of  steel  works,  and  there  seems  little 
doubt  but  that  if  proper  precautions  are  employed,  the 
method  in  skilful  hands  will  give  results  that  are  fairly 
reliable  to  within  three-  or  four-hundredths  of  a  per  cent. 
It  would  hardly  be  possible  in  this  paper  to  discuss  all 
the  precautions  which  are  deemed  essential  by  those  best 
informed.  A  chemist  of  wide  experience  with  the 
method  has  enumerated  twenty-four  points  that  must  be 
observed,  if  reliable  results  are  to  be  expefted.  Let  it 
suffice  for  us  to  say  that  even  approximate  accuracy  can- 
not be  expei5ted. 

1.  If  the  steel  whose  carbon  is  to  be  determined  and 
the  standard  steel  do  not  have  their  carbon  in  the  same 
condition.  For  example,  if  the  standard  steel  has  been 
annealed,  and  the  sample  to  be  tested  has  been  tempered, 
the  results  will  be  worthless. 

2.  If  the  attempt  is  made  to  determine  the  carbon  in 
any  steel  by  using  a  standard  widely  diiferent  from  it,  in 
carbon  content.  Using  a  0*20  per  cent  carbon  standard, 
with  a  steel  containing  0-50  or  0*60  per  cent,  is  apt  to  lead 
to  very  fallacious  results. 

The  best  results  seem  to  be  obtained  by  having  the 
carbon  in  all  steels  both  standards  and  tests  in  the  con- 
dition given  by  annealing,  by  having  a  number  of  standards 
which  differ  little  from  each  other  in  carbon  content,  and 
by  not  attempting  to  use  the  method  on  steels  containing 
very  little  or  very  large  amounts  of  carbon.  It  may  not 
be  amiss  to  add  here  that  the  praiSice  so  prevalent  in 
many  of  the  steel  works,  of  using  this  method  for  all 
carbon  determinations,  including  those  where  contracts 
are  involved,  is  reprehensible,  and  should  be  discontinued. 
The  chemist  at  the  works  does  the  best  he  can  with  the 
method  he  is  using,  and  the  amount  of  work  required  of 
him,  as  well  as  the  facilities  furnished,  do  not  admit  of  the 
use  of  a  better  method.  On  the  other  hand,  when  a  dis- 
pute arises,  and  it  is  ultimately  shown  that  the  works  are 
in  error,  the  chemist  is  blamed  and  analytical  chemistry 
brought  into  disrepute,  not  because  either  is  really  at 
fault,  but  because  more  is  expefted  of  the  colour  test 
method  than  it  is  really  able  to  give.  To  the  steel  makers 
we  say,  "  Do  not  expedt  your  chemists  to  render  you  the 
bricks  of  good  chemical  analyses,  without  you  give  him 
the  requisite  straw  of  time  and  appliances  to  do  good 
chemical  work." 

Few  of  the  constituents  of  iron  and  steel  have  more 
important  influences  on  their  valuable  qualities  than  phos- 
phorus, and  upon  few  has  more  chemical  work  been  done. 

•  Preaidential  Addresi  delivered  at  the  Troy  Meeting  of  the  Ameri. 
can  Chemical  Society,  December  ag,  1896.  From  the  Journal  oftht 
Amtnttm  Chtmical  Society,  xix.,  No.  2. 


The  present  condition  of  the  methods  for  determining  this 
constituent  seems  fairly  satisfadtory,  provided  we  are 
willing  to  take  time  enough  to  do  the  work.  In  confirma- 
tion of  this  statement,  the  work  {Proc.  Am.  Soc.  Civil 
Eng.,  xxi.,  59)  done  by  the  Sub-committee  on  Methods  of 
the  International  Committee  on  Standards  for  the  Analysis 
of  Iron  and  Steel  may  be  cited.  This  sub-committee 
consisted  of  five  members,  each  of  whom  analysed  five 
samples  of  steel,  and  each  used  his  own  method,  without 
any  attempt  at  consultation  or  agreement  with  each  other 
before  the  work  was  done.  The  methods  employed  may 
be  briefly  indicated  as  follows,  those  interested  being 
referred  to  the  Report  of  the  Committee  published  as  per 
the  reference  given  for  the  details.  Mr.  Blair  used  what 
is  known  as  the  acetate  method.  Mr.  Shimer  used  the 
molybdate  magnesia  method.  Your  speaker  used  a  com- 
bination of  the  acetate  and  molybdate  magnesia  methods. 
Dr.  Drown  used  a  combination  of  certain  features  of  the 
modern  rapid  methods  with  the  molybdate  magnesia 
method.  And  Mr.  Barba  on  one  sample  used  the  acetate 
method  as  described  by  Blair,  and  on  the  other  four 
samples  employed  certain  features  of  the  molybdate 
method  to  separate  the  phosphorus  from  the  iron,  and 
then  used  the  redudtor  to  get  the  amount  of  phosphorus, 
instead  of  weighing  as  magnesium  pyrophosphate.  It 
will  be  evident  to  any  one  carefully  reading  the  Report 
referred  to  that  the  methods  employed  differed  widely  in 
principle,  in  strength  of  solution,  and  in  manipulation,^ 
and  yet  these  methods  gave  the  following  percentages  of 
phosphorus  in  the  five  samples. 

1.            a.  3,           4.           5. 

Mr.  W.  P.  Barba  ..     0*041  o"oi5  0*095  0*091  0*041 

Mr.  A.  A.  Blair     ..     0*040  0*016  0*098  0*091  0*041 

Dr.  T.  M.  Drown  .*     0*042  0*016  0*104  0*090  0*042 

Dr.  C.  B.  Dudley  ..     0*040  0*016  0*099  0-097  0*039. 

Mr.  P.  W.  Shimer..     0*041  0-017  0*098  0*096  0*039. 

In   explanation   of  the  results,  we  quote  from  the 
Report  of  the  Sub-committtee: — 

"  Sample  No.  i  is  an  ordinary  open-hearth  steel.  Sample 
No.  2  is  a  crucible  steel.  Sample  No.  3  is  an  open-hearth 
steel  to  which  metallic  arsenic  was  added  while  in  the 
molten  condition  in  a  crucible.  Sample  No.  4  is  an  ordi- 
nary Bessemer  rail  steel.  Sample  No.  5  is  the  No.  5 
sample  of  the  Committee  on  International  Standards,  and 
is  an  open-hearth  steel. 

"  It  will  be  observed  that  the  agreement  in  the  results 
on  phosphorus  obtained  by  the  different  chemists  is  very- 
good.  The  exceptions  are  the  No.  3  steel,  which  contains 
arsenic  in  considerable  amount,  and  where  the  discrepancy 
is  0*009  per  cent,  and  in  the  No.  4  steel,  where  the  dis- 
crepancy is  0*007  per  cent.  Considerable  work  was  done 
on  the  No.  4  sample,  in  an  effort  to  reconcile  discrepan- 
cies, and  it  was  found  that  the  turnings  from  this 
sample  were  irregular,  and  that  two  different  bottles  of  the 
sample  gave  different  results.  The  average  of  six  deter- 
minations from  one  bottle  was  0*1057,  and  the  average  of 
five  determinations  from  another  bottle  was  0*0964  per 
cent.  Furthermore,  siftings  from  quite  an  amount  of  the 
turnings  gave  0*140  per  cent." 

But  these  methods  are  long  and  laborious.  It  would  be 
impossible  with  the  most  rapid  of  them  to  get  a  result  in 
much  less  than  a  day,  while  two  days  would  certainly  be 
required  for  some  of  the  others.  Accordingly,  since  the 
demand  for  rapid  phosphorus  determinations  during  the 
last  ten  or  fifteen  years  has  been  very  great,  an  enormous 
amount  of  work  has  been  done  in  trying  to  meet  this 
demand.  Modification  after  modification  has  been  intro- 
duced, and  paper  after  paper  has  been  published  on  the 
subje^.  It  is  perhaps  not  too  much  to  say  that  few 
chemical  journals  that  publish  any  original  work  at  all 
have  escaped  three  or  four  articles  per  year,  on  the  deter- 
mination of  phosphorus  in  iron  and  steel,  or  on  some 
phase  of  a  rapid  method  for  such  determination.  The 
result  of  all  this  work  has  apparently  been  constantly  in- 


270 


Some  Present  Possibilities  in  the  A  nalysis  of  Iron  and  Steel.   { ^"TeTisg"^'' 


creased  rapidity,  with  constantly  greater  approximations 
to  accuracy.  The  present  state  of  the  matter  is  perhaps 
best  shown  by  Thackray  (Trans.  Am.  Inst.  Min.  Eng., 
XXV.,  370),  in  his  paper  "  A  Comparison  of  Recent  Phos- 
phorus Determination  in  Steel."  This  writer  sent  to  some 
twenty-three  different  chemists  borings  from  two  different 
samples  of  steel,  with  a  request  to  have  the  phosphorus 
determined  in  each  sample,  and  a  description  of  the 
method  used  sent  witk  the  results.  Each  chemist  was 
told  that  samples  had  been  sent  to  others,  but  no  attempt 
-was  made  to  have  any  special  method  used.  The 
chemists  embraced  a  professor  in  a  technical  school,  the 
ckemist  of  a  large  consumer,  a  number  of  commercial 
chemists,  and  a  number  of  chemists  employed  by  steel 
and  iron  works.  On  one  sample  thirty-six  different  re- 
sults were  sent  in,  and  on  the  other  thirty-eight.  Twenty- 
seven  different  methods  were  employed,  some  of  the 
chemists  sending  in  results  by  two,  and  even  three 
methods,  and  some  sending  duplicate  determinations. 
The  results  obtained  were  obtained  as  follows,  the  figures 
being  percentages  of  phosphorus  in  the  steels : — 

Sample.  i.  3. 

Average  of  all  determinations  0*0496  0-0835 

Highest  result o'055  o'ogi 

Lowest  result o'045  0*076 

Maximum  difference     ..     ..  O'oio  0*015 


But  these  results  still  leave  something  to  be  desired. 
The  discrepancy  between  the  highest  and  the  lowest 
result  is  still  too  great.  It  is,  perhaps,  a  little  hazardous 
to  place  limits,  but  we  do  not  think  the  chemists  of  the 
country  should  be  satisfied  until  they  are  in  possession  of 
a  method  or  methods  which  are  so  carefully  worked  out  and 
so  well  described  that  in  the  hands  of  different  chemists 
of  good  fair  ability  and  experience,  results  will  be  ob- 
tained by  all,  when  working  on  the  same  steel,  that  will 
not  differ  from  each  other  more  than  0*003  P^''  cent.  The 
Sub-committee  on  Methods  of  the  International  Com- 
mittee on  Standards  for  the  Analysis  of  Iron  and  Steel, 
before  referred  to,  have  had  in  hand  now  for  some  two 
years  studies  on  a  rapid  and  accurate  method  for  the 
determination  of  phosphorus  in  steel.  It  has  been  the 
hope  of  the  Sub-committee  that  the  ideal  above  given 
would  be  attainable  by  this  method.  In  reality,  the  work 
of  the  Sub-committee  has  embraced  an  examination  of 
almost  every  chemical  point  involved,  taking  very  little  if 
anything  for  granted,  and  checking  and  proving  every  step. 
The  work  is  not  yet  quite  ready  for  publication,  one  or  two 
points  remaining  which  are  not  entirely  settled,  and  it  has 
been  deemed  advisable  to  withhold  the  method  until  these 
are  completely  cleared  up. 

(To  be  continued). 


The  methods  employed  may  be  divided  on  the  basis  of 
time  required  into  three  classes  : — 

ist.  Those  which  may  be  called  rapid,  and  which  give 
a  result  in  two  hours  or  less. 

2nd.  Those  which  may  be  called  slow,  and  which  re- 
quire considerably  more  than  two  hours,  but  still  give  a 
result  the  same  day. 

3rd.  Those  which  may  be  called  very  slow,  and  which 
do  not  give  a  result  until  the  second  day  or  later. 

Thirteen  results  on  each  sample  were  given  by  "  rapid" 
methods,  eleven  on  the  No.  i  sample,  and  twelve  on  the 
No.  2  sample  by  "  slow "  methods,  and  twelve  on  the 
No.  I  and  thirteen  on  the  No  2  by  "  very  slow  "  methods. 
Arranging  the  results  in  accordance  with  this  classifica- 
tion of  the  methods  (and  we  have  some  very  interesting 
data),  the  figures  being  as  before,  the  percentages  of  phos- 
phorus in  the  two  steels  are  : — 

Rapid  methods.  Slow  methods.         Very  slow. 

I.            2.  I.            2.               I.            2, 

Average  ..  0*0499  0*0840  0*0490  0*0826  0*0496  0*0837 

Highest  ..  0*054    0*091  0*052    o*o86  0*055    o'o8g 

Lowest   ..  0*045     0*078  0*046    0*076  0*046    0*078 

Max.  diff. .  0*009    0*013  o'oo6    0*010  0*009    o'Oii 

To  our  minds  these  figures  are  very  impressive.  It  is 
worthy  of  note — 

ist.  That  the  average  results  given  by  the  "  rapid " 
methods  only  differ  on  either  steel  from  the  averages  given 
by  the  "  slow  "  or  "  very  slow  "  methods,  by  a  little  over 
0*001  of  a  per  cent. 

2nd.  That  the  maximum  difference  between  the  highest 
and  lowest  results  given  by  the  "  rapid "  methods  on 
either  steel  is  but  a  trifle  greater  than  is  shown  by  the 
"slow"  or  "very  slow"  methods. 

In  other  words,  if  we  interpret  these  results  corredtly 
they  show  that  the  rapid  methods  for  determining  phos- 
phorus in  steel  now  known  and  in  use  in  many  laboratories 
give  results  that  are  well  nigh  as  accurate  and  reliable  as 
those  yielded  by  the  longer  and  more  laborious  methods, 
and  it  must  not  be  forgotten  that  although  we  have 
placed  two  hours  as  the  time  charadterising  a  rapid 
method,  a  number  of  the  results  given  above  were  obtained 
by  the  use  of  methods  which  give  a  single  determination 
in  forty-five  minutes,  and  enable  one  operator  to  make 
twenty  phosphorus  determinations  in  a  day.  We  are 
frank  to  say  we  do  not  believe  such  a  showing  would 
have  been  possible  five  years  ago. 


PROCEEDINGS    OF    SOCIETIES. 

CHEMICAL  SOCIETY. 
Ordinary  Meeting,  May  20th,  1897. 

Professor  Dewar,  F.R.S.,  President,  in  the  Chair. 

Messrs.  H.  E.  Gardner,  William  Barlow,  and  Paul 
Thomas  White  were  formally  admitted  Fellows  of  the 
Society. 

Certificates  were  read  for  the  first  time  in  favour  of 
Messrs.  Walter  Harry  Barlow,  152,  Osbaldiston  Road, 
Stoke  Newington,  N. ;  Ernest  Stuart  Cameron,  51, 
Pembroke  Road,  Dublin  ;  Medwin  Caspar  Clutterbuck, 
B.Sc,  Ph.D.,  61,  Beaconsfield  Villas,  Brighton  ;  Frank 
William  Harbord,  Egham ;  B.  J.  Harrington,  Ph.D., 
McGill  College,  Montreal  ;  A.  G.  Kidston  Hunter, 
Princes  Street,  Dunedin,  N.Z.;  John  Edwin  Mackenzie, 
B.Sc,  Ph.D.,  7,  Ramsay  Garden,  Edinburgh ;  Lionel 
Walter  Kennedy  Scargill,  B.A.,  14,  Brunswick  Place,  W. 
Brighton  ;  James  Porter  Shenton,  34,  Lansdowne  Road, 
W.  Didsbury,  Manchester. 

Of  the  following  papers  those  marked  *  were  read : — 

*6o.  *'The  Theory  of  Osmotic  Pressure  and  the  Hypo- 
thesis of  Electrolytic  Dissociation."  By  Holland 
Crompton. 

The  author  applies  the  results  obtained  by  Guye, 
Ramsay,  and  Shields,  and  others  in  their  investigations 
on  the  molecular  complexity  of  liquids  to  the  theory  of 
osmotic  pressure.  It  is  found  that  van  't  Hoff 's  view, 
that  the  osmotic  pressure  of  the  dissolved  substance  is  in 
dilute  solution  equal  to  the  pressure  which  the  substance 
would  exercise  in  the  same  volume  if  in  the  gaseous  state, 
is  applicable  when  both  the  dissolved  substance  and  the 
solvent  form  normal  or  monomolecular  liquids.  It  may 
also  apply  if  both  liquids  are  associated.  But  if  the  dis- 
solved substance  is  associated  and  the  solvent  is  mono- 
molecular,  the  osmotic  pressure  is  then  smaller  than  the 
theoretical,  and  becomes  inversely  proportional  to  the 
faftor  of  association  Xi  of  the  dissolved  substance.  If  the 
solvent  is  associated  and  the  dissolved  compound  is 
monomolecular,  the  osmotic  pressure  is  greater  than  the 
theoretical,  and  is  diredtly  proportional  to  the  faftor  of 
association  x  of  the  solvent.  If  the  solvent  has  also  an 
abnormal  vapour  density,  the  fadlor  of  association  of  the 


wBBMicAL  News, 
June  4,  1897. 


Heats  of  Neutralisalion  of  A  cids  and  Bases. 


271 


vapour  being  a,  the  osmotic  pressure  is  diredtly  propor- 
tional to  xja. 

By  application  of  the  above  conclusions,  it  is  shown 
that  the  latent  heat  of  fusion  r,  melting-point  on  the 
absolute  scale  T,  and  density  at  the  melting-point,  d, 
of  a  liquid  are  conneded  by  the  expression  rrf/r  =  const, 
in  the  case  of  monomolecular  liquids,  or  rdx/Ta  =  const. 
in  the  case  of  associated  liquids.  The  mean  value  of  the 
constant  is  0*099,  or  roughly  o"i.  This  formula  is  exadtly 
similar  to  the  Trouton  formula,  which  connects  the  latent 
heat  of  vaporisation,  gaseous  density,  and  boiling-point  on 
the  absolute  scale  of  liquids. 

The  molecular  redudion  of  the  freezing-point  for  mono- 
molecular  substances  in  monomolecular  solvents  is  given 
by  van  't  Hoff 's  formula,  £=0-01976  T^/r,  or  by  the  derived 
formula  £  =  o'2  Td.  If,  however,  the  dissolved  substance 
or  the  solvent  are  associated,  this  formula  no  longer 
applies, but  E  =  o'oi976T*;r/»'fl;tri,or  E  =  o'2Tdlxi.  Excep- 
tions to  van 't  Hoff 's  formula  for  the  molecular  reduction 
of  the  freezing-point  appear,  therefore,  whenever  associa- 
tion of  either  the  dissolved  substance  or  the  solvent 
takes  place,  and  it  is  shown  that  those  exceptions  ob- 
served in  the  case  of  eIe(5trolytes  in  aqueous  solution  are 
in  perfed  keeping  with  the  view  that  eledtrolytes  are 
monomolecular  compounds  in  solution  in  an  associated 
solvent,  e.g.,  water.  The  hypothesis  of  eledrolytic  dis- 
sociation is  not  only  unnecessary  in  explanation  of  these 
exceptions,  but  is  inconsistent  with  what  is  now  known 
of  the  molecular  charadler  of  liquids. 

A  connexion  is  supposed  to  exist  between  the  specific 
indudtive  capacity  of  a  liquid  and  its  power  of  promoting 
electrolytic  dissociation.  The  author  shows  that  it  is  only 
associated  liquids  that  have  high  specific  indudive 
capacities,  and  that  the  specific  indudtive  capacity  is 
approximately  proportional  to  the  cube  of  the  fadtor  of 
association  of  a  liquid.  It  is  therefore  not  on  the  degree 
of  electrolytic  dissociation  of  the  dissolved  substance,  but 
on  the  degree  of  association  of  the  solvent,  that  the  con- 
dudtivity  depends,  and  the  view  is  taken  that  eledtrolytes 
are  salts  in  the  monomolecular  fiuid  state  in  solution  in 
associated  solvents. 

*6i.  "Molecular  Rotations  of  Optically  Active  Salts," 
By  Holland  Crompton. 

A  fadt  which  is  usually  quoted  as  strong  evidence  in 
favour  of  the  hypothesis  of  eledtrolytic  dissociation,  is 
that  salts  which  contain  a  common  optically  adtive  ion — 
either  positive  or  negative — exhibit,  in  sufficiently  dilute 
aqueous  solution,  the  same  equivalent  rotatory  power. 
If,  however,  eledtrolytes  are  salts  in  the  monomolecular 
fluid  condition  (preceding  paper),  the  observed  regularities 
indicate  that  monomolecular  salts  which  contain  a 
common  optically  adlive  radicle  have  the  same  equivalent 
rotation.  Those  peculiarities  which  have  been  observed 
in  the  case  of  the  equivalent  rotations  of  optically  adlive 
eledtrolytes  in  aqueous  solution,  are  shown  by  the  author 
to  be  also  exhibited  by  the  amylic  salts  of  certain  organic 
acids,  when  these  are  examined  in  the  free  state  and  not 
in  solution  in  any  solvent.  As  eledtrolytic  dissociation  is 
in  this  case  entirely  out  of  the  question,  the  hypothesis 
becomes  an  unnecessary  one  in  other  instances,  and  the 
behaviour  of  optically  adtive  eledtrolytes  is  merely  in 
keeping  with  that  of  other  optically  adtive  monomolecular 
salts. 

♦62.  "Heats  of  Neutralisation  of  Acids  and  Basts  in 
Dilute  Aqueous  Solution."    By  Holland  Crompton. 

The  constancy  of  the  heat  of  neutralisation  of  an  acid 
by  a  base  is  usually  explained  in  accordance  with  the 
eledlrolytic  dissociation  hypothesis  by  the  assumption  that 
the  acid,  base,  and  the  resulting  salt  are  all  in  a  disso- 
ciated state,  and  that  the  only  change  occurring  in  the 
system  is  the  formation  of  water  from  its  ions.  In  this 
paper,  the  author  calls  attention  to  the  fadt  that  from 
Thomsen's  "  Thermochemische  Untersuchungen."  Band 
IV.,  it  may  be  inferred  that  the  replacement  in  any  mono- 
molecular organic  compound  RH  of  the  H  atom  by  one 


and  the  same  radicle  M,  is  attended  with  a  constant  heat 
change,  which  is  independent  of  the  charadter  of  R,  and 
that  for  monomolecular  compounds  the  heat  of  the  readtion 
RH-H  +  M  is  constant  if  M  is  constant  and  independent 
of  variations  in  R.  From  this  it  also  follows  that  the  heat  of 
the  readtion  ROH  -  OH  -}-  M  is  constant.  In  the  neutralisa- 
tion of  an  acid  RH  by  a  base  MOH,  we  have  the  changes 
M-OH,  R-H,  M-fR,  H-HOH.  If  M  is  kept  constant 
then  two  terms  in  the  readtion  will  be  constant,  M  — OH 
and  H  +  OH.  The  only  variation  is  then  in  R-H  and 
M-hR.  But  as  shown  above,  for  monomolecular  com- 
pounds RH-H-fM  is  attended  with  a  heat  change  that 
is  independent  of  R,  and  hence  if  acids  and  bases  in 
j  dilute  aqueous  solution  are  monomolecular  compounds, 
the  heat  of  neutralisation  of  any  acid  by  one  and  the  same 
base  is  a  constant  quantity.  It  may  be  shown  in  similar 
manner  that  the  heat  of  neutralisation  of  any  base  by  one 
and  the  same  acid  is  constant,  and  hence  the  heats  of 
neutralisation  of  acids  by  bases  are  always  the  same. 
The  hypothesis  of  eledtrolytic  dissociation  is  unnecessary 
in  explanation  of  the  observed  phenomena,  if  it  be  granted 
that  the  dissolved  eledtrolytes  are  monomolecular  com- 
pounds. 

In  the  above,  since  OH  is  simply  another  negative 
radicle  R,  the  heat  of  the  readtions  M-OH  and  H-i-OH 
might  be  expedled  to  exadlly  balance  that  of  the  readtions 
H-Rand  M-fR.  This  is  probably  the  case  when  the 
readtions  do  not  occur  in  dilute  aqueous  solution.  But  in 
solution,  while  the  acid,  base,  and  salt  are  in  a  condition 
comparable  with  that  of  their  vapours,  the  water  which  is 
formed  in  the  readtion  must  be  transformed  from  that  state 
to  the  liquid  state  of  the  solvent  by  which  it  is  surrounded. 
This  implies  that  the  heat  of  neutralisation  of  an  equiva- 
lent of  an  acid  by  an  equivalent  of  a  base  in  aqueous 
solution  contains  as  main  fadtor  the  heat  of  condensation 
of  a  molecule  of  water.  This  latter  quality  has  a  value 
of  about  10,800  cal.,  and  the  mean  value  of  the  heat  of 
neutralisation  is  13,500  cal.  The  difference  between  the 
two  values  is  to  be  mainly  attributed  to  the  state  of  partial 
association  of  the  base. 

Discussion. 

Mr.  Pickering  said  whether  Mr.  Crompton  had  estab- 
lished his  views  or  not,  he  had  succeeded  in  throwing 
much  new  light  on  the  subjedt  under  examination,  and 
had  given  us  further  evidence  that  the  theory  of  dissocia- 
tion was  not  the  only  one  through  which  we  might  look 
for  an  explanation  of  the  phenomena  of  dissolution. 

By  way  of  criticism,  the  speaker  suggested  that  the 
means  of  recognising  a  liquid  to  be  of  the  associated  or 
non-associated  class  at  the  freezing  temperatures  was 
somewhat  imperfedt,  and  might,  in  many  cases,  lead  to 
erroneous  conclusions.  He  doubted,  also,  whether  the 
numbers  obtained  showed  that  the  same  solvent  indicated 
consistently  the  same  degree  of  association  when  pitted 
against  various  monomolecular  solutes,  as  should  be  the 
the  case,  and  whether  the  same  associated  solute,  when 
pitted  against  various  monomolecular  solvents,  gave 
similarly  consistent  results.  A  stronger  objedlion,  how- 
ever, might  be  raised  in  the  behaviour  of  diatomic  and  tri- 
atomic  eledtrolytes  in  water.  According  to  Mr.  Crompton's 
views,  these  should  both  give  values  of  55*2  for  the  de- 
pression of  the  freezing-point  when  in  extreme  dilution  ; 
the  triatomic  eledtrolytes  do  so,  but  diatomic  eledtrolytes 
give  values  which  show  little  or  no  tendency  to  surpass 
37,  which  is  only  double  instead  of  three  times  the 
"  normal "  value. 

As  regards  the  heat  of  neutralisation,  the  speaker  con- 
sidered Mr.  Crompton's  application  of  a  general  principle 
which  has  been  established  in  organic  transformations  to 
similar  transformations  in  inorganic  solutions  to  be  both 
legitimate  and  ingenious.  The  simplicity  of  the  principle 
for  organic  substances,  no  doubt,  depends  on  the  fadt  that 
these  substances  are  nearly  saturated  compounds,  and  in 
dilute  solutions  of  inorganic  compounds  we  are  probably 
also  dealing  with  saturated  compounds.  Some  years  ago, 
the  speaker  brought  before  the  Society  an  explanation  of 


72    Crystallographical  Study  of  Normal  Selenates  of  Potasstum,  &c,  \^^j"ntt!*sg^'' 


the  constancy  of  the  heat  of  neutralisation  which  was 
based  on  chemical  grounds,  without  recourse  to  the 
theory  of  dissociation.  Residual  afHnity  was  the  explana- 
tion which  was  offered,  and  Mr.  Crompton's  explanation 
could  be  improved  by  taking  residual  af&nity  into  con- 
sideration. Mr.  Crompton  accounts  for  the  heat  evolved 
on  neutralisation  by  the  condensation  of  the  molecule  of 
water  formed ;  this  condensation  should  certamly  be 
recognised  (a  faft  which  the  speaker  had  overlooked  in 
his  own  communication  on  the  subjedt),  but  the  heat 
evolved  by  it  falls  short  of  that  of  neutralisation  by  some 
3000  cal.,  and  it  seems  probable  that  this  excess  may  be 
accounted  for  by  the  salt  formed  becoming,  in  the  pre- 
sence of  water,  more  fully  saturated  than  either  the  acid 
or  the  alkali.  Each  of  these  latter  contains  a  radicle,  H 
and  OH,  which  is  identical  with  one  of  the  radicles 
in  water  itself,  and  such  compounds  would,  therefore, 
probably  not  have  their  residual  affinity  entirely  saturated 
by  the  water,  whereas  this  is  not  so  with  the  salt,  and 
there  is  nothing  in  its  case  to  prevent  complete  satura- 
tion. 

Mr.  W.  C.  D.  Whetham  said  that  although  it  was  im- 
possible to  criticise  such  an  interesting  paper  without 
having  considered  its  details,  he  would  like  to  ask  Mr. 
Crompton  how  he  would  explain  the  phenomena  of 
eledtrical  condudtivity.  On  the  theory  that  the  ions  were 
free  from  each  other,  the  observed  faft  that  the  conduc- 
tivity of  a  dilute  solution  varied  as  the  concentration  was 
at  once  explained.  The  alternative  supposition,  that  the 
ions  worked  their  way  through  the  solution  by  means  of  a 
continual  series  of  interchanges  between  the  opposite 
parts  of  molecules  at  the  instants  of  collision,  would  lead 
to  a  different  result,  for  the  frequency  with  which  such 
collisions  would  occur,  and  therefore  the  ionic  velocities 
must  vary  as  the  square  of  the  concentration,  and  since 
the  condudtivity  depended  on  the  produdl  of  the  number 
of  ions  and  their  average  velocity,  it  would  be  proportional 
to  the  cube  of  the  concentration. 

Then,  again,  the  fadt  that  the  velocity  of  an  ion  in  dilute 
solution  was  independent  of  the  other  ion  present,  not 
only  as  calculated  from  the  condudivity,  but  also  as 
diredily  observed,  seemed  to  favour  the  idea  of  dissocia- 
tion, and  was  of  greater  weight  than  other  additive  rela- 
tions, since  it  involved  the  properties  of  the  ions  when  in 
motion. 

The  successful  calculation  of  potential  differences  at 
the  contadt  of  two  solutions  on  the  assumption  that  the 
faster-travelling  ion  moved  independently  of  the  other, 
and  so  diffused  more  quickly,  must  also  be  remembered. 
Such  phenomena  as  these  must  be  explained  before  the 
dissociation  theory  could  be  abandoned.  No  doubt  the 
theory  presented  many  difficulties,  and  a  successful 
attempt  to  explain  the  fadts  in  some  other  way  would  be  of 
extreme  interest ;  but  at  present  the  evidence  in  favour  of 
the  dissociation  theory  seemed  very  strong. 

Dr.  Shields,  after  referring  to  the  difficulty  of  dis- 
cussing the  paper  until  all  the  details  were  before  them, 
stated  that  he  was  not  satisfied  that  Mr.  Crompton  had 
made  out  his  case  that  abnormally  large  osmotic  pressures 
were  due  to  the  association  of  the  solvent.  According  to 
the  well-known  equation,  the  osmotic  pressure,  w,  of  a 
solution  containing  »  molecules  of  dissolved  substance  in 
N  molecules  of  solvent  is  represented  thus : — 

n        RT  looop     . 


N 


M 


where  M  denotes  the  molecular  weight  of  the  solvent,  p 
the  specific  gravity  of  the  solution,  T  the  absolute  tem- 
perature, and  R  is  a  constant,  viz., o'oSig  litre-atmospheres, 
when  we  express  the  osmotic  pressure  in  atmospheres, 
and  the  volume  of  the  solution  containing  i  ^-molecule 
in  litres.  In  the  above  equation,  the  produdt  N  M  is  the 
weight  in  grms.  of  the  solution  containing  n  ^-mols.  of 
the  dissolved  substances. 

If  we  make  up  a  dilute  solution  to  contain,  by  intention, 
M  ^-mols.  of  dissolved  substance  in  N  £'-mols.  of  a  solvent 


supposed,  in  the  first  instance,  to  be  normal  or  mono- 
molecular,  then  we  get  a  certain  definite  value  for  the 
osmotic  pressure.  If,  however,  the  solvent  is  associated, 
and  X  is  a  measure  of  its  molecular  complexity,  then 
instead  of  having  weighed  out  N  g'-mols.  of  solvent,  we 
have  in  reality  only  N/;«:,  and  since  the  weight  of  the  solu- 
tion remains  the  same,  the  osmotic  pressure  must  be — 

_    n  RT  1000  p     . 

""  ~  Nji   '  xM  ' 

or,  in  other  words,  remain  uninfluenced  by  the  degree  of 
association  of  the  solvent. 

As  regards  aqueous  salt  solutions,  Dr.  Shields  thought 
Mr.  Crompton  would  encounter  serious  difficulties  in 
attempting  to  explain  why  dilute  solutions  of  binary  com- 
pounds, such  as  potassium  chloride  had  a  maximum 
osmotic  pressure  of  twice  the  theoretical  value,  whilst 
compounds  like  calcium  chloride  gave  three  times  the 
pressure  one  would  expedl. 

Dr.  Shields  also  called  attention  to  the  fadt  that  asso- 
ciated liquids,  such  as  water,  become  less  associated  as 
the  temperature  is  raised,  and  asked  whether  when  the 
particular  temperature  were  reached  at  which  water  be- 
comes "  normal,"  salt  solutions  also  become  "  normal,"' 
i.e.,  show  the  theoretical  osmotic  pressure  corresponding 
to  that  temperature  and  otherwise  behave  like  indifferent 
substances  or  non-eledtrolytes. 

Mr.  Crompton,  in  reply,  explained  that  in  assigning  to 
a  particular  liquid  a  momomolecular  or  an  associated 
charadter  the  general  results  of  the  work  of  Guye,  Ramsay 
and  Shields,  and  others  had  as  far  as  possible  been  adhered 
to.  That  the  molecular  redudtion  of  the  freezing  point 
of  water  by  eledlrolytes  was  in  certain  cases,  even  in  the 
most  dilute  solutions,  below  the  value  required  for  mono- 
molecular  compounds,  indicated  that  the  salt  was  origin- 
ally associated  and  that  the  complex  molecules  only  broke 
down  slowly  with  rising  dilution.  Similar  instances  could 
be  observed  in  the  case  of  solutions  of  associated  com- 
pounds in  other  solvents,  e.g.,  benzene.  Alcohol,  which 
in  concentrated  solution  in  benzene  gave  a  molecular 
weight  far  higher  than  the  normal,  would  be  found  to  give 
corredl  values  in  very  dilute  solution.  On  the  other  hand, 
acetic  acid  gave  even  in  very  dilute  solution  in  benzene  a 
molecular  weight  of  about  no  in  place  of  60,  the  splitting 
up  of  the  associated  molecules  taking  place  apparently  with 
greater  difficulty  in  the  case  of  this  compound  than  in 
that  of  alcohol.  The  adequacy  of  the  dissociation  hypo- 
thesis to  explain  the  eledtrical  properties  of  salt  solutions 
had  not  been  called  in  question,  but  it  had  been  shown 
that  the  hypothesis  gave  no  true  account  of  certain  other 
properties  of  salt  solutions  which  it  had  hitherto  professed 
to  explain.  The  additive  charadter  of  the  molecular  con- 
dudtivities  of  dilute  salt  solutions  was  merely  in  keeping, 
with  the  additive  charadter  of  nearly  all  the  properties  of 
monomolecular  compounds  in  the  fiuid  condition,  as,  for 
example,  the  molecular  volumes,  the  molecular  refradtions, 
the  molecular  viscosities.  If  a  dissociation  hypothesis 
were  adopted  to  explain  additive  properties  in  one  case, 
this  would  have  to  be  extended  to  all,  and  such  a  thing  as 
a  monomolecular  fluid  compound  would  be  non-existent. 

'63.  '•  A  Comparative  Crystallographical  Study  of  the 
Normal  Selenates  of  Potassium,  Rubidium,  and  Ccesium." 
By  A.  E.  TuTTON. 

The  main  conclusions  of  this  investigation,  which  is 
analogous  to  the  one  formerly  presented  concerning  the 
corresponding  sulphates  {Trans,  1894,  Ixv.,  628),  are  as 
follows. 

1.  The  order  of  solubility  of  the  three  salts  follows  that 
of  the  atomic  weights  of  the  three  respedtive  metals  con- 
tained. 

2.  The  values  of  the  morphological  angles  of  the  crys- 
tals of  rubidium  selenate  are  without  exception  inter- 
mediate between  those  of  the  analogous  angles  of  the 

.  potassium  and  caesium  salts.  The  angles  are  therefore  a 
I  fundtion  of  the  atomic  weight  of  the  metal  present. 


Cmrmical  Mbws,  I 
June  4, 1897.      I 


The  Platinum-silver  Alloys. 


273 


3.  The  morphological  axial  ratios  of  rubidium  selenate 
are  likewise  intermediate. 

4.  The  usual  habits  of  the  crystals  of  the  three  salts 
exhibit  a  progressive  development  of  the  primary  forms, 
following  the  progressive  change  in  atomic  weight. 

5.  The  diredions  of  cleavage  are  identical. 

6.  The  relative  density  and  molecular  volume  increase 
when  a  lighter  is  replaced  by  a  heavier  alkali  metal.  The 
increase  in  density  is  greater  when  potassium  is  replaced 
by  rubidium  than  when  the  latter  is  replaced  by  caesium, 
and  the  increase  in  molecular  volume  is,  on  the  contrary, 
greater  when  rubidium  is  replaced  by  caesium.  The  re- 
placement of  sulphur  in  the  sulphates  by  selenium  is 
accompanied  by  an  increase  of  molecular  volume  vary- 
ing from  6"5  to  67  inversely  as  the  weight  of  the  initial 
molecule. 

7.  The  replacement  of  potassium  by  rubidium,  and  of 
the  latter  by  caesium,  is  accompanied  in  each  case  by  an 
increase  in  the  separation  of  the  centres  of  contiguous 
units  of  the  homogeneous  crystal  strudure,  along  the 
diredions  of  each  of  the  morphological  axes,  the  influence 
of  the  nature  of  the  alkali  metal  becoming  relatively 
greater  as  the  atomic  weight  rises.  An  extension  of 
volume  in  all  diredtions  also  accompanies  the  replacement 
of  sulphur  by  selenium. 

8.  An  increase  of  refraAive  index  is  observed  to  accom- 
pany an  increase  in  the  atomic  weight  of  the  alkali  metal, 
and  the  increase  becomes  relatively  greater  as  the  atomic 
weight  rises.  The  replacement  of  sulphur  by  selenium  is 
also  accompanied  by  an  increase  of  refractive  index,  and 
such  increase  diminishes  in  amount  as  the  weight  of  the 
initial  molecule  increases. 

9.  If  the  closed  optical  ellipsoidal  figures,  the  optical 
indicatrices,  of  the  three  salts  were  constru(5led  about  the 
same  origin,  the  indicatrix  of  the  caesium  salt  would  con- 
tain within  it  that  of  the  rubidium  salt,  and  this  again 
would  contain  that  of  the  potassium  salt.  The  indicatrix 
of  the  rubidium  salt  would  lie  nearer  to  that  correspond- 
ing to  the  potassium  salt. 

10.  The  replacement  of  one  alkali  metal  by  another  of 
higher  atomic  weight  is  accompanied  by  a  diminution  of 
the  already  feeble  double  refradion.  In  the  convergence 
of  the  axial  values  of  the  optical  indicatrix  towards  unity 
the  c  value  proceeds  much  more  rapidly  than  the  others. 

11.  The  latter  faft  causes  a  reversion  of  the  sign  of 
double  refradtion  from  positive  to  negative  on  attaining 
the  caesium  salt. 

12.  The  optic  axial  angles  are  precisely  such  as  would 
naturally  follow  from  the  progressive  development  of  the 
optical  indicatrix  ;  a  change  of  diredtion  of  the  acute  bi- 
sectrix and  of  the  optic  axial  plane  occurs  when  the 
caesium  salt  is  reached,  as  the  diredt  result  of  the  con- 
tinuity of  the  progression  according  to  atomic  weight. 

13.  The  optical  properties  of  the  selenates  exhibit 
marked  specific  differences  from  those  of  the  sulphates, 
owing  to  the  progressively  different  effedt  of  replacing 
sulphur  by  selenium  in  the  three  sulphates,  but  the  whole 
of  the  relationships  of  these  optical  properties  exhibited 
by  the  three  salts  of  each  group  are  of  a  precisely  parallel 
nature,  being  functions  in  each  case  of  the  atomic  weight 
of  the  alkali  metal  which  they  contain. 

14.  Progressive  changes  occur  in  the  optical  properties 
on  raising  the  temperature,  following,  even  to  the  least 
detail,  the  order  of  the  atomic  weights.  An  interesting 
diredl  consequence  is  that  a  60°  prism  of  caesium 
selenate  whose  vibration-directions  are  parallel  to  b  and 
c  affords  at  90°  C.  only  one  image  of  the  speftrometer  slit, 
the  two  images  usually  observed  coinciding  at  this  tem- 
perature, the  crystal  being  then  apparently  uniaxial. 

15.  A  further  consequence  of  the  foregoing  is  that  the 
crystals  of  caesium  selenate  exhibit  unique  interference 
phenomena  in  convergent  polarised  light  when  their  tem- 
perature is  raised,  including  crossed  axial  plane  disper- 
sion, and  two  reversals  of  the  sign  of  double  refradtion. 
Section-plates  perpendicular  to  all  three  axes  in  turn  re- 


quire to  be  employed  in  order  to  follow  the  optic  axial' 
changes  even  as  far  as  280°  C. 

16.  The  whole  of  the  molecular  optical  constants  of 
rubidium  selenate  are  intermediate  between  those  of  pot- 
assium  and  caesium  selenates.  The  replacement  of  suU 
phur  by  selenium  is  accompanied  by  an  increase  of  mole- 
cular refraction  of  3*4 — 3-8  Lorenz  or  6*2 — 67  Gladstone 
units,  according  to  the  diredtion  chosen  for  comparison. 
The  relations  of  the  three  salts  of  each  group  as  regards 
molecular  refradtion  are  identical,  but  the  adtual  differ- 
ences are  slightly  greater  in  the  selenate  group  than  in 
the  sulphate  group. 

17.  The  molecular  refradtion  of  each  of  the  three  sele- 
nates for  the  state  of  solution  in  water  is  approximately 
the  same  as  the  mean  of  the  three  values  for  the  crystal. 
When  potassium  selenate  is  dissolved  in  water,  its  refrac- 
tion equivalent  rises  by  2*8  per  cent ;  in  the  case  of  rubi- 
dium sulphate,  a  less  rise  of  I'o  per  cent  is  observed, 
while  for  caesium  selenate  there  is  no  longer  a  rise  but  a 
decrease,  to  the  extent  of  0*5  per  cent.  These  slight 
differences,  due  to  change  of  state,  thus  exhibit  a  pro- 
gression varying  diredtly  as  the  specific  refradtive  energy 
and  inversely  as  the  atomic  weight  of  the  alkali  metal 
contained  in  the  salt.  After  subjedting  Kanonnikoff's 
value  for  dissolved  potassium  sulphate  of  revision,  pre- 
cisely similar  differences  for  the  two  states  are  shown  to 
exist  in  the  sulphate  group. 

18.  The  author  finally  concludes  as  regards  the  selen- 
ates that — 

The  whole  of  the  morphological  and  physical  properties 
of  the  crystals  of  the  rhombic  normal  selenates  of  potassium, 
rubidium,  and  casium  are  functions  of  the  atomic  weight 
of  the  alkali  metal  present. 

19.  It  is  shown  that  the  joint  results  of  the  investiga- 
tions of  the  sulphates  and  selenates  agree  with  the  as- 
sumption that — 

The  characters  of  the  crystals  of  isomorphous  series  are 
functions  of  the  atomic  weight  of  the  interchangeable 
elements,  belonging  to  the  same  family  group,  which  give 
rise  to  the  series. 

Discussion. 

Dr.  Gladstone  remarked  that  everyone  recognised  in 
a  general  way  that  in  groups  of  analogous  elements 
there  is  a  gradual  progression  in  the  properties,  the  middle 
member  of  the  group  being  intermediate,  not  only  in 
atomic  weight,  but  also  in  other  respeds.  The  value  of 
Mr.  Tutton's  elaborate  papers,  is,  that  he  has  proved 
this  up  to  the  hilt  quantitatively  in  the  case  of  two 
similar,  well  defined  groups  of  salts, and  thatwith  regard  to 
a  large  number  of  properties.  The  change  in  the  specific 
refradtion  of  the  selenates  of  the  alkalis  in  their  crystal- 
line and  their  dissolved  condition  is  especialy  instrudtive, 
as  it  involves  the  change  from  plus  in  potassium  and 
rubidium  to  minus  in  caesium.  The  corredlion  of  Kanon- 
nikoffs  number  for  the  potassium  sulphate  which  Mr. 
Tutton  has  made  brings  the  atomic  refradtion  back  to  a 
figure  pradlically  identical  with  that  published  in  Dr. 
Gladstone's  paper  of  1870,  viz.,  33'ii. 

•64.  "  The  Platinum-Silver  Alloys;  their  Solubility  in 
Nitric  Acid."    By  John  Spiller. 

Referring  to  the  published  statements  in  the  text-books,, 
and  particularly  to  those  in  Percy's  "  Metallurgy  "  and 
Bloxam's  "Chemistry,"  according  to  which  5  or  even  9 
per  cent  of  platinum  followed  the  silver  into  solution 
when  their  alloys  were  treated  with  nitric  acid,  the 
author  investigated  the  properties  of  ten  graduated  alloys 
constituted  as  follows  : — Series  I,  containing  12,  g  and  5 
per  cent  of  platinum;  series  II,  containing  2,  1*5,  i  and 
0'75  per  cent  of  platinum  ;  series  III,  containing  o'5,  0*4 
and  0*25  per  cent  of  platinum.  These  alloys  were  pre- 
pared by  fusion  of  the  requisite  proportions  of  silver  and 
platinum  under  a  gas-air  blow-pipe  flame  in  shallow  por- 
celain cups,  and  then  attacked  by  nitric  acid  of  three 
different  strengths,  when  it  was  found  that  the  ordinary- 


274 


Perception  of  the  Difference  of  Phase  by  the  Two  Ears,     {^""ne^NS^''' 


concentrated  acid  of  1-42  sp.  gr.,  warmed,  proved  the 
best  solvent,  but  th'^t  even  under  the  most  favourable  con- 
ditions no  more  than  075  to  1*25,  mean  i  per  cent  of 
platinum,  could  be  dissolved  along  with  the  silver. 

When  diluted  nitric  acid  of  1-2  sp.  gr.  was  employed, 
the  maximum  amount  of  platinum  taken  up  was  only 
about  0*25  per  cent ;  whilst  the  highly  concentrated  acid 
of  1-50  sp.  gr.  proved  altogether  inappropriate,  giving  a 
bulky,  insoluble  produift  consisting  of  platinum  black, 
intermixed  with  nearly  the  whole  of  the  silver  nitrate 
formed. 

It  would  appear,  then,  that  Berthier's  account,  quoted 
by  Percy,  and  the  statement  in  Bloxam's  "  Chemistry  " 
are  incorredi. 

Discussion. 

Mr.  Vernon  Harcourt  suggested  that  the  composi- 
tion of  the  alloys  of  platinum  and  silver  might  vary  with 
the  temperature  at  which  they  were  formed,  and  that  Mr. 
Spiller  should  determine  the  solubility  of  alloys  formed  at 
higher  temperatures  than  those  he  had  employed. 

Mr.  Friswell  thought  that  impurities  in  the  nitric  acid 
might  account  for  some  of  the  discrepant  statements  on 
record. 

65.  "  Dalfon's  Law  in  Solutions.  The  Molecular  De- 
pression of  Mixtures  of  Nonelectrolytes."  By  Meyer 
Wilderman,  Ph.D. 

Since  van  't  Hoff  has  shown  that  the  generalisations 
arrived  at  by  Boyle  and  Guy-Lussac  in  the  cases  of  gases 
are  equally  applicable  to  dissolved  substances  in  dilute 
solutions,  the  conclusion  must  be  drawn  that  the  third 
gaseous  law,  the  law  of  Dalton,  holds  for  dilute  solutions 
also,  this  being  a  necessary  consequence  of  the  nature  of 
osmotic  pressure.  Following  up  the  thermodynamic  con- 
siderations of  Planck,  the  equations  for  mixtures  of  two 
or  more  eledlrolytes  and  the  experimental  proof  of  them 
are  given. 

66.  "  The  Action  of  Bromdiphenylmethane  on  Ethyl 
Sodacetoacetate."  By  G.  G.  Henderson,  D.Sc,  M.A., 
and  M.  A.  Parker,  B.Sc. 

While  bromtriphenylmethane  and  ethyl  sodacetoacetate 
interad  to  give  a  disubstituted  derivative — 

(CPh3)2:CAc-C02Et, 
and  ethyl   acetoacetate,   bromdiphenylmethane,  on    the 
other  hand,  appears  to  yield  only  amonosubstitutedester, 
ethyl  a-acetyl-$-diphenylpropionate, — 

CHPhz-CHAc-COzEt. 

This  substance  was  prepared  by  heating  bromdiphenyl- 
methane (i  mol.)  and  ethyl  sodacetoacetate  (i  mol.)  in 
presence  of  pure  dry  benzene  or  xylene  till  the  readtion 
was  completed,  filtering  from  sodium  bromide,  concen- 
trating the  benzene  solution,  and  purifying  the  crystals, 
which  then  separated,  by  recrystallisation  from  alcohol. 
It  crystallises  in  shining,  colourless  needles,  m.  p.  85°,  is 
sparingly  soluble  in  alcohol  but  readily  in  benzene,  and 
decomposes  almost  entirely  when  distilled. 

On  hydrolysis  of  this  ester  with  cold  dilute  aqueous 
potash,  a  small  quantity  of  a-acetyl-fi-diphenylpropionic 
acid,  CHPha.CHAc-COOH,  was  obtained  in  the  form  of 
extremely  unstable  crystals,  which  melt  about  90°  and 
decompose  at  a  slightly  higher  temperature.  The  salts  of 
this  acid  are  also  very  unstable.  P-diphenyethylmethylke- 
tone,  CHPh2-CH2'CO'CH3,  was  prepared  by  hydrolysing 
the  ester  with  hot  dilute  alcoholic  potash.  It  crystallises 
in  colourless  prisms  which  melt  at  87*5°  and  distils  with 
almost  no  decomposition  at  315°.  It  is  fairly  readily 
soluble  in  alcohol,  and  very  readily  in  benzene.  The 
oxime,  CHPh2-CH2-C(CH3):N-0H,  forms  small,  colour- 
less  crystals,  m.  p.  86—87°.  It  »s  sparingly  soluble  in 
alcohol  but  readily  soluble  in  benzene.  The  semicar- 
bazone,  CHPh2-CH2-C(CH3):N-NH-CO-NH2,  crystal- 
lises from  alcohol  in  small,  white  clusters  of  minute 
crystals,  which  melt  at  181°.  It  is  sparingly  soluble  in 
alcohol  and  in  benzene. 


PHYSICAL    SOCIETY. 
Ordinary  Meeting,  May  2'&th,  1897. 

Mr.  Shelford  Bidwell,  President,  in  the  Chair. 

Mr.  Elder  read  a  paper  communicated  by  Dr.  Albert 
A.  Gray,  M.D.,  on  "The  Perception  of  the  Difference  of 
Phase  by  the  Two  Ears." 

The  investigation  relates  to  certain  acoustical  results 
obtained  some  years  ago  by  Dr.  S.  P.  Thompson ;  they 
maybe  summarised  as  follows: — (a).  When  two  simple 
tones  in  opposite  phases  are  conveyed  separately,  through 
tubes  or  otherwise,  to  the  two  ears,  the  sensation  of  sound 
appears  localised  at  the  back  of  the  head.  (6).  If  the 
respective  tones  from  two  forks  mistuned  to  give  "  beats  " 
are  conduced  separately  to  the  two  ears,  they  still  pro- 
duce the  sensation  of  "  beats  "  ;  and,  to  the  observer,  this 
sensation  also  seems  localised  at  the  back  of  the  head. 
The  "  beats"  are  distindt,  but  there  are  no  true  silences, 
— at  any  rate  so  long  as  attention  is  fixed  on  the  note, 
(c).  Although  "beats"  are  heard  under  these  circum- 
stances, no  beat- tones  are  discernible  by  the  binaural 
method.  The  author  proceeds  to  explain  the  phenomena 
on  the  assumption  that  there  is  a  physiological  connexion 
between  the  nerves  of  both  ears.  His  evidence  is  derived 
from  the  following  experiments  :—(d).  A  vibrating  fork  is 
held  opposite  one  ear  ;  the  opposite  ear  is  then  closed  by 
a  finger;  the  sound  of  the  fork  now  appears  louder  to  the 
open  ear.  (e).  If  the  fork  is  held  opposite  one  ear,  and 
the  chain  of  ossicles  of  the  second  ear  is  then  pressed 
gently  inwards  by  a  fine  probe,  the  sound  of  the  fork  is 
heard  with  increased  loudness  by  the  first  ear.  (/).  If 
the  chain  of  ossicles  in  the  second  ear  is  dragged  outwards 
by  rarefadtion  of  the  air  in  the  meatus,  the  above  changes 
in  loudness  are  no  longer  perceptible.  The  theory  put 
forward  by  the  author  in  explanation  of  these  results  is, 
that  they  are  due  to  reflex  contradtions  of  the  tensor 
tympani  or  stapius  (or  more  probably  both)  of  the  first 
ear.  A  further  observation,  of  Pollak,  is  also  brought  to 
bear  upon  the  question,  i.e.,  (g).  Stimulation  of  one 
cochlea  by  sound  causes  contradtion  of  the  tensor  tympani 
of  both  ears,  and  the  contradlion  is  permanent  while  the 
sound  continues.  This  is  known  to  be  true  for  the  lower 
animals,  and  is  probably  true  for  man. 

With  regard  to  (a),  the  author  observes  that  the  mus- 
cular sense  is  there  being  appealed  to  in  a  manner  quite 
new  to  it.  The  tympani  are  by  nature  trained  each  to 
relax  or  expand  with  the  other,  and  they  are  thrown  out 
of  reckoning  if  the  phases  differ.  Or  again,  the  stimuli 
from  the  two  ears  may  collide  at  one  of  the  lower  nerve 
centres,  and  thus  be  annulled  before  any  intimation  has 
been  received  by  the  brain.  The  path  taken  by  such 
stimuli  is  from  the  nucleus  of  one  nerve,  just  after  its  en- 
trance into  the  medulla,  across  to  the  corresponding 
nucleus  of  the  opposite  side.  In  these  nuclei  the  stimuli 
from  both  ears  mix.  Some  of  the  nerve-fibres  have  no 
nuclear  intercommunication  at  the  base  of  the  brain  ; 
consequently,  stimuli  passing  by  these  paths  are  not  sub- 
jedt  to  interference  ;  this  agrees  with  (b),  where  the  silences 
are  not  complete,  (h).  It  is  to  be  observed  that  beat- 
tones  are  sometimes  perceived  by  the  ear  under  circum- 
stance where  they  cannot  set  a  resonator  into  vibration. 
This  indicates  that  beat-tones  may  be  produced  either  in 
the  ear  or  nerve-centres  of  the  listener,  and  not  exterior- 
ally.  («■).  It  has  been  shown  by  Dr.  Thompson  that 
when  two  simple  tones,  such  as  in  ordinary  hearing  pro- 
duce a  differential  tone,  are  led  singly  to  the  ears,  no 
differential  tone  is  heard.  From  this  the  author  concludes 
that  differential  tones  are  not  produced  in  the  mind  of  the 
listener,  nor  in  any  of  the  cerebral  centres.  From  (A) 
and  (J)  together,  the  point  of  produdtion  is  restrided  down 
to  the  ear  itself;  something  of  the  sort  was  suggested  by 
Helmholtz.  Again,  from  (g),  it  appears  that  when  two 
notes  are  sounded  so  as  to  give  a  differential  tone,  the 
tensor  tympani  must  be  in  a  state  of  continual  contradtion, 


Chbuical  Nbws,  I 
June  4, 1897.     I 


Chemical  Notices  jrom  Foreign  Sources. 


275 


for  the  intervals  of  silence  are  too  short  to  permit  of  any 
relaxation.  Meanwhile,  there  are  certain  periods  during 
which  the  tympani  membranes  are  not  adted  upon  by  any 
force  external  to  the  ear.  The  author  is  of  opinion  that 
if  the  movements  of  the  ossicles  upon  one  another  were 
absolutely  fridtionless,  the  membranes  would  come  to  rest 
in  a  position  where  the  force  of  the  contradling  muscle 
was  balanced  simply  by  the  tension  of  the  membrane  and 
the  ligaments  of  the  ossicles  ;  but  since  the  articulations 
of  the  ossicles  have  some  friftion,  the  equilibrium  is  other- 
wise, and  he  conjedtures  that  the  state  of  affairs  is  such  that 
any  force  ading  upon  the  hammer,  tending  to  draw  it  in- 
wards, produces  a  slight  jerk,  and  this  repeated  gives  the 
necessary  impulses  for  the  sensation  of  differential  tones. 
The  mechanics  of  this  theory  is  not  fully  worked  out, 

Mr.  J.  Rose-Innes  read  a  paper  on  "  The  Isothermals 
of  Isopentane." 

The  author  takes  advantage  of  the  recent  experimental 
work  of  Ramsay  and  Young,  upon  the  thermal  properties 
of  isopentane,  to  test  a  formula  giving  the  relation  of 
pressure  to  temperature  for  gases  generally,  over  a  con- 
siderable range  of  volume.  From  the  linear  equation, 
p  =  bT  —  a,  for  the  pressure  at  constant  volume,  where  a 
and  b  are  functions  of  the  volume,  no  formula  could  be 
found  to  give  close  agreement  with  observed  results. 
More  definite  results  are  obtained  by  examining  a  quan- 
tity depending  upon  a  and  b  together  ;  such  a  quantity  is 
the  temperature  r,  at  which,  for  each  volume,  the  sub- 
stance behaves  as  a  perfedt  gas.  It  is  shown  by  tables 
that  7- is  nearly  a  constant  for  volumes  from  350  to  about  8. 
Below  vol.  8  it  diminishes  very  rapidly  with  volume.  A 
further  investigation  refers  to  the — 


r   (avz)     Sw     *    I 


CHEMICAL 


NOTICES  FROM 
SOURCES. 


FOREIGN 


curves  of  Young,  for  isopentane,  and  a  corresponding 
formula.  At  vol.  3'4  on  this  curve  there  is  a  decided 
peak,  suggesting  discontinuity.  Ether  gives  a  similar 
curve,  and  the  question  arises  whether  such  curves  would 
not  be  better  represented  by  two  or  more  equations. 

Prof.  Young  said  the  diagrams  representing  the  ob- 
served and  calculated  isothermals  were  probably  the  best 
ever  obtained.  Divergence  among  the  values  of  r  was 
explained  in  part  by  the  smallness  of  the  angle  between 
the  theoretical  isochor  for  a  perfeft  gas,  and  the  real 
isochor.  The  point  of  coincidence  was  difficult  to 
define.  Moreover,  the  values  of  r  were  obtained  from  i 
"unsmoothed"  values  of  v.  The  evidence  against  the 
linear  law  consisted  in  a  certain  similarity  in  the  shape  of 
the  different  curves.  It  was  not  easy  to  see  where 
experimental  errors  could  come  in.  The  peak  was  a  very 
striking  feature  of  the  curves,  and  the  agreement  between 
the  results  with  ether  and  those  of  isopentane  was  very 
remarkable.  These  two  substances  had  their  boiling- 
points  close  together,  their  critical  temperatures  close 
together,  and  their  molecular  weights  nearly  alike.  The 
two  substances  not  only  agreed  in  each  giving  a  peaked 
curve,  but  the  peak  corresponded  to  almost  identical 
volumes.  Prof.  Young  hoped  at  some  future  time  to 
examine  normal  pentane,  and  to  determine  whether  t  was 
a  constant  for  this  substance  also. 

The  President  proposed  votes  of  thanks  to  the 
authors  of  the  papers,  and  the  meeting  was  adjourned  until 
June  nth. 


Results  obtained  by  the  Transformation  of  Ammo- 
nium Carbonates  into  Urea. — Leon  Bourgeois. — The 
author  finds  that  60  per  cent  of  the  carbonate  employed 
is  represented  by  the  average  amount  of  urea  obtained, 
the  figures  varying  from  3 '2  to  9*5  per  cent  when  using 
commercial  sesquicarbonate :  bicarbonate  of  ammonia 
gave  2*5  to  2*9  per  cent  of  urea;  and  carbamate  of  ammo- 
nium, CONH2,ONH4,  gave  2'6  to  37  per  cent  of  urea. — 
Bulletin  de  la  Societe  Chimique  de  Paris,  xii.-xiii.,  No.  9. 


NoTB.— All  degrees  of  temperature  are  Centigrade  unless  otherwise 
expressed. 


jfournal  de  Pharmacie  et  Chemie. 
Series  6,  vol  v.,  No.  10. 
Contribution  to  the  Study  of  Pilocarpine  and  Pilo- 
carpidine. — A.  Petit  and  M.  Polonovski. — To  show  the 
difference  existing  between  pilocarpine  and  pilocarpidine 
a  table  has  been  compiled  giving  the  properties  and  prin- 
cipal charadteristics  of  these  two  bases  and  their  deriva- 
tives. From  an  intimate  knowledge  of  these  properties 
the  authors  are  enabled  to  state  that  the  impurity  often 
found  in  commercial  salts  of  pilocarpine  is  nothing  else 
but  pilocarpidine.  These  are,  as  is  well  known,  the  alka- 
loids oijaborandi,  and  the  authors  have  proved  that  pilo- 
carpidine exists  in  the  plant  itself.  This  assertion  is  based 
on  the  following  fadls: — i.  In  the  absence  of  strong  acids 
and  alkalis,  the  adtion  of  boiling  water  alone  will  not  ex 
plain  the  formation  of  the  large  quantities  of  pilocarpidine 
which  is  sometimes  obtained,  in  view  of  its  feeble  adtion 
on  pilocarpine.  2.  Even  when  carefully  guarding  against 
heat  during  its  preparation  we  always  find  in  the  end  more 
or  less  considerable  quantities  of  pilocarpidine.  3.  The 
return  of  pilocarpidine  varies  considerably  in  quantity, 
viz.,  from  5  per  cent  up  to  75  per  cent,  according  to  the 
species  oijaborandi  used.  And,  4.  That  the  stalks  gene- 
rally produce  a  much  greater  quantity  than  the  leaves  of 
the  same  plant. 


Revue  Generate  des  Sciences  Pures  et  Appliques. 
No.  g. 

Produdtion  and  Utilisation  of  Acetylene. — F.  Dom- 
mer. — Lighting  by  means  of  acetylene  gas  has  recently 
experienced  a  temporary  check,  attributable  to  the  absence 
of  carbide  of  calcium  on  the  market,  and  to  the  fadl  that 
there  have  been  a  few  accidents  which  were  caused  by 
inexperience  and  faulty  apparatus.  Acetylene  gas  when 
properly  dealt  with  is  no  more  dangerous  than  coal-gas, 
provided  it  is  not  subjedted  to  greater  pressure  than  two 
atmospheres.  Still  the  manufadlure  of  carbide  of  calcium 
may  now  be  regarded  as  a  definite  industry,  and  in  this 
paper  the  author  goes  fully  into  the  merits  and  disadvant- 
ages of  the  different  furnaces  used  for  its  manufadture,  all 
based,  it  is  needless  to  say,  on  M.  Moissan's  eledtric  fur- 
nace ;  but  besides  the  chemical  aspedt  of  the  question,  M. 
Dommer  thoroughly  considers  and  analyses  the  question 
of  cost,  of  fitting  and  eredling  a  fadlory,  and  running  it 
successfully  when  completed. 

The  New  Tuberculine  of  Koch. — Dr.  R.  Romme. — 
Seven  or  eight  weeks  ago  the  medical  world  was  startled 
by  the  news  that  Dr.  Robert  Koch  had  discovered  a  true 
cure  for  tuberculosis.  A  few  days  afterwards  a  memoir 
was  published  in  the  D^M^ic/i^  medicinische  Wochenschrift, 
in  which  Koch  described  his  new  tuberculine.  It  differs 
entirely  from  the  oWof  1890,  which  was  admittedly  a  failure. 
The  latter  was  a  glycerin  extradl  of  tuberculous  cultures,, 
and  when  injedted  subcutaneously  caused  local  inflamma- 
tion, accompanied  by  a  general  readlion,  high  fever,  palpi- 
tation, sickness,  &c.  The  new  tuberculine,  which  is 
obtained  by  the  mechanical  trituration  of  the  Bacillus 
tuberculosis,  dried  by  successive  "  centrifugations  "  of  the 
matter  added  to  water,  causes  none  of  these  symptoms — 
no  morbid  phenomena  appear.  Both  are  toxic,  but  while 
the  old  accelerated  the  disease,  and,  to  use  the  true  word, 
killed  the  patient,  the  new  kills  the  disease  when  not  too 
far  advanced,  and  thus  cures  the  patient.  Animals  and 
human  beings  are  immunised  by  progressive  increasing 
injedlions  until  they  are  quite  insensible  to  tuberculosis.. 
This  paper  is  principally  devoted  to  explaining  in  detail 


276 


Meetings  for  the  Week, 


(Chemical  Mews, 
1      June  4,  1897. 


the  direcfting  idea  which  guided  Dr.  Koch  in  his  work  and 
the  technical  procedure  which  ensured  his  success. 


Bulletin  de  la  Societe  Chimique  de  Paris. 
Vol.  xvii.-xviii.,  No.  9. 

M.  Bechamp  made  a  first  condtnunication  on  soluble 
t  ferments. 

M.  Matignon  announced  the  preparation  of  carbide  of 
sodium  and  monosodic  acetylene,  both  pure,  by  the  direft 
a(5tion  of  acetylene  on  sodium.  The  reactions  of  these 
bodies  will  be  communicated  later  on. 

M.  Leger  has  studied  the  adlion  of  hypobromite  of 
sodium  in  excess  on  certain  phenols,  and  gives  a  short 
account  of  his  results.  He  proposes  to  extend  his  re- 
searches to  a  certain  number  of  bodies,  enclosing  one  or 
more  molecules  of  phenolic  OH,  and  to  weigh  the  produdts 
formed. 

On  a  Reatflion  of  Carbonic  Oxide.— A.  Mermet.— Air 
containing  i/500th  to  i/5000th  of  carbonic  oxide  will  de- 
colourise a  weak  solution  of  permanganate  of  potash 
acidulated  with  nitric  acid.  The  aftion  is  accelerated  by 
the  addition  of  nitrate  of  silver,  the  time  varying  from 
I  hour  to  24  hours.  The  strengths  of  the  solutions  used 
to  demonstrate  this  new  readtion  are — 2  or  3  grms.  of 
nitrate  of  silver  in  i  litre  of  water  ;  the  permanganate  of 
potash  is  prepared  by  boiling  a  litre  of  distilled  water  con- 
taining a  few  drops  of  nitric  acid  (free  from  HCl),  then 
adding  a  strong  solution  of  permanganate  drop  by  drop 
until  the  rose  colour  is  persistent;  this  is  to  destroy  what 
organic  matter  may  be  present.  On  cooling  dissolve 
I  grm.  of  crystallised  permanganate  of  potassium  and  add 
50  c.c.  of  pure  nitric  acid,  and  keep  in  the  dark.  To  per- 
form the  experiment  20  c.c.  of  the  silver  solution  is  mixed 
with  I  c.c.  of  the  permanganate  and  i  c.c.  of  pure  nitric 
acid,  and  made  up  to  50  c.c.  with  distilled  water  free  from 
organic  matter.  On  passing  air  which  has  been  cleansed 
by  first  being  passed  through  a  tube  containing  cotton- 
wool, another  containing  phosphoric  anhydride,  another 
containing  baryta  water,  &c.,  through  this  liquid,  the  de- 
colouration is  complete. 

Adtion  of  Chromate  of  Strontium  on  Mercuric 
Chloride.— H.  Imbert  and  G.  Belugou. — The  authors  find 
that  chromate  of  strontium  and  mercuric  chloride  in  a 
hydrochloric  acid  solution  form  a  double  salt — 

Cr04Sr,2HgC]2,HCl, 
which  is  undecomposable  by  water.  They  are  also  able 
to  predift  the  existence  of  a  certain  number  of  double  salts 
containing  an  excess  of  hydrochloric  acid.  In  a  further 
note  on  the  same  subjedl  M.  Belugou  obtains  analytical 
results  which  lead  him  to  believe  that  a  basic  mercuric 
chromate  is  also  formed  which  is  mixed  with  the  principal 
substance  as  an  impurity. 

Preparation  of  oajS-Triphenylethane. — J.  Rawitzer. 

Benzylidenes-diphenyl-hydrazine,  and  their  Deri- 
vatives ;  and  the  Transformation  of  these  Bodies 
into  Dibenzylidene-diphenyltetrazol.  —  H.  Causse. 
— Neither  of  these  last  two  papers  are  suitable  for 
abstradtion. 

Bssence  of  Cedar  Wood. — L.  Rousset.  —  Abso- 
lutely pure  essence  of  cedar  wood,  free  from  any  adul- 
teratioM,  was  obtained  from  the  pencil-works  at  St. 
Paul-en-Jarez,  and  fradlionated  in  vacuo.  Four-fifths  of 
the  essence  constitutes  a  hydrocarbide,  boiling  at  125°  to 
130°,  at  9  m.m.  pressure.  This  hydrocarbide  is  cedzene, 
C15H24.  It  is  a  sesquiterpene,  and  adls  on  polarised  light 
aD=-47''54'- 

Research  on  Essence  of  Geranium.  —  Eugene 
Charabot.  —  The  author  finds  that  the  lavo- rotatory 
ether,  stated  to  be  one  of  the  constituents  of  essence  of 
pelargonium,  is  not  contained  in  essence  of  palmrosa. 


NOTES    AND    QUERIES, 

*if*  Our  Notes  and  Queries  column  was  opened  for  the  purpose  of 
giving  and  obtaining  information  likely  to  be  of  use  to  our  readers 
generally.  We  cannot  undertake  to  let  this  column  be  the  means 
of  transmitting  merely  private  information,  or  such  trade  notices 
as  should  legitimately  come  in  the  advertisement  columns. 

Thorium. — Could  any  reader  give  outline  of  cheap  and  prai5lical 
method  for  the  extrad^ion  of  thorium  from  monazite  sand  ? — F.  B. 


MEETINGS    FOR    THE    WEEK. 

Tuesday,  8th.— Royal  Institution,  3.     "  The  Heart  and  its  Work," 

by  Dr.  Ernsst  H.  Starling. 
Thursday,  joth.— Royal  Institution,  3.     "  Wordsworth  and    Cole- 
ridge,'' by  Churton  Collins,  M.A. 
Friday,  I ith. — Royal  Institution,  9.     "On  Diamonds,''  by  William 
Crookes,  F.R.S. 

Physical,  5.    "  The  Effeft  of  Sea-water  on  InduiSion 

Telegraphy,"  by  C.  S.  Whitehead.  "  A  New  Defin- 
ition of  Focal   Length,  and  an  Instrument  for  its 
Determination,"  by  T.  H.  Blakesley.    "  Decompo- 
sition of  Silver  Salts  under  Pressure,"  by  Dr.  J.  E. 
Myers  and  Dr.  F.  Braun.      "New  Way  of  Deter- 
mining Hysteresis  in  Straight  Strips,"  by  Dr.  Fle- 
ming, F.R.S. 
Saturday,  i2th.— Royal  Institution,  3.  "Music  in  England  during  the 
Reign  of  Queen  Viftoria,"by  J.  A.  Fuller  Mait- 
land,  M.A. 


WILLIAM     F.     CLAY, 

CHEMICAL  BOOKSELLER  AND  PUBLISHER, 
18,  Teviot  Place,  Edinburgh. 

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ACETONE — Answering  all  requirements. 

.A.C/XJD  .A.OIETIO— Purest  and  sweet. 

;B0IE2/J^0I0— Cryst.  and  powder. 

CITIEilC — Cryst.  made  in  earthenware. 

G--A.XjIjinO— Ffo™  best  Chinese  galls,  pure. 

S-A-LICyXjIC-By  Kolbe's  process. 

•X'_^]S3"JS5"X(3;— For  Pharmacy  and  the  Arts. 

LIQUID  CHLORINE 

(Compressed  in  steel  cylinders). 

FORMALIN    (40^"  CH2O)— Antiseptic  and  Preservative. 

POTASS.  PERMANGANATE— Cryst.,  large  and  small, 

SULPHOCYANIDE   OF   AMMONIUM. 
BARIUM. 

THORIUM,  ZIRCONIUM,  and  CERIUM  SALTS. 

TARTAR   EMETIC-Cryst.  and  Powder. 

PUMICE.     TRIPOLI   AND  METAL  POWDERS. 

ALL  CHEMICALS  FOR  ANALYSIS   AND  THE  ARTS. 

Wholesale  Agents— 

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9  &  10,  ST.  MARY-AT-HILL,  LONDON,  E.G. 


Crbmical  Nbwb,  I 
June  II,  1897.     J 


Liquefaction  of  Fluorine* 


277 


THE    CHEMICAL    NEWS 


Vol.  LXXV.,  No.  1959. 


THE    LIQUEFACTION     OF    FLUORINE.* 
By  H.  MOISSAN  and  J.  DEWAR. 

The  physical  properties  of  a  large  number  of  mineral 
and  organic  compounds  of  fluorine  indicated  theoretically 
that  the  liquefadlion  of  fluorine  could  only  be  accom- 
plished at  a  very  low  temperature.  Whilst  the  chlorides 
of  boron  and  silicon  are  liquid  at  ordinary  temperatures, 
the  fluorides  are  gaseous  and  very  far  from  their  points  of 
liquefaiftion.  This  is  also  true  with  the  organic  com- 
pounds; chloride  of  ethyl  boils  at  -f  12°  C,  and  the 
fluoride  of  ethyl  at  —  32°.f  Chloride  of  propyl  boils  at 
+45°,  and  the  fluoride  of  propyl  at  —  2°4 

Similar  observations  have  been  made  by  Paterno  and 
01iveri,§  and  by  Vallach  and  Heusler,  || 

Gladstones'  experiments  on  atomic  refra(5tion1[  can  well 
be  compared  with  these  facSts. 

In  fa(fl  fluorine  by  certain  of  its  properties  resembles 
oxygen,  though  at  the  same  time  it  is  distindtly  at  the 
head  of  the  chlorine  group. 

The  conclusion  to  be  drawn  from  these  observations 
appears  to  be  that  fluorine  can  only  be  liquefied  with 
great  difficulty.  One  of  us  showed  that  at  a  temperature 
of  —95°,  at  the  ordinary  pressure,  there  is  no  change  at 
all." 

In  the  new  experiments  which  we  now  publish,  fluorine 
was  prepared  by  the  eledtrolysis  of  fluoride  of  potassium 
in  solution  in  anhydrous  hydrofluoric  acid.  The  fluorine 
gas  was  freed  from  vapours  of  hydrofluoric  acid  by  being 
passed  through  a  serpentine  of  platinum,  cooled  by  a 
mixture  of  solid  carbonic  acid  and  alcohol.  Two  platinum 
tubes  filled  with  perfectly  dry  fluoride  of  sodium  completed 
the  purification. 

The  apparatus  used  for  liquefying  this  gas  consisted  of 
a  small  cylinder  of  thin  glass,  to  the  upper  part  of  which 
was  fused  a  platinum  tube.  This  latter  contained  in  its 
axis  another  smaller  tube,  likewise  of  platinum.  The  gas  * 
to  be  liquefied  enters  by  the  annular  space,  passes 
through  the  glass  envelope,  and  escapes  through  the 
small  inner  tube.  This  apparatus  was  fused  to  the  tube 
by  which  the  fluorine  was  supplied. 

In  these  experiments  we  used  liquid  oxygen  as  the 
refrigerant.  It  was  prepared  according  to  the  method 
already  described  by  one  of  us — and  this  research,  we  may 
remark,  required  several  litres. ff 


The  apparatus  being  cooled  down  to  the  temperature 
of  quietly-boiling  liquid  oxygen  (- 183*^),  the  current  of 
fluorine  gas  passed  through  the  glass  envelope  without 
becoming  liquid.  But  at  this  low  temperature,  it  has  lost 
its  chemical  adivity,  and  no  longer  attacks  the  glass. 

If  we  now  make  a  vacuum  over  the  oxygen,  we  see,  as 
soon  as  rapid  ebullition  takes  place,  a  liquid  colledting  in 
the  glass  envelope,  while  gas  no  longer  escapes  from  the 
apparatus.  At  this  moment  we  stop  with  the  finger  the 
tube  by  which  the  gas  had  been  escaping,  so  as  to  prevent 
air  from  entering,  and  the  glass  bulb  soon  becomes  full 
of  a  clear  yellow  liquid,  possessed  of  great  mobility.  The 
colour  of  this  liquid  is  the  same  as  that  of  fluorine  gas 
when  examined  in  a  stratum  one  metre  thick.  According 
to  this  experiment,  fluorine  becomes  liquid  at  —185°. 

As  soon  as  this  little  apparatus  is  removed  from  the 
liquid  oxygen  the  temperature  rises,  and  the  yellow  liquid 
begins  to  boil  with  an  abundant  disengagement  of  gas, 
having  all  the  energetic  reaftions  of  fluorine. 

We  took  advantage  of  these  experiments  to  study  some 
of  the  readtions  of  fluorine  on  bodies  kept  at  extremely 
low  temperatures. 

Silicon,  borax,  carbon,  sulphur,  phosphorus,  and  reduced 
iron,  cooled  in  liquid  oxygen  and  then  placed  in  an  atmo- 
sphere of  fluorine,  did  not  become  incandescent.  At  this 
low  temperature  fluorine  did  not  displace  iodine  from 
iodides.  However,  its  chemical  energy  is  still  sufficiently 
great  to  decompose  benzene  and  essence  of  turpentine 
with  incandescence,  as  soon  as  their  temperatures  rose  to 
—  180°.  It  would  thus  seem  that  the  powerful  affinity  of 
fluorine  for  hydrogen  is  the  last  to  disappear. 

There  is  still  another  experiment  we  ought  to  mention. 
When  we  pass  a  current  of  fluorine  gas  through  liquid 
oxygen,  a  fiocculent  precipitate  of  a  white  colour,  which 
quickly  settles  to  the  bottom,  is  rapidly  formed.  If  we 
shake  up  this  mixture  and  throw  it  on  a  filter,  we  separate 
the  precipitate,  which  possesses  the  curious  property  of 
deflagrating  with  violence  as  soon  as  the  temperature 
rises. 

We  intend  to  follow  up  the  study  of  this  body,  as  well 
as  that  of  the  liquefadlion  and  solidification  of  fluorine, 
which  demand  further  experiments. — Comptes  Rendus, 
vol.  cxxiv.,  No.  22,  p.  1202. 


*  M.  Moissan  brought  all  his  apparatus  for  the  produftion  of 
fluorine  to  the  Royal  Institution  on  the  occasion  of  his  ledlure  there 
on  Friday,  the  28th  of  May.  The  next  day  the  writer  had  the  good 
fortune  to  witness  in  the  laboratories  of  the  Institution  by  M.  Moissan 
and  Professor  Dewar  some  of  the  experiments  which  resulted  in 
the  liquefadlion  of  fluorine.  These  experiments  mainly  owed  their 
success  to  the  unrivalled  appliances  for  the  production  of  intense  cold 
possessed  by  the  Institution,  and  the  skill  and  experience  of  Professor 
Dewar  and  his  assistants  in  preparing  a  special  apparatus  suitable 
for  the  examination  of,  and  experimenting  with,  fluid  fluorine,  and  in 
the  manipiilation  of  large  quantities  of  liquid  air. — W.  C. 

+  H.  Moissan,  "  Proprietes  et  Preparation  du  Fluorure  d'ethyle," 
Ann.  de  Chim.  et  de  Phys.,  Series  6,  vol.  xix.,  p.  266. 

t  Meslans,  Comptes  Rendus,  vol.  cviii.,  p.  352. 

§  Paterno  and  Oliveri,  "  Sur  les  trois  Acides  Fluobenzoiques 
Isomeres,  et  sur  les  Acides  Fluotoluidique  et  Fluoanisique,"  Gazetta 
Chitnica  Italiana,  vol.  xii.,  p.  85,  and  vol.  xiii.,  p,  583. 

II  Vallach  and  Heusler,  Annales  deLiebig,  vol.  ccxliii.,  p.  219. 

T  J.  ri,  Gladstone  and  G.  Gladstone,  "  Refraftion  and  Dispersion 
of  Fiuobenzene  and  Allied  Compounds,"  PIM.  Mag.,  Series  5,  vol. 
xxxi.,  p.  I. 

*•  H.  Moissan,  "  Noizvelles  Recherches  sur  le  Fluor,"  Ann.  de 
Chim.  et  de  Phys.,  Series  6,  vol.  xxiv.,  224, 

1+  J.  Dewar,  "New  Researches  on  Liquid  Air,"  Royal  Institution 
of  Great  Britain,  1836,  and  Proc.  Roy.  Inst.,  1893. 


ON   THE 

DISTILLATION    OF   VERY    DILUTE    MIXTURES 

OF    ETHYLIC    ALCOHOL    AND    WATER. 

APPLICATION     TO     THE     ESTIMATION    OF 

ALCOHOLIC    SOLUTIONS    CONTAINING    ONLY 

1/3000TH    TO    i/io,oooTH   PART. 

By    M.    NICLOUX    and    L.    BAUDUER. 

Last  June  one  of  us  brought  forward  a  method  of  esti- 
mating alcohol  in  solutions  containing  only  i/sooth  to 
i/300oth  part  (M.  Nicloux,  "  Dosage  de  I'Alcool  Ethylique 
dans  les  Solutions  ou  cet  Alcool  est  Dilue  dans  des  pro- 
portions comprises  entre  1/500  et  1/3000,"  Comptes 
Rendus  de  la  Soc.  de  Biol.,  loth  Series,  vol.  iii.,  p.  841, 
July  31,  i8g6).    We  will  recall  this  method  in  a  few  lines. 

"  If  to  a  very  dilute  solution  of  alcohol  (from  i/500th  to 
i/3000th  part)  a  weak  solution  (2  per  cent)  of  bichromate 
of  potash  be  first  added,  then  a  little  sulphuric  acid,  the 
alcohol  becomes  oxidised  and  the  bichromate  becomes  a 
chromic  salt,  in  proportion  to  the  quantity  of  alcohol 
present. 

"  If  the  bichromate  is  not  in  excess  the  solution  is 
bluish  green,  the  colour  of  weak  sulphate  of  sesquioxide 
of  chromium.  If,  on  the  contrary,  it  be  ever  so  little  in 
excess,  it  is  yellowish  green.  The  difference  between  the 
two  tints  is  very  easily  noticed. 

"  By  using  5  c.c.  ot  the  alcoholic  solution  under  exam- 
ination and  a  solution  of  20  grms.  per  litre  of  pure  crystal- 


278 


Relations  between  Melting-points  and  Latent  Heats  of  Fusion,  {^"^"^^t^i^*' 


lised  bichromate  of  potash,  of  which  x  c.c.  is  equal  to 
i/ioooth  c.c.  of  absolute  alcohol  in  the  solution  used — or, 
what  comes  to  the  same  thing,  o'l  per  cent  in  volume, 
the  number,  n,  of  cubic  centimetres  or  fradlions  of  cubic 
centimetres  used  to  obtain  the  yellowish  green  coloura- 
tion, which  indicates  the  slight  excess  of  bichromate,  will 
at  once  give  the  amount  of  alcohol  present;  this  will  be 
n/iooo,  or  o*n  per  cent. 

"  The  recognition  of  the  yellowish  green  tint  is  made 
much  easier  by  having  tubes  with  definite  quantities  of 
alcohol,  such  as  i/5O0th,  i/666th,  i/ioooth,  i/i500th, 
i/2oooth,  i/30ooth,  for  comparison.  50  c.c.  is  a  con- 
venient quantity  to  work  with." 

It  is  well  known  that  in  distilling  mixtures  of  alcohol 
and  water,  the  alcohol  being  present  in  such  quantity  as 
to  be  easily  measured,  the  whole  of  the  alcohol  is  sup- 
posed to  come  over  in  the  first  third  of  the  distillate.  We 
thought  it  would  be  interesting  to  see  if  very  dilute  solu- 
tions behaved  in  the  same  manner. 

The  following  is  the  method  we  used  : — 

60U  c.c.  of  the  dilute  solution  (i/sooth  to  i/30ooth)  is 
placed  in  a  i-Iitre  flask  and  distilled,  i/2oth  of  the  distil- 
late, or  30  c.c,  is  colledied ;  the  operation  is  repeated 
with  another  600  c.c,  and  2/2oths  of  the  distillate  is  col- 
leAed.  This  is  repeated  a  third  time,  and  3/2oths  is  col- 
lected, and  so  on.  A  priori,  it  would  appear  to  be  simpler 
to  colledt  consecutive  i/2oth8  and  to  estimate  the  alcohol 
in  each  ;  but  alcohol  comes  over  so  rapidly  that  the  esti- 
mation of  fractions  over  2/20ths  becomes  difficult,  and  the 
errors  of  observation  are  increased. 

The  method  we  adopted  is  longer,  but,  on  the  other 
hand,  is  much  more  exadl.  Our  experiments  were  carried 
out  on  mixtures  of  i/500th,  i/ioooth,  and  i/3oooth.  The 
following  table  shows  the  results  we  obtained  : — 

Amount  per  cent  of  alcohol  in  the  distillate. 

Fraftions  of  /  '  > 

distillate  coUefted.  i/500th.  i/ioootb.  i/3000th. 

l/20th  ....  50  52  55 

2/20th8  ....  75  78  79 

3/20ths  ....  88  90  gt 

4/2oths  ....  90  92  94 

5/2oths  ....  91  93  97 

6/20th8  ....  92  94  100 

7/2oths  ....  93  98  100 

io/20ths  ..     ..  100  100  100 

An  examination  of  these  figures  shows  that : — 

1.  The  distillation  of  alcohol  is  relatively  quick.     The 

first  i/20th  of  distillate  containing  50  per  cent  of 
the  total  quantity  present. 

2.  The  quantity  per  cent  of  total  alcohol  for  a  given 

fradlion  is  greater  as  the  mixture  is  more  dilute.       ' 

3.  In  mixtures  of  i/footh  and  i/ioooth  the  third  part 

(fradions  of  6/20ths  and  7/20ths)  does  not  contain 
all  the  alcohol  present. 

4.  But  with  the  mixture  of  i/30ooth  we  are  not  wrong 

in  assuming  that  the  alcohol  is  entirely  contained 

in  the  first  quarter  of  the  distillate. 
The  diredt  consequence  of  these  results  was  the  attempt 
to  estimate  alcohol  in  solutions  containing  not  more  than 
i/3000th  to  i/io,oooth.  Two  experiments  made  with 
solutions  of  i/50ooth  and  i/io,oooth  gave,  in  the  first 
quarter,  distillates  containing  i/i250th  and  i/2500th, 
which,  estimated  by  the  method  described  above,  gave  us 
the  total  alcohol  present. 

It  may  be  remarked  that  the  size  of  the  flask,  in  propor- 
tion to  the  amount  of  liquid  distilled,  did  not  appear  under 
the  conditions  described  to  have  any  particular  influence. 
—Bull,  de  la  Societe  Chimique  de  Paris,  xii.-xiii..  No.  7. 


Disinfedtion  with  Formic  Aldehyd.— Referring  to 
our  note  on  this  subjedt  (Chem.  News,  Ixxv.,  p.  251),  we 
are  informed  that  the  Medico-Hygienic  Inventions  Co., 
Lim.,  are  the  sole  agents  for  the  apparatus  known  as 
Trillat's  autoclave,  used  by  Dr.  Winter  Blyth  in  his  experi- 
ments on  disinfedion  with  formic  aldehyd. 


RELATIONS  BETWEEN  THE  MELTING-POINTS 

AND  THE  LATENT  HEATS  OF  FUSION 

OF    THE    METALS.* 

By    JOSEPH    W.    RICHARDS,    Pb;D. 

In  a  ledture  before  the  Franklin  Institute  in  January,  1893, 
on  "  The  Specific  Heats  of  the  Metals,"  I  announced  the 
fadt  that  in  the  case  of  most  of  the  metals  whose  latent 
heats  of  fusion  were  known,  this  quantity  bears  a  simple 
relation  to  the  heat  required  to  raise  the  metal  from 
absolute  zero  —273°  (C.)  to  its  melting-point.  In  most 
cases  the  former  is  one-third  the  latter.  I  even  ventured 
to  predidt  that  the  latent  heat  of  fusion  of  gold  was  about 
14  calories,  and  it  has  since  been  determined  by  Roberts- 
Austen  as  l6'3.  Further,  several  latent  heats  have  since 
been  determined  which  conform  to  the  above  relation,, 
and  I  have  thought  it  opportune  to  coUedt  these  data  and 
point  out  the  limits  of  the  relation,  with  some  other  ob- 
servations which  later  thought  on  the  subjed  has 
developed. 

In  the  following  table  there  is  given,  first,  the  heat 
required  to  raise  i  kilogrm.  of  the  metal  from  the  absolute 
zero  to  its  melting-point  (using  the  most  probable  values 
for  the  specific  heats  and  exterpolating  to  —273°,  for  a. 
discussion  of  which  data  reference  is  made  to  the  paper 
already  quoted)  ;  second,  a  simple  fradtion  of  this  quan- 
tity ;  and,  lastly,  the  a(aually  determined  latent  heats  of 
fusion,  the  experimental  errors  of  which  are  probably  5  to- 
10  per  cent : — 

Heat  absorbed  from  Latent  heat  of 

Element.  -27300.10  the  fusion. 

melting-point.  (Experimental). 

Sodium     ..     ..  107*8  J=  35*9  387 

Aluminium.     ..  2i5'o  i  =  i07'5  loo'o 

Potassium..     ..  54'9  i=   i8'3  157 

Copper      ..     ..  145-3  4=  48*4  43*0 

Zinc 7i'2  J=  23'4  226 

Gallium     ..     ..  21*9  \=  21*9  iQ'2 

Palladium..     ..  i25'o  J=  417  363 

Silver 747  4=  24*9  24  7 

Cadmium..     ..  307  4=   *o*2  iS'^ 

Tin 27-6  i=  13-8  i4*5- 

Platinum  ..     ..  83*4  4=  278  27-2 

Gold 453  4=  I5"i  i6-3 

Mercury    ....  7*5  4=     2-5  2*8 

Lead I77  4=     5'9  5*4 

Bismuth    ..     ..  14'4  t=   H"4  12-4 

Of  the  fifteen  cases,  the  relation  in  eleven  cases  is  one- 
third  (in  almost  every  case  within  the  limits  of  the  experi- 
mental  errors)  ;  in  two  cases  the  fradtion  is  apparently 
one-half,  and  in  two  cases  unity.  That  for  ten  cases  the 
ratio  should  be  so  uniform,  with  latent  heats  ranging  from 
less  than  3  to  nearly  50,  is  an  indication  of  some  intimate 
connexion  between  these  physical  constants  of  the  ele- 
ments. 

Regarding  the  exceptional  cases  it  occurred  to  me  that 
aluminium,  tin,  and  bismuth  are  known  to  adt  anomalously 
in  many  relations,  as  if  their  molecular  strudures  were 
different  from  that  of  the  other  metals.  (We  have  no  data 
from  which  to  discuss  gallium  in  these  relations).  For 
instance,  in  lowering  the  freezing-point  of  other  metals, 
aluminium  is  known  to  adt  as  if  its  molecular  formula 
were  double  that  of  other  metals  in  the  molten  state.  In 
Pidtet's  observation  of  the  connedtion  between  the 
melting-point,  coefficient  of  expansion,  and  atomic 
volume  of  an  element,  bismuth  and  tin  are  among  the 
chief  exceptions. 


*  A   Paper  read  before  the  Chemical   Seftion   of  the  Franklia. 
Institute.    From  the  Journal  of  the  Franklin  Institute,  May,  1897. 


'Chbmical  nbws,  I 
June  II,  1897.     I 


Apparatus  foY  Steam  Distillation, 


279 


[Pidlet's  rule  is  that  the  melting-points  of  the  elements 

•  tT  in  absolute  degrees)  are,  in  many  cases,  inversely  pro- 
portional to  their  coefficient  of  expansion  by  heat  (a  = 
linear  expansion  0°  to  100°  C.)  and  to  the  relative  distance 

•  of  their  atoms  apart  (l/ V,  where  V  is  the  atomic  weight 

•divided  by  the  specific  gravity,  or  atomic  volume)  for 
which  Pi(5let'8  relation  is  expressed  by — 


•-v^= 


4'5 


T  = 


4-5 


-^ 


In  fa«a,  the  produds  of  these  three  quantities  are  not 
exaAly  equal,  but  vary  between  4  and  5,  the  reason  being, 
doubtless,  that  the  average  specific  gravity  and  rate  of 
expansion  from  —273°  to  the  melting-point  varies  some- 
what from  the  gravity  at  20°  and  rate  of  expansion  at  0° 
to  100°  as  used  in  his  calculations] . 

As  already  mentioned,  bismuth  and  tin  were  Pidtet's 
chief  exceptions,  and  since  they  were  anomalous  in  regard 
to  their  latent  heat  relations,  I  was  led  to  compare  these 
■several  relations  among  themselves,  and  to  the  following 
chain  of  reasoning  : — Since  the  atomic  heats  of  the  ele- 
ments (specific  heat  into  atomic  weight)  at  20°  to  100° 
are,  by  Dulong  and  Petit's  law,  approximately  equal  to 
j6'4,  then,  assuming  that  the  average  specific  heat  from 
—  273°  to  the  melting-point  does  not  vary  much  from  the 
figure  for  20°  to  100",  the  heat  in  atomic  weight  of  a 
metal  at  its  melting-point  is  approximately  6*4  T ;  and, 
assuming  the  relation  between  the  latent  heat  of  fusion 
and  the  total  heat  in  the  metal  at  its  melting-point  as  i, 
the  latent  heat  of  fusion  of  an  atomic  weight  of  a  metal 
becomes  approximately  2"i  T. 

But  we  can  at  once  connedt  this  expression  with  Pidet's 
rule,  and  write : — 

_   4-5   X   21   _       9'5 


2-1  T  = 


^v      ».^v 


where  L  is  the  latent  heat  of  fusion  of  an  atomic  weight 
of  the  metal. 

To   test   the   validity  of  this    expression    (which,   for 
reasons  already  explained,  cannot  claim  exadt  accuracy), 

-we  will  take  Pidtet's  values  for  a  .  l/V  (which  are  based 
on  the  best  available  data)  and  make  the  calculation  for 
the  metals  whose  latent  heat  of  fusion  and  coefficient  of 
expansion  are  both  known. 


L-       9-5 

T 

Latent  heat 

experimentally 
obtained. 

a  .y\ 

At.  wt. 

Aluminium 

, .     igoo 

70-4 

I0O"O 

Copper     .. 

. .     3006 

46*2 

43 'o 

Zinc.      .. 

..     1561 

24-6 

22*6 

Palladium  . 

..     3832 

36-1 

36-3 

Silver 

..     2541 

23'5 

247 

Cadmium. . 

. •     1253 

ii'i 

13-1 

Tin    ..      .. 

..     1712 

137 

14-5 

Platinum.. 

..     5106 

26-3 

27 '2 

Gold..      .. 

..     3035 

I5'5 

163 

Mercury   . . 

..      654 

33 

2-8 

Lead..      .. 

..     1284 

6-2 

5  4 

Bismuth   .. 

. .     2777 

13  "4 

12-4 

Excepting  aluminium,  the  coincidences  are  so  close  in 
the  case  of  all  the  others  that  the  calculated  values  in 
every  case  fall  within  the  permissible  limits  of  experi- 
mental errors,  and  it  must  be  remembered  that  the  above 
table  contains  all  the  metals  for  which  the  data  are  at 
present  available.  The  non-metal  sulphur  expands  so 
irregularly  that  no  calculation  can  be  made  for  it. 

The  closeness  of  the  above  coincidences  may  lead  us  to 
.apply    the    formula    to    those    other    elements    whose 


coefficients  of  expansion  are  known,  but  whose  latent 
heat  has  not  yet  been  determined,  and  thus  to  predidt 
approximately  the  probably  value  of  their  latent  heat  of 

fusion.  ^  ,    . 

Calories. 

Magnesium 5^' 

Pure  iron ^g* 

Cobalt      68* 

Nickel      68- 

Selenium I3' 

Ruthenium     ..      ..     4^' 

Rhodium 52' 

Indium 8* 

Antimony       16* 

Tellurium       . .     .  •  17* 

Osmium 35' 

Iridium 28' 

Thallium 5'8 

In  the  case  of  those  other  elements  whose  coefficients 
of  expansion  and  specific  heat  are  both  unknown,  the 
latent  heats  of  fusion  may  be  predidted,  approximately, 
simply  from  the  melting-point,  by  using  the  relation 
L  =  2-i  T.  The  above  comparisons,  however,  have 
shown  that  the  dependence  of  the  atomic  latent  heat  of 
fusion  on  the  absolute  temperature  of  the  melting-point, 
or  on  the  total  heat  in  the  metal  at  its  melting-point, 
is  less  exadl  than  the  dependence  on  the  coefficient  of  ex- 
pansion and  atomic  volume,  and  we  should  give  the  latter 
relationship  preference  in  predidting  unknown  latent 
heats. 


APPARATUS    FOR    STEAM    DISTILLATION. 
By  WM.  CORMACK. 

In  using  the  apparatus  for  steam  distillation  described  by 
Matthews  in  the  JourtK^l  of  the  Chemical  Society,  vol. 
Ixxi.,  p.  318,  it  occurred  to  me  that  by  a  slight  modification 
in  the  strudlure  and  arrangement  of  the  parts  a  gain  both 
in  point  of  simplicity  and  freedom  of  construdlion  might 
be  secured.     The  modified  apparatus,  a  sketch  of  which 


is  annexed,  consists  of  a  head-piece,  h,  an  adapter,  a,  and 
a  receiver,  R.  The  head-piece,  which  resembles  that  of  a 
Drechsel  extradlion  apparatus,  is  fitted  into  the  neck  of 
the  flask  by  means  of  a  cork  or  of  rubber  tubing.  The 
vapours  from  the  flask  pass  along  the  tube  k  to  the  con- 
denser through  the  adapter.  A,  which  is  an  ordinary  bent 
adapter  with  a  short  tube  sealed  on  at  the  bend.     After 


280 


Explanation  of  some  Experiments  of  G*  Le  Bon's, 


\  Chemical  Mbws, 
I      June  II,  1807. 


condensation,  the  liquid  runs  down  the  vertical  tube  of 
the  adapter  into  the  receiver,  R.  As  shown  in  the  figure, 
the  apparatus  is  set  up  so  as  to  colleft  a  liquid  which  is 
heavier  than  water.  In  this  case  the  liquid  sinks  to  the 
bottom  of  the  leceiver,  and  the  water  floats  on  the  top. 
As  soon  as  the  level  of  the  water  has  attained  a  certain 
height  it  flows  back  through  the  upper  side-tube,  d,  into 
the  flask.  It  is  esential  that  D  should  be  at  a  lower  level 
than  the  lower  side-tube  of  H.  The  receiver  is  drawn  out 
at  the  bottom  and  furnished  with  a  rubber  tube,  clip,  and 
jet,  so  that  it  may  ad  at  the  same  time  as  a  separator. 
The  lower  side-tube,  E,  of  the  receiver  is  closed  by  a  cap 
of  rubber  and  glass  rod. 

If  the  liquid  to  be  collefted  is  lighter  than  water,  the 
upper  tube,  d,  is  closed  by  the  cap,  and  connedlion  made 
by  glass  and  rubber  tubing  between  the  lower  tube,  e,  and 
the  head-piece.  The  water  then  sinks  to  the  bottom,  and 
flows  back  into  the  flask  through  the  lower  tube  and  its 
connexions. 

The  chief  points  in  which  this  modification  differs  from 
the  original  apparatus  of  Matthews,  is  that  there  is  no 
fast  connedtion  between  the  condenser  and  the  receiver, 
but  merely  a  water-joint,  and  that  the  same  apparatus 
may  be  used  for  colleding  liquids  which  are  heavier  or 
lighter  than  water.  I  have  found  the  apparatus  very 
satisfadory,  so  far  as  I  have  tested  it,  especially  when 
small  quantities  of  substances  are  being  dealt  with.  The 
liquids  in  the  receiver  become  warm  after  a  time,  which 
may  or  may  not  be  advantageous,  according  to  the  nature 
of  the  substance.  If  cooling  is  required,  this  is  best 
done  by  jacketting  the  receiver. 

University  College,  Dundee. 


EXPLANATION 


OF    SOME    EXPERIMENTS 
G.  Le  BON'S. 
By    H.    BECQUEREL. 


OF 


The  Comptes  Rendus  of  one  of  our  last  sessions  contains 
a  paper  (April  20th,  1897),  ^y  M'  Perigot,  in  which  the 
author,  in  giving  account  of  certain  experiments  by  G. 
Le  Bon,  after  some  very  judicious  remarks,  invokes  the 
transparency  of  ebonite  for  white  light.  The  fa<ft  of  the 
transparence  of  the  ebonite  plates  used  in  these  experi- 
ments for  the  adlive  radiations  is  undeniable,  but  I  purpose 
showing  that  the  phenomena  observed  are  not  due  to  what 
we  call  white  light, — that  is  to  say,  to  the  radiations  em- 
ployed most  generally  in  photography, — but  to  the  red 
radiations  from  the  least  refrangible  extremity  of  the 
spedrum,  and  the  ultra-red  radiations  for  which  ebonite  is 
very  transparent. 

An  experiment  which  M.  G.  Le  Bon  has  described,  in 
reply  to  M.  Perigot,  leaves  me  no  doubt  in  this  respeft, 
and  since  Monday  last  I  have  indicated  the  following 
explanation  to  our  colleagues  MM.  d'Arsonval,  Lippmann, 
and  Poincare.  I  have  verified  its  correftness  the  next  day 
by  several  experiments. 

This  is,  in  the  first  place,  what  constitutes  the  experi- 
ments of  M.  Le  Bon  to  which  I  have  just  alluded.  We 
take  a  surface  covered  with  phosphorescent  zinc  sulphide, 
and  expose  it  to  the  light ;  then  we  cover  it  with  a  plate 
of  ebonite,  upon  which  we  arrange  as  screens  various 
objeds, — e.g.,  coin, — and  expose  the  whole  to  the  sun  for 
some  seconds.  On  examining  afterwards,  in  the  dark,  the 
surface  of  the  zinc  sulphide  (originally  phosphorescent), 
we  find  that  it  is  almost  extinguished,  except  under  the 
piece  ot  metal  where  the  phosphorescence  is  still  very 
visible.  M.  Le  Bon  thought  himself  entitled  to  conclude 
from  this  experiment  that  the  metal  sent  out  rays  which 
excite  phosporescence.  The  explanation  is  quite  different. 
These  red  acd  ultra-red  rays  sent  by  the  sun  traverse  the 
ebonite,  and,  as  it  has  been  known  long  ago,  extinguish 
the  phosphorescence  over  the  whole  luminous  surface, 


except  at  the  points  protected  by  the  metallic  screen  ;  at 
these  points  the  phosphorescence  obtained  by  the  previous 
illumination  fades  very  slowly.  I  have  not  proposed  to 
determine  what  are  the  radiations  transmitted  through 
the  ebonite.  I  will  recall  that  it  results,  from  the  very 
ancient  experiments  of  my  father  and  from  those  which 
I  have  had  occasion  to  publish,  that  the  red  and  ultra  red 
rays  determine  a  rapid  exttndtion  and  the  phosphorescence 
of  bodies  previously  illuminated,  an  extindlion  generally 
preceded  by  a  temporary  excitement  which  is  not  visible 
with  phosphorescent  zinc  sulphide  or  hexagonal  blende. 
If  we  projeft  a  spedlrum  upoiTthe  surface  of  a  phosphor- 
escent sulphide,  the  ultra-red  region  appears  in  black  - 
upon  a  luminous  ground,  in  consequence  of  the  extindion 
set  up  by  the  corresponding  radiations  ;  and  I  have  shown 
that  this  extin«Sion  presents  maxima  and  minima,  variable 
not  only  with  the  nature  of  the  luminous  source,  but  with 
the  nature  of  the  phosphorescent  substance. 

For  hexagonal  blende  the  spedrum  of  extindion  extends 
from  the  red  of  the  visible  region  to  the  wave-length  i  m  5i 
presenting  a  minimum  about  i  /^  i  and  i  /i  2,  and  a  strong 
maximum  between  1^3  and  i  /i  4. 

If  we  projed  upon  a  screen  of  hexagonal  blende,  pre- 
viously illuminated,  a  spedrum  obtained  with  the  solar 
radiations  having  traversed  a  plate  of  ebonite  0*6  m.m.  in 
thickness,  we  note  the  immediate  appearance  of  the  infra- 
red extindion-band  of  i'3  ft  to  i  8  ;u ;  then,  after  a  few 
instants,  we  see  appear,  rather  less  intense,  the  extindion 
between  the  wave-lengths  1*3  /*  2  and  the  extreme  visible 
red  near  A. 

On  concentrating  the  solar  light  with  a  lens  we  per- 
ceive red  rays  near  the  extreme  visible  red  of  the  solar 
spedrum. 

Ebonite  is  therefore  transparent  for  the  radiations  which 
extinguish   phosphorescence  of  zinc    sulphide,   and   the^ 
explanation   of  Le  Bon's   experiment   is   evidently   that- 
which  I  have  given  above. 

If  in  this  experiment  we  form  the  screen  of  a  substance 
which  arrests  the  ultra-red  rays,  as  the  red  rays  trans- 
mitted are  much  enfeebled,  the  silhouette  of  the  screen 
appears  luminous  on  an  extinguished  ground.  If  the  screen 
is  formed  of  a  diathermous  substance  like  rock-salt,  the 
totality  of  the  phosphorescent  surface  is  extind.  A  red 
glass,  or  any  substance  transmitting  the  ultra-red  rays 
and  arresting  the  luminous  rays, — blue,  violet,  and  ultra- 
violet,— which  excite  the  phosphorescence  of  blende,  will ' 
give  the  same  results  if  substituted  for  ebonite. 

This  transparence,  perfectly  demonstrated,  enables  us 
to  explain  in  all  their  details  the  photographic  experiments 
of  M.  LeBon  through  ebonite. 

It  is  known  that  my  father  showed,  as  early  as  1840,. 
that  a  photographic  plate  insensible  to  the  yellow  and  the 
red  rays,  becomes  sensitive  to  these  rays  and  even  to  the 
ultra-red  rays  if  it  is  exposed  for  a  short  time  to  light,  j.e.,- 
slightly  veiled.  The  red  and  ultra-red  rays  continue  the 
adion  commenced  by  the  white,  blue,  or  ultra-violet 
light. 

This  phenomenon,  discovered  with  Daguerre  plates,  is- 
manifested  with  most  sensitive  photographic  surfaces, 
and  in  particular  with  plates  of  silver  gelatino-bromide. 

In  the  experiments  of  M.  Le  Bon  a  photographic  plate, 
previously  veiled  (the  condition  essential  to  the  success 
of  the  experiments),  is  exposed  under  a  plate  of  ebonite 
to  the  adion  of  the  solar  rays.  Metallic  screens  placed 
on  the  ebonite  mark  their  silhouette  when  we  come  to  • 
develop  the  plate.  Under  these  conditions  the  photo- 
graphic plate  undergoes  through  the  ebonite  the  con- 
tinuing adion  of  the  red  and  ultra-red  rays.  The  metallic 
screens  proted  the  plate  against  this  adion ;  if  the 
exposure  has  been  relatively  short,  the  ground  appears  on 
development  darker  than  the  silhouette  of  the  screens  ;  if 
the  exposure  has  been  prolonged,  it  results  that,  in  con- 
sequence of  a  phenomenon  of  reversal  well  known,  the 
background  appears  less  aff'eded  than  in  the  region  pro- 
teded  by  the  screen. 
The  adive  rays  in  these  experiments  of  continuatioo- 


"june?i!'/897'^''}    Determination  of  Phosphorus  m  Chemico-legaL  InvestigationSj_ 


^iSi 


are  the  extreme  red  rays  near  A.  As  these  radiations  are 
much  weakened  by  the  ebonite,  the  exposure  must  be 
relatively  very  long,  and  the  phenomena  are  not  as  dis- 
tinct as  with  the  highly  sensitive  gelatino-bromide. 

The  same  phenomena  are  obtained  on  substituting  red 
glass  for  ebonite. 

I  will  add  that  a  plate  of  ebonite  of  0'6  m.m.  in  thick- 
ness, if  examined  with  Melloni's  apparatus,  transmits 
0*04  per  cent  of  the  dark  heat  emitted  by  a  plate  of 
copper  at  400°,  and  arrests  almost  entirely  the  radiation 
from  a  source  of  heat  at  100°. 

In  sum,  the  phenomena  which  M.  G.  Le  Bon  endea- 
vours to  ascribe  to  an  assumed  black  light  of  an  unknown 
nature  are  simply  efTeds  produced  by  the  red  or  ultra-red 
rays,  the  principal  properties  of  which  have  been  well 
known  for  more  than  fifty  years. — Comptes  Rendus,  vol. 
cxxiv.,  p.  984. 


RESEARCHES    ON    THE    BIOLOGICAL    ACTION 

OF    THE    X-RAYS. 

By  J.  SABRAZES  and  P.  RIVIERE, 

The  apparatus  used  in  our  experiments  consisted  of  a  bi- 
anodic  focus  tube  (M.  Segny's  design),  excited  by  powerful 
Ruhmkorfir  coil,  yielding  a  current  of  6  amperes  and  16 
volts,  sparks  of  35  cm.  in  length.  With  the  aid  of  this 
tube  we  obtained  radiographs  at  the  distance  of  3*50 
metres  and  behind  a  screen  of  boards.  This  arrangement 
evidently  permitted  the  easy  exploration  of  the  limbs  and 
of  the  thorax. 

The  obje(5ls  studied  were  arranged  at  about  15  cm. 
from  the  fluorescent  source;  they  were  enclosed  in  black 
paper  to  protect  them  from  luminous  radiations,  and  were 
placed  in  metallic  communication  with  the  earth. 

I.  Experiments  on  Microbacillus  prodigiosus. 

We  proposed  to  study  the  adtion  of  the  X-rays  on  a 
microbe  peculiarly  sensitive  to  changes  brought  on  in  the 
physico-chemic  conditions  of  its  development,  and  apt  to 
translate  this  sensitiveness  by  modifications  permanent 
and  easy  of  observation. 

The  Microbacillus  prodigiosus  answers  to  these  require- 
ments, especially  if  we  address  ourselves,  as  we  have 
done,  to  a  race  eminently  chromogenous. 

^If  we  cultivate  this  microbe  at  a  dysgenerictemperature 
of  37',  —  if  we  modify  the  readion  of  the  medium  by 
alkalising  it  strongly, — if  we  diminish  the  access  of  atmo- 
spheric oxygen, — if  we  expose  the  culture  to  the  solar 
radiations,  to  the  adtion  of  an  injurious  substance,  e.g.,  of 
an  antiseptic, — the  pigmentary  properties  are  attenuated 
and  effaced  progressively,  and  in  time,  although  the  colo- 
nies continue  to  grow,  they  remain  more  or  less  colourless. 
We  know  also  that  it  is  sufficient  to.  acidify  the  culture- 
bouillon,  or  to  raise  the  temperature  of  the  stove  to  50', 
to  modify  profoundly  the  aspedl  of  the  microbian  cells 
which  become  filamentary  or  even  spiriform.  It  will 
therefore  be  easy  to  appreciate  the  modifications  impressed 
on  this  microbe  by  bringing  into  play  a  novel  biological 
condition  ;  it  will  be  sufficient  to  examine  the  oscillations 
of  the  chromogenic  power  and  the  morphologic  variations 
of  the  cellules  as  compared  with  type  cultures  in  a  long 
series  of  successive  generations. 

We  have  proceeded  as  follows  : — The  cultures,  of  a  fine 
carmine-red,  were  coUeded  on  gelose,  and  arranged  in  the 
form  of  a  small  pointed  heap,  in  the  middle  of  a  sterilised 
watch-glass  wrapped  in  black  paper.  The  X-rays  adt 
diredlly  through  the  paper  upon  the  seed,  the  cavity  of  the 
watch-glass  being  placed  opposite  the  phial. 

We  operate  exadly  in  the  same  manner  with  a  check- 
culture,  except  that  the  watch-glass  covered  with  black 
paper  was  screened  from  the  X-rays. 

Daily  for  twenty  days  we  caused  the  X-rays  to  adl  upon 
he  microbe  for  an  hour  each  day. 


In  spite  of  the  power  of  our  phial,  the  number  of 
passages,  and  the  duration  of  exposure  to  the  X-rays,  we 
have  not  observed  any  appreciable  modification  of  the 
Microbacillus  prodigiosus,  either  in  its  chromogienic  pro- 
perties or  in  its  morphological  charadlers  or  its  vegeta- 
bility.  This  microbe  has  shown  itself  indifferent  to- 
Rontgen's  rays. 

2.  Experiments  on  Leucocytes. 

Two  frogs,  as  nearly  as  possible  of  the  same  bulk,  were 
fixed  upon  cork  in  the  ordinary  manner. 

After  cauterisation  with  the  thermo-cautery,  so  as  to 
avoid  any  loss  of  blood,  we  introduced — at  a  point  of 
the  leguments  chosen  at  the  level  of  the  mean  part  of 
the  abdomen — at  the  aperture  thus  made,  a  pointed  tube, 
previously  washed  with  a  culture  of  microbes  yielding 
products  of  positive  chaemiotaxis. 

We  exposed  one  of  the  frogs  to  the  X-rays  after  having 
taken  the  precautions  mentioned  above.  The  other,  which 
served  as  a  check-type,  was  withdrawn  from  the  influence 
of  the  radiation  by  a  metallic  enclosure.  We  prolonged  the 
experiment  for  several  hours,  and  at  the  end  of  the  time 
colleded  the  liquid  which  had  transuded  into  the  tubes. 
We  counted  the  leucocytes  existing  in  the  lymph  thus 
colledled,  and  examined  with  the  microscope  the  figured 
elements  held  in  suspension. 

From  the  numerous  experiments  thus  made  the  conclu- 
sion follows  that  the  X-rays  do  not  interfere  with  the 
efflux  of  the  white  globules  ;  their  number  is  sensibly  the 
same  in  both  cases.  Phagocytosis  is  equally  effeded. 
In  some  experiments  even  the  quantity  of  lymph  ema- 
nating from  frogs  submitted  to  the  X-rays  was  slightly 
greater  than  that  in  the  check-tubes. 

3.   Action  of  the  X-rays  upon  the  Heart. 

Some  observers  have  deteeSled  in  man  cardiac  disturb- 
ances following  on  application  of  the  X-rays. 

The  tracings  of  the  heart  of  a  frog  placed  below  a 
powerful  source  of  X-rays  showed  us  that  the  rhythm  of 
this  organ  was  not  modified  in  its  periods  even  after  an 
exposure  of  more  than  one  hour.  — Comptes  Rendus,  voL 
cxxiv.,  p.  979. 


DETERMINATION     OF    PHOSPHORUS 
IN     CHEMICO-LEGAL     INVESTIGATIONS. 

By  M.  SPICA. 

The  author  proceeds  as  follows :  —  The  substance  in 
question  is  divided  into  three  parts,  of  which  one  is  reserved 
for  check-experiments  ;  a  second  serves  for  the  qualitative 
detedtion  of  phosphorus  by  Mitscherlich's  process;  and 
the  third  for  the  quantitative  determination  of  phosphorus. 
For  the  last  purpose  he  employs  the  free  phosphorus,  or 
that  present  in  the  dired  volatile  state,  according  to  the 
procedure  of  R.  Fresenius  and  Newbauer,  which  he  has 
somewhat  modified.  The  flask  containing  the  material  is 
closed  with  a  stopper  having  three  perforations  for  the 
usual  entrance  and  exit  of  gas,  and  for  a  tube-funnel  closed 
with  a  glass  cock.  To  the  flask  is  connedled  a  tubulated 
receiver,  which  is  again  connected  with  three  Peligot  tubes 
containing  neutral  solutions  of  silver  nitrate.  After  the 
transmission  for  six  to  eight  hours  of  carbonic  acid  washed 
in  solution  of  silver  nitrate,  it  is  tested  anew  by  fresh  tubes 
filled  with  silver  solution,  to  determine  if  phosphoriferous 
substances  pass  over  on  a  further  passage  of  carbonic  acid. 
If  this  is  not  the  case  we  proceed  to  determine  those 
compounds  of  phosphorus  which  are  not  reduced  by 
nascent  hydrogen,  for  which  purpose  the  author  uses  the 
procedure  of  Dusart  as  modified  by  Blondlot.  After  the 
contents  of  the  flask  have  been  allowed  to  cool  in  the 
current  of  carbonic  acid,  the  purest  zinc  is  rapidly  intro- 
duced into  the  flask,  which  is  then  closed,  and  sulphuric 
acid  is  run  in  through  the  funnel  tube  until  there  sets  in 


282 


Report  of  Committee  on  A  tomic  Weights^ 


(  Chemical  NswBt 
I     June  II,  1897. 


a  slight  development  of  hydrogen,  which  is  kept  in  very 
slow  adion  for  five  to  six  days.  After  this  lapse  of  time 
we  satisfy  ourselves  as  above  of  the  completion  of  the 
readion. 

For  the  ultimate  gravimetric  determination  of  the  phos- 
phorus, the  author  oxidises  the  liquid  found  in  the  receivers 
with  nitric  acid,  and  determines  the  phosphorus  in  the 
solution  as  ammonium  phospho-molybdate. — Zeit,  Anal. 
Chemie,  xxxvi.,  p.  347. 


COLORIMETRIC    DETERMINATION    OF 

SMALL    QUANTITIES    OF    NITROUS    ACID. 

By  Prof.  Dr.  E.  RIEGLER. 

In  connection  with  my  communication  on  the  deteAion  of 
nitrous  acid  with  naphthionic  acid,  I  point  out  that  by 
means  of  this  reaction  small  quantitis  of  nitrous  acid  can 
be  easily  determined  colorimetrically.  We  dissolve  o'4o6 
grm.  pure  dry  silver  nitrite  in  hot  water,  add  sodium 
chloride  in  slight  excess,  and  dilute  after  cooling  to  i  litre. 
After  the  deposit  has  subsided  we  take  100  c.c.  of  the 
clear  solution,  and  dilute  again  to  i  litre  with  distilled 
water.  Of  this  last  solution  we  put  100  c.c,  corresponding 
to  o'ooi  grm.  N2O3,  into  a  flask,  add  a  small  penknife- 
point  (about  0*05  grm.)  full  of  crystalline  naphthionic  acid 
and  5  or  6  drops  of  concentrated  hydrochloric  acid  ;  shake 
up  well,  and  add  30  drops  of  concentrated  ammonia 
(liquid).  After  thorough  shaking  we  have  a  rose-coloured 
iquid,  the  tint  of  which  serves  as  a  standard  for  the  above 
concentration.  In  order  to  find  the  proportion  of  nitrous 
acid  in  a  water,  we  place  100  c.c.  of  the  water  in  a  fiask, 
add  a  small  penknife-point  full  of  naphthionic  acid,  shake 
well  up,  and  then  add  30  drops  of  concentrated  liquor 
ammoniac.  We  then  compare,  by  means  of  the  colorimeter, 
the  intensity  of  this  solution  with  that  of  the  standard, 
and  calculate  according  to  known  rules  the  quantity  of 
the  nitrous  acid. 

In  this  manner  o'oooox  grm.  N2O3  can  be  determined 
in  100  c.c.  of  water. 

In  case  the  water  in  question  contains  more  than  o'ooi 
grm.  N2O3  in  100  c.c,  it  must  be  suitably  diluted  with 
distilled  water  before  determination. — Zeit.  Anal,  Chemie, 
xxxvi.,  p.  306. 


FOURTH    ANNUAL     REPORT    OF    COMMITTEE 

ON    ATOMIC     WEIGHTS. 

RESULTS     PUBLISHED     IN    1896.* 

By  F.  W.  CLARKE. 

During  1896  the  adtivity  in  the  determination  of  atomic 
weights  was  only  moderate.  Comparatively  few  papers 
on  the  subjedt  appeared,  but  some  of  these  were  of  excel- 
lent quality.  The  question  is  often  asked.  Why  are  new 
determinations  important  ?  Are  not  those  we  have  good 
enough  for  all  practical  purposes.  To  this  question  I  have 
an  interesting  answer,  such  as  has  not  hitherto  been  pub- 
lished. 

There  are  two  rival  values  for  the  atomic  weight  of 
chromium.  One,  52*5  approximately,  based  on  the  old 
Avork  of  Berlin,  is  still  used  by  European  analysts.  The 
other,  52*1,  depends  upon  later  and  more  accurate  re- 
searches, and  is  used  in  the  United  States.  Mr.  William 
'Glenn,  of  the  Baltimore  Chrome  Works,  informs  me  that 
that  establishment  imports  chrome  iron  ore  by  the  ship- 
load, the  value  being  determined  by  a  volumetric  assay 
in  which  the  atomic  weight  of  chromium  is  involved.  It 
is  assayed  in  Glasgow  with  the  older  value  for  chromium, 

*  Journal  of  the  American  Chemical  Society,  xix..  No.  5. 


H  =  I. 

Aluminum 26-91 

Antimony Ii9'52 

Argon ? 

Arsenic      . .     . .     . .  74*44 

Barium       136*39 

Bismuth     206-54 

Boron 10-86 

Bromine 79'34 

Cadmium iii'io 

Caesium      131*89 

Calcium 39*76 

Carbon       11-92 

Cerium       139-10 

Chlorine 35'i8 

Chromium 5^*74 

Cobalt        58*49 

Columbium       ..     ..  93*02 

Copper       63*12 

Erbium      165*06 

Fluorine 18-91 

Gadolinium       ..     ..  155*57 

Gallium     69-38 

Germanium      ..     ..  7i'93 

Glucinum 9*01 

Gold 195*74 

Helium      ? 

Hydrogen 1*000 

Indium       112*99 

Iodine        125-89 

Iridium       191-66 

Iron 55'6o 

Lanthanum       ..     ..  137-59 

Lead 205*36 

Lithium     697 

Magnesium       ..      ..  24*10 

Manganese        ..      ..  54*57 

Mercury 198-49 

Molybdenum     ..     ..  95*26 

Neodymium      . .     . .  139*70 

Nickel        58*24 

Nitrogen 13*93 

Osmium i8g*55 

Oxygen      15*88 

Palladium 105-56 

Phosphorus       . .      . .  30  79 

Platinum 193*41 

Potassium 38-82 

Praseodymium..      ..  142-50 

Rhodium 102-23 

Rubidium 84-78 

Ruthenium        ..      ..  100-91 

Samarium 149'13 

Scandium 43*78 

Selenium 78*42 

Silicon        28*18 

Silver 107*11 

Sodium      2288 

Strontium  . .     * .      . .  8695 

Sulphur      3183 

Tantalum 181-45 

Tellurium 12652 

Terbium 158-80 

Thallium 20261 

Thorium 230*87 

Thulium 169-40 

Tin 118*15 

Titanium 4779 

Tungsten 183*43 

Uranium 237*77 

Vanadium         . .      . .  50*99 

Ytterbium 171*88 

Yttrium      88*35 

Zinc 64-91 

Zirconium 89-72 


O  =  16. 

27*11 
120*43 

? 
75-01 

13743 
208*11 

10*95 
79*95 

111*95 

13289 
40*07 
12*01 

140*20 
35*45 
5214 
58-93 
9373 
63-60 

166-32 
19-06 

156*76 

69-91 

72-48 

9*o8 

197*23 

I'ooS 
113-85 
126*85 
193*12 
56*02 
138*64 
206-92 

703 
24-28 

5499 
200-00 

95*99 
140-80 

5869 

14*04 
190-99 

16-00 
10636 

3 1  02 
194-89 

39-11 
143-60 
10301 

85*43 

101-68 

150*26 

44*12 

79-02 

28  40 

107*92 

23-05 

8761 

32*07 

182*84 

127-49 

160-00 

204-15 

232-63 

170*70 

119*05 

48*15 

184-83 

239-59 

51*38 

173*19 

89*02 

65-41 

90-40 


^j"e'»N'8p7T''}   ^ome  Present  Possibilities  in  the  Analysis  of  Iron  and  Steel, 


283 


-and  in  Baltimore  with  the  modern  datum.  A  cargo 
amounts  to  about  3500  tons  ;  and  the  difference  in  price 
due  to  the  difference  between  52*1  and  52*5  for  chromium 
amounts  to  about  367.50  dols.  per  shipload.  This  differ- 
ence is  large  enough  to  show  the  importance  of  accurately 
determined  constants  from  a  commercial  point  of  view, 
and  suggests  that  other  similar  cases  might  be  found  by  a 
careful  scrutiny  of  our  analytical  processes. 

My  own  "  Recalculation  of  the  Atomic  Weights,"  a  new 

•edition  of  the  work  published  originally  in  1882,  is  now 
complete  and  in  the  printer's  hands.  It  will  probably  be 
published  early  in  1897,  ^^^  'he  appended  table  of  values 

-represents  the  results  obtained  by  combining  all  the  best 

data. 

The  following  new  determinations  of  atomic  weights 
'represent  the  work  published  during  the  year  : — 

Oxygen.— \n  the  report  for  1895,  J.  Thomson's  gravi" 
metric  measurements  of  the  H  :  O  ratio  were  cited.  Early 
'in  i8g6the  same  chemist  (Zeit.  Anorg.  Chent.,  xii.,  4),  by 
a  novel  method,  determined  the  ratio  of  densities.  First, 
he  found  the  volume  of  hydrogen  in  litres,  liberated  by  the 
■solution  of  one  grm.  of  aluminum,  to  be  as  follows  : — 

I -24297 
1-24303 
1*24286 

I'2427X 

1-24283 
1-24260 
1-24314 
1*24294 


Mean 


1-24289  -^  000004 


In  his  earlier  research  Thomson  found  the  weight  of 
liydrogen  corresponding  to  i  grm.  of  aluminum  to  be 
0*11190  i  0-000015  grm.  Hence  i  litre  of  hydrogen  at 
-0°,  760  m.m.,  and  io-6  metres  above  sea-level,  is  0*090032 
^o-oooi2  grm.;  or  at  sea-level  in  latitude  45°,  0-089947. 

For  the  volume  of  one  grm.  of  oxygen  at  o'',  760  m.m., 
and  at  Copenhagen,  Thomsen  found,  in  litres: — 

0-69902 
0-69923 
0*69912 
o  69917 
o  69903 
o  69900 
0-69901 
0-69921 
o  69901 
069922 


Mean 


0*69910  ;f;  0*00002 


At  sea-level,  latitude  45°,  069976^  0-00002. 

Hence  one  litre  weighs  1*42906^0-00004  grm.  Di- 
viding this  by  the  value  found  for  hydrogen  we  have  for 
the  ratio  desired — 

15*8878^0*0022. 

■Correding  this  by  the  known  data  for  the  volumetric  com- 
.position  of  water  we  get — 

O  =  15-8690  J;:  0*0022, 
a  value  identical  with  that  found  gravimetrically,  and  very 
close  to  the  measurement  by  Morley. 

Silver. — The  atomic  weight  of  silver  has  been  deter- 
mined eledlrolytically  by  Hardin  {Journ.  Am.  Chem.  Soc, 
xviii.,  990  ;  Chem.  News,  Ixxv.,  28  et  seq.).  The  nitrate, 
acetate,  and  benzoate,  mixed  in  aqueous  solution  with 
solutions  of  pure  potassium  cyanide,  were  electrolysed 
in  platinum  dishes.  The  data  are  as  follows,  with  vacuum 
weights,  and  reduced  with  N  =  14-04,  C  =  12*01,  H  = 
a*oo8,  and  O  =  16. 


Nitrate  Series. 

Weight  AeNO,. 

Weight  Ag. 

Atomic  wt.  Ag. 

0*31202 

0*19812 

107*914 

0*47832 

0*30370 

107*900 

0*56742 

0*36030 

107*923 

0-57728 

0*36655 

107*914 

0-69409 

0*44075 

107*935 

0-86367 

0*54843 

107*932 

0*86811 

0-55130 

107-960 

0*93716 

0*59508 

107*924 

i"o6i70 

0*67412 

107-907 

1*19849 

0*76104 

107*932 

Mean 

..     107*924 

Acetate  Series. 

Weight  salt. 

Weight  Ag. 

Atomic  wt.  Ag. 

0*32470 

0*20987 

107*904 

0*40566 

0*26223 

107*949 

0*52736 

0*34086 

107*913 

0*60300 

0*38976 

107*921 

0-67235 

0-43455 

107*896 

0*72452 

0*46830 

107*916 

0*78232 

0*50563 

107*898 

0-79804 

0*51590 

107-963 

0-92101 

0-59532 

107*925 

1*02495 

0-66250 

107-923 

Mean 

..      107-922 

Benzoate  Series. 

Weight  salt. 

Weight  Ag. 

Atomic  wt.  Ag. 

0*40858 

0*19255 

107947 

0*46674 

0-21999 

107*976 

0*48419 

0-22815 

107-918 

0*62432 

0  29418 

107-918 

0*66496 

0-31340 

107-964 

075853 

035745 

107-935 

076918 

036247 

107-936 

0*81254 

0*38286 

107-914 

095673 

0*45079 

107-908 

1-00840 

0-47526 

107*962 

Mean     ..     107*938 

The  mean  of  all  three  series  is — 

Ag  =9107*928. 

This  value  agrees  well  with  the  values  found  by  Stas  and 
by  Marignac,  and  so  creates  a  presumption  in  favour  of 
the  eledrolytic  method,  which  Hardin  has  also  applied  to 
determining  the  atomic  weights  of  mercury  and  cadmium. 

(To  be  continued). 


SOME    PRESENT     POSSIBILITIES    IN    THE 
ANALYSIS  OF   IRON   AND   STEEL.* 

By  C.  B.  DUDLEY. 
(Concluded  from  p.  270). 

Some  years  ago,  with  the  publication  {Trans.  Am.  Inst. 
Mining  Eng.,  ix.,  397)  of  what  is  commonly  known  as 
Ford's  method,  the  determination  of  manganese  took  a 
decided  step  forward,  at  least  in  this  country,  so  far  as 
speed  is  concerned.  Previous  to  that  time  the  long  and 
laborious  acetate  method,  which  involved  the  separation 
of  the  iron  from  the  manganese  as  basic  acetate  and  sub- 
sequent precipitation  of  the  manganese  by  means  of 
bromine    or    as    pyrophosphate,    had    held    full   sway. 

'  Presidential  Address  delivered  at  the  Troy  Meeting  of  the  Ameri» 
can  Chemical  Society,  December  29, 1896.  From  the  Journal  of  the 
American  Chemical  Society,  xix..  No.  2. 


204        Some  Present  Possibilities  in  the  Analysis  of  Iron  and  Stetl. 


Cheuical  MeWKt 
June  II,  1897. 


Ford's  contribution  consisted,  as  Is  well  known,  in  sepa-  , 
rating  the  manganese  from  hot  nitric  acid  solution  of  the 
iron  or  steel,  by  means  of  poiassium  chlorate,  and 
Williams  (Trans.  Am.  Inst.  Mining  Eng.,  x.,  100)  added 
the  modification,  now  in  common  use,  of  determining  the 
separated  oxide  of  manganese,  by  its  adtion  on  a  standard 
solution  of  ferrous  sulphate  or  oxalic  acid.  This  method, 
as  now  worked  in  many  laboratories,  gives  a  single  result 
in  forty  minutes  and  two  in  an  hour,  and  enables  one 
operator  to  turn  out  twenty  to  twenty-five  determinations 
in  a  day.  The  accuracy  of  this  method  has  been 
questioned.  We  are  not  aware  of  any  recent  symposium 
on  manganese,  where  different  chemists  using  different 
methods  have  worked  on  the  same  steels.  In  our  hands 
this  method  gives  results  closely  agreeing  with  check 
work  done  by  the  more  laborious  and  generally  accepted 
accurate  methods,  provided  the  sample  contains  not  more 
than  three-fourths  of  a  per  cent.  On  samples  containing 
over  I  per  cent  of  manganese  the  results  are  apt  to  be 
low,  owing  probably  to  the  fadt  that  the  manganese  does 
not  separate  from  the  nitric  acid  solution  as  manganese 
dioxide,  but  as  some  other  oxide  whose  composition  is  not 
positively  known.  In  the  calculation  it  is  customary  to 
regard  the  separated  oxide  as  manganese  dioxide,  and  this 
leads  to  perceptible  error  on  large  amounts.  Producers 
and  consumers  rarely  contend  much  over  manganese  in 
steel,  and  methods  for  its  determination  have  perhaps 
not  received,  on  that  account,  all  the  attention  they 
deserve.  There  is  evident  need  of  more  work  on  this 
subjedt. 

The    methods  for  the    determination  of   silicon   can 
hardly  be  regarded  as  in  a  perfeftly  satisfactory  condition. 
If  evaporation  to  dryness  to  render  silica  insoluble  is  em- 
ployed, the  time  required  is  considerable.     If  dehydration 
by  means   of  sulphuric   acid  and  heat,  as  suggested  by 
Drown  (Trans.  Am.  Inst.  Mining  Eng.,  vii.,  346)  is  em- 
ployed, there  are  difficulties  which  interfere   somewhat 
with   accuracy.     There   seems   little   doubt   but   that  in 
skilled  hands,  with  sufficient  care  taken  in  the  manipula- 
tion, a  couple  of  determinations  may  be  made  on  the 
same   sample,   using   Drown's   method,   that   will  agree 
closely  with  each  other  and  with  results  given  by  the 
longer  and  more  laborious  methods.     On  the  other  hand, 
where  one  operator  is  making  a  number  of  determinations 
at  the  same  time  there  is  much  danger  of  error,  due  either 
to  failure   to   uehydrate   sufficiently  or  to   over-heating, 
resulting  in   the  formation  of  insoluble  iron  salts.     Our 
experience  indicates  that  the   margin  between  these  two 
extremes  is  not  very  wide,  and  that  it  is  fully  as  frequent 
to  have  duplicates  on  the  same  sample  disagree   as  to 
agree.     Our  observations  point  to  the  view  that  the  diffi- 
culty of  insufficient  dehydration  is  due  to  the  separation 
of  iron  salts  as  the  sulphuric  acid  concentrates.     These 
salts  enclose  gelatinous  silica,  and  prevent  the  dehydrating 
acid  from  getting  at  it.     Unless  great  pains  are  taken, 
therefore,  to  secure  this  contadt  by  sufficient  stirring,  the 
results   will  be  low.     If  by  some  modification  the  iron 
salts  could  be  kept  in  solution  until  the  silica  is  rendered 
quite  insoluble,  it  would  apparently  be  a  decided  step  for- 
ward with  this  method.     It  may  not  be  amiss  here  to  call 
attention  to  the  fadt  first  noticed  in  the  laboratory  of  the 
Pennsylvania  Railroad  Company,*  that  after  the  dehydra- 
tion and  subsequent  dilution  are  finished,  if  an  interval  of 
a  few  hours  is   allowed  to   elapse   before  filtration,  the 
silica  will   re-dissolve  and  the   results   be   low.     Appa- 
rently, as  we   are  able  to  work  the  method,  the  silica  is 
not  completely  dehydrated,  but  only  sufficiently  so  that  if 
filtered  at  once  fairly  accurate  results  will  be  obtained. 

It  is  difficult  to  say  anything  positive  about  the  speed 
and  output  of  Drown's  method.  It  is  probably  safe  to 
say  that  a  couple  of  determinations  could  be  made  in  an 
hour  and  a  half,  but,  on  account  of  the  difficulty  men- 


♦  Address  to  the  members  of  the  Chemical  Seftion  of  the 
Engineers'  Society,  at  Pittsburgh,  September  27th,  1892,  by  C.  B. 
Dudley,  on  "  Discrepancy  in  Chemical  Work  by  Different  Workers." 


tioned  above,  the  method  does  not  lend  itself  well   to - 
working   on   a  large  number   of'  samples   at  once,   and 
consequently  a  large  daily  output  is  somewhat  interfered' 
with. 

It  must  also  be  said  of  the  methods  for  the  determination 
of  sulphur  in  iron  and  steel,  that  those  most  in  use  are 
hardly  as  satisfadtory  as  could  be  desired.     The  studies 
of  Phillips  {Journal  of  the  American  Chemical  Society, 
xvii.,  891)  conclusively  show  that  when  using  the  evolution 
method  the  whole  of  the  sulphur  content  is  not  given  off 
in  such  a  form  as  to  be  retained  by  the  usual  means  em- 
ployed to  catch  the  gas.     It  seems  not  too  much  to  say 
that  it  is  hazardous  to  use  the  evolution  method  on  pig. 
or  cast  iron,  even  when  fusion  of  the  residue  is  employed. 
The  formation  of  unoxidisable  gases  containing  sulphur, 
in  the  application  of  the  evolution  method  to  steel,  has 
not,  so  far  as  our  knowledge  goes,  yet  been  demonstrated,, 
and  accordingly  the  evolution  method  is  still  used  largely 
on  steels.   But  on  pig  and  cast  irons  the  oxidation  method 
seems  the  only  one  applicable,  and  some  recent  studies 
of  Blair,  described  in  a  paper  at  this  meeting  (see  Journ. 
Amir.  Chem.  Soc,  xix.,  114),  indicate  that  on  certain  pig 
irons  all  the  sulphur  is  not  given,  even  by  this  method, 
unlessthegraphitic  residue  is  fused  with  sodium  carbonate 
and  nitre.     Both  methods  are  somewhat  slow,  and  there 
is  need  of  further  study.     If  some  means  could  be  found 
by  which  barium  sulphate  could  be  readily  and  accurately 
converted  into  sulphide,   so  that   a  volumetric   method 
could  be  applied  to  this  sulphide,  it  would  be  a  decided 
step  forward.   The  necessity  in  accurate  work  for  purifying- 
barium  sulphate,  as  first  obtained  from  almost  any  solu- 
tion, by  fusion  and  re-precipitation,  adds  quite  consider- 
ably to  the  time  required.     With  steels  and  two  sets  of 
evolution  apparatus,  using  bromine  for   oxidation,   two 
determinations  may  be  made  in  two  hours.     With  four 
sets   of    evolution   apparatus,   one    operator    can    make 
twelve  determinations  in  a  day.     In  these  cases  purifica- 
tion by  fusion  is  not  attempted.    By  the  oxidation  method 
on  pig  or  cast  iron,  two  determinations  require  about  five 
hours,  while  one  operator  with  a  supply  of  borings  ahead 
and   sufficient  appliances,   can   get   from  ten  to  twelve 
results  in  a  day.     With  this  output  purification  by  fusion 
is  not  attempted.     If  this  is  done,  the  time  for  a  pair  of 
determinations  must  be  extended  an  hour  and  a  half,  and 
the  daily  output  would  be  cut  down  at  least  a  third. 

From  what  has  preceded  in  this  hasty  and  necessarily 
imperfedl  survey  of  a  portion  only  of  the  analytical . 
methods  in  use  in  the  iron  and  steel  industry,  it  is  clearly 
evident  that  there  still  remains  an  enormous  amount  of 
work  to  be  done  in  conedtion  with  methods.  We  have 
touched  upon  only  five  of  the  fifteen  or  twenty  constituent*^ 
occurring  in  and  affedting  the  quality  of  iron  and  steel, 
and  find  the  methods  for  determining  even  those  more  or 
less  imperfedl,  and  needing  more  work.  What  will  be  our 
condition  as  chemists  if,  as  seems  probable,  nickel,, 
chromium,  aluminum,  tungsten,  and  the  gases,  oxygen^ 
hydrogen,  and  nitrogen,  either  free  or  combined,  within 
the  next  few  years,  come  into  prominence  as  constituents 
of  iron  and  steel,  and  are  made  elements  in  important 
commercial  contradls  ?  Still  further,  thus  far  our  methods 
are  concerned  almost  entirely  with  the  total  content  of 
the  various  constituents  we  are  determining.  We  know 
very  little  about  the  compounds  of  the  various  constituents- 
occurring  in  iron  and  steel,  with  the  metal  or  with  each 
other.  Is  the  phosphorus  present  as  phosphide  or  phos- 
phate, or  both  ?  How  besides  as  sulphide  does  the  sulphur 
occur  ?  Do  the  various  carbides  which  are  revealed  by 
the  microscope,  and  which  are  believed  to  be  so  closely 
dependent  on  the  heat  treatment  which  steel  receives,  and 
which  are  so  intimately  related  to  the  value  of  the  metal,, 
differ  from  each  other  in  carbon  content,  or  only  ia 
crystalline  form  ?  Who  will  be  the  first  to  isolate  any  of 
these  carbides  ?  Who  will  first  give  us  a  pradticable,  ac- 
curate, and  sufficiently  rapid  method  for  determining 
oxides  in  steel?  Who  will  first  completely  investigate  the 
relation  between  the  chemistry  and  the  chilling  properties- 


Chemical  Nbws,  ) 
Juneiz,l8g7,     » 


Water  and  Publtc  Health. 


2-85 


of  cast  iron  ?  And  who  will  first  give  us  a  study  on  the 
form  in  which  nitrogen  occurs  in  this  metal,  and  a  suffi- 
ciently rapid  and  accurate  method  for  its  determination  ? 
Truly  the  harvest  of  chemical  work  before  us  in  connexion 
with  iron  and  steel  is  bounteous.  Will  the  labourers  be 
forthcoming  to  gather  the  harvest  ? 


NOTICES  OF  BOOKS. 


Water  and  Public  Health.    The  Relative  Purity  of  Waters 

from    Different    Sources.       By  James    H.     Fuertes, 

Member  of  the  American  Society  of  Civil  Engineers. 

First    Edition.      First   thousand.       New   York:    John 

Wiley  and  Sons.      London  :  Chapman  and  Hall,  Ltd. 

1897.  Pp-  X— 75'  i2mo.,  111. 
In  this  little  volume  the  author  has  grouped  the  principal 
cities  of  the  world  into  classes  according  to  the  quality  of 
their  public  water  supplies,  and  has  made  a  comparative 
study  of  their  mortality  statistics.  This  statistical  method 
of  treatment  makes  the  importance  of  pure  water  stand 
out  in  bold  relief. 

The  author  admits  the  uncertainty  resulting  from 
incorredt  reports  of  health  boards  and  physicians,  as  well 
as  frotn  unreliable  figures  of  population  ;  but  he  assumes 
that  "in  all  large  cities  these  causes  of  error  are  perhaps 
equal,"  and  the  inaccuracies  will  counterbalance  so  as 
not  to  seriously  influence  the  general  dedudions  that  may 
be  drawn. 

The  four  chapters  of  the  book  are  entitled  :— I.  Etiology 
and  Prophylaxis  of  Typhoid  Fever.  II.  When  does  Pure 
Water  pay?  III.  Sanitary  Value  of  Impounded  and 
other  Supplies.  IV.  Conclusion.  Following  this  are 
four  Appendices,  containing  much  statistical  information. 

The  work  is  illustrated  by  no  less  than  seventy  dia- 
grams, showing  in  a  graphic  way  the  relations  of  pure 
water  and  foul  water  to  public  health  in  a  large  number 
of  cities  in  Europe  and  America. 

The  author's  conclusions  are  those  of  a  common-sense 
view  of  the  subjecft,  based  upon  the  fads  presented. 

It  is  surprising  to  learn  that  the  important  commer- 
cial city  of  Baltimore,  having  a  population  of  435,000, 
"has  as  yet  no  sewerage,"  and  "  the  house-drainage  is 
disposed  of  largely  into  cesspools  and  outhouses." 

The  author  discusses  the  outbreaks  of  cholera  and 
typhoid  fever  in  Hamburg,  Germany,  and  it  is  truly 
appalling  to  read  the  terrible  figures  of  mortality  in  that 
unhappy  city  during  the  epidemic  years. 

The  author  believes  that  "  properly  designed  and 
operated  filters  may  be  relied  upon  to  purify  any  waters 
at  present  used  for  a  public  water-supply  in  the  United 
States." 

In  Chapter  II.  the  author  treats  of  the  question  "When 
does  pure  water  pay  ?"  and  discusses  in  a  cold-blooded 
way  the  economic  value  of  an  individual  to  the  commu- 
nity, and  the  amount  of  money  which  the  community  is 
authorised  to  expend  to  accomplish  a  reduftion  in  the 
death-rate.  He  finds  that  the  "  community  can  afford  to 
invest  about  three  thousand  dollars  for  every  death 
forefended." 


The  Index  to  the  volume  is  unusually  full. 


H.C.B. 


Ninth  Annual  Report  of  the  Agricultural  Experiment 
Stations  of  the  Louisiana  State  University  for  1896. 
Baton  Rouge.     1S97. 

At  the  Audubon  Park  Station  sugar-cane  has  been  both 
the  chief  crop,  and  the  chief  study  in  the  laboratories. 
In  the  field,  experiments  covering  the  entire  subjedt  of 
proper   fertilisation   of    the   cane   have   been    continued. 


ally  pushed  during  the  year,  aifd  valuable  results  ob- 
tained. 

The  young  citrus  grove  continues  to  grow  and  increase, 
and  hardy  growths  of  oranges,  such  as  the  Satsuma  and 
Kumquat,  grafted  on  the  trifoliata  stock,  have  resisted 
the  most  intense  cold  ever  known  in  the  neighbourhood. 

The  fibre  plants,  such  as  jute,  hemp,  and  ramie,  have- 
also  been  successful,  but  unfortunately  no  trials  of  de- 
corticating by  machinery  were  made. 

At  No.  2  Station,  Baton  Rouge,  as  at  the  others, 
special  attention  was  given  to  the  growth  of  Egyptian 
cotton  ;  the  crops  have  been  gathered  in,  and  now  await 
the  arrival  of  a  cotton  gin  from  England.  We  should- 
have  thought  it  cheaper  to  send  the  cotton  to  England,  as 
other  people  do. 

Station  No.  3,  at  Calhoun,  has  been  unfortunate ;  the 
drought  was  so  severe  and  prolonged  that  everything  haa 
been   eaten  up  by  the   stock,  and  all   the   experiments  ■ 
vitiated. 


Bulletin  of  the  Agricultural  Experiment  Station.     Second  ' 

Series,  No.  46.    Leguminous  Root  Tubercles,  by  Prof* 

W.  R.  DoDsoN.  Baton  Rouge.  1897. 
It  has  long  been  known  that  leguminous  plants  are 
restorative  in  their  charafter,  when  used  for  improvement 
of  soils  in  a  system  of  rotation  of  crops.  Some  years 
since  it  was  discovered  that  the  chief  virtue  of  these 
plants  was  in  fixing  the  nitrogen  from  the  air,  which  was 
due  to  the  tubercles  which  occur  upon  their  roots.  With 
the  objedt  of  throwing  more  light  on  this  subjecS,  a  number 
of  experiments  were  made  by  Prof.  Dodson. 

When  thin  slices  of  these  tubercles  are  examined  with- 
a  high-power  microscope,  they  are  found  to  be  filled  with 
myriads  of  organisms  resembling  badleria.  It  has  been^ 
shown  that  when  plants  are  cultivated  in  pots,  under 
conditions  where  contaift  with  these  organisms  is  pre- 
vented, the  accumulation  of  nitrogen  in  the  plant  is  only 
equal  to  what  is  lost  by  the  soil;  but  in  the  opposite 
case,  v/hen  these  organisms  are  present,  the  increase  of 
nitrogen  can  only  be  accounted  for  by  the  assumption  that 
the  free  nitrogen  of  the  air  has  been  used. 

To  find  the  influence  of  deep  and  shallow  planting  on 
the  tubercle  formation  of  the  roots,  experiments  were 
made  on  cow  peas,  pea-nuts,  garden  beans.  Sec.  Seeds 
were  planted  at  a  depth  of  i,  2,  3,  4,  5,  and  6  inches* 
After  eight  weeks  the  soil  was  thoroughly  softened  and 
carefully  washed  from  the  roots.  Planting  at  2  or  3  inches 
seemed  to  give  the  maximum  roots  that  spread  near  the 
surface,  and  the  greatest  number  of  tubercles.  The  ob- 
servations made  in  these  plantings  were  supplemented  by 
an  examination  of  all  the  leguminous  plants  found  in  the 
vicinity,  and  it  was  shown  that  the  nature  of  the  soil  had 
much  to  do  with  the  depth  at  which  the  tubercles  are  well 
developed  ;  they  are  deeper  in  sandy  than  in  clayey  soil,, 
and  deeper  where  deep  cultivation  has  been  practised  than 
where  shallow  cultivation  prevailed. 

In  the  second  set  of  experiments  it  was  sought  to  obtain- 
an  approximate  idea  of  the  depth  to  which  the  nitrifying, 
organisms  penetrate,  and  find  conditions  favourable  to 
their  development.  Pots  containing  sterilised  soil  were 
planted  with  several  kinds  of  seeds, — clover,  lima  bean, . 
lupins,  &c., — and  watered  with  nutritive  solution  ;  but  all 
grew  very  badly,  and  it  was  eventually  found,  by  modi- 
fying the  experiments  somewhat,  that  though  the  organisms 
are  found  at  a  depth  of  i  foot,  they  are  not  very  abundant, 
and  in  no  case  was  the  infection  so  general  by  watering 
as  from  a  surface  inoculation. 

Other  experiments  show  that  each  plant,  or  at  most,, 
each  genusof  plants,  will  support  but  one  kind  of  parasitic 
organism  capable  of  developing  the  tubercles  on  its  roots. 
For  instance,  in  order  that  tubercles  maybe  developed  on 
alfalfa,  a  particular  organism  must  be  in  the  soil,  and  any 
quantity  of  cow  peas,  or  other  leguminous  plants,  will  not 


Physiological  investigations   of  the   sugar-cane,  both  in     furnish  that  organism.    The  cow  pea  likewise  has  its  own 
the  field  and  under  the  microscope,  have  been  energetic-  *  peculiar  parasite,  and  so  on  with  the  others.     Yet  dozens 


286 


Eittmatton  of  Carbon  in  Ferro-chrome, 


Chemical  Nbws, 
June  II,  1697. 


may  be  grown  side  by  side  in  the  same  soil,  and  each  will 
develop  its  own  tubeicles. 


Chemistry  of  Artificial  Colouring-matters.  ("  Chimie  des 
Matieres  Colorantes  Artificielles  ").  By  A.  Seyewetz 
and  P.  SiSLEY.  (Part  5).  Pp.  821.  Paris  :  Masson 
and  Co.  1897. 
The  fifth  and  final  instalment  of  this  work  has  just  ap- 
peared, and  we  must  confess  to  a  sense  of  great 
disappointment.  The  whole  book  has  up  to  the  present 
been  produced  in  an  excellent  manner,  beyond  the  style 
of  the  ordinary  French  book,  both  as  regards  printing  and 
quality  of  paper  used ;  but  with  this  last  number  before 
us  we  cannot  help  thinking  of  Mark  Twain's  description 
of  one  of  his  own  humorous  sketches,  which,  he  explains, 
is  only  a  study  in  black  and  white,  not  a  finished  pidture. 
The  present  work  is  decidedly  a  study;  but  when  we 
come  to  twelve  large  pages  ol  errata,  comprising  no  fewer 
than  128  corrections,  many  of  them  apparently  important 
ones,  we  feel  more  as  if  we  were  reading  proof  sheets 
than  a  published  book. 

We  hope  in  a  future  edition  the  work  will  be  sent  out 
more  fitted  for  the  reviewer. 


Papers  and  Notes  on  the  Genesis  and  Matrix  of  the  Diamond. 

By  the  late  Henry  Carvill  Lewis,  M.A.,  F.G.S. 
'  Edited  from  his  unpublished  MSS.,  by  Professor  T.  G. 

BeNNEY,  D.Sc,  LL.D.,  F.R.S.    London,  New  York, 

and  Bombay :  Longmans,  Green,  and  Co. 
It  is  indeed  a  mournful  story  told  by  the  Editor  in  his 
Preface,— first  the  sudden  death  of  the  author,  Prof.  H. 
C.  Lewis,  in  July,  1888,  followed  soon  after  by  that  of 
Prof.  G.  H.  Williams,  to  whom  the  MSS.  had  been 
handed  for  publication.  It  is  a  matter  of  great  satisfac- 
tion that  it  should  have  fallen  to  Prof.  Bonney,  who  had 
the  privilege,  as  he  himself  informs  us,  of  hearing  the 
papers  read  by  the  author  at  the  meetings  of  the  British 
Association,  in  i885  and  1887,  to  prevent  the  valuable  and 
interesting  contributions  to  our  knowledge  of  diamond- 
bearing  rocks  being  lost  to  Science.  The  present  time  is 
very  opportune  for  their  publication,  when  the  genesis  and 
history  of  the  diamond,  brought  into  prominence  by  the 
researches  of  Prof  Moissan  and  others,  is  occupying  con- 
siderable attention  in  the  scientific  world. 

The  book  is  small,  well  printed,  and  the  illustrations — 
particularly  those  of  a  fragment  of  diamond-bearing  rock 
from  Kimberley  and  the  micro-photographs  of  sedtions — 
are  very  good.  The  care  shown  by  the  late  Prof.  Lewis 
in  the  colledlion  of  his  notes  is  very  apparent,  and  it  is 
not  often  that  we  are  fortunate  enough  to  find  so  much 
solid  matter  in  so  small  compass. 

The  book  is  divided  into  three  sedions.  The  first — 
"  On  a  Diamond-bearing  Peridotite  and  on  the  History  of 
the  Diamond" — contains  illustrations  of  sedions  of  the 
diamond-bearing  "  pipes"  at  the  de  Beer's  mine,  and,  in 
support  of  the  suggestion  that  the  gabbro  or  euphotide  in 
which  the  diamonds  are  found  is  the  "  mother  rock,"  the 
well-known  fadt  is  quoted  that  each  of  the  several  pipes 
furnish  diamonds  distindt  in  charadler,  easily  distinguish- 
acle  from  the  others ;  the  accompanying  minerals  and 
the  formation  and  charadter  of  the  pipes  are  fully  dis- 
cussed. 

Sedlion  II.,  "  The  Matrix  of  the  Diamond."  This  sec- 
tion occupies  the  greater  part  of  the  book;  the  various 
minerals  occurring  in  the  "  blue  clay "  are  very  fully 
described  ;  in  fadt,  the  material  involves  a  mineralogical 
study  of  no  mean  order.  Prof.  Lewis  deals  with  it  very 
thoroughly,  giving  a  complete  list  of  the  constituent 
minerals,  and  then  describing  each  in  order.  The  very 
pleasant  manner  in  which  the  notes  are  given  adds  much 
-to  the  interest  of  the  subjedt.  The  occurrence  is  noted 
of  a  variety  of  garnet,  called  "  demantoid  "  in  microscopic 
crystals,  so  closely  resembling  diamonds  in  appearance  as 


to  be  sometimes  mistaken  for  them.  A  very  fuM  account 
is  given  of  the  mica  which  is  generally  looked  upon  as  an 
indication  of  the  presence  of  diamonds. 

As  a  result  of  his  study  of  the  diamantiferous  clay, 
Prof.  Lewis  concludes  that  "There  appears  to  be  no 
named  rock-type  having  at  once  the  composition  and 
strudture  of  the  Kimberley  rock.  For  this  reason,  as  also 
on  account  of  its  importance  as  the  matrix  of  the  diamond, 
it  is  now  proposed  to  name  the  rock  Kimberlite."  At  the 
conclusion  of  this  sedlion  the  resemblance  between  kim- 
berlite and  that  class  of  meteorites  known  under  the  name 
of  chondrites  is  pointed  out. 

Sedtion  IH.,  "  Kimberlite  from  the  United   States,' 
only  occupies  a  few  pages,  and  consists  of  notes  on  various 
specimens  of  diamond-bearing  rock  that  had  been  colleded 
by  Prof.  Lewis,  but  which  he  evidently  had  not  had  the 
opportunity  to  thoroughly  examine. 

The  book  concludes  with  a  short  note  by  Prof.  Bonney, 
giving  data  of  the  work  done  at  the  De  Beer's  mine  up  to 
date  i8g6. 


CORRESPONDENCE. 

ESTIMATION   OF  CARBON  IN  FERRO-CHROME. 

To  the  Editor  of  the  Chemical  News. 
Sir, — We  are  obliged  to  Prof.  Arnold  for  his  complimen- 
tary notice  of  our  paper,  and  I  beg  to  make  the  following 
observations  on  the  objedtions  he  raises. 

It  will  be  noticed  tnat  the  statement  respedling  Prof. 
Arnold's  method  is  not  an  unqualified  one.  The  kind  of 
combustion  furnace  used  (Bunsen's)  and  the  approximate 
heat  of  the  tube  was  given  ;  after  this,  I  was  justified  in 
stating  the  results.  It  is  my  opinion  that  the  furnace 
used  can  be  made  as  hot  as  those  generally  employed. 
In  one  particular,  however,  it  did  not  comply  with  the 
conditions  stated  in  Prof.  Arnold's  letter.  The  combus- 
tions were  all  made  between  10  a.m.  and  5  p.m.  The 
inconvenience  of  waiting  for  night  pressure  during  the 
summer  months  needs  no  comment.  The  gas-supply  is 
through  a  i\  (outside  diam.)  pipe,  and  gives  as  much  gas 
as  can  be  efficiently  burned.  It  should  be  noticed  in 
your  correspondent's  favour  that  it  was  necessary  to  coat 
the  tubes  with  asbestos. 

It  was  lamented  in  the  article  that  so  vague  a  descrip- 
tion of  the  necessary  tubes  should  be  deemed  sufficient ; 
I  am  sorry  to  note  that  even  now  the  Professor  goes  no 
further  than  to  say  "  such  tubes  are  not  easy  to  obtain, 
but  they  are,  nevertheless,  obtainable."  I  have  tried  to 
get  such  tubes,  and  admit  failure.  It  is  a  small  thing  to 
ask,  will  Prof.  Arnold  oblige  myself  and  others  by  saying 
what  the  tubes  are  called  and  where  they  may  be  had  ? 

As  is  surmised,  I  have  never  heated  bright  steel 
drillings  in  dry  oxygen,  but  I  am  pretty  certain  of  the 
difference  between  moist  and  dry  oxygen.  For  instance, 
that  even  carbon  cannot  be  combusted  in  chemically  dry 
oxygen  ("  Combustion  in  Dried  Gases,"  H.  B.  Baker, 
Journ.  Chem.  Soc,  1885;  Chem.  News,  li.,  150) ;  but 
Prof.  Arnold's  oxygen  is  not  chemically  dry,  and  since 
traces  of  moisture  make  the  most  marked  difference  it  is 
impossible  to  argue  about  the  need  for  employing 
moistened  asbestos  with  "  almost  chemically  dry  oxygen." 
Moreover,  why  the  necessity  of  drying  the  gas  so  com- 
pletely if  it  must  needs  be  re-moistened.  Our  own 
arrangement,  which  is  very  efficient,  is  KHO  solution  and 
successive  towers  of  KHO  sticks  and  well-dried  granular 
CaClz.  ,  ^     , 

Water  taken  up  in  a  current  of  gas  cannot,  of  course, 
be  deposited  in  a  hotter  place  ;  but  the  diagram  in 
"  Steel  Works  Analysis "  does  not  indicate,  nor  does 
the  accompanying  text  insist,  that  the  exit  end  should 
be  the  hotter.  In  fadt,  if  the  dimensions  of  the 
diagram  be  adhered  to,  the  inlet  tube  is  adually  the 


Crbuical  Nbws,  I 
t  June  II,  1897.     f 


Chemical  Notices  front  Foreign  Sources, 


287 


hotter — for  the  packing  stops  about  equidistant  from 
both  ends — and  in  the  general  instrudlions  for  combustion 
it  is  expressly  stipulated  that  the  first  plug  (inlet  end) 
shall  be  three  burners  within  the  furnace  (p.  34),  while 
the  last  plug  is  partly  without  the  furnace  (p.  36).  It  is 
right  to  state,  though  it  by  no  means  affefts  the  instruc- 
tions just  noted,  that  the  ends  of  our  tubes  were  protefted 
from  diredt  flame  radiation  by  a  sheet  of  asbestos  mill- 
board, and  kept  cool  by  means  of  a  strip  of  filter  paper 
resting  with  its  loose  ends  in  water. 

The  lead  protoxide  deposit  was  most  noticeable  in 
those  cases  which  were  combusted  three  and  four  hours. 

The  reason  in  favour  of  their  non  appearance  is  very 
"  simple  "  indeed.  Surely  Prof.  Arnold  does  not  rely  on 
the  three  asbestos  plugs :  they  are  all  purposely  per- 
forated ! — I  am,  &c., 

R.  L.  Leffler. 

P.S.— It  may  be  well  to  state  plainly  what  is  incident- 
ally noted  in  the  paper,  that  I  alone  am  responsible  for 
the  remark  on  Prof.  Arnold's  method  and  what  follows. — 
R.  L. 

The  Laboratory, 

Messrs.  Thos.  Firth  and  Sons,  Lim., 

Sheffield,  May  31,  1897. 

ESTIMATION  OF  CARBON   IN   FERRO-CHROME. 

To  the  Editor  of  the  Chemical  News. 
Sir, — in  March,  1896,  having  a  number  of  ferro-chromes 
to  test  for  carbon,  I  met  with  similar  difficulties  to  those 
mentioned  by  Brearley  and  Leffler  (Chemical  News,  vol. 
Ixxv.,  p.  241),  which  led  me  to  make  experiments  to  find 
an  efficient  method. 

These  experiments  took  me  in  much  the  same  dire(5lion 
as  Brearley  and  Leffier,  but  ended,  as  I  venture  to  think, 
in  a  method  which,  while  giving  good  results,  is  not  so 
complicated  as  theirs  ;  the  ordinary  combustion  furnace 
is  used  with  a  porcelain  tube,  the  heat  required  being 
only  a  bright  red.  No  difficulty  being  experienced  from 
spurting. 

I  also  found  that  with  copper  oxide  alone  only  about 
half  the  carbon  is  obtained,  but  that  by  mixing  copper 
oxide  with  litharge  the  whole  of  the  carbon  was  oxidised 
in  about  twenty  minutes. 

The  litharge  was  freshly-prepared  by  fusing  red-lead 
— possibly,  as  suggested  by  Brearley,  peroxide  of  lead 
might  be  better,  if  free  from  substances  which  might  be 
given  off  and  absorbed  by  the  potash. 

The  Method. — The  ferro-chrome  is  ground  fine  in  an 
agate  mortar.  0*5  grm.  is  then  mixed  with  4-5  grms.  CuO 
and  1-5  grms.  litharge,  and  the  mixture  placed  in  a  porce- 
lain boat.  The  boat  is  then  placed  in  the  furnace  and 
the  combustion  proceeded  with  in  the  ordinary  manner. 
In  about  twenty  minutes  the  whole  of  the  carbon  is  burnt 
off.  The  following  results  have  been  obtained  by  this 
method  : — 

II  per  cent  ferro-chrome       ..     5*41  per  cent  carbon. 
20  ,,  „  ..     5-67        „  „ 
3®            ..                M               ••     7*13         .. 

50  ..  1.  ••     7"94         .. 

The  object  of  using  copper  oxide  with  the  litharge  is  to 
prevent  the  latter  attacking  the  porcelain,  which  it  does 
very  rapidly  when  used  by  itself;  it  also  prevents  any 
spurting. — I  am,  &c., 

E.  H.  Saniter. 


Messrs.  Whittaker  and  Co.  will  publish  immediately 
a  work  on  Organic  Chemical  Manipulation,  on  which  Dr. 
J.  T.  Hewitt,  of  the  East  London  Technical  College,  has 
been  engaged.  The  first  part  of  the  text-book  will  gite 
an  account  of  the  methods  adopted  in  organic  analysis, 
and  the  determinations  of  molecular  weight ;  the  second 
part  being  devoted  to  a  typical  set  of  organic  prepara- 
tions, systematically  arranged  and  intended  to  give  an 
idea  of  the  methods  adopted  in  organic  work. 


CHEMICAL     NOTICES    FROM    FOREIGN 
SOURCES. 


NoTB.— All  degrees  of  temperature  are  Centigrade  unteit  otherwise 
expressed. 


Comptes  Rendus  Hebdomadaires  des  Seances,  del'Academie. 
des  Sciences,     Vol.  cxxiv.,  No.  18,  May  3,  1897. 

Researches  on  the  Composition  of  Wheats,  and  on' 
their  Analysis. — Aime  Girard. — Already  inserted. 

New  Property  of  Katbodic  Rays  which  reveals 
their  Complex  Constitution. — H.  Deslandres.  —  This- 
paper  requires  the  three  accompanying  illustrations. 

Partial  Polarisation  of  the  Radiations  Emitted  by 
some  Sources  of  Light  under  the  Influence  ot  the 
Magnetic  Field. — P.  Egoroif  and  N.  Georgiewsky. — The 
rays  of  hydrogen  and  of  helium  in  Geissler  tubes  have 
hitherto  not  given  any  definite  results,  The  metals  em- 
ployed (Cu,  Tl,  Zn,  Ca,  In,  Mg,  La,  Ba,  Fe)  demonstrate 
polarisation. 

Role  of  Peroxides  in  the  Phenomena  of  Slow  Oxid- 
ation.— A.  Bach. — The  author's  experiments  show  that 
the  theory  of  Hoppe-Seyler  is  devoid  of  foundation.  They 
also  show  that  the  oxidation  produ(5t  of  hydrogen  contains 
an  oxidiser  more  energetic  than  H2O2,  but  showing  with 
permanganate  the  same  quantity  of  a^ive  oxygen.  This 
oxidising  agent  is  probably  the  the  tetroxide  H2O4,  which-, 
is  decomposed  into  HjO-hOa-fO,  and  would  a^  upon 
permanganate  like  H202.  What  has  been  said  concerning 
the  formation  and  the  oxidising  action  of  the  peroxides 
applies  equally  to  the  processes  of  oxidation  which  take 
place  in  the  animal  organism.  The  oxidising  ferments- 
which  exist  in  the  blood  are  probably  nothing  but  these 
easily  oxidisable  substances  eminently  apt  to  form 
peroxides. 

Study  of  the  A(!tion  of  Potassium  Permanganate 
upon  Cupric  Bromide. — H.  Baubigny  and  P.  Rivals. — 
We  have  shown  in  a  former  paper  that  all  the  bromine  of 
an  alkaline  bromide  is  set  free  it,  aiter  adding  copper  sul- 
phate and  permanganate  to  the  solution  we  evaporate  to 
dryness  at  an  ordinary  temperature,  whilst  the  chlorides 
are  not  decomposed  under  the  same  conditions.  They 
have  ascribed  this  difference  to  the  fad  that  the  oxidising 
adtion  of  the  permanganate  is  produced  only  upon  the 
bromide.  The  permanganate  therefore  behaves  with 
cupric  bromide  in  a  neutral  liquid  as  it  does  with  organic 
matter.  In  order  that  the  total  elimination  of  the  bromine 
may  be  possible  a  large  excess  of  copper  must  be  present 
in  a  soluble  state.  In  practice  it  is  preferable  to  introduce 
a  weight  of  permanganate  notably  in  excess. 

Constitution  of  Metallic  Alloys. — Georges  Charpy. 
— The  author  views  alloys  as  either  eutedtic,  those  fusible 
at  the  minimum  temperature,  or  definite.  The  existence 
of  the  latter  class  has  been  strongly  contested,  but  the 
existence  of  the  compounds  CusSn  and  Cu2Sb  seems  fully 
demonstrated.  Among  binary  alloys  there  are  two  normal 
types  of  constitution.  The  first  presents  crystals  of  a 
pure  body  (which  may  be  a  single  metal  or  a  definite  com- 
pound of  two  metals)  inclosed  in  a  second  constituent, 
which  is  in  general  a  eutedlic  mixture  formed  by  the  juxta- 
position of  two  finely  divided  elements,  one  of  which  is 
that  which  forms  the  crystals.  The  second  type  is  that 
of  isomorphous  mixtures  formed  of  a  single  species  of 
crystals  occupying  the  entire  mass.  This  second  type  is 
of  very  frequent  occurrence. 

Determination  of  Oxygen  Dissolved  in  Sea-water.. 
— Albert  Levy  and  Felix  Marboutin, 

Compounds  of  Metallic  Salts  with  Organic  Bases. 
— D.  Tombeck. — It  is  known  that  metallic  salts  combining 
with  ammonium  chloride,  either  in  the  presence  or  the 
absence  of  water,  forms  compounds  which  have  been 
studied  by  several  chemists,  especially  by  Isambert.    The. 


288 


Meetings  /or  the  Week, 


{Chemical  mbws, 
June  II,  1897.,. 


author  proposes  the  study  of  analogous  bodies  in  which 
ammonia  is  replaced  by  the  bases  derived  from  ammonia. 
A  Compound  of  Silver  Chloride  and  Monomethyl- 
amine.— R.  Irry. — The  author  having  examined  the  am- 
moniacal  silver  chlorides  extends  his  researches  to  com- 
pounds  in   which   monomethylamine   is   substituted   for 

.ammoniacal  gas. 

Recognition  of  the  Yellow  of  Naphthol  S,  and  of 
Analogous  Colouring-matters  in  White  Wines  and 
Liqueurs. — Alberto  d'Aguiar  and  W.  da  Silva. — Already 

/inserted. 


MISCELLANEOUS. 


Rheostats  for  enabling  Street  Currents  to  be  used 
for  Medical  Purposes. — The  idea  of  making  use  of  large 
and  powerful  currents  for  operations  requiring  but  weak 
currents  is  nothing  new.  M.  Foveau  de  Courmelles  has 
■recently  brought  out  a  compad  and  convenient  instrument 
for  this  purpose  which  can  be  readily  fitted  to  a  wall  plug. 
It  is  specially  adapted  for  use  with  continuous  currents. 

Carborundum  Produ(5lion  and  Use.  —  The  Carbo- 
rundum Company  reports  to  the  Engineering  and  Mining 
jfournal  that  its  works  have  produced  during  the  year 

1896,  in  round  numbers,  1,191,000  pounds  or  595J  tons  of 
crystalline  carborundum.     Consideration  at  the  present  is 

.given  to  the  produdion  in  crystalline  form  only,  but 
another  important  industry  into  which  carbide  of  silicon 
promises  to  be  a  valuable  adjund  will  naturally  increase 
the  usefulness  of  the  material.  Some  mention  has  been 
made  of  the  experiments  showing  that  carborundum  can 
be  used,  and  will,  in  all  probability,  take  the  place  of 
ferro-silicon  in  the  manufadure  of  steel.  Professor 
lyuehrmann,  of  Germany,  recently  wrote  an  article  on 
this  subjed,  indicating  that  in  the  use  of  carborundum 
there  will  be  in  Germany  alone,  approximately,  2500  tons 
consumed  annually,  provided  its  cost  would  not  exceed 
6  cents  per  pound.  It  may  be  used  for  this  purpose  in  an 
amorphous  form,  and  the  Carborundum  Company  is  pre- 
pared to  furnish  it  at  a  price  slightly  under  this  figure. 
In  the  jfournal  of  the  Franklin  Institute   for  February, 

1897,  will  be  found  an  excellent  descriptive  paper  on  the 
carborundum  plant  at  Niagara  Falls,  from  the  pen  of  Mr. 
Fitzgerald,  chemical  engineer  of  the  works.  This  indus- 
try stands  as  a  conspicuous  illustration  of  the  possibilities 
of  the  eledric  furnace  as  the  source  of  hitherto  unknown 
and  valuable  produds. 


MEETINGS    FOR    THE    WEEK. 

Monday,  14th.— Society  of  Chemical  Industry,  8.      "Note  on  a  Pos- 
sible Danger  from  Fire  involved  in  the  Transport 
of  Barium  Peroxide  in  Wooden  Barrels,"  by  Dr. 
A.  Dupre,  F.R.S.      "  The  Valuation  of  Commer- 
cial  Nitrate   of   Soda,"  by  Dr.  Pauli.    "  Recent 
Improvements  in  Smokeless  Compounds  and  in 
Processes  of   Manufafture,"  by  Hudson  Maxim. 
"  Comparative  Experiments  on  the    Estimation 
of  Phosphoric    Acid,"   by    A.    Cameron.      "The 
Strength  of  Commercial  Formaldehyd  Solutions," 
by  W.  A.  Davis. 
•Thursday,  17th.— Chemical,  8.      Ballot  for  the  Eleftion  of  Fellows. 
•' Redu(aion  of  Perthiocyanic  Acid,"  by  F.  D. 
Chattaway,   M.A.,   and   H.    P.    Stevens,   B.A. 
"  Molecular  Refraiftion  of  Dissolved  Salts  and 
Acids— Part  II."  by  Dr.  J.  H.  Gladstone,  F.R.S., 
and  W.  Hibbert.     "  A  Space  Formula  for  Ben- 
zene," by  Dr.  J.  Norman  Collie,  F.R.S.    "  The 
Produftion   of    some   Nitro-  and   Amido-Oxy- 
picolines,"  by  Dr.  A.  Lapworth  and  Dr.  J.  Nor- 
man Collie,  F.R.S.      "  The  so-called  Hydrates 
of  Isopropyl   Alcohol,"  by  Dr.  T.  E.   Thorpe, 
F.R.S.      •'  The    Carbohydrates   of  the  Cereal 
Straws,"  by  C.  F.  Cross,  E.  J.  Bevan,  and  C. 
Smith.    "  Further  Experiments  on  the  Absorp- 
tion of  Moisture  by  Deliquescent  Substances," 
by  H.  Wilson  Hake. 


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^"junL^siis'r.''}   Sanitary  Problems  connected  with  Municipal  Water  Supply, 


289 


THE    CHEMICAL    NEWS 


Vol.  LXXV.,  No.  i960. 


FURTHER    NOTE     ON     THE     INFLUENCE    OF 

A    MAGNETIC     FIELD     ON     RADIATION 

FREQUENCY.* 

By  Prof.  OLIVER  LODGE,  F.R.S.,  assisted  by 
Mr.  BENJAMIN  DAVIES. 

Deferring  to  a  former  communication  of  mine,  on  the 
subjedt  of  Zeeman's  discovery,  printed  on  page  513  of 
the  Proceedings  of  the  Royal  Society,  for  Feb.  11  this 
year,  vol.  Ix,,  No.  367,  I  wish  to  add  an  observation  to 
those  previously  recorded,  as  I  have  recently  acquired  a 
concave  Rowland  grating  (3iXii  in.  ruled  surface, 
14,438  lines  to  inch,  10  feet  radius  of  curvature,  being 
the  one  used  by  Mr.  George  Higgs),  of  which  the 
spedra  of  the  first  and  third  orders  on  one  side  are  very 
satisfadlory. 

It  is  said  on  page  513,  "If  the  focussing  is  sharp 
enough  to  show  a  narrow,  dark  reversal  line  down  the 
middle  of  each  sodium  line,  that  dark  line  completely 
disappears  when  the  magnet  is  excited."  With  the 
greater  optical  power  now  available  the  dark  reversal 
line  is  often  by  no  means  narrow,  and,  though  in  some 
positions  of  the  flame  it  does  still  tend  to  disappear  or 
become  less  manifest  when  the  flame  is  subjected  to  a 
concentrated  magnetic  field,  the  reason  of  its  partial  dis- 
appearance is  that  it  is  partially  reversed  again — t.«.,that 
a  third  bright  line,  as  it  were,  makes  its  appearance  in  the 
midst  of  the  dark  line,  giving  a  triple  appearance  to  each 
sodium  line. 

More  completely  stated  the  phenomena  are  as  follows : 
— After  obtaining  each  sodium  line  with  a  prominently 
double  aspedl  by  manipulating  the  flame,  the  magnet  is 
excited,  and  the  dark  band  in  the  midst  of  each  sodium 
line  is  then  seen  to  widen  out  considerably  in  the  region 
of  most  intense  magnetisation,  while  a  bright  intrusion 
line  makes  its  appearance.  On  closer  examination  this 
new  line  is  seen  to  be  double,  by  reason  of  a  dark 
division  down  its  middle ;  and  I  apprehend  that  with 
still  more  magnetic  power  this  dark  band  might  itself 
open  out  into  two ;  but  this  last  phenomenon  I  have 
not  yet  observed. 

The  whole  sodium  group  is  thus  seen  as  if  it  were 
oduple.  The  effed  is  not  due  to  a  mere  mechanical 
disturbance  or  re-arrangement  of  the  gases  of  the  flame 
by  the  agency  of  magnetism  ;  because  a  nicol,  placed  in 
the  rays  emanating  transversely  to  the  magnetic  lines  of 
force,  cuts  off  nearly  all  the  visible  magnetic  effed  when 
oriented  so  as  to  get  rid  of  light  whose  plane  of  polarisa- 
tion contains  the  lines  of  force — that  is,  of  oscillations  or 
revolutions  whose  eledrical  components  are  across  or 
around  the  magnetic  lines.  That  it  does  not  cut  off  every 
trace  of  the  effedl  appears  to  be  due  to  the  fadt  that  the 
field  of  force  is  not  strictly  uniform,  and  so  its  lines  are 
not  stridly  parallel. 

The  following  is  a  summary  of  the  different  appearances 
that  may  be  seen,  according  to  the  state  of  the  flame  and 
the  strength  of  the  field  : — 

At  low  temperature,  and  with  the  flame  forward  in  the 
field,  when  each  sodium  line  is  sharp  and  single, 
magnetism  widens  it,  and  with  a  little  more  power 
doubles  it,  causing  a  distincft  dark  line  down  its  middle. 
The  same  efFedl  occurs  with  lithium  and  thallium  lines. 

At  higher  temperature,  and  with  the  flame  partially 
behind  the  field,  when  each  sodium   line   appears  as  a 

♦  A  Paper  read  before  the  Royal  Society,  June  3, 1897. 


broad  hazy-edged  double,  magnetisation  greatly  widens 
the  doubling,  pushing  asunder  the  bright  components 
very  markedly;  stronger  magnetisation  reverses  the 
middle  of  the  widened  dark  band,  giving  a  triple  appear- 
ance; stronger  magnetisation  still  reverses  the  middle 
once  more,  giving  a  quadruple  appearance  to  the  line. 
In  every  case  a  nicol,  suitably  placed,  cuts  off  all  the 
magnetic  efTeA,  and  restores  the  original  appearance  of 
the  line. 

A  curious  circumstance  is  that  although  both  lines,  Di 
and  D2,  show  the  effedt,  Di,  i.  e.,  the  less  refrangible  line, 
shows  it  best  and  most  sharply.  I  should  describe  the 
effedt  on  D2  as  a  coarse  widening  of  considerable  amount, 
but  without  very  clear  definition ;  whereas  the  widening 
of  Dr,  though  perhaps  no  greater  in  amount,  is  decidedly 
better  defined.  There  is  no  doubt  but  that,  with  my 
grating,  Di  is  the  line  at  which  one  finds  oneself  usually 
looking  in  order  to  see  the  details  of  the  change  best ; 
and  I  can  hardly  suppose  this  to  be  subjedtive  to  the 
grating.  I  hope  to  show  the  effedks  at  the  Soiree  of  the 
Royal  Society. 

(The  same  thing  is  seen  when  salts  of  lithium  or  of 
thallium  are  introduced  into  the  flame,  and  the  components 
of  the  doubled  red  lines  are  more  widely  separated  than 
the  components  of  the  doubled  green  lines,  the  effedl 
being  proportional  to  wave-length.  The  most  interesting 
line  to  try  was  the  red  cadmium  line,  since  this  has  been 
proved  to  be  of  specially  simple  constitution  by  Michelson. 
We  have  recently  been  able  to  get  the  cadmium  spedlrum 
well  developed  by  means  of  a  sort  of  spark  arc  between 
the  magnet  poles,  maintained  by  an  induction  coil  excited 
by  an  alternating  machine ;  and  we  find  that  the  magnetic 
doubling  of  the  chief  lines  occurs  in  precisely  the  same 
way  with  the  spark  spedrum  as  with  the  flame  spedrum, 
and  that  the  red  cadmium  line  behaves  in  the  same  way 
as  the  others.  The  magnetic  effed  is  better  seen,  from  a 
diredtion  perpendicular  to  the  line  of  force,  when  a  nicol 
is  interposed  in  the  path  of  the  light,  but  rotation  of  the 
nicol  through  go"  cuts  it  entirely  off,  accurately  so  when  a 
small  spark  is  the  source  of  light. — May  31). 


SANITARY    PROBLEMS    CONNECTED    WITH 

MUNICIPAL    WATER  -  SUPPLY.* 

By  Prof.  W.  P.  MASON. 

This  subjedl  is  in  some  danger  of  being  over-written 
to-day ;  but  we  have  about  us  material  evidence  that  it  is 
not  over-studied,  especially  by  those  Boards  of  public 
officials  whose  responsibilities  are  often  much  greater 
than  their  knowledge  of  sanitary  principles.  The  public 
also  is  far  from  being  well  posted  on  the  matter,  and  one 
encounters  all  sorts  of  odd  views,  which  are  remarkable 
not  only  for  their  charadter,  but  also  for  the  tenacity  with 
which  they  are  held. 

Ocular  evidence  of  purity  is  quite  sufficient  for  most 
people.  The  bright  and  limpid  water  from  a  well  which 
drains  a  grave-yard  is  counted  a  blessing  by  those  who 
would  shudder  at  the  thought  of  a  cholera-ship  touching 
at  one  of  our  most  distant  ports.  Nor  is  faith  in  the 
self-purifying  power  of  running  streams  any  less  pro- 
nounced. The  author  had  the  following  curious  criticism 
made  on  his  report  condemning  the  use  of  a  sewage-laden 
river-water: — "  We  would  hint  to  Prof.  Mason  that  every 
impurity  which  enters  the  river  is  either  heavier  or  lighter 
than  water.  If  it  be  heavier,  it  sinks  quietly  to  the 
bottom  ;  if  it  be  lighter,  it  will  remain  on  the  surface  a 
few  hours,  when  it  will  be  blown  ashore  by  the  wind. 

"  Water  taken  midway  between  the  surface  and  bottom 
of  the  river  will  always  be  found  as  pure  as  the  best 
spring  water." 

*  Abridged  from  a  Ledture  delivered  before  the  Franklin  Institute 
March  tgtfa,  1897. 


ago 


Sanitary  Problems  connected  with  Municipal  Water  Supply. 


Crbmical  News, 
June  i8,  1807. 


So  long  as  such  notions  find  expression  in  the  daily 
press,  so  long,  we  may  be  sure,  are  the  people  ignorant 
and  misinformed  upon  questions  very  nearly  touching 
their  safety,  and  so  long  there  is  direct  need  of  suitable 
sanitary  education. 

To  the  writer's  way  of  thinking,  a  land  should  be 
looked  upon  as  watered  by  its  smaller  lakes,  its  springs, 
and  its  brooks  and  streams,  and  sewered  by  its  great — 
especially  its  navigable — rivers.  Its  water  sources  should 
be  protected  by  law  with  exceeding  care,  and  no  stream 
or  river  should  be  added  to  its  list  of  drains,  except  after 
proper  consideration  by  the  State  Board  of  Health,  fol- 
lowed by  legislative  permission. 

Cases  such  as  the  typhoid  fever  outbreak  at  Plymouth, 
Pa.,  impress  upon  us  the  necessity  of  caring  for  our  water- 
sheds and  the  ultimate  ramifications  of  the  tributaries  to 
our  sources  of  supply. 

Many  readers  are  probably  familiar  with  the  excellent 
experiments  carried  on  at  Lawrence  by  the  Massachusetts 
State  Board  of  Health,  which  go  to  show  that,  by  care- 
fully conduced  intermittent  filtration  through  beds  of  sand 
or  gravel  stones,  city  sewage  may  be  converted  into  what 
may  pradically  be  called  potable  water.  Let  these  two  very 
important  points  be  always  kept  in  mind  however: — 
First,  the  filtration  must  be  intermittent,  for  if  it  be  con- 
tinuous the  atmospheric  oxygen  necessary  to  the  adlivity 
of  the  purifying  organisms  of  nitrification  becomes  ex- 
cluded, and  purification  ceases.  Secondly,  the  "  dose  "  of 
applied  sewage  must  not  be  larger  than  that  quantity  which 
experiment  has  shown  to  be  capable  of  disposal  by  the 
filter. 

The  general  trend  of  our  information  goes  to  establish 
the  fadl  that  proper  care  of  the  water-shed  is  as  necessary 
as  it  is  unusual,  and  I  firmly  believe  that  such  care  should 
be  carried  even  to  the  extent  of  protedling  the  ground- 
water for  a  reasonable  distance  before  it  enters  the  draining 
brooks  of  the  district. 

After  a  suitable  and  well-proteded  gathering  ground 
has  been  secured,  and  after  the  water  has  been  started 
on  its  way  to  the  consumer,  other  opportunities  for  pollu- 
tion not  infrequently  arise.  Open  channel-ways,  as  a 
means  of  conveying  water  to  a  town,  are  quite  commonly 
seen,  and  care  is  not  always  taken  that  pollution  shall  not 
reach  the  water  during  its  flow  therein.  We  find  a  very 
noteworthy  case  of  contamination,  under  just  such  cir- 
cumstances, recorded  in  the  history  of  the  cholera  epidemic 
at  Messina,  Sicily,  in  1887.  The  plague  lasted  from  the 
loth  of  September  to  the  25th  of  Odober,  during  which 
time  there  were  some  5000  cases  and  2200  deaths.  The 
Government  felt  that  a  very  possible  cause  for  the  rapid 
spread  of  the  scourge  lay  in  a  contaminated  drinking 
water,  and  enquiry  fully  confirmed  this  suspicion.  The 
water  as  it  left  the  gathering  grounds  was  of  excellent 
quality,  but,  for  the  benefit  of  the  Messina  washerwomen, 
a  portion  of  the  water  was  defleded  before  reaching  the 
wells,  and  turned  into  neighbouring  washing-pools  of 
stone.  A  fair  proportion  of  this  defledled  water,  after 
having  been  used  for  laundry  purposes,  found  its  way  back 
into  the  open  channel,  and  continued  its  course  to  the 
city.  Further  contamination  occurred  within  the  town 
itself;  the  water-mains  and  sewers  were  ofunglazed  tiles, 
very  leaky,  and  the  sewers  were  at  times  found  on  the  top 
of,  and  parallel  with,  the  water-mains  themselves.  The 
Government  sent  tank  ships  filled  with  pure  "  Serino  " 
water,  supplied  the  people  therewith,  and  the  daily  number 
of  cases  immediately  fell  from  seventy  to  five. 

Keeping  our  attention  upon  typhoid  fever,  it  will  be 
remembered  that  two  conceptions  of  its  origin  are  enter- 
tained by  opposing  schools  of  badleriologists.  On  the  one 
hand,  it  is  held  that  the  typhoid  germ  is  always  the  off- 
spring of  a  bacillus  of  its  own  kind  ;  while,  on  the  other 
side,  there  are  those  who  believe — and  it  is  a  very  con- 
ceivable belief — that  the  progenitor  in  question  is  often  a 
saprophyte  which  takes  on  its  pathogenic  properties  by 
cultivation  through  successive  generations  under  favour- 
able conditions. 


Many  illlustrations  are  available,  in  the  world  of  larger 
vegetation,  of  greater  changes  in  structure  due  to  cultiva- 
tion under  an  altered  environment. 

Roux  and  Rodet  are  perhaps  the  leaders  among  those 
who  claim  a  saprophytic  ancestry  for  the  typhoid  germ, 
but  they  are  not  without  a  strong  following  in  this 
country. 

Whatever  may  be  the  final  decision  of  the  specialists 
upon  this  knotty  point,  it  is  our  manifest  duty  to  adopt 
for  the  present  the  saprophyte  theory  as  our  working 
formula,  and  to  protedl  water-supplies  from  the  infiltration 
of  animal  waste  material. 

Diredtly  connefted  with  the  conveying  of  water  in  open 
channels  comes  the  question  of  the  self-purification  of 
water  under  such  circumstances.  Agitation  and  aeration 
do  certainly  aid  in  preventing  abundant  growth  of  Algae, 
and  an  undoubted  improvement  in  the  quality  of  water 
results  from  the  establishment  of  a  fountain  in  a  too  quiet 
reservoir  ;  but  the  expe(5tations  of  those  who  hope  to  thus 
easily  eliminate  pollution  of  a  serious  charadter  will  not 
be  realised. 

Sedimentation  plays  a  part  in  the  general  purification 
during  open  fiow,  but  it  is  commonly  a  small  one, 
particularly  small  in  such  streams  as  stand  in  special 
favour  with  the  public,  because  of  the  riffles  and  other 
interruptions  in  their  courses. 

Sedimentation,  when  we  consider  the  question  of; 
drawing  our  supply  from  a  lake,  particularly  a  large  one,, 
becomes  of  prime  importance,  and,  as  the  element  of 
time  enters  largely  into  the  consideration  of  these  cases,, 
material  changes  for  the  better  are  often  noticeable  in 
lake  waters;  thus  the  tributary  of  a  lake  may  be  unde- 
sirable for  domestic  use,  while  its  outlet  may  be  entirely 
satisfadlory. 

Referring  to  the  suggestion  recently  published  by  one 
of  our  sanitary  engineers,  to  the  effedt  that  the  cleaning 
of  storage  reservoirs  is  all  a  mistake,  and  that  it  would  be 
far  better  pradice  to  leave  the  vegetable  debris  where 
Nature  placed  it,  it  must  be  replied  that  comparative 
experiments  upon  such  reservoirs  have  shown  that 
improved  water  unquestionably  follows  cleaning:.  No 
stripping  of  the  soil  from  the  bottom  of  the  Vyrnwy 
reservoir,  which  supplies  Liverpool,  was  done,  but  the 
water  is  filtered  before  delivery  for  consumption. 

Filtration  is  so  common  in  Europe  that  the  same  care 
in  storage  is  not  so  necessary  as  in  the  United  States, 
where  the  pradlice  is  to  supply  the  raw  water  diredl  to  the 
consumer. 

Waters  from  underground  sources  should  be  distributed 
for  use  as  soon  as  possible  after  they  have  been  brought 
to  the  surface,  for  they  are  commonly  well  supplied  with 
plant-food  in  solution,  and,  under  the  influence  of  light 
and  air,  there  is  danger  of  abundant  development  of  ob- 
jedtionable  Algae  if  much  time  for  open  storage  be  allowed. 
With  surface-waters  the  case  is  quite  the  reverse,  and 
long  storage  becomes  a  distinct  advantage,  if  the  reservoir 
be  clean.  Badteria  often  die  but  slowly,  and,  although  a 
large  percentage  of  their  number  will  disappear  through 
storage,  it  should  not  be  forgotten  that  they  are  very 
small  and  very  light,  and  consequently  are  very  long  in 
settling,  so  that  it  should  not  be  expeded  that  a  reservoir 
could  do  the  efficient  work  accomplished  by  a  filter. 

From  whatever  source  the  water  may  be  derived,  it  is 
the  common  American  pradlice  to  deliver  it  "  raw  "  to  the 
consumer,  even  when  its  appearance  is  distindlly  unsightly. 
Such,  however,  is  not  the  European  custom.  Public 
sentiment  abroad  demands  that  surface-waters  should 
receive  efficient  purification  before  they  are  distributed 
for  domestic  use.  As  a  result,  filters  are  established,  or 
arrangements  are  contemplated  for  their  eredion,  to  filter 
waters,  of  a  degree  of  natural  purity,  equal  to  the  best 
supplies  America  can  show.  We  on  this  side  of  the 
Atlantic  would  consider  the  expenditure  of  money  for  the 
purpose  of  purifying  such  waters  as  we  find  at  Liverpool 
and  Zurich  quite  unnecessary  and  superfluous  ;  Europeans 
think   differently,   however,   and   their  notions   are  best 


Cbbmical  Nbws,  I 
June  i8, 1897.     t 


Viscosity  of  Mercury  Vapour. 


2gi 


expressed  by  Voltaire's  apothegm  "  Le  superflu,  chose 
tres  n^cessaire." 

It  is  very  amusing  to  note  the  care  with  which  Ameri- 
cans— perhaps  from  Albany,  Pittsburg,  or  Chicago — 
scrutinise  the  water  offered  them  in  foreign  capitals,  when 
what  they  are  in  the  habit  of  drinking  at  home  would  not 
be  tolerated  for  an  instant  in  the  great  cities  of  Europe. 

The  day  is  past  when  we  could  feel  a  sense  of  superiority 
over  the  crowded  millions  of  the  old  world,  because  of 
the  relative  magnitude  and  consequent  initial  purity  of 
the  sources  of  our  water-supplies.  Europe  has,  of  late 
years,  expended  much  labour  and  capital  in  substantial 
plants,  that  make  for  sanitary  betterments,  while  we  have 
continued  upon  a  conservative  course,  forgetful  that  our 
populations  and  industries  have  been  growing,  and  that 
the  rivers  our  fathers  drank  from  with  pleasure  and  safety 
have  become  charged  with  the  refuse  of  up-stream  com- 
munities, and  converted  into  what  may  be  properly  styled 
the  county  sewers. 

I  iThere  is  no  system  of  filtration  so  expensive  but  that  a 
community  can  well  afford  to  introduce  it  rather  than  to 
drink  a  dangerous  water  in  its  raw  state,  and  this,  too, 
from  purely  economic  considerations,  and  leaving  out  of 
sight  all  ethical  questions  whatsoever. 


THE     VISCOSITY      OF      MERCURY     VAPOUR.' 
By  A.  A.  NOYES,  Ph.D.,  and  H.  M.  GOODWIN,  Ph.D. 

The  uncertaintity  which  attaches  to  the  specific  heat 
ratio  of  gases  as  a  means  of  distinguishing  between  mon- 
atomic  and  polyatomic  molecules  has  been  recently  made 
evident  by  the  extended  discussions  of  the  significance  of 
that  property  in  connexion  with  the  atomic  weights  of  argon 
and  helium.  It  is  therefore  of  great  interest  to  investigate 
other  properties  which  may  be  expedted  to  be  related  to 
the  atomicity  of  the  molecule.  The  authors  have  therefore 
undertaken  the  investigation  of  one  of  these,  viz.,  the 
viscosity,  or  internal  fridlion,  in  order  to  determine  if  any 
marked  difference  in  its  value  exists  in  the  case  of  gases 
with  monatomic  and  those  with  polyatomic  molecules. 
To  this  end  they  have  made  comparative  measurements 
of  the  viscosity  of  hydrogen,  carbon  dioxide,  and  mercury 
vapour,  at  the  boiling  temperature  of  the  latter.  The 
authors  thought  that  monatomic  molecules  might  prove 
to  be  much  smaller  than  polyatomic  ones,  since  it  seems 
a  priori  not  improbable  that  the  spaces  between  the  atoms 
of  the  latter  are  large  in  comparison  with  the  atoms 
themselves.  The  experiments  described  show,  however, 
that  no  marked  distindtion  exists  between  monatomic  and 
polyatomic  gases  in  this  respedt. 

The  method  used  by  them  in  determining  the  relative 
viscosity  consisted  in  measuring  the  quantities  of  the  dif- 
ferent gases  which,  under  a  constant  difference  of  pres- 
sure, passed  in  a  given  time  through  the  same  capillary  ' 
kept  at  a  definite  constant  temperature.  The  apparatus 
and  experimental  method  employed  were,  for  given 
reasons,  quite  different  from  the  usual  ones,  and  are 
briefly  described.  The  capillary  used  in  the  most  com- 
plete series  of  experiments  consisted  of  a  glass  tube  74 
cm.  long  and  0-34  m.m.  internal  diameter  (a  smaller 
capillary,  49  cm.  long  and  0*22  m.m.  in  diameter, 
was  used  in  a  preliminary  series) ;  it  was  compadlly  bent 
upon  itself  so  as  to  form  five  vertical  segments  with,  of 
course,  four  elbows,  the  begmning  and  the  end  of  the 
capillary  part  of  the  tube  being  at  the  same  level.  To 
these  ends  were  fused  pieces  of  ordinary  glass  tube,  one 
of  which  was  bent  horizontal,  and  provided  at  the  point 
with  a  ground  joint;  to  the  other  was  fixed  a  vertical 
T-piece.  This  was  all  placed  in  a  heavy  steel  cylinder, 
30  cm.  high  and  2*8  cm.  internal  diameter,  having  a 
small  orifice  at  the  side  through  which  the  ground  joint 

•  Abridged  from  the  Technology  Quarterly,  vol.  x..  No.  1,  1897. 


protruded  for  about  i  cm.,  the  whole  being  held  in  position 
by  loosely-packed  asbestos.  Although  the  capillary  was 
vertical,  the  influence  of  gravity  was  eliminated  by  reason 
of  the  fadt  that  the  ascending  and  descending  parts  were 
of  equal  length.  The  top  of  the  cylinder  was  closed  by 
an  iron  plate  screwed  down  by  a  nut,  both  plate  and  nut 
were  perforated  through  the  centre,  and  into  the  latter 
was  welded  an  iron  tube,  projedling  vertically,  25  cm.  in 
length  and  2*5  cm.  diameter.  The  cylinder  was  covered, 
except  on  the  bottom,  with  a  jacket  of  asbestos  about  5 
cm.  thick,  and  spirals  of  copper  wire  were  wound  round 
the  vertical  tube,  which  was  to  serve  as  a  condenser,  in 
order  to  increase  the  cooling  surface.  Pure  mercury  was 
placed  in  the  cylinder  and  boiled  vigorously  by  means  of 
a  flame  underneath.  The  capillary  was  thus  kept  at  the 
temperature  of  the  boiling  mercury  at  atmospheric  pres' 
sure.  No  regard  was  paid  to  the  variations  of  tempera- 
ture arising  from  changes  in  barometric  pressure,  as  their 
effedt  would  evidently  be  entirely  negligible. 

Any  desired  difference  of  pressure  at  the  two  ends  of 
the  capillary  was  obtained  by  inserting  a  tube  in  the 
ground  joint  and  connedting  it  with  a  large  air  reservoir, 
which  was  in  turn  connected  with  a  sudtion-pump  and 
furnished  with  an  open  mercury  manometer.  The  gas,  or 
vapour  entered  at  the  other  end  of  the  capillary,  always 
under  atmospheric  pressure. 

In  making  the  experiments  the  rate  of  flow  of  the  mer- 
cury vapour  was  first  determined  in  the  following 
manner  : — While  the  cylinder  was  being  heated  carbon 
dioxide  was  forced  through  the  capillary  to  prevent 
the  condensation  in  it  of  liquid  mercury  and  the  formation 
of  its  oxide.  After  the  mercury  was  boiling  adtively  and 
its  vapour  entirely  enveloped  the  capillary,  shown  by  a 
thermometer  inserted  into  the  vertical  iron  tube,  it  was 
connedted  with  the  sudtion  pump  and  mercury  vapour 
drawn  through  for  half  an  hour.  The  carefully  ground 
end  of  a  weighed  bulb  was  then  inserted  in  the  ground 
joint,  and  its  other  end  connedted  by  means  of  a  clamped 
rubber  tube  with  the  air  reservoir,  in  which  the  desired 
redudlion  of  pressure  had  been  produced.  At  a  definite 
moment  the  clamp  was  opened  and  the  time  noted.  The 
mercury  vapour  was  found  to  be  completely  condensed  in 
the  weighed  tube,  about  2  or  3  cm.  from  the  ground  joint. 
There  was  a  slight  and  unavoidable  leakage*  through 
the  ground  joint,  and  it  was  therefore  necessary  to 
re-adjust  the  pressure  occasionally.  It  could  easily  be 
kept  constant  to  0'2  or  03  m.m.  Usually  after  sixty 
minutes  the  clamp  was  closed,  and  at  a  noted  instant  the 
bulb  was  removed  and  subsequently  weighed.  The 
capillary  was  removed  from  the  cylinder  and  the  lower 
end  of  the  T-piece  closed  by  fusion.  A  glass  tube,  long 
enough  to  projedt  above  the  end  of  the  iron  tube,  was 
then  fused  to  the  upper  part  of  the  T-piece,  and  the 
capillary  was  then  ready  for  the  experiments  with  carbon 
dioxide  and  hydrogen.  It  was  replaced  in  the  cylinder 
as  before,  and  the  projedting  vertical  glass  tube  connefted 
through  suitable  wash-bottles  with  the  gas  generator. 

In  order  to  maintain  the  gas  entering  the  capillary  at 
atmospheric  pressure,  a  T-tube  was  inserted  between  the 
wash-bottles  and  the  capillary,  and  its  perpendicular  arm 
was  turned  downwards  and  caused  to  dip  into  sulphuric 
acid,  barely  below  its  surface.  The  cock  of  the  generator 
was  opened  sufficiently  to  cause  the  gas  to  bubble  out 
steadily  through  the  sulphuric  acid. 

The  transpiration  measurements  were  made  as  in  the 
case  of  the  mercury.  The  carbon  dioxide  flowing  through 
in  a  definite  time,  was  determined  by  absorption  in 
weighed  tubes  filled  with  lumps  of  soda-lime.  The 
hydrogen  was  burnt  by  passing  it  over  hot  copper  oxide 
contained  in  combustion-tubes  from  which  the  air  was 
previously  displaced  by  carbon  dioxide,  and  the  water 
colledted  in  weighed  calcium  chloride  tubes. 


*  In  the  case  of  the  mercury  experiments  no  error  could  arise  from 
this  source,  as  the  leakage  was  inward.  In  the  case  of  those  of 
carbon  dioxide  and  hydrogen  it  was  proved  by  blank  experiments 
that  the  amounts  of  carbon  dioxide  and  water  which  leaked  in  were 
less  than  i  per  cent  of  the  total  weight. 


2g2 


Purification  of  Cerium, 


I  Chemical  News, 
I     June  18,  1897. 


The  results  are  given  in  the  following  tables.  The 
first  column  gives  the  symbol  of  the  substance ;  the 
second,  the  atmospheric  pressure,  pi ;  the  third,  the  dif- 
ference in  pressure  (/i— /a);  the  fourth,  the  time,  ^  ex- 
pressed in  hours  ;  the  fifth,  the  weight,  w,  in  grms.  of  the 
substance  weighed ;  the  sixth,  the  mean  weight  transpired 
in  one  hour  as  computed  from  the  separate  check  experi- 
ments ;  and  the  last,  the  quotient  obtained  by  dividing 
this  weight  by  the  molecular  weight,  m,  of  the  substance, 
the  time,  and  the  pressure  fundtion  (^,*-^g*).* 


Hg.. 


CO2 


Pi- 

753 
753 
756 

Px-Pz- 
200 

U 

0738 
0740 

0-745 

0-494 

»•  X  10 1 » 

936 

755 
755 

300 

0-685 
0-686 

0-686 

936 

754 
754 

400 

0834 
0-831 

0-833 

92-9 

752 
752 
752 

2CO 

ij 

0-237 
0239 
0-357 

0-238 

205 

759 
759 
766 

300 

0-329 
0-327 
0-324 

0-327 

203 

766 
766 
759 

400 

0-400 
0-396 
0-396 

0-397 

202 

769 
769 

Series 
150 

II.— 

Large  Capillary. 
1-548          - 
1-548         1-548 

374 

769 
769 
769 

300 

2-763 
2764 
2739 

2755 

373 

756 
765 

150 

0-704 
0706 

0-705 

774 

765 
765 

300 

1-267 
1-264 

1-265 

779 

766 
766 

150 

0-557 
0-557 

0-557 

1517 

766 
766 

300 

1-009 
1-006 

1-008 

1496 

766 
766 
764 

300 

2-728 
2746 
2743 

2739 

371 

Hg. 


CO, 


Ha 


Hg.. 


The  agreement  of  the  values  of  the  last  column  in  the 
cases  of  the  same  substances  under  different  pressures 
show  that  the  capillaries  are  of  sufficient  length  and  small 
enough  bore  to  give  the  true  values  of  the  viscosity  co- 
efficients. 

The  relative  viscosity  coefficients  of  the  different  gases 
were  calculated  from  the  values  of  the  last  column  in  the 
tables,  and  gave  the  following  results  : — 

"qq     =  2-17 (First  series). 

^  =2-08  --^^-=4-04  •^^=1-94  (Second  series). 


The  relative  values  for  mercury  and  carbon  dioxide- 
agree  within  about  4  per  cent. 

The  corresponding  values  of  the  mean  cross-sedions  as- 
calculated  are — 


9Hg 


?"^=  2-48; 


gjCOg  q  Ha 

that  is  to  say,  the  average  cross-sedtion  of  the  mercury 
molecule  or  atom  is  very  nearly  the  same  as  that  of  the 
carbon  dioxide  molecule,  and  is  about  two  and  a  half 
times  as  large  as  that  of  the  hydrogen  molecule. 

These  results  indicate  that  atoms  and  molecules  are  0/ 
the  same  order  of  magnitude,  and  that  the  spaces  between 
the  atoms  within  the  molecule,  if  any  exist,  are  not  large 
in  comparison  with  those  occupied  by  the  atoms  them- 
selves ;  and,  consequently,  the  viscosity  of  gases,  or  any 
other  property  which,  like  it,  is  dependent  only  on  the 
size  or  form  of  the  molecules,  is  not  adapted  for  distin- 
guishing between  monatomic  and  polyatomic  molecules. 

The  mercury  and  carbon  dioxide  molecules  have,  as  we 
have  seen,  the  same  cross-se<5tion,  and  therefore,  assuming 
both  to  be  of  the  same  general  form,  they  occupy  the  same 
volume.  The  mass  of  the  former  is,  however,  4-55  times 
as  great  as  that  of  the  latter.  The  density  of  the  mer- 
cury molecule  is  consequently  greater  in  this  same  pro- 
portion. But  this  difference  is  not  marked  enough  to- 
make  it  necessary  to  attribute  it  to  free  spaces  within  the 
carbon  dioxide  molecule. 


*  In  the  calculation  of  this  quantity,  the  same  mean  value  of  pi 
was  used  in  all  the  experiments  of  each  series,  namely,  760  for  those 
with  the  smaller  capillary,  765  for  those  with  the  larger. 


ON    THE    PURIFICATION     OF    CERIUM. 
By  MM.  WYROUBOFF  and  A.  VERNEUIL. 

In  spite  of  the  large  number  of  researches  on  cerium  and 
its  compounds  there  still  exists  much  uncertainty  with 
regard  to  its  most  characteristic  chemical  properties. 

These  uncertainties  come  from  two  causes — the  absence 
of  any  method  enabling  us  to  easily  obtain  cerium  quite 
free  from  its  accompanying  earths,  and  the  inadequacy  of 
the  methods  used  for  determining  its  atomic  weight. 
These  two  voids  keep  us  in  a  circle  of  errors,  from  which 
we  have  no  escape,  for  we  recognise  the  purity  of  a  body 
by  its  atomic  weight,  and  we  are  fixing  the  atomic  weight 
in  a  product  we  cannot  recognise  as  pure. 

Among  the  numerous  methods  for  the  separation  of 
cerium,  there  are  only  two  that  are  held  in  general  favour 
— the  treatment  by  chlorine  in  the  presence  of  alkalies 
employed  by  Mosander,  and  fusion  with  nitre  proposed 
by  Debray.  Both  have  the  same  fault ;  they  are  not 
based  on  any  precise  reaction,  and  exist  under  the  most 
disadvantageous  conditions  with  regard  to  the  separation 
in  view. 

Cerium  is  distinguished  from  all  similar  metals  by  a 
very  charaderistic  property,  —  the  existence  of  a  very 
stable  higher  oxide,  capable  of  easily  forming  basic  salts 
which  are  generally  insoluble.  It  is  therefore  very  natural 
to  take  advantage  of  this  property  to  isolate  the  metals  of 
its  group,  or  of  neighbouring  groups.  This  is,  in  fadt, 
what  has  been  attempted  by  Mosander  and  Debray;  but 
they  were  not  aware  of  the  existence,  between  the  lower 
oxide,  CeO,*  and  the  higher  oxide,  Ce304,  of  an  inter- 
mediate oxide,  Ce607  =  Ce304,3CeO,  very  stable,  and  also 
giving  insoluble  basic  salts,  depending  in  most  cases  on 
the  oxidation  of  the  CeO  and  the  redudlion  of  the  Ce304. 
This  oxide  becomes  even  more  stable  when  the  cerium  is 
in  the  presence  of  lanthanum  and  didymium,  both  more 
basic  than  itself,  for  it  then  invariably  forms  a  complex 
oxide,  Ce304,3MO,  in  which  M  =  Ce-|-La-HDi  in  propor- 
tions varying  according  to  circumstances.  Now,  in 
Mosander's  method,  even  the  prolonged  adlion  of  chlorine 

*  We  consider  cerium  as  being  bivalent  in  its  lower  oxide,  and  we 
shall  give,  before  long,  the  reasons  which  have  forced  us  to  adopt 
this  old  opinion  of  Berzelius. 


SRBMICAL  Rbws,  I 
June  i8,  1897.      I 


Report  of  Committee  on  A  tomic  Weights. 


293 


will  hardly  bring  about  the  formation  of  this  intermediate 
oxide ;  and  in  Debray's  process,  the  very  first  thing 
caused  by  the  adion  of  heat  is  precisely  its  produdlion. 
It  is  for  this  reason  that,  in  order  to  produce  a  body,  even 
the  purity  of  which  is  never  certain,  it  is  necessary  to 
repeat  the  operation  many  times. 

The  existence  of  the  intermediate  oxide  once  admitted, 
the  problem  of  the  separation  of  cerium  is  much  simpli- 
fied, for  it  is  reduced  to  the  two  following  points : — we 
can  either  prevent  the  formation  of  this  oxide,  or  else  find 
out  under  what  conditions  it  will  separate  into  its  two 
component  parts,  CesO^,  forming  insoluble  basic  salts, 
and  CeO  +  LaO+DiO,  giving  neutral  soluble  salts.  It  is 
this  latter,  and  far  simpler,  solution  of  the  difficulty  that 
we  have  endeavoured  to  find. 

The  oxides  resulting  from  the  moderate  calcination  of 
the  oxalates  are  dissolved  in  warm  nitric  acid.  There 
results  a  partial  redudtion,  a  disengagement  of  oxygen, 
and  the  formation  of  the  intermediate  oxide.  The  solu- 
tion is  evaporated  to  the  consistency  of  a  syrup,  to  drive 
off  the  excess  of  acid.  The  mass  is  then  easily  dissolved 
in  water,  forming  a  limpid  yellowish  solution,  which 
should  be  diluted  to  about  4  per  cent  of  oxide.  If  to  this 
warm  solution  we  add  5  per  cent  of  nitrate  of  ammonia 
the  intermediate  oxide  is  completely  dissociated  ;  the 
whole  of  the  oxide  €630^  is  precipitated  as  a  basic  salt, 
(Ce304)4N205,  and  the  protoxides  remain  in  solution, 
which  takes  the  violet  tint  of  didymium  salts.  The  pre- 
cipitate deposited  is  washed  with  5  per  cent  nitrate  of 
ammonia ;  it  contains  cerium  as  free  from  didymium  and 
lanthanum  as  from  the  yttria  earths.  These  earths  can- 
not be  associated  with  cerium  except  when  the  latter  is  in 
the  state  of  the  oxide  Ce304,3CeO,  and  the  nitrate  of 
ammonia — by  making  the  salt  of  Ce304  insoluble — 
renders  the  existence  of  this  oxide  impossible.  It  is  true 
that  by  this  method  we  only  get  about  75  per  cent  of  the 
cerium  present,  but  there  is  nothing  to  prevent  us  from 
repeating  the  operation  by  precipitating  the  filtrate  by 
oxalic  acid,  calcining  the  oxalates,  and  re-dissolving  in 
nitric  acid. 

In  cases  when  the  mixture  of  oxides  contains  more 
than  50  per  cent  of  cerium,  it  is  no  longer  integrally 
soluble  in  nitric  acid.  It  is  then  necessary  to  dissolve 
the  oxalates  in  nitric  acid,  and  add  peroxide  of  hydrogen 
and  ammonia.  This  is  boiled,  to  transform  the  brown 
peroxide  formed  into  yellow  ceroso-ceric  hydroxide;  this 
hydroxide,  after  washing,  is  dissolved  in  nitric  acid,  and 
the  operation  continued  as  we  have  just  described.  The 
cerium  thus  obtained  is  not  yet,  however,  pure ;  it  con- 
tains all  the  thorina  which  was  present  in  the  mixture  of 
the  oxides. 

We  would  further  remark,  however,  that  the  thorina 
exists  only  in  the  75  per  cent  of  cerium  of  the  first  opera- 
tion.  If  therefore  we  wish  to  obtain,  without  further 
purification,  cerium  completely  free  from  thorina,  it 
suffices  to  repeat  the  operation  on  the  oxides  remaining 
in  solution  after  the  first  precipitation.  In  any  case  it  is 
easy  to  get  rid  of  the  thorina,  by  treating  the  oxalates,  or 
better  still  the  nitrates,  made  as  near  as  possible  neutral, 
by  a  concentrated  solution  of  carbonate  of  ammonia,  to 
which  is  added  a  little  caustic  ammonia.  The  thorina  is 
easily  dissolved,  at  the  same  time  as  a  small  portion  of 
the  other  earths ;  after  two  exhaustions  there  is  not  more 
than  I  per  cent  of  thorina  left.  To  remove  this  last  trace 
we  crystallise  the  sulphate  at  60°  in  a  liquor  entirely  free 
from  free  sulphuric  acid  ;  the  thorina  accumulates  in  the 
mother-liquor,  forming  with  cerium  a  very  soluble  double 
sulphate. 

There  remains  now  nothing  but  to  rid  the  cerium  of 
iron,  which  it  retains  with  great  persistence.  To  do  this 
it  is  necessary  to  precipitate  it  several  times  from  its 
chloride  and  nitrate  solutions,  by  means  of  oxalic  acid, 
in  hot  and  acid  solution  ;  we  can  alto  eliminate  the  sul- 
phate by  dehydration  at  a  high  temperature — 400*  to 
450°  ;  the  iron  then  remains  in  an  insoluble  state. 

Cerium  thus  purified  is  always  identical  in  composition, 


and  its  atomic  weight  does  not  vary,  as  we  shall  show  in 
a  future  note.  Its  oxide,  calcined  at  a  high  temperature, 
is  absolutely  white  when  cold.  All  yellow,  chamois,  or 
rose  tints  indicate  the  presence  of  impurities,  which  can 
always  be  eliminated  by  known  methods  {Laboratoire  de 
Chimie  du  Museum  d'Histolre  Naturelle), 

M.  MoisSAN  added  the  following  remarks  d  propos  of 
the  communication  of  MM.  Wyrouboff  and  Verneuil  ••  On 
the  Preparation  of  Oxide  of  Cerium." 

The  important  researches  of  MM.  Wyrouboff  and 
Verneuil  induce  me  to  mention  the  process  I  adopted  to 
obtain  the  perfedtly  white  oxide  of  cerium,  which  I  used 
in  the  preparation  of  carbide  of  cerium. 

I  started  with  an  oxide  of  cerium  no  longer  giving  an 
absorption  spedtrum  in  a  concentrated  solution.  I  trans- 
formed it  into  carbide  in  the  eledtric  furnace.  By  dis- 
solving this  in  cold  water,  either  pure  or  slightly 
acidulated,  I  obtained  a  complex  mixture  of  carbides  of 
hydrogen,  the  composition  of  which  would  not  remain 
constant  during  the  whole  length  of  the  readtion. 

Three  hundred  grms.  of  this  carbide,  finely  powdered, 
was  then  treated  with  a  solution  of  nitric  acid,  kept  very 
dilute  in  order  to  limit  the  adtion.  The  carbide  remaining 
was  taken  up  in  a  fresh  quantity  of  weak  acid,  but  the 
solution  was  not  allowed  to  be  complete.  The  solution 
obtained  by  this  second  treatment  furnished,  by  simple 
calcination,  absolutely  white  oxide  of  cerium. 

The  iron  was  found  in  the  first  liquid,  and  the  thorina 
in  the  residue  of  unattacked  carbide. 

This  method  of  preparation  gave  me  a  white  oxide  of 
cerium,  while  that  from  the  first  solution  was  of  a  rose- 
colour,  and  that  from  the  residue  of  a  yellowish  green 
tint. — Comptes  Rendus,  vol.  cxxiv..  No.  22,  p.  1230. 


FOURTH    ANNUAL     REPORT    OF    COMMITTEE 

ON    ATOMIC     WEIGHTS. 

RESULTS     PUBLISHED     IN    1896.* 

By  F.  W.  CLARKE. 

(Concluded  from  p.  283). 

Nitrogen, — Among  the  ratios  measured  by  Penny  and  by 
Stas  relative  to  the  atomic  weights  of  nitrogen,  those  con- 
nedting  the  chlorides  and  nitrates  of  potassium  and 
sodium  were  highly  important.  These  are  now  re- 
determined by  Hibbs  (Dodtoral  Dissertation,  University 
of  Pennsylvania,  1896,  by  J.  G.  Hibbs,  yourn.  Am.  Chem.' 
Soc,  xviii.,  1044)  in  a  different  way.  The  nitrates  were 
heated  in  gaseous  hydrochloric  acid,  and  so  converted 
easily  into  chlorides,  with  considerable  accuracy.  The 
data  are  as  follows  with  vacuum  weights,  and  reduced 
with  0  =  16,  K=39'ii,  Na=23*o5,  and  Cl  =  35'45. 


Weight  KNOj. 

Weight  KCl. 

Atomic  wt,  N 

O'liogo 

0*08177 

14*011 

0*14871 

0*10965 

14*010 

o"2io67 

0*15523 

14*013 

o'2336o 

0*17223    . 

14*011 

0*24284 

0*17903 

14*014 

Mean 

..     14*01  lis 

Weight  NaNOj. 

Weight  NaCl. 

Atomic  wt.  N. 

0*01550 

0*Olo66 

14*011 

0*20976 

0*14426 

14*011 

0*26229 

0*18038 

14*014 

0*66645 

0-45829 

14*014 

0*93718 

0*64456 

Mean 

14*008 

..      14*0116 

*  Journal  of  the  American  Chemical-Society,  xix.,  No.  5. 


294 


Report  of  Committee  on  A  tomic  Weights, 


[Chemical  News, 

I      June  l8,  1897. 


These  results  seem  to  be  exceedingly  good,  and  the 
process  has  the  advantage  of  great  simplicity.  The  work 
was  done  under  the  dire(5tion  of  Prof.  E.  F.  Smith. 

Arsenic, — In  the  dissertation  already  cited  Hibbs  gives 
some  determinations  of  the  atomic  weight  of  arsenic. 
Sodium  pyroarsenate  was  heated  in  gaseous  hydrochloric 
acid  and  so  converted  into  chloride.  The  latter  was  per- 
fectly white,  unfused,  and  showed  no  trace  of  arsenic.  I 
subjoin  the  vacuum  weights,  and  the  values  found  for 
arsenic  when  0  =  i6,  Na  =  23-05,  and  01=35*45. 


Cadmium. —  Hardin's  determinations  of  the  atomic 
weight  of  cadmium  resemble  those  which  he  made  upon 
silver.  First,  the  chloride,  in  solution  with  potassium 
cyanide,  was  eledrolysed  in  a  platinum  dish.  The 
weights  in  this  and  the  other  series  are  all  reduced  to  a 
vacuum.  Computations  made  with  01  =  35*45  and  0  =  i6. 
Data  as  follows : — 


Weight  NaiAsjOy. 

Weight  NaCl. 

Atomic  wt.  As 

0'0«i77 

0-01439 

74*904 

0-04713 

0-03 1 15 

74-921 

0*05795 

0*03830 

74-927 

0*40801 

0-26981 

74-901 

0*50466 

033345 

74*916 

0-77538 

0-51249 

74-917 

0*82897 

054791 

74-917 

1-19124 

0-78731 

74*926 

1-67545 

I-10732 

74-928 

3-22637 

2-13267 

74*901 

Mean 


74-9158 


Magnesium. — Atomic  weight  determined  by  Richards 
and  Parker  {Zeit.  Anorg.  Chem.,  xiii.,  81),  who  studied 
the  carefully  purified  chloride.  First,  a  gravimetric  series, 
with  all  weights  reduced  to  a  vacuum. 


Weight  MgCI,. 

1-33550 
I-5160I 

I-32413 
1*40664 
1*25487 

Weight  AgCl. 

4-01952 
4-56369 
3-98528 
4-23297 
3*77670 

Atomic  wt.  Mg 
24-368 
24-350 
24-369 
24-386 
24-373 

Mean 


24*369 


Weight  CdCl,. 

Weight  Cd. 

Atomic  wt.  Cd 

0-43140 

0*26422 

112-054 

0  49 165 

0-30112 

112-052 

0-71752 

0-43942 

112-028 

0-72188 

0-44208 

112*021 

0-77264 

0-47319 

112-036 

0-81224 

049742 

112-023 

0-90022 

0-55135 

II2-04I 

1-02072 

0-62505 

112-002 

1*26322 

0-77365 

1 12-041 

1*52344 

0-93315 

112-078 

Mean     . . 

..      112-038 

Secondly,  the  bromide  was  treated  in  the  same  way. 
The  data  were  reduced  with  Br =79-95. 

Weight  CdBr,. 

0-57745 
0-76412 
0-91835 
1*01460 
1*15074 
1*24751 
I -2595 1 
1*51805 

1-63543 
2*15342 


Weight  Br. 

Atomic  wt.  Cd 

0*23790 

112-031 

0-31484 

112-052 

0-37842 

112-067 

0-41808 

112-068 

0-47414 

112*053 

0-51392 

II2-019 

0-51905 

112-087 

0-62556 

112-076 

0-67378 

I12-034 

0*88722 

112-041 

The  remaining  series  of  experiments  are  of  the  usual 
volumetric  charadlier. 

Second  Series. 

Weight  Ag. 

6-30284 

5-19560 

5-35989 


Mean 


1 12  053 


Weight  MgCU 
2*78284 
2*29360 
2*36579 


Atomic  wt.  Mg. 

24*395 
24-379 
24-366 


Mean 


24-380 


To  this  series  the  authors  attach  less  importance  than 
to  the  others. 

Third  Series. 


Weight  MgCI,. 

Weight  Ag. 

Atomic  wt.  Mg. 

1-99276 

4-51554 

24-349 

1-78870 

4-05256 

24363 

2*12832 

4-82174 

24-268 

2*51483 

5-69714 

24-372 

2*40672 

545294 

24-369 

1-95005 

4*41747 
Mean     . . 

24*377 

..     24-365 

Fourth  Series, 

Weight  MgCIj. 

Weight  Ag. 

Atomic  wt.  Mg 

2-03402 

4-60855 

24-360 

1-91048 

4-32841 

24-364 

2-09932 

4-75635 

24-362 

1*82041 

4-12447 

24*362 

1*92065 

4-35151 

24-363 

1*11172 

2-51876 

24-363 

In  a  third  series  of  experiments  cadmium  was  thrown 
down  simultaneously  with  silver  in  the  same  eledtric  cur- 
rent.    Weights  and  results  as  follows,  with  Ag  =  107-92. 


Weight  Ag. 

0-24335 
0-21262 
0-24515 
0*24331 
0-42520 


Weight  Cd. 

Atomic  wt.  Cd. 

0*12624 

111-928 

O-IIO52 

111-991 

0*12720 

111-952 

0*12616 

iii*gi6 

0*22058 

iri-971 

Mean 


111-952 


Mean  of  all  the  twenty-five  experiments,  Od=  112-027. 

Mercury. — Atomic  weight  also  determined  eledtrolyti- 
cally  by  Hardin,  in  the  same  paper  with  his  work  upon 
silver  and  cadmium.  With  the  oxide  he  obtained  unsatis- 
fa(Story  results ;  but  with  the  chloride,  bromide,  and 
cyanide  he  did  better.  With  the  chloride,  when  01  = 
35 '45,  his  data,  with  vacuum  weights,  are  as  follows : — 


Mean 


24*362 


These  values  are  computed  with  0  =  i6. 
When  0  =  15-88,  Mg  =  24-i79.     The  last  series  out- 
weighs all  the  others. 


Weight  HgCl,. 

Weight  Hg. 

Atomic  wt.  Hg 

0-45932 

0-33912 

200-030 

0-54735 

0-40415 

200-099 

0-56002 

0-41348 

200-053 

0-63586 

0-46941 

199-947 

0-64365 

0-47521 

200-026 

0-73281 

0*54101 

199988 

0*86467 

0-63840 

200-038 

1-06776 

0-78825 

199-946 

1-07945 

0-79685 

199-912 

1-51402 

1-11780 

200-028 

Mean 


200-006 


With  the  bromide,  when  Br=79*95,  Hardin  found  these 
weights  and  values : — 


Chemical  Nbwb,  1 
June  i8, 1897.      1 

Report  of  Committee 

Weight  HBr,. 

Weight  H4. 

Atomic  wt.  Hj. 

070002 

0-38892 

199-898 

0-56430 

0-31350 

199876 

057142 

0-31750 

199-938 

077285 

0-42932 

I99"832 

0-80930 

o'44955 

199-814 

0-85342 

0-47416 

190-911 

I"ii076 

0*61708 

199-869 

i'i7270 

0-65145 

199-840 

1-26186 

0-70107 

199-899 

I -40142 

0-77870 

109-952 

Mean     . 

.      . .      199-883 

With  the  cyanide,  wh 
found — 

en  C  =  i2'0i 

and  N  =  14-04,  Hardin 

Weight  HgC^Na. 

Weight  Hg. 

Atomic  wt.  Hg. 

0-55776 

0-44252 

200-063 

0*63290 

0*50215 

200*092 

0-70652 

0-56053 

200-038 

0-80241 

0*63663 

200-075 

0-65706 

0*52130 

200-057 

0-81678 

0*64805 

200*103 

1-07628 

0-85392 

200-077 

1*22615 

097282 

200-071 

1*66225 

i*3r88o 

200057 

2-II170 

0*67541 

200*077 

295 


Mean 


200*071 


Finally,  Hardin  made  use  of  Faraday's  law,  throwing 
down  mercury  and  silver  simultaneously  in  the  same 
eledlric  current.  The  equivalent  weights  are  as  follows, 
reduced  with  Ag=  107-92  : — 

Weight  Hg. 
0*06126 
0*06190 
0*07814 
0*10361 
0*15201 
0*26806 
0*82808 


Weight  Ag. 

Atomic  wt.  Ag 

0*06610 

200*036 

0*06680 

200-007 

0*08432 

200-02I 

0*11181 

200-011 

0*16402 

200*061 

0-28940 

199*924 

0*89388 

199929 

Mean 


199-996 


The  general  mean  of  all  four  series  is — 
Hg=  199-989. 

Tellurium,— In  all  determinations  hitherto  made  of  the 
atomic  weight  of  tellurium,  the  material  has  been  derived 
from  metallic  tellurides,  Chikashige  {Journ.  Chem.  Soc, 
Ixix.j  881)  now  gives  a  series  of  experiments  upon  tellurium 
obtained  from  Japanese  native  sulphur,  using  Brauner's 
method.  The  tetrabromide  was  titrated  with  solutions  of 
silver,  and  the  following  data  were  obtained.  Computa- 
tions were  made  upon  the  basis  of  0  =  i6. 


Weight  TeBr*. 

Weight  Ag. 

Atomic  wt.  Te 

4-1812 

4*0348 

127*57 

4*3059 

4'1547 

127-61 

4-5929 

4'43H 

127-58 

Mean 


127*587 


TMMg-s^tfw.— Schneider  {yourn.  Prakt.  Chem.,  [2!,  liii., 
288)  objects  to  the  determinations  published  by  Pennington 
and  Smith,  regarding  them  as  too  high.  He  attributes 
their  highness  to  the  fadt  that  very  small  quantities  of 
material  were  handled,  and  thinks  that  there  may  have 
been  mechanical  losses  of  small  particles  during  the  long 
heating  of  the  substance  weighed.  He  now  gives  new 
determinations  of  his  own,  with  tungstic  oxide  carefully 
freed  from  molybdenum,  and  made  partly  by  redudtion  of 
the  oxide,  partly  by  oxidation  of  the  metal.  Results  as 
follows,  with  the  percentage  of  tungsten  in  tungsten  tri- 
oxide  stated  in  a  third  column  : — 


2-0728  grms.  WO3  gave  1-6450  W 


4"o853 
6-1547 
i'5253 
31938 
37468 


W 


W  in  WOg. 
Percent, 

79-323 
79-309 
79-307 


3-2400 

4-8811 

1-9232  WO3    79-311 

4-0273      ..       79-304 

5-9848      „       79-314 


Mean 


..  ..  79-3" 
Hence  with  0  =  i6,  W=  184-007. 
On  the  other  hand,  Shinn  (Dodtoral  Thesis,  University 
of  Pennsylvania,  1896),  working  in  Smith's  laboratory, 
obtains  some  data  corroborative  of  Pennington  and  Smith. 
In  this  series  tungsten  was  oxidised  to  tungsten  trioxide. 
Results  as  follows,  computed  with  0  =  i6: — 

Atomic  weight. 

0-22297  gr™-  W  gave  0-28090  grm.  WO3        184*720 
0*17200        ,,        ,,      0*21664         ,, 
0*10989        „        „      0-13844         „ 
0*10005        „        „      0*12598         „ 


184*964 

184-753 
185*206 


Mean 


184-910 
found 


The  cause  of  the  difference  between  the  values 
and  those  of  Schneider  is  yet  to  be  made  out. 


PROCEEDINGS    OF    SOCIETIES. 

CHEMICAL  SOCIETY. 
Ordinary  Meeting,  jfune  ■^rd,  1897. 

Professor  Dewar,  F.R.S.,  President,  in  the  Chair. 

Messrs.  Thomas  Tickle  and  Thomas  Girtin  were  formally 
admitted  Fellows  of  the  Society. 

Certificates  were  read  for  the  first  time  in  favour  of 
Messrs.  John  Ball,  Ph.D.,  18,  Redshaw  Street,  Derby; 
Alec  Alfred  Beadle,  Beadonwell,  Belvedere,  Kent;  James 
Walter  Horseman,  5,  South  Parade,  Chelsea,  S.W. ; 
Charles  John  Jodrell  Mansford,  B.A.,  Lady  Manners 
Grammar  School,  Bakewell,  Notts. ;  Thomas  Southern, 
jun.,  2,  Cherry  Mount,  The  Cliflf,  Higher  Broughton, 
Manchester;  Francis  Samuel  Young,  M.A.,  Mill  Hill 
School,  N.W. 

Of  the  following  papers  those  marked  *  were  read : — 

*67.  "  On  the  Thermal  Phenomena  attending  the  Change 
of  Rotatory  Power  of  Freshly-prepared  Solutions  of  certain 
Carbohydrates ;  with  some  Remarks  on  the  Cause  of 
Multirotation."  By  Horace  T.  Brown,  F.R.S.,  and 
Spencer  Pickering,  F.R.S. 

During  an  investigation  of  the  thermal  changes 
attending  hydrolysis  under  enzyme  adtion,  whose  results 
are  described  in  the  next  paper,  it  became  necessary  to 
enquire  whether  the  change  in  the  multi-rotation  of  certain 
sugars  is  attended  with  any  heat  disturbance,  as  it  is  now 
well-known  that,  at  any  rate,  dextrose  and  maltose  are 
liberated  by  hydrolysis  in  the  "  birotatory  "  state.  The 
authors  find  that  the  changes  of  rotation  experienced  by 
dextrose,  laevulose,  and  milk-sugar  in  passing  from  the 
optically  unstable  o-  to  the  optically  stable  /3-form,  are 
accompanied  by  distindt  thermal  effedts  which,  although 
taking  place  slowly  in  the  solutions  under  ordinary  condi- 
tions, can  be  produced,  like  optical  stability,  almost 
instantaneously  by  the  addition  of  traces  of  an  alkali.  A 
full  account  is  given  of  the  apparatus  employed,  of  the 
method  of  experiment,  and  the  nature  of  the  corredtions 
to  be  applied.  In  the  cases  of  dextrose  and  milk-sugar, 
there  is  a  liberation  of  heat  accompanying  the  change  of 
rotatory  power ;  with  laevulose  there  is  a  very  decided 
absorption ;  and  with  maltose  no  thermal  disturbance  is 
recognisable.    The  following  are  the  values  obtained : — 


296 


Effect  of  Sea-water  on  Induction  Telegraphy. 


Cheuical  NbWSi 
June  18,  1897. 


Dextrose 
Lsevulose 
Milk-sugar 
Maltose 


Per  grm.  of  sugar.  Per  grm. -molecule. 
-t-o'588cal.  -fioScal. 

-4*64  cal.  -835  cal. 

-l-o'ig  cal.  +  34  cal. 


The  authors  discuss  the  various  explanations  which 
have  been  given  from  time  to  time  to  account  for  multi- 
rotation,  and  consider  that  their  experiments  favour  the 
view  that  it  is  conditioned  by  chemical  rather  than 
physical  causes,  and  that  Fischer  is  probably  corre«a  in 
his  suggestion  that  dextrose,  for  instance,  in  passing  from 
the  optically  unstable  to  the  optically  stable  modification 
in  solution,  passes  from  the  aldehyd,  CgHizOe,  to  the 
heptahydric  alcohol,  C6H14O7.  They  believe,  however, 
that  the  analogy  which  Fischer  suggested,  of  the  change 
of  a  laAone  into  its  acid,  is  less  close  than  that  afforded 
by  the  gradual  change  of  acetic  aldehyd,  in  conta(5t  with 
water,  into  ethylidene  glycol  where  the  CHO  group  be- 
comes CH(H0j2. 

•68.  "  On  the  Thermo-chemistry  of  Carbohydrate 
Hydrolysis.  (I.)  The  Hydrolysis  of  Starch  by  Vegetable 
and  Animal  Diastase.  (II.)  The  Hydrolysis  of  Cane-sugar 
by  Invertase."  By  Horace  T.  Brown,  F.R.S.,  and 
Spencer  Pickering,  F.R.S. 

The  attempts  made  to  determine  the  thermal  effeAs  of 
hydrolysis  have  hitherto  been  confined  to  indiredt  methods, 
based  on  the  heats  of  combustion  of  the  hydrolysable 
substance  and  its  products.  Such  methods,  it  is  shown, 
cannot  give  results  of  any  real  value,  as  the  thermal 
changes  to  be  measured  are  considerably  within  the  ex- 
perimental errors  of  the  combustion  values. 

The  paper  describes  the  results  obtained  by  diredt 
measurement  of  the  heats  of  hydrolysis  of  starch  and  of 
cane-sugar.  Lintner's  soluble  starch  was  for  the  most 
part  used,  as  there  are  certain  mechanical  difficulties  in 
employing  starch  paste  in  the  calorimeter,  owing  to  its 
viscidity.  The  hydrolytic  agents  used  for  starch  were  (i) 
malt-diastase,  (2)  pancreatic  diastase,  (3)  Taka-diastase, 
and  (4)  saliva.  With  malt-diastase,  the  heat  of  hydrolysis 
was  found  to  be  -h2'6o  calories  per  grm.  of  amylin  con- 
verted into  maltose.  The  amount  of  heat  is  proportional 
to  the  water  fixed,  and  is  independent  of  the  molecular 
complexity  of  the  amylin  attacked.  The  breaking  down 
of  the  starch  molecule  prior  to  hydrolysis  does  not  appear 
to  be  attended  with  any  thermal  disturbance. 

With  pancreatic  diastase,  the  heat  liberated  per  grm. 
of  amylin  hydrolysed  amounts  to  -f-i'8  cal.,  a  value 
sensibly  less  than  that  deduced  from  the  adion  of  the 
malt  diastase.  With  Taka-diastase,  the  heat  disturbance 
is  still  less  than  with  the  other  two  agents.  The  possible 
causes  of  these  differences  are  discussed. 

Cane-sugar  was  hydrolysed  with  invertase,  and  was 
found  to  give  a  thermal  effedl  of  -i-ii'2i  cal.  per  grm.  of 
cane-sugar  inverted  when  the  produdts  were  in  the 
optically  stable  /8-form,  and  13  "34  cal.  per  grm.  at  the 
moment  of  liberation  of  the  produdls,  i.e.,  when  they  are 
in  their  •'  birotatory  "  or  optically  unstable  form.  It  is 
the  larger  number  which  corredtly  represents  the  heat  of 
hydrolysis  of  cane-sugar. 

Discussion. 
Mr.  Pickering  made  a  statement  as  to  some  additional 
work  which  had  been  done  in  connedtion  with  the  subjedt 
since  the  paper  had  been  sent  in  to  the  Society.  The 
nature  of  the  change  produced  by  water  on  the  sugars  has 
been  suggested  to  be  the  conversion  of  the  aldehyd  groups 
present  into  aldehydrol  groups,  an  adtion  which  there  is 
every  reason  to  believe  occurs  in  the  case  of  acetic 
aldehyd  itself,  and  experiments  were,  therefore,  made  to 
ascertain  whether  the  adtion  in  the  case  of  aldehyd 
exhibits  the  same  peculiarity  as  in  the  case  of  the  sugars, 
of  being  greatly  accelerated  by  the  addition  of  alkali. 
This  was  found  to  be  the  case,  and  the  analogy  of  the 
two  adtions  is,  therefore,  greatly  strengthened.  In  both 
cases,  also,  the  ammonia  combines  diredtly  with  the  sub- 


stance— the  sugar  or  the  aldehyd — with  evolution  of  heat, 
but  the  results  with  aldehyd  show  that  the  formation  of 
these  compounds  is  not  the  cause  of  the  hydrating  effedt 
of  the  alkali,  for,  although  the  alkali  renders  the  hydra- 
tion instantaneous,  the  formation  of  the  aldehyd  ammonia 
proceeds  gradually,  and  with  the  quantities  used  is  com- 
plete only  after  seven  or  eight  minutes,  the  adtion 
evidently  being  independent  of,  and  posterior  to,  the 
hydration.  The  accelerative  adtion  of  the  alkali  on  the 
hydration  is  probably  due  to  its  increasing  the  number  of 
free  molecules  of  water  present  in  the  liquid,  by  forming 
continually  dissociating  compounds  such  as  NH40H,^ 
NaOH;<:HaO,  &c.,  and  a  free  molecule  of  water  would  be 
a  far  more  adlive  hydrating  agent  than  the  average  water 
aggregate  constituting  the  bulk  of  liquid. 

Mr.  A.  R.  Ling  said  he  was  under  the  impression  that 
Bechamp,  and  subsequently  ToUens,  were  the  first  to 
point  out  that  the  multirotation  of  carbohydrates  was 
correlated  with  thermic  phenomena,  but  neither  had  made 
the  exadt  measurements  now  presented.  He  wished  to 
know  if  the  authors  had  observed  any  change  in  the 
density  of  the  solutions  before  and  after  the  transition 
from  the  abnormal  to  the  normal  rotatory  power. 

Dr.  Kipping  said  that  although  it  seems  to  be  generally 
understood  that  the  phenomenon  of  birotation  is  not  the 
result  of  a  purely  physical  change,  the  assumption  that  it 
is  due  to  the  mere  hydration  of  the  aldehyd  group  might 
be  objedled  to  as  involving  the  apparent  contradidlion  that 
a  very  considerable  change  in  specific  rotation  is  brought 
about,  not  by  increasing  or  diminishing  the  number  of 
asymmetric  carbon  atoms  in  the  molecule,  but  by  merely 
altering  to  a  comparatively  slight  extent  the  asymmetry 
of  the  groups  already  present.  Important  data  in  support 
of  the  chemical  or  hydration  explanation  of  birotation 
were  afforded,  however,  by  some  experiments  made  at  the 
suggestion  of  Emil  Fischer,  as  it  had  been  found  (Jacobi,. 
Ann.,  1892,  cclxxii.,  170)  that  the  rapidity  of  the  fornna- 
tion  of  a  hydrazone  from  a  sugar  which  showed  birotation 
varied  with  the  time  which  had  elapsed  since  the  sugar 
had  been  dissolved. 

Mr.  HeRACE  Brown,  in  reply,  said  that  he  believed  Mr. 
Ling  was  mistaken  in  his  statement  that  Bechamp  or 
Tollens  had  done  anything  to  correlate  multirotation  with 
thermic  phenomena.  So  far  as  he  knew,  the  only  pre- 
vious work  on  this  subjedt  was  that  of  Berthelot,  who  had 
indiredlly  determined,  for  the  solid  state,  the  heats  of 
transformation  of  a-  and  7-dextrose  into  the  j8  form. 

Up  to  the  present  time,  the  authors  had  been  unable  to- 
discover  any  change  of  density  in  solutions  of  multi- 
rotatory  sugars. 

Whilst  fully  admitting  the  force  of  Dr.  Kipping's  ob- 
jedtions,  it  must  be  remembered  that,  so  far  as  our 
knowledge  goes  at  present,  we  are  not  justified  in  denying 
that  comparatively  small  changes  in  the  asymmetry  of 
groups  maybe  attended  with  a  considerable  change  in 
rotatory  power.  The  experiments  of  Jacobi  are  fully 
described  in  the  paper,  and  are  regarded  by  the  authors  as^ 
strongly  confirmatory  of  their  views. 
(To  be  continued). 


PHYSICAL    SOCIETY. 
Ordinary  Meeting,  June  nth,  1897. 

Mr.  Shelford  Bidwell,  President,  in  the  Chair. 

A  mathematical  paper  was  read  by  Mr.  C.  S.  White- 
head, on  "  The  Effect  of  Sea-Water  on  Induction 
Telegraphy." 

If  a  secondary  circuit  containing  a  telephone  is  rightly 
placed  with  respedl  to  the  field  of  a  primary  circuit  tra- 
versed by  an  alternating  current,  signals  may  b»  trans- 
mitted over  considerable  distances.  The  author  investigates 
the  effedt  of  filling  the  intervening  space  with  sea- water;, 
and,  generally,  the  effedl  of  a  spherical  condudling  shell 


Chkmical  News,  | 
June  i8,  iSg^.     i 


New  Definition  of  Focal  Lengthy 


297 


on  the  indu(5lion,  at  a  point  in  a  dieledtric,  due  to  an 
alternating  current  in  a  circular  circuit,  when  the  axis  of 
the  condudlor  passes  through  the  centre  of  the  shell.  In 
the  mathematical  treatment  two  cases  are  considered  : — 
(i)  To  find  the  normal  magnetic  induAion  at  any  point  in 
the  dieledtric  outside  the  shell  when  a  circular  circuit 
carrying  an  alternating  current  is  placed  in  the  dieledtric 
inside  a  spherical  condudling  shell.  (2)  To  find  the  nor- 
mal magnetic  indudion  at  any  point  on  the  remote  side 
of  an  infinite  conducing  plate,  due  to  a  circular  circuit 
parallel  to  the  plate.  In  both  cases  the  following  result  is 
arrived  at : — 

^  =   e-^\  \ 

where  Vo  is  the  maximum  value  of  the  normal  magnetic 
indudtion  at  any  point  outside ;  m,  the  maximum  normal 
magnetic  inducStion  due  to  the  current  in  the  primary, 
supposing  the  condu(5ting  shell  or  plate  absent,  at  the 
same  point  ;  j;  the  thickness  of  the  shell  or  plate  ;  and — 


'=(^) 


on  the  axis,  measured  positively,  ia  the  diredltion  of  the- 
rays.    Then — 

dv 

dm 

is  constant,  and  is  the  focal  length,  /.     If  v^  is  the  value^ 
of  »  when  m=o,  v-Vf^=f.  m. 

Let  M  be  the  position  of  the  other  focus,  and  w,  its 
value  when  »j  =  oo.     Then  m  — w^  = /.  wi-^ ;  and — 


where  yu  is  the  permeability  of  the  conducing  shell  or 
plate  ;  a  its  specific  resistance,  ^  =  27r  times  the  frequency. 
If  the  frequency  is  300,  p  =  xS8s.  For  sea-water,  <r  is 
taken  as  2X1010  0. G.S.  units,  and  /j.  =  i.  The  sea-depth 
at  the  North  Sand  Head  corresponds  to  7j  =  20oo  cm. 
Hence,  in  this  case, —  ■ 


or  79  per  cent  is  lost.  Similarly,  when  »j=iooo,  the  loss 
is  54  per  cent.  The  method  employed  in  the  investigation 
is  that  suggested  by  Lamb  and  Niven ;  the  author  adds 
an  expression  for  n,  the  solid  angle  subtended  by  the  cir- 
cuit at  any  point,  in  terms  of  Bessel's  fundions. 

Mr.  EvERSHED  referred  to  some  experiments  of  his  own, 
from  which  he  concluded  that  the  author's  formula  gave 
too  low  an  estimate  of  the  attenuation  ;  the  discrepancy 
indicated  that  some  term  had  been  negledled. 

Mr.  Yule  doubted  whether  the  equations  given  by  the 
author  were  quite  applicable  to  sea-water.  There  was 
need,  apparently,  of  a  term  involving  the  polarisation  of 
ths  medium. 

Mr.  Heaviside  communicated  a  criticism  of  the  paper. 
It  was  not  necessary  to  investigate  the  problem  for  any 
particular  form  of  circuit  from  which  the  waves  proceed. 
The  attenuating  fadtor  for  plane  waves,  due  to  Maxwell, 
was  sufficient.  Taking  the  best-known  value  for  the  con- 
dudivity  of  sea-water,  there  was  no  reason  why  the 
condudtivity  should  interfere  with  signalling.  A  consider- 
ably greater  condudivity  must  be  proved  for  sea-water 
before  it  could  be  accepted  that  the  failure  of  experiments 
on  telegraphic  communication  with  light-ships  from  the 
sea-bottom  was  due  to  that  fador.  It  was  unlikely  theo- 
retically, and  Mr.  Stevenson  had  contradidted  it  from  a 
pradlical  stand-point.  For  some  reason,  the  account  of 
the  light-ship  experiments  had  not  been  published,  so 
that  there  was  no  means  of  finding  the  real  cause  of 
failure. 

Mr.  T,  H.  Blakesley  read  a  paper  on  "A  New  Defini- 
tion of  Focal  Length,  and  an  Instrument  for  Deter- 
mining i^." 

The  author  asserts  the  principle  that  the  focal  length 
of  a  lens-combination  is  an  abstradt  quantity,  not  neces- 
sarily the  distance  between  two  particular  points.  It  is  a 
quantity  best  defined  in  terms  of  some  fundlion  of  the  two 
distances  of  objedt  and  image  from  their  appropriate  focal 
centres.  Such  a  fundtion  is  the  magnification  fadtor,  m, 
the  linear  ratio  of  image  to  objedt,  positive  if  the  image 
is  eredt  with  regard  to  the  objedt.  Consider  a  particular 
pair  of  conjugate  foci  on  the  axis  of  a  lens-system.  Let 
one  of  these  foci  be  at  distance  v  from  some  fixed  point 


M  —  M, 

The  last  expression,  w*,  may  be  called  the  "areal  mag- 
nification"— it  is  important  in  determining  photographic 
exposure.  The  author  describes  an  optical  bank,  which 
enables — 

dv 
d  m 
to  be  measured  by  a  very  simple  operation  ;  it  gives  also 
a  record,  on  a  paper  strip,  of  the  magnification  fadtor  cor- 
responding to  various    relative   positions  of   objedt   and 
image. 

Dr.  S.  P.  Thompson  said  the  paper  was  the  most  im- 
portant contribution  to  geometrical  optics  that  had 
appeared  for  many  years.  The  introdudtion  of  the  mag- 
nification fundlion  was  a  most  useful  device,  leading  ta 
exceedingly  simple  results.  The  important  thing  to 
measure  was  not  so  much  the  focal  length  as  the  reciprocal 
of  that  quantity. 

Dr.  Chree  said  the  photographic  method  at  present  used 
at  Kew  for  determinations  of  focal  length  gave  greater 
security  than  any  more  diredt  method.  The  colour  of  the 
light  had  to  be  taken  into  account. 

Mr.  Blakesley,  in  replying,  called  attention  to  the  use 
of  his  strip  diagrams  of  magnification,  for  enlarging  pur- 
poses in  photography.  When  the  magnification  along 
some  definite  line  was  known,  the  focussing-cloth  might 
almost  be  dispensed  with. 

Dr.  J.  A.  Fleming  read  a  paper  on  "^  Method  of 
Determining  Magnetic  Hysteresis  Loss  in  Straight  Iron 
Strips:' 

The  author's  process  is  based  upon  the  use  of  the  bifilar 
refledling  Watt-meter.  The  samples  of  iron,  large  or 
small,  in  the  form  of  straight  strips  are  inserted  in  a  long 
solenoid.  The  solenoid  is  traversed  by  an  alternating 
current,  and  the  square-roots  of  the  mean-square  values 
of  the  current  are  determined  by  a  Kelvin  balance.  A 
fiat  bobbin  of  fine  wire  may  be  slided  along  the  strip;  an 
eledtrostatic  voltmeter  connedted  to  the  ends  of  this  ex- 
ploring coil  gives  the  square-roots  of  the  mean-square 
values  of  the  eledtromotive  force  in  that  coil.  From  these 
measurements,  and  the  known  dimensions  of  the  solenoid 
and  coil,  the  indudlion-density,  Bi,  can  be  found  at  any 
point  of  the  length  of  the  strip.  From  these  results  a 
curve  is  drawn,  co-ordinating  the  values  of  B  to  corre 
sponding  distances  along  the  half-length  of  the  strip. 
Assuming  the  hysteresis  loss  per  cycle,  per  c.c.  of  iron,  to 
vary  as  the  i-6th  power  of  the  maximum  indudtion 
density,  and  then  raising  all  the  B  ordinates  to  the  i'6th 
power,  and  plotting  a  new  curve  over  the  first,  another 
curve  is  obtained  which  represents  the  variation  of 
hysteresis  loss  per  c.c.  of  iron  from  point  to  point  along 
the  half-length  of  strip.  Now  at  some  point  along  the 
half-length  of  strip  there  must  be  a  sedtion  where  the  in- 
dudtion density  is  Bj,  such  that  the  true  mean  hysteresis 
loss  for  the  whole  bar  is  proportional  to  Bi*-^.  Let  this 
value  of  the  indudtion  density  be  called  the  "  elective 
value "  and  the  corresponding  point  in  the  strip  the 
*'  effective  point."  Let  M.B^-^  stand  for  the  mean  ordi- 
nate of  the  curve  representing  the  varying  values  of  B^'^ 
all  along  the  half-length.    Then,  evidently,— 


Bi  =  1-6 


7 


M.Bi-6. 


298 


The  Royal  Society  Conversazione, 


Chemical  News, 
June  18,  I897. 


The  following  curious  experimental  result  is  found : — 
Whatever  may  be  the  length  or  sedtion  of  the  iron  strip, 
the  point  at  which  the  adual  indudtion  density  has  a  value 
equal  to  the  "effective"  value  always  comes  at  the  same 
.proportional  distance  from  the  centre  of  the  strip.  This 
distance  is  very  exadtly  equal  to  o'56  of  the  half-length,  as 
measured  from  the  middle,  or  0*22  of  the  whole  length 
from  one  end.  If,  therefore,  the  secondary  coil  is  placed 
at  that  spot,  and  the  secondary  voltage  then  observed  is 
used  to  calculate  the  induftion  density,  the  value  so  ob- 
tained corresponds  to  the  true  mean  value  of  the  varying 
hysteresis  loss  per  c.c.  all  along  the  strip. 

Mr.  Carter  asked  whether  roots  other  than  the  i6th 
gave  a  similar  constant  value  of  the  induftion  density. 

Dr.  Fleming  said  it  seemed  to  be  the  result  of  accident 
that  the  i'6th  root  gave  a  constant  value  for  iron* 

The  President  proposed  a  vote  of  thanks  to  the 
authors,  and  the  meeting  adjourned  until  June  25th. 


THE     ROYAL    SOCIETY. 

The  Conversazione  held  on  Wednesday,  the  16th  inst., 
at  the  Royal  Society's  Rooms,  Burlington  House,  was  in 
every  respedt  a  most  brilliant  and  interesting  gathering. 

Apart  from  the  purely  social  side  of  the  entertainment, 
there  were  a  number  of  exhibits  which  could  not  fail  to 
attradl  attention.  On  entering,  the  eye  was  immediately 
caught  by  Prof.  Rausay's  Argon  and  Helium  Tubes, 
arranged  to  form  the  words  "  Vivat  Vidoria  Regina." 

In  the  Office  upstairs,  some  of  Lord  Kelvin's  Experi- 
ments on  the  Quasi-perpetual  Motion  Adtion,  of  Uranium- 
Zinc  Contadl  were  shown. 

One  of  the  most  striking  exhibits  was  that  of  Dr.  Alex. 
MuiRHEAD,  who  had  an  adtual  working  instrument  re- 
ceiving, by  means  of  a  Kelvin  syphon  recorder,  the 
signals  transmitted  from  a  distant  room  through  the 
surging  crowd,  and  being  recorded  on  the  tape  in  dots 
and  dashes  without  the  help  of  any  intervening  wires. 

Prof.  Roberts-Austen  showed  some  Photographs  and 
Microscopic  Slides  of  Diamonds  separated  from  carburised 
iron,  made,  with  certain  modifications,  according  to  the 
method  described  by  M.  Moissan. 

The  Shadow  Photographs  illustrating  the  absorption 
of  X  rays  by  certain  elements  and  their  compounds,  ex- 
hibited  by  Dr.  J.  H.  Gladstone  and  Mr.  Walter 
HiBBERT,  were  of  peculiar  interest.  The  "  photographs  " 
were  obtained  by  subjedling  various  tubes,  containing 
equal  parts  of  certain  elements,  but  in  different  com- 
pounds, to  the  aftion  of  the  X  rays,  and  it  was  noted  in 
the  case  of  carbon  that  the  absorption  was  the  same 
whether  the  tubes  contained  charcoal,  anthracene,  or 
naphthalene ;  the  different  forms  of  combination  of  the 
carbon  having  no  influence  whatever  on  the  result. 

A  beautiful  example  of  the  work  of  our  almost  pre- 
historic forerunners  was  shown  by  Sir  John  Evans.  It 
consisted  of  a  colledtion  of  flint  knives  and  lance-heads 
from  Egypt,  dating  back  to  4000  B.C.  These  exquisitely 
fluted  blades  have  been  polished  all  over  by  grinding  before 
the  flakes  were  removed ;  the  edges  were  subsequently 
re-touched  and  serrated  with  minute  teeth  at  intervals  of 
about  35  to  the  inch. 

Medals,  struck  in  gold,  silver,  and  bronze,  to  com- 
memorate the  60th  year  of  the  reign  of  Her  Majesty  the 
vQueen,  were  exhibited  by  Mr.  Horace  Seymour,  Deputy 
Master  of  the  Mint.  These  attradled  a  good  deal  of 
attention. 

At  9.45  and  11  o'clock  Demonstrations  of  Signalling 
through  Space  without  Wires  were  given  by  Mr.  W.  H. 
Preece,  C.B.  ;  and  at  10.30  Photographs  illustrating  the 
arrangements  of  the  1896  Eclipse  Expedition  at  Kio  and 
Novaya  Zemlya,  were  exhibited  by  Mr.  J.  Norman 
XocKYER,  C.B.,  in  the  meeting  room  on  the  ground  floor. 


NOTICES  OF  BOOKS. 


Electro-chemical  Problems  for  Practice  and  for  Self- 
instruction.  Colledled  by  Dr.  Felix  Oettel.  With 
20  Woodcuts  in  the  Text.  Halle-on-Saale  :  W.  Knapp. 
1897.     Svo.,  pp.  53. 

An  unusual  degree  of  attention  seems  to  be  at  present 
diredled  to  eledtro-chemistry. 

The  work  before  us  opens  with  generalities  on  the 
necessary  arrangements.  As  a  source  of  current  the 
preference  is  given  to  accumulators  which  may  either  be 
charged  by  means  of  a  small  dynamo  or  from  a  central 
station.  For  eledlro-metallurgical  investigations  a  ten- 
sion of  4  volts  (=  2  accumulators)  is  generally  sufficient. 
For  regulation,  a  crank  regulator  with  15  to  20  contadts 
is  considered  convenient. 

As  measuring  instruments  the  author  recommends  those 
of  Meyer,  form  E,  which  are  accurately  gauged  notwith-. 
standing  their  cheapness  (25  marks),  though  the  Weston 
instruments  (made  apparently  by  a  Berlin  firm)  have 
advantage  of  rapid  adjustment,  but  are  decidedly  more 
expensive  than  the  apparatus  above  mentioned. 

The  eledlro-chemist  is  strongly  advised  to  test  the 
accuracy  of  his  measuring  instruments. 

All  the  instruments  above  mentioned  are  unaffedied  by 
currents  in  their  neighbourhood,  even  by  dynamos  in 
adlion.  But  the  instruments  which  work  with  magnetic 
needles  are  much  less  widely  useful.  They  must  be 
placed  at  least  at  the  distance  of  some  metres  from  other 
circuits. 

A  galvanometer  on  the  system  of  Deprez  d'Arsonval 
is  not  affedted  by  neighbouring  currents,  and  may  be  set 
up  anywhere. 

The  most  important  voltmeters  are  the  copper  volt- 
meter and  the  detonating-gas  instrument.  The  solution 
for  the  former  is  made  up  of  150  grms.  blue  vitriol,  50  grms. 
sulphuric  acid,  50  grms.  alcohol,  and  1000  grms.  water. 
The  liquid  must  be  agitated  during  use. 

The  detonating-gas  voltmeter,  which  is  permanently 
inserted  in  the  circuit,  is  the  most  convenient  instrument 
for  gauging  and  checking  ammeters.  This  apparatus,  as 
usually  construdled,  consists  of  a  stout  glass  cylinder 
with  two  concentric  sheets  of  nickel,  the  internal  one 
serving  always  as  anode. 

In  a  sedion  on  testing  and  guaging  measuring  appli- 
ances, there  is  first  a  comparison  between  the  silver  and 
the  copper  voltmeters,  the  former  of  which  is  universally 
regarded  as  the  most  accurate.  Then  follows  the 
checking  of  the  ammeter  respedtively  with  the  deto- 
nating-gas voltmeter  and  the  copper  voltmeter,  the  com- 
parison of  the  ammeter  with  the  tension  galvanometer, 
the  duplication  of  the  measuring  scope  of  an  ammeter 
by  a  by-connedlion. 

The  gauging  of  a  galvanometer  respedtively  as  ammeter 
and  as  voltmeter  forms  the  subjedi  of  two  short  but 
clearly  written  sedtions. 

We  next  come  to  the  dependence  of  the  tension  of  the 
bath  upon  the  following  fadtors  :  density  of  current  con- 
centration and  temperature  of  the  solution,  and  mutual 
distances  of  the  eledlrodes.  There  is  a  special  discussion 
on  the  influence  of  density  of  current  and  concentration 
upon  the  course  of  eledtro-chemical  readlion. 

Oxidation  is  most  favourable  in  a  concentrated  solution, 
and  with  a  low  density  of  anodic  current. 

Redudion  is  promoted  in  a  concentrated  solution,  but 
with  a  low  kathodic  current. 

Oxidation  is  slightest  in  a  dilute  solution,  and  with  a 
high  density  of  anodic  current. 

The  slightest  redudtion  ensues  in  dilute  solutions,  and 
with  a  high  density  of  current  at  the  kathode. 

In  accounts  on  eledtro-chemical  work  a  statement  of 
the  density  of  the  current  at  each  pole  is  therefore  neces- 
sary. We  quote  this  statement  literally,  as  a  short  time 
ago  it  was  the  subjedl  of  a  discussion. 


Chemical  News,  i 
June  i8,  1897.     ) 


Chemicai  Noticts  jrom  Foreign  Sources. 


299' 


Next  follow  the  oxidation  of  oxalic  acid;  the  eleftro- 
lysis  of  a  mixed  ferrous  and  ferric  solution  ;  the  formation 
of  hypochlorites  and  chlorates ;  and  the  eledlrolysis  of 
hydrochloric  acid  without  a  diaphragm. 

The  last  sedlions  of  the  work  treat  of  the  precipitation 
of  metals  with  soluble  and  insoluble  anodes  ;  the  intro- 
dudtion  of  auxiliary  readions  of  experiments  with  pyro- 
liquid  ele(5lrolytes  ;  the  separation  of  copper  with  bipolar 
eledlrodes  ;  the  elecftrolysis  of  sodium  acetate,  and  other 
organic  eledlrolyses. 

Dr.  Oettel  has  favoured  the  chemical  world  with  a  very 
useful,  compa(5t,  and  well-illustrated  work. 


CORRESPONDENCE. 


ESTIMATION   OF  CARBON  IN  FERRO-CHROME. 

To  the  Editor  of  the  Chemical  News. 
Sir, — I  have  neither  time  nor  inclination  to  follow  Mr. 
R.  L.  Leffler  into  the  details  of  his  letter.  Mr.  LefHer 
stated  that  my  method  gave  only  half  the  carbon  present 
in  ferrochrome:  this  statement  was  inaccurate.  That 
Mr,  Leffler  has  been  putting  up  men  of  straw  to  some- 
what ostentatiously  knock  them  down  again  will  be  seen 
from  Mr.  Saniter's  letter.  As  till  quite  recently  Mr. 
Leffler  was  a  student  of  mine,  it  would  seem  that  the 
diftates  of  common  courtesy  would  have  led  him  to  ask 
personally  for  an  explanation  of  his  low  results  before 
making  the  rash  assertion  in  the  article.  No  amount  of 
ingenuity  of  argument  on  Mr.  Leffler's  part  will  alter  the 
fadl  that  other  students  have  obtained  from  8  to  9  per  cent 
of  carbon  from  ferro-chrome  by  the  method  which  in  his 
hands  failed.— I  am,  &c., 

J.  O.  Arnold. 

The  Technical  Dept.,  University  College, 
Sheffield,  June  12,  1897. 


CHEMICAL  NOTICES  FROM  FOREIGN 
SOURCES. 

Note.— All  degrees  of  temperature  are  Centigrade  unleBBOtherwise 
expressed, 

Comptes  Rendus  Hebdomadaires  des  Seances,  deVAcadetnie 
des  Sciences.     Vol,  cxxiv,,  No.  19,  May  10,  1897. 

The  President  announced  two  severe  losses  which  the 
Academy  has  experienced.  The  illustrious  mineralogist 
M.  des  Cloiseaux,  one  of  the  oldest  members  of  the 
Academy,  is  dead.  He  was  born  in  1817,  and  was  eleded 
a  Member  of  the  Academy  in  1869,  His  principal  re- 
searches were  devoted  to  crystallography  and  to  the  optical 
properties  of  minerals.  The  Due  d'Aumale  was  indiredlly 
one  of  the  vidims  to  the  terrible  catastrophe  of  the  Rue 
Jean  Goujon,  in  which  his  niece,  the  Duchess  d'Alen^on, 
perished.  He  bequeathed  to  the  Institute  his  estate  of 
Chantilly,  formerly  the  residence  of  the  Princes  de  Conde, 
which  he  had  fitted  up  as  a  library  and  museum  of  art. 

Explanation  of  some  Experiments  of  G.  la  Bon's. 
H.  Becquerel. — Already  inserted. 

The  Solutions  of  Acetylene,  and  on  their  Explosive 
Properties. — MM.  Berthelot  and  Vieille. 

Remarks  on  the  Explosive  Decomposition  of  Solu- 
tions of  Acetylene. — MM.  Berthelot  and  Vieille. 

Some  Conditions  of  the  Decomposition  of  Pure 
Acetylene.— MM.  Berthelot  and  Vieille. 

Solubility  of  Liquids. — A.  Aignon. — One  litre  of  the 
ether  examined  can  dissolve  33  c.c.  of  water,  whilst  one 
litre  of  water  can  dissolve  132  c.c.  of  the  same  ether. 

On  Multiple  Resonance, — L,  Deconte. — This  paper 
requires  the  two  accompanying  figures. 


Diurnal  Variation  in  the  Direction  of  the  Wind.— 
Alfred  Angot. — This  memoir  also  necessitates  the  ac- 
companying illustration. 

Basic  Salts  of  Cadmium.— M,  Tassilly.— The  aftion 
of  metallic  oxides  upon  the  corresponding  haloid  salts  has 
yielded  two  novel  cadmium  compounds,  an  oxybromide 
and  an  oxyiodide.  These  bodies  have  been  obtained  by 
heating  to  200°,  in  a  sealed  tube,  a  concentrated  solution 
of  bromide  or  iodide  along  with  cadmium  oxide.  The 
yields  are  exceedingly  small.  The  bodies  obtained  are 
distindly  crystalline,  and  adt  upon  polarised  light.  The 
oxyiodide  gave  on  analysis  the  formula  Cdl2Cd0.3H20. 
It  is  little  adled  on  by  water.  At  120°  it  does  not  vary  in 
weight  either  in  a  current  of  nitrogen  or  of  air  deprived 
of  carbonic  acid  and  watery  vapour.  In  parallel  light  the 
crystals  present  an  extindtion  parallel  to  the  longitudinal 
axis.  In  converging  light  we  observe  a  lemniscate.  The 
crystal  is  bi-refringent  at  axes  widely  remote  from  each 
other.  The  oxybromide  appears  in  very  small  crystals, 
answering  to  the  formula  CdBrjCdO.sHaO,  and  ading 
upon  polarised  light.  In  conclusion  it  is  well  to  observe 
that  the  basic  salts  of  cadmium  are  always  formed  of 
equal  molecules,  contrary  to  what  takes  place  with  the 
salts  of  zinc,  which  are  capable  of  fixing  a  variable 
number  of  mols,  of  oxide  to  form  salts  which  do  not 
answer  to  a  general  type. 

Researches  on  Strontium  Sulphide,  and  a  Method 
of  Rendering  it  Highly  Phosphorescent. — Jose  R. 
Movelo. — After  many  trials  I  had  the  idea  of  modifying 
the  procedure  previously  adopted,  and  I  had  recourse  to  a 
method  by  which  I  obtained  a  strontium  sulphide  pos- 
sessing a  magnificent  phosphorescence  of  a  greenish  blue 
and  so  intense  that,  after  insolation  for  less  than  a  second, 
it  was  perceptible  by  its  shade  without  the  necessity  of 
placing  the  substance  in  the  dark.  I  took  285  grms.  of 
impure  commercial  strontium  carbonate,  62  grms.  flower 
of  sulphur,  4  grms.  crystalline  sodium  carbonate,  2'5  grms. 
sodium  chloride,  and  0-4  grm.  bismuth  subnitrate.  The 
mixture,  finely  powdered,  was  placed  in  an  earthen  cru- 
cible, pressed  down  and  covered  with  a  layer  of  tinder  in 
coarse  powder :  this  stratum  does  not  exceed  2  cm.  in 
depth.  The  crucible,  set  in  a  furnace,  is  heated  to  bright 
redness  by  a  coke  fire  for  five  hours,  and  is  then  allowed 
to  cool  slowly  for  ten  or  twelve  hours.  After  this  we  ex- 
tradl  from  the  crucible  an  agglomerate,  nearly  white, 
granular,  and  friable,  possessing  a  phosphorescent  power 
which  the  diffused  light  of  the  laboratory  is  sufficient  to 
excite  in  the  shade  and  behind  the  windows  of  the  cup- 
board in  which  the  bottle  was  inclosed.  Like  M,  Verneuil 
I  have  observed  that  most  of  the  strontium  sulphides 
which  I  have  prepared  lose  their  phosphorescent  power  if 
powdered,  but  these  pulverised  sulphides,  if  mixed  with 
tinder  and  heated  to  bright  redness  for  five  hours,  resume 
their  phosphorescent  power. 

Thermic  Study  of  Mono-  and  Di-sodic  Acetylenes. 
— Camille  Matignon. — A  thermo-chemical  paper,  suitable 
neither  for  abstradlion  nor  for  insertion  in  full. 

Contribution  to  the  Study  of  the  Preparation  of 
Common  Ether. 

A(5tion  of  Chlorine  Hydrate  upon  Phenylhydrazin- 
diphenylglyoxazol  and  its  Derivatives.. — H.  Causse. 
— The  compounds  here  described  are  trichlorethylidene- 
diphenylhydrazin,  chlorodiphenylglyoxazol,  hydroxydi- 
phenylglyoxazol,  oxydiphenylglyoxazol  antimonite,  and 
the  barium  derivative. 

Intervention  of  Manganese  in  the  Oxidations  in- 
ducsd  by  Laccase. — G.  Bertrand. — Already  inserted. 

No.  20,  May  17,  1897. 
On  the  Catbodic  Rays  and  on  certain  Phenomena 
in  Vacuum  Tubes. — The  tube  used  by  the  authors  wa» 
pear-shaped  ;  the  eledtrodes  terminating  in  two  aluminium 
discs,  one  of  which  was  placed  at  the  narrow  extremity 
of  the  tube,  whilst  the  other  was  placed  in  the  expanded 


300 


Meetings  for  the  Week, 


-part,  the  surfaces  of  the  two  discs  being  respetftively 
perpendicular.  At  the  anti-cathode  there  is  formed  a 
luminous  ring  and  a  central  spot.  If  the  disc  in  the 
narrow  part  serves  as  a  cathode,  the  following  phenomena 
^lave  been  observed : — If  we  touch  with  the  finger  the 
tube  near  the  cathode  disc  we  observe  an  attraction  of 
the  cathodic  rays.  The  glass  under  the  finger  is  rendered 
luminous  and  all  the  cathodic  bundle  is  defleded  towards 
the  hand.  We  observe  at  the  same  time  that  under  the 
anticatliodic  ring  the  phosphorescence  becomes  stronger 
towards  the  finger  and  the  central  spot  undergoes  a 
transformation  from  circular  towards  elliptical,  as  if  sub- 
jecfted  to  pressure.  There  is  in  front  of  the  anode  a 
bluish  light  which,  if  examined  with  the  spedtroscope, 
gives  the  line-spedtrum  of  nitrogen.  If  we  touch  the  tube 
with  the  finger  at  a  point  of  the  expanded  portion,  the 
anodic  light  is  energetically  repelled. 

Transparence  of  Ebonite.  —  M.  Perigot.  —  The 
phenomena  ascribed  to  "  black  light  "are  explained  by 
-the  well-known  fad  of  photographic  inversion. 

Lithium  Borate. — The  composition  of  this  salt  is 
Bo203,LiO,i6H20.  Its  specific  gravity  at  147°  is  i'397. 
Its  crystallisation  in  the  rhombohedric  system  is  distindly 
uniaxial.  Its  heat  of  hydration  is  +43*4031.  Its  solu- 
tion heat  is  —  28'4  cal.  Crystalline  lithium  borate 
ef!loresces  slowly  if  left  in  contadl  with  the  air,  and  at 
the  same  time  absorbs  small  quantities  of  carbonic  acid. 

Alloys  of  the  Silver  and  Copper  Group.— F. 
Osmond. —  M.  Charpy,  on  examining  microscopically 
different  groups  of  alloys,  has  established  that  the  struc- 
ture of  the  eutedlics  recalls  generally  that  of  the  perlite  of 
steels,  and  the  comparison  is  justified  from  all  points  of 
view.  Micrography  confirms  absolutely  the  indications 
of  the  curve  of  fusibility,  and  leaves  no  doubt  concerning 
the  non-existence  of  Ag3Cu2  as  a  definite  compound. 

Researches  on  the  Colouration  of  Glasses  by  the 
Dire<5t  Penetration  of  Metals  or  Metallic  Salts.— 
Leon  Lemal. — The  author  applies  upon  glass  a  salt  of 
silver  and  raises  the  temperature  to  500 — 550°.  The  glass, 
when  cooled  and  freed  by  washing  from  excess  of  salt,  has 
a  yellow  colour.  The  shade  obtained  may  range  from 
straw-colour  to  an  orange-red.  Glasses  thus  coloured 
present  phenomena  of  dichroism  always  yellow  by  trans- 
mitted light,  but  having  by  reflected  light  fluorescent  tints, 
from  yellowish  green  to  violet-blue. 

Adion  of  Water  upon  Phosphoryl  Chloride. — A. 
Besson. — The  limited  action  of  water  upon  POCI3  yields 
the  series  of  produds  P203Cl4,P02Cl  and  PO4H3,  in 
virtue  of  the  readtions  zPOCia-f  H20  =  2HCl-l-P203Cl4. 

Certain  New  Aromatic  Synthetic  Ureas. —  P. 
Cazeneuve  and  M.  Mar. — A  description  of  dipseudo- 
cumyl  urea,  dixyl  urea,  dipara-aminyl  urea.  These 
results  lead  to  the  conclusion  that  all  the  primary  bases 
yielding  with  guiacal  carbonate  corresponding  symmetri- 
cal ureas  are  very  easy  to  obtain. 

Amidised  Amidines. — Charles  Lauth.— The  hydro- 
chlorates  of  these  two  amidines  are  easily  diazotised. 
The  diazoics  obtained  yield,  on  conjugation  with  the 
phenols  and  the  amines,  azo-pigments  which  dye  cotton 
diredly,  in  shades  ranging  from  yellow  to  red  and  black. 
They  resist  well  the  adtion  of  chemical  reagents,  but  they 
are  not  very  fast. 

Role  of  the  Tannins  in  Plants  and  especially  in 
Fruits. — C.  Gerber. — In  fruits  containing  tannins — such 
as  the  kakis,  these  tannins  disappear  by  complete  oxida- 
tion without  giving  rise  to  carbohydrates. 


(Chemical  News, 
1    June  18,  1897. 


Royal  Institution.  —  A  General  Monthly  Meeting  of 
the  Members  of  the  Royal  Institution  was  held  on  the 
14th  inst.,  Sir  James  Crichton-Browne,  M.D.,  F.R.S.. 
Treasurer  and  Vice-President,  presiding.  The  following 
were  eledted  Members: — Dr.  Tempest  Anderson,  M.D. ; 
Mr.  Samuel  Pope,  Q.C. ;  and  Major  Clifford  Probyn. 


MEETINGS    FOR    THE    WEEK. 


Friday,  25th.— Physical,  5 .  "  A  New  Theory  of  the  Earth's  Magnet- 
ism,''by  Mr.  Sutherland.  "  Experiments  in  Critical 
Phenomena,"  by  Dr.  Kuenen.  "Attenuation  of 
Eleftric  Waves  in  Wires,"  by  Dr.  Barton.  '•  The 
Steady  Motion  of  an  EleiStrified  Ellipsoid,"  by  G.  F. 
C.  Searle. 


IMPORTANT    NOTICE. 


Change  of  Address, 

The  Printing  and  Publishing  Offices  of  the 
CHEMICAL  NEWS  have  been 

REMOVED 

From  Boy  Court,  Ludgate  Hill, 

TO 

6  4ir  7;  CREED  LANE;  LUDGATE  HILL, 
LONDON,  E.C, 

"ECLECTIC"  Disintegrator 


THE 
PATENT 


For  Grinding  in   ONE   OPERATION   from 
COARSE  to  the  FINEST  POWDER 
(changed  at  will) 
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VARIED   DESCRIPTION. 
Our  latest  Circular  (sent  on  application)  gives 
over  500  capacities  on  the  most  varied 
materials  (from  A  to  W). 

THEGRINDING  MACHINERYCO. 

16,  MARK  LANE,  LONDON,  E.G. 
Each  Machine         Working  extensively  in  the  United  Kingdom 
complete  with  Patent  and  Abroad. 

Return  Four  of  our  largest  "  Ecledtic  "  Disintegrators 

Air  Chamber.         have  been  supplied  to  H.M.'s  Government. 

Mr.  J.  G.  LORRAIN,  M.I.E.E.,  M.LM.E,  M.S.C.I., 

Fellow  of  the  Chartered  Institute  of  Patent  Agents, 

Norfolk   House,  Norfolk  Street,  London,  W.C. 

"  PATENTEE'S  HANDBOOK  "  Post  Free  on  application. 


ACETONE Answering  all  requirements. 

.A-OIID  JLCIBTIO— Purest  and  sweet. 

BOT?^  A  CTO— Cryst.  and  powder. 

CITE/IEO— Cryst.  made  in  earthenware. 

C3--A.XjXjIC/— From  best  Chinese  galls,  pure. 

S^^XjICSTXjIC— By  Kolbe's  process. 

•X'.A.ilsriEinO— For  Pharmacy  and  the  Arts. 

LIQUID  CHLORINE 

(Compressed  in  steel  cylinders). 

FORMALIN    (W"  CH2O)— Antiseptic  and  Preservative. 

POTASS.  PERMANGANATE— Cryst.,  large  and  small, 

sulphocyanide  of  ammonium. 
—  barium. 

THORIUM,  ZIRCONIUM,  and  CERIUM  SALTS. 

TARTAR    EM  ETI  C-Cryst.  and  Powder. 

PUMICE.     TRIPOLI   AND   METAL  POWDERS. 

ALL  CHEMICALS   FOR  ANALYSIS  AND  THE  ARTS. 

Wholesale  Agents— 

A.  &  M.  ZIMMERMANN, 

9  &  10,  ST.  MARY-AT-HILL,  LONDON,  E.C. 


Chbmical  Nbws,  I 

June  25,  1897.     f 


Diamonds. 


301 


THE    CHEMICAL     NEWS 


Vol.  LXXV.,  No,  1961. 


DIAMONDS.* 
By  WILLIAM  CROOKES,  F.R.S.,  M.R.L 

It  seems  but  the  other  day  I  saw  London  in  a  blaze  of 
illumination  to  celebrate  Her  Majesty's  happy  accession 
to  the  throne.  As  in  a  few  days  the  whole  Empire  will  be 
celebrating  the  Diamond  Jubilee  of  our  Queen,  who  will 
then  have  reigned  over  her  multitudinous  subjedls  for 
sixty  years,  what  more  suitable  topic  can  I  bring  before 
you  than  that  of  Diamonds  !  One  often  hears  the 
question  asked:  "Why  Diamond  Jubilee?"  I  suppose 
it  is  a  symbol  intended  to  give  a  faint  notion  of  the  pure 
brilliancy  and  durability  of  the  Queen's  reign ;  and  in 
thus  associating  Her  Majesty  with  the  precious  Diamond, 
to  convey  an  idea  of  those  noble  qualities  public  and 
private  which  have  earned  for  her  the  love,  fealty  and 
reverence  of  her  subjedts. 

From  the  earliest  times  the  diamond  has  occupied  mens' 
minds.  It  has  been  a  perennial  puzzle — one  of  the  riddles 
of  creation.  The  philosopher  Steffans  is  accredited  with 
the  didtum  that  "  Diamond  is  quartz  which  has  arrived  at 
self-consciousness  ;  "  and  an  eminent  geologist  has  paro- 
died this  metaphysical  definition,  saying  —  "Quartz  is 
diamond  which  has  become  insane  !  " 

Professor  Maskelyne,  in  a  ledure  "  On  Diamonds," 
thirty-seven  years  ago,t  in  this  very  theatre,  said : — 
"  The  diamond  is  a  substance  which  transcends  all  others 
in  certain  properties  to  which  it  is  indebted  for  its  useful- 
ness in  the  arts  and  its  beauty  as  an  ornament.  Thus,  on 
the  one  hand  it  is  the  hardest  substance  found  in  nature 
or  fashioned  by  art.  Its  refledling  power  and  refradive 
energy,  on  the  other  hand,  exceed  those  of  all  other  colour- 
less bodies,  while  it  yields  to  none  in  the  perfedion  of 
its  pellucidity" — but  he  was  constrained  to  add  "The 
formation  of  the  diamond  is  an  unsolved  problem." 

Recently  the  subjedt  has  attraded  many  men  of  science. 
The  development  of  eledlricity,  with  the  introdudtion  of 
the  eledtric  furnace,  has  facilitated  research,  and  I  think  I 
am  justified  in  saying  that  if  the  diamond  problem  is  not 
adtually  solved,  it  is  certainly  no  longer  insoluble. 

In  the  early  part  of  last  year,  accompanied  by  my  wife, 
I  visited  some  of  our  Colonies  in  South  Africa,  and  spent 
a  considerable  time  in  the  neighbourhood  of  the  famous 
Diamond  Mines  of  Kimberley,  where  I  had  an  exception- 
ally good  opportunity  of  studying  the  peculiar  geological 
formation,  and  of  noting  interesting  fadts  connedted  with 
the  occurrence  of  the  precious  stone  which  forms  the 
subjedt  of  this  evening's  ledlure. 

Although  the  experiments  I  wish  to  bring  before  you 
are  chiefly  connedted  with  the  physical  and  chemical 
properties  of  diamonds,  and  of  the  light  that  recent 
researches  throw  upon  their  probable  formation,  it  will 
possibly  adt  as  a  kind  of  compensation  for  the  dryness  of 
some  of  the  theoretical  points  if  with  the  help  of  a  few 
photographs  taken  on  the  spot,  I  bring  before  your  very 
eyes  the  general  charadter  of  the  famous  mines  and  their 
surroundings. 

The  most  famous  diamond  mines  are  Kimberley, 
De  Beers,  Dutoitspan,  Bulfontein,  and  Wesselton.  They 
are  situated  in  latitude  28°  43'  South,  and  longitude 
24°  46'  East.  Kimberley  town  is  4042  feet  above  sea- 
level.  Other  mines  in  the  distridt,  as  yet  unimportant, 
are  worked  for  diamonds.    Kimberley  is  pradtically  in  the 

*  A  Lefture  delivered  at  the  Royal  Institution,  Friday,  June  nth, 
1897. 
t  Chemical  News,  vol.  i.,  p.  208. 


centre  of  the  present  diamond-producing  area.  Besides 
these  mines,  there  are  in  the  Orange  Free  State,  about 
60  miles  from  the  Kimberley  diamond  region,  two  others 
of  some  importance  known  as  Jaggersfontein  and  Coffee- 
fontein. 

River  Washings. 

Before  describing  the  present  mode  of  diamond  ex- 
tradtion  followed  in  the  leading  mines,  I  will  commence 
with  the  so-called  "  River  Washings,"  where,  in  their 
original  simplicity,  can  be  seen  the  methods  of  work  and 
the  simple  machinery  long  since  discarded  in  the  large 
centres.  These  drifts  or  "river-washings"  present  an 
interesting  phase  of  Diamond  industry.  The  work  is 
carried  out  in  the  crude  fashion  of  early  diamond  dis- 
covery, every  man  working  on  his  own  little  claim, 
assisted  by  a  few  natives,  and  employing  primitive  ma- 
chinery.  The  chief  centre  of  the  river  washings  is  at 
Klipdam  No.  2,  about  30  miles  to  the  north-west  of 
Kimberley.  The  road  to  Klipdam  No.  2  involves  ajourneyof 
about  a  dozen  miles  in  one  of  the  old  African  coaches  now 
becoming  obsolete  through  the  spread  of  railways.  Road 
there  is  none— only  a  track  across  the  veldt  made  by 
countless  teams  of  oxen  and  mules. 

Diamonds  from  the  "river  washings"  are  of  all  kinds, 
as  if  every  mine  in  the  neighbourhood  contributed.  The 
samples  are  much  rolled  and  etched,  and  contain  a  fair 
proportion  of  stones  of  very  good  quality,  as  if  only  the 
better  and  larger  stones  had  survived  the  ordeal  of  knocking 
about. 

Diamonds  from  the  drift  fetch  about  40  per  cent  more 
than  those  from  Kimberley :  taking  the  yield  of  the 
Kimberley  and  De  Beers  mines  as  worth,  all  round, 
large  and  Small,  26s.  6d.  a  carat,  the  drift  diamonds  are 
worth  40s. 

Kimberley. 

The  town  of  Kimberley  is  a  remarkable  instance  of 
rapid  growth.  It  has  an  excellent  club  and  one  of  the 
best  public  libraries  in  South  Africa.  Parts  of  the  town, 
affedlionately  called  "the  camp"  by  the  older  inhabitants, 
are  still  in  the  galvanised  iron  or  "  tin  shanty  "  stage,  and 
the  general  appearance  is  unlovely  and  depressing. 
Reunart  reckons  that  over  a  million  trees  have  been  felled 
to  supply  timber  for  the  mines,  and  the  whole  country 
within  a  radius  of  100  miles  has  been  denuded  of  wood 
with  most  injurious  effedts  to  the  climate.  The  extreme 
dryness  of  the  air,  and  the  absence  of  trees  to  break  the 
force  of  the  wind  and  temper  the  heat  of  the  sun,  probably 
account  for  the  dust  storms  so  frequent  in  summer.  The 
temperature  in  the  day  frequently  rises  to  100°  in  the 
shade,  but  in  so  dry  a  climate  this  is  not  unpleasant,  and 
I  felt  less  oppressed  than  I  did  in  London  the  previous 
September.  Moreover,  in  Kimberley,  owing  to  the  high 
altitude,  the  nights  are  always  cool. 

The  Pipes. 

The  five  noted  diamond  mines  are  all  contained  in  a 
circle  3J  miles  in  diameter.  The  mines  are  irregularly- 
shaped  round  or  oval  pipes,  extending  vertically  down- 
wards to  an  unknown  depth,  retaining  about  the  same 
diameter  throughout.  They  are  said  to  be  volcanic  necks, 
filled  from  below  with  a  heterogeneous  mixture  of  frag- 
ments of  the  surrounding  rocks,  and  of  older  rocks  such 
as  granite  mingled  and  cemented  with  a  bluish-coloured 
hard  clayey  mass,  in  which  famous  blue  the  diamonds  are 
hidden. 

The  breccia  filling  the  pipes,  usually  called  "  blue 
ground,"  is  a  coUedtion  of  fragments  of  shale,  eruptive 
rocks,  boulders,  and  crystals  of  many  kinds  of  minerals. 

The  Kimberley  mine  for  the  first  70  or  80  feet  is  filled 
with  what  is  called  "yellow  ground,"  and  below  that 
with  "blue  ground."  This  superposed  yellow  on  blue  is 
common  to  all  the  mines.  The  blue  is  the  unaltered 
ground,  and  owes  its  colour  chiefly  to  the  presence  of 
lower  oxides  of  iron?.  When  atmospheric  influences  have 
access  to  the  iron  it  becomes  peroxidised,  and  the  ground 


302 


Action  of  certain  Substances  on  a  Photographic  Plate. 


Crkuical  News, 
June  25,  1^07. 


assumes  a  yellow  colour.  The  thickness  of  yellow  earth 
in  the  mines  is  therefore  a  measure  of  the  depth  of  pene- 
tration of  air  and  moisture.  The  colour  does  not  affedt 
the  yield  of  diamonds. 

The  diamantiferous  clay  or  blue  ground  shows  no 
signs  of  passing  through  great  heat,  as  the  fragments  in 
the  breccia  are  not  fused  at  the  edges.  The  eruptive 
force  was  probably  steam  or  water-gas,  adting  under  great 
pressure  but  at  no  high  temperature.  According  to  Mr, 
Dunn,  in  the  Kimberley  mine,  at  the  depth  of  120  feet, 
several  small  fresh-water  shells  were  discovered  in  what 
appeared  to  be  undisturbed  material. 

Let  me  cite  a  description  of  a  visit  to  Kimberley  in 
1872,  by  Mr.  Paterson,  taken  from  a  paper  read  to  the 
Geologists'  Associaton,  which  gives  a  graphic  pidlure  of 
the  early  days  of  the  Kimberley  mine: — 

"  The  New  Rush  diggings  (as  the  Kimberley  mine  was 
first  called)  are  all  going  forward  in  an  oval  space  enclosed 
around  by  the  trap  dyke,  of  which  the  larger  diameter  is 
about  1000  feet,  while  the  shorter  is  not  more  than  700 
feet  in  length.  Here  all  the  claims  of  31  feet  square  each 
are  marked  out  with  roadways  about  12  feet  in  vvidth, 
occurring  every  60  feet.  Upon  these  roadways,  beside  a 
short  pole  fixed  into  the  roadway,  sits  the  owner  of  the 
claim  with  watchful  eye  upon  the  Kafir  diggers  below, 
who  fill,  and  hoist  by  means  of  a  pulley  fixed  to  the  pole 
above,  bucketful  after  bucketful  of  the  picked  marl  stuff 
in  which  the  diamonds  occur." 

Soon  came  the  difficulty  how  to  continue  working  the 
host  of  separate  claims  without  infringements.  A  system 
of  rope  haulage  was  then  adopted.  This  mode  of  haulage 
continued  in  vogue  during  the  whole  of  1873,  and  if  the 
appearance  of  the  mine  was  less  piduresque  than  when 
roadways  existed,  it  was  by  moonlight,  particularly,  a 
weird  and  beautiful  sight. 

But  the  mine  was  now  threatened  in  two  other  quarters. 
The  removal  of  the  blue  ground  undermined  the  support 
from  the  walls  of  the  pipe,  and  frequent  falls  of  reef 
occurred,  not  only  burying  valuable  claims,  but  en- 
dangering the  lives  of  workers  below.  Moreover,  as  the 
workings  deepened,  water  made  its  appearance,  necessi- 
tating pumping. 

It  soon  became  evident  that  open  workings  were 
doomed,  and  by  degrees  the  present  system  of  under- 
ground  working  was  devised. 

During  this  time  of  perplexity,  individual  miners  who 
might  have  managed  one  or  two  claims  near  the  surface 
could  not  continue  work  in  the  face  of  harassing  diffi- 
culties and  heavy  expenses.  Thus  the  claims  gradually 
changed  hands  until  the  mine  became  the  property  first 
of  a  comparatively  small  number  of  capitalists,  then  of  a 
smaller  number  of  limited  liability  companies,  until  the 
•whole  of  the  mines  have  pradically  become  the  property 
of  the  "  De  Beers  Consolidated  Mines,  Limited." 

The  areas  of  the  mines  are  : — 

Kimberley 33  acres. 

De  Beers 22     „ 

Dutoitspan 45     „ 

Bulfontein 36     ,, 

The  contents  of  the  several  pipes  are  not  absolutely 
identical.  The  diamonds  from  each  pipe  differ  in  cha- 
radter,  showing  that  the  upflow  was  not  simultaneous 
from  one  large  reservoir  below,  but  was  the  result  of 
several  independent  eruptions.  Even  in  the  same  mine 
there  are  visible  traces  of  more  than  one  eruption. 

The  blue  ground  varies  in  its  yield  of  diamonds  in 
different  mines,  but  is  pretty  constant  in  the  same  mine. 
In  1890,  the  yield  per  load  of  blue  ground  was— 


Underground  Workings. 
In  the  face  of  constant  developments  I  can  only  describe 
the  system  in  use  at  the  time  of  my  visit.  Shafts  are  sunk 
in  the  solid  rock  at  a  sufficient  distance  from  the  pipe  to 
be  safe  against  reef  movements  in  the  open  mine.  Tunnels 
are  driven  from  this  shaft  at  different  levels,  about  120  feet 
apart,  to  cross  the  mine  from  west  to  east.  These  tunnels 
are  conneded  by  two  others  running  north  and  south,  one 
near  the  west  side  of  the  mine  and  one  midway  between 
it  and  the  east  margin  of  the  mine.  From  the  east  and 
west  tunnels  offsets  are  driven  to  the  surrounding  rock. 
When  near  the  rock,  the  offsets  widen  into  galleries,  these 
in  turn  being  sloped  on  the  sides  until  they  meet,  and 
upwards  until  they  break  through  the  blue  ground.  The 
fallen  reef  with  which  the  upper  part  of  the  mine  is  filled- 
sinks  and  partially  fills  the  open  space.  The  workmen 
then  stand  on  the  fallen  reef  and  drill  the  blue  ground 
overhead,  and  as  the  roof  is  blasted  back  the rfe6m  follows. 
When  stoping  between  two  tunnels  the  blue  is  stoped  up 
to  the  debris  about  midway  between  the  two  tunnels.  The 
upper  levels  are  worked  back  in  advance  of  the  lower 
levels,  and  the  works  assume  the  shape  of  irregular 
terraces.  The  main  levels  are  from  90  to  120  feet  apart, 
with  intermediate  levels  every  30  feet.  Hoisting  is  done 
from  only  one  level  at  a  time  through  the  same  shaft.  By 
this  ingenious  method  of  mining  every  portion  of  blue 
ground  is  excavated  and  raised  to  the  surface,  the  rubbish 
on  the  top  gradually  sinking  and  taking  its  place. 

The  scene  below  ground  in  the  labyrinth  of  galleries 
is  bewildering  in  its  complexity,  and  very  unlike  the  popu- 
lar  notion  of  a  diamond  mine.  All  below  is  dirt,  mud, 
grime;  half  naked  men,  black  as  ebony,  muscular  as 
athletes,  dripping  with  perspiration,  are  seen  in  every 
dire<aion,  hammering,  picking,  shovelling,  wheeling  the 
trucks  to  and  fro,  keeping  up  a  weird  chant  which  rises  in 
force  and  rhythm  when  a  titanic  task  calls  for  excessive 
muscular  strain.  The  whole  scene  is  more  suggestive  of 
a  coal  mine  than  a  diamond  mine;  and  all  this  mighty 
organisation,  this  strenuous  expenditure  of  energy,  this 
costly  machinery,  this  ceaseless  toil  of  skilled  and  black 
labour,  goes  on  day  and  night,  just  to  win  a  few  stones - 
wherewith  to  deck  my  lady's  finger. 
(To  be  continued). 


From  the  Kimberley  mine 
,,         De  Beers  mine 
,,         Dutoitspan  mine 
„         Bulfontein  mine 


from  i'25  to  1*5    carats. 
„     1-20  „  1-33 
„     0-17  „p'5    carat. 
.,     05     „o-33       „ 


ON     THE    ACTION     EXERTED     BY 

CERTAIN    METALS   AND   OTHER  SUBSTANCES 

ON  A  PHOTOGRAPHIC   PLATE. 

By  W.  J.  RUSSELL,  Ph.D.,  F.R  S., 
Lefturer  on  Chemistry  at  St.  Bartholomew's  Hospital. 

Having  some  years  ago  prepared  for  the  purpose  of 
spedlroscopic  examination  several  uranium  compounds,  it 
was  of  interest  to  make  further  use  of  them  by  repeating 
some  of  the  very  important  experiments  which  Becquerel 
has  made  with  these  compounds.  He  has  shown  that  if 
the  metal  or  some  of  its  salts  be  placed  on  a  photographic 
plate  in  perfedl  darkness,  and  allowed  to  remain  there  for 
some  days,  the  plate  becomes  adted  on,  the  adion  being 
rendered  evident  by  the  ordinary  photographic  process  of 
development.  This  adtion  is  readily  produced,  and  be- 
longs apparently  to  all  the  salts  of  this  metal,  and,  as 
Becquerel  has  shown,  to  uranous  as  well  as  uranic  salts. 
It  is  very  remarkable  that  this  power  belongs  also  to  the 
salts  when  in  solution,  and,  as  the  adion  passes  through 
glass,  solutions  of  the  double  chloride  or  of  the  nitrate 
contained  in  a  thin  glass  bottle,  when  placed  on  a  photo- 
graphic plate,  ad  readily  upon  it.  While  speakmg  of 
these  compounds  it  may  be  well  to  record  some  experi- 
ments which  have  been  made  to  determine  whether  they 
lost  their  peculiar  adivity  on  being  kept  in  the  dark. 

*  A  Paper  read  before  the  Royal  Society,  June  17,  1897. 


'Chbmical  Nbws,  I 
June  25,  1897.     » 


A  ction  of  certain  Substances  on  a  Photographic  Plate, 


303 


On  the  loth  August  last,  specimens  of  yellow  oxide,  re- 
crystaliised  nitrate,  and  chloride,  the  latter  in  solution, 
were  each  divided  into  two  equal  portions,  and  all  placed 
in  similar  clean  thin  glass  bottles.  One  sample  of  each 
was  then  placed  in  total  darkness,  and  the  other  kept  in 
the  light.  These  samples  have  from  time  to  time  been 
tested  by  placing  them  on  a  photographic  plate  for  a  week 
and  then  developing  the  plate  in  the  usual  manner.  Seven 
such  examinations  have  been  made  at  about  one  month's 
interval.  No  very  marked  difference  between  the  samples 
in  the  light  and  the  dark  has  occurred  ;  on  the  whole  the 
samples  preserved  in  the  dark  have  proved  slightly  the 
most  aAive,  and  this  was  decidedly  the  case  with  all  three 
specimens  at  the  last  examination  on  March  26.  Another 
experiment  was  begun  a  little  later  with  the  black  oxide 
of  uranium,  which  appears  to  be  one  of  the  most  adtive 
of  the  uranium  compounds.  Equal  weights  of  a  sample 
of  this  body  were  placed  in  two  similar  pill-boxes  with  a 
glass  bottom  ;  one  has  been  kept  in  the  dark,  and  the 
other  in  the  light ;  after  five  months  there  was  no  difference 
in  the  effedl  which  they  produced  on  the  photographic 
plate.  The  experiments  are  being  continued.  When  re- 
peating these  different  uranium  experiments  and  using  a 
card  painted  with  the  yellow  oxide,  perforated  zinc  was 
made  use  of  simply  as  a  screen  to  show  the  a<5livity  of  the 
uranium  compound  by  the  density  of  the  pidture  of  the 
pattern  formed;  but  in  place  of  obtaining  in  all  instances 
a  negative  of  the  perforated  zinc,  i.  e.,  the  adion  occurring 
where  the  plate  was  exposed,  and  none  where  covered  by 
the  zinc,  the  reverse  took  place,  and  the  greatest  amount 
of  adion  occurred  underneath  the  zinc.  This  happened 
over  and  over  again,  and  even  when  the  experiment  was 
varied  in  different  ways,  so  that  the  only  explanation  of 
the  adtion  was  that  the  zinc  itself  must  be  able  to  effedt 
a  change  of  the  same  kind  as  the  uranium,  at  all  events, 
to  adl  on  a  photographic  plate;  and  further  experiment 
with  zinc  alone  proved  this  to  be  the  case ;  later  on  it 
became  known  to  me  that  M.  Colson  had  already  described 
this  adtion  of  zinc  in  a  paper  in  the  Comptes  Rendm  in 
January  last,  and  had  also  found  that  similar  results  could 
be  obtained  with  cadmium  and  with  magnesium.  He 
explains  this  remarkable  adlion  as  due  to  vapour  given  off 
by  these  metals. 

Both  before  and  after  seeing  the  account  of  Colson's 
work  a  large  number  of  experiments  have  been  made  with 
zinc  under  different  conditions,  and  there  is  no  doubt  of 
the  ease  and  certainty  with  which  the  results  can  be  ob- 
tained. The  zinc,  as  Colson  states,  must  be  bright ;  if 
well  rubbed  with  coarse  sand-paper  it  is  most  adtive  : 
probably  this  may,  to  some  extent,  arise  from  increase  of 
surface ;  if  cleaned  with  acid  or  with  caustic  alkali  it  is 
not  so  adtive,  and  zinc  in  its  ordinary  condition  after  ex- 
posure to  the  air  ceases  to  be  adtive.  The  salts  also  have 
no  power  of  adting  in  this  way.  A  polished  piece  of  zinc 
laid  on  a  highly  sensitive  photographic  plate  will,  under 
certain  conditions,  even  in  four  or  five  hours,  so  adt  on  it 
that  on  development  a  complete  pidlure  of  the  zinc  is 
produced,  showing  the  scratches  or  any  ruled  lines  or 
faint  pattern  drawn  on  it,  or  if  flaws  in  the  metal  exist 
they  are  clearly  seen.  A  slight  pattern  produced  on  zinc 
by  pressing  on  it  a  piece  of  white  net,  and  then  rubbing 
it  down  with  fine  emery  or  sand-paper,  will  give  a  pidture 
in  which  the  pattern  is  very  evident.  In  fadt,  such  a 
pattern  forms  a  satisfadtory  test  of  this  adtion  of  the  zinc. 
Very  slight  alterations  of  the  surface  are  shown  in  the 
pidture.  Absolute  contadt  of  metal  and  plate  is  not  neces- 
sary. If  screens  of  different  thicknesses  of  any  inadtive 
substance  be  interposed  between  plate  and  metal,  thus 
preventing  contadt,  the  adtion  still  occurs  ;  if  the  screen 
be  very  thin,  a  pidture  of  the  zinc  surface  is  still  obtained, 
but  if  thicker  only  a  dark  cloudy  patch  is  formed.  Still 
further,  if  a  thick  piece  of  glass  tubing  an  inch  long  be 
placed  on  a  photographic  plate,  and  the  upper  end  covered 
with  a  piece  of  polished  zinc,  in  a  week  to  a  fortnight 
distindt  adtion  will  be  found  to  have  taken  place  below  the 
zinc.     Since  the  adtion  then  is  not  one  of  mere  contadt, 


the  next  point  was  to  ascertain  whether  it  would  be 
transmittted  through  different  solid  or  liquid  media. 
Glass,  even  of  the  thinnest  kind,  was  found  to  stop  the 
a(%ion,  but  many  other  substances  allow  of  its  trans- 
mission. For  instance,  the  adtion  takes  place  readily 
through  celluloid,  sheet  gelatin,  gutta-percha  tissue,  col- 
lodion, vegetable  parchment,  real  parchment,  gold-beater's 
skin,  tracing-paper,  and  no  doubt  many  other  bodies. 
With  all  these  bodies  experiments  have  been  made  by 
placing  the  medium  first  in  contadt  with  the  zinc  and  the 
photographic  plate,  then  by  introducing  a  screen  so  as  to 
prevent  the  medium  from  touching  the  zinc,  and  then 
placing  a  second  screen  so  that  neither  zinc  nor  plate 
were  in  contadt  with  the  medium.  The  screens  were 
made  of  different  materials,  most  commonly  of  either 
white  cardboard  or  sheet  indiarubber,  and  of  different 
thicknesses.  The  details  of  each  experiment  need  not  be 
here  described  ;  but  the  general  results  obtained  are  that 
with  thin  sheet  gelatin,  either  red,  green,  or  blue,  when 
laid  on  the  zinc,  the  a(^ion  readily  passes  through,  and  a 
good  clear  pidlure  of  the  surface  of  the  zinc  is  obtained, 
and  even  with  two  sheets  of  gelatin  a  similar  effedt  is 
produced.  With  thick  sheet  gelatin  interposed  the  adtion 
on  the  plate  still  takes  place,  but  of  course  the  exposure 
must  be  longer.  Warm  solutions  of  gelatin  were  painted 
on  polished  zinc  and  allowed  to  harden  ;  the  adtion  took 
place  through  such  layers  as  readily  as  through  the  films. 
With  screens  used  as  before  described  to  prevent  contaft 
the  gelatin  still  allowed  the  adtion  to  take  place  through 
it.  Thin  sheets  of  celluloid,  about  0*28  m.m.  in  thick- 
ness, allowed  the  adtion  to  take  place  through  them,  and 
sheets  o'8i  m.m.  in  thickness  also  allowed  the  adtion  to 
be  transmitted.  Again,  gutta-percha  tissue  was  found  to 
adt  in  the  same  kind  of  way  as  the  gelatin  and  celluloid. 
The  other  media  experimented  with,  although  possibly 
not  so  uniform  and  continuous  in  strudture  as  the  fore- 
going, also  allow  this  adtion  to  be  transmitted  to  them. 

Gold-beater's  skin  and  tracing-paper  both  allow  the 
adtion  readily  to  pass  through,  and  pidtures  of  the 
zinc  are  readily  obtained.  If  either  of  these  bodies  be 
placed  between  a  piece  of  perforated  zinc  and  the  plate, 
the  perforations  are  very  distindtly  shown,  or  if  they  be 
placed  between  a  double  screen  with  corresponding  holes 
cut,  a  pidture  of  the  holes  is  readily  obtained. 

Both  vegetable  and  real  parchment  are  also  transparent 
to  this  adtion,  but  not  so  much  so  as  the  previously-men- 
tioned substances;  the  vegetable  parchment  is  more 
transparent  than  real  parchment.  When  in  contadt  with 
the  zinc,  a  pidture  of  the  zinc  surface  is  obtained,  but  this 
is  somewhat  modified  by  the  substance  of  the  parchment. 

If  different  kinds  of  ordinary  papers,  such  as  writmg 
and  drawing  papers,  be  interposed  between  polished  zinc 
and  a  photographic  plate,  interesting  results  are  obtained, 
for  the  pidtures  formed  show  clearly  the  strudture  of  the 
papers,  and  also  show  that  papers  have  very  different 
powers  of  transmitting  this  adtion.  Certain  writing 
papers  are  quite  opaque  to  the  adtion;  with  others, 
pidtures  of  the  strudture  and  the  water-mark  are  easily 
obtained. 

The  painting  a  paper  with  India  ink  does  not  destroy 
its  transparency.  Obviously  pidtures  of  bodies,  such  as 
skeleton  leaves  or  dried  flowers,  &c.,  are  easily  obtained 
in  this  way. 

A  mere  difference  of  colour  does  not  appear  to  alter 
the  absorptive  power  of  a  medium;  at  least,  this  is  the 
case  with  gelatin.  The  thin  sheets  of  gelatin,  whether 
red,  green,  or  blue,  have  no  difference  in  their  absorptive 
power,  and  when  gelatin,  coloured  with  aniline  dyes,  is 
painted  on  polished  zinc,  the  colour  does  not  affedt  the 
amount  of  adtion  which  takes  place.  The  same  thing 
happens  if  demy  paper  be  painted  with  different  coloured 
solutions  of  gelatin.  With  ordinary  pigments  different 
results  are  obtained,  but  these  results  need  not  be  dis- 
cussed on  the  present  occasion. 

In  addition  to  the  metals  cadmium  and  magnesium, 
mentioned  by  M.  Colson,  there  are  certainly  many  others 


304 


A  ction  of  certain  Substances  on  a  Photographic  Plate, 


f  Chbmical  News, 
\     June  25,  1807. 


which  are  able  to  produce  effe(5ls  similar  to  that  produced 
by  zinc.  There  are  also  certain  alloys  which  can  ad  in 
the  same  way.  The  following  is  a  rough  list  of  adlive 
metallic  bodies  approximately  in  the  order  of  their 
adivity  : — Mercury,  magnesium,  cadmium,  zinc,  nickel, 
aluminium,  pewter,  fusible  metal,  lead,  bismuth,  tin, 
cobalt,  antimony. 

The  above  order,  even  if  not  absolutely  corred,  is 
BufHciently  so  to  indicate  that,  although  mercury  is  the 
most  adive,  the  other  metals  do  not  follow  in  the  order 
of  their  fusibility  or  exadly  according  to  any  obvious 
physical  property,  but  most  nearly  according  to  their 
position  in  the  eledrical  series.  Mercury  is,  then,  at 
ordinary  temperatures  the  most  adive  metal,  and  its 
adion  is  exercised  not  only  when  the  photographic  plate 
is  placed  half  an  inch  or  so  above  the  metal,  but  when 
gelatin,  guttapercha,  tracing-paper,  vegetable  parch- 
ment, are  interposed.  It  appears,  however,  that  the  adion 
of  the  mercury  does  not  take  place  as  readily  through 
gelatin,  but  more  readily  through  gutta-percha  than  is  the 
case  with  zinc. 

Magnesium  is  also  a  very  adive  metal,  and  very  good 
pidures,  showing  every  scratch  on  its  surface,  is  easily 
obtained,  and  also  very  marked  effeds  are  produced  when 
both  single  and  double  screens  are  used.  Cadmium  also 
produces  very  good  pidures,  and  is  rather  more  adive 
than  zinc ;  nickel  and  aluminium  are  not  quite  so  adive, 
but  give  good  pidures  ;  then  follow  lead,  bismuth,  and 
tin.  The  last  metal  is  by  far  the  least  adive.  Only  a 
few  alloys  have  at  present  been  experimented  with  ;  brass 
gives  no  adion,  but  ordinary  pewter,  and  fusible  metal, 
consisting  of  lead,  bismuth,  and  tin,  were  found  to  have 
considerable  adivity,  and  are  placed  in  the  list  between 
aluminium  and  lead.  That  certain  alloys  should  ad  in 
the  same  way  as  the  metals  is  certainly  of  interest,  and 
probably  of  considerable  importance.  The  oxide  and 
sulphate,  both  of  zinc  and  cadmium,  were  found  to  be 
devoid  of  any  power  of  ading  on  the  photographic  plate. 
Iron,  gold,  and  platinum  are  not  adive,  and  copper  only 
very  slightly.  All  the  above  results  are  founded  on 
experiments  in  which  the  exposure  lasted  for  one  week ; 
with  longer  exposure  other  metals  will  probably  produce 
some  adion. 

In  order  to  determine  whether  moisture  was  an  adive 
agent,  either  diredly  by  affeding  the  medium  or  indiredly 
by   affeding  the  photographic  plate,   experiments   were 
made  by  exposing  the  plates  under  bell-jars,  in  which  in 
one  case  there  was  water,  and  in  the  other  sulphuric  acid 
or  calcium  chloride,  and  even  in  these  extreme  cases  no 
appreciable  difference  was  found  to  occur,  and  even  if  the 
membrane  was  purposely  damped  it  did  not  appear  to  aid 
the  adion  except  by  bringing  it  closer  to  the  metal,  so 
that  aqueous  vapour  is  not  apparently  an  adive  agent  in 
producing  these  readions.   In  an  atmosphere  of  hydrogen 
the  adion  takes  place  as  it  does  in  ak.      Carbon  dioxide, 
under  ordinary  conditions,  does  produce  an  effed,  but 
this  probably  arises  from  its  adion  on  the  zinc  plate. 
Alteration  of  temperature,  on  the  other  hand,  produces 
very  marked  effeds  ;  increase  the  temperature,  and  the 
adion  of  the  zinc  is  greatly  increased  ;  for  instance,  two 
similar  plates,  both  wrapped  in  tinfoil  and  the  plates  sepa- 
rated from  the  zinc  by  means  of  a  cardboard  frame.    One 
was  placed  on  a  water-bath  and  exposed  to  a  temperature 
of  about  70°  C,  and  the  other  placed  in  a  vessel  of  ice  at 
0°  C.     After  five  hours  the  one  which  had  been  exposed 
to  the  high  temperature  had  given  a  black  pidure,  while 
the  one  at  the  low  temperature  gave  a  pidure  barely 
visible.   A  similar  experiment  was  also  made  with  nickel, 
and  this  gave,  after  heating  to  about  70°,  a  good  dark 
pidure,  but  the  corresponding  experiment,  when  the  metal 
was  kept  at  0°  for  five  hours,  gave  no  pidure  at  all. 
Aluminium,  when  treated  in  the  same  way,  gave  at  the 
higher  temperature  only  a  faint  pidure,  but  at  the  lower 
temperature,  even  after  two  days,  no  pidure  at  all.     It 
has  already  been  mentioned  that  this  adion  of  the  metals 
cannot  pass  through  even  thin  glass,  nor  can  it  pass 


through  selenite,  nor  |a  layer  of  gum  arable,  nor  one  of 
paraffin.  Glass  being  impervious  to  the  adion,  renders  it 
somewhat  difficult  to  try  satisfadorily  the  adion  exerted 
by  liquids,  but  celluloid  may  be  used  for  this  purpose ; 
also  mercury  may  be  covered  with  a  thin  layer  of  water, 
and  then  its  adion  entirely  ceases.  The  adion  of  certain 
salts  in  the  dry  state  has,  however,  been  tried  by  soaking 
non-glazed  paper  in  different  solutions,  drying  it,  and 
then  placing  it,  either  with  or  without  a  screen,  between 
the  zinc  and  the  photographic  plate.  These  experiments 
have  given  some  interesting  results  ;  for  instance,  paper 
soaked  in  the  following  solutions,  alum,  potassium 
chromate,  zinc  sulphate,  and  quinine  sulphate,  renders 
the  paper  quite  opaque  to  the  adion  of  the  zinc. 

No  doubt  this  adion  of  alum  accounts  for  certain  papers 
not   allowing  the   adion   to  pass  through  them.     Some 
singular  developments  of  this  subjed  have  arisen  from 
experiments  made  while  examining  the  metals.     A  piece 
of  polished  zinc  was  coated  with  copal  varnish  with   the 
objed  of  ascertaining  whether  the  adion  would  take  place 
through  such  a  medium,  and  in  case  it  did,  as  it  was 
thought   at  the   time,  of  demonstrating  that  the  adion 
could  not  arise  from  metal  vapour.     The  experiment  was 
quite  successful ;  the  photographic  plate,  notwithstanding 
the  varnish,  was  strongly  aded  on.     The  experiment  was 
repeated  several  times,  and  always  with  the  same  result ; 
but  the  pidures   seemed  rather   too   good,   darker  than 
those  given  by  the  zinc  alone,  and  on  trying  the  copal  on 
plain    glass    instead    of  on   zinc   it   proved   that   effeds 
apparently  similar  to  those  obtained  with  zinc  were  pro- 
duced.    What   is  known  as  pidure  copal  answers  very 
well  for  these  experiments.      That  prepared  by  Winsor 
and  Newton  has  been  used.     This  is  painted  or  poured  on 
a  clean,  warm  glass  plate,  and  allowed  to   harden  com- 
pletely.    The  plate  can  then  be  used  in  the  same  way  as 
the  zinc  plates.      If  a  photographic  plate  be  laid  on  the 
hardened  varnish  for  two  to  seven  days,  a  pidure  of  the 
varnish,  showing  the  streaks  it  happens  to  have  dried  in, 
is  produced.     If  screens  be  interposed  so  as  to  prevent 
contad  between  the  copal  and  the  plate,  the  adion  still 
occurs,  and,  in  fad,  readily  passes  down  a  tube  i   inch 
long.     Therefore,  as  with  the  zinc,  any  figure  cut  out  in 
an  inadive  screen  is  readily  produced  on  the  photographic 
plate.     Substances  which  are  transparent  or  opaque  to 
the  adion  of  the  metals  seem  to  ad  in  the  same  way  to- 
wards copal.     It  is  rather  more  adive  than  zinc.     Glass 
is  perfedly  impervious  to  its  adion,  but  celluloid,  gutta- 
percha tissue,  and  gelatin  it  permeates  more  readily  than 
zinc  does.     The  adivity  of  the  copal  varies  considerably 
under   different  conditions.      If  gum   be  sprinkled  on  a 
glass  plate  and  then   fused,  it  is  not  so  adive  as  v/hen 
pidure  varnish  is  used.     If  the  solid  gum  be  dissolved  in 
pure  alcohol  and  ether,  and  applied  to  a  glass  plate  as 
before  described,  it  is  far  more  adive  than  after  fusion. 
Heating  it  in  a  water-bath  for  a  considerable  length  of 
time  certainly  deprives  it  of  a  considerable  amount  of  its 
adivity;  but  this  can  be  revived  by  wetting  it  with  ether 
and  allowing  it  again  to  dry  at  ordinary  temperatures.  As 
with  zinc,  increase  of  temperature  increases  its  adivity 
to  a  great  extent.      Experiments   similar  to  those  with 
zinc  were  made  with  copal.     A  coated  glass  was  exposed- 
to  a  heat  of  about  70°,  and  a  similar  one  was  kept  at  0°. 
This  one  after  five  hours  gave  only  a  faint  pidure,  whereas 
the  heated  one  gave  a  dark  pidure,  and  a  considerable 
amount  of  adion  took  place  even  through  the  cardboard 
screen.     Many  other  bodies  of  the  same  nature  as  copal 
ad  in  the  same  way.     This  has  been  proved  to  be  the 
case  with   Damar  and  with   Canada  balsam,  but   copal 
seems  to  be  the  best  representative  of  the  class.     Certain 
gums,  such  as  gum  arable,  gum  Senegal,  have  not  the 
property  of  ading  in  this  way.     There  are,  however,  a 
large  number  of  bodies  which  have  the  power  of  ading  in 
a  manner  similar  to  the  copal ;  one  of  these  is  wood,  and 
it  possesses  a  very  considerable  amount  of  adivity.     Any 
ordinary  smooth  piece  of  wood  laid  on  a  photographic 
plate  will  ad  like  zinc  in  impressing  its  pidure  on  the  plate.. 


Cbbmical  Nbw8,  I 
June  25, 1897.     I 


Action  of  certain  Substances  on  a  Photographic  Plate, 


305 


A  sedlion  of  a  young  larch  tree  gave  a  good  piAure, 
showing  clearly  the  different  rings  and  the  layer  of  bark, 
which  was  the  darkest  part  of  the  pi<fture.  The  same 
sedlion,  when  a  film  of  gelatin  was  interposed  between  it 
and  the  plate,  still  gave  a  good  pidture.  Wood  which  is 
thoroughly  dried  and  hardened  is  also  able  to  adl  in  the 
same  way. 

A  piece  of  mahogany  3*5  m.m.  thick,  which  had  been 
in  this  form  for  at  least  thirty-five  years  and  been  carefully 
preserved  in  a  dark  cupboard,  gave  after  a  week's  expo- 
sure a  good  pi(5ture,  and  the  bottom  of  an  old  cigar-box 
adled  equally  well.  Bodies  such  as  straw,  hay,  bamboo, 
oiled  silk,  and,  no  doubt,  many  others,  aft  in  the  same 
way.  If  wood,  however,  be  painted  with  melted  paraffin, 
it  is  no  longer  adtive.  Ordinary  charcoal  also  depidls 
itself  on  a  photographic  plate,  but  if  it  be  heated  for  some 
hours  in  a  covered  crucible  it  loses  this  property.  An 
ordinary  piece  of  wood,  if  it  be  charred  on  one  side  by 
heating  it  with  a  Bunsen  lamp,  becomes  remarkably 
adlive,  as  shown  by  placing  it  behind  a  screen  with  a 
pattern  cut  out.  The  adtion  passes  readily  through  dif- 
ferent media,  such  as  gelatin,  tracing-paper,  &c.,  vegetable 
parchment,  &c.,  and  the  strudlure  of  the  charcoal  is  shown, 
when  the  adtion  has  taken  place,  even  through  a  sheet  of 
vegetable  parchment.  Coal  and  coke,  sulphur,  sugar,  on 
the  other  hand,  exert  no  adtion  of  this  kind.  When  trying 
whether  a  copy  of  a  lithographic  pidture  could  be  obtained 
by  placing  behind  it  a  plate  of  zinc,  some  curious  results 
occurred.  It  would  seem  that  printer's  ink  in  most  cases 
is  not  capable  of  adling,  like  copal,  on  a  photographic 
plate,  but  that  there  are  many  cases  in  which  it  is  a 
remarkably  adtive  substance.  Specially  so  is  the  ink  used 
in  printing  many  of  the  newspapers.  The  Westminster 
Gazette,  for  instance,  is  printed  with  an  ink  which  very 
readily  adts  on  a  photographic  plate.  A  portion  of  this 
paper  with  printing  on  only  one  side,  laid  with  the  blank 
side  on  the  photographic  plate,  in  a  few  days  gives  a 
remarkably  black  and  distindt  pidture.  If  there  be  printing 
on  both  sides,  then  two  pidlures  are  obtained,  the  darker 
printing  becoming  most  evident  on  whichever  side  it  may 
be.  Interpose  a  sheet,  for  instance,  of  gold-beater's  skin, 
and  still  the  pidture  is  obtained.  The  Standard  and  Daily 
Graphic  are  also  very  adlive,  and  the  Times  only  a  little 
less  so.  The  Evening  News  is  only  slightly  adlive,  and 
the  Morning  Post,  Pall  Mall,  Echo,  and  Daily  News  have 
not  the  property  of  adting  in  this  way  ;  at  least,  those 
copies  experimented  with  had  not.  An  admission  ticket 
to  the  Society  of  Arts  laid  on  a  photographic  plate,  the 
ink  away  from  the  plate,  also  gave  a  very  distindt  pifture. 
Another  singular  case  of  an  adtion  of  this  kind  was  met 
with  when  experimenting  with  the  uranium  salts.  Not 
having  a  sufficient  number  of  small  clear  glass  bottles  for 
a  certain  set  of  experiments,  one  of  the  compounds,  the 
black  oxide,  was  placed  in  a  pill-box,  believing  that  the 
adtion  of  the  uranium  would  take  place  through  the  bottom 
of  the  box,  and  on  developing  the  plate  a  dark  circular 
space  where  it  had  stood  was  visible.  The  experiment 
was  therefore  considered  very  satisfadlory,  and,  with  dif- 
ferent salts  and  for  different  objedls,  it  was  several  times 
repeated.  Ultimately  it  was  forced  ugiffn  one  that  the 
uranium  salts  adted  more  strongly  when  in  pill-boxes  than 
in  any  other  way,  and  on  placing  a  pill-box  without  any 
uranium  salt  in  it  on  a  photographic  plate  it  was  found 
that  adtion  had  occurred,  as  shown  by  the  dark  circular 
space  produced. 

The  experiment  was  repeated  over  and  over  again,  with 
the  result  that  most  pill-boxes  have  the  power  of  adting 
on  a  photographic  plate.  Both  new  and  old  pill-boxes 
from  different  sources  were  experimented  with,  and 
almost  all  of  them  found  to  be  adtive.  There  are,  how- 
ever, exceptions,  and  these,  it  was  noticed,  were  always 
the  more  expensive  and  elaborate  boxes.  On  examining 
the  strudture  of  a  pill-box  it  was  found  that  it  is  usually 
made  of  what  is  known  as  strawboard,  covered  with  a 
thin  white  paper ;  on  separately  testing  these  two 
materials   it  was   apparent  that   the  white  paper  was 


without  adtion  on  the  plate,  and  that  the  strawboard  was 
very  adtive  and  produced  exadtly  similar  effedls  to  those 
produced  by  the  adtive  pill-boxes.  The  inadtive  ones 
proved  to  be  made  of  white  cardboard,  which  is  not  an 
adtive  substance.  Samples  of  strawboard  from  several 
different  sources  have  been  tried,  and  all  found  to  be 
adlive,  and  when  separated  from  the  photographic  plate 
by  means  of  screens,  like  the  copal  and  the  zinc,  it  gives 
a  clear  adtion.  Different  substances  of  a  like  nature 
have  been  tried,  such  as  brown  papers,  &c.  Some  of 
them  are  more  or  less  adtive,  but  none  more  so  than 
common  strawboard.  Mr.  Bevan  was  good  enough  to 
examine  a  piece  of  this  adlive  strawboard,  but  was  unable 
to  find  any  material  other  than  straw  present.  Writing 
paper  and,  as  mentioned  before,  white  cardboard,  have 
not  this  power  of  adling  on  a  photographic  plate,  but 
many  kinds  of  brown  paper  and  no  doubt  many  other 
bodies  have  the  property.  Many  of  the  boxes  in  which 
photographic  plates  are  packed  are  made  of  strawboard, 
but  as  the  adlion  does  not  pass  through  glass,  the  plates 
are  but  little  or  not  at  all  adled  on  ;  but  if  a  plate  be  laid 
face  upwards  in  one  of  these  boxes  and  left  there  for  a 
week,  it  will  be  very  appreciably  affedled.  If  a  small 
piece  of  glass  be  laid  on  the  plate,  it  protedls  the  film 
beneath,  and  shows  clearly  the  amount  of  adlion  which 
has  occurred.  If  a  box  of  this  kind  be  painted  inside 
with  melted  paraffin,  this  adlion  does  not  take  place.  It 
happened  that  a  few  months  before  making  the  above  ex- 
periments others  were  in  progress  in  which  black  net  was 
placed  on  a  photographic  plate  simply  to  show  clearly 
whether  the  plate  had  been  adled  on,  and  continually  a 
reversed  pidlure  was  obtained ;  this  at  the  time  could  not 
be  accounted  for,  but  now  the  experiment  was  made  of 
simply  placing  the  black  net  on  the  photographic  plate 
and  leaving  it  there  for  some  days  ;  then  on  development 
a  clear  pidlure  of  the  net  was  produced.  The  adlion  is 
due  to  some  material  in  the  black  dye,  for  white  net  does 
not  adl  in  the  same  way. 

The  adlion  of  the  vapour  from  a  few  liquids  on  a  sensi- 
tive plate  has  been  tried.  The  plate  was  placed  about 
half  an  inch  above  the  liquid,  and  a  screen,  with  holes 
cut  in  it,  was  fastened  against  the  plate.  Methylated 
spirit  adled  slightly  on  the  plate  ;  pure  alcohol  and  ether 
had  no  adlion  ;  benzene,  coal-tar,  crude  wood  spirit, 
linseed  oil  also,  had  no  adlion,  but  turpentine  and  oil  of 
cloves  produced  a  slight  amount  of  adlion. 

Such,  in  outline,  is  an  account  of  the  experiments 
which  have  already  been  made  on  this  subjedl.  One  point 
has  led  on  to  another,  and  some  of  the  results  were  so 
unexpedled  that  the  experiments  had  to  be  repeated  many 
times  before  full  credence  could  be  given  to  them.  On 
the  present  occasion  it  is  desired  to  do  little  more  than 
record  fadls  ;  further  experiments,  it  is  hoped,  may  lead  to 
explanations  not  now  evident.  The  supposition  that  all 
these  adlive  substances,  the  metals  as  well  as  organic 
bodies,  give  off  a  vapour  capable  of  adling  on  a  photo- 
graphic plate,  naturally  suggests  itself,  and  that  copal 
does  give  off  a  vapour  which  diredlly  or  indiredllyis  adlive 
there  can  be  no  doubt.  At  the  same  time,  it  is  at  least 
difficult  to  suppose  that  the  adlivity  of  such  a  body  as 
strawboard  should,  after  the  treatment  it  has  undergone, 
give  off  at  ordinary  temperatures  sufficient  vapour  to  pro- 
duce the  effedls  described,  and  the  same  applies  to  old  dry 
wood,  &c.  Still  more  interest  attaches  to  the  adlion  of 
the  metals;  do  they  emit  a  vapour  so  delicate  in  constitu- 
tion and  in  such  a  quantity  that  it  can  readily  permeate 
celluloid,  gelatin,  &c.,  and  produce  a  pidlure  of  the  sur- 
face from  whence  it  came,  or  is  it  a  form  of  energy  (pos- 
sibly what  has  been  called  dark  light)  that  these  bodies 
emit  ?  Zinc  kept  and  polished  in  the  dark  loses  none  of 
its  adlivity.  An  experiment  has  been  made  with  the 
objedl  of  refiedling  the  zinc  adlion  from  glass.  This  did 
not  succeed  ;  whether  this  arose  from  the  glass  not  being 
capable  of  effedling  such  a  refledlion,  or  whether  a  fort- 
night was  not  sufficient  time  to  produce  in  this  way  a 
visible  effedl,  is  not  known,  but  the  experiment  is  being 


3o6 


London  Water  Supply ^ 


Chemical  News, 
lune  25, 1897. 


repeated.  A  photographic  plate,  suspended  film  upwards, 
over  a  copal  plate,  was  aded  on  round  the  edges  in  the 
way  one  would  imagine  a  vapour  to  adt.  A  similar  experi- 
ment is  being  made  over  a  zinc  plate.  The  aftion  of 
glass  proves  that  there  is  at  least  a  marked  difference  be- 
tween the  ad^ion  exerted  by  metallic  uranium  and  that 
by  zinc  and  other  metals. 

It  should  be  stated  that  it  is  only  the  most  sensitive 
photographic  plates  which,  without  extremely  long  ex- 
posures, give  the  results  described.  The  Mawson  plate 
has  generally  been  used  in  the  foregoing  experiments,  but 
the  Ilford  special  rapid  plate  adls  equally  well,  and 
Edwards's  ieochromatic  snap-shot  plates  are  particularly 
sensitive  to  the  action  of  the  uranium  salts.  Lumiere's 
extra  rapid  are  not  so  sensitive  as  the  Mawson  and  Ilford 
plates,  and  still  less  sensitive  are  the  same  firm's  plates 
for  yellow  and  green,  and  for  red  and  yellow.  Other 
sensitive  plates  have  not  been  experimented  with. 


ANALYSIS    OF  A   RECENTLY    DISCOVERED 
TOXINE   SPRING. 
By  A.  LIPP. 

The  spring  occurs  at  Seeg,  near  Fiaseen,  in  the  Bavarian 
Algau  district,  and  has  the  local  name  Marienquelle. 
Since  i8gi  it  has  been  successfully  used  for  medicinal 
purposes.  It  is  clear  and  colourless  and  has  a  temper- 
ature of  7°  to  8°  throughout  the  year. 
A  litre  of  the  water  contains : — 

Gran. 

1 0'0i487 

Br       o'oii78 

CI        1*45660 

SiOa 0*00650 

N        0*09140 

CaO 0-16050 

MgO 0*06150 

FejOs         0*00250 

Sodium,  lithium,  aluminium,  and  potassium  sulphates, 
borates,  and  phosphates  occur  in  traces. — Berichte,  xxx., 
p.  309. 


LONDON     WATER    SUPPLY. 

REPORt  ON  THE   COMPOSITION  AND   QUALITY  OF  DaILY 

Samples   of  the  Water  Supplied  to   London 
FOR  the  Month  Ending  May  31ST,  1897. 

By  WILLIAM  CROOKES,  F.R.S., 

and 

PROFESSOR  DEWAR,  F.R.S. 

To  Major-General  A.  De  Courcy  Scott,  R.E., 
Water  Examiner,  Metropolis  Water  Act,  1871. 

Londoo,  June  10th,  1897. 
Sir, — We  submit  herewith,  at  the  request  of  the 
Dire<5tors,  the  results  of  our  analyses  of  the  182  samples 
of  water  colleSed  by  us  during  the  past  month,  at  the 
several  places  and  on  the  several  days  indicated,  from  the 
mains  of  the  London  Water  Companies  taking  their 
supply  from  the  Thames  and  Lea. 

In  Table  I.  we  have  recorded  the  analyses  in  detail  of 
samples,  one  taken  daily,  from  May  ist  to  May  31st 
inclusive.  The  purity  of  the  water,  in  respetft  to  organic 
matter,  has  been  determined  by  the  Oxygen  and  Com- 
bustion processes;  and  the  results  of  our  analyses  by 
these  methods  are  stated  in  Columns  XIV.  to  XVIII. 

We  have  recorded  in  Table  II.  the  tint  of  the  several 
samples  of  water,  as  determined  by  the  colour-meter 
described  in  a  previous  report. 

In  Table  III.  we  have  recorded  the  oxygen  required  to 


oxidise  the  organic  matter  in  all  the  samples  submitted 
to  analysis. 

Of  the  182  samples  examined  all  were  found  to  be  clear, 
bright,  and  well  filtered. 

The  rainfall  at  Oxford  during  the  past  month  was  0*85 
inch  ;  the  average  fall  for  the  past  30  years  is  1*83  inches, 
showing  a  deficiency  of  0*98  inch,  reducing  the  total  ex- 
cess for  the  year  to  1*04  inches  on  an  adlual  fall  of  9*67 
inches.  All  the  rain  this  month  fell  on  the  last  five  days, 
with  the  exception  of  0*12  inch,  which  was  divided  between 
the  4th,  5th,  and  nth. 

The  results  of  our  baderiological  examinations  of  258 
samples  are  recorded  in  the  following  table ;  we  have  also 
examined  69  other  samples  taken  from  special  points 
either  at  the  different  filter  beds,  or  at  stand-pipes  : — 

Microbes 
per  c.C. 

Thames  water,  unfiltered  (mean  of  26  samples)  2937 
Thames  water,  from  the  clear  water  wells  of 
five  Thames-derived  supplies  (mean  of  128 

samples) 40 

Ditto        ditto              highest  233 

Ditto        ditto             lowest  10 

New  River,  unfiltered  (mean  of  26  samples)  . .  388 

New  River,  filtered  (mean  of  26  samples)       . .  44 

River  Lea,  unfiltered  (mean  of  26  samples)    ..  791 
River  Lea,  from   the  clear  water  well  of  the 
East  London  Water  Company  (mean  of  24 

samples)'*' 68 

*  Two  additional  samples  abnormal. 

Instead  of,  as  formerly,  examining  baderiologically  each 
water  supply  once  a  fortnight,  we  are  now  examining 
samples  from  each  water  supply  daily.  This  is  therefore 
a  much  more  severe  test  of  the  adequate  nature  of  the  fil- 
tration from  day  to  day,  and  the  mean  results  of  our  mi- 
crobial estimations  cannot  properly  compare  with  results 
obtained  at  periods  of  a  fortnight  apart.  Further,  the 
samples  we  colledt  from  the  clear  water  wells  of  the  Com- 
panies are  immediately  cooled  to  the  temperature  of 
melting  ice,  and  this  temperature  is  maintained  till  the 
plate  cultivation  is  commenced  not  later  than  five  hours 
afterwards,  and  it  is  continued  at  21°  C,  for  forty-eight 
hours,  when  the  colonies  are  counted.  Such  a  severe 
examination  of  the  process  of  filtration  at  once  enables  us 
to  warn  the  companies  if  any  of  the  filter  beds  are  working 
abnormally,  and  already  we  are  in  a  position  to  say  that 
the  average  badleriological  quality  of  all  the  London  waters 
has  been  greatly  improved  since  the  commencement  of 
this  year. 

We  are.  Sir, 

Your  obedient  Servants, 

William  Crookes. 
James  Dewar. 


PROCEEDINGS    OF    SOCIETIES. 

CHEMICAL  SOCIETY. 
Ordinary  Meeting,  jfune  ^rd,  1897. 

Professor  Dewar,  F.R.S.,  President,  in  the  Chair. 

(Concluded   from  p.  296). 
•69.  "  Optical  Inversion  of  Camphor"      By  Frederick 
Stanley  Kipping,  Ph.D.,  D.Sc,  and  William  Jackson 
Pope. 

It  was  shown  some  time  ago  (Trans.,  1896,  Ixiii.,  548) 
that  two  optically  adlive  isomeric  sulphonic  chlorides  of 
the  composition  CioHisO'SOzCl  could  be  obtained  from 
the  produdt  of  the  adlion  of  anhydrosulphuric  acid  on 
ordinary  <f-camphor;  these  two  compounds  differed  only 
in   optical   and  crystallographic   properties,  and   it   was 


Crbmical  Nhwc,  ) 
June  25,  X897.      ( 


Racemtsm  and  Pseudoracemtsm, 


307 


therefore  concluded  that  they  must  be  regarded  as  optical 
antipodes. 

This  conclusion  has  been  fully  borne  out  by  some 
recent  work,  in  the  course  of  which  the  properties  of  a 
considerable  number  of  inadlive  compounds,  prepared 
from  inadlive  camphorsulphonic  chloride,  have  been  ex- 
amined; it  has  thus  been  proved  beyond  doubt  that  these 
inadive  compounds  are  composed  of  equal  quantities  of 
twoenantiomorphouscamphor derivatives,  and  that,  conse- 
quently, either  before  or  during  sulphonation,  the  original 
d-camphor  must  be  partly  converted  into  its  optical 
antipodes,  ^-camphor. 

In  the  present  paper,  particular  attention  is  drawn  to 
this  interesting  case  of  optical  inversion,  as  the  intra- 
molecular changes  which  take  place  appear  to  be  entirely 
different  from  those  which  occur  in  the  case  of  substances 
which  contain  asymmetric  carbon  atoms  as  constituents 
of  ati  open  chain.  Although  the  constitution  of  camphor 
is  still  a  matter  for  further  investigation,  it  is  now  almost 
universally  admitted  that  the  skeleton  of  this  substance 
consists  of  two  closed  carbon  chains  having  two  or  more 
carbon  atoms  in  common  ;  further,  a  study  of  the  chemi- 
cal and  optical  properties  of  the  various  modifications  of 
camphoric  acid  leads  to  the  conclusion  that  each  of  the 
carboxyl  groups  in  camphoric  acid  is  united  to  an  asym- 
metric carbon  atom  (Aschan,  Acta  Soc.  Scient.,  xxi.,  [5], 
1 — 227).  Admitting  these  two  apparently  well-founded 
assumptions,  the  conversion  of  d-  into  /-camphor  requires 
that  part  of  one  of  the  closed  chains,  for  example,  the 
group  — CH2— CO— ,  should  change  places  with  the  two 
atoms  a  and  b,  as  shown  in  the  following  scheme. 


adlive  r-bromocamphoric  anhydride  forms  large  mono- 
symmetric  crystals,  measurements  of  which  are  given. 

Inactive  txsms-ir-camphanic  acid,  C10H14O4,  is  obtained 
by  the  decomposition  of  the  sodium  salt  of  x-chloro-  or 
T-bromocamphoric  acid.  It  crystallises  from  water  in 
monosymmetric  prisms,  which  contain  one  molecule  of 
water  of  crystallisation,  but  from  ethylic  acetate  it  is 
deposited  in  anhydrous,  monosymmetric,  six-sided  plates  ; 
the  anhydrous  crystals  change  in  crystalline  form  at 
about  130°  and  melt  at  164 — 165°,  namely,  at  the  same 
temperature  as  the  anhydrous  adlive  acid. 

Aiftive  trans-ir-camphanic  acid  {Trans.,  1896,  Ixix.,  929) 
has  been  further  investigated,  and  has  been  found  to 
exist  in  a  number  of  different  crystallographic  modifica- 
tions ;  it  separates  from  cold  water  in  hydrated  prisms, 
very  similar  to  those  of  the  inaiSive  acid  in  all  respefts, 
and  it  is  also  deposited  in  hydrated  monosymmetric 
prisms  from  its  solution  in  ethylic  acetate ;  when  crystal- 
lised from  benzene,  it  affords  either  well-defined  ortho- 
rhombic  needles  which  contain  one  molecule  of  water  of 
crystallisation,  or  a  microcrystalline  powder  of  the  aii- 
hydrous  acid,  according  to  the  conditions  of  the  experi- 
ment. From  a  mixture  of  chloroform  and  light  petroleum, 
it  is  deposited  in  large,  transparent,  anhydrous  ortho- 
rhombic  prisms  which  change  in  crystalline  form  at  100'. 

The  conclusions  to  be  drawn  from  these  and  other  fafts 
bearing  on  the  relation  between  the  adive  and  inaftive 
trans-x-camphanic  acids  are  discussed  in  the  following 
paper. 

Inactive  cis-ie-camphanic  acid,  C10H14O4,  is  the  principal 
produdl  of  the  distillation  of  trans-x-camphanic  acid.     It 


._.-G'- 


^C 


.CO 


,JCH2 


As  this  view  is  based  upon  the  two  assumptions  already 
stated,  the  matter  is  discussed  from  other  standpoints, 
and  it  is  finally  concluded  that  the  changes  which  occur 
in  the  optical  inversion  of  camnhor  are  of  the  nature 
already  suggested. 

•70.  "  Derivatives  of  Camphoric  Acid.  Part  II.  Optically 
Inactive  Derivatives."  By  F.  Stanley  Kipping,  Ph.D., 
D.Sc,  and  William  Jackson  Pope. 

The  optically  inacftive,  externally  compensated  deriva- 
tives of  camphoric  acid  described  in  this  paper  were  pre- 
pared initially  from  ordinary  rf-camphor  by  first  converting 
this  substance  into  the  approximately  inaftive  camphor- 
sulphonic chloride  {Trans.,  1893,  Ixiii.,  547)  or  camphor- 
sulphonic bromide  {Trans.,  1895,  Ixvii.,  354),  from  which 
inadive  ir-chlorocamphor  and  racemic  ir-bromocamphor 
were  then  obtained  by  the  method  previously  employed 
{Trans.,  1895,  Ixvii.,  371). 

Inactive  ir-chlorocamphoric  acid,  CioHi5C104,  prepared 
by  oxidising  inadive  ir-chlorocamphor  with  nitric  acid, 
crystallises  in  flat  plates  or  in  prisms,  and  melts  at  about 
194—195°;  its  anhydride,  C10H13CIO3,  melts  at  193— 
194°. 

Inactive  ir-bromocamphoric  acid,  CioHi5Br04,  obtained 
in  a  similar  manner  from  racemic  ir-bromocamphor,  is  a 
crystalline  powder  melting  at  about  203 — 204°  ;  its  anhy- 
dride, CioHigBrOg,  melts  at  155—156°. 

These  four  externally  compensated  substances  retemble 
the  corresponding  adive  compounds  (Kipping,  Trans., 
1896,  Ixix.,  913  ;  Lapworth  and  Kipping,  Trans.,  1897, 
Ixxi.,  I)  very  closely  in  general  properties,  but  the  inadive 
anhydrides  are  not   easily  obtainable  in   large   crystals. 


crystallises  in  large,  transparent,  hexagonal  plates,  which 
are  indistinguishable  from  those  of  the  corresponding 
adive  acid  {Trans.,  1896,  Ixix.,  943)  except  in  optical 
behaviour ;  the  crystals  of  the  adive  acid  are  circularly 
polarising,  and  all  of  one  kind,  whereas  those  of  the  in- 
adive substance  show  either  right-  or  left-handed  circular 
polarisation.  It  is  thus  possible  to  separate  this  externally 
compensated  cis-ir-camphanic  acid  into  its  d-  and  /- 
isomeric  components. 

Inactive  tTuns-camphotricarboxylic  acid,  CioHi406i  is 
obtained  when  inadive  trans-ir-camphanic  acid  is  oxidised 
with  nitric  acid  ;  it  crystallises  from  water  in  lustrous, 
transparent,  monosymmetric  prisms,  which  differ  from 
those  of  the  adive  acid  {Trans.,  1896,  Ixix.,  951)  deposited 
under  similar  conditions  in  being  anhydrous,  and  conse- 
quently also  in  crystalline  form.  It  melts  at  224 — 225°, 
whereas  the  adive  acid  melts  at  196 — 197°. 

Inactive  Uans-camphotricarboxylic  anhydride,  forms 
transparent  monosymmetric  crystals  which  are  remark- 
ably similar  to  those  of  the  adive  anhydride  ;  it  melts  at 
253 — 254°  whether  heated  alone  or  with  an  approximately 
equal  quantity  of  the  adive  substance 

•71.  *'  Racemism  and  Pseudoracemism."  By  F.  Stanley 
Kipping,  Ph.D.,  D.Sc,  and  William  Jackson  Pope. 

The  data  afforded  by  a  comparison  of  the  physical  and 
crystallographic  properties  of  the  optically  inadive  sub- 
stances described  in  the  preceding  paper  with  those  of  the 
corresponding  adive  compounds  {Trans.,  1896,  Ixix.,  913), 
and  a  number  of  other  fads  colleded  during  the  investi- 
gation of  various  adive  and  inadive  ir-derivatives  of  cam- 
phor, have  led  the  authors  to  the  conclusion  that  the  pre- 


3o8 


Apiin  and  Aptgenin, 


Chbmical  Nbws, 
June  25,  1897. 


sent  classification  of  externally  compensated  substances 
into  (a)  mere  mixtures  and  (b)  racemic  compounds,  re- 
quires modification. 

It  has  been  found  that  optically  inadtive  substances 
which  are  not  mere  mixtures  of  individual  crystals  of 
each  of  the  enantiomorphous  components  are  either  very 
similar  to,  or  extremely  different  from,  their  isomeric 
constituents  in  all  those  properties  more  immediately 
connetfted  with  crystalline  strudlure  ;  no  intermediate 
degree  of  similarity  is,  in  fadt,  observable  in  any  case 
where  these  properties  have  been  thoroughly  examined. 

Such  externally  compensated  substances  fall,  therefore, 
into  two  groups.  Those  which  closely  resemble  the  cor- 
responding active  compounds  are  called  pseudoracemic, 
the  name  racemic  compound  being  reserved  for  those  of 
the  other  group,  of  which  racemic  acid  is  the  classical 
example. 

The  subdivision  of  optically  ina(5tive  compounds  has, 
not  only  an  experimental,  but  also  a  theoretical  basis.  It 
can  be  shown  that,  in  accordance  with  the  present  theory 
of  crystalline  strudture,  optically  adtive  and  racemic  com- 
pounds cannot  assume  the  same  type  of  homogeneous 
crystalline  strufture,  but  that  an  externally  compensated 
substance  may  form  crystalline  individuals  extremely 
similar  to,  but  still  not  identical  with,  those  of  its  adtive 
isomerides ;  in  the  latter  case,  the  crystals  consist  of 
mere  intercalations  of  those  of  the  adlive  modifications, 
and  the  non-identity  is  the  result  of  the  disturbance  set 
up  by  intercalation.  It  is  to  these  substances  that  the 
term  pseudoracemic  is  applied. 

Definitions  of  pseudoracemic  and  of  racemic  compounds 
based  on  these  considerations  are  given,  and  some  of  the 
properties  of  the  two  classes  of  substances  are  then  dis- 
cussed. It  is  pointed  out  that  the  melting  point  of  an 
externally  compensated  substance  does  not  afford  conclu- 
sive evidence  as  to  its  nature  at  ordinary  temperatures, 
inasmuch  as  changes  in  crystalline  form  frequently 
occur  with  a  change  in  temperature,  and  a  mere  mixture 
may  become  a  racemic  compound,  and  vice  versa  before 
the  melting-point  is  reached  ;  numerous  experiments  are 
quoted  in  support  of  this  view.  It  is  also  concluded  that 
solubility  determinations  are  valueless  as  a  means  of 
deciding  between  the  three  classes  of  externally  compen- 
sated substances. 

The  properties  of  a  number  of  inadlive  substances 
described  by  Aschan,  Emil  Fischer,  Liebisch,  Wallach, 
and  others  are  briefly  discussed,  and  reference  is  made  to 
a  recent  paper  by  Walden,  which  deals  with  the  charac- 
teristics of  optically  adtive  and  racemic  compounds. 

Discussion. 

Dr.  Bone  enquired  what  was  the  pradtical  criterion  be- 
tween a  mixture  of  two  optically  adiive  substances  and  a 
racemic  compound  proper,  and  whether  there  is  any  dif- 
ference between  the  readiness  with  which  the  racemic  and 
pseudoracemic  forms  can  be  resolved. 

Dr.  Kipping  said  that,  in  the  majority  of  cases,  it  is 
very  difficult  to  distinguish  between  mixtures  and  racemic 
compounds  except  by  crystallographic  examination,  but 
Liebisch's  rule,  that  the  density  of  a  racemic  compound  is 
different  from  that  of  its  optically  adlive  isomeride,  if 
confirmed  by  further  experimental  data,  might  be  made 
use  of  in  many  cases.  Theoretically  a  racemic  compound 
would  probably  be  resolved  into  its  components  less  readily 
than  a  pseudoracemic  substance,  but  when  using  the 
methods  at  present  known  for  the  separation  of  externally 
compensated  substances,  it  seems  improbable  that  any 
general  difference  in  this  respedt  would  be  noticed. 

♦72.  "  Note  on  some  New  Gold  Salts  of  the  Solanaceous 
Alkaloids:'     By  H.  A.  D.  Jowett,  D.Sc. 

When  hyoscine  hydrobromide  and  auric  chloride  are 
mixed,  either  in  concentrated,  dilute,  neutral,  or  acid 
solution,  a  red  precipitate  is  formed  which  can  be  crystal- 
lised from  a  hot  aqueous  solution  acidulated  with  hydro- 
chloric acid.  On  analysis,  the  salt  is  found  to  be  an 
additive  compound  of  auric  chloride  with  hyoscine  hydro- 


bromide  [B'HBr*AuCl3.  When  this  experiment  is  con- 
dudled  in  the  presence  of  a  large  excess  of  hydrobromic 
acid,  a  chocolate-coloured  precipitate  is  formed  which 
can  be  re-crystallised  from  hot  dilute  hydrobromic  acid 
and  forms  chocolate-coloured  prisms,  which,  on  analysis, 
prove  to  be  the  auribromide  of  the  base  [B'HBr-AuBrsl. 
Even  when  excess  of  hydrochloric  acid  is  present  the  auri- 
chloride  is  not  formed.  The  analogous  compounds  of 
hyoscyamine  and  atropine  were  formed  by  similar  reac- 
tions and  resemble  the  corresponding  salts  of  hyoscine  in 
chemical  and  physical  properties. 

Experiments  were  made  to  determine  whether  the 
bromaurichloride  of  formula  B-HBrAuCls  was  an  iso- 
morphous  mixture  of  aurichloride  and  auribromide,  in 
view  of  the  evidence  adduced  by  Hertz  (jf.  Am.  C.  S„ 
xviii.,  130)  regarding  the  composition  of  the  salt  formed 
by  mixing  solutions  of  platinic  chloride  and  potassium 
bromide  (K2P'Cl4Br2).  It  was  proved,  however,  that  this 
view  could  not  be  adopted  for  the  constitution  of  the  gold 
salt,  which  must  therefore  be  considered  a  true  chemical 
compound. 

*73.  "  Production  of  Camphenol  from  Camphor"  By 
J.  E.  Marsh,  M.A.,  and  J.  A.  Gardner,  M.A. 

The  authors  have  described  {Trans.,  1897,  Ixxi.,  285) 
the  produdlion  of  an  isomeride  of  camphor,  camphenol. 
This  substance  was  obtained  by  the  adlion  of  strong  sul- 
phuric acid  on  chlorocamphene,  CicHijCl.  Camphenol 
is  produced  by  the  adtion  of  the  same  reagent  on  cam- 
phene  dichloride,  CioHigCU,  which  is  the  immediate  pro- 
dudt  of  the  adtion  of  phosphorus  pentachloride  on  cam- 
phor. The  same  camphenol  is  apparently  produced  from 
both  the  isomerides  of  the  formula  CioHigCU,  obtained 
from  ordinary  camphor,  and  a  satisfadtory  yield  is  obtained 
in  both  cases.  The  adtion  of  strong  sulphuric  acid  on 
other  chloro-derivatives  of  terpenes  has  been  examined. 
In  particular,  turpentine  dihydrochloride  behaves  in  a 
manner  very  similar  to  the  camphor  derivative,  but  the 
nature  of  the  produdl  of  the  readtion  has  not  yet  been 
determined. 

•74.  "  Preliminary  Note  on  the  Oxidation  of  Fenchene." 
By  J.  A.  Gardner  and  G.  B.  Cockburn. 

Fenchene  prepered  from  the  fenchone  of  fennel  oil  by  a 
modification  of  Wallach's  method  was  oxidised  on  the 
water-bath  by  moderately  dilute  nitric  acid  (r  part  stroiig 
acid  to  I  part  water).  The  oxidation  was  complete  in 
three  days.  After  distilling  with  steam,  the  acid  liquid 
was  neutralised  with  sodium  carbonate  and  extradted  with 
ether,  to  eliminate  some  insoluble  oily  matter.  The 
alkaline  liquid  was  now  acidified  and  repeatedly  extradted 
with  ether.  On  evaporating  the  ether  a  syrup  was  ob- 
tained which  gradually  crystallised.  The  crystals  were 
purified  from  oily  matter  by  washing  with  chloroform,  and 
after  re-crystallisation  from  water  melted  at  207° ;  they 
proved  to  consist  of  cis-camphopyric  acid.  The  oily  sub- 
stance, separated  by  chloroform,  was  distilled  under 
diminished  pressure.  A  considerable  amount  of  decom- 
position took  place,  and  an  oil  and  a  solid  distilled  over. 
The  solid  was  crystallised  from  alcohol,  and  proved  to  be 
camphopyric  anhydride  (m.  p.  187°). 

The  yield  of  camphopyric  acid  was  about  9 — 10  per  cent 
of  the  fenchene  taken. 

75.  "  Apiin  and  Apigenin."  By  A.  G.  Perkin. 
In  a  preliminary  notice  upon  this  subjedt  (Proc,  1897,. 
xiii.,  53),  some  derivatives  and  decomposition  produdts  of 
apigenin  were  described  ;  these,  together  with  an  account 
of  further  work  upon  this  colouring-matter,  are  included 
in  the  present  paper.  The  formation  of  phloroglucol  and 
parahydroxyacetophenone,  as  the  principal  produdts  of 
the  gentle  adtion  of  alkali  upon  apigenin,  have  been  con- 
firmed, and  it  is  now  shown  that,  at  200°,  protocatechuic 
acid,  parahydroxybenzoic  acid,  and  phloroglucol  are  ob- 
tained  in  the  same  way.  These  results  confirm  those  of 
Gerichten  [Ber.,  1876,  ix.,  1124),  except  as  regards  the 
produdtion  of  parahydroxyacetophenone,  which  is  not 
mentioned  by  him.     On  methylation,  apigenin   forms  a 


ChbmicalNbwb,! 
June  25, 1897.     I 


Solution  and  Precipitation  of  Cyanide  of  Gold. 


309 


dimethyl  ether,  Ci5H803(OCH3)2,  yellow  needles,  m.  p. 
X71 — 172°,  which  furnishes  with  alcoholic  potash  a  potas- 
sium salt,  decomposed  by  water,  and  with  acetic  anhy- 
dride a  monacetyl  derivative,  Ci5H703(OCH3)2C2H30, 
colourless  needles,  m.  p.  195 — 196°.  The  diethyl  ether, 
Ci5H803(OC2H5)2,  yellow  needles,  melts  at  161 — 162°, 
and  its  monacetyl  derivative,  Ci5H703(OC2H5)2C2H30, 
colourless  needles,  at  181 — 182°.  As  previously  shown, 
apigenin  contains  three  hydroxyl  groups,  consequently 
one  is  in  the  ortho-position  to  a  carbonyl  group.  Decom- 
posed with  alcoholic  potash,  the  dimethyl  ether  yields 
anisic  aldehyd,  anisic  acid,  and  a  phloroglucol  derivative, 
ethylparahydroxybenzoic  acid  being  formed  from  the 
diethyl  ether  under  similar  conditions. 

These  results,  with  the  exception  of  the  produ(5lion  of 
protocatechuic  acid  by  means  of  alkali,  point  to  a  close 
relationship  between  apigenin  and  chrysin,  C15H10O4,  the 
colouring-matter  of  poplar  buds,  which  yields  on  decom- 
position phloroglucol,  benzoic  acid,  and  acetophenone.  It 
is  probable  that  apigenin  is  a  hydroxychrysin. 

This  suggested  relationship  is  borne  out  by  the  dyeing 
properties  of  the  two  colouring-matters,  which  show  a 
close  similarity.  The  formation  of  protocatechuic  acid 
from  apigenin  appears  to  be  the  result  of  an  oxidising 
adlion,  for  there  is  no  evidence  of  a  catechol  nucleus  in 
this  substance.  Further  experiments  upon  its  constitution 
are  in  progress. 

In  the  previous  communication  {loc.  cit.)  the  author 
erroneously  assigned  the  discovery  of  the  glucosoidal 
nature  of  apiin  and  the  preparation  of  pure  apigenin  to 
Gerichten,  instead  of  to  Lindenhorn  ("  Inaug.  Diss.," 
Wiirzburg,  1867). 

76.  "Rhatnnazin."  By  A.  G.  Perkin  and  H.  W. 
Martin. 

Rhamnazin  was  isolated  from  Persian  berries  by  one  of 
the  authors  and  J.  Geldard  {Trans.,  1895,  Ixvii,  496),  and 
shown  to  be  a  quercetindimethylether.  The  present  in- 
vestigation was  instituted  to  determine  the  position  of  the 
methoxyl  groups.  On  methylation  it  yielded  quercetin- 
tetramethylether,  and  from  this  result,  and  other  experi- 
ments described  in  the  paper,  it  evidently  contains  no 
methoxyl  group  in  the  phloroglucol  nucleus  in  the  ortho- 
position  relatively  to  the  carbonyl  group.  By  fusion  with 
alkali  at  200°,  rhamnazin  yielded  phloroglucol  and  proto- 
catechuic acid,  and  digestion  with  boiling  alcoholic  potash 
gave  vanillin,  vanillic  acid,  and  a  non-crystalline  phloro- 
glucol derivative.  Oxidised  by  air  in  alkaline  solution, 
vanillic  acid  and  a  similar  phloroglucol  derivative  were 
obtained.  No  free  phloroglucol  resulted  from  either  of 
these  decompositions.  Taking  into  consideration  that 
though  the  dyeing  properties  of  rhamnazin  are  extremely 
feeble,  it  must  still  be  considered  a  colouring-matter, 
these  results  indicate  that  it  has  the  constitution  of  a 
rhamnetinmonomethylether. 

77.  "  Experimental  Verification  of  van 't  Hoff'^s  Constant 
in  Very  Dilute  Solutions."   By  Meyer  Wilderman,  Ph.D. 

In  van  't  Hoff 's  thermodynamic  argument  the  solutions 
are  assumed  to  be  very  diute,  and  the  same  assumption  is 
made  in  the  dedudionsfrom  it  of  Planck,  Riecke,  Lorentz, 
Bolzmann,  and  others.  The  experimental  verification  in 
dilute  solutions  of  van  't  Hoff's  law  is  therefore  especially 
important.  The  freezing-point  method  has  been  worked 
out  with  greater  accuracy  for  the  purpose  of  this  investi- 
gation {Trans.,  1895,  Ixvii.,  i ;  Lewis,  "On  the  Real  and 
Apparent  Freezing-point  and  the  Freezing-point  Methods," 
Proc.  Roy.  Soc,  1896  ;  Zeitsch.  fur  Physik.  Chemie,  1896, 
xix.,  233). 

The  author  has  determined  van  't  Hoff's  constant  in 
dilute  solutions  with  thermometers  graduated  to  i/iooth 
and  i/ioooth  of  a  degree  respedlively,  simultaneously  for 
a  series  of  compounds,  cane-sugar,  alcohol,  urea,  acetone, 
aniline,  phenol,  dextrose,  resorcin,  maltose,  milk-sugar,  at 
converging  temperatures  above  and  below  the  freezing- 
points,  using  different  parts  of  the  scale  of  both  thermo- 
meters.    Small  deviations    only,  from  the    theoretical 


value  of  i'87,  are  found,  due  to  the  different  sources  of 
experimental  error,  van  't  Hoff's  constant  being  thus  con- 
firmed in  dilute  solutions. 

78.  "  The  Isomeric  Dibromethylenes.  By  Thomas 
Gray,  B.Sc. 

This  paper  contains  a  record  of  an  attempt  to  prepare 
the  stereo-isomerideof  symmetrical  dibromethylene.  The 
following  readlions  are  discussed  : — (i)  the  reduAion  of 
tribromethane  by  sodium  ethoxide ;  (2)  the  union  of 
acetylene  with  bromine;  (3)  the  redudion  of  acetylene 
tetrabromide ;  and  (4)  the  addition  of  hydrogen  bromide 
to  bromacetylene. 

By  the  first  of  these  methods  Tawildarow  {Ann.,  1875, 
clxxvi.,  22)  obtained,  in  addition  to  CH2:CBr2,  a  liquid 
boiling  at  157°,  and  having  the  formula  CaH2Br2.  The 
author  confirms  the  observation  of  Michael  (Amer.  Chem. 
jfourn.,  1883,  v.,  192),  and  finds  that  the  only  produd  of 
this  readlion,  under  varying  conditions  of  concentration, 
is  CH2:CBr2,  and  he  attributes  Tawildarow's  observation 
to  the  formation  of  bromacetyl  bromide  by  oxidation 
during  the  process  of  distillation. 

The  produdl  of  three  other  readlions  is  shown  to  be  in 
every  case  the  same  symmetrical  dibromethylene — 

(CHBr:CHBr), 
boiling  at  110°.    The  author  considers  that  the  formation 
of  this  substance  by  the  fourth  method,  and  the  probable 
instability  of  the  cis-modification,   which   should   result 
from  the  second  readtion,  point  to  the  formula — 

H-C-Br 

Br-C-H 
as  representing  the  struifture  of  the  symmetrical  dibrom- 
ethylene  at  present  known. 


SOCIETE  D'ENCOURAGEMENT  POUR  L'INDUS- 

TRIE   NATIONALE. 

May  14,  1897. 

President,  M.  Mascart. 

"Art  Bronze  Castings.^'  By  M.  Maglin.  By  using  a 
mixture  of  gelatin,  glycerin,  and  glucose,  M.  Maglin  is 
able  to  make  a  complete  mould  of  a  statue  in  two  pieces, 
owing  to  the  flexibility  of  this  substance,  Perfedt  castings 
can  be  reproduced  giving  all  the  minute  detail  of  the 
original. 

M.  EuiLio  Damour  presented  to  the  Society  a  labora- 
tory form  of  regenerative  furnace  enabling  temperatures 
of  1300°  and  1400°  C.  to  be  attained.  The  furnace  burns 
gas,  and  is  made  to  heat  mufHes  as  large  as  35  cm.  x 
14  cm.   X  10  cm.  up  to  this  high  point. 


May  28,  1897. 

This  meeting  was  also  held  under  the  presidency  of  M. 
Mascart. 

The  thanks  of  the  Society  were  given  to  the  various 
donors  of  books. 

M.  Joly  was  nominated  a  member  of  the  Council. 

A  paper,  accompanied  by  numerous  experiments,  was 
read  by  M.  H.  Le  Chatelier,  on  "Gmow,"  its  nature, 
and  the  means  of  preventing  accidents.  This  paper  will' 
be  published  in  full  in  the  Bulletin, 


CHEMICAL    AND     METALLURGICAL    SOCIETY, 

JOHANNESBURG. 

April  ij,  1897. 

At  the  adjourned  discussion  on  Prof,  Christy's  paper  on 
"  The  Solution  and  Precipitation  of  Cyanide  of  Gold,"  Mr. 


310 


City  and  Guilds  of  London  Institute. 


[Chemical  News, 
une  35, 1897. 


Butters  criticised  the  method  of  precipitation  proposed. 
He  found  it  very  difficult,  he  said,  to  make  a  University 
man  realise  the  diflSculty  of  carrying  on,  on  a  commercial 
scale,  the  operations  which  may  be  successfully  done  in 
the  laboratory  ;  he  himself  dealt  with  very  many  tons  of 
ore  per  month,  nearly  100,000,  and  he  got  his  gold  all  right, 
but  he  could  not  succeed  with  this  process. 

Mr.  L.  Ehrmann  then  read  a  paper  on  the  "  Precipita- 
tion of  Gold  from  Cyanide  Solutions,"  in  which  he  describes 
a  series  of  experiments  carried  out  by  him  with  zinc,  and 
zinc  coated  with  copper,  for  precipitating  the  gold,  and  in 
every  case  he  found  that  the  return  was  higher  when  the 
-zinc-copper  couple  was  used.  Hot  treatment  accelerated 
the  precipitation  to  a  very  considerable  degree,  but  the 
pra&ical  difficulty  of  heating  1000  tons  of  liquor  a  day  up 
to  175°  F.  will  probably  prevent  its  adoption. 

A  paper  on  "Liquation  in  Cyanide  Bars"  was  then  read 
by  Dr.  Stockhausen.  He  finds  that  samples  taken  from 
different  parts  of  the  same  bar  of  j^oid  from  the  MacArthur 
cyanide  process  give  widely  dififerent  results,  owing  to 
liquation  or  want  of  homogeneity  of  the  mass.  This  very 
unsatisfadtory  jesult  is  due  to  the  negleft  of  stirring  the 
molten  metal  before  casting  the  ingot ;  dip  samples  and 
drillings  also  give  very  different  results,  and  he  comes  to 
the  conclusion  that,  to  arrive  at  correal  results  in  assaying 
"cyanide"  gold,  the  only  way  is  to  take  samples,  after 
stirring,  when  the  metal  is  in  the  molten  state. 


OBITUARY. 


PROFESSOR    FRESENIUS. 

The  present  month  must  be  viewed  as  an  epoch  in  the 
history  of  chemistry.  Dr.  C.  Remigius  Fresenius  has 
joined  the  majority.  To  estimate  what  we  owe  to  the 
late  head  of  the  Wiesbaden  School,  we  need  merely 
imagine  ourselves  engaged  in  estimating  phosphoric  or 
even  sulphuric  acid  by  the  methods  of  the  present  day, 
as  compared  with  those  of  forty  years  ago  as  laid  down 
by  experts  of  high  and  well-earned  reputation.  We  are 
far  from  asserting  that  all  the  niceties  and  improvements 
Avhich  have  been  latterly  introduced  into  the  practice  of 
the  laboratory  are  due  to  the  work  of  Fresenius ;  but  we 
know  to  what  an  extent  he  has  been,  year  by  year,  our 
guiding  soul.  He  and  his  pupils  have  taught  us  how  to 
find,  in  a  specimen  submitted  for  examination,  what  really 
exists,  and — what  is  certainly  in  many  cases  not  less 
important — to  avoid  finding  what  is  not  present,  and  thus 
to  escape  founding  erroneous  theories. 

Still  we  must  gratefully  own  that  Fresenius  had  to  a 
great  extent  completed  his  work.  For  the  last  few  years 
his  labours  had  mainly  ceased.  His  sons,  Dr.  Heinrich 
Fresenius,  Dr.  W.  Fresenius,  and  his  son-in-law.  Dr. 
Ernst  Hintz,  have  been  carefully  trained  to  follow  in  his 
steps,  and  we  feel  confident  that  the  Wiesbaden  School 
of  Chemistry  will  continue  to  do  good  and  useful  work. 
To  the  best  of  our  knowledge  the  Zeitschrift  fiir 
Analytische  Chetnie  will  continue  to  enjoy  the  cooperation 
of  the  numerous  able  chemists  who  have  heretofore  con- 
tributed to  its  pages. 


NOTICES  OF  BOOKS. 

City  and  Guilds  of  London  Institute  for  the  Advancement 

of   Chemical   Education.      Report   to   the   Governors. 

March,    1897.      Gresham   College,   Basinghall   Street, 

London,  E.G. 
This  Report  is  minute,  and  on  the  whole  satisfaftory. 

The  constitution  of  the  Institution  is   somewhat  com- 
plex.    There    is    a    list    of    Governors,    including    the 


President  (H.R.H.  the  Prince  of  Wales) ;  a  body  of  Vice- 
Presidents,  some  of  whom  hold  their  position  ex  officio, 
such  as  the  Presidents  of  the  Royal  and  the  Chemical 
Societies  and  the  Chairman  of  the  Society  of  Arts,  a 
number  nominated  or  appointed  by  the  Corporation  and 
by  the  principal  Companies.  As  the  nominees  or  repre- 
sentatives of  the  Goldsmiths'  Company,  we  notice  the 
names  of  Mr.  G.  Matthey,  F.R.S.,  F.C.S. ;  Sir  F.  Bram- 
well,  F.R.S.;  Sir  Frederick  Abel,  Bart.,  K.C.B.,  D.C.L., 
F.R.S. ;  and  many  other  gentlemen  widely  known  in  scien- 
tific and  technical  circles. 

The  Council  is  a  distindl  body,  though  including  not  a 
few  of  the  same  names. 

Then  follow  the  Executive  Committee,  in  which  we 
meet — we  may  say  welcome — not  a  few  of  the  members 
of  the  former  bodies. 

Lastly,  comes  the  Staff  of  the  Institute's  Colleges,  in- 
cluding, on  behalf  of  the  Central  Technical  College, 
Prof.  .H.  E.Armstrong,  Ph.D.,  F.R.S. ;  F.  S.  Kipping, 
Ph.D.,  D.Sc,  Assistant  at  the  Research  Laboratory  ;  G. 
S.  Moody,  D.Sc. ;  and  W.  L.  Pope,  Instruftor  in  Crys- 
tallography. 

In  the  department  of  applied  chemistry  we  find  Prof. 
Raphael  Meldola,  F.R.S.,  F.C.S.,  beside  three  assistants. 

It  does  not  appear  with  quite  sufficient  clearness  what 
are  the  duties  or  fundions  of  these  Boards. 

It  appears  that  on  April  22nd,  1896,  a  communication 
was  received  from  the  Mercers'  Company  requesting  the 
Governors  to  appoint  a  Special  Committee  to  inquire  into 
the  expenditure  of  the  Central  Technical  College  of  the 
Institute,  with  especial  reference  to  the  results  attairted. 
The  Special  Committee  appointed  consisted  of  the  Lord 
Chancellor,  six  engineers,  six  chemists  (using  the  latter 
term  in  the  acceptation  which  it  bears  in  France,  Ger- 
many,  &c.),  four  members  of  the  Technical  Education 
Board  of  the  London  County  Council,  one  member  of  the 
last  Royal  University  Commission,  and  twelve  others. 
The  results  of  the  Report  were  very  satisfadtory.  The 
conclusion  was  that  the  work  in  the  College  had  been 
eminently  successful  and  fully  commensurate  with  the 
expenditure,  and  that  its  objefts  are  well  deserving  of 
every  support  and  encouragement  that  the  Corporation 
and  City  Companies  of  London  can  give  them. 

The  various  Companies  and  other  bodies  who  support 
the  Institute  have  distindlly  expressed  themselves  satis- 
fied  with  the  work  as  carried  on.  The  gross  cost  per 
student  for  the  years  1894  and  1895  has  been  £54,  whilst 
the  cost  per  student  at  the  Ziirich  Polytechnic  is  about 
£59;  at  the  American  Institutions  from  ^'eo  to  £6^,  and 
at  the  Royal  College  of  Science  about  ;^67. 


Alumni  Report  of  the  Philadelphia  College  of  Pharmacy. 

May,  1897,  ^°''  xxxiii..  No.  8. 
The  contents  of  this  number  begin  with  a  short 
biographical  sketch  of  the  honour  students  of  1897. 
Then  follows  a  brief  account  of  the  sixth  Pharmaceutical 
Meeting  of  the  Session  1896-1897,  at  which  there  were 
discussions  on  ointment  of  mercuric  nitrate,  the  analysis 
of  "  Gelsemium,"  and  a  contribution  on  "The  Presence 
of  Starch  and  Strontium  Sulphate  in  Opium,  and  their 
Influence  on  Assaying,"  in  which  we  find  the  curious 
statement  that,  though  starch  has  been  often  found  in 
opium  in  quantities  varying  from  a  trace  to  8  per  cent,  it 
should  not  be  considered  as  an  adulterant. 

The  rest  of  the  number  contains  accounts  of  the 
annual  meeting,  reception,  &c.,and  a  list  of  the  graduates 
of  the  year. 

A  Text-book  of  Chemistry.    Translated  into  Chinese  by 

Jas.  B.  Neal,  M.D. 
We  have  received  from  the  English  author.  Prof.  Clowes, 
a  most  interesting  publication,  hailing  from  the  Flowery 
I  Land.     It  is  a  text-book  of  chemistry,  printed  throughout 


Chemical  Nkws,  i 
June  25,  1897.     f 


Chemical  Notices  from  Foreign  Sources. 


311 


in  Chinese  charaders,  being  for  the  most  part  a  trans- 
lation of  Clowes's  "Analytical  Chemistry,"  the  only 
exception  being  the  third  chapter,  which  has  been  taken 
mostly  from  Fownes's  "  Manual  of  Chemistry."  The 
book  is  intended  simply  for  laboratory  use.  It  is  the 
translator's  firm  convidtion  that  only  by  pradlical  work  in 
the  laboratary  can  a  knowledge  of  chemistry  be  gained, 
which  will  be  more  than  a  mere  learning  by  rote,  and 
especially  so  in  the  case  of  Chinese  students. 

The  elements  are,  with  four  exceptions, — viz.,  potas- 
sium, calcium,  zinc,  and  arsenic — called  by  the  names  or 
charadters  adopted  by  Dr.  Fryer :  these  four  exceptions 
are  so  frequently  met  with  in  Chinese  medical  works  that 
it  was  thought  best  to  adhere  to  the  terms  used  by  Dr. 
Kerr,  to  prevent  the  confusion  which  would  inevitably 
arise  through  the  use  of  two  sets  of  names. 


CORRESPONDENCE. 


THE     DISCOVERY     OF     OXYGEN     AND     THE 
"  ENCYCLOP.<EDIA     BRITANNICA." 

To  the  Editor  of  the  Chemical  News. 
Sir,— In  spite  of  the  indisputable  fadt  that  oxygen  gas 
was  first  isolated  and  recognised  as  a  supporter  of  com- 
bustion by  the  Rev.  Dr.  Joseph  Priestley,  on  the  ist  of 
August,  1774,  French  writers  on  the  history  of  chemistry 
have  persistently  claimed  the  honour  of  this  discovery  for 
Lavoisier.  This  unhappy  attempt  to  transfer  credit  from 
an  English  man  of  science  to  a  French  one  would  not 
have  received  the  support  of  Lavoisier  himself,  whose 
imnfiortality  in  the  annals  of  chemistry  does  not  need  to 
be  magnified  by  mendacious  claims. 

I  have  grown  accustomed  to  this  perversity  on  the  part 
of  the  French  ;  but  imagine  my  surprise  when  I  found 
that  peculiarly  English  work  the  "  Encyclopaedia 
Britannica  "  coolly  perpetuating  this  inaccuracy  for  the 
benefit  of  its  Anglo-Saxon  readers.  In  the  ninth  edition, 
under  the  caption  "  Alchemy"  (vol.  i.,  1878),  are  the  fol- 
lowing paragraphs : — 

"  Lavoisier,  who  by  discovering  oxygen  destroyed  the 
theory  of  Stahl." 

.  .  .  "  and  finally  in  disengaging  from  the  red-oxide 
of  mercury  oxygen  gas,  that  Proteus  which  so  often 
eluded  the  grasp  of  the  alchemists,  till  at  last  it  was  held 
fast  by  the  subtle  analysis  of  Lavoisier  "  (page  462). 

After  I  had  recovered  from  the  shock  at  seeing  these 
statements  in  that  monument  of  English  erudition,  I 
turned  to  the  end  of  the  article  on  alchemy  to  ascertain 
the  authorship ;  it  is  signed  "J.  A.,"  which  the  key  at  the 
close  of  the  volume  interprets  "Jules  Andrieu."  Hinc 
illee  lacrymee  I  Why  the  Editor-in-chief  sought  for  a 
Frenchman  to  write  the  article  in  question  it  is  difficult 
to  conceive.  Were  there  no  Englishmen  in  1878  com- 
petent to  compile  such  an  essay  ?  And,  having  secured 
the  article,  were  there  no  members  of  the  editorial  staff 
who  had  heard  of  Priestley  and  his  discoveries  in 
chemistry  ?  Unfortunately  for  the  staff,  the  articles 
"  Chemistry"  and  "  Priestley,"  in  which  the  fadt  is  cor- 
redlly  given,  only  appeared  in  later  volumes. 

Those  curious  in  the  matter  will  find  the  whole  article 
on  alchemy  of  interest,  but  not  because  it  is  judiciously 
written. — I  am,  &c., 

H.  C.B. 


ESTIMATION  OF  CARBON   IN   FERRO-CHROME. 

To  the  Editor  of  the  Chemical  News. 
Sir, — A  complete  and  accurate  analysis  of  ferro-chrome 
is  not  an  easy  thing  to  do.  I  am  pleased,  therefore,  to 
notice  Mr.  Saniter's  letter,  because  he  has  long  been  in- 
terested in  the  matter.  The  letter,  however,  indicates 
that  he  has  confused  the  preliminary  experiments   and 


temporary  method   with  the  procedure   finally  adopted, 
viz.,  combustion  with  lead  peroxide. 

On  page  243,  col.  i  (Chemical  News,  vol.  Ixxv.)  it  is 
stated  that  "  the  mixture  [Pb02  and  ferro-ckrome]  fuses^ 
and  there  is  the  same  need  to  quicken  the  oxygen  to 
supply  the  absorption  in  the  boat,  but  ail  else  goes  on 
with  comparative  quietness  and  at  ordinary  temperatures J'^ 
The  covered  boat,  previously  mentioned,  is  necessary  only 
with  the  lead  chromate  or  copper  oxide  at  the  higher 
temperatures. 

I  have  just  finished  a  duplicate  determination  on  I'oo 
and  1-25  grms.  respedlively,  and,  on  unwrapping  the 
asbestos  from  the  glass  tube,  find  only  a  faint  deposit 
immediately  over  the  boat.  With  such  large  amounts  of 
peroxide  and  ferro-chrome  the  readlion  is,  of  course,  more 
vigorous  than  it  would  be  with  Mr.  Saniter's  proportions. 
That  his  assays  do  not  spurt  causes  no  surprise,  and  one 
may  justifiably  suspedl  that  the  copper  oxide  is  not 
greatly  concerned  in  the  matter  when,  under  less  favour- 
able circumstances,  assays  do  not  spurt  without  it.  The 
copper  oxide  may  preserve  the  porcelain  from  the  attack 
of  the  litharge  by  diluting  it,  as  it  were  ;  but  this  is  a 
very  minor  point :  only  the  boat  can  be  attacked,  and 
with  the  peroxide  alone  we  use  them  over  and  over  again 
after  re-heating  in  the  muffle  and  pouring  away  the  melt. 

The  complication  then  narrows  itself  down  to  this : — 
Mr.  Saniter  uses  a  mixture  of  copper  oxide  and  litharge, 
and  I  use  lead  peroxide  alone. 

It  should  be  noticed  that  Mr.  Saniter's  ferro-chrome 
must  needs  be  ground  fine  in  an  agate  mortar — a  labour 
he  has  elsewhere  endeavoured  to  avoid.  It  may  be  seen 
(p.  243,  col.  2)  that  PbOa  much  more  readily  than  CuO — 
or  presumably  than  a  mixture  of  CuO  and  and  PbO — at- 
tacks the  ferro-chrome.  In  this  respedt,  then,  it  would  be 
less  troublesome  to  use  the  single  reagent. 

The  comparative  advantage  of  using  litharge  or  the 
peroxide  would  favour  the  former  if — to  use  Mr.  Saniter's 
expression — it  were  "free  from  substances  which  might  be 
given  off  and  absorbed  by  the  potash."  So  far  we  have 
found  that,  having  once  determined  the  blank  of  the  per- 
oxide, it  may  be  relied  upon  to  remain  unchanged.  The 
readtion  2Pb02  =  2PbO-t-02  seems  to  be  nearly,  if  not 
altogether,  completed  before  the  subsequent  readlion, 
2Pb04-C  =  C02-f-2Pb,*  is  begun.  It  would  be  a  slight 
advantage,  then,  if  PbO  could  be  used  straightaway,  but 
unfortunately  PbO — perhaps  the  litharge  variety  in  a  les» 
degree — absorbs  CO2  from  the  air,  and  particularly  so  if 
damp.  It  would  be  necessary,  therefore,  on  using  this- 
reagent,  to  prepare  it  immediately  before  use,  and  to  take 
the  troublesome  precaution  to  keep  it  perfedlly  dry,  and 
pradtically  out  of  contadt  with  the  air.  Thus  the  com- 
plications, if  great  accuracy  is  a  vital  consideration,  would 
seem  to  hamper  the  use  of  the  mixed  reagents. 

I  ought  to  state  that  I  have  not  largely  experimented 
with  litharge.  The  previous  considerations,  founded  on 
known  properties  of  lead  protoxide,  and  the  fadt  that  the 
peroxide  as  received  from  the  dealers  gave  a  small  con- 
stant blank,  led  me  to  prefer  the  latter. — I  am,  &c., 

H.  Brearley. 

June  14, 1897. 


CHEMICAL 


NOTICES  FROM 
SOURCES. 


FOREIGN 


Note.— All  degrees  of  temperature  are  Centigrade  unleesotherwise 

expressed. 

Comptes  Rendus  Hebdomadaires  des  Seances,  deVAcademie 
des  Sciences.     Vol.  cxxiv.,  No.  21,  May  24,  1897. 
Tools  and  Arms  of  the  Age  of  Pure  Copper  in  Egypt. 
— Prof.   Berthelot. — The   author  gives  a  list  of  antique 

*  The  third  reaftidn  in  the  tube,  which  explains  the  need  to 
quicken  the  oxygen,  may  be  written  2Pb  +  02=2PbO.  An  attempt  is 
being  made  to  substantiate  these  equations  by  direft  experiment. 
-H.  B. 


312 


Chemical  Notices  from  Foreign  Sources. 


(  Chemical  Mbws, 

I    June  25,  1897. 


articles  sent  him  by  M.  de  Morgon.  They  belong  to  the 
most  remote  ages  of  the  Egyptian  empire.  They  all  con- 
sist of  copper  nearly  pure,  sometimes  containing  arsenic, 
but  no  tin,  lead,  or  zinc.  They  were  then  succeeded  by 
bronze  and  then  by  iron. 

On  various  Liquids  contained  in  Antique  Vases. — 
Prof.  Berthelot. — Two  of  these  liquids  have  been  forwarded 
to  the  author  by  Th.  Hubert,  custos  of  the  Archaeological 
and  Ceramic  Museum  of  the  city  of  Reims  ;  they  seem  to 
belong  to  the  Gallo-Roman  epoch.  They  have  been  ex- 
tracted from  a  glass  bottle,  and  consisted  of  an  aqueous 
liquid  covered  by  fatty  matter,  chiefly  liquefied.  The 
solid  portion  consisted  of  stearic  and  palmitic  acids  accom- 
panied by  a  neutral  fatty  matter.  The  aqueous  matter 
consists  of  a  mixture  of  volatile  acids  with  watery  vapour 
(Cm"H2»i02),  and  of  fixed  acids  (CnH2n-204),  mixed  with 
acids  (C«H2n-203  ?),  A  perfectly  distindt  specimen  was 
obtained  from  a  Syrian  tomb.  It  was  merely  water  with 
small  quantities  of  calcium  bicarbonate  chloride  and 
traces  of  nitrates.  It  is  apparently  water  of  infiltration. 
Observers  should  mistrust  the  accidental  introdu(5tion  of 
water  by  infiltration  into  antique  vessels. 

Adtion  of  Light  upon  Gaseous  Mixtures,  especially 
Mixtures  of  Chlorine  and  Hydrogen. — Armand  Gautier 
and  H.  Helier. 

On  the  Sojourn  of  General  Poncelel  at  Saratow. — 
Germain  Babst. — This  paper,  though  placed  under  the 
heading  "  History  of  the  Sciences,"  is  merely  a  fragment 
of  the  history  of  the  retreat  of  the  Grande  Armee. 

New  Improvement  of  the  Grisometer. — M.  Grehont. 
— The  new  model  is  construfted  of  stout  glass  cylinder, 
with  two  concentric  plates  of  sheet  nickel.  It  is  charged 
with  soda-lye  free  from  CI  at  about  15  per  cent  NaOH. 
The  silver-voltameter  is  universally  recognised  as  the 
most  accurate  voltmeter. 

The  External  Surface  of  Cast-iron  Raised  to  a  Red 
Heat  Converts  Carbonic  Acid  into  Carbon  Monoxide. 
— M.  Grehont. — The  author  infers  from  his  researches 
that  we  must  abandon  heating  rooms  by  walls  of  cast 
metal  heated  to  redness. 

Refledtion  of  Light  by  a  Long  and  Narrow  Surface. 
— M.  Gouy. — MM.  Nichols  and  Rubens,  when  operating 
with  thermic  rays  of  great  wave-length  (24/i)  have  found 
that  a  long  narrow  band  of  silver  refledls  these  radiations 
whilst  polarising  them  perpendicularly  to  the  length  of 
the  band,  whence  there  results  an  interesting  approxi- 
mation to  eledtric  waves. 

An  Antianodic  Phosphorescent  System,  and  on  the 
Anodic  Rays. — C.  Maltezos. — The  phenomena  observed 
indicate  the  existence  under  certain  conditions  of  anodic 
rays  which  provoke  the  phosphorescence  of  glass,  visible 
and  invisible,  and  which  most  generally  are  diffused  or 
which  do  not  reach  the  glass. 

Properties  of  certain  Radiations  of  the  Spedtrum. 
— Gustave  Le  Bon. — A  reply  to  the  paper  by  Prof.  Bec- 
querel,  and  his  objedions  to  his  hypothesis  of  "  black 
rays." 

Precipitation  of  Zinc  Sulphide  for  the  Determin- 
ation of  that  Metal. — J.  Meunier. — All  chemists  who 
have  been  concerned  themselves  with  the  determination 
of  zinc  know  the  difficulties  of  coUedting  on  a  filter  zinc 
sulphide  precipitated  by  ammonium  sulphide.  The  filtrate 
is  turbid  and  the  filtration  is  soon  stopped.  To  the  solu- 
tion of  zinc,  which  is  properly  luke-warm,  he  adds  am- 
monia, and  when  the  precipitate  of  zinc  oxide  is  formed 
he  continues  to  add  this  reagent,  but  cautiously,  and 
passing  in  sulphuretted  hydrogen  bubble  by  bubble,  ceasing 
as  soon  as  the  precipitation  of  the  zinc  is  complete. 

Remarks  on  the  Formation-heat  of  Sodic  Acetylene. 
— M.  de  Forcrand.— A  thermo-chemical  paper,  not  suitable 
for  abstradtion. 

New  Compounds  of  Pyridine,  Piperidine,  and 
Quinoleine  with  the  Metallic  Salts. — Raoul  Varet.— 


The  compounds  described  are  pyridine,  bromocuprite, 
iodozincate,  cyanozincate,  bromocadmiate,  and  bromo- 
nickelate. 

Solubility  of  Ecgonm.— Oechsner  de  Coninck. — The 
author  gives  the  solubilities  of  ecgonin  in  25  solvents. 

Comparative  Study  of  the  Quotients  of  Acids  and 
of  Fermentation  observed  during  the  Ripening  of 
Fruits.— C.  Gerber. 

Denaturation  of  Alcohol. — Ernest  Barillot. 


MISCELLANEOUS. 

The  Philadelphia  Museums. — This  institution  is  in  a 
measure  similar  to  the  Imperial  Institute.  It  is  divided 
into  several  departments — that  of  Foreign  Manufadtures 
has  for  its  objedt  the  showing  to  the  American  manufac- 
turers what  their  foreign  competitors  are  exporting.  There 
is  a  large  colledtion  of  all  kinds  of  goods,  each  sample 
being  accompanied  by  the  manufadturer's  price.  One 
great  innovation  which  we  should  be  very  sorry  to  see 
introduced  into  England,  is  the  analysis  and  reporting  on 
of  all  raw  produdls  sent,  entirely  free  of  charge,  the  Insti- 
tution being  supported  by  the  public  funds.  We  hope  the 
city  also  helps  to  support  the  analytical  chemists  who 
must  be  adversely  affedied  by  this  adtion  on  its  part. 

Inauguration  of  the  Monument  Eredted  to  the 
Memory  of  Jean  Servais  Stas. — After  the  death  of  Stas 
an  international  commission  was  constituted,  and  an  appeal 
was  made  to  the  scientific  men  of  all  countries,  with  the 
objedt  of  perpetuating  the  name  and  works  of  this  illus- 
trious chemist.  With  the  funds  colledted  the  committee 
have  already  raised  one  imperishable  monument  to  his 
memory — a  complete  edition  of  his  works.  But  the  three 
volumes  of  which  this  consists  appeal  more  or  less  to  the 
elite;  so  it  was  decided  that  a  monument  of  this  man, 
who  by  his  genius  rose  from  the  ranks,  should  be  eredled, 
accessible  to  all.  J.  S.  Stas  first  studied  at  the  Faculte 
de  Medicine  at  the  University  of  Louvain,  and  from  there 
went  to  Dumas'  laboratory.  It  was  here  that,  under  the 
diredtion  and  with  the  collaboration  of  his  illustrious 
master,  he  made  his  researches  on  the  atomic  weight  of 
carbon,  and  wrote  his  "  Memoire  sur  les  types  chimiques." 
Some  years  afterwards  he  was  appointed  professor  of  che- 
mistry at  the  Military  School  at  Brussels,  but  he  worked 
under  great  difficulties.  The  Government  refusing  even 
to  complete  the  laboratory,  Stas  was  constrained  to  defray 
the  expenses  out  of  his  own  pocket.  In  i860  he  wrote  to 
an  intimate  friend:  "To  continue  my  researches  I  have 
to  make  such  sacrifices  that  I  am  reduced  to  a  condition 
bordering  on  poverty."  He  was  offered  help  by  Liebig, 
but  was  too  patriotic  to  accept  it  from  Germany,  till  at 
last  his  own  Government,  recognising  the  value  of  his 
work,  made  him  a  grant  of  6000  francs,  and  it  is  to  him 
and  his  persistent  efforts  that  the  present  position  of 
Science  in  Belgium  is  due.  We  cannot  now  follow  him 
through  his  long  and  great  career;  by  his  nobility  of  cha- 
radler,  his  rare  intelledt  and  intelligence  he  inspired  affec- 
tion and  commanded  respedt  from  all  who  knew  him,  and 
his  work,  better  than  empty  titles,  will  keep  his  memory 
green. 

NOTES    AND    QUERIES, 

*^*  Our  Notes  and  Queries  column  was  opened  for  the  purpose  of 

giving  and  obtaining  information  likely  to  be  of  use  to  our   readers 

generally.    We  cannot  undertake  to  let  this  column  be  the  means 

of  transmitting  merely  private  information,  or  such  trade   notices 

as  should  legitimately  come  in  the  advertisement  columns. 

Marking  Inks.— I  should  be  greatly  obliged  for  information  as  to 

whether  there  is  a  chance  of  obtaining  a  book,  or  one  or  a  series  of 

reports  upon  the  subje(5t  relating  to  manufafture  of  the  latest  marking 

inks,  especially  vegetable  ones.      There  are  one  or  two  societies  in 

France  dealing  with  the  subjeift,  but  I  do  not  know  whether  they 

issue  any  reports  or  books  on  that  subje(5l;  if  so,  I  should  be  glad  to 

\  learn  how  they  are  to  be  obtained.— Sulpho. 


July  9, 1897. 


INDEX. — SUPPLEMENT  TO  THE   CHEMICAL  NEWS. 


313 


INDEX. 


ABYDOS,    fatty    matters     in 
^^     Egyptian  tombs  of,  191 
Academic    des    Sciences,   Presi- 
dent's Address,  23 
Academy  of  Sciences,  47 
Acetic  acid  on  ba(5teria  in  Thames 

water,  171 
Acetylene,  275 

Bunsen  burner  for,  260 

storing,  179 

uses  of,  24 
Acid  amides,  hydrolysis  of,  200 

boric,  in  foods,  I2i 

camphoronic,  163 

citric,  162 

diacetylglyceric,  128 

dibenzoylglyceric,  128 

dithionic,  in  oxidation  of  sul- 
phurous acid,  139 

glyceric,  128 

hydration  of  metaphosphoric, 
263 

hypoiodous,  97 

hyponitrous,  232,  244, 255,  268 

ketopinic,  162 

levulic,  190 

monochlordiparaconic,  259 

nitric,  upon  nitrates,  143 

nitrous,  reaftion  for,  gS 

oleic,  transformation  into 
stearolaftone  and  moao-oxy- 
stearic  acid,  149 

paraisobutylphenoxyacetic,  215 

perthiocyanic,  212 

pinophanic,  162 

slags,  use  of,  24 

sulphuric,  determination  of 
equivalent  of,  25 

sulphurous,  dithionic  acid  in 
oxidation  of,  139 

titanic,  134 

transformation  of  mono-oxy- 
stearic  into  oleic  acid,  149 

tungstic,  separation  of  man- 
ganese from,  26 

vapours  on  metallic  sulphides, 
207 
Acids  and  bases,  heats  of  neutral- 
isation of,  271 

cetonic,  237 

diortho  ■  substituted  benzoic, 
138 

ketonic,  153, 161 
Ackroyd,   W.,  determination   of 
equivalent  of  sulphuric  acid, 

25 

Agafonoff,  V.,  absorption  by 
crystallised  media  of  lumin- 
ous rays  and  X  rays,  227 

"  Agricultural  Analysis,  Prin- 
ciples and  Praftice  of"  (re- 
view), 165 

•'  Agricultural  Journal,  Published 
by  the  Department  of  Agri- 
culture, Cape  of  Good  Hope" 
(review),  214 

Aignon,  A.,  solubility  of  liquidS| 
299 


Air  analysis,  167 
collecting    at    great     heights, 
167 
Aldoximes,  alkyl  haloids  on,  177 
Alkaline    acetates,     separations 
with,  253 
haloid    salts,   adtion    of   acids 
upon,  35 
action  exerted   upon,  by  the 
bases  which   they   contain, 
47 
sulphites,  a(5tion  of  hydrochloric 
acid  upon,  35 
Alkaloidal  stearates,  71 
Alkaloids,  tannin  and  gallic  acid 

upon,  202 

Alkyl   haloids  on  aldoximes  and 

ketoximes,  177 
Alkylammonium  hydrosulphides. 

Alloys  containing  zinc,  freezing- 
point  curves  of,  i5o 
dental,  132,  144 

of  silver  and  copper  group,  300 
Allylic  alcohol,  phosphoric  ethers 

of,  59 
Alternating    currents    in      con- 
centric conduiStors,  187 
Aluminium  analysis,  55,  66,  79 
eleiftrical  conductivity  of,  217 
tor  condensers,  221 
separation  from  cobalt,  193 
tubes,  239 
"  Alumni    Report  of  the   Phila- 
delphia College  of  Pharmacy" 
(review),  310 
Amarone,    identity  of  Laurent's 

with  tetraphenylazine,  152 
Ambuhl,  G.,  estimation  of  sugar, 

191 
Amidines,  amidised,  300 
Amines,    method    of    preparing 

primary,  131 

Ammonia  carbonates  into  urea, 

275 

upon  tellurium  bichloride,  47 

Ammoniacal  silver  chlorides,  124 

Ammonium    cyanide,   formation 

of,  215 
Amyl  derivatives  of  glyceric,  di- 
acetylglyceric, and  dibenzoyl- 
glyceric acids,  128 
Analysis  of  air,  167 

of  milk,  167 
"  Analysis  of  Fuels,  &c.,  Selec- 
tion of  Procedures  for  "  (re- 
view), 118 
Andre  and  Berthelot,  MM.,  hydra- 
tion of  metaphosphoric  acid, 
263 

transformation  of  the  sugars, 
and  on  levulic  acid,  190 
Anethol  and  its  bomologues,  143, 
239 
derivatives  of,  179 
•'  Animal  and  Vegetable  Fats  and 
Oils,  Practical  Treatise  on  " 
(review),  106, 116 


Annable,  H.,  and  G.  Young,  for- 
mation of  substituted  oxytri- 
azolfcs  from  phenylsemicarb- 
azide,  44 

Anodic  rays,  312 

Anthony,  W.  A.,  and  E.  P, 
Thompson,  "  Rontgen  Rays" 
(review),  58 

Antianodic  phosphorescent  sys- 
tem, 312 

Antimono-tungstic  compounds,  n 

Antimony  cinnabar,  20 
determination  of,  11 
peroxide,  high  temperatures  on, 

179 
tin,  and  arsenic,  separation  of, 

221 

Antipyrine,  combination  with  the 
phenols,  119 

Apigenin  and  apiin,  153,  308 

Appleyard,    R.,    mercury    films, 
249 
liquid  coherers  and  mobile  con- 
ductors, 164 

Argon,  attempt  to  cause  to  pass 
through   red-hot    palladium, 
platinum,  or  iron,  253 
in  blood,  131 

Armstrong,  H.  E.,  Chemical 
Society  eleCtion,  154,  178,  igo 

Arnold,  J.  O.,  carbon  in  ferro- 
chrome,  263,  299 

Aromatic  synthetic  ureas,  300 

Arsenic,  antimony,  and  tin,  sepa- 
ration of,  221 
separation  of  vanadium   from, 
26 

Art  bronze  castings,  309 

Arth,  G,,  free  nitrogen  in  purified 
coal-gas,  239 
"  Recueil  de  Procedes  de  Do- 
sage pour  I'Analyse  des  Com- 
bustibles, des  Minerals,  de 
Fer,  des  Fontes,  des  Aciers, 
et  des  Fers"  (review),  118 

Ash  of  coal  and  coke,  phosphorus 
in,  8 

Aston,  E.,  and  J .  N.  Collie,  oxid- 
ation products  of  dimethyl-o- 
chloro-pyridine,  213 
and  P.  A.  Guye,  influence  of 
temperature  on  rotatory 
power,  107 
and  L.  Newton,  estimation  of 
zinc  oxide,  133 

Atomic  moaels,  264 
weight  of  carbon,  i6j 
weights,  report  of  committee 
on,  75,  88,  100,  no,  282,  293 
unity  of,  49 

Austen,  P.  T„  "  Notes  for  Chemi- 
cal Students"  (review),  10 

"Australian  Medical  Directory 
and  Handbook"  (review),  83 


B 


ACH,  A.,  peroxides  in  slow 
oxidation,  287 


Bacteria  with  chemical  reagents, 
behaviour  of,  206 

Baily,  G.  H.,  and  W.  Briggs, 
"  University  Tutorial  Series 
— The  Tutorial  Chemistry, 
Pt.  I,  Non-Metals"  (review), 
83 

"  Organised   Science   Series" 
(review),  188 

Baird,  W.  H.,  and  W.  E.  Stone, 
raflanose  in  American  sugar 
beets,  193 

Baker,  J.  L.,  and  A.  R.  Ling, 
action  of  diastase  on  starch, 
126 

Balance,  who  introduced  the  use 
of  it  into  chemistry,  63 

Balland,  M.,  decrease  of  nitro- 
genous matter  in  wheats  of 
Department  Du  Nord,  95 

Ballard,  ammunition  bread,  11 

Baly,  E.  C,  passage  of  electricity 
through  gases,  57 

Barium, strontium,  and  calcium, 
separation  of,  247 

Barlow,  W.,  homogeneity  of 
structure  and  symmetry,  140 

Bartlett,  E.  J.,  and  W.  F.  Rice, 
silver  hydride,  215 

Basil,  indigenous  essence  of, 
131 

Baskerville,  C,  and  F.  P.  Ven- 
able,  oxalates  af  zirconium, 
"3 

Baubigny,  H.,high  temperatures 
on  antimony  peroxide,  179 
and  P.  Rivals,  potassium  per- 
manganate upon  cupric  bro- 
mide, 287 

separation    of    chlorine    and 
bromine,  236 

Bauduer,  L,,  and  M.  Nicloux, 
distillation  of  mixtures  of 
ethylic  alcohol  and  water,  277 

Beadle,    C,    hermite    bleaching 
solution,  73 
viscose  and  viscoid,  74,  86 

Becquerel,    H.,    explanation    of 
some  experiments  of  G,  le 
Bon's,  280 
law  of  discharge  of  eleCtrised 
uranium  into  air,  215 

Bedson,  P.  P.,  proximate  consti- 
tuents of  coal,  58 

Beebe,  A.  C,  how  soon  shall  stu- 
dent study  qualitative  analy- 
sis, 85 
"Laboratory  Manual"  (review), 

188 
teaching  of  chemistry,  190 

Beer,  carbohydrates  in,  180 

Beerwort,  constituents  of,  71 

Belabon,  H.,  absorption  of  hydro- 
gen sulphide  by  liquid  sul- 
phur, 47 

Belugou,  Q.,  and  H.  Imbert, 
chromate  of  strontium  oq 
mercuric  chloride,  276 


314 


INDEX. — SUPPLEMENT  TO  THE  CHEMICAL  NEWS. 


July  9,  iSgy, 


Benkert,  A.  L.,«nd  E.  F.  Smith, 
separation  of  bismuth  from 
lead,  27 
Benoist,  L.,  law  of  transparency 

of  gases  for  X  rays,  95 
Benzene,  constitution  of,  68 
Benzil,  condensation  with  ethyl 

alcohol,  iji 
Bertbelot,     M.,     apparatus    for 
application  of  spe£tral  analy- 
sis to  recognition  of  gases, 
179 
copper  in  Chaldea,  109 
researches  on  helium,  95 
specific    heats    of  elementary 
gases  and  their  atomic  con-  , 
Btitution,  95  1 

liquids  in  antique  vases,  312 
tools  and  arms  of  the  age  of 

pure  copper  in  Egypt,  311 
and  Andre,  MM.,  hydration  of 
metaphosphoric  acid,  263 
transformations  of  the  sugars, 
and  on  levulic  acid,  igo 
Bertrand,  G.,  manganese  in  oxi- 
dations by  laccase,  265 
Bessun,    A.,  hydrogen    sulphide 
and  selenide  upon  phosphonyl 
chloride,  95 
oxide  of  phosphorus,  202 
stannic  chlorobromides,  191 
water  upon  phosphoryl  chlor- 
ide, 300 
Biological  adlion  of  X  rays,  281 
Bismuth,  determination  of,  50 

separation  of  lead  from,  27 
Black  light,  227 

Blaise,  E.,  colour    reaAions    of 
quinine,  263 
potassium  cyanide  upon  olides 
1—4,  59 
Blakesley,  T.  H.,  focal  length, 

297 
Blanc,  G.,  isolauronic  acid,  179 
Blarez,  C.,oil  of  arachisin  olive 

oil,  251 
Bleaching  solution,  hermite,  73 
Blood,  argon  and   nitrogen    in, 

131 
Blount,  B.,  and  A.  G.  Bloxam, 
"  Chemistry    for    Engineers 
and      Manufacturers "     (re- 
view), 106 
Bloxam,  A.  G.,  and  B.  Blount, 
'•  Chemistry    for    Engineers 
and      Manufacturers "     (re- 
view), 106 
Bokorny,    T.,    toxico''j5gfcai'^'*o€-' 
haviour  of  j^j^^jicacid  and  its 
salts,  50^ 
Bonney.  ."^  .'g.,  and  H.  C.  Lewis, 
-••'IGenesis  and   Matrix  of  the 
Diamond  "  (review),  286 
Bordas  and   Ganin,  MM.,  cryo- 
scopy  in  analysis  of  milk,  167 
Boric  acid  in  foods,  I2i 
Boron  on  iron  and  steel,  91 
Bottcher,      O.,     phosphate     in 

Thomas  slags,  170 
Bouchard,  C,  Rontgen  rays  ap- 
plied   to    diagnoses  of  pul- 
monary tuberculosis,  11 
surface,  bulk,  and  composition 

of  the  human  body,  226 
and  M.  Desprez,  composition 
of   gases  evolved    from  the 
mineral  waters  of  Bagnoles 
de  I'Orme,  11 
Boucher,  G.  G.,  sulphur,  in  iron, 
steel,  and  sulphides  of  iron, 
121 
Boudouard  and  Schiitzenberger, 
MM.,    earths    in    monazitic 
sands,  167,  205 
Bourdas,  F.,  and    S.  de  Racz- 
kowski,    process    for   deter- 
mination of  glycerin,  11 
Bourgeois,  L.,  ammonia  carbon- 
ates into  urea,  275 
Boutroux,   L.,  "  Le   Pain  et   la 

Panification  "  (review),  118 
Bradley.  W.  P.,  and  F.  Kniffen, 
paraisobutylphenoxyacetic 
acid,  215 
Brannt,     W,      T.,      "  Praftical 
Treatise     on    Animal     and 
Vegetable    Fats    and    Oils" 
(review),  106, 116 


Brand,  J.,  constituents  of  beer- 
wort,  71 
Bread,  ammunition,  11 
"  Bread   and   Panification  "  (re- 

view),  118 
Brearley,   H.,  carbon   in    ferro. 
chrome,  311 
estimation    of    manganese    in 

spiegels,  &c.,  13 
separations  with  alkaline  ace- 
tates, 253 
and   R.   L.    Leffler,   carbon  in 
ferro-chrome,  241 
"Brewers,  Handbook  for"    (re- 
view), 14Z 
Briggs,   W.,  and    G.    H,   Baily, 
"  Organised  Science  Series" 
(review),  188 

"  University  Tutorial  Series, 
the      Tutorial      Chemistry. 
Part    I.,    Non-metals"  (re- 
view), 83 
Bromdiphenylmethane  on  ethyl 

sodoacetoacetate,  274 
Bromide,  nitrogen  oxides   upon, 

143 
Bromine  and  chlorine,  separation 

of.  236 
Bromocamphorsulpholaftone,  33 
Braok,  A.,    and    H.    L.    Snape, 
identity  of  Laurent's  amarone 
with  tetraphenylazine,  132 
Brown,   H.   T.,   G.   H.   Morris, 
and    J.  H.  Millar,  examina- 
tion   of    products   of    starch 
hydrolysis,  42 

rotatory  and  cupric-reducing 
powers  of  products  of  starch 
hydrolysis  by  diastase,  43 
solution  density  and  cupric- 
reducing  power  of  dextrose, 
leevulose.and  invert  sugar, 
126 
specific    rotation    of   maltose 

and  soluble  starch,  43 
and     S.    Pickering,     thermal 
phenomena  attending  change 
of  rotatory  power  of  carbo- 
hydrates, 295 

thermo-chemistry    of   carbo- 
hydrate hydrolysis,  296 
Bruck,  L.,  "  Australian  Medical 
Directory    and    Handbook " 
(review),  83 
Brussels    International    Exhibi- 
tion, 1897,  41 
Bryant,  E.G.,  bending  aluminium 
"•    =vii".239 

Buck     A'  ^■'    "  '^^^'  *  pocket 
Medicaf  1i«aion*ry  "    (re- 
view), u  „  ^  ,  , 
"  Budapest,  Generarv='a'°g"^  ef 

the   National  Mille'.^y  ^  "- 
hibitlon,  189C"  (revievJ'  ". 

Budischovsky,  E.,  and  G.  U?l*'°' 
monazitic  sands,  181 

Bunsen  burner  for  acetyle'i?' 
260 

Burgess,  W.  T.,  and  E.  Frank- 
land,  sea-water  microbes, 
I 

Burnie,  B.,  thermo-eleCtric  pro- 
perties of  some  liquid  metals, 
116 

Buttgesbach,  F.,  treatment  of 
rich  iron  ores  and  use  of  acid 
slags,  24 


QADMIUM,  basic  salts  of,  299 

determination  of,  28,  40,  54,  61, 

77,  91.  loi 
lamp,  202 
Caffeine,  aCtion  of  Wagner's  re- 
agent upon,  and  estimation 

of,  80,  90,  98 
Cailletet,  L.,  collecting    air    at 

great  heights,  167 
Calcium,  barium,  and  strontium, 

separation  of,  247 
carbide,  2,  109 
Caldecott,  W,  A.,  decomposition 

of  iron  pyrites,  259 
Campbell,  H.  H.,  "  Manufacture 

and  Properties  of  Structural 


Steel "  (review),  69 


Camphenol  from  camphor,  308 
Camphor,   optical    inversion  of, 
306 
camphenol  from,  308 
Camphoric  acid,   derivatives  of, 

307 
Camphoronic  acid,  163 
Camphoroxime,   conversion  into 
methylcamphorimine       and 
camphenylnitramine,  138 
Carapreden,    L.,    phosphorus   in 

ash  of  coal  and  coke,  8 
Canvas,  waterproofing,  108 
Caoutchouc,   aCtion  of  coal-gas 

upon,  24 
*'  Cape  of  Good  Hope,  Report  of 
Senior   Analyst    of    Depart- 
ment of  Agriculture  for  Year 
1896  "  (review),  202 
Caramel  in  wines,  21 
Carbide,    calcium,    manufacture 
of,  3,  16,  29,  37 
of  calcium,  2, 109 
Carbohydrate  hydrolysis,  thermo- 
chemistry of,  296 
Carbohydrates  in  beer,  180 
thermal  phenomena  attending 
change  of  rotatory  power  of, 
295 
"  Carbohydrates       of       Wheat, 
Maize,   Flour,  and    Bread  " 
(review),  213 
Carbon,  atomic  weight  of,  163 
in   ferrochrome,  241,  263,  286, 
287,  299, 311 
Carbonic      oxide,    explosion    of 
chlorine  peroxide  with,  259 
reaction  of,  276 
Carborundum     production    and 

use,  288 
Carey  Lea,  M.,  death  of,  239 
Cast-iron,  sulphur  in,  194 
"  Catalogue  of  Books  by  Meyer 

and  MiiUer"  (review),  46 
"  Catechism    of    Chemistry,   ar- 
ranged  for  Beginners  "  (re- 
view), 46 
Cathode  rays,  experiments  with, 

218,  233,  245 
Cathodic  rays,  299 

and     electrodes    in    rarefied 
gases,  191 
Causse,   H.,   new  derivative    of 
phenylisindazol,  167 
chlorine  hydrate  upon  phenyl- 
hydrazin-diphenyl-glyoxazol, 
299 
Cavalier,  J.,  phosphoric  ethers  of 

allylic  alcohol,  59 
Cazeneuve,  P.,  ferment  of  frac- 
ture of  wines.  203 
and    M.    Mar,  aromatic    syn- 
thetic ureas,  300 
Cedar  wood,  essence  of,  276 
Cerium,  purification  of,  292 
Cetonic  acids,  237 
Chaldea,  age  of  copper  in,  109 
Chambers,  T.  G.,   "  Register  of 
Associates  and  Old  Students 
of  the  Royal  College  of  Che- 
mistry, the  School  of  Mines, 
and       Royal       College       of 
Science  "  (review),  46 
Qi^rabot,    E.,    essence   of   ger- 
anium, 276 
pu-jpy,  G.,  constitution  of  me- 
^"^[^jllic  alloys,  287 
Qtj  .jfiau,  G.,  cobalt  and  nickel 

...phides,  II 
ChattaW  F    D.    and  H.    P. 
gjgVens,   hydrolysis   of  per- 
jujrpyanic  acid,  212 
Chauvef  *"•  ■*••  energy  expended 
ijy  n'Pscle  in   static  contrac- 
jjQ    'for    maintenance    of    a 
charf^  after  respiratory  ex- 
chani^^'  3^ 
Chauvet.  f-  /"'I    C.      Mouet, 
aneth    ^°°  ''^  homologues, 

C  Mou'^"'  ^nethol  and  homo- 
'iosues°^^°^*''°''^39 

"Chemical,  Analysis,  Abstraft 
of-Pai',,"-  .  Quant'tative 
Analvs-^      (review),  189 

"Chemical  -A-nalysis,  Abstraft 
of-Pat*  ^  '  Qualitative  Ana- 
lysis" (feview),  119 


"  Chemical  Apparatus,  &c.,  Oata« 
logue  of"  (review),  23 

"  Chemical  Students,  Notes  for  " 
(review),  lo 

Chemical       and       Metallurgical 
Society,  Johannesburg,  309 
Laboratory  of  Wiesbaden,  143 
Society,   42,  56,',i25,   137,   150, 
159,   176,  210,   259,   270,  295, 
306 
election,  154,  166,  178,  190,201 

Chemiker  Zeitung,  143 

"Chemistry,  Engineering"  (re- 
view), 117 

"Chemistry,  Manual  of"  (re. 
view),  188 

"  Chemistry  of  Artificial  Colour, 
ing  Matters  "  (review),286 

"Chemistry  of  Dairying"  (re* 
view),  117 

"  Chemistry  for  Engineers  and 
Manufacturers  "  (review),  108 

"  Chemistry,  Report  on  Teach- 
ing "  (review),  117 

"Chemistry,  Text-book  of"  (re. 
view),  310 

Chemistry,  teaching  of,  166,  190 

Chikashige,  M.,  atomic  weight 
of  Japanese  tellurium,  175 

"  Chimie  Minerale"  (review), 226 

"  Chimie  Organique"  (review), 
226 

Chloral  hydrate  crystals,  deli- 
quescence in,  45 

Chlorides,  ammoniacal  silver, 
124 

Chlorine  hydrate  upon  phenyl, 
bydrazine-diphenylglyoxazol, 

*99  .     .         , 

Chlorine  peroxide,  explosion  of 
with  carbonic  oxide,  259 

Chlorine  and  bromine,  separation 
of,  236 

Cholesterine,  227 

Christie,  T.,  enzyms  upon 
starches,  238 

Christy,  Prof.,  solution  and  pre- 
cipitation of  cyanide  of  gold, 

309 

Chromate  of  strontium  on  mqr. 
curie  chloride,  276 

Chromium  and  manganese  phos' 
phides,  95 

Citric  acid,  162 

"  City  and  Guilds  of  London  In. 
stitute.  Report,  1895-6  "  (re- 
view), 83 

"  City  and  Guilds  of  London  In- 
stitute, Report,  1897"  (re. 
view),  310 

City  and  Guilds  of  London  Insti- 
tute, 71 

Clarke,  F.  W.,  report  of  commit- 
tee on  atomic  weights,  75,  88, 
100,  no,  282,  293 

Claude,  G.,and  A.  Hass,  storing 
acetylene,  179 

Cloez,  C,  cholesterine,  227 

Coal  gas,  free  nitrogen  in  puri- 
fied, 239 

upon  caoutchouc,  24 
proximate  constitutents  of,  58 
tar  colours  in  white  wines,  264 

Cobalt,  oxides  of,  161 
separation     from    aluminium, 
193 

nickel,  193 
and  nickel  sulphides,  II 

Cobaltite,  161 

Cobaltous  salts,  hydrogen  per- 
oxide and  other  oxidising 
agents  on,  43 

Cockburn,  G.  B.,  and  J.  A. 
Gardner,  oxidation  of  fen- 
chene,  308 

Collie,  T-  N.,  Chemical  Society 
election,  166 
pyridine  derivatives  from 
ethylic  amido-crotonate,  15Q 
and  E.  Aston,  oxidation  pro- 
ducts of  dimethyl-a-chloro- 
pyridine,  213 

Colorimetry,  limit  of  accuracy  in, 

73 

Colour,  reproduction  of  by  photo- 
graphic methods,  95 

Colouration  of  glasses,  300 

Coloured  reactions,  131 


July  9, 1897. 


INDEX. — SUPPLEMENT  tO  THE   CHEMICAL  NEWS. 


3J5 


olson,  A.,aAion  oi  hydrochloric 
acid  upon  alkaline  sulphites, 

35 
decomposition  of  metallic  sul- 
phates, 59 
free  bases  upon  salts,  167 

Columbium,  derivatives  of,  8,  18, 
31.38 

"  Commercial  Fertilisers  and 
Chemicals  Inspe(5led,  &c., 
in  State  of  Georgia"  (re- 
view), 213 

Contremoulin  and  Remy,  MM., 
radio-photography  of  the  soft 
parts  of  man  and  the  lower 
animals,  102 

Cook,  E.  H.,  melting-points,  176 

Copper  alloys  and  melted  copper, 
removal  of  oxide  from,  97 
analysis  of  industrial,  11 
in  Chaldea,  109 

industrial,  of  eledlrolytic  pro- 
cess, II 
industry  in  Japan,  24 
speftra  of,  2 

Coppock,  J.  B.,  tropical  food,  265 

Cormack,  W.,  apparatus  for 
steam  distillation,  279 

Cornu,  M.  A.,  Presidential  Ad- 
dress, Academie  des  Sciences, 
23 

Corydaline,  239 

Crole,  D.,  "Tea:  a  Text-book 
on  Tea-planting  and  Manu- 
facture "  (review),  261 

Crompton,  H.,  heats  of  neutral- 
isation  of   acids  and   bases, 

271 

molecular  rotations  of  optically 
a(5tive  salts,  271 

osmotic  pressure  and  eleiftro- 
lytio  dissociation,  270 
Crookes,  H.,  adtion  of  perman- 
ganate of  potash  and  acetic 
acid  on  baAeria  in  Thames 
water,  171 

W.,  diamonds,  301 

physiological  ai^tion  of  X  rays, 

225 

and    Prof.     Dewar,      London 
water  supply,  41,99,  147,  200, 
247,  306 
Crookes  tube,  diamond  into  gra- 
phite in,  191 
Crossley,    A.    W.,     Wechsler's 
method    for     separation     of 
fatty  acids,  138 
Cryoscopic  measurements,  239 

researches,  226 
Cryoscopy  in  analysis  of  milk,  167 
Crystalline  rocks,  gases  in,  169 
salts,  refra(5tion   constants    of, 
129 
Crystals,  producing  transparent, 

143 
Curtius,    T,,    and    A.     Schwan, 
substituted     glycolic    esters 
and  glycolhydrazid,  7 
Cyanide  bars,  liquation  in,  310 
of  gold,  solution  and  precipita- 
tion of,  309 
process  for  gold  extradlion,  47 


((  rxAIRYING,  Chemistry  of" 

•*'     (review),  117 
Dalton's  law  in  solutions,  274 
Darzens,      G.,     derivatives      of 

anethol,  179 
David,     M  ,    transformation    of 
oleic  acid    into  stearolai5tone 
and    mono-oxystearic     acid, 
149 
Davies,  B.,  and  O.  Lodge,  influ- 
ence of  a  magnetic  field  on 
raaiation  frequency,  289 
D'Aguiar,  A.,   and   W.  da  Silva, 
coal-tar    colours    in      white 
wines,  264 
colouring-matters  of   coal  in 

white  wines,  157 
yellow  of  naphthol  S  in  white 
wines  and  liqueurs,  256 
Da  Silva,  W.,  and   A.  D'Aguiar, 
coal-tar    colours     in    white 
wines,  264 

colouring  matters  of  coal    in 
White  wines,  157 


Da  Silva,  W.,  and  A.  d'Aguiar, 
yellow  of  naphthol  S  in  white 
wines  and  liqueurs,  256 

De  Chalmot,  G.,  and  J.  T.  More- 
head,  manufai5ture  of  calcium 
carbide,  3,  16,  29,  37 

De    Coninck,    O,,    tannin    upon 
alkaloids  and  ureas,  179 
and  gallic  acid  upon  alkaloids, 

202 

upon  alkaloids,  167 

De  Courmelles,  F.,  and  G.  Segny, 
kathodic  apparatus  gener- 
ating X  rays,  215 

De  Koninck,  L.  L.,  and  E,  Prost, 
determination  of  zinc,  182 

De  Koninck,  O.,  high  homo- 
logue  of  urea,  107 

De  Koningh,  L.,  boric  acid  in 
foods,  121 

De  Raczkowski,  S.,  and  F. 
Bourdas,  process  for  deter- 
mination of  glycerin,  11 

De  Thierry,  M.,  atmospheric 
ozone  on  Mont  Blanc,  170 

De  Wateville,  method  for  pro- 
ducing transparent  crystals, 
143 

Defris,  R.,  and  F.  Ulzer,  shellac 
acids  in  separation  of  fatty 
acids  and  resin  acids,  70 

Delafontaine,  M.  M.,  fergusonite 
metals,  229 
separation  of  thoria  from   zir- 
conia,  230 

Delepine,  M.,  formation-heats  of 
formic  aldehyd,  215 
preparing  primary  amines,  131 

Deliquescence  in  chloral  hydrate 
crystals,  45 

Dental  alloys,  132,  144 

Deslandres,  H.,  eleftrodes  and 
cathodic  rays  in  rarefied 
gases,  191 

Desprez,  M,,  and  C.  Bouchard, 
composition  of  gases  evolved 
from  the  mineral  waters  of 
Bagnoles  de  I'Orme,  11 

Dewar,  Prof.,  and  W.   Crookes, 
London  water  supply,  41,  99, 
147,  200,  247,  306 
and   H.   Moissan,  liquefaftion 
of  fluorine,  277 

Dextrose,  lajvulose,  and  invert 
sugar,  solution  density  and 
cupric  reducing  power  of,  126 

Diacetylglyceric  acid,  128 

"  Diamond,  Genesis  and  Matrix 
of"  (review),  286 

Diamond  into  graphite  in 
Crookes  tube,  19 1 

Diamonds,  301 

Diastase  on  starch,  126 

Dibromo  1 — 3  propene,  27 

Dibenzoylglyceric  acid,  128 

"  Diiftionary,  Medical  "  (review), 
II 

Diethylammonium  chloride,  elec- 
trical conduftivity  of,  44 

Dimethyl-a-chloropyridine,  oxid- 
ation produfts  of,  213 

Dimethylketohexamethylene.  44 

Dimorphism  of  the  succinates  of 
the  camphols  +a  and  —a,  70 

Dinitroflourescine,  yellow  colour, 
ing  matter  from,  239 

Dinitrosamines  of  ethylene  ani- 
line, the  ethylene  toluidines, 
i6i 

Diortho  -  substituted  benzoic 
acids,  13:5 

Disinfeftion  with  formic  aldehyd, 
251 

Distillation  of  mixtures  of  ethylic 
alcohol  and  water,  277 

Dithionic  acid  in  oxidation  of 
sulphurous  acid,  139 

Ditte,  A.,  adtion  exerted  upon 
alkaline  haloid  salts  by  the 
bases  which  they  contain, 
47 
aftion  upon  solutions  of  alkaline 
haloid  salts  by  acids,  35 

Divers,  E.,  and  T.  Haga,  prepa- 
ration of  hydroxylamine  sul- 
phate, 181 

Dixon,  A.  E.,  halogen-substituted 
acidic  thiocarbimides,  127 


Dixon,  H.  B,,  and  E.  J.  Russell, 
explosion  of  chlorine  peroxide 
with  carbonic  oxide,  259 

Dobbie,  J.  J.,  and  F.  Marsden, 
corydaline,  259 

Dobbin,  Dr  ,  who  introduced  the 
use  of  the  balance  into  che- 
mistry ?  68 

Dodson,  W.  R.,  "Leguminous 
Root  Tubercles "  (review), 
285 

Dommer,  F.,  acetylene,  275 

Dubois,  H.  W.,  and  C.  T.  Mixer, 
manganese  in  iron  ores,  51 

Dudley,  C.  B.,  analysis   of  iron 
and  steel,  257,  269,  283 
W.    L.,    nickelo-nickelic    hy- 
drate, 65 

Duncan,  R.  K.,  acetylene,  24 

Dunstan,  W.  R.,  and  E.  Gould- 
ing,  alkyl  haloids  on  aldox- 
imes  and  ketoximes,  177 

Dupont  and  Guerlain,  MM.,  in- 
digenous essence  of  basil, 
131 

Durand,  A.,  ethylisoamylamines, 
239 

Durrant,  R.  G.,  hydrogen  per- 
oxide and  other  oxidising 
agents  on  cobaltous  salts,  43 

Dymond,  T.  S.,  and  F.  Hughes, 
dithionic  acid  in  oxidation  of 
sulphurous  acid,  139 


■pARTHS  in  monazitic  sands, 

■'-'     167, 2^5 

Ebonite,  transparence  of,  300 

Eder,  T.  M.,  and  E.  Valenta, 
spedtra  of  copper,  silver,  and 
gold,  2 

Edinburgh   University  Chemical 
Society,  no,  141 
graduation  ceremonial,  20l 

Edmunds,  L.,  and  T.  M.  Stevens, 
"Law  and  Praftice  of  Letters 
Patent  for  Inventions"  (re- 
view), 214 

Egoroff,*P.,  and  N.  Georgiewsky, 
polarisation  of  radiations 
emitted  by  some  sources  of 
light  under  influence  of  mag- 
netic field,  202,  287 

Egyptian  tombs  of  Abydos,  fatty 
matters  in,  191 

Egypt,  tools  and  arms  of  the  age 
of  pure  copper  in,  311 

Ehrmann,  L.,  precipitation  of 
gold,  310 

"  Eledtric  Furnace  "  (review), 
225,  237,  250 

Eleftric  shadows  and  lumines- 
cence, 103,  III,  122,  134 

Eleftrical  waves  in  wires,  effedV 
of  capacity  on  stationary,  187 

Eleftricity,  passage  through 
gases.  57 

Eleftrised  uranium,  law  of  dis- 
charge of  into  air,  215 

"  Eledtro-chemical  Problems  " 
(review),  298 

Ele(5trodes  and  cathodic  rays  in 
rarefied  gases,  igl 

Eleftrolysis,  116 

Eleftrolytic  dissociation  and  os- 
motic pressure,  270 
of  water,  116 

Elements,  dissemination  of,  129 

Ellis,  C.  S.,  teaching  of  chemis- 
try, 116 

Enantiomorphism,  45 

Energy  expended  by  muscle  in 
static  contradtion  for  mainte- 
nance of  a  charge  after  respi- 
ratory exchanges,  35 

"  Engineering  Chemistry  "  (re- 
view), 117 

Enzyms  upon  starches,  238 

Epsom  salts,  83 

Essence  of  cedar  wood,  276 
of  geranium,  276 

Essences  and  perfumes  industry^ 

r.     ^''3 

Esterification,  speed  of,  227 
Esters,  substituted  glycolic,  7 
Ethyl  alcohol,   condensation    of 
benzil  with,  151 


Ethlyene  aniline,  dinitrosamines 
of,  161 
nickel  upon,  187 
toluidines,  161 

Ethylic    amido-crotonate,    pyri- 
dine derivatives  from,  150 

Ethylisoamylamines,  239 

Ethylpropylpiperidonium  iodide, 
162 

Evans,    0.    de   B.,   ethylpropyl- 
piperidonium iodide,  162 

Experiments  of  G.  le  Bon's,  ex- 
planation of,  280 


((  pATS    and    Oils,    Pradtical 

•'•       Treatise  on    Animal  and 

Vegetable"  (review),  106,  116 

Fatty  acids,  Wechsler's  method 
for  separation  of,  138 
matters  in  Egyptian  tombs  of 
Abydos,  191 

Fenchene,  oxidation  of,  308 

Fenton,  H.  J.  H.,  the  sugar 
group,  161 

Fergusonite  metals,  229 

Ferric  chloride,  volatility  of,  227 

Feirochrome,  carbon  in,  241, 263 

Ferrocyanides  of  zinc  and  man- 
ganese, 186 

Ferrous  chloride,  nitrogen  oxides 
upon,  143 

Field,  C.,  and  E.  F.  Smith,  sepa- 
ration of  vanadium  from 
arsenic,  26 

Filling  for  joints,  252 

Fink,  E.,  "  Precis  d'Analyse  Chi- 
mique"  (review),  119,  189 

Fish,  cooked,  212 

Fleming,  J.  A.,  magnetic  hyster- 
esis loss  in  straight  iron 
strips,  297 

Flowers,  perfume  of,  203 

Fluorescence  of  vitrified  matters 
under  the  adtion  of  Rontgen's 
rays, 107 

Fluorine,  liquefadlion  of,  277 

Focal  length,  297 

Fodders,  potash  and  phosphoric 
acid  in,  209 

Folkard,  0.  W.,  limit  of  accuracy 
in  colorimetry,  73 

Food,  tropical,  265 

Foods,  boric  acid  in,  I2i 
sophistication  of,  252 

Formaldehyd,  test  for,  203 
detedtion  of,  71 
determination  of,  70 

Formic     aldehyd,      disinfeAion 
with,  251,  278 
formation  heat  of,  215 

Forster,  M.  O.,  conversion  of 
camphoroxime  into  methyl- 
camphorimime  and  camphe- 
nyl-nitramine,  138 

Francis,  F.  E.,  dinitrosamines  of 
ethylene  aniline,  the  ethylene 
toluidines,  161 

Frankland,  E.,  and  W.  T.  Bur- 
gess, sea-water  microbes,  i 
P.  F.,  "  Our  Secret  Friends  and 

Foes"  (review),  154 
P.,  and  T.  S.  Price,  amyl  deri- 
vatives of  glyceric,  diacetyl- 
glyceric,   and    dibenzoylgly- 
ceric acids,  128 

Free  bases  upon  salts,  167 

Freezing-point  curves  of  alloys 
containing  zinc,  160 

French  Academy  of  Sciences,  177 

French,    W.,    determination    of 
equivalent  of  sodium,  50 
interadtion   of  highly   purified 
gases, 153 

Fresenius,   H.,  fatty  matter   in 
milk,  70 
Prof.,  obituary,  310 

Freundler,  P.,  derivatives  of  fur- 
furane,  239 

Fricke,  E.,  organic  matter  in 
potable  water,  206 

Friedel.  C,  fatty  matters  in 
Egyptian  tombs  of  Abydos, 
191 

Friedheim,  C,  determination  of 
molybdenum  and  vanadium^ 
91, 125 


3i6 


INDEX. — SUPPLEMENT  TO  THE  CHEMICAL  NEWS. 


July  9, 189?. 


Fuertes,  J.  H.,  "Water  and  Pub- 
lic Health"  (review),  285 
Furfurane,  derivatives  of,  239 


/^ALLIC  acid  upon  alkaloids, 
'J     202 

Gallenkamp,  A.,  "  Catalogue  of 
Chemical     Apparatus  "    (re- 
view). 23 
Ganin  and  Bordas,  MM.,  cryo- 
scopy  in  analysis  of  milk,  167 
Gardner,  J.  A.,  and  G.  B.  Cock- 
burn,  oxidation  of  fenchene, 
308 
and  J.  E.   Marsh,  camphenol 
from  camphor,  308 
Garrett,  T.   A.,  a   nickel    stress 

telephone,  187 
Gases,  apparatus  for  application 
of  speftral  analysis  to  recog- 
nition of,  179 
discharging  eled^rised   bodies, 

II 
for  X  rays,  law  of  transparency 

of.  95 
from  mineral  waters  of  Bag- 

noles  de  I'Orme,  11 
in      crystalline       rocks       and 

minerals,  169 
interaction   of  highly  purified, 

153 
specific  heats  of   elementary, 
and  theiratomic  constitution, 

95 
Gassman,  C,  produ(5tion  of  vanil- 

line,  47 
Gatterman,  L..  and   W.  Shober, 

"  Praftical    methods   of  Or- 
ganic  Chemistry  "   (review), 

23 
Gauss  and  Weber  memorial,  252 
Georgiewsky,  >'.,  and  N.  Egoroff, 

polarisation     of     radiations 

emitted   by  some   sources  of 

light,  202,  287 
Geranium,  essence  of,  276 
Gerber,  C,  tannins  in  plants,  300 
German  Society  of  Science  and 

Arts,  228 
Gilles,   W.   S.,  and  F.  F.  Ren- 

wick,  ketopinic  acid,  162 
Girard,      A.,     composition      of 

wheats,  258 
Giaser,  C,  estimation  of  thoria, 

chemical  analysis  of  mona- 

zite  sand,  145,  157 
Glasses,  colouration  of,  300 
Glucosides,  determination  of,  25 
Glyceric  acid,  128 
Glycerin,  264 

determination  of,  11 
Glycolhydrazid,  7 
Glycolic  esters,  substituted,  7 
Gold    and      platinum      nuggets, 

stru(5ture  of,  139 
extra(5tion,  cyanide  process  for, 

47 
from  auriferous  ores,  149 
in  saline  deposits   and  marine 

plants,  139 
phosphorus  upon,  167 
precipitation  of,  310 
salts  of  the  solanaceous  alka- 
loids,jo8 
spe(5tra  of,  2 
Gomberg,  M.,  aftion  of  Wagner's 

reagent    upon    caffeine,   and 

estimation  of  caffeine,  80,  go 

98 
Gooch,  F.  A.,  and  C.  F.  Walker, 

application  of  iodic   acid  to 

analysis  of  iodides,  ig6 
molybdenum,  208 
Goodwin,    H.     M.,    and    A.    A. 

Noyes,  viscosity  of  mercury 

vapour,  291 
Gossheintz,   adtion    of    coal-gas 

upon  caoutchouc,  24 
Gould,  B.  A.  (obituary),  59 
Goulding,  E.,  and  W.   K.  Dun- 

stan,      alkyl       haloids       on 

aldoximes  andketoximes,  177 
Gouy,  M.,  refledtion  of  light,  312 
Gowalski,       A.,      working      up 

uranium  residues,  98 
Granger,  A.,  aftion  of  phosphorus 

upon  platinum,  35 


Granger,  A.,  chromium  and  man- 
ganese phosphides,  95 
phosphorus  upon  goid,  167 

Gray,  A.  E.,  perception  of  differ- 
ence   of  phase   by   the    two 
ears,  274 
T.,  isomeric  dibromethylenes, 
309 

Grehont,  M.,  new  improvement 
of  the  grisometer,  312 

Griffiths,  A.  B.,  "  Respiratory 
Proteids,  Researches  in  Bio- 
logical Chemistry  "  (review), 
262 

Grisometer,  new  improvement  of 
the,  312 

Griinwald,  A.  K.,"Ueber  gewisse 
Haupt  aufgaiben  der  Natur- 
wissenschaften"  (review),  10 

Guecbgorine,  J.,  and  P.  A.  Guye, 
isomerism  of  strudture  and 
of  rotatory  power,  98 

Guerlain  and  Dupont,  MM.,  in- 
digenous essence  of  basil,  131 

Guggenheimer,  M.,X  raysonthe 
striking  distance  of  the 
elei5tric  spark,  131 

Guilds  and  City  of  London  Insti- 
tute, 71 

"  Guilds  and  City  of  London  In- 
stitute, Report,  1895-6  "  (re- 
view), 83 

"  Guilds  and  City  of  London  In- 
stitute, Report,  1897  "  (re- 
view), 310 

Gun  paper,  191 

Guntr,  M.,  lithium  nitride,  ii 

Guye,  P.  A.,  and  J.  Guecbgorine, 
isomerism  of  structure  and 
rotatory  power,  98 
and  M.  E.  Aston,  influence  of 
temperature  on  rotatory 
power,  107 
and  P.  A.  Melikion,  normal 
rotatory  dispersion,  33 

TIJAGA,  T.,  and  E.  Divers,  pre- 

■"  paration  of  bydroxylamine 
sulphate,  181 

Haller,  A.,  and    P.  T.   Mijller, 
"  Chimie    Minerale,    Chimie 
Organique  "  (review),  226 
industry  of  essences  and  per- 
fumes, 143 

Halogen-substituted  acidic  thio- 
carbimides,  127 

Hallopeau,  L.  A.,  antimono- 
tungstic  compounds,  11 

Hambly,  F.  J.,  and  J.  Walker, 
ele(5trical  condudtiviiy  of  di- 
ethyl ammonium  chloride  in 
aqueous  alcohol,  44 

Hamy,  M.,  cadmium  lamp,202_ 

Handy,  J.  O.,  aluminum  analysis, 
55,  56,  79 

Hanes,  E.  S.,  and  A.  H.  McCon- 
nell,  oxides  of  cobalt  and 
cobaltites,  161 

Hanriot,  M.,  non-identity  of  the 
lipases  of  different  origins, 
203 

Hatben  gold  medal,  71 

Hardin,  W.  L.,  determination  of 
silver,  mercury,  and  cad- 
mium, 28,  40,  54,  61,  77,  91, 
loi 

Hart,  E.,  a  reclamation,  214 

Hartley,  W.  N.,  and  H.  Raraage, 
analysis  of  metals,  chemical 
preparations,  and  minerals 
from  Stassfurt  potash  beds, 
151 
dissemination  of  rarer  ele- 
ments, 129 

Hass,  A.,  and  G.  Claude,  storing 
acetylene,  179 

Hautzsch,  A.,  and  A.  L.  Kauf- 
mann,  hyponitrous  acid,  232, 
244,  255,  268 

Helium,  95 
atomic  weight  of,  71 
attempt      to    cause    to      pass 
through   red-hot    palladium, 
platinum,  or  iron,  253 

Helm,  G.,  and  L.  R.  Morgan, 
"  The  Principles  of  Mathe- 
matical Chemistry "  (re- 
view), 226 


Hemmy,  A.  S.,  and  S.  Ruhe- 
mann,  ketonic  acid,  153,  161 

Henderson,  G.  G.,  and  M.  A. 
Parker,  broradiphenylme- 
thane  on  ethyl  sodaceto- 
acetate,  274 

Heraus,  W.  C,  and  Reiser  and 
Schmidt,  a  technical  pyro- 
meter, 70 

Hermite  bleaching  solution,  73 

Ilerting,  O.,  sulphur  in  irons,  109 

Heycock,     C.     T.,    and    F.    H. 

Neville,  freezing-point  curves 

of  alloys  containing  zinc,  160 

X   ray   photographs    of   solid 

alloys,  260 

High  temperatures  upon  copper, 
bismuth,  silver,  tin,  nickel, 
and  cobalt  sulphides,  202 

Hirschsohn,  E.,  stannous  chlor- 
ide with  essential  oils,  71 

Hoffert,  H.  H.,  use  of  mirrors 
with  paraffin  lamp  and  scale, 
93 

Holland,  A.,  analysis  of  indus- 
trial copper  of  eleftrolytic 
process,  determinations  of 
antimony,  sulphur,  and  alien 
metals,  11 
analysis  of  industrial  copper,  11 

Homogeneity  of  structure  and 
symmetry,  140 

Hughes,  F.,  and  T.  S.  Dymond, 
dithionic  acid  in  oxidation  of 
sulphurous  acid,  139 

Human  body,  surface,  bulk,  and 
composition  of,  226 

Hyde,  F,  S.,  thalleoquin  test  for 
quinine,  207 

Hydrocarbons  from  American 
petroleum,  159 

Hydrochloric  acid,  a(5tion  upon 
alkaline  sulphites,  35 

Hydrogen      dioxide,      analytical 

methods  involving  use  of,  81 

and   nitrogen,  compounds   of, 

141 
sulphide,    absorption     of     by 
liquid  sulphide,  47 
upon  phosphonyl  chloride,  95 
and    sulphur,   combination   of, 
191 

Hydrolysed  starch  solutions,  ro- 
tation and  reducing  powers 
of,  131 

Hydrolysis  of  acid  amides,  200 

Hydroxylamine  sulphate,  i8i 

Hypoiodites,  97 

Hypoiodous  acid  and  hypoiodites, 

97 
Hyponitrous  acid,  232,  244,  255, 
268 


TCHTHYOL,  sodium  salicylate 
■*•     in  presence  of,  71 
Irabert,    H.,    and    G.    Belugou, 
chromate    of   strontium    on 
mercuric  chloride,  276 
"Inorganic   Chemical    Prepara- 
tions" (review),  46 
Institute  of  Chemistry,  71 
Institution,    Royal,  48,   83,   115, 

180, 191,  227,  251,  300 
"  IntroduiStion   to    the    Study  of 

Chemistry"  (review),  69 
Iodides,  application  of  iodic  acid 

to  analysis  of,  196 
Iodic  acid,  application  of  to  ana- 
lysis of  iodides,  196 
Iodine  solutions  for  sulphur  deter- 
minations, 218 
Iron,  adtion  of  boron  on,  91 
action  of  carbonic  acid  of  waters 

upon,  35 
analysis,  errors  in,  91 
carbide,  preparation  of,  202 
ores,  manganese  in,  51 
treatment  of,  24 
pyrites,  decomposition  of,  359 
separation  from  nickel,  193 
and  steel  analysis,  257,  269,  283 

Steel  Institute,  215 
sulphur  in,  47,  109 
temperature    upon      magnetic 
and  electric    properties    of, 
249 
Ironstone  of  the  Weald,  207 


Irry,    R ,     silver    chloride    and 

monomethylamine,  a83 
Isolauronic  acid,  179 
Isomeric  dibromethylenes,  309 
Isomerism  of  structure  and  rota- 
tory power,  98 
Isothermals  of  isopentane,  275 
Italian  Exhibition,  i8gS,  251 


JACKSON,  P.G.,  L.L.Lloyd, 

J  and  J.J.  Sudborough,  diortho- 
substituted  benzoic  acids,  13S 

Jannasch,  P.,  opening  up  of  sili- 
cates, 97 

Japan,  imperial  hygienic  labora- 
tories, 228 
copper  industry  in,  24 

Japanese  tellurium,  atomic 
weight  of,  175 

Japp,  F.  R.,  condensation  of  ben- 
zil  with  ethyl  alcohol,  151 

Jary,  R.,  ammoniacal  silver 
chlorides,  124 

Jenkins,  H.  C  ,  and  E.  A.  Smith, 
reactions  between  lead  and 
oxides  of  sulphur,  241,  260 

Johannesburg  Chemical  and  Me- 
tallurgical Society,  309 

Joints,  filling  for,  252 

"Journal  of  Agriculture,  pub- 
lished by  Department  of 
Agriculture,  Cape  of  Good 
Hope"  (review),  225 

Jowett,  H.  A.  D.,  gold  salts  of 
the  solanaceous  alkaloids, 
308 


T^ATHODIC    apparatus   gene- 
■'*■    rating  X  rays,  215 
Kaufmann,  A.  L.,and  A. Hautzsch, 

hyponitrous    acid,    232,    244, 

255,  268 
Kay,  S.  A.,  and  J.  Walker,  urea 

formation  in  aqueous  alcohol, 

177 
KelIey,J.,jun.,and  E.  F.  Smith, 

acid    vapours    on     metallic 

sulphides,  207 
Kentmann,  L.,  test  for  formalde- 

hyd,  203 
Kern,  S.,  removal  of  oxide  from 

melted    copper    and    copper 

alloys,  97 
Ketonic  acids,  153,  161 
Ketopinic  acid,  162 
Ketoxiraes,  alkyl  haloids  on,  177 
Kipping,  F.  S.,  dimethylketohexa. 

methylene,  44 
and  C.  Revis,  bromocamphor- 

sulpholaClone,  44 
and  W.  J,  Pope,  derivatives  of 

camphoric  acid,  307 
enantiomorphism,  45 
optical   inversion  of  camphor, 

306 
racemism  and  pseudoracem- 
ism,  307 
Klobb,  T.,  cetonic  acids,  237 
Kniffen,  F.,  and  W.  P.  Bradley, 

paraisobutylphenoxyacetic 

acid,  215 
Kronig,  B.,  and  T.  Paul,  behavi- 
our of  baCteria  with  chem ical 

reagents.  206 
Kriiss,  G.   and   H.,   quantitative 

analysis  of  speCtra,  5 
Kiihn,  W.,  sterilisation  by  heat, 

166 


«TABORATORY  Manual" 
•L'     (review),  188 

Laccase,  manganese  in  oxidations 
by, 265 

Lance,  D.,  formation  of  ammo- 
nium cyanide,  2x5 

Landis,  E.  K,,  iodine  solutions 
for  sulphur  determications, 
218 

Landolph,  F.,  analysis  of  urine 
and  determination  of  pro- 
teids, glucosides,  and  non- 
fermentible  saccbaroid  mat- 
ters, 25 

Langlet,  M.  A.,  atomic  weight  of 
helium,  71 


JBly  g,  1897. 


INDEX. — SUPPLEMENT  TO  THE  CHEMICAL  NEWS; 


^^1 


Laurence,  W.  T.,  citric  acid,  162 

Laurent's  amarone,  identity  with 
tetraphenylazine,  152 

Lautb,  C,  amidised  amidines, 
300 

Le  Bon,  G.,  explanation  of  some 
experiments  of,  280 
radiations  of  the  speftrum,  312 

Lead  and  oxides  of  sulphur,  reac- 
tions between,  241,  260 
separation  of  bismuth  from,  27 

Lean,  B  ,  and  W.  H.  Perkin, 
"  Introdui5tion  to  the  Study 
of  Chemistry"  (review),  69 

Leffler,  R.   L.,  carbon   in   ferro- 
chrome.  286 
and    H.    Brearley,    carbon    in 
ferrochrome,  241 

"  Leguminous  Root  Tubercles" 
ireview),  285 

Lemal,  L.,  colouration  of  glasses, 
300 

Levulic  acid,igo 

Lewis.  H.  C,  and  T.  G.  Bonney, 
"  Genesis  and  Matrix  of  the 
Diamond"  (review),  286 

Liebermann,  L.,  "  Catalogue 
General  de  i'Exposition 
Natinnale  du  Millennaire 
Budapest,  1896"  (review),  11 

Light,  refledlion  of,  312 

Ling,  A.  R..  and  J.  L.  Baker, 
a(5tion  of  diastase  on  starch, 
1*6 

Lipases  of  different  origins,  non- 
identity  of,  203 

Lipp,  A.,  analysis  of  a  toxine 
spring,  306 

Liquid  coherers  and  mobile  con- 
du(5lors,  164 

Liquids  in  antique  vases,  312 
solubility  of,  299 

Lithium  borate,  3190 
nitride,  11 

Litmus-paper,  sensitive,  48 

Liversidge,    A.,    gold    in    saline 

deposits  and  marine  plants, 

139 

structure  of  gold  and  platinum 

nuggets  and  gold  ingots,  139 

Lloyd,  L.  L.,  J.  J.  Sudborough, 
and  P.  G.  Jackson,  diortho- 
substituted  benzoic  acids, 
138 

Lodge,  O.,  and  B.  Bavies,  influ- 
ence of  a  magnetic  field  on 
radiation  frequency,  289 

"  London,   City   and    Guilds   of. 
Institute,  Report  1S95-6"  (re- 
view), 83 
Report  1897''  (review),  310 

London,  City  and  Guilds  of,  In- 
stitute, 71 
University  of,  227 
water  supply,  41,  99,  147,  200, 
247,  306 

Long,  J.  H.,  formation  of  anti- 
mony cinnabar,  20 

Lospieau,  R.,  dibromo  i — 3  pro- 
pene,  27 

"  Louisiana  State  University, 
Ninth  Annual  Repoit  of  the 
Agricultural  Experiment 
Stations  of"  (review),  285 

Lovat,  L.  A,,  aAioa  of  zinc  upon 
red  wines,  107 

Luminescence  and  ele(5tric  sha- 
dows, 103,  III,  122,  134 

Luminous  rays  and  X  rays,  ab- 
sorption by  crystallised  media 
of.  227 

Lumsden,  J.  S.,  and  J.  Walker, 
alkylammonium  hydrosulph- 
ides,  131 


IV/T ACE,  examination  of,  71 

McConnell,  A.  H.,  and  E.  S. 
Hanes,  oxides  of  cobalt  and 
cobaltites,  161 

Macdonald,  Dr.,  constitution  of 
benzene, 68 

Mackenzie,  J.  £.,  compounds  of 
nitrogen  and  hydrogen,  141 

McCrockett,  I.,  whoshall  be  hen- 
wife,  201 

Maclurin,  derivatives  of,  127 


Magalhaes,  A.  J.  da  Cruz,  detec- 
tion of  caramel  in  wines,  21 

Magitot,  M.,  sanitation  of  match 
trade, 131 

Maglin,  M.,  art  bronze  castings, 
309 

Magnesium,  atomic    weight  of, 
148,  158,  172,  183 
nitride  as  a  reagent,  152 

Magnetic  field,   influence  of  on 
radiation  frequency,  289 
hysteresis  loss  in  straight  iron 
strips,  297 

Mallet,  J.    W.,  nitrogen  iodide, 

154 
Maltezos,    C.,    antianodic    phos- 
phorescent system,  312 
Maltose,  specific  rotation  of,  43 
Manganese,  ferrocyanides  of,  186 
in  iron  ores,  51 
in  oxidations  by  laccase,  265 
in  spiegels,  13 
ores  of  in  Russia,  143 
phosphides,  95 

separation    of    tungstic     acid 
from,  26 
"Manual  of  Chemistry"  (review), 

188 
Mar,  M.,  and  P.  Cazeneuve,  aro- 
matic synthetic  ureas,  300 
Marking  inks,  312 
Marsden,   F.,  and  J.  J.  Dobbie, 

corydaline,  259 
Marsh,  J.  E.,  and  J.  A.  Gardner, 
camphenol    from     camphor, 
308 
Marshall,  Dr.,  electrolysis,  116 
Martin,  H.  W.,  and  A.  G.  Perkin, 

rhamnazin,  309 
Mason,  W.  P.,  "  Notes  on  Quali- 
tative Analysis"  (review),  10, 
69. 
sanitary  problems   connefted 
with  municipal  water  sup- 
ply, 289 
Match  trade,  sanitation  of,  131 
"  Mathematical   Chemistry,  The 
Principles  of  "  (review),  226 
Matthews,  F.  E.,   apparatus   for 

steam  distillation,  137 
Measures  and  weights,  35 
"  Medical    Chemistry,    Progress 

ot "  (review),  70 
"  Medical  Didtionary"  (review), 

II 
Mawrow,  F.  and  W.  Muthmann, 
determination  of  bismuth,  50 
Melikion,  P.  A.,  and  P.  A.  Guye, 
normal    rotatory   dispersion, 
35 
Melting-points,  176 
Memorial   to   Profs,   Gauss   and 

Weber,  252 
Mercury,  determination  of,  28,  40, 
54,  6i,  77,91,  loi 
films,  249 
purifying,  120 
vapour,  viscosity  of,  291 
Mermet,  A.,  readlion  of  carbonic 

oxide,  275 
Metallic  alloys,  constitution   of, 
287 
salts  with  organic  bases,  com- 
pounds of,  287 
sulphides,  acid  vapours  on,  207 
sulphates,  decomposition  of,  59 
M eta-phosphoric  acid,  hydration 

of,  263 
Metal  separations  by  hydrochloric 

acid  gas,  52.  63,  76 
Metals,     melting-points,      and 
latent  heats  of  fusion  of,  278 
Metzner,  R.,  selenium  anhydride, 
II 
ammonia    upon   tellurium   bi- 
chloride, 47 
formation-heat  of  selenic  acid 
and  some  seleniates,  11 
Meunier,  J.,  precipitation  of  zinc 

sulphide,  312 
Moyer,  J.  B.,  metal   separations 
by  hydrochloric  acid  gas,  52, 
63,76 
Mica,  48 

Microbes  in  sea-water,  i 
Micro-organisms,  dissemination 

of,  266 
Milk  analysis,  167 


Milk,  fatty  matter  in,  70 
Millar,  J.  H.,H.  T.  Brown,  and 
G.  H.  Morris,  rotatory  and 
cupric-reducing  powers  of 
produ  As  of  starch  hydrolysis 
by  diastase,  43 
examination    of    produiSts    of 

starch  hydrolysis,  42 
specific    rotation    of    maltose 

and  soluble  starch,  43 
solution-density    and    cupric 
reducing  power  of  dextrose, 
Isvulose,  and  invert  sugar, 
126 
Miller,   E.  H.,  ferrocyanides   of 

zinc  and  manganese,  186 
Minerals,  gases  in,  169 
Minguin,  J.,  dimorphism  of  the 
succinates  of   the  camphols 
■\-a  and  —a,  70 
Mirrors,    use    of    with    paraffin 

lamp  and  scale,  93 
Mixer,  C.  T.,  and  H.  W.  Dubois, 

manganese  in  iron  ores,  51 
Moissan,  H.,  diamond   into  gra- 
phite in  Crookes  tube,  191 
"  Le  four  Eleftrique"  (review), 

225,  237,  250 
preparation  ot  iron  carbide,  202 
and  J.  Dewar,  liquefaftion  of 
fluorine,  277 
Molecular  rotations   of  optically 

aiStive  salts,  271 
Molybdate  method  for  phosphoric 

acid,  191 
Molybdenum,  208 

determination  of,  91,  125 
Monazite  sand,   analysis  of,  143, 
157 
sands,  181 
earths  in,  167,  205 
Monochlordiparaconic  acid,  259 
Mono-oxystearic  acid,  transform- 
ation of  oleic  acid  into,  149 
Mont  Blanc,  atmospheric  ozone 

on,  170 
Morehead,  J.  T.,  and  G.  de  Chal- 
mot,  raanufafture  of  calcium 
carbide,  3,  16,  2g,  37 
Morgan,   L.   R.,  and    G.    Helm, 
"  The    Principles  of   Mathe- 
matical Chemistry''  (review), 
226 
J.    L.    R.,    "  Outline    of    the 
Theory  of  Solution  and  Re- 
sults" (review),  202 
J.  J.,  determination  of  titanic 
acid,  134 
Morris,  D.  K.,  temperature  upon 
magnetic  and  ele(5tric  proper- 
ties ot  iron,  249 
G.  H.,  H.  T.  Brown,  and  J.  H. 
Millar,  examination   of  pro- 
ducts  of  starch    hydrolysis, 
42 

solution-density   and    cupric- 
reducing  power  of  dextrose, 
Isevulose,  and  invert  sugar, 
126 
specific    rotation    of  maltose 

and  soluble  starch,  43 
rotatory  and   cupric-reducing 
powers  of  products  of  starch 
hydrolysis  by  diastase,  43 
Morton,  W.  B.,  effeft  of  capacity 
on  stationary  eleftrical  waves 
in  wires,  187 
Mouet,  C,  and  A.  Chauvet,  ane- 
thol  and  its  homologues,  143 
Moureu,    C,    and    A.    Chauvet, 
anethol   and  homologues   of 
anethol,  239 
Mourlot,   A.,  high   temperatures 
upon  copper,  bismuth,  silver, 
tin,   nickel,    and   cobalt  sul- 
phides, 202 
Movelo,   J.    R.,    strontium    sul- 
phide, 209 
Muller,  P.   T.,   and    A.    Haller, 
"(Jhimie  Minerale,"  "Chimie 
Organique  "  (review),  226 
Multirotation,  cause  of,  295 
Munby,   A.  E.,   Bunsen    burner 

for  acetylene,  260 
Musts  of  fruit,   sterilisation   of, 

179 
Muthmann,  W.,  and  F.  Mawrow, 
determination  of  bismuth,  30 


Myers,  H,  C,  nionochlordipara- 
conic  acid,  239 


K  KTATURAL    Sciences,    cer- 
•*■'    tain  Main  Problems  of" 
(review),  10 
Neal,  J.  B.,  "  Text-book  of  Che- 

mistry  "  (review),  310 
"  Nebraska,  University  of.  Calen- 
dar, 1896-7"  (review),  166 
Neville,  F.  H.,  and   C.    T.  Hey- 
cock,  freezing-point  curves  of 
alloys  containing  zinc,  160 
X    ray   photographs    of   solid 
alloys,  260 
Newman,    K.,    "  El    Kamlic    de 
Komposizion  ke  esperimenta 
el  Aqua  de  'El  Salto'  durante 
el  Imbierno"  (review),  46 
"La   Unifikazion   da   las   Me- 
didas"  (review),  83 
Newion,  L.,  and   E.  Aston,  esti- 
mation of  zinc  oxide,  133 
New  scientific  club,  166,  190 
Nickel,   separation   from  cobalt, 
193 
iron,  193 
sulphides  and  cobalt,  11 
upon  ethylene,  187 
Nickelo-nickelic  hydrate,  65 
Nicloux,    M.,   and    L.    Bauduer, 
distillation     of   mixtures    of 
ethylic    alcohol   and    water, 
277 
glycerin,  264 
Nitrates,  nitric  acid  upon,  143 
Nitric  acid  upon  nitrates,  143 
Nitride,  lithium,  ii 
Nitrogen    and    hydrogen,    com- 
pounds of,  141 
Nitrogen  gas,  oxidation  of,  137 
in  blood,  131 
iodide,  154 

oxides    upon    ferrous   chloride 
and  bromide,  143 
Nitrous   acid,   determination   of, 
282 
reaction  for,  98 
Normal  rotatory  dispersion,  35 
Norton,    T.    H.,  aluminum    for 

condensers,  221 
"  Nouveautes      Chimiques      par 

1897  "  (review),  188 
Noyes,  A.  A.,  "  Detailed  Course 
o(  Qualitative  Chemical  Ana- 
lysis of  Inorganic  Sub- 
stances "  (review),  i83 
and  H.  M.  Goodwin,  viscosity 
of  mercury  vapour,  291 


QBITUARY,  B.  A.  Gould,  59 

Georges  Ville,  130 
Professor  Fresenius,  310 
the  late    Dr.  E.  du  Bois  Rey- 
mond,  34 

Oettel,  F.,  "Ejeftro  -  chemical 
problems"  (review),  298 

Oil  of  arachis  in  olive  oil,  251 
pile,  264 

"  Oils  and  Fats,  Praftical 
Treatise  on  Animal  and 
Vegetable"  (review),  106,  116 

Oils,  stannous  chloride  with  es- 
sential, 71 

Oleic  acid,  transformation  into 
stearolaCtone  and  monoxy- 
stearic  acid,  149 

Glides  I — 4,  potassium  cyanide 
upon,  59 

Olive  oil,  oil  of  arachis  in,  231 

Ores  of  manganese  in  Russia,  143 

Organic   acids,  chromatic   reac- 
tions produced  by,  61 
matter  in  potable  water,  ao6 

"  Organised  Science  Series  "  (re- 
view), 188 

Osmond,  F.,  alloys  of  silver  and 
copper  group,  300 

Osmotic  pressure  and  electrolytic 
dissociation,  270 

Otto,  M.,  density  of  ozone,  59 
ozone  and  phosphorescence,  11 

"  Our  Secret  Friends  and  Foes  " 
(review),  154 

Oxalates  ot  zirconium,  113 


3i8 


Index. — supplement  to  the  chemical  news. 


July  9, 1897. 


Oxidation  of  fenchene,  308 
Oxide  of  phosphorus,  202 
removal   from   melted    copper 
and  copper  alloys,  97 
Oxides  of  cobalt  and  cobaltites, 
161 
of  sulphur  and  lead,  reaAions 
between,  241,  260 
Oxygen,    discovery  of,   and   the 
"  Encyclopjedia  Britannica," 
3" 
Ozone,  density  of,  59 
and  phosphorescence,  11 

(S  pAPER-MAKERS,    Direc- 

■^    tory  of"  (review),  130 
Paraisobutylphenoxyacetic    acid, 

Parker,  H.  G.,  and  T.  W. 
Richards,  atomic  weight  of 
magnesium,  148,158,  172,  183 
M.  A.,  and  G.  G.  Henderson, 
bromdiphenylmethane  on 
ethyl  sodacetoacetate,  274 

Parr,  S.  W.,  sodium  peroxide  as 
a  third  group  reagent,  198 

Passv,  J.  perfume  of  flowers,  203 

Patein,  G.,  combination  of  anti- 
pyrine  with  the  phenols,  119 

"  Patents  for  Inventions,  Law 
and  Praftice  of"  (review), 
214 

Paul,  T.,  and  B.  Kronig,  behavi- 
our of  ba(5teria  with  chemical 
reagents,  2o5 

Payne,  G.  F.,"  Commercial  Fer- 
tilisers and  Chemicals,  In- 
spe(5ted,  &c.,  in  State  of 
Georgia"  (review),  213 

Pelabon,  H.,  combination  of  sul- 
phur and  hydrogen,  191 

Pemberton's  molybdate  method 
for  phosphoric  acid,  191 

Pennington,  M.  E.,  derivatives 
of  columbium  and  tantalum, 
8,  18,31,38 

Pennsylvania  State  College,  251 

Pentane,  normal,  vapour  pres- 
sures, specific  volumes,  and 
critical  constants  of,  160 

Perception  of  difference  of  phase 
by  the  two  ears,  274 

Perfumes  and  essences  industry, 

143 
Perigot,  M.,  transparence  of  ebo- 
nite, 300 
black  light,  227 
Perkin,  W .  H.,  and  J.  F.  Thorpe, 
camphoronic  acid,  163 
and  B.  Lean,  "  Introdudtion  to 
the  Study  of  Chemistry"  (re- 
view), 69 
A.  G.,  apiin  and  apigenin,  153, 
308 

derivatives  of  maclurin^  127 
and  H.  W.  Martin,  rhamnazin, 

♦,     309 

Permanganate  of  potash  on  bac- 
teria in  Thames  water,  171 

Peroxides  in  slow  oxidation,  287 

Perrin,  J.,  discharge  of  Rontgen 
rays, 143 

Perthiocyanic  acid,  hydrolysis  of, 

212 

Petit,  P.,  aftion  of  carbonic  acid 
of  waters  upon  iron,  35 
carbohydrates  in  beer,  180 
difference  between  top  and  bot- 
tom yeasts,  59 
A.,  and  M.  Polonovski,  pilocar- 
pine and  pilocarpidine,  275 

Phenylhydrazindiphenylglyoxazol 
chlorine  hydrate  upon,  299 

Phenylisindazol,  new  derivative 
of,  167 

Phenylsemicarbazide,  formation 
of  substituted  oxytriazoles 
from,  44 

Phenylstyrenyloxytriazole,  153 

Philadelphia  museums,  312 

Phillips,  F.  C,  sulphur  in  cast- 
iron,  194 

Phipson,  T.  L.,  ironstone  of  the 
Weald,  207 

Phosphate  in  Thomas  s'ags,  170 

Phosphonyl  chloride,  hydrogen 
sulphide  and  selenide  upon, 
9S 


Phosphoric  acid  in  fodders,  209 
molybdate  method  for,  191 
ethers  of  allylic  alcohol,  59 
Phosphorus,   aftion    upon    plati- 
num, 35 
determination  of,  281 
in  ash  of  coal  and  coke,  8 
upon  gold,  167 
Phosphoryl  chloride,  water  upon, 

300 
Photographic    plate,    af^ion    ex- 
erted by  certain  metals  on, 
302 
Photography  of  ripples,  115 
Physical  Society,  57,  93,  115,  140, 

164,  187,  249,  274,  2q6 
"  Physics,    Praftical    Work    in" 

(review),  189 
Physiological  a(5tion  of  X  rays, 

226 
Pickering,  S.,  and  H.  T.  Brown, 
thermal   phenomena  attend- 
ing change  ot  rotatory  powsr 
of  carbohydrates,  295 
thermo-chemistry    of    carbo- 
hydrate hydrolysis,  296 
Picric  acid,  toxicologicai  behavi- 
our of,  50 
Pile  oil,  264 
Pilocarpine    and     pilocarpidine, 

275 
Pinerua,  E.,  chromatic  reaftions 
produced  by  organic  acids,  61 
coloured  reaftions,  131 
separation  of  nickel  from  co- 
balt,   nickel  from   iron,   and 
cobalt  from  aluminium,  193 
Pinophanic  acid,  162 
Plants,  tannins  in,  300 
Platinum,  adtion  of  phosphorus 
upon,  35 
chloride,  recovery  of  waste,  224 
lost,  142 

nuggets,  structure  of,  139 
silver  alloys,  273 
Polarisation  of  radiations  emit- 
ted by  some  sources  of  light, 
202,  287 
Polonovski,    M.,     and   A.   Petit, 
pilocarpine  and  pilocarpidine, 
275 
Ponsot,  A.,  cryoscopic  measure- 
ments, 239 
Pope,   W.  J.,    deliquescence    in 
chloral  hydrate  crystals,  45 
refrai5tion  constants  of  crystal- 
line salts,  129 
and  F.  S.  Kipping,  derivatives 
of  camphoric  acid,  307 
enantiomorphisni,  45 
optical  inversion  of  camphor, 

306 
racemism   and   pseudoracem- 
ism,  307 
Potable  water,  organic  matter  in, 

206 
Potash  in  fodders,  209 
Potassium  cyanide    upon    elides 
I— 4i  59      , 
estimation  of,  256 
permanganate  upon  cupric  bro- 
mide, 287 
Pottery  and  Glass  Trades  Bene- 
volent Institution,  228 
Poulenc,  C,  "  Lea   Nouveautes 
Chimiques    par     1897 "    (re- 
view), 188 
♦'  Practical  Methods  of  Organic 

Chemistry"  (review),  23 
Price,  W.   A.,  alternating  cur- 
rents in  concentric  conduA- 
ors,  187 
T.  S.,  and  P.  Frankland,  amyl 
derivatives   of    glyceric,   di- 
acetylglyceric,  and  dibenzoyl- 
glyceric  acids,  128 
Properties  of  highly  purified  sub- 
stances, 126 
Prost,  E.,  and  L.  L.  de  Koninck, 

determination  of  zinc,  182 
Proteids,  determination  of,  25 
Pseudoracemism  and  racemism, 

307 
Purifying  mercury,  120 
Pyrazol  series,  isomerism  in,  6 
Pyridine  derivatives  from  etbylic 

amidocrotonate,  150 
&c.,  with  metallic  salts,  31a 


Pyrometer,  a  technical,  70 


<c  (QUALITATIVE  Analysis, 
X  Notes  on  "  (review),  10,  69 

"  Qualitative  Chemical  Analysis 
of  Organic  Substances  "  (re- 
view), 188 

"Quantitative  Analysis,  Introduc- 
tory Course  of"  (review),  188 

Quinine,  colour  reactions  of,  263 


OACEMISM      and      pseudo- 

■'■^     racemism,  307 

Radiations  of  the  speftrum,  312 

Radio- photography  of  the  soft 
parts  of  man  and  the  lower 
animals,  io2 

RafKnose  in  American  sugar 
beets,  193 

Ragiquet,  M.,  fluorescence  of 
vitrified  matters  under  the 
aftion  of  Rontgen's  rays,  107 

Ramage,  H.,  and  W.  N.  Hartley, 
analysis  of  metals,  chemical 
preparations,  and  minerals 
from  Stassfurt  potash  beds, 
151 

dissemination    of   rarer    ele- 
ments, 129 

Ramsay,  W.,  Chemical  Society, 
eleAion,  179 
new  scientific  club,  190 
and  M.  W.  T ravers,  attempt 
to  cause  helium  or  argon  to 
pass  through  red-hot  pal- 
ladium, platinum,  or  iron, 
253 

Raouit,  F.  N.,  cryoscopic  re- 
searches, 226 

Rawson,  S.  G.,  separation  of 
arsenic,  antimony,  and   tin, 

221 

barium,  strontium,    and    cal- 
cium, 247 

Rayleigh,  Lord,  oxidation  of  ni- 
trogen gas,  137 

Reclamation,  214 

Red  pigment  of  grape,  solubility 
of,  179 
wines,  aflion  of  zinc  upon,  107 

"  Register  of  Associates  and  Old 
Students  of  the  Royal  College 
of  Chemistry,  Royal  School 
of  Mines,  and  Royal  College 
of  Science  "  (review),  46 

Regnard,  P.,  and  T.  Schlcesing, 
argon  and  nitrogen  in  the 
blood,  131 

Remsen,  I.,  hydrolysis  of  acid 
amides,  200 

Remy  and  Contremoulin,  MM., 
radio- photography  of  the  soft 
parts  of  man  and  the  lower 
animals,  102 

Renwick,  F.  F.,  and  W.  S.  Gilles, 
ketopinic  acid,  162 

"  Respiratory  Proteids,  Re- 
searches in  Biological  Che- 
mistry "  (review),  262 

Reverdin,  F.,  yellow  colouring- 
matter  from  dinitrofluores- 
cine,  239 

Revis,  C,  and  F.  S.  Kipping, 
bromocampborsulpholaftone 

44 
Reycbler,  A.,  tinctorial  reaAions, 

255 
Rheostats    for    enabling    street 

currents  to  be  used  for  medi- 
cal purposes,  288 
Rice,  W.  F.,  and   E.  J.  Bartlett, 

silver  hydride,  215 
Richards,  J.  W.,  melting-points 

and  latent  heats  of  tusion  of 

metals,  278 
and  J.  A.  Thomson,  eleftrical 

conductivity   of   aluminium, 

217 
T.    \V.,    and    H.    G.    Parker, 
atomic  weight  of  magnesium, 
148,  158,  172,  183 

Rideal,  S.,  '•  Water  and  its  Puri- 
fication '*  (review),  94 

Riegler,  E.,  determination  of 
nitrous  acid,  282 


Riegler,  E.,  reaction  for   nitrous 

acid,  98 
Rivals,  P.,  salicylic  aldehyd,  132 
and   H.    Baubigny,    potassium 

permanganate    upon    cupric 

bromide,  287 
separation    of    chlorine    and 
bromine,  236 
Riviere,    P.,    and   J.    Sabrazes, 

biological  adtion  of  X  rays, 

281 
Rodger,  J.  W.,and  T.  E.  Thorpe, 

viscosity  of  mixtures  of  mis- 

cible  liquids,  152 
Romijn,   G.,  detection   of  form- 

aldehyd,  71 
determination  of  formaldehyd, 

70 
Romme,  R.,  tuberculine,  275 
Ronde,  sensitive  litmus  paper,  48 
"  Rontgen  Rays  "  (review),  58 
Rontgen    rays    applied    to    pul- 
monary tuberculosis^  II 
discharge  of,  143 
fluorescence  of  vitrified   mat- 
ters under  the  aCtion  of,  107 
Rose-Innes,  J.,  isothermals  of  iso- 

pentane,  275 
Rose    Polytechnic    Institute    of 

Terre  Haute,  Indiana,  251 
Rosenstiehl,  A.,  solubility  of  red 

pigment  of  grape,  and  sterili- 
sation of  musts  of  fruit,  179 
Ross,  B.  B.,  analytical    methods 

involving  the  use  of  hydro. 

gen  dioxide,  81 
Rothenburg,   R.^von,  isomerism 

in  the  pyrazol  series,  6 
Rousset,    L.,  essence    of    cedar 

wood,  276 
Royal  Academy  of   Sciences  of 

Turin,  48 
Institution,  48,  83, 115,  180, 191, 

227,  251,  300 
Society,  250,  298 
Rubidamide,  151 
Ruhemann,  S.,and  A.S.  Heramy, 

ketonic  acids,  153,  161 
Russell,  E.  J.,  and  H.  B .  Dixon, 

explosion    of   chlorine    per- 
oxide with  Carbonic  oxide,  259 
W.  J.,  aftion  exerted  by  certain 

metals    on    a    photographic 

plate,  302 
Russia,  ores  of  manganese  in,  143 

Q?  ABATIER,  P.,  and  J.  B.  Sen- 
^   derens,  nickel  upon  ethylene, 

187 
Sabrazes,  J.,  and  P.  Riviere,  bio- 
logical action  of  X  rays,  281 
Saccharoid  matters,   determina- 
tion of,  23 
Salicylic  aldehyd,  132 
Salts,  free  bases  upon,  167 
Sand,  analysis  of  monazite,  143, 

157 

Sanitation  of  match  trade,  131 

Sanitary  problems  connected 
with  municipal  water  supply, 
289 

Saniter,  E.  H.,  carbon  in  ferro- 
chrome,  287 

Schaffer,  H.A.,and  E.  F.  Smith, 
tungsten  hexabromide,  37 

Schlcesing,  T.,  and  P.  Regnard, 
argon  and  nitrogen  in  blood, 
.  131 

Schneider,  R.,  atomic  weight  of 
tungsten,  71 

"  School  of  Mines,  Laramie, 
Wyoming, Petroleum  Series" 
(review),  262 

Schuite,  W.,  sulphur  in  iron,  47 

Schutzenberger  and  Boudouard, 
MM.,  earths  in  monazitic 
sands,  167,  205 

Scbwan,  A.,  and  T.  Curtius,  sub- 
stituted glycolic  esters  and 
glycolhydrazid,  7 

Scott,  A.,  atomic  weight  of  car- 
bon, 163 
sulphates  of  vitriol  groupi  I63 

Sea-water  microbes,  i 
on  induction  telegraphy,  296 

Segny,  G.,  and  F.  de  Courmelles, 
kathodic  apparatus  generat- 
ing X  rays, 213 


July  9, 1897. 


INDEX. — SUPPLEMENT  TO  THE   CHEMICAL  NEWS. 


319 


Selenates  of  potassium, rubidium, 
and  cassium,  272 

Seleniates,  formation  heat  of,  11 

Selenic  acid,  formation  heat  of, 
II 

Selenide,  upon  phosphonyl  chlor- 
ide, 95 

Selenium  anhydride,  ii 

Senderens,  J.  B.,  and  P.  Sabatier, 
nickel  upon  ethylene,  187 

Sensitive  litmus  paper,  48 

Serrent,  E,,  gold  from  auriferous 
ores,  149 

Seubert,  K.,  unity  of  atomic 
weights,  49 

Sewer  gas,  destroying  germ 
emanations  from,  266 

Seyewetz,  A.,  and  P.  Sisley, 
"  Chimie  des  matieres  Color- 
antes  Artificielles"  (review), 
286 

Shellac  acids  in  separation  of 
fatty  acids  and  resin  acids,  70 

Shenstone,  W.  A.,  properties  of 
highly  purified  substances, 
126 

Shober,  W.,  and  L.  Gatterman, 
"  FraAical  Methods  of  Or. 
ganic  Chemistry"  (review),  23 

Siderurgy,  sulphur  in  produfts  of, 

35 
Silicates,  97 

Silver  and  copper  group  alloys, 
300 
chloride      and     monomethyl- 

amine,  288 
determination  of,  28,  40,  54,  61, 

77,  91,  loi 
hydride,  215 
6pe(5tra  of,  2 
Sisley,    P.,    and     A.    Seyewetz, 
"  Chimie  des  matieres  Color- 
antes  Artificielles  "  (review), 
286 
Skey,   W.,  cyanide    process    for 

gold  extraftion,  47 
Smith,  E,  A.,  and  H.  C.  Jenkins, 
readtions  between  lead  and 
oxides  of  sulphur,  241,  260 
E.  F.,  and  A.  L.  Benkert, 
separation  of  bismuth  from 
lead,  27 

C.  Field,  separation  of  vana- 
dium from  arsenic,  26 
J.  Kelley,  jun.,  acid  vapours 

on  metallic  sulphides,  207 
H,  A.  Schaffer,  tungsten  hexa- 

bromide,  37 
W.  T.  Taggart,  separation  of 
manganese    from    tungstic 
acid,  26 
J.  B., "Quantitative  Estimation 
of  Urine  "  (review),  189 
Snape,   H.  L.,   and  A,   Brooke, 
identity  of  Laurent's  amar- 
one    with    tetraphenylazine, 

'52     .  .    ., 

magnesium    nitride    as    a    re- 
agent, 152 
Snyder,     H.,     "  Chemistry     of 

Dairying  "  (review),  117 
Societe    d'Encouragement    pour 

rindustrie,  309 
Society,   Chemical,    42,  56,   125, 
137.  150, 159. 176,  210,  259,  270, 
295.  306 
Edinburgh   University  Chemi- 
cal, 141 
of  Public  Analysts,  I2 
Physical,  57.  93.  ii5»  UO,  164, 

187,  249,  274, 296 
Royal,  250,  298 
Soda  and  ultramarine  manufac- 
turers, 35 
Sodamide  and  derivatives,  150 
Sodium,  equivalent  of,  50 
peroxide  as  a  third  group   re- 
agent, 198 
salicylate     in      presence      of 
ichthyol,  71 
Soil  ferments  important  in  agri- 
culture, 222.  230 
Solanaceous  alkaloids,  gold  salts 

of,  308 
•'  Solutions,  Outline  of  Theory  of, 

and  Results  "  (review),  202 
Sophistication  of  foods,  252 
Sore),  M.,  a^ion  of  K  rays,  214 


Spaeth,  E.,  examination  of  mace, 

71 
Speftra    of   copper,    silver,   and 
gold,  2 
quantitative  analysis  of,  5 
Spencer,   F,,  "  Chapters   on   the 
Aims  and  Praftice  of  Teach- 
ing" (review),  165 
Spica,  M.,  determination  of  phos- 
phorus, 281 
Spiegels,  manganese  in,  13 
Spiller,  J.,  platinum-silver  alloys, 

273 
Stannic  chlorobromides,  191 
Stannous  chloride  with  essential 

oils,  71 
Starch,  diastase  on,  126 
hydrolysis,  examination  of  pro- 
duAs  of,  42 
rotatory  and   cupric-reducing 
powers   of   products   of  by 
diastase,  43 

specific  rotatory   and  cupric- 
reducing  powers  •£  products 
of,  70 
specific  rotation  of  soluble,  43 
Starches,  enzyms  upon,  238 
Starchy  produAs,  by-produdts  of 

distillation  of,  203 
Stas  memorial,  215 

J.  S.,  monument,  312 
Stassfurt  potash  beds,   analysis 
of  metals,  chemical  prepara- 
tions,  and  minerals  from,  151 
Steam  distillation,  apparatus  for, 

137.  279 
Stearola(5tone,  transformation  of 

oleic  acid  into,  149 
Steel,  a£tion  of  boron  on,  91 

and  iron  analysis,  257,  269,  283 
"  Steel,  Manufafture  and  Proper- 
ties of  Struftural "  (review), 
69 
Sterilisation  by  heat,  166 
Stevens,  H.  P.,  and  F.  D.Chatt- 
away,  hydrolysis  of  perthio- 
cyanic  acid,  212 
T.  M.,  and  L.  Edmunds,  "  Law 
and      Practice     of     Letters 
Patent  for  Inventions  "  (re- 
view(,  214 
Stilbene    series,    researches    in, 

138 
Stillman,  T.  B.,  "  Engineering 

Chemistry"  (review),  117 
Stone,  W.  E.,  "Carbohydrates  of 
Wheat,   Maize,    Flour,    and 
Bread  "  (review),  213 
and   W.  H.  Baird,  raffinose  in 
American  sugar  beets,  193 
Stockhausen,    Dr.,    liquation  in 

cyanide  bars,  310 
Strontium,  calcium,  and  barium, 
separation  of,  247 
sulphide,  299 
Strudture  and  symmetry,  homo- 
geneity of,  140 
Student,  how  soon  study  qualita- 
tive analysis  ?  85,  107,  119 
'•  Students,  Notes  for  Chemical  " 

(review),  10 
Substituted  oxytriazoles,  forma- 
tion of,  44 
Sudborough,  J.  J.,  P.  G.Jackson, 
and   L.   L.    Lloyd,    diortho- 
substituted  benzoic  acids,  138 
researches     in     the     stilbene 
series,  138 
Sugar  beets,  ra£Bnose  in  Ameri- 
can, 193 
estimation  of,  igi 
group,  161 
"  Sugars,  Quantitative  Estima- 
tion of"  (review),  lo 
Sugars,  transformations  of,  190 
Sulphates  of  vitriol  group,  163 
Sulphur  and  hydrogen,  combina- 
tion of,  igi 
determination  of,  11 
determinations,    iodine    solu- 
tions for,  218 
in  cast-iron,  194 
in  iron,  47,  109 
steel,  and  sulphides   of  iron, 

121 
produdts  of  in  siderurgy,  35 
Sulphuric   acid,  dermination    of 
equivalent  of,  25 


Sulphurous  acid,   dithionic   acid 

in  oxidation  of,  139 
Swinton,  A.  C.  C,  experiments 

with  cathode  rays,  218,  233, 

245 


'pAGGART,  W.  T.,  and  E.  F. 
■*■      Smith,  separation  of  man- 
ganese from  tungstic  acid,  26 

Talbot,    H.    P.,     "  Introduaory 
Course  of  Quantitative  Ana- 
lysis" (review),  l8S 
volatility  of  ferric  chloride,  227 

Tannin  upon  alkaloids,  167,  179, 
202 

Tannins  in  plants,  300 

Tanret,  M.,  nitric  acid  upon  ni- 
trates, 143 

Tantalum,  derivatives  of,  8,  18, 
3'.  38 

Tasmania  Government  labora- 
tory, 22 

Tassilly,  M.,  basic  salts  of  cad- 
mium, 299 

Taylor,   R.  L„  hypoiodous  acid 
and  hypoiodites,  97 
W.  W.,  eledtrolytic   dissocia- 
tion of  water,  116 

"  Tea :  A  Text-book  on  Tea- 
Planting  and  Manufadlure" 
(review),  261 

"  Teaching,  Aims  and  Pradtice 
of  "  (review),  165 

Teaching  of  chemistry,  166 

Telegraphy,  sea-water  on  induc- 
tion, 296 

Telephone,  nickel  stress,  187 

Tellurium,  atomic  weight  of  Ja- 
panese, 175 
bichloride,  ammonia  upon,  47 

Temperature,  influence  on  rota- 
tory power,  107 

Thalleoquin  test  for  quinine,  207 

Thames  water,  permanganate  of 
potash  and  acetic  acid  on 
badteria  in,  171 

Thermal  phenomena  attending 
change  of  rotatory  power  of 
carbohydrates,  293 

Thermic  constants,  law  of,  263 

Thermo-chemistry  of  carbohy- 
drate hydrolysis,  396 

Thermo-eledtric  properties  of 
some  liquid  metals,  116 

Thermometers,  instrument  for 
comparing  with  a  standard, 
249 

Thomas,  G.  L.,  and  S.  Young, 
hydrocarbons  from  American 
petroleum,  159 
v.,  nitrogen  oxides  upon  fer- 
rous chloride  and  bromide, 
143 

Thompson,   E.   P.,   and   W.   A. 
Anthony,  "  Rontgen   Rays" 
(review),  58 
S.  P.,  eled^ric  shadows  and  lu- 
minescence, 103,  III,  122,  134 

Thomson,  J.  A.,  and  T-  W.  Rich- 
ards, eledlrical  condudtivity 
of  aluminium,  217 

Thoria,  estimation  of,  145,  157 
from  zirconia,    separation    of, 
230 

Thorium,  276 

Thorp,  F.  H.,  "Inorganic  Che- 
mical Preparations  "  (re- 
view), 46 

Thorpe,  J.  F.,  and  W.  H.  Per- 

kin,  camphoronic  acid,  163 

T.  E.,  new  scientific  club,  166 

and  J.  W.  Rodger,  viscosity  of 

mixtures  of  miscible  liquids, 

152 

Thudichum,  J.  L.  W,,  "  Progress 
of  Medical  Chemistry  "  (re- 
view), 70 

Tichborne,  C.  R.  C,  dissemina- 
tion of  micro-organisms,  266 

Tilden,  W.  A,,  gases  in   crystal- 
line rocks  and  minerals,  169 
"  Manual  of  Chemistry"   (re- 
view), 188 

Tin,  arsenic,  and  antimony,  sepa- 
ration of,  221 

Tindlorial  readtions,  256 

Titanic  acid,  134 


Titanium,  occurrence  of,  22 

Titherley,  A.  W.,  sodamide  and 
derivatives,  150 
rubidamide,  151 

Tombeck,  D.,  compounds  of  me- 
tallic salts  with  organic 
bases,  287 

Tommasi,  D.,  law  of  thermic 
constants,  263 

Toxine  spring,  analysis  of  a,  306 

Travers,  M.  W.,  and  W.  Ram- 
say, attempt  to  cause  helium 
or  argon  to  pass  through  red- 
hot  palladium,  platinum,  or 
iron,  253 

Triethylene-dlphenyl  hydrazines, 
two  isomeric,  107 

Tropical  food,  265 

Tuberculin  O  and  R,  203 

Tuberculine,  275 

Tungsten,  atomic  weight  of,  71 
hexabromide,  37 

Tungstic  acid,  separation  of  man< 
ganese  from,  26 

Turin,  Royal  Academy  of  Sci- 
ences, 48 

Tutton,  A.   E.,    refradtion    con- 
stants of  crystallised  salts, 
129 
selenates  of   potassium,   rubi- 
dium, and  caesium,  272 


TTLTRAMARINE    and     soda 

'-'     manufadturers,  35 

Ulzer,  F,,  and  R.  Defris,  shellac 
acids  in  separa'ion  of  fatty 
acids  and  resin  acids,  70 

"  Unifikasion  da  las  Medidas" 
(review),  83 

University  of  London,  227 

"  University  of  Nebraska,  Calen- 
dar 1896-7"  (review),  i55 

"  University  Tutorial  Series,  The 
Tutorial  Chemistry — Pt..  I., 
Non-Metals"  (review),  83 

Uranium  residues,  working  up, 
98 

Urbain,  G.,  and  E,  Budischov- 
sky,  monazitic  sands,  181 

Urea  formation  in  aqueous  alco- 
hol, 177 
high  homologue  of,  107 

Ureas,  aromatic  synthetic,  300 

Urine,  analysis  of,  25 

"Urine,  Q  jantitative  Estimation 
of"  (review),  189 


yALENTA,    E..    and    J.    M, 
"      Eder,  spedtra  of  copper,  sil- 
ver, and  gold,  2 

Vanadium,  determination  of,  gi, 
125 
separation  of  arsenic  from,  26 

Vanilline,  produdtion  of,  47 

Van  't  Hoff's  constant,  verifica- 
tion of,  309 

Varet,  R.,  pyridine,  &c.,  with 
metallic  salts,  312 

Vasey,  S.  A,,  lost  platinum,  142 

Venable,  F.  P.,  and  C.  Basker- 
ville,  oxalates  of  zirconium, 
"3 

Verneuil,  A.,  and  M.  Wyrouboff, 
purification  of  cerium,  292 

Villari,  E.,  discharging  eled^rised 
bodies  by  X  rays,  &c.,  11 

Ville,  Georges,  obituary,  130 

Vincent,  J.  H.,  photography  of 
ripples,  115 

Viscose  and  viscoid,  74,  85 

Viscosity  of  mixtures  of  miscible 
liquids,  152 


VITADDELL,  J.,   permeability 

'  *      to  X  rays,  263 

Wait,  0.  E.,  occurrence  of  tita- 
nium, 22 

Walker,  O.  F,,  and  F.  A.  Gooch, 
application  of  iodic  acid  to 
analysis  of  iodides,  196 
J.,  and  F.  J.  Hambly,  eledtrical 
condudlivity  of  diethyl- 
ammonium  chloride  in  aque-< 
ous  alcohol,  44 


320 


INDEX. — SUPPLEMENT  TO  THE  CHEMICAL  NEWS. 


July  9, 1897. 


Walker,  J.,  and  S.  A.  Kay,  urea 
formation  in  aqueous  alcohol, 

J.   S.   Lumsden,    alkylammo- 
nium  hydrosulphides,  151 

Warder,  R.  B.,  speed  of  esterifi. 
cation,  227 

Warren,  H.  N.,  aftion  of  boron 
on  iron  and  steel  and  errors 
in  iron  analysis,  91 
calcium  carbide,  2 
estimation  of  potassium,  256 

"  Water  and  its  purification"  (re- 
view), 94 

"  Water  and  Public  Health"  (re- 
view), 285 

Water,  eledtrolytic  dissociation 
of,  116 
supply,  London,  41,  99, 147,  200, 
247,  306 

sanitary  problems,  289 
upon  phosphoryl  chloride,  300 

Waterproofing  canvas,  108 

Watson,  W.,  instrument  for  com- 
paring thermometers  with  a 
standard,  249 

Weber  and  Gauss  memorial,  252 

Wechsler's  method  for  separa- 
tion of  fatty  acids,  138 

Weights  and  measures,  35 

Wein,  E.,and  W.  Frew.'Quan- 
titative  Estimation  of  Su- 
gars" (review),  10 

Wells'  patent  continuous  cooling 
process,  240 

Wheats,  composition  of,  258 


Wheats  of  Department  Du  Nord, 
decrease  of  nitrogenous  mat- 
ter in,  95 
White  wines  and  liqueurs,  yellow 
of  naphthol  S  in,  256 
coal-tar  colours  in,  264 
colouring  matters  of  coal  in, 

'57 
Whitehead,  C.  S.,  sea-water  on 

induction  telegraphy,  296 
Who  shall  behenwife,  201 
Wiesbaden  chemical  laboratory, 

143 
Wigley,  H.,  how  soon  shall  stu- 
dent study  qualitative  analy- 
sis, 119 
Wilcox,   A.   J„  "  Catechism    of 
Chemistry  arranged  for  Be- 
ginners" (review),  46 
Wilderman,  M.,  Dalton's  law  in 
solutions,  274 
verification  of  van 't  Hoff  's  con- 
stant, 309 
Wiley,  H.  W.,  potash  and  phos- 
phoric acid  in  fodders,  209 
"  Principles    and    Praftice    of 
Agricultural  Analysis"    (re- 
view), 165 
recovery    of    waste    platinum 

chloride,  224 
soil      ferments    important    in 

agriculture,  222,  230 
rotation  and  reducing  powers 
of   hydrolysed    starch   solu- 
tions, 131 
Williams,  K.  I.,  cooked  fish,  21a 


Wilson,  J.  A.,  specific  rotatory 
and  cupric  reducing  powers 
of  produfts  of  starch  hydro- 
lysis by  diastase,  70 

Wines,  colouring  matters  of  coal 
in  white,  157 
ferment  of  fradture  of,  203 

Wood,  Sir  H.  T.,  reproduaion  of 
colour  by  photographic  me- 
thods, 95 

Woodward,  C  J.,  how  soon  shall 
the  student  study  qualitative 
analysis,  107 

Woolcombe,  W.  Q.  "  Practical 
Work  in  Physics"  (review), 
189 

Wright,  H.  E.,  "Handbook  for 
Brewers"  (review),  142 

WyroubofF,  M.,  and  A.  Verneuil, 
purification  of  cerium,  292 


'V'-RAY    photographs   of   solid 
^^    alloys,  260 
X-Rays,  131 
ai5tion  of,  214 

and  luminous  rays,  absorption 
by  crystallised  media  of,  227 
biological  aftion  of,  281 
kathodic  apparatus  generating, 

215 
law  of  transparency   of  gases 

for,  95 
permeability  to,  263 
physiological  a^ion  of,  226 


YEASTS,  top  and  bottom,  59 

Yellow  colouring    matter    from 

dinitrofluorescine,  239 
Young,  G.,  and  H.  Annable,  for- 
mation of  substituted  oxytri- 
azoles  from  phenylsemicarb- 
azide,  44 
and  G.  L.  Thomas,  hydrocar- 
bons from  American   petro- 
leum, 159 
oxidation    of    phenylstyrenyl- 

oxytriazole.  153 
S.,  vapour  pressures,    specific 
volumes    and    critical     con- 
stants of  normal  peutane,  160 


'7  INC,  determination  of,  182 

ferrocyanides  of,  186 
freezing-point  curves  of  alloys 

containing,  160 
oxide,  estimation  of,  133 
sulphide,  precipitation  of,  312 
upon  red  wines,  acStion  of,  107 
Zirconium,  oxalates  of,  113 
Zirconia,    separation    of    thoria 

from,  230 
Zouandi,  F.,  alkaloidal  stearates 
and  their  therapeutic   appli- 
cation, 71 


END  OF  VOLUME   LXXV. 


THE   CHEMICAL   NEWS,  January  7,  1898. 


THE 


CHEMICAL  NEWS 


JOURNAL     OF     PHYSICAL     SCIENCE. 


WITH    WHICH    IS    INCORPORAT-ED   THE    "CHEMICAL   GAZETTE." 


%  |0itnxal  0f  Urartiral  Cl^^mistrj 


IN    ALL    ITS    APPLICATIONS    TO 


PHARMACY,  ARTS,  AND  MANUFACTURES. 


EDITED   BY 


SIR      WILLIAM      CROOKES,      F.R.S,,     &c. 


VOLUME    LXXVI.— 1897. 


LONDON : 
PUBLISHED  AT  THE  OFFICE,  6  &  7,  CREED  LANE,  LUDGATE  HILL,  E.C. 

AND  SOLD  BY  ALL  BOOKSELLERS. 

MDCCCXCVII. 


T  '  \      '  f  Chemical  News, 

'  I        an.7,  ligS' 


LONDON : 

PRINTED       BY      EUVVIN      JOHN      DAVEY, 

6   &    7,    CREED    LANE,   LUDGATE    HILL, 

E.C. 


THE     CHEMICAL    NEWS. 


VOLUME      LXXVI. 


EDITED    BY    WILLIAM    CROOKES,    F.R.S.,    S'C. 


No.  1962.— JULY  2,  1897. 


DIAMONDS.' 

By  WILLIAM  CROOKES,  F.R.S.,  M.R.L 

(Continued  from  vol.  Ixxv.,  p.  302). 

Depositing  Floors. 
Owing  to  the  refradlory  charadler  of  blue  ground  fresh 
from  the  mines,  it  has  to  be  exposed  to  atmospheric  in- 
.flences  before  it  will  pulverise  under  the  a(5tion  of  water 
and  mechanical  treatment.  It  is  brought  to  the  surface 
and  spread  on  the  floors.  Soon  the  heat  of  the  sun  and 
moisture  produce  a  wonderful  effedt.  Boulders,  hard  as 
ordinary  sandstone  when  fresh  from  the  mine,  commence 
to  crumble.  At  this  stage  the  treatment  of  the  diamonds 
assumes  more  the  nature  of  farming  than  mining.  To 
assist  pulverisation  by  exposing  the  larger  pieces  to  atmo- 
spheric influences,  the  ground  is  frequently  harrowed  and 
occasionally  watered.  The  length  of  time  necessary  for 
crumbling  the  ground  preparatory  to  washing,  depends  on 
the  season  of  the  year  and  the  amount  of  rain.  The 
longer  the  ground  remains  exposed  the  better  it  is  for 
washing.  When  the  process  is  complete  the  softened 
friable  blue  clay  is  again  loaded  into  trucks  and  taken  to 
the  washing  machinery,  where  it  is  agitated  with  water 
and  forced  through  a  series  of  revolving  cylinders  perfo- 
rated with  holes  about  an  inch  in  diameter ;  incorrigible 
lumps  that  will  not  pass  the  cylinders  are  again  subjefted 
either  to  the  weathering  process  or  passed  between 
crushing  rollers. 

Washing  and  Concentrating  Machinery. 
The  fine  ground  which  has  passed  through  the  holes 
in  the  cylinder,  together  with  a  plentiful  current  of  water, 
rflows  into  the  washing  pans.  These  pans  are  of  iron, 
14  feet  in  diameter,  furnished  with  ten  arms  each  having 
six  or  seven  teeth.  The  teeth  are  set  to  form  a  spiral,  so 
that  when  the  arms  revolve  the  teeth  carry  the  heavy 
deposit  to  the  outer  rim  of  the  pan,  while  the  lighter 
material  passes  towards  the  centre  and  is  carried  from  the 
pan  by  the  flow  of  water.  The  heavy  deposit  contains 
the  diamonds.  It  remains  on  the  bottom  of  the  pan  and 
near  its  outer  rim.  This  deposit  is  drawn  off  every 
twelve  hours  by  means  of  a  broad  slot  in  the  bottom  of 
the  pan.  The  average  quantity  of  blue  ground  passed 
through  each  pan  is  from  400  to  450  loads  in  ten  hours. 
The  deposit  left  in  each  pan  after  putting  through  the 
above  number  of  loads  amounts  to  three  or  four  loads, 
which  go  to  the  pulsator  for  further  concentration. 

*  A  Lefture  delivered  at  the  Royal  Institution,  Friday,  June  nth, 
a  897. 


The  Pulsator. 

The  Pulsator  is  an  ingeniously  designed,  somewhat 
complicated  machine  for  dealing  with  the  diamantit'erous 
gravel  already  reduced  one  hundred  times  from  the  blue 
ground ;  the  pulsator  still  further  concentrating  it  till  the 
stones  can  be  picked  out  by  hand.  The  value  of  the 
diamonds  in  a  load  of  original  blue  ground  is  about  30s., 
the  gravel  sent  to  the  pulsator  from  the  pans,  reduced  a 
hundred-fold,  is  worth  ;^i50  a  load. 

The  sorting  room  in  the  pulsator  house  is  long,  narrow, 
and  well  lighted.  Here  the  rich  gravel  is  brought  in  wet, 
a  sieve  full  at  a  time,  and  is  dumped  in  a  heap  on  tables 
covered  with  iron  plates.  The  tables  at  one  end  take  the 
coarsest  lumps,  next  comes  the  gravel  which  passed  the 
|-inch  holes,  then  the  next  in  order,  and  so  on.  The  first 
sorting,  where  the  danger  of  robbery  is  greatest,  is  done 
by  thoroughly  trustworthy  white  men.  Sweeping  the  heap 
of  gravel  to  the  right,  the  sorter  scrapes  a  little  of  it  to  the 
centre  of  the  table  by  means  of  a  flat  piece  of  sheet  zinc. 
With  this  tool  he  rapidly  surveys  the  grains,  seizes  the 
diamonds,  and  puts  them  into  a  little  tin  box  in  front  of 
him.  The  stuff  is  then  swept  off  to  the  left,  and  another 
lot  taken,  and  so  on,  till  the  sieve-ful  of  gravel  is  ex- 
hausted, and  another  brought  in. 

The  diamond  has  a  peculiar  lustre,  impossible  to  mis- 
take. On  the  sorting  table  the  stones  look  like  clear 
pieces  of  gum  arable,  but  with  an  intrinsic  lustre  which 
makes  a  conspicuous  shine  among  the  other  stones. 

Watching  the  white  men  in  the  sorting  room  is  an 
experience  but  tame  compared  to  the  excitement  of  taking 
a  sorter's  place  at  the  big  diamond  table  and  disinterring 
from  the  gravel  diamonds  usually  described  as  the  finest 
and  biggest  found  for  many  a  day.  The  interest,  how- 
ever, abates  when  the  amateur  sorter  is  told  that  the 
jewels  may  not  be  carried  away  as  mementos  ! 

Sometimes  as  many  as  8000  carats  of  diamonds  are 
separated  in  one  day,  representing  about  ;£'ro,ooo  in  value. 

Diamonds  occur  in  all  shades,  from  deep  yellow  to 
pure  white  and  jet-black,  from  deep  brown  to  light  cin- 
namon ;  they  are  also  green,  blue,  pink,  yellow,  orange, 
and  opaque. 

The  Diamond  Office. 

From  the  pulsator  sorting  room  the  stones  are  taken  to 
the  Diamond  Office  to  be  cleaned  in  acids  and  sorted 
into  classes  by  the  valuators,  according  to  colour  and 
purity.  It  is  a  sight  for  Aladdin  to  see  the  valuators  at 
work  in  the  strong-room  of  the  De  Beer's  Company  at 
Kimberley.  The  tables  are  literally  heaped  with  stones 
won  from  the  rough  blue  ground, — stones  of  all  sizes, 
purified,  flashing  and  of  inestimable  price ;  stones  that  will 
be  coveted  by  men  and  women  all  the  world  over;  and 


Diamonds. 


t  CbbmicalNews, 
1      July  2, 1807. 


last  but  not  least  stones  that  are  probably  destined  to 
largely  influence  the  development  and  history  of  a  whole 
huge  continent. 

When  the  diamantiferous  gravel  has  ,been  washed 
down  to  a  point  at  which  the  stones  can  be  picked  out  by 
hand,  a  good  plan  for  separating  them  is  by  their  spe- 
cific gravities.  The  following  table  gives  the  specific 
gravities  of  the  minerals  found  on  the  sorting  tables.  I 
have  also  included  the  specific  gravities  of  two  useful 
liquids : — 

Specific  gravity. 

Hard  graphite ..     ..     ..     ••     ..  2*5 

Quartzite  and  granite 26 

Beryl 27 

Mica 2'8 

Horneblende 3'o 

Methylene  Iodide       3*3 

Diamond 3*5 

Thallium  Lead  Acetate  ,.     ..  3*6 

Garnet       37 

Corundum.. 3*9 

Zircon 4*4 

Barytes      4*5 

Chrome  and  titanic  iron  ore  ..     ..  47 

Magnetite 5*0 

This  table  shows  that  if  I  throw  the  whole  mixture  of 
minerals  into  methylene  iodide,  the  horneblende  and  all 
above  that  mineral  will  rise  to  the  surface;  while  the 
diamond  and  all  minerals  below  will  sink  to  the  bottom. 
If  I  now  take  these  heavy  minerals,  and  throw  them  into 
thallium  lead  acetate,  they  will  all  sink  except  the  diamond 
which  floats  and  can  be  skimmed  off. 

In  illustration,  I  have  arranged  an  experiment.  In 
front  of  the  lantern  is  a  cell  containing  a  dense  liquid ; 
when  I  throw  into  it  several  minerals  of  different  specific 
gravities,  some  sink  whilst  others  swim,  and  these  swim- 
mers can  easily  be  skimmed  from  the  surface. 

The  "  Compound"  System. 

With  gems  like  diamonds,  where  infinite  riches  are 
concentrated  in  so  small  a  bulk,  it  is  not  surprising  that 
safeguards  against  robbery  are  elaborate.  The  Illicit 
Diamond  Buying  (I.D.B.)  laws  are  stringent,  and  the 
searching,  rendered  easy  by  the  "compounding"  of  the 
natives,  is  of  a  drastic  charadler.  In  fadt,  it  is  very  diffi- 
cult for  a  native  employe  to  steal  diamonds  ;  even  were 
he  to  succeed,  it  would  be  almost  impossible  to  dispose  of 
them,  as  a  potential  buyer  would  prefer  to  secure  the  safe 
reward  for  detedting  a  theft  rather  than  run  the  serious 
risk  of  doing  convidt  work  on  the  Cape  Town  Breakwater 
for  a  couple  of  years.  Before  the  passing  of  the  "  Diamond 
Trade  Adt"  the  value  of  stolen  diamonds  reached  nearly 
one  million  sterling  per  annum. 

One  great  safeguard  against  robbery  is  the  "  compound  " 
system  of  looking  after  the  natives.  A  "  compound  "  is  a 
large  square,  about  20  acres  in  extent,  surrounded  by  rows 
of  one-storey  buildings  of  corrugated  iron.  These  are 
divided  into  rooms  each  holding  about  twenty  natives.  A 
high  iron  fence  is  eredled  around  the  compound,  10  feet 
from  the  buildings.  Within  the  enclosure  is  a  store  where 
the  necessaries  of  life  are  supplied  to  the  natives  at  a  re- 
duced price,  and  wood  and  water  free  of  charge.  In  the 
middle  is  a  large  swimming-bath  with  fresh  water  running 
through  it.  The  rest  of  the  space  is  devoted  to  games, 
dances,  concerts,  and  any  other  amusement  the  native 
mind  can  desire.  In  case  of  accident  or  illness  there 
is  a  well-appointed  hospital  where  the  sick  are  tended. 
Medical  supervision,  nurses,  and  food  are  supplied  free  by 
the  Company. 

As  a  rule  the  better  class  of  natives — the  Zulus,  Mata- 
beles,  Basutos,  Bechuanas — when  well  treated,  are  honest 
and  loyal. 

In  the  compound  are  to  be  seen  representatives  of 
nearly  all  the  picked  types  of  African  tribes.  Each  tribe 
keeps  to  itself,  and  to  go  round  the  buildings  skirting  the 


compound  is  an  admirable  objedt-lesson  in  ethnology.  At 
one  point  is  a  group  of  Zulus;  next  we  come  to  Fingoes; 
then  Basutos ;  beyond  come  Matabele,  Bechuanas,  Pondos, 
Shangains,  Swazis,  and  other  less-known  tribes,  each 
forming  a  distindl  group,  or  wandering  around  making;, 
friendly  calls.  We  went  one  afternoon  to  the  De  Beers 
compound  when  most  of  the  natives  were  assembled,  and 
having  a  camera  with  me  I  was  naturally  glad  to  get  as 
many  photographs  aa  I  could.  I  have  to  thank  Captain 
Dallas,  Mr.  Moses,  and  Mr.  Mandy,  the  Superintendents 
of  the  respedtive  compounds,  who  speak  all  the  dialedts 
fluently,  for  their  kindness  in  showing  us  round  and 
improvising  dances  and  concerts,  for  the  benefit  of  my 
camera. 

The  clothing  in  the  compound  is  diverse  and  origitial. 
Some  of  the  men  are  great  dandies,  whilst  others  think 
that  in  so  hot  a  climate  a  bright  coloured  pocket- 
handkerchief  or  "  a  pair  of  spedtacles  and  a  smile  "  is  as 
great  a  compliance  with  the  requirements  of  civilisation 
as  can  be  expedted. 

The  Diamond. 

So  distindtive  are  the  charadters  in  diamonds  from  each- 
mine  that  an  experienced  buyer  at  once  tells  the  locality - 
of  any  particular  parcel  of  stones.  De  Beers  and  Kim- 
berley  mines  are  distinguished  by  large  yellowish  crystals. 
Dutoitspan  yields  mainly  coloured  stones,  while  Bulfontein 
— half  a  mile  off— produces  small  white  stones,  occasion- 
ally speckled  and  flawed,  but  rarely  coloured.  Diamonds 
from  the  Wesselton  mine  are  nearly  all  irregular  in  shape^ 
a  perfedt  crystal  is  rare,  and  most  of  the  stones  are  white, 
few  yellow.  Diamonds  from  the  Leicester  mine  have  a 
frosted,  etched  appearance  ;  they  are  white,  the  crystal- 
lisation irregular  ("cross-grained"),  and  they  are  very 
hard.  The  newly  discovered  "  Newlands "  mines  in 
Griqualand  West  are  remarkable  for  the  whiteness  of 
their  diamonds  and  for  their  many  perfedt  odlahedrat 
crystals.  Jagersfontein  stones,  in  the  Orange  Free  State, 
take  the  prize  for  purity  of  colour  and  brilliancy,  and  they 
show  that  so-called  "steely"  lustre  charadteristic  of  old 
Indian  gems.  Stones  from  Jagersfontein  are  worth  nearly 
double  those  from  Kimberley  and  De  Beers. 

Monster  diamonds  are  not  so  uncommon  as  is  generally 
supposed.  Diamonds  weighing  over  an  ounce  (151*5 
carats)  are  not  unfrequent  at  Kimberley,  and  there  would 
be  no  difficulty  in  getting  together  a  hundred  of  them. 
Not  long  ago,  in  one  parcel  of  stones  at  the  office  of 
Wernher,  Beit,  and  Co.,  I  saw  eight  perfedt  crystals,  each 
over  an  ounce  and  one  that  weighed  two  ounces.  The 
largest  known  diamond  —  a  true  mountain  of  light  — 
weighs  970  carats,  over  half  a  pound.  It  was  found  four 
years  ago  at  Jagersfontein.  It  is  perfedlion  in  colour,  but 
has  a  small  black  spot  in  the  centre.  Diamonds  smaller 
than  a  small  fradtion  of  a  grain  elude  the  sorters  and  are 
lost.  A  microscopic  examination  of  blue  ground  from 
Kimberley,  after  treatment  with  appropriate  solvents, 
shows  the  presence  of  microscopic  diamonds,  white, 
coloured,  and  black,  also  of  boart  and  carbonado. 

From  two  to  three  million  carats  of  diamonds  are 
turned  out  of  the  Kimberley  mines  in  a  year,  and  as  five 
million  carats  go  to  the  ton,  this  represents  half  a  ton  of 
diamonds.  To  the  end  of  1892,  ten  tons  of  diamonds 
had  come  from  these  mines,  valued  at  j£,"6o,ooo,ooa 
sterling.  This  mass  of  blazing  diamonds  could  be  accom- 
modated in  a  box  five  feet  square  and  six  feet  high. 

The  diamond  is  a  luxury  for  which  there  is  only  a 
limited  demand.  From  4  to  4i  millions  sterling  is  as 
much  as  is  spent  annually  in  diamonds;  if  produdion  is 
not  regulated  by  demand,  there  will  be  over-produdtion, 
and  the  trade  will  suffer.  By  regulating  the  output,  since 
the  consolidation  in  1888  the  diredtors  have  succeeded  in 
maintaining  prices. 

Outside  companies  and  individuals  colledl  diamonds  to 
the  value  of  about  a  million  annually. 
Graphite. 

Intermediate  between  soft  carbon  and  diamond  come 


Crbmical  Nbws,  I 
July  2,  1897.      ) 


Diamonds. 


the  graphites.  The  name  graphite  is  given  to  a  variety 
of  carbon,  generally  crystalline,  which  in  an  oxidising 
mixture  of  chlorate  of  potassium  and  nitric  acid  forms 
graphitic  acid  easy  to  recognise.  Graphites  are  of  varying 
densities,  from  2'0  to  3'o,  and  generally  of  crystalline 
aspe(5t.  Graphite  and  diamond  pass  insensibly  into  one 
another.  Hard  graphite  and  soft  diamond  are  near  the 
same  specific  gravity.  The  difference  appears  to  be  one 
of  pressure  at  the  time  of  formation. 

Sonie  forms  of  graphite  exhibit  a  remarkable  property, 
by  which  it  is  possible  to  ascertain  approximately  the 
temperature  at  which  graphites  were  formed,  or  to  which 
they  have  subsequently  been  exposed.  Graphites  are 
divided  into  "  sprouting "  and  "non-sprouting."  When 
obtained  by  simple  elevation  of  temperature  in  the  arc  or 
the  elearic  furnace  they  do  not  sprout ;  but  when  they 
are  formed  by  dissolving  carbon  in  a  metal  at  a  high  tem- 
perature and  then  allowing  the  graphite  to  separate  out 
on  cooling,  the  sprouting  variety  is  formed.  One  of  the 
best  varieties  is  that  which  can  be  separated  from 
platinum  in  ebullition  in  a  carbon  crucible.  The  pheno- 
menon of  sprouting  is  easily  shown.  I  place  a  few  grains 
in  a  test-tube  and  heat  it  to  about  170°  C,  when  as  you 
see  it  increases  enormously  in  bulk  and  fills  the  tube  with 
a  light  form  of  amorphous  carbon. 

The  resistance  of  a  graphite  to  oxidising  agents  is 
greater  the  higher  the  temperature  to  which  it  has  pre- 
viously been  exposed.  Graphites  which  are  easily  attacked 
by  a  mixture  of  fuming  nitric  acid  and  potassium  chlorate 
are  rendered  more  resistent  by  strong  heat  in  the  eledtric 
furnace. 

I  will  now  briefly  survey  the  chief  chemical  and  physical 
charadteristics  of  the  diamond,  showing  you  by  the  way  a 
few  experiments  that  bear  upon  the  subject. 

Combustion  of  the  Diamond, 
When  heated  in  air  or  oxygen  to  a  temperature  varying 
from  760°  to  875°  C.  according  to  its  hardness,  the  diamond 
burns  with  produdlion  of  carbonic  acid.  It  leaves  an  ex- 
tremely  light  ash,  sometimes  retaining  the  shape  of  the 
crystal,  consisting  of  iron,  lime,  magnesia,  silica,  and 
titanium.  In  boart  and  carbonado  the  amount  of  ash 
sometimes  rises  to  4  per  cent  but  in  clear  crystallised 
diamonds  it  is  seldom  higher  than  o'os  per  cent.  By  far 
the  largest  constituent  of  the  ash  is  iron. 

The  following  table  shows  the  temperature  of  combus- 
tion in  oxygen  of  different  kinds  of  carbon  : — 

"C. 

Condensed  vapour  of  carbon       650 

Carbon  from  sugar,  heated  in  an  eledtrical 

furnace 660 

Artificial  graphites,  generally      65o 

Graphite  from  ordinary  cast-iron 670 

Carbon  from  blue  ground,  of  an  ochrey  colour    690 
M        «,  ,,  very  hard  and  black    710 

Diamond,  soft  Brazilian       760 

,,         hard  Kimberley 780 

Boart  from  Brazil 790 

,,      from  Kimberley 790 

„      very  hard,  impossible  to  cut    ..     ..     900 

At  the  risk  of  repeating  an  experiment  shown  so  well 
at  this  table  by  Professor  Dewar,  I  will  heat  a  diamond  to 
a  high  temperature  in  the  oxyhydrogen  blowpipe  and 
then  suddenly  throw  it  in  a  vessel  of  liquid  oxygen. 
Notice  the  brilliant  light  of  its  combustion.  I  want  you 
more  especially  to  observe  the  white  opaque  deposit 
forming  in  the  liquid  oxygen.  This  deposit  is  solid  car- 
bonic acid  produced  by  the  combustion  of  the  carbon.  I 
will  lead  it  through  baryta  water,  and  you  will  see  a  white 
precipitate  of  barium  carbonate.  With  a  little  more  care 
than  is  possible  in  a  ledlure  I  could  perform  this  experi- 
ment quantitatively,  leading  the  carbonic  acid  and  oxy- 
gen, as  they  assume  the  gaseous  state,  through  baryta- 
-water,  weighing  the  carbonate  so  formed,  and  showing 
•<hat  one  gramme  of  diamond  would  yield  3-666  grammes 


of  carbonic  acid — the    theoretical    proportion    for  pure 
carbon. 

Some  crystals  of  diamonds  have  their  surfaces  beauti- 
fully marked  with  equilateral  triangles,  interlaced  and  of 
varying  sizes.  Under  the  microscope  these  markings 
appear  as  shallow  depressions  sharply  cut  out  of  the  sur- 
rounding surface,  and  these  depressions  were  supposed 
by  Gustav  Rose  to  indicate  the  probability  that  the 
diamonds  at  some  previous  time  had  been  exposed  to 
incipient  combustion.  Rose  also  noted  that  striations 
appeared  on  the  surfaces  of  diamonds  burnt  before  the 
blowpipe.  This  experiment  I  have  repeated  on  a  clear 
smooth  diamond,  and  have  satisfied  myself  that  during 
combustion  in  the  field  of  a  microscope,  before  the  blow- 
pipe, the  surface  becomes  etched  with  markings  very  dif- 
ferent in  charafter  from  those  naturally  inscribed  on  crys- 
tals. The  artificial  striae  are  cubical  and  closer  massed, 
looking  as  if  the  diamond  during  combustion  had  been 
disse6ted  into  redangular  flakes,  while  the  markings 
natural  to  crystals  appear  as  if  produced  by  the  crystal- 
lising force  as  they  were  being  built  up. 

I  exhibit  on  a  diagram  a  form  of  graphite  from  the 
Kimberley  blue  ground  (reproduced  from  M.  Moissan's 
work)  which  in  its  flaky  crystalline  appearance  strangely 
resembles  the  surface  of  a  diamond  whose  internal  struc- 
ture has  been  partially  disseifted  and  bared  by  combustion. 
It  looks  as  if  this  piece  of  graphite  was  ready  to  sepa- 
rate out  of  its  solvent  as  diamond,  but  owing  to  some  in- 
sufficient fa^or  it  retained  its  graphitic  form. 

Physics  of  the  Diamond. 
The  specific  gravity  of  the  diamond  is  from  3'5i4  to 
3*518.     For  comparison,  I  give  in  tabular  form  the  specific 
gravities  of  the  different  varieties  of  carbon  : — 

Amorphous  carbon      ..     ..  i'45    to  170 

Graphite        ..     ..     ..     ..  2'ii     ,,  3*0 

Hard  gas  coke      2*356 

Boart      3-47     „  3-49 

Carbonado 3*50 

Diamond       3514  „  3518 

The  diamond  belongs  to  the  isometric  system  of  crys- 
tallography. It  frequently  occurs  with  curved  faces  and 
edges.  Twin  crystals  (macles)  are  not  uncommon. 
Having  no  double  refradion  it  should  not  aA  on  polarised 
light.  But  as  is  well  known,  if  a  transparent  body  which 
does  not  so  &&  is  submitted  to  strain  of  an  irregular 
character  it  becomes  doubly  refradting,  and  in  the  polari- 
scope  reveals  the  existence  of  the  strain  by  brilliant 
colours  arranged  in  a  more  or  less  defined  pattern 
according  to  the  state  of  tension  in  which  the  crystal 
exists.  Under  polarised  light  I  have  examined  many 
hundred  diamond  crystals,  and  with  few  exceptions  all 
show  the  presence  of  internal  tension.  On  rotating  the 
polariser,  the  black  cross,  which  is  most  frequently  seen, 
revolves  round  a  particular  point  in  the  inside  of  the  crys- 
tal, and  on  examining  this  point  with  a  high  power,  we 
see  sometimes  a  slight  flaw,  more  rarely  a  minute  cavity. 
The  cavity  is  filled  with  gas  at  an  enormous  pressure,  and 
the  strain  is  set  up  in  the  stone  by  the  effort  of  the  gas  to 
escape. 

It  is  not  uncommon  for  a  diamond  to  explode  soon  after 
it  reaches  the  surface,  and  some  have  been  known  to  burst 
in  the  pockets  of  the  miners  or  when  held  in  the  warm 
hand.  Large  crystals  are  more  liable  to  burst  than 
smaller  pieces.  Valuable  stones  have  been  destroyed  in 
this  way,  and  it  is  whispered  that  cunning  dealers  are  not 
averse  to  allowing  responsible  clients  to  handle  or  carry 
in  their  warm  pockets  large  crystals  fresh  from  the  mine. 
By  way  of  safeguard  against  explosion,  some  dealers 
imbed  large  diamonds  in  raw  potato  to  insure  safe  transit 
to  England. 

I  will  projedt  some  diamonds  on  the  screen  by  means 
of  the  polarising  microscope,  and  you  will  see  by  the 
colours  how  great  is  the  strain  to  which  some  of  them  are 
exposed. 


Cathode  Rays  and  some  A  nalogous  Rays, 


In  the  substance  of  many  diamonds  we  find  enclosed 
black  uncrystallised  particles  of  graphite.  There  also 
occur  what  may  be  considered  intermediate  forms  be- 
tween the  well  crystallised  diamond  and  graphite.  These 
are  "  boart "  and  "  carbonado."  Boart  is  an  imperfedtly 
crystallised  diamond,  having  no  clear  portions,  therefore 
it  is  useless  for  gems.  Boart  is  frequently  found  in 
spherical  globules,  and  may  be  of  all  colours.  It  is  so 
hard  that  it  is  used  in  rock  drilling,  and  when  crushed  it 
is  employed  for  cutting  and  polishing  other  stones.  Car- 
bonado is  the  Brazilian  term  for  a  still  less  perfecSly  crys- 
tallised form  of  carbon.  It  is  equally  hard,  and  occurs  in 
porous  masses,  and  in  massive  black  pebbles,  sometimes 
weighing  a  couple  or  more  ounces. 

Diamonds  vary  considerable  in  hardness,  and  even  dif- 
ferent parts  of  the  same  crystal  are  decidedly  different  in 
their  resistance  to  cutting  and  grinding.  The  famous 
Koh-i-noor,  when  cut  into  its  present  form,  showed  a 
notable  variation  in  hardness.  In  cutting  one  of  the 
facets  near  a  yellow  flaw,  the  crystal  became  harder  and 
harder  the  further  it  was  cut  into,  until,  after  working  the 
mill  for  six  hours  at  the  usual  speed  of  2400  revolutions  a 
minute,  little  impression  was  made.  The  speed  was 
according  increased  to  more  than  3000,  when  the  work 
slowly  proceeded.  Other  portions  of  the  stone  were  found 
to  be  comparatively  soft,  and  became  harder  as  the  out- 
side was  cut  away. 

Beautifully  white  diamonds  have  been  found  at  Inverel, 
New  South  Wales,  and  from  the  rich  yield  of  the  mine 
and  the  white  colour  of  the  stones,  great  things  were  ex- 
pected. A  parcel  of  many  hundred  carats  came  to  England, 
when  it  was  found  that  they  were  so  hard  as  to  be  pradli- 
cally  unworkable  as  gems,  and  I  believe  they  were  ulti- 
mately sold  for  rock  boring  purposes. 

I  will  illustrate  the  intense  hardness  of  the  diamond  by 
an  experiment.  I  place  a  diamond  on  the  flattened  apex 
of  a  conical  block  of  steel,  and  on  the  diamond  I  bring  down 
a  second  cone  of  steel.  With  the  eledlric  lantern  I  will 
projed  an  image  of  the  diamond  and  steel  faces  on  the 
screen,  and  force  them  together  by  hydraulic  power. 
Unless  I  happen  to  have  seledted  a  diamond  with  a  flaw, 
I  shall  squeeze  the  stone  right  into  the  steel  blocks  with- 
out injuring  it  in  the  slightest  degree. 

But  it  is  not  the  hardness  of  the  diamond  so  much  as 
its  optical  qualities  that  make  it  so  highly  prized.  It  is 
one  of  the  most  refrading  substances  in  Nature,  and  it 
also  has  the  highest  refledting  properties.  In  the  cutting 
of  diamonds  advantage  is  taken  of  these  qualities.  When 
cut  as  a  brilliant  the  facets  on  the  lower  side  are  inclined 
so  that  light  falls  on  them  at  an  angle  of  24°  13',  at  which 
angle  all  the  incident  light  is  totally  refleded.  A  well- 
cut  diamond  should  appear  opaque  by  transmitted  light 
except  at  a  small  spot  in  the  middle  where  the  table  and 
culet  are  opposite."  All  the  light  falling  on  the  front  of 
the  stone  is  refledted  from  the  facets,  and  the  light  passing 
into  the  diamond  is  refledled  from  the  interior  surfaces 
and  refrafted  into  colours  when  it  passes  out  into  the  air, 
giving  rise  to  the  lightnings  and  coruscations  for  which 
the  diamond  is  supreme  above  all  other  gems. 

I  hold  some  of  Mr.  Streeter's  magnificent  diamonds  in 
the  eledlric  light,  and  by  transmitted  light  you  will  see 
they  are  black,  while  by  refledted  light  they  fill  the  room 
with  radiance  and  colour. 

The  accompanying  table  gives  the  refradlive  indices  of 
diamonds  and  other  bodies.     (See  next  column). 

According  to  Dr.  Gladstone,  the  specific  refradive 
energy,— 

M  -  I 

will  be  for  the  D  line  0*404, and  therefradlion  equivalent,— 


Refractive  Indices  jor  the  D 

Chromate  of  lead      ..     ..     2' 
Diamond      ..     ..     .,     ..     2* 

Phosphorus 

Sulphur        

Ruby 

Thallium  glass 

Iceland  spar        

Topaz 

Beryl 

Emerald      

Flint  glass 

Quartz 

Canada  balsam 

Crown  glass       

Fluor-spar 

Ice        


I  Cbbmical  News,. 

"       Jiilyz.iSc/. 

Line, 

50—2-97 

47—275 

2*22 
2'12 
178 

165 
I  61 
I  60 

I '59 
158 
I '55 
1-53 
I  "53 
1-44 

131 


in  a  dark  room.  Some  diamonds  are  fluorescent,  appearing^ 
milky  in  sunlight.  In  a  vacuum,  exposed  to  a  high- 
tension  current  of  eledricity,  diamonds  phosphoresce  of 
different  colours,  most  South  African  diamonds  shining 
with  a  bluish  light.  Diamonds  from  other  localities  emit 
bright  blue,  apricot,  pale  blue,  red,  yellowish  green, . 
orange,  and  pale  green  light.  The  most  phosphorescent 
diamonds  are  those  which  are  fluorescent  in  the  sun.  One 
beautiful  green  diamond  in  my  colledtion,  when  phos- 
phorescing in  a  good  vacuum,  gives  almost  as  much  light 
as  a  candle  and  you  can  easily  read  by  its  rays.  The 
light  is  pale  green,  tending  to  white. 

(To  be  continued). 


will  be  4'82 


111  pe  4*02. 

After  exposure  for  some  to  the  sun  many  diamonds  glow 


CATHODE  RAYS  AND  SOME  ANALOGOUS 

RAYS.» 

By  SILVANUS  P.  THOMPSON,  DSc,  F.R.S. 

I,  The  size  of  the  cathodic  shadow  of  an  objedl  depends- 
upon  its  own  eledric  state,  as  already  found  by  Crookes 
{Phil.  Trans.,  1879,  Part  II.,  p.  648).  If  it  is  negatively 
eledlrified  the  shadow  expands.  If  it  is  positively  eledri- 
fied  the  shadow  contradls.  The  position,  as  well  as  the 
size  of  a  cathodic  shadow,  may  be  affeifled  eledtro- 
statically,  the  rays  which  cast  the  shadow  being  repelled 
from  a  neighbouring  body  if  the  latter  is  negatively 
eledtrified.  In  some  cases  the  contradlion  of  the  shadow 
of  a  narrow  objedt  that  is  made  positively  eledlrical 
(anodic)  may  go  so  far  that  the  luminous  margins  ap- 
proach and  even  overlap,  giving  the  appearance  of  a 
bright  or  negative  shadow  in  place  of  a  dark  one.  The 
enlargement  of  a  shadow  when  the  objedt  is  made 
cathodic,  and  the  diminution  of  the  shadow  when  the 
objedt  is  made  anodic,  both  depend  upon  the  degree  of 
exhaustion  of  the  tube,  and  both  are  augmented  up  to  a 
certain  point  by  raising  the  degree  of  exhaustion.  They 
are  also  unequal,  the  enlargement  when  the  obje(5t  is 
made  cathodic  vastly  surpassing  the  diminution  when  the 
obje(5t  is  made  anodic,  other  things  remaining  equal.  The 
conclusion  is  reached  that  cathode  rays  are  capable  of 
being  defledted  eledtrostatically,  being  apparently  strongly 
repelled  from  a  neighbouring  cathodic  surface,  and  less 
strongly  attradled  towards  a  neighbouring  anode.  Inci- 
dentally it  was  observed  that  two  cathode  beams  from  two 
small  disc  cathodes  can  cross  through  or  penetrate  one 
another  without  interfering  with  another. 

2.  The  eledtrostatic  defledlion  of  cathode  rays  by  an 
eledtrified  objedl  is  found  to  be  dependent  upon  the  surface 
of  that  objetft  as  to  whether  it  is  a  condudor  or  not. 
Objedts  protedled  by  a  non-condudting  layer  of  glass  do 
not  at  moderately  low  exhaustions,  when  made  cathodic, 
repel  or  defledt  cathode  rays,  and  their  shadow  does  not 


*  Abstract  of  a  Paper  read  before  the  Royal  Society,  Jane  17,  1897. 


CBBMICAL  NBWSi  ' 

July  2,  1897.       I 


Change  of  Absorption  produced  by  Fluorescence, 


enlarge.  But  at  a  certain  minimum  exhaustion  they  sud- 
denly exert  an  eledrostatic  defledlion.  Naked  objedts 
made  cathodic  defletSt  the  cathode  rays  at  all  exhaustions. 

3.  The  "  splash  "  phenomenon  often  observed  on  the 
tube-wail  of  a  Crookes  tube,  where  it  is  struck  by  the 
cathode  beam,  at  the  stage  of  exhaustion  a  little  below 
that  which  suffices  to  evoke  Rontgen's  rays,  is  due  to 
eledlrostatic  deflexions  of  the  cathode  rays  by  the  charges 
on  the  glass. 

4.  A  hot  wire  used  as  an  obje(5l  casts  a  cathodic  shadow 
precisely  like  that  of  the  same  wire  cold.  Under  some 
circumstances,  if  the  wire  is  heated  by  an  elecftric 
current,  the  difference  between  the  eledrostatic  state  of 
its  different  parts  may  slightly  affedt  the  size  of  the  shadow 
it  casts. 

5.  Cathode  rays  cannot  be  concentrated  by  refledtion 
either  from  a  non-condudting  or  a  condufting  surface,  nor 
by  passage  through  a  metal  tube  which  is  itself  negatively 
eledrified. 

6.  When  cathode  rays  strike  upon  an  internal  metal 
target  or  anticathode  there  are  emitted  from  the  latter 
(both  at  exhaustions  lower  than  suffice  to  produce  Rontgen 
rays,  and  at  exhaustions  at  which  those  rays  are  also 
produced)  some  internal  rays  resembling  ordinary  cathode 
rays  in  the  following  respeds : — They  produce  a  similar 
luminescence  of  the  glass  ;  they  cast  shadows  of  objedts  ; 
they  are  susceptible  of  defledtion  both  magnetically  and 
eledrostatically.  But  they  produce  no  Rontgen  rays 
where  they  fall  upon  the  glass  surface.  They  do  not  fol- 
low either  the  law  of  specular  refledtion,  nor  that  of 
diffuse  refledtion,  but  are  emitted  from  the  anti-cathode 
surface  apparently  according  to  a  similarly  anomalous 
distribution  to  Rontgen's  rays,  i.e.,  with  nearly  equal 
intensity,  at  all  angles  up  to  go"  with  the  normal.  It  is 
proposed  to  call  these  rays  para-cathodic  rays  in  contra- 
distindlion  to  the  ordinary  or  ortho-cathodic  rays.  From 
the  similarity  of  their  distribution  with  that  of  the 
Rdntgen  rays  it  is  inferred  that  the  physical  processes 
concerned  in  their  produdtion  are  identical.  These  para- 
cathodic  rays  are  emitted  from  the  anti-cathode  both  when 
the  latter  is  made  an  anode  and  when  it  is  neutral  or  even 
made  cathodic.  From  an  anti-cathode  there  may  proceed 
at  one  and  the  same  time,  and  in  one  and  the  same 
diredlion,  para-cathodic  rays  and  Rontgen  rays,  which, 
meeting  an  interposed  objedt,  may  cast  simultaneously 
two  shadows — a  para-cathodic  shadow  on  the  glass,  and 
a  Rontgen  shadow  on  an  external  screen  of  barium 
platinocyanide.  The  former  shadow  can  be  defledled  by 
a  magnet,  the  latter  cannot.  The  former  shadow  ex- 
pands if  the  objedt  is  made  cathodic,  the  latter  does  not. 

7.  If  thin  metal  screens  are  used  to  sift  the  cathode  ^ 
rays,  the  luminescent  phenomena  change.  The  rays  of 
least  penetrating  power  appear  to  be  most  susceptible  to 
magnetic  and  electrostatic  forces.  The  various  constitu- 
ents of  a  heterogeneous  cathode  beam  are  emitted  in 
various  proportions  at  different  degrees  of  exhaustion. 
In  the  cathode  rays  emitted  at  higher  degrees  of  ex- 
haustion there  is  a  greater  proportion  of  the  less  defledtable 
rays.  The  least  defledtable  rays  are  those  which  most 
readily  penetrate  through  a  perforated  screen  when  that 
screen  is  itself  made  cathodic. 

When  ordinary  cathode  rays  fall  upon  a  perforated 
screen  which  is  itself  made  cathodic,  or  are  attempted  to 
be  passed  through  a  tubular  cathode,  there  emerge  beyond 
the  screen  or  tube  some  rays,  here  termed  dia-cathodic 
rays,  which  differ  from  the  ortho-cathodic  and  also  from 
the  para-cathodic  rays.  These  dia-cathodic  rays  are  not 
themselves  diredtly  defledted  by  a  magnet.  They  show 
themselves  as  a  pale  blue  cone  or  streak.  Where  they 
fall  on  the  glass  they  do  not  excite  the  ordinary  fluores- 
cence of  the  glass.  The  dia-cathodic  rays  excite, 
however,  a  different  or  second  kind  of  fluorescence,  the 
tint  in  the  case  of  soda-glass  being  a  dark  orange.  Inter- 
vening objedts  in  the  beam  or  cone  of  dia-cathodic  rays 
cast  shadows.  The  orange  fluorescence  evoked  on  soda- 
glass  by  the  dia-cathodic  rays  shows  in  the  spedtroscope 


the  D  lines  of  sodium  only.  The  shadows  cast  by  dia- 
cathodic  rays  are  not  defledled  by  the  magnet,  nor  da 
they  change  their  size  when  the  objedt  is  eledlrified. 


ON  THE  CHANGE  OF  ABSORPTION  PRODUCED- 
BY    FLUORESCENCE.* 

By    JOHN     BURKE,    B.A.    (Dub.), 
Berkeley  Fellow  of  the  Owens  College,  Manchester. 

If  a  body,  A,  of  some  fluorescent  substance,  such  a» 
uranium  glass,  be  transmitting  light  from  a  similar  body, 
B,  which  is  fluorescing,  the  amount  of  light  transmitted 
by  A  from  B  seems  quite  different,  according  as  A  is 
fluorescing  or  not.  There  appears  to  exist  in  a  dilute 
solution  of  fluorescine  or  eosine  a  small  difference,  but  a 
strong  solution  of  either  does  not  permit  its  fluorescent 
light  to  penetrate,  except  a  very  small  thickness  of  the 
liquid,  whether  fluorescing  or  not. 

Sulphate  of  quinine  is  too  transparent  to  the  luminous 
rays,  so  that  even  if  a  change  did  exist  it  could  hardly  be 
detedted.  The  case  is  otherwise  with  uranium  glass,  in 
which  the  effedt  is  well  marked. 

The  compounds  of  uranium  are  remarkable  for  many 
charadteristic  properties  connedted  with  fluorescence^ 
which  they  seem  to  exhibit  more  readily  than  most  other 
bodies.  The  spedtrum  of  the  fluorescent  light  emitted  by 
uranium  glass  shows  certain  maxima  and  minima,  as  was 
noticed  by  Stokes  in  1852. 

The  experiments  which  have  been  carried  out  with  a 
view  to  testing  whether  a  change  in  the  absorption  is 
produced  by  fluorescence,  have  been  almost  exclusively 
upon  uranium  glass.  Regarding  it  as  the  most  suitable 
substance  to  experiment  upon,  a  careful  series  of  experi- 
ments have  been  made  to  determine  whether  the  pheno- 
menon really  existed  or  not. 

If  we  call  a  and  /3  the  fradtions  of  the  light  from  B 
transmitted  by  A,  according  as  the  latter  is  fluorescing  or 
not,  for  uranium  glass  i  cm.  thick ;  the  values  of  a  in  a 
particular  set  of  experiments,  in  which  eye  determinations 
were  taken,  were  as  follows.  Each  experiment  consisted 
of  twenty  observations. 

Exp.     I a  =  0*54 

II =0-46 

III =0-51 

IV =036 

and  for  /3 — 

Exp.    I j3  =  o-7o 

II =084 

III =072 

IV =0*92 

The  mean  value  of  a  obtained  from  these  being 
a=o-47,  j3  =  o79. 

The  ratio  — r —  was  also  independently  determined^ 

and  found  as  the  mean  of  eighty  observations  to  be  0*507. 
The  values  of  o  and  /3  have  also  been  determined  photo- 
graphically, giving — 

o  <o-48  j3  <075 

>o-43  >o89 

If  we  take  the  maximum  value  of  a  given  photographi- 
a 
cally  0*48,  the  ratio  — r —  =    0*32,   and   instead   of  ob- 
taining equality  when  the  photometer  is  adjusted  for  thia 
value  the  difference  is  most  marked. 

The  effedt  has  also  been  shown  by  obtaining  two 
photographs  on  the  one  plate ;  one  photograph  being  the 
result  of  an  exposure  to  the  light  from  two  fluorescing 
cubes  one  behind  the  other,  and  the  second  photograph 
the  result  of  superposing  the  effedt  of  the  light  from  A 

*  AbstraA  of  a  Paper  read  before  the  Royal  Society,  June  17,  1897 


Volumetric  Determination  of  Zinc  by  Potassium  Ferrocyanide,    { ^^uTa^iS?'"' 


alone,  when  fluorescing,  upon  that  from  B  after  having 
passed  through  A,  when  the  latter  was  not  fluorescing. 
The  exposure  in  each  of  the  three  cases  being  the  same, 
a  very  distindt  difference  is  shown  in  the  result ;  the 
superposed  photographs  being  always  the  darker  in  the 
negative,  notwithstanding  the  fad  that  the  resultant 
«ffe(5t  of  superposing  two  photographs  due  to  light  of  the 
same  intensity,  or  nearly  so,  has  been  found  not  to  be 
«qual  to,  but  less  than,  that  due  to  light  of  double  the 
intensity  adling  for  half  the  time.  If  the  resultant  effedt 
were  equal  to  the  sum  of  the  separate  ones,  the  effedt 
caused  by  the  change  of  absorption  would  have  been  still 
more  marked. 

In  the  determinations  of  a  and  j3  a  null  method  has 
been  employed,  by  which  any  appreciable  want  of  uni- 
formity in  the  illumination  can  be  detedted. 

The  source  of  illumination  has  been  almost  invariably 
the  spark  discharge  of  a  Leyden  jar  between  cadmium 
eledrodes,  being  one  of  the  richest  sources  of  the  ffuor- 
escence  exciting  rays,  and  the  photometer  one  specially 
constructed  for  the  purpose. 


ON   THE 

VOLUMETRIC     DETERMINATION    OF    ZINC 

BY    POTASSIUM     FERROCYANIDE.* 

By  L.  L.  DE  KONINCK  and  EUG.  PROST. 

I.  Introduction. 
The  volumetric  estimation  of  zinc  has,  since  the  publica- 
tion in  1856  (Polytechnisches  journal  de Dingier,  vol.cxl., 
p.  114,  and  vol.  cxliii.,  p.  263  ;  jfournal  de  Pkarmacie, 
[3],  vol.  xxix.,  p.  205,  and  vol.  xxxi.,  p.  70),  by  Max 
Schaffner,  of  the  process  which  now  bears  his  name, 
been  the  subje<ft  of  numerous  researches,  which  have  had 
for  obje(5t  either  the  improvement  of  this  process — which 
at  first  left  much  to  be  desired  —  or  the  discovery  of 
Others. 

This  fadt  is  easily  accounted  for  by  the  importance  of 
having,  especially  in  the  laboratories  at  mines  and  zinc 
works,  a  trustworthy  commercial  method,  uniting  rapidity 
and  simplicity  with  a  sufficient  degree  of  exadtness  with 
regard  to  the  value  of  the  metal. 

Of  all  the  methods  proposed,  two  only  appear  to  be 
now  in  general  use. 

On  the  Continent,  so  far  as  we  know,  the  Schaffner 
process  is  almost  exclusively  used ;  it  is  even  the  only 
volumetric  one  described,  in  several  English  and  French 
books,  among  the  recent  methods  for  the  analysis  of  zinc 
ores  (Riche  and  Gelis,  Silva,  Halphen;  Clowes  and 
Coleman).  In  Germany  it  is  certainly  the  most  widely- 
used  process.  In  America,  however,  it  is  otherwise,  for, 
according  to  an  interesting  report  made  to  the  Scientific 
Society  of  Colorado  (Chem.  News,  vol.  Ixvii.,  pp.  5  and 
I7i  1893)  by  a  Committee  charged  specially  to  endeavour 
to  establish  uniformity  among  the  methods  used  in  that 
country,  it  would  appear  to  be  the  Galletti  process  (^Bull. 
Soc.  Chim,,  vol.  ii.,  p.  83,  1864)  modified  by  Fahlberg 
{Zeitsch.  f.  Anal.  Chem.,  vol.  xiii.,  p.  379) ;  that  is  to  say, 
the  process  based  on  the  precipitation  of  the  zinc  by 
ferrocyanide  of  potassium,  in  an  acid  solution,  which  is 
generally  preferred  in  the  mining  distridls ;  it  is,  in  fadl, 
the  only  one  cited  by  the  chemists  who  were  consulted. 
It  is  also  recommended  by  G.  E,  Dougherty,  in  a  note 
on  the  Analysis  of  Minerals  {Engineering  and  Mining 
yournal,  1890,  p.  178;  Zeitsch.  f.  Angew.  Ch.,  vol.  iii., 
p.  306,  1890) 

The  methods  of  Schaffner  and  Galletti  are  the  only 
ones   which   are  found  in  the  best-known  treatises   on 

*  Id  the  Chemical  News  (vol.  Izxv.,  p.  182)  we  published  a  short 
ah  tra<^t  of  this  paper;  but  we  regret  to  say  that  the  copy  which 
came  into  our  haods  was  incomplete  and  inaccurate.  We  therefore 
think  it  best  to  now  insert  the  paper  in  full,  or  at  any  rate  but  slightly 
.abridged.— £<<.  C.  N. 


quantitative  analysis  of  late  years  (Kerl,  Balling,  Post, 
Bockmann,  &c.). 

The  sulphide  of  sodium  process  of  Schaffner  has  been 
carefully  studied,  and  thoroughly  described  in  detail. 
Most  writers  are  in  accord  on  the  details  of  manipulation, 
and  notably  on  the  use  of  Polka  paper  (salts  of  lead)  as 
an  indicator.  This  unanimity  does  not  exist  in  the  case 
of  the  ferrocyanide  method.  In  this  case  the  different 
writers  are  not  even  agreed  as  to  the  formula  of  the  re- 
adtion  on  which  the  method  is  based.  According  to  some 
the  precipitate  obtained  should  be  simple  ferrocyanide  of 
zinc,  Zn4Fe2Cyi2 ;  according  to  others  it  should  be  the 
double  ferrocyanide  of  zinc  and  potassium,  K2Zn3Fe2Cyi2i 
described  long  ago  by  Mosander  (Handtuorterb.  d.  rein,  u, 
Angew.  Ch.,  1848,  p.  86).  Others,  again,  maintain  that 
the  exadt  composition  of  the  precipitate  is  more  compli- 
cated still,  and  corresponds  to  the  formula — 

Ki6Zn2o(Fe2Cyi2'7, 
or  should  be  even  more  or  less  indeterminate  (Zulkowski, 
Polyt.  yourn.  de  Dtngler,  vol.  ccxlix.,  p.  175,  1883),  for  in 
spite  of  the  high  state  of  purity  in  which  it  is  possible  to 
obtain  ferrocyanide  of  potassium,  and  the  almost  absolute 
stability  of  this  reagent,  they  recommend  the  experimental 
determination  of  the  relations  between  this  salt  and  the 
quantity  of  zinc  precipitated,  this  proportion  not  being, 
according  to  them,  so  simple  as  is  generally  expressed 
by  the  formulae  in  common  use  (Mohr,  Classen,  1886, 
p.  459). 

A  priori,  according  to  the  description  of  the  process 
given  by  most  writers,  this  would  seem  to  be  of  extremely 
simple  application,  while  such  is  not  absolutely  the  case 
with  the  Schaffner  process.  Why,  therefore,  is  the  latter 
preferred  in  our  continental  laboratories  ?  Is  it  merited, 
or  simply  a  matter  of  custom  ? 

It  is  this  question  that  we  have  set  ourselves  to  solve : 
one  of  us  having,  owing  to  a  previous  appointment,  had 
a  large  experience  in  Schaffner's  method,  we  were  enabled 
to  speak  with  authority  when  we  had  compared  the 
results  obtained  from  the  careful  study  we  made  of  the 
ferrocyanide  process. 

It  has  been  proposed  to  apply,  to  the  volumetric  esti- 
mation of  zinc,  precipitation  under  the  three  following 
conditions : — 

1.  In  acid  solution  (Galletti)  ; 

2.  In  simple  ammoniacal  solution  (A.  Renard) ; 

3.  In  a  tartaric-ammoniacal  solution  (Giudice). 
From  these  spring  three  different  processes,  which  we 

will  designate  by  the  names  of  their  respedtive  authors, 
and  which  we  hope  to  study  successively.  We  take  first 
the  Galletti  process,  the  oldest  and  most  widely  used  of 
the  three. 

II.  Historical. 
It  was  in  1864  that  M.  Galletti  described  for  the  first 
time  (Memoire  presented  to  the  Royal  Academy  of  Science 
of  Turin,  18B4— BmW.  Soc.  Chim.,  vol.  ii.,  p.  83,  1864) 
I  the  method  of  estimating  zinc  by  means  of  ferrocyanide, 
a  process  which  he  had,  however,  foreshadowed  some 
years  previously,  on  the  occasion  of  publishing  an 
analogous  process  for  the  estimation  of  copper  (Ibid., 
1856).  After  first  separating  the  iron  by  ammonia,  he 
added  acetic  acid  to  the  filtrate,  heated  to  40°,  then  ran  in 
the  titrated  solution  of  ferrocyanide ;  the  end  of  the  re- 
adlion  was  indicated  by  the  sudden  milky  appearance  of 
the  liquid.  The  titration  recommended  is  Ti2  =  o'oi  grm. 
Galletti  admits  that  the  precipitate  is  the  simple  zincic 
ferrocyanide,  and  he  attributes  to  impurities  in  the  reagent 
used  the  fadt  that  the  results  do  not  agree  with  theory,  in 
spite  of  the  very  wide  differences  found.  He  warns  one 
against  acidulating  with  mineral  acids,  any  excess  inter- 
fering with  the  readlion,  which,  he  says,  can  be  per- 
ceived by  the  yellow  colour  of  the  liquid,  due  to 
ferrocyanide  which  has  not  been  adted  on.  This  colour 
does  occur,  but  Galletti  is  mistaken  as  to  its  origin  :  we 
shall  show  later  on  to  what  this  is  due,  and  how  it  can  be 
avoided.    In  another  note  published  in  1868  (also  Zeitsch 


Chbmical  News,  1 
July  2, 1897.      I 


Method  of  Estimating  A  idehyd  in  Ether, 


f.  Anal.  Chem.,  vol.  viii.,  p.  135,  1869)  he  returns  to  the 
application  of  his  process  to  the  assay  of  minerals,  with 
a  view  to  modifying  somewhat  the  method  of  preparing 
the  zincic  solution;  but  the  adual  estimation  of  zinc  is 
done  in  exa<aiy  the  same  manner.  The  presence  of  lead 
has  no  influence ;  manganese  is  eliminated  by  adding 
bromine  to  the  ammoniacal  solution,  and  exposing  it  to 
the  air  for  twenty-four  hours.  We  shall  soon  come  to  the 
influence  this  reagent  exerts.  Finally,  the  operation  can 
be  carried  on  without  filtering  off  the  iron. 

In  1874  C.  Fahlberg  published,  as  new  {Zeitsch.  f. 
Anal.  Chem.,  vol.  xiii.,  p.  379,  1874),  without  referring  to 
Galletti,  the  ferrocyanide  process;  his  method  of  procedure  , 
■was  different  to  that  of  his  forerunner,  in  that  the  precipi- 
tation was  effedted  in  hydrochloric  solution,  and,  above 
all,  by  the  means  employed  for  detedling  the  end  of  the 
reaftion.  Fahlberg  here  utilises,  by  inverting  it,  the 
method  used  in  the  titration  of  phosphates  by  a  titrated 
solution  of  a  uranium  salt, — that  is  to  say,  he  uses  the 
spot  method,  of  a  solution  of  uranic  nitrate,  to  detedt  the 
brown  colour  which  is  produced  the  moment  the  potassic 
ferrocyanide  commences  to  predominate.  According  to 
him,  and  here  he  is  wrong,  the  presence  of  manganese 
would  be  without  influence  if  the  solution  is  sufficiently 
acid,  so  he  does  not  eliminate  it  before  titration.  In 
each  experiment  the  solution  was  acidulated  with  10  to 
15  c.c.  of  hydrochloric  acid  (sp.  gr.  i'i2  =  23'82  per  cent), 
or  2*7  to  4  grms. ;  this  is  too  much.  He  recommends,  as 
does  Galletti,  the  preparation  of  a  solution  of  ferrocyanide, 
T=o'oi  grm.,  and  the  experimental  determination  of  its 
strength  by  titrating  with  a  solution  of  pure  zinc  dissolved 
in  HCl ;  to  this  solution  he  also  adds  5  parts  of  ammonium 
chloride  for  each  i  part  of  zinc,  so  as  to  obtain  a  precipi- 
tate "  as  attenuated  as  possible,"  which  will  subside 
rapidly  without  "carrying  down  potassium  ferrocyanide." 
Fahlberg  always  describes  the  precipitate  as  a  zincic  ferro- 
cyanide ;  he  seems  to  believe,  from  what  we  have  just 
quoted,  that  such  is  really  the  case. 

To  estimate  zinc  in  an  ore,  he  dissolves  it  in  aqua  regia, 
with  excess  of  HCl,  precipitates  the  copper,  &c.,  by  sul- 
.  phuretted  hydrogen,  re-oxidises  the  iron  salts  with  nitric 
acid,  precipitates  with  excess  of  ammonia,  and  filters. 
The  ammoniacal  filtrate  is  made  acid  with  HCl  in  the 
proportion  mentioned  above ;  the  titrated  solution  of 
ferrocyanide  is  then  run  in,  little  by  little,  until  the  nitrate 
of  uranium  test  shows  the  end  of  the  operation. 

Thus,  as  we  shall  show  diredly,  the  method  of  working 
described  above  contains  sources  of  error  which  the 
author  has  quite  overlooked  ;  so  it  is  not  astonishing  that 
the  results  published  by  him— results  obtained  from  eleven 
ores  from  the  Hartz  distridt,  containing  from  3  to  23  per 
cent  of  zinc — should  not  be  of  great  value;  compared 
with  those  obtained  dosimetrically  they  show  errors 
reaching  0*49  per  cent  at  least,  on  1977  per  cent,  and  as 
much  as  0-33  per  cent  on  3-57  per  cent.  This  is  very  far 
from  the  exadlness  we  have  a  right  to  exped,  and  that 
which  can  be  obtained  by  Schaffner's  method. 

In  the  same  year,  1874,  Galletti  published  a  third 
edition  of  his  pamphlet  (Genes,  1874) ;  the  only  modifica- 
tion ir^dicated  refers  to  the  proportion  of  ammonia  and 
acetic  acid,  to  be  used  in  a  case  when  one  wishes  to 
titrate  the  zinc  without  previously  removing  the  precipi- 
tated iron. 

When  using  a  zincic  solution  with  alkaline  ferrocyanides 
K.  Zalkowski,  like  Fahlberg,  seems  to  have  entirely  over- 
looked the  work  already  done  by  others. '  When  using  a 
normal  solution  of  ferrocyanide  (los's  grms.  per  litre), 
and  a  deminormal  solution  of  a  pure  zincic  salt,  such  as 
zinco-potassic  sulphate,  K2S04,ZnS04,6H20  (mol.  weight 
442'57,  110*82  grm.  per  litre),  this  author  readily  recognises 
the  fad  that  the  readtion  between  the  zinc  salt  and  the 
ferrocyanide  is  not  so  simple  as  would  appear  from  the 
formula  which  is  generally  accepted,  viz., — 

4ZnS04+K8Fe2Cyi2 = 4K2SO4  +  Zn4FeaCyi2. 

(To  be  continued). 


METHOD    OF    ESTIMATING    ALDEHYD    IN 

ETHER. 

By  M,  FRANCOIS. 

The  almost  constant  presence  of  ordinary  aldehyd  in  so- 
called  pure  ethers,  even  that  used  for  anaesthetic  purposes, 
does  not  yet  appear  to  have  attraded  sufficient  attention 
from  pharmacologists.  This  impurity,  however,  exists  in 
a  suSiciently  high  proportion  in  the  produdts  ordinarily 
delivered  to  pharmacists,  and  ether  containing  several 
units  per  cent  of  aldehyd  is  not  unfrequently  met  with. 

Thus,  in  medicine  we  admit  a  high  proportion  of 
impurity,  which  would  not  be  tolerated  in  any  alcoholic 
industry.  M.  Adrian  {Moniteur  Scient.,  1894,  p.  835)  in  an 
excellent  note,  which  completed  the  well  known  work  of 
Regnault  and  Adrian  on  the  estimation  of  ether,  noted 
this  constant  presence  of  aldehyd,  and  gave  a  method  for 
detedting  and  eliminating  it.  This  method  consisted  of 
passing  a  current  of  dry  ammonia  gas  through  the  cooled 
ether;  crystals  of  aldehydate  of  ammonia  were  deposited, 
insoluble  in  ether.  By  this  means  we  can  detedt  the  pre- 
sence of  0*5  per  cent  of  aldehyd.  The  method  of  purifi- 
cation consists  of  filtering  and  then  eliminating  the  am- 
monia and  redtifying. 

It  occurred  to  me  to  make  use  of  the  adtion  of  bi- 
sulphited  rosaniline  for  the  estimation  of  aldehyd  in  ether, 
and  to  apply  to  this  estimation  the  colorimetric  method 
of  Mohler,  who  has  rendered  such  great  services  in  the 
analysis  of  alcohols.  In  this  method  {Mohler,  Moniteur 
Scient.,  1890,  p.  893,  and  1891,  p.  582)  we  make  use  of 
the  reddish  violet  colouration  produced  by  the  adtion  of 
bisulphited  rosaniline  on  aldehyd.  We  cause  this  reagent 
to  adt  on  an  alcohol,  whose  contents  of  aldehyd  is  known, 
and  also  on  the  alcohol  under  examination;  the  tints 
developed  are  observed  with  a  Duboscq  colorimeter,  and 
by  dilution  we  can  bring  the  two  alcoliols  to  the  same 
colour.  From  the  amount  of  dilution  we  can  calculate 
the  weight  of  aldehyd  per  litre  present. 

To  apply  this  method  to  the  estimation  of  an  ether,  it 
is  necessary  to  make  some  modifications.  Mohler's  re- 
agent, which  contains  bisulphite  of  soda,  precipitates 
sodic  salts  with  strong  alcohol  and  with  ether;  further,  it 
will  not  mix  with  ether.  We  can  get  over  this  difficulty  by 
using,  for  the  preparation  of  the  reagent,  an  aqueous  solution 
of  sulphurous  acid  instead  of  bisulphite  of  soda,  and  by 
adding  to  the  ether,  at  the  moment  of  making  the  test, 
its  own  volume  of  95  per  cent  alcohol,  free  from  aldehyd. 
With  these  modifications,  the  mixture  of  ether,  alcohol, 
and  reagent  remains  limpid,  and  the  colorimetric  deter- 
minations are  easily  made. 

Preparation  of  the  Reagent. — A  reagent  of  medium 
sensitiveness  can  be  obtained  by  using  : — 

Water  recently  saturated  with  SO2    ..     ..     220  c.c. 

Solution  of  fuchsine,  i/ioooth      30   „ 

Sulphuric  acid,  65° 3   >> 

The  solutions  of  fuchsine  and  sulphurous  acid  are  first 
mixed,  and  after  agitation  we  add  the  sulphuric  acid. 

The  reagent  should  be  colourless.  If  necessary,  we 
can  filter  after  twenty-four  hours.  The  fuchsine  used 
should  be  the  ordinary  kind,  not  acid  (Cazeneuve,  yourn. 
de  PAam.,  June  15,  1896).  The  reagent  is  the  more 
sensitive  as  it  contains  less  sulphuric  acid.  Its  sensitive- 
ness can  thus  become  exaggerated,  even  to  the  extent  of 
becoming  coloured  when  mixed  with  absolutely  pure 
alcohol  and  ether.  Increasing  the  quantity  of  sulphuric 
acid  causes  this  fault  to  disappear. 

A  mixture  of  5  c.c.  of  pure  ether,  5  c.c.  of  pure  95  per 
cent  alcohol,  and  4  c.c.  of  the  reagent  remained  uncoloured 
for  fifteen  minutes.  If  we  replace  the  pure  ether  by  an 
ether  containing  more  than  i/io,oooth  part  of  aldehyd, 
the  mixture  assumes  a  red-violet  colour,  the  more  intense 
as  it  contains  more  aldehyd,  but  not  in  diredt  proportion. 

To  perform  the  experiment  it  is  necessary  to  have 
some  freshly-made  reagent,  ether  free  from  aldehyd, 


8 


Small  Bessemer  Process  for  Steel  Castings, 


Chemical  News^ 
July  2,  1897. 


solution  of  aldehyd  in  go  per  cent  alcohol  containing  i 
grm.  of  aldehyd  per  litre,  a  similar  solution  containing 
o'l  grm.  of  aldehyd  per  litre,  and  a  Duboscq  colorimeter. 

Alcohol  containing  i/ioooth  of  aldehyd  will  serve  as  a 
comparison  for  ail  ethers  containing  more  than  i/ioooth 
of  aldehyd,  and  alcohol  at  i/io,oooth  for  ethers  containing 
from  i/ioooth  to  i/io,oooth  of  aldehyd. 

Method  of  Estimation. — Into  a  test-tube  (i)  we  pour  5 
c.c.  of  alcohol  containing  i/ioooth  part  of  aldehyd  and 
5  c.c.  of  pure  ether ;  into  a  second  tube  (2)  we  pour  5  c.c. 
of  alcohol  containing  i/io,oooth  of  aldehyd  and  5  c.c.  of 
pure  ether;  into  a  third  tube  (3)  we  pour  5  c.c.  of  pure 
95  per  cent  alcohol  and  5  c.c.  of  the  ether  to  be  examined. 
At  the  same  moment  we  add  to  each  4  c.c.  of  the  reagent, 
shake  well,  cork,  and  note  the  time.  After  fifteen  minutes 
observe  the  colour  produced. 

We  note  in  the  first  place  if  the  intensity  of  the 
colouration  is  the  stronger  in  tube  3  than  in  tube  i  ;  if  it 
be  stronger,  we  know  that  the  ether  contains  more  than 
i/ioooth  of  aldehyd,  and  we  therefore  take  tube  2  as  the 
standard  of  comparison  ;  if  the  colour  be  less  strong,  we 
know  that  the  ether  contains  less  than  i/ioooth  of  aldehyd, 
and  we  take  tube  2  as  the  standard.* 

In  the  case  of  an  ether  containing  more  than  i/ioooth 
of  aldehyd  we  note  the  colour  through  a  thickness  of  10 
m.m. 

If  N  be  the  thickness  of  the  solution  under  examina- 
tion (tube  3),  which  has  the  same  intensity  of  colour  as 
the  standard  of  comparison,  the  proportion  x  per  litre  of 
aldehyd,  taking  the  amount  present  as  proportional  to  the 
colour,  will  be  given  by  the  equation — 


I  grm.  N 

The  proportion  lo/N  indicates  how  much  the  ether 
under  examination  should  be  diluted  with  pure  ether,  so 
that  its  contents  in  aldehyd  should  be  brought  to  i  grm. 
per  litre. 

We  now  re-commence  the  estimation,  taking  tube  i  as 
the  highest,  and  preparing  tube  3  with  ether  thus  diluted, 
and  the  value  of  N  will  be  very  near  to  10  m.m.  The 
new  proportion  lo/N  enables  us  to  make  another  dilution, 
more  exadt,  and  then  to  make  a  third  and  last  trial  which 
will  give  a  complete  uniformity  of  tints.  From  the 
quantity  of  pure  ether  it  has  been  necessary  to  add,  we 
deduce  the  quantity  of  aldehyd  present  in  the  ether  under 
examination. 

For  an  ether  containing  from  i/io,oooth  to  i/ioooth  of 
aldehyd,  we  operate  in  the  same  manner,  but  taking  tube 
2  as  the  standard  ;  that  is  to  say,  a  solution  of  aldehyd  of 
1/10,000,  and  comparing  the  colours  through  a  thickness 
of  25  m.m. 

This  method  enables  one  to  estimate  very  small  quan- 
tities of  aldehyd,  and  it  can  be  done  in  less  than  an  hour. 

Preparation  of  Ether  free  from  Aldehyd. — This  is  easily 
prepared  by  the  adtion  of  permanganate  of  potash  in 
alkaline  solution  on  ether  at  65°.  We  use  anhydrous 
commercial  ether  for  choice.  This  is  placed  in  a 
stoppered  litre  flask  with  200  c.c.  of  a  saturated  solution 
of  permanganate  of  potash  and  20  grms.  of  caustic  soda. 
After  twenty-four  hours  and  frequent  agitation,  we  decant 
by  means  of  a  funnel  fitted  with  a  tap,  and  submit  the 
ether  to  the  same  treatment  over  again.  The  filtered 
ether  is  then  left  for  twenty-four  hours  in  contaA  with  a 
mixture  of  50  grms.  of  quicklime  and  50  grms.  of  fused 
chloride  of  iime ;  it  is  then  filtered  and  distilled.  The 
permanganate  has  oxidised  the  ether  and  the  alcohol,  and 
the  ether  thus  obtained  gives  no  colouration  with  the 
aldehyd  reagent,  at  least  not  after  fifteen  minutes. 

Preparation  of  Alcohol  free  from  Aldehyd. — Commercial 
alcohol  is  freed  from  aldehyd,  furfurol,  and  bases  by 
adding  to  i  litre  of  the  alcohol  10  c.c.  of  aniline  and  10 

*  It  would  seem  10  be  more  regular  to  take  as  standards  of  com- 
parison solutions  of  aldehyd  in  pure  ether;  but  we  used  solutions  of 
pure  alcohol  because  they  last  longer  without  chaaging.  The  results 
are  evidently  the  same. 


c.c.  of  phosphoric  acid  at  45°  B.,  boiling  for  an  houF 
(with  a  vertical  condenser),  and  distilling. — jfournal  d^ 
Pharmacie  et  de  Chimie,  Series  6,  vol.  v.,  No.  11. 


THE   SMALL  BESSEMER  PROCESS  FOR  STEEL 

CASTINGS. 

By  SERGIUS  KERN,  M.E.,  St.  Petersburg. 

In  the  Chemical  News,  vol.  Ixxiii.,  pp.  170,  192,  we  pub- 
lished some  notes  on  the  WalrandLegenisel  small  Bes- 
semer process.  At  the  Baltic  ShipbHilding  Works,  St. 
Petersburg,  for  some  time  past,  we  have  used  instead  of 
the  Walrand  process  the  usual  Bessemer  method  for 
making  steel  castings  in  our  convertors,  with  a  capacity 
of  two-thirds  of  a  ton  each. 

The  chief  reasons  which  induced  us  to  discontinue  the 
use  of  the  modus  operandi  advised  by  the  Walrand  process 
are  as  follows : — 

1.  The  uncertainty  of  obtaining  uniform  results.  Steel 
castings  obtained  by  the  Walrand  process  may  be  good- 
for  the  general  trade,  but  may  be  variable  when  tested  for 
tensile  strength  and  elongation. 

2.  The  extreme  difficulty  in  obtaining  steel  castings 
which  would  give  regular  results,  after  being  mechanically 
tested  according  to  the  regulations  of  the  Russian  Naval 
Technical  Committee  (28  to  35  tons  per  square  inch  of 
tensile  strength,  14  per  cent  of  elongation  in  2  inches). 

3.  No  necessity  for  the  addition  of  ferrosilicium  during 
the  blow,  in  order  to  raise  the  temperature  of  the  metal  in  the 
convertor,  before  the  casting.  In  our  convertors,  as  men- 
tioned above,  we  produce,  running  the  process  by  the  usual 
Bessemer  method,  steel  at  a  temperature  of  2200° — 2400° 
C,  quite  sufficient  for  our  shipbuilding  castings,  weighing., 
one  cwt.  and  higher. 

4.  Starting  with  a  metal  from  the  cupola  containing 
4  per  cent  of  silicon,  we  only  lengthen  the  process,  and 
make  also  the  produd  obtained  dearer.  We  start  the 
process  now,  with  a  metal  from  the  cupola,  with  2*25  per 
cent  of  silicon,  which  we  find  quite  sufficient  for  the  charge 
of  our  convertors. 

5.  We  certainlydo  not  use  from  theverycommencement,. 
as  I  pointed  out,  Mr.  Walrand's  system  to  put  the  blast 
on,  and  turn  the  convertor  up  for  an  instant,  after  making 
the  final  additions,  in  order  to  mix  them  with  the  metal. 
Such  a  serious  mistake  will  {give  metal  with  blowholes 
in  very  soft  steel,  or,  in  other  cases,  secondary  readions. 

The  following  are  some  details  of  our  present  work, 
while  making  steel  castings  for  Government  orders  ; — 

Charges  Nos.  63  and  64.    (Nearly  equal  operations). 

Charge  in  cupola : — 

Pig-iron,  Ayresome,  with  4^.  silicon  . .     900  lbs. 

Runners 700    „ 

(This  charge  was  melted  in  the  cupola  in  40  minutes, 
and  run  into  the  vessel). 
Minutes  from  the 
commencement 

of  blow.  • 

9  D  line  visible ;  pressure  7J  lbs. 

10  Green  lines  visible;  pressure  from  this 

point  to  end  of  the  operation  5^—5 
lbs.  per  sq.  inch. 
18  No  green  lines  visible  ;  convertor  turned 

down. 
Three  minutes  after  the  appearance  of  the  D  line  the 
convertor  was  turned  down  and  the  slag  cleaned  off.   This 
operation  took  2  minutes  ;  time  not  counted  in  the  above 
table. 

After  the  disappearance  of  the  green  lines,  12  pounds 
of  ferromanganese,  containing  80  per  cent  of  manganese, 
were  added  to  the  convertor,  after  cleaning  the  slags  off 
a  second  time.  A  further  charge  of  aluminium  was  made,, 
and  the  steel,  after  the  usual  tests,  was  run  into  the. 


Chviiical  News, I 
July  2, 1897.      I 


Honours  for  Men  of  Science. 


casting  ladle,  into  which  aluminium  was  also  thrown.   In 
all  2i  pounds  of  this  metal  was  used. 

The  metalhadatemperatureof  2400°C.  Prof.  Wiborgh's 
very  handy  and  reliable  thermophone  combs  were  used. 
The  metal  cast  very  quietly,  and  did  not  rise  in  the  gates 
of  the  moulds.  A  casting  weighing  8  cwts.  was  made  out 
of  the  charge  No.  63,  and  from  No.  64  other  castings  of 
different  weight  were  made. 

Out  of  a  charge  of  1600  pounds  in  the  cupola  about  1200 
pounds  is  obtained  as  finished  steel. 

The  followingare  the  chemical  and  mechanical  analyses 
of  our  steel  castings: — 

Carbon     ..     ..     cii  per  cent 

Manganese    |..     o'45       „ 

Silicon     ..     ..     o'o8       ,, 

Tensile  Elongation        Bending 

No.  of  specimen.                  strengthi       in  2  ins.  test. 

Tons,  per  sq.  in.     P.c.  Angle. 

No.  63,  annealed. .           25'i  208            141  (^) 

Ditto                        26-2  15-8 

No.  64,  annealed..           237  3i"6              5°  (b) 

Ditto                        23*5  30"i 
No.  64,  unannealed          23  o  22*6              40  {c) 
No.  64,  forged  spe- 
cimens      ..      ..           30*3  27*8            124  ((f) 
Ditto                        30'i  27*8 

Remarks, 
[a)  Bent  without  cracks,     (b)  Cracked,     (c)  Broke  with 
a   coarse   crystalline   fracflure,  one   edge  coloured 
brown,     (rf)  Without  cracks,  there  being  one  crack 
coming  in  forging. 

In  conclusion,  we  must  state  that  the  working  out  of 
many  details  and  improvements  gives  full  credit  to  the 
ingenuity  of  Mr.  Leo  Reyher,  the  manager  of  the  Steel 
Foundry  of  the  above-mentioned  Russian  Government 
Works. 
June  14,  1897. 


HONOURS    FOR    MEN     OF     SCIENCE. 

The  Honours  list  issued  on  Tuesday,  June  22nd,  in  con- 
nection with  the  Diamond  Jubilee,  contains  the  names  of 
a  number  of  men  of  science  upon  whom  Her  Majesty  has 
been  pleased  to  confer  distindlions. 

Dealing  first  with  Fellows  of  the  Royal  Society,  Mr. 
Crookes  and  Dr.  Gowers  receive  knighthoods.  In  the 
Order  of  the  Bath,  Mr.  Wolfe  Barry,  President  of  the 
Institution  of  Civil  Engineers,  Dr.  Frankland,  Foreign 
Secretary  of  the  Royal  Society,  Dr.  Huggins,  Mr.  Norman 
Lockyer,  Diredor  of  the  Solar  Physics  observatory,  Dr. 
Thome  Thorne,  Principal  Medical  Officer  to  the  Local 
Government  Board,  and  (naval  promotion)  Admiral 
Wharton,  Hydrographer  of  the  Admiralty,  are  appointed 
K.C.B. 

Mr.  Christie,  Astronomer  Royal,  and  Mr.  Niven, 
Diredtor  of  Studies  at  the  Royal  Naval  College,  are 
appointed  C.B. 

In  the  Order  of  the  Star  of  India,  Sir  Joseph  Hooker 
and  Lieut.-General  Strachey  are  promoted  to  the  grade  of 
G.C.S.I. 

In  addition  to  the  foregoing,  Baronetcies  are  conferred 
upon  Sir  Wm.  MacCormac,  President  of  the  Royal 
College  of  Surgeons  ;  Mr.  Wilks,  President  of  the  Royal 
College  of  Physicians;  and  Mr.  Thomas  Smith,  Surgeon- 
Extraordinary  to  Her  Majesty.  Mr.  Durston,  Engineer- 
in-Chief  to  the  Navy,  is  made  a  K.C.B. ,  and  knighthoods 
are  conferred  upon  Mr.  A.  R.  Binnie,  the  Engineer  to 
the  London  County  Council,  and  Dr.  Felix  Semon.— 
Nature,  June  24,  1897,  P*  ^^i. 

Preparation  of  Furfurane.— P.  Freundler.— Furfurane 
maybe  obtained  pure  and  in  a  good  proportion  by  heating 
pyromucic  acid  in  a  closed  vessel  to  260° — 275°  for  two 
hours. — Comptes  Rendus,  cxxiv.,  No.  21. 


PROCEEDINGS    OF    SOCIETIES. 

PHYSICAL     SOCIETY. 
Ordinary  Meeting,  yune  i^th,  1897. 

Mr.  Shelford  Bidwell,  President,  in  the  Chair. 

A  PAPER  by  Mr.  Sutherland,  on  "  A  New  Theory  of  the 
Earth's  Magnetism,"  was  taken  as  read. 

Dr.  KuENEN  described  some  "Experiments  on  Critical 
Phenomena,"  made  in  continuation  of  a  research  on  the 
condensation  and  critical  phenomena  of  mixtures  of 
ethane  and  nitrous  oxide,  the  results  of  which  were  pub- 
lished last  year.  The  author  now  investigates  mixtures 
of  ethane  and  acetylene,  and  mixtures  of  ethane  and  car- 
bonic acid,  and  finds  for  them  similar  properties  to  those 
of  the  mixtures  of  ethane  and  nitrous  oxide.  The  first 
part  of  the  paper  refers  to  the  preparation  of  ethane,  and 
the  effedl  of  impurities  on  its  vapour  pressure  and  critical 
constants.  Ethane  from  ethyl  iodide  is  not  very  pure  ;  it 
has  generally  several  per  cent  of  an  admixture  of  a  sub- 
stance of  higher  critical  temperature  and  higher  density 
than  ethane  :  this  substance  is  probably  butane.  Ethane 
from  sodic  acetate,  by  eledlrolysis,  is  nearly  pure ;  the 
method  of  preparation  is  described  by  the  author.  The 
pressure  and  corresponding  volumes  during  condensation 
are  given  for  this  substance  at  various  temperatures.  In 
the  former  paper,  above  referred  to,  instances  are  mentioned 
of  mixtures  having  critical  temperatures  below  those  uf 
the  component  substances.  The  only  instance  of  critical 
temperatures  above  those  of  the  components  seem  to  be 
those  relating  to  mixtures  of  carbonic  acid  and  acetylene. 
According  to  an  experiment  of  Dewar's,  however,  a  mix- 
ture of  i  CO2  and  i  C2H2  has  a  critical  temperature  of 
41°  C,  those  for  carbonic  acid  and  acetylene  being  31'' 
and  37°  respedively.  The  present  investigation  contra- 
didts  this  result.  Dewar  may  not  have  taken  sufficient 
precaution  in  avoiding  errors  of  retardation.  Mixtures 
of  carbonic  acid  and  acetylene  have  critical  temperatures 
between  those  of  the  component  pure  gases.  The  dia- 
gram connedling  temperature  and  volume  shows  that  the 
plait-point  curve  is  aline  with  small  curvature  ;  the  border- 
curve  is  relatively  narrow.  An  instance  of  a  critical  tem- 
perature above  those  of  the  components,  for  this  mixture, 
has  not  yet  been  proved.  Theory  indicates  that  this  phe- 
nomenon probably  occurs  for  mixtures  having  a  minimum 
vapour-pressure  at  low  temperatures.  Critical  temper- 
atures below  those  of  components,  seem  to  occur  for 
mixtures  having  a  maximum  vapour- pressure,  as  for 
nitrous  oxide  and  ethane.  The  law  conneding  the  two 
phenomena  is  deduced  from  van  der  Waal's  theory.  As 
a  further  application  of  this  theory,  it  is  shown  that  in 
consequence  of  certain  coincidences  between  the  real, 
border-curve  and  the  hypothetical  border-curve,  the  critical 
point  of  the  maximum  mixture  may  be  determined  in 
exadtly  the  same  way  as  for  a  single  substance.  A  remark 
is  added  with  regard  to  the  condensation  of  such  sub- 
stances as  exhibit  changes  of  molecular  systems.  If  an 
association  takes  place  of  molecules  to  more  complicated 
systems,  van  der  Waal's  formula  does  not  apply. 

Dr.  S.  P.  Thompson  asked  whether  diagrams  charadler- 
istic  of  cyanogen  had  been  obtained.  Its  remarkable 
polymerism  suggested  an  interesting  case  for  critical 
phenomena. 

Dr.  KuENEN  thought  such  a  substance  might  be  worth 
investigating. 

A  paper  by  Dr.  Barton,  on  "  The  Attenuation  of 
Electric  Waves  in  Wires,"  was  taken  as  read. 

Mr.  G.  F.  C.  Searle  read  a  paper  on  "  The  Steady 
Motion  of  an  Electrified  Ellipsoid." 

The  first  part  of  the  investigation  is  printed  in  the  Phil. 
Trans.  Roy.  Soc.  It  contains  the  principles  required  in 
the  solution  of  problems  with  respe(5t  to  moving  eledrical 


10 


Fresenius's  Quantitative  Analysis. 


{Chemical  News, 
July  2,  iSgy. 


charges.  The  second  part,  now  presented  to  the  Physical 
Society,  deals  with  the  motion  of  a  charged  ellipsoid;  the 
treatment  is  entirely  mathematical.  Wnen  any  system  of 
ele<5tric  charges  moves  with  uniform  velocity  through  the 
aether,  the  elecJtro-magnetic  field,  referred  to  axes  moving 
forward  with  the  charges,  can  be  completely  defined  by 
means  of  a  quantity  of  which  the  eledlric  force  and  the 
magnetic  force  are  simple  fundlions.  Another  veftor  con- 
cerned in  the  problem  is  the  mechanical  force  experienced 
by  a  unit  charge  moving  with  the  rest  of  the  system.  A 
distribution  of  eledlricity  on  the  surface  of  a  charged 
body,  such  as  to  give  zero  distribution  at  all  points  inside 
the  surface,  is  an  equilibrium  distribution.  Since  the 
mechanical  force  vanishes  inside  the  surface,  it  is  shown 
that  on  the  outside  of  the  surface  the  mechanical  force  is 
perpendicular  to  the  surface,  and  the  above-mentioned 
fundlion  is  constant  over  the  surface,  and  the  distribution 
•  on  an  ellipsoid  is  the  same  for  motion  as  for  rest.  When 
a  charged  sphere  is  at  rest  it  produces  the  same  efTeft  as 
a  point-charge  at  its  centre.  If  the  sphere  is  in  motion, 
it  produces  the  same  efFedt  as  an  uniformly-charged  line 
whose  length  bears  to  the  diameter  of  the  sphere  the  same 
ratio  that  the  velocity  of  the  sphere  bears  to  the  velocity 
of  light.  VVhen  the  sphere  moves  with  the  velocity  of 
light,  the  line  becomes  the  diameter  of  the  sphere;  the 
same  is  true  for  an  ellipsoid.  At  the  velocity  of  light  the 
charge  on  any  surface  is  in  equilibrium,  whatever  the  dis- 
tribution. The  force  between  two  charges  moving  with 
the  speed  of  light  is  zero.  The  lines  of  eledlric  force  for 
a  charged  sphere  in  motion  are  not  radial ;  they  form  a 
series  of  hyperbolas.  The  author  proceeds  to  calculate 
the  total  energy  possessed  by  an  ellipsoid  when  in  motion 
along  its  axis  of  figure.  Expressions  are  given  (i)  for 
the  energy  of  a  Heaviside  ellipsoid  ;  (2)  for  a  sphere;  and 
(3)  for  a  very  slender  ellipsoid.  In  all  cases  the  energy 
becomes  infinite  when  the  charges  move  at  the  velocity  of 
light.  It  would  seem  impossible  to  make  a  charged  body 
move  at  a  greater  speed  than  that  of  light. 

Prof.  Perry  said  the  paper  would  help  to  solve  many 
problems  connedted  with  the  effeft  of  the  rotation  of  the 
earth  upon  eledtrical  surface  changes.  An  expression 
might  be  found  for  the  mechanical  and  magnetic  forces 
due  to  the  motion  of  a  charge  at  any  point  of  the  earth's 
surface.  At  the  equator  a  point  moves  at  different  velocity 
at  middaytoitsmidnightvelocity;  it  might  now  be  possible 
to  determine  the  magnetic  and  mechanical  effedts  due  to 
eledric  charges  at  equatorial  points. 

Mr.  Blakesley  asked  whether,  in  calculating  the 
mutual  adtion  of  two  charged  particles,  proceeding  at  the 
velocity  of  light,  it  was  assumed  that  the  Imes  of  motion 
were  parallel. 

Mr.  Searle  said  he  had  always  considered  parallel 
lines  of  motion ;  he  could  not  say  whether  the  force 
would  be  zero  in  any  other  case.  The  results  arrived  at 
in  the  paper  could  be  applied  to  problems  connedled  with 
distributions  of  terrestrial  charges. 

The  President  proposed  votes  of  thanks  to  the 
authors ;  the  meeting  then  adjourned  until  November. 


OBITUARY. 


PROF.    SCHUTZENBERGER. 

"Chemical  Science,  not  merely  in  France  but  throughout 
the  world,  has  sustained  a  heavy  blow  by  the  death  of 
Prof.  Schiitzenberger,  at  the  age  of  67.  The  deceased 
was  a  native  of  Strasburg,  where  he  studied  medicine, 
and  became  connedted  with  the  chemical  laboratory  of 
the  Conservatoire  des  Arts  et  Metiers,  of  that  city.  He 
became  successively  Assistant-Diredlor  of  the  Sorbonne 
Laboratory  and  Head  of  the  Chemical  Department  of  the 
College  de  France,  where  he  filled  the  chemical  chair 
since  1876.    Along  with  these  posts,  which  he  held  with 


success  and  distindtion,  he  was  eledted  Head  of  the  Paris 
Municipal  School  of  Chemistry  and  Physics.  In  1884 
he  became  a  Fellow  of  the  Academy  of  Medicine. 
Lastly,  in  1888,  on  the  death  of  Debray,  he  was  eleded  a 
Fellow  of  the  Academy  of  Sciences. 

These  honours,  and  the  widely-felt  appreciation  of 
which  they  were  the  embodiment,  were  earned  by  a  series 
of  sterling  researches  in  organic  chemistry,  especially  in 
its  application  to  colours  and  their  uses  in  the  tindorial 
arts,  in  which  department  he  was  recognised  as  one  of 
the  best  authorities.  His  works  include  researches  on  the 
physiology  of  digestion  and  fermentation,  and,  above  all, 
a  cyclopaedia — as  we  may  call  it — of  tindlorial  chemistry, 
considered  both  theoretically  and  pradtically,  and  an  in- 
vestigation into  the  alkaloids. 

The  late  professor  was  universally  respedied  by  all  who 
had  the  pleasure  of  his  acquaintance.  Prof.  Schiitzen- 
berger died  on  Monday,  June  28th. 


NOTICES  OF  BOOKS. 


Fresenius^s   Quantitative  Analysis.    Vol.  ii.     Translated 

by  C.  E.  Groves,  F.R.S.     Part  IV. 
The  magnum  opus  of  the  late  "  Grand  Master  "  (Professor 
Fresenius)    is  gradually   making   its   appearance    in   an 
English  guise. 

The  present  issue  treats  in  succession  of  zinc-dust,  of 
manganese  compounds,  nickel  compounds,  iron  com- 
pounds, uranium,  silver,  mercury,  and  lead  compounds. 

The  translator  appears  to  be  doing  justice  to  the 
original.  At  the  same  time  we  cannot  approve  of  the 
system  of  publishing  the  translation  of  a  book  in  detached 
portions. 

The  Study  of  Technical  Chemistry  at  the  Universities  and 

Technical  High  Schools  of  Germany.     ("  Das  Studium 

der  Technischen    Chemie    am  den  Universitaten   und 

Technischer  Hoch-Schulen,  Deutschlands").   Opinions 

on    the.  German   System    of   Training   Chemists.      By 

Prof.  Dr.  Ferd.  Fischer. 

This  pamphlet  contains  the  opinions  of  eminent  authori- 

ties  as  to  the  cause'  of  the  relative  decline  of  certain 

English    industries.     As    a   whole,  they  agree   that   our 

failure — for  as  such  we  must  accept  it — is  due  to  our  im- 

perfedt  system  of  higher  education.    Chemical  technology 

is  for  the  universities  the  connedting  link  between  science 

and  industry. 

Among  the  heads  of  German  universities  there  prevails 
a  unanimous  opinon  that  Germany  can  maintain  its  indus- 
trial work  solely  in  virtue  of  its  chemical  eminence. 
Slight  alterations  in  the  curriculum  are  proposed  in  some 
quarters.  But  the  general  tendency  is  rather  to  intensify 
than  to  lighten  the  course  of  study. 

In  the  Presidential  Address  of  the  Society  of  Chemical 
Industry  (1895),  it  was  admitted  that  business  ability  and 
capital  cannot  suffice  to  uphold  the  chemical  industry  of 
the  country  without  a  fundamental  scientific  technical 
training. 

We  have  met  with  chemical  manufafturers  who  know 
little  of  chemical  science,  and  do  not  seek  to  know  more. 
Some  of  these  employ  an  analyst  who  has  to  limit  himself 
to  routine  work.  To  enquire  into  the  cause  of  any  dis- 
appointment is  a  "  waste  of  time." 


Chilian  Hygienic  Review.  ("  Rivesta  Chilena  de  Hi- 
jiena,"  publiceda  el  Institute  de  Hijiene  de  Santiago). 
Parts  II.  and  III. 
The  most  important  matter  in  these  issues  refers  to  the 
observance  of  quarantine,  which,  in  the  whilome  Spanish 
republics,  is  still  maintained.      In   Chili  there  are  two 


Crbmical  Nivs,  I 
July  2,  1897.      I 


Chemical  Notices  from  Foreign  Sources, 


IT 


grades  of  quarantine.  The  quarantine  of  observation  is 
imposed  upon  every  traveller  upon  entering  Chilian  terri- 
tories, which  lasts  forty-eight  hours.  During  this  period 
the  traveller  and  his  belongings  are  submitted  to  system- 
atic  disinfedtion  according  to  the  rules  laid  down. 

At  the  moment  when  the  quarantine  expires  the 
traveller  will  receive,  from  the  head  of  the  sanitary  de- 
partment, a  certificate  which  will  serve  him  as  a  passport. 
The  head  of  the  sanitary  department  will  communicate 
with  the  governor  of  the  department  to  which  the  traveller 
is  proceeding. 

Rigid  Quarantine. — If,  during  the  quarantine  of  ob- 
servation,  there  occur  suspicious  symptomi,  the  quarantine 
is  made  stridt.  Rigid  quarantine  is  then  continued  for 
eight  days.  If  the  patient  dies,  his  body,  after  disin- 
fedlion,  is  buried  in  ground  the  drainage  of  which  does 
not  enter  the  stream.  If  no  such  ground  is  obtained,  the 
body  will  be  incinerated.  His  possessions  will  be  destroyed 
by  fire,  with  the  exception  of  articles  which  the  head  of 
the  sanitary  department  may  designate. 

The  disinfedlion  of  persons  will  consist  in  a  general 
soap-bath  or  in  general  lotions,  with  a  solution  of  sub- 
limate at  1/50Q0. 

Dead  bodies  will  receive  an  injedlion  of  solution  of 
sublimate  at  1/500,  in  the  stomach,  the  bowels,  and  the 
carotid  and  femoral  arteries,  and  the  body  will  further  be 
wrapped  in  a  shroud  saturated  with  the  same  solution. 


CORRESPONDENCE. 


ESTIMATION  OF  CARBON   IN   FERRO-CHROME. 

To  the  Editor  of  the  Chemical  News. 
Sir, — Professor  Arnold's  letter  is  a  surprising  continua- 
tion of  what  I  hoped  might  prove  a  helpful  discussion. 
I  ought  first  to  disabuse  your  readers'  mind  of  the  per- 
sonal illusion  by  which  the  Professor  would  create  a  false 
relation  between  us.  He  says  that  "  until  quite  recently 
Mr.  Leffler  was  a  student  of  mine."  In  the  ordinary 
sense  this  is  not  true.  It  is  true  that  I  was  a  student  at 
the  Technical  School  for  three  years,  but  it  is  nine 
years  this  summer  since  I  left ;  that  was  some  time  before 
Prof.  Arnold  came  to  the  school.  This  he  can  readily 
verify  by  appealing  to  his  Senior  Demonstrator.  In  the 
autumn  of  1894  I  desired  to  acquaint  myself  with  the 
microscopic  analysis  of  steel,  and  worked  under  Prof. 
Arnold  two  nights  a  week  from  September  to  Christmas, 
and  ceased  work  at  his  suggestion  on  account  of  the  in- 
adequate accommodation.  This  fadt  is  a  very  slender 
thing  on  which  to  found  the  above  assertion,  and  I  feel 
that  it  in  noway  obliges  me  to  submit  to  him  any  opinion 
I  may  form  on  a  subjedl  like  the  one  under  discussion. 

I  pointed  out  in  my  last  letter  that  I  had  never  made 
the  bald  assertion  that  his  method  only  gave  half  the 
carbon  present.  The  furnace  at  our  disposal  certainly 
only  gave  about  50  per  cent  of  the  carbon,  but  I  stated 
that  on  raising  the  temperature  with  the  blowpipe  the  re- 
maining 50  per  cent  was  obtained.  Plainly,  then,  our 
furnace  was  not  hot  enough,  though  it  was  as  hot  as 
combustion  furnaces  frequently  are.  The  need  of  the 
blowpipe  was  evidence  that  the  temperature  was  too 
low,  and  I  have  never  attempted  to  deny  it. 

Prof.  Arnold  invited  a  reply  to  his  first  letter,  by  asking 
the  type  of  furnace  and  the  diameter  of  the  gas-pipe.  To 
this  information  I  attached  a  few  questions  and  other  de- 
tails, which  the  Professor  has  no  inclination  to  follow, 
although  I  refer  only  to  certain  pages  of  his  own  book, 
"  Steel  Works  Analysis." 

Prof.  Arnold  refers  to  Mr.  Saniter's  letter  as  proof  that 
I  have  put  up  straw  men.  I  cannot  imagine  to  what  part 
he  refers,  but  thank  him  for  the  reference  nevertheless, 
because  it  draws  my  attention  to  the  unprejudiced  support 
Mr.  Saniter  gives  to  my  assertion.     Saniter's  third  para- 


graph reads  "  I  also  found  that  with  copper  oxide  only 
about  half  the  carbon  is  obtained."  Now  I  admit  that  a 
little  higher  temperature  is  needed  for  combustion  with 
copper  oxide  than  with  lead  chromate;  but  copper  oxide 
will  give  perfedtly  accurate  results,  and  failed  to  do  so  in 
Mr.  Saniter's  hands  only  because  his  furnace  was  not  hot 
enough,  which  supports  my  assertion  that  our  furnace  is 
as  hot  as  those  generally  used,  but  not  enough  to  com- 
pletely eliminate  the  carbon  from  a  mixture  of  lead 
chromate  and  ferro-chrome. 

The  statement  made  was  not  inaccurate,  nor  was  it 
hastily  arrived  at,  as  the  method  was  given  a  long  and' 
fair  trial,  and  the  results  obtained  accurately  and  honestly 
recorded. — I  am,  &c., 

R.  L.  Leffler, 

The  Laboratory, 

Messrs.  Thos.  Firth  and  Sons,  Lim., 

Sheffield,  June  21,  1897. 


CHEMICAL    NOTICES    FROM    FOREIGN 
SOURCES. 


NoTB.— All  degrees  of  temperature  are  Centigrade  unless  otherwise - 
expressed. 

Comptes  Rendus  Hebdomadaires  des  Seances,  dePAcademie  ■ 
des  Sciences.    Vol.  cxxiv..  No.  22,  May  31,  1897. 

Liquefacflion  of  Fluorine. — H.  Moissan  and  J.  Dewar. 
— This  memoir  has  been  inserted  in  full. 

Part  Played  by  Humic  Matter  in  the  Fertilisation 
of  Soils. — Armand  Gautier. — The  algse  as  well  as  the 
microbia  which  solidify  nitrogen  find  in  the  humus  of  the 
soil  and  generally  in  the  organic  matter  of  excrements  a 
nutrient  which  allows  of  their  rapid  development.  1  do 
not  assert  that  soils  owe  their  fertility  to  the  diredt 
absorption  by  plants  of  organic  matter,  ternary  or 
quaternary. 

Purification  of  Cerium. — M.  Wyrouboff  and  Ar 
Verneuil. — Already  inserted. 

Remarks  on  the  above  Communication  by 
Wyrouboff  and  Verneuil. — Already  inserted. 

Alloys  of  the  Silver-copper  Group. — F.  Osmond. — - 
The  conception  of  Matthiesen,  who  saw  on  certain  alloys 
(  solidified  solutions  of  allotropic  form,  whilst  in  need  of 
certain  restridions,  seems  to  remain  vital  and  fruitful.  I 
do  not  see  that  it  is  opposed  to  the  researches  of  H.  le 
Chatelier,  whose  conclusions  would  receive  from  it  a 
charadter  of  greater  generality. 

Phosphorescence  of  Strontium  Sulphide. — Jo^e 
Rodriquez  Mourello. — We  see  that  an  oxidising  principle 
is  requisite,  as  well  as  a  peculiar  strudlure,  for  strontium 
sulphide  to  be  susceptible  of  phosphorescence  without 
omitting  the  substances  whose  influence  on  the  property 
in  question  is  dired^  or  positive. 

Contribution  to  the  Study  of  the  Preparation  of 
Common  Ether. — L.  Prunier. — In  the  ordinary  prepara- 
tion of  ether  it  escapes,  in  virtue  of  its  great  volatility,  in 
the  midst  of  a  heterogeneous  medium,  unstable,  and  in'^ 
perpetual  transformation. 

Certain  Compounds  of  Pbenylhydrazine  with 
Metallic  Chlorides. — J.  Ville  and  J.  Moitessier. — Phenyl- 
hydrazine  combines  with  different  metallic  chlorides, 
yielding  compounds  containing  i  mol.  of  chlorides  with  2 
mols.  of  pbenylhydrazine. 

Apparatus  for  the  Industrial  Analysis  of  Gases. — 
Leo  Vignon. — This  memoir  requires  the  accompanying 
illustration. 

Decomposition-produ(5ts  of  Calcium  Carbide,  and 
on  its  Use  as  an  Inse(5ticide. — E.  Chuard. — The  author 
has  obtained  a  phospho-carbide  possessing  powerful' 
insedlicide  properties. 


12 


Chemical  Notices  from  Foreign  Sources. 


f  Chemical  News, 
1      July  2,  1897. 


No.  23,  June  8,  1897. 
A(!\ion  of  Light    on    Mixtures   of    Chlorine    and 
Hydrogen. — Armand    Gautier    and    H.    Helier. — This 
paper  will  be  inserted  at  some  length. 

Observations  on  the  Limitation  of  Chemical  Re- 
acf^ions,  with  reference  to  Armand   Gautier's  Com- 
munication. —  This  memoir  will   also  be  inserted   in 
-  extenso. 

Memoir  by  M.  Berthelot  accompanying  the  Pre- 
sentation of  his  work  on  Thermo-chemistry. — A  kind 
of  preface  to  the  author's  recent  works. 

Examination  of  certain  Spectra. — Lecoq  de  Bois« 
baudran. — A  controversial  paper,  diredted  against  Drs. 
Eder  and  Valenta.  Except  the  small  ray  563'8,  seen 
with  K2SO4,  but  not  with  K2CO3,  all  the  rays  of  the 
author's  diagram  are  seen  with  K2SO4  and  K2CO3,  and 
have  not  been  observed  with  the  salts  of  Na. 


NOTES    AND    QUERIES, 

*4*  Our  Notes  and  Queries  column  was  opened  for  the  purpose  of 
giving  and  obtaining  information  likely  to  be  of  use  to  our  readers 
generally.  We  cannot  undertake  to  let  this  column  be  the  means 
of  transmitting  merely  private  information,  or  such  trade  notices 
as  should  legitimately  come  in  the  advertisement  columns. 
Annual  Consumption  of  Chemicals. — I  should  be  extremely 

obliged  if  any  reader  would  kindly  let  me  know  what  is  the  average 

amount  of  sulphate  of  barium    and  sulphurite  of  sodium   consumed 
.  annually  in  this  country,  and  in  what  industries  these  produ(5ts  are 

chiefly  used. — L.  Alsatini. 


TO    CORRESPONDENTS. 

Eugene  Ackermann. — Please  forward  address ;  a  letter  awaits  you. 

HULL  MUNICIPAL  TECHNICAL  SCHOOLS. 

CHEMISTRY  MASTERSHIP. 

The  Technical  Instru(5lion  Committee  is  pre- 
pared to  receive  applications  for  the  above  Appointment. 
Candidates  must  not  be  under  25  nor  over  40  years  of  age.  The 
Master  will  not  be  allowed  to  undertake  any  teaching  other  than  that 
required  by  the  Committee.  Salary,  £200  per  annum,  payable 
■  monthly.  Forms  of  application  and  further  particulars  may  be  ob- 
tained from  the  undersigned,  to  whom  applications  must  be  sent  not 
later  than  Wednesday,  July  14th,  1897. 

J.  T.  RILEY,  D.Sc.(Lond.), 
7,  Albion  Street,  Hull.  Diredtor  ot  Studies. 

ST.  BARTHOLOMEW'S  HOSPITAL  AND   COLLEGE. 
A  pplications    are    invited   for  the   offices    of 

/^  DEMONSTRATOR  and  ASSISTANT  DEMONSTRATOR 
of  CHEMISTRY.  Particulars  of  the  duties  and  emoluments  may 
be  obtained  on  application  to  the  undersigned,  to  whom  applications 
should  be  sent  on  or  before  July  12th  next. 

THOMAS  W.  SHORE,  Warden. 


EAST   LONDON   TECHNICAL  COLLEGE. 

DAY    CLASSES 

IN 

CHEMISTRY,   PHYSICS,  and  ENGINEERING. 
'Tphrough  the  generosity  of  the  Drapers'  Com- 

•^  pany  the  Governors  will  be  enabled  to  award  on  the  results  of 
an  Open  Competitive  Examination  in  July  next,  at  least  TWO 
SCHOLARSHIPS  of  the  value  of  £10  a  year  for  two  years,  together 
with  exemption  from  the  class  fees.  Candidates  must  be  under  17 
years  of  age.  Particulars  on  application  to  the  Director  of  Studies, 
People's  Palace,  E. 

THE  LEEDS  INSTITUTE  OF  SCIENCE,  ART,  AND 
LITERATURE. 

The  Diredlors  invite  applications  for  the  post 
of  HEAD  MASTER  of  The  Leeds  Technical  School  and 
TEACHER  of  CHEMISTRY  to  the  Boys'  and  Girls'  Modern 
Schools  of  the  Institute,  now  vacant  by  the  death  of  Mr.  S.J.  Harris, 
M.Sc. 

The  Master  appointed  will  be  expefted  to  take  classes  in  Theo- 
retical and  Pra(5tical  Inorganic  and  Organic  Chemistry  and  to  exer- 
cise a  general  supervision  over  the  other  classes  in  the  Technical 
School.  Th«  sctioot.buildings,  ere(5ied  in  1888,  are  furnished  with  all 
necessary  materials  and  apparatus  for  science  teaching. 

Salary,  partly  fixed  and  partly  dependent  upon  results,  amounts  to 
about  £'325.  Full  particulars  may  be  had  from  the  Secretary,  to 
whom  applications  must  be  sent  not  later  than  July  2oth,  1897. 

Canvassing  Diredtors  will  be  considered  a  disqualification. 

ACETONE Answering  all  requirements. 

.A-OIX)  J^CIBTIC— Purest  and  sweet. 

T=!OT?.  A  nTf!— Crvst.  and  powder. 

CXTDRIO— Cryst.  made  in  earthenware. 

^—  C^y-  A  TiTiTT^ — From  best  Chinese  galls,  pure. 

SJLnLIC^XjIC-By  Kolbe's  process 

'3['_^[]V^JCN5"ICZ!—ForPharmacy  and  the  Arts. 

LIQUID  CHLORINE 

(Compressed  in  steel  cylinders). 
POTASS.  PERMANGANATE— Cryst.,  large  and  small. 
SULPHOCYANIDE    OF   AMMONIUM. 
BARIUM. 

SODA  PHOSPHATE. 
THORIUM,  ZIRCONIUM,  and  CERIUM  SALTS. 

TARTAR    EMETIG-Cryst.  and  Powder. 

PUMICE.     TRIPOLI    AND   METAL   POWDERS. 

ALL  CHEMICALS   FOR  ANALYSIS   AND  THE  ARTS. 

Wholesale  Agents — 

A.  &  M.  ZIMMERMANN, 

9  &  10,   ST.  MARY-AT-HILL.   LONDON,  E.G. 


PATENTS,  DESIGNS,  AND  TRADE  MARKS  ACTS, 
1883  TO  1888. 

NOTICE  IS  HEREBY  GIVEN,  that 
HiPPOLYTE  Eugene  Serullas,  of  20,  Rue  Moliere,  Paris, 
France,  has  applied  for  leave  to  amend  the  Specification  of  the 
Letters  Patent  No.  11166  of  1892  for  "  Improvements  in  or  connefted 
with  an  Apparatus  for  the  Obtainmentor  Extradlion  of  Gutta-percha 
or  the  like." 

Particulars  of  the  proposed  amendments  were  set  forth  in  the 
Illustrated  Official  Journal  (Patents),  issued  on  the  i6th  June,  1897. 

Any  person,  or  persons,  may  give  notice  of  opposition  to  the 
amendment  (on  Form  G)  at  the  Patent  Office,  25,  Southampton 
Buildings,  London,  W.C.,  within  one  calendar  month  from  the  date 
of  the  said  Journal. 

(Signed)  C.  N.  DALTON, 

Comptroller  General. 
HASELTINE,  LAKE,  &  CO., 

45,  Southampton  Buildings, 

Chancery  Lane,  London,  W.C., 

Agents  for  the  Applicant. 


ELECTRICAL 
ENGINEER, 


H.W.COX 

10  &  11,  CURSITOR  STREET,  CHANCERY  LANE,  E.G., 

ManufacSlurer  of  X-Ray  Induc5tion 

Coils  and  Apparatus,  &c. 

ACTUAL  MAKER  TO  THE  TRADE. 

Crookes  Tubes,  Fluorescent  Screens,  Batteries,  do. 

WRITE  FOR  PRICES  OR  GALL. 
PraAical'  Demonstration  given  to  intending  Purchasers. 


Cbruical  News, I 

July  9,  1897.      I 


Diamonds, 


13 


THE    CHEMICAL    NEWS 


Vol.  LXXVI.,  No.  1963. 


DIAMONDS.' 

By  WILLIAM  CROOKES,  F.R.S.,  M.R.L 

(Continued  from  p.  4). 

Conversion  of  Diamond  into  Graphite. 
I  WILL  now  draw  your  attention  to  a  strange  property 
of  the  diamond,  which  at  first  sight  might  seem  to  argue 
against  the  great  permanence  and  unalterability  of  this 
stone.  It  has  been  ascertained  that  the  cause  of  phos- 
phorescence is  in  some  way  connedted  with  the  hammer- 
ing of  the  gaseous  molecules,  violently  driven  from  the 
negative  pole  on  to  the  surface  of  the  body  under  ex- 
amination, and  so  great  is  the  energy  of  the  bombard- 
ment, that  impinging  on  a  piece  of  platinum,  or  even 
iridium,  the  metal  will  adtually  melt.  When  the  diamond 
is  thus  bombarded  in  a  radiant  matter  tube  the  result  is 
startling.  It  aot  only  phosphoresces,  but  assumes  a 
brown  colour,  and  when  the  a&ion  is  long  continued 
becomes  almost  black. 

I  will  projedt  a  diamond  on  the  screen  and  bombard  it 
with  radiant  matter  before  your  eyes.  I  do  not  like  to 
anticipate  a  failure,  but  here  I  am  entirely  at  the  mercy 
of  my  diamond.  I  cannot  rehearse  this  experiment  be- 
forehand,  and  it  may  happen  that  the  diamond  I  have 
seledled  will  not  blacken  in  reasonable  time.  Some 
visibly  darken  in  a  few  minutes,  while  others,  more  lei- 
surely in  their  ways,  require  an  hour. 

This  blackening  is  only  superficial,  but  no  ordinary 
means  of  cleaning  will  remove  the  discolouration.  Ordi- 
nary oxidising  reagents  have  little  or  no  efifeft  in  restoring 
the  colour.  The  black  stain  on  the  diamond  is  due  to  a 
form  of  graphite  which  is  very  resistant  to  oxidation.  It 
is  not  necessary  to  expose  the  diamond  in  a  vacuum  to 
eledlrical  excitement  in  order  to  produce  this  change. 

I  have  already  signified  that  there  are  various  degrees 
of  refradloriness  to  chemical  reagents  among  the  different 
forms  of  graphite.  Some  dissolve  in  strong  nitric  acid  ; 
other  forms  of  graphite  require  a  mixture  of  highly  con- 
centrated nitric  acid  and  potassium  chlorate  to  attack 
them,  and  even  with  this  intensely  powerful  agent  some 
graphites  resist  longer  than  others.  M.  Moissan  has 
shown  that  the  power  of  resistance  to  nitric  acid  and 
potassium  chlorate  is  in  proportion  to  the  temperature  at 
which  the  graphite  was  formed,  and  with  tolerable  cer- 
tainty we  can  estimate  this  temperature  by  the  resistance 
of  the  specimen  of  graphite  to  this  reagent. 

The  superficial  dark  coating  on  a  diamond  after  ex- 
posure to  molecular  bombardment  I  have  proved  to  be 
graphite, t  and  M.  Moissan  +  has  shown  that  this  graphite, 
on  account  of  its  great  resistance  to  oxidising  reagents, 
cannot  have  been  formed  at  a  lower  temperature  than 
3600°  C. 

It  is  therefore  manifest  that  the  bombarding  molecules 
carrying  with  them  an  eledric  charge,  and  striking  the' 
diamond  with  enormous  velocity,  raise  the  superficial 
layer  to  the  temperature  of  the  eledlric  arc,  and  turn  it 
into  graphite,  whilst  the  mass  of  diamond  and  its  con- 
dudlivity  to  heat  are  sufficient  to  keep  down  the  general 
temperature  to  such  a  point  that  the  tube  appears  scarcely 
more  than  warm  to  the  touch. 

A  similar    adtion   occurs   with   silver,   the   superficial 
layers  of  which  can  be  raised  to  a  red  heat  without  the 
whole  mass  becoming  more  than  warm,§ 
*  A  LeAure  delivered  at  the  Royal  Institution,  Friday,  June  iitb, 

t  Chemical  News,  vol.  Ixxiv.,  p.  39,  July,  1896. 

t  Cotnptes  Rendus,  cxxiv.,  p.  653. 

§  Proc.  R.  S.,  vol.  1.,  p.  99.,  June  1891. 


This  conversion  of  diamond  into  graphite  is  I  believe  a 
pure  effedt  of  heat.  In  1880*  Professor  Dewar  in  this 
theatre  placed  a  crystal  of  diamond  in  a  carbon  tube 
through  which  a  current  of  hydrogen  was  maintained. 
The  tube  was  heated  from  the  outside  by  an  ele(Slric  arc, 
and  in  a  few  minutes  the  diamond  was  converted  into 
graphite.  I  will  now  show  you  that  a  clear  crystal  of 
diamond,  heated  in  the  eledric  arc  (temperature  3600°  C.) 
is  converted  into  graphite,  and  this  graphite  is  most 
refradtory. 

The  diamond  is  remarkable  in  another  respedt.  It  is 
extremely  transparent  to  the  Rontgen  rays,  whereas 
highly  refradling  glass,  used  in  imitation  diamonds,  is 
almost  perfedtly  opaque  to  the  rays.  I  exposed  over  a 
photographic  plate  to  the  X  rays  for  a  few  seconds  the 
large  Delhi  diamond,  of  a  fine  pink  colour,  weighing  31^ 
carats,  a  black  diamond  weighing  23  carats,  together  with 
an  imitation  in  glass  of  the  pink  diamond  lent  me  by  Mr. 
Streeter ;  also  a  flat  triangular  crystal  of  diamond  of 
pure  water,  and  a  piece  of  glass  of  the  same  shape  and 
size.  On  development,  the  impression  where  the  dia- 
mond obscured  the  rays  was  found  to  be  strong,  showing 
that  most  rays  passed  through,  while  the  glass  was  prac- 
tically opaque.  By  this  means  imitation  diamonds  and 
some  other  false  gems  can  readily  be  detedled  and  distin- 
guished from  the  true  gems.  It  would  take  a  good  ob- 
server to  distinguish  my  pure  triangular  diamond  from 
the  adjacent  glass  imitation. 

Genesis  of  the  Diamond. 

Speculations  as  to  the  probable  origin  of  the  diamond 
have  been  greatly  forwarded  by  patient  research,  and  par- 
ticularly by  improved  means  of  obtaining  high  tempera- 
tures. Thanks  to  the  success  of  Professor  Moissan, 
whose  name  will  always  be  associated  with  the  artificial 
produdlion  of  diamonds,  we  are  able  to-day  to  manufac- 
ture diamonds  in  our  laboratories — minutely  microscopic, 
it  is  true — all  the  same  veritable  diamonds,  with  crys- 
talline  form  and  appearance,  colour,  hardness,  and  adlion 
on  light  the  same  as  the  natural  gem. 

Until  recent  years  carbon  was  considered  absolutely 
non-volatile  and  infusible ;  but  the  enormous  tempera- 
tures at  the  disposal  of  experimentalists — by  the  introduc- 
tion of  eledtricity — show  that,  instead  of  breaking  rules, 
carbon  obeys  the  same  laws  that  govern  other  bodies.  It 
volatilises  at  the  ordinary  pressure  at  a  temperature  of 
about  3600°  C,  and  passes  from  the  solid  to  the  gaseous 
state  without  liquefying.  It  has  been  found  that  other 
bodies  which  volatilise  without  liquefying  at  the  ordinary 
pressure  will  easily  liquefy  if  pressure  is  added  to  tem- 
perature. Thus,  arsenic  liquefies  under  the  adlion  of 
heat  if  the  pressure  is  increased;  it  naturally  follows  that 
if  along  with  the  requisite  temperature  sufficient  pressure 
is  applied,  liquefadlion  of  carbon  will  be  likely  to  take 
place,  when  on  cooling  it  will  crystallise.  But  carbon  at 
high  temperatures  is  a  most  energetic  chemical  agent,  and 
if  it  can  get  hold  of  oxygen  from  the  atmosphere  or  any 
compound  containing  it,  it  will  oxidise  and  fly  off  in  the 
form  of  carbonic  acid.  Heat  and  pressure  therefore  are 
of  no  avail  unless  the  carbon  can  be  kept  inert. 

It  has  long  been  known  that  iron  when  melted  dis- 
solves carbon,  and  on  cooling  liberates  it  in  the  form  of 
graphite.  Moissan  discovered  that  several  other  metals 
have  similar  properties,  especially  silver;  but  iron  is  the 
best  solvent  for  carbon.  The  quantity  of  carbon  entering 
into  solution  increases  with  the  temperature,  and  on  cool- 
ing in  ordinary  circumstances  it  is  largely  deposited  as 
crystalline  graphite. 

Professor  Dewar  has  made  a  calculation  as  to  the 
Critical  Pressure  of  Carbon — that  is,  the  lowest  pressure 
at  which  carbon  can  be  got  to  assume  the  liquid  state  at 
its  critical  temperature,  that  is  the  highest  temperature 
at  which  liquefadlion  is   possible.     He  starts  from  the 

*  Proceedings  of  the  Royal  Institution,  Friday  Evening  Meeting, 
Jan.  16, 1880. 


14 


Diamonds, 


CHBMICALNBWSr 

July  9,  i8q7. 


vaporising  or  boiling  point  of  carbon,  which,  from  the 
experiments  of  Violle  and  others  on  the  eledtric  arc,  is 
about  3600°  C,  or  3874°  Absolute.  The  critical  point  of 
a  substance  on  the  average  is  1*5  times  its  absolute  boil- 
ing point.  Therefore  the  critical  point  of  carbon  is 
5811°  Ab.,  or,  say,  5800°  Ab.  But  the  absolute  critical 
temperature  divided  by  the  critical  pressure  is  for  ele- 
ments never  less  than  2*5.    Then — 

5800°  A.^        Qj.  pcy^58oo°A.  Qj  atmospheres. 

PCr  25 

The  result  is  that  the  critical  pressure  of  carbon  is 
about  2300  atmospheres,  or  say  15  tons  on  the  square 
inch.  The  highest  critical  pressure  recorded  is  that  of 
water,  amounting  to  195  atmospheres,  and  the  lowest  that 
of  hydrogen,  about  20  atmospheres.  In  other  words,  the 
critical  pressure  of  water  is  ten  times  that  of  hydrogen, 
and  the  critical  pressure  of  carbon  is  ten  times  that  of 
water. 

Now  15  tons  on  the  square  inch  is  not  a  difHcult 
pressure  to  obtain  in  a  closed  vessel.  In  their  researches 
on  the  gases  from  fired  gunpowder  and  cordite.  Sir 
Frederick  Abel  and  Sir  Andrew  Noble  obtained  in  closed 
steel  cylinders  pressures  as  great  as  95  tons  to  the  square 
inch,  and  temperatures  as  high  as  4000°  C.  Here,  then, 
if  the  observations  are  corredt,  we  have  sufficient  tempera- 
ture and  enough  pressure  to  liquefy  carbon ;  and  if  the 
temperature  could  only  be  allowed  to  adt  for  a  sufficient 
time  on  the  carbon  there  is  little  doubt  that  the  artificial 
formation  of  diamonds  would  soon  pass  from  the  micro- 
scopic stage  to  a  scale  more  likely  to  satisfy  the  require- 
ments of  science,  industry,  and  personal  decoration. 

Artificial  Manufacture  of  the  Diamond, 

I  now  proceed  to  manufadture  a  diamond  before  your 
eyes — don't  think  I  yet  have  a  talisman  that  will  make 
me  rich  beyond  the  dreams  of  avarice  !  Hitherto  the 
results  have  been  very  microscopic,  and  are  chiefly  of 
scientific  interest  in  showing  us  Nature's  workshop,  and 
how  we  may  ultimately  hope  to  vie  with  her  in  the  manu- 
fadture of  diamonds.  Unfortunately  the  operations  of 
separating  the  diamond  from  the  iron  and  other  bodies 
with  which  it  is  associated  are  somewhat  prolonged — 
nearly  a  fortnight  being  required  to  detach  it  from  the 
iron,  graphite,  and  other  matters  in  which  it  is  em- 
bedded. I  can,  however,  show  the  different  stages  of 
the  operations,  and  projedt  on  the  screen  diamonds  made 
in  this  manner. 

In  Paris  recently  I  saw  the  operation  carried  out  by  M. 
Moissan,  the  discoverer  of  this  method  of  making  carbon 
separate  out  in  the  transparent  crystalline  form,  and  I 
can  show  you  the  operations  straight  as  it  were  from  the 
inventor's  laboratory.  I  am  also  indebted  to  the  Diredtors 
of  the  Notting  Hill  Eledtric  Lighting  Co.  and  to  the 
General  Manager,  Mr.  Schultz,  for  enabling  me  to  per- 
form several  operations  at  their  central  station,  where 
currents  of  500  amperes  and  100  volts  were  placed  at 
my  disposal. 

The  first  necessity  is  to  seledt  pure  iron — free  from 
sulphur,  silicon,  phosphorus,  &c., — and  to  pack  it  in  a 
carbon  crucible  with  pure  charcoal  from  sugar.  Half  a 
pound  of  this  iron  is  then  put  into  the  body  of  the 
eledtric  furnace,  and  a  powerful  arc  formed  close  above 
it  between  carbon  poles,  utilising  a  current  of  700 
amperes  at  40  volts  pressure.  The  iron  rapidly  melts 
and  saturates  itself  with  carbon.  After  a  few  minutes' 
heating  to  a  temperature  above  4000°  C. — a  temperature  at 
which  the  lime  of  the  furnace  melts  like  wax  and  volati- 
lises in  clouds — the  current  is  stopped,  and  the  dazzling 
fiery  crucible  is  plunged  beneath  the  surface  of  cold 
water,  where  it  is  held  till  it  sinks  below  a  red  heat. 
As  is  well  known,  iron  increases  in  volume  at  the 
moment  of  passing  from  the  liquid  to  the  solid  state. 
The  sudden  cooling  solidifies  the  outer  layer  of  iron  and 
holds  the  inner  molten  mass  in  a  tight  grip.     The  expan- 


sion of  the  inner  liquid  on  solidifying  produces  an  enor* 
mous  pressure  and  under  the  stress  of  this  pressure  the 
dissolved  carbon  separates  out  in  a  transparent,  dense 
crystalline  form— in  fadt,  as  diamond. 

Now  commences  the  tedious  part  of  the  process.  The 
metallic  ingot  is  attacked  with  hot  nitro-hydrochloric  acid 
until  no  more  iron  is  dissolved.  The  bulky  residue  con- 
sists chiefly  of  graphite,  together  with  translucent  flakes 
of  a  chestnut-coloured  carbon,  black  opaque  carbon  of  a 
density  of  from  3-0  to  3*5,  and  hard  as  diamonds — black 
diamonds  or  carbonado,  in  fadt — and  a  small  portion  of 
transparent  colourless  diamonds  showing  crystalline  struc- 
tures. Besides  these,  there  may  be  carbide  of  silicon 
and  corundum,  arising  from  imparities  in  the  materials 
employed. 

The  residue  is  first  heated  for  some  hours  with  strong^ 
sulphuric  acid  at  the  boiling  point,  with  the  cautious 
addition  of  powdered  nitre.  It  is  then  well  washed  and 
allowed  for  two  days  to  soak  in  strong  hydrofluoric  acid 
in  the  cold,  then  in  boiling  acid.  After  this  treatment  the 
soft  graphite  will  disappear,  and  most  if  not  all  of  the 
silicon  compounds  will  be  destroyed.  Hot  sulphuric  acid 
is  again  applied  to  destroy  the  fluorides,  and  the  residue, 
well  washed,  is  repeatedly  attacked  with  a  mixture  of  the 
strongest  nitric  acid  and  powdered  potassium  chlorate, 
kept  warm,  but  to  avoid  explosions  not  above  60°  C. 
This  ceremony  must  be  repeated  six  or  eight  times,  when 
all  the  hard  graphite  will  gradually  be  dissolved,  and 
little  else  left  but  graphitic  oxide,  diamond,  and  the 
harder  carbonado  and  boart.  The  residue  is  fused  for  an 
hour  in  fluorhydrate  of  fluoride  of  potassium,  then  boiled 
out  in  water,  and  again  heated  in  sulphuric  acid.  The 
well  washed  grains  which  resist  this  energetic  treatment 
are  dried,  carefully  deposited  on  a  slide,  and  examined 
under  the  microscope.  Along  with  numerous  pieces  of 
black  diamond  are  seen  transparent  colourless  pieces, 
some  amorphous,  others  with  a  crystalline  appearance,  as 
I  have  attempted  to  reproduce  in  diagrams.  Although 
many  fragments  of  crystals  occur,  it  is  remarkable  that 
I  have  never  seen  a  complete  crystal.  All  appear  broken 
up,  as  if  on  being  liberated  from  the  intense  pressure 
under  which  they  were  formed  they  burst  asunder.  I 
have  diredt  evidence  of  this  phenomenon.  A  very  fine 
piece  of  artificial  diamond,  carefully  mounted  by  me  on  a 
microscopic  slide,  exploded  during  the  night  and  covered 
my  slide  with  fragments.  This  bursting  paroxysm  is  not 
unknown  at  the  Kimberley  mines. 

On  the  screen  I  will  projedl  fragments  of  artificial  dia- 
mond, some  lent  me  by  Professor  Roberts-Austen,  others 
of  my  own  make  ;  while  on  the  wall  you  will  see  drawings 
of  diamonds  copied  from  M.  Moissan's  book  on  the 
Eledtric  Furnace.  Unfortunately  these  specimens  are  all 
microscopic.  The  largest  artificial  diamond,  so  far,  is 
less  than  one  millimetre  across. 

Laboratory  diamonds  burn  in  the  air  before  the  blow- 
pipe to  carbonic  acid  ;  and  in  lustre,  crystalline  form, 
optical  properties,  density,  and  hardness  they  are  iden- 
tical with  the  natural  stone. 

Many  circumstances  point  to  the  conclusion  that  the 
diamond  of  the  chemist  and  the  diamond  of  the  mine 
are  strangely  akin  as  to  origin.  It  is  conclusively 
proved  that  the  diamond  has  not  been  formed  in  situ  in 
the  blue  ground.  The  diamond  genesis  must  have  taken 
place  at  great  depths  under  enormous  pressure.  The  ex- 
plosion of  large  diamonds  on  coming  to  the  surface 
shows  extreme  tension.  More  diamonds  are  found  in 
fragments  and  splinters  than  in  perfedt  crystals  ;  and  it 
is  noteworthy  that  although  many  of  these  splinters  and 
fragments  are  derived  from  the  breaking  up  of  a  large 
crystal  yet  in  no  instance  have  pieces  been  found  which 
could  be  fitted  together.  Does  not  this  fadt  point  to  the 
conclusion  that  the  blue  ground  i6  not  their  true  matrix  ? 
Nature  does  not  make  fragments  of  crystals.  As  the 
edges  of  the  crystals  are  still  sharp  and  unabraded,  the 
locus  of  formation  cannot  have  been  very  distant  from 
the  present  sites.     There  were   probably  many  sites  of 


*^7"y*9,''iS)r''^    Volumetric  Determination  of  Zinc  by  Potassium  Ferrocyanide, 


15 


crystallisation  differing  in  place  and  time,  or  we  should 
not  see  such  di8tin(5live  charaAers  in  the  gems  from  dif- 
ferent mines,  nor  indeed  in  the  diamonds  from  different 
jiarts  of  the  same  mine. 

(To  be  continued). 


ON  THI 

TOLUMETRIC    DETERMINATION    OF    ZINC 

BY    POTASSIUM     FERROCYANIDE. 

By  L.  L.  DB  KONINCK  and  EUG.  PROST. 

(Continued  from  p.  6). 

In  fad):,  by  running,  to  the  exadt  precipitation  point,  a 
solution  of  ferrocyanide  into  a  measured  volume  of  zinc 
solution  acidulated  with  sulphuric  acid,  he  asserts  that 
there  is  required,  for  25  c.c.  of  zincic  solution,  not  12*50.0. 
of  ferrocyanide,  but  1775  c.c.  to  ig'S  c.c,  according  to 
the  acidity  and  concentration  of  the  mixture. 

The  volume  of  ferrocyanide  used  diminishes  as  the 
acidity  increases,  and  also  with  the  dilution  of  the  zincic 
solution.  According  to  Zulkowski  it  would  be  quite  in- 
different whether  the  zinc  solution  is  run  into  the 
potassium  ferrocyanide  or  vice  versa.  By  boiling  the 
liquid,  constant  results  can  be  obtained  independent  of 
the  acidity,  and  the  precipitate — which  is  then  pulverulent 
instead  of  gelatinous — will  have  a  constant  composition.* 
Zulkowski  recognised  the  end  of  his  tests  by  the  forma- 
tion of  Prussian  blue,  by  placing  side  by  side  on  a  piece 
of  filter-paper  a  drop  of  the  mixture  and  a  drop  of  ferric 
chloride.  By  taking  note  of  the  excess  of  ferrocyanide 
necessary  to  show  with  the  ferric  chloride  (0*4  c.c.  for 
each  85  c.c.  of  the  mixture),  he  concludes  that — 

Ki6Zn2o(Fe2Cyi2)7 
is  the  corredt  formula  for  the   precipitate  obtained   by 
heating,  and  Ki6Zni2(Fe2Cyi2)5  for  that  obtained  in  the 
cold,  but  he  is  not  very  certain  of  the  latter. 

These  complicated  formulae  seem  at  first  sight  impro- 
bable,— we  shall  show,  in  fadt,  that  they  ought  to  be 
rejedted  ;  the  estimations  or  calculations  on  which  they 
are  based  are  full  of  errors.f 

F.  Regelsberger  {Zeitsch.  f.  Angew.  Ch.,  vol.  iv.,  p.  475, 
1891),  when  analysing  alloys  of  aluminium,  quotes  the 
estimation  by  ferrocyanide  as  very  rapid  and  quite  sufH- 
ciently  exadt. 

We  will  here  refer  again  to  the  work  of  Bein  and 
Bragard.  The  former,  who  evidently  had  not  the  experi- 
ence necessary  to  judge  the  value  of  volumetric  methods 
to  a  nicety,  does  not  speak  well  either  of  Schaffner's 
method  or  of  the  Galletti-Fahlberg,  but  prefers  the 
gravimetric  method. 

Bragard  gives  the  ferrocyanide  precipitate  the  compo- 
sition answering  to  the  formula  K2Zn3Fe2Cyi2  when  the 
readlion  is  at  an  end,  in  which  we  think  he  is  right;  but 
when  the  zinc  is  in  excess  the  composition  would  be 
remedied  by  the  formula  K4Znio(Fe2Cyi2)3  :  here  we  think 
he  is  mistaken.  According  to  him  the  precipitate  would 
readl  with  the  nitrate  of  uranium  used  as  indicator.  He 
also  interposes  a  sheet  of  filter-paper  between  the  rod 
carrying  the  trial  drop  and  the  paper  impregnated  with 
uranium  salt,  and  does  not  consider  the  readtion  at  an  end 
while  an  appreciable  colouration  is  produced  on  this 
second  paper.  In  our  opinion  he  thus  diminishes  the 
sensitiveness  of  the  indicator ;  also,  according  to  him,  the 
process  is  not  exadt  to  less  than  i  per  cent.  The  acidity 
of  the  liquid,  he  says,  influences  the  result,  but  not  the 


*  We  shall  se*  later  that  this  transformation  is  of  great  im- 
portance. 

-f  The  author  must  have  made  a  mistake  in  his  calculations  ;  the 
reaAion,  in  presence  of  ferrocyanide  of  potassium  in  excess,  is  very 
sharp,  and  the  relation  between  the  potassium  and  the  zinc  is  2  to  3, 
-or  8  to  12,  and  not  :6  to  12. 


dilution,  of  the  presence  of  ammonia, — he  evidently  means 
salts  of  ammonia. 

To  complete  our  references  to  work  which  has  already 
been  published,  we  must  again  mention  the  Report  made 
to  the  Society  of  Colorado.  The  Committee  charged  with 
examining  into  the  methods  employed  in  this  important 
mining  distridl  sent  to  several  chemists  five  samples  of 
minerals,  carefully  seledted,  and  analysed  with  every 
possible  precaution,  begging  them  at  the  same  time  to 
send,  with  their  results,  the  details  of  the  process  used. 
All  of  them  titrated  the  acid  solution  with  ferrocyanide, 
using  a  salt  of  uranium  as  indicator.  The  results  were 
as  follows : — 


No.    A. 


B. 


D. 


F.* 


1.  15-31    15-39  '15-66    15-08    14-62      — •       I4'38    1422 

2.  24-34     24-53     2423     23-80     22-00     23-62     22-95     23*11 

3.  I0-76    10-83    11*88    10-69    10-50    11-07     ^'5^     9'20 

4.  6-42      6-58      8-73      6-85      630      6-89      5-24      564 

5.  16-14    16-46    15*86    15-90    15*37    1608    i3"40    12  84 

*  Average  of  four  concordant  assays.    No.  i  was  not  analysed. 

The  adtual  results  obtained  gravimetrically  were : — 

14*64    24*11     10*71    6-31     16*09. 

The  samples  i  and  2,  but  especially  No.  i,  contained 
cadmium  in  appreciable  quantity,  which  will  account  for 
the  generally  high  results,  this  metal  not  having  been 
eliminated.  It  is  worthy  of  remark  that  they  do  not  as  a 
rule  use  hydrosulphuric  acid  ;  when  the  mineral  contains 
copper  they  precipitate  it  by  means  of  granulated  lead, 
which  is  well  shaken  up  in  the  acid  solution. 

We  may  conclude  from  these  results  that  the  process 
will  furnish  exadt  results,  so  long  as  it  is  carried  out  under 
specified  conditions  and  with  the  necessary  care. 

III.  Reaction  of  Ferrocyanide  of  Potassium  with  Zincic 
Salts  in  Acid  Solution. 

As  we  have  seen,  there  is  very  liitle  accord  as  to  the 
composition  of  the  precipitate,  which  is  formed  in  an  acid 
zincic  solution,  on  the  addition  of  ferrocyanide. 

All  admit  that  if  ferrocyanide  be  added  in  sufficient 
quantity  for  it  to  be  in  slight  excess,  and  to  be  detedled  in 
the  mixture  by  a  uranium  salt,  or  by  other  means,  the 
quantity  employed  is  notably  more  than  that  which  is 
necessary  theoretically  to  produce  a  simple  zincic 
ferrocyanide,  Zn4Fe2Cyi2.  Nevertheless  some  chemists 
give  this  formula  to  the  precipitate  and  explain  away  the 
difference,  although  it  is  considerable,  by  impurities  in  the 
substance  used. 

The  authors  of  this  paper,  who  have  studied  ferro- 
cyanides,  have  long  been  aware  that  the  zincic  precipitate 
obtained  by  an  excess  of  ferrocyanide  is  a  double  salt, 
K2Zn3Fe2Cyi2  (Mosander,  Handw.  d.  Reinen  u.  Angew. 
Chem.,  p.  867,  1848  ;  F,  Reindel,  Polyt.  Journ  de  Dingier, 
vol.  cxc,  p.  395,  1869;  G.  Wyrouboff,  Ann.  de  Chim. 
et  de  Phys.,  Series  5,  vol.  viii.,  p.  444,  1876);  that  has 
not  prevented  many  other  analysts  attributing  to  it  much 
more  complicated  formulae.  This  question  of  the  compo- 
sition of  the  precipitate, — that  is  to  say,  the  relation 
between  the  zinc  and  the  ferrocyanide, — being  of  the  first 
importance  to  us,  it  was  imperative  to  decide  the  point 
definitely,  once  and  for  all ;  in  this  we  have  been  success- 
ful.    Our  work  has  settled  the  point  in  dispute. 

In  fadt,  from  the  first  titrations  done  by  us,  to  get  some 
idea  of  the  true  value  of  the  ferrocyanide  process,  as 
described  by  most  writers  (diredt  titration  in  acid  solution), 
we  found,  by  running  a  decinormal  solution*  of  ferro- 
cyanide into  25  c.c.  of  a  similarly  decinormal  solution  of 
zincic  chloride, t  made  slightly  acid  and  diluted  with  water 

*  The  molecular  weight  of  KsFe.Cyn.eHtO,  being  84352,  the 
normal  weight  is  represented  by  ith  of  this  figure,  viz.,  ios'44.  Our 
deminormal  solution  was  prepared  by  dissolving  52-72  grms.  of  pure 
ferrocyanide  in  1  litre  of  water. 

+  Obtained  by  dissolving  16-2775  grms.  of  pure  zinc  in  the  smallest 
possible  quantity  of  hydrochloric  acid,  and  then  diluting  to  i  litre.     , 


i6 


Basic  Salts  of  Cadmium*. 


I  Chbuical  Nxws» 

'      July  9i  1897. 


to  150  c.c,  that,  working  with  from  26  to  28  c.c.  of  ferro- 
cyanide,  we  obtained,  by  testing  immediately  with 
uranium  salts,*  an  appreciable  brown  colouration,  which 
does  not  get  stronger  by  the  addition  of  ferrocyanide, 
which  is  further  less  sensitive  as  we  increase  the  time 
from  the  addition  of  the  titrate  and  the  touch  test,  and 
eventually  disappears  if  this  time  be  sufficiently  prolonged. 
But  with  from  33*3  to  33*5  c.c.  the  test  becomes  more  and 
more  distindt,  and  that  no  matter  what  time  elapses  before 
the  addition  of  the  ferrocyanide.  These  fadls  can  be  ex- 
plained in  several  different  manners. 

The  most  plausible  which  first  occurred  to  us  is  the 
folowing  : — When  the  ferrocyanide  is  added  to  the  zincic 
solution,  a  ferrocyanide  of  zinc,  Zn4Fe2Cyi2,  is  first 
formed,  so  long  as  the  zinc  salt  is  in  excess.  The 
formula,  4ZnCl2+K8Fe2Cyi2  =  8KCl-f-Zn4Fe2Cyi2,  would 
therefore  show  what  takes  place  during  the  first  part  of 
the  readiion, — that  is  to  say,  in  our  experiment,  up  to  the 
addition  of  25  c.c.  of  ferrocyanide. 

By  continuing  to  add  this  reagent,  the  alkaline  ferro- 
cyanide would  then  reach  more  or  less  slowly  with  the 
zincic  precipitate,  forming  the  double  ferrocyanide, 
K2Zn3Fe2Cyi2,  according  to  the  formula — 

3Zn4Fe2Cyi2-f  K8Fe2Cyi2=4K2Zn3Fe2Cyi2. 

This  readion  is  not  immediate  ;  the  mixture  will  readl 
with  the  nitrate  of  uranium,  while  neither  the  zincic 
ferrocyanide  nor  the  double  ferrocyanide  do. 

Certain  tests,  to  which  we  shall  refer  later  on,  incline 
us  to  the  belief  that  the  double  cyanide  is  really  formed 
in  the  first  instance  ;  that  it,  being  gelatinous  at  first,  can 
in  this  condition  readt  with  the  uranium  salt  so  long  as  it 
is  not  in  presence  of  a  large  excess  of  zinc ;  but  that  it 
undergoes  a  molecular  transformation  which  shows  itself 
by  passing  from  the  translucent  gelatinous  state  to  a 
more  coherent  granular  state,  in  which  it  will  not  adt  with 
the  indicator.  Perhaps  both  theories  are  corredt, — that  is 
to  say,  the  phenomena  may  be  produced  simultaneously. 
It  is  in  any  case  proved  that  the  indicator  does  not  show, 
in  a  definite  manner,  that  when  the  volume  of  ferro- 
cyanide used,  corresponds  sensibly  to  the  formation  of 
the  double  salt,  and  that  this  latter,  the  same  as  with  the 
simple  zincic  ferrocyanide,  if  there  be  one  formed,  will 
not  readt  with  the  nitrate  of  uranium  after  a  sufficient 
digestion.  It  is  equally  shown  that  an  excess  of  ferro- 
cyanide of  potassium  does  not  combine  with  the  double 
salt,  K2Zn3Fe2Cyi2,  at  least  not  under  the  conditions  of 
our  experiments,  which  were  carried  out  with  a  demi- 
normal  solution  of  zincic  chloride  and  a  solution,  J  normal 
for  zinc,t  of  ferrocyanide. 

We  here  give  the  result.  In  each  case  we  used  25  c.c. 
of  ZnC]2,  diluted  with  100  c.c.  of  water  and  acidulated 
with  hydrochloric. 

A.  Add  29  c.c.  of  ferrocyanide.  The  zinc  is  now  in 
excess,  even  allowing  the  formation  of  Zn4Fe2Cyi2,  which 
would  require  37'5  c.c.  for  complete  precipitation.  The 
precipitate,  gelatinous  at  first,  becomes  gradually  white 
and  flocculent ;  it  coUeds  and  deposits  in  less  than  fifteen 
minutes. 

B.  Add  38  c.c.  of  ferrocyanide,  that  is,  0*5  c.c.  more 
than  the  quantity  necessary  to  precipitate  the  zinc  entirely, 
as  Zn4Fe2Cyi2.  The  precipitate  behaves  in  exadlly  the 
same  way  as  in  the  preceding  experiment.  In  the  solution, 
cleared  by  sedimentation,  a  fresh  addition  of  ferrocyanide 
produces  an  abundant  precipitate  :  this  proves  the  presence 
of  zinc  in  solution,  and  it  therefore  follows  that  the  first 
precipitate  is  not  entirely  composed  of  Zn4Fe2Cyi2, — if, 
indeed,  it  contains  this  compound.  As  the  first  precipi- 
tate, A,  behaves  exadly  like  the  second  one,  we  can  only 
conclude  that  it  also,  in  spite  of  the  notable  excess  of 
chloride  of  zinc,  is  not  Zn4Fe2Cyi2. 

C.  Add  quickly  50  c.c.  of   ferrocyanide,  that  is,  the 


theoretical  amount  necessary  to  precipitate  all  the  zinc  as^ 
K2Zn3Fe2Cyi2. 

If  tested  immediately,  the  mixture  gives  a  strong  brown 
colouration  with  nitrate  of  uranium.  If  filtered  at  once, 
the  mixture  yields  at  first  an  absolutely  limpid  filtrate, 
which  gives  no  colouration  with  uranium  ;  it  is  therefore 
free  from  potassic  ferrocyanide.  After  a  few  moments  the 
filtrate  becomes  very  cloudy,  and  finally  becomes  clear 
again.  Neither  the  cloudy  filtrate  nor  the  final  clear  fil- 
trate gives  any  colour  with  the  indicator.  A  small  quantity 
of  the  unfiltered  mixture,  put  on  one  side,  remains  milky, 
and  readls  very  feebly  with  nitrate  of  uranium. 

D.  Add  quickly,  while  agitating,  50  c.c.  of  ferrocyanide. 
An  immediate  test  of  the  mixture  with  nitrate  of  uranium 
gives  an  intense  brownish  red  colouration  ;  after  half  a 
minute,  a  colour  of  "  cafe-au-lait ;"  after  a  minute,  a  clear 
cofifee-colour ;  after  another  half  minute,  a  very  feeble  re- 
adtion  ;  after  two  minutes,  nothing  at  all.  Then  add  5  c.c. 
of  ferrocyanide ;  the  mixture  will  again  show  an  intense 
brown  colour  when  tested  with  uranium  ;  the  same  result 
will  be  obtained  after  an  hour,  or  even  two  hours. 

(To  be  continued). 


BASIC     SALTS    OF    CADMIUM. 
By  M.  TASSILLY. 

The  adtion  of  metallic  oxides,  on  the  corresponding 
haloid  salts,  has  enabled  me  to  prepare  two  new  com- 
pounds of  cadmium,  an  oxybromide  and  an  oxyiodide. 

These  bodies  were  obtained  by  heating  a  concentrated 
solution  of  bromide  or  iodide  in  the  presence  of  oxide  of 
cadmium,  up  to  200°,  in  a  sealed  tube.  The  quantities 
obtained  were  very  small.  These  new  bodies  are  distindtly 
crystalline  and  &&.  on  polarised  light. 

Analysis  has  given,  for  the  oxiodide,  the  formula 
CdIa,Cd03,H30. 

Found. 


Iodine 
Cadmium 


f  46-45 
**  I46  62 
..    41-07 


Calculated. 

46-35 

>» 
4087 


This  compound  is  only  slightly  attacked  by  water.  At 
120°  it  does  not  vary  in  weight,  either  in  nitrogen  or  in 
dry  air  freed  from  carbonic  acid. 

With  parallel  rays  of  light  the  crystals  show  extindlioi» 
parallel  to  the  longitudinal  axis.  In  converging  light  we 
observe  a  lemniscate.  The  crystal  is  doubly  refradting  at 
very  wide  axes. 

The  oxybromide  is  in  very  small  crystals,  answering 
to  the  formula  CdBr2,CdO,3H20  ;  it  also  adts  on  polarised 

light. 

Found.  Calculated. 

Bromine..     ..     36*44  35'24 

Cadmium.     ..     4890  49-33 


the  fadt  that   M.   Schulten     {Comptes 
p.  1674)  obtained  both  an  oxychloride 


*  One  per  cent  solution  of  nitrate  of  uranium. 

+  We  mean  to  infer,  by  the  expression  normal  for  xinc,  a  solution 
which  will  precipitate,  volume  for  volume,  a  normal  solution  of  zinc 
in  the  form  K^ZUfFe^Cyi^. 


I  would  recall 
Rendus,  vol.  cvi.,  .        ,  .. 

and  an  oxbromide,  by  the  adtion  of  marble  on  chloride,  or 
bromide  of  cadmium,  at  about  200°,  in  a  sealed  tube,  both 
bodies  being  crystalline  and  answering  respedtively  to  the 
formula  CdCla.CdO.HaO  and  CdBr2,CdO,H20.  Their 
stability  when  heated  induced  him  to  attribute  to  these 
bodies  the  constitutions — 

M.  Habermann  (Monatshette,  vol.  v.,  p.  432,  and  Bull. 
Soc.  Chim.,  Ser.  2,  vol.  xliv.,  p.  122)  obtained  an  amor- 
phous  oxychoride  of  the  same  formula  by  adding  ammonia 
to  a  cold  solution  of  chloride  of  cadmium  as  long  as  a 
precipitate  was  formed.  It  was  then  boiled,  let  standi 
filtered,  and  the  precipitate  dried  over  quicklime  under  a 
bell-glass. 


Chrhical  News,  ) 
Tuly.9, 1897.      t 


Hypoiodous  A  cid  and  Hypoiodides, 


17 


By  afting  in  the  same  manner  on  the  bromide  and  the 
iodide,  I  obtained  two  compounds  corresponding  to  defi- 
nite formulae ;  but  the  preparation  of  these  bodies  neces- 
sitates certain  precautions.  In  fadl,  if  we  pour  strong 
ammonia  into  solutions  of  chloride  and  bromide  at  i/5th 
and  of  iodide  at  i/7th  strength,  we  obtain  at  the  same  time 
a  basic  salt  and  an  ammoniacal  salt  which  are  very  diffi- 
cult to  separate. 

Working  with  more  dilute  solutions  (i/ioth)  and  adding 
ammonia  equally  diluted  (ammonia  at  22°,  to  which  is 
added  its  own  volume  of  water),  we  obtain  first  a  precipi- 
tate of  the  basic  salt,  and  some  hours  after  decantation 
there  forms  in  the  mother-liquor  crystals  of  the  ammo- 
niacal salt.  One  can  even  prevent  altogether  the  formation 
of  ammoniacal  salts,  by  carefully  limiting  the  proportion 
of  ammonia. 

The  ammoniacal  salts  obtained  under  these  conditions 
agree  with  the  formulae  CdCl2,2NH3;  CdBr2,2NH3; 
Cdl2,2NH3. 

These  bodies  are  identical  with  those  obtained  by 
dissolving  the  corresponding  salts  of  cadmium  in  am- 
monia. 

The  oxybromide,  CdBra.CdO.HaO,  and  the  oxyiodide, 
Cdla.CdO.HjO,  gave  on  analysis  the  following  results  : — 


Bromine.. 
Cadmium  . 


Iodine     .. 
Cadmium, 


Oxybromide. 
Found, 

..     37'i7 
•  •     54'23 

Oxyiodide. 

• .     4977 
••     43  "54 


Calculated. 

38*29 
53-58 


49'63 
4375 


The  basic  salts  of  cadmium  obtained  by  precipitation 
are  decomposed  by  water. 

I  would  here  further  remark  that,  in  the  adlion  of  am- 
monia on  the  salts  of  cadmium  in  solution,  the  proportions 
of  basic  salts  obtained  decrease  from  the  oxychloride  to 
the  oxyiodide,  while,  on  the  contrary,  the  proportions  of 
ammoniacal  salts  increase  from  the  chloride  to  the  iodide. 

The  chloride  would  thus  appear  to  give  a  basic  salt 
more  easily  than  an  ammoniacal  one;  the  inverse  should 
be  the  case  for  the  iodide. 

The  thermo-chemical  study  of  these  various  bodies, 
which  I  am  now  occupied  with,  will  without  doubt  give 
the  reason  of  these  facets. 

In  finishing,  it  may  be  remarked  that  the  basic  salts  of 
cadmium  are  always  formed  in  equal  molecules,  contrary 
to  what  happens  in  the  case  of  the  salts  of  zinc,  which 
are  liable  to  fix  a  variable  number  of  molecules  of  oxygen, 
giving  rise  to  a  number  of  salts  not  corresponding  to  a 
general  type,  as  occurs  with  certain  other  metals. — Bull. 
Sac.  Chim.  de  Paris,  Series  3,  vol,  xvii. — xviii..  No.  12. 


HYPOIODOUS    ACID    AND     HYPOIODITES.* 
By  R.  L.  TAYLOR,  F,C,S. 

Hypoiodites. 
It  appears  to  have  been  always  considered  very  doubtful 
whether  hypoidous  acid  has  ever  been  prepared  at  all, 
and  many  chemists  are  hardly  willing  to  recognise  hypo- 
iodites as  very  definite  compounds.  The  information  one 
can  obtain  about  these  bodies  is  very  vague  and  indefinite, 
and  in  some  respedts  contraditftory. 

My  investigation  was  originally  undertaken  with  the 
obje(5t  of  isolating  hypoiodous  acid,  but  the  following 
experiment  led  me  to  include  hypoiodites  as  well.  I  had 
found  that  a  solution  of  iodine  in  water  adted  in  many 
respeds  very  much  better  than   any  other  solution,  or 

*  From  Memoirs  and  Proceedings  of  the  Manchester  Literary  and 
Philosophical  Society,  vol,  xli.,  Part  III. 


than  the  solid  substance,  and  trying  the  effedt  of  adding 
a  little  alkali  to  some  of  this  aqueous  solution,  I  was 
astonished  at  the  particularly  definite  character  of  the 
solution  obtained,  and  especially  at  its  bleaching  adlion, 
and  felt  sure  that  this  remarkable  solution  could  not  be 
generally  known,  or  else  hypoiodites  would  certainly  have 
met  with  better  recognition  than  they  have  hitherto 
received. 

So  far  as  I  am  aware,  the  most  important  papers  on 
hypoiodites  have  been  those  by  Schonbein  {yournal  fur 
Praktische  Chemie,  1861,  p.  387),  and  by  G.  Lunge  and 
R.  Schoch  {Berichte,  xv.,  p.  1883)  on  Calcium  Hypo- 
iodite.  The  more  important  of  these  is  that  by  Schonbein, 
and  in  the  first  part  of  this  paper  I  shall  describe  some 
of  Schonbein's  experiments,  with  others  which  I  have 
performed  and  which  confirm  and  extend  his  results.  I 
shall  refer  to  the  work  of  Lunge  and  Schoch  afterwards. 
I  find  that  Schonbein,  in  his  experiments,  used  the  very 
solution  which  I  have  already  mentioned  as  giving  such 
remarkable  results,  that  is,  iodine  dissolved  in  water. 
Unfortunately,  however,  Schonbein's  paper  has  been  badly 
summarised  in  all  the  standard  didtionaries  and  works  on 
chemistry,  and  this  important  point  is  not  usually 
mentioned.  Schonbein's  paper  is  one  of  a  series.  He 
had  been  trying  experiments  on  the  adtion  of  chlorine 
water  and  bromine  water  upon  dilute  ammonia,  and  then 
naturally  passed  on  to  iodine,  using  that  substance  also 
in  solution  in  water.  Such  a  solution  is  very  dilute,  being 
at  the  most  only  about  one  part  in  5000 ;  but  this  solu- 
tion, in  many  respedts,  gives  more  definite  results  than 
any  other. 

Schonbein  first  described  the  adtion  of  ammonia  upon 
iodine  water,  whereby  the  liquid  was  decolourised,  and 
a  solution  obtained  which  bleached  indigo,  just  as  the 
liquids  produced  by  the  adlion  of  ammonia  upon  chlorine 
water  and  bromine  water  did.  He  found,  further,  that  the 
solution  gave  a  deep  blue  colouration  with  a  mixture  of 
starch-paste  and  potassium  iodide,  and  even  with  starch- 
paste  alone.  Left  to  itself  the  liquid  lost  these  peculiarities, 
more  quickly  at  high  than  at  low  temperatures,  and  almost 
instantaneously  when  boiled.  He  then  found  that  similar 
results  were  obtained  with  potash  solution,  and  that  both 
solutions  were  decomposed  by  hydrogen  peroxide,  with 
manifest  liberation  of  oxygen.  He  also  pointed  out  that 
the  solutions  smelt  of  saffron.  He  not  unnaturally  con- 
cluded from  these  results  that  the  liquids  contained 
hypoiodites,  and  that  the  adtion  of  iodine  upon  the  alkalies 
was  similar  to  the  adtion  of  chlorine  and  bromine,  and 
might  be  represented  as  follows  : — 

I2  +  2KOH  =  KI  -f-  KOI  +  H2O. 

He  also  concluded  that,  as  the  liquids  lost  their  bleaching 

power,   they  gradually  changed  into   iodide   and  iodate, 

according  to  the  following  equation  : — 

3KOI  =  2KI  +  KIO3. 

One  thing  which  seemed  to  puzzle  him  very  much  was 
that  the  liquids  gave  a  blue  colour  with  starch  alone, 
even  when  he  added  potash  in  the  proportion  of  two 
equivalents  to  one  of  iodine.  He  thus  made  the  liquid 
strongly  alkaline,  and  capable,  as  he  said,  of  taking  up 
more  iodine;  and  he  argued,  therefore,  that  there  could 
not  be  any  free  iodine  present  in  the  excess  of  potash, 
and  that  hence  the  blue  colour  could  not  be  due  to  iodine. 
In  addition  he  pointed  out  that  the  liquid  was  almost,  if 
not  quite,  colourless.  He  found,  however,  that  the 
addition  of  potassium  iodide  turned  the  liquid  brown 
again,  manifestly  owing  to  the  liberation  of  iodine.  I 
shall  show  further  on  that  these  results  are  easily  ex- 
plained. 

I  may  mention  that  in  all  my  experiments  the  iodine 
used  was  carefully  purified  by  Stas's  method,  and  that  the 
indigo  was  a  solution  of  indigo  carmine  in  water. 

As  has  been  already  mentioned,  the  liquids  produced 
by  the  adtion  of  alkalies  upon  aqueous  iodine  have  a  most 
energetic  bleaching  adtion  upon  indigo  ;  they  also  bleach 
cochineal   and  logwood,  but  not  litmus.      In  bleaching 


i8 


Hypoiodous  A  cid  and  Hypoiodites. 


I  Chemical  NswSy 

1       July  9   1897. 


indigo  they  are  much  more  adtive  than  either  a  solution  of 
chlorine  or  of  bleaching  powder  of  anything  like  the 
same  strength  ;  in  fadt,  compared  with  Schonbein's  solu- 
tions, chlorine  and  hypochlorites  may  be  described  as  very 
sluggish. 

Borrowing,  with  some  modifications,  a  method  described 
by  Lunge  and  Schoch  in  their  paper,  I  attempted,  by 
means  of  a  standard  solution  of  indigo  carmine,  to  ascer- 
tain the  strength  of  the  bleaching  liquids,  in  order  to  find, 
if  possible, — assuming  that  the  readiongoes  as  Schonbein 
suggested,  and  as  the  corresponding  readtion  with  chlorine 
and  bromine  are  well  known  to  go, — the  amount  of  iodine 
converted  into  what  one  may  call  "  bleaching  iodine." 
After  many  attempts  I  found  that  the  best  results  were 
obtained  by  standardising  the  solution  of  indigo  carmine 
against  a  dilute  solution  of  chlorine,  which  had  been 
titrated  against  a  standard  iodine  solution  by  means  of 
potassium  iodide  and  sodium  thiosulphate  in  the  usual 
way.  The  aqueous  iodine  solution  was  also  standardised 
against  the  same  standard  solution  of  iodine.  The 
amount  of  iodine  present  in  the  aqueous  solution  was 
usually  from  0*17  to  0*22  grm.  per  litre.  One  of  the 
difiiculties  experienced  in  standardising  the  solutions  was 
due  to  the  end-readtion  with  chlorine  water  and  the 
indigo  solution  being  exceedingly  slow.  No  such  diffi- 
culty, however,  was  anticipated  with  the  iodine  bleaching 
solutions,  the  end-readtion  with  these  being  apparently 
sharp  and  distindt. 

The  method  employed  was  to  take  a  measured  volume 
(usually  20  c.c.)  of  the  aqueous  iodine  solution,  to  add 
one  or  two  drops  of  potash  or  soda,  and  then  immediately 
run  in  the  standard  indigo  carmine  until  there  was  a  dis- 
tindt green  colour.  (The  indigo  solution  is  bleached  to  a 
slightly  yellow  liquid,  and  this  of  course  becomes  green 
as  soon  as  an  excess  of  indigo  is  added).  For  a  long  time 
the  results  were  unsatisfadlory.  The  bleaching  power  of 
the  solutions  seemed  to  vary  in  an  extraordinary  manner. 
Frequently  the  results  obtained  gave  90  and  95  per  cent 
of  the  iodine  converted  into  "  bleaching  iodine,"  and 
then,  in  another  experiment,  with  the  same  solution  of 
iodine,  the  bleaching  adtion,  without  any  apparent  reason, 
ran  up  to  30  or  even  40  per  cent  above  the  theoretical 
amount, — that  is,  above  the  amount  which  it  ought  to  be 
if  the  whole  of  the  iodine  used  had  been  converted  into 
iodide  and  hypoiodite  according  to  the  equation — 

2KOH  -H  l2  =  KI  -f  KOI  +  H2O. 

Similar  anomalous  results  were  obtained  when  solutions 
of  bleaching  powder  or  of  sodium  hypochlorite  were  used 
instead  of  chlorine  water.  These  extraordinary  results 
were  ultimately  found  to  be  due  to  a  very  strange  adlion 
on  the  part  of  the  indigo,  an  adtion  of  which  I  can  at 
present  offer  no  explanation.  The  excess  of  bleaching 
adtion  upon  the  indigo  is  not  permanent ;  on  standing  for 
a  minute  or  two  the  blue  colour  returns.  This  of  course 
is  not  the  case  with  what  I  may  call  the  genuine 
bleaching  adlion.  If  i  c.c.  of  indigo  solution  in  excess  of 
what  is  permanently  bleached  be  added,  although  there 
appears  to  'be  no  indication  of  when  the  end-point  is 
being  passed,  on  standing  for  a  minute  or  two  a  blue 
colour  appears.  I  further  found  that  this  curious  tempo- 
rary bleaching  adtion  only  occurs  when  a  large  excess  of 
alkali  (in  comparison  with  the  amount  of  iodine  present) 
has  been  used. 

Now,  of  course,  it  was  possible  to  determine  the 
amount  of  permanent  bleaching  adlion.  The  following 
example  is  one  out  of  a  great  many  experiments  which  I 
made: — 

Twenty  c.c.  of  the  aqueous  iodine  solution  (=0*0035 
iodine),  after  the  addition  of  alkali,  bleached  15  c.c.  of 
standard  indigo  solution,  i  c.c.  of  which  (titrated  with 
standard  solution  of  chlorine)  corresponded  to  0*000228  of 
iodine,  so  that  the  amount  of  iodine  indicated  by  the 
bleaching  adlion  was  0*000228  x  15  =  o'oo342,  which  was 
pradlically  the  whole  of  the  iodine.  The  solutions  used 
are  extremely  dilute,  but  there  is  really  no  difficulty  in 


making  estimations  which  will  be  accurate  to  within  2  or 
3  per  cent.  The  general  result  of  these  experiments  is 
that  95  per  cent  of  the  iodine  in  Schonbein's  solutions 
undergoes  the  readlion  represented  by  the  equation — 

2KOH  +  l2= KI  -f  KOI  +  H2O. 

These  results  are  amply  confirmed  by  an  altogether 
different  method, — one  which  was  used  by  A.  Schwicker 
{Zeit.  Physikal.  Chem.,  xvi.,  303-314)  in  an  investigation 
which  he  has  recently  made  on  the  readlion  velocity  of 
potassium  hypoiodite.  He  takes  advantage  of  the  fadk 
that  potassium  bicarbonate  will  decompose  a  mixture  of 
hypoiodite  and  iodide,  with  liberation  of  iodine.  He  also 
uses  a  little  soda-water,  the  carbonic  acid  in  which  is 
intended  to  convert  any  liberated  potash  into  the  bicar- 
bonate. The  bicarbonate  apparently  decomposes  the 
mixture  of  hypoiodite  and  iodide,  with  formation  of  nor- 
mal carbonate  and  liberation  of  iodine,  according  to  the 
following  equation : — 

KOI  -f  KI  -f  2KHCO3  =  2K2CO3  +  H2O  +  I2. 
With  my  dilute  solutions,  I  find  that  it  answers  just  as 
well  to  run  into  the  liquid,  which  is  always  sufficiently 
alkaline,  a  small  quantity  of  soda-water.  This  imme* 
diately  liberates  the  iodine,  which  can  now  be  estimated 
by  means  of  a  centi-normal  solution  of  sodium  arsenite. 
Carbonic  acid  does  not  decompose  potassium  iodate,  so 
that  this  method  may  be  employed  in  all  mixtures  of 
hypoiodites,  iodates,  and  iodides.  In  one  determination 
by  this  method  97  per  cent  of  the  iodine  originally  used 
was  liberated  on  the  addition  of  the  soda-water.  We 
may  therefore  conclude  that  when  potash  adls  upon 
iodine-water  there  is  pradlically  no  iodate  formed. 

As  Schonbein  pointed  out,  the  solutions  are  very  un- 
stable. I  have  made  a  number  of  experiments  upon  the 
rate  at  which  the  change  occurs,  estimating  this  by  the 
diminution  in  bleaching  power.  I  find  that  the  presence 
of  excess  of  alkali  makes  the  solution  more  stable  ;  but 
even  then  a  solution  loses  half  its  bleaching  power  on 
standing,  in  the  dark,  for  four  hours.  In  twenty-four 
hours  75  per  cent  of  the  bleaching  power  goes.  If  a  much 
smaller  amount  of  alkali  is  used  half  the  bleaching  power 
goes  in  an  hour.  On  heating  the  solutions  they  alter  very 
rapidly,  and  every  bleaching  liquid  of  this  kind  which  I 
have  prepared  loses  its  bleaching  power  entirely  if  boiled 
for  three  or  four  minutes.  As  Schonbein  assumed,  this 
loss  of  bleaching  power  is  doubtless  due  to  a  change  of 
the  hypoiodite  into  iodide  and  iodate, — 
3KOI  =  2KI-f  KIO3. 

As  mentioned  above,  Schwicker  has  recently  investi- 
gated  the  rate  at  which  the  above  change  occurs  at  the 
ordinary  temperature  with  different  proportions  of  iodine 
and  potash  present.  The  results  do  not  appear  to  have 
been  altogether  satisfadtory.  But  he  used  iodine  dissolved 
in  potassium  iodide,  and  there  is  no  doubt  that  the  latter 
would  affedt  the  results  materially.  Probably  better  results 
would  be  obtained  by  the  use  of  a  solution  of  hypoiodite 
i  made  from  hypoiodous  acid,  which  would  not  contain  any 
iodide  at  all. 

I  may  refer  here  to  the  fad  that  whether  the  liquid 
contains  iodide  and  hypoiodite,  or  iodide  and  iodate,  the 
addition  of  an  acid  at  once  liberates  the  whole  of  the 
iodine ;  in  the  one  case  hypoiodous  and  hydriodic  acids 
are  liberated,  which  at  once  decompose  each  other — 

(H0I-HHI  =  H20-!-l2); 
in   the    other,   hydriodic   and   iodic   acids  are   similarly 
liberated,  and  in  the  exadl  amounts  needed  to  decompose 
each  other — 

(5HI-fHI03  =  3H20-f3l2). 

I  have  made  similar  bleaching  solutions  by  using  lime- 
water  and  baryta-water  with  aqueous  iodine,  and  in  nearly 
all  respedls  these  resemble  Schonbein's  solutions,  there 
being  perhaps  a  little  difference  in  their  stability  in  favour 
of  the  sodium  and  potassium  compounds.  They  are  all 
decomposed  on  boiling. 


Cbkmical  News,  ) 
July  9,  1897.       » 


Hypoiodous  Acid  and  Hypoiodites. 


19 


\  have  further  found  that,  by  using  a  little  very  finely- 
■divided  (preferably  precipitated)  iodine  with  the  aqueous 
iodine,  and  then  adding  the  alkali,  very  much  stronger 
solutions  may  be  prepared.  A  solution  made  in  this  way 
bleaches  large  quantities  of  indigo,  and  gives  further  re- 
acSions  which  add  very  strongly  to  the  evidence  that  these 
solutions  contain  hypoiodites.  Thus  they  give  a  black 
precipitate  (on  standing)  with  a  cobalt  solution ;  an 
immediate  dark  brown  precipitate  with  a  solution  of  a 
manganous  salt;  and  with  lead  salts  a  precipitate  which 
manifestly  contains  a  considerable  amount  of  the  brown 
peroxide  of  lead.  Also  these  strong  solutions  give  an  im- 
mediate and  copious  evolution  of  oxygen  with  hydrogen 
dioxide.  In  these  readtions  the  solution  ads  exadly  as 
the  corresponding  hypochlorites  and  hypobromites  do. 
The  dilute  solutions  made  with  aqueous  iodine  naturally 
do  not  give  these  reactions  so  satisfadorily  unless  large 
quantities  are  used.  On  the  other  hand,  the  stronger 
solutions  would  not  be  so  suitable  for  the  quantitative 
experiments  as  the  more  dilute  ones. 

The  solution  made  with  iodine-water  and  not  too  much 
alkali  gives  with  nitrate  of  silver  a  precipitate  which  is 
iquite  distindl  from  the  ordinary  precipitated  hydrate  of 
silver,  having  a  sort  of  dark  buff  colour.  Of  course  the 
precipitate  must  contain  silver  iodide  and  probably  also 
some  hydrate,  as  the  original  liquid  must  of  necessity  be 
somewhat  alkaline  ;  but  it  probably  also  contains  some 
silver  hypoiodite.  If  the  liquid  is  poured  off  or  filtered 
off  from  the  precipitate,  it  is  found  to  have  completely 
lost  its  bleaching  power.  On  the  other  hand,  if  the 
precipitate  is  treated  with  a  dilute  acid,  part  of  it  dissolves 
up,  leaving  the  yellow  iodide  of  silver,  and  at  the  same 
time  the  solution  acquires  bleaching  properties,  though 
not  to  anything  like  the  extent  that  would  correspond  to 
a  complete  transformation  of  the  hypoiodite  into  a  silver 
salt,  and  then  to  hypoiodous  acid.  In  the  two  trans- 
formations a  large  amount  of  the  hypoiodite  is  evidently 
decomposed. 

I  have  already  mentioned  that  Schonbein  was  greatly 
puzzled  to  account  for  his  bleaching  solutions  giving  a 
deep  blue  colour  with  starch  alone.  Lunge  and  Schoch 
in  their  paper  suggested  that  some  iodine  probably  existed 
in  the  liquid  in  combination  with  potassium  iodide.  But 
a  much  more  reasonable  explanation  had  already  been 
supplied  by  the  experiments  of  E,  Lenssen  and  J.  Lowen- 
thal  {yourn.  filr  Praktische  Chetnie,  1862,  p.  245),  who 
found  that  sodium  iodide  and  hypoiodite  decompose  each 
other,  liberating  iodine,  and  that  the  amount  of  alkali 
required  to  readl  with  free  iodine  was  greater  when 
potassium  iodide  was  present  than  when  there  was  no 
iodide.     They  pradically  stated  that  the  reaftion— 

2KOH  -f  l3  =  KI  +  KOI  +  H2O 
is  a  balanced  one,  and  that  the  addition  of  potassium 
iodide  reverses  the  adlion,  which  now  produces  potash 
and  free  iodine. 

It  follows  that  the  amount  of  alkali  required  to  complete 
the  above  readlion  must  be  greater  than  that  represented 
by  the  equation.  I  have  added  varying  amounts  of  a 
standard  solution  of  soda  to  the  same  amount  of  aqueous 
iodine.  With  one  equivalent  of  alkali  to  one  of  iodine 
the  solution  is  distinctly  yellow,  and  gives  a  deep  blue 
colour  with  starch  ;  with  two  equivalents  of  alkali  the 
liquid  is  a  very  pale  yellow,  and  the  colour  with  starch  is 
-much  less  intense ;  with  three  equivalents  the  liquid 
appears  colourless,  and  gives  only  a  slight  colour  with 
starch,  so  that  apparently  the  readlion  is  all  but  complete, 
and  with  four  equivalents  it  is  quite  complete. 

It  is  probable  that  the  charader  of  this  readlion  has 
something  to  do  with  the  comparative  failure  to  obtain 
bleaching  solutions  when  using  iodine  dissolved  in 
potassium  iodide.  It  may  also  help  to  explain  the  fadl 
that  in  the  adlion  of  ozone  upon  potassium  iodide  the 
development  of  free  iodine  may  proceed  to  quite  a 
remarkable  extent,  considering  that  its  liberation  must  be 
accompanied  by  the  formation  of  an  equivalent  amount 


of  potash.  It  is  clear,  however,  that,  as  there  is  always 
a  very  large  excess  of  potassium  iodide  present,  this  must 
tend  to  prevent  the  formation  of  any  but  the  smallest 
amount  of  hypoiodite. 

In  1882  the  paper  by  Lunge  and  Schoch  on  Calcium 
Hypoiodite  appeared.  The  authors  criticised  Schonbein's 
work  at  some  length.  They  objedled  to  the  importance 
which  Schonbein  appeared  to  attach  to  the  fadl  that  his 
solutions  gave  an  evolution  of  oxygen  with  hydrogen  per- 
oxide, pointing  out  that  a  mixture  of  potassium  iodide  and 
iodate  does  the  same  thing.  There  is  a  certain  amount 
of  weight  in  this  objedlion,  but  not  much.  It  is  quite 
true  that  a  mixture  of  iodide  and  iodate  does  evolve 
oxygen  with  hydrogen  dioxide,  but  only  either  on  standing 
or  when  gently  warmed ;  whereas,  as  I  have  already 
pointed  out,  the  stronger  hypoiodite  solutions  which  I 
have  prepared  give  an  immediate  violent  effervescence  on 
the  addition  of  the  peroxide.  Schonbein's  dilute  solutions 
certainly  do  not  give  oxygen  anything  like  so  rapidly  as 
these  stronger  ones,  but  still  much  more  rapidly  than  a 
mixture  of  potassium  iodide  and  iodate.  I  still  consider, 
with  Schonbein,  that  the  immediate  evolution  of  oxygen 
with  hydrogen  peroxide  is  a  valuable  indication  that  these 
solutions  contain  hypoiodites. 

Lunge  and  Schoch  prepared  their  "  hypoiodite  of  cal- 
cium" by  rubbing  together  for  some  time  iodine  with  a 
large  excess  of  lime  and  a  comparatively  small  amount 
of  water,  allowing  to  stand  for  some  hours,  and  then 
diluting  with  water.  They  thus  obtained  a  solution  which 
apparently  resembled  Schonbein's  solutions  in  many 
respedls,  but  gave  "  with  cobaltous  nitrate  a  green 
precipitate — no  black  peroxide."  It  bleached  cochineal, 
logwood,  and  indigo  carmine,  just  as  Schonbein's  solu- 
tions do. 

The  authors  attempted  to  estimate  the  bleaching 
strength  of  the  solution  by  means  of  a  standard  solution 
of  indigo  carmine,  standardised  against  a  dilute  solution 
of  bleaching  powder,  the  strength  of  which  was  esti- 
mated by  means  of  a  standard  solution  of  sodium  arsenite. 
But  they  could  not  succeed  in  measuring  the  bleaching 
power  of  their  iodine-lime  solution  diredlly,  because 
towards  the  end  thedecolourisation  was  so  extraordinarily 
slow.  They  therefore  added  an  excess  of  indigo  solution, 
and  allowed  to  stand  for  fifteen  minutes  ;  then  excess  of 
bleaching  powder  solution  was  added,  and  this  excess 
finally  brought  back  by  a  drop  or  two  of  sodium  arsenite 
solution.  In  this  way  they  estimated  that  in  their  solu- 
tion i4"6  per  cent  of  the  total  iodine  present  existed  as 
"  bleaching  iodine."  They  further  stated  that  the  solu- 
tion, kept  in  the  dark,  gradually  lost  its  bleaching  power, 
but  that  only  76  per  cent  of  the  bleaching  adtron  had 
disappeared  at  the  end  of  twenty-three  days.  They  also 
tried  the  effedl  of  heating  the  solution,  and  found,  on  one 
occasion,  that  when  boiled  for  one  hour  52  per  cent  of  the 
bleaching  power  had  disappeared.  In  another  experi- 
ment a  sample  was  boiled  for  seven  hours,  and  then  only 
lost  53  per  cent  of  its  bleaching  power  ! 

It  is  evident  that  there  are  some  irreconcilable  dis- 
crepancies between  these  results  and  mine.  In  the  first 
place,  I  never  found  any  difficulty  in  estimatir»g  the 
bleaching  power  of  a  solution  diredlly,  except  in  the  case 
where  the  bleaching  is  not  permanent.  Secondly,  my 
solutions  gave  black  precipitates  with  cobalt ;  and,  in  the 
next  place,  every  bleaching  solution  that  I  have  made  is 
decomposed  completely  by  boiling  for,  at  most,  four 
minutes.  Judging  from  the  analogous  bodies,  hypo- 
chlorites and  hypobromites,  and  from  the  instability  of 
hypoiodites  on  merely  keeping  them  in  the  dark,  it  is 
inherently  highly  improbable  that  any  hypoiodite  could 
stand  being  boiled  for  seven  hours  I  I  have  prepared 
what  I  should  call  calcium  hypoiodite  by  adding  lime- 
water  to  aqueous  iodine,  and  it  decomposes  completely 
when  boiled  for  three  minutes.  Whether  the  complicated 
method  adopted  by  Lunge  and  Schoch  for  estimating  the 
bleaching  adion  has  anything  to  do  with  these  dis- 
crepancies  I  am  not  prepared  to  say,  but  it  seems  quite- 


20 


Simple  Test  for  the  Halogens  in  Organic  Bodies. 


i  Chemical  News, 
I      July  9,  1897. 


plain  that  if  Schdnbein's  solutions  consist  of  hypoiodites, 
then  Lunge  and  Schoch's  solution  does  not.  I  have 
tried  to  repeat  Lunge  and  Schoch's  experiments,  following 
their  diredtions,  and  have  obtained  a  bleaching  liquid 
which  adts  praftically  like  Schdnbein's  solutions  ;  that  is, 
there  is  little  or  no  difficulty  in  estimating  the  bleaching 
power  diredtly.and  it  loses  its  bleaching  power  completely 
when  boiled  for  a  few  minutes.  If,  also,  as  I  should 
recommend,  the  iodine  and  lime  are  rubbed  together 
with  water,  and  then  diluted  immediately ,  instead  of,  as 
they  recommend,  allowing  the  mixture  to  stand  for 
several  hours,  a  solution  is  obtained  three  or  four  times 
as  strong,  which  gives  a  dark  brown  precipitate  with 
cobalt ;  but  this  also  is  decomposed  completely  when 
boiled  for  a  few  minutes.  It  also  gradually  decomposes  , 
when  kept  in  the  dark,  and  a  sample  tested  on  one  occa- 
sion, after  being  left  for  three  days,  had  lost  entirely  its 
bleaching  power. 

Since  the  appearance  of  Lunge  and  Schoch's  paper 
there  have  been  occasional  references  to  hypoiodites  in 
other  papers.  Thus  C.  Lonnes  (Zeit.  Anal.  Chem.,  xxxv., 
409-436)  has  pointed  out  that  the  conversion  of  iodine 
into  an  iodide  and  an  iodate  by  an  alkali  is  not  imme- 
diately complete,  part  remaining  uncombined,  and  part 
being  converted  into  hypoiodite,  and  that  the  hypoiodite 
has  greater  stability  in  presence  of  excess  of  alkali. 

Chattaway  {Chem.  Soc.  jfourn.,  Ixix.,  p.  1572)  has 
stated  that  in  several  of  the  decompositions  which  the 
so-called  "  nitrogen  iodide  "  undergoes,  hypoiodites  are 
produced. 

Quite  recently  (Proc.  Roy.  Soc.  Editi.,  xxi.,  235)  Dr.  J. 
Walker  and  S.  A.  Kay,  B.Sc,  have  published  a  paper  on 
the  so-called  "  Magnesium  Hypoiodite,"  a  brown  sub- 
stance formed  by  the  union  of  magnesia,  either  wet  or 
dry,  with  free  iodine,  and  which  has  sometimes  been 
supposed  to  be  magnesium  hypoiodite.  They  conclude, 
however,  that  it  is  simply  a  case  of  absorption  of  iodine, 
without  any  chemical  combination.  They  find  that  this 
brown  precipitate  is  produced  when  potash  is  added  to  a 
solution  of  iodine  in  potassium  iodide  until  the  iodine 
just  disappears,  and  then  a  solution  of  magnesium  sul- 
phate is  added,  magnesium  hydrate  being  precipitated, 
and  iodine  manifestly  liberated.  They  have  concluded 
from  this  that,  as  pointed  out  above,  the  readtion  be- 
tween iodine,  potash,  potassium  iodide,  and  water,  is  a 
balanced  one, 

(To  be  continued). 


THE  PREPARATION  OF  ZINC  ETHYL. 
By  ARTHUR  LACHMAN. 

■Of  all  the  methods  heretofore  proposed  for  the  prepara- 
tion of  zinc  alkyls,  the  Gladstone-Tribe  copper-zinc 
couple  (y.  Chem.  Soc,  1879,  570),  gives  by  far  the  best 
results.  As  originally  given,  however,  the  diredlions  are 
open  to  two  practical  objedions.  First  of  all,  it  is  not 
always  an  easy  matter  to  secure  the  zinc  filings  of  neces- 
sary fineness.  And  secondly,  while  the  careful  fusion  of 
the  filings  with  the  reduced  copper  offers  no  difficulties 
when  carried  out  with  lo-grm.  lots,  as  usually  taken  by 
the  authors,  it  is  pradtically  impossible  to  prevent  larger 
quantities  from  melting  completely  and  forming  a  worth- 
less solid  ingot  on  cooling. 

A  form  of  zinc  available  in  every  laboratory  is  zinc 
dust.  On  removing  the  coating  of  oxide  by  heating  in 
hydrogen  for  a  short  while,  it  was  found  that  50  grms. 
each  of  the  metal  and  ethyl  iodide  readied  within  ninety 
minutes,  and  gave  14  grms.  of  zinc  ethyl  (72  per  cent  of 
the  theoretical  yield).  When  this  metal  is  coupled  with 
copper,  by  reducing  an  intimate  mixture  of  zinc  dust  and 
[finely  powdered  copper  oxide,  the  time  of  readlion  is 
shortened  to  thirty  minutes,  and  the  yield  increased  to 
nearly  90  per  cent.     Different  varieties  of  zinc  dust  give 


different  yields  (ranging  from  70  per  cent  upward) ;  this 
probably  finds  its  explanation  in  the  phenomena  discussed 
by  H.  Wislicenus  ( y.  prakt.  Chem.  (2),  liv.,  i8#). 
The  adtual  quantities  of  materials  taken  also  exercise  an 
influence,  the  yield  being  somewhat  smaller  with  larger 
quantities  (100  grms.  or  more).  I  have  not  attempted  to 
ascertain  the  cause  of  this. 

The  details  of  the  process  are  extremely  simple.  Zinc 
dust  and  copper  oxide  are  mixed  in  the  ratio  of  100  to  12, 
loosely  filled  into  a  combustion  tube,  and  a  current  of 
hydrogen  passed  over  the  heated  mixture  for  about 
twenty  minutes.  In  order  to  prevent  the  condensation 
of  moisture  in  the  tube,  with  the  consequent  caking  of 
the  mass,  it  is  best  to  heat  the  tube  along  its  whole  length 
at  once.  A  dull  red  heat  seems  to  give  the  best  results; 
the  nearer  the  melting-point  of  zinc  the  better,  I  presume. 
If  the  temperature  be  kept  too  low,  the  metals  do  not 
alloy  well,  and  the  results  approach  those  given  by  zinc 
dust  alone.  I  have  usually  employed  equal  quantities  of 
ethyl  iodide  and  metal  couple,  sometimes  less  metal; 
perhaps  the  yield  might  be  increased  by  excess  thereof. 
For  further  diredtions  the  article  of  Gladstone  and  Tribe 
had  best  be  consulted.  In  place  of  the  oil-bath  for 
heating  the  zinc  ethiodide,  the  Babo  air-baths  may  be 
substituted,  as  being  cleaner  and  more  expeditious;  if  a 
small  flame  be  placed  under  them  at  first,  there  is  no 
danger  of  breaking  the  flask.  By  employing  two  sets  of 
apparatus,  and  working  up  about  100  grms.  at  a  time^ 
the  process  may  easily  be  made  continuous,  and  several 
hundred  grms.  of  zinc  etbyl  prepared  in  a  single  day. 
Mr,  F.  M.  Tschirner,  who  has  manufadlured  nearly  300 
grms.  for  me,  found  no  difficulty  in  obtaining  150  grms. 
in  an  afternoon. 

It  is  customary  to  preserve  zinc  ethyl  in  sealed  tubes. 
This  is  awkward  where  small  and  varying  quantities  are 
frequently  needed.  Small  Erlenmeyer  flasks,  with  per- 
fedlly  straight  sides  beginning  at  the  very  mouth,  greatly 
facilitate  the  operation  of  pouring  out  the  liquid,  and 
when  well  corked  form  perfedtly  safe  receptacles.  Instead 
of  requiring  an  assistant  to  keep  a  stream  of  carbon 
dioxide  upon  the  mouth  of  the  flask  when  transferring 
zinc  ethyl,  it  is  much  more  convenient  to  condudl  all 
such  manipulations  under  a  small,  inverted  funnel, 
through  which  the  gas  is  rapidly  passing. 

It  had  been  my  intention  to  compare  the  above  de- 
scribed modification  of  the  copper-zinc  couple  with  the 
original,  chiefly  with  respedl  to  its  reducing  powers,  but 
the  recent  article  of  H.  Wislicenus  {loc.  cit.)  has  made 
this  unnecessary.  Qualitative  tests  show  that  the  new 
form  readts  in  much  the  same  manner  with  alkyl  and 
alkylene  haloids  as  the  older.  I  have  attempted  to  use 
ethyl  bromide  in  place  of  the  expensive  iodide,  but  with- 
out encouraging  results.  Methyl  iodide  readts  as  readily 
as  the  ethyl  compound,  though  the  yield  of  zinc  methyl 
was  not  determined. — American  Chemical  yournal,  x\x.. 
No.  5. 


A    SIMPLE     TEST     FOR    THE     HALOGENS    IN 

ORGANIC  HALIDES. 

By  J.  H.  KASTLE  and  W.  A.  BEATTY. 

In  connedlion  with  some  work  on  the  displacement  of 
bromine  and  iodine  from  their  organic  compounds,  we 
had  frequent  occasion  to  test  for  the  halogens  in  their 
organic  derivatives,  and,  while  a  great  many  methods  for 
condudling  such  test  were  to  be  found  in  the  literature, 
few,  if  any  of  these,  could  be  condudled  rapidly ;  and 
many  involved  the  use  of  rather  large  amounts  of  sub- 
stances, such  as  lime,  soda-lime,  &c.,  which  are  not 
readily  obtained  free  from  chlorine.  It  is  unnecessary  in 
this  connedlion  to  enumerate  the  many  tests  which  have 
been  proposed  for  these  elements  in  their  organic  com- 
pounds ;  most  of  them  are  already  familiar  to  chemists*. 


Chbuical  Nbws,! 
July  9,  1897.      I 


Effect  of  Pressure  in  the  Spectrum  of  an  Element, 


21 


and  nearly  all  of  them  are  described  in  Beilstein's  "  Hand- 
buch"  and  in  Allen's  "Commercial  Organic  Analysis." 

Appreciating  the  need  therefore  of  a  simpler  and  rapid 
test  whereby  chlorine,  bromine,  and  iodine  could  be 
recognised  with  certainty  in  their  most  stable  and  volatile 
organic  combinations,  it  occurred  to  one  of  us  (Kastle) 
to  heat  such  compounds  with  a  mixture  of  silver  and 
copper  nitrates,  thereby  oxidising  the  organic  matter  and 
holding  back  any  halogen  present  by  means  of  silver.  On 
experiment  it  was  found  that  excellent  results  could  be 
obtained  with  this  mixture,  which  can  always  be  obtained 
free  from  any  traces  of  chlorine,  bromine,  or  iodine,  by 
dissolving  the  metals  in  pure  nitric  acid  and  evaporating 
to  crystallisation.  In  the  case  of  non-volatile  substances 
the  test  is  most  easily  conduced  as  follows:  A  small 
quantity  of  a  substance  to  be  tested,  usually  about  o'l 
grm.,  is  placed  in  the  test-tube,  along  with  about  0*5  grm. 
of  the  mixed  nitrates  and  a  few  drops  of  water.  The  tube 
is  then  gradually  heated  in  the  flame  of  the  Bunsen 
burner  until  the  nitrates  are  completely  decomposed  ; 
the  temperature  never  being  allowed  to  rise  higher  than 
low  red  heat.  The  tube,  in  which  some  reduced  copper 
is  often  seen,  is  allowed  to  cool,  a  little  water  and  dilute 
sulphuric  acid  poured  on  the  contents  of  the  tube  and  a 
few  pieces  of  metallic  zinc  added.  After  five  or  ten 
minutes,  during  which  time  any  halogen  compound  of 
silver  is  reduced,  the  contents  of  the  tube  are  filtered  and 
a  solution  of  silver  nitrate  added  to  the  filtrate,  together 
with  a  little  dilute  nitrate  acid,  when  the  chloride, 
bromide,  or  iodide  of  silver  will  be  precipitated,  if  either 
of  these  halogens  was  present  in  the  substance  tested. 

Excellent  tests  for  chlorine,  bromine,  and  iodine  were 
obtained  in  this  way  in  the  following  substances :  Di- 
bromnaphthalene,  eosine,  benzene  dichlorsulphonamide, 
^-brombenzene-sulphonamide,  tribromphenol,  potassium 
^-brombenzenesulphonate,  monobromacetanilide,  sozo- 
iodol  (Merck),  barium  ^-iodobenzenesulphonate.  With 
very  volatile  substances  such  as  chloroform,  it  was  found 
necessary  to  condud  the  test  in  a  tube  about  six  inches 
long  by  one-quarter  inch  internal  diameter,  closed  at  one 
end,  and  bent  twice  at  right  angles  at  equal  distances 
along  the  tube,  so  as  to  form  a  tube  having  somewhat 
the  shape  of  the  letter  S,  In  making  the  test  about  \ 
c.c.  of  the  volatile  compound  to  be  tested  was  introduced 
into  the  closed  end  of  the  tube,  and  the  tube  so  clamped 
as  to  give  its  open  end  an  upward  slant.  About  0*5  grm. 
of  the  dry  mixed  nitrates  was  then  placed  in  the  bend  of 
the  tube  farthest  removed  from  the  closed  end ;  after 
which  the  parts  of  the  tube  containing  the  substance  to 
be  tested  and  the  nitrates  were  heated  alternately,  the 
former  portion  very  gently,  so  as  not  to  drive  out  the 
volatile  substance  before  it  could  be  oxidised  by  the 
decomposing  nitrates.  The  heating  is  continued  until 
all  the  nitrates  are  decomposed,  and  all  of  the  substance 
to  be  treated  volatilised,  at  the  end  of  which  time  the 
tube  is  broken  and  the  fragments,  containing  the  oxides 
of  copper  and  silver,  placed  in  a  test-tube  with  a  small 
quantity  of  water  and  sulphuric  acid  and  a  few  small 
pieces  of  zinc.  The  test  is  then  completed  in  the  manner 
described  in  the  above.  The  following  substances  were 
tested  in  the  closed  S-shaped  tubes  with  excellent  results 
in  every  case  : — 

Chloroform,  isopropyl  bromide,  butyl  bromide,  ethyl 
chlorcarbonate,  propyl  bromide,  propyl  iodide,  bromoform, 
ethylidene  chloride,  propyl  chloride,  monobrombenzene, 
dibrombenzene,  ethylene  bromide,  monochloracetic  acid, 
benzoyl  chloride,  dibromsuccinic  acid. 

It  is  believed  that  this  test  as  applied  both  to  volatile 
and  to  non-volatile  organic  halides  has  in  it  many  points 
of  advantage  over  those  which  have  been  proposed  for 
this  purpose;  in  the  first  place  the  test  is  rapid  and 
certain  in  its  result,  and  by  means  of  it  we  can  judge  not 
only  of  the  presence  or  absence  of  the  halogens,  but  it 
can  also  be  determined  at  a  glance  whether  it  is  chlorine, 
bromine,  or  iodine  that  is  present  in  the  organic  com- 
pound.    Secondly,   only  very  small  quantities  of  sub- 


stances  are  required  to  make  the  tests,  and  the  few^ 
simple  reagents  needed  may  be  obtained  free  from  any 
traces  of  halogen  without  the  least  difficulty. — American 
Chemical  Journal,  xix.,  No.  5. 


A  NOTE  ON  THE  EFFECT  OF  PRESSURE  UPON 

THE  SERIES  IN  THE  SPECTRUM  OF  AN 

ELEMENT. 

By  J.  8.  AMES  and  W.  J.  HUMPHREYS. 

It  has  been  known  for  many  years  that  the  speiSra  of 
certain  elements,  notably  the  alkalies  and  the  alkaline 
earths,  contained  series  of  lines,  which  obeyed  a  mathe- 
matical law  like  that  giving  the  distribution  of  lines  in  the 
spedtrum  of  hydrogen.  These  series  have  been  thoroughly 
studied  by  Kayser  and  Runge,  who  have  classified  them 
according  to  their  physical  charadleristics  as  principal, 
first  subordinate,  second  subordinate.  Only  a  few  ele- 
ments, lithium,  sodium,  potassium,  have  in  their  spedlra 
all  three  series  ;  while  the  last  two  series,  the  subordinate 
ones  so-called,  are  common  to  some  ten  others ;  the  wave- 
lengths being  different  in  the  spedtra  of  the  different 
elements,  the  physical  properties  being  the  same. 

While  the  shift  of  the  lines  in  the  spedlra  of  the 
elements  was  under  investigation,  it  seemed  important  to 
study  in  particular  the  effedt  of  pressure  upon  the  series 
of  the  various  elements.  To  this  end,  photographs  were 
taken  of  the  arc-spedlra  of  all  elements  which  give  series, 
both  at  ordinary  pressure  and  at  increased  pressure ;  and 
the  shifts  were  carefully  measured  of  as  many  of  the  lines 
as  possible.  In  certain  cases  eye-observations  were  also 
made.  The  results  for  each  element  may  be  thus  briefly 
stated  : — 

1.  The  lines  of  any  one  series  of  a  particular  element 
are  shifted  alike,  i.  t.,  according  to  the  same  law,  which 
may  be  written  : — 

where  \  is  the  wavelength,  A\  is  the  shift  produced  by  an 
increase  of  pressure  pi — po,  /S  is  a  constant  for  any  one 
series  of  a  definite  element. 

2.  The  constant  0  is  different  for  the  different  series  of 
the  same  element,  the  change  being  such  that,  very  nearly, 
fi  for  the  principal  series  is  one-half /S  for  the  first  subor- 
dinate and  one-quarter  that  of  the  second  subordinate. 

3.  The  constant  j3  is  different  for  the  same  series  of 
dii^erent  elements.  Special  attention  is  called  to  this 
fadt  in  another  note  in  this  Circular.  One  apparent  irregu- 
larity which  demands  attention  is  the  fadt  that,  approxi- 
mately, the  value  of  /3  for  similar  elements  {e,  g,,  zinc, 
cadmium,  mercury)  varies  as  the  cube-root  of  the  atomic 
weight. 

No  satisfadtory  theory  has  been  advanced  to  account  for 
these  shifts  of  the  spedtrum  lines  when  the  arc  is  under 
pressure.  There  is  every  evidence  that  it  is  not  due  to  a 
temperature  effedl  of  any  ordinary  kind.  It  would  certainly 
be  expedled  that  the  outer  envelope  of  an  arc  would  be  at 
a  much  lower  temperature  than  the  core,  and  that  different 
eledlric  currents  might  cause  different  temperatures  in  the 
arc  ;  yet  no  shift  due  to  these  variations  has  been  observed. 
It  is  our  intention  to  observe  the  arc  under  these  condi- 
tions with  a  Michelson  refradtometer  as  soon  as  possible, 
and  so  to  learn  what  adtually  occurs.  Again,  the  tem- 
perature of  the  arc  should  be  much  greater  than  that  of  a 
Bunsen  flame  which  is  being  fed  with  sodium ;  but  the 
difference  in  the  wavelength  of  Dj  under  the  two  condi- 
tions is  not  perceptible  with  a  21  ft.  concave  grating, 
15,000  lines  to  the  inch  ;  i.e.,  a  shift,  if  any,  must  be  less 
than  o'002  of  an  Angstrom  unit.  The  words  "temper- 
ature of  the  arc  "  are  used  with  considerable  hesitation, 
because  so  little  is  known  as  to  the  mean  condition  of  the 
molecules  of  the  vapour  which  are  producing  the  light. 

One  can  easily  understand,  however,  that,  if  the  pressure 


22 


Surface  Tension  of  Water  and  of  A  queous  Solutions, 


{Chemical  Nbwi, 
July  9, 1897. 


on  a  gas  is  increased,  the  number  of  collisions  per  second 
must  increase  ;  and  it  is  not  impossible  that  this  increased 
internal  energy  of  a  molecule,  as  thus  produced,  is  the 
immediate  cause  of  a  change  in  the  a(5iual  size  of  the 
molecule.  The  extent  of  this  change  would  depend  upon 
the  looseness  of  constru(flion  of  the  molecule,  apparently ; 
and  this  quantity  is  measured  to  a  certain  degree  by  the 
coefficient  of  expansion  of  the  element  in  the  solid  form. 
Therefore,  it  might  be  expefted  that  the  measured  shift 
would  vary  in  the  same  diredtion  as  the  coefficient  of  ex- 
pansion of  the  solid.  This  is  actually  the  case,  with  no 
exception.  Again,  since  on  any  theory  of  emission  of 
waves  the  wave  length  varies  diredlly  as  the  linear  dimen- 
sion of  the  portion  of  matter  producing  the  waves,  it 
would  be  expedled  that  the  measured  shift  would  vary 
diredlly  as  the  coefficient  of  linear  expansion,  which  is 
found  to  be  the  case.  If  a  is  this  coefficient,  it  may  be 
stated  as  an  experimental  law  that,  for  different  elements 
fi  =  ca  where  c  is  a  constant,  which  in  some  way  connects 
-the  ordinary  changes  in  size  of  a  solid  due  to  temperature 
changes  with  the  hypothetical  changes  in  the  size  of  the 
molecules  of  the  vapour  due  to  pressure  changes. 

It  is  not  difficult  to  see  that  one  would  expedt,  as  con- 
sequences of  the  above  ideas,  that  the  shift  would  be  pro- 
portional to  the  total  increase  of  pressure,  regardless  of 
its  mode  of  produdlion  ;  and  that  it  should  also  vary 
direftly  as  the  wave-length  in  any  one  series  or  group  of 
lines,  for  in  such  a  case  the  longer  waves  indicate  greater 
linear  dimensions  of  the  vibrating  segments,  if  the  term 
may  be  used.  These  are  observed  phenomena,  as  is 
stated  above. 

The  fadl  that  the  shift  charadleristic  of  a  principal  series 
is  less  than  that  of  the  first  subordinate,  and  this  in  turn 
less  than  that  of  the  second  subordinate  would  be  expedted, 
in  accordance  with  these  ideas,  if  the  molecules  pro- 
ducing the  principal  series  were  of  a  simpler  structure 
than  those  producing  the  first  subsidiary;  and  if  the  mole- 
cules producing  the  second  subsidiary  were  the  most 
complex  of  all.  For,  since  the  shift  of  a  series  depends 
upon  the  looseness  of  the  molecular  strufture,  it  would  be 
expefted  that,  if  these  molecules  split  up  in  any  way,  the 
fragments  would  be  more  stable  and  firm  than  the  original 
molecules,  and  therefore  the  shift  of  the  original  molecules 
would  be  greater  than  that  of  the  fragments.  It  is  diffi- 
cult, however,  to  see  any  reason  why  the  shift  of  the 
different  series  should  vary  according  to  any  simple  law, 
or  why  the  shift  of  the  same  series  of  different  elements 
should  be  in  accordance  with  any  formula  so  simple  as 
that  of  the  cube  root  of  the  atomic  weight.  If  it  could 
be  assumed  that  the  shift  was  proportional  to  the  linear 
dimensions  of  the  segment  producing  the  waves,  most 
interesting  deduftions  might  be  drawn  ;  but  there  seems 
to  be  no  justification  for  the  assumption. — yohns Hopkins 
University  Circular,  xvi..  No.  130. 


SURFACE    TENSION    OF    WATER    AND    OF 

DILUTE  AQUEOUS  SOLUTIONS. 

By  N.  ERNEST  DORSEY. 

During  the  past  year  I  have  been  endeavouring  to  deter- 
mine the  surface  tension  of  dilute  aqueous  solutions  by 
means  of  the  method  of  ripples.  All  work  previously  done 
on  the  surface  tension  of  solutions  has  been  on  solutions 
of  about  one-half  normal  concentration,  or  greater,  and 
most  of  the  observers  have  deduced  the  surface  tension 
from  the  measured  rise  of  the  solution  in  capillary  tubes. 
For  at  least  two  reasons  the  method  of  capillary  tubes 
is  open  to. serious  objedlions.  First,  the  height  a  liquid 
rises  in  a  tube  depends  upon  the  angle  between  the  wall 
of  the  tube  and  the  surface  of  the  liquid  where  it  meets  the 
tube.  This  contadt  angle  can  not  possibly  be  measured, 
since  the  surface  of  the  liquid  lies  entirely  on  one  side  of 
the  point  where  we  wish  to  know  its  inclination ;  and  as 


we  can  measure  the  inclination  of  a  finite  surface  only 
every  measured  value  of  the  contad  angle  must  be  too 
large. 

The  second  objeftion  is  that  probably  the  surface 
tension  of  the  solution-glass  surface,  as  well  as  that  of  the 
solution-air  surface,  varies  with  the  concentration  of  the 
solution.  If  such  is  the  case  the  surface  tension  found 
will  depend  upon  two  changes  which  can  not  be  readily 
separated,  and  which  render  the  interpretation  of  the 
results  difficult. 

For  these  reasons  I  decided  to  use  the  method  of  ripples, 
which  was  first  successfully  used  by  Lord  Rayleigh, 
although  with  his  arrangement  of  apparatus  individual 
observations  differ  by  about  2  per  cent.  After  trying 
many  plans  one  was  finally  adopted  that  gives  individual 
results  that  agree  to  about  J  per  cent;  and  the  average 
departure  of  single  observations  from  the  mean  of  several 
seldom  exceeds  |  per  cent. 

The  waves  were  generated  by  a  fork  whose  frequency 
was  often  determined  and  was  always  near  62'87  double 
vibrations  per  second.  The  water  and  solutions  were 
contained  in  a  porcelain  tray  i  by  12  by  14  inches.  The 
wave  length  was  measured  by  means  of  a  telescope 
mounted  on  a  dividing  engine,  whose  screw  had  a  pitch 
of  i*0328  m.m.  The  waves  were  visible  under  ordinary 
conditions,  but  were  observed  by  Foucault's  method  for 
rendering  visible  small  vibrations  in  plane  or  spherical 
surfaces. 

The  water  used  was  especially  distilled  by  Mr.  W.  T. 
Mather  from  chromic  acid  and  alkaline  potassium  per- 
manganate, and  was  condensed  in  a  block  tin  condenser  ; 
it  was  the  kind  used  by  him  for  his  eledtrolytic  work. 
The  salts  were  obtained  from  Eimer  and  Amend  and 
were  said  to  be  chemically  pure. 

With  this  apparatus  I  have  determined  the  surface 
tension  of  water  and  of  solutions  of  sodium  chloride, 
potassium  chloride,  sodium  carbonate,  potassium  car- 
bonate, and  zinc  sulphate,  of  concentrations  varying  from 
0*05  normal  to  normal. 

The  value  found  for  water  is  T  =  75.98  dynes  per  centi- 
metre  at  0°  C,  while  Sentis  Jowr.  de  Phys.  (3)  vi.,  183, 
1897)  working  by  an  entirely  different  method  found 
T =76-09  at  0°  C,  which  differs  from  the  other  by  only 
o*i4  per  cent.  These  values  agree  very  well  with  the 
values  given  by  Lord  Rayleigh,  Hall,  Volkmann,  and 
others,  but  are  much  lower  than  Quincke's  value. 

It  was  found  that  the  surface  tensions  of  dilute  aqueous 
solutions  are  linear  functions  of  the  concentration  ;  so  that 
we  may  write  Ts  =  Tw  -f*  0,  where  T8  =  surface  tension 
of  the  solution.  1w  =  surface  tension  of  water  at  the  same 
temperature,  A  is  a  constant,  C  is  the  concentration  in 
grm.  molecules  per  litre.  Below  is  a  table  showing  the 
value  of  k  as  determined  by  different  observers. 

Dorsey.        Volkmann.        Quincke.      Rother. 
NaCl         k=  1.53  1-59  1-57  i-38 

KCL  2.23  1.41  1.57  1-47 

i  NaaCOa  2.00  0.987  1.57  — 

J  K2CO3  1.77  1-78  1-57  — 

ZnS04  1.86  _  _  — 

Volkmann  found  that  the  curve  for  NaaCOj  at  great 
dilution  becomes  steeper  than  the  one  for  K2CO3  which 
agrees  with  my  results.  Quincke's  value,  1-57,  does  not 
agree  with  his  results  except  for  KCl  and  NaCl.  I  cannot 
account  for  the  very  high  value  I  found  for  KCl,  but  it 
must  be  borne  in  mind  that  the  values  given  above  are  not 
fairly  comparable,  since  my  values  are  for  solutions 
generally  less  concentrated  than  i  normal,  while  the 
others  are  found  for  solutions  of  greater  concentration.— 
Johns  Hopkins  University  Circular,  xvi..  No.  130. 

A  Menthoglycol.— Ph.  Barbier  and  G.  Lenr.— In 
addition  to  isopulegol  and  menthoglycol,  there  is  formed 
during  the  adlion  of  dilute  sulphuric  acid  upon  citronallal, 
a  small  quantity  of  C20H34O,  a  body  boiling  at  185"  under 
the  pressure  of  10  m.m.— Comptes  Rendus,  cxxiv.,  No.  23. 


Chbmical  Nbws,  I 
July  9, 1897.      J 


Chemical  Notices  from  Foreign  Sources. 


23 


CHEMICAL 


NOTICES    FROM 
SOURCES. 


FOREIGN 


NoTB.— All  degrees  of  temperature  are  Centigrade  anlessotherwiBe 

expressed. 

Comptes  Rendus  Hebdomadaires  des  Seances,  deVAcademie 
des  Sciences.    Vol.  cxxiv.,  No.  23,  June  8,  1897. 

Correspondence. —  The  Secretary  read  a  letter  an- 
nouncing the  dispatch  of  25,000  francs  derived  from  a 
subscription  gathered  in  Russia  as  a  contribution  to  the 
fund  for  the  eredion  of  a  monument  to  Lavoisier. 

Properties  of  Simple  Kathodic  Rays.  Relations 
with  Simple  Eledric  Radiations. — H.  Deslandres, — 
The  author's  experiments,  and  in  particular  an  experiment 
with  the  Tesla-d'Arsonval  arrangement,  lead  to  the  fol- 
lowing conclusion  : — The  simple  kathodic  rays  correspond 
to  the  simple  eledlric  oscillations.  Further,  the  Crookes 
tube,  completed  by  arrangements  described  in  the  author's 
paper,  constitutes  an  apparatus  capable  of  furnishing 
rapid  and  valuable  indications  on  the  eledrication  of  con- 
duiStors  submitted  to  high  tensions. 

Atomic  Weight  of  Cerium. — M.  Wyrouboff  and  A. 
Verneuil. — On  operating  with  products  stridly  pure,  and 
employing  methods  as  free  as  possible  from  errors,  cerium, 
of  whatever  origin,  shows  an  atomic  weight  very  close 
upon  92*7.  Considering  the  indire(5l  charadler  of  the 
method  employed,  this  figure  can  only  be  considered  as 
approximative  to  about  0*2 — o"3. 

Heat  Liberated  on  the  addition  of  Bromine  to 
some  Non-saturated  Substances. — W.  Louguinine 
and  Jas.  Kablukow. — The  addition-heats  of  Br  to  allylic 
alcohol  and  its  derivatives  vary  little  among  themselves. 
For  allyl  chloride  and  bromide  they  are  almost  equal. 
The  substitution  of  phenyl  (CeHj)  for  hydrogen  in  allylic 
alcohol  diminishes  notably  the  addition-heat  of  bromine. 

Combinations  of  Phenylhydrazine  with  Metallic 
Bromides. — J.  Moitessier. — Not  suitable  for  abridgment. 

Chemical  Study  on  the  Culture  of  the  Cattleya. — 
Alex  Hebert  and  G.  Truffaut. — The  generated  bulbs  con- 
tain a  diminished  proportion  of  dry  matter,  of  organic  and 
nitrogenous  matter,  and  of  ash ;  the  decrease  falling 
principally  upon  the  potassa,  lime,  magnesia,  and  phos- 
phoric acid. 

Examination  of  Aluminium  Utensils. — M.  Balland. 
—The  aluminium  utensils  must  contain  99  to  99*5  of  pure 
aluminium.  In  alloys  of  copper  and  aluminium,  the 
copper  must  not  exceed  2  to  3  per  cent.  The  vessels, 
&c.,  must  not  be  cleansed  with  soda. 


Bulletin  de  la  Societe  Chimique  de  Paris, 
Series  3,  Vol.  xvii.-xviii.,  No.  10.  May  20,  1897. 
A(5tion  of  Dilute  Nitric,  Sulphuric,  Hydrochloric, 
and  Phosphoric  Acids  on  Nitrates  in  the  Presence 
of  Ether. — C.  Tanret. — When  two  liquids,  insoluble 
in  each  other,  one  of  which  has  in  solution  a  body  equally 
soluble  in  the  other,  are  shaken  up  together,  these  two 
liquids  will  divide  the  soluble  body  between  them  in  such 
a  manner  that  the  quantity  as  dissolved  in  given  volumes 
of  each  will  always  have  a  constant  relation  one  to  the 
other.  Having  occasion  to  apply  this  method  to  the  de- 
tedlion  of  small  quantities  of  nitric  acid  in  a  liquid  rich  in 
nitrate  of  ammonia,  the  author  obtained  some  quite  un- 
expedled  results.  The  acid  dissolved  in  ether  as  an  organic 
acid  would  have  done,  then,  after  agitation  with  water, 
passed  to  a  great  extent  into  the  latter.  Nitric  acid 
therefore  possesses  two  coefficients,  according  to  whether 
nitrate  of  ammonia  is  present  or  not.  This  research  was 
the  outcome  of  this  observation,  and  the  author  maintains 
that  the  action  of  nitrates  on  the  coefficient  of  "division" 


of  the  nitric  acid  is  expiained  if  we  admit  that,  in  dis- 
solving in  nitric  acid,  the  neutral  nitrate  becomes  an  acid 
nitrate.  Now,  water  does  not  completely  decompose 
acid  salts  into  free  acid  and  neutral  salts,  because  these 
two  tend  to  re-combine  and  re-form  the  original  salt.  It 
follows,  then,  that  in  adding  either  an  excess  of  acid 
with  regard  to  the  amount  of  neutral  salt  present,  or  an 
excess  of  neutral  salt  with  regard  to  the  acid  present, 
the  tendency  is  to  augment  the  stability  of  the  acid  salt. 
This  latter  case  is  precisely  the  result  obtained  in  these 
experiments. 

Formation  of  Metallic  Sulphides  by  Mechanical 
Agencies.  —  L.  Franck.  —  This  paper  contains  an 
account  of  several  simple  experiments,  which  prove  the 
combination  of  two  bodies  by  mechanical  influence  and 
mutual  contadt,  by  the  fridtion  of  the  two  bodies.  Small 
quantities  of  sulphides  have  been  obtained  by  rubbing 
flowers  of  sulphur,  and  the  powder  of  certain  metals, 
— such  as  iron,  copper,  aluminium,  &c., — between  two 
sheets  of  paper. 

Acf^ion  of  Chloride  of  Chloracetyl  on  some  Aro- 
matic Hydrocarbides,  in  the  presence  of  Chloride  of 
Aluminium.  —  A.  Collet.  —  In  a  previous  note  the 
author  described  the  adtion  of  various  chlorides  of  acid 
halogens  on  benzene  in  the  presence  of  chloride  of 
aluminium  ;  he  now  describes  the  produdts  obtained  with 
chloride  of  chloracetyl  in  a  similar  manner. 

On  some  Derivatives  of  Anise-aldehyd.  —  A. 
Reychler. — Not  suitable  for  abstradlion. 

Contribution  to  the  Study  of  Coumarin.  —  A. 
Reychler. —  The  author  finds  that  by  using  pure  by- 
produdts,  and  working  at  a  sufficiently  high  temperature, 
the  Perkin  readtion  does  not  appear  to  need  the  presence 
of  any  great  proportion  of  alkaline  salts. 

Produ(5\s  of  the  A(5tion  of  Benzhydrol-diamide  and 
Tetramethyl,  on  Para-  and  Meta-sulphanilic  Acids. 
— M.  Seals. — Not  suitable  for  abstradtion. 

On  a  New  Method  of  Extradting  the  Perfume  from 
Flowers. — J.  Passy. — The  author  soaks  the  flowers  in 
water,  without  killing  them ;  the  scent  goes  into  the 
water,  as  it  does  into  air ;  the  water  is  then  treated  with 
ether,  which  colledls  the  scent.  This  renders  maceration 
unnecessary. 

Study  of  Chlorophyll.  —  J.  Stoklasa.  —  The  author 
finds  that  the  cellular  germ  does  not  form — not  only 
without  phosphorus  but  also  without  iron — if  the  chloro- 
phyll contains  only  phosphorus. 

Schiff  Readtion  applied  to  Acid  Fuschine. — L. 
Lefevre. — The  author  finds  that  M.  Cazeneuve's  conclu- 
sion, that  fuschine  decolourised  by  SOj  would  not  regain 
its  colour  when  treated  with  aldehyds,  is  not  corredt. 
The  success  of  the  readlion  depends  entirely  on  the 
quantities  used. 


Bulletin  des  Travaux  de  la  Soci€ti  de  Pharmacie  de 
Bordeaux.     May,  1897. 

New  Method  of  Testing  for  Biliary  Calculus. — 
G.  Deniges. — Not  suitable  for  abstradtion. 

Experiments  on  Commercial  Albumen. — P.  Carles. 
— The  adoption  of  albumen  as  a  clarifier  by  several 
industries  has  brought  a  number  of  different  brands  on 
the  market ;  some  can  be  used  with  every  confidence,  but 
unfortunately,  with  a  view  to  cheapen  its  produ<ftion, 
there  are  also  brands  carelessly  made,  and,  what  is  worse, 
adulterated.  Some  samples  have  been  found  to  contain 
from  12  to  25  per  cent  of  insoluble  coagulated  matter, 
having  no  clarifying  power  whatever.  Gum,  dextrine,  and 
gelatin  are  also  used  as  adulterants.  To  examine  the 
purity  of  albumen,  2  grms.  should  be  made  into  a  paste 
with  distilled  water,  then  more  water  gradually  added,  up 
to  200  c.c. ;  if  the  albumen  be  free  from  coagulated 
particles  this  solution  will  be  translucent.    To  100  c.c.  of 


24 


Chemical  Notices  from  Foreign  Sources. 


(Chemical  news, 
July  g,  1897. 


this  solution  add  35  c.c.  of  a  i  per  cent  solution  of  tannin, 
then  o'2  grm.  of  powdered  bitartrate  of  potash.  Shake 
well  and  filter;  to  one  part  of  the  filtrate  add  a  few  drops 
of  a  solution  of  five  parts  per  thousand  of  grenatine,  and 
to  the  other  a  few  drops  of  the  tannin  solution  above 
mentioned.  If  there  is  no  change  the  albumen  is  pure  ; 
if  the  grenatine  gives  a  precipitate  it  shows  that  there  is 
tannin  in  excess,  and,  therefore,  that  the  albumen  is  either 
adulterated  with  some  inert  body  or  has  been  over-heated 
in  making ;  if,  however,  the  tannin  gives  a  precipitate  in 
the  last  tube,  it  proves  the  presence  of  gelatin  in  the 
flample,  as  gelatin  will  precipitate,  weight  for  weight,  four 
times  as  much  tannin  as  dried  albumen  can. 

Phenomenon  of  Oxidation  produced  by  Different 
Milks. — R.  Dupouy. — Not  suitable  for  abstradion. 

New  Form  of  Oven  for  Desiccation  and  Sterilisa- 
tion.— M.  Soulard. — The  large  number  of  different  desic- 
cating ovens  now  used  in  laboratories  show  that  perfedlion 
is  very  difficult  to  attain.  Physical  science  teaches  us 
that  the  rapidity  of  desiccation  depends  on  the  temper- 
ature, on  the  degree  of  saturation  of  the  surrounding 
atmosphere,  on  the  renewing  of  this  atmosphere,  and  on 
the  amount  of  surface  for  evaporation.  Most  ovens  will 
not  allow  of  the  conditions  being  at  their  best.  The  oven 
made  by  the  author  seems  to  conform  to  the  stale  of 
things  required.  It  is  made  of  sheet  copper,  with  double 
walls,  and  so  ingeniously  put  together  that  the  inner 
chamber  is  heated  diredtly  by  the  flame,  while  at  the 
same  time  a  current  of  hot  fresh  air  enters  at  one  side 
near  the  bottom,  and  by  means  of  alternate  trays  circu- 
lates— or  rather  zigzags — throughout  the  interior  until  it 
reaches  the  top,  where  it  escapes.  The  temperature  can 
be  so  regulated  that  the  oven  can  be  used  for  evaporations 
and  desiccations,  or  it  can  be  raised  to  and  maintained  at 
160°  or  200°  for  sterilisations. 

Societede  I'Industrie  Minerale,  Comptes  Rendus  Mensuels. 
April,  1897. 

Ele(5\roIysis  of  Solid  Bodies. — M.  Mayen9on. — For 
these  experiments  a  bichromate  battery  of  six  cells  is 
sufficient,  and  the  whole  apparatus  necessary  is  of  a  very 
simple  charadter — such  as  an  agate  mortar,  a  platinum 
crucible,  one  or  two  spatulas,  a  glass  funnel,  &c.  The 
adion  of  the  current  is  shown  first  on  a  few  simple  bodies 
capable  of  forming  acids ;  for  instance,  carbon  is  trans- 
formed by  the  oxygen  of  water  into  carbonic  acid,  when 
it  is  employed  as  the  anode,  the  cathode  being  of  platinum. 
To  show  this  a  small  quantity  of  baryta  water  is  poured 
into  a  test-tube,  and  a  few  drops  of  chloride  of  barium 
added  ;  when  the  current  is  passed  through  as  described, 
a  white  precipitate  of  carbonate  of  baryta  is  formed, 
soluble  in  acids.  In  a  like  manner  sulphur  forms  sulphuric 
acid,  and  then  sulphate  of  barium  when  moistened  with 
chloride  of  barium.  As  a  final  experiment  on  insoluble 
simple  bodies,  phosphorus  was  transformed  into  phos- 
phoric acid,  by  passing  the  current  through  small  pieces 
of  phosphorus  moistened  with  nitro-molybdate  of  ammonia, 
when  the  yellow  phospho-molybdate  of  ammonia— inso- 
luble in  acids  and  soluble  in  ammonia — was  formed. 

The  decomposition  of  a  silicate  by  means  of  the  eledtric 
current  is  also  performed,  but  it  is  not  easy  to  show  the 
presence  of  silica  by  absolutely  charadteristic  readtions. 
Orthose  gives  on  one  pole  silica,  at  the  other  potash,  and 
garnierite  in  a  similar  manner  gives  metallic  nickel. 
Further  experiments  are  being  made,  and  will  shortly  be 
-communicated. 

Bulletin  de  la  Societe  tC Encouragement  pour  I'' Industrie 
Nationale.    Series  5,  Vol.  ii.,  No.  5.     May,  1897. 

Estimation  of  the  Oxidation  of  Oils. — W.  Bishop. 
— This  is  a  report  to  the  Society  by  M.  Berard,  on  the 
work  done  by  M.  Bishop  on  this  subjedt.  This  work 
Avas  inspired  by  an  experiment  made  by  Chevreul  in  1856, 
n  which  he  found  that  linseed  oil  mixed  with  manganese 


absorbed  ten  times  more  oxygen  than  the  pure  oil  itself. 
M.  Bishop,  however,  uses  as  drying  agent  a  kind  of  soap 
made  by  mixing  oxide  of  manganese  with  resin.  He  dis- 
solves this  resinate  in  the  oil  to  be  tested  in  the  proportion 
of  o'2  grm.  of  the  former  to  10  grms.  of  the  oil.  Then, 
to  facilitate  the  access  of  air,  he  adds  i  grm.  of  a  light 
silicate,  obtained  by  precipitation  and  calcination.  The 
desiccation  is  then  allowed  to  proceed.  The  table  of  the 
order  of  oxidation  confirms  what  has  already  been  shown 
by  M.  Livache  with  regard  to  this  order.  M.  Bishop  ob- 
tained for  linseed  oil  an  absorptive  value  of  oxygen  of  14 
per  cent  in  twenty-four  hours.  He  has  successfully 
applied  his  method  to  the  comparison  of  different  com- 
mercial oils  and  the  recognition  of  possible  mixtures 
which  could  be  made. 

Composition  of  Clays. — Georges  Vogt. — A  very  long 
paper,  not  suitable  for  abstradtion. 

Researches  on  the  Colouration  of  Glass  by  the 
Dire(5t  Penetration  of  Metals  or  Metallic  Salts. — 
Leon  Lemal. — Reprinted  from  the  Comptes  Rendus,  May 
17,  1897. 

On  Solutions  of  Acetylene  and  their  Explosive 
Properties.  —  MM.  Berthelot  and  Vieille.  —  From  the 
Comptes  Rendus,  May  10,  1897. 

THE 

DAVY  FARADAY  RESEARCH  LABORATORY 

OF 

THE    ROYAL    INSTITUTION. 

Directors : 

The  Right  Hon.  LORD  RAYLEIGH,  M.A.,  D.C.L.,  LL.D.,F.R.S, 

Professor  DEWAR,  M.A.,  LL.D.,  F.R.S. 

Superintendent  of  the  Laboratory  : 

Dr.  Alexander  Scott,  M.A.,  D.Sc. 

This  Laboratory,  which  has  been  founded  by 
Dr.  LuDwiG  MoND,  F.R.S.,  as  a  Memorial  of  Davy  and 
Faraday  "  for  the  purpose  of  promoting  original  research  in  Pure  and 
Physical  Chemistry,"  is  now  open.  The  next  Term  begins  on  the 
4th  of  Oftober,  1897. 

Under  the  Deed  ot  Trust,  workers  in  the  Laboratory  are  entitled, 
free  of  charge,  to  Gas,  Electricity,  and  Water,  as  far  as  available, 
and  at  the  discretion  of  the  Direftors,  to  the  use  of  the  apparatus 
belonging  to  the  Laboratory,  together  with  such  materials  and 
chemicals  as  may  ba  authorised. 

All  persons  desiring  to  be  admitted  as  workers,  must  send  evidence 
of  scientific  training,  qualification,  and  previous  experience  in 
original  research,  along  with  a  statement  of  the  nature  of  the  investi- 
gation they  propose  to  undertake.  Further  information,  together  with 
forms  of  application,  can  be  had  from  the  Assistant  Secretary, 
Royal  Institution. 


HULL  MUNICIPAL  TECHNICAL  SCHOOLS. 

CHEMISTRY  MASTERSHIP. 

The  Technical  Instrudlion  Committee  is  pre- 
pared to  receive  applications  for  the  above  Appointment. 
Candidates  must  not  be  under  25  nor  over  40  years  of  age.  The 
Master  will  not  be  allowed  to  undertake  any  teaching  other  than  that 
required  by  the  Committee.  Salary,  £200  per  annum,  payable 
monthly.  Forms  of  application  and  further  particulars  may  be  ob- 
tained from  the  undersigned,  to  whom  applications  must  be  sent  not 
later  than  Wednesday,  July  14th,  1897. 

J.  T.  RILEY,  D.Sc.(Lond.), 
7,  Albion  Street.  Hull. Direaor  ot  Studies. 

THE  LEEDS  INSTITUTE  OF  SCIENCE,  ART,  AND 
LITERATURE. 

The  Diredlors  invite  applications  for  the  post 
of  HEAD  MASTER  of  The  Leeds  Technical  School  and 
TEACHER  of  CHEMISTRY  to  the  Boys'  and  Girls'  Modern 
Schools  of  the  Institute,  now  vacant  by  the  death  of  Mr.  S.  J.  Harris, 
M  Sc. 

The  Master  appointed  will  be  expefted  to  take  classes  in  Theo- 
retical and  Praftical  Inorganic  and  Organic  Chemistry  and  to  exer- 
cise a  general  supervision  over  the  other  classes  in  the  Technical 
School.  The  school  buildings,  erefted  in  1888,  are  furnished  with  all 
necessary  materials  and  apparatus  for  science  teaching. 

Salary,  partly  fixed  and  partly  dependent  upon  results,  amounts  to 
about  £325.  Full  particulars  may  be  had  from  the  Secretary,  to 
whom  applications  must  be  sent  not  later  than  July  20th,  1897. 

Canvassing  Directors  will  be  considered  a  disqualification. 


Cbbmical  Nbws,  I 

July  16, 1897.   r 


Diamonds . 


THE    CHEMICAL    NEWS 


Vol.  LXXVL,  No.  1964. 


DIAMONDS.* 

By  WILLIAM  CROOKES,  F.R.S.,  M.R.I. 

(Concluded  from  p.  15). 

The  Mechanism  of  the  Diamantiferous  Pipes. 
How  the  great  diamond  pipes  originally  came  into  exist- 
ence  is  not  difficult  to  understand,  in  the  light  of  the  fore- 
going fads.  They  certainly  were  not  burst  through  in 
the  ordinary  manner  of  volcanic  eruption;  the  surrounding 
and  enclosing  walls  show  no  signs  of  igneous  adtion,  and 
are  not  shattered  nor  broken  even  when  touching  the 
"  blue  ground."  These  pipes  after  they  were  pierced  were 
•filled  from  below,  and  the  diamonds  formed  at  some  pre- 
vious epoch  too  remote  to  imagine  were  erupted  with  a 
mud  volcano,  together  with  all  kinds  of  debris  eroded 
from  the  adjacent  rocks.  The  diredtion  of  flow  is  seen  in 
the  upturned  edges  of  some  of  the  strata  of  shale  in  the 
'Walls,  although  I  was  unable  at  great  depths  to  see  any 
upturning  in  most  parts  of  the  walls  of  the  De  Beers 
mine. 

Let  me  again  refer  you  to  the  pidture  of  the  sedlion 
through  the  Kimberley  mine.  There  are  many  such  pipes 
in  the  immediate  neighbourhood.  It  may  be  that  each 
volcanic  pipe  is  the  vent  for  its  own  special  laboratory — 
a  laboratory  buried  at  vastly  greater  depths  than  we  have 
reached  or  are  likely  to  reach — where  the  temperature  is 
comparable  with  that  of  the  eledtric  furnace,  where  the 
pressure  is  fiercer  than  in  our  puny  laboratories  and  the 
melting-point  higher,  where  no  oxygen  is  present,  and 
where  masses  of  carbon-saturated  iron  have  taken  centu- 
ries, perhaps  thousands  of  years,  to  cool  to  the  solidifying 
point.  Such  being  the  conditions,  the  wonder  is,  not  that 
diamonds  are  found  as  big  as  one's  fist,  but  that  they  are 
not  found  as  big  as  one's  head.  The  chemist  arduously 
manufadlures  infinitesimal  diamonds,  valueless  as  orna- 
mental gems;  but  Nature,  with  unlimited  temperature, 
inconceivable  pressure,  and  gigantic  material,  to  say 
nothing  of  measureless  time,  produces  without  stint  the 
dazzling,  radiant,  beautiful  crystals  I  am  enabled  to  show 
you  to-night. 

The  ferric  origin  of  the  diamond  is  corroborated  in  many 
ways.  The  country  round  Kimberley  is  remarkable  for 
its  ferruginous  charadter,  and  iron-saturated  soil  is  popu- 
larly regarded  as  one  of  the  indications  of  the  near  pre- 
sence of  diamonds.  Certain  artificial  diamonds  present 
the  appearance  of  an  elongated  drop.  From  Kimberley  I 
have  with  me  diamonds  which  have  exadtly  the  appear- 
ance of  drops  of  liquid  separated  in  a  pasty  condition  and 
crystallised  on  cooling.  At  Kimberley  and  in  other  parts 
of  the  world,  diamonds  have  been  found  with  little  appear- 
ance of  crystallisation  but  with  rounded  forms  similar  to 
those  which  a  liquid  might  assume  if  kept  in  the  midst  of 
another  liquid  with  which  it  would  not  mix.  Other  drops 
of  liquid  carbon  retained  above  their  melting-point  tor 
sufficient  time  would  coalesce  with  adjacent  drops,  and 
on  slow  cooling  would  separate  in  the  form  of  large  perfedt 
crystals.  Two  drops,  joining  after  incipient  crystallisa- 
tion, would  assume  the  not  uncommon  form  of  interpene- 
trating twin  crystals.  Illustrations  of  these  forms  from 
Kimberley  are  here  to-night.  Other  modified  circum- 
stances would  produce  diamonds  presenting  a  confused 
mass  of  boarty  crystals,  rounded  and  amorphous  masses, 
or  a  hard  black  form  of  carbonado. 

Again,  diamond  crystals  are  almost  invariably  perfedt 

*  A  Lecture  delivered  at  the  Royal  Institution,  Friday,  June  nth, 
tl897. 


on  all  sides.  They  show  no  irregular  side  or  face  by  which 
they  were  attached  to  a  support,  as  do  artificial  crystals 
of  chemical  salts;  another  proof  that  the  diamond  must 
have  crystallised  from  a  dense  liquid. 

When  raised  the  diamond  is  in  a  state  of  enormous 
strain,  as  I  have  already  shown  by  means  of  polarised 
light.  Some  diamonds  exhibit  cavities  which  the  same 
test  proves  to  contain  gas  at  considerable  pressure. 

The  ash  left  after  burning  a  diamond  invariably  con- 
tains iron  as  its  chief  constituent ;  and  the  most  common 
colours  of  diamonds,  when  not  perfedtly  pellucid,  show 
various  shades  of  brown  and  yellow,  from  the  palest  "off 
colour"  to  almost  black.  These  variations  accord  with 
the  theory  that  the  diamond  has  separated  from  molten 
iron,  and  also  explains  how  it  happens  that  stones  from 
different  mines,  and  even  from  different  parts  of  the  same 
mine,  differ  from  each  other.  Along  with  carbon,  molten 
iron  dissolves  other  bodies  which  possess  tindtorial  powers. 
One  batch  of  iron  might  contain  an  impurity  colouring 
the  stones  blue,  another  lot  would  tend  towards  the  form- 
ation of  pink  stones,  another  of  green,  and  so  on.  Traces 
of  cobalt,  nickel,  chromium,  and  manganese,  metals 
present  in  the  blue  ground,  might  produce  all  these 
colours. 

An  hypothesis,  however,  is  of  little  value  if  it  only 
elucidates  one  half  of  a  problem.  Let  us  see  how  far  we 
can  follow  out  the  ferric  hypothesis  to  explain  the  volcanic 
pipes.  In  the  first  place  we  must  remember  these  so- 
called  volcanic  vents  are  admittedly  not  filled  with  the 
eruptive  rocks,  scoriaceous  fragments,  &c.,  constituting 
the  ordinary  contents  of  volcanic  dudts.  At  Kimberley 
the  pipes  are  filled  with  a  geological  plum  pudding  of 
heterogeneous  charadler — agreeing,  however,  in  one  par- 
ticular. The  appearance  of  shale  and  fragments  of  other 
rocks  shows  that  the  melange  has  suffered  no  great  heat 
in  its  present  condition,  and  that  it  has  been  erupted  from 
great  depths  by  the  agency  of  water  vapour  or  some  similar 
gas.     How  is  this  to  be  accounted  for  ? 

It  must  be  borne  in  mind  I  start  with  the  reasonable 
supposition  that  at  a  sufficient  depth*  there  were  masses 
of  molten  iron  at  great  pressure  and  high  temperature, 
holding  carbon  in  solution,  ready  to  crystallise  out  on 
cooling.  In  illustration  I  may  cite  the  masses  of  erupted 
iron  in  Greenland.  Far  back  in  time  the  cooling  from 
above  caused  cracks  in  superjacent  strata  through  which 
watert  found  its  way.  On  reaching  the  iron  the  water 
would  be  converted  into  gas,  and  this  gas  would  rapidly  dis- 
integrate and  erode  the  channels  through  which  it  passed, 
grooving  a  passage  more  and  more  vertical  in  the  endea- 
vour to  find  the  quickest  vent  to  the  surface.  But  steam 
in  the  presence  of  molten  or  even  red-hot  iron  rapidly 
attacks  it,  oxidises  the  metal  and  liberates  large  volumes 
of  hydrogen  gas,  together  with  less  quantities  of  hydro- 
carbons! of  all  kinds — liquid,  gaseous,  and  solid.  Erosion 
commenced  by  steam  would  be  continued  by  the  other 
gases,  and  it  would  be  no  difficult  task  for  pipes,  large  as 
any  found  in  South  Africa,  to  be  scored  out  in  this  manner. 
Sir  Andrew  Noble  has  shown  that  when  the  screw  stopper 
of  his  steel  cylinders  in  which  gunpowder  explodes  under 
pressure  is  not  absolutely  perfedt,  gas  finds  its  way  out 
with  a  rush  so  overpowering  as  to  score  a  wide  channel  in 
the  metal ;  some  of  these  stoppers  and  vents  are  on  the 
table.  To  illustrate  my  argument  Sir  Andrew  Noble  has 
been  kind  enough  to  try  a  special  experiment.  Through 
a  cylinder  of  granite  is  drilled  a  hole  02  inch  diameter, 
the  size  of  a  small  vent.  This  is  made  the  stopper  of  an 
explosion  chamber,  in  which  a  quantity  of  cordite  is  fired, 
the  gases  escaping  through  the  granite  vent.  The  pressure 
is  about  1500  atmospheres,  and  the  whole  time  of  escape 

•  The  requisite  pressure  of  fifteen  tons  on  the  square  inch  would 
exist  not  many  miles  beneath  the  surface  of  the  earth. 

f  There  are  abundant  signs  that  a  considerable  portion  of  this  part 
of  Africa  was  oace  under  water,  and  a  fresh-water  shell  has  been 
found  in  apparently  undisturbed  blue  ground  at  Kimberley.     ' 

{  The  water  sunk  in  wells  close  to  the  Kimberley  mine  is. some- 
times impregnated  with  paraffin,  and  Sir  H.  Roscoe  |extra(5ted  a 
solid  hydrocarbon  from  the  "  blue  ground."'     .-, 


26 


is  less  than  half  a  second.  Notice  the  erosion  produced 
by  the  escaping  gases  and  by  the  heat  of  fridtion,  which 
have  scored  out  a  channel  over  half  an  inch  diameter  and 
melted  the  granite  along  their  course.  If  steel  and  granite 
are  thus  vulnerable  at  comparatively  moderate  gaseous 
pressure,  is  it  not  easy  to  imagine  the  destrudlive  upburst 
of  hydrogen  and  water-gas  grooving  for  itself  a  channel  in 
the  diabase  and  quartzite,  tearing  fragments  from  resisting 
rocks,  covering  the  country  with  debris,  and  finally,  at  the 
subsidence  of  the  great  rush,  filling  the  self-made  pipe 
with  a  water-borne  magma  in  which  rocks,  minerals,  iron 
oxide,  shale,  petroleum,  and  diamonds  are  churned  together 
in  a  veritable  witch's  cauldron  !  As  the  heat  abated  the 
water  vapour  would  gradually  give  place  to  hot  water, 
which  forced  through  the  magma  would  change  some  of 
the  mineral  fragments  into  the  now  existing  forms. 

Each  outbreak  would  form  a  dome-shaped  hill,  but  the 
eroding  agency  of  water  and  ice  would  plane  these  emi- 
nences until  all  traces  of  the  original  pipes  were  lost. 

Anions,  such  as  I  have  described,  need  not  have  taken 
place  simultaneously.  As  there  must  have  been  many 
molten  masses  of  iron  with  variable  contents  of  carbon, 
different  kinds  of  colouring  matter,  solidifying  with  varying 
degrees  of  rapidity,  and  coming  in  contadt  with  water  at 
intervals  throughout  long  periods  of  geological  time — so 
must  there  have  been  many  outbursts  and  upheavals, 
giving  rise  to  pipes  containing  diamonds.  And  these 
diamonds,  by  sparseness  of  distribution,  crystalline  cha- 
radler,  difference  of  tint,  purity  of  colour,  varying  hardness 
brittleness  and  state  of  tension,  would  have  impressed 
upon  them,  engraved  by  natural  forces,  the  story  of  their 
origin — a  story  which  future  generations  of  scientific  men 
may  be  able  to  interpret  with  greater  precision  than  we 
can  to-day. 

Who  knows  but  that  at  unknown  depths  in  the  earth's 
metallic  core  beneath  the  present  pipes  there  are  still 
masses  of  iron  not  yet  disintegrated  and  oxidised  by 
aqueous  vapour, — masses  containing  diamonds,  unbroken, 
and  in  greater  profusion  than  they  exist  in  the  present 
blue  ground,  inasmuch  as  they  are  enclosed  in  the  matrix 
itself,  undiluted  by  the  numerous  rock  constituents  which 
compose  the  bulk  of  the  blue  ground. 

Meteoric  Diamonds, 

There  is  another  diamond  theory  which  appeals  to  the 
fancy.  It  is  said  that  the  diamond  is  a  diredt  gift  from 
Heaven,  conveyed  to  earth  in  meteoric  showers.  The 
suggestion,  I  believe,  was  first  broached  by  A.  Meyden- 
bauer  (Chemical  News,  Ixi.,  p.  209,  1890),  who  says: — 
"  The  diamond  can  only  be  of  cosmic  origin,  having  fallen 
as  a  meteorite  at  later  periods  of  the  earth's  formation. 
The  available  localities  of  the  diamond  contain  the  resi- 
dues of  not  very  compadl  meteoric  masses,  which  may, 
perhaps,  have  fallen  in  historic  ages,  and  which  have 
penetrated  more  or  less  deeply,  according  to  the  more  or 
less  resistant  charader  of  the  surface  where  they  fell. 
Their  remains  are  crumbling  away  on  exposure  to  the  air 
and  sun,  and  the  rain  has  long  ago  washed  away  all  pro- 
minent masses.  The  enclosed  diamonds  have  remained 
scattered  in  the  river  beds,  while  the  fine  light  matrix  has 
been  swept  away." 

According  to  this  hypothesis,  the  so-called  volcanic 
pipes  are  simply  holes  bored  in  the  solid  earth  by  the 
impadt  of  monstrous  meteors — the  larger  masses  boring 
the  holes,  while  the  smaller  masses,  disintegrating  in 
their  fall,  distributed  diamonds  broadcast.  Bizarre  as 
such  a  theory  may  appear,  I  am  bound  to  say  there 
are  many  circumstances  which  show  that  the  notion  of 
the  heavens  raining  diamonds  is  not  impossible. 

In  1846  a  meteorite  fell  in  Hungary  (the  "  Ava 
meteorite  ")  which  was  found  to  contain  graphite  in  the 
cubic  crystalline  system.  G.  Rose  thought  this  cubic 
graphite  was  produced  by  the  transformation  of  a  dia- 
mond. Long  after  this  predidtion  was  verified  by 
Weinschenk,  who  found  transparent  crystals  in  the  Ava 
fneteorite.     Mr.  Fletcher  has  found  in  two  meteoric  irons 


Diamonds.  {'^Vi."'V-^»'''"'' 

'      July  10,  1897. 

— one  from  Yondegin,  East  Australia,  and  one  from 
Crosby's  Creek,  United  States  —  crystals  absolutely 
similar  to  those  in  the  Ava  meteorite. 

In  1886  a  meteorite  falling  in  Russia  contained,  besides 
other  constituents,  about  i  per  cent  of  carbon  in  light 
grey  grains,  having  the  hardness  of  diamond,  and  burning: 
in  oxygen  to  carbonic  acid. 

Daubree  says  the  resemblance  is  manifest  between  the 
diamantiferous  earth  of  South  Africa  and  the  Ava 
meteorite,  of  which  the  stony  substance  consists  almost 
entirely  of  peridot.  Peridot  being  the  inseparable  com- 
panion  of  meteoric  iron,  the  presence  of  diamonds  in  the 
meteorites  of  Ava,  of  Yondegin,  and  of  Crosby's  Creek,, 
bring  them  close  to  the  terrestrial  diamantiferous  rocks. 

Hudleston  maintains  that  the  bronzite  of  the  Kimberley 
blue  ground  is  in  a  condition  much  resembling  the 
bronzite  grains  of  meteorites ;  whilst  Maskelyne  says 
that  the  bronzite  crystals  of  Dutoitspan  resemble  closely 
those  of  the  bronzite  of  the  meteor  of  Breitenbach,  but 
are  less  rich  in  crystallographic  planes. 

But  the  most  striking  confirmation  of  the  meteoric 
theory  comes  from  Arizona.  Here,  on  a  broad  open 
plain,  over  an  area  about  five  miles  diameter,  were 
scattered  one  or  two  thousand  masses  of  metallic  iron, 
the  fragments  varying  in  weight  from  half  a  ton  to  a  frac- 
tion of  an  ounce.  There  is  little  doubt  these  masses 
formed  part  of  a  meteoric  shower,  although  no  record 
exists  as  to  when  the  fall  took  place.  Curiously  enough, 
near  the  centre,  where  most  of  the  meteorites  have  been 
found,  is  a  crater  with  raised  edges,  three-quarters  of  a 
mile  in  diameter,  and  about  600  feet  deep,  bearing  exadtly 
the  appearance  which  would  be  produced  had  a  mighty 
mass  of  iron  or  falling  star  struck  the  ground,  scattered 
in  all  directions,  and  buried  itself  deep  under  the  surface. 
Altogether  ten  tons  of  this  iron  have  already  been  col- 
ledted,  and  specimens  of  the  Canyon  Diablo  meteorite  are 
in  most  colledtors'  cabinets. 

An  ardent  mineralogist,  the  late  Dr.  Foote,  in  cutting 
a  sedtion  of  this  meteorite,  found  the  tools  were  injured 
by  something  vastly  harder  than  metallic  iron,  and  an 
emery  wheel  used  in  grinding  the  iron  had  been  ruined. 
He  examined  the  specimen  chemically,  and  soon  after 
announced  to  the  scientific  world  that  the  Canyon  Diablo 
meteorite  contained  black  and  transparent  diamonds. 
This  startling  discovery  was  afterwards  verified  by 
Professors  Friedel  and  Moissan,  who  found  that  the 
Canyon  Diablo  meteorite  contained  the  three  varieties  of 
carbon — diamond  (transparent  and  black),  graphite,  and 
amorphous  carbon.  Since  this  revelation,  the  search  for 
diamonds  in  meteorites  has  occupied  the  attention  of 
chemists  all  over  the  world. 

I  am  enabled  to  show  you  photographs  of  true  diamonds 
I  myself  have  extradled  from  pieces  of  the  Canyon 
Diablo  meteorite,  five  pounds  of  which  I  have  dissolved 
in  acids  for  this  purpose — an  adl  of  vandalism  in  the 
cause  of  science  for  which  I  hope  mineralogists  will  for- 
give me.  A  very  fine  slab  of  the  meteorite,  weighing 
about  seven  pounds,  which  has  escaped  the  solvent,  is  on 
the  table  before  you. 

Here,  then,  we  have  absolute  proof  of  the  truth  of  the 
meteoric  theory.  Under  atmospheric  influences  the  iron 
would  rapidly  oxidise  and  rust  away,  colouring  the 
adjacent  soil  with  red  oxide  of  iron.  The  meteoric 
diamonds  would  be  unaffedted,  and  would  be  left  on  the 
surface  of  the  soil  to  be  found  by  explorers  when  oxidation 
had  removed  the  last  proof  of  their  celestial  origin. 
That  there  are  still  lumps  of  iron  left  at  Arizona  is 
merely  due  to  the  extreme  dryness  of  the  climate  and  the 
comparatively  short  time  that  the  iron  has  been  on  our 
planet.  We  are  here  witnesses  to  the  course  of  an  event 
which  may  have  happened  in  geologic  times  anywhere  on 
the  earth's  surface. 

Although  in  Arizona  diamonds  have  fallen  from  above, 
confounding  all  our  usual  notions,  this  descent  of  precious 
stones  seems  what  is  called  a  freak  of  Nature  rather  than 
a  normal  occurrence.     To  the  modern  student  of  science- 


Chemical  News,  I 
July  l6,  1897.      ) 


Hypoiodous  A  cid  and  Hypotodides, 


27 


there  is  no  great  difference  between  the  composition  of 
our  earth  and  that  of  extra-terrestrial  masses.  The 
mineral  peridot  is  a  constant  extra-terrestrial  visitor, 
present  in  most  meteorites.  And  yet  no  one  doubts  that 
peridot  is  also  a  true  constituent  of  rocks  formed  on  this 
earth.  The  speftroscope  reveals  that  the  elementary 
composition  of  the  stars  and  the  earth  are  pretty  much 
the  same  ;  so  does  the  examination  of  meteorites.  In- 
deed, not  only  are  the  selfsame  elements  present  in 
meteorites,  but  they  are  combined  in  the  same  way  to 
form  the  same  minerals  as  in  the  crust  of  the  earth. 

This  identity  between  terrestrial  and  extra-terrestrial 
rocks  recalls  the  masses  of  nickeliferous  iron  of  Ovifak. 
Accompanied  with  graphite  they  form  part  of  the  colossal 
■eruptions  which  have  covered  a  portion  of  Greenland. 
They  are  so  like  meteorites  that  at  first  they  were  con- 
sidered to  be  meteorites  till  their  terrestrial  origin  was 
proved.  They  contam  as  much  as  I'l  per  cent  of  free 
■carbon. 

It  is  certain  from  observations  I  made  at  Kimberley, 
corroborated  by  the  experience  gained  in  the  laboratory, 
that  iron  at  a  high  temperature  and  under  great  pressure 
will  a<a  as  the  long-sought  solvent  for  carbon,  and  will 
allow  it  to  crystallise  out  in  the  form  of  diamond — con- 
ditions existent  at  great  depths  below  the  surface  of  the 
earth.  But  it  is  also  certain,  from  the  evidence  afforded 
by  the  Arizona  and  other  meteorites,  that  similar  con- 
ditions have  likewise  existed  among  bodies  in  space,  and 
that  a  meteorite  freighted  with  its  rich  contents,  on  more 
than  one  occasion  has  fallen  as  a  star  from  the  sky.  In 
short,  in  a  physical  sense,  Heaven  is  but  another  name 
for  Earth,  or  Earth  for  Heaven. 


A  NEW  FORM  OF  REFLECTING  TELESCOPE. 

By  CHARLES   LANE   POOR. 

Dr.  Poor  explained  some  experiments  that  he  has  carried 
out  in  grinding  and  polishing  a  new  form  of  parabolic 
mirror  for  refledling  telescopes.  The  mirror  is  a  portion 
of  a  paraboloid  of  revolution  cut  at  the  extremity  of  the 
latus  redum.  The  refleded  beam  is  at  right-angles  to  the 
incident  light ;  no  second  mirror  is  therefore  necessary  ; 
the  full  aperture  of  the  mirror  being  used. 

The  advantages  of  such  a  form  of  mirror  were  pointed 
out,  and  the  great  simplification  in  equatorial  mountings 
indicated.  The  declination  axis  becomes  the  telescope 
tube,  the  image  being  formed  at  the  intersedlion  of  the 
polar  and  declination  axis  and  is  always  in  the  same  posi- 
tion ;  the  observer  remains  at  rest  while  viewing  any  and 
every  part  of  the  visible  heavens.  No  dome  is  required. 
Other  advantages  were  indicated,  and  several  modifica- 
tions of  the  general  form  pointed  out — Johns  Hopkins 
University  Circular,  xvi..  No.  130. 


TESTIMONIAL  TO  PROF.  ATTFIELD,  F.R.S. 

An  interesting  ceremony  was  performed  on  Saturday 
afternoon  last,  the  loth  July,  when  Prof.  Attfield  was  pre- 
sented with  a  testimonial  on  the  occasion  of  his  retire- 
ment from  the  Chair  of  Praftical  Chemistry  in  the  School 
of  the  Pharmaceutical  Society  of  Great  Britain,  after 
having  occupied  the  position  for  thirty-four  years. 

The  testimonial  took  the  form  of  an  album  containing 
the  signatures  of  one  thousand  old  pupils  and  two  hundred 
other  friends  of  Prof.  Attfield,  a  silver  tray,  and  a  silver 
tea  and  ^coffee  service — all  of  which  were  suitably  in- 
scribed. 

The  presentation  was  made  at  Prof.  Attfield's  residence, 
at  Ashlands,  Watford,  where  Mrs.  Attfield  had  a  garden- 
party  and  reception.  We  trust  he  will  live  long  to  enjoy 
/the  rest  he  has  so  well  earned. 


HYPOIODOUS     ACID     AND     HYPOIODITES.* 

By  R.  L.  TAYLOR,  F.C.S. 

(Concluded  from  p.  20). 

Hypoiodous  Acid. 
So  far  as  I  have  been  able  to  ascertain,  it  has  always 
been  stated  that  all  attempts  to  obtain  hypoiodous  acid 
by  the  adtion  of  iodine  and  water  upon  mercuric  oxide 
have  failed,  and  that  nothing  but  iodic  acid  was  formed. f 
I  had  tried  the  adtion  once  more  with  the  aqueous 
solution  of  iodine,  and  had  apparently  been  as  unsuccess- 
ful as  ever.  I  had  succeeded,  as  I  believe,  in  obtaining 
the  acid  by  other  methods,  to  be  presently  described,  and 
had  noticed  the  curious  anomaly  that  the  free  acid,  or 
what  I  took  to  be  the  free  acid,  bleached  indigo  with  far 
less  energy  than  the  hypoiodites  described  in  the  first  part 
of  this  paper;  but  I  had  failed,  as  others  no  doubt  had 
frequently  failed,  to  obtain  any  bleaching  solution  by  the 
aftion  of  iodine  and  water  upon  mercuric  oxide. 

In  the  paper  already  referred  to  by  Walker  and  Kay, 
the  authors  state  that  they  "  made  a  solution  of  hypo- 
iodous acid  by  agitating  pure  aqueous  solution  of  iodine 
with  mercuric  oxide,"  filtered,  neutralised  with  potash, 
and  added  magnesium  sulphate,  so  obtaining  a  white  pre- 
cipitate. The  addition  now  of  a  few  drops  of  potassium 
iodide  stained  the  precipitate  brown.  This  certainly 
pointed  to  the  presence  of  a  hypoiodite,  which  would  be 
decomposed,  with  liberation  of  iodine,  by  potassium  iodide. 
I  thought  the  readion  might  possibly  be  due  to  iodic  acid, 
which  is  usually  said  to  be  the  sole  produdt  of  the  adion 
of  iodine  on  mercuric  oxide ;  but  experiment  convinced 
me  that  it  was  not.  Further  investigation  soon  showed 
that  hypoiodous  acid  is  really  produced  when  iodine  water 
is  shaken  up  with  mercuric  oxide  (the  precipitated  oxide 
is  far  the  best)  and  filtered.  Many  others  besides  Walker 
and  Kay  have  no  doubt  prepared  the  acid  in  this  way,  but 
failed  to  recognise  it.  The  explanation  is  that  the 
bleaching  adtion  of  the  free  acid  is  excessively  feeble  as 
compared  with  Schonbein's  solutions.  Contadl  with  the 
indigo  solution  for  a  long  time  causes  the  colour  slowly  to 
disappear,  but  the  addition  of  a  drop  of  alkali  immediately 
transfoi;ms  the  acid  into  as  strong  a  bleaching  solution  as 
Schonbein's  solutions. 

I  may  at  once  state  what  appears  to  me  a  possible 
explanation  of  what  seems  at  first  sight  a  most  extra- 
ordinary anomaly — that  a  free  acid  has  a  very  much 
feebler  oxidising  power  than  one  of  its  salts  !  When 
hypoiodous  acid  bleaches,  I  suppose  it  does  so  according 
to  the  following  equation  : — HOI  =  HI  +  0.  It  thus  pro- 
duces hydriodic  acid,  an  extremely  unstable  body  itself, 
and,  further,  a  compound  which  would  immediately  de- 
compose the  remaining  hypoiodous  acid.  On  the  other 
hand,  in  presence  of  an  alkali,  the  result  of  losing  oxygen 
would  be  to  produce  sodium  or  potassium  iodide,  both 
perfectly  stable  bodies,  and  with  any  tendency  to  decom- 


*  From  Uemoin  and  Proceedings  of  the  Manchester  Literary  and 
Philosophical  Society,  vol.  xli.,  Part  IIL 

+  So  long  ago  as  1845,  Kone  (Poggendorff's  Ann.,  Ixvi.,  p.  302) 
tried  the  experiment  of  shaking  up  precipitated  mercuric  oxide  with 
an  alcoholic  solution  of  iodine,  and,  from  the  t&6t  that  he  obtained  an 
unstable  solution  which  gradually  liberated  iodine,  and  from  analogy 
with  the  chlorin*  compounds,  he  concluded  that  hypoiodous  acid  was 
formed.  I  have  repeated  the  experiment,  and  there  certainly  appears 
to  be  a  hypoiodous  compound  produced  ;  the  alcohol  which  is  present, 
however,  interferes  with  the  reactions.  The  filtered  liquid  contains 
a  considerable  amount  of  mercury.  It  gives  a  yellowish  precipitate 
with  water,  and  if  a  little  alkali  is  added  to  this  it  possesses  very 
strong  bleaching  properties.  The  precipitate  produced  with  water 
dissolves  up  in  sodium  hydrate,  but  in  a  few  seconds  another  precipi- 
tate appears  which  is  manifestly  iodoform ;  at  the  same  time  the 
liquid  loses  its  bleaching  power.  This  appears  to  point  to  the  con- 
clusion that  the  formation  of  a  hypolodide  is  the  necessary  prelude  to 
the  formation  of  iodoform  (see  Van  Deventer  and  van  't  Hoff,  Chem. 
Central.,  1888,  p.  362).  On  account  of  this  rapid  change  in  presence 
of  an  alkali,  the  solution  does  not  give  the  cobalt  reaflion.  If  the 
precipitate  produced  by  water  in  the  alcoholic  solution  is  allowed  to 
stand  (or  some  hours,  scarlet  mercuric  iodide  separates  out.  The 
alcoholic  solution  is  moderately  stable,  but  it  gradually  liberates 
iodine  on  standfng. 


28 


Hypoiodous  A  cid  and  Hypoiodttes. 


I  Chkmical  News, 
t      July  i6   1897. 


pose  the  remaining  hypoiodite  counteradled  by  the 
presence  of  the  alkali.  Then  there  is  also  the  further 
consideration  that  apparently  hypoiodous  acid  can  only 
have  about  one-half  the  total  bleaching  power  that  a 
hypoiodite  will  have,  because,  as  soon  as  any  of  it  does 
bleach  it  produces  hydriodic  acid,  which  would  imme- 
diately decompose  an  equivalent  amount  of  the  remaining 
hypoiodous  acid.  (In  one  comparative  experiment  that  I 
made,  the  bleaching  power  of  the  free  acid  was  almost 
exadly  half  that  of  an  equal  volume  of  the  same  iodine 
solution  to  which  soda  had  been  added.  But  the  bleaching 
continued  for  two  hours,  so  that  the  eiTed  would  be 
complicated  by  the  spontaneous  decomposition  of  the  free 
acid). 

When  a  little  alkali  is  added  to  the  hypoiodous  acid 
prepared  in  this  way,  the  solution  behaves  almost  exadlly 
like  Schonbein's  solutions.  It  bleaches  strongly,  and 
some  determinations  I  have  made  with  the  standard 
indigo  solution  gave  a  bleaching  adion  equivalent  to  So 
per  cent  of  the  iodine  used, — that  is,  representing  40  out 
of  a  possible  50  per  cent  of  iodine  existing  as  hypoiodous 
acid.  This  result  again  is  confirmed  by  experiments  by 
Schwicker's  method,  only  in  the  case  of  this  solution, 
when  it  is  neutralised  by  an  alkali,  it  forms  nothing  else 
but  hypoiodite,  and  consequently  the  addition  of  soda- 
water  simply  liberates  hypoiodous  acid,  and  there  is  no 
separation  of  iodine.  In  order  to  complete  the  deter- 
mination potassium  iodide  has  to  be  added,  when  there  is 
an  immediate  liberation  of  iodine.  A  determination  by 
this  method,  which  is  probably  more  accurate  than  the 
bleaching  method,  gave  liberated  iodine  equal  to  go  per 
cent  of  that  originally  used,  so  that  45  out  of  a  possible 
50  per  cent  of  iodine  existed  in  the  solution  as  hypo- 
iodous acid. 

The  hypoiodous   acid  solution  to  which  a  little  alkali 
has  been  added  gives  a  precipitate  with  cobalt  solution, 
which  gradually  turns  brown  and  then  black,  and  an  im- 
mediate brown  precipitate  with  a  manganous  salt.     With 
silver  nitrate  it  gives  a  buff-colured  precipitate  similar  to 
the  one  I  had  previously  obtained  from  Schonbein's  solu- 
tions, but  in  this  case  of  course  it  will  not  be  mixed  with 
so  much  silver  iodide.     If  nitrate  of  silver  is  added  to  the 
solution  containing  the  free  acid  a  milkiness  is  produced, 
and  on  boiling  there  is  a  further  precipitate,  which  con- 
tains silver  iodide  and  iodate ;  the  iodate  can  be  dissolved 
■•ut  by  ammonia.     This  readtion  I  had  previously  noticed 
with  the  acid  prepared  in  another  way.     The  hypoiodous 
acid    is   manifestly   converted   into   hydriodic   and   iodic 
acids,  3HIO  =  2HI-t-HI03.     The  aqueous  solution  of  the 
free  acid  appears  to  be  moderately  stable.     When  it  de- 
composes, as  one  would  anticipate,  it  appears  to  do  so 
according  to  the  equation  given  above,  only  in  this  case 
the    two     acids    immediately    decompose     each     other, 
liberating  iodine.*     In  the  case  of  the  solution  made,  as 
described,  with  the  use  of  aqueous  solution  of  iodine,  the 
appearance  of  free  iodine  in  the  liquid  is  very  slow  ;  but, 
by  using  iodine-water  with  a  little  suspended  precipitated 
iodine,  a  much  stronger  solution  of  the  hypoiodous  acid 
is  obtained,  in  which  the  brown  colour  of  iodine  begins  to 
show  itself  within  a  minute  or  two  of  its  being  filtered. 
(It  appears  also  that  some  mercury  comes  through,  be- 
cause on  standing  for  some  hours  there  is  a  slight  deposit 
of  the  scarlet  iodide  of  mercury).      After   standing  for 
some  time,  this  solution,  which  manifestly  contains  free 
iodine  (carbon  bisulphide  shaken  up  with  it  is  coloured 
deep  violet),  gives  no  blue  colour  with  starch  until  the 
addition  of  a  drop  of  alkali,  or  until  it  has  been  exposed 
to  the  air  for  some  time.     If  a  little  of  the  mixture  of  the 
brown   solution   with    starch  is  poured   into    a   shallow 

*  It  will  be  somewhat  difficult  to  measure  the  rate  at  whieh  the 
hypoiodous  acid  decomposes.  Neither  of  the  two  methods  men- 
tioned in  the  text  for  estimating  the  amount  of  hypoiodite  is 
applicable  when  once  the  decomposition  of  the  acid  has  started,  be- 
cause each  of  ihem  would  require  the  preliminary  addition  of  a  little 
alkali,  and  this  would  at  once  convert  any  liberated  iodine  into 
iodide  and  hypoiodite. 


vessel,  or  is   poured  backwards  and  forwards  from  one 
vessel  to  another,  it  soon  turns  blue.* 

Some  time  before  obtaining  the  free  hypoiodous  acid  in 
the  way  described  above,  I  had  obtained  what  must  have 
been  either  the  acid  or  a  solution  of  its  silver  salt  by 
another  method.  It  was  pointed  out  by  Dancer  (Chem. 
Soc.  jfourn.,  xv.,  447)  that  hypobromous  acid  could  be 
obtained  by  the  a&ion  of  bromine-water  upon  solution  of 
nitrate  of  silver,  according  to  the  following  equation : — 
AgNOa-HBra-}- H2O  =  AgBr-1- HOBr-l- HNO3. 

Chlorine  adts  in  a  similar  way,  producing  hypochlorous 
acid.  A  solution  of  nitrate  of  silver  with  powdered 
iodine  appears  to  form  nothing  but  iodide  and  iodate  of 
silver ;  but  I  found  that  iodine  suspended  in  water  gave  a 
bleaching  liquid  when  shaken  up  with  solution  of  silver 
sulphate,  or  with  a  paste  of  silver  carbonate,  the  carbonate 
giving  the  better  result.  Wishing  to  obtain  some  quanti- 
tative results,  I  began  to  use  an  aqueous  solution  of  iodine, 
instead  of  having  it  merely  suspended  in  water.  Shaking 
up  this  solution  with  a  little  silver  carbonate  and  rapidly 
filtering,  a  liquid  is  obtained  which  contains  a  small 
amount  of  silver,  but  which  gives  all  the  reaiitions  which 
I  have  described  as  charadteristic  of  Schonbein's  solutions, 
complicated  a  little,  in  some  cases,  by  the  silver  which  is 
present.  It  bleaches  indigo  slowly,  but  much  more  rapidly 
than  the  acid  prepared  with  mercuric  oxide ;  it  also 
bleaches  cochineal  and  logwood,  and  oxidises  cobalt  and 
manganese  salts  in  presence  of  an  alkali.  The  adion  of 
the  iodine  upon  the  silver  carbonate  may  probably  be 
represented  by  the  following  equation  : — 

Ag2C03-f2l2+H20  =  2AgI-f2H0I-f-C02. 

If  a  drop  of  silver  nitrate  is  added  to  the  solution  and 
the  liquid  boiled,  a  yellow  precipitate  is  produced,  con- 
taining iodide  and  iodate  of  silver. 

I  made  many  attempts  to  ascertain,  by  various  methods, 
the  proportion  of  the  iodine  used  which  was  converted 
into  hypoiodous  acid.    I  filtered  the  liquid  into  an  acidified 
solution  of  potassium  iodide,  whereby  iodine  is  liberated, 
the  amount  of  which  I  estimated.     Another  method  tried 
was  to  allow  the  liquid  to  run  into  a  standard  solution  of 
sulphurous  acid,   and   then  to  find  the   amount  of  this 
which  was  oxidised.     The  results  were  not  satisfaftory, 
as  I  seldom  found  that  more  than  50  per  cent  of  the  iodine 
was  converted  into  bleaching  iodine.     I  have  reason  to 
believe  that  this  result  was  due  to  some  insoluble  hypo- 
iodite of  silver  being  left  in  the  precipitate.     Finally  I 
tried  the  standard  indigo  solution,  and  found  that  it  was 
possible  to   estimate  the   bleaching  power  even   in  the 
muddy  liquid  containing  the  excess  of  silver  carbonate 
and  the  silver  iodide  which  was  produced  in  the  readlion. 
Shaking  up  a  known  volume  of  the  iodine  solution  with 
silver  carbonate  and  immediately  running  in  the  indigo 
solution,  the  bleaching  adlion  indicated  about  50  to  5o  per 
cent  of  the  theoretical  amount ;  but  the  addition  of  a  few 
drops  of  dilute  sulphuric  acid  carried  the  bleaching  power 
still  further,  owing  no  doubt  to  the  decomposition  of  some 
insoluble  silver  hypoiodite  by  the  acid.     By  adding  the 
dilute  acid  immediately  after  shaking  together  the  iodine 
and  the  silver  carbonate,  a  bleaching  adion  was  obtained 
equal  to  from  90  to  95  per  cent  of  the  theoretical  amount. 
Subsequently  I  found  that,  with  the  aqueous  solution  of 
iodine,  nitrate  of  silver  reads  perfedly  well,  producing  a 
bleaching   liquid  which    gives   all  the   readions  already 
described,  complicated  a  little  by  the  presence  of  excess 
of  silver.     The   bleaching   adion,  immediately  after  the 
silver  nitrate  has  been  added,  indicates  95  per  cent  of  the 
theoretical  amount. 

The  solutions  prepared  by  the  use  of  these  silver  salts 


*  Dr.  A.  Harden  tells  me  that  he  has  found  that  a  mixture  of 
aqueous  iodine  and  iodic  acid,  in  certain  proportions,  behaves  in 
exaftly  the  same  way  as  the  above  solution.  It  is  known  that  iodine 
forms  no  blue  compound  with  starch  unless  an  iodide  be  present  ;  but 
I  can  oflTer  no  explanation  of  the  effeft  which  the  air  appears  to  have 
on  the  above  reaftion. 


^^uiy'ieS^**!    Volumetric  Determination  of  Zinc  by  Potassium  Ferrocyanide, 


29 


are  extremely  unstable  ;  that  made  with  the  silver  nitrate 
loses  go  per  cent  of  its  bleaching  power  on  standing  five 
minutes.  This  I  think  may  be  attributed  to  the  presence 
of  silver  in  the  solution,  and  to  the  tendency  of  the  iodine 
and  silver  to  form  the  insoluble  silver  iodide.  The  solu- 
tions prepared  in  this  way  are  considerably  more  sluggish 
in  their  bleaching  adlion  than  the  alkaline. hypoiodites,  but 
very  much  more  rapid  than  the  free  acid  prepared  by  the 
mercuric  oxide  method.  If  the  explanation  which  I 
suggested  for  the  difference  between  the  free  acid  and 
Schonbein's  solutions  is  corredt,  it  seems  to  me  that  it 
would  apply  in  this  case  as  well.  There  is  silver  present 
in  the  solutions,  and  therefore  when  the  bleaching  is 
finished  the  final  produft  will  be  silver  iodide,  a  much 
more  stable  body  than  hydriodic  acid. 

I  have  to  thank  Mr.  G,  P.  Varley,  B.Sc,  and  Mr.  J.  H. 
Wolfenden,  B.Sc,  for  assistance  given  me  in  some  portions 
of  this  work. 


ON   THE 

VOLUMETRIC     DETERMINATION     OF    ZINC 

BY    POTASSIUM     FERROCYANIDE. 

By  L.  L.  DE  KONINCK  aid  EUG.  PROST, 

(Continued  from  p.  26). 

E. — The  zincic  solution  is  placed  in  a  matrass  graduated 
to  200  c.c. ;  we  add  25  c.c.  of  ferrocyanide,  and  fill  with 
water  up  to  the  mark,  shake  well,  then  let  stand.  The 
precipitate  behaves  as  in  experiments  A  and  B.  After 
standing  three  hours,  we  take  100  c.c.  of  the  clear  liquid 
and  titrate  diredlly,  in  the  cold,  with  ferrocyanide  solu- 
tion, until  the  mixture  when  tested  with  uranium  gives  a 
very  faint  brown  tint,  even  if  the  test  is  repeated  after  a 
few  minutes.  Using  ii"30  c.c.  with  an  extra  two  drops 
of  ferrocyanide,  the  uranium  test  gives  a  distincft  colour- 
ation, showing  an  excess  of  the  reagent.  Total  ferro- 
cyanide used  for  25  c.c.  of  zincic  solution  : — 

25  +  (2X  li-3o)  =  47'6o, 

instead  of  50  c.c,  the  theoretical  quantity.  The  im- 
portance  of  this  test,  from  the  point  of  view  of  obtaining 
an  exadt  knowledge  of  the  rea(5tion,  decided  us  to  repeat 
it  under  slightly  difTerent  conditions. 

E'.  We  used  the  same  zincic  solution,  i  normal,  but  a 
solution  of  ferrocyanide,  i  normal  for  zinc, — that  is  to 
say,  corresponding  exa(5tly  to  that  of  zincic  chloride 
under  the  conditions  of  the  formation  of  K2Zn3Fe2Cyi2 : 
25  c.c.  of  the  zincic  chloride,  diluted  with  100  c.c.  of 
water  acidulated  with  hydrochloric  acid,  are  placed  in  a 
flask  graduated  to  200  c.c;  we  run  in  13  c.c.  of  ferro- 
cyanide, and  fill  with  water  up  to  the  mark.  The  precipi- 
tate is  very  gelatinous,  and  remains  so.  After  standing 
forty-eight  hours  it  has  not  changed,  and  still  occupies 
two-thirds  of  the  total  volume  ;  the  supernatant  liquid  is 
perfectly  clear. 

Filter  ofT  100  c.c.  of  clear  liquid  (I.).  That  part  of  the 
precipitate  remaining  on  the  filter  is  completely  removed; 
the  filter  is  washed,  and  the  washings  added  to  the  part 
remaining  in  the  fiask  (II.)  This  experiment  was  done  in 
duplicate. 

I.  To  determine  the  quantity  of  zinc  remaining  in  (1.) 
we  added  6  c.c  of  ferrocyanide.  After  digesting  for 
ftfteen  minutes  the  precipitate  becomes  of  an  opaque  white 
colour;  we  found  with  nitrate  of  uranium  the  presence  of 
an  excess  of  the  reagent,  which  is  titrated  back  with 
chloride  of  zinc. 

First  test.  Second  test. 

ZnCla  —  i  normal  used      ..     i'70  c.c  175  c.c. 

The  end  of  the  readlion  is  shown  very  sharply. 

II.  To  the  troubled  liquor  (II.)  we  first  add,  as  a  pre- 
liminary, 6  c.c.  of  ferrocyanide  ;  an  immediate  uranium 
test  gives  an  intense  readion,  but  after  a  few  instants  no 


readtion  at  all.  Add  a  further  2  c.c.  of  ferrocyanide ;  an 
immediate  test  again  gives  a  very  marked  readtion,  but 
after  a  few  seconds  only  a  faint  tint,  until,  after  a  further 
addition  of  i  c.c,  the  test  shows  an  excess  of  the  reagent 
even  after  standing  for  some  minutes. 

In  the  second  parallel  operation  we  used  at  once  g  c.c. 
of  ferrocyanide.  On  the  precipitate  becoming  white,  we 
titrated  back  with  zincic  chloride  after  a  lapse  of  twenty 
minutes. 

First  test.  Second  test. 

ZnClj  —  i  normal  used 


1-25  c.c. 


1-35  c.c 


The  end  of  the  readtions  was  not  so  distindtly  marked ; 
this  we  attribute  to  the  relatively  large  quantity  of  the 
precipitate. 

The  conclusion  to  be  drawn  from  the  experiments  E 
and  £'  is  that,  even  in  the  presence  of  a  large  excess  of 
zincic  salt  (50  and  48  per  cent),  the  precipitate  produced 
by  the  ferrocyanide  is  formed  principally  of  zincico- 
potassic  ferrocyanide,  but  contains  nevertheless  zincic 
ferrocyanide ;  this  latter  readts  with  the  potassic  salt,  and 
combines  with  it  so  as  to  form  KjZnsFegCyia. 

If  the  ferrocyanide  is  in  sufficient  proportion,  or,  better 
still,  in  excess,  the  precipitate  is  formed  exclusively  of  the 
compound  KaZusFejCyia.  At  the  moment  of  its  formation 
this  body  is  gelatinous,  and  readts  sharply  with  salts  of 
uranium;  but  it  aggregates  rapidly,  and  soon  gives  no 
further  such  readtion. 

Formed  in  presence  of  an  excess  of  zinc,  the  precipitate 
contains  a  small  proportion  of  zincic  ferrocyanide ;  that 
is,  at  least,  what  appears  to  result  from  the  last  experi- 
ment,  since  titration  only  detedled  respedtively  go'4,  Ji'J, 
and  70*8  per  cent  of  the  quantities  which  should  be 
present  if  the  precipitate  had  been  formed  solely  ot 
KaZngFezCyij. 

But  whatever  may  be  the  form  under  which  this  excess 
of  zinc  exists  in  the  first  precipitate,  it  still  readts  with 
the  ferrocyanide  in  such  a  manner  as  to  finally  produce 
KzZnsFejCyia,  but  without  doubt  more  slowly  than  if  it 
were  in  solution. 

IV.  Research  on  the  best  Method  of  Working  to  be  used. 

It  would  appear,  from  what  has  preceded,  that  the  re- 
adtion would  be  more  regular,  and  its  termination  more 
sharply  marked,  if  we  proceeded  in  such  a  manner  that 
the  ferrocyanide  should  be  always,  as  far  as  possible,  in 
excess  with  regard  to  the  zinc, — that  is  to  say,  if  we  added 
the  zincic  solution  to  the  ferrocyanide,  instead  of  running 
this  latter  into  that  containing  the  zinc  ;  this  has  already 
been  noted  by  Zulkowski.  To  efifedt  this  it  is  necessary, 
in  estimating  zinc,  either  to  operate,  by  inverse  titration, 
which  is  not  very  pradlicable,  or  else  to  titrate  back. 
This  method  of  working  has,  further,  an  advantage  ob- 
served by  Mohr  (Mohr-Classen,  1886,  p.  458)  of  letting  us 
know  when  we  are  approaching  the  end  of  the  readlion, 
this  being  shown  by  the  diminution  of  intensity  of  the 
colouration  produced  by  the  indicator,  while  in  diredt  ti- 
tration the  termination  is  shown  suddenly,  and  it  is  easy 
to  overshoot  the  mark. 

For  these  reasons  we  have  given  the  preference  to 
titrating  back. 

We  would  wish,  however,  to  mention  what  accuracy 
can  be  obtained  by  diredt  titration.  Our  experiments  in 
this  diredtion  having  soon  brought  us  to  the  conclusion 
that  titrating  back  is  much  more  preferable,  we  will  not 
go  into  much  detail,  but  will  content  ourselves  with  saying 
that  working  in  the  cold,  either  in  hydrochloric  or  acetic 
solution,  the  end  of  the  readtion  is  very  indistindt;  thus, 
as  we  have  already  shown,  the  drop  test,  done  imme- 
diately after  the  addition  of  the  ferrocyanide,  gives  a 
distindt  colouration,  diminishing  in  clearness  as  we  leave 
a  longer  time  between  the  addition  of  the  liquid  and 
taking  the  drop.  By  stopping  the  estimation  at  the  mo- 
ment when  the  nitrate  of  uranium  begins  to  show,  we,  as 
a  rule,  obtain  results  which  cannot  be  called  very  exadt, 
varying  considerably  with  the  conditions  of  the  experi- 


30 


Precipitation  of  Copper  by  Magnesium. 


Chkhicai.  News, 
July  i6,  J897. 


ment, — that  is  to  say,  with  the  state  of  the  precipitate  ; 
if  the  operation  is  carried  out  warm,  the  readion  is 
sharper.  By  working  slowly,  under  definite  conditions, 
especially  using  heat,  we  can,  however,  obtain  results 
which  might  be  considered  satisfactory  if  we  did  not 
possess,  in  "titrating  back,"  a  much  more  satisfadtory 
method. 

Titrating  back  with  permanganate  of  potash  has  already 
been  proposed  by  Renard  (Comptes  Rendus,  vol.  Ixvii., 
p.  450,  1868),  but  this  method  necessitates  the  removal  of 
the  precipitate  by  filtration,  and  the  zincic  or  zincico- 
potassic  ferrocyanide  reads  with  the  permanganate.  The 
back  titration  by  means  of  a  solution  of  zincic  chloride 
enabled  us  to  obtain  very  satisfadlory  results,  either  with 
solutions  of  salts  of  pure  zinc  or  with  minerals.  It  now 
remains  to  establish  by  experiment  the  most  favourable 
conditions  of  working. 

Influence  of  Time. — From  what  we  have  seen,  a  great 
deal  depends  on  whether  we  perform  the  "  touch  "  test  with 
nitrate  of  uranium,  immediately  after  the  mixture  of  the 
zincic  salt  and  the  ferrocyanide,  or  whether  we  wait  for  a 
few  minutes.  It  was  therefore  necessary  to  determine 
the  minimum  time,  aiter  which  the  test  gives  constant 
results. 

In  the  following  experiments  we  proceeded  each  time 
by  pouring  20  c.c.  ZnClji  i  normal,  into  a  mixture  con- 
taining— 

50  c.c.  ferrocyanide,  J  normal  for  zinc; 
10  c.c.  HCl,  5  normal; 
50  c.c.  AmCl,  at  20  per  cent ;  * 
100  c.c.  water. 

Back  titration  by  the  same  i  normal  solution  of  zincic 
chloride : — 

1.  Titration  done  as  rapidly  as  possible,  used  for  this 

5 "50  ZnCla;  total,  25*50. 

2.  Titration  done  at  once,  but  without  undue  haste, 

used  5'oo  ZnCls  ;  total  25'oo. 

3.  Titration  after  7*5  minutes,  used  4-65  ZnCla  ;  total, 

24-65. 

4.  Titration  after  15  minutes,  used  4-55  ZnCU;  total, 

24-55. 

5.  Titration  after  30  minutes,  used  4*55  ZnClj;  total, 

24"55- 

Fifteen  minutes  therefore  suffice  to  obtain  a  complete 
transformation  of  the  precipitate. 

Influence  of  the  Initial  Excess  of  Ferrocyanide. — We 
may  ask  if  a  notable  excess  of  potassic  ferrocyanide  is 
necessary  to  transform,  integrally  and  rapidly,  into  a 
double  cyanide  the  small  quantity  of  zincic  ferrocyanide 
which  seems  to  form  when  we  mix  the  alkaline  ferro- 
cyanide and  the  zinc  solution.  I'he  following  series  of 
experiments  answer  this  question  : — Five  solutions  were 
prepared,  each  containing,  as  in  the  preceding  series,  10 
c.c.  HCl,  5  normal ;  50  c.c.  AmCl  at  20  per  cent,  and 
100  c.c.  of  water ;  then  respe(5lively  5,  10,  15,  20,  and  24 
c.c.  of  ZnCla,  \  normal.  Into  each  was  run  50  c.c.  of 
^  normal  ferrocyanide,  and  titrated  back  after  a  quarter  of 
an  hour's  digestion.     This  required  respectively — 

19-50,  14-55,  9"5o.  4*45.  0-80  ZnCIa, 

or  a  total,  for  the  50  c.c.  of  ferrocyanide,  of — 

24-50,  24-55,  24-50,  24*45,  24-80  ZnOa. 

We  see  from  these  results  that  an  excess  corresponding 
to  5  c.c.  on  25,  or,  20  per  cent  is  quite  sufficient  to  produce 
the  transformation  in  fifteen  minutes.  The  only  result 
which  is  notably  away  from  the  average  is  that  where  the 
excess  of  ferrocyanide  corresponds  to  less  than  i  c.  of  the 
zincic  solution. 

Influence  of  the  Order  of  Mixing. — It   is   indifferent 
whether  the  zinc  solution  is  poured  into  the  ferrocyanide 


or  vice  versd.  We  have  in  many  assays,  worked  either 
one  way  or  the  other,  without  noticing  the  slightest  dif- 
ference in  the  results,  or  even  in  the  rapidity  with  which 
the  molecular  transformation  of  the  precipitate  takes 
place.     Special  tests  have  moreover  proved  it. 

Influence  of  Chloride  of  Ammonium. — In  each  of  the 
experiments  in  the  two  following  series  we  used  20  c.c. 
ZnClj,  i  normal ;  50  c.c.  of  ferrocyanide,  J  normal ;  10 
c.c.  of  hydrochloric  acid,  5  normal ;  and  150  c.c.  of  a 
mixture  of  water  and  a  20  per  cent  solution  of  ammonium 
chloride,  in  the  proportions  given  below,  titrating  back 
with  the  same  zincic  solution. 


Zi 

jClj. 

ZnClj 

Total. 

AmCl. 

H,0. 

Series  I. 

Series  II. 

Series  I. 

Ser.II. 

I. 

0 

150 

5*05 

— 

25-05 

— 

2. 

— 

— 

5'oo 

4-80 

25-00 

24-80 

3. 

25 

125 

475 

4-40 

2475 

24-40 

4- 

50 

100 

4-55 

4"33 

24-55 

24-33 

5. 

75 

75 

4-60 

424 

2460 

2424 

b. 

100 

50 

4-50 

4-10 

24-50 

24-10 

7- 

125 

25 

455 

4-05 

24-55 

25-05 

8. 

150 

0 

475 

3-85 

24-75 

23-85 

(To  be  continued). 

♦  We  showed  by  later  experiments,  described  further  on,  the 
influence  of  the  presence  of  chloride  of  ammonium;  we  added  it  in 
a  large  number  of  experiments,  so  as  to  get  as  near  as  possible  to 
the  conditions  of  mineral  analysis. 


PRECIPITATION   OF  COPPER  BY  MAGNESIUM. 
By  E.  G.  BRYANT. 

I  WAS  induced,  by  a  paragraph  in  the  South  Kensington 
Chemistry  Syllabus,  to  try  some  experiments  on  the  adtion 
of  magnesium  on  solutions  of  copper  salts,  and  though 
the  method  used  was  necessarily  extremely  crude,  the 
results  seemed  so  decisive  that  I  thought  they  might  be 
of  interest  to  others.  It  was  intended  that  the  work,  if 
successful,  should  be  attempted  by  mere  beginners  in 
practical  chemistry ;  therefore  the  method  used  was  made 
as  simple  as  possible,  all  filtering  being  dispensed  with. 
The  materials  used  were  commercial  magnesium  ribbon, 
copper  sulphate,  and  chloride.  The  magnesium  was 
thoroughly  cleaned  and  the  CUSO4  re-crystallised.  After 
precipitation,  the  copper  was  well  washed  by  decanta- 
tion,  dried,  and  weighed  either  as  copper  or  copper  oxide. 
My  experience  seems  to  show  that  it  is  easier,  unless  a 
furnace  or  foot  blowpipe  be  at  hand,  to  get  good  results 
with  metallic  copper  than  with  the  oxide,  as  an  ordinary 
Bunsen  takes  a  considerable  time  to  oxidise  even  a 
hundred  or  so  milligrms.  of  the  metal. 

To  show  the  degree  of  accuracy  which  may  be  obtained 
under  such  circumstances,  101-7  m.grms.  of  Cu  were  ob- 
tained by  placing  105-2  m.grms.  of  zinc  in  a  warm  solu- 
tion of  copper  sulphate,  which  gives  an  equivalent  of  62*8 
for  the  copper. 

I  have  made  a  large  number  of  experiments  with  mag- 
nesium and  copper  sulphate  and  chloride,  using  both 
dilute  and  concentrated  solutions,  at  about  18°,  50°,  and 
go°  C,  also  solutions  made  alkaline  with  ammonia  and 
sodium  hydrate,  but  invariably  with  unsatisfactory  results. 
The  copper  or  copper  oxide  obtained  varies  greatly  in 
amount,  but  is  never  much  above  70  per  cent  of  the  theo- 
retical quantity.  The  highest  results  were  given  by  hot 
concentrated  solutions ;  in  dilute  or  cold  solution  the 
process  required  hours  to  complete,  and  the  results  were 
under  50  per  cent.  In  every  case  a  considerable  amount 
of  hydrogen  was  generated,  and  more  or  less  of  the  mag- 
nesium became  oxidised.  The  magnesium  oxide  in  turn 
displaced  copper  hydrate,  so  that  a  greenish  sediment  was 
always  found  accompanying  the  precipitated  copper.  This 
result  by  itself  would  be  enough  to  prove  that  the  reaction 
was  not  a  quantitative  one.  Very  dilute  hydrochloric 
acid  was  used  to  dissolve  this  greenish  substance,  and  a 
small  quantity  of  the  copper  was  removed  at  the  same 
time  (not  more  than  8  to  10  per  cent). 


'Cbbmical  Nk^vs, 
Jaly  r6.  1897. 


Certain  Double  Halogen  Salts  of  Ccesium  and  Rubidium. 


31 


I  give  one  or  two  of  my  results : — 


Mg. 
0-055  grm. 

0-055     I. 
0-065     „ 


Cu.    Cu  (theoretical). 
0-079         0*144 


Strong  solution  at 
about  50°  C.  One 
hour  required. 

0*064  0-144  Strong  solution  at 
18°  C.  Several  hours. 

0-137  0*171  Cone.  sol.  at  about  80° 
C.  A  few  minutes 
only. 

The  [results  obtained  from  perfedtly  pure  magnesium 
might  be  very  different  from  the  above,  but  I  have  not 
been  able  to  use  any  but  the  commercial  metal. 

An  excess  of  magnesium  oxide  removes  every  trace  of 
oopper  from  solutions  of  the  sulphate  and  chloride,  and  a 
bluish  residue  is  obtained  containing  copper  hydrate  (?) 
and  magnesium  oxide.  It  settles  readily,  filters  easily, 
and  is  unchanged  by  long  boiling,  or  by  exposure  to  air 
or  water  for  some  weeks. 


ANALYSIS    OF   BRONZES    AND    BRASSES    BY 

THE    ELECTROLYTIC    PROCESS. 

By  A.  HOLLAND. 

The  objeft  of  this  communication  is  to  give  in  detail  the 
procedures  for  the  accurate  and  easy  determination  of 
copper,  tin,  zinc,  &c. ,  entering  into  the  composition  of 
bronzes  and  brasses. 

I.  Bronzes. 
Determination  of  Copper  [Electrolysis  in  Acid  Solution). 
— Five  grms.  of  alloy  are  treated  in  a  beaker  (Bohemian 
glass)  with  a  mixture  of  25  c.c.  nitric  acid,  at  sp.  gr.  I'Si", 
and  15  c.c.  concentrated  sulphuric  acid.  In  presence  of 
60  large  a  proportion  of  sulphuric  acid  the  tin  dissolves, 
at  least  in  part.  We  dilute  to  350°,  and  heat  the  liquid 
to  a  temperature  close  upon  ebullition,  keeping  it  at  this 
temperature  until  the  insoluble  part  which  contains  the 
tin  has  colledted  at  the  bottom  of  the  vessel.  We  thus 
obtain  a  perfedtly  clear  liquid,  into  which  we  can  plunge 
without  causing  turbidity,  the  platinum  cone  and  spiral 
serving  as  eledlrodes.  For  the  progress  of  the  eledtro- 
lysis  we  follow  the  indications  given  in  Comptes  Rendus, 
cxxiii,  p.  1003. 

Determination  of  Tin  {Electrolysis  in  Hydrochloric 
Solution,  with  the  addition  of  Ammonium  Oxalate). — The 
liquid,  free  from  copper,  is  evaporated  on  the  sand-bath 
until  there  remain  only  a  few  drops  of  sulphuric  acid. 
The  residue  is  taken  up  in  hydrochloric  acid  and  water, 
and  the  tin  is  precipitated  by  a  current  of  sulphuretted 
hydrogen  in  the  ordinary  manner.  The  tin  sulphide, 
washed  as  usual  with  a  solution  of  sodium  chloride,  is 
dissolved  in  yellow  ammonium  hydrosulphate,  and  this 
solution  is  evaporated  to  dryness  on  the  water-bath.  The 
residue  obtained  is  attacked  with  9  grms.  of  potasium 
chlorate  dissolved  in  water  and  an  excess  of  hydrochloric 
acid.  The  solution  of  tin  thus  obtained  is  again  evapor- 
ated to  dryness  on  the  water-bath,  and  the  residue  taken 
up  in  30  c.c.  of  hydrochloric  acid  and  water.  We  filter 
this  new  solution,  and  dissolve  in  it  30  grms.  of  pure 
ammonium  oxalate ;  and  lastly,  heated  to  about  90°  and 
eledrolysed,  using  a  current  of  07  ampere.  At  the  end 
of  twelve  hours  the  deposition  is  complete,  and  the 
deposit  is  strongly  adhesive. 

Determination  of  Zinc  by  Electrolysis. — The  liquid,  free 
from  copper  and  tin,  is  heated  to  expel  all  the  hydrogen 
sulphide  in  solution,  then  evaporated  to  dryness  on  the 
sand-bath  until  there  remain  only  a  few  drops  of  sulphuric 
acid.  The  zinc  sulphate  thus  formed  is  dissolved  in 
'Water,  neutralised  with  ammonia,  and  to  the  solution 
Ahere  are  added  15  grms.  of  ammonium  citrate  and  4  c.c. 


glacial  acetic  acid,  ammonia  up  to  neutralisation,  and, 
lastly,  3  c.c.  crystallisable  acetic  acid. 

The  bath  thus  obtained  contains,  besides  zinc  in  the 
state  of  sulphate,  ammonium,  acetate  and  citrate,  and 
acetic  acid.  It  is  exposed  for  about  twelve  hours  to  a 
current  of  o-6  ampere.  At  the  end  of  this  time  all  zinc 
is  deposited  upon  the  cone  as  a  very  adhesive  deposit. 

If  the  bronze  contains  iron,  this  will  be  deposited  with 
the  zinc,  in  part  at  least.  In  this  case  the  weight  of  the 
iron  (determined  by  permanganate)  is  deducted  from  the 
weight  of  the  zinc  thus  found. 

Lead,  which  is  often  met  with  in  bronzes,  is  deter- 
mined by  ele(ftrolysis  in  a  fresh  nitric  solution. 

II.  Brasses. 
Copper  is  determined  as  in  Comptes  Rendus,  cxxiii.,  p. 
1003.     The   determination   of  zinc  and  of  impurities  is 
effeded  by  the  procedures  given  above.— Cow^^ej  Rendus, 
cxxiv.,  p.  1451. 


ON    CERTAIN    DOUBLE    HALOGEN    SALTS    OF 

CfESIUM    AND    RUBIDIUM. 

By  H.  L.   WELLS  and  H.  W.  FOOTE. 

I.  The  Complicated  Rubidium-antimony  Chloride. 
Remsen  and  Saunders  [Am.  Chem.  yourn.,  xiv.,  155)  have 
described  a  salt  to  which  they  gave  the  formula 
23RbCl.ioSbCl3  as  the  most  probable  one.  Wheeler 
(Am.  yourn.  Set.,  xlvi.,  269),  working  in  the  Sheffield 
Chemical  Laboratory,  New  Haven,  confirmed  Remsen 
and  Saunders's  results  and  discovered  besides  an  an- 
alogous bromide,  to  which  the  probable  formula 
23RbBr.  ioSbBr3  was  given.  Remsen  and  Brigham  [Am. 
Chem.  yourn.,  xiv.,  174)  prepared  the  salt  23RbCl.ioBiCl3. 
Herty  [Am.  Chem.  yourn,,  xvi.,  490)  has  since  described 
the  two  potassium  salts,  23KCl.ioSbCl3  and 
23KBr.ioSbBr3.27H20,  and  some  mixtures  of  these  two 
salts. 

In  view  of  all  this  work  there  can  scarcely  be  a  doubt 
as  to  the  existence  of  a  type  of  salts  with  a  somewhat 
complicated  ratio,  but  in  view  of  the  fadt  that  this  com- 
plicated ratio  23  :  10  is  apparently  an  exception  to  the 
simplicity  of  composition  of  all  other  carefully  investi- 
gated double  halogen  salts,  the  subjedl  seemed  worthy  of 
some  further  investigation.  For  the  purpose,  we  have 
studied  only  the  rubidium-antimony  chloride  of  Remsen 
and  Saunders,  as  this  salt  is  readily  prepared  and  is 
capable  of  repeated  re-crystallisation  from  hydrochloric 
acid  solution. 

The  possibility  suggested  itself  that  the  produdt  might 
consist  of  two  simpler  salts  of  similar  or  identical  crys- 
talline form,  which  were  capable  of  crystallising  together, 
and  that  previous  investigators  had  made  use  of  condi- 
tions which  resulted  in  obtaining  a  constant  mixture  of 
two  such  salts.  Although  this  supposition  had  scarcely 
any  probability  in  view  of  the  existence  also  of  the 
rubidium-antimony  bromide  and  of  the  two  potassium 
salts,  we  have  put  the  question  to  test  by  repeatedly  re- 
crystallising  the  salt,  using  not  only  ordinary  dilute  hydro- 
chloric acid  for  this  purpose,  but  also  more  dilute  and 
much  more  concentrated  acid  and  also  an  alcoholic 
hydrochloric  acid  solution.  As  will  be  seen  from  the 
analyses,  given  beyond,  no  variation  in  composition 
could  be  detedted  by  the  use  of  these  widely  varying  sol- 
vents for  re-crystallisation,  and  it  therefore  appears  im- 
possible that  the  salt  can  be  a  mixture. 

As  a  starting-point,  we  used  a  solution  in  hydrochloric 
acid  containing  the  constituents  RbCl  and  SbCl3  in  the 
exadl  molecular  proportion  23  :  10.  Produdt  A  was  the 
first,  B  the  third,  and  C  the  fifth  re-crystallisation  from 
pure  dilute  hydrochloric  acid.  The  produdl  D  was  ob- 
tained  by  adding  concentrated   hydrochloric  acid  to   a 


32 


Certain  Double  Halogen  Salts  ofCcBsium  and  Rubidium, 


Chemical  NswSt 

July  l6,  1897. 


nearly  saturated  warm  solution  of  the  salt  in  dilute 
hydrochloric  acid.  E  was  obtained  from  a  very  strong 
hydrochloric  acid  solution  formed  by  passing  a  rapid  cur- 
rent of  hydrogen  chloride  gas  into  the  solution  as  it 
cooled.  F  was  obtained  by  re-crystallising  the  salt  from 
hydrochloric  acid  which  was  kept  as  dilute  as  it  could  be 
without  producing  the  basic  double  salt  to  be  described 
beyond.  G  was  a  produdt  abtained  by  re-crystallising  the 
salt  from  a  mixture  of  equal  volumes  of  dilute  hydro- 
chloric acid  and  alcohol. 

The  two  produdls  obtained  from  concentrated  hydro- 
chloric acid  solution  had  a  pale  yellow  colour,  while  the 
others  were  all  white.  The  crystals  were  usually  well- 
formed  six-sided  plates  which  showed  no  definite  optical 
properties. 

The  analyses  of  the  various  produds  are  as  follows  : — 

Rubidium.       Antimony.       Chlorine. 


A 3923  23-85 

B 39-23  2384 

C —  23-91 

D 39-25  23-98 

E 39-31  2389 

F 39-03  23-86 

G 39'ii  23-90 

Average      ..     ..  39*19  23-89 


37-01 
36-99 


37*00 


Method  of  Analysis. — For  the  determination  of  anti. 
mony  and  rubidium,  a  portion  of  about  i  grm.  was  dis- 
solved in  water  and  enough  hydrochloric  acid  to  prevent 
antimony  oxychloride  from  precipitating.  The  solution 
was  heated  to  boiling  and  hydrogen  sulphide  passed  in. 
The  solution  was  then  cooled,  and  the  antimony  sulphide 
filtered  on  a  Gooch  crucible  and  washed  with  water  and 
with  alcohol.  The  crucible  was  then  slowly  heated  to 
230°  and  cooled  in  an  oven  filled  with  carbonic  acid.  The 
precipitate  was  weighed  as  SbjSs.  The  filtrate  containing 
rubidium  was  evaporated  with  sulphuric  acid  and  the 
residue  ignited  in  a  stream  of  air  containing  ammonia, 
and  weighed  as  RbaSO^.  Chlorine  was  determined  by 
dissolving  a  separate  portion  in  water  acidified  with 
tartaric  and  nitric  acids  and  precipitating  with  silver 
nitrate.  This  was  allowed  to  stand  for  some  time  and 
the  precipitate  was  then  colledled  on  a  Gooch  crucible 
and  weighed.  The  methods  used  are  almost  identical 
with  those  of  Wheeler. 

The  accuracy  of  the  antimony  determination  was 
checked  in  the  following  manner  : — The  salt,  Cs3Sb2CIg, 
was  prepared  from  very  pure  materials  and  carefully  re- 
crystallised,  and  antimony  determined  by  the  above 
method.  The  per  cent  of  antimony  is  nearly  the  same  as 
in  the  rubidium-antimony  salt  under  consideration.  The 
following  results  were  obtained  : — 


Per  cent  Sb  found 
„  ,,    calculated 


I.  II. 

25-37     25-42 
2513       — 


III. 
25 '43 


IV. 
25-44 


The  atomic  weights  used  in  all  the  calculations  were 
Rb,  85-43  ;  Sb,  120-43  ;  CI,  35-45  ;  S,  32-07  ;  Ag,  107-92  ; 
Cs,  132-89. 

Since  the  method  used  for  the  determination  of  anti- 
mony gives  results  which  are  slightly  too  high,  we  believe 
that  a  dedudion  of  the  average  error  0-25  per  cent  from 
the  antimony  found  in  the  analyses  of  the  rubidium  salt 
will  give  a  result  which  is  nearer  the  truth. 


Average  previously  given  . . 
Average  with  correction  for  Sb 
Calculated  for  Rb23SbioClj3  . . 
Calculated  for  Rb7Sb3Cli6      . . 


Rb. 

39"i9 
39"i9 
3892 
39-18 


Sb. 
2389 
2364 
23-86 
23-66 


CI. 

37  "oo 
37-00 

37'22 

37-16 


It  may  be  noticed  that  the  results  agree  rather  more 
satisfatSorily  with  the  formula  7RbC1.3SbCl3  than  with 
the  more  complicated  one  advanced  by  Remsen  and 
Saunders.    The  differences  between  these  formulie  are, 


Calculated  for 

II. 

2RbCl.SbCI,.SbOC]. 

26-68 

2668 

37-36 

37-61 

32-80 

33*21 

316 

2-50 

however,  so  slight  that  it  is  probably  entirely  impossible  to  • 
decide  between  them  by  means  of  chemical  analysis,  the 
ratio  Rb  :  Sb  being  230  :  100  in  one  case,  and  in  the  other 
233  :  100.  However,  since  it  is  customary  to  use  the 
simplest  applicable  formula  for  a  chemical  compound,  we 
propose  the  formula  7RbC1.3SbCl3  for  this  salt,  and 
corresponding  formulae  for  other  salts  of  this  series. 
Herty's  hydrous  salt,  to  which  he  gave  the  formula 
23KBr.ioSbBr3.27H20,  agrees  well  with  the  formula 
7KBr.3SbBr3.8H2O.  It  must  be  admitted  that  the  7  :  3 
ratio  is  an  unusually  complicated  one,  but  it  is  far  simpler 
than  23  :  10,  and  is  scarcely  a  marked  exception  to  the 
general  simplicity  of  double  halogen  salts. 

2.  A  Rubidium-antimony  Oxychloride,  2RbCl.SbCl3.SbOCl. 

In  attempting  to  re-crystallise  the  salt  7RbC1.3SbCl3, 
from  very  dilute  hydrochloric  acid,  just  enough  to  prevent 
the  formation  of  antimony  oxychloride,  this  new  salt  was 
obtained  in  the  form  of  short  colourless  prisms  possessing 
a  rather  high  lustre.  It  can  be  re-crystallised  from  very 
dilute  hydrochloric  acid. 

The  following  results  were  obtained  from  analyses  of 
separate  crops : — 

I. 

Rb 26-54 

Sb 37*58 

CI 3275 

0(bydifl.)      ..       3-13 

It  is  interesting  to  notice  that  Benedi£t  {Proc.  Am. 
Acad.,  xxix.,  212)  has  described  the  potassium  salt 
2KCl.SbCl3.SbOCl,  which  corresponds  exaftly  to  this 
rubidium  compound. 

3.  The  Casium-bismuth  Chlorides  and  Iodides, 
The  double  chlorides  of  bismuth  with  caesium  have  been 
described  by  Remsen  and  Brigham  (Am.  Chem.  jfourn.y 
xiv.,  179).  These  authors  did  not  state,  however,  how 
widely  the  conditions  had  been  varied,  and  we  have 
repeated  the  work,  varying  the  proportions  of  caesium  and 
bismuth  as  much  as  possible,  and  have  found  exaAly  th& 
same  salts  as  described  by  them.     These  salts  are, — 

3CsCl.BiCl3 

3CsC1.2BiCl3 
3CsCi.BtC/3.— This  salt  forms  in  colourless  plates  when 
50  grms.  of  csesium  chloride  are  mixed  in  hydrochloric 
acid  solution  with  from  i  to  25  grms.  of  bismuth  chloride. 
The  analyses  were  made  on  samples,  dried  but  a  short 
time  in  the  air,  which  apparently  contained  a  little 
mechanically  included  water.  The  following  results  were 
obtained: — 

I. 

Bt 24*80 

Cs 47*94 

CI — 

3C5C/.2B/C/3.— When  50  grms.  of  bismuth  chloride 
are  mixed  with  from  i  to  80  grms.  of  caesium  chloride, 
the  salt  3CsC1.2BiCl3  crystallises  in  light  yellow  needles, 
sometimes  broadening  and  looking  like  plates  and  again 
much  shorter  and  thicker. 
The  following  analyses  were  made  : — 

Calculated  for 
I.  II. 

..      ..      36*99  36-58 

..      ..     34-69  34*94 


II. 

Calculated  for 
aCsCl.BiCl,. 

24*47 

25*36 
4866 
25-98 

Bi 
Cs 
CI 


3CsC1.2BiCI,. 

36-67 

35*17 
28-16 


3CsI.2Bil3.     Casium-bismuth  Iodide. 

We  could  obtain  only  one  double  iodide  of  bismuth  and 

caesium,  although  the  proportions  of  caesium  and  bismuth 

were  varied  greatly.      The  salt  formed  as  a  crystalline 

I  precipitate,  difficultly  soluble  especially  in  an  excess  of 


Cbbhical  MBW8,I 
July  i6, 1897.     I 


The  Chlorination  Process. 


33 


caesium  iodide,  when  i  grm.  of  bismuth  iodide  was  added 
to  50  grms.  of  caesium  iodide,  and  when  i  grm.  of  CKsium 
iodide  was  added  to  50  grms.  of  bismuth  iodide.  With 
an  excess  of  caesium,  the  colour  was  a  bright  red,  while 
with  an  excess  of  bismuth  the  colour  was  more  of  a 
reddish  brown. 

Methods  of  Analysis. — The  methods  here  given  were 
used  in  both  the  double  chlorides  and  iodide  of  bismuth. 

Halogens  were  determined  as  the  silver  salts,  being 
precipitated  from  a  solution  acidified  with  tartaric  and 
nitric  acids,  and,  after  standing,  filtered  and  weighed  on 
a  Gooch  crucible.  As  Remsen  and  Brigham  had  men- 
tioned a  difficulty  in  determining  bismuth,  we  made  a 
few  determinations  of  it  in  Bi203,  which  was  made  by 
precipitating  BiONOg  with  water  from  a  nitric  acid  solu- 
tion of  Bi{N03)3,  ^""^  heating  the  precipitate  to  constant 
weight  in  a  platinum  dish.  The  method  finally  adopted 
was  to  dissolve  the  substance  in  water  slightly  acidified 
with  hydrochloric  acid  and  precipitate  Bi2S3  from  the 
cold  solution  with  hydrogen  sulphide.  The  precipitate 
was  filtered  and  immediately  dissolved  in  nitric  acid  and 
digested  for  some  time  on  the  water-bath  until  completely 
decomposed.  The  sulphur  was  filtered  off  and  the 
filtrate,  diluted  to  about  300 — 400  c.c,  was  healed  and 
ammonium  carbonate  added  in  slight  excess.  It  was 
placed  on  the  water-bath  for  an  hour  or  two,  until  the 
liquid  had  become  nearly  clear  and  the  excess  of  ammo- 
nium carbonate  had  been  driven  off,  and  it  was  then 
filtered  on  a  Gooch  crucible  and  ignited  strongly  over  a 
Bunsen  burner  and  weighed  as  BijOg. 

Two  determinations  on  Bi203  gave  the  following  re- 
sults : — 

Grm.  Grm. 

I.  Amt.  Bi203  taken  =  o*ig79     Amt.  BiaOs  found  =  o'i974 
II.  „  „        =0*3604  „  „        =0-3617 

The  filtrate  from  the  bismuth  precipitation  was  evapo- 
rated with  sulphuric  acid  and  ignited  in  a  stream  of  air 
containing  ammonia.  The  residue  was  weighed  as 
CS2SO4. 

The  results  obtained  from  the  analysis  of  the  double 
iodide  were  as  follows  : — 

Calculated  for 
I.  II.  CsjBijIj, 

Bi 2i'34  2i'i5  2i'25 

Cs 2075  20'3i  20*38 

I       —  58"02  58-37 

— American  yournal  of  Science,  iii.,  No.  18,  June,  1897. 


PROCEEDINGS    OF    SOCIETIES. 

CHEMICAL    AND     METALLURGICAL    SOCIETY, 

JOHANNESBURG. 

May  15,  1897. 

After  a  few  remarks  on  Prof.  Christy's  paper,  read  at  a 
previous  meeting,  the  Society  proceeded  to  discuss  and 
comment  on  Mr.  Ehrmann's  paper  on  the  ^*  Precipitation 
of  Gold  from  Cyanide  Solutions." 

The  drift  of  the  discussion  was  as  to  the  advantage,  if 
any,  compared  with  the  increased  cost,  to  be  gained  by 
heating  the  solution  to  promote  rapid  precipitation; 
it  does  not  appear  to  be  at  all  certain  whether  there  is 
any  appreciable  quickening  of  the  process  during  the 
summer  months  as  compared  with  the  winter,  and,  as  is 
well  known  to  those  who  have  lived  in  the  country,  the 
range  of  temperature  is  very  great.  The  cost  of  heating 
large  quantities  of  solution  would  be  very  prohibitive. 

A  few  remarks  were  made  on  Dr.  Stockhausen's  paper 
on  •'  The  Liquation  in  Cyanide  Bars,"  and  Mr.  D.  J. 
Williams  then  read  a  few  notes  on  "  The  Estimation  of 
head  in  Slags  and  other  By  products." 


SOCIETE  D'ENCOURAGEMENT  POUR  L'lNDUS- 

TRIE   NATIONALE. 

yune  25,  1897, 

M.  Mascart,  President,  in  the  chair. 

After  reading  the  correspondence  and  hearing  the  reports 
of  the  committees  on  the  Mechanical  Arts  and  the  Eco- 
nomic Arts  a  communication  was  made  by  M.  Cheysson 
on  the  "  Insurance  in  French  Industries  against  Accidents." 
The  author  was  warmly  thanked  for  his  paper,  which  was 
ordered  to  be  inserted  in  ih&,Bulletin. 

The  President  delivered  a  long  discourse  on  the  pro- 
gress of  the  Society,  and  made  special  reference  to  absent 
and  foreign  members.  A  list  of  medals  and  prizes  awarded 
was  then  read,  and  the  meeting  adjourned. 


NOTICES  OF  BOOKS. 


The  Chlorination  Process.  By  E.  P.  Wilson,  E.M.  First 
Edition,  first  thousand.  New  York:  John  Wiley  and 
Sons.  London  :  Chapman  and  Hall,  Limited.  1897. 
Pp.  v — 125,  i2mo.,  111. 

Plattner  laid  the  foundation  for  the  process  of  extrading 
gold  from  its  ores  by  the  agency  of  chlorine,  in  1856,  and 
since  then  the  method  has  undergone  many  improve- 
ments. The  first  to  make  a  practical  and  commercial 
success  of  chlorination  was  Mr.  G.  F.  Deitken,  in 
California.  Mears  and  Theis  subequently  replaced  tank- 
lixiviation  by  barrel-chlorination,  and  the  latter  method 
of  treatment  prevails. 

Mr.  Wilson  has  written  very  clearly  and  explicitly, 
showing  familiarity  with  the  literature  of  the  subjedt,  and 
with  the  pradical  workings  of  many  American  works.  In 
successive  chapters  he  describes  the  preparation  of  the 
ore,  the  methods  of  roasting,  the  furnaces,  the  leaching 
process,  filtering  methods,  precipitation,  and  the  refining 
of  the  precipitated  gold  ;  the  final  chapter  is  devoted  to 
the  cost  of  chlorination. 

Mr.  Wilson  shows  a  great  deal  of  common  sense  in  his 
occasional  remarks,  as  in  the  following  paragraph  : — 
"  Some  wise  person  has  stated  that  '  all  is  not  gold  that 
glitters,'  and,  if  he  were  alive  and  a  miner,  he  could  have 
added  two  other  fadls  which  history  has  established,  viz.y 
that  all  gold-bearing  rocks  do  not  contain  gold  in  paying 
quantities ;  also,  that  some  gold-bearing  rocks  contain 
considerable  quantities  of  gold,  but  are  commercially 
valueless." 

Due  consideration  of  these  statements  might  have  pre- 
vented great  losses  in  gold-mining  ventures. 

Again  he  writes: — "The  chlorination  process  has  not 
been  more  generally  adopted  because  those  who  run 
mines  are  not  capable  of  carrying  it  on,  and,  knowing 
their  weakness,  let  it  alone.  And  parties  haying  mining 
machinery  to  sell  discourage  the  chlorination  process. 
Lastly,  mine-owners,  thinking  they  will  have  to  pay  higher 
salaries  to  good  men,  are  willing  to  suffer  loss  of  gold 
rather  than  do  so." 

The  book  has  been  written  in  a  style  intelligible  to 
mine-owners  as  well  as  to  students  of  metallurgy,  though 
the  interests  of  the  latter  have  been  regarded  by  the  intro- 
dudtion  of  chemical  equations. 

Mr.  Wilson,  in  common  with  so  many  writers  of 
English,  uses  the  French  word  resume  where  "  summary" 
will  serve  equally  well. 

This  little  work  forms  a  companion  volume  to  the 
author's  "  Cyanide  Processes."  The  book  is  well  printed 
on  good  paper,  and  contains  an  Index. 

^        ^  ^    '  H.  C.  B. 


34 


Chemical  Notices  from  Foreign  Sources. 


Chemical  mbws, 
July  i6,  1897. 


The  Agricultural  yournal.     Department  of  Agriculture, 
Cape  of  Good  Hope.    Vol.  x.,  No.  10,  May  13,  1897. 

A  GREAT  deal  of  this  number  is  taken  up  with  matter 
purely  of  interest  to  farmers  and  stock-breeders ;  some 
attention  is  being  paid  to  artificial  manuring,  as  the 
farmers  there  are  beginning  to  realise  that,  unless  the  pro- 
dudtion  can  be  increased,  farming  will  not  pay,  and  that 
what  is  taken  from  the  soil  must  be  returned  to  it. 

There  are  some  long  extradls  from  Dr.  Wm.  Newton's 
paper  on  Nitrates,  read  before  the  Liverpool  Meeting  of 
the  British  Association  last  year ;  and  some  further  re- 
marks by  Dr.  Dyer  on  the  use  of  sulphate  of  ammonia 
for  the  same  purpose. 

In  connexion  with  the  experiments  being  now  condu(£led 
in  the  colony  for  the  extirpation  of  Tcerya  Purchasi  (Aus- 
tralian bug)  and  scale  insedls,  by  the  introduftion  of 
ladybirds  from  California  and  Australia,  an  instrudtive 
communication  is  produced,  showing  how  entirely  success- 
ful the  same  experiment  has  been  in  the  Hawaiian 
Islands.  The  first  importation  was  made  in  1890,  when 
Vedalia  cardinalis  was  sent  over,  at  the  time  when  most 
trees  were  in  a  deplorable  condition  from  the  attacks  of 
Tcerya;  the  Vedalia  was  a  complete  success.  It  became 
perfe(5tly  naturalised,  increased  prodigiously  for  a  time, 
pradlically  cleared  the  trees,  and  then— as  the  Tcerya  be- 
came comparatively  scarce — decreased  in  numbers,  while 
at  the  present  time  it  is  evident  that  the  number  of  the 
scale  insedt  and  its  destroyer  has  arrived  at  a  fixed  pro- 
portion. The  ladybird  has  previously  done  excellent 
service  in  the  fruit  orchards  in  Lower  Cali*^ornia.  The 
effedt  is  not  imaginary,  but  proven.  In  June,  1895,  ^ 
lovely  forest  in  Hawaii — 5000  feet  above  sea-level — was 
found  to  be  much  affected  by  a  black  Aphis.  By  beating 
the  trees  the  blight  came  down  in  abundance.  One  or 
two  introduced  ladybirds  were  also  noticed.  By  September 
the  ladybirds  were  present  in  thousands, — the  blight  and 
native  insedts  in  small  numbers.  In  August,  1896,  not 
an  Aphis  was  to  be  found,  and  only  one  or  two  stray  lady- 
birds.    They  had  done  their  work  and  disappeared. 


Thirty  third  Annual  Report  on  Alkali,  SfC,  Works.  By 
The  Chief  Inspector.  London  :  Eyre  and  Spottis- 
woode.     1897. 

Following  the  appointment  of  an  additional  Sub- 
inspedlor,  there  has  been  a  re-distribution  of  distridt  areas, 
which  has  relieved  the  work  in  some  of  the  distridts.  The 
number  of  Works  now  registered  in  England,  Ireland, 
and  Wales  under  the  Adt  is  1074.  Of  these  98  only  are 
works  decomposing  salt,  and  so  scheduled  as  Alkali 
Works,  while  the  remainder,  976,  carry  on  processes  which 
are  scheduled  under  the  Adls  of  1881  and  1892.  These 
numbers  show  a  decrease  of  three  alkali  works  and  an 
increase  of  twelve  other  works  since  1895.  There  are 
also  125  works  registered  in  Scotland,  bringing  the  total 
number  registered  to  1199. 

There  has  been  one  prosecution  for  "  obstrudtion  " 
under  Sedlion  17  of  the  Adt  of  1881.  The  important 
point  was  that,  after  the  works  had  been  passed  for  regis- 
tration, on  the  basis  of  plans  supplied  by  the  proprietor, 
the  manager  had  carried  out  the  deception  of  the  by-pass 
pipes,  which  prevented  the  Inspedtor  from  examining  the 
effluent  gases.  The  works  in  question,  for  the  manu- 
fadture  of  carbon  bisulphide,  are  now  closed,  and  it  is  not 
likely  the  manufadture  will  be  resumed.  In  addition,  there 
were  five  cases  of  unregistered  works  being  carried  on  ; 
but  in  each  case  the  fees  were  accepted  by  the  Board,  it 
appearing  that  ignorance  existed  of  the  obligations  of 
the  Adt. 

The  amount  of  salt  decomposed  in  the  Leblanc  process 
again  shows  a  redudtion,  and  one  more  considerable  than 
has  occurred  since  1893.  On  the  other  hand,  the  ammonia- 
soda  process  has  largely  increased  its  lead  over  its  rival, 
obtained  for  the  first  time  last  year. 


A  new  departure  in  the  manufadture  of  chlorate  of  soda, 
a  salt  much  used  by  calico-printers,  has  taken  place  during 
the  year,  by  the  introdudtion,  on  the  large  scale,  of  Mr.  J. 
Hargreaves's  process  for  chlorinating  hydrated  sodium 
carbonate  diredtly,  in  an  absorbing  tower,  in  which 
lixiviation  of  the  produdts  to  remove  the  sodium  chloride 
is  also  condudled. 

There  has  been  an  increase  in  the  amount  of  ammonia 
recovered  and  made,  but  it  is  anticipated  that  in  a  few 
years  there  will  be  a  decrease,  owing  to  the  extensive 
adoption  by  gas  engineers  of  carburetted  water-gas  plant 
in  connedtion  with  gas  manufadture  in  many  parts  of  the 
country.  In  America  coal-gas  has  been  displaced  to  the 
extent  of  over  70  per  cent  by  carburetted  water-gas  ;  in 
this  manufadture  no  ammonia  is  produced. 


General  Index  to  the  Proceedings  of  the  Society  of  Public 
Analysts.  Compiled  by  J.  C.  Welch,  F.C.S.  London: 
Bailliere,  Tindall,  and  Cox.  1897. 
The  compiler  originally  commenced  this  work  for  his  own 
private  convenience,  but  the  allusion  to  this  subjedt  made 
by  Mr.  Otto  Hehner,  in  his  Presidential  Address  in  1893, 
led  him  to  offer  the  manuscript  to  the  Society  when  com- 
pleted to  the  end  of  the  twentieth  volume. 

The  thanks  of  public  analysts  generally  are  due  to  Mr. 
Welch  for  the  care  he  has  taken  and  the  time  he  has  ex- 
pended in  the  laborious  task. 


CORRESPONDENCE. 


THE   PREPARATION   OF  ZINC    ETHYL. 

To  the  Editor  of  the  Chemical  News. 
Sir,— In  the  last  issue  of  the  Chemical  News  (vol.  Ixxvi., 
p.  20)  there  appears  under  this  heading  an  abstradt  of  a 
paper  by  A.  Lachman  from  the  American  Chemical  your- 
nal. Mr.  Lachman  employs  a  copper-zinc  couple,  which 
he  prepares  by  mixing  zinc-dust  with  copper  oxide,  and 
then  reducing  the  copper  by  passing  hydrogen  over  the 
heated  mixture.  For  many  years  I  have  been  in  the  habit 
of  preparing  zinc  ethyl,  using  a  copper-zinc  couple  con- 
sisting  of  a  mixture  of  zinc  dust  and  copper  oxide,  without 
reducing  the  copper  oxide  to  the  metallic  state,  and  a  de- 
scription of  the  process  was  published  in  my  "  Chemical 
Ledure  Experiments  "  in  1892.  Such  a  mixture  ads  upon 
ethyl  iodide  with  extreme  readiness ;  I  have  perforrned 
the  entire  operation  of  preparing  zinc  ethyl  and  distilling 
it  off  during  a  ledture  of  an  hour. — I  am,  &c., 

G.  S.  Newth. 
Royal  College  of  Science,  London. 


CHEMICAL 


NOTICES    FROM 
SOURCES. 


FOREIGN 


NoTB.— All  degrees  of  temperature  ate  Centigrade  unle«i  otherwise 
expressed. 

Comptes  Rendus  Hebdomadaires  des  Seances,  deVAcademit 
des  Sciences.     Vol.  cxxiv..  No.  24,  June  14,  1897. 

Contribution  to  the  History  of  the  Phosphorias 
Iodides.— A.  Besson.— The  solution  appears  to  contain 
an  instable  compound,  P3I4,  which  is  the  pivot  of  the 
apparent  transformation  of  white  phosphorus  into  red 
phosphorus  by  the  adlion  of  iodine. 

Procedure  of  Oxidation  and  Chloridation.— A. 
Villiers.— When  an  oxidisable  body  occurs  in  a  medium 
capable  of  furnishing  oxygen,  but  under  such  conditions 


Chbmical  Nbws,  I 
July  i6, 1897.     I 


Chemical  Notices  jrom  Foreign  Sources, 


3=. 


that  the  oxidation  either  does  not  begin  at  all  or  takes 
place  very  slowly,  the  addition  of  a  trace  of  a  salt  of 
manganese  determines  the  reaction  or  accelerates  it  con- 
siderably. 

Splitting  up  of  the  Fundamental  Band  of  the 
Chlorophylls. — A.  Etard. — The  number  of  chlorophyll 
bands  and  the  wave-length  of  their  mean  axis  may,  by  the 
method  of  limited  dilutions,  be  counted  exa(5tly,  and  may 
serve  to  charadlerise  the  chemical  species.  The  diversity 
of  the  chlorophylls  is  demonstrated  by  the  wave-length 
of  the  axes  of  their  bands,  whether  pre-existing  or  in- 
duced by  the  aiftion  of  reagents.  The  fundamental  band 
of  the  chlorophylls  is  not  always  uniformly  obscure ;  it 
may  be  double  or  triple. 

On  the  Oxidising  A(5tion  of  Manganese  Salts,  and 
on  the  Chemical  Constitution  of  the  Oxidases. — G. 
Bertrand. — All  the  manganous  salts  which  the  author  has 
tried  possess  the  property  of  fixing  free  oxygen  uponhydro- 
quinone.  They  behave  in  the  same  manner  with  pyro- 
gallol,  paramidophenol,  and  other  kindred  bodies. 

A(5\ion  of  Nickel  upon  Ethylene.  Synthesis  of 
Ethane. — Paul  Sabatier  and  J.  B.  Senderens. — If  we 
dire(5t  a  mixture  of  equal  vols,  of  ethylene  and  hydrogen 
upon  nickel  recently  reduced  and  slightly  heated  (30°  to 
45"),  we  observe  a  notable  rise  of  temperature,  owing  to 
the  formation  of  ethane  ;  copper,  iron,  and  cobalt  cannot 
serve  to  effedt  this  synthesis. 

Isolauronolic  Acid. — G.  Blanc. — This  memoir  will 
be  inserted  at  length  if  possible. 

A(Jtion  of  Acetylene  upon  Silver  Nitrate. — R. 
Chavastelon. — CaHj  forms  with  silver  nitrate,  according 
to  the  nature  of  the  solvent,  C2Ag2.N03Ag  — CjAgj.  In 
future  communications  the  author  will  describe  a  pro- 
cedure for  the  determination  of  acetylene  applicable 
in  a  great  number  of  cases.  He  will  also  study  the  crys- 
talline compounds  of  acetylene  with  cuprous  chloride  and 
mercuric  chloride. 

Determination  of  Resin  Oil  in  Oil  of  Turpentine. — 
A.  Aignon. — The  author  gives  his  results  in  the  form  of 
a  table.  It  is  possible,  even  on  redifying  at  loo*  under  a 
pressure  reduced  to  o"o6  metre,  to  obtain  a  dextro-rotatory 
residue.  The  pure  oil,  if  treated  in  the  same  manner, 
gives  only  laevo-rotatory  residues. 

Adive  Principles  of  some  Aroids. — Mile.  Chau- 
liaguet,  A.  Hubert,  and  F.  Hein. — The  authors  have  not 
been  able  to  deteft  the  presence  of  hydrocyanic  acid. 
The  symptoms  of  poisoning  by  arums  and  the  appearances 
observed  on  autopsy  do  not  resemble  those  occasioned  by 
hydrocyanic  acid. 

Adtion   of   Albumoses    and    Peptones    on    Inter- 
vascular   Injedlion. — E.  Fiquet. — The    author's  results  ^ 
are  interesting  physiologically  rather  than  chemically. 


Revue  Unwerselle  des  Mines  et  de  la  Metallurgie. 
Series  3,  Vol.  xxxviii.,  No.  2. 
This  issue  contains  no  matter  of  chemical  interest. 


Rtvue  Oenirale  des  Sciences  Pures  et  Appliques. 
No.  10,  May  30,  1897. 
This  number  contains  no  original   matter  of    special 
chemical  interest. 


journal  de  Pharmacie  et  Chemie. 
Series  6,  vol  v.,  No.  11. 
Contribution  to  the  Study  of  the  Preparation  of 
Ordinary  Ether. — L.  Prunier. — In  the  study  of  the  pre- 
paration of  ordinary  ether  by  means  of  sulphuric  acid  and 
alcohol,  most  workers  have  omitted  to  take  notice  of 
the  presence  of  sulphonic  acids  and  their  derivatives. 
This  group  of  bodies  is,  however,  to  be  found  in  notable 


quantities  in  commercial  ethers.  It  is  also  found  in  con-- 
siderable  proportions  in  the  oils  which  have  been  used  in 
the  redtification  of  the  raw  produdl.  By  direft  experiment 
it  is  possible  to  prove  the  formation  of  several  sulphonic 
derivatives,  especially  towards  the  end  of  the  operation. 
To  separate  the  derivatives  adtually  formed  by  the  adtion 
of  sulphuric  acid,  it  suffices  to  heat  sulphovinic  acid  with 
dilute  sulphuric  acid  to  140°,  then  add  a  little  alcohol. 
By  this  means  a  small  quantity  of  ordinary  ether  is 
formed,  and  several  sulphonic  derivatives  of  varying 
volatilities,  some  of  which  even  distil  over  with  the  ether. 
They  are  formed  in  greatest  abundance  when  the  temper- 
ature exceeds  140°,  and  above  all  if  undiluted  sulphuric 
acid  be  used.  It  is  exadtly  the  same  as  in  the  prepara- 
tion of  ethylene  ;  if  the  operation  be  interrupted  when 
the  liquid  becomes  dark  (165°  to  175°)  we  can  at  that 
moment  detedt  the  presence  of  a  large  quantity  of  sul- 
phonic compounds  which  exist  in  the  liquid,  along  with 
the  sulphuric  acid  in  excess,  traces  of  sulphovinic  acid 
neutral  sulphuric  ether,  polyethylenic  compounds,  and 
also  sulphurous  acid. 

Researches  on  the  Composition  of  Extradls  of 
Meat.— J.  Bruylants. — It  has  long  been  admitted  that 
extradts  of  meat  contain,  as  proteic  substances,  but  a 
small  quantity  of  gelatin.  A  large  proportion  of  the 
nitrogen  belongs  to  other  proteic  substances,  albumoses, 
and  peptones  ;  that  is  to  say,  to  substances  whose  nutri- 
tive value  is  greater  than  that  of  albumides,  since  they 
have  already  undergone  some  of  the  modifications  due  to 
digestion.  The  result  of  the  examination  of  a  number  of 
different  samples  of  extradts  shows  that  Liebig's  extradl 
is  the  richest  in  the  most  nutrient  and  assimilable  sub- 
stances, though  dry  Bovril  is  not  far  below  it;  liquid 
Bovril  is  comparatively  poor. 

Method  of  Estimating  Aldehyd  in  Ether.— L. 
Francois. — Already  inserted. 

Different  varieties  of  Chestnuts.— M.  Balland.— Not 
suitable  for  abstradtion. 

Readtion  enabling  Naphthol-a  to  be  easily  Distin- 
guished from  Naphthol-j3.— E.  L6ger.— On  April  7th 
the  author  made  a  communication  on  the  adiion  of 
hypobromite  of  sodium  on  certain  phenols.  In  view  of 
the  fadls  therein  described,  he  prepares  from  the  supposed 
mixture  a  saturated  aqueous  solution  ;  this  solution,  when 
diluted  with  its  own  volume  of  water,  will  not  give  the 
naphthol-/3  readlion  with  2  drops  of  hypobromite,  but  if 
the  substance  under  examination  contain  naphthol-a  we 
get  a  violet  or  violet-rose  colouration.  By  this  means  it 
is  easy  to  detedt  i  part  of  naphthol-a  in  100  parts  of 
naphthol-3. 


Bulletin  de  la  Societe  Chimique  de  Paris. 
Series  3,  Vol.  xvii.-xviii..  No.  11.    June  5,  1897. 

Adtion  of  Hydrate  of  Chloral  on  Phenylhydrazine. 
Diphenylglyoxazol  and  its  Derivatives.  —  H.  M. 
Causse.  —  Hydrate  of  chloral  unites  very  easily  with 
phenylhydrazine,  forming  as  a  rule  a  crystalline  compound, 
but  sometimes  an  oil  denser  than  water  is  produced  ;  the 
crystals,  however,  are  very  unstable,  so  much  so  that 
analysis  is  impossible,  the  spontaneous  decomposition 
being  so  rapid.  The  author  has  therefore  been  obliged 
to  pass  over  the  intermediary  compounds  and  confine  his 
research  to  the  final  produdts. 

Monobromated  Camphor.  —  Ch.  Moureu.  —  Mono- 
bromated camphor  is  possessed  of  a  remarkable  stability  ; 
the  brown  appears  to  be  united  to  the  carbon  as  firmly  as 
in  aromatic  bodies.  Heated  to  200°  with  phosphoric 
anhydride,  an  energetic  readlion  takes  place,  tarry  pro- 
dudls  are  formed,  an  abundance  of  gas  is  given  off,  and  a 
liquid — fuming  very  strongly  in  contadt  with  air — is  dis- 
tilled over.  This  latter  has  been  found  to  be  tribromide 
of  phosphorus,  the  formation  of  which  is  of  great  inte- 
rest. 


r.6 


Iron  and  Steel  Institute, 


{Ohbuical  News, 
July  i6,  1S97. 


MISCELLANEOUS. 


Iron  and  Steel  Institute. — The  autumn  meeting  of 
the  Iron  and  Steel  Institute  will  be  held  at  Cardiff,  under 
the  presidency  of  Edward  Martin,  Esq.,  on  the  3rd,  4th, 
5th,  and  6th  of  August  next.  The  following  papers  will 
be  read,  and  members  wishing  to  take  part  in  the  dis- 
cussions will,  on  application  to  the  Secretary,  Mr.  B.  H. 
Brough,  have  copies  of  the  papers  forwarded  to  them  a 
week  in  advance,  as  far  as  that  may  be  possible  : — 

"  On   Passive  Iron."     By  J.  S.  de   Benneville  (Phila- 
delphia. 
"  On  the  Diffusion  of  Sulphides  through  Steel."     By 

E.  D.  Campbell  (Ann  Arbor,  Michigan). 
"  On  the  Manufafture  of  Tin  Plates."     By  George  B. 

Hammond  (Penarth). 

"  On  a  SpeiStroscopic  Analysis  of  Iron  Ores."    By  Prof. 

W.  N.  Hartley,  F.R.S.,  and  Hugh  Ramage,  Assoc. 

R.C.Sc.I.,F.I.C.  (Royal  College  of  Science,  Dublin). 

•'  On   Improvements   in    Shipping   Appliances    in   the 

Bristol   Channel."     By  Sir   W.  T.   Lewis,   Bart. 

Member  of  Council. 

"  On  the  Iron  Industry  of  Hungary."     By  D.  A.  Louis, 

F.I.C.  (London). 
*•  On  a  Thermo-chemical  Study  of  the  Refining  of  Iron.' 

By  Prof.  Honor6  Ponthiere  (Louvain). 
"  On  Carbon  and  Iron."     By  E.  H.  Saniter  (Wigan). 
"  On  some  Mechanical  Appliances  at  Penarth  Docks." 

By  T.  Hurry  Riches,  M.Inst.C.E.  (Cardiff). 
"  On  the  Application  of  Travelling  Belts  to  the  Ship- 
mentof  Coal."  By  Thomas  Wrightson,  M.Inst.C.E. 
(Thornaby-on-Tees). 
There    will    be,    as  usual,   a   number  of  excursions  to 
works  and  other  places  of  interest  in  the  neighbourhood, 
particulars  of  which,  together  with  the  full  programme  of 
the 'meeting,   may  be  obtained   from   the   Secretary,   at 
28,  Vidtoria  Street,  London,  S.W. 

Combustion  of  Nitrogen. — O.  Bleier  (Berichte). — 
Nitrogen  is  mixed  with  oxygen  in  the  proper  proportion, 
introduced  into  an  enamelled  autoclave,  or  other  suitable 
vessel,  containing  dilute  alkali,  and  an  excess  of 
detonating  gas  is  pumped  in.  The  mixture  is  exploded, 
and  the  oxides  of  nitrogen  are  removed  by  shaking  up 
with  alkali.  Detonating  gas  is  again  introduced,  and  the 
process  is  repeated. 

Royal  Institution.  —  A  General  Monthly  Meeting  of 
the  Members  of  the  Royal  Institution  was  held  on  the 
5th  inst.,  Sir  James  Crichton-Browne,  M.D.,  F.R.S., 
Treasurer  and  Vice-President,  presiding.  The  following 
were  eledled  Members: — H.  H.  Baird,  Ivon  Braby,  J.  M. 
Davidson,  M.B.,C.M.,  A.  C.  Hill,  B.A.,  J.  Y.  Johnson, 
L.  Kamm,  M.  E.  Stephens,  The  Rev.  Henry  Wace,  D.D., 
Julius  Wernher,  and  Henry  Wilde,  F.R.S.  The  Special 
Thanks  of  the  Members  were  returned  to  Sir  Andrew 
Noble  for  his  donation  of  ;^ioo  to  the  Fund  for  the  Pro- 
motion of  Experimental  Research  at  Low  Temperatures. 


NOTES    AND    QUERIES. 

f^*  Our  Notes  and  Queries  column  was  opened  for  the  purpose  of 
giving  and  obtaining  information  likely  to  be  of  use  to  our  readers 
generally.  We  cannot  undertake  to  let  this  column  be  the  means 
of  transmitting  merely  private  information,  or  such  trade  notices 
as  should  legitimately  come  in  the  advertisement  columns. 
Marking  Inks. — (Reply  to  "  Sulpho  "). — Ample  information  upon 

the  subject,  with   the   latest  recipes,  will   be  found  in  the  Second 

Series  of  Spon's  "  Workshop  Receipts,"  1890. — George  Turner,  5, 

South  Street,  E.O. 


Mr.  J.  a.  LORRAIN,  M.I.E.E.,  M.I.M.E,  M.S.C.I., 

Fellow  of  the  Chartered  Institute  of  Patent  Agents, 

Norfolk  House,  Norfolk  Street,  London,  W.C. 

"PAT£NT££'S  HANDBOOK"  Post  Free  on  applicaUon. 


DAVY  FARADAY  RESEARCH  LABORATORY 

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THE    ROYAL    INSTITUTION. 

Directors : 

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Professor  DEWAR,  M.A.,  LL  D.,  F.R.S. 

Superintendent  of  the  Laboratory : 
Dr.  Alexander  Scott,  M.A.,  D.Sc. 

T^his  Laboratory,  which  has  been  founded  by 

-^  Dr.  LuDWiQ  MoND,  F.R  S.,  as  a  Memorial  of  Davy  and 
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chemicals  as  may  bs  authorised. 

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forms  of  application,  can  be  had  from  the  Assistant  Secretary, 
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Estimation  of  Oxygen  dissolved  in  Sea-water, 


37 


THE    CHEMICAL    NEWS 


Vol.  LXXVL,  No.  1965. 


MIGRANT     MATTER. 
By  STEPHEN  H.  EMMENS  and  NEWTON  W.  EMMENS. 

On  the  5th  of  March,  in  this  year,  we  cut  a  circular  disc, 
I  inch  in  diameter,  from  a  thin  sheet  of  lead  purchased  as 
being  "chemically  pure"  and  showing  no  residual  metal 
on  cupellation.  We  also  cut  a  similar  disc  from  a  thin 
fiheet  of  silver  purchased  as  being  "  chemically  pure." 
These  discs  were  then  weighed  and  placed  in  contadt  with 
the  two  ends  of  a  short  spiral  of  copper  wire  of  known 
weight ;  and  the  system  thus  composed  was  suspended 
inside  a  wide-mouthed  glass  bottle  by  means  of  a  string 
depending  from  the  cork  and  passing  through  the  spiral 
and  central  holes  in  the  discs.  The  silver  disc  formed  the 
lowest  member  of  the  system. 

On  the  15th  of  March  the  bottle,  which  had  meanwhile 
stood  on  one  of  the  shelves  in  our  laboratory,  was  opened, 
and  the  discs  and  spiral  were  take  apart  and  weighed. 
They  were  then  replaced  as  at  first,  and  allowed  to 
remain  untouched  until  the  and  inst.,  when  they  were 
again  weighed. 

The  figures  (in  grms.)  of  the  three  weighings  were  as 

follows: — 

Lead.  Silver,  Copper. 

March  5    ..     o'Sgsi        0*50845        1-5421 

„      15    ..     0-8932        0-50830        1-5420 

June  2       ..     0*8932        o'5o8io        i'542i 

We  dissolved  the  copper  in  nitric  acid.  The  solution' 
on  being  tested  with  hydrochloric  acid,  gave  no  readlion 
for  silver.  But  the  lead  disc,  on  cupellation,  gave  a  silver 
bead  weighing  0*00003  grm. 

It  would  appear,  from  this  experiment,  that  what  is 
commonly  recognised  as  solid  silver  is,  in  part  at  least,  a 
migrant  mode  of  matter.  It  would  also  appear  possible 
that  the  gold  found  by  Prof.  Roberts-Austen  in  cylinders 
of  lead  which  had  been  standing  for  some  time  upon 
golden  bases  may  have  migrated  from  the  outer  surface  of 
such  bases  instead  of  travelling  through  the  interior  of 
the  metallic  column.  The  atmosphere  certainly  seems  to 
be  the  path  of  least  resistance. 

We  use  the  term  "  migrant  matter  "  because  the  travel- 
ling particles  to  which  we  refer  are  (in  common  with 
odours  generally)  much  more  akin  to  Crookes's  "  fourth 
form  "  than  to  gases. 

Argentaurutn  Laboratory, 
June  5, 1897. 


ON  THE 

ESTIMATION     OF    OXYGEN     DISSOLVED     IN 
SEA-WATER. 

By  ALBERT  LEVY  and  F.  MARBOUTIN. 

Some  time  ago  one  of  us  published  the  details  of  a  precise 
and  rapid  method  of  estimating  the  oxygen  dissolved  in 
waters.  It  having  been  in  constant  use  for  fifteen  years 
at  the  Observatory  at  Montsouris,  we  have  been  able  to 
follow,  week  by  week,  the  variations  existing,  from  the 
point  of  view  of  oxygen  dissolved,  in  waters  from  springs, 
rivers,  and  drainage.  The  method  consists  in  partially 
peroxidising,  by  the  help  of  the  oxygen  dissolved  in  the 
water,  an  excess  of  protoxide  of  iron,  and  completing  the 
oxidation  by  means  of  a  titrated  solution  of  permanganate 


of  potash.  We  have  described  in  the  different  Annals  of 
Montsouris  the  method  of  procedure,  and  have  each  year 
discussed  the  results  obtained.  This  method,  however, 
presented  several  difficulties  when  we  wished  to  apply  it 
to  the  analysis  of  waters  containing  much  chlorides,  such 
as  sea-water.  In  this  case,  at  the  moment  of  adding  the 
permanganate,  we  observe  a  disengagement  of  chlorine 
which  conduces  to  a  too  high  reading : — 

50  c.c.  fresh  water,  reading  22-80  c.  c.    No  chlorine. 

50  c.c.  fresh  water  -f-  50  c.c.  of  chloride  solution, 
reading  23*00  c.c.    CI  given  off. 

50  c.c.  fresh  water  +  100  c.c.  of  chloride  solution, 
reading  23*30  c.c.    CI  given  off. 

We  can,  however,  even  with  waters  high  in  chlorides, 
succeed  in  getting  good  results  with  permanganate,  by 
making  a  special  datum  of  comparison  for  each  water  and 
agitating  the  liquid  cautiously,  and  always  working  in  an 
identical  manner. 

But  we  prefer,  for  such  waters  high  in  chlorides,  to  re- 
place the  permanganate  by  bichromate  of  potash,  and  to 
determine  the  end  of  the  operation,  by  means  of  the  touch 
test,  with  ferrocyanide  of  potassium.  We  have  made  the 
following  observations: — 

I.  In  the  case  of  a  spring  or  river  water,  the  perman- 
ganate and  the  bichromate  give  precisely  the  same  result, 
and  this  result  is  identical  with  that  obtained  by  extracting 
the  gas  with  a  mercury  pump. 

Eau  d'Avre,  taken  10th  March,  1897,  from  the  Reservoir 
in  the  Rue  Villejust. 
Permanganate  method :  volume  of  water  95*2  c.c. 

Datum  ..  24*00  c.c.  Reading  ..   1730  c.c. 

In  I  litre  of  water, — 

24-00-17-30  X  J60-8     ..     ..     11-32  m.grms. 
95*2 
Bichromate  method :  volume  of  water  96*6  c.c. 

Datum  ..  23*80  c.c.  Reading  ..  17*000.0. 

In  I  litre  of  water, — 

23-80-17*00  ^  jg^.^     ^^ 


96*6 


11*26  m.grms. 


Oxygen  extradted  by  the    mercury    pump: — Amount 

operated  on,  364-8  c.c.  Oxygen  measured  at  0°  C.  and 
760  m.m.,  2*872  c.c. 

In  I  litre  of  water, — 


1-43  X 


2*873  X  1000 
3648 


11*26  m.grms. 


2.  The  oxygen  dissolved  in  sea-water  is  estimated  very 
exadly  by  the  use  of  bichromate,  in  spite  of  the  large 
quantity  of  chlorides  and  magnesian  salts. 

We  worked  on  a  sample  taken  in  a  carboy,  sent  from 
Concarneau  by  the  kindness  of  M.  Fabre-Domergue. 

Three  determinations  by  means  of  bichromate  gave, 
per  litre  of  water, — 


ist.  23-50~i7-40  ^  160.0 
102*6 

2nd.  ^3-50-i7-65   ^  ^q^'o 
98-3 

3rd.  .^3-50-i775  X  160-0 
96*6 


,.     9*52  m.grms. 


,.    9*52  m.grms. 


9*53  m.grms. 


Oxygen  extrafted  with  the  mercury  pump :  Amount 
operated  on,  364*800  c.c.  Oxygen  measured  at  0°  C.  and 
760  m.m.,  2*432  c.c. 

In  I  litre  of  water, — 

2*432  X  1000 


1-43  X^ 


9*51  m.grms. 


364-8 

When  waters  such  as  sea-water  contain  much  magne- 
sia, at  the  moment,  following  our  method,  when  we  make 
the  liquid  alkaline  with  potash,  we  see  the  magnesia  pre- 
cipitated in  the  form  of  little  cylinders  similar  to  grains 


38 


Volumetric  Dtterminatton  of  Zinc  by  Potassium  Ferrocyanide,    \ '^Y^'tyl'^^a^^'^ 


of  rice.  This  precipitate  in  no  way  interferes  with  the 
success  of  the  operation  ;  it  is  only  necessary  to  turn  the 
tube  holding  the  liquid  up  and  down  a  few  times,  so 
that  the  precipitate  may  be  equally  disseminated  through- 
out the  solution. 

Bichromate  retains   its   titration    almost    indefinitely. 
— Bull.  Soc.  Chitn.,  Series  3,  vol.  xvii.-xviii.,  No.  12. 


ON  THE 

VOLUMETRIC    DETERMINATION     OF    ZINC 

BY     POTASSIUM     FERROCYANIDE. 

By  L.  L.  DE  KONINCK  and  EUG.  PROST. 

(Continued  from  p.  30). 

The  two  series  were  done  at  an  interval  of  several  days, 
and  with  different  ferrocyanide  solutions  ;  that  used  for 
the  first  series  (Solution  A)  was  prepared  from  salt  puri- 
fied by  crystallisation,  the  other  (Solution  B)  from  ordinary 
commercial  ferrocyanide.  It  may  be  noted  that  the 
figures  of  the  second  series  diminish  more  regularly  than 
those  of  the  first ;  that  is  caused  by  the  reason,  that  in 
the  second  series  the  titration  back  was  not  done  until 
after  digestion  for  from  twenty  to  forty-five  minutes ; 
while  in  the  first,  no  account  was  kept  of  the  time — its 
influence  on  the  result  being  not  then  known  to  us. 

One  sees  that  the  influence  of  chloride  of  ammonium  is 
very  marked  ;  the  result  differs  considerably  according  to 
whether  the  solution  does  (Nos.  3  to  8)  or  does  not  (Nos. 
I  and  2)  contain  any,  but  within  the  ordinary  limits  of 
pradlical  working  (Nos.  3  and  4)  there  does  not  seem  to 
be  much  influence.  It  will  evidently  be  necessary  in 
making  estimations  in  the  presence  of  chloride  of  ammo- 
nium to  work  in  such  a  manner  that  the  quantity  of  this 
salt  should  be  as  near  as  possible  constant,  and  to  titrate 
the  ferrocyanide  in  presence  of  a  similar  quantity. 

We  are  unable  to  find  any  explanation  of  the  influence 
of  chloride  of  ammonium  in  showing  a  higher  relation 
between  the  ferrocyanide  and  the  zinc.  At  first  sight  one 
might  think,  as  with  hydrochloric  acid,  that  ferrocyanide 
being  slightly  soluble  in  the  reagent  in  question— in  this 
case  a  salt  of  ammonia — an  excess  of  ferrocyanide  would 
be  necessary  to  produce  a  complete  precipitation ;  but 
this  is  not  so,  as  a  very  simple  experiment  shows. 

By  dropping  2  drops  of  i  normal  ferrocyanide  into  15 
c.c.  of  water  to  which  has  been  added  i  drop  of  a  Jth 
normal  solution  of  neutral  zincic  salt,  a  hardly  noticeable 
cloudiness  is  produced,  while  if  we  repeat  the  experiment, 
but  substitute  a  20  per  cent  solution  of  ammonium 
chloride  for  the  water,  we  get  a  very  distincft  cloudiness. 
On  the  other  hand,  if  we  divide  the  liquid  of  the  first  ex- 
periment into  two  equal  parts,  then  add  to  one  10  c.c.  of 
water,  and  to  the  other  10  c.c.  of  20  per  cent  ammonium 
chloride,  we  notice  that  the  latter  becomes  distindly 
cloudy,  while  the  former  shows  no  change.  Thus, 
chloride  of  ammonium  favours  precipitation. 

The  end  of  the  reaction  is  very  distinctly  marked, 
especially  in  Experiments  3  to  6. 

Influence  of  Nitrate  of  Ammonium. — In  the  analysis  of 
minerals  one  is  liable  to  have  a  small  quantity  of  nitrate 
of  ammonia  present,  from  the  fadt  of  using  nitric  acid  in 
dissolving  the  sample  or  for  the  oxidation  of  ferrous  salts. 
We  thought  it  advisable  to  ascertain  the  influence  of  this 
salt. 

The  experiments  were  carried  out  by  using  20  c.c.  of 
J  normal  ZnCij,  50  c.c.  of  J  normal  A  solution  of  ferro- 
cyanide, 10  c,c.  off  normal  HCl,  50  c.c.  of  20  per  cent 
AmCl,  and  100  c.c.  of  water,  and  titrating  back  with 
chloride  of  zinc  after  digestion  for  fifteen  minutes. 


AraNOa. 
o  grm. 
2  grms. 
5      » 


ZnClj  back. 

4'55 
4-55 
4*55 


ZnCI,  total. 

24"55 
24-55 
24  "55 


The  end  of  the  experiment  was  perfedly  clearly  marked. 
We  see  thus  that  nitrate  of  ammonia  is  without  any  influ- 
ence whatever  within  these  limits,  and  we  did  not  think 
it  worth  while  pushing  the  experiments  any  further. 

Influence  of  Hydrochloric  Acid. — In  these  experiments 
we  used  20  c.c,  of  i  normal  ZnClz,  50  c.c.  of  J  norma! 
ferrocyanide,  50  c.c.  of  20  per  cent  AmCl,  and  no  c.c.  of 
water,  and  5  normal  hydrochloric  acid  in  the  proportions 
shown  below : — 


ZnCI 

I  back. 

ZnCl 

2  total. 

5  normal 
HCl.    Water. 

'    I. 

II, 

I. 

II. 

I. 

..      10          100 

5  00 

4-85 

25*00 

24-85 

2. 

. .      20           go 

4-8o 

471 

24-80 

24-71 

3- 

. .     30           80 

475 

4-56 

2475 

2456 

4- 

..     —           — 

4*6o 

— 

24-60 

5- 

. .      40           70 

440 

4-46 

24-40 

24-46 

b. 

..50           60 

4*20 

4-21 

24-20 

24-21 

7- 

..     —           — 

440 

— 

24-40 

— 

a. 

. .      60           50 

4"05 

3-91 

24-05 

23-91 

9- 

. .      70           40 

375 

372 

2375 

23-72 

As  in  the  case  of  the  experiments  with  chloride  of  am- 
monium, we  again  notice  the  difference  of  regularity  be- 
tween the  first  and  second  series ;  the  reason  of  this  differ- 
ence is  the  same  as  before ;  the  back  titration  of  the 
second  series  was  not  done  until  after  digesting  for 
twenty  minutes  in  the  case  of  No.  i,  to  forty  minutes  for 
No.  g;  while  in  the  first  series  the  back  titration  was 
done  immediately,  but  without  taking  any  note  of  the 
time  elapsing  between  the  addition  of  the  ferrocyanide 
and  the  titrating  back. 

It  is  obvious  that  the  influence  of  hydrochloric  acid  is 
similar  to  that  of  chloride  of  ammonium  ;  the  greater  the 
acidity,  the  more  ferrocyanide  there  is  required  to  com- 
pletely precipitate  the  zinc,  or  at  any  rate  to  show  with 
the  indicator. 

As  we  have  already  remarked  with  regard  to  ammonium 
chloride,  it  is  necessary,  in  order  to  obtain  very  exadb 
results  in  the  estimation  of  zinc,  to  use  a  solution  of  as 
near  as  possible  constant  acidity  for  the  estimations 
themselves,  as  well  as  in  the  titration  of  the  ferrocyanide. 

Influence  of  Sulphurous  Acid. — A  freshly-prepared  solu- 
tion of  ferrocyanide  of  potassium  has  hardly  any  colour^ 
but  after  some  time  it  assumes  a  yellowish  tint.  When 
we  make  an  estimation  of  zinc  with  such  a  solution,  we 
note — after  the  precipitate  has  entirely  settled — that  the 
liquid  also  has  a  distinct  yellow  colour.  This  colouration, 
which  Galletti  attributed  to  the  solution  of  zincic  ferro- 
cyanide in  the  acid  liquor,  is  due  to  ferricyanide.  This 
is  easily  shown  by  means  of  ferric  chloride.  When,  in 
the  analysis  of  a  mineral,  it  is  necessary  to  treat  the  so- 
lution with  hydrosulphuric  acid,  so  as  to  precipitate  the 
copper,  cadmium,  &c.,  we  ought  to  re-oxidise  the  salts  of 
iron  with  nitric  acid,  or  bromine,  and  then  only  precipi- 
tate the  iron  with  ammonia. 

When,  in  our  first  experiments  on  minerals,  of  which 
we  shall  speak  later  on,  we  used  nitric  acid  for  re-oxida- 
tion, in  the  ordinary  way,  we  found  that  the  resulting 
solution  had,  after  the  precipitate  had  settled,  a  yellow 
colouration,  considerably  more  intense  than  in  the  case  of 
minerals  which  had  not  been  subjeded  to  re-oxidation. 
We  were  easily  enabled  to  prove  that  this  phenomenon 
was  due  to  the  oxidation  of  a  part  of  the  ferrocyanide  by 
the  nitrous  acid  (Schaffer's  readlion.  Sill.  Amer.  yourn.. 
Series  2,  vol.  xii.,  p.  117,  1854;  see  also  Van  Deventer, 
Ber.,  xxvi.,  p.  sSg,  i8g3  ;  and  Van  Deventer  and  Jorgens 
ibid.,  g32).  This  latter  results  from  the  nitrite  of  ammo- 
nium formed  by  the  adlion  of  ammonia  on  the  nitrous 
compounds  produced  by  the  oxidation  of  the  ferrous  salts 
by  nitric  acid.  The  ammoniacal  filtrate  separated  froni 
the  ferric  hydrate  precipitate  contains  a  good  amount  of 
nitrite,  for  if  we  add  a  little  chloride  of  potassium  and 
then  acidulate  the  solution  it  shows  a  distincft  colour  front' 
the  iodine  set  free. 

Similar  phenomena  to  those  we  have  just  described  are- 


Chemical  News.  ) 
July  23,  1807.      { 


The  Solenoid  Electro-magnet. 


39 


roticed  if  we  use  an  excess  of  bromine  to  oxidise  the 
ferrous  salts,  and  then  precipitate  the  manganese  with 
the  iron  by  means  of  ammonia.  By  the  adtion  of  the 
ammonia  on  the  excess  of  bromine,  there  is,  without 
doubt,  a  little  hypobromide  or  bromate  of  ammonia  pro- 
duced ;  for  on  making  the  liquid  acid,  we  can  detedt  the 
presence  of  a  small  quantity  of  free  bromine,  and  if  we 
titrate  with  ferrocyanide  under  these  conditions  we  note 
also  the  formation  of  ferricyanide.  We  can,  however, 
get  over  these  difficulties  by  adding  a  small  quantity  of 
sulphite  of  soda  to  the  ammoniacal  solution  before 
making  it  acid.  Solutions  treated  in  this  manner  are, 
after  titration  and  when  the  precipitate  has  settled,  abso- 
lutely colourless. 

Before  recommending  the  use  of  sulphite  of  soda,  we 
thought  it  necessary  to  assure  ourselves  that  it  was  really 
innocuous.  That  we  did  in  the  following  manner: — We 
used  20  c.c.  of  i  normal  ZnClj,  100  c.c.  of  water,  and  15 
c.c.  of  5  normal  HCl.  We  then  added  50  c.c.  of  j  normal 
ferrocyanide  (A),  and  after  digesting  for  fifteen  or  twenty 
minutes,  we  titrated  back  with  zincic  chloride. 

A.  Without  the  addition  of  sulphite  of  soda  : — 

1.  ZnClg  back    465  c.c.  ZnCla  total    24*65 

2.  „        „        462    „  ,,        „        24-62 

B.  With  the  addition  of  10  c.c.  of  normal  sulphite  of 

soda  (12-5  grms.  Na2S03,7H20  per  litre)  to  the 
zincic  solution: — 

3.  ZnClj  back    4  6g  c.c.  ZnClz  total    2469 
4-        n          I.          470     ».  II  II         2470 

The  solutions,  after  the  sulphide  was  added,  smelt 
strongly  of  sulphurous  anhydride.  The  end  of  the  reac- 
tion showed  more  slowly,  but  as  distinctly,  with  sulphur- 
ised solutions  as  with  others,  only  the  brown  colouration 
of  ferrocyanide  of  uranium  is  less  distinct,  and,  in  the 
case  of  weak  solutions,  disappears  after  a  few  minutes. 
It  must  be  remembered  that  the  quantity  of  sulphite  here 
used  is  considerable,  and  corresponds  molecularly  to  the 
20  c.c.  of  ^  normal  ZnClj  on  which  the  experiments  were 
made,  while  in  ordinary  estimations  o'l  to  02  c.c.  of 
normal  sulphite  would  be  amply  sufficient.  It  is  evident 
that  in  this  proportion  its  adtion  on  the  indicators  would 
be  nil,  as  we  have  conclusively  shown. 

Influence  of  Bromine, — Although  itwould  appear  evident 
d  priori  that  the  adverse  influence  of  the  excess  of  bro- 
mine used  to  oxidise  the  ferrous  salts  might  be  neutralised 
by  means  of  sulphurous  acid,  we  thought  it  well  to  verify 
the  fadt  by  experiment. 

1.  20  c.c.  of  J  normal  ZnClz  were  made  alkaline  with 
10  c.c.  of  commercial  ammonia,  then  acidulated  with  30 
c.c.  of  5  normal  HCl.  We  then  added  100  c.c.  of  water, 
and  ran  in  50  c.c.  of  J  normal  ferrocyanide. 

2.  To  20  c.c.  of  i  normal  ZnClz  we  added  15  c.c.  of 
■water  saturated  with  bromine,  then  treated  it  with  am- 
monia, and  acidulated  with  30  c.c.  of  acid  ;  the  solution 
turned  a  deep  yellow.  The  bulk  of  the  bromine  was 
driven  ofif  by  boiling,  the  last  traces  were  got  rid  of  by  a 
few  drops  of  normal  sulphite  of  soda,  the  liquid  was  cooled, 
and  50  c.c.  of  J  normal  ferrocyanide  were  added.  The 
back  titration  with  chloride  of  zinc  gave — 

I.  ZnCIa  back    4*15  c.c.         ZnClj  total    24-45 
2«      i»        II        4*50    11  II        M       24-50 

The  use  of  bromine  has  therefore  no  influence,  or 
rather  it  is  neutralised  by  the  use  of  sulphite  of  soda. 

Influence  of  Nitric  Acid. — The  following  experiments 
were  carried  out  with  the  objedt  of  satisfying  ourselves 
that  the  addition  of  sulphite  of  soda  to  the  zincic  solu- 
tion would  neutralise  the  adtion  of  the  nitrous  acid,  which 
is  formed,  under  the  conditions  we  have  already  stated,  by 
the  oxidation  of  the  ferrous  salts  with  nitric  acid.  A 
cuprous  and  ferruginous  calamine,  of  which  five  assays 
were  made,  either  with  sodic  sulphide  or  with  ferrocyanide 
and  sodic  sulphite,  showed  a  proportion  of  23-94  to  24-39 
j)er  cent  of  zinc.    After  treatment  with  hydrosulphuric 


acid  and  re-oxidation  of  the  salts  of  iron  by  nitric  acid  it 
gave  the  following  results  : — In  a  preliminary  experiment 
in  duplicate,  30-84  per  cent  Zn  ;  in  a  second  31-32  and 
31*48  per  cent  Zn — either  an  error  of  more  than  7  per 
cent  of  the  mineral  or  of  nearly  29  per  cent  of  the  Zn 
present.  The  solutions,  after  the  deposition  of  the  pre- 
cipitate, were  of  a  very  deep  yellow  colour.  The  con- 
cordance of  the  results  obtained  with  this  sample  of  ore, 
on  the  one  hand  with  sulphite  of  sodium,  and  on  the  other 
with  ferrocyanide  and  the  addition  of  sulphite,  shows  that 
the  influence  of  the  nitrite  can  be  entirely  done  away  with 
by  this  latter  reagent.  We,  however,  made  a  special  ex- 
periment to  prove  it. 

We  used  a  5  normal  solution  of  nitrite  of  soda  (6'g 
grms.  per  litre)  and  a  normal  solution  of  sulphite  of  soda 
in  the  proportions  given  below. 

The  solutions  were  prepared  as  follows: — To  30  c.c.  of 
i  normal  zincic  chloride  we  added  the  sulphite  of  soda, 
the  nitrite  diluted  to  100  c.c.  with  water,  10  c.c.  of  20  per 
cent  chloride  of  ammonium,  10  c.c.  of  5  normal  hydro- 
chloric acid,  and  35  c.c.  of  ferrocyanide  of  potassium 
approximately  i  normal  for  zinc.  After  standing  not  less 
than  twenty  minutes,  we  titrated  back  with  the  zincic 
solution. 

NaNOj.  NajSO,.  ZnClj. 

i  normal.  Normal.  \  normal. 

I —  0*50.0.  3-94  C.c. 


2.       .. 

I  C.c. 

i-o 

3  93 

3-     •• 

2 

2*0 

3-90 

4.   .. 

••       5 

30 

388 

5*     .. 

..     10 

5-0 

3-90 

The  use  of  sulphite  thus  neutralises  the  adtion  of  the 
nitrite  absolutely;  the  final  solution  is  quite  colourless. 

Influence  of  Manganese. — Manganese,  which  is  some- 
times found,  though  in  small  quantities  only,  in  zinc  ores, 
requires  special  care  in  its  elimination.  It  has  been 
thought  that  in  acid  solutions  it  was  not  precipitated  by 
ferrocyanide,  and  was  therefore  without  influence. 

A  quantitative  experiment  is  sufficient  to  show  that  in 
order  to  prevent  the  precipitation  of  manganous  ferro- 
cyanide there  must  be  present  such  a  proportion  acid  as 
to  seriously  influence  the  precipitation  of  the  zinc  itself. 
However,  we  made  a  definite  experiment.  We  used  20 
c.c.  of  i  normal  ZnCla,  50  c.c.  of  J  normal  ferrocyanide, 
50  c.c.  of  20  per  cent  AmCl,  10  c.c.  of  5  normal  HCl,  and 
100  c.c.  of  water,  and  digested  for  fifteen  minutes. 

1.  Without  manganese       . .     . .     ZnCU  back    4-50  c.c. 

2.  With  0*0275  grm.  manganese        ,,        ,,        2*27    ,, 

The  manganese  thus  adted  on  the  ferrocyanide  the 
same  as  2-23  c.c.  of  i  normal  ZnCla-  The  quantity  of 
manganese  added  was  equal  to  2  c.c.  of  \  normal  solution, 
and  one  sees  that  this  metal  requires  for  its  precipitation 
at  least  as  much  ferrocyanide  as  zinc  does.  Manganese 
must  therefore  be  entirely  eliminated  before  titration. 

(To  be  continued). 


THE    SOLENOID    ELECTRO-MAGNET. 
By  H.  N.  WARREN,  Principal,  Liverpool  Research  Laboratory. 

This  powerful  type  of  eledlro-magnets,  which  after  a 
lengthy  and  exhaustive  research,  has  just  been  perfedled 
at  the  Research  Laboratory,  differs  from  all  other  magnets 
in  the  construdtion  of  the  iron  core ;  they  being  intended 
for  either  supporting  great  weights  in  general,  or  the 
accommodation  of  spherical  bodies,  for  which  reception  a 
hollow  cavity  is  cut  from  each  extremity,  the  sedtion  of 
each  cavity  representing  a  semicircle. 

For  the  construdtion  of  the  iron  core,  iron  oxides,  free 
from  sulphides,  silicates,  and  carbonaceous  matter,  were 
selected,   and  reduced  in  an  atmosphere  of  hydrogen, 


40 


London  Water  Supply, 


ICbbuical  Mbw8, 

I       July  23,  1807. 


puddled  through  a  hot-blast  Siemens  furnace,  and  drawn 
into  bars ;  the  bars  are  next  imbedded  in  quicklime, 
brought  to  a  full  white  heat,  and  allowed  to  cool  in  that 
substance.  After  cooling,  each  limb  before  yoking  is 
drilled  to  within  half  an  inch  of  its  circumference  and 
one-quarter  of  its  total  length  (if  the  bar  be  less  than 
half  inch  from  starting,  a  corresponding  allowance  has 
naturally  to  be  made). 

The  following  diagram  illustrates  the  sedtion  of  a 
magnet  with  its  accompanying  keeper,  the  separate  parts 
being  further  described  in  the  specified  table.  The  magnet 
was  construdled  to  suspend  a  weight  of  10  tons,  and 
required  to  be  excited  by  a  current  obtainable  from  25 
boron  carbon  cells  only. 


D 


The  subjoined  table  will  better  explain  a  few  of  the 
more  important  magnets  thus  construdled,  and  giving 
approximate  quantities  of  their  component  parts  : — 


Length  and  diameter 

Weight 

Voltage 

Weight 

of  core. 

of  primary. 

required. 

supported 

2  inches 

X      J 

4  ozs. 

6 

8  lbs. 

6      ., 

X     i 

lib. 

10 

80    „ 

28      „ 

X    2 

g  lbs. 

50 

5  cwts. 

28      „ 

X  4 

100  „ 

50 

2  tons. 

36      „ 

X   4t 

112  „ 

50 

10    „ 

iS,  Albion  Street,  £verton.  Liverpool. 
Liverpool  Research  Laboratory, 


From  the  above  diagram  it  will  be  readily  observed 
that  when  the  keeper  is  applied  with  its  two  iron  pro- 
jedlions,  B  B,  which  are  construdled  of  such  dimensions 
as  to  exadlly  coincide  with  the  openings  A  a  ;  not  only  s 
the  magnetic  power  fully  utilised,  but  any  side-slipping  of 
the  keeper  is  absolutely  impossible.  All  the  magnets  thus 
described  were  wound  with  No.  14  double  cotton-covered 
wire,  the  winding  afterwards  being  covered  with  paraffined 
insulation,  wound  with  thread,  and  varnished  with  best 
eledlro  shellac  varnish  :  they  are  at  present  doing  excel- 
lent service  in  researches  on  dimagnetism  and  polarisa- 
tion of  light. 


LONDON    WATER   SUPPLY. 
Report  on  the  Composition  and  Quality  of  Daily 
Samples   of  the  Water  Supplied  to   London 
FOR  the  Month  Ending  June  30TH,  1897. 

By  WILLIAM  CROOKES,  F.R.S., 

and 

PROFESSOR  DEWAR,  F.R.S. 

To  MAJOR-GENERAL  A.  De  Courcy  Scott,  R.E., 
Water  Examiner,  Metropolis  Water  Act,  1871. 

London,  July  loth,  1S97. 
Sir, — We  submit  herewith,  at  the  request  of  the 
Diredlors,  the  results  of  our  analyses  of  the  168  samples 
of  water  colledled  by  us  during  the  past  month,  at  the 
several  places  and  on  the  several  days  indicated,  from  the 
mains  of  the  London  Water  Companies  taking  their 
supply  from  the  Thames  and  Lea. 

In  Table  I.  we  have  recorded  the  analyses  in  detail  of 
samples,  one  taken  daily,  from  June  ist  to  June  30th 
inclusive.  The  purity  of  the  water,  in  respedl  to  organic 
matter,  has  been  determined  by  the  Oxygen  and  Com- 
bustion processes ;  and  the  results  of  our  analyses  by 
these  methods  are  stated  in  Columns  XIV.  to  XVIII. 

We  have  recorded  in  Table  II.  the  tint  of  the  several 
samples  of  water,  as  determined  by  the  colour-meter 
described  in  a  previous  report. 

In  Table  III.  we  have  recorded  the  oxygen  required  to 
oxidise  the  organic  matter  in  all  the  samples  submitted 
to  analysis. 

Of  the  168  samples  examined  all  were  found  to  be  clear, 
bright,  and  well  filtered. 

The  rainfall  at  Oxford  during  June  was  I'y  inches;  the 
average  for  the  last  30  years  is  2*68  inches;  this  leaves 
a  deficiency  of  o'gS  inch  on  the  month,  making  an  adlual 
excess  of  o'o6  inch  for  the  year,  on  a  fall  of  ii"37  inches. 

The  results  of  our  badleriological  examinations  of  230 
samples  are  recorded  in  the  following  table ;  we  have  also 
examined  and  reported  on  34  other  samples  taken  at  various 
places,  such  as  stand-pipes,  and  different  filter-beds  : — 

Microbes 
per  c.c. 
Thames  water,  unfiltered  (mean  of  24  samples)  73893 
Thames  water,  from  the  clear  water  wells  of 
five  Thames-derived  supplies  (mean  of  112 

samples) 74 

Ditto        ditto  highest      558 

Ditto        ditto  lowest  6 

New  River,  unfiltered  (mean  of  24  samples)  . .     2005 
New  River,  filtered  (mean  of  23  samples)      . .         69 
River  Lea,  unfiltered  (mean  of  24  samples)   ..  66822 
River  Lea,  from  the  clear  water  well  of  the 
East  London  Water  Company  (mean  of  23 
samples) 


69 

The  remarks  made  last  month  as  to  the  impossibility 

of  comparing  microbial  estimations  on  the  same  water  by 

I  different  experimenters  unless  the  samples  were  taken  at 

*  the  same  time  and  place,  and  the  subsequent  processes 


*^"ry2"S7T''*}    Behaviour  of  Chloral  Hydrate  with  Ammonium  Sulphide, 


41 


of  treating  the  samples  for  plate  cultivation  of  baderia 
were  absolutely  identical,  are  strikingly  borne  out  by  a 
report  recently  addressed  to  the  London  County  Council 
by  their  chemist,  where  stress  is  laid  on  a  great  discre- 
pancy between  the  numbers  given  by  Sir  Edward  Frank- 
land  and  ourselves. 

A  discussion  of  differences  of  this  kind  will  only  be 
possible  when  all  the  analysts  adopt  the  same  method  of 
badteriological  cultivation. 

Samples  of  raw  river  water  show  continual  variations 
according  to  the  season,  atmospheric  conditions,  and 
rainfall.  For  instance,  on  June  8th  we  found  in  the 
Thames,  270,320  microbes  per  c.c,  and  on  the  gth  9920. 
On  the  loth  we  obtained  982,080,  and  on  the  nth  58,640. 
In  the  river  Lea  on  June  14th  we  found  over  1,500,000 
microbes  per  c.c:  on  the  i6ch,  240;  on  the  17th,  120; 
and  on  the  i8tb,  9920. 

We  take  several  samples  daily  and  give  the  averages. 
Other  chemists  taking  samples  once  a  week  or  once  a 
month  could  not,  unless  by  mere  chance,  hit  upon  the 
averages  we  record. 

We  are.  Sir, 

Your  obedient  Servants, 

William  Crookes. 
James  Dewar. 


NOTES    ON    LUCIUM. 
By  WALDRON   SHAPLEIGH. 


In  May  of  last  year  I  secured  several  samples  of  the  so- 
called  "  lucium  "  which  had  been  prepared  by  Dr.  Leon 
Schiitzenberger,  of  Paris,  and  at  the  same  time  saw  a 
report  in  which  this  chemist  gave  very  fully  the  methods 
which  he  used  in  preparing  it,  and  his  conclusions  regarding 
the  same,  also  samples  of  the  monazite  sand  used. 

The  methods  he  employed  follow  very  closely  those  set 
forth  in  the  patent  of  Mr.  P.  Barriere. 

The  monazite  sand  was  a  low-grade  North  Carolina 
sand,  containing  minerals  rich  in  titanium,  zirconium,  and 
yttrite  earths,  such  as  menaccanite,  rutile,  zircon  crystals, 
samarskite,  euxenite,  and  xenotime,  and  it  is  probable  that 
from  the  last  three  minerals  the  "  lucium  "  is  obtained. 

On  experimenting  with  a  solution  of  the  lucium  nitrate 
the  ignited  ash  or  residue  I  found  to  be  of  a  dirty  grey 
colour,  and  nearly  entirely  soluble  in  hydrochloric  and 
nitric  acids  even  when  diluted.  This  solution  was  clear 
and  pink,  and  gave  the  absorption  bands  of  erbium.  As 
the  time  recommended  by  Mr.  Barriere  for  digesting  with 
the  potassium  sulphate  for  the  separation  of  the  cerite 
group  seemed  to  be  rather  short,  I  saturated  the  solution 
with  potassium  sulphate  in  the  cold  and  allowed  it  to  stand 
forty-eight  hours,  thereby  obtaining  a  precipitate  con- 
sisting oi  the  cerite  group,  and  in  the  solution  the  yttrite 
group.    Analysis  showed: — 

Yttrite  group  oxides 93*98 

Lanthanum,  cerium,  didymium  oxides  ..  3*74 

Thorium  oxide 107 

Titanium,  zirconium,  potassium,  sodium 
oxides,  and  sulphuric  acid,  not  sepa- 
rated    1*21 


The  oxides  of  the  yttrite  group  after  this  thorough  puri- 
fication by  potassium  sulphate  were  of  a  light  buff  or  yellow 
colour,  fully  and  completely  soluble  in  dilute  acids.  Sodium 
hyposulphite  did  not  give  a  precipitation  in  a  fairly  con- 
centrated solution,  nor  was  there  any  difificulty  in  making 
a  partial  separation  of  the  erbium  nitrate  in  the  fused 
nitrates  by  Bahr  and  Bunsen's  method.  Although  the 
quantity  at  my  disposal  was  small,  I  obtained  the  erbium  ' 


nitrate  crystals  and  showed  the  possibility  of  this  sepa* 
ration. 

Regarding  the  precipitation  with  sodium  hyposulphite, 
on  which  great  stress  is  laid  as  a  readtion,  showing 
"  lucium  "  to  be  a  new  element,  if  "a  solution  of  yttrite 
sulphates  in  a  concentrated  solution  of  potassium  sulphate 
made  by  cold  digestion  is  heated,  a  copious  precipitation 
will  ensue.  Though  not  a  perfedt  separation,  yet  advan- 
tage can  be  taken  of  this  reaction  in  separating  yttrium 
from  erbium,  and  this  readtion  should  be  borne  in  mind 
when  separating  the  cerite  from  the  yttrite  group,  as  some 
text-books  recommend  using  hot  saturated  solutions.  By 
doing  so,  some  of  the  yttrium  will  be  precipitated  with  the 
cerite  group. 

This  adion  of  heat  on  the  double  sulphate  solution  of 
the  yttrite  group,  if  it  does  form  similar  salts  to  the  cerite 
group,  I  have  not  met  with  in  the  text-books.  Therefore, 
inasmuch  as  Schiitzenberger  and  Barriere  added  the 
sodium  hyposulphite  to  the  concentrated  solution,  and 
then  heated  the  resulted  mixture,  I  believe  the  precipitation 
was  due  to  the  above  adlion  of  heat  rather  than  to  a  pre- 
cipitation by  the  sodium  hyposulphite.  In  a  10  per  cent 
solution  of  the  yttrite  group,  oxides,  I  obtained  but  a  slight 
precipitation  with  sodium  hyposulphite,  which,  on  re- 
solution and  treatment,  did  not  again  precipitate. 

Barriere's  methods  introduce  titanium  and  zirconium, 
both  of  which  are  exceedingly  difficult  to  separate  after- 
wards. 

To  obtain  the  pink  colour  of  the  erbium  oxide  it  must 
be  exceedingly  pure.  One  can  easily  be  misled  by  the 
colour  of  these  rare  oxides  when  in  combination.  Some 
when  alone  are  white,  yet  when  combined  are  of  a  dark 
colour,  even  brown. 

In  order  to  obtain  a  larger  sample  of  •'  lucium  "  to  work 
with,  I  took  1  kilo,  of  an  average  of  several  hundred 
samples  of  North  Carolina  monazite  sand,  carefully  fol- 
lowing Barriere's  method,  making,  however,  each  sepa- 
ration thoroughly,  and  failed  to  obtain  any  earth  answering 
to  the  readtions  of  "  lucium,"  only  getting  as  a  result  less 
than  I  per  cent  of  the  mixed  oxides  of  the  yttrite  group  of 
a  buff  colour  and  very  freely  soluble  in  dilute  acids. 

Since  making  these  experiments  much  work  has  been 
done  by  Crookes  and  others  to  prove  that  "  lucium  "  is 
not  entitled  to  a  place  in  the  list  of  elements,  but  is  im- 
pure yttrium. — yournal  of  the  Franklin  Institute,  July, 
1897. 


BEHAVIOUR    OF    CHLORAL     HYDRATE    WITH 

AMMONIUM     SULPHIDE. 

By  JOSEPH  LESINSKY  and  CHARLES  GUNDLICH. 

While  studying  the  readtions  of  chloral  hydrate,  we 
observed  that,  when  dissolved  in  water  and  mixed  with  a 
little  ammonium  sulphide,  it  threw  down  a  precipitate 
only  after  a  certain  time  had  elapsed.  This  precipitate 
separated  out  almost  instantaneously  after  a  certain 
number  of  seconds  had  been  counted.  Upon  further  ex- 
periment we  found  that,  if  the  concentrations  are  the 
same,  the  precipitate  will  appear,  every  time  the  experi- 
ment  is  tried,  in  exadlly  the  same  number  of  seconds, 
provided  the  temperature  is  the  same. 

At  first  we  had  considerable  difificulty  in  repeating  the 
experiment,  as  we  had  prepared  a  fresh  quantity  of  am- 
monium sulphide.  It  was  found,  however,  that  this  did 
not  readt  with  the  chloral  hydrate,  even  after  standing  a 
long  time.  We  were  more  successful  on  using  a  well- 
saturated  solution  of  ammonium  sulphide,  and  especially 
a  solution  that  had  been  standing  for  several  days, — in 
other  words,  a  solution  of  the  polysulphides. 

To  show  this  readlion,  the  following  conditions  were 
observed : — 

Two  grms,  of  chloral  hydrate  were  dissolved  in  25  c.c. 
of  water,  10  c.c.  of  this  solution  run  out  of  a  burette  into 


42 


A  ction  of  Phosphorus  Pentachlonde  on  A  nUine. 


I  Chkuical  News, 


July  23,  1897. 


a  narrow  beaker,  and  5  c.c.  of  yellow  ammonium  sulphide 
poured  in,  not  run  in.  The  liquids  must  be  mixed  as 
quickly  as  possible.  It  is  best  to  shake  the  mixture 
slightly,  and  allow  it  to  stand  on  a  piece  of  white  paper, 
so  that  the  sudden  appearance  of  the  precipitate  can  be 
seen  from  a  distance  in  showing  the  experiment. 

At  different  temperatures  the  reaction  is  retarded  or 
hastened,  the  time  necessary  for  the  precipitate  to  form 
being  inversely  proportional  to  the  temperature  and  con- 
centration. 


as  the  others,  the  precipitate  requiring  two  or  three 
seconds  for  complete  separation. — American  Chemical 
jfournal,  vol.  xix.,  No.  7. 


the  separation  took  place  in  44  seconds. 


At    i''C. 
„  20"  C. 

»  45°  C.  ,,  ,,  8        ,, 

„  65°  C.  „  „  3         „ 

For  every  20°  rise  we  have  a  gradual  decrease  in  time. 

The  difference  between  45° 

»i  >»  45° 

ii  ..  20° 


and  65°  being  5  seconds, 
and  20°     ,,      10         „ 
and    1°     ,,      20        „ 


The  best  way  to  show  this  readlion  is  to  start  a  metro- 
nome ticking,  mix  the  two  solutions  quickly,  andi  while 
observing  the  mixture,  count  the  number  of  seconds  it 
takes  before  the  precipitate  appears.  The  exaft  nature  of 
this  readlion  is  not  understood,  especially  as  the  resulting 
precipitate  is  evidently  a  mixture  of  sulphur  and  perhaps 
some  sulphur  compound  of  a  mercaptan  charader,  the 
odour  being  very  charadleristic.  The  precipitate  was  fil- 
tered off,  and  the  solution,  which  was  red,  extradted  with 
ether,  the  resulting  oil  emitting  a  very  powerful  odour,  and, 
when  diluted  with  water,  suggesting  the  odour  of  walnuts. 
If  the  concentrations  of  the  two  substances  are  changed, 
the  resulting  precipitate  will  vary  in  appearance.  In  our 
first  experiments  the  precipitate  was  of  a  pinkish  colour, 
and  the  solution  red ;  on  heating  a  little  on  the  water- 
bath,  the  precipitate  became  yellow  and  then  brown,  a 
remarkable  succession  of  changes  in  colour  being  ob- 
served. In  the  above-mentioned  experiments  the  precipi- 
tate was  yellowish  brown  in  colour,  the  solution  itself 
being  yellow,  and  on  warming  the  precipitate  the  colour 
became  almost  black. 

In  order  to  obtain  the  pink  precipitate  it  is  advisable  to 
use  an  excess  of  chloral  hydrate,  but  it  requires  some 
experimenting  to  obtain  the  conditions  favourable  for  the 
formation  of  the  precipitate. 

Perhaps  these  reaftions  may  be  of  value  in  the  ex- 
amination of  chloral  hydrate  as  to  its  purity.  It  is  our 
intention  to  study  the  same,  and  also  to  determine  the 
nature  of  the  precipitate  and  the  cause  of  the  "  retarded 
precipitation." 

There  are  only  two  such  cases  of  retarded  precipitation 
known  to  us,  besides  the  one  described  by  us,  and,  even 
in  those  cases,  it  has  been  impossible  to  ascertain  the 
causes,  although  the  readions  are  not  complicated,  as  in 
the  case  with  the  one  described  by  us. 
The  reactions  are  as  follows  : — 

I,  The  adion  of  sodium  thiosulphate  upon  hydro- 
chloric acid: — 


HzSjOj  -t-  acid  =  H2O  +  SO2  +  S. 


lapse 


Here  the  sulphur  separates  out  suddenly  after  a 
of  time. 

2.  The  adtion  of  hydriodic  acid  with  a  starch  solution 
when  sulphuric  acid  is  added  : — 

iHI  +  H2SO4  +  starch  solution  =  2H2O  +  SO2  + 121  or 

2HIO3  +  5SO2  +  4H2O  =  5H2SO4  +  I2. 

The  last  readtion  is  the  mostcharaderistic  of  the  three, 


the  iodine  separating  out  so  suddenly  that  most  accurate 
results  can  be  obtained  in  measuring  the  time.  We  have 
furthermore  succeeded  in  procuring  the  same  results  by 
employing  butyl  chloral  (croton  chloral)  instead  of  chloral 
hydrate,  the  resulting  precipitate  being  of  a  beautiful 
lemon-yellow  colour.   This  last  readtion  is  not  as  striking 


ACTION    OF    PHOSPHORUS    PENTACHLORIDE 

ON    ANILINE    AND     ITS    SALTS.* 

By  J.  ELLIOTT  GILPIN. 

The  constant  occurrence  of  chlorphosphuret  of  nitrogen 
(PNC^s  as  a  by-produdt  in  the  formation  of  orthosulpho- 
benzoic  acid  from  commercial  saccharine  diredted  attention 
in  this  laboratory  (Chem.  Labor.,  Johns  Hopkins  Uni- 
versity) to  this  very  interesting  substance.     Discovered 
by  Liebig,  it  was  studied  by  Liebig  and  Wohler   {Ann. 
Chem.,   Liebig,  xi.,    139),   Gladstone  and  Holmes  {Ann. 
C/iew., Liebig,  lxxvi.,74),  Laurent,  {ComptesRendus,  1850, 
Sept.  9),    Wichelhaus  {Ber.   d.   Chem.  Ges.,    iii.,    163), 
Hofmann  (,Ber.  d.  Chem.  Ges.,  xvi.,  1910),   and   Stokes 
{Amer.  Chem.  yourn.,  xvii.,  275).     Hofmann  studied  its 
adtion  with  aniline  and  paratoluidine,  and  obtained  deriva- 
tives in  which  the  chlorine  had  been  replaced  by  residues 
of  aniline  and  paratoluidine,  the  produdl  with  the  aniline 
having  the  composition  P3N3(NHC6H5)6.   Besson  {Compt. 
Rendus,  cxiv.,  1264)  has  repeated  the  work  done  on  this 
substance  and  obtained  the  compound  PNCI2.     He  says 
the  compound  described  by  Gladstone  as  having  the  com- 
position (PNCl2)3  and  the  melting-point  210°  is  probably 
a  polymeric  form  of  PNCI2;  but  there  is  evidently  some 
mistake  here,  as  Gladstone  found  the  melting-point  to  be 
110°  and  not  210°,  while  according  to  Besson  it  is  114°. 
As   the  formation  of  the  chlorphosphuret  of  nitrogen  is 
due  to  the  adtion  of  phosphorus  pentachloride  on  ammo- 
nium chloride,  the  possibility  was  suggested  of  obtaining 
a  derivative  of  it  by  using  instead  of  ammonium  chloride 
a  substitution-produdl,  aniline  hydrochloride.     Although 
the  substance  obtained  in  this  adtion  is  not  a  derivative  of 
the  chlorphosphuret  of  nitrogen,  still  a  comparison  of  the 
two  forms  an  interesting  study.     They  show  the  tendency 
of  phosphorus  and  nitrogen  to  combine  sometimes  in  a 
very  stable  form,  as  in  the  chlorphosphuret  of  nitrogen 
and  a  substance  obained  in  this  investigation,  which  will 
be  discussed  later.     The  former  can  be  heated  with  con- 
centrated acids  and  alkalies  without  undergoing  change; 
but  the  trichlorphosphanil,  obtained  in  this  work,  is  very 
unstable,  decomposing  with  nearly  all  reagents,  and  even 
slowly  when  exposed  to  moisture. 

Up  to  the  time  when  this  investigation  was  begun  the 
study  of  the  adlion  of  aniline  on  the  chlorides  of  phos- 
phorus had  not  led  to  satisfadtory  results,  and  the  adlion 
with  the  trichloride  only  had  been  studied.  By  the  adtion 
of  aniline  on  phosphorus  trichloride,  Tait  {Zeitsch.  Chem., 
1865,  648)  obtained  a  compound  to  which  he  gave  the 
formula  P(NH2C6H5C1)3.  Jackson  and  Menke  {Amer. 
Chem.  yourn.,  vi.,  89)  repeated  this  work,  but  were  un- 
able to  obtain  the  produdt  described  by  Tait.  They 
obtained  a  produdt  which  they  thought  had  the  compo- 
sition PCl(NHC6Hs)2i  but  were  unable  to  isolate  it.  By 
dissolving  it  in  alcohol  and  precipitating  with  water  they 
obtained  the  compound  P(OH)(NHC6H5)2,  which  they 
considered  to  be  its  hydroxyl  derivative.  Weyer  ("  Dis- 
sertation," Bonn,  1891)  studied  the  aftion  of  aniline  on 
trichloride  of  arsenic,  and  obtained  two  definite  produdls 
by  the  successive  substitution  of  aniline  residues  for  the 
chlorine  atoms.  These  were  represented  by  the  formulae 
AsCl2(NHC6H5)  and  AsCl(NHC6H5)2.  The  third  step 
he  was  unable  to  take.  In  the  present  investigatioii,  in 
which  the  adtion  of  phosphorus  pentachloride  on  aniline 
and  its  salts  is  under  investigation,  four  definite  sub- 
stances have  been  isolated.  They  are  formed  by  the 
substitution  of  residues  of  aniline  for  one  or  more  chlorine 


*  Amtrican  Chemical  Journal,  vol.  xix.,  No.  5. 


Cbbmical  News,  I 
July  23.  1897.       ( 


Action  of  Phosphorus  Pentachloride  on  Aniline, 


43 


atoms  of  the  phosphorus  pentachloride,  one  being  ob- 
tained by  the  adion  of  phosphorus  pentachloride  on 
aniline  hydrochloride,  and  three  by  the  adlion  on  aniline. 
The  trichlorphosphanil,  having  the  composition — 

PClaCNCeHs), 

which  was  obtained  from  the  aniline  hydrochloride,  shows 
great  similarity  to  the  first  derivative  obtained  by  Weyer. 
They  are  both  very  sensitive  to  moisture,  and  decompose 
with  water  and  alcohol  in  a  similar  manner.  The  other 
substances  were  more  stable,  and  were  obtained  from 
their  solutions  in  alcohol  in  the  form  of  well-defined 
crystals. 

During  the  progress  of  this  investigation  an  article  by 
Michaelis  and  Schroeter  {^Ber.  d.  Chem.  Ges.,  xxvii.,  490) 
has  appeared,  in  which  a  substance,  formed  by  the  adtion 
of  aniline  on  phosphorus  trichloride,  of  the  composition 
C6H5N — PCI,  is  described.  This  substance  bears  the 
same  relation  to  phosphorus  trichloride  as  the  trichlor- 
phosphanil, described  in  this  paper,  does  to  phosphorus 
pentachloride. 

Action  of  Phosphorus  Pentachloride  on  Aniline  Hydro- 
chloride—Trichlorphosphanil,  PCljCNCeHs) 

After  considerable  experimenting,  the  following  method 
was  adopted  as  the  best  for  the  preparation  of  this  sub- 
stance :  —  Phosphorus  pentachloride  and  perfedlly  dry 
aniline  hydrochloride  are  mixed  in  molecular  quantities, 
not  more  than  10  grms.  of  the  aniline  hydrochloride  being 
used  at  a  time.  The  intimately  mixed  compounds  are 
placed  in  a  distilling-bulb,  and  connedted  with  a  condenser. 
A  tub*  at  the  lower  end  of  the  condenser  passes  into  a 
vessel  of  water,  to  absorb  the  hydrochloric  acid  formed 
and  show  the  rate  of  the  adlion.  The  bulb  is  half  im- 
mersed in  a  sulphuric-acid  bath.  Before  the  temperature 
at  which  the  trichlorphosphanil  is  formed  is  reached,  a 
small  quantity  of  phosphorus  pentachloride  sublimes  in 
the  upper  part  of  the  neck.  If  the  temperature  is  kept  at 
170°  for  six  to  eight  hours,  the  trichlorphosphanil  con- 
denses on  the  cool  part  of  the  bulb,  and  sometimes  in  the 
condenser,  as  a  white  coating,  covered  on  the  inside  with 
nodules.  After  the  evolution  of  hydrochloric  acid  has 
ceased,  the  material  can  be  obtained  in  a  very  pure  con- 
dition, if  the  part  in  the  neck  of  the  bulb  is  discarded. 
After  being  powdered,  it  is  placed  in  a  desiccator  over 
caustic  potash  to  remove  the  hydrochloric  acid.  It  must 
be  kept  perfedtly  dry,  and  cannot  be  purified  by  crystal- 
lisation, as  water,  alcohol,  ether,  acetone,  and  other 
solvents  decompose  it.  Even  when  re-sublimed  some 
decomposition  takes  place.  In  every  case  there  was  a 
small  quantity  of  a  dark,  green,  sticky  material  left  in  the 
bulb  after  the  adion  was  over.  This  may  have  been  due 
to  impurities  in  the  phosphorus  pentachloride,  as  the 
ordinary  commercial  article  was  used.  When  heated 
with  water  this  green  material  ads  quite  violently  at 
first,  in  consequence  no  doubt  of  the  presence  of  a  small 
excess  of  phosphorus  pentachloride,  and  a  tar-like  mass 
is  formed,  which  is  unafted  on  by  water,  alkali,  and  dilute 
acid,  and  solidifies  on  cooling.  It  is  soluble  in  alcohol, 
with  a  green  colour ;  so  some  was  dissolved  in  alcohol 
and  precipitated  by  addition  of  water,  filtered,  and 
washed.  This  was  repeated  several  times,  and  the  green 
powder  obtained  was  analysed  ;  but  different  preparations 
varied  in  composition,  and  it  was  evidently  not  a  single 
definite  compound. 

The  formation  of  the  trichlorphosphanil  probably  takes 
place  as  represented  in  the  following  equation  : — 

PCl5-fC6H5NH2HCl  =  PCl3(NC6H5)-f3HCl. 

Concentrated  sulphuric  and  nitric  acids  both  decompose 
it,  the  former  with  the  evolution  of  hydrochloric  acid. 
Alcohol  and  ether  adt  on  it  with  the  evolution  of  hydro- 
chloric acid  and  the  generation  of  considerable  heat. 
Sodium  hydroxide  adls  on  it  to  a  slight  extent,  and 
changes  it  to  a  hard  brittle  mass.  When  boiled  with 
water  it    is  decomposed  into  aniline,  hydrochloric  and 


phosphoric  acids,  so  that  the  chlorine  and  phosphorus 
can  be  determined  in  the  same  specimen,  the  chlorine  as 
silver  chloride,  and  the  phosphorus  as  magnesium  pyro- 
phosphate. To  be  sure  that  none  of  the  hydrochloric 
acid  was  lost  in  boiling,  several  determinations  were  made 
by  the  Carius  method,  but  they  agreed  with  those  made 
in  the  other  way.  i 

The  following  are  the  results  of  the  analyses  : — 

Preparation  I. 
0-3662  grm.  of  the  substance  gave  0*6754  grm.  AgCl. 
o'2848  grm.  of  the  substance  gave  05226  grm.  AgCI. 
0*2560  grm.  of  the  substance  gave  0*4672  grm.  AoCl. 
0*3662  grm.  of  the  substance  gave  01788  grm.  Mg2P207. 
0*2848  grm.  of  the  substance  gave  0*1367  grm.  Mg2P307. 
0*2560  grm.  of  the  substance  gave  0*1242  grm.  Mg2Pa07. 
02755  grm,  of  the  substance  gave  0*0609  grm.  H2O  and 

0*3196  grm.  CO2. 
0*4078  grm,  of  the  substance  gave  22  c.c.  N  at  16°  and 

772*5  m.m. 

Preparation  II. 

0*2568  grm.  of  the  substance  gave  0*4635  grm.  AgCl. 
0*3535  grm-  of  the  substance  gave  0*6354  g"""!-  AgCl. 
o*3535  grm.  of  the  substance  gave  0*1695  g^m.   Mg2P207. 
0*4237  grm.  of  the  substance  gave  23  c.c.  N  at  11*5°  and 

762  m.m. 
0*3698  grm.  of  the  substance  gave  0*0765  grm.  H2O  and 

0*4081  grm.  CO2. 
0*3646  grm,  of  the  substance  gave  0*0748  grm.  H2O  and 
0*4078  grm.  CO2. 

Found. 
Calculated  for        Preparation  I.                      Preparation  II. 
PCls(NC,Ha).      . ' . ' > 

c    31-55    —     31*63    —     30*09    —     30*50 

H        219       —  2*45       —  2*29       —  2  27 

CI   46*53   45*59   45-36  45*11   4443     —     44-61 

P      13*58     13*64     13*41    13*56       —        13*40 

N        6*17      —         6*38       —         —         647       — 

While  these  results  leave  much  to  be  desired,  they 
point  clearly  to  the  formula  given,  and  are  fairly  satisfadory 
considering  the  instability  of  the  substance. 

The  sulphate  and  nitrate  of  aniline  were  also  treated 
with  phosphorus  pentachloride,  but  they  did  not  ad  like 
the  hydrochloride.  The  adtion  of  the  nitrate  was  very 
violent,  taking  place  as  soon  as  they  were  mixed,  without 
the  aid  of  heat.  The  whole  mass  was  carbonised  in  a 
short  time.  Paratoluidine  hydrochloride  was  also  treated 
with  phosphorus  pentachloride,  but  no  volatile  produdl 
was  formed. 

Decomposition  of  Trichlorphosphanil  with  Water. 
When  trichlorphosphanil  is  heated  with  water  it  first 
melts  and  forms  an  oil  which  is  decomposed  by  further 
boiling.  The  decomposition  gives  rise  to  the  formation  ot 
aniline,  and  hydrochloric  and  phosphoric  acids,  and  can 
be  represented  thus  : — 
PC]3(NC6H5)-|-4H20  =  C6H5NH2.HCl-f  2HC1-I-H3P04. 

The  crystals  which  separated  out,  after  decomposing 
with  water  and  evaporating,  were  re-crystallised  and 
analysed.  The  results  of  the  analyses  showed  it  to  be 
aniline  hydrochloride.  Another  portion  was  decomposed 
with  water,  an  excess  of  barium  hydroxide  added  to  lilie- 
rate  the  aniline,  and  this  then  distilled  off.  After  filtering 
off  the  excess  of  the  hydroxide,  the  presence  of  barium 
chloride  was  proved,  showing  that  free  hydrochloric  acid 
had  been  present.  The  barium  was  precipitated  with 
sulphuric  acid  and  the  phosphoric  acid  obtained  by 
evaporating  the  solution. 

Decomposition  of  Trichlorphosphanil  with  Sulphuric  Acid. 
Trichlorphosphanil  dissolves  in  warm  concentrated  sul- 
phuric acid,  with  evolution  of  hydrochloric  acid  gas.  An 
equal  volume  of  water  is  added  to  this,  and  the  liquid  is 
allowed  to  stand,  when  a  substance  crystallised  out  which 


44 


Double  Fluorides  of  Zirconium^ 


Chbuical  News, 

July  23,  1897. 


was  found  to  be  sulphanilic  acid.     Several  of  its  salts 
were  made  and  analysed. 

Action  of  Phosphorus  Pentachloride  on  Aniline.  Chlor- 
phostetranilide,  PC1(NHC6H5)4. 
When  phosphorus  pentachloride  is  slowly  added  to 
aniline  and  the  mass  constantly  stirred,  there  is  immediate 
adtion  and  hydrochloric  acid  is  evolved.  The  whole  mass 
becomes  hot,  and  after  all  the  aniline  has  been  used  up, 
and  further  addition  of  phosphorus  pentachloride  causes 
no  action,  it  solidifies.  This  mass,  when  cool,  is  broken 
up  and  heated  with  water  to  extradt  any  aniline  hydro- 
chloride and  phosphorus  pentachloride  present,  then 
filtered,  washed,  and  dried.  This  producft,  which  is  a 
light  yellow  powder,  is  insoluble  in  water,  but  slightly 
soluble  in  alcohol.  It  consists  largely  of  one  substance, 
but  several  others  are  present  in  small  quantities. 

If  the  dried  mass  is  shaken  with  two  separate  quantities 
of  cold  alcohol,  and  the  liquid,  after  being  filtered,  is 
allowed  to  evaporate  slowly,  besides  some  needle-shaped 
crystals  there  will  be  found  some  well-defined  monoclinic 
crystals,  which  grow  to  a  considerable  size.  These  have 
to  be  separated  from  the  other  produdl  mechanically.  If 
the  solution  from  which  these  have  been  obtained  is  fil- 
tered and  allowed  to  evaporate  still  further,  in  some 
cases,  tufts  of  fine,  radiating,  silky  needles  separate  out. 
Both  these  and  the  large  crystals  will  be  discussed  later. 
After  treating  several  times  with  cold  alcohol,  the  original 
material  is  treated  repeatedly  with  small  quantities  of  hot 
alcohol,  until  on  evaporation  only  one  substance  separates 
out  from  the  solution.  By  this  process  a  definite  sub- 
stance is  obtained  in  pure  condition.  This  is  slightly 
soluble  in  alcohol  and  insoluble  in  water.  When  crystal- 
lised from  alcohol  it  usually  consists  of  long  irregular- 
shaped  crystals ;  but  when  the  evaporation  is  very  slow, 
and  absolute  alcohol  is  used,  monoclinic  crystals,  with 
well-defined  basal  planes  and  fundamental  prisms,  are 
formed.  The  composition  of  this  substance  is  represented 
by  the  formula  PC1(NHC6H5)4,  and  its  mode  of  formation 
is  expressed  as  follows  : — 

PCI5  +  4C6H5NH2  =  PC1(NHC6H5)4  -f  4HCI. 

It  is  not  decomposed  when  boiled  with  water,  concen- 
trated alkali,  or  hydrochloric  acid ;  but  when  heated  with 
water  in  a  sealed  tube  to  180°  for  several  hours,  aniline, 
aniline  hydrochloride,  and  phosphoric  acid  are  formed. 
This  substance  is  charaiSterised  by  its  great  insolubility. 
It  is  practically  insoluble  in  ethyl  ether,  acetone,  benzene, 
ligroin,  and  amyl  alcohol,  but  slightly  soluble  in  ethyl 
alcohol.  When  heated,  a  volatile  produdt,  which  proved 
to  be  a  mixture  of  aniline,  aniline  hydrochloride,  and 
some  diphenylamine  hydrochloride,  formed  by  the  aftion 
of  aniline  on  aniline  hydrochloride,  was  formed,  and  an 
amorphous  black  substance  remained.  The  great  sta- 
bility of  this  substance  is  shown  by  the  faft  that  only  a 
small  amount  was  decomposed  when  it  was  heated  in  a 
porcelain  tube,  in  a  current  of  oxygen,  over  the  blast-lamp 
for  several  hours. 

A  qualitative  analysis  of  this  substance  showed  that  it 
contains  phosphorus,  nitrogen,  and  carbon.  The  black 
stable  residue  is  very  similar  to  a  produdt  described  by 
Rose  (^nn.  der,  Phys.  Pogg.,  xxviii.,  529;  Ann.  Chem., 
Liebig,  xi.,  130).  By  the  adion  of  phosphorus  trichloride 
on  ammonia  he  obtained  a  produdt  in  which  he  gave  the 
formula  PCls-^sNHs.  When  this  was  heated,  ammonium 
phosphate  and  ammonium  chloride  were  formed,  and  a 
white  substance,  phospham,  PN2H,  was  left  behind.  A 
comparison  of  this  and  the  black  residue  is  worthy  of 
notice.  Neither  is  soluble  in  water  or  dilute  acids.  They 
are  only  partly  decomposed  by  boiling  with  fuming  nitric 
acid  for  some  time.  Concentrated  sulphuric  acid  attacks 
the  phospham,  but  acid  potassium  sulphate  is  necessary 
to  decompose  the  black  residue.  Neither  is  adted  on  when 
heated  in  a  stream  of  chlorine.  They  are  decomposed  by 
fused  alkali,  and  also  with  generation  of  phosphorus  or  a 
compound  of  phosphorus  and  hydrogen,  when  heated  to 


redness  in  a  current  of  hydrogen.  The  black  residue  may 
also  contain  a  small  amount  of  hydrogen  ;  but  this  can- 
not be  considered  as  certain,  for  the  decomposition  of  the 
substance  is  accomplished  with  so  great  difficulty  that  the 
sources  of  error  introduced  may  account  for  the  presence 
of  the  hydrogen. 

The  formation  of  this  compound  prevented  the  deter- 
mination of  the  carbon  and  hydrogen  by  the  usual  method 
in  the  case  of  all  the  compounds  studied,  except  that  of 
the  trichlorphosphanil,  which  is  volatile.  In  some  cases, 
when  the  substances  were  heated  in  platinum  boats,  a 
transparent  film  was  formed  about  the  small  particles  of 
carbon,  preventing  their  complete  combustion.  The 
method  finally  adopted  for  the  determination  of  carbon, 
and  the  only  one  by  which  satisfadtory  results  could  be 
obtained,  was  that  described  by  Fritsch  [Ann.  Chem., 
Liebig,  ccxciv.,  79),  in  which  the  substance  was  oxidised 
by  potassium  chromate  and  sulphuric  acid. 

The  nitrogen  was  determined  both  by  the  absolute  and 
by  the  Kjeldahl  methods.  The  chlorine  and  phosphorus 
were  determined  as  silver  chloride  and  magnesium  pyro- 
phosphate respedtively,  the  substance  being  decomposed 
by  heating  it  with  fuming  nitric  acid  in  a  sealed  tube  to 
180"  for  several  hours. 

(To  be  continued). 


ON  THE  DOUBLE   FLUORIDES  OF  ZIRCONIUM 

WITH  LITHIUM,  SODIUM,  AND  THALLIUM. 

By  H.  L.  WELLS  and  H.  W.  FOOTE. 

In  a  previous  article  {Amer.  jfourn.  Science,  IV.,  i.,  18)  we 
have  described  the  caesium-zirconium  fluorides,  and  upon 
comparing  these  with  the  corresponding  ammonium  and 
potassium  salts,  which  had  been  previously  described  by 
Marignac  (Am.  Chim.  Phys.,  ix.,  257)  it  was  observed  that 
the  types  of  salts  formed  varied  with  the  molecular 
weights  of  the  alkaline  fluorides  in  an  interesting  manner. 
The  fluorides  of  smaller  molecular  weight  gave  types  with 
a  larger  relative  number  of  these  molecules,  while  the 
fluorides  of  higher  molecular  weights  combined  with 
more  zirconium  fluoride  than  the  others.  This  relation  is 
made  clear  in  the  following  table,  which  was  given  in  the 
previous  article  referred  to : — 

3  :  I  Type.  2  :  x  Type.  i  :  i  Type.  2 :  3  Type. 

3NH4F.ZrF4  2NH4F.ZrF4         —  -- 

3KF.ZrF4        2KF.ZrF4        KF.ZrF4  — 

—  2CsF.ZrF4      CsF.ZrF4  2CsF,3ZrF4.2H20 

The  present  investigation  was  undertaken  with  the 
view,  in  the  first  place,  of  testing  the  apparent  rule  with 
lithium  fluoride,  which  has  a  lower  molecular  weight  than 
the  fluorides  previously  experimented  upon.  Our  expedta- 
tions  were  realised  by  the  preparation  of  the  salt 
4LiF.ZrF4.IH2O.  The  salt  2LiF.ZrF4  was  also  obtained, 
but,  in  spite  of  a  careful  search,  no  intermediate  3  :  i  salt 
could  be  discovered.  The  following  table,  giving  the 
lithium,  potassium,  and  caesium  salts,  shows  a  perfedtly 
symmetrical  gradation  in  types  according  to  the  atomic 
weights  of  the  alkali  metals,  except  that  the  intermediate 
lithium  salt  is  missing  : — 

Potassium  salts. 
Type.        Lithium  salts.  (Marignac).  Cesium  salts. 

4  :  I  4LiF.ZrF4.lH2O  —  — 

3:1  —  3KF.ZrF4  — 

2  :  I  2LiF.ZrF4  2KF.ZrF4         2CsF.ZrF4 

1:1  —  KF.ZrF4.H2O  CsF.ZrF4.H2O 

2:3  —  —  2CsF.3ZrF4.2H2O 

Marignac's  two  ammonium  salts,  3  :  i  and  2  :  i,  also 
enter  the  series  symmetrically. 

We    have   investigated    also    the   thallous    zirconium- 


Cbbhical  News,  i 
July  23,  1897.     J 


Double  Fluorides  of  Zirconium, 


45 


fluorides,  since  the  high  atomic  weight  of  thallium  led  us 
to  expedt  that  it  would  possibly  yield  a  series  of  salts 
symmetrical  with  those  of  the  alkali  metals  with  a  still 
higher  ratio  of  zirconium  than  was  the  case  with  caesium. 
Such  was  not  the  case,  however.  The  salts  discovered 
were  :  — 3TlF.ZrF4,  5TlF.3ZrF4.H2O,  TlF.ZrF4,  and 
TlF.ZrF4.H2O.  Two  of  these  three  types  of  thallous 
salts  correspond  to  types  of  alkali-metal  salts;  while  one 
type,  the  5  :  3,  is  a  new  one,  but  the  series  is  not  sym- 
metrical with  the  others  according  to  the  atomic  weights. 

Since  Marignac  had  described  but  one  sodium-zirconium 
fluoride,  5NaF.2ZrF4,  and  since  this  differs  from  all  other 
alkaline  zirconium  fluorides,  we  have  undertaken  a  new 
investigation  of  the  sodium  salts.  As  a  result,  we  have 
fully  confirmed  Marignac's  results  as  to  the  5  :  2  salt, 
which  is  the  one  most  readily  obtained,  and  we  have 
succeeded  in  preparing  a  new  salt,  2NaF.ZrF4,  which 
corresponds  to  the  most  usual  type  of  double  halogen  salts 
of  tetravalent  elements.  It  is  evident,  however,  that  the 
sodium  salts,  like  those  of  thallium,  do  not  form  a  sym- 
metrical series  with  the  others. 

The  following  table  gives  a  list  of  the  sodium  and  thal- 
lium salts  and  shows  the  positions,  "  X,"  of  the  other 
compounds  prepared  by  Marignac  and  ourselves  : — 


Type. 


B  S 


J     < 


Thallium  salts. 


C     S 


2S     -^ 

a—      H 


4:  I     X     —  —  —    —  — 

3  :  I     —     X  —  X     —       3TlF.ZrF4 

5:2     —     —     5NaF.2ZrF4     —     —  — 

2  :  I     X      X     2NaF.ZrF4       XX  — 

5:3     —     —  —  —     —  5TlF.3ZrF4.H2O 

XX  Wl-l'l^ 


1:1     — 
2:3     — 


X 


\TlF.ZrF4.H2O 


While  our  investigation  has  shown  that  the  rule  for  the 
variation  of  the  types  with  the  atomic  weights  applies 
only  partially  to  the  zirconium  double  fluorides,  we  have 
shown  at  least  that  the  variety  of  types  is  remarkable,  and 
it  is  also  noticeable  that  the  ratios  are  nearly  the  simplest 
that  can  exist  in  such  number  between  the  extreme  limits 
4 : 1  and  2  :  3. 

Preparation. — Thallium  fluoride  was  prepared  by  dis- 
solving the  metal  in  sulphuric  acid,  adding  an  excess  of 
baryta  water,  filtering,  and  passing  carbonic  acid  into  the 
hot  solution.  The  filtrate  from  this  precipitation  was 
evaporated  and  treated  with  hydrofluoric  acid  in  excess. 
The  salts  were  prepared  by  mixing  the  acid  solutions  of 
the  fluorides  in  varying  proportions,  evaporating,  and 
cooling  to  crystallisation.  The  salts  were  then  removed 
and  pressed  between  filter  papers  till  dry.  In  all  cases 
they  were  stable  in  the  air. 

Method  of  Analysis. — Zirconium  and  the  alkalis  were 
determined  by  evaporating  the  salt  with  sulphuric  acid  to 
drive  off  hydrofluoric  acid,  precipitating  zirconium 
hydroxide  with  ammonia  and  weighing  ZrOj.  The  filtrate 
was  evaporated  to  dryness  and  the  alkali  determined  as 
sulphate,  either  by  igniting  with  ammonium  carbonate  or 
heating  in  a  current  of  air  containing  ammonia.  When 
thallium  was  present,  the  fluoride  was  dissolved  in  water, 
a  little  sulphurous  acid  added  to  make  sure  that  the  thal- 
lium was  all  in  the  univalent  condition,  and  the  zirconium 
precipitated  with  ammonia.  The  precipitate  needed  to 
be  very  thoroughly  washed.  The  filtrate  was  evaporated 
nearly  or  quite  to  dryness  to  remove  free  ammonia,  diluted 
to  a  volume  of  about  100  c.c,  heated  to  boiling,  and 
potassium  iodide  added  in  excess  to  precipitate  thallium 
iodide.  This  was  colle(5led  on  a  Gooch  crucible,  washed 
with  80  per  cent  alcohol,  dried  at  100°  C,  and  weighed. 


Fluorine  was  determined  by  the  ordinary  calcium  fluoride 
method  after  precipitating  zirconium  with  ammonia  and' 
removing  ammonium  salts  by  evaporation  with  sodium 
carbonate.  Water  was  determined  by  heating  the 
salt  in  a  combustion  tube  behind  a  layer  of  dry  sodium 
carbonate  and  colledting  the  water  in  a  calcium  chloride 
tube. 

Salts  of  Lithium. 

iLiF.ZrF^. — This  salt  forms  when  from  07  grm.  to  2 
grms.  of  lithium  fluoride  are  added  to  20  grms.  of  zirconium 
fluoride.  The  crystals  are  hexagonal,  showing  prism  and 
pyramid,  and  rarely  a  basal  plane.  In  appearance  they 
are  very  much  like  crystals  of  quartz  from  Herkimer  Co., 
N.Y.,  but  they  are  very  small.  On  re-crystallising,  the 
4  :  I  salt  was  formed. 

Separate  crops  were  analysed  with  the  following  re- 
sults : — 

Calculated  f«r 
I.  II.  LiaZrFj. 

Li 6-03  6*39  6*42 

Zr 4i'8i  4f64  4i"28 

F —  51-62  52-30 

4L1F.ZyF4.lff 20- — This  was  the  most  unsatisfadtory 
salt  obtained,  though  it  seems  undoubtedly  to  establish 
the  4  :  I  type.  As  lithium  fluoride  is  very  insoluble, 
only  a  comparatively  small  amount  could  be  dissolved  in 
zirconium  fluoride,  and  apparently  we  could  not  go  far 
enough  toward  the  lithium  end  to  get  the  salt  in  pure  con- 
dition. It  formed  in  a  crust  ordinarily,  and  the  crystals 
were  very  small.  Under  the  microscope,  no  mixture  with 
another  salt  could  be  found  in  the  crops  analysed.  Once, 
however,  it  was  obtained  mixed  with  the  2  :  i  salt,  as 
seen  under  the  microscope,  showing  there  could  probably 
be  no  intermediate  salt.  Various  conditions  were  tried, 
and  crops  were  obtained  from  both  hot  and  cold  solu- 
tions. It  forms  when  5  to  7  grms.  of  lithium  fluoride  are 
mixed  with  20  grms.  of  zirconium  fluoride.  On  re-crystal- 
lising, lithium  fluoride  is  precipitated. 

Following  are  the  results  of  the  analyses  : — 


Li. 


Zr. 


HjO. 


F. 


1 9"54  33"i4  4*83  — 

n —        —  4*93  — 

in 9-79  33-30  4-35  53-16 

IV —  33-23  —  — 

V —  3302  —  — 

Calculated  for  Li4ZrF8.§H20  9-93  31-91  4-26  53*90 

Salts  of  Sodiunti, 
zNaF.ZrF^. — This  salt  crystallises  in  very  minute  crys- 
tals of  hexagonal  outline,  coming  down  in  a  crust  when 
from  one  to  two  parts  of  sodium  fluoride  are  added  to 
fourteen  parts  of  zirconium  fluoride.  The  salt  does  not 
re-crystallise.  The  following  results  were  obtained  from 
separate  crops.  The  water  was  probably  mechanically 
included. 

Calculated  for 
I.  II.  Na,ZrF,. 

Na        18-66  18  41  18-40 

Zr         3478  36-21  3600 

H2O 1-96  050  .    — 

F  (by  difference)  .  44-60  44-88  45  "So 

5NaF.2ZrF^. — Marignac  has  previously  described  this 
salt,  which  comes  down  under  wide  conditions  in  very 
good  crystals  and  re-crystallises  easily.  Prof.  L.  V. 
Pirsson  has  kindly  examined  the  crystals  and  made  the 
following  report : — 

"  The  crystals  show  good  sharp  forms,  but  are  very 
small.  They  appear  distindly  orthorhombic  in  habit, 
consisting  in  the  main  of  rather  stout  prisms,  made  up  of 
two  prismatic  planes,  m  and  m',  and  terminated  by  a 
rather  steep  brachydome.  In  another  habit,  which  is 
rarer,  the  front  pinacoid,  a,  is  broadly  developed^  while 
the  prisms  are  very  small  ;  this  type  also  shows  at  times 


46 


Chemical  Notices  from  Foreign  Sources. 


f  Chemical  News, 
July  23,  1897. 


a  pyramid,  ^.  The  plane  of  the  optic  axes  lies  in  the 
base  and  a=C,  i  =  8,  c  =  b.  The  optic  angle  is  large,  and 
it  could  not  be  told  whether  a  or  i  was  the  acute  disedtrix. 
The  double  refradion  is  very  low.  The  crystals  in  their 
form  strongly  recall  the  figures  of  chrysolite  (olivine) 
shown  in  the  mineralogies." 

The  analyses  gave  the  following  results  from  different 
crops  :— 


Na      2i"i5 


Zt 

F  (by  difference) . 


33-63 
45-22 


II. 

21'09 

33"55 
45*36 


Calculated  for 
NaiZr^Pi,. 

2I-23 
33-22 

45'57 


Salts  of  Thallium. 
TlF.ZrF4.H2O  and  TlF.ZrF^.— These  salts  crystallise 
in  somewhat  concentrated  solutions  when  one  part  of 
thallium  fluoride  is  mixed  with  three  or  four  parts  of  zir- 
conium fluoride.  The  analyses  invariably  sh(/W  an  excess 
of  zirconium  fluoride.  The  hydrous  salt  crystallises  in 
needles,  if  the  solution  be  cooled  before  precipitation 
occurs.  If  the  solution  is  evaporated  until  crystals  begin 
to  form  and  then  cooled,  the  anhydrous  salt  deposits  in 
minute  square  plates.  The  salt  gives  the  5  :  3  type  on 
re-crystallising.     The  following  results  were  obtained : — 


I. 

Tl        4«-43 

Zr       2293 

F — 

H2O 389 

I. 

Tl       5o'i6 

Zt       23-86 

F — 


II. 

47  "9 1 

23*16 

23-17 

4-80 


II. 
49-91 
24-08 
24-32 


Calculated  for 
TlZrFi.HjO. 

50-05 

22-15 

23  "37 

4*43 

Calculated  for 
TlZrFj. 

52-37 
23-17 
24-46 


5TlF.sZrF4.H2O.— This  salt  crystallises  in  needles 
when  from  i  to  3i  parts  of  thallium  fluoride  are  added  to 
I  part  of  zirconium  fluoride.  When  about  4  parts  of 
thallium  fluoride  are  added,  the  same  salt  crystallises  in 
a  different  habit,  forming  prisms  of  hexagonal  outline 
which  under  the  microscope  are  seen  to  be  twinned, 
resembling  in  this  respedl  the  hexagonal-shaped  crystals 
of  aragonite.  On  re-crystallising,  both  habits  give  the 
needle-shaped  crystals. 

The  following  analyses  were  made  of  the  two  kinds  of 
crystals.  A  rather  large  number  of  determinations  was 
made  on  account  of  the  existence  of  two  different  forms. 

Tl.  Zt.  HijO,        F. 

1 61-58  16-88      —         — 

II 62-05  16-84      —         — 

III 6137  17-14  1-40       — 

IV 61-58  1688  1-17  19-31 

.y. 61-74  17*04  1-42  — 

vi —     —  1-31  — 

VII ■ 62-91     16-42      —        — 

Calculated  for TlsZrgFiy.HjO    62*47     16-58     i-ii     19-84 

3TZF.ZrF4.— Crystals  of  this  salt  form  in  brilliant 
odiahedra  when  one  part  of  zirconium  fluoride  is  added  to 
from  four  to  twenty  parts  of  thallium  fluoride.  It  is  easily 
re-crystallised. 

The  following  analyses  were  made : — 

Calculated  for 
I.  II.  TlaZrF,. 

Tl        72-82  73*20  73'24 

Zr       10-91  10-38  10*80 

^ 1565  —  15*96 

— American  journal  of  Science,  iii.,  No.  18,  June,  1897. 


NOTICES  OF  BOOKS. 


jfournal    of    the    Tokyo    Chemical    Society      ("  Tokyo 

Kwagakukwai "),  Vol.  xviii.,  No.  3,  March,  1897. 
Molecular  Conductivity  of  Amido-sulphonic  Acid. — J.  Sa- 
kurai. — This  paper,  read  before  the  Society  and  printed 
in  Japanese  charadlers,  takes  up  about  two-fifths  of  the 
number,  and  is  illustrated  with  cuts  of  the  apparatus  used. 
The  remaining  pages  are  devoted  to  Abstradts  of  Che- 
mical Papers  published  in  other  Journals  and  Miscella- 
neous Notes.  The  journal  appears  to  be  doing  well, 
but,  owing  to  unavoidable  circumstances,  we  are  unable  to 
make  any  detailed  observations  on  the  contents. 

Vol.  xviii.,  No.  4,  April,  1897. 
This  number  contains  an  original  paper  entitled  "  Report 
of  Experiments  on  the  Manufadlure  of  Japan  Camphor 
(No.  II.),"  by  M.  Moriya,  Rigakushi.  The  rest  of  the 
number  is  taken  up  with  the  Report  on  the  general  Pro- 
ceedings of  the  Society,  Abstradls  of  Chemical  Papers 
published  in  other  Journals,  and  Miscellaneous  Notes. 


The  Agricultural  jfournal  of  the  Cape   of  Good   Hope. 

Vol.  X.,  No.  II,  May  27,1897.    Cape  Town:  Townshend, 

Taylor,  and  Snashall. 
In  this  number  we  find  an  account  of  some  interesting 
experiments  on  rinderpest,  which  is  now  ravaging  South 
Africa  ;  they  were  carried  out  by  Dr.  Kohlstock  under  the 
diredtion  of  Dr.  Koch.  He  found  that  immunisation  was 
produced  by  serum,  but  is  of  short  duration,  not  longer 
than  from  ten  to  twenty  days.  Serum  taken  from  healthy 
full-grown  animals  after  mild  rinderpest,  which  had  been 
inoculated  with  20  c.c,  of  virulent  blood,  without  effedt,  to 
prove  its  immunity,  gave  the  strongest  serum.  Twenty- 
four  cattle  were  used  for  this  experiment.  The  best  serum 
was  given  by  an  animal  which  was  first  injedted  with  gall, 
and  then  with  rinderpest  blood,  before  immunity  was 
established,  so  that  it  suffered  from  a  mild  attack  :  this  is 
the  method  recommended  by  Dr.  Koch,  and  has  been 
established  by  further  experiments.  The  serum  seems  to 
be  strongest  when  taken  between  the  tenth  and  twentieth 
days — say  the  fifteenth. 

One  animal  appeared  to  be  naturally  immune  ;  it  was 
an  ox  which  had  been  destined  to  produce  gall ;  but  the 
introdudlion  of  10,  20,  and  even  50  c.c.  of  rinderpest 
blood  failed  to  produce  any  effedt.  Experiments  are 
being  made  with  serum  from  this  animal.  Two  calves 
born  on  the  station  proved  to  be  immune  ;  they  were  both 
produced  by  cows  which  had  previously  been  rendered 
immune.  Dr.  Kohlstock  firmly  believes  that  if  gall  in- 
oculation is  made  in  the  manner  indicated,  rinderpest  will 
soon  be  a  thing  of  the  past  in  South  Africa  :  we  sincerely 
hope  this  is  the  case. 


CHEMICAL  NOTICES  FROM  FOREIGN 
SOURCES. 

NoTB.— All  degrees  of  temperature  are  Centigrade  unleBtothorwiie 
expreised. 

Comptes  Rendus  Hebdomadaires  des  Seances,  deVAcademie 
des  Sciences.  Vol.  cxxiv.,  No.  25,  June  21,  1897. 
Examination  of  some  Spedtra.— Lecoq  de  Boisbau- 
dran.— MM.  Eder  and  Valenta  resume  the  critique  of  my 
spedtrum  of  Au  undertaken  by  Prof.  Kriiss.  Demar9ay 
has  shown  that  the  objedions  of  Prof.  Kriiss  are  un- 
founded. Except  the  weak  ray  433-8,  the  origin  of  which 
I  do  not  presume  to  assert,  but  which  I  always  see  in  the 


Chemical  News,  » 


July  23,  1897. 


Chemical  Notices  Jrom  Foreign  Sources. 


47 


non-condensed  spark  with  the  very  concentrated  solution 
of  AUCI3,  M.  Deniar9ay  has  recognised  all  my  metallic 
rays.  It  was,  moreover,  improbable  that  the  strong  ray 
Au  5230  could  be  due  to  Pd,  and  that  Au  406-4,  the 
strongest  of  all  with  a  short  wire,  was  alien  to  gold.  The 
pure  gold  of  commerce  would  give  an  appreciable  spec- 
trum of  palladium,  and  I  did  not  fail  to  thoroughly  purify 
my  gold.  Except  433'8,  all  my  metallic  rays  have  been 
seen  by  Eder  and  Valenta.  The  other  rays  (except, 
possibly,  592'5)  are  found  in  the  spedlrum  of  the  flame  of 
AUCI3.  The  weak  ray  592*5  (A.)  is  difficult  to  see  or  to 
measure.  I  have  obtained  it  formerly  with  AUCI3  and 
eledtrodes  of  Pd  or  Pt.  Having  examined  it  again,  I  have 
found  it  slightly  fainter  and  more  cloudy  than  it  is  shown 
in  my  sketch.  Measurements  gave  about  592'56  (A.).  In 
the  flame,  the  thick  band  59r3  would  mask  592*5  if  this 
ray  exists  there.  I  see  therefore  always  the  faint  ray 
592-5  with  AUCI3  in  the  spark,  but  1  cannot  assert  any- 
thing as  to  its  origin.  Eder  and  Valenta  have  a  faint  and 
indistindt  ray  at  592-143  (Rd.),  592-043  (A.).  Can  this  be 
the  same  ?  If  I  read  their  text  corredtly,  Eder  and 
Valenta  say  that  my  band  560-1  does  not  belong  to  gold, 
no  more  than  my  ray  521-2.  On  referring  to  my  sketches, 
we  find  560-1  and  521-2  among  the  principal  rays  or 
bands  volatilised  in  the  flame.  Eder  and  Valenta  say 
that  my  ray  444*2  does  not  belong  to  gold.  I  have  not 
this  ray,  but  I  have  one  at  44377  (A.),443-84  (Rd.),but  it 
has  been  seen  by  Eder  and  Valenta  at  443-787  (Rd.).  I 
have  not  given  the  ray  434*5,  I  have  only  seen  there  the 
ray  433*8i  (A.),  433*87  (Rd.).  I  have  made  new  experi- 
ments on  the  subjedi  of  this  ray  433*8.  A  series  of 
measurements  (difficult)  has  given  433*83  (A.),  433*89 
(Rd.),  In  a  vacuum  tube  the  CI  has  a  dense  cloudy  ray, 
which  I  have  measured  at  about  434*30  (A.).  This  seems 
to  me  rather  remote  from  443*83.  Moreover,  the  aspedls 
of  the  rays  are  very  different.  In  the  open  air,  between 
platinum  points,  the  condensed  spark  gives  a  thick  ray 
which  I  find  at  434*75  (A.) ;  this  is  far  from  433*83.  In 
the  neighbourhood  of  433*8  I  only  see  with  the  condensed 
spark  (taken  between  dry  or  moist  poles)  a  faint  ray,  sensibly 
more  refrangible  than  that  seen  with  AUCI3.  The  ray 
AUCI3  433*8  does  not  seem  to  belong  to  hydrogen,  though 
near  to  it  (Angstrom  gives  H =434*01).  A  moderately 
concentrated  solution  of  AUCI3  has  not  shown  me  433*8 
with  the  condensed  spark.  In  fine,  the  ray  433*8  is  seen 
always,  though  not  without  difficulty,  with  the  uncon- 
densed  spark  and  a  very  concentrated  solution  of  AUCI3. 
No  more  than  Demar9ay,  with  his  short  coil,  or  Eder  and 
Valenta  have  I  seen  this  ray  between  poles  of  metallic 
gold,  nor  by  the  use  of  the  condensed  spark.  I  do  not 
succeed  in  identifying  it  with  certainty  with  any  of  the 
rays  of  CI,  H,  C,  N,  Ar — bodies  present  in  the  spark 
drawn  from  AUCI3. 

Potassium  Sulphantimonites.  —  M.  Pouget.  — 
Antimony  sulphite  forms  with  potassium  sulphide  a 
normal  sulphantimonite,  SbS3K3  ;  a  pyrosulpho- 
antimonite,  SbaS5K4;  a  metasulphoantimonite,  SbSaK; 
and,  lastly,  a  compound  containing  still  less,  Sb4S7K3. 

Fluidity  of  Melted  Nickel. —  Jules  Gamier. — The 
great  fluidity  of  nickel  when  melted  at  high  temperatures 
may  serve  to  explain  the  increase  of  resistance  which  it 
gives  to  irons. 

Combinations  of  Tellurium  Iodide  and  Bromide 
with  the  Corresponding  Hydracids. — R.  Metzner. 

Analysis  of  Bronzes  and  Brasses  by  the  Ele(!\ro- 
lytic  Process. — A.  Holland. — Already  inserted. 

Formic  Aldehyd.  A(ftion  of  Potassa. — M.  Delepine. 
— Not  suitable  for  abstradion. 

Destrudion  of  Organic  Matters  in  Toxicology. — 
A.  Villiers. — The  author's  process  is  founded  on  the  use 
of  the  salts  of  manganese.  Organs  such  as  the  liver,  the 
spleen,  and  the  lungs  are  dissolved  in  a  few  minutes. 
Muscular  fibres  are  disintegrated  and  then  dissolved  in 
about  an  hour,  leaving  merely  a  fatty  residue. 


Caffeotannic  Acid.— P.  Cazeneuve  and  M.  Haddon. — 
Not  suitable  for  abstraftion. 

Coleopterine :  a  Red  Pigment  from  the  Elytra  of 
certain  Coleoptera.— Dr.  A.  B.  Griffiths.—  Pyrochroa 
coccinea,  Lina  populi,  and  Coccinella  septempunctata  yield 
one  and  the  same  pigment,  which  is  soluble  in  alcohol 
and  ether.  The  pigment  is  composed  of  C7H8NO5. 
When  isolated,  the  pigment  is  decolourised  by  light.  Its 
solutions  yield  no  charadteristic  absorption  bands.  The 
author  names  it  provisionally  "  coleopterine." 

"Fradture"  of  Wines.— M.  Lagata.— The  author 
refers  this  morbid  phenomenon  to  the  atftion  of  iron. 

No.  26,  June  28,  1897. 

The  Death  of  Prof.  Schijtzenberger.— The  President 
officially  informed  the  Academy  of  the  death  of  the  late 
illustrious  Professor.  The  deceased,  it  may  be  said,  died 
in  adtion,  leaving  in  his  laboratory  important  researches 
incomplete. 

Nomination. — M.  de  Lapparent  was  elefted  a  member 
of  the  Sedlion  of  Mineralogy,  vice  the  late  Prof,  des 
Cloizeaux. 

Medical  Use  of  Ozone.  —  Charles  Chardin.  —  The 
author  recommends  a  treatment  with  ozone  in  cases  of 
cancer  and  other  infedtious  maladies. 

Researches  on  Nickel  Steels,  Permanent  Magnetic 
Properties  and  Deformations. — Ch.  Ed.  Guillaume. 

Silver  Sulphantimonites. —  M.  Pouget. —  The  adtion 
of  silver  nitrate  upon  normal  sulphantimonite,  SbS3K3, 
yields,  according  to  the  conditions  of  the  operation,  two 
well-defined  bodies,  SbSsAgjK,  either  in  an  amorphous 
or  a  crystalline  state.  The  author  has  only  succeeded  in 
obtaining  the  salt,  SbSsAgK^. 

Part  of  Manganese  in  certain  Oxidations. — Ach. 
Livache. — In  a  litharged  or  manganesed  oil,  the  lead  or 
the  manganese  play  the  part  of  intermediaries,  taking 
oxygen  from  the  air  and  handing  it  over  in  continuous 
manner  to  the  oil,  which  is  thus  oxidised  more  rapidly 
than  it  would  be  in  their  absence. 

The  Colour  of  the  Phosphorescence  of  Strontium 
Sulphide. — Jose  Rodriguez  Mourale. — The  experiments 
prove  thai  the  temperature  at  which  the  sulphides  are 
formed  has  not  a  great  influence  on  the  phosphorescence, 
for  the  most  phosphorescent  sulphides  are  not  those  whose 
formation  requires  the  strongest  or  the  most  prolonged 
heat.  Strontium  sulphide  always  presents  a  phosphor- 
escence of  a  green  more  or  less  pure  and  intense.  This 
property  appears  closely  connedted  with  the  properties  of 
produdlion,  and  with  substances  which  affedt  the  purity  of 
the  bodies  employed. 

Observations  on  the  Molecular  Volumes  at  0°  of 
Various  Crystallised  Hydrates  of  Carbon.  —  M. 
Pionchon. 

Trioxymethylene  and  Paraformaldehyd. — M.  Dele- 
pine.  —  A  thermo-chemical  paper,  not  suitable  for  ab- 
stradtion. 

On  certain  Compounds  of  Phenylhydrazine  with 
the  Metallic  Iodides.— J.  Moitessier.— The  compounds 
here  discussed  are  the  phenylhydrazinic  zinc  iodides,  a 
and  b;  the  phenylhydrazinic  cadmium  iodide  ;  the  phenyl- 
hydrazinic manganous  iodide  ;  and  the  phenylhydrazinic 
nickel  iodide.  The  nitrates  of  the  various  metals  of  the 
magnesian  series  form  crystallinic  compounds  with 
phenylhydrazine. 

Compounds  of  Metallic  Salts  with  the  Organic 
Bases,  Homologues  of  Aniline,  and  their  Isomers. — 
D.  Tombeck. — An  examination  of  compounds  formed  by 
toluidine,  xylidine,  picoline,  and  lutidine. 

Adtion  of  Acetylene  upon  Silver  Nitrate.— G.  Arth^ 
— Not  suitable  for  abstradion. 


48 


Chemical  Notices  from  Foreigh  Sources, 


{Chemical  News, 
July  23,  1897. 


Bulletin  de  la  Societe  Chimique  de  Paris. 
Series  3,  Vol.  xvii.-xviii.,  No.  11.    June  5,  1897. 

Notice  on  the  Life  and  Works  of  Alphonse 
Combes.  —  Ch.  Friedel.  —  A  long  and  interesting  bio- 
graphical sketch  of  the  career  of  the  late  Alphonse 
Combes,  at  one  time  President  of  this  Society.  He  was 
a  comparatively  young  man,  having  been  born  in  1858, 
and  his  death  was  extremely  sudden.  The  memoir  is 
accompanied  by  an  excellent  portrait. 

Rea<J\ion  facilitating  the  Recognition  of  Naphthola 
from  Naphthol  /3. — E,  L6ger. — An  aqueous  solution  of 
the  matter  under  examination  is  made  by  triturating  the 
crystals  in  a  mortar.  To  10  c.c.  of  this  solution  are  added 
2  drops  of  a  solution  of  hypobromite  of  soda.  With 
naphthol  a  a  colouration,  or  even  a  dirty  violet  precipi- 
tate, is  produced  ;  with  naphthol  /8  a  yellow  colour  first 
appears,  gradually  becoming  greenish ;  it  then  passes  to 
a  brownish  green,  to  again  become  yellow.  It  is  of  im- 
portance that  all  the  solutions  used  should  be  freshly 
prepared. 

On  Two  New  Alkaloids  isolated  from  a  Species  of 
Jaborandi. — A.  Petit  and  M.  Polonovski. — These  two 
alkaloids  have  been  found  in  a  specimen  of  the  plant  for 
which  the  name  Pilocarpus  spicatus  has  been  proposed. 
The  alkaloid  o  is  a  colourless  syrup,  with  a  very  alkaline 
reaftion,  easily  soluble  in  water,  alcohol,  and  chloroform. 
The  authors  have  named  it  pseudojaborine  ;  the  base  j3, 
which  they  have  named  pseudopilocarpine,  presents  the 
same  charadleristics  as  pilocarpine,  except  that  it  does 
not  ai5t  upon  polarised  light. 

Contributions  to  the  Study  of  Pilocarpine  and 
Pilocarpidine. — A.  Petit  and  M.  Polonovski. — These  two 
bodies  have  been  the  subjeft  of  a  good  deal  of  research. 
At  the  present  time,  however,  though  the  properties  of 
pilocarpine  are  fairly  well  known,  those  of  pilocarpidine 
are  to  a  certain  extent  under  a  cloud.  The  authors  find 
the  observations  of  MM.  Hardy  and  Calmels  on  this  sub- 
jedl  are  not  sufficiently  exadt;  this  causes  them  to  think 
that  their  theoretical  conclusions  are  too  arbitrary;  they, 
the  authors,  have  therefore  set  forth  in  this  note  the  points 
of  difference  they  have  found,  in  a  somewhat  extended  re- 
search, between  their  own  results  and  those  of  the  other 
afore-mentioned  experimentalists. 

Remarks  on  the  Congealing-point  of  Milk.  —  J. 
Winter.— The  author  gives  as  a  constant  the  temperature 
—  0'556°,  remarking  that  variations  of  o'oi"  above  or  below 
this  can  be  observed.  His  results  have  been  confirmed 
by  other  workers  on  the  subjefl;. 


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Separations  with  Alkaline  Acetate. 


49 


THE    CHEMICAL    NEWS 


Vol.  LXXVI.,  No.  1966. 


SEPARATIONS    WITH    ALKALINE    ACETATE. 

By  HARRY  BREARLEY. 

(Continued  from  vol.  Ixxv.,  p.  254]. 

II. — Nickel  from  Iron. 
Nickel  is  frequently  separated  from  iron  by  repeated  re- 
precipitation  with  alkaline  acetate.  A  method  previously 
proposed  (Chemical  News,  vol.  Ixxiv.,  p.  16),  in  which 
the  error  introduced  by  using  large  amounts  of  acetate  is 
eliminated  by  using  large  amounts  of  acetic  acid  with 
hydrate-free  solution,  worked  very  satisfacftorily.  Further 
experience  with  alkaline  acetate,  under  more  precise  con- 
ditions, has  shown  that  accuracy  over  a  wider  range  may 
be  secured  without  using  so  wastefully  large  a  volume  of 
reagents.  The  present  intention  is  to  determine,  and 
state  in  definite  terms,  under  what  conditions  the  separa- 
tion can  best  be  made. 

It  would  be  too  laborious,  perhaps  unnecessary,  to  vary 
the  proportion  of  dissolved  hydrate  and  examine  each 
with  series  of  free  acetic  acid  and  acetate.  The  suc- 
cessful separation  in  solutions  containing  no  dissolved 
hydrate  which  had  been  formerly  experienced  led  me  to 
work  out  the  series  tabulated  below  : — 


Table  III. 

Ammonium  acetate.    C,c. 


220. 


260. 


Acetic 

acid.      /— — — 

C.c.  140.      160.      180. 

o  33-0  31-66  30-55      —      — 

10  —    32-82  31-96  30-4      — 

20  —        —     32-7     31-77  3I-I 

40  — 

60  — 


Range  of 
temperature 
— ^    turbidity. 
600.         °C. 


400 

—  —     86—68 
_        _     87-76 

—  —      90 — 82 
—    32-47  32-0     30-6  29-89  91—78 

32-68  31-57  30-96  95—83 

The  work  was  done  on  a  5  per  cent  nickel  steel.  The 
figures  represent  c.c.'s  of  the  potassium  cyanide  used  in 
titrating  the  filtrate. 

A  shorter  series  was  gone  through  in  which  the  acetic 
was  replaced  by  hydrochloric  or  nitric  acid,  and  another 
in  which  the  sample  was  dissolved  in  nitric  acid  instead 
of  aqua  regia.  The  results  obtained  were  quite  as  good 
as  those  tabulated,  but  no  marked  improvement  on  them. 
The  separations  with  soda  acetate  were  slightly  better 
than  those  with  ammonium  acetate. 

Separations  from  solutions  containing  the  maximum 
amounts  of  dissolved  hydrate  gave — 


Acetic  acid. 
0 

Ta 

BLE   IV. 
Acetate.    C.c. 

5. 
0-0498 

10. 
0-0483 
0-0500 
0-0504 

20. 
0-0477 
0-0498 
0-0504* 

The  line  marked  with  an  asterisk  refers  to  soda  salts. 
'The  samples  adtually  contained  0-0500  grm.  Ni.  Ex- 
periments were  made  with  solutions  containing  half  the 
dissolved  hydrate.  They  were  neither  better  nor  worse 
than  those  already  tabulated. 

It  became  necessary  to  choose  what  amounts  of  dis- 
solved hydrate,  acid,  and  acetate  should  be  adopted  in 
order  that  the  effedt  of  certain  other  variations  might  be 
observed.  I  believe  that  almost  any  volume  of  acetate, 
with  a  suitable  amount  of  free  acid,  could  be  satisfadlorily 
employed;  and,  similarly,  any  proportion  of  dissolved 
hydrate  might  be  fixed  upon.     Chiefly  in  deference  to 


customary  practice  I  chose  solutions  containing  the  total 
soluble  hydrate.*  But  such  solutions  have  an  irritating 
tendency  to  become  turbid  if  they  are  left  for  any  length 
of  time  at  this  stagef ;  and,  moreover,  a  few  c.c.  of  such 
dilute  acetate  as  is  used  made  a  deal  of  difference  to  the 
separation.  For  these  reasons  I  add  also  10  c.c.  of  acetic 
acid.    The  choice  proved  a  good  one. 

I  will  now  describe  the  method  for  separating  nickel 
and  iron.  The  details  rest  upon  observations  either 
already  made  or  subsequently  to  be  made.  It  is  written 
as  applying  to  alloys  of  the  two  metals  ;  it  can,  of  course, 
readily  be  adapted  to  those  elements  in  other  states. 

Dissolve  in  hydrochloric  acidandoxidisewith  nitric  acid. 
In  case  the  alloy  contains  little  or  no  carbon  it  may  be 
straightway  dissolved  in  nitric  acid.  Dilute,  cool,  add 
carbonated  alkali  until  a  slight  permanent  precipitate 
forms  (if  the  sample  is  always  dissolved  in  the  same 
amount  of  acid  the  volume  of  standard  alkali  will  be 
approximately  known) ;  add  10  c.c.  acetic  acid,  dilute  to 
somewhat  less  than  a  litre  (say)  with  either  hot  or  cold 
water,  add  10  to  12  c.c.  ammonia  (soda)  acetate,  of  the 
strength  previously  mentioned,  for  each  grm.  of  iron  in 
solution.  If,  on  nearing  the  boiling-point,  owing  to  im- 
perfect neutralisation,  no  turbidity  occurs,  add  acetate  (2 
or  3  c.c.  at  a  time)  until  it  does.  Boil,  measure  volume, 
cheese  until  precipitate  settles,  and  filter  aliquot  part 
through  asbestos.  Then  cool,  neutralise,  add  measured 
quantity  of  dilute  ammonia,  titrate  with  KCN  and  Agl, 
or  estimate  Ni  in  any  other  way. 

The  following  variations  show  that  the  method  is 
widely  applicable,  They  are  a  selection  only  from  a  list 
embracing  every  likely  variation  I  could  think  of. 

Dr.  Wolcot  Gibbs  (Chemical  News,  vol.  xi.,  p.  102  ; 
Crookes,  •'  Seledt  Methods,"  3rd  edition,  p.  227), 
respedting  the  separation  of  iron  and  nickel  says  : — "  The 
solution  from  which  the  iron  is  to  be  precipitated  must 
be  dilute.  Half  a  litre  should  not  contain  more  than  one 
grain  (0-065  §'''"•)  of  the  sesquioxide."  From  a  solution 
containing  i  grm.  of  iron  (7I  grains)  to  the  half  litre,  I 
have  already  separated  nickel  up  to  5  per  cent  of  the  alloy. 
As  the  separations  of  nickel  from  iron  by  means  of  soda 
phosphate  in  acetic  solutions  is  said  to  be  applicable  only 
when  the  nickel  does  not  exceed  3  per  cent  ("  SeleiS 
Methods,"  p.  205),  it  was  anticipated  that  with  higher 
percentages  the  separation  with  acetate  would  become 
less  accurate.  This  fear  was  not  realised,  at  least  not 
with  the  somewhat  abnormal  quantities  shown  below. 
Each  sample  contained  i  grm.  of  iron. 


Table  V. 

Ni  taken. 

Ni  found. 

Per  cent  recovery 

o-iooo  grm.* 

O-I0O2 

100-2 

0-2000 

0-2008 

100-4 

0-3000 

0-3009 

100-3 

0-5000 

0-4993 

99-86 

0*8000* 

o-8oo8 

loo-i 

These  were  done  with  ammonia  salts.  Soda  salts 
were  tried  in  two  cases  only,  and  gave — Nickel  taken, 
o-iooo,  0-2000  grm.;  Ni  found,  0-1002,  0-1996.  The 
potassium  cyanide  was  standardised  with  quantities  of 
nickel  corresponding  to  that  in  the  filtrates  marked  with 
an  asterisk.  The  values  for  the  KCN  obtained  were  not 
quite  proportional.     The  variation  was  nearly  i  per  cent. 


*  The  "Foreign  Science"  letter  in  the  Chemical  News,  vol. 
xvii.,  p.  286,  chronicles  experimentswhich  are  interesting  in  relation 
to  the  remarks  on  dissolved  hydrate  in  my  previous  paper.  It  is 
related  that  M.  Jeaunel  prepared  in  the  cold  a  solution  of  ferric 
chloride  containing  nine  times  as  much  iron  as  the  officinal  solu- 
tion. "  A  few  drops  thrown  into  water  produce  a  voluminous  brown 
precipitate.  The  solution  of  ferric  chloride  is  decomposed  and  pre- 
cipitated by  small  quantities  of  sulphuric  acid  or  of  sulphates,  It  is 
likewise  decomposed  by  citric,  tartaric,  or  by  a  few  drops  of  HCl  or 
HNOg. 

t  Boiling  at  this  point  without  the  addition  of  any  further  reagent 
forms  what  is  known  as  Herschel's  or  Schwarzenberg's  method, 
Dittmar  ("  Quant.  Chem.  Anal.,"  p.  74),  in  1887,  speaks  of  it  as  "  the 
best  method."    (See  also  *'  Fresenius'  Quant.  Anal."). 


50 


Separations  with  A  Ikaline  A  cetate. 


f  Cbbmical  News, 
1      July  30,  1807. 


The  values  for  the  intermediate  tests  were  calculated  by 
interpolation  from  those  found  experimentally.  No  pro- 
portions of  the  two  metals  less  favourable  to  a  perfeft 
separation  than  the  above  are  likely  to  be  found  in 
pradlice. 

If  one  has  not  long  been  used  to  perfedlly  neutralising  iron 
solutions,  it  will  frequently  happen,  through  imperfedt 
neutralisation,  that  the  acetate  prescribed  is  insufificient  to 
even  cause  a  turbidity  at  boiling-point.  In  such  cases  could 
more  acetate  be  added  without  introducing  error?  It  has 
been  repeatedly  pointed  out  that  the  acetate  should  be 
added  to  the  cold  solution.  This  precaution  probably  arose 
through  the  almost  universal  custom  of  adding  wastefully 
large  amounts  of  acetate.  The  following  experiments 
answer  the  question,  at  least  for  the  present  elements  and 
mode  of  operating. 

Two  samples  containing  i  grm.  iron  and  o'l  grm.  Ni, 
and  in  other  ways  treated  as  usual,  except  that  no  acetate 
was  added,  were  heated  to  go — 100°  C. ;  13  c.c.  and  15 
c.c.  were  dropped  from  a  burette,  the  solution  being 
meanwhile  vigorously  stirred.  Each  drop  as  it  touched 
the  iron  solution  formed  a  precipitate  which  was  imme- 
diately dissolved  in  the  agitated  liquid.  In  the  first  case 
a  faint  turbidity,  and  in  the  second  case  a  decided  tur- 
bidity, was  apparent  before  the  last  drop  of  acetate  was 
delivered.  There  was  recovered  o'looi  gr.  nickel  in  each 
case.  The  dropping  of  the  acetate  and  stirring  of  the 
liquid  seem  needless  precautions.  Two  samples,  pre- 
pared as  before,  were  heated  to  97°  C,  and  15  c.c. 
acetate  wfire  run  in  and  allowed  to  become  mixed  by  the 
conve(5tive  movement  of  the  liquid.  The  amounts  of 
nickel  recovered  were  O'ioo3  and  o'looi  grm.respeiftively. 

When  too  much  acetate  has  been  inadvertently  added, 
and  the  iron  is  precipitated  at  low  temperatures,  more 
acid  may  be  added,  the  assay  re-started ;  or,  where 
neither  is  desirable,  the  heating  should  be  discontinued 
as  soon  as  the  precipitate  gathers  into  flocks  and  the  solu- 
tion against  a  white  rod  shows  itself  only  slightly 
coloured  ;  the  flask  well  shaken,  cheesed,  &c.,  as  usual. 
In  this  way  the  recovery  is  greater  than  if  the  solution  is 
raised  to  boiling,  although  it  is  not  necessarily  a  coni- 
plete  recovery.  On  the  other  hand,  if  the  solution  is 
turbid  at  boiling-point,  but  the  precipitation  of  the  iron 
not  so  complete  as  to  give  a  clear  filtrate,  instead  of 
adding  more  acetate  the  iron  may  be  further  precipitated 
by  prolonged  boiling.  The  table  shows  that  no  error  is 
thereby  introduced.     One  grm.  iron  present  in  each  case. 


Table  VI. 

inutes  boiled. 

Ni  present. 

Ni  found 

X 

O'lOOO 

o"ioo3 

40 

O'lOOO 

O'lOOI 

50 

O'lOOO 

0*1003 

Even  when  there  is  no  precipitate  at  boiling-point  the 
separation  may  be  effeded  by  partially  confining  the 
steam,  and  thus  raising  the  temperature.  But  such  an 
arrangement  is  troublesome,  and  has  been  of  no  service 
yet.     Under  other  circumstances  it  may  be. 

Additional  quantities  of  ammonium  nitrate  or  chloride 
aft  in  two  ways.  They  lessen  the  quantity  of  alkali 
necessary  to  neutralise  the  iron  solution,  and  they  lower 
the  temperature  of  turbidity.  In  the  accompanying  table 
there  was  added  to  1.  nothmg;  to  II.  ammonium  chloride 
equal  to  10  c.c.  HCl  ;  and  to  III.  ditto  equal  to  20  c.c. 
HCl.  The  same  vol.  of  acetate,  14  c.c,  was  added  in 
each  case. 

Table  VII. 
Ni  added.  Ni  iaund. 

I.  o'looo  0*0998 

II.  o'looo  0*0998 

III.  o"ioco  0*0996 

Jewett  (Chemical  News,  xl.,  273)  finds  that  if  ammo- 
nium chloride  is  present  the  separation  of  Ni  and  Fe  is 
more  complete  than  otherwise. 


If  the  nickel  is  to  be  estimated  by  titration  with  cyanide 
and  silver  iodide,  it  is  but  a  slight  disadvantage  should 
the  filtrate,  owing  to  imperfedt  separation  of  iron,  be 
slightly  tinted.  Such  small  amounts  may  be  separated 
by  adding  ammonia,  or  more  acetate  and  boiling  and 
filtering,  or  by  proceeding  with  the  titration  as  usual.  In 
the  latter  case,  where  so  much  is  present  as  to  interfere 
with  the  end  readtion,  a  slight  excess  of  the  KCN  may  be 
added,  the  solution  run  through  an  asbestos  filter,  and  the 
clear  filtrate  taken  to  faint  turbidity  with  the  silver  nitrate. 
Comparatively  large  quantities  of  suspended  ferric  hydrate 
are  known  to  introduce  no  inaccuracy  in  cyanide  titrations 
of  cupric  ammonium  solutions,  so  that  examples  to 
justify  the  practice  with  nickel  are  unnecessary. 

Obvious  enough  is  the  suggestion  that  in  precipitating 
the  iron  with  alkali  and  acetate,  or  alkali  alone,  adding 
excess  KCN  and  going  back  in  a  filtered  aliquot  part  with 
silver  nitrate,  lies  a  rapid  approximate  method,  such  as 
might  be  serviceable  where  a  large  number  of  assays  had 
to  be  completed  in  little  time.  Precipitating  with  ammo- 
nium carbonate,  adding  ammonia,  and  titrating  as  just 
suggested,  yielded  99  per  cent  of  the  Ni  present.  The 
separation  was  better  in  cold  than  in  hot  solutions,  and 
better  when  the  precipitation  was  made  with  carbonate 
than  with  ammonia. 

There  are  elements  sometimes  associated  with  nickel 
in  the  filtrate  which  are  not  without  adtion  on  the  cyanide. 
Of  zinc  and  cobalt,  which  rarely  appear  in  steel  works' 
laboratories,  nothing  need  be  said  now.  Such  quantities 
of  manganese  as  are  found  in  steel  have  no  influence 
whatever  when  ammonia  salts  are  used  throughout.  But 
the  titrating  of  a  filtrate  containing  severally  0*05  grm.  of 
nickel  and  manganese  begins  to  present  difficulties  when 
separated  from  iron  as  previously  described.  The  ammo- 
nia salts  present  are  unable  to  keep  the  manganese  in 
solution  for  any  considerable  time.  In  presence  of  larger 
quantities  of  ammonia  salts  a  satisfadtory  titration  may 
be  made  with  double  this  quantity  of  manganese  present. 
I  need  scarcely  point  out  that  if  soda  salts  are  used  the 
manganese  must  be  separated  at  some  stage  prior  to  the 
titration,  as  suspended  oxide  of  manganese  causes  low 
results  (Chemical  News,  i.,  25;  xxxiii.,  152).  Copper 
is  conveniently  separated  from  the  filtrate  as  sub-sulpho- 
cyanide  ("  Seleft  Methods,"  p.  294).  Chromium,  in  the 
presence  of  large  amounts  of  acetic  acid,  would  be  partly 
in  the  filtrate,  but  with  the  amount  used  (10  c.c.)  appears 
to  be  altogether  precipitated  with  the  iron.  Large  amounts 
of  aluminium  would  demand  exceptional  treatment.  I 
pro{)ose  to  postpone  this  item  until  the  separation  of 
aluminium  and  iron  is  considered. 

Addenda. 
,  Remarks  on  the  Titration. 

The  means  adopted  in  this  paper  of  estimating  the 
nickel  have  been  largely  used  and  highly  spoken  of  during 
the  past  few  years.  Titration  with  KCN,  in  which  the 
indicator  was  the  solubility  of  the  previously  formed  pre- 
cipitate in  an  excess  of  the  reagent,  or  the  decolouration 
of  added  cupric  ferrocyanide,  had  been  previously  used. 
The  use  of  silver  iodide,  formed  in  the  solution,  as  indi- 
cator makes  the  titration  as  perfedl  as  can  be.  Deniges 
{Comptes  Rendus,  cxvii.,  p.  1078;  Chemical  News,  Ixix., 
p.  42)  shows  how  any  compound  of  silver,  or  anything 
capable  of  modifying  such  a  compound,  can  be  accurately 
estimated  by  these  means.  Moore  (Chemical  News, 
Ixxii.,  p.  92)  gives  a  good  account  of  nickel  titration  after 
separating  that  element  from  steel.  The  method  has  also 
been  adopted  in  the  same  conneftion  by  American  writers 
(Campbell  and  Andrews,  yourn.  Amer.  Chem.  Soc, 
Feb.,  1895). 

Before  entering  on  the  work  previously  described,  the 
titration  was  performed  in  the  presence  of  varying  amounts 
of  reagents.    They  are  not  altogether  without  influence. 

The  presence  of  ammonium  salts  deepens  the  turbidity 
formed  by  the  silver  nitrate  and  potassium  iodide.    If 


Cbbmical  Nbws. 
July  30,  1807. 


Volumetric  Determination  of  Zinc  by  Potassium  Ferrocyanide.       51 


-equal  volumes  of  sulphuric,  nitric,  and  hydrochloric  acid 
are  added  to  separate  solutions  before  neutralising,  the 
iodide  precipitate  is  decreasingly  turbid  in  the  same 
order.  Hence,  as  has  been  previously  recommended, 
about  2  C.C.  of  H2SO4  should  be  added  unless  large  quan- 
tities of  ammonium  (or  soda)  salts  are  already  present. 

It  is  well  known  that  very  large  quantities  of  ammonia 
introduce  error  into  the  titration  ;  however,  statements 
on  this  head  are  not  very  precise,  and  leave  much  to  indi- 
vidual discretion.  Deniges  says  "Variations  even  very 
considerable  in  the  proportions  of  ammonia  added,  the 
presence  of  potash  or  soda,  free  or  as  salts,  have  no 
influence  on  the  quantity  of  silver  nitrate  used."  Camp- 
tell  and  Andrews  —  "  The  solution  should  have  Just 
enough  free  ammonia  to  give  a  slight  but  distinft  odour  " ; 
and  so  on.  To  test  the  point,  ammonia  (o'88o)  v^as 
diluted  with  three  times  its  volume  of  water.  A  solution 
was  prepared  containing  ammonium  sulphate,  potassium 
iodide,  and  ammonia  to  faint  alkalinity,  then  4  c.c.  in  ad- 
dition, and  made  up  to  two  litres.  100  c.c.  of  this  mixture 
was  made  up  to  300  c.c.  with  water,  a  measured  amount 
of  silver  nitrate,  and  varying  amounts  of  ammonia.  The 
table  shows  the  result  with  the  indicator  alone,  and  ditto 
to  which  has  been  added  o-oi  grm.  nickel.  The  two  sets 
of  solutions  were  not  identically  alkaline  to  begin  with. 


Ammon.  added     o 


10       20    50C.C. 
4-88   4-68,  4-43 


4        2         5 

C.C.    I  Indicator  5-38,  5-03,  4'93,  4'88 

KCN  1  Do.-fNi  19-27,  ig-o,  ig-o,  1895, 18-94, 18-59,  io-6(!)' 

*  This  was  several  times  repeated. 

The  chloride,  nitrate,  and  acetate  of  ammonia  are 
without  any  appreciable  influence. 

A  few  drops  of  artificial  alizarin  solution  may  be  used 
as  indicator  when  neutralising  the  free  acid.  In  an  alka- 
line solution  it  has  a  pink  colour,  and  this,  along  with  the 
creamy  silver  iodide,  produced  a  purple  tint,  which 
changes  to  pink  again  when  the  Agl  is  dissolved.  It  is 
easy  to  titrate  by  gas-light  in  this  way. 

Moore  finds  that  when  the  temperature  of  the  solution 
exceeds  20°  C,  the  titrations  are  irregular.  Some  labora- 
tories are  frequently  hotter  than  this.  Solutions  which 
have  stood  about  in  our  own  are  at  present  25°  C,  but  no 
irregularity  has  been  noticed  on  this  account.  Titration 
certainly  ought  not  to  be  performed  in  hot  solutions,  be- 
cause else  the  KCN  is  decomposed  apart  from  any  metal 
which  may  be  in  solution,  nor  should  solutions  be 
unnecessarily  exposed  to  the  air,  because  they  absorb 
CO2  and  give  off  HCN  ;  hence  the  slight  perceptible 
odour  (Gmelin,  vii.,  416).  But  Deniges  finds  that,  in 
presence  of  fixed  alkali, — "  soap-boilers'  lye," — a  solution 
of  KCN  can  be  kept  unimpaired  for  an  indefinite  time, 
and  even  boiled  for  five  minutes  without  appreciable 
alteration. 

I  am  obliged  to  Mr.  H.  Jervis  for  material,  though 
indiredl,  assistance. 


ON  THE 

'.VOLUMETRIC     DETERMINATION     OF     ZINC 
BY     POTASSIUM     FERROCYANIDE. 
By  L.  L.  DE  KONIN'CK  and  EUG.  PROST. 
(Concluded  from  p.  39). 

.  Application  of  the  Method  to  the  Estimation  of  Zinc  in 

Minerals,  &'C. 
The  titrimetric  estimation  of  zinc  by  ferrocyanide  in  acid 
solution,  in  minerals  and  zinciferous  metallurgical  pro- 
dudls,  necessitates  the  preliminary  removal  of  metals 
susceptible  of  reading  with  the  ferrocyanide.  The  method 
is  approximately  the  same  as  that  adopted  for  preparing 
the  solution  when  using  Schaffner's  method.  To  the 
ammoniacal  solution  finally  obtained,  containing  a  more 
or  less  constant  quantity  of  ammonic  compounds,  are 


added  a  few  drops  of  sodic  sulphite;  it  is  then  neutralised 
with  hydrochloric  acid  ;  then  acidulated  with  a  quantity 
of  the  same  acid,  which  quantity  should  be  kept 
constant. 

To  this  solution  is  added  a  measured  volume  of  ferro- 
cyanide, constituting  an  excess  of  20  to  25  per  cent  on 
the  quantity  necessary  for  exadt  precipitation.  After 
digesting  for  ten  or  fifteen  minutes,  the  back  titration  is 
performed  by  means  of  a  neutral  or  slightly  acid  titrated 
solution  of  ZnCij.  The  quantity  of  zinc  corresponds  to 
the  excess  of  the  reagent. 

Solutions  employed. 

A.  A  zincic  solution  TZn  =  o-oi  grm. — that  is  to  say, 
10  grms.  per  litre;  it  should  be  slightly  acid.  This  solu- 
tion is  made  by  dissolving  10  grms.  of  pure  zinc  in  the 
smallest  possible  quantity  of  hydrochloric  acid,  in  a  litre 
flask,  at  a  moderate  temperature.  When  the  solution  is 
complete  we  bring  the  volume  up  to  about  half  the  final, 
neutralise  the  excess  of  acid  with  potassic  carbonate, 
until  there  is  a  faint  permanent  precipitate,  which  dis- 
appears on  adding  a  drop  or  two  of  hydrochloric  acid. 
The  solution  is  then  cooled  to  the  normal  temperature, 
and  the  flask  filled  exa(5tly  to  the  mark  with  distilled 
water. 

B.  A  solution  of  ferrocyanide  of  potassium.  Although 
in  all  our  experiments  we  used  normal  solutions,  we  think  it 
would  be  an  advantage  to  give  this  solution  the  titration 
TZn  =  0-00625  grn^'t  or  i  more  than  the  titration  0-005. 
When,  as  is  frequently  the  case  in  industrial  assays,  the 
quantity  of  zinc  present  is  approximately  known,  it  is  best 
to  use  2  c.c.  of  ferrocyanide  per  centigrm.  of  zinc  ex- 
peded,  and  we  should  then  have  the  excess  of  about  25 
per  cent  that  we  recommend. 

According  to  the  formula — 

3ZnCl2+K8Fe2Cyi2  =  K2Zn3Fe2Cyi2-t-6KCl, 

the  ferrocyanide  solution  ought  to  contain  per  litre  the 
weight  given  by  the  proportion — 

3Zn  :  K8Fe2Cyia,6H20_, 
I95'33  :  843-52 
This  is  therefore  the  weight  to  take  if  we  have  perfedlly 
pure  ferrocyanide ;  if  not,  we  take  a  little  more,  and  after 
having  found  the  exa<St  titration  of  the  liquid  we  dilute  it 
to  bring  it  to  the  titration  wished  for.  Let  us  further 
remark  that,  on  account  of  the  influence  of  the  acid,  and 
of  the  ammonium  chloride,  which  is  generally  present  in 
the  solutions  under  examination,  it  is  preferable  in  every 
case  to  determine  the  titration  by  direft  experiment,  and 
also  that  it  is  by  no  means  necessary  to  know  exadtly  the 
titration  of  the  liquid,  if  we  do  the  assays  by  comparison 
with  pure  zinc.  In  such  a  case  it  would  suffice  to  prepare 
the  reagent  by  dissolving  27  grms.  of  commercial  ferro- 
cyanide weighed  on  the  assay  balance. 

C.  The  indicator.  A  i  per  cent  aqueous  solution  of 
crystallised  nitrate  of  uranium. 

Experimental  Determination  of  the  Titration  of  the 
Solution  of  Ferrocyanide,  and  its  Volumetric  Relation 
to  the  Zincic  Solution. 

With  a  view  to  counterbalancing  the  influence  of  acid 
and  salts  of  ammonia  on  the  estimations,  it  is  important 
that  the  determination  of  this  relationship  should  be  made 
under  conditions  as  similar  as  possible  to  those  of  an 
assay;  we  therefore  proceed  as  follows  : — 

Twenty  c.c.  of  ZnCl2,  100  c.c.  of  water,  50  c.c.  of 
AmCl,*  2  drops  of  sulphite, f  and  10  c.c.  of  hydrochloric 
acid  I  are  poured  into  a  flask. 


=  625  grms. :  X  =  26-99  grms. 


*  A  solution  of  AmCI,  containing  200  grms-.  per  litre  =  375 
normal.  The  proportion  of  AmCl  is  considerable  ;  it  would  certainly 
be  preferable  to  employ  less,  if  possible,  but  we  are  obliged  to  use 
this  quantity  in  order  to  reach  the  proportion  which  accumulates  in 
an  assay  by  the  neutralisation  of  the  ammoniacal  solution. 

+  A  solution  of  10  grms.  of  Na^SO^rHjO  per  100  c.c.  of  water.  As 
very  little  of  this  is  used,  and  as  it  changes  in  contaft  with  the  air, 
not  much  should  be  prepared  at  a  time. 

t  Pure  H  CI,  sp.  gr.  1-075.  This  acid  is  approximately  5  normal 
and  contains  about  182  grms.  of  HCl  per  litre. 


52 


Volumetric  Determination  of  Zinc  by  Potassium  Ferrocyanide.   {^']l'Sl^!8^.'^ 


With  the  exception  of  the  ZnClj  solution,  which  should 
be  measured  with  an  accurate  pipette,  the  measurements 
may  be  made  with  an  ordinary  graduated  glass. 

Into  this  mixture  we  pour4oc.c.  of  ferrocyanide,  consti- 
tuting an  excess  of  25  per  cent ;  stir  well,  and  let  stand 
ten  or  fifteen  minutes.  The  precipitate,  which  was  at 
first  gelatinous,  has  by  this  time  become  coherent  and 
settled.  We  then  titrate  back  with  the  zincic  solution, 
stirring  well  after  each  addition ;  a  tube  is  more  convenient 
than  a  rod  for  the  touch  test. 

After  each  addition  of  zincic  chloride,  a  drop  of  the 
mixture  is  taken  and  let  fall  into  a  drop  of  the  indicator. 
We  regulate  the  quantity  of  ZnClg  to  be  added  each  time 
by  the  intensity  of  the  colour  produced  by  contacft  with 
the  uranium  salt,  and  stop  when  the  addition  of  one  or 
two  drops  no  longer  gives  a  brown  colouration,  even  after 
two  minutes  contadt  with  the  indicator;  this  point  is 
shown  with  great  clearness. 

The  operation  we  have  just  described  enables  us  to 
establish  once  for  all  the  relation  of  the  value  of  the  two 
solutions  and  the  titration  of  the  ferrocyanide ;  in  faft, 
this  solution  will  keep  without  any  change  if  we  keep  it 
away  from  the  light.  The  slight  amount  of  ferricyanide 
which  may  be  formed  is  without  influence  on  the  assay  if 
— as  we  have  shown — we  add  a  small  quantity  of  sodic 
sulphite  to  the  solution  to  be  titrated,  as  the  ferri-  is  then 
re-converted  into  ferrocyanide. 


Assay  of  Minerals. 

Preparation  of  the  Solution. — We  treat  a  sample  of  2*5 
grms.  of  the  mineral,  dried  at  100°,  with  nitric  acid,  in  the 
case  of  a  blende  ;  or  with  fuming  hydrochloric  acid,  if 
we  have  to  do  with  a  calamine.  After  complete  solution 
we  evaporate  to  dryness,  so  as  to  make  the  silica  insoluble, 
and  take  up  the  residue  with  5  c.c.  of  fuming  hydrochloric 
acid  and  a  little  water;  then,  after  well  heating  so  as  to 
dissolve  the  basic  salts,  add  50  or  60  c.c.  of  water  and 
heat  to  70°.  We  then  pass  a  current  of  sulphuretted  hy- 
drogen ;  during  the  passage  of  the  gas  we  gradually  add 
100  c.c.  of  water,  to  facilitate  the  precipitation  of  the  lead 
and  cadmium,  which  would  not  come  down  in  a  too  acid 
solution  ;  but  we  should  not,  on  the  other  hand,  keep  up 
the  current  of  gas  beyond  the  necessary  time,  nor  dilute 
the  solution  too  much,  or  some  of  the  zinc  might  be  pre- 
cipitated. The  precipitated  sulphides  are  colledted  on  a 
filter,  with  the  silica,  if  we  do  not  want  to  estimate  the 
latter  separately;  and  washed  with  100  c.c.  of  water,  to 
which  is  added  5  c.c.  of  hydrochloric  acid  charged  with 
sulphuretted  hydrogen. 

The  washing  is  complete  when  the  last  drops,  made 
alkaline  with  ammonia,  no  longer  give  the  slightest  pre- 
cipitate with  sodic  sulphide;  the  filtrate  is  then  boiled 
until  all  the  sulphuretted  hydrogen  is  driven  off.  We  then 
add  10  c.c.  of  fuming  hydrochloric  acid,  and  10  to  25  c.c. 
of  saturated  bromine  water,  according  to  the  quantity  of 
iron  present,  so  as  to  re-oxidise  the  ferrous  salts  and  to 
assist  the  precipitation  of  the  manganese;  it  is  then 
poured,  a  little  at  a  time,  with  constant  shaking,  into  a 
500  c.c.  matras,  containing  100  c.c.  of  strong  ammonia* 
and  10  c.c.  of  a  20  to  25  per  cent  of  bicarbonate  of 
ammonia. 

On  cooling  we  add  water  up  to  the  mark,  shake  well, 
let  the  precipitate  settle,  and  filter,  but  taking  care  that 
the  filter  and  all  the  apparatus  is  dry. 

This  method  is  one  which  would  be  used  for  the  most 
complex  minerals.  The  addition  of  bromine  would  not 
be  necessary  if  there  were  no  manganese  present. 

We  take  100  c.c.  of  the  ammoniacal  filtrate,  add  a  few 

♦  Sp.  gr.  o'93,  or  approximately  10  normal.  It  is  desirable  to  use 
the  smallest  possible  quantity  of  both  ammooia  and  of  bicarbonate, 
so  as  to  keep  down  the  contents  of  ammonium  chloride  in  the  final 
liquid;  but  it  would  be  well  to  know  if  this  diminution  might  not 
augment  the  quantity  of  rinc  carried  down  by  the  hydrated  precipi- 
tates of  iron  and  aluminium.  Not  having  had  the  time  to  thoroughly 
study  this  question,  we  have  adhered  to  the  method  generally  em- 
ployed at  the  present  day,  for  the  preparation  of  the  solution  for  an 
estimation  by  SchafTner's  method. 


drops  of  sulphite,  add  hydrochloric  acid  (sp.  gr.  I'oys)^ 
until  neutral  (about  30  c.c),  then  add  10  c.c.  more  of  the 
same  acid. 

If  after  acidulating  the  liquid  becomes  brown,  owing  to 
the  liberation  of  bromine,  it  is  because  the  quantity  of 
sulphite  is  insufficient,  and  it  is  then  necessary  to  add  a 
little  more  than  sufficient  to  cause  the  disappearance  of 
this  brown  colour. 

Into  the  solution  thus  prepared  we  run  such  a  volume- 
of  ferrocyanide,  that  there  may  be  an  excess  of  20  to 
25  per  cent  on  the  quantity  necessary  for  the  exadt  pre- 
cipitation of  the  zinc  contained  in  the  100  c.c.  of  the 
ammoniacal  solution  used  for  the  test. 

These  100  c.c.  contain  the  zinc  from  0*5  grm.  of 
mineral.  It  is  easy  to  understand,  after  what  we  have- 
said  previously  apropos  of  the  value  of  the  titration 
chosen  for  the  ferrocyanide,  that  it  is  necessary  to  use- 
here  a  volume  represented  by  the  centesimal  contents; 
for  example,  38  c.c,  if  we  are  dealing  with  a  mineral, 
containing  38  per  cent.  In  pradtice,  we  take  it  as  40  c.c. 
in  round  numbers.  This  has  the  advantage  of  permitting, 
the  use  of  calibrated  pipettes,  which  are  more  easily  used 
than  a  burette  for  repeated  measurements  of  the  same 
solution,  and  also  of  giving,  we  think,  more  accurate  re- 
sults when  working  quickly. 

If  we  do  not  know  sufficiently  nearly  the  value  of  the 
ore,  we  do  a  diredl  assay  to  determine  the  volume  of  th© 
ferrocyanide  to  be  used.  For  this  purpose  we  take  50  or 
100  c.c.  of  the  ammoniacal  solution,  treat  as  above,  then 
run  in  ferrocyanide  a  little  at  a  time,  shaking  well,  until 
a  test  with  nitrate  of  uranium  gives,  even  when  tried 
after  waiting  some  instants,  a  distind  brown  colouration, 
indicating  the  presence  of  a  faint,  but  appreciable,  excess 
of  the  reagent. 

We  should  use  for  the  final  assay  a  volume  higher  by 
one-fifth  to  one-fourth  than  that  used  for  the  preliminary 
test ;  or  double  this,  of  course,  if  we  were  working  on  50 
c.c.  only.  The  assay  is  finished  after  digesting  ten  or 
fifteen  minutes,  by  titrating  back  to  find  the  excess  of 
ferrocyanide. 

By  subtradting  the  weight  of  the  zinc  contained  in  the 
quantity  of  the  zincic  chloride  used  in  titrating  back  (10 
m.grms.  per  c.c)  from  the  weight  corresponding  to  the 
ferrocyanide,  we  obtain  that  contained  in  0*5  grm.  of  the 
mineral;  this  latter  multiplied  by  2  gives  the  centesimal' 
contents  in  centigrms. 

In  assays  requiring  the  highest  degree  of  exadtitude, 
such  as  in  cases  of  dispute,  it  is  preferable  to  work  by 
comparison  ;  that  is  to  say,  to  make  two  parallel  estima- 
tions— one  on  the  mineral  itself,  the  other  on  an  artificial 
solution  imitating  as  nearly  as  possible  the  value  in  zinc 
of  the  mineral.  In  other  words,  on  a  solution  of  pure 
zinc  containing  as  nearly  as  possible  a  weight  of  zinc 
equal  to  the  weight  of  zinc  in  the  sample  taken  of  the  ore. 
This  artificial  solution  is  prepared  by  dissolving  in  a 
500  c.c.  flask  as  much  zinc  as  can  be  taken  up  by  20  c.c. 
of  fuming  hydrochloric  acid,  adding  to  this  100  c.c  of 
water,  then  100  c.c.  of  strong  ammonia  and  10  c.c.  of  the 
solution  of  carbonate  of  ammonium,  as  with  the  mineral ; 
after  cooling,  make  the  volume  up  to  500  c.c.  with  dis- 
tilled water. 

We  know  that  the  hydrated  precipitates  of  iron  and 
aluminium  produced  by  ammonia  in  metallic  solutions 
retain  a  quantity  of  zinc  by  no  means  negligible  (E.  Prost 
and  Hassreidter,  Zeit.  Anorg.  Chem.,  1892).  To  obtain 
complete  separation  it  is  necessary  to  have  recourse  to  • 
double  precipitation,  which  complicates  the  operation. 

By  working  by  comparison  we  can  avoid  this  complica- 
tion by  adding  to  the  artificial  solution,  before  treating 
with  ammonia,  such  a  volume  of  ferric  chloride  of  known 
strength  that  the  weight  of  iron  thus  introduced  shall  be 
as  nearly  as  possible  equal  to  that  contained  in  the 
sample  of  ore  taken.* 

*  To  facilitate  calculation,  it  is  best  to  prepare  a  solution  con- 
taining 10  or  25  grms.  of  iron  per  litre,  and  take  the  necessary  volume- 
by  means  of  a  graduated  pipette. 


*^^]liylo^i^S^''}   Volumetric  Determination  of  Zinc  by  Potassium  Ferrocyanide, 


In  this  manner  the  influence  of  the  iron  will  be  neutral- 
ised. We  operate  side  by  side  on  the  two  solutions, 
taking  loo  c.c.  of  each;  acidulating  them  both  with  the 
same  quantity  of  hydrochloric  acid,  adding  the  same 
volume  of  ferrocyanide,  and  titrating  back  with  the  same 
solution  of  zincic  chloride  after  sufficiently  digesting  the 
precipitate. 

The  centesimal  value,  expressed  in  centigrms.,  will  be 
found  by  the  expression — 

Za  per  cent  =  2[o-2  P  +  o-oi  (N-N')]  ; 

in  which  P  represents  the  weight  of  zinc  used  for  the  pre- 
paration of  the  artificial  solution,  N  and  N'  the  number 
of  c.c.'s  of  the  zincic  solution  at  o-oi  of  zinc  per  c.c.  used 
for  the  back  titrations  respedlively  of  the  loo  c.c.  of  arti- 
ficial solution  and  the  loo  c.c.  of  the  solution  of  the 
mineral.  In  fa(ft,  as  in  both  cases  we  have  used  the  same 
volume  of  ferrocyanide,  the  weights  of  zinc  contained 
finally  in  each  experiment  should  be  equal.  For  the  arti- 
ficial solution  this  weight  is — 

»  P  =  0-2P, 

augmented  by  coi  grm.  for  every  c.c.  of  chloride  of  zinc 
used  ;  if,  for  example,  it  be  o'oi  N,  then  the  total  will  be 

0'2  P  -J-  O'OI  N. 

For  the  mineral  the  weight  of  zinc  will  be  that 
contained  in  0*5  grm.  of  the  sample;  we  represent  it 
by  X,  also  augmented  by  o'oi  grm.  for  each  c.c.  of  zincic 
chloride  used  ;  this  will  be  X  =  o'oi  N'.  From  this  we  get 
the  equation — 

X+O'oi  N'=o-2  P+o-oi  N 

X  =  0-2  P  -1-  o-oi  (N  -  N'). 

When  working  with  50  grms.  this  must  be  doubled.  It 
must  not  be  overlooked  that  if  N'  be  greater  than  N,  the 
expression  o'oi  (N  — N')  becomes  negative,  and  the  cor- 
responding quantity  must  be  subtraded  from  o°2  P. 

Examples. 

I,  If  the  ore  contains  about  40  per  cent  zinc,  to  prepare 
the  artificial  solution  we  take — 

P  =  i"o  grm.  =  (2 "5  X  0-40)  ; 

then  if  N  =  4*7  c.c.  and  N'  =  4"i  c.c,  the  zinc  present 
will  be — 

2[O*2XI'O  +  O'Ol(47-4*l)]  =  2[O*2  +  O'O06]=O'4I2, 

or  41*2  per  cent. 

II.  If  the  ore  contains  about  30  per  cent  of  zinc,  for 
the  artificial  solution  we  take  P  =  o'75  grm.  Then  let 
N  =  2'3  c.c.  and  N'  =  3'9  c.c,  the  zinc  present  will  be— 

2[o'2X075+o'oi(2*3-3'9)]  =  2[o*i5  — o'oi6]  =0*268, 
or  268  per  cent. 

Direct  Titration. 

For  ordinary  daily  assays,  not  requiring  such  extreme 
accuracy,  we  can  use  diredt  titration.  For  this  purpose 
we  run  the  carefully  titrated  ferrocyanide  into  the  acid 
zincic  solution  (warmed  to  60°  or  70°)  until  a  touch  test 
with  nitrate  of  uranium  gives  a  faint  brownish  colour.  We 
do  not  consider  the  reaction  at  an  end  until  two  touch  tests, 
done  at  an  interval  of  two  or  three  minutes,  both  give  a 
colour,  and,  further,  that  after  the  addition  of  two  or  three 
drops  of  ferrocyanide  the  touch  test  should  give  a  dis- 
tinftly  stronger  reaiflion.  In  dired  titration  we  prefer  to 
use  a  solution  of  ferrocyanide,  TZn  =  o'oi  grm.,  corres- 
ponding to  the  solution  of  zincic  chloride. 

Finally,  we  give  the  results  obtained  by  us,  by  V. 
Hassreidter,  and  by  Van  de  Casteele,  using  our  process 
on  several  ores.  In  our  own  assays  we  did  the  back 
titration  with  a  \  normal  solution  of  chloride  of  zinc, 
T  =  o"oi628  grm. 

The  ferrocyanide  solutions  were  various  and  were  used 
in  varying  quantities ;  but  as  all  the  assays  were  done  by 
comparison  with  an  artificial  solution,  and  as  in  every 
analysis  the  volume  of  the  two  solutions  was  the  same, 


53^ 

it  is  unnecessary  to  give  the  strength  and  volume  of  this 
reagent.  -  '-^;' 

The  values  given  immediately  after  the  description  of 
the  mineral  are  those  found  by  SchafFner's  process  in  an 
independent  estimation  by  ferrocyanide. 

I. 
Roasted  ore,  free  from  copper,  &c.      . .     45*28,  45*3^0  Zn. 

Artificial  solution      1*125  grms.  of  pure  Zn. 

ZnCla  used  in  titrating  back  . .    280,  2-92,  2*84,  2*89  c.c. 

Mean a*85  c.c. 

Ore  used 2*5  grms. 

ZnClz  used  in  titrating  back  ..     ..     ..     273,  2*70,  2*70 

Zn  per  cent 45'42,  45*52i  45'52 

II. 

Roasted  plumbiferous  blende 62*86°/)  Zn. 

Artificial  solution      1*5  grm.  of  pure  Zn. 

ZnClj  used  in  titrating  back   ..  6'02,  6"o8,  6*05,  6'04  c.c. 

Mean 6*050.0. 

Ore  used      2*5  grms. 

ZnClz  used  in  titrating  back   ..     ..  5*18,  5*15,  5*08,  5*16 
Zn  per  cent 62*83,  62*93,  63-16,  62*89 

III. 

Cupriferous  calamine 24*30^  2fn. 

Artificial  solution       0*6  grm.  pure  Zn. 

ZnCl2  used  in  titrating  back 11*90,  11*95  c.c. 

Mean     , 11*9250.0. 

Ore  used       2*5  grms. 

ZnClj  used  in  titrating  back    ..  ii'go,  11*87,  11*92.  ii'95 
Zn  per  cent 24*10,24*20,24*04,23*94 

IV. 

Crude  calamine 55*80^  Zn. 

Artificial  solution       1*375  grm.  of  pure  Zn. 

ZnClj  used  in  titrating  back 2*290.0. 

Ore  used       2*5  grms. 

ZnCla  used  in  titrating  back 2*20,2*18 

Znpercent 55*30,55*35 


Calamine  No.  i  (Hassreidter)  ..     ..      48*3  per  cent  Zn. 
By  the  ferrocyanide  process      . .     . .      48*1        „         „ 

VI. 
Calamine  No.  2  (Hassreidter)  ..     ..      51*65       ,,  ,» 

By  the  ferrocyanide  process     ..     ..      51*59       „  „ 

VII. 
Blende  No.  i  (Hassreidter) 
By  the  ferrocyanide  process     . . 

VIII. 
Blende  No.  2  (Hassreidter) 
By  the  ferrocyanide  process     . . 

IX. 
Van  de  Casteele 38*29      „         „ 

Bythe  ferrocyanide  process  (ist  assay)  I  ^0.27      "         " 
..  (-d  assay)  j38:4i       ..         .. 

The  concordance  between  the  different  assays  of  the 
same  mineral  shows  beyond  a  doubt  that  Galletti's 
method,  as  we  have  modified  it,  merits  as  much  confi- 
dence as  that  of  Schaffner.  The  almost  absolute  con- 
cordance of  the  results  we  obtained  in  the  five  assays 
relative  to  the  influence  of  nitrous  acid — minimum,  33*88 
c.c;  maximum,  33*94  c.c.  ZnClj — the  last  done  before 
we  turned  to  minerals,  show  the  exadlitude  of  which  our 
method  is  susceptible  when  used  in  experienced  hands, 
while  the  results  obtained  by  MM.  Hassreidter  and  Van 
de  Casteele  prove  that  long  experience  is  not  necessary 
in  order  to  obtain  satisfadtory  results.  We  consider  our 
process  to  be  much  simpler  and  quite  as  quick  as  that  of 
Schaffner.     We  leave  it  to  our  confreres,  whose  position 


36*50 
36*80 


42*45 
42*15 


54 


Action  of  Phosphorus  Pentachloride  on  Aniline. 


I  Crbmical  Nbwbi 

1      July  30,  1897. 


necessitates  them  making  frequent  estimations  of  zinc,  to 
decide  if  one  of  these  processes  should  replace  the  other, 
trusting  that  they  will  give  them  an  impartial  trial. 


ACTION    OF    PHOSPHORUS    PENTACHLORIDE 

ON    ANILINE    AND    ITS    SALTS.* 

By  J.  ELLIOTT  GILPIN. 

(Concluded  from  ',p.  44). 

Analysis  of  the  Dry  Powder, 

Preparation  I. 

The  specimen  of  aniline  used  for  this  was  not  purified 

and  was  very  dark,  and  the  products  retained  some  of  the 

impurities. 

0*2332  grm.  of  the  substance  gave  0*0746  grm.  AgCl. 
0*19765  grm.  of  the  substance  gave  o*o63i  grm.  AgCl. 
O'2io2  grm.  of  the  substance  gave  0-0553  grm.  Mg2P207. 
0-154  grm.  of  the  substance  gave  03724  grm.  CO2. 
0-1974  grm.  of  the  substance  gave  0-4784  grm.  COj. 

Preparation  II. 
0-2366  grm.  of  the  substance  gave  0-0784  grm.  AgCI. 
02366  grm,  of  the  substance  gave  0-0595  grin.  MgaPaOy. 
0-2096  grm.  of  the  substance  gave  0-0691  grm.  AgCl. 
0-2096  grm.  of  the  substance  gave  0-0552  grm.  Mg2P207. 
0-488  grm.  of  the  substance   gave   0-0633144  grm.   N 

(Kjeldahl). 
0*189  grm,  of  the  substance  gave  22-23  c.c  N  at  25-8°  and 

758-8  m.m. 
0*1584  grm.  of  the  substance  gave  0-3863  grm.  CO2. 

Preparation  III. 
0*1966  grm.  of  the  substance  gave  0-0655  grm.  AgCI. 
0-2025  grm.  of  the  substance  gave  0*494  grm-  CO2. 

Analyses  of  the  Crystals. 
0-2258  grm.  of  the  substance  gave  0-057  grm.  Mg2P207. 
0-2309  grm.  of  the  substance  gave  0-0792  grm.  AgCl. 
0-2309  grm.  of  the  substance  gave  00612  grm.  Mg2P207. 
0-2324  grm.  of  the  substance  gave  0-0792  grm.  AgCl. 
0-1613  grm.  of  the  substance  gave  0-0553  g''"^-  AgCl. 
0-1613  grm.  of  the  substance  gave  0-0435  grm-  Mg2P207. 
0*1483  grm.  of  the  substance  gave  0-0503  grm.  AgCl. 


tals,  on  cooling.     The  following  method  was  used  for  the 
preparation  of  the  compound  formed  in  the  adlion  : — 

The  tetranilide  was  treated  with  as  small  a  quantity 
of  sulphuric  acid  as  possible,  and  the  solution  warmed  to 
complete  the  decomposition  and  expel  the  hydrochloric 
acid.  After  cooling,  water  was  added,  in  volume  about 
twice  that  of  the  acid,  and  the  solution  heated  to  dissolve 
the  substance  precipitated  by  the  water.  This  solution, 
on  standing,  deposits  clear  odtahedral  crystals,  which  can 
be  filtered  off,  and  re-crystallised  from  water.  These 
crystals  are  extremely  efflorescent,  and  begin  to  lose  their 
water  of  crystallisation  before  the  water  which  they  hold 
mechanically  can  be  removed. 

It  has  acid  properties  and  is  very  soluble  in  water  and 
alcohol,  as  are  also  the  barium  and  lead  salts,  which  are 
formed  by  neutralising  a  solution  of  the  acid  with  barium 
and  lead  carbonates,  and  filtering  and  evaporating  the 
solutions. 

On  account  of  the  ease  with  which  these  salts  dissolve 
in  water,  they  could  not  be  obtained  in  a  crystallised  con- 
dition suitable  for  analysis,  but  in  each  case  were  evapo- 
rated to  dryness  over  the  water-bath.  The  adlion  of  the 
sulphuric  acid  on  the  tetranilide  is  as  follows  : — 
PC1(NHC6H5)4  +  4H2S04  = 

=  P(OH)(NHC6H4S03H)4+3H20-I-HCl. 

The  sulphur  and  phosphorus  were  determined  as  barium 
sulphate  and  magnesium  pyrophosphate  respedtively.  The 
substance  was  decomposed  accordingto  the  Pierson  method 
with  nitric  acid  and  potassium  chlorate. 

0*1518  grm.  of  the  substance  gave  0-1927  grm,  BaS04. 

0-2086  grm.  of  the  substance  gave  0-0313  grm.  Mg2P207. 


Calculated  for 
PCKNHCeHjU. 
CI    ..     8-14        7-90 
P      ..      713 

N    ..  12-89 


Found  (powder). 
Preparation  I.  II. 


789         — 
—  —        7'44 


8-19 
7-02 


8-14 
7'36 


III. 
8-24 


—  —  —       12-97     13-04        — 


CI 
P 
N 
C 


8-14  — 

7-13  7-05 

i2-8g  — 

66-29  65-94 


Found  (crystals) 
8-47  8-42  8-47 

7-40  — 

66-09  —  66-50 


838 
7'53  — 

66-52 

Attempts  made  to  substitute  a  residue  of  aniline  for  the 
chlorine  atom  in  the  compound,  PC1{NHC6H5)4,  have  up 
to  the  present  been  unsuccessful.  Some  of  the  powder 
was  added  to  boiling  aniline,  in  which  it  readily  dissolved ; 
but  the  produft  which  separated  out  when  it  cooled  had 
the  same  composition  as  the  original  material. 

Action  of  Sulphuric  Acid  on  Chlorphostetranilide, 
PC1(NHC6H5)4. 

When  chlorphostetranilide  is  treated  with  concentrated 
sulphuric  acid,  hydrochloric  acid  is  given  off,  and  the 
substance  goes  into  solution.  If  the  acid  is  warmed  and 
saturated  with  the  tetranilide  it  becomes  solid,  with  crys- 

♦  American  Chemical  Journal,  vol.  xix.,  No,  5, 


Calculated  for 
P{0H)(NHCaH,SO,H)«, 

Found. 

s 
p 

17"39 

4-21 

17'44 
4-19 

The  determinations  of  the  barium  and  lead  in  the  salts 
gave  the  following  results  : — 

0-4358  grm.  of  the  substance  gave  0-1614  grm.  BaS04. 

0-4499  grm.  of  the  substance  gave  0-1694  grm.  BaS04. 

0-6464  grm,  of  the  substance  gave  0-2741  grm.  PbS04. 

0-6333  grm.  of  the  substance  gave  0-2676  grm.  PbS04. 

These  results  cannot  be  explained  on  the  assumption  of 
the  formation  of  a  simple  compound  ;  but  they  agree  with 
a  salt  of  the  following  composition,  in  which  part  of  the 
hydrogen  of  two  molecules  of  the  sulphonic  acid  is 
replaced  by  the  metals  : — 

/NHC6H4SO3H 

P(OH)  J  NHCeH^SO^-^^'  ^^"^  Ar=bariura  or  lead. 
tNHC6H4SoL 
(NHC6H4S03'^^ 


P(OH)  SS^!g^iS3>. 


NHC6H4SO3- 
tNHC6H4S03H 


Ba 
Pb 


Calculated  for 
these  salts, 

.      21-89 
.      29-69 


Found. 


21-78 
28-95 


22  14 

28-88 


Action  of  Phosphorus  Pentachloride  on  the  Toluidines. 

When  the  three  toluidines  are  treated  under  the  same 
conditions  as  the  aniline  with  phosphorus  pentachloride, 
they  give  compounds  analogous  to  chlorphostetranilide. 
The  method  of  purification  was  the  same  as  that  used 
with  the  aniline  compound.  The  results  of  the  analyses 
were  as  follows : — 

Orthotoluidine. 

0-2011  grm.  of  the  substance  gave  0-0599  grm.  AgCl. 
0-2888  grm.  of  the  substance  gave  0-0692  grm.  Mg2P207. 

Metatoluidine. 
0-213  grm.  of  the  substance  gave  0*066  grm.  AgCl. 


Crpmical  News,  t 
July  30, 1897.      » 


A  luminum  A  Icoholates. 


55 


Paratoluidine. 
o'2gi8  grm.  of  the  substance  gave  0*08x4  grm.  AgCI. 

Found. 


Calculated. 

Ortho, 

Meta. 

Para. 

7-21 

7-36 

7-65 

6-89 

6-32 

6-29 

— 

— 

CI 

p 

Besides  the  compounds  already  mentioned,  two  other 
substances  have  been  obtained  by  treating  aniline  with 
phosphorus  pentachloride,  under  different  conditions. 
The  results  of  the  investigation  carried  out  on  these  sub- 
stances will  be  published  shortly. 


ALUMINUM    ALCOHOLATES. 
By  H.  W.  HILLYER, 

In  a  former  paper  {Amer.  Chem.  yourn,,  xix,,  p.  37)  we 
detailed  the  results  of  a  research  in  regard  to  the  adion 
of  aluminum  on  ethyl  alcohol  to  which  a  small  amount  of 
fuming  stannic  chloride  had  been  added.  Since  sending 
that  paper  to  the  publisher,  other  observations  have  been 
made,  which  add  somewhat  to  our  knowledge  of  this  re- 
adtion;  and  similar  studies  have  been  made  with  methyl 
alcohol  and  the  two  propyl  alcohols. 

As  stated  in  the  article  referred  to,  various  anhydrous 
chlorides,  which  are  soluble  in  alcohol,  were  used  in  an 
attenipt  to  avoid  a  difficulty  encountered  in  using  mercuric 
chloride.  When  absolute  alcohol  is  poured  upon  chipped 
aluminum,  and  either  platinic  chloride,  mercuric  chloride, 
or  stannic  chloride  is  then  added,  a  rapid  deposition  of 
the  metal  is  soon  noticed,  and  then,  with  rise  in  tempera- 
ture, an  increasing  evolution  of  hydrogen  followed  by  a 
slower  evolution,  which  is  long  continued,  even  on  appli- 
cation of  external  heat.  A  large  amount  of  aluminum  is 
dissolved,  enough,  in  some  cases,  to  make  the  solution 
pasty  or  even  solid  with  the  produft  of  the  readlion.  It 
has  been  found  that  sublimed  ferric  chloride  will  also,  to 
a  slight  degree,  bring  about  the  aAion  of  aluminum  on 
alcohol,  and  that  even  aluminum  chloride  produces  a 
slight  evolution  of  hydrogen  when  the  chloride  is  freshly 
prepared  by  adion  of  dry  hydrochloric  acid  on  metallic 
aluminum.  External  application  of  heat  is  necessary  to 
the  progress  of  any  considerable  readlion  in  the  case  of 
ferric  chloride  or  aluminum  chloride. 

By  passing  dry  hydrochloric  acid  gas  into  absolute 
alcohol  standing  over  chipped  aluminum,  the  metal  is 
readily  dissolved  with  evolution  of  hydrogen  and  develop- 
ment of  heat.  So  much  aluminum  may  dissolve  in  this 
way  that  on  allowing  the  solution  to  cool  it  becomes  solid 
by  separation  of  a  crystalline  compound— probably  an 
addition-produdl  of  alcohol  and  aluminum  chloride.  If, 
instead  of  passing  into  the  alcohol  a  continuous  stream 
of  hydrochloric  acid  gas,  a  small  amount  of  an  alcoholic 
solution  of  the  gas  is  added  to  the  alcohol,  the  adtion  is 
slower  to  begin,  but  increases  in  vigour  till  its  rate  is 
quite  comparable  with  that  induced  by  the  use  of  anhy- 
drous chlorides  of  the  metals.  This  form  of  the  readtion 
is  very  nicely  shown  by  letting  hydrochloric  acid  gas 
bubble  into  the  alcohol  standing  over  the  chipped 
aluininum,  but  removing  the  gas  delivery  tube  as  soon  as 
a  fairly  rapid  evolution  of  hydrogen  is  noticed.  The  re- 
adlion will  then  continue  at  a  good  rate,  if  the  mixture  is 
slightly  heated  occasionally,  for  more  than  an  hour,  until 
enough  aluminum  has  dissolved  to  make  a  jelly  when 
mixed  with  an  equal  quantity  of  water.  This  hydroxide 
or  basic  chloride  is,  however,  entirely  soluble  in  a  large 
quantity  of  water. 

In  all  the  cases  noted  aluminum  chloride  has  been 
added,  or  the  conditions  were  such  that  it  could  be 
formed  by  decomposition  of  the  hydrochloric  acid  or  an- 
hydrous chloride  present.  In  the  case  of  some  of  the 
alcohols  it   was  found,  when  the  stannic  chloride  was 


dissolved  in  a  small  portion  of  alcohol,  and  this  solution 
then  added  to  the  main  portion  of  the  alcohol,  that  the 
adlion  on  the  aluminum  was  more  vigorous  than  when 
the  same  amount  of  the  chloride  was  added  to  the  whole 
of  the  alcohol.  To  explain  this,  it  seems  to  us  that  in 
adding  the  stannic  chloride  to  the  smaller  quantity  of 
alcohol  the  temperature  was  raised  high  enough  to  cause 
the  formation  of  an  addition-produdt  of  the  alcohol  and 
stannic  chloride,  and  that  it  was  upon  this  compound  that 
the  aluminum  adled  first,  and  that  later  it  adled  on  an 
addition-produdlof  the  alcohol  with  the  aluminum  chloride 
which  had  been  found.  It  is  known  that  all  of  the  an- 
hydrous chlorides  used  form  addition-produdls  with 
common  alcohol.  Such  addition-produdts  are  also  known 
with  other  alcohols,  and  it  may  be  said  that  we  obtained 
a  crystalline  compound  by  adiion  of  stannic  chloride  on 
isopropyl  alcohol — probably  SnCl4:3C3H70H  as  shown 
by  analysis. 

For  a  rapid  and  satisfadtory  solution  of  the  aluminum, 
it  may  be  desirable  to  have  a  "  couple"  of  the  more  easily 
reducible  metals  and  the  aluminum,  though  our  later  ex- 
periments with  hydrochloric  acid  gas  seem  to  show  that 
it  is  not  necessary. 

With  the  readtions  involving  the  use  of  stannic 
chloride  and  hydrochloric  acid  gas,  it  is  also  necessary  to 
have  complete  dehydration.  When  the  readtion  is  in  full 
career,  the  addition  of  a  little  water  will  nearly  or  en- 
tirely stop  the  adtion.  In  this  respedl  there  is  another 
marked  contrast  with  the  readlions  involving  mercuric 
chloride  where  the  presence  of  water  seems  to  work  no 
harm. 

The  observations  made  would  then  seem  to  show  that, 
in  general,  it  is  necessary  to  a  satisfadtory  adtion  of 
aluminum  on  alcohol,  that  it  should  be  anhydrous,  that  it 
should  contain  an  anhydrous  chloride  with  which  it  can 
form  an  addition-produdt,  and  that  the  aluminum  should 
be  coupled  with  a  more  easily  reducible  metal. 

Aluminum  Methylate. — The  methyl  alcohol  used  was 
dehydrated  by  anhydrous  copper  sulphate,  and  subse- 
quently distilled.  Aluminum  adls  on  methyl  alcohol 
under  conditions  similar  to  those  favourable  to  its  adtion 
on  common  alcohol.  On  driving  off  the  excess  of  alco- 
hol a  gelatinous  mass  remains,  but  on  attempting  to  distil 
under  diminished  pressure  the  mass  does  not  fuse,  but 
simply  crumbles  to  a  black  powder  and  yields  no  con- 
densable distillate.  Only  two  readlions  suggest  themselves 
for  the  adtion  of  aluminum  on  methyl  alcohol.  They  are 
expressed  by  the  following  equations  : — 

2AI  +  6CH3OH  =  2A1(0H)3  -t-  3C2H6. 
2AI  +  6CH3OH  =  2A1(0CH)3-H3H2. 

It  was  found  that  the  evolved  gases,  passed  through 
sulphuric  acid  to  retain  the  alcohol,  when  mixed  with  air, 
exploded  violently,  and  gave  no  indication  of  the  presence 
of  carbon  dioxide  when  clear  lime-water  was  added  to  the 
gaseous  residue  after  the  explosion,  thus  showing  the 
presence  of  hydrogen  only.  From  this  the  second  equa- 
tion seems  the  more  probable  during  the  first  part  of  the 
readlion  at  least.  At  a  later  stage  it  might  be  that  the 
nascent  hydrogen  adled  on  the  methylate  previously 
formed  and  changed  it  to  the  hydroxide,  as  indicated  by 
the  equation — 

Al(OCH3)3  +  3H2  =  A1{0H)3  +  3CH4. 

The  following  experiments  show,  however,  that  this  is 
not  the  case. 

In  some  cases,  if  not  every  case,  the  aluminum  alco- 
holates  are  soluble  in  the  alcohol  from  which  they  are 
derived.  With  this  thought  in  mind,  an  attempt  was 
made  to  determine  whether  aluminum  methylate  had 
really  been  formed  and  decomposed  on  heating,  or 
aluminum  hydroxide  had  been  the  final  produdl  of  the  re- 
adlion of  the  aluminum  on  the  alcohol.  After  a  completion 
of  a  readlion  with  aluminum,  methyl  alcohol,  and  stannic 
chloride,  a  large  excess  of  methyl  alcohol  was  added,  and 
the  whole  allowed  to  stand  over  night.  The  liquid  was 
decanted  from  an  insoluble  residue,  and  filtered  out  of 


56 


Preparation  of  Tellurium  at  Schemnitz. 


{Ckbuical  Nbws, 
July  30,  1897. 


contadt  with  the  air.  In  measured  quantities  of  this  so- 
lution, the  aluminum  and  the  chlorine  were  determined  to 
ascertain  how  much  of  the  aluminum  could  be  accounted 
for  as  chloride :  10  c.c.  of  the  filtrate  were  diluted  with 
water,  acidified  with  hydrochloric  acid,  and  the  aluminum 
precipitated  by  ammonia.  From  this  hydroxide  0*2245 
grm.  of  aluminum  oxide  were  obtained,  equivalent  to 
0*1189  grni'  of  aluminum.  To  determine  the  chlorine, 
ID  c.c.  of  the  same  solution  were  diluted  with  water, 
acidified  with  nitric  acid,  and  brought  to  boiling.  On 
adding  silver  nitrate  a  precipitate  was  formed,  but  it  re- 
quired persistent  and  very  careful  filtration  to  bring  the 
filtrate  to  final  clearness.  The  reason  for  this  difficulty 
in  clearing,  and  the  cause  of  the  failure  of  the  silver 
chloride  to  become  curly,  has  not  yet  been  found.  The 
silver  chloride  formed  weighed  0"4ii3  grm.,  equivalent  to 
0*0897  grm.  of  chlorine,  an  amount  corresponding  to  0*025 
grm.  of  aluminum  as  chloride. 

Considering  the  similarity  of  the  reaction  with  this 
alcohol  to  those  of  the  other  alcohols,  and  the  fadt  of  the 
evolution  of  hydrogen  during  the  reaction  rather  than  a 
hydrocarbon,  the  presence  of  aluminum  in  solution  in  a 
form  not  the  chloride  can  be  most  easily  explained  on  the 
supposition  that  the  readion  is  normal,  that  aluminum 
methylate  is  formed,  but  that  it  is  decomposed  on 
attempting  to  distil  it. 

Aluminum  Propylate. — The  normal  propyl  alcohol  used 
in  these  experiments  was  dehydrated  by  anhydrous  copper 
sulphate.  It  boils  at  97°.  In  carrying  out  one  of  our 
experiments,  10  grms.  of  aluminum  and  150  c.c.  of  alcohol 
were  placed  in  a  retort,  and  then  2  c.c.  of  fuming  stannic 
chloride  were  slowly  added.  No  perceptible  effeft  was 
produced.  On  applying  heat  a  slight  evolution  of  gas 
occurred,  but  ceased  on  removing  the  source  of  heat.  On 
adding  i  c.c.  of  the  chloride  an  evolution  of  gas  com- 
menced, which  was  slow  at  first,  but  soon  became  so 
violent  that  external  cooling  was  necessary  to  prevent 
boiling  over.  After  this  spontaneous  adion  became  weak, 
external  heating  induced  further  aiSlion,  which  continued 
several  hours  until  the  mass  in  the  retort  became  quite 
viscous.  In  a  subsequent  experiment  approximately  the 
same  amounts  of  aluminum  and  of  alcohol  were  used, 
instead  of  adding  the  chloride  direftly  to  the  whole 
amount  of  the  alcohol,  it  was  first  dissolved  in  a  small 
quantity  of  the  alcohol  and  then  added  :  5  c.c.  of  stannic 
chloride  were  dissolved  in  10  c.c.  propyl  alcohol,  and  of 
this  solution  2i  c.c.  were  slowly  added  to  the  main  bulk 
of  the  alcohol  already  standing  on  the  chipped  aluminum. 
Adlion  did  not  become  noticeable  for  about  ten  minutes, 
but  then  tin  began  to  be  deposited ;  a  slow  evolution  of 
hydrogen  was  noticed,  which  rapidly  increased,  and  soon 
became  violent,  as  before.  The  subsequent  treatment  of 
the  produft  of  readlion  was  similar  to  that  used  with  the 
ethylate.  The  second  of  the  two  operations  described 
above  gave  a  much  larger  yield  of  the  propylate  on  dis- 
tilling, and  it  showed  less  indication  of  the  presence  of 
aluminum  chloride  by  fumes  at  the  commencement  of  the 
distillation.  When  the  produds  were  re-distilled  at  a  low 
pressure,  they  gave  an  amber-coloured  distillate,  some- 
times solidifying  to  a  clear  mass,  which  gradually  became 
opaque,  and  sometimes  immediately  solidified  to  an 
opaque  solid  of  the  appearance  and  consistency  of  fresh 
commercial  grape-sugar.  By  fractionating,  a  producS  was 
obtained  melting  at  65°  and  boiling  under  15  m.m.  pressure 
between  235°  and  255°.  The  first  fradlions  were  more 
yellow  than  the  last  fradlion,  which  boiled  with  approxi- 
mate constancy  at  255°.  The  aluminum  in  the  part 
boiling  at  255°  was  determined  by  dissolving  in  nitric 
acid,  heating  the  solution  till  oxidation  was  no  more  ap- 
parent, evaporating,  and  igniting  the  residue.  An  amount 
of  oxide,  AI2O3,  was  left,  which  indicated  14*3  per  cent  of 
aluminum.  By  dissolving  in  hydrochloric  acid  and  pre- 
cipitating with  ammonia,  the  percentage  of  aluminum 
found  was  13*2.  There  should  be  in  aluminum  propylate 
13*1  per  cent  of  aluminum.  The  produd,  made  by 
another  operation  and  distilling  between  257°  and  262° 


at  20  millimetres  pressure,  was  analysed  by  combus- 
tion. In  order  to  proted  it  from  the  moisture  of  the  air, 
it  was  melted  and  drawn  into  weighed  glass  bulbs  with 
capillary  ends,  and  these,  after  cleaning  and  weighings 
were  dropped  into  the  combustion-tube.  The  combustioa 
gave — 

Per  cent. 

H 10*4 

C     53-4 

The  theory  requires — 

H 10*2 

C      529 

Aluminum  Isopropylate. — Isopropyl  alcohol  is  aded  on 
by  aluminum  in  presence  of  stannic  chloride  with  evolu- 
tion of  hydrogen  under  conditions  like  those  used  for  the 
normal  alcohol,  but  with  less  apparent  readiness.  On 
heating  the  produdt  under  diminished  pressure,  however^ 
no  distillation  takes  place,  but  a  decomposition  like  that 
observed  with  methyl  alcohol. 

Amyl  alcohol  yields  a  volatile  aluminum  compound,  of 
a  yellow  colour,  and  boiling  at  291°  C.  under  a  pressure 
of  12  m.m. 

By  the  use  of  aluminum  as  a  reducing-agent,  and  stan- 
nic chloride,  platinic  chloride,  or  mercuric  chloride  as  the 
sensitising  agent,  there  seems  no  doubt  that  redudlion 
may  be  performed  in  entire  absence  of  water,  when  the 
substance  to  be  reduced  can  be  dissolved  in  any  of  the 
alcohols,  in  benzene,  ether,  or  any  solvent  with  which 
alcohol  will  mix  when  it  is  added  to  evolve  hydrogen  with 
the  sensitised  aluminum.  From  later  experiments  it  is 
doubtful  whether  the  presence  of  the  precipitated  tin, 
platinum,  or  mercury  is  essential.  Commercial  aluminum 
at  least,  containing  slight  impurities  of  carbon  and  iron, 
evolves  hydrogen  quite  freely  under  the  conditions  indi- 
cated above,  by  starting  the  adtion  with  hydrochloric  acid. 

I  wish  to  express  here  my  hearty  thanks  to  Mr.  O.  E. 
Crooker,  and  especially  to  Mr.  R.  F.  Hastreiter,  by  whom 
much  of  the  experimental  work  detailed  above  has  been 
done  in  connexion  with  graduating  theses  in  this  labora- 
tory.— American  Chemical  journal,  vol.  xix..  No.  7. 


PREPARATION  OF  TELLURIUM  AT  SCHEMNITZ. 


According  to  a  long  description  recently  published  by 
Herr  J.  Farbaky  in  the  Zeitschrift  fur  Angewandte 
Chemie,  the  Schemnitz  tellurium  works,  in  Hungary, 
were  established  in  1891,  and  at  first  the  metalloid  was 
extracted  from  the  ore  by  precipitation  with  zinc  ;  but 
since  1895  ^^^  process  of  precipitation  by  means  of 
sulphur  dioxide,  proposed  by  Dr.  A.  Maly,  has  been  ex- 
clusively employed.  The  first  stage  is  to  attack  the  ore 
by  strong  sulphuric  acid,  to  which  end  350  kilos,  of  con- 
centrated acid  are  raised  to  boiling-point  in  a  cast-iron 
pot,  into  which  150  kilos,  of  Transylvania  ore  are  ladled 
with  continuous  stirring.  This  results  in  the  decomposi- 
tion of  the  metallic  carbonates,  and  the  solution  of  lead, 
copper,  and  zinc  along  with  the  tellurium  and  a  part  of 
the  silver,  leaving  gold  and  silica  in  the  residue.  The 
adlion  of  the  acid  is  assisted  by  gradual  and  progressive 
heat  until  the  mass  is  of  a  syrupy  consistency,  a  stage 
attained  usually  in  about  six  hours.  The  mass  is  next 
lixiviated  with  250  to  300  litres  of  boiling  water  containing 
10  to  15  per  cent  of  hydrochloric  acid,  to  extrad  the 
soluble  compounds  formed,  the  acid  adting  as  a  precipi- 
tant of  the  dissolved  silver  and  re-dissolving  the  tellurium 
hydroxide  thrown  down  during  the  dilution  of  the  mass. 
This  operation,  with  continued  stirring,  lasts  for  six 
hours,  and  on  the  following  day  the  liquid  and  solid 
materials  are  separated  by  filtration  under  pressure,  the 
gold  and  silver  in  the  residual  cake  being  recovered  in 
the  ordinary  manner.  The  filtrate  is  run  into  lead-lined 
wooden  precipitating  tanks  about  i  m.  long  by  0*50  ra^ 
wide,  into  which  a  current  of  gaseous  sulphur  dioxide: 


Cbbmical  News,  i 
July  30, 1897.     f 


Carbide  0/  Calcium, 


57 


(purchased  in  a  liquid  form  in  strong  cylinders)  is  passed. 
At  the  end  of  twelve  hours  the  green  solution  turns  brown 
and  black  flakes  of  tellurium  begin  to  separate  out;  and 
when  a  sample  of  the  liquor  ceases  to  give  a  precipitate 
with  a  little  hydrochloric  acid  and  sodium  sulphite,  the 
operation  is  at  an  end.  The  mother-liquor  is  absorbed 
by  slaked  lime  and  ashes,  and  roasted,  &c.,  for  recovering 
the  other  metals  present.  The  six  days  required  for  pre- 
cipitation in  the  tanks  may  be  abbreviated  to  one-fourth 
or  even  less  by  increasing  the  contad  between  the  sul- 
phurous acid  and  the  liquor — by  using  carboys  instead  of 
precipitating  tanks. 

The  produdl  is  usually  between  72  and  85  per  cent  pure, 
the  chief  impurity  being  copper,  of  which  about  6  per  cent 
is  present,  along  with  about  8  per  cent  of  tellurium  oxide. 
So  far  it  is  not  apparent  how  the  copper  is  precipitated, 
and  experiments  on  this  point  are  in  progress ;  the  pro- 
cess, however,  compared  favourably  in  this  respedl  with 
the  zinc  process,  since  the  crude  tellurium  obtained  by 
the  latter  was  only  about  29  per  cent  pure,  and  contained 
some  13  per  cent  of  lead,  15  per  cent  of  copper,  and  12 
per  cent  of  antimony.  It  was  hoped  by  repeated  solution, 
re-precipitation,  and  washing  to  obtain  a  produdl  94  to  97 
per  cent  pure,  but  the  process,  though  efficient  on  a  small 
scale,  is  unsatisfactory  in  pradlice,  besides  being  expen- 
sive, so  the  produift  is  dried  carefully  at  a  low  tem- 
perature to  prevent  oxidation,  and  the  mass  is  fused  in 
luted  earthenware  crucibles  and  either  cast  in  sticks  of 
I  to  2  in.  in  diameter  or  granulated. — Engineering  and 
Mining  Journal. 


CARBIDE    OF    CALCIUM. 

Since  the  Order  in  Council  of  the  26th  February,  1897, '" 
virtue  of  which  certain  parts  of  the  Petroleum  Adls,  1871 
to  1881,  were  applied  to  carbide  of  calcium,  the  question 
of  the  expediency  of  exempting  small  quantities  of  this 
substance  from  the  operation  of  the  Order  has  occupied 
the  attention  of  the  Home  Office,  and  the  Secretary  of 
State  having  been  advised  that  such  exemption  might  be 
safely  extended  to  quantities  of  carbide  of  calcium  not 
exceeding  5  lbs.,  when  kept  in  separate  substantial 
hermetically  closed  metal  vessels  containing  not  more 
than  I  lb.  each,  an  Order  in  Council  was  made  on  the 
7th  July,  1897,  authorising  the  keeping  of  not  more  than 
5  lbs.  of  carbide  of  calcium,  in  vessels  as  above  described, 
without  a  license;  and  the  original  Order  of  the  26th 
February  has  been  amended  accordingly.  The  amending 
Order  appeared  in  the  London  Gazette  of  the  gth  July, 
1897. 

It  is  to  be  observed  that  where  the  carbide  of  calcium 
is  not  kept  in  vessels  as  above  described,  no  quantity  may 
be  kept  without  a  license. 

Whitehall,  23rd  July,  1897. 


PROCEEDINGS    OF    SOCIETIES. 

SOCIETE  D'ENCOURAGEMENT  POUR  L'lNDUS- 

TRIE   NATIONALE. 

July  9,  1897. 

M.  Mascart,  President,  in  the  chair. 

The  President  announced  the  sad  death  of  M.  Schiitzen- 
berger,  Member  of  the  Committee  of  Chemical  Arts.  The 
obituary  eulogium,  written  by  M.  Troost,  was  read  by  M. 
Aime  Girard, 

Letters  of  thanks  were  announced  from  the  recipients 
of  the  medals  and  prizes  bestowed  at  the  last  meeting,  and 
several  new  candldatas  for  membership  were  nominated. 


CHEMICAL    AND     METALLURGICAL    SOCIETY, 

JOHANNESBURG. 

Annual  Meeting,  June  19,  1897. 

Mr.  W.  R.  Feldtmann  presided. 

The  Secretary  read  the  Annual  Report  of  the  Council. 
For  the  year  under  review  the  Randt  has  been  passing 
through  an  industrial  crisis,  which  has  now  reached  an- 
acute  stage.  During  the  past  year  several  members  of  the 
council  have  resigned,  and  others  have  been  eledled  to  fill 
their  places.  Twelve  ordinary  general  meetings  have  been 
held,  at  which  papers  have  been  read  and  discussed.  The 
membership  of  the  Society  has  been  increased  by  twenty 
during  the  year,  and  now  numbers  107.  The  financial 
position  of  the  Society  is  satisfadtory. 

The  President  then  gave  his  valedidlory  Address,  in 
which  he  pointed  out  the  great  success  which  had  attended 
the  formation  and  growth  of  the  Society  since  its  inception 
three  years  ago,  in  spite  of  wars  or  rumours  of  wars  and 
commercial  depression,  and  he  foretold  a  respected  and 
prosperous  old  age. 

Mr.  Butters  was  then  unanimously  eledled  President 
and  Dr.  Loevy  Vice-President  for  the  ensuing  year. 

Mr.  E.  H.  Johnson  then  read  some  "Notes  on  the  Re- 
duction 0/  Zinc-Gold  Slimes,"  in  which  he  describes  an 
improved  method  of  cleaning  up,  by  using  an  improvised 
filter-pump,  and  well  washing  the  slimes  with  a  10  per 
cent  solution  of  sulphuric  acid  to  remove  the  zinc.  He  finds 
one  pound  of  dilute  acid  to  one  pound  of  moist  slimes  gives 
very  good  results.  Working  with  dilute  acid,  and  not 
heating,  he  was  able  to  get  a  perfedl  settlement  within  an 
hour  after  leaving  off  stirring.  The  advantages  of  this 
method  over  the  old  are — the  elimination  of  the  zinc 
without  calcination ;  immunity  from  '*  dusting,"  the  slimes 
being  wet  throughout  except  in  the  final  operation  ;  and 
the  saving  of  time,  which  need  not  be  more  than  three  or 
three  and  a  half  days  from  the  commencement  of  the  clean 
up  to  having  the  bars  of  gold  in  the  safe. 


NOTICES  OF  BOOKS. 


Reports  on  the  Experiments  on  the  Manuring  of  Oats,  Hay, 

Turnips,  and  Potatoes.    Glasgow  and  West  of  Scotland 

Technical  College.  Glasgow,  1897. 
Each  experiment  reported  on  has  been  conduced  on  a 
number  of  farms,  and  the  conclusions  are,  as  a  rule,  based 
on  the  average  results  :  there  are  a  number  of  conditions 
and  circumstances  which  cause  great  differences  in  various 
soils,  quite  apart  from  their  original  composition,  such  as 
the  effedt  of  drainage,  underground  water,  previous 
ploughings,  manurings,  &c.  On  this  account  some  ex- 
ception has  been  taken  to  average  results,  on  the  grounds 
that  they  are  from  a  soil  which  does  not  exist,  but,  on  the 
other  hand,  it  may  be  said  that  a  soil  which  possesses 
every  property  does  not  exist,  so  that  perfedly  accurate 
results  cannot  be  obtained  for  comparison. 

Averages  may  be  misleading ;  if,  for  example,  ten  farms 
give  one  result  and  ten  farms  give  another,  the  average  of 
the  twenty  is  pradlically  valueless ;  but  at  the  same  time, 
over  a  large  number  of  cases  and  apart  from  great  ex- 
tremes, we  think  the  average  becomes  more  and  more  the 
standard  as  time  goes  on. 

The  experiments  on  the  manuring  of  oats  were  carried 
out  on  fifteen  farms.  The  objed  aimed  at  was  to  find  if 
it  was  profitable  to  apply  artificial  manure  to  oats,  and  it 
was  found,  amongst  other  things,  that  superphosphate 
increases  the  proportion  of  grain  ;  that  farm-yard  manure 
largely  increases  the  crop,  but  principally  in  straw;  that 
readily  available  nitrogenous  manures,  such  as  nitrate  of 
soda  and  sulphate  of  ammonia,  give  considerable  and- 
profitable  increases. 


The  Prospector^s  Handbook.     A  Guide  for  the  Prospeftor 
and   Traveller   in   search    of    Metal-bearing    or   other 
Valuable    Minerals.      By    J.    W.     Anderson,    M.A. 
(Cantab.),  F.R.G.S.      Seventh   Edition.     Revised  and 
much  Enlarged.    Pp.  176.     London  :  Crosby  Lockwood 
and  Son.     1897. 
Since  the  first  edition  was  published,  in  1885,  several 
important  discoveries  and  openings  up  of  metal-producing 
countries   have   occurred.      South    Africa    and  Western 
Australia  are  the  most  important  of  these,  though  we  are 
now  hearing  remarkable  stories  of  the  fabulous   wealth 
lying  about  in  the  Klondike  and  Yukon  regions  of  North- 
West  Canada. 

The  geological  lessons  learnt  in  South  Africa  are  of 
great  importance,  in  that  they  teach  us  to  prosped  with 
eyes  and  mind  open  to  new  impressions  and  ideas,  instead 
of  only  looking  out  for  such  indications  which  old 
experience  has  taught  us  to  associate  with  gold-bearing 
strata. 

Among  the  additions  to  the  Handbook  may  be  men- 
tioned the  reference  to  aluminium  ores.  This  metal,  as 
is  well  known,  is  not  found  in  the  free  state,  but  gene- 
rally in  combination  with  silica,  oxygen,  and  fluorine. 
Its  principal  ores,  besides  corundum,  are  beauxite  and 
cryolite. 

The  general  arrangement  of  the  book  is  the  same  as  in 
the  previous  editions ;  it  comprises  chapters  on  prospering ; 
blowpipe  testing;  the  charadler,  description,  and  occur- 
rence  of  rocks,  minerals,  and  metallic  ores ;  the  assaying 
and  treatment  of  ores  ;  and  lastly  surveying.  There  is  an 
Appendix  containing  the  usual  tables  we  expe(ft  to  find, 
and  very  useful  they  are  sometimes,  when  miles  away 
from  everywhere ;  and  a  Glossary  of  terms  used  in  con- 
nexion with  prospering,  mining,  &c.  Young  prospedtors 
should  beware  of  the  Glossary,  lest,  by  learning  too  much 
of  it,  they  "  give  themselves  away,"  and  show  their  in- 
experience. 


of  Government  work,  viz.,  1547  samples.  As  is  to  be 
expedled,  by  far  the  largest  number  of  samples  examined 
were  of  sugar-cane,  sugars,  and  articles  of  food  and  drink. 
It  is  remarkable  to  observe  that  during  these  three  years 
no  fewer  than  38,  46,  and  12  samples  respedtively  were  of 
human  viscera,  in  cases  of  suspeded  poisoning.  We 
thought  a  knife  or  machete  was  the  favourite  instrument 
for  argument  in  the  West  Indies.  But  we  are  glad  to  see 
that  the  latter  year,  1896-7,  is  the  lowest  (with  1893  when 
it  was  the  same)  in  such  cases  of  suspefted  poisoning  ever 
recorded  in  the  colony. 


58  Agricultural  Work  in  the  Botanic  Gardens y  British  Guiana.  {^Y^yl'^^g^^ 

Experiments  on  the  manuring  of  hay  show  that  neither 
bone-meal  nor  slag  are  much  good  the  first  year, — with 
chloride  of  potassium  added  it  is  beneficial  to  clover, 
more  so  than  with  superphosphate  ;  nitrate  of  soda  alone 
gives  large  increase  of  grass,  but  diminishes  the  clover;  a 
combination  of  nitrogenous,  phosphatic,  and  potassic 
manures  is  the  best,  and  benefits  both  grass  and  clover 
alike,  and  gives  a  highly  profitable  return. 

Some  experiments  on  the  use  of  seaweed  as  a  manure 
for  potatoes  shows  that  seaweed  gives  a  crop  quite  equal 
in  weight  to  that  obtained  with  an  equal  weight  of  dung; 
at  the  same  time,  however,  the  "  seaweed  "  potatoes,  both 
in  the  raw  and  cooked  conditions,  were  not  considered  to 
be  of  so  good  a  quality  as  those  from  the  dunged  plots. 

The  last  experiments  on  the  manuring  of  turnips 
showed  that  in  all  soils,  in  the  south  and  west  of  Scotland, 
tasic  slag,  however  used,  was  not  so  effedlive  in  producing 
an  increase  in  the  turnip  crop  as  was  superphosphate  con- 
-  taining  the  same  amount  of  phosphoric  acid.  In  peaty 
or  mossy  soils  different  results  were  obtained ;  slag  is  then 
better  when  sown  with  drills  than  when  scattered  broad- 
cast ;  phosphatic  and  potassic  manures  without  nitrogen 
cannot  be  relied  on,  but  a  combination  of  the  three  makes 
a  good  turnip  manure.  These  conclusions  are  based 
solely  on  the  amount  of  yield  shown  by  the  weight  of 
the  crop. 


Reports  of  the  Government  Analyst  for  British  Guiana 
for  1894-5,  1895-6,  and  1896-7.  Georgetown,  Deme- 
rara:  C.  K.  Jardine,  Printer  to  the  Government, 
1895-6-7. 

The  work  done  in  the  Government  Laboratory  has  in- 
creased from  2097  samples  in  1894-5  ^o  2399  samples  in 
11896-7,  and  we  note  that  the  number  of  official  samples 
has  decreased  in  that  period  from  1472  to  1450 ;  but  in 
the  intermediate  year,  1895-6,  there  was  a  large  increase 


Report  of  the  Agricultural  Work  in  the  Botanic  Gardens 

for  the  Years  1893-4-5.     British  Guiana.     Georgetown, 

Demerara:  C.  K.  Jardine,  Printer  to  the  Government. 

1897. 

The  Report  over  the  past  three  years  has  been  delayed, 

with  the  objedt  of  recording  the  termination  of  the  period 

of  the  first  set  of  manurial  experiments  with  sugar-cane. 

This  period  came  to  an  end  in  December,  1895,  and,  as 

many  experiments  overlapped,  it  was  considered  unde- 

sirable  to  report  at  arbitrary  intermediate  periods. 

The  first  experiments  discussed  in  this  Report  are  those 
with  seedling  canes,  and,  as  has  been  pointed  out  in  a 
previous  Report,  it  is  found  to  be  impossible  to  form  any 
opinion  of  the  richness  of  the  seedling  progeny  from  the 
richness  of  the  adual  parent,  on  account  of  the  range  of 
variation  being  so  great,  and  we  are  forced  to  regard  the 
saccharine  richness  of  a  seedling  equally  problematical, 
as  are  conjedures  beforehand  as  to  its  colour  and  size. 
It  is  believed  that,  in  the  future,  improvement  lies  in 
raising  year  by  year  new  varieties  from  seed,  seleding 
those  of  greatest  vigour,  most  abundant  field  yield,  and 
high  saccharine  contents,  in  the  hope  of  obtaining  a  new 
variety:  the  "pedigree"  seedlings  already  obtained  by 
this  means  show  that  the  experimenters  are  on  the 
threshold  of  this  advance. 

The  general  dedudions  as  to  the  adion  of  manures  and 
lime  upon  four  crops  of  sugar-canes  grown  upon  very 
heavy  clay  land  may  be  briefly  summarised  thus  :— 

1.  That  nitrogen  in  the  forms  of  sulphate  of  ammonia, 
nitrate  of  soda,  and  dried  blood,  is  without  doubt  the 
manurial  constituent  the  supply  of  which  mainly  governs 
the  yield  of  the  plant. 

2.  When  applied  in  quantities  capable  of  supplying  not 
more  than  40  lbs.  of  nitrogen  per  acre,  there  was  prafti- 
cally  no  difference  in  the  effedls  of  sulphate  of  ammonia 
and  nitrate  of  soda,  but  the  former  was  cheaper.  Dried 
blood  was  decidedly  inferior.  The  best  results  were  with 
one-third  nitrate  of  soda  and  two-thirds  sulphate  of 
ammonia. 

3.  From  2j  to  3  cwt.  of  sulphate  of  ammonia  per  acre 
appeared  to  be  the  most  certainly  profitable  application 
of  nitrogen. 

4.  Upon  plant  canes,  superphosphate  of  lime  gave  con- 
siderable and  profitable  increase  of  yield  when  added  to 
manurings  of  nitrogen  and  potash. 

5.  Mineral  phosphates  require  to  be  applied  m  such 
heavy  dressings  as  to  render  their  use  unprofitable. 

6.  Slag  phosphate  appears  to  be  a  promising  source  of 
phosphate  for  plant  canes,  instead  of  superphosphate  of 

lime.  .      ^  „       ■     .      r 

7.  The  addition  of  potash  has  little  eflea ;  nitrate  of 
potash  instead  of  nitrate  of  soda  was  unsatisfadtory. 

8.  The  use  of  lime  resulted  in  largely  increased  yields. 
It  is  satisfadory  to  note  that   the  West  Indian  sugar 

colonies  have  not  been  tamely  allowing  themselves  to  be 
driven  out  of  the  sugar  market,  and  the  colonies  them- 
selves  destroyed,  by  the  hostile  German  Sugar  Bounties. 
The  planters  and  others  of  the  colony  of  British  Guiana, 
we  are  informed,  make  great  use  of  the  scientific  facilities 
placed  at  their  disposal  by  the  Government ;  and  we  are 
glad  to  be  able  to  corred  the  idea,  which  is  perhaps  too 
widely  prevalent,  that  the  tropical  colonists  of  Great 
Britain  take  but  little  interest  in  the  scientific  asped  of 


Chemical  News,  I 
July  30,  1897.     I 


Chemical  Notices  Jrom  Foreign  Sources, 


59 


their  work.  Reports  such  as  the  one  now  before  us  show 
conclusively  that  the  present-day  planters  are  not  content 
to  follow  the  old  methods  of  a  century  ago,  but  are  doing 
their  best  to  help  themselves  in  their  almost  hopeless 
struggle  against  the  effefts  of  German  Sugar  Bounties. 


CORRESPONDENCE. 

PRECIPITATION   OF  COPPER  BY  MAGNESIUM. 

To  the  Editor  of  the  Chemical  News. 
Sir, — In  connedlion  with  the  subjeft  of  the  displacement 
of  copper  by  magnesium  in  solutions  of  copper  sulphate, 
the  following  note  may  be  of  some  interest. 

The  adlion  appears  to  be  conditioned  by  the  purity  of 
the  copper  sulphate. 

Specimens  of  bright  magnesium  ribbon  were  immersed 
in  an  excess  of  solution — (i)  of  ordinary  blue  vitriol,  (2) 
of  re- crystallised  copper  sulphate,  bought  as  pure,  and  (3) 
of  a  specimen  of  copper  sulphate  which  had  been  frac- 
tionally re-crystallised  by  myself  four  times  from  2  kilos. 
of  a  sample  equal  in  initial  purity  to  (2). 

After  immersion  for  two  and  a  half  hours,  the  second 
specimen  was  found  to  have  deposited  a  very  small  trace 
of  copper.  In  the  third  instance  the  magnesium  was 
withdrawn  apparently  as  bright  as  when  first  immersed. 
On  solution  it  was  found  to  contain  a  minute  trace  of 
copper. 

The  aftion  appears  to  be  accelerated  as  time  goes  on, 
but  even  after  four  days  a  considerable  amount  of  magne- 
sium is  found  in  the  solid  residue. 

On  the  other  hand,  the  purest  zinc  at  my  disposal  was 
instantly  covered  with  a  deposit  of  copper  in  each  in- 
stance, and  the  adtion  was  found  to  be  completed  in 
twelve  hours,  no  trace  of  zinc  being  discoverable  in  the 
washed  pulverulent  copper. 

I  regret  that  other  scientific  work  has  prevented  me  from 
continuing  these  experiments,  but  I  hope  that  in  the 
course  of  the  winter  one  or  two  of  my  students  will  have 
something  to  say  on  the  adtion  of  purified  magnesium  on 
purified  copper  sulphate  solutions. — I  am,  &c., 

Sidney  A.  Sworn. 

Chemical  Laboratory, 

Municipal  Technical  School, 

Gravesend,  July  27,  1897. 


CHEMICAL    NOTICES   FROM    FOREIGN 
SOURCES. 


NoTB.— All  degrees  of  temperature  are  Centigrade  unlesBotberwise 
expressed. 

Bulletin  de  la  Sociite  Chimique  de  Paris. 
Series  3,  Vol.  xvii.-xviii.,  No.  12,  June  20,  1897. 

M,  Freundler  has  studied  the  decomposition  of  pyro- 
mucates  of  the  alkaline  earths  under  various  conditions. 
This  decomposition  gives  rise  to  the  formation  of  a  small 
quantity  of  furfurane,  to  a  carbide,  C3H4,  and  to  oxide  of 
carbon. 

M.  Tardy  has  separated  carbides  from  bitter  fennel  and 
found  many  interesting  bodies. 

M.  Ponsot,  in  thinking  over  a  cryoscopic  experiment 
from  the  calorimetric  point  of  view,  finds  a  means  of  de- 
teding  whether  a  cryoscopic  method  regularly  used  has 
systematic  errors. 

On  Yellow  Ligbt  for  Polarimetry. — F.  Dupont. — 
The  author  finds  that  a  mixture  of  common  salt  and  tri- 
basic  phosphate  of  soda,  fused  together  in  proportions 
similar  to  their  molecular  weights,  answers  perfedly  and 
gives  excellent  results.     The  mixture  melts  more  easily 


than  sea  salt,  does  not  decrepitate,  and  gives  a  remarkably 
steady  yellow  light.  Polarimetric  observations  are  by  its 
use  very  easy  and  exadt. 

Precipitation  of  Chloride  of  Copper  by  Aluminium. 
— J.  B.  Senderens. — A  reply  to  the  remarks  of  M.  Tom- 
masi. 

On  Borate  of  Lithium. — H,  Le  Chatelier. — Lithium 
shows  several  analogies,  both  to  the  alkaline  metals  and 
the  alkaline  earths.  The  author  has  endeavoured  to  find 
whether  its  borates,  even  by  their  composition,  show  more 
precise  analogies,  considering  the  great  variations  observed 
between  one  metal  and  another,  in  the  number  and  compo- 
sition of  the  borates  of  each. 

Basic  Salts  of  Cadmium. — M.  Tassilly. — Already  in- 
serted. 

On  Dextro-Licarhodol. — Ph.Barbier  and  G.  Leser. — 
Pure  licareol  is  heated  for  eight  hours  at  150°  or  160°  with  ■ 
its  own  weight  of  acetic  anhydride.  At  the  end  of  this 
time  the  acetic  acid  is  removed  by  successive  washings, 
the  produdt  of  the  readtion  is  dried  and  redtified  in  vacuo 
in  three  fradlions:  the  first,  from  50°  to  80°,  consists  princi- 
pally of  a  mixture  of  tetratomic  terpenes,  CioHie;  the 
second,  from  80°  to  105°,  which  still  contains  some  unadted 
upon  licareol,  is  again  submitted  to  the  adtion  of  acetic 
anhydride,  but  under  modified  conditions ;  the  third,  from 
105°  to  130,  submitted  to  a  minute  fradtionation  in  vacuo, 
gives  an  abundant  colourless  liquid,  of  agreeable  odour, 
boiling  at  119°  to  120°  under  a  pressure  of  10  m.m.,  and 
which  has  the  composition  of  the  acetic  ether  of  an  alco- 
hol, CioHisO. 

On  some  Properties  of  Caffeine. — E.  Tassilly. — Crys- 
tals  of  caffeine  from  aqueous  solution  were  carefully  air- 
dried  for  a  week ;  they  then  gave  on  analysis  the  formula 
CsHioN^Oz.HzO.  On  heating  to  50° — 55°  this  body  com- 
mences to  lose  weight,  and  on  increasing  the  temperature 
this  loss  of  weight  continues;  but  the  whole  of  the  water 
of  crystallisation  is  not  driven  off  even  at  150°,  while  the 
caffeine  itself  is  volatile  at  this  temperature.  Experiments 
showed  the  caffeine  is  carried  off  by  water  vapour  when 
evaporated  on  a  water-bath,  or  even  when  heated  up  to 
110°.  Further  experiments  were  made  on  the  adtion  of 
alkalies  on  caffeine,  and  it  was  found  that  though  magnesia 
has  no  adtion,  the  same  cannot  be  said  of  baryta  and  lime, 
which  decompose  it  with  the  produdtion  of  ammonia. 

On  an  Isomer  of  Disulphide  of  Diphenylene. — P. 
Genvresse. — This  body  is  formed  while  preparing  disul- 
phide of  diphenylene  by  the  adtion  of  sulphur  on  benzene, 
in  the  presence  of  chloride  of  aluminium ;  it  is  almost 
insoluble  in  all  solvents,  and  takes  an  emerald-green 
colour  under  the  influence  of  sulphuric  acid. 

Decomposition  of  Pyromucates  of  the  Alkaline 
Earths  by  Heat. — P.  Freundler. — This  paper  deals  with 
furfurane  and  its  preparation ;  the  only  pradlical  method 
of  preparing  this  body  is  that  of  Limpricht,  who  obtained 
it  by  the  distillation  of  pyromucate  of  barium  with  soda- 
lime.  In  vacuo  the  decomposition  of  pyromucates  takes 
place  at  a  lower  temperature,  but  a  small  quantity  of 
cetone  is  also  formed ;  under  pressure  pyromucates  can 
be  heated  up  to  375°  without  undergoing  any  change,  but 
towards  400°  it  decomposes  brusquely. 

On  the  Carbide  C3H4,  a  Secondary  Produ(5t  of  the 
Decomposition  of  Pyromucate  of  Barium. — P.  Freund- 
ler.— This  carbide  fixes  bromine  in  the  cold  and  gives  a 
small  quantity  of  a  dibromide  boiling  at  about  50°  in  vacuo  ; 
it  is  extremely  irritating  to  the  eyes.  The  principal  pro- 
dudl,  however,  is  a  liquid  tetrabromide,  C3H4Br4,  boiling 
at  162°  under  a  pressure  of  20  m.m.  This  latter  body  has 
not  been  obtained  quite  pure,  on  account  of  its  hygrosco- 
picity  and  because  it  loses  hydrobromic  gas  rapidly  at 
ordinary  tempera:tures. 

On  some  Derivatives  of  Piperonal. — S.  Baude  and 
A.  Reychler. — Piperonal  easily  lends  itself  to  the  prepa- 
ration of  a  series  of  derivatives  similar  to  those  prepared 
from  anisaldehyd,  such  as  methylenedioxycinnamate  of 


6o 


Chemical  Notices  from  Foreign  Sources. 


/Chemical  News, 
I     July  30, 1897. 


ethyl,  methylenedioxyphenylpropiolic  acid,  and  methylene- 
dioxyphenylacetylene. 

On  Amidised  Amidines. —  Charles  Lauth. — The 
author  hsa  prepared  two  amidines  giving  similar  colours, 
but  they  are  not  very  stable  under  the  influence  of  light. 

Intervention  of  Manganese  in  the  Oxidations 
brought  about  by  Laccase. — G.  Bertrand. — Some  time 
ago  the  author  found,  while  studying  the  chemical  com- 
position of  laccase,  that  the  ash  contained  a  relatively 
high  proportion  of  manganese,  but  he  did  not  then  esti- 
mate it.  He  has  now  returned  to  the  subjedt,  and  has 
found  as  much  as  2*5  per  cent  of  manganese  present.  In  j 
the  adlion  of  the  ferment  he  is  of  the  opinion  that  man- 
ganese cannot  be  replaced  by  any  other  metal,  not  even 
by  iron. 

Estimation  of  the  Oxygen  Dissolved  in  Sea-water. 
— A.  Levy  and  Felix  Marboutin. — Already  inserted. 

Estimation  of  Cream  of  Tartar  in  Wines. — H.  Jay. 
— Several  writers  on  the  subjedl  of  the  estimation  of  bi- 
tartrate  of  potash  rely  more  on  methods  of  crystallisation 
than  on  precipitation ;  they  assume,  in  fad,  that  the 
former  is  more  exadt.  The  author  has  carefully  investi- 
gated the  subjedt,  and  arrives  at  the  conclusion  that  the 
results,  intrinsically  and  direftly  inexadt,  obtained  by  the 
methods  of  Berthelot  and  of  Fleurieu,  are  by  their  correc- 
tions, which  are  constant,  nearer  the  truth  than  those  ob- 
tained by  crystallisatoin,  in  which  he  finds  the  excess  is 
not  constant. 

On  the  Yellow  Colouring-matter  of  the  Oil  in  White 
Wines  containing  Caramel. —  Alberto  D'Aguiar  and 
Wenceslau  da  Silva. — Already  inserted. 

Commercial  Re(5tification  of  Organic  ProduAs. — E. 
Barillot. — An  interesting  paper,  which,  however,  requires 
the  accompanying  diagram. 


MISCELLANEOUS. 

Seventy-seventh  Annual  Announcement  of  the 
Philadelphia  College  of  Pharmacy,  1897. — Previous  to 
1840  pharmacists  were  not  recognised  in  pharmacopceial 
conventions,  but  in  that  year  the  College  was  invited  to 
co-operate  with  the  Committee  on  Final  Publication  and 
Revision.  Since  then  pharmacists  have  so  improved  their 
position  that  at  the  last  convention  in  1890  they  numbered 
sixteen  of  the  twenty-six  members.  Since  the  establish- 
ment of  the  institution  14,661  students  have  matriculated, 
and  4416  persons  have  taken  the  degree  of  Graduate  in 
Pharmacy. 

Paris  International  Fire  Prevention  Congress,  1897. 
— The  terrible  catastrophe  at  the  Charity  Bazaar  in  May 
last  has  determined  a  number  of  influential  men  to  form 
a  committee,  and  call  together  an  International  Congress, 
to  discuss  all  means  to  prevent  and  minimise  fire  risks  in 
theatres,  concert  halls,  and  places  of  public  resort.  The 
date  of  the  congress  has  not  yet  been  finally  decided  on,  but 
will  be  announced  shortly.  In  conjundtion  with  the  Con- 
gress there  is  being  organised  an  International  Exhibition 
of  all  engines,  inventions,  produfts,  and  plans  for  the  pre- 
vention and  extinguishing  of  fires.  Inventors,  manufac- 
turers, and  engineers  are.invited  to  exhibit  their  machines 
and  inventions ;  in  this  way  scientific  discussion  will  be 
strengthened  by  pradlical  demonstration.  One  hundred 
and  fifty  Senators,  Deputies,  Municipal  Councillors,  and 
scientific  men  have  already  joined  the  committee,  and  the 
British  Secretary,  Mr.  Frederick  Hoare,  249^,  High  Hol- 
born,  will  be  glad  to  receive  any  data  or  useful  information 
bearing  upon  the  business  of  the  Congress.  France  is 
decidedly  behindhand  in  this  matter,  and  we  doubt  if  she 
can  get  outside  help  better  than  in  England. 


Wanted,  place  as  Assistant  at  Chemical 
Laboratory  or  Porter,  by  experienced  Young  Man,  aged  24; 
single.  Good  references.— Address,  R.  Baggott,  9,  Shroton  Street, 
Xisson  Grove. 


TTNIVERSITY      COLLEGE,      BRISTOL, 

^  CHEMICAL   DEPARTMENT. 

Professor— SYDNEY  YOUNG,  D.SC,  F.R  S 
Lefturer— FRANCIS  E.  FRANCIS,  B.Sc,  Ph.D. 
Junior  Demonstrator — 

The  SESSION  1897-98  begins  on  Oftober  5th.  Leftures  on  Inor- 
ganic, Organic,  and  Advanced  Chemistry  will  be  delivered.during  the 
Session.  The  Laboratories  are  fitted  with  the  most  recent  improve- 
ments for  the  study  of  Praftical  Chemistry  in  all  its  branches.  In  the 
Evening  the  Laboratory  is  opened  and  Le<ftures  on  Inorganic  Che- 
mistry, at  reduced  lees,  are  delivered.  Several  Scholarships  are 
tenable  at  the  College. 

CALENDAR,  containing  full  information,  price  is.  (by  post 
IS.  ^d.). 

For  Prospeftus  and  further  particulars  apply  to— 

JAMES  RAFTER,  Secretary. 

WENS     COLLEGE,    VICTORIA     UNL 

VERSITY,    MANCHESTER. 

PROSPECTUSES  for  the  SESSION  1897-8  will  be  forwarded  on 
application. 

1.  DEPARTMENT   of  ARTS,    SCIENCE,    and    LAW;    and 

DEPARTMENT  for  WOMEN. 

2.  DEPARTMENT  of  MEDICINE. 

3.  EVENING  and  POPULAR  COURSES. 
Special  Prospeftuses  can  also  be  obtained  of — 

4.  DEPARTMENT  of  ENGINEERING. 

5.  DEPARTMENT  of  LAW. 

6.  DEPARTMENT  of  PUBLIC  HEALTH. 

7.  DENTAL  DEPARTMENT. 

8.  PHARMACEUTICAL  DEPARTMENT;  and 

9.  FELLOWSHIPS,  SCHOLARSHIPS,  EXHIBITIONS,  and 

PRIZES.  ' 

Apply  to  Mr.  Cornish,  16,  St.  Ann's  Square,  Manchester;  or  at 
the  College. 

SYDNEY  CHAFFERS,  Registrar. 

HERIOT-WATT  COLLEGE,  EDINBURGH. 

F.  GRANT  OGILVIE,  M.A.,  B.Sc,  F.R.S.E.,  Principal. 
DAY  CLASSES— SESSION  1897.98. 

The  SESSION  extends  from  TUESDAY, 
October  5th,  1897,  to  Friday,  June  3RD,  1898. 
These  Classes  provide  Courses  of  Study  extending  over  one  or 
more  years,  suitable  for  Students  who  have  previously  passed  through 
the  Curriculum  of  a  Secondary  School.  The  principal  Courses  are: — 
Physical  and  Chemical,  Mechanical  Engineering  and  Eieftrical 
Engineering.  There  are  also  Classes  in  French,  German,  Drawing, 
and  Praftice  of  Commerce.  Class  Fees  from£i  is.  to  £4  4s.;  Session 
Fee,  £10  los. 

There  is  also  a  preparatory  Course  of  Instruftion  for  Agricultural 
Students ;  Session  Fee,  £5  5s.  An  extradt  from  the  Calendar  of  the 
College  giving  particulars  of  the  Day  Classes,  and  of  the  various 
Appliances,  Laboratories,  and  Workshops  available  for  instrutStion, 
may  be  had  on  application  to  the  Librarian,  at  the  College,  or  to  the 
Treasurer  of  George  Heriot's  Trust. 

DAVID  LEWIS, 
Treasurer's  Chambers,  20,  York  Place,  Treasurer. 

Edinburgh,  July  14th,  1897. 

ACETONE Answering  all  requirements. 

J^OIX)     ^A.CEa?IG-Purest  and  sweet. 

EOI^-A-CIC-Cryst.  and  powder. 

CimS-IO— Cryst.  made  in  earthenware. 

r=^  A  T.T.Tr^— From  best  Chinese  galls,  pure. 

S-A-XjICSTXjIO— By  Kolbe's  process. 

LIQUID  CHLORINE 

(Compressed  in  steel  cylinders). 
POTASS.  PERMANGANATE— Cryst.,  large  and  small, 

SULPHOCYANIDE   OF   AMMONIUM. 
BARIUM. 

SODA  PHOSPHATE. 
THORIUM,  ZIRCONIUM,  and  CERIUM  SALTS, 

TARTAR   EMETIG-Cryst.  and  Powder. 

PUMICE.     TRIPOLI   AND   METAL  POWDERS. 

ALL  CHEMICALS   FOR  ANALYSIS   AND  THE  ARTS. 

Wholesale  Agents— 

A.  &  M.  ZIMMERMANN, 

9  &  10,  ST.  MARY-AT-HILL,  LONDON,  E.G. 


Chemical  Nbwb,I 

Aug.  6,  1897.      I 


Recent  Progress  of  Alchemy  in  America. 


61 


THE    CHEMICAL     NEWS 


Vol.  LXXVL,  No.  1967. 


RECENT     PROGRESS    OF    ALCHEMY    IN 
AMERICA. 

Reported  by  H.  CARRINGTON  BOLTON,  Ph.D. 

The  suicide  of  Dr.  James  Price,  the  Fellow  of  the  Royal 
Society  who  preferred  ignominious  death  to  an  investiga- 
tion of  his  claim  to  success  in  transmuting  base  metals 
into  silver  and  gold,  was  a  heavy  blow  to  the  pretensions 
of  alchemists  in  England,  for  we  hear  but  little  of  the 
disciples  of  Hermes  in  Great  Britain  during  the  hundred 
years  that  have  elapsed  since  that  tragic  event.  Of  vulgar 
swindlers,  such  as  the  American  confidence-men  who 
attempted  to  cheat  the  Bond-street  jeweller  by  a  pretence 
of  "multiplying"  sovereigns,  there  are  occasional  ex- 
amples ;  and  there  have  been  instances  of  successful 
imposture  practised  on  the  Royal  Commissioners  of 
Patents,  who  have  granted  patents  for  "  getting  gold  from 
wheat "  by  skimming  water-washed  straw,  and  for  de- 
teding  underground  treasures  by  a  certain  divining-bottle; 
but  these  are  exceptional,  and  need  not  be  chronicled  in 
sketching  the  progress  of  alchemy  in  the  nineteenth 
'Century. 

In  the  United  States  of  America  the  claims  of  alche- 
mists have  rarely  been  seriously  considered,  the  people 
being  free  from  the  fetters  of  authority  and  tradition,  and 
possessing  a  shrewd,  calculating  spirit,  symbolised  in  the 
word  "  Yankee."  A  smart  and  educated  French  chemist, 
named  Paraff,  visited  America  a  few  years  ago,  pretending 
to  know  a  process  for  converting  copper  into  gold,  and  for 
a  while  he  succeeded  in  transferring  gold  from  the  pockets 
of  ignorant  persons  to  his  own;  but  when  the  courts  of 
Peru  required  him  to  condudl  a  transmutation  in  their 
•presence  the  career  of  this  modern  Cagliostro  came  to  a 
disastrous  end.  Within  the  last  twelve  months,  however, 
two  claims  to  success  in  transmutation,  or  creation  of 
gold,  have  been  made  with  such  boldnes,  publicity,  and 
persistency,  by  persons  assuming  to  have  superior  scien- 
tific qualifications,  that  it  has  been  impossible  to  ignore 
their  representations,  and  in  one  instance  the  Diredtor  of 
the  United  States  Mint  has  been  called  upon  to  endorse 
or  condemn  the  secret  process  of  the  inventor. 

The  first  of  these  claims  was  announced  in  August, 
1896,  by  Dr.  Stephen  H.  Emmens,  a  well-known  chemist 
of  New  York  city,  whose  name  is  attached  to  the  high 
explosive  "  Emmensite"  invented  by  him.  Dr.  Emmens 
is  a  member  of  several  learned  societies,  and  author  of 
papers  on  chemistry,  eledtricity,  and  metallurgy,  as  well 
as  of  several  novels  and  poems.  In  his  "  Argentaurum 
Papers"  he  presents  erudite  considerations  respefting  the 
Newtonian  dodlrine  of  gravitation. 

To  avoid  doing  injustice  to  Dr.  Emmens  the  following 
account  of  his  discovery  is  given  almost  wholly  in  his 
own  words  : — 

The  Transmutation  of  Silver  into  Gold. 
"  Our  work,  which  converts  silver  into  gold,  had  its 
origin  in  the  course  of  certain  investigations  which  I  un- 
dertook for  the  purpose  of  preparing  chemically  pure 
nickel.  This  was  in  the  year  1892.  Commodore  Folger, 
who  was  then  Chief  of  the  Bureau  of  Ordnance  of  the 
United  States  Navy  Department,  had  forwarded  to  me  for 
investigation  a  very  remarkable  specimen  of  rustless 
nickel  steel  which  it  was  proposed  to  use  as  a  material  for 
torpedo  netting.  I  found  the  physical  properties  of  this 
material  to  be  so  extraordinary  that  I  desired  to  investi- 
gate the  physical  behaviour  of  a  similar  alloy  made  with 


absolutely  pure  iron  and  pure  nickel.  In  attempting  to 
prepare  these  pure  metals,  a  certain  produdt  was  obtained 
which  seemed  to  differ  from  anything  recorded  in  the  text- 
books. The  same  produdt  was  subsequently  found  when 
the  investigation  was  extended  to  the  case  of  metallic 
cobalt.  And,  finally,  those  who  were  associated  with  me 
in  the  investigation  agreed  with  me  in  considering  that 
the  phenomenon  observed  afforded  indications  of  the 
existence  of  some  substance  common  to  the  whole  of  the 
elements  in  what  is  known  as  Series  4  of  Group  8  of 
the  Classification  of  Chemical  Elements,  now  universally 
adopted  by  scientists,  in  accordance  with  what  is  known 
as  the  '  Periodic  Law  of  the  Elements.'  We  did  not 
further  pursue  the  particular  line  of  investigation  upon 
which  we  had  set  out,  because  it  appeared  to  us  almost 
self-evident  that  if  we  were  right  in  supposing  a  common 
substance  to  be  present  in  any  single  series  of  elements 
the  same  would  hold  good  for  each  group. 

"  And  as  Group  I.  of  the  classification  contains  the 
precious  metals — gold  and  silver — it  was  obvious  that  our 
time  and  attention  should  be  diredled  to  these  metals 
rather  than  to  any  others.  .     .     . 

"  It  is,  of  course,  out  of  the  question  for  me  to  make 
public  the  whole  of  our  knowledge  in  the  matter;  but  I 
may  without  danger  to  our  interests  give  a  general  ex- 
planation of  the  work  which  will  be  satisfa^ory  to  the 
scientific  world. 

"  Our  starting-point,  so  far  as  silver  and  gold  were  con- 
cerned, was  afforded  by  the  remarkable  discoveries  of  Mr. 
Carey  Lea  with  regard  to  the  changes  that  could,  by 
laboratory  methods,  be  induced  in  the  molecular  strudure 
of  metallic  silver.  That  gentleman  discovered  a  means 
of  causing  silver,  while  still  in  a  metallic  condition,  to 
enter  into  aqueous  solution.  In  other  words,  he  dis- 
covered a  method  of  reducing  metallic  silver  to  a  condition 
of  extremely  minute  subdivisions.  It  was  found,  as  might 
have  been  expedted  by  anybody  familiar  with  the  periodic 
law  of  the  elements,  that  this  subdivision  of  metallic 
silver  was  attended  by  very  considerable  changes  in  the 
physical  properties  of  the  substance.  The  inference  was 
obvious  that,  if  such  subdivisions  could  be  pushed  a  stage 
further,  the  silver  molecules  would  become  dissociated  if 
they  were  in  themselves  of  composite  strudure  ;  and,  as 
all  chemists  have  long  been  agreed  respefting  the  reality 
of  such  composite  strudture,  we  felt  absolutely  sure  of 
our  ground. 

"  Accordingly,  when  by  certain  physical  methods  and 
by  the  aid  of  certain  apparatus,  we  succeeded  in  bringing 
about  a  further  subdivision  of  the  silver,  we  were  not 
surprised  to  find  that  the  substance  obtained  differed  so 
far  from  ordinary  silver  that  it  could  no  longer  be  regarded 
as  the  same  elementary  substance.  It  seemed  to  require 
a  new  name  and  a  new  chemical  symbol.  Inasmuch, 
therefore,  as  our  theory  was  that  this  substance  was 
common  to  both  gold  and  silver,  and  in  reality  was  the 
raw  material  out  of  which  both  gold  and  silver  were  con- 
strudled  by  the  hand  of  Nature,  we  named  the  sub- 
stance "Argentaurum."  We  gave  it  also  the  chemical 
symbol  "Ar." 

"  The  next  step  was  to  ascertain  whether  this  substance 
could  be  so  treated  as  to  be  grouped  into  molecules  of 
greater  density  than  those  of  silver.  Here  the  element 
of  personal  danger  was  introduced  into  our  researches, 
and  the  success  of  our  work  on  a  commercial  scale  has 
yet  to  be  assured  by  the  construdtion  and  safe  manipula- 
tion of  new  apparatus,  in  which  vast  energy  will  be 
employed.  Working  upon  the  necessarily  microscopical 
scale  of  our  experimental  researches,  we  found  that  the 
substance  called  by  us  '  Argentaurum  '  can  be  aggregated 
into  molecules  having  a  density  considerably  superior  to 
that  of  silver  molecules,  and,  we  think,  identical  with 
that  of  ordinary  gold  molecules.  Whether  we  areright  as 
to  this  or  not,  the  condensed  argentaurum  presents  the 
appearance  and  is  endowed  with  the  properties  of  ordinary 
metallic  gold.  For  example,  it  is  green  by  transmitted 
light  and  yellow  by  refledted  light, — properties  which,  as 


62 


Recent  Progress  of  A  Ichemy  in  A  merica. 


I  Chbuical  Mbws^ 
I       Aug.  6,  1897. 


all  chemists  know,  are  possessed  by  gold  alone.  Its  re- 
sistance to  the  adlion  of  either  nitric  or  hydrochloric  acid 
alone,  and  its  solution  by  a  mixture  of  these  acids,  are 
also  distinguishing  properties  of  pure  gold,  and  of  no 
other  yellow  metal.  Under  the  microscope  it  is  indis- 
tinguishable from  ordinary  gold." 

After  some  comments  on  the  Periodic  Law,  Dr.  Emmens 
continues: — 

"  If  Mendelejeff's  table  be  examined,  it  will  be  seen 
that  a  vacant  space  exists  in  the  Sub-group  of  Group  I., 
and  that  this  vacant  space  stands  immediately  between 
silver  and  gold.  Our  claim  is  that  the  hitherto  missing 
element  in  question  is  our  argentaurum,  which  in  itself 
therefore  is  neither  silver  nor  gold,  but  which  may,  by  our 
new  physical  methods,  be  converted  into  gold." 

Referring  to  the  question  of  cost  the  discoverer  says: — 
"  We  do  not  consume  any  chemicals  and  other  costly 
materials  in  our  process  ;  what  we  use  is  mainly  energy 
in  some  of  its  various  forms,  such  as  heat,  eledtricity, 
magnetism,  gravity,  cohesion,  chemical  afSnity,  X  rays, 
and  the  like."  "  Our  chief  source  of  expense  is  the  time 
required  for  bringing  about  the  desired  molecular  changes." 
And  further  discussing  the  expenses.  Dr.  Emmens  esti- 
mates that  "one  ounce  of  silver  will  produce  three- 
quarters  of  an  ounce  of  gold,"  and  that  "we  can  reckon 
on  a  profit  of  at  least  three  dollars  per  ounce  upon  all  the 
silver  we  employ." 

In  a  pamphlet,  published  in  July  of  this  year,  Dr, 
Emmens  states  that  the  process  of  transforming  silver 
into  gold  depends  largely  on  mechanical  treatment,  and 
hints  at  "  the  combined  effedt  of  impadt  and  a  very  low 
temperature."  He  now  operates  on  Mexican  dollars, 
and,  as  substantial  proof  of  his  labours  in  transmutation, 
he  has  sold  to  the  United  States  Assay  Office  six  ingots 
of  an  alloy  of  silver  and  gold,  aggregating  in  value  954 
dollars  and  80  cents.  These  ingots  have  been  sold  since 
April  13th,  and  have  been  delivered  at  the  rate  of  two 
per  month ;  they  varied  in  weight  from  7  ounces  to 
16^  ounces. 

Dr.  Emmens  remarks  in  this  connexion,  *' The  gold- 
producing  work  in  our  Argentaurum  laboratory  is  a  case 
of  sheer  Mammon-seeking  ;  it  is  not  being  carried  on  for 
the  sake  of  Science,  or  in  a  proselytising  spirit;  no 
disciples  are  desired,  and  no  believers  are  asked  for.  I 
have  every  confidence  that  the  produdion  of  Argentaurum 
gold  will  be  brought  up  to  50,000  ounces  monthly  within 
a  year." 

The  second  claimant  for  a  process  of  converting  base 
metals  into  precious  ones  is  Edward  C.  Brice,  of  Chicago, 
who  has  lived  a  rather  chequered  life  as  an  enlisted  man 
in  the  Army,  a  member  of  the  Police  force  of  Washington 
city,  a  promoter  of  a  scheme  for  manufaduring  a  patent 
brick,  and  a  discoverer  of  the  Philosopher's  Stone.  Ac- 
cording to  the  newspapers,  Brice  began  his  operations 
about  three  years  ago,  in  Washington,  by  interesting 
some  rich  and  credulous  men  in  a  secret  process  for 
transmutation ;  several  experiments  made  in  their  presence 
seemed  to  confirm  the  promoter's  statements,  but  one  of 
those  who  was  supplying  money  became  suspicious,  and 
thought  he  detedled  the  introduction  of  gold-leaf  into  the 
crucibles  used  ;  and  later,  by  skilful  diplomacy,  he  learned 
from  Mrs.  Brice  that  her  husband  had  been  buying  much 
gold-leaf  for  gilding  pidture-frames  !  This  unkind  ex- 
posure seems  to  have  caused  a  temporary  suspension  of 
Brice's  operations,  but  in  no  wise  discouraged  him,  for  he 
next  appears  in  Chicago,  where  he  pushed  his  old  schemes 
with  great  success,  securing  the  financial  backing  of 
some  of  the  prominent  capitalists  of  that  city,  bankers, 
presidents  of  trust  companies,  and  railway  men.  All  were 
impressed  with  the  frank  manner  and  attradive  plans  of 
Brice,  and  they  advanced  him  about  five  thousand  dollars, 
with  which  he  established  a  small  plant  capable  of 
yielding  fifteen  hundred  dollars  in  gold  and  silver  weekly. 
Business  men  of  ordinary  common  sense  came  to  the 
conclusion  that  Brice  "  had  either  gotten  something  that 
s  invaluable  to  any  Government — or  he  is  a  rank  fraud." 


Brice  himself  said  to  one  of  these  wealthy  men : — "  We 
do  not  want  capital,  we  make  our  capital  here.  What  we 
need  is  Government  protedlion,  either  in  the  way  of  pur- 
chase or  special  legislation  ;  the  Government  alone  can 
entrust  the  secret  to  experts.  Our  experts  would  go- 
somewhere  to  a  remote  place  and  make  all  the  gold  they 
wanted  as  fast  as  we  educated  them."  When  capitalists 
offered  to  purchase  the  secret  from  Brice  he  refused, 
saying  the  Government  alone  should  have  the  first  option.. 
His  claim  to  obtain  gold  and  silver  from  chemically  pure 
antimony  was  examined  by  Robert  W.  Hunt,  a  Chicago 
chemist,  and  his  favourable  report  "  gave  support  to  the 
credulous  and  disconcerted  the  doubters." 

On  the  7th  of  May,  1897,  Brice  filed  an  application  in 
the  United  States  Patent  Office  for  a  patent  on  a  process 
for  creating  gold  and  silver  by  operating  on  lead,  tin, 
antimony,  and  other  base  metals.  The  Patent  Office 
twice  refused  to  grant  the  claim,  on  the  ground  that  no 
practical  application  of  the  process  had  been  made;  but 
as  Brice  continued  to  press  his  suit,  the  officials  consented 
to  grant  him  an  experimental  demonstration  of  his 
methods.  Owing  to  inadequate  laboratory  facilities  in  the 
Patent  Office  building,  application  was  made  to  the 
Secretary  of  the  Treasury  for  permission  to  use  the  com- 
plete and  spacious  laboratory  of  the  Mint  Bureau. 
Accordingly  the  Secretary  of  the  Treasury  requested  Mr. 
R.  E.  Preston,  Diredtor  of  the  Mint,  to  make  a  thorough 
investigation  of  Brice's  process,  and  three  expert  assayers 
were  appointed  for  the  purpose.  The  materials  needed 
for  the  research  were  bought  of  reliable  dealers  in  chemicals 
by  Mr.  Preston ;  they  comprised  3  pounds  of  pure  anti*^ 
mony,  2  pounds  of  rolled  sulphur,  i  pound  01  sheet  iron, 
and  some  pulverised  charcoal.  The  assay  commission 
made  a  series  of  experiments  according  to  Brice's  in- 
strudtions,  and  three  weeks'  later  submitted  a  report  of 
much  interest  and  value,  showing  that  commercial  anti- 
mony contained  a  very  small  percentage  of  gold,  which 
was  partially  recovered  by  Brice's  process.  I  am  indebted 
to  Mr.  R.  E.  Preston,  for  a  copy  of  this  report,  which  is 
subjoined. 

Public  exposure  of  Brice's  scheme  for  raising  money, 
in  the  daily  press,  followed  this  official  report ;  he  himself 
expressed  dissatisfadlion  with  the  work  of  the  Commis- 
sioners, and  still  claims  that  his  plant  in  Chicago  is  a 
financial  success.  Brice's  attorney  has  entered  a  protest 
against  the  findings  of  the  assayers,  and  here  the  matter 
rests. 

The  circumstances  connedled  with  this  claim,  the 
appeal  to  Government  authorities,  the  trial  by  Officers  of 
the  Mint,  and  the  unfavourable  report  as  well  as  the  per- 
sistence of  the  claimant,  almost  exadtly  duplicate  the 
events  associated  with  the  name  of  Theodore  Tiffereau,  in 
Paris,  about  forty  years  ago  ;  and,  like  Brice,  the  French- 
man still  maintains  his  discovery,  for  as  recently  as 
December,  1896,  Tiffereau  addressed  a  sealed  letter  to  the 
Academy  of  Sciences  describing  a  new  process  to  prove 
that  metals  are  compounds. 

These  nineteenth  century  experiences  seem  worth  re- 
cording, if  only  to  show  how  many  features  they  have  in 
common  with  those  of  the  mediaeval  chemists,— secret 
processes,  vagueness  of  description,  an  assumption  of 
esoteric  knowledge  expressed  in  pseudo-philosophic  lan- 
guage, personally-condudted  experiments  with  seeming 
success,  and  magnificent  financial  prospedts,  yet  an  im- 
perative present  need  of  gold. 


(Report). 
Washington,  D.C.,  May  22nd,  1897. 
Hon.  R,  E.  Preston, 

Diredtor  of  the  Mint, 

Washington,  D.C. 
Sir, — In  accordance  with  your  instrudlions  under  date  of 
May  3rd,  we  met  at  the  Mint  Bureau  on  May  5th,  to  in- 
vestigate  the  claim  of  Mr.  E.  C.  Brice  to  a  process  for 


CbbuicalNbws, 

Aug.  6,  1807. 


Recent  Progress  of  Alchemy  in  America. 


63 


producing  or  creating  silver  and  gold  from  the  base  metals, 
oxides,  &c. 

Mr.  Brice  has  applied  for  a  patent  on  this  process,  and 
■his  application  has  been  twice  rejedted  on  the  ground  that 
the  process  is  inoperative. 

We  found  that  you  had  purchased  from  the  most 
reputable  chemical  dealers  the  materials  asked  for  by 
Mr.  Brice,  in  a  written  memorandum,  and  that  the  sup- 
plies were  labelled  "  chemically  pure,"  as  requested  by 
Mr.  Brice.  A  test  made  by  us  showed  small  but  weigh- 
able  quantities  of  gold  and  silver  in  the  so-called 
"  chemically  pure"  antimony.  Other  samples  were  pro- 
cured from  different  sources  with  a  like  result. 

While  seeking  for  pure  antimony,  we  accepted  the  offer 
•of  Mr.  Brice  that  he  should  supervise  and  diredl  a  trial  of 
his  process  upon  antimony  known  to  contain  small 
amounts  of  silver  and  gold,  and  that  he  should  condudt 
an  assay  of  the  same  antimony  for  a  comparison  of  re- 
sults, from  his  own  assay  methods  with  those  from  his 
"  creative  process."  His  assay,  in  which  he  scorified 
one-half  assay  ton  (one  assay  ton  equals  29*166  grms.) 
with  one-half  assay  ton  of  lead,  showed  the  antimony 
to  contain  o'o66  ounce  of  gold  and  0*3 17  ounce  of  silver 
per  ton. 

Mr.  Brice  now  subjefted  five  (5)  ounces  of  this  antimony 
to  his  creative  process.  His  yield,  after  treatment,  showed 
gold,  0*084  ounce  per  ton  of  antimony,  and  0*670  ounce 
silver  per  ton  of  antimony  used. 

Your  Committee  followed  up  this  work  by  making  an 
assay  of  the  same  metal,  following  well-known  and  ap- 
proved methods  of  assaying,  with  the  following  results : — 
Gold,  0*100  ounce  per  ton;  and  silver,  1*20  ounces  per 
ton  of  antimony.  A  comparison  of  this  result  will  show 
that  Mr.  Brice  found  by  his  assay  sixty-six  per  cent  (6654) 
of  the  gold,  and  twenty-six  and  forty-one  hundredths  per 
cent  (26-4iy«)  of  the  silver  adiually  present  in  the  ma- 
■terials  used. 

By  his  "  creative  process  "  he  recovered  eighty-four  per 
cent  (84°/o)  of  the  gold  and  fifty-five  and  eighty-four  hun- 
dredths per  cent  (55*847'.)  of  the  silver  originally  present 
in  the  materials. 

It  was  judged  by  the  Commission  that  they  were  not 
likely  to  obtain  decisive  results  so  long  as — working  on 
materials  containing  appreciable  quantities  of  silver  and 
gold — comparisons  would  have  to  be  made  between 
minute  quantities  of  those  metals  found  by  assay  with 
those  obtained  by  the  creative  process  of  Mr.  Brice. 
These  differences  might  be  within  the  limits  of  error  in 
working,  as  the  amounts  obtained  were  at  best  very 
minute,  and  at  times  so  minute,  indeed,  that  only  the 
most  delicate  balance  in  the  Institution  barely  indicated 
any  weight,  although  this  instrument  is  sensitive  to  the 
i/250th  part  of  a  m.grm.  (6/100000  grain). 

To  eliminate  the  doubt  which  might  thus  arise  in  the 
minds  of  those  unfamiliar  with  the  limits  of  accuracy  in 
assaying,  it  was  decided  to  obtain,  if  possible,  metals  en- 
tirely free  from  gold  and  silver. 

The  Preparation  of  Pure  Antimony, 
We  had  found  all  available  samples  of  metallic  antimony 
to  contain  minute  but  appreciable  quantities  of  gold  and 
silver.  We  undertook  the  task  of  preparing  antimony, 
which  upon  assay  should  not  show  even  a  trace  of  either 
of  those  metals.  Various  methods  to  attain  this  end  were 
considered.  Distillation  of  the  metal  would  be  obviously 
jneflfedlive,  since  in  Mint  pradtice  it  is  well  known  that 
small  amounts  of  silver  and  gold  are  carried  off  in  the 
vapours  of  the  volatile  metals,  such  as  antimony,  zinc, 
&c.  An  effort  was  made  to  prepare  pure  metal  in  the  wet 
way  from  antimony  sulphide,  but  the  operation  was  pro- 
bably conduded  with  too  much  haste,  since  the  resultant 
metal  contained  the  seemingly  inevitable  trace  of  gold  and 
silver.  We  then  had  recourse  to  the  process  of  Capitaine, 
which  is  recommended  by  Gmelin  as  furnishing  the  purest 
antimony  (vol.  iv.,  p.  320,  published  in  full  in  journal  ' 
Pharm.,  xxv.,  516).     This  process  consists  essentially  in 


the  redudtion  of  metallic  antimony  from  pure  double 
tartrate  of  antimony  and  potash.  To  prevent  the  reduc- 
tion of  the  potash  from  excess  of  carbon  present,  and  to 
form  a  more  fluid  melt  from  which  the  antimony  could 
settle  more  perfectly,  we  added  a  sufficient  amount  of 
pure  potassium  nitrate  to  oxidise  the  excess  of  carbon 
present  beyond  that  necessary  for  the  redudtion  of  the 
oxide  of  antimony. 

The  reguline  metal  thus  obtained,  amounting  to  about 
20  ounces,  was  melted  under  a  covering  of  potassium 
I  nitrate.     This  operation  of  fusing  with  the  nitrate  was 
repeated  until,  besides  any  possible  potassium  present,  a 
I  considerable  portion  of  the  antimony  had  been  oxidised. 
I      The  metal  thus  obtained,  now  only  some  18  ounces, 
was  finely  powdered  and  treated  to  a  prolonged  boiling  in 
distilled  water.     Not  the  faintest  alkaline  readtion  was 
shown  by  this  treatment.     We  assured  ourselves  of  the 
absence  of  gold  and   silver  by  repeated  assays,  and  the 
metal  so  prepared  was  used  in  our  subsequent  experi- 
ments. 

Pure  Lead. 

Lead  is  used  either  as  metal  or  oxide  in  all  assaying 
processes.  It  is  evident  therefore  that,  in  this  investiga- 
tion, lead  free  from  gold  and  silver  was  equally  desirable. 
It  is  well  known  to  chemists  and  assayers  that  even  the 
so-called  "  chemically  pure"  and  specially-prepared  leads 
contain  traces  of  these  metals.  Becker,  in  his  Mono- 
graph on  the  Comstock  Lode  {Geological  Survey,  1882}, 
describes  the  difficulty  he  encountered  in  using  even  the 
purest  leads  available,  since  the  trace  of  gold  and  silver 
was  so  unevenly  distributed  that  he  could  not  make  an 
allowance  for  the  same  with  any  assurance  of  accurate 
results.  After  much  time  and  labour  expended  in  an 
attempt  to  prepare  lead  or  litharge  free  from  gold  and 
silver,  he  was  forced  to  use  a  lead  containing  approxi- 
mately 0*07  ounce  of  silver  per  ton.  All  the  leads  sold 
by  chemical  dealers  to-day  as  "  chemically  pure,"  though 
i  more  free  than  Mr.  Becker's  lead  from  gold  and  silver,  are 
)  only  comparatively  so,  since  they  all  show  a  minute  bead 
of  those  metals  if  sufficient  quantity  be  taken  for  the 
i  test. 

In  the  hope  of  producing  a  lead  which  should  be  abso- 
lutely free  from  gold  and  silver,  we  procured  a  quantity  of 
Squibb's  "chemically  pure"  lead  acetate.  This  was  dis- 
solved in  distilled  water, — a  few  dropsof  potassium  iodide 
added  to  produce  the  most  insoluble  salt  of  silver  known 
to  us  under  the  circumstances, — and,  when  thoroughly 
mixed,  a  few  centimetres  of  dilute  sulphuric  acid  produced 
a  bulky  precipitate  of  lead  sulphate  which  served  the  pur- 
pose of  colledting  and  carrying  down  any  silver  iodide 
which  might  have  been  present.  It  may  not  be  amiss  to 
mention  the  fadt  for  the  benefit  of  chemists  that  this  lead 
sulphate  precipitate  yielded  a  notable  quantity  of  silver 
when  reduced. 

The  acetate  solution  thus  freed  as  we  hoped  and  sup- 
posed from  silver,  was  precipitated  by  dilute  sulphuric 
acid,  the  lead  sulphate  washed  with  distilled  water  until 
free  from  acid.  It  was  then  boiled  with  a  solution  of 
ammonia  and  ammonium  carbonate,  until  the  sulphate 
was  converted  into  carbonate.  This  compound,  when 
thoroughly  washed  so  as  to  be  free  from  ammonia  salts, 
was  converted  into  lead  oxide  (litharge)  by  heat.  Very 
much  to  our  surprise,  four  assay  tons  of  the  litharge  thus 
prepared  yielded  a  weighable  quantity  of  gold  and  silver. 
In  view  of  the  limited  time  at  our  disposal,  we  abandoned 
further  efforts  in  this  diredlion,  and  having  obtained 
through  Mr,  Jacob  Eckfeldt,  Assayer  of  the  Mint  at 
Philadelphia,  a  sample  of  lead,  which  when  two  (2)  assay 
tons  were  used  for  test,  showed  no  visible  bead  of  silver, 
we  used  this  lead  in  our  subsequent  experiments  so  long 
as  the  limited  supply  lasted.  Having  now  at  our  disposal 
antimony  and  lead,  neither  of  which  showed  any  silver  or 
gold  visible  to  the  eye,  when  used  in  reasonable  quantity, 
we  proceeded  to  repeat  the  "  creative  process  "  of  Mr. 
Brice,  following  stridtly  his  instrudtions  as  given  by  him 


64 


Estimation  of  Gtycerin  by  Bichromate  of  Potash,  &c. 


I  Chemical  News, 
\      Aug.  6,  1897. 


in  his  first  exhibition  of  his  process,  and  as  slightly  modi- 
fied by  his  written  communication  of  May  15th. 

For  this  trial  we  took  two  (2)  assay  tons  of  our  specially 
prepared  antimony,  —  carried  it  carefully  through  each 
step  of  the  "Brice"  process,  which  necessitated  the  use 
of  six  (6)  assay  tons  of  lead  for  its  completion. 

The  result  was  entirely  negative,  no  trace  of  gold  or 
silver  being  visible. 

The  experiments  thus  conduded  would  seem  to  dispose 
effe(5lually  of  Mr.  Brice's  claim  to  any  creation  of  gold 
and  silver.  But  it  was  deemed  best  to  invite  the  claimant 
with  his  friends  to  witness,  and  he  to  diredl,  a  repetition 
of  the  test.  This  offer  was  made,  and  promptly  declined 
by  Mr.  Brice  when  he  learned  that  the  result  of  our  test 
was  entirely  negative.  He,  however,  insisted  on  the  trial 
of  two  other  and  distindly  different  methods,  neither  of 
which  up  to  this  time  had  been  suggested.  We  yielded, 
and  were  given  to  understand  that  these  methods  were 
improvements  on  the  original  process  shown  us,  and  that 
a  much  larger  produdlion  of  the  precious  metals  might  be 
expeifted. 

Experiment  No.  i.  —  At  the  behest  of  Mr.  Brice  we 
weighed  out  two  and  one-half  assay  tons  of  antimony, 
and  subjedled  it  to  treatment  under  his  immediate  direc- 
tion. The  result  was  a  regulus  weighing  three  assay 
tons.  Mr.  Brice  diredled  that  the  whole  of  this  regulus 
should  be  scorified  with  nine  assay  tons  of  lead,  and  the 
final  button  cupelled.  The  final  result  was  a  minute 
bead  of  metal,  which,  when  placed  on  the  delicate 
balance  used,  weighed  75/1000  of  a  milligramme  (i/iooo 
grain). 

This  bead  was  treated  with  nitric  acid,  and  a  slight 
trace  of  gold  remained. 

Experiment  No.  2. — Two  (2)  assay  tons  of  antimony 
were  treated  by  a  still  different  method  under  the  direction 
of  Mr.  Brice. 

A  regulus  was  obtained  weighing  four  and  one-quarter 
assay  tons.  This  was  pulverised  and  treated  by  a  process 
in  which  a  new  feature  was  introduced.  The  resulting 
ore  was  divided  into  two  parts,  because  of  the  necessity 
of  using  two  different  leads,  the  remaining  six  assay  tons 
of  that  from  the  Philadelphia  Mint  serving  for  only  two 
assay  tons  of  the  ore.  For  the  remaining  two  and  one- 
quarter  assay  tons  we  were  compelled  to  use  seven  assay 
tons  of  test  lead  obtained  from  Richards  and  Co.,  and 
marked  "Stridlly  free  from  gold  and  silver."  From  neither 
of  these  operations  comprised  in  Experiment  No.  2  was 
any  visible  bead  obtained. 

The  contents  of  the  Richards'  lead  in  silver  and  gold 
being  an  unknown  quantity,  it  was  thought  prudent  to 
condudl  a  check  assay  upon  this  lead,  using  seven  assay 
tons  for  the  purpose. 

A  bead  was  recovered  weighing  25/1000  of  a  m.grm., 
which  when  treated  with  nitric  acid  showed  a  slight  trace 
of  gold.  Mr.  Brice  in  his  operation,  using  this  same  lead, 
failed  to  recover  the  silver  and  gold  shown  to  be  present 
in  the  materials  used  by  him.  The  loss  of  this  minute 
quantity  of  silver  and  gold  would  have  no  significance 
but  for  the  statement  on  the  part  of  Mr.  Brice  that  it  was 
from  this  variation  of  his  process  that  he  expeded  his  best 
creative  results. 

Referring  to  Experiment  No  i,  of  May  :8th,  it  should 
be  stated  that  we  subsequently  received  a  further  supply 
of  the  Philadelphia  lead,  together  with  a  letter  from  the 
firm  furnishing  it,  in  which  they  state  that  the  lead  was 
specially  prepared  for  them,  and  was  the  purest  known  to 
them.  They  state  that  it  contains  less  than  0*02  ounce 
of  silver  per  ton.  An  assay  made  by  us  upon  a  large 
amount  of  the  lead  confirms  the  statement  of  the 
Philadelphia  firm  as  to  its  high  degree  of  purity,  yet  it 
contains  in  nine  assay  tons  sufficient  silver  and  gold  to 
fully  account  for  the  minute  bead  obtained  by  Mr.  Brice 
in  Experiment  No.  i  of  May  i8th. 

Conclusion. 
During  these  experiments,  which  have  extended  over 


some  three  weeks,  and  have  involved  an  amount  of  pains- 
taking labour  which  we  hope  has  not  been  entirely  wasted, 
we  have  seen  not  the  slightest  evidence  of  any  "creation" 
or  transmutation. 

On  the  contrary,  the  claimant  failed  in  every  instance 
to  recover  the  entire  amount  of  silver  and  gold  known  to 
be  present  in  the  materials.  The  claimant  seems  to  have 
devised  a  variety  of  irrational  and  wasteful  methods  for 
recovering  a  portion  of  the  silver  and  gold  known  to 
metallurgists  as  being  present  in  many  commercial 
metals,  such  as  antimony  and  lead. 

RespedfuUy  submitted, 
(Signed)     Andrew  Mason, 

Sup't.  U.S.  Assay  Office, 
New  York. 
(Signed)     D.  K.  Tuttle, 

Melter  and  Refiner,  U.S.  Mint, 
Philadelphia. 
(Signed)    Cabell  Whitehead, 

Assayer,  Bureau  of  the  Mint, 
Washington. 


ON   THE 

ESTIMATION   OF   GLYCERIN   BY  BICHROMATE- 

OF    POTASH    AND    SULPHURIC    ACID. 

By  F.  BORDAS  and  SIG.  de  RACZKOWSKI. 

We  have  given  the  following  equation  as  the  formula  for 
the  oxidation  of  glycerin  by  bichromate  and  sulphuric 
acid : — 

8SO4H2  +  3K2Cr207  +  (CH20H)2CH0H  =  HCOOH  + 
2CO2  +  iiH20-|-2Cr2(S0a)  +  KiSO^+KzCriOy  + 
K2SO4  {Socteie  de  Biologic,  Series  10,  vol.  lii.,  p. 
1067). 

Chromic  acid  oxidises  glycerin,  giving,  in  every  case, 
carbonic  acid,  water,  formate  of  chromium,  chromate  of 
chromium,  formic  aldehyd,  &c.  In  the  presence  of  sul- 
phuric acid  there  is  produced,  therefore,  besides  the  car- 
bonic acid  and  the  \i3,\^x ,  free  formic  acid  and  sulphate  of 
sesquioxide  of  chromium. 

Let  us  assume  the  formation  of  the  double  salt 
(K2S04-fK2Cr207)  composed  of  sulphate  and  bichromate 
of  potash.  Now,  as  this  salt  will  only  form  when  the 
proportion  of  sulphuric  acid  is  insufficient  to  saturate  the 
whole  of  the  potash  of  the  bichromate,  we  must  admit 
that,  as  we  have  an  excess  of  sulphuric  acid,  the  bi- 
chromate is  entirely  decomposed,  and  therefore  this  salt 
cannot  be  formed  under  the  conditions  existing.  The 
amended  equation  will  therefore  be — 

8S04H2-J-2K2Cr207-|-  (CH20H)2CH0H  = 

=  H,CO,OH-j-2C02-|-iiH20-t-2Cr2(S04)3-f-2K2S04, 

While  in  the  preceding  expression  i  part  of  glycerin  would 
correspond  to  g'62  of  bichromate,  in  the  new  one  it  cor- 
responds to  only  6'4i. 

The  titration  value  of  the  bichromate,  of  which  i  c.c. 
should  correspond  to  i/ioooth  (the  experiment  being  on 
5  c.c.  of  glycerin  solution),  which  was  48  grms.  per  litre, 
now  becomes  32  grms.  per  litre. 

In  a  recent  note  (yourn.  de  Pharm.  et  de  Chim.,  p.  426, 
May  I,  1897)  M.  Nicloux  asserts  that  the  oxidation  of 
glycerin  does  not  produce  formic  acid,  and  he  adopts  the 
following  equation  as  the  formula  of  the  readlion  : — 

28S04H2+7Cr207K2-f3{CH20H,CHOH,CH20H)  = 

=  7(S04)3Cr2+7S04K2-|-9C02-|-4oH20. 

In  this  formula  the  transformation  of  glycerin  into  car- 
bonic acid  and  water  is  effeded  integrally.  He  deduces- 
from  this  that  the  titration-value  of  the  bichromate  solu- 
tion should  be  37*28  per  1000.  M.  Nicloux  then  pro- 
poses to  modify  our  process  by  employing  a  solution  oS 
this  value. 


Cbbmical  News,  1 
Aug.  6,  1897.      f 


Qualitative  Separation  of  Iron,  &c. 


65 


We  could  show  that  M.  Nicloux  is  mistaken  in  his 
statements  concerning  the  oxidation  of  the  glycerin  by 
quoting  experiments  which  prove  that  its  decomposition 
under  the  influence  of  bichromate  of  potash  and  sulphuric 
acid  does  not  proceed  integrally,  producing  carbonic  acid 
and  water,  and  that  there  is  always  undecomposed  formic 
acid  present  when  operating  in  the  way  we  have 
described.  In  fadt,  the  adion  of  chromic  acid  on  formic 
acid  is  far  from  being  energetic,  seeing  that  if  we  heat 
formic  acid  with  chromic  acid,  in  excess  or  not,  one  part 
decomposes  into  carbonic  acid  and  water,  another  part 
volatilises,  and  the  remainder  combines  with  the  sesqui- 
oxide  of  chromium,  forming  formate  of  chromium. 

It  is  only  after  heating  for  some  time  in  presence  of  an 
excess  of  sulphuric  acid,  and  cooling  gradually,  that  the 
decomposition  is  complete. 

We  prefer,  however,  not  to  insist  on  this  point,  as  dis- 
cussion is  of  no  interest,  given  that  neither  the  solution 
of  bichromate  of  potash  at  48  grms.  per  litre;  that  of  32 
grms.  per  litre,  resulting  from  the  modification  of  our 
equation  ;  nor,  finally,  that  of  38  grms.  per  litre  advocated  I 
by  M.  Nicloux,  represent  definite  titration  values. 

The  influence  of  the  proportion  of  sulphuric  acid  em- 
ployed is  shown  at  about  one-tenth  of  a  cubic  centimetre,  i 
It  results,  therefore,  that  the  titration  of  the  solution  of  I 
bichromate,  being  intimately  allied  to  this  proportion  of 
sulphuric  acid,  is  absolutely  empirical,  or  that  the  quan- 
tity of  this  solution  necessary  to  obtain  the  yellowish 
green  tint  varies  with  the  quantity  of  acid,  and  also  with 
its  degree  of  concentration.  This  is  easily  verified  by 
experiment.  We  can  see  that,  given  a  solution  of  bi- 
chromate of  any  titration  value,  we  can  determine  by 
successive  trials  the  quantity  of  acid  to  use,  so  that 
when  we  use  5  c.c.  of  glycerin  solution,  a  definite  volume 
of  this  latter — say,  i  or  2  c.c,  for  example — will  cor- 
respond to  18  grms.  per  litre  of  glycerin.* 

The  modus  operandi  proposed  by  M.  Nicloux,  which 
consists  of  using  a  solution  of  38  grms.  per  litre  in  the 
presence  of  4  or  even  5  c.c.  of  pure  concentrated  sulphuric 
acid,  boiling  if  possible,  prevents  the  grave  inconvenience 
of  giving  four  different  results,  according  as  we  work  with 
one  or  the  other  of  the  proportions  indicated  by  him,  for 
4  and  5  c.c.  of  pure  concentrated  sulphuric  acid,  and  the 
same  quantities  boiling  constitute  four  different  propor- 
tions. 


*  It  can  be  conceived  that  there  may  be  under  these  conditions  an 
unlimited  number  of  modifications  in  our  method  of  estimation, 
taking  care,  of  course,  to  vary  in  the  same  manner  both  the  bichro- 
mate solution  and  the  quantity  of  sulphuric  acid  to  be  added. 


In  conclusion,  we  can  only  confirm  what  we  have 
already  said  {Comptes  Rendus,  Dec.  14,  1896,  p.  1072  ; 
and  Societe  de  Biologic,  vol.  iii.,  p.  1067),  viz.,  that  a 
solution  of  pure  crystallised  bichromate  of  potash  at  24 
grms.  per  litre  serves  perfectly  well ;  that  2  c.c.  of  such  a 
solution  corresponds  to  i  grm.  per  litre  of  glycerin,  when 
working  on  5  c.c.  of  glycerin  solution  and  employing 
exactly  2*5  c.c.  of  pure  concentrated  sulphuric  acid." 

Finally,  we  would  remark  that  we  never  pretended  to 
produce  a  process  giving  the  glycerin  to  o"ooi ;  for,  being 
colorimetric,  there  are,  of  course,  difficulties  which  are 
inherent  to  such  methods.  As  we  have  described  it,  the 
process  appears  to  us  pradticable  and  able  to  give  results 
sufficiently  near  for  the  purpose  tor  which  we  devised  it; 
that  is  to  say  for  the  estimation  of  glycerin  in  wood  fer- 
ments.— jfourn.  de  Pharm.  et  de  Chim.,  Series  6,  vol.  vi., 
No.  2. 


A    NEW    AND    RAPID    METHOD 

FOR  THE 

QUALITATIVE     SEPARATION     OF     IRON, 

ALUMINIUM,      CHROMIUM,      MANGANESE, 

ZINC,    NICKEL,   AND   COBALT. 

By   ALEXANDER    RAMSAY    CUSHMAN. 

Add  ammonium  chloride,  ammonia  to  alkaline  readlion 
and  then  ammonium  sulphide  in  slight  excess.  Warm 
and  filter.  Wash  the  precipitate  and  remove  from  the 
filter  while  still  moist.  Warm  with  moderately  dilute 
hydrochloric  acid  in  a  porcelain  dish.  Complete  solution 
of  the  precipitate  shows  the  absence  of  nickel  and  cobalt. 
If  a  black  residue  remains,  one  or  both  are  present,  in 
which  case  add  aqua  regia,  and  warm  gently  until  dis- 
solved. Expel  excess  of  acid  and  free  chlorine  by  evapo- 
ration, and  then  make  the  solution  strongly  alkaline  with 
ammonia,  after  previously  adding  ammonium  chloride  in 
case  the  amount  of  hydrochloric  acid  used  upon  the  sul- 
phides was  small.  Add  bromine  solution  in  excess,  and 
allow  to  stand  a  few  minutes.     Filter  and  wash. 

The  Table  shows  the  course  of  the  analysis  after  this 
point  is  reached. — American  Chemical  jfournal,  vol.  xix.. 
No.  7. 


*  We  mentioned  2  c.c.  of  sulphuric  acid  as  being  the  proportion  to 
use.  Now,  with  this  quantity,  2*i  c.c.  of  solution  of  bichromate  at 
24  grms.  per  litre  is  necessary  to  obtain  a  yellowish  green  tmt;  this 
would  cause  an  error  of  o'Oj  per  1000. 


Precipitate  i."Fe203,Mn02. 
H20,Al2(OH)6,Cr2(OH)6. 
Remove  from  the  filter 
and  add  KOH  in  excess, 
then  Br  solution  and  fil- 
ter. 


Filtrate  i.-ZnC1.2NH4Cl,NiCl2.NH4Cl,[Cl.Co(NH3)5lCl2.    Add  KOH  in  large  excess, 
allow  to  stand  a  few  minutes  and  filter. 


Residue  2.  —  Fe203,  Mn02. 
H2O.     Divide  in  2  parts. 

Part  I.  Dissolve  in  HCl, 
add  a  few  drops  of  NH4 
CNS.  Blood  red  colour 
shows  Fe2(CNS)6  and 
proves  Fe. 

Part  2.  Fuse  with  NagCOs 
-l-NaN03  in  O,  F.  of 
blowpipe.  Bluish  green 
mass  proves  Mn. 


Filtrate  2.— K2Al204,K2Cr 
O4.     Divide  in  2  parts. 

Part  I.  Acidify  with  HCl, 
add  excess  of  (NH4)2C03 
and  boil.  A  white  floc- 
culent  precipitate  shows 
Al2(OH)6  and  proves  Al. 

Part  2.  Acidify  with  HC2 
H3O2  and  add  Pb(C2H3 
02)2-  A  yellow  precipi- 
tate shows  PbCr04  and 
proves  Cr. 


Precipitate  3.  —  Ni(0H)2. 
(Greenish  white).  Con- 
firm in  salt  of  phosphorus 
bead  in  the  R.  F.  of  the 
blowpipe.  Yellow  bead, 
cold,  proves  Ni. 


Precipitate  4.  —  Co(OH)3. 
Confirm  in  borax  bead, 
in  the  O.  F.  of  the  blow- 
pipe. Blue  bead  proves 
Co. 


Filtrate  3.— [Cl.CO(NH3)5l 
Cl2,K20,ZnO.  Heat  to 
boiling  and  filter. 


Filtrate  4. —  Acidify  with 
HC2H3O2,  and  saturate 
with  H2S.  A  white,  floc- 
culent  precipitate  shows 
ZnS.  Confirm  by  ignition 
with  Co(N03)2  on  char- 
coal. Yellow-green  mass 
proves  Zn. 


66 


Production  of  some  Nitro-  and  A  mido-Oxy  pica  lines 


I  Chemical  Nbws, 
'       Aug.  6,  1897. 


PROCEEDINGS    OF    SOCIETIES. 

CHEMICAL  SOCIETY. 
Ordinary  Meeting,  jfune  17th,  1897. 

Professor  Dewar,  F.R.S.,  President,  in  the  Chair. 

Mr.  Samuel  Pollitt  was  formally  admitted  a  Fellow  of  the 
Society. 

A  Certificate  was  read  for  the  first  time  in  favour  of 
Mr.  Oscar  Guttmann,  12,  Mark  Lane,  B.C. 

The  following  were  duly  eledled  Fellows  of  the 
Society  :  —  William  Ackroyd ;  Walter  Harry  Barlow  ; 
William  Malam  Brothers ;  Gerald  Noel  Brown ;  Ernest 
Stuart  Cameron  ;  Medwin  C.  Clutterbuck,  B.Sc,  Ph.D  ; 
William  Cranfield ;  A.  Bilderbeck  Gomess ;  Frederick 
Roscoe  Grundey,  B.Sc. ;  Edward  Halliwell ;  Frank  Wil- 
liam Harbord;  Harold  Harman  ;  B.J.  Harrington,  Ph.D.; 
John  Edwin  Mackenzie,  B.  Sc,  Ph.D. ;  William  Robertson 
Pollock;  Lionel  Walter  K.  Scargill,  B.A. ;  James  Porter 
Shenton ;  William  Taverner. 

Of  the  following  papers  those  marked  •  were  read : — 

•79.  "Molecular  Refraction  of  Dissolved  Salts  and 
Acids."  Part  II.  By  J.  H.  Gladstone,  D.Sc,  F.R.S., 
and  W.  HiBBERT. 

The  present  paper  is  a  continuation  of  a  previous  com- 
munication to  the  Society  two  years  ago,  under  the  same 
title  (Proc,  1895,  xi.,  120).  It  is  especially  concerned  in 
replying  to  the  questions,  "  Has  a  salt  the  same  molecular 
refradtion  whether  it  be  in  the  crystalline  state  or  in 
solution  ? "  and  "  How  far  is  any  refradion  change  de- 
pendent on  the  solvent  used  ?  "  The  paper  also  gives 
some  conclusions  to  which  the  data  appear  to  lead. 

In  a  table  previously  published  (Trans.,  1895,  Ixvii., 
831)  there  were  many  comparisons  between  the  specific 
refradtion  of  solid  salts  and  their  value  in  solution,  but  no 
crystals  were  examined  excepting  those  which  had  only 
one  axis,  or  where  the  different  indices  were  very  near 
together.  By  adopting  the  method  of  Damien  as  suggested 
by  Pope,  we  now  add  seventeen  more  cases  having  two  or 
three  indices  of  refradlion.  The  observations  are  in  ac- 
cordance with  the  conclusions  previously  drawn,  the 
refradtion  of  the  salt  in  solution  being  in  some  cases 
greater,  and  in  other  cases  smaller,  than  that  of  the  crys- 
tallised body.  The  change  of  refradtion,  however,  rarely 
if  ever,  amounts  to  4  per  cent. 

In  making  experiments  on  the  effedt  of  different  solvents 
we  have  examined  nine  salts  and  acids,  including  those 
published  in  1870  (Trans.,  1870,  xxiii.,  loi).  The  first 
resntt  is  to  show  that  the  specific  refradtion  of  the  sub- 
stances dissolved  in  water  does  not  generally  differ  much 
from  the  value  yielded  by  solution  in  other  solvents.  If, 
however,  we  examine  those  substances  which  show  a 
great  change  of  refradtion  when  deduced  from  different 
strengths  of  solution  in  water,  the  result  is  very  striking. 
A  comparison  of  hydrochloric  acid  when  dissolved  in 
water  and  in  different  alcohols  and  ethers,  is  shown  in  a 
diagram  of  curves.  Whilst  in  water  the  specific  refrac- 
tion of  the  acid  is  raised  in  the  first  instance  from  about 
0*300  to  o"386,  and  then  gradually  rises  on  dilution  to 
0*400 ;  the  acid  dissolved  in  the  different  alcohols  shows 
a  lower  starting-point  and  a  more  gradual  rise,  in  the 
following  order  : — Methyl,  ethyl,  amyl,  and  capryl  alco- 
hols, followed  by  a  very  low  starting-point  in  the  case  of 
ethyl  ether,  with  an  adtual  decrease  on  dilution,  and  by 
scarcely  any  change  at  all  in  the  case  of  amylic  ether. 

In  the  case  of  lithium  chloride,  which  gives  in  water  a 
curve  rising  on  dilution  second  only  to  that  of  hydrochloric 
acid  itself,  the  solution  in  alcohol  yields  a  curve  very 
similar  in  charadler.  Ferric  chloride,  which  is  the  most 
striking  instance  of  a  great  decrease  in  refradtion  occurring 
on  dilution  with  water,  shows  also  a  decrease  when  it  is 
dissolved  in  alcohol  and  acetic  ether.  Nitric  acid,  when 
mixed  with  water,  shows  a  great  change  of  specific  re- 


fradtion, but  when  dissolved  in  nitrobenzene  shows  little 
if  any. 

The  authors  express  their  growing  convidtion  that 
neither  the  salt  nor  the  solvent  really  changes  its  specific 
refradtion,  but  that  by  their  interadlion  some  new  produdt 
or  produdts  result,  in  quantities  determined  by  the  propor- 
tionate amount  of  the  two  original  substances.  The 
adtion  may  be  one  of  dissociation  or  of  association,  or  of 
some  hitherto  unrecognised  re-distribution.  It  is  the 
changing  proportion  of  this  tertium  quid  which  makes 
itself  apparent  by  the  changing  specific  refradtion  of  the 
solution. 

Discussion. 
The  President  said  that  the  Society  was  much  in- 
debted to  Dr.  Gladstone  for  this  last  addition  to  his  great 
work  on  the  refradlive  indices  of  chemical  substances. 
He  wished  it  were  possible  to  determine  diredlly  the  re- 
fradlive index  of  fluorine,  which  seemed,  from  Dr.  Glad- 
stone's results  with  fluorine  compounds,  to  possess  the 
smallest  refradtive  power  of  any  of  the  elements. 

Professor  Dunstan  asked  whether  the  authors  had 
considered  the  possible  influence  of  the  formation  of  the 
alkyl  chlorides  on  the  solutions  of  hydrogen  chloride  in 
alcohols. 

Dr.  Gladstone,  in  reply,  said  they  had  been  unable  to 
detefi  the  formation  of  any  alkyl  chloride  in  the  solutions. 
•80.  ••  On  a  Space  Formula  for  Benzene."    By  J.  Nor- 
man Collie,  Ph.D.,  F.R.S.     (This  paper  will  appear  in 
our  next  issue). 

*8i.  "  On  the  Production  of  some  Nitro-  and  Amido- 
Oxypicolines."  By  A.  Lapworth,  D.Sc,  and  J.  Norman 
CoLLiB,  Ph.D.,  F.R.S. 

When  dioxypicoline  {Trans.,  1891,  59,  617)  is  warmed 
with  60  per  cent  nitric  acid,  a  nitro-compound  is  at  once 
produced,  C6H7N02-f-HN03  =  C6H6N204-hH20.  This 
nitrodioxypicoline  possesses  all  the  properties  of  a  nitro- 
phenol,  it  is  light  yellow  in  colour,  and  forms  salts  with 
bases. 

When  it  is  carefully  reduced  with  tin  and  hydrochloric 
acid,  an  amido-oxypicoline  results,  but  should  the  tem- 
perature rise  too  high  a  secondary  reaction  occurs  and  a 
trioxypicoline  is  formed  instead — 

(i)  C6H6N204+3H2  =  C6H6N02(NH2)-f2H20, 
(2)  C6H6N02NH2+H20  =  C6H6N02(OH)  +  NH3. 
The  molecular  constitution  of  these  three  compounds  may 
be  expressed  by  the  formulae : — 


CH3-C 


N 


C-GH 

I 
HC  CNO2 

\     / 
C 
OH 

Nitro-compound. 


CH,-C 


/ 


N 


'COH 

II  I 

HC  CNH2 

\     /- 
C 
OH 

Amido-com  pound. 


CH,— C 


/ 


COH 


HC  COH 

\    / 
C 
OH 

Trioxypicoline. 

The  amido-compound  is  remarkable  for  the  series  of 
brilliant  colours  it  produces  when  treated  with  various 
oxidising  agents ;  deep  indigo-blue  with  ammonia  and 
air,  orange  yellow  with  nitric  acid,  a  deep  moss  green 
with  alkaline  ferricyanide  of  potassium,  and  a  brilliant 
magenta  with  weak  acetic  acid  and  potassium  bichromate. 
These  colourations  are  very  similar  to  those  produced 
when  various  alkaloids  are  treated  in  a  similar  manner. 


wBBUICAL  NBWB,  ) 
Aug.  6,  1897.      I 


Action  0/ Light  on  a  Solution  of  Nitrobenzene. 


67 


This  amido-oxypicoline  forms  salts  with  strong  mineral 
acids  but  is  also  capable  of  liberating  carbon  dioxide  from 
alkaline  carbonates. 

When  its  hydrochloride  is  only  partially  neutralised 
with  sodium  carbonate  and  the  solution  is  boiled,  an  ex- 
cessively insoluble  substance  separates,  which  seems  to 
be  a  compound  of  the  dioxyamidopicoline  and  the  trioxy- 
^picoline — 

2C6H6N02(NH2)  +  H20  =  Ci2Hi3N304+NH3  +  H20. 
This   insoluble    compound    by   persistent    boiling    with 
strong  hydrochloric  acid  is  finally  changed  into  the  tri- 
oxypicoline  and  ammonia. 

The  trioxypicoline  may  be  prepared  at  once  from  the 
dioxyamidopicoline  hydrochloride,  by  using  the  full 
amount  of  sodium  carbonate  necessary  to  neutralise  the 
hydrochloric  acid,  and  then  boiling  for  half  an  hour.  It 
then  crystallises  out  in  long,  needle-shaped  crystals. 

This  trioxypicoline  resembles  pyrogallol  in  many  of  its 
readions,  it  is  an  excessively  powerful  reducing  agent, 
and  in  alkaline  solution  will  develop  photographs.  It 
will  precipitate  silver  from  a  solution  containing  a  con- 
siderable quantity  of  free  nitric  acid,  and  it  also  gives  with 
oxidising  agents  a  series  of  colour  tests  similar  to  those 
of  the  dioxyamidopicoline. 

•82.  "  Further  Experiments  on  the  Absorption  of  Mois- 
ture by  Deliquescent  Substances."  By  H.  Wilson  Hake, 
Ph.D. 

In  a  preliminary  note  {Proc,  1896,  12,  33)  the  author 
showed  that  certain  deliquescent  salts,  when  exposed  to 
the  air,  attained  a  maximum  of  hydration,  and  that  its 
maximum  corresponded  to  a  definite  number  of  molecules 
in  a  large  number  of  cases. 

In  the  preliminary  experiments  no  reference  was  made 
to  the  vapour-pressure  of  water  in  the  air,  but  in  experi- 
ments since  made,  the  condition  of  the  atmosphere  as 
regards  moisture  has  been  carefully  noted,  or  an  artifi- 
cially saturated  atmosphere  has  been  contrived  under 
known  conditions  of  temperature. 

Having  now  experimented  with  10  deliquescent  chlorides 
(lithium,  magnesium,  cadmium,  calcium,  copper,  nickel, 
cobalt,  iron,  manganese,  and  platinum),  3  nitrates  (sodium, 
magnesium,  and  manganese)  with  sulphuric  acid  and  with 
sodium  formate,  under  various  conditions,  it  was  found 
that  (x)  they  attrad  quantities  of  water  corresponding  in 
all  cases  to  a  definite  hydrate,  (2)  after  deliquescing  to  a 
maximum  there  followed  in  all  cases  a  decline  in  weight, 
and  in  four  instances  the  salts  returned  to  their  original 
hydration  and  crystallised  out,  and  that  (3)  the  amount 
of  hydration,  though  apparently  always  corresponding  to 
a  definite  number  of  molecules  of  water,  is  not  always  the 
same,  but  seems  to  depend  within  certain  limits  both  on 
the  temperature  and  the  relative  humidity  of  the  atmo- 
sphere and  also  on  the  conditions  under  which  the  air  has 
access  to  the  salt. 

The  author  suggests  that  the  above  experiments  demon- 
strate the  phenomenon  of  deliquescence  to  be  caused  by 
hydration  of  the  deliquescent  salt. 

•83.  •'  The  Fusion  Point,  Boiling  Point,  and  [Specific 
Gravity  of  Nitto-benzene."     By  R.J.  Friswell. 

Great  discrepancies  are  found  in  the  books  as  to  the 
above  constants. 

Schultz  gives  in  his  first  edition,  1882,  1*2002  at  0°  and 
i*i866  at  I4'4° ;  in  his  second  edition,  1*208  at  15°. 
Pusion  point  4-3°. 

Beilstein  gives  the  same,  and  quotes  Mitscherlich  for 
the  fusion  point  and  Kopp  for  the  specific  gravity. 

Gmelin  gives  1*209  ^^^  +3°>  ^"d  quotes  Mitscherlich. 
As  to  boiling  point,  Gmelin,  quoting  Mitscherlich,  gives 
213°,  Schultz,  1882,  gives  210°;  in  1886,  206—207°,  Beil- 
stein quoting  Stadeler,  205°  at  730  m.m. 

It  would  thus  appear  that  several  of  these  numbers 
have  been  quoted  unverified  for  over  60  years. 

No  statement  of  specific  gravity  of  solid  nitrobenzene 
has  been  published  excepting  that  in  Watts^  Dictionary, 
given  to  A.  G.  Green  in  a  private  communication  by 


R.  J.  Friswell.  Determinations  of  the  various  points 
have  been  made.  Calculated  for  comparison  with  water 
at  4°  the  sp.  grs.  are  : — 

t  d 

Solid      1-5  i'3440 

Liquid 3-8  1*2220 

,,        13*0  1*2160 

, 28*0  i*i93i 

Boiling  point  corredted  209*0°. 
Melting  and  solidifying  point  -fs'. 

Nitrobenzene  is  remarkable  as  having  a  distindly 
coloured  vapour  very  closely  resembling  that  of  chlorine. 
The  colour  is  easily  visible  in  a  thickness  of  about  2  inches 
and  is  strongly  marked  when  6—8  inches  are  examined. 
The  author  is  not  aware  of  any  other  organic  vapour  of  so 
simple  a  constitution  which  is  visibly  coloured. 

No  bands  of  absorption  are  shown  in  the  visible 
spedrum  when  light  is  transmitted  through  this  vapour. 
The  violet  and  blue  are  absorbed  as  with  the  fluid  but 
less  strongly. 

*84.  ••  The  Action  of  Light  on  a  Solution  of  Nitro- 
benzene in  Concentrated  Sulphuric  Acid."  By  R.  J. 
Friswell. 

Nitrobenzene  is,  as  has  long  been  known,  readily 
soluble  in  concentrated  sulphuric  acid  of  1*84  sp.  gr.  and 
upwards,  but  a  comparatively  small  amount  of  dilution 
precipitates  it  and  at  about  17  the  solubility  is  very 
slight. 

When  a  solution  in  pure  concentrated  acid  is  exposed 
to  light  it  slowly  darkens.  When  exposed  to  dired  sun- 
light, the  darkening  goes  on  with  great  rapidity,  and  in  a 
few  minutes  the  solution  becomes  quite  black  and  opaque, 
then  the  aftion  ceases.  The  light  from  burning  magne- 
sium produces  the  same  efTedt. 

The  solution  has  been  kept  unchanged  in  the  dark  for 
upwards  of  four  years.  If  the  exposure  to  light  takes 
place  in  a  stoppered  bottle,  a  slight  odour  of  sulphurous 
acid  is  perceptible  after  some  time  in  the  air  above  the 
solution. 

If  the  nitrobenzene  thus  used  is  recovered  and  re-distilled 
and  re-dissolved  in  sulphuric  acid  it  behaves  in  exadtly  the 
same  way. 

Attempts  were  made  to  increase  the  change  by  spread- 
ing the  solution  on  glass  beads  and  between  sheets  of 
glass,  but  the  depth  of  the  colour  of  the  produdt  soon 
brought  all  change  to  an  end. 

Several  hundred  grammes  of  the  black  solution  were 
prepared  and  attempts  made  to  isolate  the  produds  of 
change,  but  though  a  brownish  calcium  salt  was  obtained 
and  an  ammonium  salt  in  solution,  the  latter  decomposed 
on  evaporation  with  a  caramel  like  odour  ;  what  was  left 
was  treated  with  phosphoric  chloride,  but  no  satisfadlorily 
pure  produdl  could  be  obtained  :  the  matter  needs  further 
investigation. 

The  rate  of  Iblackening  of  the  solution  is  undoubtedly 
a  measure  of  the  adinic  power  of  the  light. 

Discussion. 

Mr.  A.  G.  Green  remarked  on  the  possible  similarity 
between  the  adion  of  sulphuric  acid  on  nitrobenzene  in 
the  presence  of  light,  and  the  eledlrolytic  redudion  of  a 
solution  of  nitrobenzene  in  sulphuric  ocid  which  had  been 
investigated  by  Gattermann.  In  this  case  it  was  shown 
that  at  first  phenylhydroxylamine,  then  paramidophenol 
was  the  produd. 

Dr.  Hewitt  said  that  he  had  noticed  that  colouration 
occurred  in  sulphonating  nitrobenzene,  even  in  the  dark. 

The  President  drew  attention  to  the  ia&.  that  in  its 
changes  of  density  near  its  solidifying  point  nitrobenzene 
appeared  to  show  the  same  peculiarity  as  water,  viz.,  an 
enormous  change,  but  in  an  opposite  diredion.  Tne 
adion  of  light  on  the  nitrobenzene  solution  in  sulphuric 
acid  was  remarkable.  If  a  flash  of  magnesium  light  were 
permitted  to  fall  on  the  nitrobenzene  solution  through  a 


68 


Constitution  of  Tri-derivatives  of  N aphthalene,  { 


Chemical  NBwa» 
Aug.  6,  1897. 


quartz  window,  he  thought  that  the  blackening  would  | 
furnish  a  good  ledure  illustration. 

Mr.  Frisvvell,  in  reply,  said  that  he  thought  it  quite 
possible  that  the  change  in  the  solution  of  nitrobenzene 
in  sulphuric  acid  when  exposed  to  light  was  of  tha  same 
kind  as  that  induced  by  eledlrolysis.  He  had  never 
observed  any  colouration  on  sulphonating  nitrobenzene 
when  the  materials  wer  pure  and  light  was  excluded. 

85.  "  The  Reduction  of  PertUocyanic  Acid"  By  F.  D. 
Chattaway,  M.A,,  and  H.  P.  Stevens,  B.A. 

The  atoms  forming  the  molecule  of  perthiocyanic  acid 
have  been  assumed  to  be  arranged  in  a  simple  ring  from 
the  observation  that  on  redudlion  it  yields  thiourea  and 
carbon  bisulphide.  As,  however,  the  properties  of  the 
substance  render  it  probable  that  its  molecule  is  larger 
than  that  represented  by  the  simplest  possible  formula, 
H2N2C2S3,  the  conclusion  that  in  this  complex  molecule 
all  the  strudural  units  have  a  similar  atomic  arrange- 
ment is  only  valid  if  the  amounts  of  thiourea  and  carbon 
bisulphide  obtained  on  redudtion  approach  those  given  by 
theory.  The  redudlion  of  perthiocyanic  acid  has  there- 
fore been  carefully  carried  out  in  various  ways  to  deter- 
mine the  exadl  amounts  of  carbon  bisulphide  and  thiourea 
obtainable  and  the  nature  and  amount  of  any  other  pro- 
duds  of  the  aftion. 

When  perthiocyanic  acid  is  reduced  by  tin  and  hydro- 
chloride acid,  carbon  bisulphide  and  thiourea  are  pro- 
duced in  almost  theoretical  amount, 

H2N2C2S3-J-2H  =  CS(NH2)2  +  CS2, 

only  very  small  quantities  of  hydrogen  sulphide  and  car- 
bon  dioxide  are  produced  in  addition,  these  being  doubt- 
less formed  by  the  hydrolysis  of  a  small  portion  of  the 
perthiocyanic  acid  under  the  influence  of  the  hydrochloric 
acid,  H2N2C2S3-l-2H20  =  CS(NH2)2  +  H2S-l-C02+S. 

86.  ••  The  So-called  Hydrates  oflsopropyl  Alcohol:'  By 
T.  E.  Thorpe,  LL.D,,  F.R.S. 

Four  hydrates  of  isopropyl  alcohol  are  stated  to  exist : — 
2C3H8OH2O, 
isolated  by  Erlenmeyer  in  1863  ; 

sCgHsO-zHjO  and  3C3H80-H20, 
discovered  by  Linneman  in  1865;  and  C3H80"H20,  pre- 
pared by  Ruhemann  and  Carnegie  in  1888.  All  these 
Hydrates  boil  within  a  comparatively  small  range — from 
78°  to  81° — whereas  the  amount  of  water  they  contain 
varies  from  9  to  23  per  cent. 

The  author  gives  reasons  for  doubting  the  existence  of 
these  hydrates  as  distindt  chemical  entities  capable  of 
definite  isolation.  By  studying  the  behaviour  of  mixtures 
of  isopropyl  alcohol  and  water,  it  would  appear  that 
within  certain  fairly  wide  limits,  water  and  the  alcohol 
distil  together  in  indefinite  proportions,  and  that  the 
water  tends  to  pass  over  more  rapidly  than  the  alcohol, 
and  hence  is  found  in  the  largest  proportion  in  the 
fradlions  of  lowest  boiling  point.  There  is  no  evidence 
for  the  existence  of  these  hydrates  at  their  respedlive  boil- 
ing  points.  Nor  is  there  any  more  evidence  for  their 
existence  at  ordinary  temperatures. 

By  synthetically  forming  them  by  the  diredt  addition  o' 
the  required  amount  of  water  to  the  alohol,  and  allowing 
them  to  partially  evaporate  at  the  ordinary  temperature 
of  the  air,  it  is  found  that  the  alcoholic  strength  of  the 
residue  is  greatly  increased  ;  or,  in  other  words,  the  water 
evaporates  faster  than  the  alcohol,  although  the  latier 
boils  20°  lower  than  the  former.  The  two  substances, 
therefore,  are  not  in  stable  union,  even  at  ordinary  tem- 
peratures. 

When  the  relative  densities  of  the  synthetically  formed 
"  hydrates  "  are  plotted  in  terms  of  the  amount  of  water 
they  contain,  the  values  are  found  to  lie  on  what  is  pradli- 
cally  a  straight  line ;  or,  in  other  words,  the  density  of 
the  mixture  is,  within  the  limits  studied,  very  nearly  a 
linear  function  of  the  amount  of  the  constituents. 


87.  "  The  Carbohydrates  of  the  Cereal  Straws."  By  C.  F. 
Cross,  E.  J.  Bevan,  and  Claud  Smith. 

This  paper  deals  with  the  results  of  further  investiga- 
tions  of  the  produdlts  of  acid  hydrolysis  of  the  cereal 
straws  and  of  the  celluloses  isolated  from  them,  including 
also  the  closely  related  esparto-cellulose.  The  results 
confirm  those  previously  communicated  {Trans,,  1896,  69, 
804 — 118),  that  the  furfural-yielding  constituents  (fur- 
furoids)  are  seledtively  attacked  and  for  the  most  part 
(90  per  cent)  dissolved;  also  from  the  exceptionally  high 
numbers  for  cupric  redudtion,  that  they  must  exist  in 
solution  in  a  fully  hydrolysed  form  (monoses). 

The  solutions  when  neutralised  ferment  with  yeast ; 
carbonic  acid  and  alcohol  are  produced,  and  a  propor- 
tionate effect  upon  the  constants  of  the  solution  is  shown 
(density,  opticity,  cupric  reduction,  and  furfural).  Under 
the  conditions,  the  proportion  of  the  celluloses  fermented 
amounts  to  30  per  cent  of  the  total  dissolved  solids. 
Similar  conclusions  are  deducible  from  a  recent  paper  by 
Tollens  {J.  fur  Landw.,  1897,  106—107),  in  which  the 
fate  of  malt-furfuroids  in  beer-fermentations  is  discussed. 
The  experimental  numbers  in  this  paper  show  the  dis- 
appearance of  a  large  proportion  of  these  constituents  in 
the  process. 

Since  the  pentoses  entirely  resist  alcoholic  fermenta- 
tion, as  shown  by  Tollens  [Kohlenhydrate,  ii.),and  further 
confirmed  by  the  authors,  as  well  as  by  later  observations 
of  Tollens  privately  communicated,  it  is  evident  that  the 
group  of  furfuroids  thus  fermented  is  constitutionally 
distindt  from  the  pentoses. 

Incidentally  to  observations  on  alcoholic  fermentation 
with  mixtures  of  known  hexoses  and  pentoses,  the 
authors  find  that  the  latter  remain  unafTedled  in  presence 
of  hexoses  undergoing  fermentation.  Under  certain  con- 
ditions, however,  the  pentoses  are  removed  from  solution 
by  the  yeast  organism  ;  the  necessary  condition  appears 
to  be  that  of  "  starvation,"  in  the  sense,  i.e.,  of  the  absence- 
of  hexoses.  The  disappearance  of  the  pentose  under  these 
conditions  is  indicated  by  determinations  of  furfural  and 
the  fall  of  the  furfural  numbers.  This  phenomenon  ap- 
pears to  be  the  simple  one  of  assimilation  by  the  yeast 
organism,  as  shown  by  Bokorny  {Dingl.  jf.,  1897,  Y->  303>- 
The  pentose  undergoes  constitutional  change  in  such 
assimilation,  as  the  yeast  shows  no  increase  in  its  normal- 
small  furfural  number. 

The  authors  further  discuss  the  question  of  the  consti- 
tution of  furfuroids  thus  shown  to  yield  to  alcohol  on  fer- 
mentation, and  conclude  that  the  hypotheses  of  the  exist- 
ence of  methylene  ethers  of  the  pentoses,  or  pentose  for- 
mals,  affords,  up  to  the  point  arrived  at,  a  consistent  view 
of  their  differentiation  from  the  pentoses. 
The  history  of  "piperonal" — 
0 

COH 
is  cited  in  explanation  of  the  exceptional  difficulty  of  ar- 
riving at  positive  final  proof  of  the  analogous  constitu- 
tional formula — 

C5H803<^    ^CH2, 

which  sums  up  the  above  hypothesis  in  relation  to  the 
group  of  furfuroids  in  question.  The  instability  of  the 
pentose  as  compared  with  the  aromatic  residue  prevents 
the  application  of  readtions  of  resolution  (Fittig)  or  syn- 
thesis (Wegscheider)  such  as  have  established  the  methyl- 
enic  constitution  of  piperonal. 

88.  "  Studies  on  the  Constitution  of  Tri-derivatives  of 
Naphthalene  No.  16.  Conversion  of  Chloronaphthalene- 
disulphonic  Acids  into  Dichloronaphthalenesulphonic  Acids. 
By  Henry  E.  Armstrong  and  W.  P.  Wynne. 

In  the  course  of  their  studies  of  naphthalene  deriva- 


Crbmical  IMEWS,  I 
Aug.  6,  1807.      I 


Constitution  of  Tri-derivatives  oj  Naphthalene. 


69 


tives,  the  authors  have  had  occasion  to  make  great  use  of 
phosphorus  pentachloride  as  an  agent  for  displacing  the 
SO3H  radicle  by  chlorine.  It  was  therefore  necessary  to 
establish  in  every  possible  way  the  validity  of  this  method 
of  determining  constitution  in  the  naphthalene  series,  as 
it  is  obvious  that  the  occurrence  of  isomeric  change  in 
any  one  case  would  materially  weaken  the  force  of  all 
arguments  based  on  its  application. 

With  regard  to  the  nature  of  the  interadlion,  it  is  to  be 
noted  that  in  a  previous  communication  (Proc,  1895,  "'-i 
83)  it  has  been  shown  that  it  is  usually  possible  to  dis- 
pense with  the  pentachloride,  and  to  obtain  the  chloro- 
naphthalene  corresponding  with  the  given  sulphonic 
chloride  by  merely  heating  the  latter  alone  under  appro- 
priate conditions,  but  that  as  a  rule  the  chloronaphthalene 
is  obtained  somewhat  more  readily  and  in  larger  relative 
amount  when  the  pentachloride  is  used.  In  other  words, 
the  main  fundtion  of  the  pentachloride  is  to  promote  the 
elimination  of  SOg  from  the  SO2CI  radicle. 

In  the  case  of  the  chloronaphthalenesulphonic  chlorides, 
the  amount  of  dichloronaphthalene  obtained  by  means  of 
phosphorus  pentachloride  is  relatively  considerable,  and 
the  residue  left  after  its  removal  from  the  crude  produdt 
by  distillation  with  steam  yields  nothing  but  the  original 
chloronaphthalenesulphonic  acid  on  hydrolysis. 

The  chloronaphthalenedisulphonic  chlorides,  however, 
behave  somewhat  differently,  affordingbut  a  comparatively 
poor  yield — rarely  exceeding  30  per  cent  of  the  theoretical 
amount — of  trichloronaphthalene. 

While  preparing  a  full  account  of  their  work,  the 
authors  have  felt  it  to  be  incumbent  on  them  to  thoroughly 
examine  the  residues  left  after  separating  the  trichloro- 
naphthalenes,  which  they  have  had  occasion  to  produce 
on  a  large  scale  {Proc,  1895,  xi.,  86).  Although,  in  view 
of  the  uniformity  of  the  end-produdls,  it  was  improbable 
that  any  change  in  orientation  had  taken  place  at  the 
somewhat  high  temperatures  at  which  the  interadions 
were  effedled,  it  was  obviously  important  to  ascertain  in 
every  possible  way  whether  such  was  the  fadl.  The  re- 
sults to  be  recorded  are  of  interest,  as  they  serve  in  every 
case  to  justify  the  conclusion  previously  arrived  at,  that 
the  treatment  of  sulphonic  chlorides  with  phosphorus 
pentachloride  may  be  thoroughly  trusted  as  a  means  of 
determining  constitution  in  the  naphthalene  series.  Two 
cases  may  be  quoted  as  typical  of  the  behaviour  of  chloro- 
naphthalene disulphonic  chlorides  in  general. 

When  2-chloronaphthalene-4' :  2'-disulphonic  chloride 
[Proc,  1890,  vi.,  129)  is  heated  with  the  theoretical  quan- 
tity of  phosphorus  pentachloride  at  175°  during  two  hours, 
it  yields  both  2  :4' :  2'-trichloronaphthalene  and  2:4'- 
dichloronaphthalene-2'-sulphonic  chloride  in  about  equal 
proportions,  about  50  per  cent  of  the  material  remaining 
unchanged.  2  m'-Dichloronaphthalene-2'-sulphonic  acid 
affords  a  sparingly  soluble  barium  salt,  crystallising  with 
3i  molecular  proportions  of  water  in  microscopic  needles  ; 
a  sparingly  soluble  potassium  salt,  containing  li  molecu- 
lar proportions,  in  thin  scales;  a  chloride  crystallising 
from  benzene  in  small  prisms  melting  at  156°;  an  amide 
crystallising  from  dilute  alcohol  in  slender  needles 
melting  at  196°;  and  when  the  chloride  is  heated  at  180 
— 185°  with  phosphorus  pentachloride  it  is  converted  into 
2:4':  2'-trichloronaphthalene.  On  hydrolysing  the 
chloride  in  sealed  tubes  with  concentrated  muriatic  acid 
at  290°,  or  the  potassium  salt  with  a  mixture  of  sulphuric 
and  phosphoric  acids  and  superheated  steam,  2 : 4'- 
dichloronaphthalene  is  obtained.  The  course  of  change 
may  therefore  be  thus  represented  : — 


CI 


/\/\ 


CI 


CI 


CI 


/\/\ 


S02C1 


bOzCi 


SO2CI 


When  2-chloronaphthalene-i' :  3'-disuIphonic  chloride 
{Proc,  1890,  vi.,  13)  is  similarly  heated  with  phosphorus 


pentachloride,  it  yields,  besides  2:3':  I'-trichloronaphtha- 
lene,  a  somewhat  larger  proportion  of  a  mixture  of  2  :  i'- 
dichloronaphthalene -3'- sulphonic  and  2  :  3'-dichloro- 
naphthalene-i'-sulphonic  {Proc,  1890,  vi.,  84)  chlorides, 
about  50  per  cent  of  the  material  remaining  unchanged. 
2  :  1' -Dichloronaphthalene-^' -sulphonic  acid,  the  isomeride 
present  in  the  larger  proportion,  yields  an  anhydrous 
potassium  salt,  crystallising  in  thin  elongated  scales,  but 
exhibiting  a  tendency  to  separate  in  a  gelatinous  form  ;  a 
chloride  crystallising  from  benzene  and  light  petroleum  in 
small  prisms  melting  at  130° ;  and  an  amide  crystallising 
from  dilute  alcohol  in  slender  needles  melting  at  218°. 
When  the  chloride  is  heated  at  180 — 185°  with  phosphorus 
pentachloride,  2:  i' :  3'-trichloronaphthalene  is  formed. 
On  hydrolysing  the  chloride  in  sealed  tubes  with  concen- 
trated muriatic  acid  at  290°,  or  the  potassium  salt  mixed 
with  sulphuric  and  phosphoric  acids,  in  superheated 
steam,  2  :  I'-dichloronaphthalene  is  obtained.  The  course 
of  change  may  therefore  be  thus  represented  :— 


SO2CI 


SO2CI 


SO2CI 

ci/VN 


»nd 


\/\/ 


SO2CI 


\/\/ 


CI. 


The  other  o  6-disulphonic  chlorides  behave  similarly, 
the  tendency  being,  however,  as  in  the  first  of  the  above 
instances,  to  form  only  one  of  the  two  possible  isomeric 
dichloronaphthalenesulphonic  chlorides,  no  doubt  because- 
the  SO2  of  the  SO2CI  radicle,  like  the  SO3H  radicle,  is 
more  easily  displaced  from  a-  than  from  j8-positions.  It 
is  not  certain  that  these  produds  are  intermediate  in  the 
strid  sense  of  the  term,  as  the  effedl  of  prolonging  the 
heating  with  phosphorus  pentachloride  at  the  minimum- 
temperature  at  which  the  readion  takes  place  serves  only 
to  increase  the  yield  both  of  the  dichloro-  and  trichloro- 
derivatives.  As  the  dichloronaphthalenesulphonic 
chlorides  produced  in  these  interadions  decompose  at 
temperatures  a  few  degrees  higher — 10°  to  15°  in  most 
cases — than  those  at  which  the  corresponding  chloro- 
naphthalenedisulphonic chlorides  from  which  they  are 
obtained  undergo  change,  it  is  not  difficult  to  understand 
why  they  escape  attack  by  phosphorus  pentachloride 
under  the  conditions  observed. 

89.  "  Conversion  0/1:1'-  into  i  :  4' -Dichloronaphthalene 
by  Hydrogen  Chloride.  The  Products  of  Hydrolysis  of 
I :  i'-Dichloronaphthalene-2-sulphonic  Acid."  By  Henry 
E.  Armstrong  and  W.  P.  Wynne. 

When  I  :  I'-dichloronaphthalene  is  heated  with  concen- 
trated muriatic  acid  at  290°,  it  is  wholly  converted,  save 
for  a  trace  of  carbonisation,  into  the  isomeric  i  :  4'-di- 
chloronaphthalene.  This  remarkable  isomeric  change 
does  not  seem  to  occur  at  temperatures  below  200°,  but 
is  noticeable  at  250°,  and  complete  at  290°;  it  does  not 
occur  when  i  :  I'-dichloronaphthalene  is  heated  either 
alone,  or  with  water,  or  with  concentrated  phosphoric 
acid  at  300°,  but  does  happen  when  it  is  heated  with  sul- 
phuric acid  of  a  strength  to  cause  considerable  carbonisa- 
tion. None  of  the  isomeric  dichloronaphthalenes  show 
any  tendency  to  change  under  these  conditions. 

The  experiments  which  led  to  these  results  were  made 
in  consequence  of  the  perplexing  behaviour  of  i  :  i'- 
dichloronaphthalene-3-sulphonic  acid  on  hydrolysis.  The 
isomeric  o-sulphonic  acid  {Proc,  1890,  vi.,  81)  requires 
only  a  temperature  of  230°  to  effe<5t  its  hydrolysis,  and 
gives  only  i  :  I'-dichloronaphthalene.  whatever  be  the 
hydrolytic  agent  used  ;  the  j8-sulphonic  acid,  on  the  con- 
trary, is  not  hydrolysed  below  285°,  and  according  to  the- 


70 


Reform  of  Chemical  and  Physical  Calculations. 


Chemical  r«Bws, 
Aug.  6,  1897. 


agent  used   gives  one  or  other  of  no   less  than  three 
dichloronaphthalenes. 

I  '  '^':Pi<^hloronaphthalene-ystilphonic  acid  is  obtained 
in  addition  to  about  an  equal  proportion  of  i  :  i'  :  3-tri- 
chloronaphthalene  when  i-chloronaphthalene-i' :  3-disul- 
phonic  chloride  {Proc,  1890,  vi.,  16)  is  heated  with  phos- 
phorus pentachloride  at  160°  (compare preceding  abstradt). 
It  forms  a  sparingly  soluble  anhydrous  potassium  salt 
crystallising  in  thin  elongated  scales;  a  chloride  crystal- 
lising from  benzene  in  thin  scales  melting  at  158°;  an 
amide  crystallising  from  dilute  alcohol  in  short  slender 
needles  melting  at  197°;  and  1:1':  s-trichloronaphtha- 
lene  when  its  chloride  is  heated  either  with  phosphorus 
pentachloride  at  170°,  or  alone  at  200—230°.  On  hydro- 
lysing  the  potassium  salt  with  dilute  acids,  such  as  i  per 
cent  sulphuric  acid  or  50  per  cent  phosphoric  acid  at 
290°,  about  5—10  per  cent  of  the  theoretical  quantity  of 
I  :  I'-dichloronaphthalene  is  obtained,  the  residue  being 
unchanged  salt— a  result  by  which  the  constitution  of  the 
acid  is  determined  beyond  doubt.  When  heated  with  5 
per  cent  sulphuric  acid  or  60  per  cent  phosphoric  acid, 
carbonisation  largely  occurs,  and  with  these  and  stronger 
acids  a  small  amount  of  i  :  4'-dichloronaphthalene  is  the 
only  substance  obtained,  a  better  yield— some  20  per  cent 
<al  the  theoretical— being  got  when  the  chloride  is  heated 
with  concentrated  muriatic  acid  at  290''-  The  produdiion 
of  I  :  4'-  instead  of  the  expefted  i  :  I'-dichloronaphtha- 
lene  under  these  conditions  is  to  be  referred  to  the  adlion 
of  hydrogen  chloride,  either  present  or  formed  during  the 
carbonisation  of  the  salt. 

On  effedting  hydrolysis  by  heating  the  potassium  salt, 
mixed  with  sulphuric  and  phosphoric  acids,  in  super- 
heated steam  instead  of  in  sealed  tubes,  an  unexpeded 
result  was  obtained,  pure  i  :  2'-dichloronaphthalene,  to 
the  extent  of  40  per  cent  of  the  theoretical  amount,  being 
the  produdt,  the  remainder  of  the  salt  being  carbonised. 
The  explanation  of  this  change  has  yet  to  be  given.  It 
is  certain  that  the  i  :  2'-compound  is  not  an  intermediate 
step  in  the  conversion  of  i  :  i'.  into  i  :  4'-dichloro- 
naphthalene  during  hydrolysis  in  sealed  tubes,  both  be- 
cause it  is  unaffedled  by  prolonged  heating  with  concen- 
trated  muriatic  acid,  and  because  1  :  2'-dichloronaphtha- 
lene-3-sulphonic  acid  cannot  be  detedled  in  the  material 
which  has  escaped  hydrolysis,  and,  moreover,  behaves 
normally  on  hydrolysis  (compare  preceding  abstraft).  It 
is  possible  that,  under  the  conditions  specified,  further 
sulphonation  may  precede  hydrolysis,  and  that  in  conse- 
quence of  the  transference  of  chlorine  to  the  para-posi- 
tion being  thereby  prevented,  i  :  2'-dichloronaphthalene 
is  formed,  thus  : — 

CI    CI 


CI     CI 


\/\/ 


\y\/  ^ 

CI 

ci/\/\ 


CI 


CI 


s 

Further  experiments  are  being  made  to  test  this  view. 

Of  the  trichloro-naphthalenes  the  1:2:8  modification 
is  the  only  one  which  undergoes  change  when  heated  with 
concentrated  muriatic  acid.  Its  sulphonic  and  disulphonic 
acids  behave  similarly,  but  the  course  of  the  adlion  has 
not  yet  been  worked  out,  owing  to  want  of  material. 
(To  be  continued). 


Atflion  of  Tannin  and  Gallic  Acid  upon  the  Quino- 
leic  Bases.— Oechsner  de  Coninck.— The  bases  behave 
with  tannin  and  gallic  acid  not  only  like  the  pyridic  bases, 
but  like  pyridic  hydrides.— Com^f«  Rendus,  cxxv..  No.  i. 


NOTICES  OF  BOOKS. 


Reform    of  Chemical   and    Physical    Calculations.      By 
C.   J.  J.  Hanssen,   C.E.      Printed   by   the  Carlsberg 
Foundation  in  Copenhagen.     London:  E.  and   F.  N. 
Spon.      New  York:    Spon   and   Chamberlain.      1897. 
Pp.  72. 
The  deduftions  contained  in  this  volume  are  based  upon 
the  natural  laws  of  atomic  combination,  heating,  expan- 
sion, and  compression  of  aeriform  substances,  and  upon 
the  fadl  discovered  by  the  author — that  near  the  41°  of 
latitude  the  specific  gravity  of  oxygen  gas  of  atmospheric 
density,   at   the    temperature  of  melting  ice,   is  exadtly 
i/700th  of  the  gravity  of  distilled  water  at  its  temperature 
of  greatest  density. 

In  different  text-books  there  is  great  want  of  uniformity 
in  the  values  given  for  many  specific  gravities,  specific 
heats,  &c.  (we  know  one  standard  work  wherein  are 
given  no  fewer  than  six  values  of  i  grm.  in  grains).  This 
is  perhaps  because  some  authors  reduce  their  weights  to 
sea-level,  while  others  take  the  latitude  and  elevation  of 
whatever  town  they  may  be  in.  The  proposed  reform  is 
to  reduce  all  chemical  and  physical  calculations  to  one 
common  starting-point,  from  which  they  can  all  be  fixed 
by  calculation.  The  proper  unit  of  gravity  is  hydrogen, 
but  owing  to  the  difficulty  in  accurately  weighing  this  gas 
it  is  better  to  calculate  it  from  oxygen  and  nitrogen,  both 
of  which  have  been  determined  with  great  accuracy.  As 
all  astronomers  use  the  longitude  of  Greenwich,  so,  says 
the  author,  should  all  chemists  adopt  a  common  circle  of 
latitude,  to  which  all  calculations  of  gravity  should  be 
reduced.  At  a  certain  latitude,  between  41"  and  42°,  the 
weight  of  I  cubic  metre  of  oxygen  at  the  mean  atmospheric 
pressureando°C.isio/7kilogrms.  Thislatitude  theauthor 
proposes  to  call  the  circle  of  international  gravity.  At 
this  latitude  the  velocity  of  falling  bodies  during  the  first 
second  is  4'90ii5  metres,  and  the  length  of  a  pendulum 
making  one  oscillation  per  second  =  0'993i8i  metre,  A 
large  number  of  values  of  various  kinds  are  calculated 
and  given,  such  as  the  international  &imo%^h&r\c  pressure, 
boiling-point,  specific  heats,  relative  heats,  expansion  and 
compression  of  gases,  &c.,  &c.  But  there  is  one  impor- 
tant point  with  which  we  cannot  agree,  the  author  wishes 
to  do  away  with  decimals  and  go  back  to  the  dark  ages 
of  vulgar  fradlions.  Some  of  his  calculations  done  in  this 
manner  have  a  weird  and  forbidding  aspedt.  Think  of  it ! 
in  adding,  subtradling,  or  multiplying  to  have  to  deal  with 
such  terminals  as  64/i85ths,  6/37ths,  2/7ths,  25/37ths, 
112/iiiths,  867/i4oths.  These  all  come  in  one  short  cal- 
culation of  the  calories  of  sensible  heat  generated  by  the 
combustion  of  i  kilogrm.  of  Dowson's  gas. 

There  is  a  certain  amount  of  fascination  in  Mr.  Hans- 
sen's  idea,  but  we  think  it  is  extremely  improbable  that 
such  a  botileversement  will  be  adopted  ;  it  cannot  be  done 
gradually,  and  it  is  certain  that  even  if  it  were  largely 
adopted,  it  would  not  be  universal,  and  we  should  then 
have  confusion  worse  confounded. 


Electrolytic  Quantitative  Analysis.  ("  Quantitative  Analyse 
durch  Eledtrolyse.")  By  Dr.  Alexander  Classen. 
Fourth  Edition,  with  74  Illustrations  and  6  Plates.  Pp. 
249.     Berlin :  Julius  Springer.     1897. 

The  fourth  edition  of  Dr.  Classen's  excellent  work  will  be 
welcomed  by  chemists.  Eledlricity  and  chemistry  com- 
bined are  making  such  rapid  strides  of  late  years,  as  well 
in  the  laboratory  and  assay  office  as  in  the  metallurgical 
workshop,  that  it  is  only  by  frequent  editions  of  such 
books  as  this  that  we  are  enabled  to  ktep  ati  fait  with 
what  is  latest  and  newest  in  the  methods  employed.  It 
is  hardly  necessary  to  go  through  the  book  seriatim ; 
suffice  it  to  say  that  Dr.  Classen  begins  at  the  beginning, 
both  with  regard  to  the  theoretical  and  pradlical  side  of 


Chemical  News,  i 

Aug.  6, 1897.  r 


Chemical  Notices  /rom  Foreign  Sources. 


the  question,  and  gradually  leads  the  reader  up  to  his  own 
ingenious  and  refined  methods  of  eledtro-chemical  analy- 
sis. The  special  bits  of  apparatus  he  has  designed  for 
this  work  are  all  described  and  illustrated,  and  the  best 
methods  of  manipulation  and  procedure  with  all  the 
metals,  and  their  electrolytic  separation  one  from  another, 
are  given  at  length.  Among  the  six  plates  at  the  end  of 
the  book  we  find  a  contrast  between  the  old  purely 
chemical  laboratory  and  the  modern  eleftro-chemical 
laboratory.  Like  so  many  foreign  books,  it  labours  under 
the  disadvantage  of  not  having  an  Index,  which  is  hardly 
made  up  for  by  an  excellent  table  of  contents. 


CHEMICAL  NOTICES  FROM  FOREIGN 
SOURCES. 


NoTB.— All  degrees  of  temperature  are  Centigrade  unlessotberwise 
expressed. 

Comptes  Rendus  Hebdomadaires  des  Seances,  deVAcademie 
des  Sciences.     Vol.  cxxv.,  No.  i,  July  5,  1897. 

Nomination. — In  nominating  a  Foreign  Associate  wjc« 
the  late  M.  Tchebicheff,  Prof.  Virchow  obtained  an  jibso- 
lute  majority  of  votes  (32).  Prof.  Stokes,  the  second 
candidate  on  the  list,  received  nine  votes. 

Thermic  Mercurial  Ammeter. — Charles  Carmichel. 
— The  authorhasthe  honourofsubmittingto  the  Academy 
novel  mercurial  ammeters  and  voltmeters. 

New  Mercurial  Pump  without  Cocks  and  Valves. 
H.  Hanriot. —  This  paper  requires  the  accompanying 
illustration. 

A(5\ion  of  Tellurium  Chloride  and  Fluoride  upon 
the  corresponding  Hydracids. — R.  Metzner, 

Redudion  of  Molybdenum  Anhydride  by  Hydro- 
gen.— M.  Guichard. — The  redudlion  of  the  oxide  M0O3 
below  470°  is  continuous,  and  leads  diredlly  to  the  inter- 
mediate oxides  MO2O5  or  M05O12.  These  intermediate 
oxides  cannot  be  obtained  by  means  of  hydrogen.  The 
author  promises  to  give  the  results  of  his  experiments  on 
the  redudtion  of  molybdic  anhydride  by  means  of  hydrogen 
at  temperatures  exceeding  470°. 

On  Manganomolybdate. — E.  Pechard. — There  do  not 
seem  to  exist  compounds  for  the  other  acids  which,  like 
tungstic  acid,  yield  complex  acids. 

On  Veratrylene-Diamine. — Ch.  Moureu. 

OnParaxylyl-AceticAcidand  Dimethyl-Phenethyl- 
oic-2  Acid. — M.  Guerbet. 

A  Novel  Carbohydrate,  Carubine. — Jean  Effront. — 
Carubine  is  widely  dififused  in  nature.  We  have  detedted 
it  in  oats  and  barley,  and  it  is  probably  present  in  beer. 

Fermentations  in  Compound  Mediums  of  Solid 
Particles. — Th.  Schlcesing,  jun. — The  author  concludes 
that  aeration,  even  without  agitation,  does  not  aifedt  the 
cause  of  fermentation. 

No.  2,  July  12,  1897. 

The  Secretary  announced  the  death  of  Dr.  Steenstrup, 
a  corresponding  member  of  the  Sedlion  of  Anatomy  and 
Zoology,  which  took  place  on  June  20th. 

ElecJ^ion. — M.  Goyon  was  elefted  a  Correspondent  for 
the  Sedion  of  Rural  Economy,  vice  the  late  M.  Hell- 
riegel. 

Use  of  Cupric  Salts  to  Prepare  for  the  Determina- 
tion of  various  Elements  in  Cast-irons  and  Steels. — 
MM.  Ad,  Carnot  and  Goutal. 

Complexity  of  the  Sheaf  of  X  Rays. — MM.  A.  Imbert 
and  Bertin-Sans. — A  practical  conclusion  to  be  drawn  from 
the  phenomena  observed  is,  that  to  obtain  a  good  radio- 
graph, i.e.,  a  proof  presenting  much  contrast,  we  must 


make  use  of  a  tube  which  is  still  far  from  being  resistant. 
On  the  contrary,  to  effedt  the  radioscopy  of  a  dense  medium 
we  must  utilise  the  vacuum  at  the  moment  when  the  less 
absorbable  X  rays  are  present  in  a  sufficient  quantity. 

On  various  Basic  Copper  Salts,  and  on  Brown 
Cupric  Hydrate. — Paul  Sabatier, 

Redudtion  of  Molybdenum  Anhydride  by  Hydrogen, 
and  the  Preparation  of  Pure  Molybdenum, — M,  Gui- 
chard.— We  have  established  by  experiments  made  at  a- 
constant  temperature  that,  in  hydrogen  between  300°  and 
470°,  the  redudtion  of  molybdic  anhydride  leads  to  the 
oxide  M0O2  without  passing  through  the  oxides  M02O5 
and  M02O12. 

Adtion  of  Benzoyl  Chloride  upon  the  Mono-substi 
substituted  Orthodiamines. — Fernand  Mattalet. — The 
author  undertakes  to  examine  what  is  the  adtion  of  ben- 
zoyl chloride  upon  the  mono-substituted"^  orthodiamines 
answering  to  the  general  formula — 
NH.R 
NO2— NH2 
in  which  the  radicle  R  may  be  either  fatty  or  aromatic. 

Formation  of  the  Mixed  Hydrates  of  Acetylene 
and  some  other  Gases. — MM,  de  Forcrand  and  Sully 
Thomas, — This  paper  is  not  adapted  for  useful  abstrac- 
tion. 

Adlion  of  Sulphuric  Acid  upon  Lavoterebenthene, 
— G.  Bouchardat  and  J.  Lafont. — Among  the  liquid  pro- 
dudls  of  the  readlion  there  has  been  found  fenchene, 
C26H16,  derived  from  fenchol  by  dehydration. 

Development  of  Aromatic  Principles  by  Ferment- 
ation in  presence  of  certain  Leaves. — Georges  Jacque- 
min. — To  prevent  the  loss  of  the  volatile  aromatic  prin- 
ciples the  gases  of  fermentation  should  be  passed  through 
a  condenser  charged  with  alcohol. 

New  Hydrolytic  Enzyme — "  Caroubinase."  —  J. 
Effront. — Caroubinase  adls  energetically  at  40°,  and  its 
adlion  increases  with  the  temperature  up  to  50°.  At  70° 
the  adtion  becomes  very  feeble,  and  at  80°  the  enzyme  is 
destroyed. 

Optical  Analysis  of  Urine:  Diabetic  Sugar  Thermo- 
optically  Positive  and  Negative. — F.  Landalgh. 

Composition  of  Haricots,  Lentils,  and  Peas. — 
Egyptian  lentils,  as  well  as  beans  of  the  same  origin,  are 
the  richest  in  nitrogen.  Those  of  Auvergne  are  more 
nitrogenous  than  those  of  Bohemia,  Spain,  Moravia,  and 
Russia.  Immature  peas  are  more  nitrogenous  than  those 
gathered  at  full  maturity. 


Revue  Generale  des  Sciences  Pures  et  Appliques. 
No.  II,  June  15,  1897. 

On  Gas  and  Petroleum  Engines. — Aime  Witz. — 
This  long  and  interesting  article  is  more  suited  to  an 
engineering  than  a  chemical  paper,  but  it  will  well  repay 
perusal  by  chemical  engineers.  The  history  of  the  gas- 
engine,  which  is  claimed  as  a  French  invention,  is  traced 
from  the  commencement  in  1799  to  the  present  time,  and 
a  number  of  illustrations  are  given. 

Liquefadlion  of  Fluorine. — H.  Moissan  and  J,  Dewar. 
— Already  inserted  in  full.  In  a  footnote  by  the  editor 
the  readers  are  informed  that  the  experiments  described 
in  this  paper  were  carried  out  in  the  laboratory,  and  with 
the  resources,  of  the  Royal  Institution  of  Great  Britain. 

The  Dinosauriens.— A.  Bigot.— Not  suitable  for  ab- 
stradlion. 

The  Cultivation  of  Cocoa  in  the  French  Colonies. 
— H.  Lecompte,  —  Cocoa  was  originally  found  only  in 
Mexico,  but  has  since  been  introduced  into,  and  found  in, 
many  other  countries.  The  largest  quantity  is  produced 
in  Brazil  and  the  English  possessions  in  Central  America, 
where  the  produdtion  is  steadily  increasing ;  that  in  the 
French  colonies  remains  stationery. 


72 


Chemical  Notices  from  Foreign  Sources. 


(Chemical  News, 
Aug.  6,  isg7. 


No.  12,  June  30,  1897. 
This  number  contains  no  original  matter  of  chemical 
'interest. 

No.  13,  June  15,  1897. 
On  X  Rays  and  Dissociation. — Ch.  Guillaume. — The 
idea  of  dissociation  put  forth  by  Sainte-Claire  Devillewas 
familiar  to  spedtroscopists,  who  found  therein  an  ex- 
planation of  the  identity  of  the  spedra  of  salts,  or  of  a 
base,  under  varying  conditions.  The  author  claims  that 
it  is  proved  that  dissociation  is  also  caused  by  X  rays. 
When  adting  on  the  flesh  the  ions  cause  attenuation  of 
virus,  excitation  of  muscle,  and  vascularisation.  The 
physiological  adlions  of  X  rays  and  of  currents  of  high 
frequency  have  not  merely  a  chance  analogy,  the  ultimate 
cause  is  the  same  in  either  case. 

On  Cape  Diamonds. — L.  De  Launay.— This  paper, 
which  describes  the  Kimberley  Diamond  Mines  and  the 
mining  industry,  does  not  materially  differ  from  the  Lec- 
ture delivered  by  Sir  William  Crookes  last  year  at  the 
Imperial  Institute  on  the  same  subjedt,  but  we  can  find 
no  acknowledgment  of  the  source. 

Applications  of  ElecJtricity  to  Artillery.  —  G.  La- 
vergne. — Not  suitable  for  abstradtion  in  these  columns. 


MISCELLANEOUS. 

Reagents,  Reaaions,  Methods,  and  Formulae. — 
The  Editor  of  the  Pharmaceutical  yournal  proposes  re- 
publishing in  book  form  the  list  of  *'  Reagents,  Readlions, 
Methods,  and  Formulae,  known  by  the  Names  of  their 
Authors,"  which  has  appeared  in  the  Pharmaceutical 
Review,  and  has  since  been  published  as  a  pamphlet.  In 
order  to  make  the  list  as  complete  as  possible  he  will  be 
glad  to  receive  from  their  authors  particulars  of  any  tests 
or  processes  associated  with  the  names  of  any  chemists. 
AVith  the  idea  of  increasing  its  utility  the  list  is  now  ex- 
tended by  the  addition  of  particulars  regarding  a  large 
number  of  microscopical  and  badteriological  methods  and 
formulae  from  the  works  of  Lee,  Squire,  Crookshank,  and 
others. 

The  Yorkshire  College,  Leeds. — The  report  of  the 
work  of  the  Textile  Industries,  Dyeing,  and  Art  Classes 
of  this  College,  shows  that  in  the  Session  1896-7  there 
has  been  a  slight  increase  in  the  number  of  students,  and 
That  satisfadory  progress  has  been  made  in  both  the  theo- 
retical and  experimental  work.  The  teaching  is  being 
constantly  improved  and  expanded,  to  keep  up  with  the 
developments  constantly  taking  place  in  the  weaving  indus- 
tries. During  the  last  five  of  six  sessions  there  has  been 
a  constant  and  satisfadtory  increase  of  senior  students.  A 
twelve  horse-power  gas-engine  has  been  put  down  since 
the  last  session,  and  it  is  now  possible  to  run  all  the 
machinery,  looms,  &c.,  of  the  department  at  one  time.  It 
is  proposed  to  add  a  Carding  and  Spinning  Department, 
and  the  draft  plans  have  been  passed  and  are  now  in  the 
hands  of  the  architedl.  They  will  provide  ample  room  for 
a  complete  plant  of  scouring,  carding,  combing,  and  spin- 
ning machinery  for  both  woollen  and  worsted  yarns,  and 
also  suitable  rooms  for  conditioning  purposes,  and  for 
warping,  beaming,  and  sizing  machinery. 

Carbide  of  Calcium  and  the  Petroleum  Adls.— In 
view  of  the  growing  importance  of  carbide  of  calcium,  this 
substance  has,  by  Order  in  Council,  been  brought  under 
the  provisions  of  the  Petroleum  Adts,  1871  to  1881,  and  it 
is  now  necessary  for  all  users  of  carbide  of  calcium  to 
obtain  from  the  local  authorities  under  the  Petroleum  Adts 
a  license  to  store  it.  The  Acetylene  Illuminating  Co., 
Limited,  has  been  manufadluring  carbide  of  calcium  since 
the  spring  of  1895,  and  has  always  laid  the  greatest  stress 
■on  the  necessity  for  proceeding  with  caution  in  developing 
this  new  industry.  When  proper  precautions  are  taken, 
there  is  no  more  risk  attending  the  use  of  acetylene  gas 
than  there  is  with  coal-gas.     As  manufadturers  of  carbide 


of  calcium,  the  above-named  company  are  of  opinion  that 
the  legislative  restridtions  will  not  prove  a  hardship,  and 
they  prefer  to  see  this  new  industry  on  a  well-defined, 
instead  of  on  an  uncertain,  basis.  Carbide  of  calcium  in 
itself  is,  as  is  well-known,  non-explosive;  but  when  water 
is  added  to  it,  or  if  it  be  exposed  to  a  damp  atmosphere, 
acetylene  gas  is  evolved,  and  if  this  gas  comes  in  contadt 
with  a  light  an  explosion  will  naturally  follow.  Its  pre 
sence  is,  however,  easy  to  detedt  on  account  of  its  pun- 
gent odour.  The  authorities  very  properly  require 
that  carbide  should  be  "commercially  pure";  that 
is  to  say,  it  must  not  contain  any  impurities  liable 
to  generate  siliciuretted  or  phosphoretted  hydrogen, 
which  might  render  the  gas  spontaneously  explosive. 
Great  stress  is  laid  on  the  importance  of  not  allowing 
carbide  of  calcium  or  acetylene  to  come  in  contadt  with 
copper,  on  account  of  the  ease  with  which  acetylide 
of  copper  is  formed  —  this  body  being  highly  explo- 
sive, a  touch  being  enough  to  set  it  off.  The 
Fire  Insurance  Companies  require  that  carbide,  liquid 
acetylene,  or  acetylene  gas  must  be  stored  in  a  separate 
building,  at  least  ten  feet  from  any  other  building,  and  a 
safety  valve  must  be  fitted  to  the  reservoir  or  pipes,  which 
will  allow  the  free  escape  of  the  gas,  outside  the  building, 
when  the  pressure  exceeds  4  ozs.  to  the  square  inch.  We 
have  mentioned  a  few  of  the  more  prominent  rules  which 
have  been  proposed,  but  they  are  all  in  course  of  revision, 
it  being  considered  that  some  are  too  lax,  while  others 
are  too  stringent ;  it  may,  however,  be  well  to  emphasize 
the  fadt  that  with  ordinary  precautions  there  is  no  more 
danger  than  with  coal-gas. 


Mr.  J.  G-.  LORRAIN.  M.I.E.E.,  M.I.M.E,  M.S.C.I., 

Fellow  of  the  Chartered  Institute  of  Patent  Agents, 
Norfolk   House,  Norfolk  Street,  London,  W.C. 

"  PATENTEE'S  HANDBOOK  "  Post  Free  on  application. 

IFOR,    SJ^XjB. 


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Magnetic  Deviation  of  the  X  Rays. 


73 


THE    CHEMICAL    NEWS 


Vol.  LXXVL,  No.  1968. 


ON    THE    EXPLANATION     OF    A 

PHENOMENON  ATTRIBUTED  TO  A  MAGNETIC 

DEVIATION  OF  THE  X  RAYS. 

By  Sir  G.  G.  STOKES. 

In  the  Comptes  Rendus  for  July  15,  1897  (P*  I7)>  '^^"^^ 
appeared  a  note  by  M.  G.  de  Metz,  in  which  he  described 
an  experiment  of  which  the  result,  according  to  him, 
could  only  be  explained  by  one  or  the  other  of  these  two 
hypotheses  : — Either  the  X  rays  are  capable  of  magnetic 
deviation  in  an  extremely  high  vacuum,  or  the  cathodic 
rays  are  able  to  traverse  the  glass  envelope  of  a  Crookes 
tube.  I  do  not  think  that  either  of  these  alternatives 
contains  the  true  explanation,  and  I  beg  the  Academy  to 
allow  me  to  submit  what  is,  in  my  mind,  the  true  ex- 
planation of  the  phenomenon.  Everything  tends  to  prove 
that  the  X  rays  are  a  vibration  of  the  ether,  and  we  may 
to-day  consider  it  as  pradlically  established  that  this 
vibration  is  transversal.  If  these  rays  are  a  vibration  of 
the  ether,  to  suppose  that  they  are  capable  of  magnetic 
deviation  opens  up  great  theoretical  difficulties ;  but, 
apart  from  this,  I  am  not  aware  that  such  a  deviation 
has  ever  been  demonstrated  experimentally.  As  for  the 
so-called  cathodic  rays,  it  seems  to  me  absolutely  certain 
that  they  are  not  true  rays  at  all,  but  simply  currents  of 
molecules  charged  with  eledtricity,  thrown  off  by  the 
cathode.  There  would  be,  without  doubt,  a  great  difficulty 
from  this  point  of  view,  if  we  were  obliged  to  imagine 
these  molecules  capable  of  passing  through  the  glass  of 
a  Crookes  tube ;  the  more  so,  that  Crookes  himself 
(Phil.  Trans.,  p.  150,  1879)  showed  long  ago  that  the 
cathode  rays  are  stopped  by  a  thin  screen  of  glass,  quartz, 
or  mica.  But  it  is  in  no  way  necessary  to  have  recourse 
to  this  supposition  to  explain  the  results  obtained  by  M. 
de  Metz.  It  seems  evident  to  me  that  the  phenomena 
which  are  observed  in  very  high  vacua  are  of  the  nature 
of  those  which  have  been  examined  by  Spottiswoode  and 
Moulton  under  the  name  of  relief-effect  {Phil.  Trans.,  p. 
177, 1879).  The  masses  of  extremely  rarefied  air,  situated 
respectively  in  the  Crookes  tube  and  in  the  cylindrical 
tube,  constitute  the  two  surfaces  of  a  Leyden  jar,  of  which 
the  dieledtric  is  formed  by  that  portion  of  the  envelope  of 
the  Crookes  tube  corresponding  with  the  contour  of  the 
cylindrical  tube.  At  each  discharge  of  the  induction  coil 
a  torrent  of  negatively  electrified  molecules  is  projedled 
against  the  anti-cathode,  or  the  first  surface  of  the 
dielectric,  which  communicates  its  charge,  or  a  great  part 
of  it,  either  direCtly  to  the  anode,  or,  in  the  first  place,  to 
some  other  part  of  the  internal  surface  of  the  Crookes 
tube.  Each  momentary  charge  of  the  first  surface  of  the 
dielectric  aCls  inductively  on  the  contents  of  the  cylindrical 
tube,  and  produces  reciprocally  a  discharge  between  the 
second  surface  of  the  dielectric  and  the  aluminium 
cylinder  connected  to  earth ;  and  in  this  phase  of  th^ 
reciprocal  discharge,  where  the  second  surface  aCts  as  the 
cathode,  the  molecules  are  projected  from  this  second 
surface,  exaCtly  as  from  the  cathode  of  the  Crookes  tube, 
and  they  affeCt  a  platino-cyanide  of  barium  screen  in  the 
same  manner. 

Although,  as  I  am  firmly  convinced, — and  I  believe  the 
greater  number  of  physicists  agree  with  me, — the  cathodic 
rays  and  the  X  rays  are  of  a  completely  different  nature, 
they  are  both  equally  capable  of  affeCting  a  photographic 
plate  or  of  exciting  the  fluorescence  of  a  screen  of  platino- 
cyanide  of  barium.     This  being  admitted,  the  results  ob- 


tained by  M.  de  Metz  are  capable  of  a  very  simple  ex- 
planation.  When  the  air  in  the  interior  of  the  cylindrical 
tube  was  at  the  atmospheric  pressure,  or  only  at  a 
moderate  vacuum,  the  fluorescence  observed  was  due  to 
the  X  rays.  For,  as  Lenard  has  shown  {Wiedermann^s 
Annalen,  li.,  p.  225,  1894),  'he  cathodic  rays— supposing 
they  exist — would  be  promptly  stopped  by  the  air,  and 
would  not  therefore  reach  the  screen  ;  consequently,  the 
rays  producing  the  fluorescence  were  found  to  be  insen- 
sible to  the  magnet.  On  the  other  hand,  at  a  high 
vacuum,  the  cathodic  rays,  set  up  by  the  molecules 
thrown  off  by  the  surface  which  was  made  cathodic  by 
induction,  were  able  to  reach  the  screen ;  and  as  they 
were  also  able  to  excite  a  fluorescence  much  more  intense 
than  the  X  rays,  the  effeCt  observed  was  principally  due 
to  the  cathodic  rays ;  and  it  is  thus  that  the  exciting  rays 
were  found  to  be  susceptible  of  deviation  by  the  magnet. 

In  offering  this  explanation,  I  wish  to  proteCt  myself 
against  the  idea,  which  might  be  attributed  to  me,  of  ex- 
plaining in  the  same  manner  the  apparition  of  the 
cathodic  rays  coming  from  the  second  surface  of  a  sheet 
of  aluminium  of  which  the  first  surface  receives  the 
cathodic  rays.  In  this  case  the  processus  is  probably 
more  direCt,  and  presents— to  my  mind — some  analogy 
with  electrolysis.— Com^<«  Rendus,  cxxv.,  No.  4. 


ARTIFICIAL    LIGHT: 
MODERN     METHODS     COMPARED —  ELECTRIC 
INCANDESCENT,  WELSBACH,  ACETYLENE.* 
By  Prof.  D.  S.  JACOBUS. 

At  the  commencement  of  this  LeCture  experiments  were 
made  to  show  the  appearance  of  various  colours  when 
under  different  lights.  The  two  sets  of  lights  to  be  com- 
pared were  placed  about  6  feet  apart,  and  screens  were 
arranged  to  shade  the  audience  from  the  direCt  glare  of 
the  lamps.  The  colours  to  be  examined  were  on  large 
sheets  of  cardboard,  bent  down  the  middle  to  a  conve- 
nient angle,  the  apex  towards  the  audience;  this  being 
placed  between  the  lamps  to  be  compared,  allowed  each 
surface  to  be  illuminated  by  a  different  set  of  lamps. 
Many  colours  appeared  of  a  different  shade  when  viewed 
by  the  acetylene  and  the  Welsbach  lights ;  the  lighter 
shades  of  pink  especially  appeared  brighter  under  the 
acetylene  than  under  the  Welsbach  light;  but  the  reverse 
is  the  case  for  some  other  colours.  Ordinary  gas,  and  the 
incandescent  eleCtric  light  also,  produced  more  lifelike 
tints  when  the  experiment  was  made  of  holding  the  hand 
between  them  and  a  Welsbach  lamp. 

In  a  table  of  the  comparative  illuminating-power  of 
water-gas  and  acetylene-gas,  we  see  that  acetylene  gives 
ten  times  as  much  light  as  ordinary  illuminative  water- 
gas  when  burned  in  a  flat-flame  burner,  and  about  three 
times  as  much  when  the  latter  is  burned  in  a  Welsbach 
burner.  The  percentage  of  the  total  heat  of  combustion 
of  the  gas,  transformed  into  light,  is  also  greater  for  the 
acetylene  than  for  the  ordinary  illuminating  gas.  For  a. 
given  illumination  the  atmosphere  is  vitiated  by  the  car- 
bonic acid  formed  in  burning  the  acetylene,  to  a  slightly 
less  extent  than  when  burning  ordinary  illuminating  gas 
in  a  Welsbach  burner. 

If  3  per  cent  of  acetylene  be  mixed  with  air  an  explosive 
mixture  is  produced.  In  the  case  of  hydrogen  5  per  cent 
is  required,  and  for  coal-gas  8  per  cent.  The  maximum 
amount  of  acetylene  that  can  be  mixed  with  air  to  form 
an  explosive  mixture  is  82  per  cent.  It  therefore  appears 
that  acetylene  is  more  explosive  than  either  hydrogen  or 
coal-gas;  but,  as  the  burners  used  for  acetylene  would 
discharge  a  less  amount  of  gas — say  one-fifth  that  of  an 

*  From  a  Led^ure  delivered  before  the  Franklia  Institute,  March 
12th,  1897. 


H 


AHi^cial  Light, 


tCBBUlCAL  NBWk, 
Aug.  13,  1897. 


ordinary  gas-burner — the  accidental  opening  of  a  burner 
would  cause  the  atmosphere  of  the  room,  as  a  whole,  to 
be  much  less  contaminated,  in  a  given  time,  than  with 
coal-gas.  On  the  other  hand,  acetylene-gas  is  so  much 
more  nearly  of  the  density  of  air  than  ordinary  illuminating 
gas  that  it  will  not  be  diffused  as  rapidly  through  the  air 
in  case  of  leakage,  and  will  have  a  greater  tendency  to 
colledt  in  a  partially  enclosed  space,  and  thus  cause  an 
explosion  in  case  the  gas  were  ignited. 

According  to  Berthelot,  if  gaseous  acetylene,  under  a 
pressure  of  about  15  pounds  above  the  atmosphere,  or 
over,  be  ignited  by  a  spark,  or  by  a  heated  platinum  wire, 
it  will  decompose  explosively  without  the  presence  of  air, 
the  explosion  becoming  more  violent  as  the  initial  pressure 
is  increased.  In  exploding,  the  carbon  and  hydrogen  are 
dissociated,  and  the  heat  absorbed  in  the  original  forma- 
tion is  set  free.  This  heat,  according  to  Berthelot,  is 
sufficient  to  increase  the  temperature  about  5000°  F.  (pro- 
vided the  pressure  be  kept  constant),  or  to  increase  the 
pressure  eleven  times  if  the  volume  be  kept  constant. 

Berthelot  likewise  found  that  liquid  acetylene,  as  trans- 
ported in  tanks  under  pressure,  would  explode  as  readily 
as  the  gas.  He  also  made  experiments  to  determine  if 
blows  or  shocks  would  cause  explosions  in  cylinders  of  the 
liquid,  and  he  found  that  a  shock  would  not  of  itself  start 
an  explosion,  but  that  when  steel  cylinders  of  the  liquid 
acetylene  were  smashed  the  blow  was  usually  followed  by 
an  explosion,  probably  produced  by  the  sparks  generated 
by  the  fridtion  of  the  pieces  of  broken  steel ;  the  sudden 
opening  of  a  stop-cock  may,  he  thinks,  cause  local  heating, 
and  thus  an  explosion. 

These  investigations  show  how  dangerous  acetylene  is 
when  stored  under  pressure  greater  than  that  of  the  at- 
mosphere. That  such  is  the  case  is  borne  out  by  the  fadl 
that  a  number  of  accidents,  accompanied  by  loss  of  life, 
have  occurred  where  it  has  been  used  under  such 
conditions. 

The  cost  per  hour  for  the  production  of  i6-candle  power 
of  light  in  New  York  is  as  follows : — 

Incandescent  eledlric  light I'o  cent. 

(Ordinary  4  ft.  burner  at  1*25 
dollars  per  1000  cubic  feet.  05     „ 
Welsbach   i"i4  ft.  burner  at 
I -25  dollars  per  1000  cub.  ft.  o'ly  „ 

I' Calcium    carbide,  converted 
into  gas  at  40  dollars  per 
ton,    to    replace    ordinary 
-    ...     .      .      burners       0-5     „ 

Calcium  carbide,  converted  in- 
to gas  at  19*30  dols.  per  ton, 
to  replace  Welsbach,  cost  of 
renewing  mantles  included  0*17  „ 


distribution. 


Paid  by  consumers  per  day,  500,000 

feet  at  1*25  dollars  per  1000  feet   ..  625*00  dollars. 
Cost  of  gas  in  holder  at  40  cents  per 

1000  feet 2oo'oo    „ 


Constant  daily  expenses,  together  with 
profit  of  gas 425-00    „ 

To  supply  the  consumers  with  the  same  amount  of  light 
with  the  flat-flame  burners  would  require  one-tenth  the 
volume  of  acetylene, — hence  50,000  cubic  feet  of  acetylene 
would  have  to  be  stored  in  the  holder  for  200  dollars  in 
order  that  there  might  be  the  same  amount  of  profit  for 
the  company.  This  50,000  feet  would  be  produced  by  5  tons 
of  carbide ;  hence  the  cost  of  i  ton  of  carbide,  together 
with  making  the  gas,  would  have  to  be  40  dollars  to  com- 
pete with  ordinary  gas  at  1*25  dollars  per  1000  feet  burned 
in  flat  flame  burners.  In  the  same  way  it  is  calculated 
that  to  compete  with  the  Welsbach  the  calcium  carbide 
must  be  supplied  and  converted  into  gas  at  about  ig'50 
dollars  per  ton. 

In  some  of  the  earlier  literature  on  acetylene,  it  was 
proposed  to  convert  eledtric-lighting  plants  into  plants  for 
the  production  of  acetylene,  and  thus  obtain  economic 
results.  This  could  not  be  done  economically,  for  only 
about  half  as  much  light  could  be  obtained  from  the 
acetylene  as  by  using  the  eledtricity  direct  for  incandescent 
lamps.  The  results  obtained  at  Spray  show  that  2  cubic 
feet  of  acetylene  could  be  produced  per  hour  per  electrical 
horse  power.  This  would  furnish  80  candle  power.  If 
the  eledricity  were  used  diredt  with  incandescent  lamps 
requiring  4i  watts  per  candle  power,  the  light  produced 
would  be  166  candle  power  per  electrical  horse  power,  or 
about  twice  as  much  light  as  would  be  produced  by  the 
acetylene.  To  be  as  cheap  an  illuminant,  therefore,  as 
electricity,  the  carbide  must  be  made  by  some  means,  say 
water  power,  where  the  cost  of  power  and  attendance  is 
much  less  than  at  the  eleClric  lighting  station.  It  has 
been  shown  that  for  equal  illumination  the  incandescent 
electric  light  costs  twice  as  much  as  gas,  when  the  latter 
is  burned  in  flat-flame  burners.  The  eleClric  light  has, 
however,  held  its  own  against  gas  on  account  of  its  su- 
perior qualities ;  that  it  has  done  so  at  a  higher  cost  to 
the  consumer  for  a  given  candle  power,  is  proof  that  other 
elements  enter  into  the  problem  of  artificial  lighting  as 
strongly  as  the  cost  of  a  given  amount  of  light.  From 
this  standpoint  it  may  be  argued  that  acetylene,  producing 
as  it  does  a  more  brilliant  light  than  any  now  used  for 
interior  lighting,  and  having  the  quality  of  showing  the 
complexion  in  life-like  tints,  will  have  its  own  field,  even 
should  it  be  the  most  costly  style  of  illumination. 

The  whole  situation  may  be  summed  up  by  saying  that 
each  system  of  lighting  has  its  own  field  of  usefulness, 
on  account  of  properties  peculiar  to  itself,  which  make  it 
more  desirable  than  the  others  for  certain  classes  of 
work. 


It  will  be  seen  from  this  table  that,  to  compete  with  an 
ordinary  illuminating  water-gas,  selling  at  i'25  dollars 
per  1000  feet,  the  carbide  would  have  to  be  furnished  to 
the  gas-company  and  converted  into  gas  for  40  dollars  per 
ton,  to  make  the  same  profit  and  to  be  as  economical  to 
the  consumer  as  ordinary  illuminating  gas  in  a  flat-flame 
burner.  To  be  as  economical  as  ordinary  gas  burned  in 
Welsbach  burners,  it  would  have  to  be  made  for  ig'so 
dollars  per  ton. 

The  figures  for  the  acetylene  are  obtained  in  the  fol- 
lowing way:— Assume  a  plant  which  is  furnishing  an 
illuminating  water-gas  at  1*25  dollars  per  1000  feet.  If 
this  plant  were  converted  to  an  acetylene  plant,  there  are 
certain  expenses — such  as  cost  of  distribution,  office  ex- 
penses, &c. — which  would  remain  the  same  :  these  con- 
stant expenses  would  be  practically  all,  except  the  cost  of 
making  and  storing  the  gas.  To  simplify  matters,  let  us 
consider  a  plant  of,  say,  500,000  feet  of  gas  per  diem. 
Then  we  have— 


CALCULATION     OF    THE     COEFFICIENTS    OF 

EXPANSION   OF    GASES    FOUNDED    ON 

MY  THEORY  OF  VALENCE.* 

By  JOACHIM  SPERBER. 

According  to  Gay-Lussac's  law  all  gases  and  vapours, 
mutatis  mutandis,  expand  equally  for  an  equal  rise  of  tem- 
perature, and  indeed  for  1°  by  0"O0366  of  their  original 
volume  at  0°. 

In  gases  of  equal  relative  heat  we  may  always  procetd 
from  volumes  in  which  1°  is  at  the  same  time  i  cal. 

The  relative  heat  of  air,  hydrogen,  oxygen,  and  nitrogen 
is  approximately  that  for  which  i  cubic  metre  is  in  the 
mean  0*30726;  the  relative  heats  of  chlorine  and  bromine 

*  A  Reprint  from  the  Zeitschrift  dnorg.  Chtmie. 


Cbbmical  News. 
Aug.  13,  i8q7. 


}   Report  of  the  Committee  on  Indexing  Chemical  Literature. 


75 


vapour  are  approximately  equal,  being  in  the  mean  o'388i2 
per  cubic  metre  in  the  average. 

Hence  jt  follows  that  in  the  former  gases  the  volume  is 
3'254  cubic  metres,  and  in  the  latter,  for  2-576  cubic  metres, 
1"  is  at  the  same  time  1  cal. 

The  author  gives  the  expansion  in  the  case  of  those 
elements  whose  dissociation-  and  combining-heats  have 
been  calculated. 

I.  Fluorine. — In  the  chemical  dissociation  of  fluorine  the 
amplitude  of  the  fluorine  atoms  is  extended  by  o'0266,  for 
which  a  dissociation-heat  of  87'3  cals.  per  gramme-atom 
is  needed. 

II.  Chlorine. — In  the  chemical  dissociation  of  chlorine 
the  amplitude  of  the  chlorine  atoms  is  extended  by  0'0i34 
if  a  dissociation-heat  of  44  cals.  per  gramme-atom  is  re- 
quired. 

III.  Bromine. — In  the  chemical  dissociation  of  bromine 
the  amplitude  of  the  bromine  atoms  is  extended  by  0*005, 
requiring  a  dissociation-heat  of  16*4  cals.  per  gramme- 
atom. 

IV.  Oxygen. — In  the  chemical  dissociation  of  oxygen 
the  amplitude  of  the  oxygen  atoms  is  extended  by  0005, 
requiring  a  dissociation-heat  of  83'g  cals.  per  equivalent, 
or  i67"8  calories  per  gramme-atom. 

The  expansions  of  oxygen  and  chlorine  are  inversely  as 
the  relative  heats  of  these  elements. 

The  expansions  of  the  amplitudes  of  the  atoms  of  these 
various  elements  per  calorie  coincide  up  to  the  sixth  deci- 
mal and  amount  to  a  mean  of  0*000304  (6).  This  number 
may  be  suitably  named  the  linear  atomistic  coefficient  of 
expansion. 

Dired^  determinations  have  yielded  0'00366,  as  is  well 
known. 

Our  computations  refer  purely  to  diatomic  gases,  in 
which  both  the  atomic  weights  and  the  molecular  weights 
are  the  weights  of  equal  volumes. 


FIFTEENTH    ANNUAL    REPORT 

OF    THE    COMMITTEE     ON     INDEXING 

CHEMICAL     LITERATURE.* 

The  Committee  on  Indexing  Chemical  Literature  pre- 
sents to  the  Chemical  Sedlion  its  Fifteenth  Annual 
Report,  covering  the  twelve  months  ending  August,  1897. 

Works  Published. 

"  Re-calculation  of  the  Atomic  Weights."  By  Frank 
Wigglesworth  Clarke.  New  edition,  revised  and 
enlarged.  Constants  of  Nature,  Part  V.  Smith- 
sonian  Miscellaneous  CoUedtions,  1075.  City  of 
Washington,  1897.     Pp*  v'* — 370'     8vo. 

'•  Index  to  the  Literature  of  the  Periodic  Law."  In  : 
"  Development  of  the  Periodic  Law."  By  F,  P. 
Venable.     Easton,  Pa.,  1896.     i2mo. 

"  Partial  Bibliography  of  Argon."  By  C.  Le  Roy  Parker. 
Accompanying  his  paper:  "  Our  Present  Knowledge 
of  Argon."  jf.  Am.  Chem.  Soc,  xix.,  124  (Feb., 
1897). 

"Bibliography   of  Agricultural   Chemistry  (American)." 
Bulletins    of    the    Office    of    Experiment    Stations, 
United  States  Department  of  Agriculture. 
In  our  Fourteenth  Annual   Report  the  following  cor- 

redlion  should  be  made  :  for  Bulletin  No.  9  read  Bulletin 

No.  19,  and  add  Bulletin  No.  27  (1896). 

A  card  index  to  Experiment-Station  Literature  is  issued 

by  the  Office  of  Experiment  Stations ;  this  is  sent  gratis 

to  all  the  Agricultural  Colleges  and  Experiment  Stations 

in  the  United  States,  and  is  sold  to  a  limited  number  of 

♦  Advance  proofs  from  the  Proceedings  0/ the  American  Association 
for  the  Advancement  of  Science,  vo\.%lvi,,  1897.    Communicated  by  , 
H.  CarringtoQ  Bolton.  ' 


individuals  and  institutions.     Eleven  thousand  cards  had 
been  distributed  prior  to  September,  1896. 

The   detailed   index   included   in   each  volume   of  the 

Experiment  Station  Record  contains  numerous  references 

to  chemical  articles  published  by  the  Experiment  Stations 

in  the  United  States  and  in  foreign  countries. 

"  Abstrafts   of  Chemical  Work  in  Agricultural  Science," 

published  in :  Experiment  Station  Record   issued  by 

the   Office    of    Experiment  Stations,    United  States 

Department  of  Agriculture. 

These  Abstrads  were  begun  in  vol.  i.,  No.  i  (September, 

1889).      Abstrads   of  foreign   investigations   were   added 

beginning  with  vol.  ii.,  No.  8  (March,  1891),  and  these 

have  been  included,  with  a  quite  rapid  growth  in  the  field 

covered,  up  to  the  present  time.     The  work  is  in  charge 

of  Dr.  E.  W.  Allen,  who  is  assisted  by  Mr.  W.  H.  Beal 

in  the  departments  of  fertilisers  and  soils,  and  by  the 

Committee  on  Abstradting  of  the  Association  of  Official 

Agricultural  Chemists. 

••  The  Review  of  American  Chemical  Research,"  edited 
by  Prof.  Arthur  A.  Noyes,  began  in   April,  1895,  arid 
formerly  published  in   the  Technology  Quarterly,  is 
continued  in  the  journal  of  the  American  Chemical 
Society. 
"  Periodicals  relating  to  Chemistry  and  Physics  "  in  the 
New  York  Public  Library  and  Columbia  University 
Library.     Bulletin  of  the  New  York  Public  Library 
Astor,  Lenox,  and  Tilden  Foundations.  Vol.  i.,  No. 6. 
June,  1897.     Page  152. 
A  very  convenient    check-list    compiled    with  biblio- 
graphical accuracy,  especially  useful  to  students  residing 
in  New  York  and  vicinity. 

"  Bibliography  of  the  Analysis  of  Chrome-iron  Ore, 
Ferro-chromium,  and  Chrome-steel."  By  S.  Rideal 
and  S.  Rosenblum.  Chem.  News,  vol.  Ixxiii.,  p.  2. 
(Jan.  3,  1896). 

"  A  Bibliography  of  the  Chemistry  of  Chlorophyll,"  by 
L.  Marchlewski,  accompanies  his  monograph  :  "  Die 
Chemie  des  Chlorophylls."  Hamburg  and  Leipzig. 
1895.    8vo. 

Reports  of  Progress. 

"A  Bibliography  of  the  Metals  of  the  Platinum  Group," 
1748 — 1896,  by  Professor  James  Lewis  Howe,  has 
been  completed,  and  after  examination  by  your  Com- 
mittee has  been  recommended  to  the  Smithsonian 
Institution  for  publication.  The  work  is  now  going 
through  the  press. 

"  A  Review  and  Bibliography  of  Metallic  Carbides,"  by  Mr. 
J.  A.  Mathews,  of  Columbia  University,  was  sub- 
mitted to  your  Committee,  and,  after  examination  by 
each  member,  the  MS.  was  returned  to  the  author  for 
minor  improvements.  The  suggestions  of  the  Com- 
mittee were  promptly  accepted  by  Mr.  Mathews,  and 
the  revised  work  has  been  recommended  to  the 
Smithsonian  Institution  for  publication. 

"  A  Bibliography  of  Basic  Slags,  Technical,  Analytical, 
and  Agricultural,"  has  been  completed  by  Karl  T. 
McElroy,  of  the  Division  of  Chemistry,  U.S.  Depart- 
ment of  Agriculture.  The  channel  of  publication 
has  not  been  determined. 

The  second  edition  of  the  "  Catalogue  of  Scientific  and 
Technical  Periodicals,"  1665— 1895,  by  Dr.  H.  Car- 
rington  Bolton,  is  entirely  printed,  but  publication  is 
deferred  owing  to  the  preparation  of  a  new  Library 
Check  List,  with  which  it  will  be  accompanied.  The 
new  edition  contains  8603  titles. 

"  A  Supplement  to  the  Seledl  Bibliography  of  Chemistry," 
1492 — 1896,  has  been  completed  by  Dr.  H.  Carrington 
Bolton,  who  has  presented  the  MS.  to  the  Smithsonian 
Institution.  This  Supplement  contains  about  9000 
titles,  including  many  chemical  dissertations,  and  is 
brought  down  tQ  the  en4  of  the  year  i8g6. 


76 


Space  Formula  for  Benzene, 


(Chemical  News, 
Aug.  13,  1897. 


Dr.  C.  H.  Joiiet  reports  his  "  Index  to  the  Literature  of 
Thorium"  nearly  finished. 

Dr.  F.  W.  Traphagen  reports  "  fair  progress "  on  his 
"  Index  to  the  Literature  of  Tantalum." 

Mr.  George  Wagner  reports  that  he  has  made  progress  on 
the  "  Bibliography  of  Oxygen." 

Mr.  H.  E.  Brown,  under  the  diredlion  of  Professor  A.  B. 
Prescott,  is  preparing  a  "  Bibliography  of  the  Con- 
stitution of  Morphine  and  Related  Alkaloids." 

Professor  William  Ripley  Nichols,  of  the  Massachusetts 
Institute  of  Technology,  at  the  time  of  his  death  left 
an  unfinished  "  Index  to  the  Literature  of  Carbonic 
Oxide";  the  MS.  was  taken  in  hand  by  Professor 
Augustus  H.  Gill,  of  the  same  institution,  who  has 
done  considerable  work  upon  it ;  he  now  reports  that 
he  is  not  in  a  position  to  finish  the  task,  and  he  is 
perfedtly  willing  to  relinquish  the  large  amount  of 
material  accumulated  to  anyone  who  would  under- 
take to  complete  it. 

Professor  Clement  W.  Andrews,  formerly  of  the  Massa- 
chusetts Institute  of  Technology,  and  now  Librarian 
of  the  John  Crerar  Library,  Chicago,  reports  that  he 
is  obliged  to  abandon  work  on  his  "  Index  to  the 
Literature  of  Milk,"  and  will  be  very  glad  to  turn  over 
the  material  to  anyone  who  cares  to  undertake  to 
complete  the  bibliography. 

It  has  always  been  the  aim  of  the  Committee  on 
Indexing  Chemical  Literature  to  prevent  duplication  of 
work,  but  failure  to  inform  the  Committee  of  work  in 
progress  may  defeat  this  undertaking.  An  announcement 
in  the  Fourteenth  Annual  Report,  of  certain  work  having 
been  nearly  completed,  surprised  a  chemist  in  another 
part  of  the  country,  and  has  led  to  the  abandonment  by 
the  latter  of  much  laborious  indexing. 

In  conclusion,  the  Committee  repeats  the  statement 
that  it  labours  to  encourage  individual  enterprise  in  che- 
mical bibliography,  and  to  record  in  the  annual  reports 
works  issued  and  works  in  progress. 

Address  correspondence  to  the  Chairman,  at  Cosmos 
Club,  Washington,  D.C. 

Committee  : — 

H.  Carrington  Bolton,  Chairman, 

F.  W.  Clarke, 

A.  R.  Leeds, 

A.  B.  Prescott, 

Alfred  Tuckerman, 

H.  W.  Wiley. 


PROCEEDINGS    OF    SOCIETIES. 

CHEMICAL  SOCIETY. 
Ordinary  Meeting,  June  lyth,  1897. 

Professor  Dewar,  F.R.S.,  President,  in  the  Chair. 

(Concluded  from  p.  70). 
•80.  "  On  a  Space  Formula  for  Benzene."  By  J.  Norman 
Collie,  Ph.D.,  F.R.S. 

In  this  formula  six  tetrahedra  (to  represent  the  six  car- 
bon atoms)  are  arranged  symmetrically  in  space  equi- 
distantly  from  a  common  centre,  and  so  that  they  would 
occupy  the  six  solid  angles  of  an  odtahedron.  They  are 
connedted  also  symmetrically  with  one  another  by  single 
linkings.  If  the  six  hydrogen  atoms  (of  benzene)  are  then 
arranged  symmetrically  on  these  tetrahedra,  it  will  be 
found  that  there  will  be  three  on  one  side  of  the  figure 
and  three  on  the  other  side. 

Movement  in  this  arrangement  might  take  place  in 
two  ways ;  a  movement  of  e^ch  tetr^hedroQ  about  its  own 


centre,  and  a  movement  of  each  tetrahedron  about  the 
centre  of  gravity  of  the  whole  mass. 

In  the  first  case,  simultaneous  rotational  movement  of 
each  tetrahedron  about  its  centre  would  bring  the  com- 
bined hydrogen  atoms  towards  the  centre  of  the  mass  in 
two  distinct  sets  ;  those  on  the  i,  3,  5  carbon  atoms  and 
those  on  the  2,  4,  6  carbon  atoms,  and  a  projeAion  of  this 
configuration  might  be  expressed  as  follows  : — 


In  the  second  case,  movement  about  the  common 
centre  would  alter  the  relative  positions  of  the  tetrahedra 
with  regard  to  one  another,  bringing  into  play  the  six  un- 
saturated points  of  attradtion  on  these  tetrahedra.  The 
projedtion  of  these  different  phases  can  be  represented  by 
the  formula  given  in  Fig.  i. 

This  space  formula  is  therefore  in  complete  accord 
with  that  of  Kekule  and  the  centric  formula,  and  shows 
how  they  are  mutually  convertible  the  one  into  the  other. 
It  also  shows  how  the  supposed  double  bindings  in  the 
Kekule  formula  shift  between  the  carbon  atoms,  thus 
rendering  two  orthochlorobenzenes  impossible.  But  it 
differs  from  both,  in  that  it  shows  how  there  may  be  two 
distindl  sets  of  hydrogen  atoms,  and  that  when  one  set  is 
inside  the  molecule,  the  other  set  is  outside  the  molecule. 

It  can  offer  an  explanation  also  of  the  fadt  that  when 
one  set  of  groups  is  present  in  a  benzenoid  compound, 
further  substitution  gives  ortho-  and  para-diderivatives ; 
whilst,  when  another  set  is  present,  on  further  substitu- 
tion meta-diderivatives  only  are  formed. 

When  chlorine  adts  on  nitrobenzene,  the  chief  produdl 
is  metachloronitrobenzene.  The  nitro-group  belongs  to  the 
group  that  favours  the  produdtion  of  meta-diderivatives. 
This  nitro-group.  being  in  a  sense  unsaturated,  might 
possess  a  certain  amount  of  "residual  affinity"  which 
would  be  sufficient  to  attradl  the  entering  chlorine  mole- 
cule, and  diredt  it  towards  the  hydrogen  atoms  that  come 
to  the  centre  at  the  same  moment  that  it  does  itself.  (See 
Fig.  2). 

On  the  other  hand,  in  the  case  of  chlorobenzene,  if 
nitric  acid  be  allowed  to  readt  with  it,  no  such  additive 
compound  would  be  produced,  and  the  attradtion  of  the 
three  hydrogen  atoms  attached  to  the  other  three  carbon 
atoms  might  just  be  sufficient  to  determine  its  readtion 
with  them.     (See  Fig.  3). 

Discussion. 

Professor  Tilden  thought  the  paper  a  valuable  contri- 
bution to  the  theory  of  the  construdtion  of  the  benzene 
molecule,  though  he  felt  doubtful  about  the  validity  of  the 
division  of  the  substituents  into  saturated  and  unsaturated, 
since  this  distindtion  was,  in  any  case,  not  a  sharp  one. 

Mr.  Sworn  considered  that  the  formula  proposed  did 
not  differ  materially  from  the  odtahedral  formula  of  Vidlor 
Meyer  and  others,  nor  did  the  explanation  by  the  law  of 
substitution  now  suggested  differ  substantially  from  one 
proposed  by  himself  in  a  paper  published  in  the  PhilO' 
sophical  Magazine. 

Dr.  Kipping  said  he  was  not  satisfied  with  the  conclu- 
sion that  three  hydrogen  atoms  in  benzene  occupy  different 
positions  to  the  other  three.  If  this  were  true  then  two 
monosubstitution  derivatives  become  possible.  From  the 
readiness  with  which  rings  are  formed  from  side  groups,  it 
would  appear  that  the  meta-position  corresponds  with  the 
ortho-position. 

Mr.  Friswell  said  that  the  ordinary  nitration  of 
toluene  gave  a  mixture  of  about  65  parts  of  orthonitro- 
toluene  and  35  of  paranitrotoluene,  or  very  nearly  2  to  i. 
In  conjundtion  with  Dr  .T.  A.  Lawson  he  had  endeavoured 


Cbbhical  News,  ) 
Aug.  13, 1897.     t 


Formation  of  Diacetanilide. 


77 


H  H 


First  phase. 


H         H 


H         H 


H         H 


H  H 


Centric  "      Kekule's 

formula.  T      Iformuia. 


Fig.  2. 


NpgClg 


paia. 


drtho. 


to  alter  these  proportions.  Every  possible  variation  of 
temperature  down  to  nitration  at  or  near  zero  or  as  high 
as  40°,  every  variation  of  nitrating  mixture  from  large 
proportions  of  sulphuric  acid  to  the  use  of  nitric  acid  alone, 
every  variation  in  the  order  and  rate  of  mixture,  the  nitra- 
tion of  toluene  in  which  paranitrotoluene  had  been  pre- 
viously dissolved,  had  been  tried.  Yet  no  important 
variation  of  the  proportions  of  the  two  produdts  had  been 
produced.  Mr.  A.  G.  Green  had  repeated  these  experi- 
ments, and  confirmed  them.  The  space  formula  now 
suggested  by  Dr.  Collie  afforded  an  explanation,  since 
there  were  two  orthohydrogen  atoms  during  the  rotation 
postulated  inside  the  ring,  and  only  one  para-hydrogen 
atom  in  that  condition.  He  had  long  considered  this 
problem,  and  he  had,  in  conjundtion  with  Mr.  C.  Mills, 
commenced  to  experiment  in  order  to  ascertain  whether 
the  results  might  not  be  due  to  the  existence  of  two  iso- 
meric toluenes. 

Professor  Collie,  in  reply,  pointed  out  that  the  space 
formula  for  benzene  which  he  had  proposed  was  neces- 
sarily similar  in  many  respedts  to  others,  notably  those  of 
Vaubel  and  Sachse  ;  but  the  point  on  which  he  wished  to 
lay  especial  stress  was,  that  there  were  two  sets  of  hydro- 
gen atoms,  and  that  when  one  set  was  inside  the  molecule 
the  other  set  was  outside. 

90.  "  Note  on  the  Formation  of  Diacetanilide."  By 
George  Young,  Ph  D. 

The  introdudtion  of  a  second  acetyl  group  into  acet- 
anilide  has  been  described  in  recent  years  by  several 
authors.  Kay  {Ber.,  1893,  xxvi.,  2853)  treated  acetanilide 
with  acetyl  chloride  at  170—180°  from  three  to  four 
hours.    Bistrzycki  and  Ulffers  {Ber.,  1894,  xxvii.,  91) 


heated   a   mixture   of  acetanilide  and  acetic  anhydride, 
under  pressure,  eight  to  ten  hours  at  200 — 205°.    Blacher 
{Ber.,    1895,  xxviii.,  2356)   boiled    sodio-acetanilide   sus- 
pended   in    xylene    with    acetic    anhydride.       Tassinari 
{Gazz.,  1894,  xxiv.,  i.,  61)  adted  with  acetyl  chloride  on 
sodio-acetanilide  suspended   in  benzene.      The   English 
and  German  abstradts  of  Tassinari's  paper  state  that  this 
author  also  prepared  diacetanilide  by  treatment  of  acet- 
anilide with  acetic  anhydride,  but  the  following  quotations 
from  the  original  paper  show  that  the  method  used  consisted 
in  boiling  a  mixture  of  acetanilide,  acetic  anhydride,  and 
sodium  acetate  on  a  reflux  apparatus  for  some  hours.     In 
the    introdudtion    to    his    paper,    Tassinari    makes    the 
general   statement,   "  le   diacidanilidi  si   formano   anche 
con  anidride  acetica  ed  acetato  sodico  a  ricadere."     It  is 
true  that  in  describing  the  preparation  of  diacetanilide, 
he  does  not  mention  sodium  acetate — "  Trattando  dell' 
acetanilide  con  anidride  acetica,  come  e  detto  sopra  per 
la   formanilide     .     .     .     ,"  but   the   passage   referred  to 
runs  :  "  Scaldando  a  ricadere  per  alcune  ore  un  misto  di 
formanilide,  anidride  acetica,  ed  acetata  sodico.     .     .     ." 
Further,  in  a  later  paper  {Gazz.,  1894,  xxiv.,  i.,  444),  in 
which  the  work  of  Bistrzycki  and  Uiffers  is  quoted,  no 
notice  is  taken  of  a  statement  by  these  authors  {loc.  cit.) 
that,  although  acetanilide  undergoes  some  change  when 
boiled  for  two  hours  with  acetic  anhydride,  they  were  un- 
able to  obtain  any  pure  produdt  from  the  readtion. 

The  introdudtion  of  the  second  acetyl  group  takes  place 
much  more  easily  than  might  be  imagined  from  the 
results  quoted.  If  acetanilide  be  boiled  with  two  to  three 
times  its  weight  of  acetic  anhydride  for  half  an  hour,  over 
75  per  cent  is  converted  into  the  diacetanilide,  which  may 


'8 


Stereoisomeric  Dt-derivatives  ot  Camphor. 


Cbkmical  ^bwb, 

Aug.  13, 1897. 


be  easily  purified  by  the  following  method : — The  cooled 
produdt  is  shaken  with  benzene  and  sodium  carbonate 
solution.  After  drying  over  calcium  chloride,  the  benzene 
solution  is  distilled  as  far  as  possible  on  the  water-bath, 
and  the  residue  treated  with  light  petroleum.  The  un- 
changed acetanilide  is  removed  by  filtration,  and  the 
filtrate  evaporated.  The  residue  solidifies  on  cooling  to 
a  crystalline  mass,  melting  at  37 — 38°.  A  single  re- 
crystallisation,  by  extradlion  with  cold  light  petroleum 
and  evaporation  of  the  extract,  is  sufficient  to  purify  it  for 
analysis,  when  it  melts  sharply  at  38°. 

0*1792  gave  0*4449  COa  and  0*1025  HjO.  €  =  67*71; 
H  =  6*35  per  cent. 

CfiHsNCCOCHsJa  requires  0  =  67*79;  H  =  6*2i  percent. 

Part  of  the  diacetanilide  formed  is  probably  hydrolysed 
by  the  treatment  with  sodium  carbonate  solution,  but  by 
working  with  not  too  large  quantities,  and  performing  the 
purification  as  rapidly  as  possible,  a  yield  equal  to  the 
weight  of  acetanilide  taken  may  easily  be  obtained. 

91.  "Derivatives  of  Phenetol  Azo-phenols.  By  J.  T. 
Hewitt,  M.A.,  D.Sc,  Ph.D.,  T.  S.  Moore,  and  A.  E. 
Pitt. 

One  of  the  authors  has  shown  (Ber.,  1895,  xxviii.,  799) 
that  certain  substitution  derivatives  of  benzeneazophenol 
can  form  addition  produds  with  half  a  molecule  of  water, 
differing  very  sharply  in  colour  and  other  physical  proper- 
ties from  the  corresponding  anhydrous  compounds.  In 
order  to  obtain  further  knowledge  of  this  subjed,  various 
series  of  substituted  benzeneazophenols  are  being  pre- 
pared and  examined.  This  communication  deals  with  ortho- 
and  para-phenol  azophenols,  C3H50*C6H4*N:N-C6H40H, 
the  examination  of  the  meta-derivative  being  deferred. 
When  a  paraoxyazo-compound  does  form  an  addition 
product  with  water,  the  addition  of  the  latter  can  be  most 
frequently  brought  about  by  dissolving  the  azo-compound 
in  benzene  and  precipitating  it  by  gaseous  hydrogen 
chloride  as  a  hydrochloride  of  the  general  formula, 
X  — N:N*C6H40H,HC1,  and  decomposing  this  with  water. 
Frequently  the  molecule  of  hydrogen  chloride  is  thus  re- 
placed by  a  half  molecule  of  water. 

Orthophenetolazophenol  was  prepared  according  to  the 
method  given  by  Jacobson  and  F.  Meyer  {Annalen,  1895, 
cclxxxvii.,  213).  The  melting-point  was  found  to  be  128° 
C.  (corr.),  Jacobson  gives  131°  C.  The  hydrochloride 
melted  between  124°  and  129"  C.  On  decomposition  with 
water,  the  azophenol  was  regenerated;  after  air  drying  it 
melted  at  127 — 128°.  It  may  be  assumed  that  no  water 
had  been  added.  In  order  to  further  charaderise  the  azo- 
phenol, the  two  following  derivatives  were  prepared. 

Orthophenetolazophenylbenzoate, — 

C2H50*C6H4*N:N*C6H40-COC6H5 ; 
light  scarlet  needles,  m.  p.  98°  (corr.).      Orthophenetol- 
azophenylbenzene  sulphonate, — 

C2H50-C6H4*N:N*C6H4*0*S02C6H5 ; 
brilliant  red  needles,  m.  p.  83°  (corr.). 

Paraphenetolazophenol  has  been  prepared  by  Riedel 
(D.  R.P.,  xlviii.,  453),  and  also  by  Jacobson  and  F.  Meyer 
{Ann.,  1895,  cclxxxvii.,  215).  The  former  gives  the  melting- 
point  as  104*5°  0.,  the  latter  as  125 — 126'.  The  method 
of  the  latter  chemists  was  used  to  prepare  the  compound. 
The  melting-point  was  found  to  be  125°  (corr.).  The 
hydrochloride  gave  no  very  sharp  melting  point,  beginning 
to  melt  at  131°,  fusion  not  being  complete  until  154°.  On 
treatment  with  water,  a  pale  yellow  powder  is  obtained 
melting  at  about  100°.  The  same  substance  may  also  be 
obtained  by  dissolving  phenetolazophenol  in  glacial  acetic 
acid,  adding  fuming  hydrochloric  acid,  and  pouring  into 
water.  After  careful  drying  in  air  the  substance  melted  at 
104 — 109°  C.  Apparently  this  substance  consists  of  equi- 
molecular  proportions  of  water  and  paraphenetolazo- 
phenol. 

Calc.  CuH„NaOa,HaO.  Found.  Me&n. 

C     ••     ••     64-62  65*10     64*49    64*39  64-68 

H    k^     ••      6*15  6*40      6*29      5*95  6*31 


The  following  derivatives  of  paraphenetolazophenol 
have  been  prepared. 

Paraphenetolazophenyl  acetate, — 

C2H50*C6H4*N:N  C6H4O  COCH3  ; 
yellow  leaflets,  m.  p.  n8°  (corr,).    Paraphenetolazophenyl 
benzoate,  C2H50*C6H4*N:N*C6H40-COC6H5  ;  small  red- 
dish brown  crystals,  m.  p.  126°  (corr.). 

Paraphenetulazophenylbenzene  sulphonate, — 
C2H50*C6H4*N:NC6H4*OS02C6H3 ; 
large  pale  yellow  plates,  m.  p.  104°  (corn). 

92.  "  S-Ketopinic  Acid  and  Camphoic  Acid."  By  W.  S. 
GiLLES  and  F.  F.  Renwick. 

In  the  description  first  given  of  ketopinic  acid  {cf.  Arm- 
strong, Trans.,  1896,  Ixix,,  1397),  it  was  stated  that  the 
acid  was  optically  inadtive,  even  when  prepared  by 
oxidising  the  most  adlive  chlorocamphydrene  (pinene 
hydrichloride)  obtainable.  As  it  was  a  matter  of  import- 
ance to  determine  whether  the  inaiftivity  was  an  inherent 
property  or  due  to  compensation,  the  authors  have  applied 
Pasteur's  method,  and  have  succeeded  in  separating  a 
dextrorotatory  modification  by  fradlionally  crystallising 
the  mixture  of  salts  obtained  by  combining  the  inactive 
acid  with  strychnine.  d-Ketopinic  acid  has  the  same 
melting-point  as  the  "inadive"  acid  from  which  it  is 
separated. 

In  their  previous  note  (Proc,  1897,  xiv.,  64)  the  authors 
have  stated  that  when  ketopinic  acid  is  oxidised  by  per- 
manganate, it  is  converted  into  a  tribasic  acid  resembling 
the  camphoic  acid  described  by  Marsh  and  Gardner;  they 
are  now  able  to  state  that  the  produdt  is  camphoic  acid, 
having  obtained  from  it  the  cis-  and  trans-camphopyric 
acids  and  camphopyric  anhydride  of  these  chemists. 

An  amount  of  camphoic  acid  equal  to  80  per  cent  of  the 
weight  of  the  acid  oxidised  may  be  obtained  by  boiling 
ketopinic  acid  with  a  solution  containing  50  per  cent  of 
nitric  acid  and  adding  small  quantities  of  stronger  acid 
(^=1*42)  from  time  to  time,  as  the  adtion  proceeds. 

The  authors  will  endeavour  to  ascertain  if  pinophanic 
and  camphoic  acids  also  exist  in  optically  adtive  forms,  and 
what  is  the  behaviour  of  adtive  ketopinic  acid  on  oxidation. 
Acids  which  are  probably  cis-  and  trans-  forms  of  pino- 
phanic acid  have  already  been  obtained. 

93.  "  Note  on  Stereoisomeric  Di-derivatives  of  Camphor, 
and  on  Nitrocamphor."     By  T.  M.  Lowry,  B.Sc. 

Having  learned  from  Dr.  Armstrong  that,  in  the  course 
of  his  early  studies  of  camphor  derivatives,  he  had  ob- 
served that  the  substances  obtained  on  the  one  hand  by 
chlorinating  bromocamphor  and  on  the  other  by 
brominating  chlorocamphor  are  apparently  different,  the 
author  has  submitted  the  two  produdts  to  examination. 

Brominated  chlorocamphor,  according  to  Cazeneuve, 
melts  at  51*5°.  The  author  finds  that,  on  warming  a 
mixture  of  chlorocamphor  and  bromine  and  once  crystal- 
lising the  produdt  from  spirit,  well-defined  crystals  are 
obtained  which  melt  at  53—55°  ;  on  analysis,  these  give 
results  showing  them  to  be  bromo-chlorocamphor.  By 
repeated  re-crystallisations  from  a  variety  of  solvents, 
this  produdt,  however,  may  be  resolved  into  two  fradtions, 
alike  in  composition,  but  widely  different  in  specific  rota- 
tory power.  The  less  soluble  produdl,  after  being  twenty, 
five  times  re-crystallised,  fused  at  61° ;  its  specific  rota- 
tory power  was  [a]D  =  16°.  The  more  soluble  fradlion— 
obtained  by  evaporating  the  mother  liquor,  distilling  the 
residue  with  steam,  and  re-crystallising  the  produdt  from 
dilute  spirit— fused  at  55°;  its  specific  rotatory  power 
was  [a]  =  63 -9°. 

On  diredlly  chlorinating  bromocamphor,  an  oil  was  ob- 
tained which  could  not  be  caused  to  crystallise;  but  a 
crystalline  chlorinated  bromocamphor  was  obtained  with- 
out difficulty  by  heating  bromocamphor  with  sulphury! 
chloride  at  130°.  After  being  twice  crystallised  from  spirit, 
the  produdl  fused  at  56°;  its  specific  rotatory  power  was 
[aJD  =  25*7''  instead  of  51° — the  value  observed  in  the  case 
of  the  corresponding  produdt  from  chlorocamphor.  As  in  the 


CRrMlCALNsWSil 

Aug.  13.  1897.      J 


Hexanaphihaiene  and  its  Derivatives* 


79 


former  case,  by  repeatedly  re-crystallising  this  produift,  a 
less  soluble  fradtion  was  separated  melting  at  61*5°,  the 
specific  rotatory  power  of  which  was  [ajo  =  I0'3° ;  the 
more  soluble  fraction  from  the  mother-liquor  had  the 
specific  rotatory  power  [a]  d  =  28'3°.  There  can  be  no 
doubt  that  the  two  products  examined  were  isomorphous 
mixtures  of  constituents  differing  slightly  in  solubility  but 
widely  in  specific  rotatory  power,  careful  study  of  the 
crystalline  properties  showing  the  constants  to  be  nearly 
identical  in  the  two  cases.  As  both  yield  nothing  but 
ordinary  chlorocamphor  on  redudlion,  it  follows  that,  in 
each  case,  the  apparently  simple  produdl  is  a  mixture  of 
the  two  stereoisomeric  ao-chlorobromocamphors  : — 


CsH, 


./^<- 


N, 


CO 


\co 


These  observations,  in  fadl,  undoubtedly  afford  the 
proof  hitherto  wanted,  that  in  the  ordinary  derivatives  of 
camphor  containing  halogens,  the  halogen  atoms  are  both 
associated  with  the  same  carbon  atom. 

A  careful  examination  both  of  ordinary  dibromocamphor 
and  of  nitrobromocamphor  has  also  been  made,  the  re- 
sult of  which  is  that  neither  of  these  is  resolvable  into  iso- 
morphous constituents. 

The  author  finds  that  when  nitrobromocamphor  is  re- 
duced by  means  of  an  alcoholic  solution  of  potash,  a 
nitrocamphor  is  obtained  which  has  the  properties  attri- 
buted by  Cazeneuve  to  that  prepared  from  nitrochloro- 
camphor;  the  substance  obtained  by  R.  Schiff  must  have 
been  impure.  By  the  adtion  of  bromine  on  nitrocamphor 
dissolved  in  acetic  acid,  bromonitrocamphor  is  reproduced 
— not  the  compound  C3oH43Br2N30n,  which,  according 
to  Schiff,  is  obtained  on  subjeding  the  potassium  salt  of 
nitrocamphor  to  the  adtion  of  bromine. 

Nitrocamphor  appears  to  be  a  birotatory  substance,  its 
rotatory  power  in  solution  diminishing  to  a  considerable 
extent  as  time  proceeds — thus,  a  solution  in  benzene  con- 
taining 10  per  cent  of  the  substance,  gave  as  initial  value 
[a]D  =  —  ii2'4°,  but  after  three  hours  — 1027°,  and  at  the 
expiry  of  twenty-two  hours,  when  the  rotatory  power  on 
longer  changed,  —  86*5°. 

A  further  observation  of  interest  has  been  made,  viz., 
that  when  a  solution  of  nitrocamphor  in  benzene  is 
evaporated  on  the  water-bath,  and  the  residue  is  further 
heated  during  about  an  hour,  a  produ(5t  is  obtained  which 
is  less  soluble  than  the  original  nitrocamphor,  and  which 
melts  at  igo°  instead  of  at  103°.  The  same  substance  is 
formed  on  heating  fused  nitrocamphor  slightly  above  its 
melting-point.  The  specific  rotatory  power  of  this  sub- 
stance  in  benzene  (a  5  per  cent  solution)  is  \_d\o  =  +187°, 
and  in  chloroform  -{-167°. 

94.  "  The  Interaction  of  Ethylene  Bichloride  and  Ethylic 
Sodiomalonate"  By  Bevan  Lean,  D.Sc,  B.A.,  and 
Frederic  H.  Lees. 

It  has  been  shown  by  Prof.  Perkin  that,  when  ethylene 
dibromide  is  adled  on  with  ethylic  sodiomalonate,  the 
chief  produ(ft  is  i :  i-ethylic  trimethylene  dicarboxylate 
(208—210°,  760  m.m.),  thus  : — 


CH 


»>C{C00Et)a+CHa(C00Et)a+2NaBr. 


In  a  later  paper,  he  has  shown  that  a  small  quantity  of 
an  oil  of  high  melting-point  is  formed,  viz.,  ethylic 
butanetetracarboxylate  (b.  p.  240°,  40  m.m.),  and  he  has 
represented  the  adlion  thus  :— 

2(C00Et)2CHNa-|-BrCH2'CH2Br  = 

=  (COOEt)2CH-CH2CH2-CH(COOEt)2-fNa2Br. 
In  later  papers,  he  has  shown  that  by  substituting 
ethylene  chloride  for  ethylene  bromide  the  yield  of  ethylic 
butanetetracarboxylate  can  be  materially  increased,  and 


it  has  been  proved  by  Bone  and  Perkin  that  the  adtion  is 
represented  by  the  equation — 

(COOEt)2CH2+92*>C(COOEt)2  = 
CHj     o 

=  (COOEt)2CH'CH2-CHa-CH(CO0Et)a. 

fi  a 

The  authors  now  show  that  at  the  same  time  small 
quantities  of  ethylic  butanetricar  boxy  late, — 

(COOEt)2CH-CH2-CH2-CH2-COOEt 

(b.  p.  200 — 205°,  40  m.m.)  and  ethylic  adipate  (b.  p.  245°, 
760  m.m.)  are  formed.  They  attribute  the  formation  of 
these  two  substances  to  the  adlion  of  sodium  ethoxide  (or 
perhaps  sodium  hydroxide,  since  the  materials  cannot  be 
entirely  free  from  moisture)  upon  ethylic  butanetetra- 
carboxylate. It  cannot  be  doubted  that  a  similar  adlion 
is  of  frequent  occurrence,  in  greater  or  lesser  degree, 
whenever  substances  containing  two  alkylic  carboxylic 
groups  attached  to  one  carbon  atom  are  treated  with 
haloid  compounds  in  the  presence  of  sodium  ethoxide. 
The  following  derivatives  have  been  obtained  from  ethylic 
butanetricarboxylic  acid.  Ethylic  a-ethylbutanetricar- 
box)late,  (C00Et)2CEfCH2-CH2-CH2C00Et,  a  colour- 
less oil,  b.  p.  200 — 202°,  32  m.m.  Montemartini  {Abitr., 
1897,  Ixxii.,  ig)  has  also  prepared  it ;  he  gives  the  b.  p. 
205 — 208°  at  35  m.m.  a- Ethylbutanetricarboxylic  acid, 
(C00H)2CEfCH2CH2-CH2-C00H,  white  crystals,  m.  p. 
155 — 158°.  Montemartini  describes  it  as  an  oil.  a-EthyU 
adipic  acid,  COOH-CHEfCH2-CH2;CH2-COOH,  white 
crystals,  m.  p.  48 — 50°  (Montemartini,  46—49°). 

95.  Hexanaphthene  and  its  Derivatives.^'  Preliminary 
Note.    By  Emily  C.  Fortey,  B.Sc. 

In  view  of  work  now  being  carried  on  with  respedt  to 
the  naphthenes  (Markownikoff,  Ber.,  1897,  xxx.,  974, 
1211,  &c. ;  Zelinsky,  Ber,,  1897,  xxx.,  387,  1532),  the 
author  wishes  to  give  a  short  account  of  some  results,  as 
yet  incomplete,  on  hexanaphthene  and  its  derivatives. 

The  substance  was  obtained  from  American  light  petro- 
leum by  fradional  distillation  with  the  aid  of  a  long 
fradlionating  column  made  by  Professor  Sydney  Young, 
and  precisely  similar  to  the  one  described  by  him 
(Chemical  News,  1895,  Ixxi.,  177).  Benzene  and  toluene 
were  removed  by  prolonged  treatment  with  a  mixture  of 
strong  nitric  and  sulphuric  acids.  The  hydrocarbon 
finally  obtained  (after  33  distillations)  was  not  quite  free 
from  paraffins;  but  the  purest  fradtion  which  boiled  at 
8055 — 8o'65°,  and  had  the  specific  gravity  07722  at  o7o°, 
gave,  on  analysis,  the  following  result  as  the  mean  of 
three  determinations: — 0,85*23;  H,  14*60.  Calculated 
for  C6H12  : — C,  85*72;  H,  14*28.  The  liquid  boiling 
within  0-4  of  a  degree  was  chlorinated  by  means  of  a 
current  of  chlorine  in  presence  of  iron,  and  a  mixture  of 
di-,  tri-,  and  tetrachlorhexanaphthene  was  obtained.  By 
the  adtion  of  alcoholic  potash  on  the  fradtion  boiling  at 
135 — 140°  under  a  pressure  of  30  m.m.,  consisting  chiefly 
of  trichlor-hexanaphthene,  hydrochloric  acid  was  elimi- 
nated, and  the  formation  of  a  small  quantity  of  benzene 
was  proved  by  nitrating  it  and  reducing  the  nitrobenzene 
to  aniline,  which  gave  the  charadleristic  colouration  with 
bleaching-powder  solution.  Benzene  having  thus  been 
obtained  from  hexanaphthene,  the  identity  of  the  latter 
with  hexamethylene  is  no  longer  questionable. 

A  small  quantity  of  benzene  hydrochloride,  CeH^CI, 
was  also  obtained  by  the  adtion  of  alcoholic  potash  on 
trichlorhexanaphthene.  It  boiled  at  135 — 140°,  and  an 
analysis  gave  the  following  result  :—C,  63*20;  H,  5*91; 
CI,  30*36.  Calculated  for  C3H7CI :— C,  62*93  ;  H,  612 ; 
CI,  30*95.  Hexanaphthene,  when  heated  with  fuming 
nitric  acid,  was  found  to  be  oxidised  to  adipic  acid,  as 
stated  by  Markownikoff  {Ber.,  1897,  xxx.,  975).  As  both 
this  chemist  and  Zelinsky  appear  to  have  obtained  methyl 
pentamethylene  by  the  adlion  of  hydriodic  acid  on  deriva- 
tives of  hexanaphthene  {Ber,,  1897,  xxx.,  387,  1214),  it 
became  of  interest  to  see  whether  the  hydrocarbon  itself 


8o 


Mineral  Oils  and  their  By-products. 


Chbhical  NbW8, 

Aug.  13,  1897. 


would  undergo  isomeric  change  under  similar  conditions. 
Hexanaphthene  boiling  at  8o"o— 8o*i°  was  therefore 
heated  in  a  sealed  tube  with  about  five  times  its  volume 
of  hydriodic  acid,  sp.  gr.  1*96,  and  a  little  amorphous 
phosphorus.  The  tube  was  heated  to  about  160°  for  six 
hours,  from  250°  to  270°  for  three  hours,  and  was  main- 
tained at  about  250°  for  four  hours  longer.  The  hydro- 
carbon, after  being  washed  and  dried,  boiled  almost 
constantly  at  80°,  showing  that  it  was  unchanged  hexa- 
methylene. 

Zelinsky  has  found  that  methylhexamethylene  is  con- 
verted into  dimethylpentamethylene  by  heating  with 
hydriodic  acid  {Ber.,  1897,  "^x.,  1532);  it  is  therefore  in- 
teresting to  note  that  hexamethylene  itself  appears  to  be 
much  more  stable  than  its  derivatives. 

It  is  hoped  to  obtain  a  fresh  supply  of  the  substance  by 
the  fratftional  distillation  of  Galician  petroleum,  when  the 
experiments  will  be  continued. 


NOTICES  OF  BOOKS. 


A  Practical  Treatise  on  Mineral  Oils  and  their  By-products  ; 

including   a   Short   History  of  the   Scotch   Shale   Oil 

Industry,  the  Geological  and  Geographical  Distribution 

of  Scotch  Shales,  Recovery  of  Acid  and  Soda  used  in 

Oil-refining,  and  a  List  of  Patents  relative  to  Apparatus 

and  Processes  for  obtaining  and  refining  Mineral  Oils. 

By  Iltyd   I.    Redwood,   Member  of  the   Society  of 

Chemical  Industry  (England).    London  :  E.  and  F.  N. 

Spon,  Lim.,    125,    Strand.      New    York:    Spon    and 

Chamberlain.     1897. 

Mr.  Iltyd  I.  Redwood  merits  the   gratitude    of   the 

chemico-technical  world  for  his  comprehensive  work,  the 

value  of  which  is  enhanced  by  the  portrait  of  the  late 

James  Young,  the  founder  of  the  Scottish  mineral  oil 

industry. 

The  first  chapter  treats  of  the  history  of  the  trade. 
James  Young  was  what  is  called  a  "  self-made  man," 
He  became  demonstrator  and  assistant  to  Professor 
Graham,  and  amidst  many  difificulties  laid  the  foundation 
of  the  new  manufadlure.  The  famous  Bathgate  Oil-works 
were  eredted  in  1851,  and  after  many  ups  and  downs  have 
reached  their  present  position. 

Mr.  Redwood  foretells  that  unless  a  unanimous  and 
harmonious  combination  of  the  Companies  soon  takes 
place,  we  "  shall  in  a  few  years  be  left  to  mourn  the  loss 
of  one  of  Scotland's  most  important  industries." 

The  true  shales  are  confined  to  a  distridt  extending 
12  miles  north  and  south  by  about  25  miles  east  and 
west.  They  lie  in  the  calciferous  sandstone  series,  lying 
between  the  Mountain  and  the  Buriehouse  limestones. 

Shale  is  distinguished  from  coal  by  the  lack  of  the  in- 
tense blackness  of  the  latter  mineral ;  it  is  less  easily 
broken,  and  then  displays  a  conchoidal  fra£i:ure. 

The  proportions  of  crude  oil  yielded  by  the  mineral 
vary  in  different  localities.  Thus  the  Denbrae  shale 
yields  lO'go  gallons  of  crude  oil  per  ton,  whilst  the  true 
Boghead  mineral  yields  from  85  to  128  gallons  and  the 
methyl  brown  coal  from  65  to  90  gallons.  A  large  yield 
of  crude  oil  is  not  always  a  proof  of  high  value,  since  a 
high  yield  of  oil  is  often  accompanied  by  a  low  per- 
centage of  paraffin  wax  and  an  abundance  of  lubricating 
oils  of  low  specific  gravity. 

We  learn  that  mineral  oils  alike  in  specific  gravity 
often  vary  greatly  in  viscosity.  Hence  consumers  prefer 
to  buy  oils  by  the  viscosity  test  rather  than  by  specific 
gravity.  Still  it  is  not  safe  to  rely  exclusively  upon  vis- 
cosity. The  consumer  is  therefore  recommended  to  have 
the  cold  test  and  the  viscosity  of  samples  both  carefully 
ascertained.  The  relation  between  these  two  sets  of  data 
is  shown  in  a  table  given  on  p.  221.  Further  tables 
(p.  225)  show  the  melting-points  of  mixtures  of  wax  and 


stearine,  which  latter  substance  reduces  the  melting-point 
of  the  mixture  below  that  of  either  of  the  ingredients. 

We  regret  to  find  the  un-English  orthography  "  vise  " 
for  "  vice  "  adopted  in  the  chapter  on  the  purification  of 
crude  oil. 

A  very  important  feature  of  this  work  is  the  catalogue 
of  patents  and  list  of  patentees.  Perhaps  we  may  be 
permitted  to  regret  the  number  of  patents  which  form  one 
of  the  difficulties  of  the  shale-oil  trade. 


The  Analysis  of  Food  and  Drugs.  Part  I. — Milk  and 
Milk-produds.  By  T.  H.  Pearmain  and  C.  G,  Moor, 
M.A.  (Cantab.).  Pp.  132.  London:  Bailliere,  Tindall, 
and  Cox.     1897. 

As  this  work  may  run  to  some  800  or  900  pages,  it  has 
been  decided  to  bring  it  out  in  several  parts,  so  that  each 
portion  may  be  as  complete  as  possible  and  contain  all 
the  latest  information.  Each  part  will  be  complete  in 
itself,  and  will  have  its  own  index,  while  a  general  index 
will  be  issued  with  the  last  part. 

The  chief  need  at  the  present  time  is  the  formation  of 
standards  to  which  the  various  articles  of  food  should 
conform,  especially  in  the  case  of  milk,  one  of  the  most 
important  and  universal  foods  we  have. 

It  is  to  the  analysis  and  examination  of  milk  and  milk- 
products  that  this  part  is  devoted.  Milk,  which  has  been 
described  by  a  well-known  dodor  as  a  solid  food,  is  the 
only  article  occurring  in  Nature  which  combines  in  the 
right  proportions  all  the  necessary  elements  requisite  to 
secure  proper  nutrition,  but  it  is  too  voluminous  to  serve 
as  the  sole  food  of  adults  :  it  is  to  prevent  this  proportion 
being  upset  by  the  interference  of  the  milk-seller  that  has 
brought  milk  analysis  into  the  prominent  position  it  now 
holds,  and  renders  necessary  the  small  army  of  inspedlors 
who  are  constantly  on  the  look-out  for  adulteration. 

For  our  knowledge  of  the  composition  of  milk  we  are 
indebted,  in  this  country,  mainly  to  the  elaborate  and  pro- 
longed researches  of  Adams,  Bell,  Hehner,  Stokes,  and 
others.  It  is  found  that  genuine  cow's  milk  does  not  nor- 
mally differ  much  from  the  typical  analysis  here  given;  it  is 
on  the  rarest  occasions  that  there  is  less  than  3 '5  percent 
of  fat  present,  while  the  average  is  4  per  cent,  and  the 
solids-not-fat  may  be  taken  as  8'5  per  cent. 

It  is  not  surprising  that  the  adulteration  of  milk  to  a 
certain  degree  is  so  universal,  when  in  most  cases  20  per 
cent  of  water,  or  30  per  cent  of  skimmed  milk,  may  be 
added  without  the  resulting  mixture  falling  below  the 
present  standard. 

The  comparison  of  many  thousands  of  samples  a  year, 
for  the  six  years  1890-5,  shows  a  regular  steady  rate  of 
adulteration  of  about  12  per  cent,  and  the  authors  con- 
sider that  "it  is  not  too  much  to  say  that  the  disgraceful 
state  of  the  milk  trade  in  this  country  is  fostered,  if  not 
adlually  caused,"  by  the  ridiculously  low  standard  adopted 
by  the  Laboratory  of  the  Inland  Revenue  Department,  "by 
which,  of  course,  analysts  are  compelled  to  abide,  or  take 
the  risk  of  being  over-ruled  by  the  referees,  who  are 
thought  to  be  infallible  in  the  eyes  of  some  magistrates," 

There  are  several  different  methods  of  determining  the 
fat,  such  as  the  mechanical  methods,  and  simple  extraction 
with  a  solvent  of  the  dried  milk  by  Bell's,  Adams's,  or 
Macfarlane's  method ;  or  extradtion  of  the  fat  by  ether, 
after  destroying  the  casein  by  acid.  All  these  methods, 
as  well  as  those  for  the  estimation  of  proteids,  are  fully 
described  in  these  pages. 

The  most  commonly  used  preservatives  to  be  found  in 
milk  are  borax,  formaldehyd,  salicylic  acid,  and  potassium 
chromate,  and  there  is  no  doubt  that  formaldehyd,  or 
formalin, — by  which  name  it  is  also  known, — being,  it  is 
alleged,  the  most  effedive,  will,  when  it  becomes  more 
generally  known,  supersede  boric  acid  as  a  preservative. 
Two  or  three  drops  of  formalin  in  a  pint  of  milk  are  said 
to  keep  it  fresh  for  several  days,  and  the  addition  of  o  05 
per  cent  should  preserve  milk  for  months. 


^rug'^a'^rs"?"'}  Relations  between  Melting-points  and  Latent  Heats  of  Fusion, 


8i 


Potassium  chromate  is  not  known  as  a  milk  preservative 
in  this  country,  but  it  is  stated  to  be  used  on  the 
Continent. 

Milk  contains,  as  a  rule,  a  large  number  of  badleria,  for 
the  most  part  derived  from  the  external  conditions  and 
surroundings  of  the  cow ;  the  numbers  may  even  run  so 
high  as  three  or  more  millions  per  c.c. ;  and  as  many  of 
these,  which  are  capable  of  causing  disease,  do  so  by 
producing  toxic  decomposition  produdls,  which  is  greatly 
increased  by  a  rise  of  temperature,  it  is  essential  that  the 
very  greatest  care  should  be  taken  to  keep  the  temperature 
as  low  as  possible,  from  the  time  when  the  milk  is  drawn 
to  the  time  when  it  is  consumed  or  cooked.  There  is 
little  doubt  that  the  great  mortality  among  young  children 
from  intestinal  tuberculosis,  is  due  to  the  presence  of 
the  tubercle  bacillus  in  the  milk  used. 

The  sterilisation  of  milk  is  a  most  important  subjedl, 
and  we  are  sorry  to  see  that  it  is  very  lightly  passed  over 
in  this  volume ;  it  is  of  course  very  necessary  to  have 
everything  connedted  with  the  milk  supply  scrupulously 
clean,  but  it  is  also  necessary  to  have  some  regular 
recognised  process  by  which  the  ubiquitous  Bacillus  tuber- 
culosis can  be  killed  instead  of  remaining  to  breed  in  the 
milk.  Pasteurisation  is  coming  widely  into  use  on  the 
Continent,  and  we  should  be  glad  to  hear  of  its  general 
adoption  in  this  country. 

The  authors  are  to  be  congratulated  on  having  produced 
a  most  useful  and  readable  book,  and  we  can  only  hope 
the  parts  yet  to  come  will  be  worthy  of  Part  I. 


Monopolies  by  Patents,  and  the  Statutable  Remedies 
available  to  the  Public.  By  J.  W.  Gordon,  of  the 
Middle  Temple,  Barrister-at-Law.  Pp.  300.  London  : 
Stevens  and  Sons,  Lim.     1897. 

In  his  Preface  the  author  explains  his  reason  for  taking 
the  word  "  Monopoly"  for  the  purpose  of  the  title  of  this 
book.  The  word  Monopoly,  as  now  generally  accepted, 
no  longer  has  the  meaning  in  law  that  it  had  in  the  time 
of  Blackburn  ;  want  of  a  better  one  is  the  reason  of  the 
present  title  used  in  the  now-forgotten  sense  which  it 
formerly  had,  a  sense  in  which  it  implies  that  not  a  single 
individual  must  be  prevented  from  freedom  to  follow  any 
lawful  trade. 

The  Patent  Law  took  its  rise  from  the  time  of  Queen 
Elizabeth,  when,  owing  to  the  interference  caused  to 
lawful  trade  by  the  large  number  of  monopolies  she  had 
granted,  a  readlion  was  produced  in  the  public  mind, 
which  might  have  resulted  in  a  political  convulsion  had 
she  not  afforded  some  relief  by  recalling  a  few  of  the 
most  iniquitous  of  the  monopolies  she  had  granted. 

The  law,  which  has  since  become  the  law  of  England 
and  the  Colonies,  besides  that  of  many  foreign  States, 
was  laid  down  in  the  year  1602.  It  was  some  years, 
however,  before  popular  feeling  was  satisfied  with  the 
adtion  taken  by  King  James  II.  One  circumstance,  how- 
ever, which  helped  to  set  the  public  mind  at  rest  was  the 
publication  of  the  King's  Book  of  Bounty,  a  volume  re- 
markable for  its  career,  and  which  is  reprinted  in 
facsimile  as  a  part  of  this  work  in  Appendix  I. 

In  1621  the  grievance  had  again  assumed  serious  pro- 
portions, and  an  Adt  was  passed  adtually  comprising  a 
declaration  the  King  had  made  some  years  previously  in 
a  moment  of  candour.  The  fourth  sedtion  of  this  Adl  was 
considered  of  great  importance  in  protedting  the  public 
against  monopolies  ;  nothing  is  omitted  which  could  make 
proceedings  easy  for  an  aggrieved  person  in  assertion  of 
his  rights;  in  fadt,  it  might  be  considered  as  the  utmost 
Parliament  could  do  to  protedt  the  weak  against  the 
strong.  The  growing  tendency  in  our  own  times  of 
patentees  to  threaten  legal  proceedings  against  all  and 
sundry,  has  given  patents  a  new  and  formidable  charadler. 
The  interests  of  the  public  as  against  that  of  the  patentee 
is  a  matter  of  great  and  growing  importance,  and  in 
which  vast  interests  are  involved. 


The  power  to  seize  infringing  goods  is  no  longer  in- 
cluded in  a  patent  grant,  but  it  is  at  the  present  day  a 
common  form  of  pleading  to  ask  for  the  giving  up  of  such 
goods,  as  part  of  the  damages  asked  for,  and  the  Courts 
do  not  shrink  from  allowing  this  in  certain  cases:  it  is  a 
recent  innovation,  dating  from  the  year  1846,  and  the 
author  considers  that  it  arises  from  what  are,  it  is  con- 
tended, insufficient  authorities.  The  earliest  report  in 
which  the  author  has  been  able  to  find  an  order  for 
destrudtion  is  in  1864,  but  there  seems  to  have  been  some 
confusion  in  its  drawing  up.  But  in  Tangye  v.  Stott,  in 
1866,  the  defendant  had  the  option  of  giving  up  or 
destroying  the  incriminating  goods,  so  that  it  does  not 
appear  to  be  definitely  recognised  that  the  property  in 
them  may  pass  to  the  patentee. 

The  celebrated  Case  of  Monopolies,  which  the  author 
considers  to  be  one  of  the  most  interesting  reports  in  the 
English  Law  Books,  is  here,  and  now  for  the  first  time  col- 
ledled  and  published  in  complete  form.  Considered  alto- 
gether, the  author  thinks  "  it  is  not  too  much  to  say  that  in 
the  whole  of  legal  history  there  is  no  other  deliverance  in 
any  tongue  which  has  proved  to  be  so  fruitful  of  results, 
nor  any  which  has  contributeimore  to  the  advancement 
of  society  in  modern  times." 

The  book  cannot  fail  to  be  of  great  interest  to  those 
whose  minds  are  cast  in  a  legal  mould,  and  it  will  un- 
doubtedly be  of  great  service  to  those  whose  business 
comes  within  its  scope.  Besides  an  excellent  general 
Index,  there  are  19  pages  of  Cases  which  are  referred  to 
in  the  work,  also  carefully  indexed. 


CORRESPONDENCE. 

RELATIONS  BETWEEN  MELTING-POINTS  AND 
LATENT    HEATS    OF    FUSION.      , 

To  the  Editor  of  the  Chemical  News. 
Sir, — In  the  Chemical  News  of  June  ii  (vol.  Ixxv.,  p. 
278)  there  appeared  a  paper  by  Dr.  Joseph  W.  Richards 
dealing  with  relations  existing  between  the  absolute 
melting  points  (T)  and  the  latent  heats  of  fusion  (L)  of  the 
metals.  Dr.  Richards,  in  1893,  announced  that  the  latent 
heats  of  the  metals  bears  a  simple  ratio  to  the  heat  required 
to  raise  the  metal  from  the  absolute  zero  to  its  melting- 
point. 

In  June,  1895,  in  a  short  paper  I  forwarded  to  the 
Chemical  Society,  I  proposed  this  relation,  which  is 
pradlically  the  same  as  that  of  Dr.  Richards : — "  That 
where  the  valency  is  the  same,  the  absolute  temperature, 

L 
T,  of  the  melting-point  is  proportional  to  the  quantity  g; 

L  being  the  latent  heat  of  fusion,  and  S  being  the  specific 
heat  which  has  to  be  treated  as  a  constant.  The  quantity 
L 

c-  I  termed  the  temperature  equivalent  of  fusion.  Ex- 
pressed in  this  way  the  numerical  agreement  was  very 
striking. 

Dr.  Richards  does  not  include  the  non-metals  in  ex- 
pressing his  relation ;  but  between  bromine  and  iodine 
there  is  an  exadt  agreement,  although  the  number  obtained 
from  these  elements  does  not  tally  with  that  given  by 
sodium,  potassium,  and  silver — metallic  monovalent  ele- 
ments— but  is  almost  exadtly  the  number  given  by  the 
latter. 

This  relation  of  mine  was  proposed  as  a  corol- 
lary to  a  relation  brought  forward  by  Mr.  Holland 
Crompton  before  the  Chemical  Society,  in  April  or  May, 

1895,  when  he  proposed  the  relation  =  K  V;    A 

being  the  atomic  weight,  V  the  valency,  and  K  a  constant. 
Previous  to  this  (in  May  or  June,  1895),  ^  ^^^  "^^^^  ^ 


82 


Chemical  Notices  from  Foreign  Sources, 


t  Chemical  News, 
I      Aug.  13,  l»97. 


paper  before  the   Physical  Society,  in  which   I  brought 
forward  this  relation,^ 


{^  +  l+> 


constant, 


as  holding  between  the  members  of  any  family  in  the 
periodic  classification  of  the  elements  ;  a  being  the  mean 
coefficient  of  expansion  between  T  and  —273°.  The 
values  thus  found  were  satisfadtory,  but  the  argument 
following  which  the  relation  was  obtained  was  received 
with  considerable  adverse  comment.  This  relation,  com- 
bined with  that  of  Mr.  Holland  Crompton,  mentioned 
above,  leads  to  these  relations,  with  the  same  restri(5tion 
as  before : — 

T  a      =     constant. 

L 

_a      =     constant. 
S 

The  calculated  values  of  these  quantities  were  confirm- 
atory of  the  truth  of  the  relations. 
At  that  time  I  had  not  seen  Pidtet's  rule, — 


■»^  = 


constant ; 


V  being  the  atomic  volume  of  the  element  in  question. 
Now,  i f  T  a  =  constant  for  the  members  of  a   periodic 

family,  and  also  Ta  i  /  V  =  constant    generally,   then 

3  /" —  ^ 

must   i  /Vbe  constant  for  the  members  of  a  periodic 

family. 

Dr.  Richards  concludes  his  paper  by  showing  that,  by 
combining  his  relation  with   Pidet's  rule,   the  relation 

L  =  2*1  T  =  — ~ —  is  obtained.     On  exadly  the  same 

{grounds,  by  combining  my  relation  T  a  =  constant  with 

Piftet's  rule,  we  obtain  the  relation  L  =  2t  T  =  . 

a 

This  relation,  as  before,  being  restrided  to  members  of 

the  same  periodic  family. 

Dr.  Richards,  in  his  paper,  concludes  with  calculating 
certain  unknown  latent  heats.  For  one  of  these  (thallium) 
he  gives  the  value  5-8 ;  this  has  been  determined  by  Messrs. 
Neville  and  Heycock — unless  my  memory  misleads  me — 
to  be  5*1. 

Dr.  Richards  quotes  the  latent  heat  of  copper  as  43  ; 
this  quantity  was  not  available  when  I  read  my  paper 
before  the  Physical  Society ;  I  stated  then  that  a  value  of 
about  40  would  bring  that  element  into  line  with  its  fellow 
members  in  its  periodic  relationships. 

I  regret  that  I  am  unable  to  quote  any  actual  figures, 
but  placed  as  I  am — on  a  sugar  estate  some  distance  from 
a  town — no  data  are  available  for  me. 

A  short  abstradt  of  my  paper  appeared  in  the  Chemical 
News  (vol.  Ixxi.,  p.  303).  The  Physical  Society  did  not 
think  fit  to  publish  it  in  their  Proceedings. 

In  conclusion,  I  wish  to  say  that  what  I  have  written 
is  in  a  friendly  spirit,  and  that  I  have  no  desire  to  break  a 
lance  with  so  redoubtable  an  antagonist  as  Dr.  Richards. 
— I  am,  &c., 

Noel  Deerr. 

The  Laboratory, 

Plantation,  Windsor  Forest, 

West  Coast,  Demerara. 


On  Cafetannic  Acid. — P.  Cazeneuve  and  M.  Haddon. 
— Recent  researches  based  on  the  adtion  of  phenylhydra- 
zine,  either  on  cafetannic  itself  or  on  the  sugar  formed  by 
its  splitting  up,  show  us  that  the  formula  adopted  for  cafe- 
tannic acid  is  entirely  wrong,  and  that  the  sugar  formed 
is  a  new  sugar,  which  cannot  be  confounded  with  manni- 
tane  or  with  any  known  sugar. — jfournal  de  Pharmacie  et 
Chetnte,  vi.,  No.  2. 


CHEMICAL 


NOTICES  FROM 
SOURCES. 


FOREIGN 


Note.— All  degrees  of  temperature  are  Centigrade  unless  otherwise 
expressed. 

jfournal  de  Pharmacie  et  Chemie. 
Series  6,  vol  v.,  No.  12. 

Aftion  of  Sodium  on  Albumenoid  Matters.  —  E. 
Lepinois. — The  halogen  proteids  of  Blum  and  the  iodised 
albumen  of  Renault  are  very  complex  and  variable  in 
their  composition  and  their  adion  on  organisms.  The 
author  has  therefore  diredled  his  endeavours  to  producing 
a  compound  always  identical  and  whose  composition  is 
well  known  :  for  this  purpose  he  used  an  aqueous  solution 
of  iodine,  and  let  it  adt  in  the  cold,  so  as  to  avoid  violent 
readtions.  He  has  worked  on  casein  as  well  as  albumen. 
The  experiments  on  pure  casein  were  unsatisfadtory 
owing  to  its  feeble  solubility,  so  he  had  recourse  to  milk 
itself,  and  to  this  he  added  a  solution  of  iodised  iodide 
{iode  iodure)  until  a  slight  excess  could  be  detedted  by 
means  of  chloroform,  even  after  standing  twenty-four 
hours.  At  the  end  of  this  time  an  equal  volume  of  dis- 
tilled water,  containing  a  little  acetic  acid,  is  added  ;  there 
is  thus  obtained  a  yellowish  brown  coagulum,  which  is 
well  washed  with  water  and  treated  with  weak  soda :  the 
colour  disappears,  and  a  soluble  caseinate  is  formed.  From 
the  filtered  liquid  we  can  again  precipitate  the  casein  by 
acetic  acid.  To  obtain  it  perfedly  pure  this  must  be  re- 
peated five  or  six  times ;  it  then  has  a  constant  compo- 
sition and  leaves  no  ash  on  calcination.  There  is  no 
doubt  that  this  body  contains  iodine  in  its  molecule,  for  if 
treated  with  soda  and  nitrate  of  soda,  and  taking  up  the 
mass  with  water,  it  is  easy  to  detedt  the  presence  of 
iodine.  We  may  therefore  conclude  that  this  casein  is 
adtually  iodised.  To  show  its  constant  composition  five 
different  analyses  were  made,  and  they  gave  average  re- 
sults of  2i"6  per  cent  iodine  and  I4'i5  per  cent  nitrogen, 
the  greatest  variations  being  20*0  and  22*4  per  cent  for 
iodine  and  14-1  and  I4'23  per  cent  for  nitrogen.  The 
first  yellowish  brown  coagulum  loses  its  colour  not  only 
when  treated  with  soda,  but  also  by  losing  a  portion  of 
its  iodine  when  treated  with  hyposulphite  of  soda  or  sul- 
phurous acid ;  but  in  neither  case  is  all  the  iodine 
removed.  The  author  hopes  that,  owing  to  its  constant 
proportion  of  iodine,  this  iodo-casein  may  become  useful 
in  therapeutics,  and  he  proposes  carrying  out  some  experi- 
ments on  digestion  with  men  and  animals. 

Presence  of  Lead  in  some  Sterilised  Artificial 
Serums. — M.  Chevretin. — A  case  of  poisoning  by  an  in- 
jedlion  of  an  artificial  serum  having  been  observed,  M. 
Chevretin  sought  for  the  cause,  and  he  found  that,  by 
keeping  an  artificial  physiological  serum  (7  per  1000 
solution  of  NaCl)  at  120°  for  twenty  minutes,  in  different 
flasks,  when  lead  glass  was  used  the  liquid  became 
charged  with  this  poison  ;  and  if  this  serum  be  used  for 
subcutaneous  or  intra-veinous  injedtions,  there  is  naturally 
a  very  grave  risk  of  lead-poisoning  :  the  presence  of  lead 
is  easily  proved  by  means  of  iodide  of  potassium. 

Series  6,  vol.  vi.,  No.  i. 
On  a  Method  of  Oxidation  and  Cblorination — A. 
Villiers. — The  addition  of  a  trace  of  a  salt  of  manganese 
will,  in  many  cases,  accelerate  oxidation.  This  adion 
can  be  explained  by  the  produdtion  of  easily  decomposable 
salts,  similar  to  those  produced  in  the  preparation  of 
chlorine ;  the  presence  of  traces  of  manganese  can  not 
only  keep  the  oxidation  in  media  containing  special 
oxidising  materials,  but  can  in  certain  cases  facilitate  the 
diredl  absorption  of  oxygen  from  the  air.  The  conditions 
under  which  oxidation  takes  place,  under  the  influence  of 
salts  of  manganese,  in  the  case  of  oxalic  acid,  are  rather 
curious.     The  disengagement  of  gas  can  be  seen  in  the 


Chemical  Nbws,  i 
Aug.  13,  1897.     f 


Chemical  Notices  Jrom  Foreign  Source^. 


fei 


cold.  It  will  last  several  weeks,  probably  even  several 
years.  These  readions,  of  which  several  are  already 
known,  have  the  charadleristics  of  fermentations  produced 
by  chemical  ferments,  and  may  be  rightly  classed  as 
mineral  ferments. 

On  Isomerism  of  Pilocarpidine  and  Pilocarpine. — 
A.  Petit  and  M,  Polonovski.  —  Two  experiments  have 
sufficed  to  satisfy  the  authors  that  the  transformation  of 
pilocarpine  into  pilocarpidine  takes  place  inter-molecularly. 
After  boiling  a  salt  of  pilocarpine  with  an  excess  of  dilute 
soda  for  some  hours,  in  a  flask  fitted  with  a  vertical  con- 
denser, the  condenser  was  lowered  and  three-quarters  of 
the  solution  distilled,  although  nearly  all  the  pilocarpine 
was  transformed,  they  were  unable  to  detedt  the  least 
trace  of  methylic  alcohol ;  there  is  therefore  no  elimina' 
tion  of  a  methyl  group  during  the  transformation  of  pilo- 
carpine into  pilocarpidine.  Another  experiment  was  still 
more  decisive.  Chlorhydrate  of  pilocarpine,  kept  in  a 
state  of  fusion  for  a  few  instants,  was  entirely  converted 
into  chlorhydrate  of  pilocarpidine.  Full  details,  weights, 
and  temperatures,  employed  in  this  experiment,  are  given. 

Contribution  to  the  Study  of  the  Preparation  of 
Ordinary  Ether. —  L.  Prunier.— In  making  ether  from 
sulphuric  acid  and  alcohol  we  are  in  the  habit  of  regarding 
the  transformation  as  in  two  successive  phases,  forming  a 
complete  cycle,  being  indefinitely  renewed ;  this  con- 
tinuity does  not  exist  in  pradice.  The  readion  certainly 
does  take  place  in  an  acid  medium,  but  the  presence  of 
sulphuric  acid  is  not  indispensable ;  etherification  takes 
place  in  its  absence,  the  acidity  being  due  to  sulphurous 
acid,  sulphovinic  acid,  or  its  derivatives,  the  latter  perhaps 
being  of  considerable  importance.  Isoethionic  acid  and 
its  derivatives  are  taken  as  a  type  of  the  group,  as  their 
properties  are  well  known,  and  in  the  author's  experience 
the  sulphonic  derivatives  have  been  charaderised  by 
groups  and  not  by  distind  species.  Instead  of  admitting 
the  continual  regeneration  of  free  sulphuric  acid,  the 
author  prefers  to  think  that  the  alcohol,  added  gradually, 
ads  principally  on  the  two  sulphuric  ethers,  and  above  all 
on  their  produds  of  decomposition, — the  sulphonic  deriva- 
tives, acid  and  neutral,— which  constitute,  in  great  part, 
the  residues,  and  allow  of  the  explanation  of  the  pheno- 
mena observed. 

Series  6,  vol.  vi..  No.  2. 

Research  on  the  Rapid  Estimation  of  Boric  Acid 
(Preservative)  in  Milk. — G  Deniges. — The  author  ex- 
presses surprise  at  Mr.  Farrington's  recent  results  on  the 
acidity  of  boric  acid,  and  he  thinks,  after  having  repeated 
the  experiments,  that  the  latter  has  not  obtained  the 
corred  results,  though  the  seme  of  his  experiments  may 
be  corred.  By  the  modified  method  the  author  proposes, 
he  claims  that  his  results  are  exad  when  the  quantity  of 
boric  acid  present  does  not  exceed  3  grms.  per  litre,  and 
when  the  quantity  of  ladose  present  in  the  milk  is  from 
40  to  50  grms.  per  litre.  When  these  figures  are  exceeded 
it  is  necessary  to  dilute  the  milk. 

Estimation  of  Glycerin  by  Bichromate  of  Potas- 
sium and  Sulphuric  Acid.  —  F.  Bordas  and  Sig.  de 
Raczkowski. — Already  inserted ' 

Destrud\ion  of  Organic  Matter  in  Toxicology. — A. 
Villiers. — A  very  convenient  mineral  ferment,  for  the 
destrudion  of  organic  matter  in  toxicological  research, 
can  be  produced  by  the  aid  of  salt  of  manganese.  The 
material  to  be  treated  is  placed  in  a  flask  with  dilute  hydro- 
chloric acid  (3  to  i).  Add  a  few  drops  of  a  solution  of  a 
manganese  salt,  and  a  little  nitric  acid,  which  must  be 
renewed  as  it  becomes  used  up.  The  mixture  must  be 
gently  heated.  The  gases  produced  are  carbonic  acid  and 
nearly  pure  nitrogen,  and  no  disagreeable  odours  are 
evolved.  Materials  such  as  liver,  lungs,  &c.,  are  dissolved 
in  a  few  minutes  ;  muscular  fibre  takes  about  an  hour,  and 
a  fatty  mass  remains  which  resists  the  oxidising  adion  of 
the  mixture,  and  which  appears  to  contain  produds  of 
substitution. 


On  Pseudo-intestinal  Calculus.— Marcel  Delepine. — 
The  author  found,  after  considerable  trouble  and  groping 
in  the  dark,  that  certain  balls  which  had  been  sent  to  him 
to  examine  as  intestinal  calculi  were  merely  undigested 
balls  of  bread  crumb,  which  the  patient  had  been  in  the 
habit  of  making  and  swallowing. 


/?evue  Umverselle  des  Mines  et  de  la  Metdlurgie. 
Series  3,  vol.  xxxviii.,  No.  3. 

This  number  contains  no  matter  of  chemical  interestt 

Series  3,  vol.  xxxix.,  No.  i. 

Saline  Deposits  of  the  Plains  of  Northern  Ger- 
many. —  Franz  and  Biittgenbach.  —  There  are  three 
rivers  in  Germany  named  Saale.  This  name  is  evidently 
derived  from  the  numerous  saline  sources  which  are  to  be 
found  in  their  valleys.  In  1837  attempts  were  made  to 
augment  the  supply  of  mineral  waters  by  sinking  shafts, 
but  the  work  was  abandoned,  as  it  was  found  that  the 
waters  thus  obtained  "  artificially "  were  not  equal 
dietetically  to  those  which  rose  naturally.  But  in  1861 
the  commercial  value  of  the  potassic  salts  {kalisalze)  was 
recognised,  and  the  industry  at  Stassfurt  soon  assumed 
colossal  dimensions.  The  deposits  are  of  a  very  compli- 
cated  nature,  and  the  deposition  and  formation  of  the 
beds  must  have  proceeded  and  been  interrupted  many 
times  and  at  different  temperatures.  There  are  at  the 
present  time  twenty-five  different  species  of  deposits 
known  ;  these  are  all  given  in  the  order  of  deposition. 
The  most  important  of  these  salts  are  sylvine,  KCl,  and 
kainite,  K2S04,MgS04,MgCl2-|-6H20.  These  two  salts 
are  found  in  the  ashes  oi  most  plants,  and  are  for  this 
reason  much  sought  after  as  manures.  The  mean  thick- 
ness of  the  beds  of  the  potassic  salts  is  at  least  20  metres, 
and,  considering  the  area  covered,  the  author  estimates 
the  quantity  available  at  10  milliard  (10,000,000,000)  tons, 
and,  at  the  present  output  of  3,000,000  tons  a  year,  the 
beds  will  last  for  33  centuries. 


MISCELLANEOUS. 


Obituary.  —  Professor  Vidor  Meyer  died  a  few  days 
ago.  His  death  seems  to  have  been  sudden ;  but  aC'> 
cordant  and  trustworthy  accounts  of  his  end  seem  as  yet 
wanting. 

Sixty-ninth  Meeting  of  the  German  Association  of 
Natural  Science  and  Medicine. — This  Association  will 
meet  at  Brunswick,  after  an  absence  of  fiity-six  years,  on 
the  2oth  to  the  25th  of  September,  1897.  There  will  be 
two  principal  Sedions,  the  first  deahng  with  Natural 
Science ;  it  is  subdivided  into  three  Sub-sedions. 

1.  Sedion  for  Mathematics,  Physics,  Chemistry,  Agri- 

culture, Instruments,  &c. 

2.  Sedion    for    Mineralogy,    Botany,    Zoology,    Geo- 

graphy, &c. 

3.  Sedion  for  instrudion  in  Mathematical  and  Natural 

Science. 
The    second    principal   Sedion  is   devoted  to    Medical 
Science,  and  comprises  five  Sub- sedions. 

1.  Sedion  for  General  Medicine:  Pathology,  Anatomy, 

Surgery,  &c. 

2.  Sedion  for  Specialism  :  Nervous  diseases.  Ophthal- 

mology, Laryngology,  Dermatology,  &c. 

3.  Sedion   for  Anatomical   Physiology:  Physiological 

Chemistry,  Pharmacology. 

4.  Sedion  for  General  Hygiene,  Baderiology,  Climat- 

ology, Military  Sanitation,  Veterinary  Science,  &c. 

5.  Sedion  for  Pharmacy. 


84 


German  Associatmt  of  Natural  Science.. 


i  Chemical  News, 
\     Aug.  13, 1897. 


A  large  number  of  papers  have  been  promised ;  these, 
after  reading,  will  be  followed  by  discussions.  Though 
the  sedions  will  be  all  over  on  the  25th,  the  meeting  will 
not  break  up  till  the  27th,  the  two  extra  days  being  devoted 
to  excursions  and  social  pleasure. 


HERIOT-WATT  COLLEGE,  EDINBURGH. 

F.  GRANT  OGILVIE,  M.A.,  B.Sc,  F.R.S.E.,  Principal. 
DAY  CLASSES— SESSION  1897-98. 

qphe   SESSION   extends   from   TUESDAY, 

■*■      October  jth,  1897,  to  Friday,  June  3RD,  1898. 

These  Classes  provide  Courses  of  Study  extending  over  one  or 
more  years,  suitable  for  Students  who  have  previously  passed  through 
the  Curriculum  of  a  Secondary  School.  The  principal  Courses  are: — 
Physical  and  Chemical,  Mechanical  Engineering  and  Eieftrical 
Engineering.  There  are  also  Classes  in  French,  German,  Drawing, 
and  Pradtice  of  Commerce.  Class  Fees  from  £1  is,  to  £4  4s. ;  Session 
Fee,  £10  los. 

There  is  also  a  preparatory  Course  of  Instruftion  for  Agricultural 
Students;  Session  Fee,  £5  5s.  An  extradt  from  the  Calendar  of  the 
College  giving  particulars  of  the  Day  Classes,  and  of  the  various 
Appliances,  Laboratories,  and  Workshops  available  for  instrudlion, 
may  be  had  on  application  to  the  Librarian,  at  the  College,  or  to  the 
Treasurer  of  George  Heriot's  Trust. 

DAVID  LEWIS, 

Treasurer's  Chambers,  20,  York  Place,  Treasurer 

Edinburgh,  July  14th,  1897. 


M 


ASON       COLLEGE      BIRMINGHAM. 


FACULTIES    OF    ARTS    AND    SCIENCE. 

SESSION  1897-98. 


THE  NEXT   SESSION   COMMENCES    ON  THURSDAY, 
SEPTEMBER  30. 

COMPLETE  COURSES  OF  INSTRUCTION  are  provided  for 
the  various  Examinations  in  Arts  and  Science,  and  the  Preliminary 
Scientific  (M.S.)  Examination  of  the  University  of  London  ;  for 
Students  of  Civil,  Mechanical,  and  Eledtrical  Engineering;  and  for 
those  who  desire  to  obtain  an  acquaintance  with  some  branch  of 
Applied  Science,  including  Chemistry,  Metallurgy,  &c.  Students 
may,  however,  attend  any  class  or  combination  of  classes. 

There  is  also  a  Faculty  of  Medicine,  aSyllabus  of  which  containing 
full  particulars  may  be  had  gratis  from  Messrs.  Cornish,  New  Street. 

A  SYLLABUS  of  the  Arts  and  Science  Faculties,  with  full  infor- 
mation as  to  the  various  lecture  and  laboratory  courses,  le(5ture  days 
and  hours,  fees,  entrance  and  other  scholarships,  prizes,  &c.,  may  be 
bad  gratis  from  Messrs.  Cornish,  New  Street,  Birmingham,  or  on 
application  to  the  Registrar,  at  the  College. 

BOROUGH^  OF   DARLINGTON. 


MESSRS.  MACMILLAN  &  CO.'S  BOOKS 

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CHEMICAL  STUDENTS. 

NOW  READY,  Globe  8vo,  28.  6d. 
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NEW  EDITION,  Now  ready. 
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By  FRANCIS  JONES,  F.R.S.E.,  F.C.S.,  Chemical  Master  in 

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THC 

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THE  GASES  OF  THE  ATMOSPHERE:  The  History 

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CBBUICAL  NBW8|I 

Aug.  20, 1897.    I 


British  Association. — The  President's  Address. 


85 


THE    CHEMICAL    NEWS 


Vol.  LXXVI.,  No.  1969. 


BRITISH  ASSOCIATION 

FOR  THE 

ADVANCEMENT    OF    SCIENCE. 


Toronto,  1897, 

INAUGURAL  ADDRESS  OF  THE  PRESIDENT, 

Sir  John  Evans,  K.C.B.,  D.C.L.,  LL.D.,  Sc.D., 

Treas.R.S,,  V.P.S.A.,  FOR.SEC.G.S., 

CORRESPONDANT    DE    L'InSTITUT    DE    FRANCE,  &C. 

Once  more  has  the  Dominion  of  Canada  invited  the 
British  Association  for  the  Advancement  of  Science  to 
hold  one  of  the  annual  meetings  of  its  members  within 
the  Canadian  territory ;  and  for  a  second  time  has  the 
Assocation  had  the  honour  and  pleasure  of  accepting  the 
proffered  hospitality. 

In  doing  bo  the  Association  has  felt  that,  if  by  any 
possibility  the  scientific  welfare  of  a  locality  is  promoted 
by  its  being  the  scene  of  such  a  meeting,  the  claims  should 
be  fully  recognised  of  those  who,  though  not  dwelling  in 
the  British  Isles,  are  still  inhabitants  of  that  Greater 
Britain  whose  prosperity  is  so  intimately  conne(5ted  with 
the  fortunes  of  the  Mother  Country. 

Here,  especially,  as  loyal  subjedls  of  one  beloved 
Sovereign,  the  sixtieth  year  of  whose  beneficent  reign 
has  just  been  celebrated  with  equal  rejoicing  in  all  parts 
of  her  Empire  ;  as  speaking  the  same  tongue,  and  as  in 
most  instances  connefted  by  the  ties  of  one  common 
parentage,  we  are  bound  together  in  all  that  can  promote 
our  common  interests. 

There  is,  in  all  probability,  nothing  that  will  tend  more 
to  advance  those  interests  than  the  diffusion  of  science 
in  all  parts  of  the  British  Empire,  and  it  is  towards  this 
end  that  the  aspirations  of  the  British  Association  are 
ever  dire(5ted,  even  if  in  many  instances  the  aim  may  not 
be  attained. 

We  are,  as  already  mentioned,  indebted  to  Canada  for 
previous  hospitality ;  but  we  must  also  remember  that, 
since  the  time  when  we  last  assembled  on  this  side  of  the 
Atlantic,  the  Dominion  has  provided  the  Association  with 
a  President,  Sir  William  Dawson,  whose  name  is  alike 
well  known  in  Britain  and  America,  and  whose  reputation 
is  indeed  world-wide.  We  rejoice  that  we  have  still 
among  us  the  pioneer  of  American  geology,  who  among 
other  discoveries  first  made  us  acquainted  with  the  "Air- 
breathers  of  the  Coal,"  the  terrestrial,  or  more  properly 
arboreal,  Saurians  of  the  New  Brunswick  and  Nova 
Scotia  Coal-measures. 

On  our  last  visit  to  Canada,  in  1884,  our  place  of 
assembly  was  Montreal,  a  city  which  is  justly  proud  of 
her  McGill  University ;  to-day  we  meet  within  the 
buildings  of  another  of  the  Universities  of  this  vast 
Dominion, — and  in  a  city,  the  absolute  fitness  of  which 
for  such  a  purpose  must  have  been  foreseen  by  the 
native  Indian  tribes  when  they  gave  to  a  small  aggrega- 
tion of  huts  upon  this  spot  the  name  of  Toronto — "the 
place  of  meetings." 

Our  gathering  this  year  presents  a  feature  of  entire 
novelty  and  extreme  interest,  inasmuch  as  the  sister 
Association  of  the  United  States  of  America,  —  still 
mourning  the  loss  of  their  illustrious  President,  Professor 
Cope, — and  some  other  learned  societies,  have  made  special 
arrangements  to  allow  of  their  members  coming  here  to 
join  us.  I  need  hardly  say  how  welcome  their  presence 
is,  nor  how  gladly  wp  look  forward  to  th^ir  taking  part  in 


our  discussions,  and  aiding  us  by  interchange  of  thought. 
To  such  a  meeting  the  term  "international"  seems 
almost  misapplied.  It  may  rather  be  described  as  a 
family  gathering,  in  which  our  relatives  more  or  less  dis> 
tant  in  blood,  but  still  intimately  connedted  with  us  by 
language,  literature,  and  habits  of  thought,  have  sponta- 
neously arranged  to  take  part. 

The  domain  of  Science  is  no  doubt  one  in  which  the 
various  nations  of  the  civilised  world  meet  upon  equal 
terms,  and  for  which  no  other  passport  is  required  than 
some  evidence  of  having  striven  towards  the  advancement 
of  natural  knowledge.  Here,  on  the  frontier  between  the 
two  great  English-speaking  nations  of  the  world,  who  is 
there  that  does  not  inwardly  feel  that  anything  which 
conduces  to  an  intimacy  between  the  representatives  of 
two  countries,  both  of  them  aftively  engaged  in  the  pur- 
suit  of  science,  may  also,  through  such  an  intimacy,  readt 
on  the  affairs  of  daily  life,  and  aid  in  preserving  those 
cordial  relations  that  have  now  for  so  many  years  existed 
between  the  great  American  Republic  and  the  British 
Islands,  with  which  her  early  foundations  are  indissolubly 
connedled  ?  The  present  year  has  witnessed  an  inter- 
change of  courtesies  which  has  excited  the  warmest 
feelings  of  approbation  on  both  sides  of  the  Atlantic.  I 
mean  the  return  to  its  proper  custodians  of  one  of  the 
most  interesting  of  the  relics  of  the  Pilgrim  Fathers, 
the  Log  of  the  "  Mayflower."  May  this  return, 
trifling  in  itself,  be  of  happy  augury  as  testifying  to  the 
feelings  of  mutual  regard  and  esteem  which  animate  the 
hearts  both  of  the  donors  and  of  the  recipients ! 

At  our  meeting  in  Montreal  the  President  was  an  inves- 
tigator who  had  already  attained  to  a  foremost  place  in 
the  domains  of  Physics  and  Mathematics,  Lord  Rayleigh. 
In  his  address  he  dealt  mainly  with  topics  such  as  Light, 
Heat,  Sound,  and  Eledtricity,  on  which  he  is  one  of  our 
principal  authorities.  His  name  and  that  of  his  fellow- 
worker.  Professor  Ramsay,  are  now  and  will  in  all  future 
ages  be  associated  with  the  discovery  of  the  new  element, 
Argon.  Of  the  ingenious  methods  by  which  that  dis- 
covery was  made,  and  the  existence  of  Argon  established, 
this  is  not  the  place  to  speak.  One  can  only  hope  that 
the  element  will  not  always  continue  to  justify  its  name 
by  its  inertness. 

The  claims  of  such  a  leader  in  physical  science  as  Lord 
Rayleigh  to  occupy  the  Presidential  chair  are  self-evident, 
but  possibly  those  of  his  successor  on  this  side  of  the 
Atlantic  are  not  so  immediately  apparent.  I  cannot  for 
a  moment  pretend  to  place  myself  on  the  same  purely 
scientific  level  as  my  distinguished  friend  and  for  many 
years  colleague,  Lord  Rayleigh,  and  my  claims,  such  as 
they  are,  seem  to  me  to  rest  on  entirely  different 
grounds. 

Whatever  little  I  may  have  indiredly  been  able  to  do  in 
assisting  to  promote  the  advancement  of  science,  my  prin- 
cipal efforts  have  now  for  many  years  been  direded 
towards  attempting  to  forge  those  links  in  the  history  of 
the  world,  and  especially  of  humanity,  that  connedt  the 
past  with  the  present,  and  towards  tracing  that  course  of 
evolution  which  plays  as  important  a  part  in  the  physical 
and  moral  development  of  man  as  it  does  in  that  of  the 
animal  and  vegetable  creation. 

It  appears  to  me,  therefore,  that  my  election  to  this 
important  post  may,  in  the  main,  be  regarded  as  a 
recognition  by  this  Association  of  the  value  of  Archaeology 
as  a  science. 

Leaving  all  personal  considerations  out  of  question,  I 
gladly  hail  this  recognition,  which  is,  indeed,  in  full  ac- 
cordance with  the  attitude  already  for  many  years  adopted 
by  the  Association  towards  Anthropology,  one  of  the  most 
important  branches  of  true  Archaeology. 

It  is  no  doubt  hard  to  define  the  exadt  limits  which  are 
to  be  assigned  to  Archaeology  as  a  science,  and  Archaeology 
as  a  branch  of  History  and  Belles  Lettres.  A  distintSlion 
is  frequently  drawn  between  science  on  the  one  hand,  and 
knowledge  or  learning  on  the  other ;  but  translate  the 
terms  into  Latin,  and  the  distindion  at  once  disappears, 


86 


British  Association^ — 7'he  Presidents  Address. 


(Crbmical  Nbws, 
Aug.  20,  i8q7. 


In  illustration  of  this  I  need  only  cite  Bacon's  great 
work  on  .the  "  Advancement  of  Learning,"  which  was, 
with  his  own  aid,  translated  into  Latin  under  the  title 
"  De  Augmentis  Scientiarum." 

It  must,  however,  be  acknowledged  that  a  distinction 
does  exist  between  Archaeology  proper  and  what — for 
want  of  a  better  word — may  be  termed  Antiquarianism. 
It  may  be  interesting  to  know  the  internal  arrangements 
of  a  Dominican  convent  in  the  Middle  Ages ;  to  distin- 
guish between  the  different  mouldings  charadleristic  of 
the  principal  styles  of  Gothic  architefture ;  to  determine 
whether  an  English  coin  bearing  the  name  of  Henry  was 
struck  under  Henry  II.,  Richard,  John,  or  Henry  III.,  or 
to  decide  whether  some  given  edifice  was  eredted  in 
Roman,  Saxon,  or  Norman  times.  But  the  power  to  do 
this,  though  involving  no  small  degree  of  detailed  know- 
ledge and  some  acquaintance  with  scientific  methods,  can 
hardly  entitle  its  possessors  to  be  enrolled  among  the 
votaries  of  science. 

A  familiarity  with  all  the  details  of  Greek  and  Roman 
mythology  and  culture  must  be  regarded  as  a  literary 
rather  than  a  scientific  qualification ;  and  yet  when 
among  the  records  of  classical  times  we  come  upon  traces 
of  manners  and  customs  which  have  survived  for  genera- 
tions,  and  which  seem  to  throw  some  rays  of  light  upon 
the  dim  past,  when  history  and  writing  were  unknown, 
we  are,  I  think,  approaching  the  boundaries  of  scientific 
Archaeology. 

Every  reader  of  Virgil  knows  that  the  Greeks  were  not 
merely  orators,  but  that  with  a  pair  of  compasses  they 
could  describe  the  movements  of  the  heavens  and  fix  the 
rising  of  the  stars ;  but  when  by  modern  Astronomy  we 
can  determine  the  heliacal  rising  of  some  well-known  star, 
with  which  the  worship  in  some  given  ancient  temple  is 
known  to  have  been  connedled,  and  can  fix  its  position  on 
the  horizon  at  some  particular  spot,  say,  three  thousand 
years  ago,  and  then  find  that  the  axis  of  the  temple  is 
diredled  exaiftly  towards  that  spot,  we  have  some  trust- 
worthy scientific  evidence  that  the  temple  in  question 
must  have  been  eredted  at  a  date  approximately  iioo 
years  B.C.  If  on  or  close  to  the  same  site  we  find  that 
more  than  one  temple  was  eredted,  each  having  a  different 
orientation,  these  variations,  following  as  they  may  fairly 
be  presumed  to  do  the  changing  position  of  the  rising  of 
the  dominant  star,  will  also  afford  a  guide  as  to  the 
chronological  order  of  the  different  foundations.  The  re- 
searches of  Mr.  Penrose  seem  to  show  that  in  certain 
Greek  temples,  of  which  the  date  of  foundation  is  known 
from  history,  the  adlual  orientation  corresponds  with  that 
theoretically  deduced  from  astronomical  data. 

Sir  J.  Norman  Lockyer  has  shown  that  what  holds 
good  for  Greek  temples  applies  to  many  of  far  earlier 
date  in  Egypt,  though  up  to  the  present  time  hardly  a 
sufficient  number  of  accurate  observations  have  been 
made  to  justify  us  in  foreseeing  all  the  instruSive  results 
that  may  be  expedted  to  arise  from  Astronomy  coming  to 
the  aid  of  Archaeology. 

The  intimate  connedtion   of   Archaeology  with   other  | 
sciences  is  in    no  case    so    evident  as  with  respedt  to 
Geology,  for,  when  considering  subjedts  such  as  those  I 
shall  presently  discuss,   it  is   almost  impossible  to  say 
where  the  one  science  ends  and  the  other  begins. 

By  the  application  of  geological  methods  many 
archaeological  questions  relating  even  to  subjedls  on  the 
borders  of  the  historical  perioa  have  been  batisfadtorily 
solved.  A  careful  examination  of  the  limits  of  the  area 
over  which  its  smaller  coins  ase  found  has  led  to  the 
position  of  many  an  ancient  Greek  city  being  accurately 
ascertained  ;  while  in  England  it  has  only  been  by  treating 
the  coins  of  the  Ancient  Britons,  belonging  to  a  period 
before  the  Roman  occupation,  as  if  they  were  adtual 
fossils,  that  the  territories  under  the  dominion  of  the 
various  kings  and  princes  who  struck  them  have  been 
approximately  determined.  In  arranging  the  chrono- 
logical sequence  of  these  coins,  the  evolution  of  their 
t^pes— a  process  almpst  as  reinarkable,  apd  certainly  as 


well-defined,  as  any  to  be  found  in  Nature— has  served  as 
an  efficient  guide.  I  may  venture  to  add  that  the  results 
obtained  from  the  study  of  the  morphology  of  this  series 
of  coins  were  published  ten  years  before  the  appearance 
of  Darwin's  great  work  on  the  "  Origin  of  Species." 

When  we  come  to  the  consideration  of  the  relics  of 
the  Early  Iron  and  Bronze  Ages,  the  aid  of  Chemistry 
has  of  necessity  to  be  invoked.  By  its  means  we  are 
able  to  determine  whether  the  iron  of  a  tool  or 
weapon  is  of  meteoritic  or  volcanic  origin,  or  has  been 
reduced  from  iron-ore,  in  which  case  considerable  know- 
ledge of  metallurgy  would  be  involved  on  the  part  of 
those  who  made  it.  With  bronze  antiquities  the  nature 
and  extent  of  the  alloys  combined  with  the  copper  may 
throw  light  not  only  on  their  chronological  position,  but 
on  the  sources  whence  the  copper,  tin,  and  other  metals 
of  which  they  consist  were  originally  derived.  I  am  not 
aware  of  there  being  sufficient  differences  in  the  analyses 
of  the  native  copper  from  different  localities  in  the  region 
in  which  we  aie  assembled,  for  Canadian  Archaeologists 
to  fix  the  sources  from  which  the  metal  was  obtained 
which  was  used  in  the  manufadture  of  the  ancient  tools 
and  weapons  of  copper  that  are  occasionally  discovered 
in  this  part  of  the  globe. 

Like  Chemistry,  Mineralogy  and  Petrology  may  be 
called  to  the  assistance  of  Archaeology  in  determining 
the  nature  and  source  of  the  rocks  of  which  ancient  stone 
implements  are  made  ;  and,  thanks  to  researches  of  the 
followers  of  those  sciences,  the  old  view  that  all  such  im> 
plements  formed  of  jade  and  found  in  Europe  must  of 
necessity  have  been  fashioned  from  material  imported 
from  Asia  can  no  longer  be  maintained.  In  one  respedt 
the  Archaeologist  differs  in  opinion  from  the  Mineralogist 
— namely,  as  to  the  propriety  of  chipping  off  fragments 
from  perfedt  and  highly  finished  specimens  for  the  purpose 
of  submitting  them  to  microscopic  examination. 

I  have  hitherto  been  speaking  of  the  aid  that  other 
sciences  can  afford  to  Archaeology  when  dealing  with 
questions  that  come  almost,  it  not  quite,  within  the  fringe 
of  history,  and  belong  to  times  when  the  surface  of  our 
earth  presented  much  the  same  configuration  as  regards 
the  distribution  of  land  and  water,  and  hill  and  valley,  as 
it  does  at  present,  and  when,  in  all  probability,  the 
climate  was  much  the  same  as  it  now  is.  When,  how- 
ever, we  come  to  discuss  that  remote  age  in  which  we  find 
the  earliest  that  are  at  present  known  of  Man's  appear- 
ance upon  earth,  the  aid  of  Geology  and  Palaeontology 
becomes  absolutely  imperative. 

The  changes  in  the  surface  configuration  and  in  the  ex- 
tent of  the  land,  especially  in  a  country  like  Britain,  as 
well  as  the  modifications  of  the  fauna  and  flora  since 
those  days,  have  been  such  that  the  Archaeologist  pure 
and  simple  is  incompetent  to  deal  with  them,  and  he  must 
either  himself  undertake  the  study  of  these  other  sciences 
or  call  experts  in  them  to  his  assistance.  The  evidence 
that  Man  had  already  appeared  upon  the  earth  is  afforded 
by  stone  implements  wrought  by  his  hands,  and  it  falls 
stridly  within  the  province  of  the  Archaeologist  to  judge 
whether  given  specimens  were  so  wrought  or  not ;  it  rests 
with  the  Geologist  to  determine  their  stratigraphical  or 
chronological  position,  while  the  Palaeontologist  can  pro- 
nounce upon  the  age  and  charadter  of  the  associated  fauna 
and  flora. 

If  left  to  himself  the  Archaeologist  seems  too  prone  to 
build  up  theories  founded  upon  form  alone,  irrespedive  of 
geological  conditions.  The  Geologist,  unaccustomed  to 
archaeological  details,  may  readily  fail  to  see  the  difference 
between  the  results  of  the  operations  of  Nature  and  those 
of  Art,  and  may  be  liable  to  trace  the  effeSs  of  man's 
handiwork  in  the  chipping,  bruising,  and  wearing  which 
in  all  ages  result  from  natural  forces ;  but  the  united 
labours  of  the  two,  checked  by  those  of  the  Palaeontolo- 
gist, cannot  do  otherwise  than  lead  towards  sound  con- 
clusions. 

It  will  perhaps  be  expedled  of  me  that  I  should  on 
the  present  occasion  bring  under  review  the  state  of  our 


^bbmicalNbws. 

Aug.  20,  i8q7. 


British  Association. — The  President's  Address. 


present  knowledge  with  regard  to  the  Antiquity  of  Man  ; 
and  probably  no  fitter  place  could  be  found  for  the  dis- 
cussion of  such  a  topic  than  the  adopted  home  of  my 
venerated  friend,  the  late  Sir  Daniel  Wilson,  who  first 
introduced  the  word  "  pre-historic "  into  the  English 
language. 

Some  among  us  may  be  able  to  call  to  mind  the  excite- 
ment, not  only  among  men  of  science  but  among  the 
general  public,  when,  in  1859,  the  discoveries  of  M. 
Boucher  de  Perthes  and  Dr.  Rigollot  in  the  gravels  of 
the  valley  of  the  Somme,  at  Abbeville  and  Amiens,  were 
confirmed  by  the  investigations  of  the  late  Sir  Joseph 
Prestwich,  myself,  and  others,  and  the  co-existence  of 
Man  with  the  extin(5l  animals  of  the  Quaternary  fauna, 
such  as  the  mammoth  and  woolly-haired  rhinoceros,  was 
first  virtually  established.  It  was  at  the  same  time 
pointed  out  that  these  relics  belonged  to  a  far  earlier  date 
than  the  ordinary  stone  weapons  found  upon  the  surface, 
which  usually  showed  signs  of  grinding  or  polishing,  and 
that  in  fadt  there  were  two  Stone  Ages  in  Britain.  To 
these  the  terms  Neolithic  and  Palaeolithic  were  subse- 
quently applied  by  Sir  John  Lubbock. 

The  excitement  was  not  less  when,  at  the  meeting  of 
this  Association  at  Aberdeen  in  the  autumn  of  that  year, 
Sir  Charles  Lyell,  in  the  presence  of  the  Prince  Consort, 
called  attention  to  the  discoveries  in  the  valley  of  the 
Somme,  the  site  of  which  he  had  himself  visited,  and  to 
the  vast  lapse  of  time  indicated  by  the  position  of  the 
implements  in  drift-deposits  a  hundred  feet  above  the 
existing  river. 

The  conclusions  forced  upon  those  who  examined  the 
fadts  on  the  spot  did  not  receive  immediate  acceptance 
by  all  who  were  interested  in  Geology  and  Archaeology, 
and  fierce  were  the  controversies  on  the  subjedl  that  were 
carried  on  both  in  the  newspapers  and  before  various 
learned  societies. 

It  is  at  the  same  time  instrudtive  and  amusing  to  look 
back  on  the  discussions  of  those  days.  While  one  class 
of  obje<aors  accounted  for  the  configuration  of  the  flint 
implements  from  the  gravels  by  some  unknown  chemical 
agency,  by  the  violent  and  continued  gyratory  adtion  of 
water,  by  fradlure  resulting  from  pressure,  by  rapid  cooling 
when  hot  or  by  rapid  heating  when  cold,  or  even  regarded 
them  as  aberrant  forms  of  fossil  fishes,  there  were  others 
who,  when  compelled  to  acknowledge  that  the  implements 
were  the  work  of  men's  hands,  attempted  to  impugn  and 
set  aside  the  evidence  as  to  the  circumstances  under 
which  they  had  been  discovered.  In  doing  this  they 
adopted  the  view  that  the  worked  flints  had  either  been 
introduced  into  the  containing  beds  at  a  comparatively 
recent  date,  or  if  they  adlually  formed  constituent  parts 
of  the  gravel  then  that  this  was  a  mere  modern  alluvium 
resulting  from  floods  at  no  very  remote  period. 

In  the  course  of  a  few  years  the  main  stream  of  scien- 
tific thought  left  this  controversy  behind,  though  a  ten- 
dency to  cut  down  the  lapse  of  time  necessary  for  all  the 
changes  that  have  taken  place  in  the  configuration  of  the 
surface  of  the  earth  and  in  the  charadter  of  its  occupants 
since  the  time  of  the  Palaeolithic  gravels,  still  survives  in 
the  inmost  recesses  of  the  hearts  of  not  a  few  observers. 

In  his  Address  to  this  Association  at  the  Bath  meeting 
of  1864,  Sir  Charles  Lyell  struck  so  true  a  note  that  I  am 
tempted  to  re-produce  the  paragraph  to  which  I  refer  :— 

"  When  speculations  on  the  long  series  of  events  which 
occurred  in  the  glacial  and  post-glacial  periods  are  in- 
dulged in,  the  imagination  is  apt  to  take  alarm  at  the 
immensity  of  the  time  required  to  interpret  the  monu- 
ments of  these  ages,  all  referable  to  the  era  of  existing 
species.  In  order  to  abridge  the  number  of  centuries 
which  would  otherwise  be  indispensable,  a  disposition  is 
shown  by  many  to  magnify  the  rate  of  change  in  pre- 
historic times  by  investing  the  causes  which  have 
modified  the  animate  and  inanimate  world  with  extra- 
ordinary and  excessive  energy.  It  is  related  of  a  great 
Irish  orator  of  our  day  that  when  he  was  about  to  con- 
tribute somewhat  parsimoniously  towards  a  public  charity, 


he  was  persuaded  by  a  friend  to  make  a  more  liberal 
donation.  In  doing  so  he  apologised  for  his  first  apparent 
want  of  generosity  by  saying  that  his  early  life  had  been 
a  constant  struggle  with  scanty  means,  and  that '  they 
who  are  born  to  affluence  cannot  easily  imagine  how  long 
a  time  it  takes  to  get  the  chill  of  poverty  out  of  one's 
bones.'  In  like  manner  we  of  the  living  generation,  when 
called  upon  to  make  grants  of  thousands  of  centuries  in 
order  to  explain  the  events  of  what  is  called  the  modern 
period,  shrink  naturally  at  first  from  making  what  seems 
so  lavish  an  expenditure  of  past  time.  Throughout  our 
early  education  we  have  been  accustomed  to  such  stridt 
economy  in  all  that  relates  to  the  chronology  of  the  earth 
and  its  inhabitants  in  remote  ages,  so  fettered  have  we 
been  by  old  traditional  beliefs,  that  even  when  our  reason 
is  convinced,  and  we  are  persuaded  that  we  ought  to  make 
more  liberal  grants  of  time  to  the  Geologist,  we  feel  how 
bard  it  is  to  get  the  chill  of  poverty  out  of  our  bones." 

Many,  however,  have  at  the  present  day  got  over  this 
feeling,  and  of  late  years  the  general  tendency  of  those 
engaged  upon  the  question  of  the  antiquity  of  the  human 
race  has  been  in  the  diredlion  of  seeking  for  evidence  by 
which  the  existence  of  Man  upon  the  earth  could  be 
carried  back  to  a  date  earlier  than  that  of  the  Quaternary 
gravels. 

There  is  little  doubt  that  such  evidence  will  be  eventu- 
ally forthcoming,  but,  judging  from  all  probability,  it  is 
not  in  Northern  Europe  that  the  cradle  of  the  human 
race  will  eventually  be  discovered,  but  in  some  part  of  the 
world  more  favoured  by  a  tropical  climate,  where  abundant 
means  of  subsistence  could  be  procured,  and  where  the 
necessity  for  warm  clothing  did  not  exist. 

Before  entering  into  speculations  on  this  subjeft,  or 
attempting  to  lay  down  the  limits  within  which  we  may 
safely  accept  recent  discoveries  as  firmly  established,  it 
will  be  well  to  glance  at  some  of  the  cases  in  which  im- 
plements are  stated  to  have  been  found  under  circum- 
stances which  raise  a  presumption  of  the  existence  of 
Man  in  pre-Glacial,  Pliocene,  or  even  Miocene  times. 

Flint  implements  of  ordinary  Palaeolithic  type  have, 
for  instance,  been  recorded  as  found  in  the  Eastern 
Counties  of  England,  in  beds  beneath  the  Chalky 
Boulder  Clay  ;  but  on  careful  examination  the  geological 
evidence  has  not  to  my  mind  proved  satisfaiSory,  nor  has 
it,  I  believe,  been  generally  accepted.  Moreover,  the 
archaeological  difficulty  that  Man,  at  two  such  remote 
epochs  as  the  pre-Glacial  and  the  postGlacial,  even  if  the 
term  Glacial  be  limited  to  the  Chalky  Boulder  Clay,  should 
have  manufadlured  implements  so  identical  in  charadter 
that  they  cannot  be  distinguished  apart,  seems  to  have 
been  entirely  ignored. 

Within  the  last  few  months  we  have  had  the  report  of 
worked  flints  having  been  discovered  in  the  late  Pliocene 
Forest  Bed  of  Norfolk;  but  in  that  instance  the  signs  of 
human  workmanship  upon  the  flints  are  by  no  means 
apparent  to  all  observers. 

But  such  an  antiquity  as  the  Forest  Bed  is  as  nothing 
when  compared  with  that  which  would  be  implied  by  the 
discoveries  of  the  work  of  men's  hands  in  the  Pliocene 
and  Miocene  Beds  of  England,  France,  Italy,  and  Portu- 
gal, which  have  been  accepted  by  some  geologists. 
There  is  one  feature  in  these  cases  which  has  hardly 
received  due  attention,  and  that  is  the  isolated  charadter 
of  the  reputed  discoveries.  Had  man,  for  instance,  been 
present  in  Britain  during  the  Crag  Period,  it  would  be 
strange  indeed  if  the  sole  traces  of  his  existence  that  he 
left  were  a  perforated  tooth  of  a  large  shark,  the  sawn  rib 
of  a  manatee,  and  a  beaming  full  face,  carved  on  the  shell 
of  a  pedunculus  1 

In  an  address  to  the  Anthropological  Sedtion  at  the 
Leeds  meeting  of  this  Association,  in  i8go,  I  dealt  some- 
what fully  with  these  supposed  discoveries  of  the  remains 
of  human  art  in  beds  of  Tertiary  date,  and  I  need  not 
here  go  further  into  the  question.  Suffice  it  to  say  that  I 
see  no  reason  why  the  verdidt  of  "  not  proven  "  at  which 
I  then  arrived  should  be  reversed. 


ss 


British  Association. — The  Pntident^s  Address, 


{CtlBUICAL  NbWS, 
Aug.  20, 1897. 


In  the  case  of  a  more  recent  discovery  in  Upper  Burma 
in  beds  at  first  pronounced  to  be  Upper  Miocene,  but  sub- 
sequently "  definitely  ascertained  to  be  Pliocene,"  some 
of  the  flints  are  of  purely  natural  and  not  artificial  origin, 
80  that  two  questions  arise : — First,  Were  the  fossil 
remains  associated  with  the  worked  flints  or  with  those  of 
natural  forms  ?  And  second,  Were  they  actually  found  in 
the  bed  to  which  they  have  been  assigned,  or  did  they 
merely  lie  together  on  the  surface  ? 

Even  the  Pithecanthropus  erectus  of  Dr.  Eugene  Dubois 
from  Java  meets  with  some  incredulous  objedtors  from 
both  the  physiological  and  the  geological  sides.  From 
the  point  of  view  of  the  latter  the  difficulty  lies  in  deter- 
mining the  exadt  exadt  age  of  what  are  apparently  alluvial 
beds  in  the  bottom  of  a  river  valley. 

When  we  return  to  Palaeolithic  man,  it  is  satisfaftory 
to  feel  that  we  are  treading  on  comparatively  secure 
ground,  and  that  the  discoveries  of  the  last  forty  years  in 
Britain  alone  enable  us  to  a  great  extent  to  re-constitute 
his  history.  We  may  not  know  the  exadt  geological 
period  when  first  he  settled  in  the  British  area,  but  we 
have  good  evidence  that  he  occupied  it  at  a  time  when  the 
configuration  of  the  surface  was  entirely  different  from 
what  it  is  at  present :  when  the  river  valleys  had  not  been 
cut  down  to  anything  like  their  existing  depth,  when  the 
fauna  of  the  country  was  of  a  totally  dififerent  charadler 
from  that  of  the  present  day,  when  the  extension  of  the 
southern  part  of  the  island  seaward  was  in  places  such 
that  the  land  was  continuous  with  that  of  the  continent, 
and  when  in  all  probability  a  far  more  rainy  climate  pre- 
vailed. We  have  proofs  of  the  occupation  of  the  country 
by  man  during  the  long  lapse  of  time  that  was  necessary 
for  the  excavation  of  the  river  valleys.  We  have  found 
the  old  floors  on  which  his  habitations  were  fixed,  we  have 
been  able  to  trace  him  at  work  on  the  manufadture  of 
flint  instruments,  and  by  building  up  the  one  upon  the 
other  the  flakes  struck  off  by  the  primaeval  workman  in 
those  remote  times  we  have  been  able  to  reconstrudt  the 
blocks  of  flint  which  served  as  his  material. 

That  the  duration  of  the  Palaeolithic  Period  must  have 
extended  over  an  almost  incredible  length  of  time  is 
sufficiently  proved  by  the  fadt  that  valleys,  some  miles  in 
width  and  of  a  depth  of  from  100  to  150  feet,  have  been 
eroded  since  the  deposit  of  the  earliest  implement-bearing 
beds.  Nor  is  the  apparent  duration  of  this  period 
diminished  by  the  consideration  that  the  floods  which 
hollowed  out  the  valleys  were  not  in  all  probability  of  such 
frequent  occurrence  as  to  teach  Palaeolithic  man  by  ex- 
perience the  danger  of  settling  too  near  to  the  streams, 
for  had  he  kept  to  the  higher  slopes  of  the  valley  there 
would  have  been  but  little  chance  of  his  implements 
having  so  constantly  formed  constituent  parts  of  the 
gravels  deposited  by  the  floods. 

The  examination  of  British  cave-deposits  affords  cor- 
roborative evidence  of  this  extended  duration  of  the 
Palaeolithic  Period.  In  Kent's  Cavern  at  Torquay,  for 
instance,  we  find  in  the  lowest  deposit,  the  breccia  below 
the  red  cave  earth,  implements  of  flint  and  chert  corre- 
sponding in  all  respedts  with  those  of  the  high  level  and 
most  ancient  river  gravels.  In  the  cave-earth  these  are 
scarcer,  though  implements  occur  which  also  have  their 
analogues  in  the  river  deposits;  but,  what  is  more  remark- 
able, harpoons  of  reindeer's  horn  and  needles  of  bone 
are  present,  identical  in  form  and  charadter  with  those  of 
the  caverns  of  the  Reindeer  Period  in  the  South  of  France, 
and  suggestive  of  some  bond  of  union  or  identity  of 
descent  between  the  early  troglodytes,  whose  habitations 
were  geographically  so  widely  separated  the  one  from  the 
other. 

In  a  cavern  at  Creswell  Crags,  on  the  confines  of 
Derbyshire  and  Nottinghamshire,  a  bone  has  moreover 
been  found  engraved  with  a  representation  of  parts  of  a 
horse  in  precisely  the  same  style  as  the  engraved  bones  of 
the  French  caves. 

It  is  uncertain  whether  any  of  the  River>drift  specimens 
belong  to  so  late  a  date  as  these  artistic  cavern-remains ; 


but  the  greatly  superior  antiquity  of  even  these  to  any 
Neolithic  relics  is  testified  by  the  thick  layer  of  stalagmite, 
which  had  been  deposited  in  Kent's  Cavern  before  its 
occupation  by  men  of  the  Neolithic  and  Bronze  Periods. 

Towards  the  close  of  the  period  covered  by  the  human 
occupation  of  the  French  caves,  there  seems  to  have 
been  a  dwindling  in  the  number  of  the  larger  animals 
constituting  the  Quaternary  fauna,  whereas  their  remains 
are  present  in  abundance  in  the  lower  and  therefore  more 
recent  of  the  valley  gravels.  This  circumstance  may 
afford  an  argument  in  favour  of  regarding  the  period 
represented  by  the  later  French  caves  as  a  continuation 
of  that  during  which  the  old  river  gravels  were  deposited, 
and  yet  the  great  change  in  the  fauna  that  has  taken 
place  since  the  latest  of  the  cave-deposits  included  in  the 
Paleolithic  Period  is  indicative  of  an  immense  lapse  of 
time. 

How  much  greater  must  have  been  the  time  required 
for  the  more  conspicuous  change  between  the  old 
Quaternary  fauna  of  the  river  gravels  and  that  chara(^er- 
istic  of  the  Neolithic  Period  I 

As  has  been  pointed  out  by  Prof.  Boyd  Dawkins,  only 
thirty-one  out  of  the  forty-eight  well-ascertained  species 
living  in  the  post-Glacial  or  River-drift  Period  survived 
into  pre-historic  or  Neolithic  times.  We  have  not,  in- 
deed, any  means  at  command  for  estimating  the  number 
of  centuries  which  such  an  important  change  indicates ; 
but  when  we  remember  that  the  date  of  the  commence^ 
ment  of  the  Neolithic  or  Surface  Stone  Period  is  still 
shrouded  in  the  mist  of  a  dim  antiquity,  and  that  prior 
to  that  commencement  the  River-drift  period  had  long 
come  to  an  end  ;  and  when  we  further  take  into  account 
the  almost  inconceivable  ages  that  even  under  the  most 
favourable  conditions  the  excavation  of  wide  and  deep 
valleys  by  river  adtion  implies,  the  remoteness  of  the  date 
at  which  the  Palaeolithic  Period  had  its  beginning  almost 
transcends  our  powers  of  imagination. 

We  find  distindt  traces  of  river  adtion  from  100  to  200 
feet  above  the  level  of  existing  streams  and  rivers,  and 
sometimes  at  a  great  distance  from  them ;  we  observe  old 
fresh-water  deposits  on  the  slopes  of  valleys  several  miles 
in  width;  we  find  that  long  and  lofty  escarpments  of  rock 
have  receded  unknown  distances  since  their  summits  were 
first  occupied  by  Palaeolithic  man ;  we  see  that  the  whole 
side  of  a  wide  river  valley  has  been  carried  away  by  inva- 
sion of  the  sea,  which  attacked  and  removed  a  barrier  of 
chalk  cliffs  from  400  to  600  feet  in  height ;  we  find  that 
what  was  formerly  an  inland  river  has  been  widened  out 
into  an  arm  of  the  sea,  now  the  highway  of  our  fleets, 
and  that  gravels  which  were  originally  deposited  in  the 
bed  of  some  ancient  river  now  cap  isolated  and  lofty 
hills. 

And  yet,  remote  as  the  date  of  the  first  known  occupa* 
tion  of  Britain  by  man  may  be,  it  belongs  to  what, 
geologically  speaking,  must  be  regarded  as  a  quite  recent 
period,  for  we  are  now  in  a  position  to  fix  with  some 
degree  of  accuracy  its  place  on  the  geological  scale. 
Thanks  to  investigations  ably  carried  out  at  Hoxne  in 
Suffolk,  and  at  Hitchin  in  Hertfordshire,  by  Mr.  Clement 
Reid,  under  the  auspices  of  this  Association  and  of  the 
Royal  Society,  we  know  that  the  implement-bearing  beds 
at  those  places  undoubtedly  belong  to  a  time  subsequent 
to  the  deposit  of  the  Great  Chalky  Boulder  Clay  of  the 
Eastern  Counties  of  England.  It  is,  of  course,  self- 
evident  that  this  vast  deposit,  in  whatever  manner  it  may 
have  been  formed,  could  not,  for  centuries  after  its  depo- 
sition was  complete,  have  presented  a  surface  inhabitable 
by  man.  Moreover,  at  a  distance  but  little  farther  north, 
beds  exist  which  also — though  at  a  somewhat  later  date- 
were  apparently  formed  under  Glacial  conditions.  At 
Hoxne  the  interval  between  the  deposit  of  the  Boulder 
Clay  and  of  the  implement-bearing  beds  is  distindly 
proved  to  have  witnessed  at  least  two  noteworthy  changes 
in  climate.  The  beds  immediately  reposing  on  the  Clay 
are  charaderised  by  the  presence  of  alder  in  abundance, 
of  hazel,  and  yew,  as  well  as  by  that  of  numerous  flower* 


CHEMICAL  News,  ) 
Aug.  20,  1807.     ) 


British  Association. — The  President's  Address, 


§9 


ing  plants  indicative  of  a  temperate  climate  very  different 
from  that  under  which  the  Boulder  Clay  itself  was  formed. 
Above  these  beds  charaderised  by  temperate  plants, 
comes  a  thick  and  more  recent  series  of  strata,  in  which 
leaves  of  the  dwarf  Ardic  willow  and  birch  abound,  and 
which  were  in  all  probability  deposited  under  conditions 
like  those  of  the  cold  regions  of  Siberia  and  North 
America. 

At  a  higher  level  and  of  more  recent  date  than  these — 
from  which  they  are  entirely  distindt — are  the  beds  con- 
taining Palaeolithic  implements,  formed  in  all  probability 
under  conditions  not  essentially  different  from  those  of  the 
present  day.  However  this  may  be,  we  have  now  con- 
clusive evidence  that  the  Palaeolithic  implements  are,  in 
the  Eastern  Counties  of  England,  of  a  date  long  posterior 
to  that  of  the  Great  Chalky  Boulder  Clay. 

It  may  be  said,  and  said  truly,  that  the  implements  at 
Hoxne  cannot  be  shown  to  belong  to  the  beginning 
rather  than  to  some  later  stage  of  the  Palaeolithic  Period. 

The  changes,  however,  that  have  taken  place  at  Hoxne 
in  the  surface  configuration  of  the  country  prove  that  the 
beds  containing  the  implements  cannot  belong  to  the  close 
of  that  period. 

It  must,  moreover,  be  remembered  that  in  what  are 
probably  the  earliest  of  the  Palaeolithic  deposits  of  the 
Eastern  Counties,  those  at  the  highest  level,  near  Brandon 
in  Norfolk,  where  the  gravels  contain  the  largest  propor- 
tion of  pebbles  derived  from  Glacial  beds,  some  of  the 
implements  themselves  have  been  manufadlured  from  ma. 
terials  not  native  to  the  spot,  but  brought  from  a  distance, 
and  derived  in  all  probability  either  from  the  Boulder 
Clay  or  from  some  of  the  beds  associated  with  it. 

We  must,  however,  take  a  wider  view  of  the  whole 
question,  for  it  must  not  for  a  moment  be  supposed  that 
there  are  the  slightest  grounds  for  believing  that  the 
civilisation,  such  as  it  was,  of  the  Palaeolithic  Period 
originated  in  the  British  Isles.  We  find  in  other  countries 
implements  so  identical  in  form  and  charadler  with  British 
specimens  that  they  might  have  been  manufadtured  by  the 
same  hands.  These  occur  over  large  areas  in  France 
under  similar  conditions  to  those  that  prevail  in  England. 
The  same  forms  have  been  discovered  in  the  ancient  river 
gravels  of  Italy,  Spain,  and  Portugal.  Some  few  have 
been  recorded  from  the  north  of  Africa,  and  analogous 
types  occur  in  considerable  numbers  in  the  south  of  that 
continent.  On  the  banks  of  the  Nile,  many  hundreds  of 
feet  above  its  present  level,  implements  of  the  European 
types  have  been  discovered ;  while  in  Somaliland,  in  an 
ancient  river  valley  at  a  great  elevation  above  the  sea, 
Mr.  Seton-Karr  has  colledted  a  large  number  of  imple- 
ments formed  of  flint  and  quartzite,  which,  judging  from 
their  form  and  charadler,  might  have  been  dug  out  of  the 
drift  deposits  of  the  Somme  or  the  Seine,  the  Thames  or 
the  ancient  Solent, 

In  the  valley  of  the  Euphrates  implements  of  the  same 
kind  have  also  been  found,  and  again  farther  east  in  the 
lateritic  deposits  of  Southern  India  they  have  been  ob- 
tained in  considerable  numbers.  It  is  not  a  little  remark- 
able, and  it  is  at  the  same  time  highly  suggestive,  that  a 
form  of  implement  almost  peculiar  to  Madras  re-appears 
among  implements  from  the  very  ancient  gravels  of  the 
Manzanares  at  Madrid.  In  the  case  of  the  African  dis- 
coveries we  have  as  yet  no  definite  Palaeontological 
evidence  by  which  to  fix  their  antiquity;  but  in  the 
Narbada  Valley  of  Western  India  Palaeolithic  implements 
of  quartzite  seem  to  be  associated  with  a  local  fauna  of 
Pleistocene  age,  comprising,  like  that  of  Europe,  the 
elephant,  hippopotamus,  ox,  and  other  mammals  of  spe- 
cies now  extindt.  A  correlation  of  the  two  faunas  with  a 
view  of  ascertaining  their  chronological  relations  is  beset 
with  many  difficulties,  but  there  seems  reason  for  accepting 
this  Indian  Pleistocene  fauna  as  in  some  degree  more 
ancient  than  the  European. 

Is  this  not  a  case  in  which  the  imagination  may  be 
fairly  invoked  in  aid  of  science  ?  May  we  not  from  these 
data  attempt  in  some  degree  to  build  up  and  reconstruct 


the  early  history  of  the  human  family  ?  There,  in 
Eastern  Asia,  in  a  tropical  climate,  with  the  means  of 
subsistence  readily  at  hand,  may  we  not  pidture  to  our- 
selves our  earliest  ancestors  gradually  developing  from  a 
lowly  origin,  acquiring  a  taste  for  hunting,  if  not  indeed 
being  driven  to  protedt  themselves  from  the  beasts  around 
them,  and  evolving  the  more  complicated  forms  of  tools 
or  weapons  from  the  simpler  flakes  which  had  previously 
served  them  as  knives  ?  May  we  not  imagine  that,  when 
once  the  stage  of  civilisation  denoted  by  these  Palaeolithic 
implements  had  been  reached,  the  game  for  the  hunter 
became  scarcer,  and  that  his  life  in  consequence  assumed 
a  more  nomad  charadter  ?  Then,  and  possibly  not  till 
then,  may  a  series  of  migrations  to  "  fresh  woods  and 
pastures  new  "  not  unnaturally  have  ensued,  and  these, 
following  the  usual  course  of  "  westward  towards  the 
setting  sun,"  might  eventually  lead  to  a  Palsiolithic  popu- 
lation finding  its  way  to  the  extreme  borders  of  Western 
Europe,  where  we  find  such  numerous  traces  of  its 
presence. 

How  long  a  term  of  years  may  be  involved  in  such  a 
migration  it  is  impossible  to  say,  but  that  such  a  migra- 
tion took  place  the  phenomena  seem  to  justify  us  in 
believing.  It  can  hardly  be  supposed  that  the  process  that 
I  have  shadowed  forth  was  reversed,  and  that  Man,  having 
originated  in  North-Western  Europe,  in  a  cold  climate 
where  clothing  was  necessary  and  food  scarce,  subse- 
quently migrated  eastward  to  India  and  southward  to  the 
Cape  of  Good  Hope  !  As  yet,  our  records  of  discoveries 
in  India  and  Eastern  Asia  are  but  scanty ;  but  it  is  there 
that  the  traces  of  the  cradle  of  the  human  race  are,  in  my 
opinion,  to  be  sought,  and  possibly  future  discoveries  may 
place  upon  a  more  solid  foundation  the  visionary  strudture 
that  I  have  ventured  to  eredt. 

It  may  be  thought  that  my  hypothesis  does  not  do 
justice  to  what  Sir  Thomas  Browne  has  so  happily  termed 
"that  great  antiquity,  America."  I  am,  however,  not 
here  immediately  concerned  with  the  important  Neolithic 
remains  of  all  kinds  with  which  this  great  continent 
abounds,  I  am  now  confining  myself  to  the  question  of 
Palaeolithic  man  and  his  origin,  and  in  considering  it  I  am 
not  unmindful  of  the  Trenton  implements,  though  I  must 
content  myself  by  saying  that  the  "  turtleback  "  form  is 
essentially  different  from  the  majority  of  those  on  the 
wide  dissemination  of  which  I  have  been  speculating,  and, 
moreover,  as  many  here  present  are  aware,  the  circum- 
stances of  the  finding  of  these  American  implements  are 
still  under  careful  discussion. 

Leaving  them  out  of  the  question  for  the  present,  it 
may  be  thought  worth  while  to  carry  our  speculations 
rather  further,  and  to  consider  the  relations  in  time  be- 
tween the  Palaeolitic  and  the  Neolithic  Periods.  We  have 
seen  that  the  stage  in  human  civilisation  denoted  by  the 
use  of  the  ordinary  forms  of  Palaeolithic  implements  must 
have  extended  over  a  vast  period  of  time  if  we  have  to 
allow  for  the  migration  of  the  primaeval  hunters  from 
their  original  home,  wherever  it  may  have  been  in  Asia  or 
Africa,  to  the  west  of  Europe,  including  Britain.  We 
have  seen  that,  during  this  migration,  the  forms  of  the 
weapons  and  tools  made  from  silicious  stones  had  become, 
as  it  were,  stereotyped,  and  further,  that,  during  the  sub- 
sequent extended  period  implied  by  the  erosion  of  the 
valleys,  the  modifications  in  the  form  of  the  implements 
and  the  changes  in  the  fauna  associated  with  the  men 
who  used  them  were  but  slight. 

At  the  close  of  the  period  during  which  the  valleys 
were  being  eroded  comes  that  represented  by  the  latest 
occupation  of  the  caves  by  Palaeolithic  man,  when  both  in 
Britain  and  in  the  South  of  France  the  reindeer  was 
abundant;  but  among  the  stone  weapons  and  implements 
of  that  long  troglodytic  phase  of  man's  history  not  a 
single  example  with  the  edge  sharpened  by  grinding  has 
as  yet  been  found.  All  that  can  safely  be  said  is  that  the 
larger  implements  as  well  as  the  larger  mammals  had 
become  scarcer,  that  greater  power  in  chipping  flint  had 
been  attained,  that  the  arts  of  the  engraver  and  the 


90 


British  Association. — The  President's  Address, 


sculptor  had  considerably  developed,  and  that  the  use  of 
the  bow  had  probably  been  discovered. 

Diredly  we  encounter  the  relics  of  the  Neolithic  Period, 
often,  in  the  case  of  the  caves  lately  mentioned,  separated 
from  the  earlier  remains  by  a  thick  layer  of  underlying 
stalagmite,  we  find  flint  hatchets  polished  at  the  edge  and 
on  the  surface,  cutting  at  the  broad  and  not  at  the 
narrow  end,  and  other  forms  of  implements  associated 
with  a  fauna  in  all  essential  respects  identical  with  that  of 
the  present  day. 

Were  the  makers  of  these  polished  weapons  the  dire(5t 
descendants  of  Palaeolithic  ancestors  whose  occupation  of 
the  country  was  continuous  from  the  days  of  the  old  river 
gravels?  or  had  these  long  since  died  out,  so  that  after 
Western  Europe  had  for  ages  remained  uninhabited,  it 
was  re-peopled  in  Neolithic  times  by  the  immigration  of 
some  new  race  of  men  ?  Was  there,  in  fadt,  a  "  great 
gulf  fixed  "  between  the  two  occupations  ?  or  was  there 
in  Europe  a  gradual  transition  from  the  one  stage  of 
culture  to  the  other  ? 

It  has  been  said  that  "  what  song  the  Syrens  sang,  or 
what  name  Achilles  assumed  when  he  hid  himself  among 
women,  though  puzzling  questions,  are  not  beyond  all 
conjecture";  and  though  the  questions  now  proposed 
may  come  under  the  same  category,  and  must  await  the 
discovery  of  many  more  essential  fadts  before  they  receive 
definite  and  satisfa^ory  answers,  we  may,  I  think,  throw 
some  light  upon  them  if  we  venture  to  take  a  few  steps 
upon  the  seductive  if  insecure  paths  of  conjedture.  So  far 
as  I  know  we  have  as  yet  no  trustworthy  evidence  of  any 
transition  from  the  one  age  to  the  other,  and  the  gulf  be- 
tween them  remains  pra(5lically  unbridged.  We  can,  in- 
deed, hardly  name  the  part  of  the  world  in  which  to  seek 
for  the  cradle  of  Neolithic  civilisation,  though  we  know 
that  traces  of  what  appear  to  have  been  a  stone-using 
people  have  been  discovered  in  Egypt,  and  that  what 
must  be  among  the  latest  of  the  relics  of  their  industry 
have  been  assigned  to  a  date  some  3500  to  4000  years 
before  our  era.  The  men  of  that  time  had  attained  to  the 
highest  degree  of  skill  in  working  flint  that  has  ever  been 
reached.  Their  beautifully  made  knives  and  spear-heads 
seem  indicative  of  a  culminating  point  reached  after  long 
ages  of  experience  ;  but  whence  these  artists  in  flint  came 
or  who  they  were  is  at  present  absolutely  unknown,  and 
their  handiworks  afford  no  clue  to  help  us  in  tracing 
their  origin. 

Taking  a  wider  survey,  we  may  say  that,  generally 
speaking,  not  only  the  fauna  but  the  surface  configuration 
of  the  country  were,  in  Western  Europe  at  all  events, 
much  the  same  at  the  commencement  of  the  Neolithic 
Period  as  they  are  at  the  present  day.  We  have,  too,  no 
geological  indications  to  aid  us  in  forming  any  chrono- 
logical scale. 

The  occupation  of  some  of  the  caves  in  the  south  of 
France  seems  to  have  been  carried  on  after  the  erosion  of 
the  neighbouring  river  valleys  had  ceased,  and  so  far  as 
our  knowledge  goes  these  caves  offer  evidence  of  being 
the  latest  in  time  of  those  occupied  by  Man  during  the 
Palaeolithic  Period.  It  seems  barely  possible  that, 
though  in  the  north  of  Europe  there  are  no  distintft  signs 
of  such  late  occupation,  yet  that,  in  the  south,  Man  may 
have  lived  on,  though  in  diminished  numbers ;  and  that 
in  some  of  the  caves,  such,  for  instance,  as  those  in  the 
neighbourhood  of  Mentone,  there  may  be  traces  of  his 
existence  during  the  transitional  period  that  connedts  the 
Palaeolithic  and  Neolithic  Ages.  If  this  were  really  the 
case,  we  might  expert  to  find  some  traces  of  a  dissemina- 
tion of  Neolithic  culture  from  a  North  Italian  centre,  but 
I  much  doubt  whether  any  such  traces  actually  exist. 

If  it  had  been  in  that  part  of  the  world  that  the  transi- 
tion took  place,  how  are  we  to  account  for  the  abundance 
of  polished  stone  hatchets  found  in  Central  India  ?  Did 
Neolithic  man  return  eastward  by  the  same  route  as  that 
by  which  in  remote  ages  his  Palaeolithic  predecessor  had 
migrated  westward  ?  Would  it  not  be  in  defiance  of  all 
probability  to  answer  such  a  question  in  the  affirmative  ? 


tCBIUICAL  NKWS, 
Aug.  20, 1897. 

We  have,  it  must  be  confessed,  nothing  of  a  substantial 
character  to  guide  us  in  these  speculations;  but,  pending 
the  advent  of  evidence  to  the  contrary,  we  may,  I  think, 
provisionally  adopt  the  view  that  owing  to  failure  of  food, 
climatal  changes,  or  other  causes,  the  occupation  of 
Western  Europe  by  Palaeolithic  man  absolutely  ceased, 
and  that  it  was  not  until  after  an  interval  of  long  duration 
that  Europe  was  re-peopled  by  a  race  of  men  immigrating 
from  some  other  part  of  the  globe  where  the  human  race 
had  survived,  and  in  course  of  ages  had  developed  a 
higher  state  of  culture  than  that  of  Palaeolithic  man. 

I  have  been  carried  away  by  the  liberty  allowed  for 
conjecture  into  the  regions  of  pure  imagination,  and  must 
now  return  to  the  realms  of  (&&,  and  one  fadt  on  which  I 
desire  for  a  short  time  to  insist  is  that  of  the  existence  at 
the  present  day,  in  close  juxtaposition  with  our  own 
civilisation,  of  races  of  men  who,  at  all  events  but  a  few 
generations  ago,  lived  under  much  the  same  conditions  as 
did  our  own  Neolithic  predecessors  in  Europe. 

The  manners  and  customs  of  these  primitive  tribes  and 
peoples  are  changing  day  by  day,  their  languages  are  be- 
coming obsolete,  their  myths  and  traditions  are  dying  out, 
their  ancient  processes  of  manufacture  are  falling  into 
oblivion,  and  their  numbers  are  rapidly  diminishing,  so 
that  it  seems  inevitable  that  ere  long  many  of  these  in- 
teresting populations  will  become  absolutely  extindt.  The 
admirable  Bureau  of  Ethnology  instituted  by  our  neigh- 
bours in  the  United  States  of  America  has  done  much  to- 
wards preserving  a  knowledge  of  the  various  native  races 
in  this  vast  continent ;  and  here  in  Canada  the  annual 
Archaeological  Reports  presented  to  the  Minister  of 
Education  are  rendering  good  service  in  the  same  cause. 

Moreover,  the  Committee  of  this  Association  appointed 
to  investigate  the  physical  characters,  languages,  and  in- 
dustrial and  social  conditions  of  the  North-Western  tribes 
of  the  Dominion  of  Canada  is  about  to  present  its  twelfth 
and  final  report,  which  in  conjundtion  with  those  already 
presented  will  do  much  towards  preserving  a  knowledge 
of  the  habits  and  languages  of  those  tribes.  It  is  sad  to 
think  that  Mr.  Horatio  Hale,  whose  comprehensive  grasp 
of  the  bearings  of  ethnological  questions,  and  whose  un- 
remitting labours  have  so  materially  conduced  to  the  suc- 
cess of  the  Committee,  should  be  no  longer  among  us. 
Although  this  report  is  said  to  be  final,  it  is  to  be  hoped 
that  the  Committee  may  be  able  to  indicate  lines  upon 
which  future  work  in  the  dire&ion  of  ethnological  and 
archaeological  research  may  be  profitably  carried  on  in 
this  part  of  Her  Majesty's  dominions. 

It  is,  however,  lamentable  to  notice  how  little  is  being 
or  has  been  officially  done  towards  preserving  a  full  record 
of  the  habits,  belief,  arts,  myths,  languages,  and  physical 
charadteristics  of  the  countless  other  tribes  and  nations 
more  or  less  uncivilised  which  are  comprised  within  the 
limits  of  the  British  Empire.  At  the  meeting  of  this 
Association  held  last  year  at  Liverpool  it  was  resolved  by 
the  General  Committee  "  that  it  is  of  urgent  importance 
to  press  upon  the  Government  the  necessity  of  estab- 
lishing a  Bureau  of  Ethnology  for  Greater  Britain,  which 
by  colledting  information  with  regard  to  the  native  races 
within  and  on  the  borders  af  the  Empire  will  prove  of 
immense  value  to  science  and  to  the  Government  itself." 
It  has  been  suggested  that  such  a  bureau  might  with  the 
greatest  advantage  and  with  the  least  outlay  and  per- 
manent expense  be  connected  either  with  the  British 
Museum  or  with  the  Imperial  Institute,  and  the  projedt 
has  already  been  submitted  for  the  consideration  of  the 
Trustees  of  the  former  establishment. 

The  existence  of  an  almost  unrivalled  ethnological  col- 
legion  in  the  museum,  and  the  presence  there  of  officers 
already  well  versed  in  ethnological  research,  seem  to 
afford  an  argument  in  favour  of  the  proposed  bureau  being 
connected  with  it.  On  the  other  hand,  the  Imperial  Insti- 
tute was  founded  with  an  especial  view  to  its  being  a 
centre  around  which  every  interest  connedted  with  the 
dependencies  of  the  Empire  might  gather  for  information 
and  support.     The  establishment  within  the  last  twelve 


CkRMICAL  NbwS.  ) 

Aug.  20.  1897.     / 


British  Association, — Professor  Ramsay*s  Address, 


^i 


months  of  a  Scientific  Department  within  the  Institute, 
with  well-appointed  laboratories  and  a  highly  trained 
staff,  shows  how  ready  are  those  concerned  in  its  manage- 
ment to  undertake  any  duties  that  may  conduce  to  the 
welfare  of  the  outlying  parts  of  the  British  Empire;  afaft 
of  which  I  believe  that  Canada  is  fully  aware.  The  Insti- 
tute is  therefore  likely  to  develop,  so  far  as  its  scientific 
department  is  concerned,  into  a  Bureau  of  advice  in  all 
matters  scientific  and  technical,  and  certainly  a  Bureau  of 
Ethnology  such  as  that  suggested  would  not  be  out  of 
place  within  its  walls. 

Wherever  such  an  institution  is  to  be  established,  the 
question  of  its  existence  must  of  necessity  rest  with  Her 
Majesty's  Government  and  Treasury,  inasmuch  as  without 
funds,  however  moderate,  the  undertaking  cannot  be 
carried  on.  I  trust  that  in  considering  the  question  it 
will  always  be  borne  in  mind  that  in  the  relations  between 
civilised  and  uncivilised  nations  and  races  it  is  of  the  first 
importance  that  the  prejudices  and  especially  the  religious 
or  semi-religious  and  caste  prejudices  of  the  latter  should 
be  thoroughly  well  known  to  the  former.  If  but  a  single 
"little  war"  could  be  avoided  in  consequence  of  the  know- 
ledge acquired  and  stored  up  by  the  Bureau  of  Ethnology 
preventing  such  a  misunderstanding  as  might  culminate 
in  warfare,  the  cost  of  such  an  institution  would  quickly 
be  saved. 

I  fear  that  it  will  be  thought  that  I  have  dwelt  too  long 
on  primaeval  man  and  his  modern  representatives,  and  that 
I  should  have  taken  this  opportunity  to  discuss  some  more 
general  subject,  such  as  the  advances  made  in  the  various 
departments  of  science  since  last  this  Association  met  in 
Canada.  Such  a  subjecSt  would  no  doubt  have  afforded  an 
infinity  of  interesting  topics  on  which  to  dilate.  Spedlrum 
analysis,  the  origin  and  nature  of  celestial  bodies,  photo- 
graphy, the  connection  between  heat,  light,  and  eledlricity, 
the  pra(5tical  applications  of  the  latter,  terrestrial  mag- 
netism, the  liquefadion  and  solidification  of  gases,  the 
behaviour  of  elements  and  compounds  under  the  influence 
of  extreme  cold,  the  nature  and  uses  of  the  Rontgen  rays, 
the  advances  in  baderiology  and  in  prophyladtic  medicine, 
might  all  have  been  passed  under  review,  and  to  many  of 
my  audience  would  have  seemed  to  possess  greater  claims 
to  attention  than  the  subjecSt  that  I  have  chosen. 

It  must,  however,  be  borne  in  mind  that  most,  if  not 
indeed  all,  of  these  topics  will  be  discussed  by  more  com- 
petent authorities  in  the  various  Seftions  of  the  Associ- 
ation by  means  of  the  Presidential  addresses  or  otherwise. 
Nor  must  it  be  forgotten  that  I  occupy  this  position  as  a 
representative  of  Archaeology,  and  am  therefore  justified 
in  bringing  before  you  a  subjedt  in  which  every  member 
of  every  race  of  mankind  ought  to  be  interested — the 
antiquity  of  the  human  family  and  the  scenes  of  its 
infancy. 

Others  will  diredl  our  thoughts  in  other  diredlions,  but 
the  farther  we  proceed  the  more  clearly  shall  we  realise 
the  connection  and  interdependence  of  all  departments  of 
science.  Year  after  year,  as  meetings  of  this  Association 
take  place,  we  may  also  foresee  that  "many  shall  run  to 
and  fro  and  knowledge  shall  be  increased."  Year  after 
year  advances  will  be  made  in  science,  and  in  reading 
that  Book  of  Nature  that  lies  ever  open  before  our  eyes  ; 
successive  stones  will  be  brought  for  building  up  that 
Temple  of  Knowledge  of  which  our  fathers  and  we  have 
laboured  to  lay  the  foundations.  May  we  not  well  exclaim 
with  old  Robert  Recorde  ? — 

"  Oh  woorthy  temple  of  Goddes  magnificence :  Oh 
throne  of  glorye  and  seate  of  the  lorde :  thy  substance 
most  pure  what  tonge  can  describe  ?  thy  signes  are  so 
wonderous,  surmountinge  mannes  witte,  the  effedls  of  thy 
motions  so  diuers  in  kinde :  so  harde  for  to  searche,  and 
worse  for  to  fynde— Thy  woorkes  are  all  wonderous,  thy 
cunning  unknowen  :  yet  seedes  of  all  knowledge  in  that 
booke  are  sowen — And  yet  in  that  boke  who  rightly  can 
reade,  to  all  secrete  knowledge  it  will  him  straighte  leade  " 
(Preface  to  Robert  Recorde's  Castle  of  Knowledge^ 
X556). 


ADDRESS     TO    THE    CHEMICAL    SECTION 

OF    THE 

BRITISH    ASSOCIATION. 
Toronto,  1897. 

By  Professor  WILLIAM  RAMSAY,  Ph.D..  LL.D.,  Sc.D.,  F.R.S., 

President  of  the  Section. 

An  Undiscovered  Gas, 
A  SECTIONAL  address  to  members  of  the  British  Associa- 
tion falls  under  one  of  three  heads.  It  may  be  historical, 
or  actual,  or  prophetic  ;  it  may  refer  to  the  past,  the  pre- 
sent, or  the  future.  In  many  cases,  indeed  in  all,  this 
classification  overlaps.  Your  former  Presidents  have 
given  sometimes  a  historical  introduction,  followed  by  an 
account  of  the  aCtual  state  of  some  branch  of  our  science, 
and,  though  rarely,  concluding  with  prophetic  remarks. 
To  those  who  have  an  affeCtion  for  the  past,  the  historical 
side  appeals  forcibly ;  to  the  practical  man,  and  to  the  in- 
vestigator engaged  in  research,  the  aCtual,  perhaps,  pre- 
sents more  charm,  while  to  the  general  public,  to  whom 
novelty  is  often  more  of  an  attra^ion  than  truth,  the  pro- 
phetic aspect  excites  most  interest.  In  this  address  I 
must  endeavour  to  tickle  all  palates  ;  and  perhaps  I  may 
be  excused  if  I  take  this  opportunity  of  indulging  in  the 
dangerous  luxury  of  prophecy,  a  luxury  which  the 
managers  of  scientific  journals  do  not  often  permit  their 
readers  to  taste. 

The  subject  of  my  remarks  to-day  is  a  new  gas.  I 
shall  describe  to  you  later  its  curious  properties;  but  it 
would  be  unfair  not  to  put  you  at  once  in  possession  of 
the  knowledge  of  its  most  remarkable  property— it  has 
not  yet  been  discovered.  As  it  is  still  unborn,  it  has  not 
yet  been  named.  The  naming  of  a  new  element  is  no 
easy  matter.  For  there  are  only  twenty-six  letters  in  our 
alphabet,  and  there  are  already  over  seventy  elements. 
To  select  a  name  expressible  by  a  symbol  which  has  not 
already  been  claimed  by  one  of  the  known  elements  is 
difficult,  and  the  difficulty  is  enhanced  when  it  is  at  the 
same  time  required  to  seleCt  a  name  which  shall  be 
descriptive  of  the  properties  (or  want  of  properties)  of  the 
element. 

It  is  now  my  task  to  bring  before  you  the  evidence  for 
the  existence  of  this  undiscovered  element. 

It  was  noticed  by  Dobereiner,  as  long  ago  as  1817,  that 
certain  elements  could  be  arranged  in  groups  of  three. 
The  choice  of  the  elements  selected  to  form  these  triads 
was  made  on  account  of  their  analogous  properties,  and 
on  the  sequence  of  their  atomic  weights,  which  had  at 
that  time  only  recently  been  discovered.  Thus  calcium, 
strontium,  and  barium  formed  such  a  group  ;  their  oxides, 
lime,  strontia,  and  baryta  are  all  easily  slaked,  combining 
with  water  to  form  soluble  lime-water,  strontia-water,  and 
baryta-water.  Their  sulphates  are  all  sparingly  soluble, 
and  resemblance  had  been  noticed  between  their  respec- 
I  tive  chlorides  and  between  their  nitrates.  Regularity  was 
{  also  displayed  by  their  atomic  weights.  The  numbers 
then  accepted  were  20,  42*5,  and  65;  and  the  atomic 
weight  of  strontium,  42*5,  is  the  arithmetical  mean  of 
those  of  the  other  two  elements,  for  (65-H2o)/2=42'5. 
The  existence  of  other  similar  groups  of  three  was  pointed 
out  by  Dobereiner,  and  such  groups  became  known  as 
"  Dobereiner's  triads." 

Another  method  of  classifying  the  elements,  also 
depending  on  their  atomic  weights,  was  suggested  by 
Pettenkofer,  and  afterwards  elaborated  by  Kremers, 
Gladstone,  and  Cooke.  It  consisted  in  seeking  for  some 
expression  which  would  represent  the  differences  between 
the  atomic  weights  of  certain  allied  elements.  Thus,  the 
difference  between  the  atomic  weight  of  lithium,  7,  and 
sodium,  23,  is  16 ;  and  between  that  of  sodium  and  of 
potassium,  39,  is  also  16.  The  regularity  is  not  always  80 
conspicuous;  Dumas,  in  1857,  contrived  a  somewhat 
complicated  expression  which,  to  some  extent,  exhibited 
regularity  in  the  atomic  weights  of  fluorine,  chlorine,  bro* 


92 


British  Association. — Professor  Ramsay's  Address. 


Chemical  Nswki 
Aug.  20, 1897. 


mine,  and  iodine ;    and   also  of   nitrogen,  phosphorus, 
arsenic,  antimony,  and  bismuth. 

The  upshot  of  these  efforts  to  discover  regularity  was 
that,  in  1864,  Mr.  John  Newlands,  having  arranged  the 
elements  in  eight  groups,  found  that  when  placed  in  the 
order  of  their  atomic  weights,  "  the  eighth  element, 
starting  from  a  given  one,  is  a  kind  of  repetition  of  the 
first,  like  the  eighth  note  of  an  oftave  in  music."  To  this 
regularity  he  gave  the  name  •'  The  Law  of  Odtaves." 

The  development  of  this  idea,  as  all  chemists  know,  was 
due  to  the  late  Professor  Lothar  Meyer,  of  Tiibingen,  and 
to  Professor  Mendeleeff,  of  St.  Petersburg.  It  is  generally 
known  as  the  "  Periodic  Law."  One  of  the  simplest 
methods  of  showing  this  arrangement  is  by  means  of  a 
cylinder  divided  into  eight  segments  by  lines  drawn 
parallel  to  its  axis  ;  a  spiral  line  is  then  traced  round  the 
cylinder,  which  will,  of  course,  be  cut  by  these  lines 
eight  times  at  each  revolution.  Holding  the  cylinder 
vertically,  the  name  and  atomic  weight  of  an  element  is 
written  at  each  intersedlion  of  the  spiral  with  a  vertical 
line,  following  the  numerical  order  of  the  atomic  weights. 
It  will  be  found,  according  to  Lothar  Meyer  and  Men- 
deleeff, that  the  elements  grouped  down  each  of  the  verti- 
cal lines  form  a  natural  class  ;  they  possess  similar  pro- 
perties, form  similar  compounds,  and  exhibit  a  graded  re- 
lationship between  their  densities,  melting-points,  and 
many  of  their  other  properties.  One  of  these  vertical 
columns,  however,  differs  from  the  others,  inasmuch  as  on 
it  there  are  three  groups,  each  consisting  of  three  ele- 
ments with  approximately  equal  atomic  weights.  The 
elements  in  question  are  iron,  cobalt,  and  nickel ;  pal- 
ladium, rhodium,  and  ruthenium  ;  and  platinum,  iridium, 
and  osmium.  There  is  apparently  room  for  a  fourth 
group  of  three  elements  in  this  column,  and  it  may  be  a 
fifth.  And  the  discovery  of  such  a  group  is  not  unlikely, 
for  when  this  table  was  first  drawn  up  Professor  Men- 
deleeff drew  attention  to  certain  gaps,  which  have  since 
been  filled  up  by  the  discovery  of  gallium,  germanium,  and 
others. 

The  discovery  of  argon  at  once  raised  the  curiosity  of 
Lord  Rayleigh  and  myself  as  to  its  position  in  this  table. 
With  a  density  of  nearly  20,  if  a  diatomic  gas,  like  oxygen 
and  nitrogen,  it  would  follow  fluorine   in   the  periodic 
table ;  and  our  first  idea  was  that  argon  was  probably  a 
mixture  of  three  gases,  all  of  which  possessed  nearly  the 
same  atomic  weights,  like  iron,  cobalt,  and  nickel.    In- 
deed, their  names  were  suggested,  on  this  supposition, 
with  patriotic  bias,  as  Anglium,  Scotium,  and  Hibernium  ! 
But  when  the  ratio  of  its  specific  heats  had,  at  least  in 
our  opinion,  unmistakably  shown  that  it  was  molecularly 
monatomic,  and  not  diatomic,  as  at  first  conje(5tured,  it 
was  necessary  to  believe  that  its  atomic  weight  was  40, 
and  not  20,  and  that  it  followed  chlorine  in  the  atomic 
table,  and  not  fluorine.    But  here  arises  a  difficulty.    The 
atomic  weight  of  chlorine  is  35*5,  and  that  of  potassium, 
the  next  element  in  order  in  the  table,  is  39-1 ;  and  that 
of  argon,  40,  follows,  and  does  not  precede,  that  of  potas- 
sium, as  it  might  be  expected  to  do.     It  still  remains  pos- 
sible that  argon,  instead  of  consisting  wholly  of  monatomic 
molecules,  may  contain  a  small  percentage  of  diatomic 
molecules;  but  the  evidence  in  favour  of  this  supposition 
is,  in  my  opinion,  far  from  strong.     Another  possibility  is 
that  argon,  as  at  first  conjedured,  may  consist  of  a  mix- 
ture of  more  than  one  element ;  but  unless  the  atomic 
weight  of  one  of  the  elements  in  the  supposed  mixture  is 
very  high,  say  82,  the  case  is  not  bettered,  for  one  of  the 
elements  in  the  supposed  trio  would  still  have  a  higher 
atomic  weight  than  potassium.    And  very  careful  experi- 
ments, carried  out  by  Dr.  Norman  Collie  and  myself,  on 
the  fractional  diffusion  of  argon,  have  disproved  the  exist- 
ence of  any  such  element  with  high  atomic  weight  in 
argon,  and,  indeed,  have  pra(5tically  demonstrated  that 
argon  is  a  simple  substance,  and  not  a  mixture. 

The  discovery  of  helium  has  thrown  a  new  light  on  this 
subjedt.  Helium,  it  will  be  remembered,  is  evolved  on 
heating    certain    minerals,    notably    those    containing 


uranium ;  although  it  appears  to  be  contained  in  others 
in  which  uranium  is  not  present,  except  in  traces.  Among 
these  minerals  are  cleveite,  monazite,  fergusonite,  and  a 
host  of  similar  complex  mixtures,  all  containing  rare  ele- 
ments, such  as  niobium,  tantalum,  yttrium,  cerium,  &c. 
The  spedtrum  of  helium  is  charadterised  by  a  remarkably 
brilliant  yellow  line,  which  had  been  observed  as  long  ago 
as  1868  by  Professors  Frankland  and  Lockyerin  the  spec- 
trum of  the  sun's  chromosphere,  and  named  •'  helium  "  at 
that  early  date. 

The  density  of  helium  proved  to  be  very  close  to  2'0, 
and,  like  argon,  the  ratio  of  its  speciflc  heat  showed  that 
it,  too,  was  a  monatomic  gas.  Its  atomic  weight  there- 
fore is  identical  with  its  molecular  weight,  viz.,  4'o,  and 
its  place  in  the  periodic  table  is  between  hydrogen  and 
lithium,  the  atomic  weight  of  which  is  j'o. 

The  difference  between  the  atomic  weights  of  helium 
and  argon  is  thus  36,  or  40  — 4.  Now  there  are  several 
cases  of  such  a  difference.  For  instance,  in  the  group  the 
first  member  of  which  is  fluorine  we  have — 


Fluorine ig 

Chlorine 35*5 

Manganese 55 


i6-5 
19-5 


In  the  oxygen  group — 

Oxygen 16     ^q 

Sulphur 32 

Chromium 52*3 


20*3 


In  the  nitrogen  group — 

Nitrogen       14 

Phosphorus 31        ' 


Vanadium 51*4 

And  in  the  carbon  group — 

Carbon 12 

Silicon 28'3 


Titanium 


48-1 


20*4 


i6-3 
ig-S 


These  instances  suffice  to  show  that  approximately  the 
differences  are  16  and  20  between  consecutive  members 
of  the  corresponding  groups  of  elements.  The  total  dif- 
ferences between  the  extreme  members  of  the  short  series 
mentioned  are — 


Manganese  —  Fluorine 
Chromium  —  Oxygen 
Vanadium  —  Nitrogen 
Titanium  —  Carbon 


36 
36-3 
37-4 
36' I 


This  is  approximately  the  difference  between  the  atomic 
weights  of  helium  and  argon,  36. 

There  should,  therefore,  be  an  undiscovered  element  be- 
tween helium  and  argon,  with  an  atomic  weight  16  units 
higher  than  that  of  helium,  and  20  units  lower  than  that 
of  argon,  namely  20.  And  if  this  unknown  element,  like 
helium  and  argon,  should  prove  to  consist  of  monatomic 
molecules,  then  its  density  should  be  half  its  atomic 
weight,  10.  And  pushing  the  analogy  still  farther,  it  is 
to  be  expedled  that  this  element  should  be  as  indifferent 
to  union  with  other  elements  as  the  two  allied  elements. 

My  assistant,  Mr.  Morris  Travers,  has  indefatigably 
aided  me  in  a  search  for  this  unknown  gas.  There  is  a 
proverb  about  looking  for  a  needle  in  a  haystack ;  modern 
science,  with  the  aid  of  suitable  magnetic  appliances, 
would,  if  the  reward  were  sufficient,  make  short  work  of 
that  proverbial  needle.  But  here  is  a  supposed  unknown 
gas,  endowed  no  doubt  with  negative  properties,  and  the 
whole  world  to  find  it  in.  Still,  the  attempt  had  to  be 
made. 

We  first  diredted  our  attention  to  the  sources  of  helium 
— minerals.  Almost  every  mineral  which  we  could  ob- 
tain was  heated  in  a  vacuum,  and  the  gas  which  was 
evolved  examined.  The  results  are  interesting.  Most 
minerals  give  off  gas  when  heated,  and  the  gas  contains, 
[  as  a  rule,  a  considerable  amount  of  hydrogen,  mixed  with 


CHBUICAL  MBWS,t 

Aug.  20, 1897.     I 


Bacteriological  Study  of  A  mbergris. 


93 


carbonic  acid,  questionable  traces  of  nitrogen,  and  car- 
bonic oxide.  Many  of  the  minerals,  in  addition,  gave 
helium,  which  proved  to  be  widely  distributed,  though 
only  in  minute  proportion.  One  mineral — malacone — 
gave  appreciable  quantities  of  argon ;  and  it  is  note- 
worthy that  argon  was  not  found  except  in  it  (and, 
curiously,  in  much  larger  amount  than  helium),  and  in  a 
specimen  of  meteoric  iron.  Other  specimens  of  meteoric 
iron  were  examined,  but  were  found  to  contain  mainly 
hydrogen,  with  no  trace  of  either  argon  or  helium.  It  is 
probable  that  the  sources  of  meteorites  might  be  traced 
in  this  manner,  and  that  each  could  be  relegated  to  its 
particular  swarm. 

Among  the  minerals  examined  was  one  to  which  our 
attention  had  been  diredled  by  Professor  Lockyer,  named 
eliasite,  from  which  he  said  that  he  had  extra(5led  a 
gas  in  which  he  had  observed  speftrum  lines  foreign  to 
helium.  He  was  kind  enough  to  furnish  us  with  a  speci- 
men of  this  mineral,  which  is  exceedingly  rare,  but  the 
sample  which  we  tested  contained  nothing  but  undoubted 
helium. 

During  a  trip  to  Iceland  in  1895,  I  colledted  some  gas 
from  the  boiling  springs  there  ;  it  consisted,  for  the  most 
part,  of  air,  but  contained  somewhat  more  argon  than  is 
usually  dissolved  when  air  is  shaken  with  water.  In  the 
spring  of  1896  Mr.  Travers  and  I  made  a  trip  to  the 
Pyrenees  to  collet  gas  from  the  mineral  springs  of 
Cauterets,  to  which  our  attention  had  been  diredted  by 
Dr.  Bouchard,  who  pointed  out  that  these  gases  are  rich 
in  helium.  We  examined  a  number  of  samples  from  the 
various  springs,  and  confirmed  Dr.  Bouchard's  results, 
but  there  was  no  sign  of  any  unknown  lines  in  the  spec- 
trum of  these  gases.     Our  quest  was  in  vain. 

We  must  now  turn  to  another  aspeft  of  the  subjeiSl. 
Shortly  after  the  discovery  of  helium,  its  speftrum  was 
very  carefully  examined  by  Professors  Runge  and 
Paschen,  the  renowned  spedtroscopists.  The  spectrum 
was  photographed,  special  attention  being  paid  to  the  in- 
visible portions,  termed  the  "  ultra-violet  "  and  "  infra- 
red.'' The  lines  thus  registered  were  found  to  have  a 
harmonic  relation  to  each  other.  They  admitted  of 
division  into  two  sets,  each  complete  in  itself.  Now,  a 
similar  process  had  been  applied  to  the  spedtrum  of 
lithium  and  to  that  of  sodium,  and  the  spedtra  of  these 
elements  gave  only  one  series  each.  Hence,  Professors 
Runge  and  Paschen  concluded  that  the  gas,  to  which  the 
provisional  name  of  helium  had  been  given,  was,  in 
reality,  a  mixture  of  two  gases,  closely  resembling  each 
other  in  properties.  As  we  know  no  other  elements  with 
atomic  weights  between  those  of  hydrogen  and  lithium, 
there  is  no  chemical  evidence  either  for  or  against  this 
supposition.  Professor  Runge  supposed  that  he  had  ob- 
tained evidence  of  the  separation  of  these  imagined  ele- 
ments from  each  other  by  means  of  diffusion  ;  but  Mr. 
Travers  and  I  pointed  out  that  the  same  alteration  of 
spedlrum,  which  was  apparently  produced  by  diffusion, 
could  also  be  caused  by  altering  the  pressure  of  the  gas 
in  the  vacuum  tube ;  and  shortly  after  Professor  Runge 
acknowledged  his  mistake. 

These  considerations,  however,  made  it  desirable  to 
subjedt  helium  to  systematic  diffusion,  in  the  same  way 
as  argon  had  been  tried.  The  experiments  were  carried 
out  in  the  summer  of  1896  by  Dr.  Collie  and  myself.  The 
result  was  encouraging,  It  was  found  possible  to  sepa- 
rate helium  into  two  portions  of  different  rates  of  diffusion, 
and  consequently  of  different  density  by  this  means.  The 
limits  of  separation,  however,  were  not  very  great.  On 
the  one  hand,  we  obtained  gas  of  a  density  close  on  2'o  ; 
and  on  the  other,  a  sample  of  density  2-4  or  thereabouts. 
The  difficulty  was  increased  by  the  curious  behaviour, 
which  we  have  often  had  occasion  to  confirm,  that  helium 
possesses  a  rate  of  diffusion  too  rapid  for  its  density. 
Thus,  the  density  of  the  lightest  portion  of  the  diffused 
gas,  calculated  from  its  rate  of  diffusion,  was  i'874 ;  but 
this  corresponds  to  a  real  density  of  about  2*0.  After  our 
paper,  giving  an  account  of  these  experiments,  had  been 


published,  a  German  investigator,  Herr  A,  Hagenbach, 
repeated  our  work  and  confirmed  our  results. 

The  two  samples  of  gas  of  different  density  differ  also 
in  other  properties.  Different  transparent  substances 
differ  in  the  rate  at  which  they  allow  light  to  pass  through 
them.  Thus,  light  travels  through  water  at  a  much  slower 
rate  than  through  air,  and  at  a  slower  rate  through  air 
than  through  hydrogen.  Now  Lord  Rayleigh  found  that 
helium  offers  less  opposition  to  the  passage  of  light  than 
any  other  substance  does,  and  the  heavier  of  the  two  por- 
tions  into  which  helium  had  been  split  offered  more  oppo- 
sition than  the  lighter  portion.  And  the  retardation  of 
the  light,  unlike  what  has  usually  been  observed,  was 
nearly  proportional  to  the  densities  of  the  samples.  The 
spedtrum  of  these  two  samples  did  not  differ  in  the 
minutest  particular  ;  therefore  it  did  not  appear  quite  out 
of  the  question  to  hazard  the  speculation  that  the  process 
of  diffusion  was  instrumental,  not  necessarily  in  sepa- 
rating two  kinds  of  gas  from  each  other,  but  adtually  in 
removing  light  molecules  of  the  same  kind  from  heavy 
molecules.  This  idea  is  not  new.  It  had  been  advanced  by 
Prof.  Schiatzenberger(whose  recent  death  all  chemists  have 
to  deplore),  and  later,  by  Sir  William  Crookes,  that  what 
we  term  the  atomic  weight  of  an  element  is  a  mean ; 
that  when  we  say  that  the  atomic  weight  of  oxygen  is  16, 
we  merely  state  that  the  average  atomic  weight  is  16 ;  and 
it  is  not  inconceivable  that  a  certain  number  of  molecules 
have  a  weight  somewhat  higher  than  32,  while  a  certain 
number  have  a  lower  weight. 

We  therefore  thought  it  necessary  to  test  this  question 
by  diredt  experiment  with  some  known  gas  ;  and  we  chose 
nitrogen,  as  a  good  material  with  which  to  test  the  point. 
A  much  larger  and  more  convenient  apparatus  for  diffusing 
gases  was  built  by  Mr.  Travers  and  myself,  and  a  set  of 
systematic  diffusions  of  nitrogen  was  carried  out.  After 
thirty  rounds,  corresponding  to  180  diffusions,  the  density 
of  the  nitrogen  was  unaltered,  and  that  of  the  portion 
which  should  have  diffused  most  slowly,  had  there  been 
any  difference  in  rate,  was  identical  with  that  of  the  most 
quickly  diffusing  portion — i.e.,  with  that  of  the  portion 
which  passed  first  through  the  porous  plug.  This  attempt, 
therefore,  was  unsuccessful;  but  it  was  worth  carrying 
out,  for  it  is  now  certain  that  it  is  not  possible  to  separate 
a  gas  of  undoubted  chemical  unity  into  portions  of  dif 
ferent  density  by  diffusion.  And  these  experiments 
rendered  it  exceedingly  improbable  that  the  difference  in 
density  of  the  two  fractions  of  helium  was  due  to  separa- 
tion of  light  molecules  of  helium  from  heavy  molecules. 

(To  be  continued). 


BACTERIOLOGICAL     STUDY    OF    AMBERGRIS. 
By  H.  BEAUREGARD. 

I  HAVE  formerly  shown,  in  concert  with  the  regtetted 
Professor  G.  Gouchet,  that  ambergris  is  an  interesting 
calculus  which  is  developed  and  has  its  seat  in  the  redtum 
of  the  sperm  whale. 

This  calculus,  composed  of  crystals  of  ambrine  mixed 
with  a  larger  or  smaller  amount  of  black  pigment  derived 
from  the  redtal  lining,  contains  also  star-coral  debris. 
When  it  is  fresh,  i.  e.,  when  it  is  just  extradled  from  the 
redtum  by  the  fishermen,  it  is  of  a  soft  consistency,  and 
its  odour  is  not  at  all  agreeable  on  account  of  its 
predominant  excrementitious  charadter.  But  after  being 
preserved  for  some  years  in  an  air-tight  tin  case  it  is 
gradually  freed  from  this  excrementitious  odour,  though 
losing  little  of  its  weight,  and  retains  merely  a  delicate 
perfume  sui  generis,  which  gives  it  such  a  value  that  it 
reaches  the  price  of  from  3000  to  7000  frs.  per  kilometre. 
This  is  not  a  case  of  slow  desiccation,  and  cannot  be  imi- 
tated or  accelerated  by  the  withdrawal  of  water.  The 
change  is  due  to  a  microbe  for  which  the  author  proposes 


b4 


Report  of  Her  Majesty's  Inspectors  of  Explosives. 


f  Chbuical  News, 
1     Aug.  20,  1897. 


the  name  Spirillum  recti  Physeteris.  As  regards  poly- 
morphism this  microbe  is  comparable  to  the  spirillum  of 
cholera.  It  is  probable  that  the  destrudlion  of  the  faecal 
odour  and  the  genesis  of  the  delicate  perfume  are  micro- 
bial phenomena.  It  remains  to  determine  if  the  spirillum 
in  question  is  pathogenous,  at  lest  for  terrestrial  animals. 
— Comptes  Rendus,  cxxv.,  p.  254. 


NOTICES  OF  BOOKS. 


Twenty-first  Annual  Report  of  Her  Majesty^ s  Inspectors  of 

Explosives  ;  being  their  Annual  Report  for  the  Year  1896. 

Pp.  184.  London  :  Eyre  and  Spottiswoode.  1897. 
During  the  past  year  a  further  modification  of  the 
Explosives  A£t  of  1875  has  taken  place,  the  Orders  in 
Council  relating  to  premises  registered  for  mixed  ex- 
plosives having  been  repealed,  and  a  new  Order  (No.  16) 
substituted.  The  main  objeift  of  this  new  Order  was  to 
give  relief  in  the  storage  of  small-arm  nitro-compounds. 

The  number  of  fadtories  making  explosives  has  had  a 
further  increase,  five  new  ones  having  been  started  since 
1895,  while  seven  applications  for  new  licenses  are  still 
under  consideration.  In  the  case  of  magazines  there  is  a 
net  increase  of  two,  and  there  are  nine  further  applications 
under  consideration. 

Every  fadtory  has  been  visited  by  the  Inspedlors  at  least 
once  a  year,  and  nearly  one-half  of  them  twice ;  and  it  is 
satisfactory  to  note  that  there  has  been  no  falling  off  in 
the  high  standard  previously  attained  in  the  great  majority 
of  these  establishments,  while  some  which  had  been  be- 
hind have  been  much  improved. 

A  striking  example  of  the  great  improvement  in  the 
condudt  of  the  fadtories,  since  the  passing  of  the  Explo- 
sives Adt,  is  to  be  found  in  the  fad  that  only  one  death 
from  accidents  by  fire  or  explosion  in  any  fadtory  has 
occurred  during  the  year,  and  this  in  spite  of  the  large 
increase  in  the  number  of  fadtories,  which  is  now  139, 
though  three  are  temporarily  closed. 

In  Appendix  A  will  be  found  a  table  of  all  fadtories  now 
in  existence,  with  the  classes  of  explosives  authorised  to 
be  manufadtured  therein ;  and  Appendix  E  gives  their 
distribution  about  the  country.  There  have  been  six 
additions  to  the  list  of  authorised  explosives  during  the 
year,  particulars  of  which  are  set  forth  in  Appendix  D  (i). 
As  already  explained  in  a  previous  Report,  all  nitro- 
cotton  is  now  admitted  to  be  explosive  ;  collodion  cotton, 
therefore,  appears  on  the  authorised  list,  but  the  ex- 
emptions— when  it  is  in  solution  in  alcohol  and  ether,  or 
wet  with  methylated  spirit,  and  enclosed  in  air-tight  cases, 
still  hold  good. 

Of  the  358  samples  taken  during  the  year,  and  examined 
by  Dr.  Dupre,  only  32  were  rejedted,  and  of  these  9  were 
amorces. 

One  convidtion  has  been  obtained  during  the  year  for 
manufadluring  fireworks  containing  sulphur  and  chlorate, 
contrary  to  the  provisions  of  the  Order  in  Council, ;  one 
for  manufadturing  amorces  and  throw-downs  with  an  excess 
of  composition ;  while  at  two  fadtories  explosives  have 
been  placed  under  seizure.  Although,  as  we  mentioned 
above,  there  has  been  only  one  death  from  accident,  there 
have  been  46  accidents  from  one  cause  and  another,  by 
which  in  addition  26  persons  were  injured  :  details  are  to 
be  found  in  Appendix  W,  and  in  the  accident  sedtion  of 
this  Report. 

It  is  satisfadtory  to  see  that  no  case  of  illegal  manu- 
fadture  has  come  under  the  notice  of  the  Inspedtors  during 
the  year. 

There  have  been  416  visits  paid  during  the  year  to  the 
384  magazines  in  the  United  Kingdom,  and  in  every  case 
the  Inspedtors  were  well  satisfied,  and  there  has  been  no 
accident  by  fire  or  explosion  at  any  one  of  them  during 
this  period.    There  has  been  no  fault  found  with  the 


charadter  of  the  packing  of  explosives,— as  a  rule  it  has 
been  excellent. 

The  amount  of  foreign  nitro-glycerin  compounds  im- 
ported during  1896  shows  a  considerable  increase  over 
that  imported  in  1895  !  *he  increase  being  from  880,070 
lbs.  to  1,259,200  lbs.,  most  of  which  was  in  carbonite  : 
this  explosive  now  heads  the  list,  gelatin-dynamite  no 
longer  holding  first  place. 

The  Inspedtors  have  no  reason  to  modify  their  previously 
expressed  opinion  that  their  powers  of  search  and  seizure 
are  ample  and  satisfadtory.  The  total  cases  of  seizure 
of  all  sorts  was  15,  the  average  for  the  previous  ten  years 
being  24*9. 

As  usual,  the  registered  premises  have  been  the  most 
troublesome  branch  of  the  Inspedtor's  duties  ;  their  num 
her,  their  distribution,  and  the  apparently  extreme 
ignorance  of  the  occupiers  in  many  cases  renders  it  diffi- 
cult to  make  much  impression  on  them  as  a  mass, — still 
it  is  exceptional  now  to  find  large  excesses  of  explosives 
stored  in  them. 

A  detailed  list  of  all  the  accidents  which  came  under 
the  notice  of  the  Inspedlors  is  given ;  perhaps  the  most 
interesting  of  these  was  the  one  at  the  Arklow  Fadtory 
on  December  ist.  A  charge  of  glycerin  was  being  ni- 
trated in  the  ordinary  way,  and  it  is  believed  that  about 
60  lbs.  of  nitro-glycerin  was  in  the  nitrator.  The  acids 
had  been  blown  in,  and  cooled,  and  the  injedtion  of  gly- 
cerin had  proceeded  for  about  ten  minutes,  when  suddenly, 
without  warning,  the  charge  fumed  off.  The  connedlions 
to  the  drowning  tank  were  immediately  opened,  but  it  was 
subsequently  found  that  no  nitro-glycerin  was  among  the 
water  and  acids  in  the  drowning  tank,  this  leading  to  the 
conclusion  that  the  whole  of  the  60  lbs.  of  nitro-glycerin 
had  fumed  off,  in  the  few  seconds  from  the  first  establish- 
ment of  the  adtion  to  the  escape  of  the  charge  into  the 
drowning  tank ;  and  as  the  thermometer  did  not  show 
any  increase  of  temperature — it  stood  at  12°  C. — it  is 
assumed  that  a  leak  in  one  of  the  coils  had  occurred  and 
caused  a  local  rise  of  temperature  :  such  a  leak  was  found 
after  the  accident,  though  it  is  confidently  stated  that  the 
coils  were  tested  by  air  pressure  before  the  commence- 
ment of  the  operation,  and  that  no  leak  existed  then. 
Fortunately  there  was  no  loss  of  life  or  personal  injury. 

Among  foreign  explosions,  one  of  the  most  tremendous 
of  modern  times  occurred  on  the  19th  of  February,  at 
Johannesberg,  South  Africa,  when  no  less  than  55  tons 
of  blasting  gelatin,  contained  in  ten  trucks,  exploded  on 
the  railway,  about  300  yards  from  Johannesburg  station, 
under  circumstances  which  in  our  opinion  amount  to 
criminal  negligence,  and  almost  inconceivable  stupidity. 
The  trucks  containing  the  blasting  gelatin  had  been 
standing  for  three  and  a  half  days,  without  supervision, 
in  the  blazing  sun,  in  a  place  surrounded  by  human  habita- 
tions ;  dynamite  and  detonators  were  carried  in  the  same 
truck  ;  the  trucks  were  so  badly  packed  that  several  cases 
of  dynamite  had  fallen  off  in  transit,  and,  further,  this 
particular  consignment  was  not  packed  in  cases  thick 
enough  and  strong  enough  according  to  the  law.  It  is  not 
so  much  a  matter  of  surprise  that,  when  a  train  that  was 
being  shunted  ran  into  the  trucks,  owing  to  the  points 
being  wrongly  turned,  an  explosion  took  place,  as  it  is, 
that  in  this  maze  of  ignorance  and  carelessness  many 
other  explosions  had  not  already  occurred. 


A  Course  of  Practical  Chemistry.  By  M.  M.  Pattison 
MuiR,  M.A.  Parti. — Elementary.  Pp.318.  London: 
Longmans,  Green,  and  Co.     1897. 

The  author's  experience  as  a  teacher  for  twenty-five 
years  has  convinced  him  that  qualitative  analysis  cannot 
be  properly  learned  at  an  early  stage  of  a  course  of  prac- 
tical chemistry.  He  therefore,  in  this  volume,  lays  more 
stress  on  the  simple  work  of  preparations,  and  experi- 
ments on  the  readtions  of  the  chief  inorganic  compounds, 
before  going  on  to  a&ual  analysis.    This  is  as  it  should 


Chemical  Nsws,  I 
Aug.  20, 1897.     f 


Chemical  Notices  Jrom  Foreign  Sources, 


05 


be ;  an  apprentice  to  a  carpenter  learns  to  saw  straight 
before  he  begins  to  make  a  cabinet. 

The  volume  now  before  us  (Part  I.)  is  divided  into 
three  sections,  and  these  again  are  subdivided  into  fifty- 
two  lessons. 

Sedlion  I.  deals  with  experiments  on  chemical  change  ; 
preparations  of  various  compounds;  and  the  readlions  oi 
acids,  alkalies,  and  salts — in  which  all  the  ordinary  ele- 
mentary work  of  a  chemical  laboratory  is  fully  described. 
There  are  also  some  notes  preceding  the  adtual  lessons 
giving  useful  hints  to  a  beginner,  straight  and  to  the 
point.  E.g.,  "  Note  II.  Always  read  the  whole  of  the 
diredlions  before  beginning  an  experiment."  "  When  you 
are  told  to  '  heat  gently,'  this  means  use  a  small  Bunsen 
flame  for  heating,  and  keep  the  flame  at  some  distance 
from  the  apparatus  to  be  heated." 

Section  II.  concerns  volumetric  estimations  of  acids, 
alkalis,  iron  salts,  chlorides,  iodine,  &c.,  the  necessary 
standard  solutions  being  given. 

In  Secftion  III.  we  arrive  at  qualitative  analysis,  begin- 
ning with  experiments  to  illustrate  the  methods  used  for 
dividing  the  metals  into  groups,  and  distinguishing  the 
several  metals  in  these  same  groups,  going  all  through  the 
six  groups,  and  finally  coming  to  the  examination  of  a 
solid  by  dry  or  blowpipe  tests. 

The  Appendices,  of  which  there  are  five,  contain, 
amongst  other  information,  instrudions  for  making  simple 
apparatus,  the  usual  tables,  list  of  reagents  and  their 
preparation,  standard  solutions,  and  a  list  of  substances 
suitable  for  the  various  exercises.  The  Index  is  good  and 
complete,  and  the  whole  arangement  of  the  book  seems 
to  be  very  convenient. 


CHEMICAL 


NOTICES   FROM 
SOURCES. 


FOREIGN 


NOTB.— All  degrees  of  temperature  are  Centigrade  unless  otherwise 
expressed. 

Cotnptes  Rendus  Hebdomadaires  des  Seances,  deVAcadetnit 
des  Sciences.    Vol.  cxxv..  No.  3,  July  19,  1897. 

The  Minister  of  Public  InstruAion  communicated  the 
text  of  the  decree  by  which  the  President  of  the  French 
Republic  approves  the  eledtion  of  Prof.  Virchow  as  a 
Foreign  Associate  vice  M.  Tchebicheff,  deceased. 

Researches  on  the  State  of  Elements  other  than 
Carbon  in  Cast-irons  and  Steels. — Ad.  Carnot  and  M. 
Goutal. — Will  be  inserted  in  full. 

Phenomenon  of  the  Eledtric  Arc. — A.  Blondei. — 
This  paper  requires  the  accompanying  diagram. 

Action  of  Eledric  Charges  on  the  property  of  Dis- 
charge created  by  the  X  Rays  in  the  Air. — E.  Villari. 
— It  is  known  that  gases  traversed  by  the  X  rays  acquire 
the  property  of  discharging  eledtrised  condudors.  I  have 
demonstrated  that  they  retain  this  property,  though  in  a 
less  degree  after  having  traversed  tubes  of  glass  or  of  lead 
of  20  metres  in  length,  or  even  upwards.  I  have  arrived 
at  the  following  conclusions: — Air  traversed  by  the  X  rays 
and  blown  against  the  end  of  a  wire  in  its  natural  state 
retains  entirely  its  discharging  power  undiminished.  If 
blown  against  the  end  of  an  eledtrised  wire  (^  it  entirely 
loses  its  power  of  discharging  an  electroscope  {-^  having 
the  same  sign  as  that  of  the  wire.  Air  traversed  by  the 
X  rays  and  drawn  against  the  approximating  ends  of  two 
wires  having  opposite  charges  loses  all  discharging  power. 
The  air  traversed  by  X  rays,  on  passing  by  an  ozoniser,  adts 
in  these  experiments  as  it  its  mols,  had  opposite  charges  by 
which  it  can  discharge  eledtrised  bodies. 

Properties  of  Gases  Traversed  by  the  X  Rays,  and 
on  the  Properties  of  Luminescence  on  Pbotograpbic 
Bodies.— G.  Sagnac. 


The  Spetftrum  of  Carbon.— A.  de  Gramont.— This 
paper  requires  the  accompanying  diagram. 

AcAion  of  Cupric  Hydrate  upon  Solutions  of  Silver 
Nitrate  and  Basic  Argentic  Cuprate.— Paul  Sabatier. 
— The  formation  of  a  basic  mixed  argento-cupric  salt  is 
not  confined  to  the  nitrates.  An  analogous  produdion 
ensues  on  setting  out  from  the  sulphates,  chlorates,  and 
hyposulphates,  as  the  author  intends  to  show  in  a  future 
communication. 

Hydrobenzamide,  Amarine,  and  Lophine. — Marcel 
Delepine. —  An  elaborate  thermo-chemical  memoir,  in 
which  we  recognise  the  constant  universality  of  the  thermic 
laws  regulating  the  chemical  transformations  of  the  com- 
plicated molecules. 

New  Syntheses  by  means  of  Cyano-succinic  Ether. 
— L.  Earth. — Not  adapted  for  useful  abstradtion. 

Certain  Compounds  of  Phenylbydrazine  and  Me- 
tallic Nitrates. — J.  Moitessier. — The  nitrates  of  the  mag- 
nesian  metals  combine  diredly  with  phenylbydrazine  like 
the  corresponding  haloid  salts,  yielding  crystalline  com- 
pounds presenting  the  readions  of  phenylbydrazine  and 
those  of  the  metals  which  they  contain.  They  deflagrate 
if  heated,  as  do  the  nitrates  in  presence  of  carbon,  leaving 
a  more  or  less  abundant  residue  of  metallic  oxide. 

On  the  Aloines. — E.  Leger. — The  aloines  may  be 
divided  into  two  groups:  the  first  including  barbaloine, 
socaloine,  zanaloine,  and  curaraloine  ;  whilst  the  second 
contains  a  single  representative,  mataloine. 


MISCELLANEOUS. 

Adion  of  X  Rays  upon  the  Temperature  of 
Animals. — L.  Lecercle. — Exposure  to  X  rays  modifies 
the  cutaneous  and  redtal  temperatures  both  in  the  same 
diredion.  Under  their  influence  these  temperatures 
sink  at  first,  and  then  rise  above  the  initial  degree. — 
Cotnptes  Rendus,  cxxv..  No.  4. 

Ai^ino-Eledric  EffeiJls  of  the  Rontgen  Rays.— S. 
Puggenheimer. — The  author  has  obtained  the  following 
results: — If  we  plunge  two  identical  electrodes  into  a 
liquid  and  expose  the  n-th  one  to  the  X  rays  there  is  set 
up  a  current  which  ordinarily  flows  from  the  plate  exposed 
to  the  X  rays  to  the  n-th  of  the  external  circuit.  The 
intensity  of  the  current  depends  on  the  intensity  of  the 
radiation.— Com/>^«5  Rendus,  cxxv.,  No.  i. 

On  the  Applications  of  Eledrolysis  to  Organic 
Chemistry. — L.  Gourwitsch. — The  aftion  of  eledrolysis 
on  the  salts  of  the  fatty  acids  nearly  always  gives  rise  to 
the  formation  of  alcohols,  ethers,  acids,  &c.,  in  quantities 
variable  according  to  the  conditions  of  the  experiment. 
A  large  number  of  experiments  made  by  Loeb,  Bourgoin, 
Kolbe,  Brown  and  Walker,  Mulliken,  and  many  others, 
are  quoted,  and  the  "  mechanism  "  of  the  reactions  are 
discussed.  Iodoform  is  now  being  prepared  eledtrolytic- 
ally  by  substitution,  by  pa'^sing  the  current  through  a 
solution  of  iodide  of  potassium  in  alcohol  or  aqueous 
acetone,  and  neutralising  the  excess  of  potash  formed  by 
carbonic  acid  ;  the  iodine  and  the  potash  formed  by  the 
adtion  of  the  current  read  with  the  solvent,  and  form 
crystals  of  perfedly  pure  iodoform.  The  nitrified  deriva- 
tives of  the  aroma;  ic  series  serve  best  for  studying  the 
redudion  by  eledrolysis.  In  1882  Kendall  patented  the 
manufaduie  01'  aniiiue  and  toluidine  by  the  actio.i  of  the 
eledric  current  on  mixtures  of  nitrobenzene  and  nitro- 
toluene  with  concentrated  sulphuric  acid  ;  but  the  return 
was  very  bad,  and  the  process  was  of  no  pradical  value. 
Twelve  years  later  the  subjed  was  again  taken  up,  and  it 
was  shown  that  aniline  was  formed  even  in  acid  solution. 
It  is  interesting  to  note  that  the  platinum  eledrodes  were 
strongly  attacked  in  the  experiments  on  carbamate  of 
ammonia,  a  complicated  platino-ammoniacal  base  being 
{oim&i.—MoniteHr  Scientifique,  xi.,  Part  1, 


96 


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the  Zenolan  and  Wambeyan  Caves,  the  Blue  Mountains, 
&c.  All  particulars  can  be  obtained  from  the  Hon. 
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NOTES    AND    QUERIES, 


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fairly  large  quantity  of  water,  say  three  or  four  pails  full,  for  use  in  a 

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D.J.  P. 


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THE    CHEMICAL    NEWS 


Vol.  LXXVI.,  No.  1970. 


ADDRESS    TO    THE    CHEMICAL    SECTION 

OF    THE 

BRITISH    ASSOCIATION. 
Toronto,  1897. 

By  Professor  WILLIAM  RAMSAY,  Ph.D.,  LL.D.,  Sc.D.,  F.R.S., 
President  of  the  Sedtion, 

(Concluded  from  p.  93). 

The  apparatus  used  for  diffusion  had  a  capacity  of  about 
two  litres.  It  was  filled  with  helium,  and  the  operation 
of  diffusion  was  carried  through  thirty  times.  There  were 
six  reservoirs,  each  full  of  gas,  and  each  was  separated 
into  two  by  diffusion.  To  the  heavier  portion  of  one  lot, 
the  lighter  portion  of  the  next  was  added,  and  in  this 
manner  all  six  reservoirs  were  successively  passed  through 
the  diffusion  apparatus.  This  process  was  carried  out 
thirty  times,  each  of  the  six  reservoirs  having  had  its  gas 
diffused  each  time,  thus  involving  180  diffusions.  After 
this  process,  the  density  of  the  more  quickly  diffusing  gas 
was  reduced  to  202,  while  that  of  the  less  quickly  dif- 
fusing had  increased  to  2*27.  The  light  portion  on  re- 
diffusion  hardly  altered  in  density,  while  the  heavier  por- 
tion, when  divided  into  three  portions  by  diffusion,  showed 
a  considerable  difference  in  density  between  the  first  third 
and  the  last  third.  A  similar  set  of  operations  was 
carried  out  with  a  fresh  quantity  of  helium,  in  order  to 
accumulate  enough  gas  to  obtain  a  sufficient  quantity  for 
a  second  series  of  diffusions.  The  more  quickly  diffusing 
portions  of  both  gases  were  mixed  and  re-diffused.  The 
density  of  the  lightest  portion  of  these  gases  was  198; 
and  after  other  15  diffusions,  the  density  of  the  lightest 
portion  had  not  decreased.  The  end  had  been  reached; 
it  was  not  possible  to  obtain  a  lighter  portion  by  diffusion. 
The  density  of  the  main  body  of  this  gas  is  therefore 
1-98;  and  its  refradivity,  air  being  taken  as  unity,  is 
0'i245.  The  spedlrum  of  this  portion  does  not  differ  in 
any  respedl  from  the  usual  spedtrum  of  helium. 

As  re-diffusion  does  not  alter  the  density  or  the  re- 
fradtivity  of  this  gas,  it  is  right  to  suppose  that  either  one 
definite  element  has  now  been  isolated,  or  that,  if  there 
are  more  elements  than  one  present,  they  possess  the 
same,  or  very  nearly  the  same,  density  and  refradivity. 
There  may  be  a  group  of  elements,  say  three,  like  iron, 
cobalt,  and  nickel ;  but  there  is  no  proof  that  this  idea  is 
corredt,  and  the  simplicity  of  the  spedtrum  would  be  an 
argument  against  such  a  supposition.  This  substance, 
forming  by  far  the  larger  part  of  the  whole  amount  of  the 
gas,  must,  in  the  present  state  of  our  knowledge,  be  re- 
garded as  pure  helium. 

On  the  other  hand,  the  heavier  residue  is  easily  altered  in 
density  by  re-diffusion,  and  this  would  imply  that  it  con- 
gists  of  a  small  quantity  of  a  heavy  gas  mixed  with  a 
large  quantity  of  the  light  gas.  Repeated  re-diffusion 
convinced  us  that  there  was  only  a  very  small  amount  of 
the  heavy  gas  present  in  the  mixture.  The  portion  which 
contained  the  largest  amount  of  heavy  gas  was  found  to 
have  the  density  2'275,  and  its  re'radlive  index  was 
found  to  be  o'i333.  On  re-diffusing  this  portion  of  gas 
until  only  a  trace  sufficient  to  fill  a  Pliicker's  tube  was 
left,  and  then  examining  the  spedtrum,  no  unknown  lines 
could  be  detedted,  but,  on  interposing  a  jar  and  spark  gap, 
the  well-known  blue  lines  of  argon  became  visible;  and 
even  without  the  jar  the  red  lines  of  argon  and  the  two 
green  groups  were  distindlly  visible.    The  amount  of 


argon  present,  calculated  from  the  density,  was  i'64  per 
cent,  and  from  the  refradlivity  IT4  per  cent.  The  con- 
clusion had  therefore  to  be  drawn  that  the  heavy 
constituent  of  helium,  as  it  comes  off  the  minerals  con- 
taining it,  is  nothing  new,  but,  so  far  as  can  be  made  out, 
merely  a  small  amount  of  argon. 

If,  then,  there  is  a  new  gas  in  what  is  generally  termed 
helium,  it  is  mixed  with  argon,  and  it  must  be  present  in 
extremely  minute  traces.  As  neither  helium  nor  argon 
has  been  induced  to  form  compounds,  there  does  not  ap- 
pear to  be  any  method,  other  than  diffusion,  for  isolating 
such  a  gas,  if  it  exists,  and  that  method  has  failed  in  our 
hands  to  give  any  evidence  of  the  existence  of  such  a  gas. 
It  by  no  means  follows  that  the  gas  does  not  exist ;  the 
only  conclusion  to  be  drawn  is  that  we  have  not  yet 
stumbled  on  the  material  which  contains  it.  In  fadt,  the 
haystack  is  too  large  and  the  needle  too  inconspicuous. 
Reference  to  the  periodic  table  will  show  that  between  the 
elements  aluminium  and  indium  there  occurs  gallium,  a 
substance  occurring  only  in  the  minutest  amount  on  the 
earth's  surface  ;  and  following  silicon,  and  preceding  tin, 
appears  the  element  germanium,  a  body  which  has  as  yet 
been  recognised  only  in  one  of  the  rarest  of  minerals, 
argyrodite.  Now,  the  amount  of  helium  in  fergusonite, 
one  of  the  minerals  which  yields  it  in  reasonable  quantity, 
is  only  33  parts  by  weight  in  100,000  of  the  mineral;  and 
it  is  not  improbable  that  some  other  mineral  may  contain 
the  new  gas  in  even  more  minute  proportion.  If,  however, 
it  is  accompanied  in  its  still  undiscovered  source  by  argon 
and  helium,  it  will  be  a  work  of  extreme  difficulty  to  effedt 
a  separation  from  these  gases. 

In  these  remarks  it  has  been  assumed  that  the  new  gas 
will  resemble  argon  and  helium  in  being  indifferent  to  the 
adlion  of  reagents,  and  in  not  forming  compounds.  This 
supposition  is  worth  examining.  In  considering  it,  the 
analogy  with  other  elements  is  all  that  we  have  to 
guide  us. 

We  have  already  paid  some  attention  to  several  triads 
of  elements.  We  have  seen  that  the  differences  in  atomic 
weights  between  the  elements  fluorine  and  manganese, 
oxygen  and  chromium,  nitrogen  and  vanadium,  carbon  and 
titanium,  is  in  each  case  approximately  the  same  as  that 
between  helium  and  argon,  viz.,  36.  If  elements  further 
back  in  the  periodic  table  be  examined,  it  is  to  be  noticed 
that  the  differences  grow  less,  the  smaller  the  atomic 
weights.  Thus,  between  boron  and  scandium  the  difference 
is  33;  between  beryllium  (glucinum)  and  calcium,  31; 
and  between  lithium  and  potassium,  32.  At  the  same 
time,  we  may  remark  that  the  elements  grow  liker  each 
other,  the  lower  the  atomic  weights.  Now,  helium  and 
argon  are  very  like  each  other  in  physical  properties.  It 
may  be  fairly  concluded,  I  think,  that  in  so  far  they  justify 
their  position.  Moreover,  the  pair  of  elements  which 
show  the  smallest  difference  between  their  atomic  weights 
is  beryllium  and  calcium  ;  there  is  a  somewhat  greater 
difference  between  lithium  and  potassium.  And  it  is  in 
accordance  with  this  fragment  of  regularity  that  helium 
and  argon  show  a  greater  difference.  Then  again,  sodium, 
the  middle  element  of  the  lithium  triad,  is  very  similar  in 
properties  both  to  lithium  and  potassium;  and  we  might, 
therefore,  expedl  that  the  unknown  element  of  the  helium 
series  should  closely  resemble  both  helium  and  argon. 

Leaving  now  the  consideration  of  the  new  element,  let 
us  turn  our  attention  to  the  more  general  question  of  the 
atomic  weight  of  argon,  and  its  anomalous  position  in 
the  periodic  scheme  of  the  elements.  The  apparent  diffi- 
culty is  this: — The  atomic  weight  of  argon  is  40;  it  has 
no  power  to  form  compounds,  and  thus  possesses  no 
valency;  it  must  follow  chlorine  in  the  periodic  table,  and 
precede  potassium  ;  but  its  atomic  weight  is  greater  than 
that  of  potassium,  whereas  it  is  generally  contended  that 
the  elements  should  follow  each  other  in  the  order  of  their 
atomic  weights.  If  this  contention  is  corredt,  argon  should 
have  an  atomic  weight  smaller  than  40. 

Let  us  examine  this  contention.  Taking  the  first  row 
of  elements,  we  have  ; — 


98 


British  Association. — Pro/essur  Ramsay's  Address. 


Chemical  Mbwsi 
\      Aug.  27, 1897. 


Li  =  7,  Be  =  9'8,  B  =  ii,  C  =  i2,  N=i4,  0  =  i6,  F  =  i9, 

?  =  20. 

The  differences  are : — 

2'8,  f2,  I"0,  2*0,  2'0,  3"o,  I'O. 

It  is  obvious  that  they  are  irregular.  The  next  row 
shows  similar  irregularities.     Thus  : — 

(?  =  20,  Na  =  23,  Mg=24-3,  Al  =  27,  Si  =  28,  P  =  3i,  8  =  32, 
Cl  =  35"5.  A  =  40. 
And  the  differences  : — 

3-0,  1-3,  27,  I'O,  3-0,  10,  35,  45. 

The  same  irregularity  might  be  illustrated  by  a  con- 
sideration of  each  succeeding  row.  Between  argon  and 
the  next  in  order,  potassium,  there  is  a  difference  of 
—  09;  that  is  to  say,  argon  has  a  higher  atomic  weight 
than  potassium  by  o'g  unit,  whereas  it  might  be  expedted 
to  have  a  lower  one,  seeing  that  potassium  follows  argon 
in  the  table.  Farther  on  in  the  table  there  is  a  similar 
discrepancy.     The  row  is  as  follows  : — 

Ag=io8,  Cd  =  ii2,   In  =  ii4,   Sn  =  ii9,   Sb  =  i20'5, 
Te  =  i277,  1=  127. 

The  differences  are  :— 

40,  20,  50,  i'5,  7-2,  -07. 

Here,  again,  there  is  a  negative  difference  between  tellu- 
rium and  iodine.  And  this  apparent  discrepancy  has  led 
to  many  and  careful  re-determinations  of  the  atomic 
weight  of  tellurium.  Professor  Brauner,  indeed,  has  sub- 
mitted tellurium  to  methodical  fractionation,  with  no 
positive  results.  All  the  recent  determinations  of  its 
atomic  weight  give  pradtically  the  same  number,  1277. 

Again,  there  have  been  almost  innumerable  attempts  to 
reduce  the  differences  between  the  atomic  weights  to 
regularity,  by  contriving  some  formula  which  will  express 
the  numbers  which  represent  the  atomic  weights,  with  all 
their  irregularities.  Needless  to  say,  such  attempts  have 
in  no  case  been  successful.  Apparent  success  is  always 
attained  at  the  expense  of  accuracy,  and  the  numbers  re- 
produced are  not  those  accepted  as  the  true  atomic 
weights.  Such  attempts,  in  my  opinion,  are  futile.  Still, 
the  human  mind  does  not  rest  contented  in  merely 
chronicling  such  an  irregularity  ;  it  strives  to  understand 
why  such  an  irregularity  should  exist.  And,  in  connedion 
with  this,  there  are  two  matters  which  call  for  our  con- 
sideration. These  are  : — Does  some  circumstance  modify 
these  "combining  proportions"  which  we  term  "  atomic 
weights"?  And  is  there  any  reason  to  suppose  that  we 
can  modify  them  at  our  will  ?  Are  they  true  "  constants 
01  Nature,"  unchangeable,  and  once  for  all  determined  ? 
Or  are  they  constant  merely  so  long  as  other  circum- 
stances, a  change  in  which  would  modify  them,  remain 
unchanged  ? 

In  order  to  understand  the  real  scope  of  such  questions, 
it  is  necessary  to  consider  the  relation  of  the  "  atomic 
weights  "  to  other  magnitudes,  and  especially  to  the  im- 
portant quantity  termed  "energy." 

It  is  known  that  energy  manifests  itself  under  different 
forms,  and  that  one  form  of  energy  is  quantitatively  con- 
vertible into  another  form,  without  loss.  It  is  also  known 
that  each  form  of  energy  is  expressible  as  the  produdt  of 
two  fadtors,  one  of  which  has  been  termed  the  "  intensity 
fadlor,"  and  the  other  the  "  capacity  fador."  Professor 
Ostwald,  in  the  last  edition  of  his  "  Allgemeine  Chemie," 
classifies  some  of  these  forms  of  energy  as  follows  : — (see 
next  column). 

In  each  statement  of  fadors  the  "  capacity  faftor  "  is 
placed  first,  and  the  "  intensity  fadtor"  second. 

In  considering  the  "  capacity  fadlors  "  it  is  noticeable 
that  they  may  be  divided  into  two  classes.  The  two  first 
kinds  of  energy,  kinetic  and  linear,  are  independent  of  the 
nature  of  the  material  which  is  subjed  to  the  energy.  A 
mass  of  lead  offers  as  much  resistance  to  a  given  force, 
or,  in  other  words,  possesses  as  great  inertia,  as  an  equal 
mass  of  hydrogen.    A  mass  of  iridium,  the  densest  solid, 


Kinetic  energy  is  the  produdt  of  Mass  into  the  square 

of  velocity. 
Linear        ,,  ,,  Length  into  force. 

Surface       ,,  ,,  Surface  into  surface 

tension. 
Volume      „  ,,  Volume  into  pressure. 

Heat  ,,  „  Heat-capacity  (entropy) 

into  temperature. 
Ele&rical  „  ,,  Eledric  capacity  into 

potential. 
Chemical  „  „  "  Atomicweight"into 

aiBnity. 


counterbalances  an  equal  mass  of  lithium,  the  lightest 
known  solid.  On  the  other  hand,  suriate  energy  deals 
with  molecules,  and  not  with  masses.  So  does  volume 
energy.  The  volume  energy  of  2  grms.  of  hydrogen, 
contained  in  a  vesiel  01  i  litre  capacity,  is  equal  to  that 
)  of  32  grms.  of  oxygen  at  the  same  temperature,  and  con- 
tained in  a  vessel  of  equal  size.  Equal  masses  of  tin  and 
lead  have  not  equal  capacity  for  heat;  but  119  grms.  of 
tin  has  the  same  capacity  as  207  grms.  of  lead, — that  is, 
equal  atomic  masses  have  the  same  heat  capacity.  The 
quantity  of  eledtricity  conveyed  through  an  eledtrolyte 
under  equal  difference  of  potential  is  proportional,  not  to 
the  mass  of  the  dissolved  body,  but  to  its  equivalent, — 
that  is,  to  some  simple  fraction  of  its  atomic  weight.  And 
the  capacity  fadtor  of  chemical  energy  is  the  atomic 
weight  of  the  substance  subjedled  to  the  energy.  We 
see,  therefore,  that  while  mass  or  inertia  are  important 
adjundts  of  kinetic  and  linear  energies,  all  other  kinds  of 
energy  are  connedled  with  atomic  weights,  either  diredlly 
or  indiredtly. 

Such  considerations  draw  attention  to  the  fad  that 
quantity  of  matter  (assuming  that  there  exists  such  a 
carrier  of  properties  as  we  term  "  matter")  need  not 
necessarily  be  measured  by  its  inertia,  or  by  gravitational 
attradlion.  In  fadl,  the  word  "  mass "  has  two  totally 
distindt  significations.  Because  we  adopt  the  convention 
to  measure  quantity  of  matter  by  its  mass,  the  word 
"  mass  "  has  come  to  denote  "  quantity  of  matter."  But 
it  is  open  to  anyone  to  measure  a  quantity  of  matter  by 
any  other  of  its  energy  fadtors.  I  may,  if  I  choose,  state 
that  those  quantities  of  matter  which  possess  equal  capa- 
cities for  heat  are  equal ;  or  that  "  equal  numbers  of 
atoms  "  represent  equal  quantities  of  matter.  Indeed,  we 
regard  the  value  of  material  as  due  rather  to  what  it  can 
do,  than  to  its  mass ;  and  we  buy  food,  in  the  main,  on 
an  atomic,  or  perhaps  a  molecular,  basis,  according  to  its 
content  of  albumen.  And  most  articles  depend  for  their 
value  on  the  amount  of  food  required  by  the  producer  or 
the  manufadlurer. 

The  various  forms  of  energy  may  therefore  be  classified 
as  those  which  can  be  referred  to  an  "  atomic  "  fadlor, 
and  those  which  possess  a  "  mass  "  fadlor.  The  former 
are  in  the  majority.  And  the  Periodic  Law  is  the  bridge 
between  them  ;  as  yet,  an  imperfedl  connedlion.  For  the 
atomic  fadlors,  arranged  in  the  order  of  their  masses, 
display  only  a  partial  regularity.  It  is  undoubtedly  one 
of  the  main  problems  of  physics  and  chemistry  to  solve 
this  mystery.  What  the  solution  will  be  is  beyond  my 
power  of  prophecy ;  whether  it  is  to  be  found  in  the  in- 
fluence of  some  circumstance  on  the  atomic  weights, 
hitherto  regarded  as  among  the  most  certain  "  constants 
of  Nature";  or  whether  it  will  turn  out  that  mass  and 
gravitational  attradlion  are  influenced  by  temperature,  or 
by  eledrical  charge,  I  cannot  tell.  But  that  some  means 
will  ultimately  be  found  of  reconciling  these  apparent 
discrepancies,  I  firmly  believe.  Such  a  reconciliation  is 
necessary,  whatever  view  be  taken  of  the  nature  of  the 
universe  and  of  its  mode  of  adtion ;  whatever  units  we 
may  choose  to  regard  as  fundamental  among  those  which 
lie  at  our  disposal. 

In  this  address  I  have  endeavoured  to  fulfil  my  promise 
to  combine  a  little  history,  a  little  adluality,  and  a  little 


Crbmical  NBVB,  ' 

Aug.  27,  1897. 


A  Posdble  New  Element. 


99 


prophecy.  The  history  belongs  to  the  Old  World  ;  I  have 
endeavoured  to  share  passing  events  with  the  New  ;  and 
I  will  ask  you  to  join  with  me  in  the  hope  that  much  of 
the  prophecy  may  meet  with  its  fulfilment  on  this  side  of 
the  Ocean. 


A     POSSIBLE     NEW     ELEMENT,     OR 

POSSIBLE     NEW     ELEMENTS,     IN     CAST-IRON 

AND     BLAST-FURNACE     BOILER-DUST. 

By  G.  G.  BOUCHER. 

It  will  appear  at  first  somewhat  surprising  to  those 
accustomed  to  make  analyses  of  cast-iron  that  there 
exists  in  that  metal  another  element  besides  the  elements 
C,  Si,  S,  P,  Mn,  Cu,  As,  Sb,  Cr,  W,  Ti,  Ni,  Co,  Al,  K, 
Na,  Mg,  Ca,  Li,  and  V,  already  known  to  be  present  in 
cast-iron.  There  does,  however,  appear  to  be  another 
metal  present,  and  in  this  article  I  have  attempted  to 
describe  a  metal  which  I  discovered  in  the  iron  and 
boiler-dust  made  at  these  works.  I  have  described  it  as 
a  possible  new  element,  because  as  yet  it  has  not  been 
examined  spedtroscopically,  and,  although  its  properties 
are  unlike  those  of  any  metal  I  know,  it  is  possible  that 
it  may  be  one  of  those  compounds  so  difficult  to  separate 
by  chemical  means,  the  properties  of  which  can  only  be 
determined  by  means  of  the  spedlroscope.  I  thought  it 
better,  therefore,  not  to  call  it  a  new  element  till  the 
result  of  the  spedrum  analysis  is  known,  A  small 
quantity  of  the  metal  is  now  in  the  hands  of  Sir  William 
Crookes,  to  whom  I  wrote  describing  my  discovery,  and 
requesting  that  he  would  take  a  little  for  analysis.  He 
very  kindly  consented  to  do  so,  and  I  hope  in  a  short 
time  to  be  able  to  give  the  result  of  his  analysis.  In  the 
meantime  I  have  written  this  article  hoping  that  it  may 
prove  interesting. 

To  prepare  the  metal  it  is  necessary  to  take  large  quan- 
tities of  iron,  as  the  metal  is  present  in  very  small 
quantities.  On  four  different  occasions  I  obtained  o'oo33 
per  cent,  0*0027  per  cent,  o'oo53  per  cent,  and  o'oo6o  per 
cent  of  the  metal,  using  100  grms.  of  iron  in  each  case. 
An  analysis  of  an  average  sample  of  iron  ore  only  yielded 
O'ooig  per  cent  of  the  metal. 

To  obtain  the  metal,  100  grms,  of  iron  are  weighed  out 
into  a  large  beaker  capable  of  holding  about  3  litres ; 
2000  c.c.  of  dilute  H2SO4  (i  acid  to  5  H2O)  are  run  in, 
the  beaker  is  covered  with  a  clock  glass,  placed  on  a  warm 
plate,  and  the  iron  completely  dissolved.  The  beaker  is 
then  removed,  the  contents  allowed  to  cool,  H2S  is  passed 
through  the  solution  to  precipitate  any  small  quantities  of 
metal  which  may  have  dissolved,  and  it  is  then  allowed  to 
stand  till  all  the  graphite,  &c.,  have  settled.  The  clear 
liquid  is  poured  off;  the  graphite,  &c.,  are  filtered  into  a 
quick  filter-paper,  and  thoroughly  washed  with  hot  water 
till  free  from  iron.  The  graphite,  Si02,  As,  Sb,  Cu,  and 
unknown  metal  colleAed  on  the  paper,  are  washed  off  into 
a  beaker  and  treated  with  4  or  5  grms.  of  KCIO3  and 
50  c.c.  HCl.  The  beaker  is  placed  on  a  hot  plate  and 
gradually  heated  to  boiling,  and  boiled  till  all  free  CI  is 
evolved.  The  metals  being  converted  into  chlorides,  the 
silica  and  graphite  are  filtered  off,  well  washed  with  hot 
water,  and  the  filtrate  saturated  with  H2S.  The  precipi- 
tate— which  consists  of  the  sulphides  of  As,  Sb,  Cu,  and 
unknown  metal — is  allowed  to  settle,  then  filtered,  and 
well  washed  with  H2S  water.  The  sulphides  with  filter- 
paper  are  placed  in  a  small  beaker,  HCl  is  added,  and 
about  2  grms.  KCIO3 ;  the  beaker  is  placed  on  a  warm 
plate,  and  when  the  sulphides  are  completely  dissolved 
and  the  free  chlorine  driven  off,  the  solution  is  filtered, 
the  bulk  of  the  liquid  being  kept  as  small  as  possible. 
The  As  is  precipitated  by  MgCl2.  AmHO,  and  AmCl,  the 
solution  being  allowed  to  stand  with  repeated  stirring 
about  twelve  hours.  When  the  As  is  entirely  precipitated 
it  is  filtered  off,  and  the  solution  saturated  with  HjS  to 


precipitate  the  Cu  ;  the  CuS  is  allowed  to  settle,  filtered 
off,  and  the  solution  made  slightly  acid  with  HCl.  The 
Sb  and  unknown  metal  are  precipitated  as  sulphides,  the 
precipitate  being  as  a  rule  of  a  brown  colour.  The 
sulphides  are  allowed  to  settle,  and  when  the  liquid  is 
quite  clear  it  is  poured  off;  30  c.c.  HCl  (i  acid  to  2  H2O) 
are  poured  on  to  the  sulphide,  and  the  solution  boiled. 
The  precipitate  is  allowed  to  settle,  the  clear  liquid  poured 
off,  andanother  30  c.c.  dilute  HCl  are  added;  the  solution 
is  boiled  again,  and  the  precipitate  then  allowed  to  settle. 
This  is  repeated  three  or  four  times,  till  all  the  Sb2S3  is 
completely  dissolved.  The  unknown  metal  rema-ns  be- 
hind as  a  heavy  dark  brown  sulphide,  it  being  almost 
insoluble  in  boiling  dilute  HCl  (i  to  i).  This  sulphide  is 
thoroughly  washed  with  hot  water,  and  then  dissolved  in 
a  dilute  solution  of  KHO ;  the  solution  is  saturated  with 
H2S.  and  filtered  from  any  small  quantities  of  CuS  or 
other  sulphides  formed.  The  filtrate  is  made  slightly  acid 
with  HCl  and  the  brown  sulphide  precipitated  filtered  off; 
it  is  again  dissolved  in  KHO,  the  solution  saturated  with 
H2S,  and  filtered.  HCl  is  added  to  precipitate  the  sul- 
phide; it  is  filtered  on  to  a  paper,  and  thoroughly  washed 
with  hot  water.  This  process  is  repeated  till  the  KHO 
solution  of  the  sulphide  produces  no  precipitate  with  H2S. 
The  brown  metallic  sulphide — which  should  now  be  abso- 
lutely free  from  As,  Sb,  Sn,  Bi,  and  Cu — is  thrown  on  to 
a  filter-paper,  thoroughly  washed  with  hot  distilled  water, 
and  dissolved  in  hot  HNO3  (i  to  2).  The  solution  is  fil- 
tered, and  made  just  alkaline  with  AmHO  to  precipitate, 
or  make  doubly  sure  of  the  absence  of,  Sb,  Sn,  Bi,  and  Te. 
These  metals  are,  however,  hardly  likely  to  be  present. 
The  metal  is  again  precipitated  as  sulphide,  filtered  off, 
well  washed  with  hot  water,  and  dried  in  the  water-oven. 
When  quite  dry  the  precipitate  is  brushed  off  the  filter- 
paper  into  a  porcelain  crucible,  and  placed  in  a  muf!le 
which  is  hardly  red-hot.  The  sulphide  burns  to  an  oxide 
of  a  pale  yellow  colour,  which  melts  very  easily,  and  at  a 
full  red-heat  completely  vapourises  ;  hence  it  is  necessary 
to  keep  the  crucilile  at  a  very  low  red-heat,  and  to  watch 
this  part  of  the  process  very  carefully.  The  oxide  can 
also  be  obtained  by  dissolving  the  sulphide  in  HNO3, 
evaporating  to  dryness,  and  heating  gantly  as  described 
before,  but  it  is  not  in  such  a  good  condition  for  redudtion 
as  that  obtained  by  oxidation  in  a  muffle.  The  metal  can 
be  obtained  from  the  oxide  either  by  heating  it  in  a  current 
of  hydrogen  or  by  fusing  it  with  pure  KCN. 

The  metal  so  obtained  is  a  black  powder,  slightly 
soluble  in  cold  strong  HCl  and  H2SO4,  and  very  little 
more  soluble  on  boiling  in  these  acids.  It  is  soluble  in 
dilute  and  strong  HNO3,  and  very  easily  soluble  in  aqua 
regia.     It  is  insoluble  in  dilute  HCl  and  H2SO4. 

Heated  in  a  current  of  air  the  metal  glows,  and  is  con- 
verted into  the  yellow  oxide,  part  of  which  vapourises  and 
condenses  on  the  side  of  the  tube. 

The  oxide  so  formed,  as  I  have  said  before,  melts  at  a 
low  temperature,  and  when  allowed  to  cool  crystallises 
out  in  long  transparent  pointed  crystals,  which  are  very 
beautiful  when  examined  through  the  microscope.  If  a 
small  quantity  of  the  oxide  be  placed  in  a  covered  porce- 
lain crucible  and  heated  to  a  full  red  heat  for  one  or  two 
minutes  in  a  muffle,  on  taking  it  out  and  examining  it 
the  crucible  side  will  be  found  to  be  covered  with  long 
transparent  colourless  crystals.  I  have  in  my  possession 
crystals  prepared  in  this  manner  over  a  quarter  of  an  inch 
long.  The  first  lot  of  crystals  I  obtained  were  very 
nearly  half  an  inch  long  and  almost  completely  filled  the 
crucible;  they  were  quite  transparent  and  appeared  to  be 
I  capable  of  refrading  light. 

The  oxide,  heated  with  borax,  gives  in  the  outer  flame 
'  a  clear  colourless  bead,  and  in  the  reducing  flame  a  light- 
[  coloured  pink  bead.  Heated  with  microcosmic  salt  it 
gave  a  clear  chrome-green  bead,  both  in  oxidising  and 
reducing  flame;  the  bead  obtained  in  the  reducing  flame 
beingconsiderably  darker  in  colour  than  that  obtained  in  the 
oxidising  flame.  Fused  with  Na2C03  it  gave  a  colourless 
mass  completely  soluble  in  water.    The  oxide  is  difficultly 


100 


Nitrogen  in  Analyses. 


i  (JRBMICAL  NbWS, 
I      Aug.  27,  1897. 


soluble  in  HCl,  almost  insoluble  in  H2SO4,  and  insoluble 

in  HNO3. 

Wet  Reactions. 
Chloride  of  the  Metal. 
Reagent.  Observation. 

HCl No  precipitate. 

H2S A    dark    brown    precipitate    from 

slightly  acid  solutions,  soluble  in 
SAma,  SjAma,  NajS,  KHO,  and 
NaHO  ;  insoluble  in  boiling  dilute 
HCl  (i  to  i)  and  H2SO4 ;  soluble 
in  aqua  regia  and  HNO3. 

NaHO,  KHO, AmHO  No    precipitate,    but    slight    blue 
colouration  of  the  solution. 

Na2S203 A  violet  colouration,  which  turns 

brown  on  heating  with  a  few 
drops  of  HCl ;  the  metal  being 
precipitated  as  sulphide. 

NaaSOs No  precipitate  or  apparent  change 

even  on  boiling. 

SnCl2      No  precipitate  or  apparent  change 

even  on  boiling.  j 

FeS04 No  precipitate  or  apparent  change  1 

even  on  boiling.  I 

BaC03,  (Am)2C03  .     No  precipitate. 

CaC03,  Na2C03    ..      „  „ 

Magnesia     mixture 
(AmCl  and  AmHO)      „  „ 

AmCl,  KCl     ....      „ 

Zn,  Fe     A  fine  black  deposit  of  metal.  Part 

of  the  metal  is  evolved  in  com- 
bination with  hydrogen.  On 
lighting  the  issuing  gas  at  a  jet 
and  placing  a  cold  porcelain  lid 
in  the  f!ame,  the  metal  is  deposited. 
The  deposit  is  almost  black  and 
has  very  little  lustre.  It  is  in- 
soluble In  HCl,  and  a  freshly  pre- 
pared solution  of  bleaching  powder 
has  no  adion  on  it. 

K2Cr04 No  precipitate. 

KCN       

Na2HP04  and 

NaCaHaOz      „ 

KjFeCye .,  >, 

K4FeCy6 A  dark  brown  f!occulent  precipitate 

from  neutral  solutions.  Soluble 
in  acids  and  alkalis. 

H2SO4,  HCl  . .  . .  The  most  charaderistic  reaftion  for 
this  metal  appears  to  be  that  pro- 
duced by  the  addition  of  a  few 
drops  of  H2S04to  the  chloride  or 
nitrate.  On  evaporating  down 
till  fumes  of  H2SO4  are  driven  ofif, 
and  allowing  to  cool,  the  liquid 
assumes  after  a  short  time  a  most  | 
magnificent  blue  colour.  Very 
minute  quantities  of  the  metal 
can  be  detedted  by  this  means. 
The  same  colour  is  produced  by 
evaporating  down  two  or  three 
times  with  HCl  to  very  nearly 
dryness.  The  colour  is  entirely 
destroyed  by  the  addition  of 
water. 

The  Metal  in  Boiler  Dust. 

A  similar  metal  in  every  respeft  but  one  I  have  also 
found  in  the  boiler  dust.  It  has  the  same  appearance, 
forms  an  oxide  to  all  appearances  the  same  as  the  other, 
and  produces  the  same  chemical  changes  with  the  re  • 
agents  given  with  the  exception  of  SnCla.  This  reagent 
produces  a  dark  blue  colour,  which  on  boiling  with  a  little 
HCl  turns  to  a  dark  brown. 

It  is  almost  more  difficult  to  obtain  this  metal  from 


boiler  dust  than  it  is  to  obtain  the  metal  from  iron,  as  it 
is  present  in  such  minute  quantities.  To  obtain  about 
o'3  grm.  of  the  metal  I  had  to  treat  quite  a  ton  of  dust, 
and  as  this  was  done  in  small  quantities,  taking  about  28 
lbs.  at  a  time,  it  required  considerable  time,  patience,  and 
labour.  It  is  not  always  possible  to  obtain  the  metal,  as 
at  times  it  seems  to  disappear  altogether;  at  one  time  I 
was  unable  to  find  it  for  quite  two  months.  It  also 
seems  to  be  present  only  in  the  dust  from  a  few  of  the 
boilers.  The  lighter  dust  does  not  appear  to  contain  any 
of  the  metal,  it  being  only  in  heavy  and  dark  coloured 
dust  that  I  have  been  able  to  find  it. 

To  prepare  the  metal,  about  28  lbs.  of  dust  are  placed 
in  a  large  canvas  filter  and  well  washed  with  water,  the 
washings  being  allowed  to  run  into  a  Winchester  quart 
bottle.  To  save  using  a  large  quantity  of  water,  the 
washings  are  run  through  several  times  till  they  are 
saturated  with  the  salts  K2SO4  and  Na2S04,  which  are 
present  in  large  quantities.  If  the  metal  is  present  the 
solution  generally  has  a  dark  yellow  colour.  H2S  is 
passed  into  this  solution  for  about  ten  or  fifteen  minutes, 
and  then  about  50  c.c.  strong  HCl  are  run  in  and  the 
bottle  thoroughly  shaken.  The  metal  is  precipitated  as 
sulphide,  and  in  about  twelve  hours  settles  at  the  bottom 
of  the  bottle.  The  clear  liquid  is  syphoned  off,  and  the 
sulphide  washed  into  a  large  stoppered  bottle,  there  to 
wait  till  many  more  such  precipitates  have  been  added 
to  it. 

When  a  sufficient  quantity  has  been  colledled,  it  is 
filtered  off,  washed  into  a  large  porcelain  basin,  and  dis- 
solved in  aqua  regia.  15  c.c.  H2SO4  are  added,  and  the 
solution  is  evaporated  down  till  fumes  of  H2SO4  appear. 
The  solution  is  allowed  to  cool,  water  is  added,  and  it  is 
then  filtered  from  the  insoluble  residue  of  PbS04,  Si02,  S, 
&c.  The  filtrate  is  made  alkaline  with  AmHO  and  satu- 
rated with  H2S.  The  CuS,  61283,  &c.,  are  filtered  off, 
washed  with  SAma  water,  and  the  solution  is  acidified 
with  HCl  to  precipitate  the  metal.  It  is  filtered  on  to 
a  paper,  well  washed  with  hot  water,  afterwards  dissolved 
in  KHO,  and  treated  as  described  before,  under  the  pre- 
paration of  the  metal  from  iron. 

A  glance  at  the  readions  of  these  metals  will  show 
that  there  is  some  reason  to  believe  that  there  is  some- 
thing new  about  them — as  will  be  easily  seen  from 
a  comparison  of  the  readions  of  these  metals  and  those 
which  they  seem  to  most  closely  resemble.  It  is  more 
than  probable  that  these  metals  will  turn  out  to  be  the 
same,  but  whether  spedrum  analysis  will  show  them  to 
be  metals  already  discovered  remains  to  be  seen.  I  hardly 
think  they  can  be.  These  metals  are,  however,  very 
interesting,  inasmuch  as  I  believe  they  have  not  been 
discovered  in  cast-iron  or  boiler  dust  before. 

It  may  be  interesting  to  know  that  I  also  found  in 
the  boiler  dust  the  metals  thallium,  cadmium,  zinc,  lead, 
bismuth,  arsenic,  and  antimony. 

North  Lonsdale  Iron  and  Steel  Co., 
Ulverston,  August  18, 1897. 


NITROGEN     IN    ANALYSES.* 

By  C.  F.  JURITZ,  M.A., 
Senior  Analyst,  Government  Laboratory,  Cape  Town. 

The  ordinary  farmer  is  no  doubt  much  perplexed  at  the 
wide  range  of  figures  expressing  the  percentages  of  nitro- 
genous constituents,  when  comparing  the  results  of 
analyses  by  different  authors,  of  articles  regarding  whose 
composition  he  is  desirous  of  learning  something. 

Comparing  one  fertiliser  with  another  of  the  same 
class,  such  as  bone  meal,  for  example,  one  authority  may 
tell  him  that  it  contains  3  J  per  cent  of  nitrogen,  another 
that  it  contains  20  per  cent  of  nitrogenous  matter,  while 

•  Abridged  from  the  Agricultural  Journal,  Cape  of  Good  Hope, 
June  10,  1897. 


CHEMICAL  NeWA. 

Aug.  27,  1897. 


Experimental  Researches  on  Glasses 


lot 


a  third  might  possibly  return  it  as  containing  4i  per  cent 
of  ammonia. 

Suppose  a  farmer  is  using  linseed  cake,  and  wishes  to 
compare  results.  He  finds  one  cake  contains  27  per  cent 
of  albuminous  compounds,  while  another  has  only  4!  per 
cent  of  nitrogen.  "  What  a  difference  !  "  he  says,  thmking 
that  the  same  substance  is  referred  to  in  each  case.  Again, 
he  finds  that  wheat  contains  12  per  cent  of  nitrogenous 
compounds,  while  peas  do  not  contain  more  than  4  per 
cent  of  nitrogen  ;  this  puzzles  him,  because  he  has  always 
understood  that  peas  were  of  the  '*  nitrogen-loving  "  sort. 

It  is  really  a  very  simple  matter  to  reconcile  these 
seeming  differences.  As  17  parts  of  ammonia  contain  14 
parts  of  nitrogen,  we  know  that  17  per  cent  of  ammonia 
is  equivalent  to  14  per  cent  of  nitrogen.  Again,  the 
terms  "  nitrogenous  matter,"  "  albumenoids,"  &c.,  are 
frequently  used  interchangeably  for  a  certain  class  of 
substances  which  contain  about  16  per  cent  of  nitrogen ; 
that  is,  I  part  of  nitrogen  in  6J  parts  of  nitrogenous 
matter.  If,  therefore,  we  have  a  bone-meal  containing  3i 
per  cent  of  nitrogen  ;  to  find  how  much  ammonia  this  is 
equal  to,  we  must  multiply  by  17  and  divide  by  14.  The 
amount  of  nitrogenous  matter  is  found  by  multiplying  the 
nitrogen  by  6J  and  vice  versa. 

Now,  taking  the  first  instance  quoted,  viz.,  the  three 
samples  of  bone-meal — The  first  contained  3^  per  cent  of 
nitrogen  ;  the  second  20  per  cent  of  nitrogenous  matter — 

that  is,    ^°  X  ^P   =  3 '2  per  cent  of  nitrogen— or  really 

100 
less  than  No.  i.      The  third  shows  4i  per  cent  of  am- 
monia, or    4i  X  14  —  j.g  percent  of  nitrogen.  Similarly 

with  the  two  samples  of  linseed  cake ;  the  latter  contams 
more  nitrogen  than  the  former,  being  4I  x  6J,  or  pradtically 
30  per  cent. 

As  a  matter  of  faft,  most  text-books  explain  their  results 
by  a  footnote,  as  in  the  following  analysis  of  hay  : — 

Moisture       16-50  per  cent 

•Nitrogenous  substances    ..  I5"8i         ,, 

Carbonaceous  principles  ..  37'63         ,, 

Woody  fibre 22*47        „ 

Mineral  matter  .,     ..     ..  6-59        ,, 

99"oo 
♦  Containing  nitrogen,  2*53  (equal  to  ammonia,  2*08  per  cent). 


EXPERIMENTAL  RESEARCHES  ON  GLASSES, 

Carried  out  under  the  Direction  of  the 

"  Committee  of  Chemical  Arts,"  of  the   Soci^te 

DE   L'EnCOURAGEMENT.* 
By  L.  GRENET. 

The  objed  of  these  researches,  for  which  the  proprietor 
of  the  glass-works  at  Blanzy,  M.  Solvay,  and  the  Com- 
pany of  Saint-Gobain,  kindly  offered  the  use  of  their 
works  to  the  Committee,  was  to  determine  the  relations 
existing  between  the  chemical  composition  of  glass  and 
its  most  important  properties,  such  as  dilatation,  fusi- 
bility, tenacity,  refrangibility,  and  alterability.  The  first 
part,  which  concerns  dilatation,  and  has  been  done  in 
conjundlion  with  M.  Chatenet,  is  now  finished,  and  forms 
the  subjedt  of  this  article. 

Very  little  work  has  till  now  been  done  on  the  dilata- 
tion of  glass — that  of  Fizeau,  Schott,  and  Damour  being 
all  that  is  worth  recalling. 

The  tension  of  an  enamel  applied  to  a  body  less 
dilatable  is  easily  found  by  the  following  equation  :— 

i-A(T-0=  [i-a(T-0]  (1+^) 

*  Abridged  from  the  Bull,  dc  la  Soc.  dt  V Encouragement t  Series  5, 
Vol.  ii..  No.  6,  June,  1897. 


when  A  =  the  coefficient  of  dilatation  of  the  body  to  be 
enamelled ; 

S.  Coefficient  of  dilatation  of  the  enamel; 

T.  The  temperature  beyond  which  the  enamel  must  not 
be  raised  without  becoming  permanently  de- 
formed ; 

t.  The  lowest  temperature  to  which  the  enamelled  body 
is  reduced ; 

R.  Tension  of  the  enamel; 

E.  Coefficient  of  elasticity  of  the  enamel. 

Compared  with  metals  the  dilatation  of  enamel  is  almost 
always  too  feeble,  and  if  the  tension  due  to  the  difference 
of  dilatation  is  too  great  the  adherence  of  the  enamel  to 
the  metal  may  be  insufficient  to  resist  it,  and  the  enamel 
will  crack  off;  but  it  is  better,  if  the  coefficients  of  dilata- 
tion cannot  be  made  to  agree,  that  that  of  the  enamel 
should  be  the  lesser,  so  that  it  remains  under  com- 
pression. 

The  measurements  in  all  these  experiments  were  made 
by  M.  Fizeau's  method.  The  apparatus  used  was  very 
completely  described  by  M.  Damour,  modified  by  M.  le 
Chatelier,  in  the  Bulletin  of  February,  1896  :  the  only 
important  modification  since  this  time  has  been  the  sub- 
stitution of  warming  by  means  of  water  instead  of  by  air. 
It  consists  of  three  points  of  tempered  steel,  which  serve 
as  a  support  for  the  glass  under  examination.  Parallel  to 
the  base  of  this  tripod,  and  2  cm.  from  it,  are  three 
levelling  screws  of  hardened  steel.  The  glass,  cut  into 
a  prism  of  2  or  3  cm.  high  and  polished  on  its  lower 
surface,  is  placed  on  the  tripod,  and  adjusted  by  means  of 
the  screws  in  such  a  manner  that  its  polished  face  coin- 
cides almost  exadtly  with  the  base  of  the  tripod. 

Under  these  conditions,  if  we  place  this  over  a  bi- 
convex lens,  and  illuminate  with  monochromatic  light, 
we  can  observe  Newton's  rings.  The  prism  and  its  support 
on  the  biconvex  lens  are  placed  on  the  top  of  a  vertical 
tube,  at  the  lower  end  of  which  two  prisms  are  arranged, 
at  its  jundlion  with  a  horizontal  tube.  The  yellow  light 
from  a  Bunsen  is  received  on  and  totally  refiedled  up  by  a 
prism,  to  the  glass  under  experiment;  from  there  it  is 
refleded  down  the  vertical  tube  again  on  to  another  prism 
fitted  with  a  lens  which  again  refleds  it  further  along  the 
horizontal  tube,  where  the  image  of  the  rings  can  be 
examined  on  a  screen  by  aid  of  a  microscope. 

On  warming  up  the  vessel  containing  the  prism  under 
examination  and  its  support,  the  rings  at  first  appear  very 
rapidly,  and  the  black  centres  which  appear  are  counted. 
After  about  three-quarters  of  an  hour  the  equilibrium  of 
temperature  becomes  established  and  the  rings  no  longer 
pass,  and  the  temperature  is  noted.  Each  passage  of  a 
black  centre  corresponds  to  a  difference  in  elongation  of 
half  a  wave-length  between  the  prism  and  its  support. 
The  dilatation  of  the  glass  in  question  is  then  found  by 
the  equation — 

if  =  A±L47l/xio-, 
-^      9 

when  A  =  Dilatation  of  the  support; 

/.  The  number  of  rings  which  pass  ; 

6.  Difference  between  the  extremes  of  temperature. 

There  may  be  a  systematic  error  due  to  the  graduation 
of  the  support,  but  this  is  reduced  to  a  minimum  by  taking 
the  mean  of  several  experiments. 

Most  of  the  samples  of  glass  used  in  this  research  were 
made  in  a  Schlcesing  furnace  in  a  platinum  crucible,  then 
cast  into  triangular  prisms  30  to  40  m.m.  long  and  of  8  to 
12  m.m.  width  of  face,  in  moulds  of  clay  or  wood  char- 
coal ;  they  were  then  annealed  at  a  dull  red-heat,  and 
allowed  to  cool  very  slowly;  when  cool  they  were  ground, 
and  one  end  was  polished.  By  using  platinum  crucibles 
there  is  no  fear  of  any  variation  in  the  composition  of 
the  glass. 

Our  first  endeavours  were  to  try  and  verify  the  truth  o» 
the  law  conne(5ting  dilatation  and  chemical  composition, 
which  was  admitted  by  Schott  without  sufficiently  con- 
clusive proofs  ;  he  thought  that  the  dilatation  of  glass  in_ 


102 


Chemical  Composition  of  the  Mineral  Rutile. 


creased  in  a  similar  mariner  to  densit}-,  by  the  simple 
addition  of  certain  bodies.  To  decide  this  point  we  had 
to  have  recourse  not  to  ordinary  commercial  glass  of 
complex  charadter,  but  to  glass  of  very  simple  charader 
prepared  in  the  laboratory,  and  of  which  the  constituent 
parts  varied  in  proportions  as  widely  apart  as  possible. 
After  becoming  convinced  of  the  inexadlitude  of  this  law, 
we  tried  to  find  some  precise  qualitative  indications  of  the 
manner  in  which  variations  in  a  given  glass  affeded  its 
dilatation. 

The  curves  made  for  the  comparison  of  the  results  give 
to  dilatation  a  function  of  the  volume,  and  that  seems 
more  reasonable  than  to  imagine  a  relation  between 
dilatation  and  the  weight  of  the  component  parts  of  the 
glass. 

Silicates  of  soda  and  potash  are  vitreous,  from  the  state 
of  NaOjSiOz  and  K0,Si02  up  to  SiOj ;  but  when  more 
alkaline  than  NaO.aSiOa  and  KO,3Si02,  they  become  too 
hygrometric  to  allow  of  pradical  measurement  of  the 
dilatation. 

All  the  silicates  of  lithium  we  prepared  became  de- 
vicrified.  Contrary  to  what  occurs  with  alkaline  silicates, 
the  dilatation  of  silicate  of  lithium  increases  with  the 
proportion  of  silica :  it  is  true  that  the  mixtures  are  not 
vitreous,  so  this  increased  dilatation  is  probably  due  to 
the  presence  of  crystals  of  silica;  the  mean  dilatation  of 
quartz  is,  in  fadt,  very  high,  viz.,  1206x10-8. 

Borates  of  soda  and  lithia  can  be  obtained  in  the 
vitreous  stale,  from  the  condition  of  NaO,  2BO3,  and 
LiO,3B03,  up  to  BO3. 

The  only  borate  of  zinc  obtainable  is  ZnO,  0"67B03, 
and  this  becomes  devitrified  very  rapidly  into  cubic 
crystals. 

One  per  cent  of  boric  acid  is  lost  when  heated  to  bright 
red  for  fifteen  minutes,  but  this  small  loss  does  not  inter- 
fere with  the  measurements  of  the  easily  fusible  borates. 
The  measurements  made  on  a  large  number  of  samples 
of  borates  show  that  there  is  a  very  sharply  defined 
minimum, — that  the  dilatation  decreases  with  a  slight  in- 
crease in  the  proportion  of  the  bases  ;  it  reaches  the 
minimum,  and  then  increases  rapidly.  This  is  an  im- 
portant fadt,  and  shows  by  itself  that  Schott's  law  is 
incorredl;  moreover,  the  same  was  observed  with  more 
complex  samples  of  glass  containing  boric  acid. 

As  much  as  6g  per  cent  of  boric  acid  can  be  added  to 
white  glass,  but  beyond  that  the  excess  separates  out,  and 
even  with  this  high  proportion  the  glass  is  not  really 
homogeneous.  Bottle  glass  devitrifies  when  there  is 
more  than  15  per  cent  of  boric  acid  present,  but  even  under 
the  microscope  there  is  no  trace  of  crystallisation. 

From  the  results  shown  in  the  table  it  can  be  seen  that 
the  coefficient  of  dilatation  of  boric  acid  is  about  350,  and 
it  is  this  figure  that  must  be  taken  in  considering  the  in- 
fluence of  small  additions  of  boric  acid  in  commercial 
glasses. 

In  certain  cases  oxide  of  lead  is,  like  boric  acid, 
capable  of  giving  a  minimum  of  dilatation  ;  but  the  effed 
produced  is  never  strongly  marked,  and  does  not  appear  to 
be  general.  By  adding  6  per  cent  of  oxide  of  lead,  M. 
Damour  increased  the  dilatation  from  514  to  551.  It  can 
be  added  up  to  60  per  cent  without  devitrification  in  the 
case  of  bottle  glass,  but  the  glass  is  then  no  longer  homo- 
geneous. 

Alumina,  when  in  large  proportion,  has  the  eifedt  of 
making  the  glass  almost  infusible  :  this  necessarily  limits 
its  use.  Oxide  of  lead  seems  to  be  the  body  which  best 
dissolves  alumina.  The  measurements  made  show  that 
when  increasing  quantities  of  alumina  aie  added  a  mini- 
mum of  dilatation  is  reached,  in  the  same  way  as  with 
borate  of  lead.  An  interesting  fadl  noticed  is,  that  the 
separation  of  boric  acid  from  Pb03,  3BO3,  and  from 
3ZnO,2B03,  is  stopped  by  alumina,  although  when  in  the 
crucible  these  borates  are  as  liquid  as  water.  Finally, 
the  addition  of  small  quantities  of  alumina  to  glass  has 
the  effedt  of  lowering  the  coefficient  of  dilatation  ;  this 
eifedt  is  more  marked  the  more  acid  the  glass  is. 


tCHf^HicA:  News, 
I     Aug.  27,  1897. 

Some  of  the  conclusions  to  be  drawn  from  this  research 
are,  that  a  large  number  of  bodies,  such  as  BO3,  PbO, 
CaO,  MnO,  AI2O3,  &c.,  when  added  to  the  glass  in  small 
quantity,  lower  the  dilatation  first  to  a  minimum,  and 
afterwards  increase"  it  as  the  proportion  added  is  raised. 
This  has  not  been  observed  in  the  case  of  potash,  soda, 
or  silica  glass ;  possibly  it  occurs  with  such  a  minute 
addition  as  not  to  be  pradlicable.  Nevertheless  the  double 
silicates  of  potash  and  soda  have  a  lower  dilatation  than 
the  corresponding  simple  silicates.  Alumina,  while 
greatly  lowering  the  dilatation,  allows  us,  on  account  of 
the  special  fixity  it  communicates  to  glass,  to  obtain  very 
alkaline  silicates  of  high  dilatation,  offering  great  resist- 
ance to  water. 

Fluoride  of  calcium,  in  spite  of  the  high  dilatation 
given  by  fluorine,  only  increases  it  very  slightly,  and  when 
the  proportion  added  becomes  at  all  large  the  glass  is 
completely  devitrified.  To  sum  up,  the  bodies  studied  can 
be  divided  into  two  classes: — i.  Those  which  increase  the 
dilatation,  KO,  NaO,  LiO,  CaO,  PaOj.sCaO,  CaFlj,  and 
crvolite.  2.  Those  which  decrease  the  dilatation,  BO3, 
Si'Oa,  AI2O3,  PbO,  SiO,  ZnO,  Y&zO^,  and  the  colouring 
oxides. 


NOTE   ON   THE    CHEMICAL    COMPOSITION    OF 

THE    MINERAL    RUTILE. 

By  B.  HASSELBERG. 

In  my  researches  on  the  arc-spedrum  of  titanium  I  em- 
ployed, as  elsewhere  stated  {Svenska  Vetensk.  Akad. 
Handl.  ;  also  Ap.  y.,  v.,  194 — igS,  1897),  instead  of  the 
commercial  metallic  powder,  a  Norwegian  specimen  of 
the  mineral  rutile,  mainly  on  account  of  the  far  greater 
steadiness  of  the  arc  thus  formed.  According  to  the 
hitherto  published  chemical  analyses  of  this  mineral 
(Dana,  "  Descriptive  Mineralogy,"  fifth  edition.  New 
York,  1883,  p.  160),  I  had  no  good  reason  to  expedt  any 
foreign  lines  of  importance  other  than  those  of  iron,  the 
more  conspicuous  of  which  would  be  present  in  any  case 
on  account  of  impurities  in  the  carbons.  However,  upon 
examining  the  arc-spedtrum  01  vanadium  obtained  from  a 
specimen  of  this  metal  presented  to  Baron  Nordenskiold 
by  Moissan,  of  Paris,  I  found,  to  my  great  surprise,  that 
several  of  its  strongest  lines  coincided  exadlly  with  faint 
lines  in  my  titanium  spedtrum,  thus  indicating  a  very 
appreciable  percentage  of  vanadium  in  the  rutile  analysed. 
This  induced  me  to  investigate  more  closely  the  spedlra 
of  other  specimens  of  the  mineral  in  question,  particularly 
as  I  had  the  opportunity  to  seledt  from  among  the  rich 
coliedtions  of  the  Royal  Mineral  Cabinet  varieties  from 
different  quarters  of  the  world. 

In  the  comparisons  I  have  used  only  the  part  of  the 
spedtrum  included  between   \  460   and  \  427.      This  is 

I  sufficient,  for  in  this  region  there  is  situated  one  of  the 
most  prominent  groups  of  the  whole  vanadium  spedtrum, 

I  namely,  the  group  \  441 — 438,  the  presence  of  which  in  the 
spedtrum  of  any  rutile,  even  though  feeble  in  intensity, 
would  indicate  indubitably  the  presence  of  a  sensible  per- 
centage of  the  metal.  In  order  to  decide  definitely  con- 
cerning the  coincidences,  the  above-named  part  of  the 
vanadium  spedtrum  was  photographed  upon  the  same 
plate  witn  the  same  region  of  ttie  spedtra  01  the  different 
rutiles,  and  on  these  plates  the  intensities  of  the  rutile 
lines  corresponding  to  vanadium  were  estimated  on  a 
scale  in  which  i  denotes  the  faintest,  and  6  the  strongest 
lines.  A-H  or  —  after  a  number  indicates  the  intensity 
of  the  line  in  question  to  be  nearer  to  this  number  than 
to  the  next.  Thus,  i -f  denotes  an  intensity  greater  than 
I,  but  not  attaining  1-2  and  so  on.  In  this  way  the  fol- 
lowing table  has  been  construdted,  which  contains  the 
Jesuits  of  the  investigation  of  twelve  rutiles,  namely: — 

I.  Rutile  from  Krageroe. 
Norway  ..      ..-j      2.       „        „      Langoe. 

3.      ,,        ,,      Lofteshagen. 


CHiiMicAL  News,  ' 
Aug.  27,  1897.     ] 


Chemical  Compasition  of  the  Miner  a  L  R  utile. 


163 


Table 

A. 

Vanadi 

Rutile  from — 

um 

'~ 

Loftes- 

Karing. 

Tacho- 

Binnen- 

Frei- 

Graves 

Arkan- 

A 

I 

Krageroe. 

Langoe, 

hagen. 

bricka. 

waja. 

Miask. 

thal 

Vrieix. 

berg.  Castilia.  Mountain. 

sas. 

Remarks. 

4268  85 

3 

1  + 

.. 

I 

I 

I- 

.. 

trace 

I  — 

I 

1  + 

trace 

The   word 

71-80 

3 

.. 

I 

.. 

.. 

.. 

.. 

'trace'  in- 

433015 

3 

I- 

trace 

I 

trace 

trace 

trace 

trace 

I 

dicatesan 

33-00 

3 

I 

I 

I 

I 

trace 

.. 

trace 

1- 

I '2 

.. 

intensity 

41-15 

3 

1  + 

I 

I- 

I 

trace 

trace 

I  — 

I 

1-2 

trace 

too  feeble 

53'05 

3-4 

1  + 

1  + 

1-2 

1  + 

trace 

trace 

I- 

I 

1-2 

trace 

to  be  es- 

79-42 

4-5 

2 

3 

2-3 

3- 

23 

2- 

trace 

2 

2 

23 

2-3 

2- 

timated. 

84-95 

4-5 

2 

2-3 

2  + 

2-3 

2  + 

1-2 

trace 

2- 

2- 

2  + 

2  + 

1-2 

90-15 

4-5 

2 

2 

2 

2  + 

2 

I 

1-2 

X-2 

2- 

2 

1  + 

95-40 

4-5 

I 

1-2 

1-2 

2 

I'2 

trace 

.. 

1  + 

I 

1  + 

2- 

I 

4400-75 

4 

1-2 

2- 

12 

2 

2- 

I 

1  + 

1-2 

1-2 

2  — 

2- 

1  + 

06-85 

4-5 

.. 

12 

1-2 

2- 

1-2 

trace 

I 

I 

1  + 

2- 

I 

07-90 

4-5 

1-2 

2- 

2  — 

2 

2  — 

I 

trace 

1-2 

1-2 

2  — 

2  + 

1  + 

08  40 

4 

1-2 

2- 

2- 

2 

2- 

I 

.. 

1-2 

12 

z- 

2  + 

1  + 

08  65 

4-5 

1-2 

2  — 

2- 

2 

2- 

I 

1-2 

1*2 

2  — 

2  + 

1  + 

16-65 

3 

2 

.. 

.. 

2 

.. 

, . 

.. 

.. 

. . 

38-03 

3-4 

I 

I  — 

I 

I 

I 

.. 

trace 

trace 

I 

.. 

41-90 

3-4 

1-2 

2- 

2- 

2  — 

1-2 

1-2 

1  + 

.. 

1-2 

1-2 

2- 

I 

Ti 

44-40 

3-4 

.. 

2- 

2- 

1-2 

1-2 

1-2 

1-2 

1-2 

1-2 

2  — 

I 

Ti 

52  12 

4 

I 

I  - 

I- 

trace 

trace 

. . 

trace 

I  — 

1-2 

59-95 

4 

trace 

1  + 

1  + 

1-2 

1-2 

I  — 

I  — 

I 

I 

1  + 

I 

60-45 

4-5 

I 

I'2 

1-2 

2  — 

2 

I 

1  + 

1-2 

1-2 

2- 

I- 

62-55 

3-4 

trace 

I 

I 

, , 

trace 

trace 

I 

I 

69  90 

3-4 

I- 

I  — 

trace 

trace 

trace 

I  — 

I 

454562 

3-4 

.. 

1-2 

1  + 

I 

I 

I 

1  + 

1  + 

49-85 

3 

3-4 

3-4 

3-4 

3-4 

3-4 

3 

3*4 

3-4 

Belongs 

77-40 

4 

trace 

1  + 

1  + 

I  — 

trace 

I 

I 

trace 

to    Ti, 

80-55 

4 

I 

1-2 

1-2 

I 

I 

1  + 

1  + 

I 

Co. 

8655 

4-5 

I 

1-2 

1-2 

I  — 

I 

i-f 

1  + 

I 

94-30 

4-5 

I 

I'2 

2- 

I  — 
Table 

B. 

I 

1  + 

1  + 

I 

Chromium. 

4254-49 

6 

trace 

3 

3 

2-3 

3 

trace 

.. 

2-3 

2-3 

2'3 

2 '3 

.. 

74-91 

6 

.. 

2-3 

2-3 

2- 

2  + 

.. 

2 

2 

2 

2+ 

.. 

89-87 

6 

•• 

2 

2 

2  — 

2 

•• 

•• 

1-2 

2- 

2- 

2 

•• 

Sweden 
Russia 


Switzerland 
France    . . 
Germany  . 
Spain 

America  . . 


9- 
10. 
II. 


Rutile  from  Karingbricka. 
,,        ,,      Tachowaja,  Ural. 
,,         ,,      Miask,  Orenberg. 
,,        „      Binnenthal,  Wallis. 
„        „      Yrieix. 
„        „      Freiberg. 
,,        ,,      New  Castilia. 
,,        ,,      Graves  Mountain,  Lin- 
coln Co. 
,,        ,,      MagnetCaves, Arkansas 

■  From  Table  A  it  will  be  seen  that,  with  one  exception, 

all  the  rutiles  examined  contain  vanadium  in  varying 
proportions.  This  exception  is  found  in  the  Anatas  from 
Binnenthal,  Canton  Wallis,  in  Switzerland,  in  the  spec- 
trum of  which  the  vanadium  lines  are  almost  absolutely 
wanting.  This  statement  is  not  invalidated  by  the  greater 
intensity  of  the  two  lines  4444-40  and  4441-90,  for  these 
lines  belong  without  doubt  to  titanium,  although  they 
differ  so  very  little  in  position  from  the  vanadium  lines 
that  a  separation  on  my  speftrograms  is  impossible. 

On  comparing  the  intensities  of  the  vanadium  lines  in 

the  different  specimens  of  rutile,  the  singular  fadt  at  once 

manifests  itself  that  varieties   from    neighbouring   lodes 

contain  a  very  different  percentage  of  the  metal.      Thus, 

among  the  Norwegian  rutiles,  the  two  specimens  from 

Langoe    and  Lofteshagen  contain  vanadium  in  a  much 

larger  proportion  than  the  Krageroe  rutile,  and  the  same 

^U     holds  good  for  the  two  Russian  and  also  for  the  American 

^L    rutiles.     This  peculiarity  finds  a  counterpart  in  the  case 

^^k  of  another  component  of  some  rutiles,  namely,  chromium, 

^^B  of  which  metal  a  very  notable  amount  was  discovered  in 


(Dana,  "Mineralogy,"  p.  161),  and  is  now  detedled  in 
some  of  the  varieties  under  discussion. 

In  order  to  prove  that  the  observed  titanium  lines  are 
not  to  be  ascribed  to  an  impurity  of  the  carbons,  the  spec- 
trum of  the  latter  was  photographed  with  that  of  vanadium 
before  introducing  rutile  into  the  arc.  Besides  the 
ordinary  carbon  bands  the  resulting  plates  show  feebly 
only  a  few  of  the  most  conspicuous  iron  and  calcium 
lines,  but  of  vanadium  not  the  least  trace  is  seen.  The 
purity  of  the  carbons  analysed  is  thus  to  be  considered  as 
entirely  satisfadory. 

While  the  presence  of  vanadium  in  the  rutile  thus  forms 
a  hitherto  entirely  unknown  feature  of  this  mineral,  the 
presence  of  chromium  in  the  Swedish  variety  was,  as  above 
stated,  detedted  by  chemical  analysis  as  early  as  1803,  and 
has  since  then  been  verified  in  some  other  specimens.  The 
present  method  of  research,  however,  permits  of  a  much 
easier  decision  in  this  resped  on  account  of  the  occur- 
rence of  one  of  the  strongest  groups  of  the  whole  spec- 
trum of  chromium,  viz.,  X  4289-9,  4274-9,  4254-5  just 
within  the  part  here  photographed.  It  is  not  very  diffi. 
cult  to  find  them  out  among  the  crowd  of  titanium  lines 
on  the  photographs,  and  from  their  estimated  intensities, 
to  form  at  least  an  approximate  idea  of  the  greater  or  less 
quantity  of  chromium  contained  in  the  specimens  ex- 
amined. The  results  of  these  comparisons  are  given  in 
Table  B. 

It  will  be  seen  that  in  different  rutiles  the  chromium 
lines  show  differences  of  intensity,  fully  justifying  the 
conclusion  of  a  corresponding  disparity  in  the  amounts  of 
the  metal.  Thus,  while  the  Anatas  and  also  the  Arkansas 
rutile  are  absolutely  free  from  chromium,  and  in  the 
rutiles  from  Krageroe  and  Miask  only  a  feeble  trace  is 


104 


London  Water  Supply. 


I  CHEMICAL  News, 
I    Aug.  27, 1897. 


present,  the  other  specimens  contain  a  very  considerable 
percentage  of  this  metal.  But  the  most  peculiar  feature 
in  this  respecfl  appears  upon  comparing  chromium  with 
vanadium.  It  is  thus  found  that  in  those  varieties  of 
rutile  which  contain  vanadium  in  any  very  appreciable 
amount,  chromium  is  also  present,  while  a  small  per- 
centage of  the  former  metal  is  accompanied  by  a  corre- 
sponding scarcity  or  even  complete  absence  of  the  latter. 
In  conclusion,  it  should  be  remarked  that  in  the  case  of 
the  Norwegian  rutile  from  Langoe  the  preceding  results 
have  been  completely  confirmed  by  ordinary  chemical 
analysis  kindly  undertaken  by  Baron  Nordenskiold.  It  is 
thus  evident  that  the  accepted  chemical  analyses  of  the 
present  mineral  by  no  means  possesses  the  completeness 
or  accuracy  which  the  usual  chemical  methods  are  capable 
of  giving. — Astrophysical  journal,  vL,  No.  i,  June,  1897. 


LONDON     WAfER   SUPPLY. 
Report  on  the  Composition  and  Quality  of  Daily 
Samples    of  the  Water   Supplied  to    London 
FOR  the  Month  Ending  July  31ST,  1897. 

By  SIR  WILLIAM  CROOKES,  F.R.S., 

and 

PROFESSOR  DEWAR,  F.R.S. 

To  Major-General  A.  De  Courcy  Scott,  R.E., 
Water  Examiner,  Metropolis  Water  Act,  1871. 

London,  August  loth,  1897. 
Sir, — We  submit  herewith,  at  the  request  of  the 
Diredors,  the  results  of  our  analyses  of  the  189  samples 
of  water  colledled  by  us  during  the  past  month,  at  the 
several  places  and  on  the  several  days  indicated,  from  the 
mains  of  the  London  Water  Companies  taking  their 
supply  from  the  Thames  and  Lea. 

In  Table  I.  we  have  recorded  the  analyses  in  detailof 
samples,  one  taken  daily,  from  July  ist  to  July  3i8t 
inclusive.  The  purity  of  the  water,  in  respedt  to  organic 
matter,  has  been  determined  by  the  Oxygen  and  Com- 
bustion processes;  and  the  results  of  our  analyses  by 
these  methods  are  stated  in  Columns  XIV.  to  XVIII. 

We  have  recorded  in  Table  II.  the  tint  of  the  several 
samples  of  water,  as  determined  by  the  colour-meter 
described  in  a  previous  report. 

In  Table  III.  we  have  recorded  the  oxygen  required  to 
oxidise  the  organic  matter  in  all  the  samples  submitted 
to  analysis. 

Of  the  189  samples  examined  all  were  found  to  be  clear, 
bright,  and  well  filtered. 

The  rainfall  at  Oxford  during  July  was  2*57  inches,  of 
which  2-25  inches  fell  on  the  19th,  20th,  and  21st  inst, ; 
the  average  for  the  last  30  years  is  2-63  inches;  this  leaves 
a  deficiency  of  o"o6  inch  on  the  month.  There  was  an 
excess  of  o"o6  inch  on  the  first  six  months  of  the  year;  so 
this  is  exaftly  balanced  by  the  deficit  of  this  month  ;  and 
the  acftual  fall  this  year,  up  to  the  end  of  July,  is  identical 
with  the  30  years'  average,  viz.,  13*94  inches. 

The  results  of  our  baderiological  examinations  of  265 
samples  are  recorded  in  the  following  table ;  we  have  also 
examined  53  other  samples  taken  at  special  points,  stand- 
pipes,  wells,  &c.,  making  a  total  of  318  samples : — 

Microbes 
per  c.c. 
Thames  water,  unfiltered  (mean  of  27  samples)    4971 
Thames  water,  from  the  clear  water  wells  of 
five  Thames-derived  supplies  (mean  of  133 

samples)     .. 83 

Ditto        ditto  highest      496 

Ditto        ditto  lowest  4 

New  River,  unfiltered  (mean  of  27  samples)  . .       754 
New  River,  filtered  (mean  of  25  samples)       . .         44 
River  Lea,  unfiltered  (mean  of  27  samples)   ..     2494 
River  Lea,  from  the  clear  water  well  of  the 
East  London  Water  Company  (mean  of  26 
samples) 125 


The  average  badleriological  quality  of  the  London 
waters  has  been  good  during  the  month.  On  some  days, 
however,  in  the  case  of  two  of  the  Thames-derived  waters, 
there  has  been  an  excess  of  microbes,  and  the  water  from 
the  Lea  has  not  all  the  time  been  up  to  its  best  standard. 
We  have  been  in  communication  with  the  Companies 
respedting  certain  alterations  in  the  filter  beds,  which  are 
likely  to  improve  their  efficiency.  Our  suggestions  are 
being  considered,  and  during  the  latter  part  of  the  month 
the  badlerial  quality  of  the  water  has  greatly  improved. 

We  are.  Sir, 

Your  obedient  Servants, 

William  Crookes. 
James  Dewar. 


PAINT    TESTS. 


Max  Toltz,  in  a  paper  read  before  the  Civil  Engineers' 
Society  of  St.  Paul,  December  7th,  1896,  and  printed  in 
the  jfournal  of  the  Association  of  Engineering  Societies 
(June,  1897),  has  gone  comprehensively  into  the  compara- 
tive value  of  paints  for  protedting  iron  surfaces.  The 
paints  experimented  with  were  (i)  true  asphaltic  varnish 
paints ;  (2)  so-called  asphaltic  varnishes,  of  inferior 
qualities  ;  (3)  black  carbon  paints,  of  which  the  vehicle  is 
pradically  a  varnish  ;  (4)  iron  oxide  paints ;  (5)  graphite 
and  silica  graphite  paints.  Red-lead  was  not  tested. 
Within  the  last  ten  years  this  material  has  been  to  a  large 
extent  discarded  by  progressive  engineers,  and  although  it 
has  still  warm  advocates,  even  they  are  beginning  to  add 
carbon-black  or  graphite  to  it,  says  Mr.  Toltz.  One  set  of 
tests  made  by  Mr.  Toltz  consisted  in  painting  sheet-iron 
dishes,  12  inches  diameter  by  o'5  in.  deep.  The  scale  or 
skin  was  carefully  removed  before  painting.  Two  dishes 
were  then  painted  with  each  kind  of  paint,  one  receiving 
one  coat  and  the  other  two  coats,  the  first  coat  having 
dried  at  least  a  week  before  the  second  was  put  on.  After 
the  second  coat  had  dried  thoroughly,  a  given  amount  of 
water  was  placed  in  the  dishes  and  allowed  to  evaporate 
at  the  ordinary  temperature  of  the  room,  this  being  re- 
peated until  the  dishes  showed  more  or  less  rust.  After 
most  of  the  water  had  evaporated  there  remained  at  the 
jundion  around  the  edge  a  thin  film  of  water,  which  in 
contad  with  the  air,  and  the  carbonic  and  other  acids  of 
the  air,  adled  on  the  paint  in  such  a  way  that  the  iron 
under  it  began  to  rust.  In  adual  pradiice  the  same  thing 
will  happen,  the  only  difference  being  that  the  rust  will 
extend  under  the  paint  and  will  not  show  as  plainly  as  ou 
the  dish.  This  is  a  severe  test,  but  in  Mr.  Toltz's 
opinion  no  paint  which  fails  to  withstand  it  is  desirable 
for  the  proteftion  of  iron  and  steel  strudures.  The  cheap 
asphaltum  paints  and  iron  oxide  paints  failed  under  this 
test.  Another  severe  test  consisted  in  exposing  sheet  iron 
coated  with  various  kinds  of  paint  to  a  temperature  of 
220—300"  F.,  this  test  being  of  value  as  showing  promptly 
whether  a  paint  will  keep  its  elasticity  or  will  become  so 
brittle  that  it  may  be  easily  removed  from  the  surface. 

In  the  discussion  which  followed  this  paper  exception 
was  taken  to  various  statements  made  by  Mr.  Toltz,  but 
the  expressions  of  opinion  were  generally  in  support  of 
his  conclusions. 

From  our  present  knowledge,  the  following  system  for 
painting  iron  and  steel  bridges,  and  other  metallic  struc- 
tures, is  recommended  by  Mr.  Toltz  : — 

First.  Give  the  iron  and  steel  a  coat  of  the  best  grade 
of  refined  linseed  oil,  properly  boiled  and  settled  clear ; 
or,  still  better,  mix  linseed  oil  with  about  10  per  cent  of  a 
good  grade  of  lamp-black,— this  coat  to  be  applied  at  the 
mills,  the  iron  or  steel  being  first  carefully  cleaned  from 
loose  scales. 

Second.    After  the  struAures  have  been  erected,  give 


^rug'-^^lgT^"'}  Report  of  the  Connecticut  Agricultural  Experiment  Station, 


105 


them  one  coat  of  real  asphaltic  varnish  paint,  made  from 
the  best  grade  of  asphalt,  linseed  oil,  and  gum,  com- 
pounded properly,  so  as  to  form  a  true  varnish  ;  or  of  a 
paint  made  from  carbon  black  and  properly  boiled  varnish, 
compounded  of  the  best  grade  of  linseed  oil  and  gum. 
This  coat  should  be  carefully  applied  by  a  skilful  painter, 
after  the  metal  has  been  thoroughly  cleaned  from  all  loose 
scale,  rust,  shavings,  filings,  shrivelled  oil  or  paint,  grease, 
dirt,  or  any  foreign  matter,  because  it  is  of  the  utmost 
importance  that  the  paint  should  be  spread  and  worked  in 
such  a  way  so  as  to  cover  the  surface  properly,  and  be  as 
free  as  possible  from  air-bubbles  and  form  a  continuous 
coating.  This  priming  or  first  coat  should  be  applied 
fairly  thick,  the  thickness  depending,  to  some  extent,  on 
the  nature  of  the  paint  used.  Before  the  second  coat  is 
applied,  the  first  one  should  be  thoroughly  dried  and 
hardened  by  natural  oxidation,  which  will  require  at  least 
ten  days.  If  pradlicable,  it  would  be  a  great  deal  better, 
as  well  as  more  economical,  to  apply  the  second  coat  not 
less  than  four  weeks  after  the  first  one. 

Third.  As  a  second  coat,  a  good  grade  of  graphite 
paint  is  to  be  applied  as  thickly  as  possible,  working  the 
paint  thoroughly  with  the  brush.  From  the  examinations 
made  of  the  various  grades  of  graphite  paints,  as  far  as 
graphitic  pigments  are  concerned,  there  appears  to  be  but 
little  difference  between  them,  provided,  of  course,  that 
the  pigment  contains  at  least  33  per  cent  of  pure  graphite, 
the  rest  of  the  pigment  being  natural  rock,  ground  very 
fine  in  pure  linseed  oil.  The  graphite  paint  should  be 
bought  in  paste  form,  well  ground,  and  contain  not  less 
than  70  per  cent  of  pigment  and  30  per  cent,  by  weight, 
of  the  best  quality  of  boiled  linseed  oil;  the  paste  should 
be  mixed  with  boiled  linseed  oil  at  the  place  where  it  is 
to  be  applied.  No  turpentine,  no  benzine,  and  no  Japan 
or  driers  should,  under  any  circumstances,  be  allowed  in 
this  paint. 

Fourth.  There  are  certain  parts  of  steel  or  iron  bridges, 
viadudls,  or  tunnels  that  should  have  an  additional  (third) 
coat  of  paint.  These  include  such  places,  or  parts  of 
strudures,  as  are  diredtly  exposed  to  the  steam,  fumes, 
and  gases  from  passing  engines.  For  such  a  coat  some 
cheaper  asphalt  paints,  applied  very  thickly  over  the  coats 
above  recommended,  would  be  all-sufficient.  Such  a  coat 
would  protedt  the  underlying  primary  coats  for  many 
years,  preserving  their  natural  toughness  and  elasticity, 
and  preventing  atmospheric  adtion  on  the  strufture. 

From  the  investigations  made,  as  well  as  from  praiSical 
experiments,  it  appears  that  the  iron-oxide  paints  are  not 
very  desirable,  at  least  for  the  first  coat  or  two,  for  iron 
or  steel  ;  but  as  a  third  coat,  for  the  protedtion  of  the 
underlying  paints,  they  may  be  recommended. 

However,  the  extensive  investigation  of  the  graphite 
paints  that  can  be  obtained  in  the  markets  to-day  shows  I 
that,  if  properly  applied,  they  are  far  superior  to  iron- 
oxide  paints  for  the  second  or  third  coat,  especially  as  they 
withstand  the  adlion  of  moisture  and  water  much  better 
than  the  best  iron-oxide  paint  so  far  examined.  Besides, 
a  graphite  paint,  in  paste  form,  well  ground  and  mixed 
with  boiled  linseed  oil,  will  not  cost  very  much  more  per 
gallon  than  the  cheapest  iron-oxide  paint  in  the  market. 

In  recommending  asphalt  varnish  paint  or  carbon  paint 
for  the  first  coat,  great  stress  is  laid  upon  the  necessity  of 
havino;  the  surfaces  of  iron  or  steel  as  free  from  moisture 
as  possible  while  the  strudlures  are  being  painted,  other- 
wise there  is  great  danger  that  the  coating  will  not  adhere 
very  firmly,  and  that  it  will  thus  adlually  nullify  the  value 
of  the  paint.  This  precaution  is  less  important  when  an 
ordinary  iron-oxide  paint  or  red-lead  paint,  simply  mixed 
with  linseed  oil,  is  used;  because  linseed  oil  itself  has  the 
property  of  absorbing  moisture  quite  readily,  whereas 
carbon  or  asphalt  paint  will  not.  The  lack  of  this  pro- 
perty in  the  two  last-named  paints  is  one  of  the  principal 
reasons  why  they  are  superior  to  any  other  class  of  paints. 
— Engineering  and  Mining  yournal. 


NOTICES  OF  BOOKS. 


Twentieth  Annual  Report  of  the  Connecticut  Agricultural 
Experiment  Station  for  1896.  Pp.  414.  New  Haven : 
The  Tuttle,  Morehouse,  and  Taylor  Press.     1897. 

The  Report  on  Food  Stuffs,  which  comes  first  in  this 
volume,  contains  the  results  of  examinations  of  849 
articles  of  food,  of  thirteen  different  kinds.  With  the 
exception  of  Martius  yellow,  found  in  minute  quantity  in 
certain  samples  of  mustard,  no  poisonous  adulterants 
have  been  found,  though  254  samples  were  found  to  be 
adulterated  and  24  were  reported  as  doubtful.  The  most 
frequent  adulteration  was  found  in  coffee.  White 
strained  honey  was,  as  a  rule,  the  purest  article  ex- 
amined. 

The  law  with  regard  to  adulteration  seems  to  be  in  a 
very  lax  condition.  It  appears  that  a  "  Dairy  Com- 
missioner "  was  appointed  under  the  Statute  regulating 
the  sale  of  imitation  butter,  molasses,  and  vinegar,  but  no 
one  is  charged  with  the  execution  of  the  laws  regarding 
the  adulteration  of  milk,  candy,  spirituous  liquors,  drugs, 
and  medicines.  Boards  of  Health,  we  are  informed,  are 
permitted  to  ad  under  the  Statute  regarding  the  adultera- 
tion of  food ;  but  there  is  no  record  of  any  action  having 
been  taken  under  any  of  these  Statutes.  Surely  the 
work  of  the  "Dairy  Commissioner"  is  somewhat 
anomalous. 

Under  the  Report  on  Commercial  Fertilisers  we  note 
that  255  distindl  brands  of  fertilisers  have  been  offered 
for  sale  by  fifty-two  firms.  During  the  year  492  samples 
of  fertilisers  and  manurial  waste  produdts  have  been 
analysed,  results  of  the  examinations  being  given  in  detail ; 
after  which  comes  a  comprehensive  review  of  the  fertiliser 
market.  The  average  monthly  quotations  show  that 
nitrate  of  soda  has  ruled  lower  this  year  than  for  some 
years  previously,  and  there  has  been  but  a  slight  demand 
for  sulphate  of  ammonia  in  the  Connedticut  market. 
Nitrogen  in  the  form  of  animal  matter  has  also  been 
cheaper. 

A  number  of  experiments  have  been  carried  out,  and 
are  here  described,  on  various  agricultural  matters,  such 
as  the  prevention  of  potato-scab,  and  the  susceptibility 
of  various  roots  to  potato-scab,  and  it  was  found  from 
trials  made  on  eight  different  kinds  of  roots  —  viz., 
radishes,  parsnips,  salsify,  carrots,  turnips  (two  kinds), 
mangolds,  and  beets— that  the  radishes  and  carrots  alone 
remained  unquestionably  free  from  scab,  the  salsify  and 
parsnips  showed  little  if  any,  while  the  turnips  gave 
averages  of  21  per  cent  and  15  per  cent  of  scab,  the 
mangolds  40  per  cent,  and  the  beets  63  per  cent. 

Other  experiments  dealt  with  a  leaf  blight  of  melons,  a 
destrudlive  fungus  disease  of  tobacco,  the  so-called 
"  shelling"  of  grapes,  &c. 

The  work  done  at  the  Experimental  Station  is  of  varied 
charadter  and  of  considerable  interest,  while  great  care  is 
evidently  exercised  in  carrying  out  the  plan  of  campaign. 
The  volume  closes  with  a  good  Index  of  fifteen  pages. 


Contribution  to  the  Polyhedric  Origin  of  Species.     ("  Con- 
tribution a  rOrigine  Polyedrique  des  Especes").     By 
Arthur  Soria  Et  mata.    Part  I.,  pp.  203.     Madrid  : 
Chamartin  de  la  Rosa.     1897. 
The  author  has  studied  the  regular  polyhedra,  from  the 
point  of  view  of  making  them,  and  combinations  of  them, 
represent  the  elements  and  their  compounds ;  and  from 
the  curious  figures  evolved  he  has  endeavoured,  with  a 
certain  amount  of  success,  to  reproduce  the  strudture  of 
chemical  compounds  and  minerals,  showing  the   angles, 
faces,  planes  of  cleavage,  &c.,  and  he  claims  that  if,  from 
a  mass  of  polyhedral  groups,  as  shown  by  the  figures  he 
has   built   up,  he  can  show  a  regular  and  systematic 
arrangement  which  reproduces  a  large  number  of— if  not 


io6 


Chemical  Notices  from  Foreign  Sources. 


(Chemical  News, 

I      Aug.  27,  1897. 


all — the  known  crystalline  forms,  it  must  well  be  admitted 
that  his  hypothesis  holds  good  until  another  and  more 
perfedl  one  comes  to  replace  it. 

Starting  from  the  idea  of  an  atom,  which  idea  was  not 
conceived  without  many  doubts  and  much  hesitation,  we 
must  admit  motion,  or  no  phenomena  could  take  place; 
and  from  this  point  he  works  up  to  lines  of  atoms  moving 
in  unison  and  communicating  their  movement  one  to 
another,  the  total  force  being  neither  augmented  or  di- 
minished, though  passing  and  changing  without  ceasing 
from  lines  to  faces,  angles,  and  solid  figures;  this  is  not  a 
long  step,  and  he  classifies  all  the  figures  necessary  for  his 
hypothesis  into  three  groups,  viz. : — the  tetrahedron,  the 
common  origin  of  all  bodies  of  three  dimensions ;  the 
cube,  which  contains  the  beta-tetrahedron  and  the  odla- 
hedron,  the  typical  form  of  chemical  species  and  minerals ; 
and  the  dodecahedron,  which  contains  many  regular 
polyhedra,  and  represents  the  probable  initial  form  of  the 
cell,  and  all  the  animal  and  vegetable  species.  The 
theory  is  a  pretty  one,  but  is  open  to  many  objedtions, — 
still,  as  the  author  says,  it  may  stand  till  another  comes 
to  replace  it. 

We  cannot  agree  with  the  authoi's  supposition  of  the 
interpenetrability  of  atoms  ;  this  supposition  must  con- 
cede mass,  and  therefore  if  two  "  masses  "  can  penetrate 
each  other  *'  until  their  centres  are  coincident,  without 
losing  their  respedive  independence  of  movement,"  there 
is  an  end  of  matter,  as — carrying  the  argument  further — 
all  atoms  would  be  self-contained  in  the  mass,  position, 
or  volume,  whichever  it  maybe,  of  one,— which  is  absurd. 

The  book  is  accompanied  by  four  large  sheets  of  thick 
paper,  on  which  are  marked  out  a  number  of  figures,  all 
ready  for  cutting  out  and  glueing  up  into  the  forms  referred 
to  in  the  letterpress. 


OBITUARY. 


VICTOR    MEYER. 

The  sudden  and  unexpedled  death  of  Professor  Dr. 
Vidlor  Meyer,  on  the  7th  inst.,  has  left  a  painful  impression 
not  merely  at  Heidelberg,  but  throughout  the  chemical 
world.  The  regretted  event  was  at  first  ascribed  to 
apoplexy,  but  it  has  since  been  stated — on  what  evidence 
it  is  not  certainly  known — that  Prof.  Meyer  fell  a  vidlim 
to  poisoning.  We  should  add  that  those  who  regard  the 
death  of  Prof.  Meyer  as  suicide,  allege  that  he  suffered 
from  domestic  troubles. 

Vidor  Meyer,  the  son  of  the  calico-printer,  Jacques 
Meyer,  of  Berlin,  was  born  on  September  8th,  1848. 
After  his  earlier  education  at  the  Werder  Gymnasium  he 
entered,  in  his  sixteenth  year,  the  University  of  Berlin, 
and  after  one  term  that  of  Heidelberg,  where  he  devoted 
himself  to  the  study  of  Chemistry  under  Prof.  Bunsen, 
whose  assistant  he  became.  After  graduating  at  Heidel- 
berg he  continued  his  studies  at  Berlin  under  A.  von 
Baeyer.  In  1871  he  was  called  to  the  Polytechnicum  at 
Stuttgart  as  First  Assistant  of  Fehling,  and  (titular) 
Professor  of  Organic  and  Theoretical  Chemistry.  After 
a  year  he  received  a  call  as  Professor  of  General  Chemistry 
at  the  Polytechnicum  at  Zurich,  vice  Wislicenus.  In  1885 
removed  to  Gottingen,  and  in  1889  he  was  transferred  to 
the  University  of  Heidelberg  as  the  successor  of  Bunsen, 
who  had  recommended  him  as  the  highly  gifted  of  his 
pupils.  Under  his  leadership  chemical  studies  at  Heidel- 
berg experienced  a  rapid  rise.  In  the  last  year  from  fifty 
to  sixty  applications  had  to  be  rejedled  in  every  term. 

Through  Vidor  Meyer's  researches  our  science  experi- 
enced important  extensions  in  various  diredions.  The 
methods  of  determining  vapour  densities  were  greatly 
Bimplified  and  facilitated  by  his  procedures.  His  results 
at  high  temperatures  (up  to  1800°  and  beyond)  yielded  a 
firm  basis  for  pyro-chemistry.    We  are  indebted  to  him  for 


the  discovery  of  the  aldoximes  and  ketoximes  (classes  of 
bodies  which  become  of  fundamental  importance  for  the 
recognition  of  the  aldehyds  and  ketones.  They  became 
of  prominent  importance  in  the  development  of  stereo- 
chemistry, especially  that  of  nitrogen. 

His  most  brilliant  discovery  in  organic  chemistry  was 
that  of  thiophene  in  benzene,  proceeding  from  which 
Vidtor  Meyer  may  be  said  to  have  created  a  new  branch 
of  chemistry.  As  a  Professor  he  was  unsurpassed  ;  few 
Academic  teachers  equalled  him  in  the  art  of  stimulating 
his  hearers.  Both  his  discourse  and  his  carefully  prepared 
experiments  afforded  his  pupils  a  high  enjoyment. 

In  1885  Prof.  Vidtor  Meyer  was  eledted  an  honorary 
member  of  the  British  Chemical  Society. 


CHEMICAL  NOTICES  FROM  FOREIGN 
SOURCES, 

Note.— All  degrees  of  temperature  are  Centigrade  unless  otherwise 

expreBsed, 

CompUs  Rendus  Hebdomadaires  des  Seances,  dePAcademit 
des  Sciences.     Vol.  cxxv.,  No.  4,  July  26,  1897. 

Composition  of  Drainage  Waters. — P.  P.  Deherain. 
— From  March,  1895,  to  March,  1896,  the  fields  kept  in 
fallow  alone  have  yielded  drainage  water;  the  lands 
sown  with  annual  plants,  already  impoverished  in  water 
by  the  vegetation  itself,  have  been  so  thoroughly  dried  by 
the  exceptional  temperature  of  the  autumn  of  1895  ^^^^ 
the  autumnal  rains  could  not  saturate  them.  If  we  cal- 
culate for  the  surface  of  a  hedtare,  we  find  that  the 
drainage  of  the  plots  in  fallow  has  removed  109  kilos,  of 
nitric  nitrogen — a  figure  analogous  to  that  of  1893  and 
1894,  but  very  inferior  to  that  of  1892.  The  rain  has  been 
very  unequally  distributed  during  the  agricultural  year, 
March,  i8g6,  to  March,  1897.  Scanty  at  the  outset,  it 
became  abundant  in  June,  moderate  in  July  and  August, 
but  it  was  extremely  plentiful  in  September  and  Odtober 
(130  and  136  m.m.  respedlively).  The  quantities  of  nitric 
nitrogen  in  the  fallow  land,  deprived  of  nitrogenous 
manures,  rose,  during  the  moist  years,  to  200  kilos,  per 
hedlare,  representing  1250  kilos,  nitrate  of  soda,  and  ex- 
ceed the  requirements  of  the  most  greedy  crops.  The  soils 
under  crops  elaborate  a  much  smaller  quantity  of  nitrates, 
for  the  abundant  evaporation  of  the  herboraceous  plants 
dries  the  soil  so  completely  as  to  admit  of  an  energetic 
nitrification.  When  rain  is  very  abundant  we  obtain, 
without  nitrogenous  manures,  very  good  harvests,  con- 
taining a  sufficiency  of  nitric  nitrogen. 

Researches  on  the  Conditions  in  which  there  occur 
Elements  other  than  Carbon  in  Cast-Irons  and 
Steels. — Ad.  Carnot  and  M.  Goutal. — This  paper  will  be 
inserted  in  full. 

Explanation  of  a  Phenomenon  attributed  to  a 
Magnetic  Deviation  of  the  X  Rays. — Sir  G.  G,  Stokes. 
— Already  inserted. 

Phthalic  Green:  its  Preparation  and  Constitution. 
— A.  Haller  and  A.  Guyot. — Otto  Fischer  has  given  this 
name  to  a  green  pigment  obtained  in  small  quantities  by 
causing  phthalyl  chloride  to  adt  upon  dimethyl.  The 
authors  have  found  that  in  addition  to  diphenylphthalide 
there  are  formed  small  quantities  of  a  new  compound, 
C20H18O.  This  compound  is  formed  by  other  methods, 
and  in  particular  by  the  adiion  of  aluminium  chloride 
upon  phthalyl  and  benzene  tetrachloride  in  the  diphenyl- 
anthrone  described  by  one  of  us  in  a  former  com- 
munication. The  compounds  here  described  are  the 
hydrochlorate,  C32H35N30C1  -f  H2O  ;  the  nitrate, 
C32H34N3O.NO3,  is  a  very  stable  substance.  The  chloro- 
platinate,  (C32H34H30Cl-|-3HCl)3PtCl4,  is  obtained  in 
fine  vermilion-red  crystals.  The  leucobase  of  phthalic 
green  has  the  composition  C32H35N3O. 


Chemical  News,  I 
Aug.  27, 1897.     I 


Chemical  Notices  /rom  Foreign  Sources, 


107 


Transformation  of  the  X  Rays  by  Metals.—  G. 
Sagnac. — The  various  metals  exert  an  eledtive  absoipLion 
upon  the  X  rays.  At  the  same  time  the  superficial  layer 
of  the  metal  emits  anew  rays  much  less  easily  trans- 
mitted than  the  X  rays  by  mica,  aluminium,  black  paper, 
and  the  air  itself.  These  new  rays  are  themselves  trans- 
formed by  aluminium.  We  foresee  that  we  shall  gradu- 
ally succeed  in  filling  up  the  space  which  separates 
the  X  rays  from  the  known  ultra-vioiet  rays,  and  perhaps 
identify  them  with  such  rays. 

Photographic  Veiling  in  Radiography. — P.  Villard. 
— Radiographic  proofs  often  present  a  veiled  aspedt, 
especially  in  the  case  of  thick  objefts.  We  admit  readily 
that  this  result  is  due  to  X  rays  of  a  peculiar  nature 
capable  of  traversing  almost  all  bodies  without  notable 
absorption. 

Adion  of  X  Rays  upon  the  Temperature  of 
Animals. — L.  Lecercle. — Already  inserted. 

Line  Spe(5lrum  of  Carbon  in  Fused  Salts. — A.  de 
Gramont. — Tables  of  the  wave-lengths  forming  the  line- 
spedtrum  of  carbon  as  recognised  and  measured  in  melted 
carbonates. 

Relation  between  the  Polymerisation  of  Liquids 
and  their  Dissociating  Power  upon  Eledtrolytes. — 
Paul  Dutoit  and  Mile.  £.  Aston. 

A  New  Group  of  Amidines. — Fernand  Muttolet. — 
These  two  papers  will  be  inserted  as  soon  as  possible. 

Procedure  for  Determining  Acetylene  applicable 
toCarbides  of  the  Form  R— C  =  — H.  — M.  Chavestelon. 
— The  author  brings  back  the  determination  of  acetylene 
to  an  acidiinetric  estimation. 

Determination  of  Lime,  Alumina,  and  Iron  in 
Mineral  Phosphates. — L.  Lindet. — This  memoir  will  be 
inserted  in  full. 

Absorption  of  Oxygen  in  the  Fradure  of  Wines, 
— J.  Laborde. 

Badieriological  Study  of  Ambergris. — H.  Beauregard 
— Already  inserted. 

Revue  Geuerale  des  Sciences  Pures  et  Appliques. 
No.  14,  July  30,  1897. 
Annual  Review  of  Pure  Chemistry. — A.  Etard. — 
One  of  the  most  important  events  of  the  year  in  pure 
chemistry  is  the  liquefadion  of  fluorine  by  Messrs. 
Moissan  and  Dewar,  whose  paper  has  already  been 
printed  in  full  in  these  columns.  Of  the  other  less  im- 
portant work,  the  author  sees  nothing  but  a  little  more 
confusion,  owingto  the  monotonous  continuity  of  scientific 
produdions  of  unequal  value.  The  science  of  chemistry 
is  extending  every  year  in  new  diredlions.  It  now  in- 
cludes pressure,  cold,  eledricity,  &c.,  &c..  It  is  being 
enriched  principally  by  the  determination  of  volumes,  by 
the  measurement  of  constants,  and  in  more  minute  work 
striving  to  show  if  what  we  have  so  long  admitted  is 
really  true.  After  a  long  period,  during  which  it  has 
seemed  that  science  was  getting  so  pure  as  to  be  useless, 
savants  are  coming  back  to  the  traditions  of  Gay-Lussac 
and  Berthollet,  and  are  endeavouring  to  adapt  the  modern 
lofty  ideas  to  the  wanis  of  mankind.  Thus,  Lord  Rayleigh 
proposes  to  make  the  diredt  oxidation  of  the  nitrogen  of 
the  air  commercially  pradticable  by  means  of  the  eledtric 
currents  which  aie  now  at  tiie  disposal  of  chemists.  He 
found  that  with  an  eleclromotive  force  of  6000  volts  the 
absorption  of  air  in  a  7-litre  flask,  in  which  played  a  spray 
of  potash,  reached  6880  c.c.  per  hour.  Mr.  Liversidge 
has  tested  various  deposits  of  maritime  origin  for  gold, 
and  has  found  that  the  Stassfurt  salts  contain  0*13  grm. 
per  ton.  But  it  is  not  only  gold  that  is  so  widely  dis- 
seminated, but,  as  Mr.  Hartley  has  shown,  also  the  so- 
called  rare  earths  and  metal?.  In  92  different  iron  ores 
he  found  always  either  silver,  rubidium,  copper,  gallium, 
indium,  or  thallium.  Mr.  Shenstone  has  found  that  the 
halogens  CI,  Br,  and  I  combine  with  mercury  when  in  a 


state  of  perfed  dryness,  but  ozone  will  not  do  so  except  in 
the  presence  of  aqueous  vapour.  Mr.  Chattaway  has 
studied  the  composition  of  iodide  of  nitrogen,  and  comes 
to  the  conclusion  that  NH3I2  is  the  most  probable  formula, 
certainly  the  rapport  N  :  I2  has  been  established. 


Advertiser   (A.I.C.),   with   small    amount   of 

■^^  Capital,  desires  position  of  Chemist,  Manager,  or  Partner  in 
Works  or  Laboratory.  Ten  years'  experience  in  large  Chemical 
Manure  "Work.  Good  references. — Address,  Q.  Z.,  Chemical  News 
Office,  6  &  7,  Creed  Lane,  Ludgate  Hill,  London,  E.C. 


A  nalytical  Chemist  required  in  Works  Labora- 

**•  tory  near  London. — State  age,  experience,  references,  and  salary 
expe(5ted  to*F.  L  C,  Chemical  News  Office,  6  &  7,  Creed  Lane, 
Ludgate  Hill,  London,  E.C. 

'T^he  post  of  Manager  (Technical  Chemist)  in 

-*■  a  Chemical  Faftory  in  the  North  of  Italy  will  be  vacant  by 
January  ist,  i8g8.  The  chief  produfts  are — Sulphuric,  Nitric,  and 
Hydrochloric  Acids,  as  well  as  Chemical  Manures. — Address,  No. 
H.  88SgT.,  care  of  Haasenstein  and  Vogler,  Turin,  Italy. 


n^he  Proprietors  of  a  large  Wholesale  Chemi- 

-*■  cal  Business  in  Geimany,  with  ready  sales  in  Borax  and 
Boracic  Acid,  wish  to  correspond  with  large  Borax  Manufadturers 
with  a  view  to  business. — Apply,  R.  M.,  care  of  Messrs.  Henry 
Wiggins  and  Co.,  Lim.,  Birminghani. 

Wanted,  a  Teaching  Assistant,  for  a  limited 
time,  who  has  taken  Honours,  or  First-class  Advanced 
(Science  and  Art  Department)  in  Theoretical  and  Praftical  Inorganic 
Chemistry.  Post  allows  t^me  for  stuHy  for  further  examination. — 
Address,  D.  C,  Chemical  News  Office,  6  &  7,  Creed  Lane,  Ludgate 
Hill,  London,  E.C.  


Wanted  for  Johannesburg,  a  capable  and 
qualified  Salesman  for  Chemicals  and  Chemical  Appurten- 
ances as  used  in  Gold  Mining. — Apply,  stating  experience  and  salary 
expefted,  to  "  Salesman,"  Chemical  News  Office, 6  &7,  Creed  Lane, 
Ludgate  Hill,  London,  E.C. 

Wanted  immediately,  Junior  Assistant,  tem- 
porary engagement,  for  a  Public  Analyst's  Laboratory.  Ap- 
plicant must  have  experience  in  the  Analysis  of  Water,  Foods,  and 
Drugs. — Address,  stating  age,  training,  and  fullest  particulars,  to 
A.  H.,  Chemical  News  Office,  6  &  7,  Creed  Lane,  Ludgate  Hill, 
London,  E.C; 

X/oung  Technical  Chemist,  Dr.  Phil.,  German, 

-•-  acquainted  with  the  manufadture  of  Cyanides  from  gas  puri- 
fying matter,  with  the  Smelting  Process,  and  with  the  manufafture 
of  Chlorine,  wants  Situation.— Address,  "  -.  W.  361,"  care  of  Rudolf 
Mosse,  Frankfort-on-the-Main. 


,TO  WHOLESALE   DRUGGISTS  AND   OTHERS. 
BY  ORDER  OF  THE  RECEIVER. 

Messrs. TOPLIS  &  HARDING  are  instruded 
to  offer  FOR  SALE  bv  Tender  the  whole  of  the  STOCK-IN- 
TRADE  of  Messrs.  LANGTON,  EDDEN,  &  CO.,  Wholesale 
Druggists,  38,  Wilson  Street,  Finsbury,  E.G.,  comprising  Turmeric, 
Cascara,  ocnna,  Aloes,  Liquorice,  Scammony,  Cinnamon  Oil,  Es- 
sences, Oils,  Tincftures,  and  a  large  assortment  of  Drugs  and  Phar- 
maceutical preparations. 

May  be  viewed  and  catalogues  had  on  the  premises  and  of  the 
Audtioneers,  6C,  Cannon  Street,  E.C. 

Tenders  to  be  opened  on  September  4th. 


CT.     PAUL'S      SCHOOL,      LONDON.— 

^  An  Examination  for  filling  up  about  20  Vacancies  on  the 
Foundation  will  be  held  on  the  14th,  15th,  i6th,  17th,  and  20th  Sept- 
ember next. — For  iniormation  apply  to  the  Bursar,  St.  Paul's  School, 
West  Kensington,  W. 


TTNIVERSITY     COLLEGE,     BRISTOL, 

vJ  CHEMICAL  DEPARTMENT. 

Professor— SYDNEY  YOUNG,  D.SC,  F.R.S. 
Lefturer— FRANCIS  E.  FRANCIS,  B.Sc,  Ph.D. 
Junior  Demonstrator — 
The  SESSION  1897-98  begins  on  Odtober  5th.    Leftures  on  Inor" 
ganic.  Organic,  and  Advanced  Chemistry  will  be  delivered  during  the 
Session.    The  Laboratonei  are  fitted  with  the  most  recent  improve- 
ments for  the  study  of  Praftical  Chemistry  in  all  its  branches.  In  the 
Evening  the  Laboratory  is  opened  and  Lectures  on  Inorganic  Che- 
mistry, at  reduced  lees,  are  delivered.     Several   Scholarships  are 
tenable  at  the  College. 

CALENDAR,  containing   full   information,   price  is.   (by  post 
IS.  4d.). 
For  Prospeftus  and  further  particulars  apply  to— 

JAMES  RAFTER,  Secretary. 


io8 


Advertisements. 


(Chemical  News, 
I      Aug.  27,  1397. 


The  NEW  YORK  HERALD  in  its  issue  of  January  3rd,  1897,  devoted  nearly  a 
whole  page  to  a  notice  of  the  undermentioned  work,  which  it  described  as  being 
"  A  REMARKABLE  SCIENTIFIC  MEMORIAL."  It  also  stated  that  "Nothing  more 
revolutionary  than  Dr.  Emmens^  memorial  has  been  advanced  in  the  name  of  science  since  the  day 
when  Sir  Isaac  Newton  presented  to  the  Royal  Society  his  doctrine  of  universal  gravitation." 


THE     ARGENTAURUM     PAPERS, 

No.  I. 

Some  Remarks  concerning  Gravitation, 

ADDRESSED   TO 

THE  SMITHSONIAN    INSTITUTE,    THE  ACADEMIE    DES   SCIENCES,   THE    ROYAL   SOCIETY, 

AND    ALL    OTHER    LEARNED    BODIES. 

BY 

STEPHEN    H.    EMMENS, 

Member  of  the  American  Institute  of  Mining  Engineers,  Member  of  the  American  Chemical  Society, 

Membre  Fondateur  oj  the  Societe  Ititernationale  des  Electriciens,  Sometime  Fellow  of  the 

Institute  of  Actuaries  of  Great  Britain  and  Ireland,  Member  of  the  United 

States  Naval  Institute,  Member  of  the  Military  Service 

Institution  of  the  United  States. 

CONTENTS. 


Sec.  I.  Foreword.  Sec.  2.  The  Newtonian 
Do(5lrine.  Sec.  3.  The  Defedl:  of  Newton's 
Proof  respedling  the  Centre  of  Force  of  a  Sphe- 
rical Shell.  Sec.  4.  The  Newtonian  Demon- 
stration respetfting  the  AttracSlion  exerted  by 
Spheres  upon  External  Bodies.  Sec.  5.  An 
Inquiry  as  to  the  Reason  of  the  Defedt  in  the 
Newtonian  Doclrine  of  Attracfling  Spheres 
having  remained  undiscovered  until  now.  Sec.  6. 
The  Newtonian  Dodlrine  of  Internal  Attracflions. 
Sec.  7.  The  Dodtrine  of  Gravitating  Centres 
as  distinguished  from  Centres  of  Gravity.  Sec.  8. 
The  Calculus  of  Gravitating  Centres.  Sec.  9. 
The  Gravitating  Centre  of  a  solid,  homogeneous 
Sphere  with  relation  to  external  bodies.  Sec.  10. 
The  case  of  a  Spheroid.  Sec.  11.  The  Preces- 
sion of  the  Equinoxes.  Sec.  12.  The  Density 
of  the  Earth.  Sec.  13.  The  Internal  Attracflive 
Force  of  a  Spherical  Shell.  Sec.  14.  The  In- 
ternal Attradlive  Force  of  a  Solid  Sphere.  Sec. 
15.  The  status  of  a  Solid  Sphere  with  regard  to 
Internal  Pressure.  Sec.  16.  The  Centrifugal 
Theory  of  Cosmical  Bodies.  Sec.  17.  The  Vari- 
ation of  Density  as  regards  the  Earth's  Crust. 
Sec.  18.  The  Significance  of  Earthquakes. 
Sec.  ig.  The  Temperature  of  the  Earth.  Sec.  20. 
The  Source  of  Terrestrial  Heat.     Sec.  21.  The 

The   above-mentioned  work  is  Published   by  the  Plain   Citizen 
Publishing  Company,  i,  Broadway,  New  York  City,  N.Y.,  U.S.A. 

PRICE,  Cloth  Bound,  $2  00  Post  free  to  any  Address. 


Source  of  Solar  Heat.  Sec.  22.  Saturn  and 
Jupiter.  Sec.  23.  The  Volcanic  Charadter  and 
Quiescent  Status  of  the  Moon.  Sec.  24.  The 
Obliquity  of  the  Ecliptic.  Sec.  25.  Elevation, 
Subsidence,  and  Glacial  Epochs.  Sec.  26.  The 
Cooling  and  Shrinking  of  the  Earth's  Crust. 
Sec.  27.  The  Arch  Theory  of  the  Earth's  Crust. 
Sec.  28.  The  cause  of  Ocean-beds  and  Moun- 
tains. Sec.  29.  Terrestrial  Magnetism  and 
Ele(flricity.  Sec.  30.  The  Presence  of  Gold  in 
the  Ocean.  Sec.  31.  The  Verification  of  the 
Centrifugal  Theory.  Sec.  32.  Universal  Gravi- 
tation. Sec.  33.  E  pur  si  muove.  Sec.  34. 
The  Error  of  the  Dyne.  Sec.  35.  The  Variation 
of  Produdts.  Sec.  36.  The  Infinite  Concomitant 
of  Newtonian  Particles.  Sec.  37.  The  self- 
lifting  Power  of  the  Newtonian  Particles.  Sec. 
38.  Howtwo  equally-heavy  Newtonian  Particles, 
taken  together,  weigh  less  than  the  sum  of  their 
separate  Weights.  Sec.  39.  The  self-contra- 
di(5tory  chara(5ter  of  the  Newtonian  Law.  Sec. 
40.  The  superior  limits  of  Newtonian  Gravita- 
tion. Sec.  41.  The  Correlation  of  Space  and 
Energy.  Sec.  42.  The  outline  of  a  system  of 
Universal  Physics.  Sec.  43.  Conclusion. — 
Envoy. 


N.B.  We  widely  advertised  an  offer  of  10,000  dels,  in  Prizes  to  any  persons  who  would  point  out 
any  scientific  errors  in  the  above-mentioned  book.      NO  CLAIMANT  HAS  COME  FORWARD. 


^BRMICAL  MBWS,  I 

Sept.  3.  1897.      I 


Laboratory  Notes  jrom  New  Zeaiand 


109 


THE    CHEMICAL     NEWS 


Vol.  LXXVI.,  No.  1971. 


LABORATORY    NOTES   FROM    NEW   ZEALAND. 

By  WILLIAM   SKEY, 
Analyst  to  the  Mines  Department,  N.Z. 

I.  If  gold  in  potassic  cyanide  (weak  or  strong)  is  con- 
neded  with  platinum  in  an  acid  (say  hydrochloric  acid) 
and  interpolar  connexion  made,  a  stream  of  hydrogen  is 
given  off  from  the  platinum.  For  this  experiment  it  is 
necessary  to  have  the  negative  pole  very  small  as  com- 
pared with  the  size  of  the  gold.  I  do  not  get  this  readtion 
if  the  platinum  is  in  an  alkaline  solution, — probably  be- 
cause there  is  an  oxidation  of  the  hydrogen  by  the  free 
oxygen  in  solution,  induced  by  the  affinity  of  potash  for 
water.  Copper  is  easily  precipitated  upon  a  gold  or  silver 
pole  out  of  its  sulphate,  by  gold  or  silver  in  a  cyanide 
solution. 

2.  If  platinum  or  gold,  in  a  solution  of  tannic  acid  and 
potash,  is  paired  with  platinum  or  gold  in  an  acid  such  as 
acetic  or  sulphuric  acid,  an  evolution  of  hydrogen  also 
takes  place,  and  continues  till  all  the  tannic  acid  is 
oxidised.  By  the  use  of  the  tannic  acid  or  tannin  battery 
of  a  few  cells,  we  can  get  all  the  manifestations  of  a  very 
intense  current.  To  conserve  the  tannic  acid  there  should 
be  a  layer  of  kerosene  oil  upon  it,  to  keep  out  the  air ;  or 
the  cells  may  be  closed  with  cork,  and  the  connedions  run 
through  it. 

In  these  two  experiments  it  appears  that,  in  the  one 
case,  it  is  the  hydrocyanic  acid  of  the  hydrocyanate  of 
potash  that  is  decomposed,  because  this  compound  must 
be  in  the  nature  of  things  the  most  easily  decomposable 
eledlrolyte  present  under  the  circumstances.  Nature's 
work  is  always  done,  as  we  know,  upon  the  lines  of  least 
resistance.  In  the  second  experiment  it  appears  that 
water  is  decomposed.  In  neither  of  these  experiments  is 
it  at  all  likely  that  any  assistance  is  given  to  the  operation 
by  the  eledlric  current  generated.  The  metals  and  the 
eledlrolytes  merely  allow  of  eledtricity  being  made,  the 
free  flow  of  which  is  necessary  or  favourable  to  continuous 
chemical  adtion. 

3.  Platina  that  has  been  for  three  days  in  a  solution 
of  potash  is  still  positive  in  that  solution  to  platina  in 
acids  generally,  and  throws  down  gold  on  platina  from 
its  chloride  or  potassic  aurate,  also  silver  from  its  ammo- 
niate.  The  platina  was  the  purest  I  could  obtain,  and 
was  digested  for  a  long  time  with  nitric  acid,  then  well 
washed  before  use.  An  ignition  of  the  metal  prior  to  use 
did  not  afifedt  the  results. 

4.  Platina  in  a  concentrated  solution  of  comm  n  salt 
alkalised  with  pota«h  that  had  been  just  boiled  to  expel 
air;  also  deposited  gold  from  its  chloride  on  a  platina 
wire.  As  paired  with  platina  in  muriatic  acid,  it  vigor- 
ously defleded  a  galvanometric  needle  for  a  short  time  ; 
then  defledled  it  feebly,  but  persistently,  for  an  indefinite 
time. 

The  vigorous  defledtion  may  denote  an  oxidation  of 
the  platina  itself,  while  the  after  defledtion  may  denote 
an  induced  combination  of  the  small  minute  quantity  of 
oxygen  and  nitrogen  that  find  their  way  to  the  surface  of 
the  platina  that  is  in  the  saline  solution.  This  has  yet 
to  be  tested. 

5.  Platina  in  a  weak  or  strong  potash  solution,  paired 
with  platina  in  a  solution  of  ierrosulphate,  is  positive 
thereto,  and  if  a  decomposition  cell  with  platina  poles 
and  an  eledtrolyte  of  auric  chloride  be  put  in  the  circuit, 
a  little  gold  is  soon  deposited  upon  that  pole  which  is 
metallically  connedted  with  the  platina  in  the  potash  solu- 


tion. These  results  clearly  show  that  a  chemical  adtion 
is  taking  place  in  the  potash  cell  that  is  of  a  more  intense 
charadter  than  that  which  we  have  in  the  case  of  oxidation 
of  protoxide  of  iron  to  the  sesquioxide. 

For  these  kind  of  experiments  bibulous  paper  for  the 
eledlrical  connedlion  is  not  at  all  adapted,  as  the  mixing 
of  the  eledtrolyte  has  to  be  avoided.  The  best  methor 
that  I  have  yet  devised  is  the  "gelatine  connection,"  A 
strong  aqueous  solution  of  gelatine  is  poured  into  a  glass 
tube  bent  to  a  convenient  form  till  it  is  full.  This  when 
cold  is  very  convenient  for  the  purpose,  and  absolutely 
prevents  the  blending  of  the  solutions  for  days  or  weeks, 
according  to  their  nature.  To  increase  their  condudtive 
power  where  necessary,  a  little  salt  may  be  used.  When 
made  very  stiff,  even,  it  still  condudts,  showing  that  the 
molecules  therein  are  still  capable  of  moving  to  form  the 
interpolar  lines. 

6.  If  an  insulated  voltaic  cell  be  connedled  with  the 
insulated  silver  plates — say  6  inches  square  and  about  an  ' 
inch  apart — in  the  air,  a  current  of  eledricity  still  obtains; 
this  is  so  weak,  however,  that  a  pretty  sensitive  galvano- 
meter does  not  indicate  it.  By  passing  the  current  into 
a  solution  of  auric  chloride  by  means  of  platina  poles 
gold  is  deposited  in  a  day  or  so  (on  the  positive  pole)  in  a 
very  thin,  coherent,  continuous,  and  bright  film.  With 
the  positive  pole  of  gold  the  adtion  is  much  accelerated. 


RESEARCHES    ON    THE    STATE    IN    WHICH 

ELEMENTS    OTHER    THAN    CARBON 

ARE    FOUND    IN    CASTINGS     OF     STEELS. 

By  AD.  CARNOT  and  M.  GOUTAL. 

We  propose  here  continuing  the  study  of  the  chemical 
condition  of  the  elements  which  emer  into  the  compo- 
sition of  castings  and  steels,  occupying  ourselves  first  with 
the  metals  properly  called  manganese,  copper,  nickel, 
and  chromium  ;  then  the  rarer  elements  generally  ranged 
along  with  the  metals  titanium,  tungsten,  and  molyb- 
denum. 

Manganese. — The  experiments  which  we  have  already 
described  show  that  manganese  has  an  especial  affinity  for 
sulphur  and  silica,  and  that,  when  it  is  in  small  propor- 
tion in  a  casting,  it  may  be  found  entirely  in  the  state  of 
manganese  sulphide  or  silicide.  When  it  is  in  a  large 
proportion,  the  solvents  which  we  employ  for  iron  cause 
the  manganese  to  disappear  at  the  same  time. 

Copper. — Potassium  cupro-chloride  does  not  allow  us  to 
isolate  the  copper  contained  in  a  steel ;  but  we  may  effedt 
this  easily  by  the  use  of  a  weak  acid,  such  as  hydrochloric 
acid  at  5  per  cent,  if  it  is  employed  with  the  exclusion  of 
air,  e.g.,  in  a  current  of  carbonic  acid  gas. 

Nickel. — Nickel  disappears  entirely  under  the  adlion  of 
the  neutral  potassium  cupro  reagent. 

Chromium. — Ferrochromes  of  a  high  standard  are  not 
readily  attacked  by  acids.  Hence  we  have  been  obliged 
to  operate  upon  steels  containing  not  more  than  2'5o  per 
cent  of  chrome.  The  insoluble  residues  consist  of 
chrome,  iron,  and  carbon. 

Titanium. — The  ferrotitanates  may  be  attacked  either 
by  acids  or  by  the  cupric  salt.  The  titanium  is  un- 
combined. 

Tungsten. — The  attack  of  a  tungsten  steel  by  dilute 
hydrochloric  acid,  at  a  gentle  heat  and  with  the  exclusion 
of  air,  leaves  as  residue  a  compound  of  iron  and  tungsten 
of  the  composition  Fei,W. 

Molybdenum. — Molybdenum  steels,  treated  with  dilute 
acids  in  the  absence  of  air,  leave  a  residue  answering 
exadlly  to  the  Fe3Mo2. 

In  fine,  manganese,  nickel,  copper,  and  titanium  seem 
to  be  simply  dissolved  in  the  steels  ;  a  portion  of  man- 
ganese may  be  in  the  statQ  of  sulphide  or  silicide  in  the 
cast  metals, 


no 


Contribution  to  the  Study  of  Thorium. 


•  Chemical  NewSt 
I       Sept.  3, 1897. 


Chromium  forms  complex  and  perhaps  multiple  com- 
pounds with  iron  and  carbon. 

Tungsten  and  molybdenum  are  in  the  state  of  definite 
combinations  with  iron  represented  by  the  formulae  Fe3W 
and  FesMoa. 

These  elements,  generally  considered  as  metals,  behave 
therefore  in  steel  like  non-metals,  whilst  arsenic,  on  the 
contrary,  plays  a  part  analogous  to  that  of  the  true 
metals. — Comptes  Rendus,  cxxv,,  p.  221. 


ON  "A    COLORIMETRIC     REACTION     OF 

DISULPHURIC     ACID. 

By  M.  £.  BARRAL. 

WliEN  the  powdered  parabichloride  of  hexachloridised 
benzene,  CeCle.Clz^-*,  is  dissolved  gradually  in  sulphuric 
acid  containing  disulphuric  acid,  a  magnificent  reddish 
violet  colouration  is  produced. 

By  adding  water  or  ordinary  sulphuric  acid,  or  even  by 
leaving  the  mixture  in  contadt  with  moist  air,  the  colour- 
ation disappears  as  soon  as  all  the  disulphuric  acid  has 
been  transformed  into  SO4H2.  Under  the  influence  of 
water  and  S04H2,  CgCig  gives  both  perchloridised  ben- 
zene, perchlorised  quinone,  hydrochloric  acid,  and  free 
chlorine : — 

aCeCls  +  2H2O  =  CeCle  +  C6CI4O2  +  4HCI  +  CI2. 
To  show  that  this  colouration  is  not  due  to  the  impurities 
of  the  Nordhausen  acid,  and  that  it  is  not  produced  in 
the  presence  of  the  anhydride,  I  prepared  some  sulphuric 
anhydride  synthetically  by  passing  SO2+O  over  spongy 
platinum.  By  grinding  together  CgCls  and  SO3,  being 
careful  to  exclude  all  moisture,  nothing  is  produced,  while 
a  beautiful  reddish  violet  colouration  appears  as  soon  as 
the  mixture  is  exposed  to  moist  air. 

Volumetric  Estimation.  —  The  disappearance  of  the 
colouration  at  the  moment  when  all  the  disulphuric  acid 
is  transformed  into  SO4H21  enables  us  to  make  use  of 
C6Cl6,Cla^~*  as  an  indicator  in  the  volumetric  estimation 
of  disulphuric  acid. 

A  given  volume  of  Nordhausen  acid  (25  c.c.  for  ex- 
ample) is  poured  into  a  flask,  a  little  powdered  CeCls  is 
added,  and  the  mixture  is  shaken  up  until  the  colouration 
appears.  We  then  run  in,  drop  by  drop,  some  carefully 
titrated  sulphuric  acid  (acid  at  66°,  to  which  is  added 
one-tenth  its  weight  of  water),  until  the  disappearance  of 
the  reddish  tint :  a  simple  calculation  enables  us  to  esti- 
mate the  quantity  of  disulphuric  acid  present  in  the 
Nordhausen  acid. 

This  method  of  estimation,  which  enables  us  to  adt  di- 
redtly  on  the  acid,  gives  excellent  results  in  cases  when 
the  acid  is  colourless  or  only  faintly  coloured.  Unfor- 
tunately it  loses  a  good  deal  of  its  sensitiveness  with 
commercial  Nordhausen  acids  ;  these  being  as  a  rule  more 
or  less  yellow,  or  even  brown,  the  disappearance  of  the 
reddish  tint  is  difficult  to  observe  very  accurately. — jfourn. 
de  Pharm.  et  de  Chim.,  Series  6,  vol.  vi.,  No.  3. 


CONTRIBUTION  TO  THE  STUDY  OF  THORIUM. 
By  G.  URBAIN. 

I.  When  we  wish  to  obtain  thorium  from  thorite,  we 
treat  the  latter  with  hydrochloric  acid  and  evaporate  to 
dryness  to  render  the  silica  insoluble.  We  separate  the 
lead  and  the  tin  by  means  of  sulphuretted  hydrogen, 
which  is  afterwards  driven  off  by  boiling.  We  then  add 
a  little  chlorine-water  to  peroxidise  the  iron  before  pre- 
cipitating it  with  oxalic  acid,  if  the  mineral  does  not  con- 
tain the  alkaline  earths  in  any  notable  quantity.  The 
pxalates  are  then  calcined,  and  the  oxides  converted  into 


anhydrous  sulphates,  which  are  dissolved  by  projecting 
them — a  little  at  a  time — into  iced  water. 

This  is  rather  a  delicate  operation  ;  above  all,  when 
working  on  large  quantities,  because  the  sulphates  of  the 
cerium  group  have  a  strong  tendency  to  become  hydrated, 
and  for  this  reason  are  very  difficult  to  dissolve.  It  is  there- 
fore necessary  to  take  great  care  to  rid  these  sulphates  of 
all  trace  of  free  acid,  and  to  add  them  to  the  water  in 
minute  quantity  only  if  we  wish  to  get  them  entirely  dis- 
solved.  It  has  been  noticed  that  a  little  acetate  of  am- 
monia increases  the  solubility  of  the  sulphates  of  this 
group  enormously. 

A  cold  saturated  solution  of  acetate  of  ammonia,  diluted 
with  twice  its  bulk  of  water,  dissolves  flocculent  sulphate 
of  thorium  instantly.  The  double  potassic  sulphates  of 
thorium,  cerium,  lanthanum,  and  didymium  also  dissolve 
with  great  ease  in  the  same  reagent,  and  they  are  not  pre- 
cipitated on  boiling. 

The  sulphate  of  thorium  containing  8H2O,  when  treated 
with  a  saturated  solution  of  acetate  of  ammonia,  forms  a 
felty  mass  composed  of  fine  needles  of  acetate  of  thorium. 
In  a  weaker  solution  it  is  completely  dissolved.  It  is 
slightly  precipitated  on  boiling,  and  at  the  same  time 
acetic  acid  is  given  off,  and  the  turbidity  does  not  dis- 
appear by  adding  water  or  acetic  acid,  but  only  on  the 
addition  of  hydrochloric  acid.  The  presence  of  free 
acetic  acid  diminishes  the  solubility  of  the  acetates  very 
considerably. 

Formate  of  ammonia  appears  to  behave  in  a  very  dif- 
ferent manner,  and  I  intend  to  return  to  this  subje(a  later 
on. 

The  method  of  purifying  thorium,  as  described  by 
Nelson,  is  long  and  tedious.  It  consists  of  precipitating 
the  thorium  in  the  state  of  a  flocculent  sulphate,  and  it 
gives  very  bad  results. 

The  solution  of  the  oxalate  in  oxalate  of  ammonium 
carries  with  it  a  large  proportion  of  cerium.  The  hypo- 
sulphite method  gives  results  hardly  better  than  the  in- 
complete precipitations  obtained  by  alkalis.  None  of 
these  methods  give  even  approximately  pure  thorium, 
except  by  repeating  the  operations  several  times. 

2.  I  obtained  thorium,  which  did  not  show  a  trace  of 
cerium,  very  rapidly  by  the  adtion  of  peroxide  of  hydrogen 
on  its  hydrate,  with  the  formation  of  an  acetylacetonate. 
For  this  purpose  I  used  a  relatively  pure  thorium  which 
I  had  prepared  in  the  following  manner : — The  raw 
oxalates  were  treated  with  oxalates  of  ammonia,  and 
instead  of  precipitating  the  oxalate  from  this  solution  by 
means  of  an  acid,  I  found  it  more  advantageous  to  pre- 
cipitate it  by  ammonia. 

The  acetylacetonate  of  thorium  was  obtained  very 
easily  by  treating  the  hydrate  of  thorium,  suspended  in 
dilute  alcohol,  by  acetylacetone,  evaporating  to  dryness 
on  the  water-bath,  and  taking  up  with  chloroform,  which 
dissolves  the  acetylacetonate  of  thorium  and  leaves  it,  on 
slow  evaporation,  in  well-defined  crystals. 

The  molecular  weight  was  taken  in  bromide  of  ethyl 
by  the  cryoscopic  method. 

Substance  used      1-308  grms. 

Weight  of  solvent 94"i57     » 

Loss  of  weight       o'26       ,, 

Found.  Calculated. 

Molecular  weight 630  6284 

This  was  done  by  taking  the  atomic  weight  found  by 
Nelson,  viz.,  232*4. 

I  have  also  estimated  the  thorium  by  treating  the 
acetylacetonate  with  nitric  acid  and  then  calcining  the 
nitrate : — 

Substance  used 0*570  grm. 

Thoria  found      ••     0*241     „ 


Per  cent. 


Found. 
42*2 


Calculated, 
42*1 


CRbmical  NeWs. 

Sept.  3,  lSq7. 


Separation  of  Aluminum  and  Beryllium^ 


III 


Combustron  gave  me  the  following  figures  : — 

Substance  used o'570  grm. 

Water 0-115     „ 

Carbonic  acid 0*389    „ 


Summary  of  Analyses. 

Found. 

Th 37-09) 

C 3775  [79*38 

H 4-54J 

O 4*54 


Calculated. 
36-98) 
38-19 

4'45, 
20-38 


79-62 


Total..     ..     100-00 

The  acetylacetonate  of  thorium  therefore  corresponds 
to  the  formula  Th (0511702)4. 

Under  similar  conditions,  the  hydrate  of  cerium  is 
transformed  into  a  grey  amorphous  body,  almost  insoluble 
in  chloroform  and  alcohol.  The  analysis  of  this  body 
shows  it  to  be  an  ill-defined  compound  very  like  a  basic 
salt— 

CeO-CH<gOCH3, 

We  can  obtain  acetylacetonate  of  thorium  just  as 
easily  by  the  double  decomposition  which  takes  place 
between  acetylacetonate  of  soda  and  any  salt  of  thorium. 
The  liquid  is  well  shaken  up  with  chloroform,  which  is 
then  distilled  off, 

3.  Acetylacetonate  of  thorium,  though  but  slightly 
soluble  in  water,  is  dissolved  by  most  organic  solvents. 
It  is  very  soluble  in  alcohol  and  chloroform,  but  less  so  in 
ether  and  bromide  of  ethyl.  Its  crystals  are  of  the 
clinorhombic  system,  and  when  formed  from  ether  or 
chloroform  they  appear  as  elongated  prisms  : — 

e'  :e'  =  82°  16' 
e'  :  m  =  30°  05' 
m  :  m     =     80°  55 ' 

When  formed  from  bromide  of  ethyl  the  crystals  are  only 
microscopic. 

Acetylacetonate  of  thorium  melts  at  171 — 172°  and  sub- 
limes  in  vacuo, — Bull.  Soc.  Chim.,  Series  3,  vol.  xv.,  p. 
347- 


THE    SEPARATION     OF 

ALUMINUM     AND      BERYLLIUM      BY    THE 

ACTION     OF     HYDROCHLORIC    ACID.' 

By  FRANKE  S.  HAVENS. 

In  a  former  paper  (Gooch  and  Havens,  Am.  yourn.  Set., 
ii.,  December,  1896)  a  method  was  described  for  the 
determination  of  aluminum  in  the  presence  of  iron, 
based  upon  the  fadt  that  the  hydrous  aluminum  chloride, 
AICI3.6H2O,  is  pradically  insoluble  in  a  mixture  of  strong 
hydrochloric  acid  and  anhydrous  ether  saturated  with 
hydrochloric  acid  gas,  while  the  ferric  chloride  is  entirely 
soluble  in  that  medium. 

The  work  to  be  described  in  this  paper  is  an  extension 
of  this  process  to  cover  the  separation  of  aluminum  from 
beryllium,  with  the  subsequ'ent  determination  of  the 
beryllium  by  weighing  as  the  oxide  after  conversion  to 
the  nitrate  and  ignition. 

The  aluminum  chloride  solution  was  prepared  by  dis- 
solving the  so-called  pure  aluminum  chloride  of  com- 
merce in  as  little  water  as  possible,  precipitating,  and 
washing  free  from  iron  with  strong  hydrochloric  acid, 
dissolving  the  chloride  thus  obtained  in  water,  precipi- 
tating the  hydroxide  by  ammonia,  washing  the  precipi- 
tate free  from  all  alkalis,  and  re-dissolving  it  in  hot  hydro- 
chloric acid.      From  this  solution,  after  cooling,  gaseous 

♦  Contributions  from  the  Kent  Chemical  Laboratory  of  Yale  Uni- 
versity. From  the  American  Journal  of  Sc«»«, Series  4,  Vol.  iv., 
Ho.  20,  August,  1897. 


hydrochloric  acid  precipitated  the  pure  hydrous  chloride. 
This  prepared  chloride  was  dissolved  in  water  and  the 
solution  standardised  by  precipitating  with  ammonia  the 
hydroxide  from  weighed  portions  and  weighing  as  the 
oxide.  The  solution  of  beryllium  used  was  made  by  dis- 
solving in  water  beryllium  chloride  found  to  be  free  from 
iron  by  the  sulphocyanate  test,  and  giving  no  precipitate 
when  tested  by  the  gaseous  hydrochloric  acid  process,  to 
be  described  later  on.  This  was  standardised  by  precipi- 
tating with  ammonia  the  hydroxide  from  weighed  portions 
and  weighing  the  ignited  oxide  in  the  usual  manner. 

In  the  experiments  of  Table  I.,  weighed  portions  of  the 
aluminum  solution  were  mixed  with  portions  of  the 
beryllium  chloride  solution  representing  from  o-oi  to  o'lo 
grm.  of  the  oxide,  an  equal  volume  of  a  mixture  of  strong 
hydrochloric  acid  and  ether  (taken  in  equal  parts)  was 
added  to  the  solution  of  the  mixed  chlorides,  and  the 
whole  was  completely  saturated  with  gaseous  hydrochloric 
acid  while  kept  at  a  temperature  of  about  15°  C.  by  im- 
mersing the  receptacle  in  running  water.  Ether  was 
added,  equal  in  volume  to  the  aqueous  aluminum  and 
beryllium  solutions  originally  taken,  and  the  current  of 
gas  again  turned  on  until  saturation  was  complete.  By 
this  treatment  there  is  present  at  the  end  of  the  saturation 
a  volume  of  ether  equal  to  that  of  the  aqueous  hydro- 
chloric  acid  introduced  and  generated.  The  finely- 
crystalline  precipitate  of  aluminum  chloride  was  caught 
on  asbestos  in  a  filter  crucible,  washed  with  a  previously- 
prepared  mixture  of  hydrochloric  acid  and  ether  in  equal 
parts,  saturated  at  15°  C.  with  hydrochloric  acid  gas,  and 
dried  for  half  an  hour  at  a  temperature  of  150°  C.  It  was 
next  covered  with  a  layer  of  pure  mercuric  oxide,  which 
had  been  tested  and  found  to  leave  no  residue  on  volati- 
lising, and  the  crucible  was  gently  heated  over  a  low  flame 
under  a  ventilating  hood  and  finally  ignited  over  the 
blast. 

Table  I. 


AljO, 

found. 


AlxOg  taken  in  solution 
as  the  chloride. 

1.  0-1046  0*1044 

2.  0'i046  0-1038 

3.  0-1067  o-io66 

4.  0'i07i  0-1063 

5.  0*1059  0*1054 


Final  volume. 
C.m.«. 

12 
12 
12 
12 
30 


Error. 
0*0002  — 
0*0008  — 
0*0001  — 
0*0008  — 
0*0005  ■" 


From  these  results  it  is  obvious  that  the  aluminum 
chloride  may  be  determined  in  the  presence  of  beryllium 
chloride  with  reasonable  accuracy. 

The  beryllium  may  be  recovered  in  the  filtrate  from  the 
aluminum  chloride  by  precipitation  with  ammonia  after 
nearly  complete  evaporation  of  the  acid.  It  was  found, 
however,  upon  trial  that  the  conversion  of  the  chloride  to 
the  oxide  without  precipitation  and  filtration  may  be 
easily  accomplished  by  treatment  with  nitric  acid  and 
ignition.  The  results  of  Table  II.  indicate  this  clearly. 
In  these  experiments  weighed  portions  of  the  beryllium 
solution  were  evaporated  just  to  dryness  on  a  radiator, 
care  being  taken  not  to  heat  to  the  volatilising-point  of 
the  beryllium  chloride,  a  few  drops  of  strong  nitric  acid 
were  added,  the  liquid  was  evaporated,  and  the  residue 
heated— at  first  gently,  to  break  up  the  nitrate  safely, 
and  finally  on  the  blast.  It  was  found  that  this  conver- 
sion of  the  beryllium  to  the  nitrate  can  be  carried  on  in 
platinum  without  attacking  that  metal  appreciably,  pro- 
viding care  be  taken  to  remove  thoroughly  all  excess  of 
hydrochloric  acid  before  the  nitric  acid  is  added  to  the 
dry  residue. 

Table  II. 


BeO  taken  in  solution 
as  the  chloride. 

0*0483 
0*0483 
0-1076 


BeO  found. 
00481 
0*0483 
0*1085 


Error. 
0*0002  — 
O'OOOO 
0*0009  + 


In  Table  III.  (i  to  9)  are  given  the  results  of  experi- 
nients  in  which  both  the  aluminum  and  the  beryllium 


112 


Vanadium  in  Scandinavian  Rutile. 


I  Cbbmical  News, 

I      Sept.  3.  1807. 


were  determined — the  former  by  precipitation  as  the 
hydrous  chloride  and  weighing  as  the  oxide  after  igniting 
with  mercuric  oxide  ;  the  latter  by  the  conversion  of  the 
chloride,  through  the  nitrate,  into  the  oxide.  In  Expt.  10 
(made  to  get  a  comparison  of  the  methods)  the  beryllium 
was  recovered  by  precipitating  the  hydroxide  with  am- 
monia from  the  partially  evaporated  solution  of  the 
chloride  after  removing  the  aluminum. 

In  Experiments  i  to  5  inclusive,  the  aluminum  was 
determined  exadtly  as  previously  described  ;  in  6  and  7, 
the  solutions  (being  originally  larger)  were  concentrated 
by  evaporation  previous  to  the  addition  of  the  ether  and 
hydrochloric  acid  mixture.  In  Experiments  8,  9,  and  10 
the  treatment  was  varied  advantageously  by  saturating 
the  aqueous  solution  diredlly  with  hydrochloric  acid  gas 
before  adding  an  equal  volume  of  ether,  and  completing 
the  saturation. 

Table  III. 


•-I 

.S| 

si 

B 

e  rt 

5  OT3 

3 
"3 

a 

a9  0 

> 

a 

3.2 

°  So 

•2 
0 

0 

< 

<         u 

C.m.s 

n 

n 

w 

z. 

0'i059 

0*1058   0*0001  — 

12 

0*0198 

00204 

00006  + 

2. 

0-1053 

0-1044  0*0009  — 

12 

00194 

00196 

00302  + 

3- 

0-1065 

0*1059  0*0006  — 

12 

0-0197 

00205 

0-0008  + 

4. 

01068 

0*1060  o*ooo8  — 

12 

0*0199 

0*0207 

0*0008  + 

5- 

0-1049 

0*1047  0*0002  — 

12 

0*0198 

0*0208 

o*ooio  + 

6. 

O'io6o 

0*1057  0-0003- 

12 

0*0977 

0*0969 

o-ooo8  — 

7- 

0-1064 

0-1063  0*0001  — 

12 

0*1085 

0-1084 

0  0001- 

8. 

01046 

0*1038  0*0008  — 

30 

0*1083 

0-1087 

0*0004+ 

9. 

0-1051 

0-1048  0-0003- 

30 

0*1071 

0*1078 

0*0007  + 

10. 

0*1076 

0*1075  o-oooi- 

30 

0*1086 

0*1094 

o*ooo8+ 

These  results  are  plainly  very  good. 

The  manipulation  of  the  process  is  not  difficult.  The 
gaseous  hydrochloric  acid  is  most  conveniently  produced 
by  the  well-known  method  of  treating  with  strong  sul- 
phuric acid,  in  regulated  current,  a  mixture  of  strong 
aqueous  hydrochloric  acid  and  common  salt.  A  platinum 
dish  hung  in  an  inverted  bell-jar,  provided  with  inlet  and 
outlet  tubes  through  which  the  current  of  water  for 
cooling  is  passed,  makes  the  best  container  for  the  solu- 
tion to  be  saturated  with  the  gas.  It  is  advantageous  to 
arrange  the  filtration  upon  asbestos,  so  that  the  filtrate 
and  washings  may  be  caught  diredly  in  the  crucible 
(placed  under  the  bell-jar  of  the  filter-pump)  in  which  the 
subsequent  evaporation  is  to  be  effected.  The  heating  of 
the  strong  acid  solution  must  be  gradual  and  conduced 
with  care  to  prevent  mechanical  loss  by  a  too  violent 
evolution  of  the  gaseous  acid. 

It  only  remains  to  thank  Professor  Gooch  for  kind  sug- 
gestions and  advice. 


ON 


THE     OCCURRENCE     OF    VANADIUM 

SCANDINAVIAN    RUTILE.* 

By  B.  HASSELBERQ. 


IN 


The  problem  of  assigning  to  each  chemical  element  its 
definite  emission  speftrum  has  been  carried  perceptibly 
nearer  to  its  solution,  since  the  necessary  basis  was 
established  by  the  classical  work  of  Rowland.  Yet  when 
the  attempt  is  made  to  extend  it  to  the  fainter  radiations, 
as  well  AS  to  the  principal  lines  of  the  spedrum,  the  ques- 
tion becomes  complicated  to  such  an  extent  that  an  ex- 
haustive solution  seems  to  be  well  nigh  hopeless.  It  is 
therefore  necessary,  in  this  department  of  spedroscopic 

♦  "Ueber  das  Vorkommen  des  Vanads  in  den  Skandinavischen 
Rutilarten,"  Bihattg  till  Svenska  vcUnsk.  Akad  Handl.,  xxii.,  Afd.  i, 
No.  7.    From  the  Astrophysical  Journal,  v.,  No.  3, 


research,  to  be  contented  with  a  series  of  approximations  ; 
and  no  very  great  surprise  need  be  felt  if  in  a  single  case, 
where  every  effort  has  been  made  to  eliminate  such  im- 
purities as  were  most  likely  to  occur,  other  impurities 
have  been  encountered,  the  presence  of  which  there  was 
in  the  beginning  scarcely  any  reason  to  suspeft.  The 
present  lines  are  devoted  to  a  preliminary  account  of  such 
a  case  as  the  above. 

For  producing  the  spe(5trum  of  titanium  in  the  eledlric 
arc  I  have  used  titanic  acid  in  the  form  of  rutile  with 
materially  better  success  than  when  commercial  titanium 
was  employed,  since  the  metal  burns  much  too  quickly 
when  introduced  into  the  arc,  and  is  scattered  in  all  direc- 
tions. This  rutile,  which  was  kindly  obtained  for  me  by 
Baron  Nordenskiold,  comes  from  Krageroe,  in  Norway. 
As  in  other  kinds  of  rutile,  its  chief  component  is  titanic 
acid,  since,  according  to  analysis  of  a  number  of  varieties 
of  this  mineral  (Dana's  "  Descriptive  Mineralogy,"  5th 
edition,  160,  New  York,  1883),  the  only  other  constituent 
to  be  expedled  is  oxide  of  iron  in  the  proportion  of  from 
I  to  2  per  cent.  After  eliminating  the  iron  lines  which 
are  thus  caused  to  appear  on  the  spedtrograms,  as  well  as 
other  metallic  lines,  whose  presence  was  revealed  by  com- 
parison with  my  own  investigations  of  metallic  spedra 
and  with  those  of  Kayser  and  Runge,  I  considered  myself 
justified  in  ascribing  the  remaining  lines  to  pure  titanium, 
or  at  least  in  considering  that  only  a  few  isolated  cases 
remained  in  which  contamination  by  a  foreign  metal 
might  subsequently  be  proved.  The  continuation  of  my 
spedlroscopic  researches  has  shown,  however,  that  this 
does  not  entirely  hold  good,  since  among  the  fainter  and 
faintest  lines  of  my  titanium  spedtrum  there  are  several 
that  doubtless  belong  to  vanadium.  Having  obtained 
through  Baron  Nordenskiold  a  large  piece  of  this  metal, 
which  was  made  by  Moissan,  of  Paris,  in  the  eledric 
furnace,  I  recently  began  a  re-examination  of  the  spec- 
trum, and  discovered  several  strong  groups  of  lines  in  the 
blue  and  violet  parts,  the  approximate  wave-lengths  of 
which  agreed  very  closely  with  those  of  faint  lines  pre- 
viously measured  in  the  spedlrum  of  titanium.  In  order 
to  obtain  a  final  decision  on  this  point,  the  parts  of  the 
spedtrum  in  question  of  vanadium  and  rutile  were  photo- 
graphed in  juxtaposition  on  the  same  plate,  in  the  usual 
manner,  and  compared  line  by  line.  The  result  of  this 
investigation  of  approximate  coincidences  is  shown  in  the 
accompanying  table. 

In  the  first  two  columns  of  this  table  are  given  the 
approximate  wave-lengths  and  intensities  of  vanadium 
lines,  in  the  region  \  403 — \  405,  for  which  corresponding 
fine  lines  occur  on  the  comparison  plates  of  the  spedtrum 
of  Norwegian  rutile.  These  lines  are  given,  with  their 
intensities,  in  the  two  following  columns,  the  wave-lengths 
being  those  of  my  former  catalogue  of  titanium  lines.  As 
will  be  seen,  the  coincidences  are  almost  all  exadt ;  and 
hence  the  corresponding  faint  titanium  lines  are  to  be  re- 
moved from  the  titanium  spedrum  as  properly  belonging 
to  vanadium. 

I  must  confess  that  I  have  been  greatly  surprised  by 
this  result.  It  will  be  granted,  I  think,  that  there  were 
no  possible  reasons  for  suspedting  it  in  advance,  since 
vanadium  has  never  been  found  in  any  of  the  numerous 
varieties  of  rutile  hitherto  known.  Under  these  circum- 
stances it  seemed  to  me  desirable  to  subjedt  another  kind 
of  rutile  to  the  same  test.  For  this  purpose  Swedish 
rutile  from  Karingbricka  in  Westmanland  was  chosen, 
one  reason  among  others  for  doing  so  being  that  the  re- 
sults of  Ekeberg  (Svenska  vetensk.  Akad.  Handl.,  xlvi., 
1893 ;  Dana's  "  Mineralogy "),  according  to  which  this 
particular  kind  also  contains  chromium,  could  be  tested 
at  the  same  time.  A  double  exposure  to  the  spedrum  of 
this  mineral  and  of  vanadium  in  the  region  A.  425 — \  445 
having  been  made,  the  same  series  of  coincidences  was 
found  as  in  the  cat>e  of  the  Norwegian  rutile  (see  the  fifth 
and  sixth  columns  of  the  table),  and  hence  at  the  same 
time  the  fadt  was  demonstrated  that  Swedish  rutile  also 
contains  vanadium. 


Cbbhical  News,  \ 

V 

Sept.  3, 

1897.     1 

r 

Vanadium. 

Rutile  I, 

X 

i. 

A 

i. 

403303 

1-2 

.. 

90*70 

3 

90-73 

I 

92-87 

3 

92-83 

1-2 

95-60 

3 

95-65 

I 

4ioo'oo 

3-4 

4099-94 

1-2 

05-30 

3 

0531 

1-2 

0995 

3-4 

09-92 

1-2 

12-00 

4 

II-9I 

23 

15-30 

3-4 

15-32 

2 

16-65 

3 

16-64 

1-2 

23-65 

3 

23-68 

2-3 

28-25 

3-4 

28-20 

2 

31-35 

I 

31-38 

1-2 

34-60 

3*4 

3460 

1-2 

59-87 

2-3 

59-79 

2-3 

69-45 

12 

69-46 

2 

83-45 

83-45 

1-2 

4227-95 

2 

27-80 

2 

68'85 

3 

.. 

I 

71  80 

3 

•  • 

I 

4330-15 

3 

I  — 

33-00 

3 

I  — 

41-15 

3 

•  • 

1  + 

53-05 

3-4 

53*01 

I 

79-45 

4-5 

79-40 

2 

84-90 

4*5 

84-85 

2 

90-15 

4-5 

go-ii 

2 

95-40 

4 

•  • 

2 

4400-75 

4 

00-74 

1-2 

06-85 

4-5 

.. 

1-2 

07-90 

4-5 

0785 

1-2 

08-40 

4 

08-39 

1-2 

08-65 

4-5 

08-70 

1-2 

1665 

3 

1670 

2 

41-90 

3*4 

41-86 

1-2 

44-40 

3-4 

44-41 

3 

Vanadium  in  Scandinavian  Rutile, 


113 


Rutile  II. 


Remarks. 


Also  a  weak  line  in  Ti. 


., 

I      • 

, , 

I 

1  + 

.. 

1  + 

.. 

1-2 

53-01 

1-2 

7940 

3 

84-85 

2-3 

90-15 

2+ 

.. 

2 

00-74 

2 

2 

07-85 

2  + 

08-39 

2  + 

0870 

2+, 

16-70 

2 

41-86 

44-41 

.Coincident,  belong  to  Va.    All  the  rutile  lines  are  weaker 
on  the  comparison  plate  than  here  represented. 


Divided.  A.  Ti  >  \  "Va. 
Coinc.  Belongs  to  Va. 
Divided.  A.  Ti  <  A  Va. 
Coinc.  Belongs  to  Va. 
Divided.  A  Ti  <  \  Va. 
Clearly  divided.  A  Ti  >  \  Va. 
Probably  divided.  A  Ti  >  \  Va. 
Widely  separated. 


All  these  lines  occur  on  the  rutile  photographs  with  the 
observed  intensities.  The  blanks  in  the  columns  3  and 
5  of  wave-lengths  indicate  that  these  lines  do  not  occur 
in  my  catalogue  of  the  titanium  lines.  On  the  plates 
here  investigated  they  occur  with  the  given  intensities. 


Clearly  divided.     \  Ti  >  X  Va. 
Perhaps.     ATi>AVa. 
Probably  divided.     X  Ti  >  A  Va. 


If,  further,  the  observed  intensities  of  the  vanadium  lines 
which  occur  in  the  photographic  spedra  of  the  two  kinds 
of  rutile  are  compared,  it  will  be  seen  that  the  intensities 
for  Rutile  II.,  obtained  at  Karingbricka,  are  greater 
throughout  the  spedtrum  than  those  for  Rutile  I.  Since 
this  fa(5t  appears  to  indicate  that  Swedish  rutile  contains 
a  greater  amount  of  vanadium  than  Norwegian,  it  was  of 
interest  to  test  the  relation  of  the  two  varieties  in  this 
respedt  by  a  special  experiment,  in  which  the  exposure 
and  development  were  exaftly  the  same.  With  this  ob- 
jedt,  two  exposures  in  the  upper  region  of  the  spedlrum 
were  made  on  the  same  plate,  using  for  each  a  different 
half  of  the  slit,  with  eledtrodes  which  in  one  case  were 
made  of  Norwegian  and  in  the  other  case  of  Swedish 
rutile.  The  exposure  was  in  each  case  1-5  minutes.  The 
developed  plate  showed  the  titanium  lines  with  identically 
the  same  intensity  in  both  spedlra,  while  the  vanadium 
lines  were  considerably  stronger  in  the  spedrum  of  the 
Swedish  rutile.  In  order  that  this  fadt  may  be  clearly 
brought  out,  I  have  made  a  photographic  copy  of  a 
drawing,  in  which  the  appearance  of  the  negative  under 
the  microscope  of  the  measuring  engine  is  represented 
with  all  possible  exactness.  By  this  it  will  be  seen  that 
vanadium  lines  of  the  Norwegian  rutile  have  a  distindtly 
lower  intensity,  so  that,  in  fadt,  some  of  the  weakest  of 
them  fail  to  appear. 

From  what  has  been  given  above,  I  believe  that  it  may 
be  regarded  as  proved  that  both  kinds  of  rutile  contain 
vanadium,  the  Norwegian  as  well  as  the  Swedish,  but  that 
the  Swedish  variety  contains  a  considerably  greater 
amount  of  this  metal  than  the  other.  Whether  this 
amount  of  vanadium  is  great  enough  to  be  recognised  or 
quantitatively  determined  by  ordinary  chemical  analysis 
is  a  question  for  the  solution  of  which  the  above  experi- 
ments afford  no  data,  or  at  least  only  such  as  are  highly 


uncertain,  for  we  have  as  yet  no  trustworthy  information 
as  to  the  sensitiveness  of  the  spedtral  readions  of  the 
elements. 

On  the  plates  which  contain  the  spedtra  of  the  two  kinds 
of  rutile,  the  correspondence  of  lines  (leaving  out  of  con- 
sideration the  difference  of  intensity  of  the  vanadium 
lines  already  mentioned)  is  complete,  with  one  exception. 
This  exception  is  found  in  three  quite  strong  lines  which 
occur  in  the  spedtrum  of  the  Swedish  rutile,  but  of  which 
there  is  scarcely  a  trace  in  the  other  variety.  By  refer- 
ring their  positions  to  neighbouring  titanium  lines  I  ob- 
tained for  these  lines  the  following  wave-lengths: — 

\  =  4254-50 

74-90 

89-90 
while  the  strongest  lines  in  the  whole  chromium  spedlrum 
have,  according  to  my  earlier  measures,  the  wave-lengths 

A  =  4254-49 

74*91 
89-87 

The  lines  therefore  belong  to  chromium,  the  presence 
of  which  is  thereby  demonstrated,  and  this  result  is  in 
agreement  with  the  analysis  of  Ekeberg. 


Probable  Antiquity  of  Mining  for  Tin  in  Bretagne. 
— L.  Davy, — All  authors  who  have  studied  the  ancient 
working  of  tin  in  the  west  of  Europe  admit  that  it  was 
far  anterior  to  the  occupation  of  the  country  by  the 
Romans,  and  think  that  the  mines  of  Abbaretz-Nozay 
were  abandoned  by  the  Gauls  about  the  date  of  the 
Roman  invasion.— Cow^f«  Rendus,  cxxv.,  No.  5. 


IM 


Critical  Review  of  the  Methods  of  Determining  Minerals.    {^^s"e"pt"!;f8^' 


A    CRITICAL    REVIEW    OF    THE     METHODS 
OF    DETERMINING    MINERALS.* 

By  Dr.  JOSEPH  W.  RICHARDS, 

Of  the  Department  of  Metallurgy  and  Mineralogy  of  the  Lebigh 

University. 

The  determining  of  a  mineral  consists  in  finding  out  its 
species,  and  in  doing  this  so  conclusively  as  to  prove  that 
it  is  the  species  named  to  the  exclusion  of  all  other  simi- 
lar related  minerals. 

The  question  must  be  met  at  the  outset,  •'  What  con- 
stitutes a  mineral  species  ?  "  I  will  answer  by  quoting 
our  one-time  professor  of  chemistry  at  the  Institute,  Dr. 
Persifor  Frazer,  whose  word  in  geology  and  mineralogy 
carries  with  it  the  weight  of  an  authority.  Says  Dr. 
Frazer,  *'  Every  true  mineral  is  a  definite  chemical  com- 
pound or  element,  homogeneous  throughout  its  parts, 
and  capable  of  expression  in  a  formula,  Its  molecule  is 
a  distindive  whole — the  unit  of  its  mass — and  incapable 
of  division  as  long  as  the  mineral  retains  its  charaderistic 
properties." 

It  is  one  of  the  easiest  things  in  the  world  to  accept 
the  present  scientific  definition,  and  to  forget  the  laborious 
steps  by  which  such  an  apparently  simple  conclusion  was 
evolved.  Dr.  Frazer's  definition  appears  to  us  so  nearly 
self-evident  that  it  is  difficult  to  realise  that  eighty  years 
ago  mineralogists  were  hotly  debating  the  question  as  to 
whether  the  identity  of  a  mineral  consisted  in  its 
chemical  composition  or  in  the  sum  total  of  its  physical 
properties.  Thence  arose  two  schools  of  mineral 
classification.  Werner  and  his  followers  adopted  the 
natural-history  method  of  classification  on  the  basis  of 
physical  properties  alone,  and  prided  themselves  on  having 
achieved  a  classification  entirely  independent  of  any  aid 
from  chemistry.  The  other  school,  of  which  Berzelius 
was  one  of  the  founders,  insisted  on  the  chemical  compo- 
sition as  the  basis  of  a  proper  classification,  but  were  not 
so  exclusive  as  the  other  school,  and  admitted  physical 
distindtions,  particularly  that  of  form  {i.e.,  crystallisation), 
into  their  smaller  subdivisions. 

It  will  help,  in  our  further  consideration  of  the  subjedt, 
to  examine  more  closely  these  two  schemes,  particularly 
ihe  Wernerian. 

Cronstedt,  about  1750,  divided  the  mineral  kingdom  into 
four  great  divisions,  viz. : — 

I.  Earth  and  stones.        III.  Combustibles. 
II.  Salts.  IV.  Ores. 

Werner,  the  first  of  the  illustrious  teachers  of  mineralogy 
at  Freiberg,  adopted  this  division  and  extended  it  greatly. 
He  divided  the  first  order  into  nine  genera,  as  follows : — 

Earths. 


z. 

Zirconian. 

«)■ 

Calcareous 

2. 

Siliceous. 

6. 

Barytic. 

3- 

Aluminous. 

7- 

Strontian. 

4- 

Magnesian. 

Stones. 

8. 

Diamond. 

9- 

Hallites. 

Here,  indeed,  it  would  appear  that  the  classification 
was  nothing  less  than  purely  chemical,  yet  it  was  not.  A 
certain  number  of  external  charadters  which  siliceous 
minerals,  for  instance,  usually  exhibit  being  assumed  as 
generic  charadters,  or  as  a  type  of  the  genus,  every 
mineral  possessing  those  charaders,  whether  it  contains 
any  silex  or  not,  is  arranged  under  the  siliceous  genus. 
And  80  with  the  other  of  the  nine  genera.  Under  these 
principles,  Werner  saw  no  inconsistency  in  placing 
sapphire  in  the  siliceous  genus  and  opal  in  the  aluminous. 
I  need  not  expatiate  on  the  absurdity  of  this  procedure 
from  our  modern  standpoint,  but  it  is  only  the  stupendous 
development  of  chemical  investigation  in  recent  years 
that  has  lifted  mineralogy  out  of  that  confusion. 

•  The  Journal  of  the  Franklin  Institute,  cxliv.,  p.  139, 


Salts,  according  to  Werner,  included  only  such  minerals 
as  have  some  taste  and  a  considerable  degree  of  solubility 
in  water;  and  they  were  divided  into  carbonates,  nitrates, 
muriates,  and  sulphates. 

Combustibles  were  divided  into  sulphur,  bitumen, 
graphite,  and  resin. 

Ores  were  divided  into  as  many  genera  as  there  were 
distindt  metals  found  as  ores.  Thus,  all  the  iron  ores 
constituted  one  genus.  The  genera  were  divided  into 
species,  depending  on  their  external  charadters.  This 
was  a  true  chemical  basis  to  start  with,  but  far  inferior  to 
the  classification  according  to  the  acid  ingredient  instead 
of  the  base. 

The  key-note  of  this  system  is  found  in  the  following 
quotation  from  Werner  himself : — "Whenever  the  external 
charadters  and  the  chemical  composition  are  at  variance, 
the  species  is  determined  solely  by  the  external  characters." 
According  to  this  method  of  reasoning,  gypsum  and 
selenite  were  classed  as  different  species  because  they 
looked  different,  although  of  exadlly  the  same  composi- 
tion, while  calamine  and  smithsonite  were  classed  together 
as  one  mineral  because  they  looked  alike,  although  of  very 
different  composition. 

Coming  to  the  chemical  systems  of  classification,  they 
were  far  from  being  above  reproach,  .yet  they  showed 
fewer  inconsistencies  than  the  other  method.  Many  mis- 
takes were  made,  it  is  true,  principally  owing  to  the 
imperfedl  state  of  chemical  science.  The  phenomena  of 
dimorphism  were  yet  awaiting  the  light  of  Mitscherlich's 
genius  for  their  explanation,  and  the  reproach  was  cast 
on  the  chemical  method  that  it  had  to  classify  together 
calcite  and  aragonite  as  one  species,  while  everybody 
knew  they  were  different.  Many  were  the  hours  spent  by 
zealous  adherents  of  the  chemical  side,  in  trying  to 
establish  by  analysis  some  essential  difference  between 
calcite  and  aragonite,  and  thus  to  silence  their  opponents. 
Mitscherlich's  researches  on  isomorphism  and  dimorphism, 
however,  cleared  up  so  many  of  these  difficult  points  that 
in  1841  Rammelsberg  was  able  to  resuscitate  the  almost 
defeated  chemical  method,  and  to  champion  it  so  effedtively 
as  to  have  made  it  the  present  accepted  basis  of  mineral 
classification. 

A  very  striking  example  of  this  change  of  base  in 
mineral  classification  is  shown  in  the  successive  standard 
American  works  on  mineralogy.  Shepard's  work,  issued 
in  1835,  1844,  and  1857,  in  successive  editions,  was  on  the 
natural-history  method.  J.  D.  Dana's  first  edition,  in 
1837,  followed  the  same  system;  the  second  edition,  in 
1844,  was  similar,  but  described  in  an  appendix  Rammels- 
berg's  chemical  system;  the  third  edition,  in  1850,  dis- 
carded  the  natural-history  method  of  classification,  and 
adopted  altogether  the  chemical  method.  This  has  been 
retained  in  ail  subsequent  editions  of  this  magnificent 
work,  which  has  become  not  only  the  American  authority 
on  mineralogy,  but,  one  may  almost  say,  the  international 
authority.  The  importance  of  this  classification  to  our 
discussion  merits  that  it  be  given  at  once,  in  outline,  as 
follows : — 

Dana's  Classification  of  Minerals. 

I.  Native  elements. 
II.  Sulphides,    arsenides,    antimonides,   selenides,   and 
tellurides. 

III.  Chlorides,  bromides,  and  iodides. 

IV.  Fluorides. 

V.  Oxygen  compounds, 
(i)  Oxides. 
(2)  Ternary  oxygen  compounds,  or  oxygen  salts. 

1.  Silicates. 

2.  Tantalates  and  columbates,  &c. 

3.  Phosphates,  arsenates,  vanadates,  &c. 

4.  Borates. 

5.  Tungstates,  molybdates,  chromates,  &c. 

6.  Sulphates. 

7.  Carbonates. 
VI.   Hydrocarbons. 


^"''pt"'^  Isg^'  I    Critical  Review  of  ths  Methods  of  Determining  Minerals, 


"5 


It  is  now  proper  to  inquire  into  the  subjedl  of  the  identi- 
fication of  a  mineral,  t.  e.,  its  determination. 

The  question  is  how  to  most  quickly,  easily,  and  surely 
identify  an  unknown  specimen.  This  is  not  exadlly  the 
same  sort  of  question  as  the  one  of  classifying  properly  a 
mineral  after  it  is  completely  described ;  they  are  two 
aspe<5ts  of  the  same  problem,  but  from  different  points  of 
view;  for,  as  Dr.  Sterry  Hunt  has  said,  '♦  A  natural  sys- 
tem of  classification  is  not  subordinate  to  the  end  of 
identifying  species,  but  should  consider  objeds  in  all  their 
alliances  and  relations."  Systems  for  identifying  species 
are  not  therefore  necessarily  along  the  identical  lines  of 
mineral  classification.  However,  the  natural -history 
method  of  classification  by  outward  charaders  adapts 
itself  very  readily  to  schemes  of  identification  in  which 
the  physical  properties  are  given  the  pre-eminence  in  de- 
terminmg  the  mineral.  Determinations  of  hardness, 
streak,  lustre,  gravity,  fusibility,  form,  &c.,  are  easily  made 
without  any  special  training,  and  therefore  are  most  use- 
ful to  beginners  in  the  science  of  determining  minerals. 
The  chemical  system  of  classification,  however,  at  once 
suggests  chemical  analysis  as  the  true  basis  of  a  deter- 
minative method,  and  lends  itself  most  kindly  to  that 
means  of  identification.  Moreover,  the  methods  of 
chemical  analysis,  particularly  those  of  blowpipe  analysis, 
have  developed  coincidently  with  the  growth  of  the 
chemical  classification  of  minerals. 

The  postulate  may  be  made,  that  if  every  mineral  species 
is  a  definite  chemical  compound,  then  the  true  basis  of  iden- 
tifying the  mineral  should  be  the  chemical  analysis.  In 
many  cases  this  may  not  be  the  quickest  way,  but  it  is 
bound  to  be  the  surest.  But  shall  we  throw  away  all  the 
aid  to  be  derived  from  physical  tests  ?  By  no  means.  If 
from  the  properties  at  once  evident  on  casual  inspection 
memory  suggests  a  familiar  mineral,  let  chemical  analysis 
at  once  come  in  to  confirm  or  deny  the  determination. 
In  the  great  majority  of  cases  the  physical  determination  is 
practically  valueless  without  the  analytical  confirmation  ; 
and  there  are  very  few  cases  in  which  the  chemical  con- 
firmation is  absolutelyunnecessaryoruseless.  Onthe other 
hand,  whenever  a  mineral  is  not  at  once  recognised  on 
inspedion,  the  true  basis  of  search  to  determine  it  should 
be  to  fix  as  nearly  as  possible  its  composition  by  chemical 
analysis,  and  then  to  utilise  physical  tests  to  distinguish 
between  minerals  difficult  or  impossible  to  separate  by 
differences  in  their  composition. 

Tables  based  entirely  on  physical  tests  have  been  con- 
struded ;  mixed  tables,  based  on  a  combination  of  both 
physical  and  chemical  tests,  have  been  devised ;  I  have 
preferred  to  attack  unknown  minerals  entirely  from  the 
chemical  side,  and  will  later  on  explain  what  appear  to  me 
the  advantages  of  this  method. 

It  is,  of  course,  superfluous  to  analyse  in  detail  every 
one  of  the  numerous  schemes  of  determinative  mineralogy 
which  have  been  construdted ;  it  will  suffice  to  seled  a 
few  typical  examples,  and  to  discuss  them  on  general 
principles. 

Dana  gives  in  an  appendix  to  his  text-book  on  Mineral- 
ogy one  set  of  tables  based  primarily  on  the  crystal 
system,  then  on  lustre  (metallic  and  non^metallic),  and 
then  with  the  minerals  arranged  according  to  specific 
gravity.  This  classification  is  very  useful  if  the  mineral 
shows  clearly  its  crystallisation,  and  is  truly  of  the  system 
which  it  appears  to  be  ;  but  every  mineralogist  knows 
that  minerals  are  oftener  uncrystallised  than  crystallised, 
and  that  in  probably  one  case  out  of  three  the  system  is 
not  what  it  appears  to  be.  The  question  of  lustre  may 
sometimes  mislead.  The  specific  gravity  may  be  depended 
upon  in  probably  three  cases  out  of  four.  Summing  up 
the  probabilities  that  a  mineral  could  be  identified  by  the 
use  of  such  a  table,  they  are  about  one  in  two  if  the  speci- 
men is  crystallised,  and  not  more  than  one  in  ten  if  it  is 
uncrystallised.  In  scarcely  any  case  would  the  identifi- 
cation be  completely  satisfactory  without  the  chemical 
confirmation. 

A  set  of  tables  in  more  extensive  use  than  Dana's,  and 


based  also  on  physical  tests  alone,  is  that  of  Dr.  Weisbach, 
well  known  in  English  by  Dr.  Frazer's  translation.  The 
following  outline  shows  the  scheme  of  this  classifi- 
cation : — 

Weisbach^s  Tables. 
I.  Minerals  with  metallic  lustre. 

I.  Red.       2.  Yellow.       3.  White.       4.  Grey. 
5.  Black. 
II.  Minerals   of  sub-metallic   or  ordinary  lustre,   and 
with  coloured  streaks,  as  follows  : — 

I.  Black.       2.  Brown.      3.  Red.      4.  Yellow. 
5.  Green.      6.  Blue. 
III.  Minerals   of  ordinary   lustre,   with   white   or  grey 
streak. 
I.  Very  soft.    2.  Soft.    3.  Semi-hard.    4.  Hard. 
5.  Very  hard. 
Supplementary  table  for  Class  III. : — 

A.  Soluble  in  water. 

B.  Effervescing  in  HCl  (carbonates). 

C.  Not  soluble  in  water  or  containing  COa- 

1.  Containing  water — Easily  fusible  to  infusible. 

2.  Anhydrous — Easily  fusible  to  infusible. 

In  using  these  tables,  if  there  is  no  question  as  to  the 
lustre,  or  colour,  or  streak  or  hardness,  that  is,  if  all  these 
properties  are  normal  and  observed  corredly,  the  specimen 
thereupon  falls  into  a  class  varying  in  number  from  five 
to  sixty-three,  among  which  it  is  to  be  distinguished  by  a 
critical  comparison  of  its  other  physical  properties.  In 
the  case  of  the  class  of  five,  this  is  an  easy  matter ;  in 
the  majority  of  cases,  the  classes  averaging  thirty  to  fifty, 
this  is  an  arduous  or  impossible  task.  We  have  further 
to  consider  that  sometimes  the  lustre  is  doubtfully  metal- 
lic, frequently  the  colour  is  not  easy  to  judge,  that  the 
streak  is  often  misleading,  and,  most  of  all,  the  hardness 
very  seldom  to  be  relied  upon.  I  should  say  in  all  fair- 
ness, taking  all  these  points  into  consideration,  that  a 
careful  observer  would  not  place  more  than  fifty  out  of 
one  hundred  promiscuous  specimens  in  the  class  to  which 
Weisbach  assigns  them,  and,  out  of  those  fifty  corredtly 
classed,  would  not  be  able  to  identify  over  twenty-five 
with  any  reasonable  degree  of  certainty  without  having 
recourse  to  the  chemical  composition  for  confirmation. 

One  of  the  best  examples  of  tables  based  on  mixed 
physical  and  chemical  tests  is  that  of  Von  Kobell,  which 
is  the  basis  of  the  classification  so  well  known  and  largely 
used  in  the  United  States,  viz..  Brush's.  They  are  as 
follows : — 

Von  KobeWs  Tables. 
I.  Metallic  lustre. 

a.  Native  malleable  metals  and  mercury. 

A.  Fusible  at  i  to  5  or  easily  volatile,  containing — 
I.  Arsenic.     2.  Selenium.     3.  Tellurium.    4.  An- 
timony.    5.  Sulphur.     6.  None  of  these. 

B.  Fusible  above  5,  or  infusible,  not  volatile. 

I.  Containing  manganese.      2.  Magnetic  B.B 
3.  All  others. 
II.  Without  metallic  lustre. 

A.  Easily  volatile  or  combustible. 

B.  Fusible  at  i  to  5. 

(I.)  Reduces   to  metallic  button,  or    magnetic 
B.B. 

I.  Silver.        2.  Lead.        3- Copper  j^^'^g^^' 

4.  Cobalt.     5.  Magnetic  B.B.    6.  AH  others. 
(II.)  Not  belonging  to  (I.) 

1.  Alkaline  after  ignition. 

2.  Soluble  in  HCl,  without  residue. 

3.  Soluble  in  HCl,  with  gelatinous  residue. 

4.  Soluble  in  HCl,  with  sandy  residue. 

5.  Insoluble  in  HCl,  has  Mn. 

6.  All  others. 
I.  Metallic  lustre. 

II.  Without  metallic  lustre. 

A.  Easily  volatile  or  combustible. 

B.  Fusible  at  i  to  5. 

C.  Fusible  above  5,  or  infusible. 


ii6 


Incompatibilities  in  Prescriptions. 


(  CremiCal  News, 
1     Sept.  3,  1897. 


1.  With  cobalt  nitrate  show  alumina. 

2.  With  cobalt  nitrate  show  zinc. 

3.  Readt  alkaline  after  ignition. 

4.  Soluble  in  HCI,  contain  no  silica. 

5.  Soluble  in  HCI,  contain  silica. 

(i).  Hydrous. 
(2).  Anhydrous. 

6.  Not  belonging  to  the  foregoing  divisions. 

(i).  Hardness  under  7. 
(2).  Hardness  7  or  over. 
It  will  be  seen  that  the  basis  of  this  classification  is 
primarily  and  secondarily  physical,  afterwards  chemical 
composition  plays  an  important  part.  The  superiority  of 
this  method  over  the  previous  ones  based  solely  on  phy- 
sical tests,  lies  almost  altogether  in  the  extent  to  which  the 
chemical  tests  ate  introduced.  There  is  still  some  uncer- 
tainty as  to  lustre  being  correftly  determined,  and  con- 
siderable uncertainty  is  introduced  by  the  fadtor  of 
fusibility  where  it  lies  anywhere  near  to  five  ;  but,  granting 
that  these  are  correcStly  determined,  then  the  chemical 
tests  are  reached  and  the  uncertainties  mostly  cease.  No 
one  worthy  of  being  called  a  chemist  can  mistake  sulphur 
for  selenium  or  silver  for  lead  ;  the  identification  of  such 
charadleristic  elements  is  pradtically  a  certainty.  With 
such  chemical  tests  as  solubility  in  hydrochloric  acid,  with 
a  gelatinous  or  sandy  residue  or  no  residue  at  all,  there  is 
still  considerable  room  for  uncertainty,  and  the  scheme  is 
weak  in  proportion  as  they  are  introduced. 

Dr.  Fuchs  introduced  mixed  tables  based  primarily  on 
chemical  composition,  and  to  that  extent  superior  to 
Weisbach's.  As  a  whole  I  have  found  these  tables  (or 
subsequent  ones  based  upon  them)  to  be  the  most  satis- 
fadlory  tables  published.  To  observers  skilled  in  blowpipe 
analysis  they  furnish  the  most  satisfadtory  means  of 
identification  of  an  unknown  specimen.  The  scheme  is 
as  follows : — 

Fuchs's  Tables. 
{By  the  Blowpipe). 

I.  Heated  B.B.  on  charcoal. 
I.  Volatilises  or  burns. 

j  metallic, 
(non-metallic. 
3.  Selenium  fumes.      4.  Shows  antimony. 
5.  Shows  tellurium. 

I  soluble, 
(non-soluble. 
7.  Residue  magnetic. 
II.  Reduced  B.B.  with  soda,  on  charcoal. 

1.  Reads  for  sulphur  and  gives  metallic  button. 

2.  Reads  for  sulphur  and  gives  no  metallic  button. 

3.  No  sulphur  readion,  but  gives  metallic  button. 

III.  Shows  manganese  in  the  beads  |  'metallic  lustre. 

°  (non-metalliclustre. 

IV.  Shows  zinc  with  cobalt  solution. 
V.  Soluble  in  HCI,  without  residue, 

1.  Fusible  B.B.     (a).  Hydrous,     {b).  Anhydrous. 

2.  Infusible  B.B.     (a).  Hydrous,     {b).  Anhydrous. 

VI.  Soluble  in  HCI  to  a  jelly  (silica). 

(Classified  similarly  to  V.). 

VII.  Soluble  in  HCI,  with  separation  of  silica  (no  jelly). 

I.  Hydrous.     2.  Anhydrous. 

VIII.  Insoluble  in  HCI,  but  bead  test  shows  silica. 

I.  Fusible  B.B.     2.  Infusible  B.B. 

IX.  Belonging  to  none  of  the  previous  divisions. 

The  weakest  point  of  these  tables  is  in  the  adionpf 
hydrochloric  acid,  where  there  is  room  for  some  uncer- 
tainty, and  where  tests  for  the  elements,  as  in  the  previous 
divisions,  are  generally  much  more  satisfadory.  Division 
IV.  should  also  be  abolished,  and  placed  as  a  fourth  sub- 
division of  H.,  for  by  reducing  with  soda  and  a  little  borax 
on  charcoal,  zinc  is  more  certainly  identified  than  by  the 
cobalt  nitrate  test.  Cadmium  minerals  could  also  have 
been  included  under  the  same  subdivision.  Taking  these 
tables  altogether,  I  would  call  them  the  most  satisfadory 
of  the  published  tables. 

(To  be  continued). 


2.  Arsenic  fumes 


6.  Reads  alkaline- 


NOTICES  OF  BOOKS, 


Incompatibilities  in  Prescriptions ;  for  Students  in  Phar- 
macy and  Medicine,  and  Pradicing  Pharmacists  and 
Physicians.  By  Edsel  A.  Ruddiman,  Ph.M.,  M.D. 
New  York  :  John  Wiley  and  Sons.  London  :  Chapman 
and  Hall,  Lim.     1897.     Pp*  vi. — 267.    8vo. 

The  author  of  this  valuable  work  holds  the  Professorship 
of  Pharmacy  and  Materia  Medica  in  Vanderbilt  Univer- 
sity, Nashville,  Tennessee,  and,  having  the  Degrees  of 
Master  in  Pharmacy  and  Dodor  of  Medicine,  is  well 
qualified  for  his  undertaking.  There  are  two  distind 
divisions  of  the  book.  Part  I,  contains,  in  a  condensed 
form,  the  more  common  incompatibilities,  the  substances 
being  arranged  in  alphabetical  order  of  their  Latin  names. 
Part  II.  contains  325  prescriptions,  with  a  criticism  of 
each  explaining  the  difficulties  of  compounding,  or  the 
objedions  to  the  form  in  which  they  are  written.  In  the 
first  part  the  ordinary  readions  of  the  given  substance 
are  stated,  and  the  decompositions  liable  to  ensue  when 
brought  into  contad  with  other  substances  by  trituration, 
and  aqueous  or  alcoholic  solution. 

The  several  readions  in  each  paragraph  are  numbered 
for  convenience  of  reference;  thus  antipyrinum  is  treated 
in  twenty-three  short  items,  and  acidum  tannicum  in 
twenty-six  items. 

Carelessness  on  the  part  of  the  medical  man,  or  on  the 
part  of  the  apothecary's  assistant,  may  cause  explosions 
when  certain  substances  are  triturated  in  a  mortar  or 
brought  together  in  solution  ;  the  adive  substances  may 
be  entirely  changed  by  oxidation,  redudion,  or  double  de- 
composition ;  an  insufiSciency  of  a  solvent  may  interfere 
with  the  desired  form  of  prescription  ;  the  order  in  which 
ingredients  are  mixed  may  greatly  affed  the  result ;  the 
proportion  of  the  substances  may  have  to  be  altered  to 
obtain  the  end  sought ;  and  some  ignorant  praditioners 
may  adually  send  to  the  pharmacist  prescriptions  which 
cannot  be  filled  without  danger  to  the  compounder  or  to 
the  patient.  All  these  cases  are  abundantly  illustrated 
and  carefully  explained  in  the  second  part  of  the  book,  by 
citing  adual  prescriptions  and  criticising  them.  Prescrip- 
tion No.  36  calls  for  potassium  chlorate,  precipitated 
sulphur,  sulphide  of  antimony,  and  sugar,  and  the  author 
remarks  that  each  substance  should  be  powdered  sepa- 
rately and  mixed  lightly,  which  is  certainly  a  wise  caution. 
Prescription  No.  132  contains  amyl  nitrite,  potassium 
iodide,  alcohol,  and  syrup  of  lemons,  with  the  diredion 
Cito  dipensetur  !  Dr.  Ruddiman  recommends  that  this 
should  not  be  dispensed  as  written,  but  that  the  physician 
should  be  communicated  with.  Prescription  No.  87  is 
said  to  be  part  of  the  Keely  cure  for  alcoholism  ;  it  con- 
tains chloride  of  gold  and  sodium,  sulphate  of  strychnine, 
sulphate  of  atropine,  and  fluid  extrad  of  cinchona. 

The  author  suggests  that  the  student  of  pharmacy 
study  each  prescription  thoroughly  before  consulting  the 
note  accompanying  it. 

The  work  shows  care  throughout,  but  the  author  over- 
looks the  formation  of  sodium  nitrate  in  his  note  to 
prescription  No.  170.  Two  indices  complete  the  well- 
printed  volume,  one  to  incompatibilities  and  one  to 
prescriptions. 

It  would  be  interesting  to  learn  the  sources  of  the 
prescriptions  cited  by  the  author;  they  are  presumably 
from  the  note-books  of  apothecaries  and  from  published 
medical  treatises,  a  list  of  which  he  gives  as  the  authori- 
ties consulted.  To  the  lay  mind  many  of  them  appear  to 
be  horrible  mixtures,  almost  as  objedionable  as  the  nos- 
trums of  Paracelsus  and  his  followers;  and  the  question 
arises.  Does  the  physician  who  prescribes  substances  that 
mutually  decompose  when  mixed  (sometimes  generating 
bodies  quite  different  from  their  original  forms)  take  into 
consideration  the  physiological  adion  of  the  newly-formed 
compounds,  or  does  he  attribute  the  eifeds  to  the  primary 
ingredients  ? 


ObBUICAL  News,  I 

Sept.  3,  J897.      I 


Modern  Alchemy, 


ii> 


This  volume  will  be  invaluable  to  students  of  pharmacy 
and  to  young  praflitioners  ;  but  is  not  its  existence  a 
commentary  on  the  deficient  education  in  the  fundamental 
truths  of  chemistry  of  those  licensed  to  compound  and 
to  administer  medicines  to  a  long-suffering  people  ? 

H.  C.  B. 


Sessions  of  the  Superior  Board  of  Health,  corresponding 

to  the  Year  1896.     ("  Sessiones  del  Consejo  Superior  de 

Hijiene  Publica,  correspondientes  al   Aiio  de  i8g6"). 

Santiago  de  Chile. 

Considerable  attention  seems  to  have  been  paid  to  the 

potable  waters  of  Valparaiso.     There  have  been  in  that 

city  many  cases  of  typhoid  fever  and  of  acute  intestinal 

catarrh  ;  the  public  water-supply  passes  through  seats  of 

infedion.     It   was   pronounced   necessary  that   Santiago 

should  be  severed  ;  that  it  is  not  possible  to  use  for  the 

disinfedion  of  the  sewage-waters  the  chemical  procedures 

already  in  use,  and  that  it  is  impossible  to  disinfed  all  the 

irrigation-waters  of  Santiago. 


A  Detailed  Course  of  Qualitative  Chemical  Analysis  of 
Inorganic   Substances,   with   Explanatory    Notes.      By 
Arthur  A.  Noyes,  Ph.D.,  Assistant  Professor  of  Che- 
mistry at  the  Massachusetts  Institute  of  Technology. 
Third  Edition.      London  and  New  York :  Macmillan 
and  Co.,  Lim,     1897.     8vo.,  pp.  89. 
We  have  here  what  may  be  regarded  as  an  abridgment 
of  the  well-known  treatise  on  Qualitative  Analysis  by  the 
late  Prof.  Remigius  Fresenius.  We  can  find  little,  if  any- 
thing, to  which  we  have  any  right  to  objedl.     It  seems  to 
us  slightly  strange  to  find  the  author  recommending  that 
the  laboratory  work  should  be  accompanied  by  recitations 
in  which  the  process  of  analysis  is  discussed  in  detail. 


CORRESPONDENCE. 


MODERN  ALCHEMY. 

To  the  Editor  of  the  Chemical  News. 
Sir, — As  you  have  allowed   Dr.  Bolton  to  indulge  in  a 
little  modern  scientific  witch-finding  at  my   expense,  I 
hope    you  will    permit   me   to   make   the   following   re- 
joinder:— 

1.  My  accuser  says  that  I  have  "with  boldness,  pub- 
licity, and  persistency,"  made  claim  to  "success  in 
transmutation  or  creation  of  gold."  This  charge  is  not  in 
accordance  with  the  fads  of  the  case.  Dr.  Bolton  is 
sufficiently  well  versed  in  modern  newspaper  methods  to 
know  that  publicity  frequently  takes  place  in  opposition 
to  the  desires  of  the  parties  concerned.  He  knows  that 
this  has  largely  been  so  with  regard  to  my  work  respedting 
the  interchangeability  of  the  so-called  "  elements."  He 
knows  that  the  average  reporter  makes  a  surprising  hash 
of  scientific  statements,  and  that  the  average  catchpenny 
newspaper  editor  takes  reprehensible  liberties  even  with 
signed  communications  and  interviews.  He  knows  that 
when  I  was  applied  to  respeding  the  accuracy  or  otherwise 
of  the  report  printed  in  the  New  York  jfournal,  I  declined 
to  admit  that  it  was  more  than  "substantially  corred," — 
a  fad  which  surely  should  have  precluded  such  report 
being  quoted  in  your  columns  as  my  "own  words." 

2.  The  following  correspondence  has  passed  between 
my  accuser  and  myself,  viz.  : — 

a.  Bolton  to  Emmens,  June  21st,  1897: — 

"I  am  preparing  for  an  English  paper  an  account  of 
your  work  of  converting  silver  into  nrgentaurum,  and 
write  to  enquire  whether  you  can  send  me  any  later 
publication  of  your  own  than  your  announcement  made 
in  August,  i8g6. 


"  I  will  be  obliged  for  any  circular  or  other  publication 
you  have  issued  in  resped  to  Ar." 

b.  Emmens  to  Bolton,  June  22nd,  1897: — 

"  Replying  to  your  letter  of  yesterday,  I  have  to  say 
that  it  will  give  me  much  pleasure  to  send  you  additional 
information.  The  little  pamphlet  will  be  ready  in  a  few 
days,  and  then  I  will  mail  you  a  copy.  It  will,  I  think, 
interest  you,  even  if  you  be  not  a  Unitarian  in  material 
philosophy." 

c.  Bolton  to  Emmens,  July  nth,  1897  • — 

"  Your  polite  note  was  duly  received,  and  I  shall  be 
very  glad  to  receive  a  copy  of  your  forthcoming  pam- 
phlet as  soon  as  issued." 

d.  Emmens  to  Bolton,  July  13th,  1897: — 

"  Yours  of  the  nth  has  reached  me,  and  I  now  have 
the  pleasure  of  sending  you  by  this  mail  a  copy  of  the 
just-completed  pamphlet,  '  Arcana  Naturse';  and  inas- 
much as  reference  is  made  therein  to  my  '  Argentaurum 
Papers  No.  i,'  I  also  enclose  a  copy  of  that  book." 

e.  Bolton  to  Emmens,  July  i6th,  1897: — 

"  I  acknowledge  with  thanks  your  letter  of  July  13th, 
and  your  publications  received  to-day.  I  had  heard  of 
your  work  on  Gravitation,  but  had  not  seen  it,  and  shall 
examine  it  with  interest. 

"The 'Arcana  Natura; '  gives  me  just  the  informa- 
tion I  needed.  Thanking  you  for  your  courtesy,  I  am, 
&c." 

The  pamphlet  alluded  to  in  these  letters  is  not  a  publica- 
tion for  sale,  I  prepared  it  in  order  to  save  time  and  trouble 
in  replying  to  the  numerous  enquiries  that  are  addressed  to 
me  from  all  parts  of  the  world.  It  contains  an  explana- 
tion as  to  various  developments  and  modifications  that 
have  taken  place  in  my  gold-work  since  the  original 
announcement  in  the  New  York  newspapers.  Yet,  with 
this  explanation  staring  him  in  the  face,  my  accuser, 
under  the  guise  of  reporting  "  Recent  Progress  of  Alchemy 
in  America,"  has  served  up,  for  the  information  of  your 
eminent  circle  of  readers,  a  mere  copy  of  a  popular 
article  in  a  sensational  newspaper  published  on  August 
i8th,  1896,  and  has  suppressed  the  particulars  with  which 
I  civilly  furnished  him  at  his  own  request. 

3.  The  pamphlet  contains  a  clear  and  explicit  account 
of  a  process  of  producing  from  Mexican  dollars  a  sub- 
stance that  will  pass  muster  as  gold.  My  accuser  with- 
holds this  from  your  readers,  and  then  goes  on  to  charge 
me  with  "  secret  processes  "  and  "  vagueness  of  descrip- 
tion." 

4.  The  pamphlet  contains  more  than  one  explicit  con- 
fession of  my  ignorance  of  natural  things.  Yet  my 
accuser  charges  me  with  "  an  assumption  of  esoteric 
knowledge  expressd  in  pseudo-philosophic  language." 

5.  My  accuser  charges  me  with  "  an  imperative  present 
need  of  gold."  In  one  sense  of  the  words  it  may  be  con- 
ceded that  every  scientific  man,  as  well  as  every  scientific 
institution,  is  in  need  of  gold.  But  this  is  not  the  sense 
in  which  Dr.  Bolton  wrote.  No  reader  can  be  so  obtuse 
as  not  to  understand  the  "  fling  "  ;  it  is  a  piece  of  personal 
abuse  for  which  my  accuser  cannot  adduce  one  jot  or 
tittle  of  justification.  I  have  not  appealed  to  him  or  to 
the  public  for  one  cent.  I  have,  on  the  contrary,  made 
him  and  other  correspondents  a  free  gift  of  information 
which  has  cost  me  many  thousands  of  dollars  to  acquire. 
I  think  your  readers  will  be  of  opinion  that  the  learned 
gentleman  owes  it  to  them  and  himself  to  tender  me  an 
apology. 

6.  I  will  conclude  with  the  narration  of  what  may  perhaps 
be  deemed  an  interesting  historical  fad.  On  March  i6th, 
1897,  I  sent  to  the  United  States  Assay  Ofifice,  in  New 
York,  a  Mexican  dollar  to  be  tested  for  gold.  The  report 
was  nil.  Thinking  that  this  might  have  been  an  accidental 
case  of  individual  purity,  I  then  sent  four  Mexican  dollars 
to  the  same  Assay  Office  and  had  them  there  cut  into 
halves.  One  set  of  halves  was  oiBcially  assayed  with 
the  same  nil  result  as  before.    The  other  set  was  treated 


ii8 


The  Alleged  New  Element  in  Iron. 


(  Chemical  News, 
1      Sept.  3,  1897. 


in  the  Argentaurum  Laboratory,  without  the  addition  of 
gold  in  any  form,  and  the  result  was  a  relatively  consider- 
able produdion  of  a  metal  which  answered  to  all  the  usual 
tests  of  gold,  and  was  subsequently  purchased  as  gold  by 
the  U.S.  Assay  Office. 

For  my  own  mental  satisfadtion  I  then  instituted  en- 
quiries at  the  Assay  Office  as  to  the  precise  meaning  to 
be  attached  to  a  report  of  nil ;  and  I  was  informed  that, 
where  small  weights  of  bullion  are  concerned,  the  report 
means  that  the  amount  of  gold  is  less  than  one  part  in 
ten  thousand — a  proportion  which,  of  course,  was  vastly 
exceeded  by  the  gold  adtually  produced  by  my  treatment 
of  the  four  half-dollars.  One  of  two  alternative  conclu- 
sions was  therefore  compulsory :— Either  some  of  the 
silver  or  copper  in  the  dollars  had  been  changed  into 
gold  or  its  simulacrum  by  my  treatment;  or  the  gold 
already  existed  in  the  dollars  and  was  separated  by  my 
treatment,  though  not  by  the  treatment  in  vogue  at  the 
U.S.  Assay  Office.  I  make  every  chemist  a  present  of 
the  dilemma.  For  my  own  part  my  *'  assumption  of 
esoteric  knowledge  "  does  not  carry  me  so  far  as  to  make 
me  believe  myself  a  more  skilful  assayer  of  bullion  than 
Mr.  Andrew  Mason  and  his  assistants. — I  am,  &c., 

Stephen  H.  Emmens. 

Argentaurum  Laboratory, 

ao,  Central  Avenue,  New  Brighton, 

Staten  Island,  New  York,  U.S.A., 

August  16, 1897, 

[A  specimen  of  argentaurum  sent  me  by  Dr.  Emmens 
has  been  examined  in  the  spedtrograph.  It  consists  of 
gold  with  a  fair  proportion  of  silver  and  a  little  copper. 
No  lines  belonging  to  any  other  known  element,  and  no 
unknown  lines,  were  detedted. — W.  C] 


HYPONITROUS    ACID. 

To  the  Editor  of  the  Chemical  News. 
Sir, — As  you  have  published  in  the  Chemical  News  a 
translation  of  Hautzsch  and  Kaufmann's  paper  upon 
Hyponitrous  Acid,  which  appeared  in  Liebig's  Annalen, 
you  will,  I  am  sure,  permit  me  to  point  out,  also  in  the 
Chemical  News,  some  errors  which  have  entered  into 
that  paper,  through  its  authors'  negledt  to  read  the  litera- 
ture of  the  subjecft. 

Hautzsch  and  Kaufmann  say  that  Maumene  discovered 
hyponitrous  acid.  The  fads  are,  however,  as  I  have  fully 
shown  in  the  Annalen,  that  I  am  the  undisputed  dis- 
coverer, and  that  Maumene  never  experimented  on  the 
Bubjed  at  all,  and  adually  denied  the  existence  of  the 
acid,  on  purely  theoretical  grounds  (Chem.  News,  xxiii., 
206  ;  XXV.,  153  and  285). 

The  method  for  preparing  hyponitrous  acid,  which  the 
authors  call  Zorn's,  and  claim  to  have  perfedted  (with 
what  propriety  will  be  shown  some  other  time),  is  my 
method,  my  original  method, — that  is,  for  I  have,  in  con- 
jundtion  with  Haga,  published  two  others. 

Piloty's  method,  referred  to  by  the  authors,  had  been, 
seven  years  before,  anticipated  by  Haga  and  me  (^yourn. 
Chem.  Sac,  Iv.,  760)  in  a  much  simpler  and  less  expensive 
form,  with  the  same  satisfadory  yield  of  more  than  half 
the  theoretical  quantity.  In  place  of  benzo-sulphydroxamic 
acid,  we  had  used  sulphydroxamic  acid  (oxyamidosulphonic 
acid) ;  that  was  all  the  difference.  The  equation  in  our 
case  was — 

2NaO-S02-NH-OH  +  4KOH  =  aNaO-SOj-OK  +  (K0N)2, 

and  that  in  Piloty's  case, — 

aCeHs'SOa-NH-OH  +  4KOH  =  2C6H5-SOa'OK  +  (KON)^. 

Concerning  ammonium  hyponitrite  the  authors  should 

roperly  have  referred  to  me  as  authority  rather  than  to 

Zorn,  since  I  had  stated  so  many  years  earlier  (Chem. 


News,  xxiii.,  208)  that  ammonium  chloride  and  silver 
hyponitrite  give  silver  chloride  and  an  alkaline  solution 
which  at  once  evolves  ammonia. 

The  indudlion  of  the  readion  of  a  hyponitrite  with 
ferrous  sulphate  as  a  nitrate  or  nitrite  by  contadl  with 
undiluted  sulphuric  acid,  which  is  made  a  point  of  by  the 
authors,  had  already  been  recorded  by  me. 

There  are  two  important  erroneous  experimental  ob- 
servations contained  in  the  paper,  which  the  authors 
would  have  saved  themselves  from  making  had  they 
become  sufficiently  acquainted  with  the  literature  of  their 
subjedl  before  publishing,  but  the  consideration  of  these 
I  reserve  till  I  publish  the  sequel  to  my  first  paper. 

I  wish  to  state  that  the  corredlness  of  the  contents  of 
this  letter  is  not  disputed.  Professor  Hautzsch  and  also 
Mr.  Piloty  have  each  in  turn  courteously  acknowledged 
their  oversight,  and  Professor  Hautzsch  has,  without  my 
adion,  recognised  one  of  the  errors  as  to  experimental 
fad  above  alluded  to. 

It  is  the  re-appearance  of  Hautzsch  and  Kaufmann's 
paper  in  the  Chemical  News  which  has  obliged  me  to 
publish  this  letter.  Also,  to  prevent  misconception,  I  will 
add  that  no  work  upon  hyponitrous  acid — and  there  has 
been  much — surpasses,  if  it  equals,  in  value  that  done  by 
the  excellent  Russian  chemist  Zorn,  who  died  very  young, 
to  the  great  loss  of  chemistry. — I  am,  &c,, 

Edward  Divers. 

Imperial  University  of  Tokyo, 
July  4,  1897, 

PS,  The  number  of  the  Chemical  News  which  con- 
tains  the  beginning  of  Hautzsch  and  Kaufmann's  paper 
has  also  a  letter  from  Mr.  Thomas  Christie  in  commenda- 
tion of  taka-diastase,  so  successfully  discovered  and 
studied  by  Mr.  Takamine,  F.C.S.  I  take  this  opportunity 
to  express  the  pleasure  I  feel  in  the  fad  that  Mr.  Takamin6 
is  the  first  Japanese  pupil  I  ever  had,  and  that  he  pursued 
chemistry  under  me  for  four  years. — E.  D. 


THE  ALLEGED  NEW  ELEMENT  IN  IRON. 

To  the  Editor  of  the  Chemical  News. 

Sir, — I  was  much  interested  in  Mr.  Boucher's  article  in 
the  last  issue  of  the  Chemical  News  (vol.  Ixxvi.,  p.  gg), 
describing  a  possible  element  in  pig-iron,  and  as  I  have 
come  across  a  constituent  of  steel  during  the  last  few 
months  resembling  in  every  resped  the  description  of  its 
properties  as  given  by  Mr.  Boucher,  it  may  be  of  some 
interest  if  I  give  my  experience. 

A  few  months  ago  I  received  a  small  sample  of  steel 
drillings  which  had  originally  come  from  the  Continent, 
and  in  the  course  of  an  analysis,  in  which,  beside  the 
ordinary  constituents,  appreciable  quantities  of  arsenic, 
copper,  cobalt,  and  nickel  were  found,  I  separated  a  dark 
brown  sulphide  in  the  arsenic  group  which  had  all  the 
properties  as  described  by  Mr.  Boucher — the  most  re- 
markable of  them  being  the  beautiful  blue  colour  on 
evaporating  down  with  sulphuric  or  hydrochloric  acid.  I 
had  a  very  limited  amount  of  the  steel,  and  was  working 
on  5  grms.  After  repeated  precipitation  and  purification 
of  the  sulphide  to  eliminate  any  arsenic  and  antimony, 
the  precipitate  weighed  0017  grm.;  showing  a  very  con- 
siderable proportion  of  this  element — a  quantity  much 
too  great  to  negled.  I  therefore  wrote  to  my  clients  re- 
questing them  to  send  me  a  further  sample,  as  the  steel 
contained  a  rare  element  which  I  wished  to  investigate 
further;  this  they  were  unable  to  do,  and  so  the  matter 
has  stood  in  abeyance.  The  experiments  I  performed 
resembled  closely  those  detailed  by  Mr.  Boucher,  with  the 
exception  that  I  used  nitro-hydrochloric  acid  to  dissolve 
the  steel,  instead  of  sulphuric  acid. 

At  first  sight  it  appeared  to  resemble  molybdenum,  but 
this  was  contradided  by  many  of  its  readions,  and  I  shall 


Chemical  Notices  from  Foreign  Sources, 


chbmicalniws,!  Chemical  Notices  from  Foreis^n  Sources.  iig 

Sept.  3,  1097.     I       ^ o ^ 

await  Sir  William  Crookes's  report  with  much  interest.—  1      On  the  Applications  of  Eledrolysis  to    Organic 
I  am   &c.  Chemistry. — L.  Gourwitsch. — Already  inserted. 

Fredk.  G.  Ruddock. 

Laboratory  and  Assay  Office, 

19,  Stanley  Street,  Warrington, 

August  31,  1897. 


CHEMICAL  NOTICES  FROM  FOREIGN 
SOURCES. 


Note.— All  degrees  of  temperature  are  Centigrade  unlcBBOtherwiBe 
expressed. 

Comptes  Rendus  Hebdomadaires  des  Seances,  de  V Academit 
des  Sciences.     Vol.  cxxv.,  No.  5,  August  2,  1897. 

Outset  of  the  Combination  between  Hydrogen  and 
Oxygen.— M.  Berthelot. 

Analysis  of  Aluminium  and  its  Alloys. — Henri 
Moissan. 

Fixation  and  Nitrification  of  Nitrogen  in  Arable 
Soils. — P.  P.  Deherain. 

Poisoning  by  the  Sweat  of  a  Healthy  Man.  — 
8.  Arloing. — This  paper  shows  that  sweat  contains  sub- 
stances energetically  poisonous,  possessing  analogies 
with  the  certain  microbian  toxines. 

On  the  Symmetric  Tetramethyldiamidodiphenyl- 
dianthranaltetrameihyldiamide  of  the  corresponding 
Oxanihranol. — A.  Halier  and  A.  Guyot. — The  conditions 
in  which  we  have  operated,  the  composition  of  the  sub- 
stance which  we  have  obtained,  enable  us  to  conclude 
that  we  are  in  the  presence  of  the  diamidodimethylamido- 
phenyloxanthranaldimethyl. 

Atomic  Weights  of  Nitrogen,  Chlorine,  and  Silver. 

A.  Leduc. —  The  author  admits  the  following   atomic 

weights:— 0  =  16  (base),  N  =  i4-oo5,  H  =  i-oo76,  Cl  = 
35'470,  Ag  =  io7'9ii6.  As  for  sulphur  we  deduce  from  the 
experiments  of  Sias  the  atomic  weight  32"056,  he  adopts 
this  number,  although  the  experiments  of  Dumas  lead  to 
3i'86,  and  those  of  Erdmann  and  Marchand  to  32'oo5. 

Thermo-chemical  Determinations  relating  to  the 
Cupric  Compounds.  —  Paul  Sabaiier.  —  A  thermo- 
chemical  paper  not  suited  for  useful  abstratSlion. 

On  certain  Bromo-ketones. — A.  Collet. — The  author 
describes  the  parabromopropionyltoluene,  the  parabromo- 
butyryltoluene,  the  bromopropionyiparaxylene,  the  bromo- 
propionyldiphenyl,  and  the  chloride  of  dibromophenyl- 
propionyl. 

Observations  on  the  Conjund^ion  of  the  Diazo- 
denvatives  with  the  Phenols. — Ch.  Gassman  and 
Henry  George. — Not  suitable  for  useful  abstra(ftion. 

Carubinose. — J.  Effront.— Carubinose  appears  as  a 
syrupy  substance,  not  crystallisable,  soluble  in  water  and 
alcohol,  and  answering  to  the  formula  CeHiaOg.  It  fer- 
ments readily  with  beer  yeasts.  The  rotatory  power  of 
carubinose,  its  melting-point,  and  the  crystalline  form  of 
its  combinations  with  phenylhydrazin  distinguish  these 
sugars  from  the  other  monosaccharides. 

On  an  Organic  Compound  rich  in  Manganese 
extraded  from  the  Woody  Tissue.— G.  Guerin. — This 
compound,  as  obtained  from  beech-wood,  yielded  per  cent 
—0,52-762;  H,  5-04;  N,4-6o;  S,  0-666;  P,  1-297;  Mn, 
0-402. 

Moniteur  Scientifique, 
Series  4,  Vol.  xi.,  Part  i. 

Progress  realised  in  our  Knowledge  of  the  Con- 
stitution of  the  Alkaloids  of  Quinine. — Ch.  Gassmann. 
—Not  suitable  for  abstradtion. 


Gourwitsch. — Already  inserted. 

Part  2. 
On  the  role  played  by  Peroxides  in  the  Phenomena 
3f  Slow  Oxidation. — A.  Bach. — Already  inserted. 


Btiletinal  Societatii  de  Sciinte  diu  Bucuresci 

(Bulletin  of  the  Scientific  Society  of  Bucharest), 

No.  2,  1897. 

The  Secretary-General,  in  a  short  obituary  notice,  an- 
nounces the  lamented  death,  after  a  painful  illness,  of 
C.  Gogu,  Professor  of  Mathematics  in  the  University  of 
Bucharest,  and  President  of  this  Society,  and  he  bears 
tribute  to  the  loss  the  Society  has  sustained  in  his  death. 
A  biographical  sketch  of  his  life  work  will  be  printed  in 
the  Annales  of  the  Society. 

Subterranean  Water  in  the  North-west  region  of 
Bucuresilor. — N.  Cucu  St.— The  author  has  sunk  a 
number  of  shafts  in  various  parts  of  the  distrift,  and  has 
found  water  in  considerable  quantity  in  several  places.  He 
fully  describes  all  the  works  carried  out  and  gives  excel- 
lent illustrations  of  some  of  the  "  fountains." 

On  a  very  Sensitive  Reaction  for  Nitric  Acid. — 
E.  Riegler.  —  Reprinted  from  the  Pharmaceutischen 
Centralhalle,  Nos.  13  and  14,  1897. 

Notes  on  the  Constitution  and  Classification  of  the 
Sulpho-arsenical,  Sulpho-antimonial,  and  Sulpho- 
bismuthic  Minerals, — V.  C.  Butureanu. — There  is,  as  is 
well  known,  an  important  group  of  minerals  in  nature 
known  generally  as  sulpharsenides,  sulphantimonides, 
and  sulphbismuthides.  The  author  has  examined  all  of 
these  that  he  has  been  able  to  obtain,  and  classified  them 
according  to  their  chemical  formula,  expressed  graphically. 

Classification  of  the  Crystalline  Rocks  of  the 
Central  Zone  of  the  Roumanian  Carpathians. — L. 
Mrazec. — The  rocks  of  this  distridl  are  divided  into  three 
groups.  The  first  comprises  the  distindtly  crystalline 
rocks  of  the  granitic  gneiss  type  ;  the  second,  those  of  the 
well-crystallised  mica-schists;  and  the  third,  the  slightly 
crystalline  chloritic  schists.  The  second  group  is  the 
one  the  author  deals  principally  with  in  this  paper. 


Erratum.— P.  73,  col.  i,  line  32  from  top,  for  "  0-00366 "  read 
"  000363." 


TTNIVERSITY     COLLEGE,     BRISTOL, 

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121 


THE    CHEMICAL    NEWS. 

Vol.  LXXVI.,  No.  1972. 
(STUDENTS'     NUMBER). 

A    WORD    TO    STUDENTS. 

In  spite  of  the  recognised,  and  we  might  almost  say 
the  boasted,  superiority  of  German  chemists  in  the 
quantity  of  research  yearly  executed,  and  in  their 
number  of  investigators,  our  Continental  rivals 
have  not  the  slightest  disposition  to  rest  and  be 
thankful.  In  a  pamphlet  by  Prof.  Dr.  Ferd.  Fischer 
we  find  recommendations  for  further  extending  and 
securing  their  position  in  technical  chemistry  as 
compared  with  that  of  other  countries.  The  author 
has  here  colledled  the  views  of  his  colleagues  on 
the  subjedl  in  question,  and  lays  them  before  the 
world. 

We  find  that  there  are  in  Germany  four  thousand 
technical  chemists,  exclusive  of  about  two  hundred 
others  who  study  chemistry  as  a  pure  science.  We 
cannot  ascertain  whether  the  figure  of  four  thousand 
includes  German  technical  chemists  living  and 
praftising  in  other  countries.  We  suspect  that 
this  is  not  the  case.  At  most  of  the  technical 
schools  it  is  proposed  to  extend  the  curriculum,  and 
to  introduce  examinations  as  a  test  for  the  proficiency 
of  the  students.  Whether,  and  in  how  far,  these 
proposals  will  lead  to  results  of  practical  value  time 
alone  can  decide.  It  will  be  noted  that  the  course 
of  study  in  the  polytechnics  and  technical  high 
schools  varies  greatly. 

In  many  instances  subjedts  are  introduced  which, 
however  important  in  themselves,  seem  to  us  un- 
necessary in  the  special  training  of  a  technical 
chemist.  Wc  must  keep  in  mind  that,  even  for  the 
most  able  and  the  most  industrious  student,  there 
are  only  twenty-four  hours  in  the  day,  and  further 
that  the  great  principle  of  division  of  labour  must 
never  be  overlooked. 

Instrudlion  in  law,  with  the  single  special  excep- 
tion of  patent  law,  seems  to  us  a  needless 
encroachment  on  the  spheres  of  the  solicitor  and 
the  barrister. 

We  perceive  that  in  some  departments  the  can- 
didate has  a  choice  ot  subje(5ts.  Thus  at  Berlin,  in 
the  examination  in  chief,  the  student  may  seledt 
{a)  geology,  (6)  spetSlrum  analysis  or  general  metal- 
lurgy. 

We  think  that  we  in  Britain  are  recovermg  some 
of  the  lost  ground ;  but  an  immense  field  lies  before 
us.  Above  all  things  we  have  to  fight  against  the 
claims  of  the  word-mongers  ;  they  are  still  far  too 
strong  and  too  influential  to  admit  of  our  taking  the 
foremost  position  in  the  the  world  of  Science. 


UNIVERSITIES  AND  COLLEGES. 

UNIVERSITY  OF  LONDON. 
Candidates  for  any  Degree  in  this  University  must  have 
passed  the  Matriculation  Examination.  No  exemption 
from  this  rule  is  allowed  on  account  of  Degrees  obtained 
or  Examinations  passed  at  any  other  University.  This 
and  all  other  Examinations  of  the  University,  together 
with  the  Prizes,  Exhibitions,  Scholarships,  and  Medals 
depending  upon  them,  are  open  to  Women  upon  exadly 
the  same  conditions  as  to  Meq. 


There  are  two  Examinations  for  Matriculation  in  each 
year  ;  onecommencing  on  the  second  Monday  in  January, 
and  the  other  on  the  second  Monday  in  June. 

The  Examination  is  conduced  by  means  of  Printed 
Papers ;  but  the  Examiners  are  not  precluded  from 
putting,  for  the  purpose  of  ascertaining  the  competence  of 
the  candidates  to  pass,  viva  voce  questions  to  any  candidate 
in  the  subjedls  in  which  they  are  appointed  to  examine. 
These  Examinations  may  be  held  not  only  at  the  Uni- 
versity of  London,  but  also,  under  special  arrangement, 
in  other  parts  of  theUnited  Kingdom,  or  in  the  Colonies. 

Every  candidate  forthe  Matriculation  Examination  must, 
not  less  than  five  weeks  before  the  commencement  of  the 
Examination,  apply  to  the  Registrar  for  a  Form  of  Entry, 
which  must  be  returned  not  less  than  four  weeks  before 
the  commencement  of  the  Examination,  accompanied  by 
a  Certificate  showing  that  the  candidate  has  completed 
his  sixteenth  year,  and  by  his  Fee  for  the  Examination. 
As  no  candidate  can  be  admitted  after  the  List  is  closed, 
any  candidate  who  may  not  have  received  a  Form  of 
Entry  within  a  week  after  applying  for  it  must  communi- 
cate immediately  with  the  Registrar,  stating  the  exadl 
date  of  his  application  and  the  place  where  it  was  posted. 

Every  candidate  entering  for  the  Matriculation  Exami- 
nation for  the  first  time  must  pay  a  Fee  of  £2  to 
the  Registrar.  If  a  candidate  withdraws  his  name,  or 
fails  to  present  himself  at  the  Examination,  or  fails  to 
pass  it,  the  Fee  shall  not  be  returned  to  him,  but  he  shall 
be  allowed  to  enter  for  any  subsequent  Matriculation 
Examination  upon  payment,  at  every  such  entry,  of  an 
additional  Fee  of  £1,  provided  that  he  comply  with 
the  Regulations  in  the  preceding  paragraph. 

Candidates  are  not  approved  by  the  Examiners  unless 
they  have  shown  a  competent  knowledge  in  each  of  the 
following  subjedls  :-T-Latin.  Any  one  of  the  following 
Languages  :  —  Greek,  French,  German,  Sanskrit,  or 
Arabic.  The  English  Language,  and  English  History, 
with  the  Geography  relating  thereto.  Mathematics. 
Mechanics,  One  of  the  following  branches  of  Science  : — 
Chemistry,  Heat  and  Light,  Magnetism  and  ElecSlricity, 
Botany. 

The  Examination  in  Chemistry  is — Chemistry  of  the 
Non-metallic  Elements  ;  including  their  compounds, 
their  chief  physical  and  chemical  characters,  their  pre- 
paration, and  their  charaderistic  tests. 

A  Pass  Certificate,  signed  by  the  Registrar,  will  be 
delivered  to  each  successful  candidate  after  the  Report  of 
the  Examiners  has  been  approved  by  the  Senate. 

If  in  the  opinion  of  the  Examiners  any  candidates  in 
the  Honours  Division  of  not  more  than  twenty  years  of 
age  at  the  commencement  of  the  Examination  possess 
sufficient  merit,  the  first  six  among  such  candidates  will 
receive  an  Exhibition  of  thirtv  pounds  per  annum  for 
the  next  two  years ;  the  second  among  such  candidates 
will  receive  an  Exhibition  of  twenty  pounds  per  annum  for 
the  next  two  years;  and  the  third  will  receive  an  Exhibi- 
tion of  fifteen  pounds  per  annum  for  the  next  two  years ; 
such  exhibitions  are  payable  in  quarterly  instalments 
provided  that  on  receiving  each  instalment  the'  Exhibi- 
tioner declares  his  intention  of  presenting  himself  either 
at  the  two  Examinations  for  B.A.,or  at  the  two  Examina- 
tions for  B.S^.,  or  at  the  Intermediate  Examination  in 
Laws,  or  at  the  Preliminary  Scientific  M.B.  Examina- 
tion, and  Intermediate  Examination  in  Medicine,  within 
three  academical  years  from  the  time  of  his  passing 
the  Matriculation  Examination. 

Under  the  same  circumstances,  the  fourth  among  such 
Candidates  will  receive  a  prize  to  the  value  of  ten 
pounds  in  books,  philosophical  instruments,  or  money ;  and 
the  fifth  and  sixth  will  each  receive  a  prize  to  the  value  of 
five  pounds  in  books,  philosophical  instruments,  or  money. 

Any  candidate  who  may  obtain  a  place  in  the  Honours 
Division  at  the  Matriculation  Examination  in  January  is 
admissible  to  the  Intermediate  Examination  either  in 
Arts  or  in  Scienge  in  the  following  July. 


122 


Schools  of  Chemistry, 


(  Chemical  Nswt, 
\     Sept.  10,  1897. 


Intermediate  Examination  in  Science. 

The  Intermediate  Examination  in  Science  will  com- 
mence on  the  third  Monday  in  July. 

No  candidate  (with  the  exception  of  such  as  have 
obtained  Honours  at  the  Matriculation  Examination  in 
the  preceding  January)  is  admitted  to  this  Examination 
within  one  academical  year  of  the  time  of  his  passing  the 
Matriculation  Examination. 

The  Fee  for  this  Examination  is  £5. 

Examination  for  Honours. 

Candidates  for  Honours  in  Chemistry  will  be  examined 
in  Inorganic  Chemistry,  treated  more  fully  than  in  the 
Pass  Examination.  In  addition,  they  will  be  examined 
pradtically  in  Simple  Qualitative  Analysis.  This  Ex- 
amination will  consist  of  six  hours'  examination  by 
two  printed  papers  and  of  six  hours'  pradlical  work. 

In  the  Examination  for  Honours,  the  Candidate,  not 
being  more  than  22  years  of  age  at  the  commencement  of 
the  Pass  Examination,  who  most  distinguishes  himself 
will  receive  an  Exhibition  of  £^0  per  annum  for  the  next 
two  years. 

B.Sc.  Examination. 

The  B.Sc.  Examination  will  be  held  on  the  third  Monday 
in  Odlober. 

Candidates  for  this  Examination  are  required  to  have 
passed  the  Intermediate  Examination  in  Science  at  least 
one  academical  year  previously. 

The  Fee  for  this  Examination  is  £5. 

Examination  for  Honours. 

The  examination  for  Honours  in  Chemistry  will  take 
place  on  Monday,  Tuesday,  and  Wednesday  in  the  week 
following  the  Examination  for  Honours  in  Mathematics  ; 
on  Monday  by  printed  papers  (chiefly  on  Organic  Che- 
mistry), and  on  Tuesday  and  Wednesday  by  practical 
examination  in  Qualitative  and  Quantitative  Analysis. 

The  candidate,  being  not  more  than  23  years  of  age, 
who  most  distinguishes  himself  in  Chemistry,  will  receive 
£50  per  annum  for  the  next  two  years,  with  the  style  of 
University  Scholar. 

Doctor  of  Science. 

The  examination  for  the  Degree  of  Dodtor  of  Science 
takes  place  annually  within  the  first  twenty-one  days  of 
June. 

No  candidate  is  admitted  to  the  examination  for  the 
Degree  of  D.Sc.  until  after  the  expiration  of  two  Aca- 
demical Years  from  the  time  of  his  obtaining  the  Degree 
of  B.Sc.  in  this  University. 

Every  candidate  for  this  Degree  must  state  in  writing 
the  special  subjedt  within  the  purview  of  the  Faculty  of 
Science,  as  set  out  in  the  Programme  of  the  B.Sc.  Ex- 
amination, upon  a  knowledge  of  which  he  rests  his 
qualification  for  the  Dodtorate  ;  and  with  this  statement 
he  shall  transmit  an  original  Dissertation  or  Thesis  (at 
least  six  copies),  printed,  type-written,  or  published 
in  his  own  name,  treating  scientifically  some  special 
portion  of  the  subjedl  so  stated,  embodying  the 
result  of  independent  research,  or  showing  evidence 
of  his  own  work,  whether  condudted  independently  or 
under  advice,  and  whether  based  on  the  discovery  of  new 
f&Gts  observed  by  himself,  or  of  new  relations  of  fads 
observed  by  others,  or,  generally,  tending  to  the  advance- 
ment of  Science,  Every  candidate  may  further  specify  any 
printed  contribution  or  contributions  to  the  advancement 
of  Science  which  he  has  at  any  time  previously  published. 
If  the  Dissertation  or  Thesis  be  approved  by  the 
Examiners,  the  candidate  shall  be  required  to  present 
himself  at  the  University  upon  such  day  or  days  within 
the  first  twenty-one  days  of  June  as  may  be  notified  to 
him,  and  shall,  at  the  discretion  of  the  Examiners,  be 
further  tested,  either  orally  or  pradtically,  or  by  printed 
questions  or  by  all  of  these  methods,  with  reference  both 
to  the  special  subjeA  selected  by  him  and  to  the  Thesis. 
Preliminary  Scientific  (M.B.)  Examination. 

This  Examination  takes  place  twice  in  each  year,— 
once,  for  Pass  and  Honours,  commencing  on  the  thir^ 


Monday  in  July  ;  and  once  for  Pass  Candidates  only,  com- 
mencing on  the  third  Monday  in  January. 

No  candidate  shall  be  admitted  to  this  Examination 
unless  he  shall  have  passed  the  Matriculation  Examina- 
tion. Not  less  than  five  weeks  before  the  commencement 
of  the  Examination  he  must  apply  to  the  Registrar  for  a 
Form  of  Entry,  which  must  be  returned  not  less  than  four 
weeks  before  the  Examiantion,  accompanied  with  the 
candidate's  fee. 

The  Fee  for  this  examination  is  Five  Pounds. 

UNIVERSITY   OF    OXFORD. 

Waynflete  Professor  of  Chemistry — W.  Odling,  M.A., 
F.R.S. 

Every  Student  must  reside  in  one  or  other  of  the  Col- 
leges or  Halls,  or  in  licensed  lodgings,  for  a  period  of  three 
years.  Students  of  Chemistry  can  obtain  the  degree  of 
B.A.  by  passing  preliminary  examinations  in  Arts  and  in 
Science,  and  a  final  Honour  examination  in  Chemistry. 
Chemistry  may  also  be  taken  as  part  of  the  examination 
for  a  Pass  degree.  Graduates  of  other  Universities  suitably 
qualified  can  obtain  the  degree  of  Bachelor  of  Science 
after  an  approved  course  of  study  or  research  and  two 
years'  residence. 

University  Laboratory. — Demonstrators,  W.  W.  Fisher, 
V.  H.  Veley,  F.R.S.,  J.  E.  Marsh — The  fee  for  students 
working  in  the  Laboratory  for  three  days  in  the  week 
during  the  Term  is  £^ ;  for  students  working  every  day,  £5. 

Christ  Church  Laboratory. — A.Vernon  Harcourt,  F.R.S. 

Scholarships  of  about  the  value  of  ^'So  are  obtainable 
at  the  majority  of  the  colleges,  by  competitive  examina- 
tion in  Natural  Science. 

More  detailed  information  may  be  obtained  from  the 
Examination  Statutes  ;  the  Student's  Handbook  to  the 
University ;  and  from  the  professors  and  college  tutors. 


UNIVERSITY   OF   CAMBRIDGE. 

Professor  0/  Chemistry — G.  D.  Liveing,  M.A.,  F.R.S. 

jfacksonian  Professor  of  Natural  and  Experimental  Phi- 
losophy—]. Dewar,  M.A.,  F.R.S. 

The  Student  must  enter  at  one  of  the  Colleges  or 
Hostels,  or  as  a  Non-collegiate  Student,  and  keep  terms 
for  three  years  by  residence  in  the  University.  He  must 
pass  the  previous  examination  in  Classics  and  Mathe- 
matics, which  may  be  done  in  the  first  or  third  term  of 
residence,  or,  through  the  Oxford  and  Cambridge  Schools 
Examination  Board,  or  through  the  Senior  Local  Exami- 
nations, before  commencing  residence.  He  may  then 
proceed  to  take  a  Degree  in  Arts,  either  continuing 
mathematical  and  classical  study,  and  passing  the  or- 
dinary examinations  for  B.A.,  or  going  out  in  one  of  the 
Honour  Triposes. 

The  scholarships,  ranging  in  value  from  ;^20  to  ;£'ioo 
a  year,  are  chiefly  given  for  mathematical  and  classical 
proficiency.  Scholarships,  or  Exhibitions,  are  given  for 
Natural  Science  in  King's,  Trinity,  St.  John's,  St.  Peter's, 
Clare,  Trinity  Hall,  Queen's,  Jesus,  Christ's,  Sidney,  Pem- 
broke, Caius,  and  Downing  Colleges ;  the  dates  of  the 
examinations  vary,  but  are  always  fully  advertised. 

The  Chemical  Laboratory  of  the  University  is  open 
daily  for  the  use  of  the  Students.  The  Demonstrators 
attend  daily  to  give  instructions.  A  list  of  the  ledtures  is 
published  annually,  in  June,  in  a  special  number  of  the 
Cambridge  University  Reporter,  which  may  be  had  from 
the  Cambridge  Warehouse,  in  Paternoster  Row,  or  through 
any  bookseller. 

Non-collegiate  Students  are  allowed  to  attend  certain 
of  the  College  Le(5tures  and  all  the  Professors'  Ledlures, 
and  have  the  same  University  status  and  privileges  as  the 
other  Students.  Full  particulars  may  be  obtained  by 
forwarding  a  stamped  diredled  envelope  to  the  Assistant 
Registrar,  Cambridge,  or  from  the  Cambridge  University 
Calendar, 


ClIBUICAL  NKWI,  I 

Sept.  lo,  1807.     f 


Schools  of  Chemistry, 


123 


UNIVERSITY   OF  DUBLIN. 
Trinity  College. 

Professor  of  Chemistry — J.  Emerson  Reynolds,  D.Sc, 
M.D.,  F.R.S. 

Assistant  Lecturer— Emil  A.  Werner,  F.C.S.,  F.I.C. 

Demonstrator — J.  Percy  Bailey,  B.A. 

The  general  Laboratories  include  working  accom- 
modation for  120  Students,  and  the  Quantitative  and 
Research  Laboratories  for  about  40  Students.  The 
Laboratories  will  open  on  the  ist  of  Odtober.  Ledtures 
will  commence  about  November  ist. 

The  Laboratories  and  the  Ledtures  ofthe  Professor  of 
Chemistry  can  now  be  attended  by  Students  who  do  not 
desire  to  reside  in  the  University  or  proceed  to  its  Degrees. 

The  full  Course  of  General  and  Analytical  Chemistry 
occupies  three  years,  but  a  Student  is  free  in  his  third  year 
to  devote  most  of  his  time  to  a  special  department  of 
Pure  or  Technical  Chemistry.  Students  can  enter  for 
any  portion  of  the  Course.  The  following  Ledlures  are 
delivered : — 

1.  Inorganic   Chemistry    and  Chemical  Philosophy.  — 

Elementary,  first  year  ;  advanced,  second  year. 

2.  Organic   Chemistry.  —  General,  second   year;     ad- 

vanced, third  year. 

3.  Metallurgy. — A  Course  for  Engineering  and  Tech- 

nical Students. 

The  Laboratories  are  open  every  day  from  10  to  5 
o'clock  (except  Saturdays,  when  they  close  at  i  o'clock). 

The  Summer  Course  of  Practical  Chemistry  for  Medical 
Students  begins  during  the  first  week  in  April  and  termi- 
nates with  the  first  week  in  July. 

The  University  of  Dublin  grants  the  Degree  of  Dodor 
of  Science  to  graduates  of  Master's  standing  whose  in- 
dependent researches  in  any  branch  of  Science  are  of 
sufficient  merit. 

KING'S  COLLEGE. 

(Division  of  Engineering  and  Applied  Science). 

Professor  of  Chemistry— ].  M.  Thomson,  F.R.S.,  F.C.S. 

Demonstrator  of  Practical  Chemistry — Herbert  Jackson, 
F.C.S. 

Assistant  Demonstrators— P.  H.  Kirkaldy,  F.C.S.,  and 
W.  H.  Sodeau,  B.Sc. 

The  Academical  Year  consists  of  Three  terms.  The 
days  fixed  for  the  Admission  of  New  Students  in  the 
Academical  Year  1897-98  are  September  30,  January  13, 
and  April  27. 

Students  of  the  First  Year  are  admitted  to  the  Course 
of  Theoretical  and  Applied  Chemistry.  The  Course 
commences  with  a  view  of  the  conditions  suitable  for 
the  produdion  of  Chemical  Phenomena,  after  which  the 
laws  of  Chemical  Attraftion  are  discussed,  and  the  Non- 
metallic  Elements  and  their  principal  compounds  are 
described.  The  Metals  and  their  principal  compounds 
are  next  examined,  care  being  taken  to  point  out  the 
applications  of  the  Science  to  the  Arts ;  and  the  pro- 
cesses of  the  different  Manufadtures  and  of  Domestic 
Economy  are  explained  and  illustrated.  Examinations  of 
the  Class,  both  vivd  voce  and  by  written  papers,  are  held 
at  intervals  during  the  course  at  the  usual  Ledture  hour. 

Second  Year. — Students  attend  in  the  Laboratory  twice 
a  week,  and  they  go  through  a  course  of  Manipulation  in 
the  most  important  operations  of  Chemistry,  includinp  the 
first  steps  of  Analysis.  Any  Student  of  this  Division 
may  be  admitted  to  this  Class  at  any  period  of  his  study 
on  payment  of  an  extra  fee. 

Experimental  and  Analytical  Chemistry  in  the  Labora- 
tory.— The  objedl  of  this  Class  is  to  afford  to  Students 
who  are  desirous  of  acquiring  a  knowledge  of  analysis,  or 
of  prosecuting  original  research,  an  opportunity  of  doing 
so  under  the  superintendence  of  the  Professor  and  De- 
monstrator ;  Students  may  enter,  upon  payment  of  extra 
fees,  at  any  time  except  during  the  vacation,  and  for  a 
period  of  one,  three,  six,  or  nine  months,  as  may  best  suit 
their  convenience.    The  laboratory  hours  are  from  ten  till 


four  daily,  except  Saturday,  on  which  day  the  hours  are 
from  ten  till  one. 

In  addition  to  the  Laboratory  Fee,  each  Student  defrays 
the  expenses  of  his  own  experiments.  The  amount  01 
this  expense,  which  is  comparatively  trifling,  is  entirely 
under  his  own  control. 

Special  hours  and  fees  are  arranged  for  the  convenience 
of  such  Third  Year  Students  as  wish  to  study  Analytical 
Chemistry. 

Fees. — Chemistry  per  term,  £3  3s.  od. ;  per  ann., 
;^8  8s,  od. ;  Pradlical  Chemistry  per  term,  £4.  4s.  od.  ;  per 
ann.,  ;£'io  los.  od. ;  Experimental  and  Analytical  Chemistry 
— Daily  attendance  :  One  month,  £4  4s. ;  Three  months, 
£10  los. ;  Six  months,  ;^i8  i8s. ;  Nine  months,  ;£"26  5s. 
Three  days  a  week  :  One  month,  £2  12s.  6d.  ;  Three 
mos.,  ;£"6  6s.  ;  Six  mos.,  ^11  iis.  ;  Nine  mos.,  ;£'i5  15s. 
Metallurgy. 

Professor-A.  K.  Huntington,  F.I.C,  F.C.S.,  &c. 

The  following  subjedls  are  treated  of  in  the  Ledlures  : 
The  Seledtion  and  Economic  Preparation  of  Fuel  and  of 
RefraSory  Materials ;  the  methods  by  which  metals  are 
obtained  from  thsir  ores,  and  the  means  by  which  they  are 
rendered  suitable  for  the  various  requirements  of  the  Arts. 

Particular  attention  is  paid  to  the  study  of  the  Nature 
and  Properties  of  Metals  and  Alloys  available  for  Con- 
strudtive  Purposes. 

In  the  Metallurgical  Laboratory,  which  is  always  open 
during  College  hours,  the  relation  between  the  Chemical 
Composition  of  Metals  and  their  Mechanical  Properties 
may  be  studied  by  the  aid  of  Testing  Machinery. 

Photography. 
Lecturer— Trof.  J.  M.  Thomson,  F.R.S.,  F.C.S. 
In  addition  to  the  regular  College  Course  in  Photography 
occasional  classes  may  he  formed.     For  further  particu- 
lars application  should  be  made  to  Prof.  Thomson. 
Evening  Classes, 
Classes  for  Evening  Instrudtion  in  various  subjedts  are 
held  during  the  months  from  Odtober  to  March,  inclusive, 
and  during  the  months  of  April,  May,  and  June. 

UNIVERSITY  COLLEGE. 
Faculty  of  Science. 

Pro/«sor— William  Ramsay,  Ph.D.,  F.R.S. 

Assistants — Morris  Travers,  B.Sc,  Alexander  Kellas, 
B.Sc,  and  J.  W.  Walker,  M.A.,  Ph.D. 

The  Session  is  divided  into  three  Terms,  as  follows,  all 
the  dates  being  inclusive  : — 

First  Term,  from  Tuesday,  Odlober  5th,  until  Friday, 
December  17th ; 

Second  Term,  from  Tuesday,  January  nth,  1898,  till 
Friday,  Anril  ist  ; 

Third  Term,  from  Tuesday,  April  26th,  till  Tuesday, 
July  5th.     Class  Examinations  begin  on  June  22nd. 
yunior  Courses  of  Inorganic  Chemistry. 

First  Term  :  Tuesday,  Thursday,  and  Saturday  at  10. 
Second  and  Third  Terms :  Tuesday,  Thursday,  and 
Saturday.     Fee  : — £4  4s. 

These  Courses  will  each  consist  of  about  thirty  lessons, 
partly  theoretical  and  partly  pradlical,  on  the  non-metallic 
elements.     Frequent  exercises  will  be  given. 

Senior  Course  of  Inorganic  Chemistry. 

First  and  Second  Terms  :  The  Class  meets  four  times  a 
week,  on  Mondays,  Wednesdays,  Fridays,  and  Saturdays, 
at  9,  for  Ledtures   Examinations,  and  Exercises. 

Feex  :— For  the  Course,  £y  7s. ;  Perpetual,  £g  gs. ;  for 
the  First  or  Second  Terms,  £4  4s. 

This  Course  and  the  Pradtical  Class  cover  the  subjedt 
as  prescribed  for  the  Preliminary  Scientific  (M.B.)  and 
Int.  Examination  in  Science  of  the  University  of  London. 

For  the  Preliminary  Scientific  Examination  Students 
who  take  the  three  subjedls  for  that  examination  in  July 
attend  during  the  First  and  Second  Terms. 
Advanced  Course  of  Chemistry. 

Second  and  Third  Terms.— The  glass  meets  twice  j^ 


124 


Schools  of  Chemistry, 


week,  on  Tuesdays  and  Thursdays,  at  g,  beginning  on 
January  13.  The  hour  will  be  altered  by  special  arrange- 
ment with  the  class  if  necessary. 

Fee : — For  the  Course,  £3  3s. ;  for  a  Term,  £2  2s. 

This  Course  will  be  found  suitable  for  those  about  to 
proceed  to  graduation  as  Bachelor  of  Science  in  London 
University,  and  to  those  who  intend  to  choose  Chemistry 
as  a  profession.  Such  students  should  also  work  in  the 
Laboratory  during  as  many  hours  as  they  can  spare. 
Organic  Chemistry. 

Tuesday,  Thursday,  and  Saturday,  at  9,  in  the  First 
Term ;  Tuesday,  Thursday,  and  Saturday,  at  10,  in  the 
Second  Term ;  and  Tuesday  and  Thursday  at  9,  and 
Saturday  at  11,  in  the  Third  Term.  The  hour  of  meeting 
will  be  altered  should  the  class  desire  it. 

This  Course  of  Organic  Chemistry  is  intended  for  those 
who  are  studying  the  subjedl  from  a  scientific  standpoint. 
Candidates  for  Honours  at  the  Int.M.B.  are,  however, 
recommended  to  attend  this  Course  besides  the  Special 
Summer  Course. 

The  Course  includes  the  subjedts  required  at  the  B.Sc. 
Examination,  Pass  and  Honours  ;  but  no  previous  ac- 
quaintance with  Organic  Chemistry  will  be  expeifted  of 
those  joining  the  Class. 

Fee  : — For  the  Course,  £6  6s. ;  for  the  Second  and 
Third  Terms,  £4  14s.  6d. ;  for  a  Term,  £2  12s.  6d. ;  for  a 
Second  Course,  £i  3s. 

Practical  Classes. 

Pradlical  Classes  in  Inorganic  and  Organic  Chemistry 
are  conduced  by  the  Assistants. 

Analytical  and  Practical  Chemistry. 

The  Laboratory  is  open  daily  from  9  a.m.  to  4  p.m., 
Saturdays  excepted,  from  October  until  the  middle  of 
luly,  with  a  short  recess  at  Christmas  and  at  Easter. 

Fees  :  for  the  Session,  £26  5s. ;  six  months,  ;^i8  i8s. ; 
three  months,  £10  los.  ;  one  month,  £4  4s. 

Three  specified  days  a  week  : — for  the  Session,  £15  15s. ; 
six  months,  ;i^ii  lis. ;  three  months,  ;^6  6s. ;  one  month, 
£2  I2S.  6d.,  exclusive  of  expense  of  materials.  Students 
may  enter  at  any  period  of  the  Session. 

The  Laboratory  Course  includes  the  Practical  Chemistry 
required  at  the  following  Examinations  of  the  University 
of  London  :—Prel.  Sci.  (M.B.),  Intermediate  M.B.,  Inter- 
mediate Science,  B.Sc. 

Students  who  wish  to  attend  the  Ledtures  on  Chemical 
Technology  may  acquire  here  the  requisite  knowledge 
of  Pradlical  Chemistry  and  Analysis. 

When  accompanied  by,  or  preceded  by,  attendance  on 
the  Ledtures  on  Inorganic  and  Organic  Chemistry,  the 
Laboratory  Course  qualifies  Students  in  the  application  of 
Chemistry  to  Manufadlures,  Metallurgy,  Medicine,  or  Agri- 
culture, &c. 

There  is  also  a  Chemical  Library  containing  the  chief 
Journals  and  Standard  Works  on  Chemistry. 

Certificates  of  Honour  are  granted  to  competent 
Students  on  the  work  done  during  the  Session.  The 
Tuffnell  Scholarship  Ofioo  for  two  years)  will  also  be 
competed  for  in  the  Session  1897-98;  also  the  Cloth- 
worker's  Scholarship  of  £30. 

ROYAL    COLLEGE    OF    SCIENCE     AND 
ROYAL     SCHOOL     OF     MINES. 

Professor— W.  A.  Tilden,  D.Sc,  F.R.S. 

Assistant  Professor— W.  P.  Wynne,  D.Sc,  F.R.S. 

Demonstrators — H.  Chapman  Jones  and  J.  W.  Rodger, 
A.R.C.S. 

Assistants— G.  S.  Newth,  A.  Eiloart,  Ph.D.,  B.Sc,  and 
M.  O.  Forster,  Ph.D. 

The  Royal  College  of  Science  at  South  Kensington  is 
intended,  primarily,  for  the  instrudtion  of  teachers,  and  of 
students  of  the  industrial  classes  seledted  by  competition 
in  the  examinations  of  the  Science  and  Art  Department. 
The  Royal  School  of  Mines  is  incorporated  with  the  Royal 
College  of  Science.  Students  entering  for  the  Associateship 
of  the  Royal  School  of  Mines  obtain  th^ir  general  scientific 


f  Chbuical  News, 
_^ 1    Sept,  10, 1&97. 

training  in  the  Royal  College  of  Science.  The  instrudlion 
in  the  Royal  College  of  Science  is  arranged  in  such  a 
manner  as  to  give  the  Students  a  thorough  training  in  the 
general  principles  of  Science,  followed  by  advanced  instruc- 
tion in  one  or  more  special  branches  of  Science.  The 
Associateship  is  granted  in  certain  divisions  or  lines  of 
study.  Students  who  go  through  any  one  of  the  prescribed 
courses  of  instrudtion  and  pass  the  necessary  Examina- 
tions receive  a  Certificate  of  Associateship  of  the  Royal 
College  of  Science,  or  of  the  Royal  School  of  Mines. 
Students  who  are  not  candidates  for  the  Associateship 
are  permitted  to  enter  as  occasional  students  in  one 
or  more  special  branches  of  science,  and  on  passing  the 
examination  receive  a  Certificate  to  that  effedt.  The 
Associateship  of  the  Royal  College  of  Science  is  given 
in  one  or  more  of  the  following  divisions ; — Mechanics, 
Physics,  Cheniistrj',  Biology,  Geology,  and  Agriculturs, 
and  the  Associateship  of  the  Royal  School  of  Mines  in 
Metallurgy  and  Mining. 

The  course  of  instrudtion,  which  lasts  for  three  years, 
is  the  same  for  all  the  divisions  during  the  first  year,  after 
which  it  is  specialised  in  accordance  with  the  Scheme 
detailed  in  the  Prospedtus  of  the  School. 

The  Session  is  divided  into  two  Terms.  The  first  Term 
begins  on  the  7th  of  Odtober  and  ends  about  the  middle 
of  February.  The  second  Term  begins  in  the  middle  of 
February  and  ends  about  the  middle  of  June. 

Examinations  are  held  at  the  end  of  each  course  of  in- 
strudtion and  at  such  other  periods  as  may  be  found  neces- 
sary. On  the  results  of  these  examinations  the  successful 
candidates  are  arranged  in  two  classes,  first  and  second. 
There  are  also  '•  Honours  "  examinations  for  the  subjedls 
of  the  third  year,  the  successful  candidates  being  placed  in 
order  of  merit.  A  student  obtains  the  Associateship  who 
passes  in  all  the  subjedts  of  the  first  two  years  and  in  the 
third  year  those  of  the  special  division  he  seledts  for  his 
Associateship.  A  student  who  goes  through  the  prescribed 
course  of  instrudtion  in  any  subjedt  and  passes  the  final 
examination  in  it  receives  a  certii^cate  to  that  efTedt. 

Students  who  do  not  wish  to  attend  the  ledtures  are 
admitted  for  short  periods  to  the  laboratories,  at  the  dis- 
cretion of  the  Professors.  The  fees  for  the  laboratories 
are  £4.  per  month. 

Students  not  entering  for  the  Associateship  are  admitted 
to  any  particular  course  of  study,  so  far  as  there  is  room, 
on  payment  of  the  fees  shown  in  the  following  table : — 

Ledlures.    Laboratory. 

Chemistry        

Physics     

Biology  with  Botany 
Geology  with  Mineralogy 

Mechanics 

Metallurgy       2 

Mining      4 

Astronomical  Physics    ....     2  3 

Agricultural  Chemistry,  per  term,  £13.  Mathematics 
and  Mechanical  Drawing,  ;^3  per  term.  Model  and  Free- 
hand Drawing,  £1  per  term.  Descriptive  Geometry,  £3 
per  session.     Mme  Surveying,  ;£"io. 

The  fees  for  the  first  two  years  amount  to  about 
£75,  and  for  the  remainder  of  the  course  for  the  Asso- 
ciateship they  vary  from  ;^30  to  about  £40. 

Both  the  private  and  the  State-aided  students  are  re- 
quired to  furnish  themselves  with  certain  instruments  and 
apparatus  before  the  commencement  of  the  courses.  These 
are  enumerated  in  the  syllabuses  of  the  several  subjedts. 

Officers  of  the  Army,  Navy,  and  Civil  Service,  recom- 
mended by  their  respedive  Departments,  are  admitted  to 
the  Ledtures  and  Laboratories  at  half  fees. 

Associates  of  the  Royal  College  of  Science  or  of  the 
Royal  School  of  Mines  have  the  privilege  of  free  admis- 
sion to  the  Library  and  to  all  the  courses  of  ledtures. 

Bona  fide  teachers  qualified  to  earn  payments  for 
teaching  Science  according  to  the  rule  of  the  Science  and 


£ 

£ 

3 

13 

5 

12 

■> 

12 

4 

8 

4 

6 

2 

13 

Chemical  News,  ) 
Sept.  10, 1897.     I 


Schools  Of  Chemistry, 


125 


Art  Diredory  may  obtain  permission  to  attend  free  any 
course  of  ledtures. 

Several  valuable  Exhibitions,  Scholarships,  and  Prizes 
are  attached  to  the  studentship. 

Summer  Courses  for  Teachers. — Short  courses  ol  in- 
strudlion  are  given  annually,  about  July,  in  different 
branches  of  science  for  the  benefit  of  teachers  of  science 
schools  in  the  country.  The  courses  last  three  weeks. 
About  250  teachers  are  admitted  to  them,  and  they  re- 
ceive third  class  railway  fare  to  and  from  South  Kensington, 
and  a  bonus  towards  their  incidental  expenses  of  ;^3  each. 
(See  Science  and  Art  Diredory.) 

Working  Men's  Lectures. — Notification  of  these  will 
be  given  in  the  newspapers, 

THE    SCHOOL    OF    THE 

PHARMACEUTICAL     SOCIETY    OF    GREAT 
BRITAIN. 

The  Fifty-sixth  Session  will  commence  on  Monday, 
Oiftober  4th, 1897. 

Professors — Chemistry,  J.  Norman  Collie,  Ph.D., 
F.R.S. ;  Botany,  J.  Reynolds  Green,  Sc.D.,  F.R.S., 
F.L.S. ;  Materia  Medica  and  Pharmacy,  Henry  G. 
Greenish,  F.I.C.,  F.L.S,  (Dean). 

A  Course  of  Ledtures  on  Physical,  Inorganic,  and 
Elementary  Organic  Chemistry  commences  in  Odober 
and  terminates  at  the  end  of  June.  An  Advanced 
Course  of  Le<ftures  begins  in  0<flober  and  extends  to  the 
end  of  March.  These  Ledures  are  adapted  to  the 
requirements  of  Pharmaceutical  and  Medical  Students, 
and  also  those  who  are  proceeding  to  degrees  at  the  Uni- 
versity of  London,  or  who  are  preparing  for  the  examina- 
tions of  the  Institute  of  Chemistry. 

Entries  may  be  made  for  single  classes.  Certificates  of 
attendance  at  the  two  Courses  of  Ledlures  on  Chemistry 
and  at  the  Chemical  Laboratories  are  accepted  as  evi- 
dence of  chemical  training  by  the  Institute  of  Chemistry 
in  connexion  with  the  Examinations  for  the  Associate- 
ship,  and  also  by  the  conjoint  Board  of  the  Royal  Colleges 
of  Physicians  and  Surgeons,  as  well  as  by  other  examining 
bodies. 

Prospeduses  and  further  information  may  be  obtained 
from  Mr.  Richard  Bremridge,  Secretary  and  Registrar, 
17,  Bloomsbury  Square,  London,  W.C. 

UNIVERSITY  COLLEGE  OF  WALES, 

ABERYSTWYTH. 

University  of  Wales. 

Professor  — H.  LI.  Snape,  D.Sc.  (Lond.),  Ph.D. 
(Gcettingen),  F.I.C. 

Assistant  Lecturer  and  Demonstrator — A.  W.  Warring- 
ton, M.Sc.  (Vic.).,  F.I.C. 

Lecturer  in  Agricultural  Chemistry — J.  Alan  Murray, 
B.Sc.  (Edin.). 

The  College  is  open  to  male  and  female  students  above 
the  age  of  sixteen  years.  The  Session  commences  on 
Tuesday,  Odober  5,  on  which  day  all  Students  will 
be  expeded  to  meet  the  Professors  in  the  Examination 
Hall  of  the  College. 

Lecture  Courses. — (i)  Matriculation  Course  ;  three  lec- 
tures weekly  during  the  Michaelmas  and  two  weekly 
during  the  Lent  and  Easter  Terms.  (2)  Intermediate 
Science  Pass  Course ;  four  ledures  weekly  during  the 
Lent  and  Easter  Terms.  (3  and  4)  B.Sc.  Courses ;  A, 
three  ledures  weekly  on  Organic  Chemistry ;  B,  two 
ledlures  weekly  on  Chemical  Theory.  (Courses  A  and  B 
will  generally  be  given  in  alternate  Sessions ;  for 
1897-8,  Course  A.)  (5  and  6)  Courses  in  Agricultural 
Chemistry,  For  students  in  their  first  year,  3  ledures, 
and  for  those  in  their  and  year,  2  ledlures  weekly  through- 
out the  Session. 

Laboratory  Courses. — The  Laboratory  is  open  daily 
from  10  a.m.  to  i  p.m.,  and  from  2,15  to  5  p.m., 
except  on  Wednesdays  and  Saturdays.  Classes  for 
the  Systematic  Study  of  Qualitative  and  Quantitative 
Analysis  will  be  formed,  and  Special  Courses  will  be 


I  arranged  for  those  who  intend  to  follow  Medicine  or 
Pharmacy,  or  any  one  particular  branch  of  Applied 
Chemistry,  always  provided  that  such  Students  possess 
the  requisite  knowledge  of  Theoretical  Chemistry. 
The  hours  will  be  arranged,  as  far  as  possible,  to  suit  the 
requirements  of  the  individual  Student. 

The  College  is  recognised  by  the  Royal  University  of 
Ireland,  and  by  the  Colleges  of  Physicians  and  Surgeons 
of  England,  Scotland,  and  Ireland  as  an  institution  at 
which  the  instrudlion  necessary  for  their  respedlive 
Diplomas  in  Medicine,  in  Chemistry,  Physics,  and 
Biology  may  be  given.  One  year  for  graduation  in  Medi- 
cine and  two  years  for  graduation  in  Science  may  be  spent 
at  Aberystwyth. 

Fees. — The  Fee  for  the  whole  Session,  if  paid  in  ad- 
vance, is  ;£'io  ;  if  paid  by  Single  Terms,  for  the  first  term 
of  attendance  in  each  Session,  £i^  ;  for  the  second  term, 
£^  IDS.  ;  for  the  third  term,  £i.  These  composition  fees 
enable  the  Student  to  attend  any  or  all  the  Classes  of  the 
College,  with  the  exception  that  a  small  extra  fee  is 
charged  for  Laboratory  Instrudlion.  Thus,  for  Pradlical 
Chemistry,  the  additional  fee  is,  for  six  hours'  work  per 
week,  los.  per  term,  and  for  twelve  hours,  20s.  per  term. 
The  fees  for  those  who  desire  to  spend  several  days 
weekly  in  the  laboratory  may  be  learned  on  application 
to  the  Registrar.  Fee  for  a  single  Ledlure  Course  £1 
per  term. 

Scholarships  and  Exhibitions  varying  in  value  from  ;^io 
to  £^0  per  annum  will  be  offered  for  competition  at 
examinations  which  commence  on  September  21,  and 
exhibitions  are  awarded  at  the  end  of  the  Session  on  the 
results  of  the  class  examinations. 

The  Chemical  Laboratories  in  connedlion  with  this 
College  have  been  recently  built,  and  are  fitted  with  every 
convenience  for  the  prosecution  of  chemical  studies. 

Intending  Students  requiring  further  information  are 
recommended  to  write  to  the  Registrar  for  a  copy  either 
of  the  General  Prospedlus  or  of  one  of  the  Special  Pros- 
pedluses  issued  for  the  Agricultural  and  Normal  Depart- 
ments. 

UNIVERSITY  COLLEGE  OF  NORTH  WALES, 

BANGOR. 

A  Constituent  College  of  the  University  of  Wales. 

CAemtsfry.— Professor,  James  J.  Dobbie,  M.A.,  D.Sc. 
Demonstrator,  Fred.  Marsden,  Ph.D.,  B.Sc.  Assistant 
Ledlurer  in  Agricultural  Chemistry,  F.  V.  Dutton. 

Physics.  —  Professor,  Andrew  Gray,  M,A.,  LL.D., 
F.R,S. 

The  Session  opens  Odlober  5th,  1897.  ^1'  regular 
classes  are  open  to  men  and  women  students  above  the 
age  of  16  years.  The  following  Courses  of  Ledlures  will 
be  given. 

Matriculation  Course. — Subjedls:  Those  prescribed  for 
the  Matriculation  Examination  of  the  University  of 
Wales.  Fee  for  the  Term  £2  2S.  A  class  for  revision  of 
Matriculation  Work  will  be  held  during  the  Summer 
Term.     Fee  for  the  Term,  ;^i  is. 

Intermediate  Course. — Inorganic  Chemistry  and  Ele- 
mentary Physical  Chemistry.     Fee  for  the  Term  £2  2s. 

B.Sc.  Course.— Advanced  Inorganic  Chemistry.  Fee 
for  the  Session,  £3  38. 

Medical  Course. — Fee,  £4.  4s. 

Agricultural  Chemistry. — Fee,  £2  2S. 

Laboratory  Courses. — The  laboratory  is  open  on  five 
days  of  the  week  from  10  a.m.  to  4  p.m.  for  instrudlion  in 
Chemical  Analysis  and  in  the  Application  of  Chemistry 
to  Medicine  and  the  Industrial  Arts.  Fees :  six  hours 
per  week,  ;^i  is.  per  Term ;  twelve  hours,  £2  2S. ; 
eighteen  hours,  £s  38.  ;  twenty-four  hours,  £4  4s.  Com- 
position Fee  for  all  Laboratory  Classes  of  the  Intermediate 
Science  Course  taken  in  one  year,  £4  4s. 

The  Chemistry,  Botany,  Zoology,  and  Physics  Courses 
are  recognised  for  Medical  graduation  in  the  Universities 
of  Edinburgh  and  Glasgow,  and  students  can  make  one 
Annus  medicus  at  the  college.     The  Science  Courses  are 


126 


Schools  of  Chemistry, 


i  Chemical  Nbws, 
1     Sept.  10,  1897. 


recognised  for  part  of  the  science  degree  course  of  the 
University  of  Edinburgh. 

UNIVERSITY    COLLEGE    OF    SOUTH   WALES 
AND    MONMOUTHSHIRE,     CARDIFF. 

Professor— C.  M.  Thompson,  M.A.,  D.Sc,  F.C.S. 

Demonstrators — E.  P.  Perman,  D.Sc,  F.C.S.,  and 
A.  A.  Read,  F.I.C.,  F.C.S. 

The  Session  commences  Odlober  4th,  and  terminates 
on  June  24th,  and  is  divided  into  three  terms. 

The  Junior  Course  (delivered  during  the  Michaelmas 
term  only)  consists  of  about  50  ledlures,  and  will  cover  the 
Bubjedls  prescribed  for  the  Matriculation  examinations  of 
the  University  of  Wales  and  the  University  of  London. 
Fee,  £2  2S,    A  revision  class  is  held  in  the  Summer  term. 

The  Intermediate  Course  consists  of  about  80  ledlures 
held  during  the  Lent  and  Summer  terms  in  continua- 
tion of  the  Junior  Course,  and  is  the  qualifying  course  for 
the  Intermediate  Examination  of  the  University  of  Wales. 
Together  with  laboratory  pradtice,  it  will  cover  the  sub- 
jedts  required  for  the  Intermediate  Examination  in 
Science  and  the  Prel.  Sci.  (M.B.)  Examination  of  the 
University  of  London.     Fee,  ;£"4  4s. 

The  Senior  Course  consists  of  some  90  ledtures  on  Or- 
ganic Chemistry ;  Fee,  £2  3s. 

A  course  of  20  ledtures  on  Qualitative  Analysis  and  a 
short  course  on  Organic  Chemistry  will  also  be  given. 

The  following  ledlures  on  Metallurgy  will  be  given  by 
Mr.  Read  : — 10  ledtures  on  Fuel ;  Fee,  los.  6d.  20  lec- 
tures on  General  Metallurgy ;  Fee,  £1  is.  30  ledtures  on 
the  Manufadture  of  Iron  and  Steel ;  Fee,  £1  is.  A  prac- 
tical course  on  Iron  and  Steel  Analysis  will  also  be  held, 
and  pradtical  instrudtion  in  Dry  Assaying  will  be  given  in 
the  Metallurgical  Laboratory,  which  is  fitted  with  the 
necessary  furnaces  and  apparatus. 

In  the  laboratory  each  student  works  independently,  so 
that  the  course  of  study  may  be  adapted  to  the  require- 
ments of  the  individual.  Hours,  9  to  i  and  2  to  5  ;  Satur- 
day, 9  to  I.  Fees — Six  hours  per  week,  £^  3s.  per  session  ; 
twelve  hours,  £2  2S.  per  term ;  eighteen  hours,  £i  3s. 
per  term  ;  twenty-four  hours  £'4  4s.  per  term. 

Registered  medical  students  can  prepare  for  the  Inter- 
mediate M.B.  Examination  of  the  University  of  London, 
and  spend  three  out  of  their  five  years  of  medical  study 
in  Cardiff.  Medical  students  wishing  to  graduate  at  a 
Scottish  University,  or  preparing  for  a  Conjoint  Board 
Surgical  and  Medical  Diploma,  or  for  the  Diploma  of  the 
Society  of  Apothecaries,  can  spend  two  years  in  Cardiff. 
For  further  information  see  the  prospedtus  of  the  Faculty 
of  Medicine,  which  may  be  obtained  from  the  Registrar. 

The  College  is  recognised  as  an  institution  at  which 
two  years  of  the  course  for  the  degree  of  Bachelor  of 
Science  of  the  University  of  Edinburgh  may  be  spent. 

Students  by  making  a  payment  of  ;£"io  at  the  com- 
mencement of  each  session  may  compound  for  all  ledlure 
fees  for  the  whole  session.  Laboratory  fees  are  not  in- 
cluded in  the  composition  fee,  but  Students  preparing  for 
the  Science  Examinations  of  the  University  of  Wales 
and  of  the  University  of  London  may,  by  making  a 
payment  of  ;^i3  13s.  at  the  commencement  of  each 
Session,  compound  for  both  Ledlure  and  Laboratory  Fees 
during  the  Session. 

At  the  entrance  examination  in  September,  and  the 
annual  examination  in  June,  several  scholarships  and 
exhibitions  are  awarded.  Great  importance  is  attached 
to  special  excellence  in  one  subjedt. 

The  College  Prospedtus,  and  also  further  information  as 
to  scholarships,  may  be  obtained  from  the  Registrar. 

A  Hall  of  Residence  for  Women  Students  is  attached  to 
the  College. 

UNIVERSITY   COLLEGE,  BRISTOL. 
Professor  of  Chemistry — Sydney  Young,  D.Sc,  F.R.S. 
Lecturer — Francis  E.  Francis,  B.Sc,  Ph.D. 
The  session  1897-98  will  begin  on  Odlober  5th.  Lectures 
and  classes  are  held  every  day  and  evening  throughout 


the  Session.  In  the  Chemical  Department  ledlures  and 
classes  are  given  in  all  branches  of  theoretical  chemistry, 
and  instrudtion  in  pradtical  chemistry  is  given  daily  in  th« 
chemical  laboratory.  The  department  of  experimental 
physics  includes  various  courses  of  ledtures  arranged  pro- 
gressively, and  pradtical  instrudtion  is  given  in  the  physical 
and  eledtrical  laboratories.  The  Department  of  Engineering 
and  the  Construdlive  Professions  is  designed  to  afford  a 
thorough  scientific  education  to  students  intending  to 
become  engineers,  or  to  enter  any  of  the  allied  professions, 
and  to  supplement  the  ordinary  professional  training  by 
systematic  technical  teaching.  This  department  includes 
courses  specially  arranged  for  students  intending  to 
become  civil,  mechanical,  eledtrical,  or  mining  engineers, 
surveyors,  or  architedts.  Those  who  attend  the  mechanical 
engineering  course  enter  engineering  works  during  the 
six  summer  months,  and,  in  accordance  with  this  scheme, 
various  manufadturing  engineers  in  the  neighbourhood 
have  consented  to  receive  students  of  the  College  into 
their  offices  and  workshops  as  articled  pupils  at  reduced 
terms.  Medical  education  is  provided  by  the  Faculty  of 
Medicine  of  the  College.  Several  Scholarships  are  tenable 
at  the  College.  Full  information  may  be  obtained  from 
the  Secretary. 

Day  Lectures. 
Inorganic  Chemistry. 

The  Courses  treat  of  the  principles  of  Chemistry,  and  of 
the  Chemistry  of  the  Non-Metals  and  Metals. 

yunior  Course. — Two  Ledlures  a  week  will  be  given 
during  the  First  and  Second  Terms.     Fee,  £1  38. 

Special  Course, — A  special  course  of  Ledtures  is  also 
given  to  Engineering  Students. 

Senior  Course. — Three  Ledlures  a  week  will  be  given 
throughout  the  Session.  Fee,  £^  5s.  There  will  be 
tutorial  classes  in  connedlion  with  the  Junior  and  Senior 
Courses. 

Advanced  Course, — One  Ledlure  a  week  will  be  given 
throughout  the  Session.      Fee,  £2  12s.  6d. 

Organic  Chemistry. 
This  Course  will  relate  to  the  more  important  groups  of 
the  Compounds  of  Carbon. 

Two  Ledlures  a  week  will  be  given  during  the  Second 
Term,  and  three  Ledlures  a  week  during  the  Third  Term. 
Fee,  £'i  3s.  An  advanced  course  of  ledlures  will  also  be 
given  one  day  a  week  during  the  session.  Fee,  £2  12s.  6d. 
Practical  Chemistry. — Laboratory  Instruction. 
The  Laboratory  will  be  open  daily  from  lo  a.m.  to  5 
p.m.,  except  on  Saturdays,  when  it  will  be  closed.  Instruc- 
tion will  be  given  in  the  Laboratory  ia  all  branches 
of  Pradlical  Chemistry,  including  Qualitative  and  Quanti- 
tative Inorganic  and  Organic  Analysis,  the  preparation  of 
Chemical  Produdls,  and  Inorganic  and  Organic  Research. 
Special  facilities  will  be  afforded  to  those  who  desire  to 
study  Pradlical  Chemistry  as  applied  to  the  different  pro- 
cesses employed  in  the  Arts  and  Manufadlures.  Fees 
in  Guineas — 

5  Days  a  4  Days  a  3  Days  a  2  Days  a  i  Day  a 
Week.       Week.      Week.    Week.    Week. 
Per  Session..     ..     15  12^        10        7i  5 

„    Two  Terms..     11  9  7!      si  3i 

„    One  Term    ..7  6  4i      3i  2i 

Students  may  arrange  to  divide  their  days  of  laboratory 
work  into  half-days. 

Chemical  Scholarship.-^ Among  others,  a  Chetliical 
Scholarship  of  ;^25  is  offered  for  competition. 

Evening    Lectures. 

Two  courses  of  Ledlures  will  be  delivered  during 
the  First  and  Second  Terms ;  they  will  be  devoted  to  the 
consideration  of  the  general  Principles  of  Chemistry  and 
Chemical  Physics  and  the  Chemistry  of  Non-Metallic 
and  Metallic  Elements.  Special  attention  will  be  paid 
throughout  to  those  produdls  which  have  a  pradlical 
application  in  the  Arts  and  Manufadlures.  Fee  for  each 
course,  7s.  6d. 

Practical  Chemistry —  Laboratory   Instruction,  —  Thg 


CHbuICAL  NBWSt  I 
Sept.  10.  1897.     ' 


Schools  of  Chemistry . 


i^f 


Laboratory  will  be  open  on  Tuesday  and  Wednesday  even- 
ings from  7  till  9.  InstrudVion  will  be  given  in  Qualitative 
and  Quantitative  Analysis,  and  in  the  Preparation  of 
Chemical  Produdts.  Fees  :— (Two  Terms)  Two  Evenings, 
25s. ;  One  Evening,  15s.  (One  Term)  Two  Evenings,  15s. ; 
One  Evenmg,  los  6d. 

University  College,  Bristol,  has  been  approved  by  the 
Council  of  the  Institute  of  Chemistry  as  a  College  at 
which  all  the  subjedls  required  for  the  admission  of 
Associates  to  the  Institute  are  taught. 

The  Calendar  of  the  College,  price  is.  (post-free, 
IS.  4d.),  containing  detailed  information  of  the  various 
Courses,  may  be  obtained  on  application  to  the  Secretary. 

MASON    COLLEGE,    BIRMINGHAM. 
Professor— Percy  F.  Frankland,  Ph.D.,  B.Sc,  F.R.S. 
Assistant   Lecturer — C.  F.  Baker,  Ph.D.,  B.Sc. 
Demonstrator — W.  R.  Innes,  Ph.D.,  M.Sc. 
The  Session  will  be  opened  on  September  30th,  1897. 

Elementary  Course. 

Forty  Ledlures  adapted  to  the  requirements  of  beginners 
will  be  given  in  the  Winter  and  Spring  Terms.  Ledure 
days — Wednesdays  and  Fridays  at  11.30. 

Persons  entirely  unacquainted  with  Chemistry  are 
recommended  to  attend  this  Course  before  entering  for 
the  General  Course.  Candidates  for  the  Matriculation 
Examination  of  the  University  of  London  also  are  advised 
to  attend  this  Course. 

General  Course. 

The  General  Course  of  Ledtures  on  Chemistry  will  be 
found  useful  by  Students  who  are  afterwards  to  become 
Engineers,  Architedts,  Builders,  Brewers,  or  Manufac- 
turers (such  as  Metallurgists,  Alkali,  Soap,  Manure,  Glass, 
or  Cement  Makers,  Bleachers  and  Dyers,  &c.) 

Students  preparing  for  the  Intermediate  Examination 
in  Science  and  Preliminary  Scientific  (M.B.)  Examination 
of  the  University  of  London  should  attend  the  Ledlures 
on  Inorganic  Chemistry  (Winter  and  Spring  Terms). 

Candidates  for  Intermediate  Examinations  in  Medicine 
will  in  general  require  only  that  part  of  the  course 
(Summer  Term)  which  relates  to  Organic  Chemistry. 

The  full  course,  extending  over  three  terms,  will  also 
satisfy  the  requirements  of  Students  preparing  for  the 
Associateship  of  the  Institute  of  Chemistry,  so  far  as 
attendance  at  ledtures  on  General  and  Theoretical 
Chemistry  is  concerned. 

1.  From  Odtober  to  March  (Winter  and  Spring  Terms). 
About  eighty  ledlures  on  Inorganic  Chemistry  and 
Chemical  Philosophy  will  be  given  on  Mondays,  Tuesdays, 
Wednesdays,  and  Thursdays  from  October  to  December, 
and  on  Mondays,  Tuesdays,  and  Wednesdays  from 
January  to  March,  at  9.30  a.m.  A  Tutorial  Class  is  held 
in  connection  with  this  Course  once  a  week  throughout 
the  Session.     Fee,  £^  5s.  for  the  course. 

2.  April  to  June  (Summer  Term).  About  thirty  ledtures 
will  be  given  on  Elementary  Organic  Chemistry,  or  the 
chemistry  of  the  most  important  series  of  carbon  com- 
pounds. This  course  will  include  all  the  subjedls  required 
for  the  Intermediate  Examination  in  Medicine  of  the  Uni- 
versity of  London.  Ledture  Days— Monday,  Wednesday, 
and  Friday  at  12  noon    Fee,  ;^i  iis.  6d. 

The  General  Course  (including  Inorganic  and  Organic 
ledtures)  qualifies  for  graduation  in  the  medical  faculties 
of  the  universities  of  Edinburgh,  Glasgow,  Aberdeen,  and 
Durham. 

Special  Courses  of  Ledtures  and  of  Laboratory  Instruc- 
tion are  given  for  Medical  Students  preparing  for  the 
Conjoint  Board  Examinations. 

Advanced  Course. 
An  Advanced  Course  for  the  study  of  Theoretical 
Chemistry  and  those  parts  of  the  subjedt  which  are 
required  for  the  degree  of  B.Sc.  in  the  University  of 
London  will  meet  twice  a  week.  Pee  for  the  session 
£338. 


Laboratory  Practice. 
The   College   Laboratory  is   open  daily  from    9.30  to 
5,  except  on  Saturdays,  when  it  is  closed  at  i  p.m. 

Candidates  for  Intermediate  Examination  in  Science, 
Preliminary  Scientific  (M.B.),  B.Sc,  and  Intermediate 
Examination  in  Medicine  of  the  University  of  London, 
may  obtain  in  the  Laboratory  of  the  College  the  instruc- 
tion necessary.  The  three  months  Course  of  Pradlical 
Chemistry  for  the  B.Sc,  Edinburgh,  in  the  department 
of  Public  Health,  may  be  taken  in  the  Mason  College 
Laboratory.     Fees  : — 

. ,,  ,  Three  hours 

All  day.  per  day. 

One  Term 7  guineas     ..     ..     4i  guineas. 

Two  Terms        ....     13        „           ..     ..     8i       „ 
Three  Terms      ....     18       12        „ 

A  Course  of  short  demonstrations  and  exercises  is 
given  by  the  Professor  or  one  of  his  Assistants  once  a 
week.  All  first-year  Students  are  required  to  attend, 
unless  exempted  for  special  reasons  by  the  Professor.  No 
Fee. 

Metallurgy. 

Three  Courses  of  Ten  Ledlures  will  be  given  on  the 
Principles  and  Pradlice  of  Metallurgy.  Fee,  los.  6d.  for 
each  of  the  first  two  courses,  and  for  each  of  the  two  sec- 
tions of  the  third  course.  A  more  advanced  course  of 
about  sixty  ledlures  upon  seledled  subjedls  is  also  given. 

There  is  a  separate  laboratory  for  metallurgical  students 
in  which  provision  is  made  for  instrudlion  in  assaying,  &c. 

Evening  Classes. 

Special  Courses  of  Evening  Ledlures  are  arranged 
during  the  Winter  and  Spring  Terms  of  each  session.  The 
subjedls  are  treated  in  a  less  technical  manner  and  the 
fees  are  nominal. 

Scholarships. 

Priestley  Scholarships.— Thvse  Open  Scholarships  in 
Chemistry  of  the  value  of  £100  each  are  awarded  annually 
in  September. 

Bowen  Scholarship.— One  Open  Scholarship  in  Metal- 
lurgy of  the  value  of  ;^ioo  is  awarded  annually  in  Sep- 
tember. 

Forster  Research  Scholarship.— A  Scholarship  of  the 
value  ol  £so  is  annually  awarded. 

For  particulars  apply  to  the  Registrar. 

Excursions. 
During  previous  Sessions  permission  has  been  obtained 
to  visit  some  of  the  great  fadlories  in  or  near  Birmingham, 
in  which  chemical  and  metallurgical  industries  are  carried 
on.  Students  have  thus  had  most  valuable  opportunities 
of  gaining  a  pradlical  acquaintance  with  some  branches  of 
Applied  Science.  The  privilege  thus  courteously  granted 
by  several  manufadlurers  will,  it  is  hoped,  be  enjoyed  in 
every  future  Session.  The  excursions  will  be  condudled 
by  the  Professor  or  Ledlurer. 


BRADFORD    TECHNICAL    COLLEGE. 
Chemistry  and  Dyeing  Department. 

Head  Master— W.  M.  Gardner,  F.C.S. 

Demonstrator  and  Lecturer  on  Geology— A.  B.  Knaggs, 
F.C.S.  ^      ^ 

Lecturer  on  Botany  and  Biology— WiWiam  West,  F.L.S. 

The  school  year  is  divided  into  three  terrns.  The 
Session  commences  on  September  14th  and  terminates  on 
July  17th.  The  course  of  instrudlion  extends  over  two 
years,  and  embraces  Ledlure  Courses  on  Inorganic  and 
Organic  Chemistry,  the  technology  of  the  textile  fibres  , 
mordants,  natural  and  artificial  colouring  matters, 
technical  analysis,  and  laboratory  pradlice  in  analytica  1 
chemistry,  chemical  preparations,  and  dyeing.  Fee,  £5 
per  Term,  or  £13  per  Session. 

During  the  first  and  second  terms  Evening  Classes  are 
held  for  the  benefit  of  persons  engaged  during  the  day  and 
for  pharmaceutical  students. 


128 


Schools  of  Chemistry. 


{Chemical  News, 
Sept.  10, 1897. 


ROYAL    AGRICULTURAL    COLLEGE, 

CIRENCESTER. 

Chemical  Department. 

Professor— Piof.  E.  Kinch,  F.C.S.,  F.I.C. 

Assistants — Cecil  C.  Duncan,  F.I.C,  and  W.  James. 

Systematic  courses  of  Ledlures  are  given  on  the  various 
branches  of  Chemistry  in  its  relation  to  Agriculture,  illus- 
trated by  experiments,  and  by  the  colledlions  in  the  College 
Museum.  They  comprise  the  laws  of  Chemical 
Combination  and  the  general  Chemistry  of  mineral 
bodies,  and  of  the  more  frequently  occurring  bodies  of 
organic  origin,  with  the  relationships  of  their  leading 
groups ;  and,  finally,  the  applications  to  pradical  opera- 
tions of  the  Chemistry  of  the  atmosphere,  of  soils  and 
manures,  of  vegetation  and  stock  feeding,  and  of  the  pro- 
cesses and  produdts  of  the  dairy. 

In  the  Laboratory  praftical  instrudtion  is  given  in 
the  construdtion  and  use  of  apparatus  and  in  Chemical 
manipulation  and  analysis,  both  qualitative  and  quantita- 
tive. After  studying  the  simple  operations  and  the 
properties  of  the  commonly  occurring  substances,  the 
Students  are  taught  to  analyse  a  series  of  compounds, 
and  apply  the  knowledge  thus  obtained  to  the  analysis  of 
manures,  soils,  waters,  feeding  stuffs,  dairy  produdls,  and 
other  substances  met  with  in  the  ordinary  course  of  Agricul- 
tural pradtice.  Chemico-agricultural  researches  are  under- 
taken by  the  senior  Students  under  the  diredlion  of  the 
Professor  and  his  Assistants. 

VICTORIA     UNIVERSITY. 
THE  YORKSHIRE  COLLEGE,  LEEDS. 
Professor  of  Chemistry — Arthur  Smithells,  B.Sc.  Lond., 
F.I.C. 

Lecturer  in  Organic  Chemistry — Julius  B.  Cohen,  Ph.D., 
F.I.C. 

Assistant  Lecturer  and  Demonstrator— 'Hethett  Ingle, 
F.I.C. 
Demonstrator — T.  S.  Patterson,  Ph.D. 
The  Session  begins  Odlober  5,  1897. 
Lecture  Courses. 

1.  General  Course  of  Chemistry. — Monday,  Wednesday, 
and  Friday,  at  11.30  a.m.,  from  Odtober  to  the  end  of  the 
second  term,  and  during  part  of  the  third  term.  Fee  for 
the  Course,  £4  4s. 

2.  Inorganic  Chemistry. — First  year  Honours  Course, 
Non-metals.  Monday,  Wednesday,  and  Friday,  at  9.30 
a.m.     Fee,  £3  13s.  6d. 

3.  Inorganic  Chemistry.  —  Second  year  Honours 
Course,  Metals.  Tuesday,  Thursday,  and  Saturday  at 
9.30  a.m.     Fee,  ;^3  13s.  6d. 

4.  Organic  Chemistry.  —  Tuesday,  Thursday,  and 
Saturday  at  12  noon     Fee  £1  13s.  6d. 

5.  Organic  Chemistry  Honours  Course. — 'Wednesday 
and  Friday  at  12  noon.     Fee,  £2  12s.  6d. 

6.  Theoretical  Chemistry. — Advanced  Course.  Tuesdays 
and  Thursdays  at  9.30  a.m.     Fee,  £2  12s.  6d. 

7.  Chemistry  as  Applied  to  Coal  Mining. — ■  Tuesday 
during  the  First  Term,  at  4  p.m. 

8.  Chemistry  for  Teachers. — Saturdays  from  g.30  to 
12.30  in  the  first  and  second  terms.     Fee,  ;^4  4s. 

Laboratory  Courses. 

The  College  Laboratory  will  be  open  daily  from  9  a.m. 
to  I  p.m.,  and  from  2  to  5  p.m.,  except  on  Saturdays, 
when  it  will  close  at  i  p.m. 

Fees  for  the  Session — Students  working  six  days  per 
week,  ;^2i ;  five,  ;£'i8  i8s.  ;  four,  £16  16s. ;  three,  ;^i3  13s. 

Class  in  Practical  Chemistry,  Saturday  mornings,  from 
g.30  to  12.30.     Fee  ;;^i  IIS.  6d. 

Practical  Chemistry  for  Medical  Students. — Tuesdays, 
9,30  to  11.30  Oftober  to  end  of  December;  Thursdays, 
2  to  4  from  January  to  end  of  March. 

Practical  Course  in  Sanitary  Chemistry. — Tuesdays  and 
Thursdays  from  2  to  5  p.m.,  from  January  to  March.  Fee, 

^5  58. 
Practical  Organic  Chemistry  for  Medical  Students.-^ 


Tuesdays  and  Thursdays  from  10  to  I2  during  the  Third 
Term.    Fee,  £2  2s. 

Evening  Class. 

A  Course  of  twenty  Ledtures  by  Mr.  Ingle,  on  the 
Chemistry  of  Photography  will  begin  during  the  first  and 
second  Terms.    Fee,  10s.  6d. 

Dyeing  Department. 

Professor — J.  J.  Hummel,  F.I.C. 

Lecturer  and  Research  Assistant  —  A.  G.  Perkin, 
F.R.S.E. 

Assistant  Lecturer — R.  B.  Brown. 

This  Course  extends  over  a  period  of  three  years,  and 
is  intended  for  those  who  wish  to  obtain  a  full  scientific 
and  pradtical  education  in  the  art  of  dyeing.  It  is  suitable 
for  those  who  purpose  in  the  future  to  take  any  part  in 
the  diredtion  of  the  operations  of  dyeing  or  printing  of 
textile  fabrics,  e.g.,  the  sons  of  manufadturers,  calico 
printers,  managers,  master  dyers,  &c. 

Leather  Industries  Department. 

Professor— n.  R.  Prodter,  F.I.C. 

The  full  Course,  which  extends  over  a  period  of  three 
years,  is  suitable  to  all  who  intend  to  become  Technical 
Chemists  in  the  Leather  Industry,  or  managers  of  im- 
portant works,  and  is  recommended  to  sons  of  tanners. 
The  Course  includes  instrudlion  in  chemistry,  engineering, 
leather  manufadture,  and  pradtical  work  in  the  Leather 
Industries  Laboratory. 

Agricultural  Department. 

Professor — James  Clark,  M.A.,  Ph.D. 

The  full  Course  occupies  two  years,  and  includes  in- 
strudlion in  chemistry,  physics,  botany,  engineering  and 
surveying,  and  the  principles  of  agriculture,  as  well  as 
pradtical  work  in  the  various  laboratories  and  out-door 
agriculture. 

Research  Students  are  admitted  to  the  College 
Laboratories  on  reduced  terms. 

Several  valuable  Scholarships  are  at  the  disposal  of  the 
College,  viz.,  the  Cavendish,  Salt,  Akroyd,  Brown,  Emsley, 
Craven,  and  Clothworkers'  Scholarships,  and  the  Leighton 
Trustees'  Exhibition,  and  one  of  the  1851  Exhibition 
Scholarships.  The  West  Riding  County  Council  Scholar- 
ships are  tenable  at  the  Yorkshire  College. 

UNIVERSITY  COLLEGE,  LIVERPOOL. 

Professor—].  Campbell  Brown,  D.Sc; 

Lecturer  on  Organic  Chemistry  —  C.  A.  Kohn,  B.Sc, 
Ph.D. 

Lecturer  on  Metallurgy — T.  L.  Bailey,  Ph.D. 

Demonstrators  and  Assistant  Lecturers  —  T.  L.  Bailey, 
Ph.D.,  C.  A.  Kohn,  B.Sc,  Ph.D.,  and  A.  W.  Titherley, 
M.Sc,  Ph.D. 

Assistant — H.  H.  Froysell. 

The  Session  commences  Odtober  4th. 

The  William  Gossage  Chemical  Laboratory  has  been 
completed  and  opened  for  Advanced  Students,  the  Metal- 
lurgical  Laboratory  has  been  enlarged,  and  new  Gas 
Analysis  and  Eledtro-Chemical  rooms  have  been  added, 
with  a  third  Ledlure  Room. 

The  Classes  meet  the  requirements  of  candidates  for 
the  Ordinary  B.Sc.  Degree,  for  Chemistiy  Honours,  or 
for  the  M.Sc  or  DSc.  Degree  in  Vidtoria  University  ;  for 
Degrees  in  Medicine  of  Vidtoria,  London,  and  Edin- 
burgh ;  for  the  Pharmaceutical  Diplomas ;  for  a  special 
Technological  Certificate  of  University  College  ;  and 
for  those  studying  Chemistry  as  a  preparation  for 
professional,  technical,  or  commercial  life.  The  Classes 
qualify  for  the  Fellowship  of  the  Institute  of  Chemistry  of 
Great  Britain  and  Ireland,  and  other  Examination  Boards^ 
Lecture  Courses. 

General  Elementary  Course  on  the  principal  non- 
metallic  elements  and  the  most  important  metals,  the 
principles  of  Chemical  Philosophy,  and  an  introdudtory 
sketch  of  Organic  Chemistry.    Three  Terms.     Fee,  £^. 

Engineer's  Course  of  Le^ures  with  Pradtical  Class. 
Two  Terms.    Fee,  £^. 


Chkmical  News,  ) 
Sept.  lo,  1897.     ) 


Schools  Of  Chemistry. 


12^ 


Dental  Course,  LeAures  and  Pradlical.     Fee,"  £s  5s. 

Course  A. — Non-metals.     Fee,  £^  los. 

Course  B. — Metals.     Fee,  £3  los. 

Course  C. — Organic  Chemistry.     Fee,  £s  los. 

Course  H. — Special  Organic  Subjeds.     Fee,  £1. 

Course  D. — Physical  Chemistry.     One  Term.    Fee,  ;£■!. 

Course  E. — History  of  Chemistry  and  of  the  Develop- 
ment of  Modern  Chemical  Philosophy.  Three  Terms. 
Fee,  £2. 

Courses  F. — Technological  Chemistry  and  Metallurgy  : 
Ledures  on  Technology  are  given  in  connexion  with 
Laboratory  work  at  hours  to  be  arranged.  The  subjeds 
are  varied  in  different  years,  (i)  Alkali  and  Allied  Manu- 
fadures.  (2)  Copper,  Iron,  and  Steel.  (3)  Lead,  Silver 
and  Gold,  Aluminium,  and  other  Metals.  (4)  Distillation 
of  Coal  and  Tar  Industries.  (5)  Fuel  and  Gas.  (6) 
Chemistry  Applied  to  Sanitation.  (7)  Technical  Gas 
Analysis.    Three  terms.     Fee,  each  course  £1  los. 

Practical  Classes, 

(1)  Junior.  (2)  Intermediate :  Qualitative  Analysis  of 
Inorganic  Substances  and  of  some  of  the  more  common 
Organic  Substances.  (3)  Revision  Class.  (4)  Senior : 
Pradical  Organic  (Advanced  Medical  Class).  (5)  Pradical 
Exercises  on  Technology,  Pharmaceutical  Chemistry, 
Saitanry  subjeds.  Examination  of  Water  and  Air,  of 
Animal  Secretions,  Urinary  Deposits,  Calculi,  and 
Poisons.  (6)  Quantitative  Class  :  Course  arranged  to 
suit  the  requirements  of  the  London  University  B.Sc. 
Examinations,  Pass  and  Honours,  and  for  Intermediate 
M.B.  Honours. 

Chemical  Laboratory. 

The  Chemical  Laboratories  provide  accommodation  for 
every  kind  of  chemical  and  metallurgical  work. 

The  William  Gossage  Laboratory,  opened  in  1897,  ^°^' 
sists  of  a  large  and  well-fitted  general  Laboratory  for 
advanced  Students,  a  new  gas  analysis  room,  an  addi- 
tional ledure-room  for  Metallurgy  and  other  classes,  and 
an  addition  to  the  Research  Laboratory.  New  stores  for 
students'  apparatus  and  chemicals  have  also  been  built 
and  placed  in  charge  of  a  skilled  dealer. 

Students  desirous  of  gaining  a  thorough  theoretical  and 
pradical  acquaintance  with  Technical  Chemistry,  or  who 
intend  to  adopt  Chemical  work  as  a  profession,  must 
devote  three  or  four  years  to  special  study,  for  which  a  full 
curriculum  is  provided. 

Table  of  Fees. 

One  Term,  Three  Terms, 

t'er  Week.                        Three  Months.  One  Session. 

One  day £4  £7 

Two  days 6  10 

Three  days 8  13 

Four  days g  1610s. 

Whole  week 10  los.  21 

Pharmaceutical  Course  (see  special  syllabus). 

Technological  Curriculum. 

Preliminary  Year. — Chemistry,  the  Elementary  Course. 
Pradical  Classes  i  and  2.  Mathematics,  or  Mechanics, 
or  Physics.  Elementary  Engineering,  Drawing,  and 
Design  (in  this  or  one  of  the  following  years).  German. 
Or,  the  Vidoria  Preliminary  Course  and  Examination 
may  be  taken. 

First  Year. — Chemistry — Courses  A  and  B  ;  Chemical 
Laboratory  three  days  per  week ;  Pradical  Organic 
Class  during  the  Summer  Term  ;  Technological  Che- 
mistry, Course  F.  Physics,  with  laboratory  work,  one 
day  per  week.  Mathematics  (intermediate).  German. 
Engineering,  First  Year  Course,  Autumn  and  Lent  Terms. 
Intermediate  B.Sc.  Examination  may  be  passed. 

Second  Year. — Chemistry,  Ledure  Course  C,  on  Organic 
Chemistry,  Ledure  Course  E  or  D,  Technological  Chemis- 
try, Course  F,  on  Metallurgy.  Chemical  Laboratory, 
four  days  per  week.  Engineering  or  Physics  (Ad- 
vanced). The  Final  Examination  for  the  Vidoria  B.Sc, 
or  the  Intermediate  Examination  of  the  Institute  of 
Chemistry,  may  be  taken* 


Third  ^ear. — Courses  D,  F,  and  C.  Any  other 
Courses  omitted  in  a  previous  year.  Laboratory,  five 
days  per  week.  Students  may  finally  choose  a  special 
subjed  either  of  research  or  of  applied  Chemistry. 
The  Final  Examination  for  the  Associateship  of  the 
Institute  of  Chemistry  of  Great  Britain  and  Ireland  may 
be  taken.  Three  years  study  after  passing  the  Preli- 
minary Examination  of  Vidoria  University  are  required 
for  the  B.Sc.  Degree  in  the  Honours  School  of  Chemistry. 

The  Sheridan  Muspratt  Chemical  Scholarship  of  ;£'50 
per  annum,  tenable  for  two  years,  will  be  competed  for  in 
December,  1897,  on  an  Examination  in  subjeds  which  are 
included  in  the  first  two  years  of  the  above  curriculum. 
Other  Scholarships,  Entrance  Scholarships,  and  Free 
Studentships  are  also  available  to  Students. 
Evening  Classes, 

Classes,  including  laboratory  work,  will  be  held  on 
Chemistry,  Metallurgy,  and  on  Analysis  of  Gases. 

The  Prospedus  containing  full  particulars  may  be 
obtained  from  the  Registrar,  University  College,  Liverpool. 

DURHAM     COLLEGE    OF    SCIENCE, 
NEWCASTLE-ON-TYNE. 

Professor  of  Chemistry — P.  Phillips  Bedson,  M.A., 
D.Sc,  F.I.C.,  F.C.S. 

Lecturer  in  Chemistry — Saville  Shaw,  M.Sc,  F.C.S. 

Lecturer  in  Agricultural  Chemistry — R.  Greig  Smith, 
M.Sc,  F.C.S. 

Assistant  Lecturer  and  Demonstrator— F.  C.  Garrett, 
M.Sc,  F.C.S. 

The  Session  will  commence  on  September  27th,  1897. 

1.  General  Course.  —  This  Course  of  Ledures  will 
extend  over  the  three  terms  of  the  Session,  and  is 
intended  to  serve  as  an  introdudion  to  the  Science. 
The  Ledures  will  be  of  an  elementary  charader,  and 
whilst  framed  to  meet  the  requirements  of  First  Year 
Students  will  also  be  serviceable  to  such  as  intend  pursuing 
Chemistry  in  its  various  applications  in  the  arts  and 
manufadures,  as,  for  instance.  Brewing,  Metallurgy,  the 
Manufadure  of  Soda,  Soap,  Glass,  &c  The  subjeds 
treated  will  include  an  exposition  of  the  Principles  of 
Chemistry,  and  a  description  of  the  preparation  and 
properties  of  the  chief  Elementary  Substances,  both 
metallic  and  non-metallic,  and  their  more  important 
native  and  artificial  compounds.  A  sedion  of  this  Course 
will  be  devoted  to  an  outline  of  Organic  Chemistry.  The 
class  will  meet  on  Mondays,  Wednesdays,  and  Fridays, 
at  II  a.m.,  and  will  commence  on  Wednesday,  Odober 
6th.     Fee,  £3  los.  for  the  Session. 

2.  Advanced  Course. — Inorganic  Chemistry,  Tuesdays 

3  to  4  p.m.,  during  the  Session.     Fee,  £2 ;  or  for  students 
taking  Organic  Chemistry,  £1. 

3.  Organic  Chemistry. — A  Course  of  Ledures  will  be 
given  throughout  the  Session,  the  subjeft  of  which  will  be 
theChemistry  of  the  Carbon  Compounds  and  an  introduc- 
tion to  Chemical  Theory.  This  class  will  meet  on 
Tuesdays  and  Thursdays,  at  11  a.m.,  and  Fridays  3  to 

4  p.m.,  and  will  commence  on  Thursday,  Odober  7th4 
Fee,  ;^3  los.  for  the  Session. 

Advanced  Classes  will  be  formed  for  the  study  of 
Inorganic,  Organic,  and  Theoretical  Chemistry.  Fee  for 
the  course,  ;^3  los. 

A  Ledure  Course  in  Analytical  Chemistry  will  be  given 
on  Mondays,  at  3  p.m. 

Metdllurgy  and  Assaying. — -Ledurer,  Saville  Shaw, 
M.Sc,  F.C.S.  A  Metallurgical  Laboratory  is  provided,  in 
which  instrudion  is  given  in  the  ordinary  processes  of 
Dry  Assaying,  and  in  the  preparation  and  analysis  of 
Alloys,  &c.     Fee  as  for  Chemical  Laboratory, 

Agricultural  Chemistry. — The  instrudion  in  this  branch 
of  Chemistry  will  consist  of  a  series  of  Ledures  and  df 
special  pradical  work  in  the  Chemical  Laboratory. 
Students  will  be  expeded  to  have  a  knowledge  of  Ele- 
mentary Chemistry,  such  as  may  be  obtained  by  attending 
the  General  Course. 

The  Ledure    Course  in  AgriculturiU    Chemistry  is 


130 


Schools  oj  Chemistry, 


arranged  for  two  days  a  week  throughout  the  Session. 
Fee,  ^3  lo. 

Practical  Chemistry. — The  Laboratory  is  open  from 
lo  a.m.  to  I  p.m.,  and  from  2  to  5  p.m.,  except  on  Satur- 
days, when  it  closes  at  i  p.m.  Laboratory  Fees. — Students 
working  two  days,  £2  los.  per  term,  £6  per  session ;  one 
day  per  week,  ;^i  los.  per  term,  ;^3  los.  per  session. 

Courses  of  Study. — Students  will  be  divided  into  two 
classes: — (i)  Regular,  or  Matriculated  Students,  who 
are  also  Members  of  the  University  of  Durham  ;  and 
(2)  Non-Matriculated  Students.  Regular  Students  will  be 
required  to  follow  such  a  course  of  study  in  the  subjedls 
professed  in  the  College  as  will  enable  them  to  pass  the 
Examinations  for  the  title  of  Associate  in  Physical  Science 
of  the  University  of  Durham.  Non-Matriculated  Students 
will  attend  such  classes  as  they  may  seleft.  Every  can- 
didate for  admission  as  a  matriculated  student  must  pass 
an  examination  on  entrance,  in  reading,  writing  from 
dictation,  English  or  Latin  Grammar,  arithmetic 
(including  decimals),  and  geography.  Registered  students 
in  medicine  are  exempted  from  this  examination,  or  stu- 
dents who  produce  a  certificate  of  having  passed  either 
of  the  two  following  examinations : — 

1.  Durham  Examination  for  certificate  of  proficiency 
in  General  Education,  held  in  March  and  September. 

2.  Durham  Examination  for  Students  in  Arts  in  their 
first  year,  or  any  examination  of  a  similar  nature  that  may 
be  accepted  by  the  Council. 

Associateship  in  Physical  Science. — Every  candidate  for 
the  Associateship  in  Physical  Science  will  be  required  to 
satisfy  the  examiners  in — Mathematics,  Physics,  Che- 
mistry, and  either  Geology  or  Natural  History — in  an 
examination  to  be  held  at  the  end  of  the  candidate's  first 
year.  Associates  in  Science  are  admissible  one  year  after 
obtaining  the  title  of  Associate  to  examination  for  the 
degree  of  Bachelor  of  Science  of  the  University  of  Durham, 
^  Exhibitions. — Three  Exhibitions  of  the  value  of  £25, 
;f  15,  and  £10  respectively  will  be  awarded  in  Odtober  next 
to  Candidates  desirous  of  attending  the  first  year  course  of 
study  in  the  College. 

The  examination  will  be  held  at  the  College,  and  wil 
commence  on  Wednesday,  September  29th. 

Evening  Lectures. — Courses  of  Evening  Leflures  will 
be  given,  with  a  Pradtical  Class  for  Laboratory  instrudion. 

Two  Exhibitions  of  £^15  each  will  be  awarded  at  the  next 
examination  of  "  Persons  not  members  of  the  University," 
which  will  be  held  at  Durham  in  March  next. 

Several  other  valuable  Scholarships  are  available  for 
students. 

OWENS  COLLEGE, 
VICTORIA  UNIVERSITY,   MANCHESTER. 

Professor  and  Director  oj  the  Chemical  Laboratory — 
Harold  B.  Dixon,  M.A.,  F.R.S. 

Professor  of  Organic  Chemistry — W.  H.  Perkin,Ph.D., 
F.R.S. 

Demonstrators  and  Assistant  Lecturers — George  H. 
Bailey,  D.Sc,  Ph.D.  ;  Arthur  Harden.  M.Sc,  Ph.D. ;  P. 
J.  Hartog,  B.Sc.  ;  and  E.  Haworth,  M.Sc. 

Lecturer  in  Technical  Organic  Chemistry — Jocelyn  F. 
Thorpe,  Ph.D. 

Assistant  Lecturer  in  Metallurgy — J.  Crowther. 

The  Session  begins  on  Oftober  5,  1897,  ^"<^  ^^^  0° 
July  2,  1898. 

The  instruftion   is   given   by   means   of  Experimental 
Leftures  and  Tutorial  Classes.     The  Chemical  Classes 
form  part  of  the  Courses  for  Chemistry  in  the  University. 
Chemistry  Lecture  Courses. 

General  Chemistry  Course. — Tuesdays,  Thursdays,  and 
Saturdays,  at  g.sc),  during  the  two  Winter  Terms. 

Introduction  to  Organic  Chemistry. — Wednesdays  and 
Fridays,  at  9.30,  during  Lent  Term. 

Th6se  courses  are  intended  for  Medical  Students  and 
others  beginning  the  study  of  chemistry. 

First  Year  Honours  Course. — Mondays,  Wednesdays, 
and  Fridays,  u.30  a.m.,  during  the  two  Winter  ^Terras. 
The  NoQ-Metals. 


f  Chemical  News, 
I     Sept.  10, 1897. 

Second  Year  Honours  Course. — Mondays,  Wednesdays, 
Fridays,  3.30  p.m.,  during  the  two  Winter  Terms.  The 
Metals. 

Third  Year  Honours  Course. — At  times  to  be  arranged. 
Physical  Chemistry. 

Organic  Chemistry  (General). — Mondays  and  Fridays, 
9  30,  during  two  Winter  Terms. 

Organic  Chemistry  {Advanced). — Tuesdays  and  Thurs- 
days, 9.30,  during  the  two  Winter  Terms. 

History  of  Chemistry  and  Chemical  Philosophy .  — 
Wednesdays,  9.30,  during  the  Session. 

Metallurgy. — Lectures  :  The  Metallurgy  of  Copper, 
Lead,  Silver,  Gold,  and  the  Metallurgy  of  Iron  and  Steel 
will  be  given  in  alternate  years.  Practical :  The  Labora- 
tory will  be  open  to  students  every  day. 

The  Chemical  Laboratories  are  open  daily  from  g.30. 
a.m.  to  4.30  p.m.,  except  on  Saturdays,  when  they  are 
closed  at  12.30  p.m. 

Courses  for  B.Sc.  Degree.  —  To  qualify  for  the  B.Sc. 
Degree  of  the  Vi(5loria  University,  Students  have  to 
attend  a  prescribed  course  of  study  extending  over  three 
years,  and  to  pass  the  Preliminary  Examination  of  the 
University  either  on  entering  or  at  the  end  of  a  year's 
Course. 

The  Honours  Course  of  Chemistry  is  as  follows : — 
First  year :  First  year  Honours  Ledures ;  Mathematics 
(3  hours  a  week) ;  Physics  (3  hours  a  week) ;  a  Language 
(3  hours  a  week)  ;  Chemical  Laboratory  (3  days  per 
week).  Second  year :  Second  year  Honours  Ledtures  ; 
General  Organic  Ledlures  ;  Applied  Chemistry  Ledtures  ; 
Physics  Laboratory  (i  day  per  week) ;  Chemical  Labora- 
tory (3  days  per  week).  Third  year:  Third  year  Honours 
Ledures;  Honours  Organic  Ledtures;  History  of  Che- 
mistry Ledtures ;  Chemical  Laboratory  (5  days  per  week). 

The  following  awards  are  made  to  successful  Students 
in  the  Honours  Examination  : — A  University  Scholarship 
of  £5°  ;  ^  Mercer  Scholarship  of  £25.  A  University 
Fellowship  of  £^150  is  awarded  annually  among  the 
Graduates  in  Science  for  the  encouragement  of  Research. 
Among  the  College  Scholarships  open  to  Chemical 
Students  are  the  Dalton  Chemical  Scholarship,  ;^5o  per 
annum  for  two  years;  the  1851  Exhibition  Scholarship ; 
the  John  Buckley  Scholarship;  &c. 

Applied  Chemistry. 

First  Course. — Sulphuric  Acid  and  Alkali  Manufadtures* 
General  Principles  of  Chemical  Engineering. 

Second  Course. — The  Chemistry  of  Fuel.  The  Manu* 
fadture  of  Illuminating  Gas  and  Gaseous  Fuel. 

Third  Course. — Natural  and  Artificial  Dye-stuffst  and 
the  Principles  of  Dyeing  and  Printing. 

Certificates  in  Applied  Chemistry. 

The  course  extends  over  a  period  of  three  years,  and 
comprises  systematic  instrudtion  by  means  of  ledtures  and 
pradtical  work  in  the  laboratories. 

Before  admission  to  the  first  year's  course  students  are 
required  to  give  such  evidence  of  elementary  knowledge 
of  Mathematics  and  Chemistry  as  shall  be  considered 
satisfactory  by  the  Senate. 

The  first  year's  course  is  the  same  for  all  students 
working  for  the  certificate. 

In  the  second  and  third  years  a  choice  may  be  made 
between  Inorganic  and  Organic  Chemistry.  By  this 
division  of  the  subjedt  a  student  wishing  to  apply  himself 
specially  to  the  inorganic  side  of  the  science,  may  attend 
during  his  second  year  the  Honours  course  in  Metals,  and 
courses  on  Geology  or  Mineralogy,  and  during  his  third 
year,  courses  on  Metallurgy  and  on  Geology  or 
Mineralogy;  while  a  student  wishing  to  apply  himself 
specially  to  the  organic  side  of  the  science,  may  attend 
during  his  second  and  third  years  the  Courses  on  Organic 
Chemistry,  and  courses  on  the  Coal  Tar  Colours  and  on 
Dyeing  and  Printing. 

Part  of  the  Laboratory  pradtice  in  the  second  and  third 
years  will  consist  in  the  examination  and  analysis  of  raw 
materials,  produi^  from  chemical  works,  &c.,  in  connedion 


Ohbmical  Nbws,  ) 

Sept.  10,  1897.      I 


Schools  of  Chemistry. 


131 


with  the  special  courses  of  ledures  on  Applied  Chemistry. 
In  the  Chemistry  and  Physical  laboratories  the  pradlical 
work  in  the  second  year  will  be  arranged  in  accordance 
with  the  branch  of  Chemistry  seledled  by  the  candidate. 

In  the  third  year  the  student,  if  sufficiently  advanced, 
will  be  set  to  work  on  some  analytical  process  or  problem 
in  Applied  Chemistry,  under  the  dired^ion  of  the  teaching 
sta£f. 

UNIVERSITY     COLLEGE,     NOTTINGHAM. 

Departments  of  Chemistry  and  Metallurgy. 

Professor  of  Chemistry — Frank  Clowes,  D.Sc.  Lond., 
F.I.C. 

Demonstrators  of  Chemistry — J.  J.  Sudborough,  D.Sc, 
Ph.D.,  F.LC;  R.  M.  Caven,  B.Sc,  F.I.C. ;  and  Q.  Mel- 
land,  B.Sc,  A.R.S.M.,  F.I.C. 

The  Classes  of  the  College  are  open  to  students  of  both 
sexes  above  sixteen  years  of  age. 

The  Session  commences  on  Odlober  nth. 

Lecture  Courses. — The  Chemistry  Day  Ledlures  extend 
over  three  years.  In  the  first  year  a  student  enters  for 
the  course  on  Non-Metals  for  the  first  two  terms  and  for 
Elementary  Organic  Chemistry  in  the  third  term.  In  his 
second  year  he  takes  the  course  on  Metals  for  the  first  two 
terms.  In  his  third  year  he  attends  a  course  on  Advanced 
Organic  Chemistry  or  Applied  Chemistry.  Fee  for  Day 
Ledlures  and  Classes  :  Non-Metals  or  Metals  42s.  ; 
Organic  Chemistry  (one  term)  21s. ;  Advanced  Organic 
Chemistry,  21s.  per  term. 

Demonstrations  and  Ledlures  on  Analytical  Chemistry 
will  be  given  in  the  day  and  evening,  and  shiuld  be 
attended  by  all  students. 

A  Chemical  Calculation  Class  is  also  held.  Fee  per 
Term,  5s. 

Students  may  qualify  themselves  by  attendance  at  these 
leftures  and  classes  for  the  Examinations  of  the  Univer- 
sities of  London,  Cambridge,  or  Oxford,  and  for  the 
Medical  Examinations  of  the  Royal  College  of  Surgeons 
and  of  the  Universities  of  Cambridge  and  Edinburgh  : 
they  may  also  obtain  instrudlion  in  Chemistry  for  technical 
or  other  purposes,  and  can  enter  for  a  full  Chemical 
Engineering  Curriculum.  Special  attention  is  given  to 
the  requirements  of  candidates  for  the  Associateship  of 
the  Institute  of  Chemistry. 

Practical  Chemistry  and  Metallurgy. — The  Chemical 
and  Metallurgical  laboratories  are  open  every  day  from  9 
to  5,  except  on  Saturday,  when  the  hours  are  from  9  to 
I  ;  also  on  Tuesday  and  Thursday  evenings  from  7  to  9. 
Each  Student  works  independently  of  other  Students  at  a 
course  recommended  by  the  Professor.  Instrudtion  is  given 
in  general  Chemical  Manipulation,  in  Qualitative  and 
Quantitative  Analysis,  and  in  the  methods  of  Original 
Chemical  Investioation  and  Research  ;  Students  are  also 
enabled  to  work  out  the  applications  of  Chemistry  to 
Pharmacy,  Metallurgy,  Dyeing,  Agriculture,  Brewing, 
Iron  and  Steel,  Tanning,  and  other  Manufacturing  Pro- 
cesses. Fees  for  day  students :  For  one  term,  £y ;  for 
the  session,  ;^i8  ;  for  six  hours  weekly  40s.,  and  5s.  extra 
for  each  additional  hour  per  week.  For  evening  students, 
10s.  for  two  hours  per  week,  three  hours  15s.,  four  hours 
20s.,  six  hours  30s.,  per  term. 

Courses  of  Technical  Chemistry  Lectures  are  also  given 
on  Engineering,  Dyeing  and  Bleaching,  Brewing,  Plumb- 
ing, Bread-making,  Gas  Manufafture,  and  on  other  pro- 
Cesses  of  applied  Chemistry. 

Pharmaceutical  Students  can  at  all  times  work  in  the 
Chemical  Laboratory,  taking  work  suitable  for  the  pre- 
paration for  the  Minor  Examinations.  Special  ledlurea 
will  also  be  given  in  Chemistry  and  Materia  Medica. 

Government  Lectures  and  Classes. — Evening  Ledures 
and  Laboratory  instrudlion  will  be  given  by  the  Demon- 
rators  of  Chemistry  to  Students  who  intend  to  present 
themselves  for  Examination  by  the  Government  Science 
and  Art  Department  in  May  next.  Inorganic,  organic, 
and  pradlical  chemistry,  agricultural  chemistry,  and 
metallurgy  will  be  taught  in  the  elementary,  advanced,  and 


honours  stages,  each  of  which  commences  at  the  beginning 
of  the  College  Session  in  September.  Fee  for  each  Ledture 
Course,  5s. ;  for  each  Laboratory  Course,  los. 

An  Agricultural  Course  of  instrudlion,  extending  over 
two  years,  is  now  organised  under  the  general  diredlion 
of  Mr.  M.  J.  R.  Dunstan,  M.A.,  F.R.S.E.  It  includes 
instrudlion  in  chemistry,  botany,  agriculture,  with  pradtical 
work  on  experimental  fields,  dairy  work,  farriery,  land 
surveying,  &c.  The  instruftion  is  designed  for  those  who 
intend  to  become  farmers,  bailiffs,  land  agents,  or 
colonists,  and  may  be  extended  to  a  third  year  if  desired. 
Fee,  £15  per  annum  for  residents  in  Notts,  £20  to 
residents  in  other  counties. 

Full  information  concerning  all  College  Classes  is  given 
in  the  College  Prospedlus,  price  one  penny. 

UNIVERSITY  COLLEGE,  SHEFFIELD. 

Professor  of  Chemistry — W.  Carleton  Williams,  B.Sc, 
F.C.S. 

Demonstrators  and  Assistant  Lecturers  —  G.  Young, 
Ph.D.,  and  L,  T.  O'Shea,  B  Sc,  F.C.S., 

The  Session  will  commence  on  October  6th. 

First  Coures. — Chemistry  of  the  Non-Metallic  Elements. 
Tuesday  and  Friday  from  10  to  11  a.m.     Fee,  £2  12s.  6d. 

Second  Cowrjif.— Chemistry  of  Metals.  Monday  and 
Thursday  from  10  to  11  a.m.     £2  its.  6d. 

Third  Course. — Inorganic  Chemistry,  Honours  Course^ 
Monday,  3.     Fee,  £1  lis.  6d. 

Organic  Chemistry. — Elementary:  Wednesdays,  10  to 
II  ;  fee,  15s.  Honours:  Tuesdays  and  Thursdays,  12  to 
I ;  fee,  £2  I2s.  6d.  Advanced  :  Thursdays,  4  to  5  ;  fee, 
;£'i  I  IS.  6d.  Special  Course :  Hours  to  be  arranged ;  £1  is. 
Chemistry  of  the  Colouring  Matters :  Fridays,  12  to  i  ; 
fee,  ;^i  IIS.  6d. 

Snort  Courses  of  Ledlures  are  also  given  by  L.  T. 
O'Shea  on  the  Chemistry  of  Coal  Mining,  and  on  Thermic 
Chemistry. 

A  Course  of  Ledlures  is  arranged  for  Medical  Students, 
with  a  special  class  in  Qualitative  Analysis. 

Laboratory. — Working  hours  to  be  arranged  between 
Professor  and  Students. 

Sessional  Fees  for  Day  Students  :  — Six  hours  per  wetk^ 
£S  5s.;  Nine,  ;f7;  Twelve,  ;^8  8s.;  Eighteen,  ;^ii  5s.: 
Twenty-four,  £'14  ;  Thirty-two,  £iy. 

Day  Students  may  not  enter  for  less  than  six  hours  a 
week.  Students  joining  the  Laboratory  at  Christmas 
will  be  charged  two-thirds  and  at  Easter  one-third  ot 
the  Fees  for  the  whole  Session. 

Fees  for  short  periods  (working  thirty-two  hours  per 
week)  : — For  one  month,  £3  3s.;  two  months,  ^5  5s. 

An  arrangement  has  been  entered  into  with  the  Science 
and  Art  Department,  South  Kensington,  which  will  enable 
Science  Teachers  to  work  in  the  Chemical  Laboratory  for 
three,  six,  or  twelve  hours  a  week  on  payment  of  one- 
quarter  of  the  usual  fee,  the  Department  being  willing 
to  pay  the  remainder  under  certain  conditions,  of  which 
full  information  may  be  obtained  on  application  to  the 
Registrar. 

Evening  Classes. — Ledlures,  Wednesday,  8  to  g.  Labo- 
ratory instruction,  Wednesday,  6  to  g,  and  another  series 
to  be  arranged  if  desired.  Sessional  Fee,  one  evening  jJer 
Week,  ;^i  los. ;  two,  30s.  ;  or  Ledlure  Class  and  Labora- 
tory,  on  Wednesday  evening,  £1  los.  Fee  for  one  term^ 
17s.  6d. 

UNIVERSITY  COLLEGE,  DUNDEE. 
University  of  St.  Andrews. 

Professor  of  Chemistry — James  Walker,  Ph.D.,  D.SCi 

Assistant  Lecturer — J.  S.  Lumsden,  Ph.D.,  B.Sc. 

Lecture  Assistant  and  Laboratory  Steward — J.  Foggie^ 
F.C.S. 

The  Winter  Session  begins  on  Odlober6th,  and  ends  on 
March  i6th.  The  Summer  Session  extends  from  the  middle 
of  April  to  the  end  of  June. 

The  First  Year's  Lecture  Course  on  Systematic  Che- 
mistry  is  given  daily  during   the  Winter  Session,  and 


132 


Schools  of  Chemistry, 


lOaBUICAL  NBW^t 

\    Sept.  10.  1807. 


embraces  the  Elements  of  Inorganic  and  of  Organic 
Chemistry. 

Advanced  Courses,  of  about  fifty  ledures  each,  will  be 
given  during  the  year  as  follows: — 

Organic  Chemistry ;  Inorganic  Chemistry,  including 
the  more  important  technological  applications;  Theo- 
retical and  Physical  Chemistry  ;  Bleaching  and  Dyeing, 
including  the  Chemistry  of  the  Textile  Fibres. 

Pradtical  Instrucftion  in  all  of  the  above  branches  will 
be  given  in  the  Laboratories  and  Dye-house.  Special 
facilities  are  afforded  to  Research  Students. 

The  Leftures  and  Laboratory  Practice  in  Chemistry  are  re- 
cognised by  the  Medical  Colleges  of  London  and  Edinburgh. 
The  Courses  are  suitable  for  the  degrees  of  the  University  of 
London  and  for  the  Civil  Service  appointments,  and  will 
also  satisfy  the  requirements  of  Students  in  Pharmacy, 
and  of  Students  who  intend  to  become  candidates  for  the 
Associateship  of  the  Institute  of  Chemistryo  as  far  as 
qualification  in  Chemistry  is  concerned. 

UNIVERSITY    OF     EDINBURGH. 
Department  of  Chemistry. 

Professor— k\&TS..  Crum  Brown,  M.D.,  D.Sc,  F.R.S. 

Lecturers — L.  Dobbin,  Ph.D.,  and    H.  Marshall,  D.Sc. 

Assistants— "^ .  W.  Taylor,  M.A.,  B.Sc,  and  J.  P. 
Longstaff. 

The  working  terms  are — Winter  Session,  from  middle 
of  Odlober  to  middle  of  March  ;  Summer  Session,  from 
beginning  of  May  to  end  of  July. 

Lecture  Courses. — During  the  Winter  Session  a  General 
Course  of  Chemistry  for  medical  and  science  students  is 
given  by  the  Professor.  The  class  meets  daily  ;  fee  £^  4s. 
An  Advanced  Course  of  twenty- five  leftures  is  also  given 
in  the  Winter  Session  ;  fee,  £2  2S.  A  class  on  Organic 
Chemistry  is  held  in  summer  ;  fee,  £2  2s.  There  is  also 
a  class  on  Chemical  Theory,  by  Dr.  Dobbin  ;  fee  £1  is.  : 
and  a  class  on  Mineralogy  and  Crystallography,  by  Dr. 
Marshall ;  fee,  £2  2s.  All  these  Lectures,  except  the 
General  Course,  are  now  open  to  women. 

In  addition  to  the  above,  Ledture  Courses  are  given  by 
the  Assistants  on  some  particular  branch  of  Organic 
and  Inorganic  Chemistry.  These  Ledlures  are  free  to 
Laboratory  Students. 

Tutorial  classes  are  held  in  connection  with  the 
General  Course. 

Laboratories. — Pra(^ical  classes  for  Medical  Students 
meet  daily  during  the  latter  part  of  the  Winter  Session 
and  in  the  Summer  Session.  (Fee,  ;^3  3s.)  The  labora- 
tories for  analytical  and  advanced  pradical  work  are 
open  daily  from  9.30  till  4.30.  (Fees :  Whole  Day — Winter 
Session,  ;^io  los.,  Odt.-Dec,  Jan. -March;  or  Summer 
Session,  £$  5s.  Half  Day — Winter  Session,  £6  6s.,  Odt.- 
Dec,  Jan.-March;  or  Summer  Session,  ;£"3  38.  Preference 
wili  be  given  to  students  in  the  above  order.  Students 
who  are  not  Matriculated  may  attend  the  Chemical 
Laboratory  on  payment  of  the  entrance  fee  of  5s.  in  addi- 
tion to  the  Laboratory  fees.  Full  Courses  of  instrudtion 
are  given  in  Analytical,  Pra(5tical  Organic  and  Inorganic 
Chemistry,  including  Gas  Analysis,  Metallurgy,  and 
Assaying.  Facilities  are  afforded  to  advanced  students 
who  desire  to  undertake  chemical  investigations. 

Various  prizes  and  scholarships  are  attached  to  the 
laboratory  and  general  class. 

Graduation. — Two  Degrees  in  Pure  Science  are  con- 
ferred, viz..  Bachelor  of  Science  (B.Sc.)  and  Do(Stor  of 
Science  (D.Sc). 

Candidates  for  Degrees  in  Science,  if  not  graduates  (by 
examination)  in  Arts  in  one  of  the  Universities  of  the 
United  Kingdom  or  in  a  Colonial  or  Foreign  University 
recognised  for  the  purpose  by  the  University  Court,  must 
pass  a  preliminary  examination  in  (i)  English  ;  (2)  Latin, 
Greek,  French,  or  German;  (3)  Mathematics;  (4)  One  of 
the  languages  Latin,  Greek,  French,  German,  Italian,  not 
already  taken  under  (2),  or  Dynamics.  In  the  case  of  a 
student  whose  native  language  is  other  than  European, 
the  SenatUB  may)  at  the  Preliminary  Examinatioa,  accept 


such  language  as  a  substitute  for  a  modern  European 
language.  The  Senatus  may  also  in  such  a  case  accept 
as  an  alternative  to  Latin  or  Greek  any  other  classical 
languages,  such  as  Sanscrit  or  Arabic. 

The  First  B.Sc.  Examination  embraces  Mathematics, 
or  Biology  {i.e.,  Zoology  and  Botany),  Natural  Philosophy, 
and  Chemistry.  The  Second  B.Sc.  Examination  includes 
any  three  or  more  of  the  following  subjedts : — Mathe- 
matics, Natural  Philosophy,  Astronomy,  Chemistry, 
Human  Anatomy,  including  Anthropology,  Physiology, 
Geology,  including  Mineralogy,  Zoology,  including  Com- 
parative Anatomy,  and  Botany,  including  Vegetable  Phy- 
siology.  Chemistry  in  this  examination  embraces  Inor- 
ganic, including  Mineralogical,  Chemistry  ;  Organic  Che- 
mistry  ;  Physical  Chemistry  ;  Chemical  Crystallography  ; 
History  of  Chemistry.  Pradical  Examination  : — Complex 
Qualitative  Analysis;  Quantitative  Analysis,  including 
Gas  Analysis  and  Organic  Analysis;  Preparation  of  Pure 
Substances,  organic  and  inorganic  ;  Physico-chemical 
Measurements. 

In  the  Courses  for  Final  Examination  in  Pure  Science, 
two  written  papers  are  set  in  each  subjedt  professed,  the 
second  of  a  higher  standard  than  the  first.  Candidates 
must  pass  the  first  sedtion  in  all,  and  the  second  section  in 
at  least  one,  of  the  subjedts  professed;  the  same  regula- 
tions apply  also  to  the  Pradlical  and  Oral  Examinations. 

A  candidate  for  the  D.Sc.  Degree  must  submit  a  thesis 
on  original  work  done  by  him.  The  Thesis  must  be 
approved  before  the  candidate  is  allowed  to  proceed  to 
Examination.  The  candidate  in  Chemistry  may  be  re- 
quired to  pass  a  searching  examination  in  one  of  the 
following  branches : — (i)  The  Chemistry  and  Chemical 
Technology  of  Inorganic  Bodies,  including  Metallurgy  ; 
(2)  Organic  Chemistry  ;  and  to  show  a  thorough  pradlical 
acquaintance  with  chemical  analysis  in  all  its  branches, 
and  with  the  preparation  of  pure  substances. 

HERIOT-WATT    COLLEGE,    EDINBURGH. 

Professor— ]ohn  Gibson,  Ph.D.,  F.R.S.E. 

Assistant  Professor — (Vacant). 

Demonstrators — Andrew  F.  King  and  James  B.  Shand. 

The  Session  begins  Odtober  5th,  1897. 

The  curriculum  of  this  College  comprises  both  Day 
and  Evening  Classes,  each  department  providing  the 
higher  general  and  technical  education. 

Chemistry. — The  first  course  for  day  students  is  a  com- 
bination of  Ledtures  with  Laboratory  instrudtion.  In  the 
Ledtures  some  of  the  more  important  elements  and  their 
compounds  are  discussed  in  detail,  so  as  to  lead  to  a 
knowledge  of  the  general  laws  of  chemical  adtion.  Other 
important  elements  are  treated  in  less  detail,  and  the 
relations  and  classification  of  the  elements  generally  are 
broadly  indicated.  In  the  Laboratory  each  student  will 
receive  instrudtion  in  general  chemical  manipulation,  in 
accurate  weighing,  volumetric  measurements,  and  in 
some  of  the  simpler  methods  of  quantitative  analysis. 
After  making  a  series  of  simple  preparations,  he  works 
through  a  number  of  experimental  exercises  illustrating 
chemical  combination,  oxidation,  redudtion,  and  double 
decomposition.  These  exercises  are  followed  by  in- 
strudtion in  simple  methods  of  qualitative  analysis,  especial 
attention  being  given  to  dry  way  testing  and  the  use  of 
the  spedtroscope.  Students  attending  a  further  course 
may  take  up  the  study  of  systematic  analysis,  and 
extend  the  knowledge  they  have  gained  of  quantitative 
analysis  by  exercises  in  gravimetric,  volumetric,  and 
eledtrolyttc  methods.  Ultimately  they  may  make  a  spe* 
ciality  of  any  branch  of  the  subjedt  which  may  be  most 
necessary  for  their  future  work.  Great  attention  has 
been  paid  to  the  thorough  equipment  of  Advanced 
Laboratories,  and  special  facilities  are  given  to  advanced 
students  who  may  wish  to  engage  in  any  class  of  Ke* 
search  (Inorganic  or  Organic)  whether  of  a  purely  che 
mical  or  of  a  technical  nature. 

The  teaching  in  the  Evening  Classes  is  based  on  the 
Syllabus  of  the  Science  and  Art  Department,  and  in- 


Cbbmical  Nbws.  I 

Sept.  10,  i8q7.     , 


Schools  of  Chemistry. 


133 


eludes  Elementary,  Advanced,  and  Honours  Courses  in 
Theoretical  and  Pradtical  Inorganic  and  Organic  Che- 
mistry. 

GLASGOW    AND     WEST    OF     SCOTLAND 
TECHNICAL     COLLEGE. 

Professor  of  Chemistry — G.  G.  Henderson,  D.Sc,  M.A. 

Professor  of  Technical  Chemistry — E.  J.  Mills,  D.Sc, 
F.R.S. 

Agricultural  Chemistry  Lecturer — John  W,  Paterson, 
B.Sc,  Ph.D. 

Professor  of  Metallurgy — A.  Humboldt  Sexton,  F.C.S., 
F.R.S.E. 

The  main  objedts  of  this  College  are  to  afford  a 
suitable  education  to  those  who  wish  to  qualify  themselves 
for  following  an  industrial  profession  or  trade,  and  to 
train  teachers  for  technical  schools.  It  was  founded  by 
an  Order  in  Council,  dated  26th  November,  1886, 
according  to  a  scheme  framed  by  the  Commissioners 
appointed  under  the  provisions  of  the  Educational 
Endowments  (Scotland)  Ad:,  whereby  Anderson's  College, 
the  Young  Chair  of  Technical  Chemistry  in  connexion 
with  Anderson's  College,  the  College  of  Science  and  Arts, 
Allan's  Glen's  Institution,  and  the  Atkinson  Institution 
were  placed  under  the  management  of  one  governing 
body. 

The  Diploma  of  the  College  is  awarded  to  Day  Students 
who  have  attended  prescribed  courses  of  instrudion  and 
passed  the  necessary  examinations.  The  ordinary  courses 
extend  over  three  years,  but  arrangements  are  made  for 
advanced  students  continuing  their  studies  in  special 
departments. 

Complete  courses  of  instruAion  in  Metallurgy  and 
Mining  will  be  given  in  both  Day  and  Evening  Classes. 

Copies  of  the  Calendar  for  1896-97  may  be  had  from  Mr. 
John  Young,  B.Sc,  the  Secretary,  38,  Bath  Street, 
Glasgow,  price  by  post,  is.  4d. 

UNIVERSITY    OF    ST.    ANDREWS. 
United  College  of  St.  Leonard  and  St.  Salvator. 

Professor  of  Chemistry  — T.  Purdie,  B.Sc,  Ph.D., 
F.R.S. 

The  Session  begins  on  Odlober  6th.  A  Competitive 
Examination,  open  to  intending  Students  of  Arts  or 
Science,  for  about  fifty  Entrance  Bursaries,  ranging  in 
value  from  £^0  to  ;^io  each  per  annum,  will  be  held  on 
September  25th  and  following  days.  About  thirty  of 
these  Bursaries  are  restrided  to  Men  and  twenty  to 
Women,  the  latter  being  intended  for  women  who  at  the 
conclusion  of  their  Arts  or  Science  Course  will  proceed 
to  Medicine.  Two  are  open  to  students  of  either  sex. 
Two  Scholarships  of  £^100  each,  tenable  for  one  year,  will 
be  open  for  competition  to  Graduates  of  Science  at  the 
close  of  Session  1897-98.  A  Hall  of  Residence  is 
provided  for  Women  Students.  Two  Degrees  in  Science 
are  conferred  by  the  University  of  St.  Andrews,  viz.. 
Bachelor  of  Science  (B.Sc.)  and  Dodlor  of  Science  (D.Sc), 
and  Chemistry  is  also  included  in  the  curriculum  for  the 
M.A.  Degree  ;  the  regulations  will  be  found  in  the 
'*  University  Calendar." 

Lecture  Courses. 

Two  distindl  Courses  of  Ledtures  are  given,  each  com- 
prising at  least  one  hundred  meetings  of  the  class. 

First  Yearns  Course. — This  Class  meets  at  11  o'clock 
on  five  days  in  the  week.  The  introdudlory  ledtures 
treat  of  the  Nature  of  Chemical  Adion,  the  Classification 
of  Substances  into  Elements  and  Compounds,  the  Phe- 
nomena of  Oxidation,  and  the  Composition  of  Air  and 
Water.  The  Laws  of  Chemical  Combination  and  the 
Atomic  Theory  are  next  discussed,  after  which  the  more 
commonly  occurring  elements  and  inorganic  compounds 
are  described  systematically.  Elementary  Organic  Che- 
mistry is  also  included  in  the  Course. 

The  chemistry  of  manufadures  is  referred  to  only 
cursorily  ;    special    attention,  on    the   other    hand,  is 


given  to  those  parts  of  the  science  which  are  of  general 
educational  value,  and  as  much  of  the  theory  of  chemistry 
is  introduced  as  is  compatible  with  elementary  treat- 
ment. The  Ledlures  are  supplemented  by  a  short  Course 
of  Laboratory  Pradice,  intended  to  illustrate  the  principles 
of  the  science. 

These  courses  of  instrudlion  are  intended  to  meet  the 
requirements  of  the  Arts'  Curriculum  ;  also  of  candidates 
for  the  First  B.Sc  Examination,  and  of  students  of 
medicine,  so  far  as  Theoretical  Chemistry  is  concerned. 

Second  Yearns  Course. — The  first  part  of  the  Course 
is  devoted  to  Organic  Chemistry,  and  the  second  part 
treats  of  the  General  Principles  and  Theory  of  Chemistry, 
and  of  more  advanced  Inorganic  Chemistry,  the  instruc- 
tion in  general  being  such  as  is  required  for  the  Second 
B.Sc.  Examination. 

Certificates  are  awarded  on  the  results  of  examinations, 
and  the  "  Forrester  Prize  "  of  about  ;£'io  is  awarded  to 
the  best  Student  of  the  year. 

Fee  for  the  Session,  for  each  Course,  £3  3s. 
Practical  Chemistry, 

The  Laboratory  is  open  daily  from  g  a.m.  to  4 
p.m.,  except  on  Saturdays,  when  it  is  closed  at  i 
p.m.  The  work  pursued  in  the  Laboratory  comprises  :  — 
(i)  The  performance  of  experiments  illustrative  of  the 
Principles  of  Inorganic  and  Organic  Chemistry  ;  (2) 
Qualitative  and  Quantitative  Analysis  ;  (3)  Original 
Investigation.  Each  student  pursues  an  independent 
course  of  study  under  the  supervision  of  the  Professor  or 
Demonstrator,  the  nature  of  the  work  varying  with  the 
proficiency  of  the  student  and  the  particular  obje(a  he 
may  have  in  view.  Suitable  courses  of  instrudlion  in 
Pradical  Chemistry  are  provided  for  candidates  for 
the  First  and  Second  B.Sc.  Examinations,  and  for 
Students  of  Medicine. 

The  fees  for  Pradtical  Chemistry  vary  according  to  the 
number  of  hours  taken  weekly.  A  certain  number  of 
working  places  in  the  Laboratory  will  be  available  with- 
out  fee  for  students  who  are  capable  of  undertaking 
original  investigation. 

QUEEN'S  COLLEGE,  BELFAST. 

Professor— E.  A.  Letts,  Ph.D.,  D.Sc,  F.R.S.E.,  &c. 

The  Session  commences  on  Tuesday,  Odtober  ig,  1897. 

I. — Chemistry. — The  ledures  are  delivered  at  3  p.m., 
on  the  first  five  days  of  each  week  until  the  beginning 
of  April,  and  on  three  days  of  each  week  after  May  ist, 
at  2  p.m.  The  course  is  divided  into  three  parts: — (i) 
Chemical  Philosophy ;  (2)  Inorganic  Chemistry ;  (3) 
Organic  Chemistry.     Fee,  £2. 

II. — Practical  Chemistry. — In  this  course  the  Students 
are  instrudled  in  the  general  methods  of  condudling 
Chemical  Analyses.     Fee,  £^. 

III. — Laboratory  Pupils. — The  Chemical  Laboratory 
is  open  from  November  until  the  end  of  March,  and  from 
May  ist  until  the  third  week  of  July,  on  the  first  five 
days  of  the  week,  from  10  a.m.  until  4  p.m.  Students  are 
admitted  as  working  pupils  on  payment  of  afeeof;£"5 
for  the  first  period,  or  of  £3  los.  for  the  second  period  (or 
for  a  single  term). 

Scholarships. — In  addition  to  various  Scholarships 
awarded  in  the  Faculties  of  Arts  and  Medicine  in  which 
Chemistry  forms  a  part  of  the  examination,  there  are  other 
valuable  Scholarships  awarded  specially  in  connedlion 
with  the  schools  of  Chemistry  and  Phj'sics. 

QUEEN'S  COLLEGE,  CORK. 

Professor — Augustus  Edward  Dixon,  M.D. 

Demonstrator — R.  E.  Doran,  F.C.S. 

The  College  Session  begins  on  Odtober  19th,  1897,  ^"^ 
ends  on  June  nth,  1898.  The  classes  are  open  to  male 
and  female  students. 

Systematic  Chemistry. — (t)  General  course  of  Inorganic 
Chemistry,  Elementary  Organic  Chemistry,  and  Chemical 
Philosophy. — Fee  for  each  Sessional  Course,  £2.    Each 


134 


Schools  of  Chemistry. 


1  Chemical  News, 
Sept.  10,  1897. 


subsequent  Course,  £1.  (2)  Advanced  Organic  Chemis- 
try, and  Chemical  Philosophy. 

Practical  Chemistry. — (i)  Two  ordinary  Courses  of 
Pradiical  Chemistry  will  be  held,  each  of  three  months' 
duration ;  one  commencing  on  January  3rd,  1898,  and 
adapted  to  the  requirements  of  Students  proceeding  to 
the  Examinations  of  the  Royal  University  of  Ireland;  the 
other  ending  about  the  last  week  in  June,  and  suitable  for 
Medical  Students  intending  to  present  themselves  for  the 
Examinations  of  other  Licensing  Bodies.  Fee  for  each 
Sessional  Course,  ;^3.  (a)  A  Course  for  Pharmaceutical 
Students  will  be  held  in  the  second  and  third  terms  ;  fee, 
:^5'     (3)  Special  Courses. 

The  Chemical  Laboratory  is  open  daily  from  10  to  4 
o'clock  (except  during  class  hours  and  on  Saturdays) 
under  the  Superintendence  of  the  Professor,  to  Students 
entering  for  special  courses  of  qualitative  and  quantitative 
analysis  ;  organic  chemistry  ;  or  for  the  purpose  of  original 
investigation. 

QUEEN'S  COLLEGE,  GALWAY. 

Professor— Mhed  Senier,  Ph.D.,  M.D.,  F.LC. 

Demonstrator — Hugh  Ryan,  B.A. 

The  College  Session  is  divided  into  three  terms.  The 
First  Term  extends  from  Odtober  rg  to  December  22,  the 
Second  Term  from  January  6  to  April  2,  and  the  Third 
Term  from  April  18  to  June  11. 

Chemistry  is  studied  by  attendance  at  Ledtures,  by 
work  in  the  Laboratories,  and  by  the  use  of  the  College 
Library.  The  Courses  in  the  several  faculties  are 
arranged  with  a  view  to  the  requirements  of  the  Royal 
University  of  Ireland,  but  are  adapted  also  to  those  of 
other  Universities  and  licensing  bodies. 

Lecture  Courses.  Faculty  of  Arts.  —  i.  Second  year's 
Course,  Inorganic  and  the  Elements  of  General  Che- 
mistry. 2.  Third  year's  Course,  Advanced  Organic 
Chemistry.  3.  Fourth  year's  Post-Graduate  Course,  Ad- 
vanced General  Inorganic  and  Organic  Chemistry.  Faculty 
of  Medicine.  —  First  year's  Course,  Inorganic  and  Ele- 
mentary Organic  Chemistry.  School  of  Engineering. — 
First  year's  Course,  Inorganic  Chemistry. 

Laboratory  Courses.  Faculty  of  Arts. — i.  Second 
year's  Course,  Exercises  in  Inorganic  Qualitative  Analysis. 
2.  Third  year's  Course,  Quantitative  Analysis  and  other 
experiments  to  suit  the  requirements  of  individual  Stu- 
dents. 3.  Fourth  year's  Post-Graduate  Course,  Advanced 
Quantitative  Analysis,  Organic  and  Inorganic  Prepara- 
tions, and  determination  of  their  Physical  and  Chemical 
charaders.  4.  The  Laboratories  are  also  open  to  Stu- 
dents for  work  in  other  branches  of  Chemistry.  Faculty 
of  Medicine.  —  i.  Second  year's  Course,  Inorganic  and 
Organic  Elementary  Qualitative  Analysis,  and  the 
Chemical  Examination  of  Urine.  School  of  Engineering. 
—I.  Second  year's  Course,  Inorganic  Qualitative  Analysis. 

For  Fees,  Regulations  as  to  Scholarships,  and  other 
particulars  apply  to  the  Registrar,  from  whom  the 
Calendar,  published  in  December,  and  the  Extradts  from 
Calendar,  published  in  advance  in  July,  may  be  obtained. 

ROYAL  COLLEGE  OF  SCIENCE  FOR  IRELAND, 

Stephen's  Green,  Dublin. 

(Science  and  Art  Department). 

Professor  of  Chemistry— W.  N.  Hartley,  F.R.S. 

Assistant  Chemist — Hugh  Ramage,  F.l.C,  Associate 
of  the  Royal  College  of  Science,  Dublin. 

Demonstrator  of  Chemistry  and  Assaying  —  J.  Holms 
Pollok,  B.Sc. 

The  Session  commences  on  Tuesday,  Oftober  5th,  1897. 

The  Royal  College  of  Science  for  Ireland  supplies,  as 
far  as  pradticable,  a  complete  course  of  instrudtion  in 
Science  applicable  to  the  Industrial  Arts,  and  is  intended 
also  to  aid  in  the  instruction  of  teachers  for  the  local 
Schools  of  Science. 

Diplomas  are  awarded  in  the  Faculties  of  Mining, 
Engineering,  and  Manufactures,  Physics,  and  Natural 
Science.    The  Diploma  of  Associate  of  the  Royal  College 


of  Science  in  the  Faculty  of  Manufactures  is  recognised  by 
the  Council  of  the  Institute  of  Chemistry  of  Great 
Britain  and  Ireland  as  ualifying  candidates  for  admission 
to  the  practical  examinations  of  the  Institute. 

The  instruction  in  Chemical  Science  includes  (i)  General 
Chemistry;  (2)  Advanced  Chemistry,  includmg  Chemical 
Manufactures  and  Metallurgy;  (3)  Analytical  and  Experi- 
mental Chemistry  ;  (4)  Instructions  in  Cnemical  Research. 

Fees  payable  by  Non-Associates  : — £2  for  each  separate 
Course  of  LeClures.  For  Analytical  Chemistry  and 
Research — £2  for  a  special  course  of  one  month  ;  ^5  for 
three  months;  £g  for  six  months;  ;^i2  for  the  entire 
session.  For  Assaying — ;^5  for  three  months  ;  £g  for  six 
months     ;£'i2  for  the  entire  session. 

Note. — Important  changes  have  been  made  in  the 
Curriculum  for  Associate  Students.  Full  particulars  are 
contained  in  the  Directory  of  the  College,  which  may  be 
had  on  application  to  the  Secretary. 

The  following  are  supplementary  courses  of  instrudion 
arranged  for  those  who  are  attending  a  Course  of 
Lectures  : — 

(i)  Laboratory  Instruction  in  the  Theory  of  Chemistry. 

(2)  An   Analytical  Course  for  Students   in  Engineering. 

(3)  A  Course  of  Practical  Chemistry  for  Medical  Students. 

(4)  The  Analysis  of  Water,  Air,  Food,  and  Drugs,  in- 
tended for  the  instruction  of  Public  Analysts  and  Medical 
Offi:ers  of  Health.     (5)  Assaying. 

There  are  four  Royal  Scholarships  of  the  value  of  £'50 
each  yearly,  with  Free  Education,  including  Laboratory 
Instruction,  tenable  for  two  years ;  two  become  vacant 
each  year  ;  they  are  awarded  on  the  results  of  their 
examinations  to  Associate  Students,  not  being  Royal 
Exhibitioners,  who  have  been  a  year  in  the  College. 
There  are  also  nine  Royal  Exhibitions  attached  to  the 
College,  of  the  yearly  value  of  ;^5o  each,  with  Free 
Education,  including  Laboratory  Instruction,  tenable  for 
three  years ;  three  become  vacant  each  year,  and  are 
competed  for  at  the  May  Examinations  of  the  Depart- 
ment  of  Science  and  Art. 


CHEMICAL  LECTURES,  CLASSES,  AND 
LABORATORYJLNSTRUCTION. 

City  and  Guilds  of  London  Institute  for  the 
Advancement  of  Technical  Education. — The  opera- 
tions of  the  City  and  Guilds  of  London  Institute  are 
divided  broadly  into  four  branches:  the  educational  work 
of  three  London  Colleges,  and  of  the  Technological 
Examinations.  Programmes  of  the  London  Colleges 
may  be  had  on  application  to  the  Head  Office  of  the 
Institute,  Gresham  College,  Basinghall  Street,  London, 
E.G.,  or  from  the  respective  Colleges.  The  Technolo- 
gical Examinations  (Examinations Department,  Exhibition 
Road,  S.W.),  are  conducted  once  every  year  at  various 
centres  throughout  the  kingdom.  Programme,  with 
Syllabus  of  Subjects,  &c.,  may  be  obtained  of  Messrs. 
Whittaker  and  Co.,  Paternoster  Square,  London,  or 
through  any  bookseller,  price  lod.,  net.  —  City  and 
Guilds  Technical  College,  Exhibition  Road. —  Professor 
of  Chemistry,  H.  E.  Armstrong,  Ph  D.,  F.R.S.  The  objeCl 
of  this  Institution  is  to  give  to  London  a  College  for  the 
higher  technical  education,  in  which  advanced  instruction 
shall  be  provided  in  those  kinds  of  knowledge  wnich  bear 
upon  the  different  branches  of  industry,  whether  Manufac- 
tures or  Arts.  The  main  purpose  of  the  instru<aion  given 
is  to  pradtically  demonstrate  the  application  of  different 
branches  of  science  to  various  manufacturing  industries. 
In  order  that  this  instruction  may  be  efficiently  carried 
out,  the  Institution,  in  addition  to  the  leCture  theatres 
and  class  rooms,  is  fitted  with  laboratories,  drawing 
offices,  and  workshops ;  and  opportunities  are  afforded 
for  the  prosecution  of  original  research,  with  the  objeCt  of 
the  more  thorough  training  of  the  students,  and  for  the 
elucidation  of  the  theory  of  industrial  processes.    ThQ 


Cbbmical  Nbws,  \ 
Sept.  10, 1897.    » 


Schools  Of  Chemistry, 


135 


courses  of  instrudlion  are  arranged  to  suit  the  require- 
ments of — I.  Persons  who  are  training  to  become 
Technical  Teachers  ;  2.  Persons  who  are  preparing  to 
enter  Engineers'  or  Architedls'  offices,  or  Manufacturing 
works  ;  3.  Persons  who  desire  to  acquaint  themselves  with 
the  scientific  principles  underlying  the  particular  branch 
of  industry  in  which  they  are  engaged.  The  Matriculation 
Examinations  will  begin  on  Tuesday,  Sept.  21st,  and 
the  Winter  Session  opens  on  Monday,  October  4th. 
City  and  Guilds  Technical  College,  Finsbury. — Professor 
of  Chemistry,  Raphael  Meldola,  F.R.S.  The  operations 
of  the  Technical  College,  Finsbury,  are  divided  into  two 
distinct  portions  :  Day  Classes  for  those  who  are 
able  to  devote  one,  two,  or  three  years  to 
systematic  technical  education ;  Evening  Classes  for 
those  who  are  engaged  in  industrial  or  commercial 
occupations  in  the  daytime  and  who  desire  to  receive 
supplementary  instruction  in  the  application  of  Science 
and  of  Art  to  the  trades  and  manufactures  in  which  they 
are  concerned  or  employed.  Each  Professor  is  assisted 
by  Demonstrators.  Besides  these  there  are  Lecturers 
and  Teachers  in  special  subjects.  An  examination  for 
the  admission  of  Students  will  be  held  at  the  College 
at  10  o'clock  on  Tuesday,  September  21st,  1897. 
South  London  Technical  Art  School.  — Classes  in  Model- 
ling, Drawing  and  Painting  from  the  Life,  and  House 
Decoration. 

City  of  London  College,  White  Street.  Moorfields. 
— Courses  of  Evening  Ledures  and  Laboratory  Practice 
in  Chemistry  and  Physics,  conduced  by  Mr.  1.  S.  Scarf, 
F.LC,  F.C.S.,  assisted  by  Messrs.  H.  W,  Harris,  F.C.S., 
H.  V.  Buttfield,  F.C.S.,  and  C.  A.  West,  A.R.C.S.,  F.C.S. 
Session  commences  September  27. 

Battersea  Polytechnic. — Principal,  Mr.  Sidney  H. 
Wells.  Wh.  Sc.  Inorganic,  Organic,  and  Technological 
Chemistry,  Mr.  W.  A.  Bone,  D.Sc.  (Vidt.),  Ph.D.,  assisted 
by  Mr.  J.  Wilson,  M.Sc.  (Vidl.).  Day  and  Evening 
Classes  in  Science  and  Art  subjedls. 

BiRKBECK  Literary  and  Scientific  Institution, 
Bream's  Buildings,  Chancery  Lane.  —  Chemistry 
Courses  will  be  conduced,  commencing  September  27, 
adapted  for  the  Elementary,  Advanced,  and  Honours 
Examinations  of  the  Science  and  Art  Department,  and  for 
the  Matriculation,  B.Sc,  and  M.B.  Degrees  of  the  London 
University,  by  Mr.  J.  E.  Mackenzie,  Ph.D.,  B.Sc. 

Imperial  College  of  Chemistry  and  Pharmacy,  51, 
Imperial  Buildings,  Ludgate  Circus. — Mr.  F.  Davis,  B.Sc. 

Borough  Polytechnic  Institute,  St.  George's 
Circus.— Mr.  F.  MoUwo  Perkin,  Pn.D.  Lectures  and 
Laboratory  work  in  Chemistry  and  Physics.  Session  com- 
mences Monday,  September  27,  1897. 

Brixton  School  of  Chemistry  and  Pharmacy,  12, 
Knowle  Road,  Brixton.— Dr.  A.  B.  Griffiths,  F.R.S.E., 
F.C.S.,  &c. 

Metropolitan  College  OF  Pharmacy,  i62,Kennington 
Park  Road,  S.E.— Principal,  W.  Watson  Will,  F.C.S. 

South-West  London  Polytechnic,  Manresa  Road, 
Chelsea. — Principal,  Herbert  Tomlinson,  B.A.,  F.R.S. 
Technical  Day  Classes  in  Chemical  Industries,  com- 
mencing September  28th. 

The  Goldsmiths'  Institute,  New  Cross,  S.E, — 
Head  of  the  Chemistry  Department,  Mr.  W.  J.  Pope; 
Assistants,  Mr.  S.  J.  Peachy  and  others.  Ledures 
and  PratStical  Classes  in  General  Chemistry,  also  in  Che- 
mistry applied  to  Gas  Manufadture  and  other  industries, 
are  held  in  the  evenings  from  7.30  to  10. o,  and  are  open 
to  both  sexes.  Special  attention  is  paid  to  Technical 
Laboratory  work  and  the  investigation  of  manufacturing 
difficulties. 

University  Tutorial  College,  32,  Red  Lion  Square. 
Holborn,  W.C.  (Science  Department  of  the  Univ.  Corn 
Coll.). — Chemical,  Biological,  and  Physical  laboratories. 
Morning,  Afternoon,  and  Evening  Classes.  Students 
may  work  either  for  long  or  short  periods,  either  for  ex- 
amination or  for  private  pratStice.  The  Laboratories 
accommodate  over  100  Students, 


South  London  School  of  Pharmacy,  Lim.,  325, 
Kennington  Road,  S.E.  —  Ledures  on  Chemistry 
and  Physics,  by  Dr.  John  Muter,  F.R.S.E.,  F.I.C,  and 
Mr.  J.  Thomas,  B.Sc.  (Lond.),  Daily,  at  12  noon. 
Ledures  on  Botany  daily  at  i  p.m.  and  at  2.30  p.m.  on 
Materia  Medica  and  Pharmacy,  by  Mr.  Dodd,  F.C.S. 
The  Laboratories  for  Qualitative  and  Quantitative  Ana- 
lysis open  daily  from  9  till  5,  under  the  diredtion  of  Mr. 
de  Koningh,  F.I.C,  F.C.S.  The  Students'  Laboratory  of 
this  Institution  is  specially  designed  to  accommodate  40 
Students.  The  Technical  Laboratory  is  open  daily  from  9 
till  5,  and  is  fully  fitted  with  all  apparatus  for  teaching  the 
manufacture  of  drugs  and  chemicals.  Periodical  Examina- 
tions of  the  Students  are  held  by  Visiting  Examiners 
appointed  by  the  Council  of  Education,  and  Medals  and 
Certificates  are  awarded  on  the  results  thereof.  Fees  for 
the  first  three  months  12  guineas;  afterwards  3  guineas 
per  month,  inclusive  of  all  departments. 

East  London  Technical  College,  People's  Palace, 
E.— Chemistry:  Professor,  J.  T.  Hewitt,  M.A.,  D.Sc, 
Ph.D.;  Demonstrator,  F.  G.  Pope;  Assistants,  H.  A. 
Phillips  and  W.  T.  Gidden.  Lectures  and  Practical 
Classes  are  held  in  the  daytime  in  connection  with  the 
three  years'  course  of  the  Day  Technical  College. 
Evening  Classes  are  also  held,  offering  instruction  in  the 
courses  of  the  Science  and  Art  Dc^partment  and  for  the 
examinations  of  the  University  of  London. 

Polytechnic  Institute,  309,  Regent  Street,  London, 
W. — Mr.  R.  A.  Ward  and  Assistants. — Evening  Classes 
in  Theoretical  and  Pradical  Chemistry,  &c..  The  Classes 
are  open  to  both  sexes.  The  next  term  commences  on 
Monday,  September  27th. 

Westminster  College  of  Chemistry  and  Pharmacy 
Trinity  Square,  Borough,  S.E.  —  Messrs.  Wills  and 
Wootton.     Day  and  Evening  Classes. 

The  Clifton  Laboratory,  Berkeley  Square,  Bristol.— 
Principal,  E.  H.  Cook,  D.Sc.  (Lend.),  F.I.C.  Students 
are  received  either  as  Piivate  Pupils  or  Members  of  a 
Class.  Instruction  is  given  to  those  requiring  to  use 
science  or  scientific  methods  in  Commercial  and  Indus- 
trial pursuits,  or  in  preparing  for  Examinations.  Students 
are  urged  to  undertake  researches  and  receive  special 
attention  from  the  teachers.  Every  effort  is  made  to  pro- 
duce thorough  chemists  rather  than  successful  examinees. 

Leeds  Technical  School  (late  School  of  Science  and 
Technology),  Cookridge  Street.  —  Head  Master  and 
Ledtureron  Chemistry,  Mr.  RE.  Barnett,B.Sc.,  A.R.C.S., 
assisted  by  Mr.  R.  W.  Ferguson,  A.R.C.S.  Evening 
Courses  are  oiTered  in  Inorganic  and  Organic  Chemistry, 
both  theoretical  and  pradttcal.  The  Laboratory  is  well 
equipped,  and  arrangements  are  made  for  pharmaceutical 
study,  research,  or  other  special  work,  for  which  purpose 
it  is  open  also  in  the  daytime.  In  Metallurgy,  Ledturer 
Mr.  B.  A.  Burrell,  F.I.C,  F.C.S,  elementary,  advanced, 
and  honours  Courses  of  Ledlures  and  Laboratory  work 
are  held.  In  Physics,  Ledturer  Mr.  J.  E.  Tindall,  B.Sc, 
theoretical  and  pradical  classes  are  held,  and  in  the  latter 
provision  is  made  for  candidates  for  Inter.  Sci.  and  B.Sc. 
There  are  also  Courses  in  Engineering,  Botany,  Geology, 
and  several  Technological  subjedts.  The  new  Session 
commences  at  7.0  p.m.  on  Monday,  September  20th.  Fee 
for  any  Evening  Course  of  Ledlures : — Elementary,  2s.  6d. ; 
Advanced  or  Honours,  3s,  6d.  ;  Laboratory  Courses  from 
5s.  to  15s. 

The  Municipal  Technical  School,  Princess  Street, 
Manchester. — Theoretical  and  Pradlical  Chemistry,  Mr, 
E.  Knecht,  Ph.D.,  F.I.C,  Mr.  J.  Grant,  F.I.C,  F.C.S., 
Mr.  L.  G.  Radcliffe,  and  Mr.  J.Allan,  Metallurgy,  Mr. 
E.  L.  Rhead.  At  this  important  Municipal  School,  with 
an  attendance  of  upwards  of  3500  Students,  there  are 
organised  Day  Courses  in  Pure  Cnemistry,  with  applica- 
tions to  Dyeing,  Bleaching,  Printing,  Brewing,  and  Metal- 
lurgy. In  addition  there  are  Evening  Courses,  not  only 
in  Pure  Chemistry,  but  in  Metallurgy,  Mineralogy,  Iron 
and  Steel  Manufacture,    Brewing,    Bleaching  ,  Dyeing, 


136 


Schools  of  Chemistry. 


(Chemical  News, 
1     Sept.  10, 1897. 


and  Printing,  Coal  Tar  Products,  Paper  Manufadlure, 
Gas  Analysis,  Gas  Manufacture,  Chemical  Engineering, 
Chemistry  for  Engineers  and  Builders,  and  Photography. 
The  complete  Syllabus  (4d.,  by  post  6d.)  may  be  obtained 
on  application  to  Mr.  J.  H.  Reynolds,  Diredtor  and  Secre- 
tary, Princess  Street,  Manchester. 

The  Manchester  Colege  of  Pharmacy,  Oxford 
Street,  Manchester. — Director,  Mr.  Charles  Turner,  F.C.  S . 
Classes  and  Lectures  specially  designed  to  meet  the  re- 
quirements of  Pharmaceutical  Students. 

Chemical  and  Bacteriological  Laboratory,  Barton 
Arcade,  Manchester. —  Mr.  George  J  Allen,  F.C.S. — 
Special  Instrudlion  and  Pradice  in  Applied  Science. 

Higher  Grade  School,  Patricroft. — Science  and 
Art  Day  and  Evening  School,  and  Institute  for  Women. 
Demonstrator  in  Chemistry,  Mr.  R.  J.  B.  Sanderson. 

Sheffield  Pharmaceutical  and  Chemical  Society, 
New  Surrey  St. — Chemistry  and  Physics,  Mr.  H.  His;hfield. 
Materia  Medica  and  Botany,  Mr.  John  Austen  and  Mr. 
E.  C.  Exell.     Session  commences  first  week  in  Odlober. 

Hartley  College,  Southampton.  —  Principal,  R. 
Wallace  Stewart,  D.Sc.  (Lond.).  Lecturer  in  Chemistry, 
D.  R.  Boyd.  B.Sc,  Ph.D.  Session  commences  Tuesday, 
September  28,  1897. 

Stockport  Technical  School.  —  Department  of 
Chemistry  and  Dyeing. — Principal  :  Mr.  R.  J.  Brown, 
M.Sc.  A  syllabus  with  full  particulars  of  the  courses  of 
instrudtion,  hours,  fees,  &c.,  is  obtainable  on  application. 
Special  instruftion  is  given  in  the  Dyeing  of  Felt,  &c.,  as 
applied  to  Hat  Manufacture. 

Technical  Institute,  Swansea.  —  Classes  in 
Theoretical  and  Pradtical  Organic  and  Inorganic  Chemis- 
try, Metallurgy,  Hygiene,  Mathematics,  Phvsiology, 
Sound.  Light,  and  Heat,  from  Odtober  to  May.  Principals, 
D.  J.  Morgan,  B.  A.  (Cantab.),  C  A.  Seyler,  B.Sc,  F.I.C. 

Aberdeen  University. — Prof.  Japp. 

School  of  Medicine,  Edinburgh. — Dr.  S.  Macadam, 
Mr.  King,  Mr.  I  Macadam. and  Drs.  Aitken  and  Readman. 

St.  Mungo's  College  and  School  of  Medicine, 
Edinburgh. — Dr.  Marshall. 

Surgeon's  Hall,  Nicolson  Street,  Edinburgh.— Dr. 
Stevenson  Macadam,  Lecturer.  Classes  for  Medical  and 
General  Students.  Lectures  commence  Tuesday,  October 
12,  1897. 

Glasgow  University. — Prof.  J.  Ferguson. 

Anderson's  College,  Glasgow.— Mr.  J.  R.  Watson. 

Royal  College  of  Surgeons  in  Ireland,  Dublin. — 
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Purification  and  A  tomic  Weight  of  Cerium, 


137 


THE    CHEMICAL     NEWS. 


Vol.  LXXVL,  No.  1973. 


VANADIUM     IN     RUTILE. 
By  W.  B.  GILES,  F.I.C. 

In  the  Chemical  News  (vol.  Ixxvi.,  p.  102)  there  appears 
a  paper  by  B.  Hasselberg  entitled  "  Notes  on  the  Che- 
mical Composition  of  the  Mineral  Rutile,"  in  which  the 
following  passage  occurs : — "  While  the  presence  of 
vanadium  in  the  rutile  thus  forms  a  hitherto  entirely  un- 
known feature  of  this  mineral."  1  wish  to  point  out  that 
this  is  not  corredt,  for  rutile  has  been  known  to  contain 
vanadium  for  over  thirty  years.  Ste.-ClaireDeville  showed 
that  this  mineral  contained  not  only  vanadium,  but  also 
molybdenum.  He  says  indeed  in  his  paper,  "  Ou  voit 
que  le  rutile  est  une  matiere  dont  ou  peut  extraire  le 
vanadium  avec  le  plus  grand  advantage."  1 1 

In  100  grms.  of  the  rutile  from  Saint  Yrieix  he  found — 
0*323  grm,  of  vanadic  acid,  and 
0*486  grm.  of  molybdic  acid. 

He  also  shows  that  vanadium  is  found  in  bauxite,  in 
most  clays,  in  cerite  from  Bastnas,  and  in  cryolite,  as  well 
as  in  the  emerald  and  a  variety  of  other  substances.  I 
may  further  point  out  that  in  these  interesting  researches 
he  established  the  presence  of  tellurium  and  titanium,  as 
well  as  vanadium  in  cerite,  of  tantalic  acid  in  wolfram, 
and  of  niobic  acid  in  cryolite.  The  methods  he  employed 
for  the  detedlion  and  estimation  of  the  vanadium  are  very 
good,  and  probably  no  better  way  of  effedting  the  separa- 
tion of  this  widely-diffused  element  is  known  even  at  the 
present  time.  These  researches  are  to  be  found  in  the 
Annales  de  Chimie  et  de  Physique,  3me  Series,  t.  Ixi.,  and 
also  in  the  Comptes  Rendus,  t.  xlix.,  pp.  210  to  301. 


ON     A    QUANTITATIVE    SEPARATION     OF 

ARSENIC    FROM     ANTIMONY. 

By  OSCAR  PILOTY  and  ALFRED  STOCK. 

The  quantitative  separation  of  arsenic,  antimony,  and 
tin  is  one  of  the  most  difficult  problems  of  mineral 
analysis  if  the  separation  of  each  element  is  required. 

We  shall  now  describe  a  procedure  which  we  have 
elaborated  for  the  separation  of  arsenic  from  antimony, 
and  which  seems  to  us  calculated  to  solve  this  question 
with  accuracy  and  expedition.  We  have  carried  out  this 
method  quantitatively  as  regards  arsenic  and  antimony. 
The  separation  from  tin  has  been  tried  only  qualitatively. 

The  observation  upon  which  our  method  depends  is  the 
volatility  of  arsenic  with  hydrogen  sulphide  in  a  strongly 
hydrochloric  acid  solution.  This  fafl  may  perhaps  throw 
a  light  on  the  causes  of  some  of  the  many  discrepancies 
observed  in  the  precipitation  of  arsenic  as  sulphide.  If 
we  heat  arsenic  tersulphide  with  very  strong  hydrochloric 
acid  until  there  is  a  brisk  discharge  of  hydrochloric  acid, 
the  chief  part  of  the  arsenic  escapes  with  moderate  ease, 
and  the  yellow  arsenic  sulphide  disappears  almost  entirely. 
Indeed  our  experiments  showed  that  from  a  solution  of 
arsenic  teroxide  or  pentoxide  no  sulphide  is  precipitated 
by  sulphuretted  hydrogen  if  it  is  heated  to  ebullition  with 
a  simultaneous  introdudion  of  gaseous  hydrochloric  acid. 
Under  these  conditions  the  arsenic  distils  away  entirely 
in  a  short  time  from  the  solution,  probably  as  trichloride. 

From  the  foregoing  it  will  be  readily  seen  that  the  pre- 
cipitations of  arsenic  can  be  accurate  only  if  the  solutions 


containing  the  metal  are  but  slightly  acid,  or  are  not 
heated  in  presence  of  much  hydrochloric  acid. 

We  must  emphasize  this  condition  the  more  as  we  can- 
not find  it  mentioned  either  in  journalistic  literature  or  in 
standard  works  on  chemical  analysis.  On  the  contrary, 
it  has  often  been  definitely  shown  that  arsenic  penta- 
sulphide  precipitates  in  heat  from  a  hydrochloric  solution, 
and  contains  tersulphide  in  abundance,  in  full  contra- 
didtion  with  the  statements  of  Bunsen  concerning  the 
precipitation  of  pentasulphide.  Our  observation  seems 
to  us  fully  to  explain  this  contradidion. 

The  partial  redudlion  of  arsenic  acid  on  heating  in  con- 
centrated hydrochloric  acid  has  been  already  noticed. 
Latterly  Neher  has  reported  on  this  observation.  He 
informs  us  that  under  certain  circumstances,  on  precipi- 
tating such  a  boiling  solution  with  hydrogen  sulphide, 
there  is  formed  above  the  liquid  a  cloud  of  arsenic  tri- 
sulphide.  But  he  also  failed  to  notice  the  behaviour  of 
concentrated  hydrochloric  solution  on  the  atftion  of 
sulphuretted  hydrogen,  and  the  decomposability  of  the 
tersulphide  already  precipitated. 

We  should  here  remark  that  the  precipitation  of  the 
arsenic  in  the  slightly  hot  hydrochloric  solution,  as  first 
used  by  Bunsen,  always  gives  excellent  results.  The  at- 
tributes of  arsenic  pentasulphide  are  so  striking  that  the 
weighing  of  arsenic  in  this  form  seems  preferable  to  all 
other  methods. 

Since  other  metals  on  the  permanent  presence  of  an 
excess  of  hydrochloric  acid  are  not  affedled  by  hydrogen 
sulphide,  it  was  our  task  to  apply  the  described  behaviour 
to  arsenic  for  its  quantitative  separation  from  all  other 
metals.  We  undertook,  in  the  first  place,  its  separation 
from  antimony,  and  we  obtained  very  accurate  results. 

We  are  now  engaged  with  experiments  to  dispense  with 
a  double  precipitation  of  arsenic. 

We  have  hitherto  pradicallv  effedled  only  the  separation 
of  arsenic  from  antimony.  We  shall  next  report  on  the 
separation  of  arsenic  from  tin  and  the  other  elements  of 
arsenic  sulphide  group. — Berichte,  No.  12,  p.  164. 


ON   THE 

PURIFICATION    AND    ATOMIC    WEIGHT 

OF    CERIUM.* 

By  MM.  WYROUBOFF  and  VERNEUIL. 

Of  all  the  metals  which  we  are  in  the  habit  of  calling 
rare,  cerium  is  without  doubt  the  least  known.  A  large 
number  of  researches  have  been  devoted  to  it,  and  one 
would  think  in  reading  them  that  the  subjedt  must  be 
well  nigh  exhausted.  H  >wever,  in  taking  the  fads  which 
seem  the  most  incontestable  one  by  one.  we  soon  see  that 
we  are  in  a  domain  of  uncertainty  and  contradidlions. 
We  only  know  the  atomic  weight  of  cerium  approximately, 
we  are  uncertain  as  to  its  valence,  and  we  are  not  even 
quite  sure  of  its- identity.  Is  it  really  a  simple  element, 
as  we  have  hitherto  attempted  to  believe,  or  does  it  con- 
sist of  a  group  like  the  didymium  of  Mosander?  like  the 
erbium  of  Bahr  and  Bunsen  ?  This  last  opinion  has  been 
upheld  quite  recently  by  the  late  M.  Schiitzenberger  in  a 
series  of  important  memoirs  {'omptes  Rendus,  cxx.,  ipp, 
663,  962;  cxxiv.,  p.  481).  There  should  be,  according  to 
this  eminent  chemist,  several  elements  presenting  all  the 
chemical  and  physiol  charaderistics  of  cerium,  and  having 
atomic  weights  varying  from  85  to  104  (Ce  being  taken 
as  bi-valent).  If  such  were  the  case,  all  the  chemistry  of 
cerium  which  has  bet-n  done  up  to  the  present  would  have 
no  longer  any  raison  d'etre,  and  every  effort  should  be  di- 
reded  towards  the  separation  of  the  different  simple  bodies 
of  which  it  is  formed. 

We  now  extrad,  from  a  comprehensive  research  which 
will  appear  shortly,  that  which  appears  to  concern  the 

*  Bull.  Soc,  Chim.,  Series  3,  vol.  xvii.-xviii.,  No.  14. 


138 


Purification  and  A  tomic  Weight  of  Cerium, 


I  Chbhical  News, 
1      Sept.  17,  1897. 


capital  question  of  the  identity  of  cerium,  for  the  purpose 
of  showing  that  it  is  a  definite,  distindt  body,  possessing 
always — no  matter  what  its  origin  may  be — the  same 
atomic  weight,  and  incapable  of  being  split  up  into  more 
simple  elements  by  any  known  process. 

Two  misconceptions  dominate  the  whole  chemistry  of 
cerium ;  the  one  has  regard  to  its  separation  from  its 
neighbouring  metals,  the  other  to  the  determination  of 
its  atomic  weight.  It  is  these  two  misconceptions  which 
appeared  to  us  important  to  first  of  all  clear  up. 

Purification  of  Cerium. — There  are  three  impurities 
associated  with  cerium  which  are  very  difficult  to  get  rid 
of.  These  are,  in  order  of  difficulty  of  elimination,  iron, 
didymium-lanthanum-yttria,  and  thoria. 

Iron. — It  is  generally  believed  that  a  precipitation  of 
oxalic  acid,  or  oxalate  of  ammonia,  suffices  to  completely 
eliminate  the  iron.  This  is  entirely  erroneous.  Two  or 
even  three  precipitations,  in  warm  and  acid  solution, 
hardly  suffice  to  remove  the  last  traces  of  iron.  Its 
presence,  even  in  minimal  quantities,  is  manifested  by  the 
colour  of  the  calcined  ceroso-ceric  oxide,  which  takes  a 
more  or  less  pronounced  rose  tint,  sometimes  even 
reddish. 

Didymium  and  Lanthanum. — We  have  admitted,  as  a 
fadk  without  question,  that  Debray's  process — which  con- 
sists, as  is  well  known,  in  the  twice-repeated  fusion  with 
nitre  at  about  320° — separates  integrally  the  cerium  from 
the  other  metals  of  its  group.  Nothing,  however,  is  less 
certain.  This  process,  which  is  purely  empiric,  appears 
to  be  based  on  the  more  and  more  difficult  decomposition 
of  the  nitrates  of  protoxide  of  cerium,  didymium,  and 
lanthanum  ;  in  reality  it  is  accompanied  by  a  phenomenon 
infinitely  more  complex.  The  cerous  nitrate  passes 
firstly  to  the  state  of  eerie  nitrate,  which  easily  gives  an 
extremely  stable  basic  salt,  and  this  nitrate  combines  at  a 
higher  temperature  with  the  nitrates  of  didymium  and 
lanthanum  to  form  a  complex  oxidised  salt,  to  which  we 
shall  return  later.  We  can  follow  this  reaction  by 
evaporating  the  red  solution  obtained  by  dissolving 
the  calcined  oxides  in  nitric  acid  to  dryness,  and  heating 
to  increasing  temperatures.  Towards  120°,  when  all  the 
nitric  acid  is  driven  off,  the  mixture  has  a  bright  yellow 
colour.  If  at  this  moment  we  treat  it  with  water,  we 
obtain  a  pale  yellow  insoluble  body,  consisting  of  abso- 
lutely pure  cerium  in  the  state  of  nitrate  {Ce304)4.N205, 
and  a  violet  liquid  containing  cerium  in  the  state  of 
protoxide,  with  all  the  lanthanum  and  didymium.  On  re- 
heating the  mass,  it  gives  off  nitrous  fumes  and  takes  a 
chamois  colour,  which  becomes  accentuated  as  the  heating 
proceeds;  taken  up  with  water,  the  mass  gives  an 
opalescent  liquid  which  it  is  impossible  to  filter.  This 
change  of  colour  and  of  properties  indicates  that  a  new 
nitrate,  of  an  oxide  altogether  different  to  €6304,  is 
formed.  In  fadt,  in  the  presence  of  protoxides  of  more 
energetic  basicity,  the  ceroso-ceric  oxide  tends  to  form  an 
oxide,  Ce304,3MO,  which  becomes  remarkably  stable  at 
high  temperatures  when  M  =  Di  or  La.  This  oxide, 
which  we  propose  to  study  in  detail  in  a  future  note,  gives 
very  beautiful  salts,  which  do  not  by  any  means  resemble 
the  yellow  salts  of  the  oxide  Ce304.  It  follows  from  this 
that  Debray's  process  does  exadtly  the  opposite  to  what 
he  proposes;  instead  of  separating,  it  tends  to  combine 
€0^04  with  DiO-(-LaO.  No  doubt  by  keeping  the  tem- 
perature up  to  330''  for  a  long  time  we  can  decompose 
this  complex  nitrate,  but  this  decomposition  is  only 
achieved  with  great  difficulty ;  it  is  for  this  reason  that 
we  can  only  arrive  at  a  more  or  less  complete  separation, 
after  a  long  series  of  fusions.  It  appeared  to  us  to  be 
much  more  rational  to  stop  the  reai^ion  at  the  moment 
when  the  oxide  Ce304  cannot  combine  with  the  DiO  +  LaO, 
for  at  this  moment  the  cerium  should  be  absolutely  free, 
not  only  from  the  two  other  metals,  but  also  from  the 
metals  of  the  yttria  group  which  are  always  found  in 
company  with  didymium. 

Experience  fully  confirms  this  forecast,  and  we  have 
lieen  able  to  prepare  in  one  day  several  hundred  grms.  of 


perfedly  pure  cerium.  This  is  how  we  set  to  work:— We 
calcine  the  oxalates  gently,  and  treat  them  with  nitric 
acid  ;  here  two  different  cases  may  present  themselves.* 

a.  If  the  mixture  contains  more  than  50  per  cent  of 
cerium,  nitric  acid  will  not  dissolve  it  integrally,  even 
with  the  aid  of  heat.  One  might  be  inclined  to  believe 
that  the  insoluble  residue  is  formed  of  the  pure  oxide 
06304,  but  such  is  not  the  case.  It  is  a  complex  com- 
bination of  the  oxide  06304  with  DiO-|-LaO.  In  this  case 
it  is  necessary  to  dissolve  the  oxalates  in  nitric  acid,  add 
an  excess  of  peroxide  of  hydrogen  and  ammonia,  and  boil. 
The  voluminous  reddish  brown  precipitate  of  peroxide  of 
cerium,  and  of  the  peroxides  of  Di  and  La  which  are 
formed,  quickly  lose  oxygen,  and  become  first  orange- 
colour  and  then  yellow.  Having  arrived  at  this  state 
they  then  consist  of  ceroso-ceric  hydroxide,  06304,31120, 
mixed  with  the  protoxides  of  DiO  and  LaO.  It  only  re- 
mains now  to  wash  the  precipitate  to  get  rid  of  the  nitrate 
of  ammonia  which  interferes  with  the  subsequent  reaftion, 
to  dissolve  it  in  hot  nitric  acid,  and  to  continue  the  treat- 
ment according  to  b. 

b.  If  the  calcined  oxides  dissolve  in  nitric  acid,  we 
evaporate  the  solution  to  a  syrupy  consistency.  It  has  a 
deep  red  colour,  and  contains  cerium  in  the  state  of  a  salt 
of  the  oxide  06304,3060  =  06507.  To  this  semi-fluid 
mass  we  add  a  solution  of  5  per  cent  nitrate  of  ammonia 
(thirty  to  forty  times  the  weight  of  the  oxides),  and  boil. 
If  no  precipitate  is  formed  it  is  because  the  solution  is  too 
acid  ;  we  therefore  add  a  weak  solution  of  ammonia,  drop 
by  drop.  Each  drop  will  cause  the  formation  of  a  floc- 
culent  violet  precipitate,  which  re-dissolves  on  agitation 
up  to  the  moment  when  a  persistent  pale  yellow  precipi- 
tate appears.  When  the  supernatant  liquor  has  no  longer 
the  least  trace  of  yellow  colour,  but  takes  the  charader- 
istic  violet  colour  of  didymium  salts,  the  readion  is  at  an 
end.  The  precipitate  can  be  filtered  and  washed  with  the 
greatest  ease,  and  when  the  wash  water  no  longer  gives  a 
precipitate  with  oxalate  of  ammonium,  the  precipitate  is 
absolutely  free  from  lanthanum,  didymium,  and  the  earths 
of  the  yttria  group.  But  the  cerium  thus  obtained  only 
represents  a  portion,  about  75  per  cent,  of  the  total  con- 
tained in  the  solution.  It  is  not  difficult  to  understand 
the  reason.  The  adion  of  nitrate  of  ammonium  disso- 
ciates the  oxide  06304,3060,  an  oxide  in  which  OeO  is, 
by-the  bye,  partially  replaced  by  DiO  and  LaO  ;  06304  is 
precipitated  as  nitrate  (06304), NjOs,  and  OeO  remains  in 
solution  with  the  other  earths  in  the  state  of  a  neutral 
salt. 

This  process — the  only  one  which  enables  us  to  obtain 
cerium  completely  free  from  lanthanum  and  didymium  at 
one  operation — can  even  be  made  to  serve,  as  we  shall 
show,  for  a  sufficiently  accurate  method  of  qualitative 
separation.  The  cerium  thus  obtained,  however,  still 
contains  an  impurity  from  which  it  is  not  easy  to  separate 
it.  At  the  same  time  as  the  cerium  is  precipitated,  all  the 
thorium  in  solution  comes  down  also. 

Thorium. — This  metal,  which  is  only  just  becoming 
known,  and  very  little  at  present,  nearly  always  accom- 
panies cerium  in  its  ores,  even  in  cerite.  All  the  ordinary 
methods  in  use  will  give  us  thorium  free  from  cerium,  but 
none  of  them  give  cerium  free  from  thorium.  Such  is  the 
case  with  the  two  best  known  of  them,  the  hyposulphite 
of  soda  (Chydenius)  and  the  suboxide  of  copper  method 
proposed  by  Lecoq  de  Boisbaudran.  We  know  that  the 
former  precipitates  barely  85  per  cent  of  thorina,  and  ex- 
periments made  on  synthetic  mixtures  have  shown  us  that 
the  latter  removes  only  about  35  per  cent.  Furthermore, 
in  both  cases,  a  notable  quantity  of  cerium  is  carried 
down,  but  this  can  be  separated  by  repeating  the  operation 
two  or  three  times.  It  is  through  not  being  sufficiently 
careful  to  guard  against  the  presence  of  thorium,  and 
through  having  accumulated  it  in  successive  fradional 
crystallisations,   that   we  have    sometimes    found    such 

*  When  the  oxides  coDtain  more  than  10  per  cent  of  thorium,  it  is 
as  well  to  get  rid  of  the  greater  part  of  it,  by  means  of  carbonate  of 
ammonia,  as  will  be  ebown  further  on. 


^slpuir, X?.^' }    Critical  Review  of  the  Methods  of  Determining  Minerals. 


13^ 


strange  variations  in  the  atomic  weight  of  cerium.  The 
solution  of  the  mixed  sulphates  of  thorium  and  cerium, 
containing  an  excess  of  the  latter,  behave  on  evaporation 
quite  differently  to  what  one  would  be  inclined  to  expedt 
from  the  indications  found  in  classic  works.  It  is  cerium, 
the  most  soluble,  which  separates  out  first :  this  goes  to 
show  that  an  excessively  soluble  double  salt  is  formed, 
which  crystallises  with  difficulty  ;  it  dries  at  the  ordinary 
temperature  to  the  condition  of  a  transparent  varnish. 
The  analysis  of  this  dehydrated  salt  leads  us  approxi- 
mately to  the  formula  4S04Ce,S04Th.  At  the  ordinary 
temperature  100  parts  of  water  dissolve  66  parts  of  the 
anhydrous  salt. 

The  best  way  of  getting  rid  of  the  thorium,  when  it  is 
present  in  any  quantity,  is  to  treat  the  oxalates,  or  better 
still  the  nitrates,  with  carbonate  of  ammonium  to  which 
has  been  added  a  little  ammonia.  The  thorium  dissolves 
with  the  greatest  facility,  and  after  two  or  three  leachings 
there  is  only  an  insignificant  quantity  (i  per  cent)  of 
thorium  left. 

To  remove  the  last  traces  we  make  use  of  the  property 
we  have  just  mentioned,  by  crystallising  the  sulphate,  free 
from  free  sulphuric  acid,  at  50°  to  60°.  The  thorina 
remains  in  the  mother-liquor,  and  after  two  or  three 
crystallisations  nitride  of  potassium — the  most  sensitive 
known  reagent  for  thorium — will  no  longer  give  any  pre- 
cipitate. Cerium  thus  prepared  may  be  considered  as 
pure,  at  least  within  the  limits  of  our  adual  knowledge, 
and  when  transformed  into  sulphate  will  serve  for  the 
determination  of  the  atomic  weight. 

(To  be  continued). 


A    CRITICAL     REVIEW    OF    THE     METHODS 
OF     DETERMINING     MINERALS.* 

By  Dr.  JOSEPH  W.  RICHARDS, 

Of  the  Department  of  Metallurgy  and  Mineralogy  of  the  Lebigh 

University. 

(Concluded  from  p.  116). 

I  WILL  end  this  review  by  describing  the  methods  o 
determinative  mineralogy  taught  at  the  Lehigh  Uni- 
versity, and  which  my  ten  years'  experience  has  proven 
the  most  certain  way  of  teaching  a  student  to  identify 
minerals. 

First  of  all,  the  basis  is  the  chemical  identification,  but 
with  the  aid  of  physical  tests  brought  in  at  the  most 
profitable  stage  of  the  inquiry. 

The  observer  is  to  first  examine  the  specimen  carefully, 
noting  everything  that  is  to  be  seen  or  observed  by  the 
most  simple  tests,  such  as  approximate  hardness  and 
streak,  but  not  to  spend  any  length  of  time,  more  than  a 
minute  or  two,  at  such  observation.  The  objed  of  this 
casual  inspedtion  is  to  determine  whether  the  mineral  is 
similar  to  any  that  the  observer  has  seen  before;  if  it  is, 
and  therefore  suggests  one  or  even  several  species,  the 
observer  is  immediately  to  make  a  confirmatory  test, 
preferably  chemical,  and  as  general  as  possible,  to  see  if 
it  can  possibly  be  what  is  suspeifted.  If  the  test  is 
affirmative,  then  other  confirmatory  tests  must  be  applied, 
with  the  particular  purpose  of  excluding  all  related  mine- 
rals of  closely  allied  composition.  If  the  test  is  negative, 
and  no  other  mineral  or  minerals  suggest  themselves,  then 
the  general  method  of  procedure,  based  solely  on  chemical 
composition,  is  to  be  followed. 

As  an  illustration,  suppose  a  mineral  appears  on  casual 
inspection  to  be  wavellite.  The  first  test  is  to  determine 
whether  it  is  a  phosphate  or  not.  If  it  is,  then  alumina, 
water,  and  finally  fluorine,  can  be  tested  for  to  complete 
the  identification.  If  not  a  phosphate,  it  may  have  been 
observed  that  the  mineral  glowed  strongly  and  gave  a 
calcium  flame,  which  would  suggest  ara^onite,  and  a  test 

*  Tht  Journal  of  the  Franklin  Institute,  cxliv.,  p.  139. 


for  carbonic  acid  would  be  in  order.  Or  it  might  have 
been  observed  that  it  fused  easily,  thus  suggesting  a 
radiated  zeolite,  and  tests  for  silica  and  water  would  be  in 
order.  If  none  of  these  were  observed,  then  the  mineral 
would  have  to  be  attacked  along  broader  lines  ;  but  if  any 
of  these  tests  have  resulted  affirmatively,  then  the  observer 
has  profited  by  his  previous  knowledge  to  obtain  a  short 
cut  to  the  identification  of  the  specimen.  It  is  evident 
that  the  wider  the  observer's  previous  acquaintance  with 
numerous  varieties  of  numerous  species,  the  more  he  will 
profit  by  his  experience  and  be  able  to  put  it  to  use  in 
identifying  the  specimen. 

If  the  observer  has  no  definite  idea,  from  this  casual 
inspedtion,  of  what  the  mineral  may  be,  or  if  the  ideas 
given  by  casual  inspection  were  negatived  by  the  con- 
firmatory tests,  then  some  regular  outline  of  procedure 
must  be  followed,  and  the  following  outline  is  offered  as 
having  been  used  very  successfully  for  several  years  by 
your  ledurer.  Leaving  aside  the  first  three  items,  as 
being  intended  for  identifying  a  few  simple  mineral  spe- 
cies, clearing  the  ground,  so  to  speak,  the  real  classifica- 
tion begins  at  IV.  All  the  species  included  in  I.,  II.,  and 
III.  are  included  in  the  later  classes. 

The  outline  is  as  follows  : — 

Lecturer's  Methods. 

I. — If  metallic  and  malleable,  look  for  native  metals. 

II. — If  very  light  and  black,  examine  for  hydrocarbons. 

III.— If  it  has  a  taste,  examine  for  chlorides,  nitrates, 
sulphates,  &c. 

IV. — If  of  metallic,  adamantine,  or  resinous  lustre, 
test  in  the  open  tube  for  S,  As,  Sb,  Se,  Te.  If  present, 
roast  thoroughly,  and  test  by  beads,  flame,  and  redudtion. 

V. — If  of  any  other  lustre,  or  if  no  test  is  obtained  in 
IV.,  make  bead  test  for  silica.  If  present,  make  flame 
test,  &c. 

VI. —  If  silica  is  absent,  test  for  phosphates  and 
borates.  If  test  is  obtained,  make  bead  test,  redudlion, 
&c. 

VII. — If  P  and  B  are  absent,  test  for  carbonates.  If 
test  is  obtained,  make  flame  test,  beads,  redudtion,  &c. 

VIII. — If  CO2  is  absent,  test  for  sulphuric  acid.  If 
test  is  obtained,  make  flame  test,  beads,  redudtion,  &c. 

IX.— If  SO3  is  absent,  test  with  KHSO4  for  volatile 
acids.     If  test  is  obtained,  make  flame  test,  beads,  &c. 

X. — If  volatile  acids  are  absent,  make  test  IV.  (open 
tube),  if  it  has  not  previously  been  made. 

XI. — If  open  tube  has  already  shown  nothing,  make 
the  bead  tests  very  carefully,  to  find  the  weaker  acids, 
such  as  Cr,  V,  U,  Ti,  Mo.  If  present,  make  any  other 
tests. 

XII. — If  weaker  acids  are  absent,  substance  is  probably 
an  oxide.     Make  any  blowpipe  tests  not  already  made. 

It  will  be  observed  that  the  outline  follows  generally 
the  broad  lines  of  the  classification  of  mineral  species 
used  by  Dana,  the  primary  idea  being  to  class  the  mineral 
first  by  finding  its  acid  constituent.  This  has  the  dis- 
advantage  of  bringing  most  of  the  oxides  and  native 
metals  last  in  the  classification,  and  makes  it  desirable 
that  the  observer  be  well  informed  with  those  classes  by 
previous  acquaintance,  as  thus  much  time  is  frequently 
saved.  If  there  is  any  doubt  about  the  lustre,  the  testing 
begins  at  IV. ;  if  the  lustre  is  certainly  not  of  the  kinds 
therein  named,  it  is  best  to  begin  at  once  at  V. 

In  testing  for  the  acid  ingredient,  those  are  tested  for 
first  which  are  most  likely  to  be  present  (other  things 
being  equal),  and  also  those  tests  are  made  first  which  are 
the  quickest  to  make  (other  things  being  equal).  Thus, 
silica  is  tested  for  before  carbonic  acid,  because  the  sili- 
cates are  more  numerous  ;  while  phosphates  are  tested 
for  before  carbonates,  because  the  test  takes  less  time. 

After  an  acid  is  found,  the  diredlion  of  the  testing  is 
towards  the  basic  ingredient.  It  should  be  observed, 
however,  that  if  the  tests  at  any  time  in  in  any  way  such 
information  about  the  mineral  that  the  observer  suspedbs 
what  it  is,  then  let  him  at  once  leave  the  general  outline, 


1^0 


A  tomic  Mass  of  Tungsten. 


I  Chbuical  NKW8 
I    Sept.  17, 1897. 


and  by  diredl  tests  confirm  or  deny  his  suspicion.  If,  for 
instance,  when  testing  for  phosphorus  the  barium  flame 
is  seen,  and  the  observer  then  looks  at  the  mineral  again 
and  suspedts  barite,  then  he  should  test  at  once  for 
sulphuric  acid  to  afifirm  or  negative  his  suspicion,  without 
going  through  the  form  of  testing  for  carbonic  acid.  If 
sulphuric  acid  is  absent,  then  let  him  take  up  the  scheme 
again  where  he  left  it,  and  test  in  regular  order  for  car- 
bonic acid. 

By  following  these  diredlions,  the  composition  of  a 
mineral,  or  at  least  one  acid  and  one  base  present,  can 
quickly  be  found.  The  question  then  arises,  how  many 
minerals  can  contain  the  ingredients  so  far  found  ;  and 
in  order  to  facilitate  the  search  for  minerals  containing 
certain  elements,  I  have  prepared  tables  of  minerals 
arranged  according  to  the  elements  they  contain.  These 
tables  contain  under  the  heading  of  each  element  a 
classification  of  all  the  minerals  containing  that  element, 
arranged  primarily  according  to  the  acid  ingredients,  in 
the  order  in  which  they  would  be  found  when  following 
the  outline  of  procedure  I  have  indicated.  Under  each 
acid  the  minerals  are  further  classified  according  to  the 
other  constituents  which  may  be  present,  arranged  in  the 
order  in  which  they  are  most  quickly  and  surely  identified 
by  blowpipe  tests,  followed  by  these  minerals  containing 
only  the  acid  and  the  base,  or  possibly  containing  some 
other  ingredients  not  recognisable  by  blowpipe  tests. 
Wherever,  as  often  happens,  a  list  is  obtained  of  several 
minerals  containing  exadtly  the  same  ingredients,  a  small 
table  of  physical  properties  placed  to  the  right  gives  the 
means  of  distinguishing  them  apart.  A  sample  page  is 
as  follows : — 

Lecturer's  Tables  (sample  page). 
Copper. 


Physical  Properties, 

Composition,  &c. 

Sulphates  :— 

With  Pb : 

t  CI: 

Caracolite. 

+  Fe: 

Beudantite. 

» 

Caledonite,  linarite. 

WithZn: 

t  Al: 

Aluminite  (impure). 

• 

Serpierite. 

With  Fe : 

t  Al: 

Cyanotrichite. 

« 

Phillipite,  pisanite. 

•With  U  i 

t  Ca: 

Uranochalcite. 

« 

Voglianite,  johannite  (HjO— 3  per  cent). 

Zippeite  (H^O— 16  per  cent). 

With  Na*: 

With  K  : 

With  Ca : 

With  CI  : 

WithHjO: 

It  will  be  observed  that,  granting  that  the  experimenter 
has  found  sulphuric  acid  and  copper,  if  he  does  not  at 
once  identify  the  specimen  by  that  information,  his  next 
step  should  be  to  reduce  with  soda  for  lead  and  zinc  ;  if 
lead  is  found,  then  tests  for  chlorine  or  iron  are  in  order ; 
and  if  neither  of  these  be  present,  the  mineral  must  be 
caledonite  or  linarite,  which  must  be  told  apart  by 
reference  to  their  physical  properties.  If  the  redudtion 
with  soda  has  shown  nothing,  the  bead  test  for  iron  and 
uranium  is  in  order.  If  these  are  absent,  the  flame  test 
for  sodium,  potassium,  and  calcium  is  to  be  made  ;  and  if 
these  are  absent,  the  special  test  for  chlorine,  and  then 
water.  If  none  of  these  are  present,  the  mineral  will  be 
found  in  the  list  following  the  double  asterisks,  and  dis- 
tinguished in  that  list  by  its  physical  properties.  (The 
names  of  these  latter  minerals  and  the  physical  properties 
are  omitted  in  this  sample  page  for  lack  of  space). 

It  will  be  objeAed  to  this  method  that  with  minerals 


which  may  contain  small  amounts  of  many  ingredients 
their  classification  will  be  very  difficult.  This  is  admitted ; 
but  by  classifying  these  minerals  under  each  heading  that 
they  can  possibly  come,  as  well  as  under  that  heading 
where  they  must  invariably  come,  the  careful  observer 
cannot  fail  to  identify  them,  no  matter  what  known  variety 
of  composition  they  may  show. 

The  essential  idea  of  this  method  of  working  is  to  use 
the  physical  properties  as  suggestive  or  confirmatory — 
suggestive  on  casual  inspection  of  what  the  mineral  may 
be,  such  suggestion  to  be  confirmed  by  chemical  tests ; 
confirmatory  after  a  determination  by  chemical  tests. 
Conversely,  the  chemical  properties  or  composition  are 
used  as  the  true  determinative  fadlors,  to  which  the  phy- 
sical tests  are  subsidiary  or  confirmatory.  Several  years' 
practical  use  in  the  mineralogy  laboratory  has  demon- 
strated, as  far  as  my  experience  goes,  the  superiority  of 
this  method  of  determination,  both  in  reliability  and — 
taking  the  average— in  quickness. 

(At  the  close  of  the  ledlure  there  was  shown  a  portable 
specific  gravity  hydrometer,  made  by  Wood  and  Comer, 
of  Philadelphia,  with  especial  reference  to  the  use  of  the 
mineralogist,  and  which  gives  rapidly  and  accurately  the 
specific  gravity  of  pieces  weighing  not  over  i  grm.  Its 
use  in  the  laboratory  work  at  Lehigh  University  has 
demonstrated  this  claim,  and  shown  that  it  meets  the 
present  need  for  a  cheap,  portable,  and  accurate  instrument 
for  determining  specific  gravities). 


THE    ATOMIC     MASS    OF    TUNGSTEN.* 
By  WILLETT  LEPLEY  HARDIN. 

A  REVIEW  of  the  literature  on  the  determinations  of  the 
atomic  mass  of  tungsten  will  show  that  a  careful  exam- 
ination of  the  methods  employed  is  of  fundamental  import- 
ance. Fifteen  experimenters  have  made  determinations 
of  this  constant,  but  with  widely  varying  results.  The 
method  of  investigation,  with  few  exceptions,  has  been  to 
reduce  tungsten  trioxide  in  a  current  of  hydrogen  at  a 
white  heat,  and  then  to  re-oxidise  the  metal  thus  obtained. 
Deviations  occur  not  only  in  the  results  of  the  different 
experimenters,  but  also,  with  few  exceptions,  in  the  dif- 
ferent  observations  of  the  same  experimenter.  Clarke 
("  A  Re-calculation  of  the  Atomic  Weights,  1897  ")  closes 
his  summary  of  all  the  work  on  the  atomic  mass  of 
tungsten  with  the  following  words  : — "  Further  investiga- 
tion is  required  in  order  to  fully  establish  the  true  atomic 
weight  of  tungsten." 

Deviations  in  the  results  of  any  atomic  mass  determina- 
tions are  due  either  to  an  inaccurate  method  or  to  experi- 
mental  errors.  It  is  not  always  an  easy  matter,  however, 
to  determine  the  source  of  error  in  a  given  series  of 
variable  results ;  but  with  several  series  of  results  from 
different  experimenters,  the  question  can  be  decided  with 
a  reasonable  degree  of  accuracy.  If,  for  instance,  we 
have  several  series  of  results  by  the  same  method  from 
different  experimenters,  and  if  the  different  series,  with 
the  exception  of  one,  agree  with  each  other,  the  probability 
is  that  the  deviations  in  the  one  series  are  due  to  experi- 
mental errors.  If,  on  the  other  hand,  deviations  occur  in 
each  series,  and  are  more  or  less  similar,  the  probability 
is  that  the  method  is  inaccurate. 

Almost  every  series  of  results  on  the  atomic  mass  of 
tungsten,  obtained  by  the  redudtion  of  the  trioxide  in  a 
current  of  hydrogen,  and  by  the  re-oxidation  of  the  re- 
sulting metal,  shows  a  variation  between  the  maximum 
and  minimum  results  of  from  one  to  two  units,  and  in  ex- 
ceptional cases  the  deviation  is  much  greater.  In  view 
of  these  fadts,  it  seems  desirable  to  make  a  careful  study 
of  the  method  which  has  usually  been  employed  in  this 
work,  rather  than  add  to  the  already  large  number  of  re- 


♦  Contribution  from  the  John  Harrison  Laboratory  of  Chemistry. 
From  the  Journal  of  the  American  CkemiciU  Society,  xix,,  No.  8. 


CBBHicAL  News, 
Sept.  17,  1807. 


A  tomic  Mass  of  Tungsten, 


141 


suits;  for,  if  the  method  is  unreliable,  no  experimental 
skill  can  make  the  results  trustworthy. 

The  following  summary  will  show  the  lack  of  concord- 
ance in  the  results  of  the  earlier  determinations: — 

Berzelius  {Pogg.  Ann.,  viii.,  i,  1826)  was  the  first  to 
determine  the  atomic  mass  of  tungsten.  By  reduction  of 
the  trioxide  he  obtained  the  value  189-6  as  a  mean  of  two 
experiments  for  the  atomic  mass  of  tungsten.  The  differ- 
ence between  the  two  results  was  3-0.  These  results  and 
those  that  follow  are  calculated  on  the  basis  of  0  =  i6. 

Schneider  (jfourn.  Prakt.  Ghent.,  I.,  152,  1850),  working 
with  material  which  had  been  carefully  purified,  obtained 
two  series  of  results  for  the  atomic  mass  of  tungsten,  one 
by  the  redudtion  of  tungstic  acid  and  the  other  by  re- 
oxidation  of  the  metal. 


Redudlion  series. 
184-18 

183-37 
184*01 
18428 
184-45 


Oxidation  series. 
184-21 
184-16 
183-36 


Maximum  diff. 


0-85 


Maximum  diif. 


108 


The  quantity  of  material  used  in  these  experiments 
varied  from  2  to  6  grms. 

Marchand  (Ann.  Ckem.  Pharm.,  Ixxvii.,  261,  1851)  re- 
duced the  trioxide  of  tungsten  and  re-oxidised  the  resulting 
metal ;  the  following  results  were  obtained  for  the  atomic 
mass  of  tungsten  : — 

'183-96}  K^'^^'^'^^^- 


JgJ!'^  I  Oxidations. 


■f^' 


Maximum  difference..       0-60 

Borch  {jfourn.  Prakt.  Chetn.,  liv.,  254,  185 1)  made 
seven  redudions  of  tungstic  acid  in  a  current  of  hydro- 
gen, and  two  oxidations  of  the  metal.  The  results  were 
as  follows : — 

ReduAions.  Oxidations. 

l84'lO  184*53 

182-90  184*32 

183-77  

184-10       Difference     ..    0*21 
183*03 

18377 
183*91 

Maximum  diff.  ..     1*20 

The  quantities  of  material  varied  from  2  to  8  grms. 

By  weighing  the  water  obtained  in  the  reduftion  of 
tungstic  acid  in  hydrogen,  Riche  {jfourn.  Prakt.  Chem., 
Ixix.,  10,  1857)  obtained  the  value  174  for  the  atomic 
mass  of  tungsten  as  a  mean  of  two  experiments.  The 
difference  between  the  two  was  1*78. 

Dumas  {Ann.  Chem.  Pharm.,  cxiii.,  23,  i860)  reduced 
the  trioxide  of  tungsten  in  hydrogen  and  obtained  the  fol- 
lowing results  for  the  atomic  mass  of  tungsten  :— 

184*00 
183*42 
184-16 
183-76 
183-62 
184-80 
18416 
184-08 

Maximum  difference  =  1-38 

The  quantities  of  material  varied  from  1  to  4fg  grms. 

Bernoulli  {Pogg.  Ann.,  cxi.,  573,  i860)  reduced  tungstic 
acid  at  a  very  high  temperature  in  a  current  of  hydrogen. 
The  results  were  as  follows : — 


Reduction  series. 
186-78 
18586 
186  75 
i86-8i 
186-70 
17773 


Oxidation  series. 
18681 
187*94 
186-77 
186*76 


Maximum  diff.  =  1*18 


Maximum  diff.    =  9*08 

The  maximum  difference  in  the  two  series  is  10*21.  He 
found  that  the  greenish  coloured  oxide  gave  the  same  re- 
sults as  did  the  yellow  oxide. 

Persoz  {Ann.  Chim.  Phys.,  [4],  i.,  93,  1864)  made  two 
redudtions  of  the  trioxide  of  tungsten  and  obtained  con- 
cordant results. 

183*93 
183-94 


Difference  =  0*01 

Scheibler  {yourn.  Prakt.  Chem.,  Ixxxiii.,  324,  1861), 
from  determinations  of  the  water  in  barium  meta- 
tungstate,  obtained  the  value  184*00  for  the  atomic  mass 
of  tungsten.     Maximum  difference  =  1-03. 

Zettnow  (Pogg.  Ann.,  cxxx.,30,  1867)  obtained  the  value 
184-08  for  the  atomic  mass  of  tungsten  as  a  mean  from 
four  analyses  of  the  tungstate  of  iron.  From  silver 
tungstate  he  obtained  the  value  183*80. 

Roscoe  (Ann.  Chem.  Pharm.,  clxii.,  368,  1872)  made 
three  reductions  and  two  oxidations  of  the  same  sample 
of  material,  beginning  with  7*8840  grms.  of  tungstic  acid. 
The  results  were  as  follows  : — 

ReduAions.  OxidationSt 

182*72  182-49 

183-71  183*87 

183-97 


Difference  =  1*38 


Maximum  diff.   =   1-25 

From  two  analyses  of  tungsten  hexachloride,  Roscoe 
obtained  the  value  184-25  for  the  atomic  mass  of  tungsten. 
Waddell  (Am.  Chem.  Journ.,  viii.,  280, 1886),  from  care- 
fully purified  tungstic  acid,  obtained  by  redudtion  in  hy- 
drogen the  following  values  for  the  atomic  mass  of 
tungsten : — 

184*55 

184-37 

184-59 

184*00 

183*67 

Maximum  difference  =  0*92 

The  quantities  of  material  varied  from  i  to  4^  grms. 

The  material  used  in  the  work  of  Pennington  and  Smith 
{Zeit.  Anorg.  Chem,,\'m,,  198)  differed  from  that  of  all  the 
preceding  experimenters,  in  that  the  last  traces  of  molyb- 
denum were  removed  by  gently  heating  the  tungstic  acid 
in  a  current  of  hydrochloric  acid  gas.  The  method  of 
operation  was  also  somewhat  different  from  those  of  the 
earlier  experimenters.  The  metallic  tungsten  used  in  the 
oxidations  was  obtained  by  the  reduction  of  tungstic  acid 
in  a  platinum  crucible  at  a  white  heat,  in  a  current  of  hy- 
drogen, which  was  condudled  through  the  lid  of  the 
crucible.  The  mean  of  nine  results  from  the  oxidation  of 
the  metal  is  184*921  for  the  atomic  mass  of  tungsten. 
The  maximum  difference  in  the  series  is  0*043.  The 
quantities  of  material  used  varied  from  0*43  to  1-08  grm. 

Smith  and  Desi  {Zeit.  Anorg.  Chem.,  viii.,  205)  weighed 
the  water  obtained  in  the  reduction  of  tungstic  acid,  and 
from  that  calculated  the  atomic  mass  of  tungsten.  The 
mean  of  six  determinations  is  184*704.  Maximum  differ- 
ence 0*071. 

Schneider  {yourn.  Prakt.  Chem.,  liii.,  288,  1896)   made 

a    second    series    of   redutSlions    and   oxidations.      The 

material    used    in    these    experiments  was    freed    from 

t  molybdenum  by  gently  heating  the  tungstic  acid  in  a  cur- 


142 


Expert  Testimony. 


f  Chemical  NbW8« 
1    Sept,  17,  1897. 


rent  of  hydrochloric  acid  gas.      The  values  obtained  for 
the  atomic  mass  of  tungsten  were  as  follows  : — 

Reduction  series.  Oxidation  series. 

184*14  184*00 

183*98  18392 

183*96  184-04 


Maximum  diff.  =  0*18     Maximum  diff.  =  0*12 

The  quantities  of  material  varied  from  2  to  6  grms. 

Shinn  (Thesis,  University  of  Pennsylvania,  1896)  ob- 
tained by  oxidation  of  metallic  tungsten  the  following 
values  for  the  atomic  mass  of  tungsten  : — 

184*72 
184*96 

18475 
185*22 


Maximum  difference  =  0*48 

The  quantities  of  material  used  varied  from  0*10  to  0*22 
grm.  of  metal. 

A  glance  at  the  foregoing  results  will  show  a  remark- 
able variation.  The  extremely  high  value  obtained  by 
Berzelius  is  supposed  to  be  due  to  the  presence  of  alka- 
line impurities  in  the  material  used. 

The  observations  of  Schneider,  Marchand,  Borch, 
Dumas,  and  Waddell  are  very  similar.  The  method  of 
operation  was  the  same  in  each  case,  and  the  material 
used  was  purified  with  considerable  care.  It  is  difficult 
to  account  for  the  variations  which  occur  throughout 
these  results.  Molybdic  acid  is  probably  the  only  im- 
purity that  could  have  contaminated  the  material  used  in 
the  experiments.  Such  an  impurity  would  probably  have 
lowered  the  separate  results  by  the  same  amount,  and 
hence  would  not  have  produced  the  variations.  The 
deviations  between  the  maximum  and  minimum  results  of 
the  different  experimenters  are  as  follows : — Schneider 
i*o8,  Marchand  o*6o,  Borch  i'63,  Dumas  1*38,  and 
Waddell  ogz. 

The  results  of  Riche  and  Bernoulli  differ  widely  from 
those  obtained  by  other  experimenters.  The  extremely 
low  value  obtained  by  the  former  is  probably  due  to  the 
method.  The  high  results  obtained  by  Bernoulli  are 
more  difficult  to  explain.  The  material  used  was  care- 
fully purified.  The  tungstic  acid  used  in  some  of  the 
experiments  was  of  a  greenish  tinge.  Some  have  assumed 
that  this  material  was  incompletely  oxidised,  and  in  this 
way  account  for  the  high  results.  Bernoulli  found,  how- 
ever, that  the  greenish  coloured  oxide  and  the  yellow 
oxide  gave  the  same  results  when  reduced.  Furthermore, 
neither  the  colour  of  the  original  oxide  nor  the  state  of 
oxidation  could  affedt  the  results  obtained  in  the  re-oxida- 
tions of  the  metal.  The  results  obtained  by  the  latter  ' 
method  are  higher  than  those  obtained  in  the  reduftions. 
In  view  of  these  fads,  the  explanation  which  has  been 
offered  to  account  for  these  high  results  is  entirely  un- 
satisfadory. 

Scheibler's  results  on  barium  metatungstate  show  a 
variation  of  more  than  one  unit,  and  it  must  be  added 
that  the  results  obtained  by  the  determination  of  the 
barium  and  tungsten  in  this  salt  were  still  more  variable 
and  were  not  used  by  Scheibler  in  calculating  the  atomic 
mass  of  tungsten.  The  two  short  series  of  results  on 
ferrous  and  silver  tungstates  by  Zettnow  are  reasonably 
concordant. 

Roscoe's  experiments  on  the  same  sample  of  material 
are  rather  interesting.  The  material  was  reduced  and  re- 
oxidised  several  times  without  being  removed  from  the 
porcelain  boat.  The  maximum  difference  in  a  series  of 
five  results  is  i^  units.  If  the  method  employed  by 
Roscoe  is  accurate,  it  is  difficult  to  account  for  this 
variation. 

The  most  concordant  series  of  results  on  the  atomic 
mass  of  tungsten  is  that  of  Pennington  and  Smith.  The 
value  ob     ne  is  higher  thati  that  obtained  by  most  ex- 


perimenters. Schneider  (yourn,  Prakt.  Chem.,  liii.,  283, 
1896)  has  attempted  to  account  for  the  high  values  ob- 
tained in  these  experiments ;  but,  inasmuch  as  these  re- 
sults agree  very  closely  with  those  obtained  by  Smith  and 
Desi  and  Shinn,  it  is  useless  to  offer  an  explanation  for 
this  high  value  until  the  true  atomic  mass  of  tungsten  is 
known  with  greater  certainty,  at  least  until  a  series  of 
concordant  results  has  been  obtained  which  differs  from 
these. 

Schneider's  last  determinations  consist  of  two  series  of 
results,  each  series  containing  three  observations.  From 
these  two  short  series  of  reasonably  concordant  results, 
Schneider  concludes  that  the  atomic  mass  of  tungsten 
may  be  safely  considered  equal  to  184*00.  The  evidence, 
however,  is  far  from  satisfadory.  In  view  of  the  wide 
variations  in  the  earlier  determinations,  the  number  of 
results  in  these  experiments  is  entirely  too  small  to 
establish  anything  with  certainty  with  regard  to  the  true 
atomic  mass  of  tungsten.  This  fa<^  is  shown  in  the  work 
of  Waddell,  who  made  five  determinations.  The  maxi- 
mum variation  in  the  first  three  observations  was  only 
0*22,  while  in  the  series  of  five  the  variation  was  0*92. 
The  same  is  noticed  in  the  work  of  other  experimenters. 
And  in  the  present  investigation,  consisting  of  more  than 
sixty  determinations,  a  series  of  five  concordant  results 
were  sometimes  obtained,  after  which  considerable  varia- 
tion was  obtained.  Attention  will  be  called  to  this  fad 
again  in  the  discussion  of  the  following  observations. 

(To  be  continued). 


EXPERT     TESTIMONY.* 
By  WILLIAM  P.  MASON. 

It  will  be  remembered  that  a  would-be  facetious  barrister 
once  remarked  that  prevaricators  might  be  properly 
arranged  in  an  ascending  series,  to  wit,  ordinary  fibbers, 
liars,  and  experts, — an  arrangement  which  I  fear  meets 
with  the  approval  of  many  members  of  the  bench  and  bar 
to-day.  The  cause  for  such  harsh  classification  is  not  so 
very  far  to  seek.  It  is  based  upon  ignorance  on  the  part 
of  the  bar,  and  at  times  upon  what  is  worse  than  ignorance 
on  ihe  side  of  the  "expert."  With  the  culpable  adls  of 
the  pseudo  scientist  we  cannot  waste  our  time.  That  he 
merits  prompt  condemnation  is  axiomatic;  but  a  word  is 
wanted  touching  upon  what  may  be  termed  the  ignorance 
of  the  court. 

•'  When  I  take  my  place  upon  the  witness  stand,"  said 
a  prominent  toxicologist  once  to  me,  "  I  can  never  predidl 
in  what  shape  I  shall  be  upon  leaving  it,"  a  feeling  with 
which  most  of  us  can,  I  fancy,  sympathise  pretty  keenly* 

Is  it  that  we  fear  exposure  of  the  weak  points  in  our 
professional  armour  ?  Do  we  dread  to  say  in  public  "  I 
do  not  know  ?  "  Hardly  that,  I  take  it.  We  are  now 
possessed  of  so  very  little  of  that  which  one  day  may  be 
known,  that  no  true  scientist  hesitates  for  an  instant  to 
plead  legitimate  ignorance.  What  really  troubles  us  upon 
cross-examination  is  that  the  court  does  not  speak  our 
language,  a  language  often  quite  difficult  of  dired  trans- 
lation ;  that  it  is  but  rarely  schooled  in  the  principles  of 
our  science;  and  that,  in  consequence,  it  frequently  insists 
upon  categorical  answers  to  the  most  impossible  kind  of 
questions. 

The  hypothetical  questions  showered  upon  the  expert 
witness  are  sometimes  veritable  curiosities,  so  peculiar 
are  they  in  their  monstrosity.  Who  among  us  but  has 
felt  that  the  layman,  who  has  simply  to  testify  to 
observed  fads,  has  an  easy  time  of  it  indeed,  when  com- 
pared with  him  from  whom  there  is  expcded  an  opinion 
under  oath  ? 

*  An  Address  by  Vice-President  William  P.  Mason,  Chairman  of 
Sefiion  C,  before  theSedlion  of  Chemistry,  American  Association  for 
the  Advancement  of  Science,  Detroit  Meeting,  August,  1897. 


Chbhical  Nbws.  I 
Sept.  17,  i8q7,     f 


Expert  Testimony^ 


Hi 


All  scientific  men  are  willing  and  anxious  to  have  their 
work  scrutinised  carefully  by  their  peers ;  but  to  be  ex- 
posed to  the  one-sided  criticism  frequently  encountered  at 
the  bar  is  quite  another  matter ;  for  it  must  be  remembered 
that  after  the  adverse  counsel  has  opened  up  what  appears 
to  be  a  glaring  inconsistency  in  the  testimony,  the  re-direi5t 
examination  may  utterly  fail  to  repair  the  breach,  because 
of  a  lack  of  familiarity  with  a  technical  subjei^  on  the 
part  of  the  friendly  attorney. 

This  leaves  the  witness  in  the  unenviable  position  of 
disagreeing  with  the  general  drift  of  his  own  testimony, 
while  it  deprives  him  of  suitable  means  of  insisting  upon 
its  revision  and  corre(5tion. 

According  to  the  writer's  view  there  is  but  one  way  to 
escape  such  dilemma,  and  that  is  by  diredt  and  immediate 
appeal  to  the  judge,  urging  that  the  oath  taken  called  for 
a  statement  of  the  whole  truth,  and  not  the  misleading 
portion  already  elicited. 

To  illustrate  how  serious  a  matter  the  partial  testimony 
of  an  expert  witness  may  be,  and  to  show  also  to  what 
extent  lawyers  may  go  who  look  only  to  the  winning  of 
their  causes,  permit  me  to  refer  to  an  already  reported 
poison  case  in  which  T  was  employed  by  the  people.  It 
may  be  roughly  outlined  as  follows  : — 

Much  arsenic  and  a  very  little  zinc  were  found  in  the 
stomach. 

The  body  had  not  been  embalmed,  but  cloths  wrung  out 
in  an  embalming  fluid  containing  zinc  and  arsenic  had 
been  spread  upon  the  face  and  chest. 

Medical  testimony  showed  that  no  fluid  could  have  run 
down  the  throat.  Knowing  the  relative  proportions  of 
zinc  and  arsenic  in  the  embalming  fluid,  the  quantity  of 
arsenic  found  in  the  stomach  was  twelve  times  larger 
than  it  should  have  been  to  have  balanced  the  zmc  also 
there  present,  assuming  them  to  have  both  come  from 
the  introdudion  of  the  said  embalming  fluid  by  cadaveric 
imbibition.  Other  circumstantial  evidence  was  greatly 
against  the  prisoner. 

At  the  time  of  my  appearing  for  the  people,  on  the  oc- 
casion of  the  first  tria  '  of  the  case,  my  diredt  testimony 
brought  out  very  strongly  the  adt  that  a  fatal  quantity  of 
arsenic  had  been  found  in  the  stomach,  but  no  opportunity 
was  given  me  to  testify  to  the  presence  of  the  zinc  found 
there  as  well,  although  the  fadt  of  its  existence  in  the  body 
was  known  to  the  prosecution  through  my  preliminary 
report.  Through  ignorance  of  the  nature  of  such  report 
on  the  part  of  the  defence,  no  change  was  made  in  the 
character  of  my  testimony  during  the  cross-examination, 
and  I  was  permitted  to  leave  the  witness-stand  with  a 
portion  of  my  story  untold.  No  witnesses  were  called  for 
the  defence,  and  the  case  was  given  to  the  jury  with  the 
darkest  of  prospedts  for  the  prisoner. 

For  many  reasons,  unnecessary  to  recount  here,  I  was 
distinctly  of  the  opinion  that  murder  had  been  committed, 
but  I  felt  nevertheless  that  common  justice  demanded 
that  the  prisoner  should  have  been  entitled  to  whatever 
doubt  could  have  been  thrown  upon  the  minds  of  the  jury, 
no  matter  how  far-fetched  the  foundations  for  such  doubt 
might  have  been. 

The  first  trial  having  resulted  in  a  disagreement  of  the 
jury,  I  was  pleased  to  learn,  before  the  second  hearing  of 
the  case  began,  that  the  defence  was  prepared  to  go  into 
the  question  of  the  embalming  fluid  ;  for  the  responsibility 
of  permitting  only  a  part  of  what  I  knew  to  be  drawn 
from  me,  to  the  entire  exclusion  of  the  remaining  portion, 
was  greater  than  I  wished  to  assume.  The  nature  of  my 
report  to  the  coroner  having  been  established,  and  certain 
opinions  relating  thereto  having  been  fully  ventilated,  the 
jury  were  possessed  of  "  reasonable  doubt  "  and  acquitted 
the  prisoner.  What  now  were  the  duties  of  the  expert 
upon  the  occasion  of  the  first  trial  of  this  case,  and  how 
should  he  have  construed  the  meaning  of  his  oath  ? 

One  eminent  legal  light,  to  whom  the  question  was  re- 
ferred, held  that  the  expert  was  distindlly  the  property  of 
the  side  employing  him,  and  that  his  duty  was  simply  to 
answer  truthfully  the  questions  put  to  him,  without  aU 


tempting  to  enlighten  the  court  upon  fadts  known  to  him, 
but  not  brought  out  by  the  examination,  no  matter  how 
vital  such  fadts  might  be. 

Another  held  that  although  the  above  course  would  be 
proper  in  a  civil  case,  yet,  in  a  matter  involving  life  and 
death,  the  witness  should  insist  upon  the  Court  becoming 
acquainted  with  his  whole  story.  Do  not  such  differences 
in  legal  opinion  make  it  very  desirable  that  the  expert, 
at  least  in  capital  cases,  should  be  the  employe  of  the 
bench  rather  than  of  the  bar,  in  order  that  whatever  sci- 
entific investigations  are  made  may  be  entirely  open  to 
public  knowledge  and  criticism  ? 

Although  the  expert  should  earnestly  strive  to  have 
what  he  has  to  say  presented  in  the  best  form,  he  must 
remember  that  to  secure  clearness,  particularly  before  a 
jury,  technicalities  should  be  reduced  to  a  minimum.  To 
a  degree  they  are  unavoidable,  but  let  them  be  as  few  as 
possible.  Illustrations  should  be  homely  and  apt,  capable 
of  easy  grasp  by  the  jury's  minds,  and,  if  possible,  taken 
from  scenes  familiar  to  the  jury  in  their  daily  lives. 

It  is  an  unfortunate  fadt  that  the  expert  must  be  prepared 
to  encounter  in  the  Court-room  not  only  unfamiliarity 
with  his  specialty,  but  also  deep-rooted  prejudices  and 
popular  notions  hoary  with  age  and  not  to  be  lightly  re- 
moved from  the  mind  by  the  words  of  a  single  witness. 
As  President  Jordan  has  well  said,  "  There  is  no  nonsense 
so  unscientific  that  men  called  educated  will  not  accept  it 
as  science,"  and,  let  me  add,  they  will  calmly  attempt  to 
shove  the  burden  of  proof  upon  the  scientific  man  who  is 
opposed  to  their  views.  Sanitary  experts,  in  particular, 
run  up  against  all  sorts  of  popular  superstitions,  and  are 
inveighed  against  as  "  professors  "  by  those  who  consider 
themselves  the  "  pradlical  "  workers  of  the  time;  and,  let 
it  be  noted,  the  burden  of  proof  is  uniformly  laid  upon 
these  "  professors'  "  shoulders,  while  the  most  astounding 
and  occult  statements  made  by  the  "  pradtical "  men  may 
be  received  without  verification. 

One  source  of  trouble,  which  perhaps  is  peculiar  to  the 
water  expert,  lies  in  the  impossibility  of  utilising  analytical 
results  such  as  were  made  many  years  ago. 

Those  who  are  not  chemists  fail  to  grasp  the  fadl  that 
the  examination  of  water  may  not  be  looked  upon  from 
the  same  point  of  view  as  the  analysis  of  an  iron  ore. 
The  statement  that  water  analysis  is  but  of  recent  birth, 
and  that  it  is  yet  in  its  infancy,  is  hard  for  them  to 
appreciate,  holding,  as  they  naturally  do,  that  what  was 
true  twenty  years  ago  must  be  true  to-day,  if  science  does 
not  lie. 

A  pit  into  which  many  an  expert  witness  falls  is  pre- 
pared for  him  by  insidious  questions  leading  him  to 
venture  an  opinion  upon  matters  outside  of  his  specialty. 
It  is  a  fatal  error  to  attempt  to  know  too  much.  Terse, 
clear  answers,  well  within  the  narrow  path  leading  to  the 
point  in  question,  are  the  only  safe  ones  ;  and  when  the 
line  of  inquiry  crosses  into  regions  where  the  witness 
feels  himself  not  truly  an  expert,  his  proper  course  is  to 
refuse  to  testify  outside  of  the  boundaries  of  his  legitimate 
province. 

Unfortunately  the  expert  is  as  often  invited  to  take  these 
collateral  flights  by  the  side  employing  him  as  by  the 
opposition.  Affidavits  in  submitted  cases  are  commohly 
written  by  the  lawyers  and  not  by  the  expert,  although 
they  are,  of  course,  based  upon  his  reports.  In  the 
strength  of  his  desire  to  win  the  case,  the  lawyer  often 
prepares  a  much  stronger  affidavit  than  his  witness  is 
willing  to  swear  to. 

The  writer  has  had  no  little  difficulty  just  at  this  point, 
and  has  had  plenty  of  occasion  to  observe  the  irritation 
displayed  by  counsel  upon  a  refusal  to  endorse  statements 
which  have  been  "  too  much  expanded." 

Every  expert-witness,  especially  in  his  early  cases,  is 
sure  to  have  adverse  authorities  quoted  against  him ; 
therefore  it  behoves  him  to  be  so  familiar  with  the  litera- 
ture of  his  subjedt  as  to  be  capable  of  pointing  out  that 
such  and  such  a  writer  is  not  up  to  date,  or  that  such  and 
<  such  a  passage,  if  quoted  in  full,  would  not  bear  the  ad- 


144 


Expert  Testimony. 


f  Cbbmical  Nbws, 

I     Sept.  17,  1807. 


verse  construdlion  that  its  partial  presentation  carries. 
When  the  expert  reaches  a  position  of  such  prominence 
that  he  can  state  a  thing  to  be  so  because  he  says  it, 
irrespedlive  of  whatever  may  be  written  on  the  subjedt  to 
the  contrary,  his  course  then  is  greatly  simplified  ;  but 
long  before  he  attains  that  altitude  he  will  have  put  him- 
self upon  record  in  many  cases,  and  happy  for  him  if  the 
record  so  made  be  such  as  cannot  be  quoted  to  his  dis- 
advantage. 

•'  If  I  had  only  not  written  my  first  book,"  is  the  reflec- 
tion of  many  a  distinguished  author;  while  one  of  the 
great  masters  of  music,  referring  to  an  opera,  said  "  It  is 
one  of  my  early  crimes." 

Above  all  things,  the  expert  "  should  provide  things 
honest  in  the  sight  of  all  men." 

It  is  well  for  him  to  be  deeply  interested  in  his  case,  to 
feel  in  a  measure  as  if  it  were  his  own ;  but  it  is  unwise 
in  him  to  become  so  partisan  as  to  let  his  feelings  affedt 
his  good  judgment,  and  it  would  be  indeed  criminal  should 
he  permit  his  interest  in  any  way  to  contort  the  fads. 

Before  the  case  is  brought  to  a  final  hearing  it  may  be 
apparent  that  experiments  before  the  Court  are  possible, 
and  they  may  be  demanded  by  the  counsel  in  charge  of 
the  case.  If  such  experiments  be  striking,  easy  of  execu- 
tion, and  not  too  long,  by  all  means  make  them. 

Pradtical  illustrations,  particularly  such  as  involve  some 
fundamental  principle,  have  great  weight  with  the  Court; 
but  these  illustrations  must  not  be  such  as  would  turn  the 
Court-room  into  a  temporary  laboratory  and  involve  the 
loss  of  much  time  in  vexatious  waitings. 

Such  experiments  as  are  determined  upon  should  be 
thoroughly  rehearsed  beforehand,  no  matter  how  simple 
they  may  be;  for,  of  all  failures,  the  Court-room  ex- 
periment which  declines  to  "  go  off"  is  perhaps  the  most 
dismal. 

This  brings  to  mind  a  kindred  topic  upon  which  there 
should  be  a  word  of  caution  :  laboratory  experiments 
which  work  to  perfedtion  may  utterly  fail  when  expanded 
to  commercial  proportions,  so  that  it  is  wise  to  bear  in 
mind  the  danger  of  swearing  too  positively  as  to  what 
will  happen  in  large  plants,  when  the  opinion  is  based 
only  upon  what  is  observed  to  occur  upon  the  smaller 
scale.  Like  conditions  will,  of  course,  produce  like 
results ;  but  it  is  marvellous  how  insidiously  unlooked-for 
conditions  will  at  times  creep  into  one's  calculations,  and 
how  hard  it  is  even  to  recognise  their  presence. 

When  preparing  his  case  for  presentation,  the  expert 
often  errs  in  not  dwelling  more  largely  upon  certain  points 
because  he  thinks  them  already  old  and  well  known.  To 
him  they  may  be  old,  but  to  the  public  they  may  be  of  the 
newest.  Not  only  is  the  public  unequally  posted  with  the 
specialist,  but  what  it  once  knew  upon  the  subjeft  may 
have  been  forgotten.  It  is  well  therefore  to  insert,  in  a 
special  report,  matters  that  would  be  properly  omitted 
from  a  paper  prepared  for  a  professional  audience. 

Sanitary  problems  are  of  especial  interest  to  the  public, 
but  the  amount  of  ignorance,  or  rather  false  knowledge, 
displayed  concerning  them  is  surprising  and  often  difficult 
to  combat.  The  sanitarian  is  not  unfrequently  called 
upon  suddenly  to  defend  a  position  involving  complex 
statistics  ;  and  because  the  data  cannot  be  forthwith  pro- 
duced, the  inference  is  drawn  that  his  points  are  really 
without  fads  to  support  them,  and  that  they  are  conse- 
quently not  well  taken. 

Long  before  he  gets  into  court,  particularly  if  the  time 
for  preparation  of  the  case  be  short,  the  expert  may  well 
"  pray  to  be  delivered  from  his  friends."  He  may  receive 
a  peremptory  order  by  telegraph  to  *'  determine  the  mine- 
ral qualities  of  this  rock,"  when  the  telegram  should  have 
read  "  Assay  this  ore  for  silver,"  and  later  it  may  be  a 
matter  of  surprise  that  a  quantitative  knowledge  of  the 
copper  present  was  not  obtained  while  passing  along  the 
line  for  the  determination  of  the  silver;  for  it  is  generally 
not  known  that  the  complete  analysis  of  anything  is  quite 
rare  and  correspondingly  tedious  and  expensive. 

Toxicologists  who  hear  me  may  call  to  mind  some  case 


involving  a  search  for  the  presence  of  an  alkaloid,  strych- 
nia for  example,  during  which  search  the  distridl  attorney, 
in  his  eagerness  for  information,  may  have  asked  to  know 
what  the  indications  were  as  to  the  presence  of  the  poison, 
at  a  time  when  the  extraneous  organic  matter  was  not 
nearly  removed.  He  may  have  wished  no  final  report, 
but  only  the  simple  probabilities,  whereon  to  base  a  pos- 
sible arrest.  Such  requests  are  very  common,  and  are 
akin  to  a  demand  for  a  proof  of  the  pudding  during  the 
early  baking,  when  we  all  know  that  such  proof  comes  at 
a  much  later  stage  of  the  proceedings. 

Finally,  *'  When  dodors  disagree  who  shall  decide  ?  " 

This  question  is  often  very  vigorously  settled  by  the 
jury,  as  was  instanced  in  a  recent  celebrated  murder  trial 
in  New  York  city.  In  that  case  what  the  experts  had  to 
say  on  either  side  was  simply  thrown  overboard  as  a 
whole,  and  the  finding  was  based  upon  the  testimony  of 
the  remaining  witnesses. 

What  can  be  said  upon  this  question  of  the  disagree- 
ment of  expert  witnesses  ?  First,  it  must  be  noted,  they 
are  far  from  being  the  only  class  of  people  who  fail  to 
agree,  and  that  too  on  very  important  subjeds.  Do  my 
hearers  think  it  would  be  a  very  difficult  task  to  find  a 
small  army  of  men  who  would  testify  very  variously  and 
very  positively  upon  questions  of  politics  or  religion  ? 
Would  it  be  hard  to  find  "good  men  and  true"  who 
would  give  under  oath  greatly  differing  opinions  concerning 
the  propriety  of  instituting  free  trade  or  establishing  an 
inheritance  tax  ?  Experts  are  subjed  to  the  same  errors 
of  judgment  as  befall  the  rest  of  professional  humanity, 
and,  when  their  opinions  clash,  they  are  entitled  to  the 
same  resped  that  we  grant  to  the  members  of  the  Bench 
when  they  hand  down  the  decision  of  a  divided  court. 

One  fruitful  opportunity  for  disagreement  always  arises 
when  questions  are  brought  into  court  touching  upon 
matters  newly  discovered,  and  apart  from  the  well-beaten 
path  of  common  professional  knowledge.  Doubt  is  often 
left  upon  the  minds  of  those  seeking  the  light,  even  when 
the  testimony  is  given  by  the  specialist  who  originally 
developed  the  new  point  in  question,  for  one  cannot  be 
expeded  to  be  thoroughly  educated  in  that  which  he  has 
himself  but  recently  discovered. 

Many  of  us  have  dreaded  to  see  the  "  ptomaines,"  or 
putrefadive  alkaloids,  make  their  way  into  court  with 
their  mystifying  influences  upon  judge  and  jury  and  their 
tendency  to  proted  crime.  Now  that  they  are  in,  what  is 
to  be  the  end  ?  Even  with  no  "  ptomaine  theory  "  pos- 
sible, the  ptomaine  form  of  argument  is  not  unknown. 
The  writer  was  once  asked,  in  an  arsenic  case,  whether 
he  was  willing  to  swear  that  at  some  future  time  an  ele* 
ment  would  not  be  discovered  giving  the  stated  readions 
now  called  arsenical  ?  Such  nonsense  is  of  course  insti- 
tuted to  impress  the  jury,  and  is  suggested  by  similar 
questioning  in  the  alkaloid  cases. 

A  recent  and  somewhat  amusing  instance  arose  from 
an  attempt  to  introduce  the  rather  new  conception  of 
"  degeneracy  "  into  a  murder  trial.  The  defence  sought 
to  show  that  the  prisoner  was  a  "  degenerate,"  and 
offered  expert  testimony  as  to  the  meaning  of  the  term 
and  as  to  the  signs  whereby  such  a  condition  was  to  be 
recognised  ;  whereupon  the  prosecution  called  attention 
to  the  fad  that  the  defendant's  experts  themselves  ex- 
hibited every  one  of  the  signs  in  question. 

Having  said  all  that  he  was  to  say,  and  having  stated 
it  to  the  best  advantage,  should  the  expert  depend  upon 
the  stenographer's  so  recording  it  as  to  allow  of  its  being 
used  in  future  without  corredion  ?     Decidedly  not. 

The  average  stenographer  is  unfamiliar  with  technical 
terms,  especially  such  as  are  chemical,  and  the  witness 
who  fails  to  supervise  the  minutes  may  find  out  later  that 
he  was  sworn  to  a  most  remarkable  array  of  "  fads." 
The  writer  once  discovered  that  he  had  recommended,  as 
a  very  efficient  method  of  purifying  a  city  water,  the 
filtering  of  the  entire  supply  "  through  a  layer  of  black 
mud."  Not  to  take  your  time  further,  let  us  summarise 
what  has  thus  been  briefly  said :— 


CbBMICAL  NBWS,  ' 

Sept.  17,  1897. 


Chemical  Notices  from  Foreign  Sources. 


145 


The  expert  witness  should  be  absolutely  truthful,  of 
course ;  that  is  assumed,  but  beyond  that  he  should  be 
clear  and  terse  in  his  statements,  homely  and  apt  in  his 
illustrations,  incapable  of  being  led  beyond  the  field  in 
which  he  is  truly  an  expert,  and  as  fearless  of  legitimate 
ignorance  as  he  is  fearful  of  illegitimate  knowledge. 

Mounting  the  witness-stand  with  these  principles  as  his 
guide,  he  may  be  assured  of  stepping  down  again  at  the 
close  of  his  testimony  with  credit  to  himself  and  to  the 
profession  he  has  chosen. 


NOTICES  OF  BOOKS. 


Organic  Chemical  Manipulation.      By   J.    T.    Hewitt, 
M.A.,  D.Sc,  Ph.D.,  F.C.S.  (London  and  Berlin),  Pro- 
fessor of  Chemistry   in    the   East   London  Technical 
College.     With   63  Illustrations.      London  and   New 
York  :  Whittaker  and  Co.     1897.     ^P*  260. 
It  is  very  satisfadory   to   find   the   evidently  increased 
attention    now   paid   to   organic   chemistry,   both   in   its 
analytical  and  its  synthetical  phases.     Dr.  Hewitt,  in  the 
work  before  us,  is  contributing  ably  to  meet  the  demand 
thus  springing  up. 

The  first  chapter  discusses  the  purification  of  organic 
substances.  In  the  second  we  come  to  the  ultimate 
analysis  of  organic  compounds,  the  determination  of 
equivalent  and  molecular  weights ;  whilst  the  fourth 
chapter  treats  of  the  estimation  of  special  groups  of  atoms 
in  organic  compounds. 

The  second  part  enters  upon  the  preparation  of  organic 
substances,  classified  under  the  heads  of  "  Compounds  of 
the  Fatty  Series  "  and  *'  The  Aromatic  Hydrocarbons  and 
their  Derivatives." 

After  a  careful  inspedlion,  we  feel  fully  warranted  in 
recommending  this  little  work  to  the  earnest  student. 


Manueli  Hoepli.      Metallic  Alloys  and  Amalgams  ;  Alu- 
minium, Nickel ;  the  Precious  Metals  and  their  Imita- 
tions ;  Bronze,  Brass,  Coins,  Medals,  Solders.      By  the 
Engineer  S.  Ghersi,     Milan:  Ulrico  Hoepli. 
We   find   here    a  very  complete  account   of   alloys   in 
general,  their  composition  and  properties.     Special  atten- 
tion has  been  paid  to  the  influence — generally  deleterious 
— of    traces    of    foreign    metals.       The     tin    of    Banca 
approaches    very   closely   to    chemical    purity,    that    of 
Queensland   taking   the  second  place.      The  coppers  of 
Australia  and  of  Lake  Superior  differ  little  in  their  degrees 
of  purity. 

The  following  alloy  exhibits  a  curious  modification  of 
colour ;  it  is  purple  with  ruby-red  refledtions.  The  com* 
pound  of  22  per  cent  of  gold  with  78  per  cent  of  aluminium 
— known  as  Margot's  alloy — is  perhaps  the  most  beautiful, 
but  it  is  deficient  in  malleability.  Margot  is  of  opinion 
that  its  colour  is  due  to  microscopic  crystals  of  alumina 
disseminated  in  the  mass;  but  this  is  open  to  doubt.  The 
yellow  alloy  of  platinum  and  aluminium  can,  by  a  modifi- 
cation of  the  proportions,  be  rendered  violet  or  greenish. 

The  experiments  of  Krupp  are  in  favour  of  the  use  of 
iron-nickel  for  artillery  and  metal  plating.  If  steel  is  of 
an  inferior  quality  it  is  not  improved  by  the  addition  of 
nickel. 

A  rose-coloured  alloy  is  obtained  with  750  parts  gold, 
200  parts  silver,  and  50  parts  of  copper. 


Tables  for  Gas  Analyses,  Gas  Volumetric  Analyses, 
Determination  of  Nitrogen,  S'C.  ("  Tabellen  fiir  Gas 
Analysen,  Gas  Volumetnsche  Analysen,  Stick  StofT- 
bestimmungen,  &c.").  By  Prof.  Dr.  G.  Lunge.  London, 
Edinburgh,  and  Oxford  :  Williams  and  Norgate.    1897. 

A  set  of  useful  analytical  tables,  conveniently  arranged 

for  laboratory  use. 


CORRESPONDENCE. 


OCCURRENCE    OF    VANADIUM. 

To  the  Editor  of  the  Chemical  News. 
Sir, — Apropos  of  the  description  of  the  occurrence  of 
vanadium  in  rutile  by  Hasselberg  (see  Chemical  News, 
vol.  Ixxvi.,  p.  112),  the  following  analysis  of  a  sample  of 
rock  from  South  Africa  may  be  of  interest.  It  was  sent 
here  for  analysis  as  a  sanlple  of  iron  ore  : — 

SiOa        o'99 

AI2O3      2'06 

FeaOs 7285 

FeO        5-24 

MnO      o'2o 

CaO       0*40 

MgO      0-54 

TiOg      1500 

V2O5      o'59 

NiO       030 

Cr303 026 

Combined  H2O    ..      ..  1*37 

Moisture        0*58 

Phosphorus nil 

Sulphur trace 

Arsenic nil 


100 '38 
— I  am,  &c., 

F.  W.  Daw,  A.R.C.SC.,  F.C.S. 

Ebbw  Vale,  Sjptembjf  4,  1S97. 


CHEMICAL    NOTICES   FROM    FOREIGN 
SOURCES. 


NoTB.— All  degrees  of  temperature  are  Centigrade  unless  otherwiae 
ezprcBsed. 

Comp/es  Rendus  Hebdomadaires  des  Seances,  de  V Academie 
des  Sciences,     Vol.  cxxv..  No.  7,  August  16,  1897. 
Dr.  Ferrand  made,  through  the  mediation  of  Armand 
Gautier,  a  claim  of  priority  as  regards  vaccination  against 
cholera. 

Researches  on  the  Simple  Cathodic  Rays. —  H. 
Deslandres. 

A(5\ion  of  Rontgen  Tubes  behind  Screens  Opaque 
to  X  Rays. — Abel  Buguet. — The  radiations  concerned 
do  not  come  essentially  from  the  solid  bodies  employed 
in  the  experiments.  They  are  attenuated  when  the 
sensitive  surface  is  more  or  less  masked  by  sheets  of 
paper,  aluminium,  tin,  silver,  or  lead.  They  did  not 
traverse  a  sheet  of  lead  of  0*5  m.m.  The  radiations  may 
be  used  in  the  radiography  of  partially  opaque  bodies  in 
cases  where  the  diredt  adlion  of  the  X  rays  is  arrested  by 
impassable  obstacles.  The  phenomenon  is  not  affeded 
by  a  magnetic  field,  nor  by  a  powerful  current  of  air 
playing  over  the  surface  of  the  sensitive  body. 


Bulletin  des  Travaux  de  la  Sociite  de  Pharmacie  de 

Bordeaux.  July,  1897. 
Analysis  of  the  Oil  of  American  Black  Walnuts 
(Juglous  nigra, L.). — MM.  Barthe  and  Boutineau. — The 
tree  producing  these  nuts  was  imported  into  Europe  in 
1656.  It  is  now  common  in  the  Gironde  and  Lower 
Pyrenees,  where  it  grows  to  a  considerable  size.  And 
although  the  nut  itself  is  not  so  agreeable  to  the  taste  as 
the  ordinary  walnut,  on  account  of  its  slight  flavour  of 
turpentine,  it  gives  a  useful  and  quickly-drying  oil.    One 


146 


British  Association  for  the  Advancement  of  Science, 


ICHKUtCAL  NtWS, 
Sept.  17,  1897. 


kilogrm.  of  the  kernel  gives,  as  a  rule,  470  grms.  of  oil ; 
its  specific  gravity  is  0929  at  15°  C. ;  its  acid  index,  ex- 
pressed in  m.grms.  of  caustic  potash,  is  4*12  ;  its  index  of 
saponification  is  195;  its  index  of  refradion  is  +26°  at 
15°  C.  in  Jean's  refradtometer ;  and  it  dissolves  in  abso- 
lute alcohol  to  the  extent  of  6  grms.  per  litre. 

Examination  of  the  Officinal  Solution  of  Per- 
chloride  of  Iron. — E.  Falieres. — This  solution  should 
contain  26  per  cent  of  anhydrous  ferric  chloride,  or  8*96 
per  cent  of  iron  ;  its  density  is  then  1*26.  It  may,  how- 
ever, be  adulterated  and  its  density  then  brought  up  to 
the  right  point  by  the  addition  of  salts  of  soda  or  potash. 
The  author  has  sought  for  a  rapid  method  of  estimating 
its  purity,  and  found  that  this  could  be  best  done  by 
alkalimetric  titration  of  the  quantity  of  acid  in  combina- 
tion with  the  iron,  and  the  estimation  of  the  chlorine  by 
nitrate  of  silver. 

Possible  Manner  of  the  Formation  of  the  Fossil 
Phosphates  of  Lime  in  the  Province  of  Oran. — M. 
Dion. — The  author  concludes  that  these  fossil  phosphates 
have  an  aqueous  origin  ;  that  they  are  formed,  from  above, 
downwards,  by  the  acSion  of  infiltrating  rain-water;  and 
that  animal  remains  were  the  only  source  of  phosphorus 
in  these  deposits,  as  no  phosphates  belonging  to  the  crys- 
talline minerals  are  to  be  found  in  the  neighbourhood. 


Bulletin  de  la  Societe  Chimique  de  Paris. 
Series  3,  Vol.  xvii.-xviii..  No.  13. 

M.  Gautier  presented,  on  behalf  of  M.  Helier  and  him- 
self, the  researches  they  have  carried  out,  on  the 
combination  of  chlorine  and  hydrogen  under  the  influence 
of  light  and  heat. 

M.  Villlers  pointed  out  a  method  of  oxidation  of  mine- 
rals, and  of  organic  compounds  of  the  fatty  series ;  and 
of  substitution  for  the  compounds  of  the  aromatic  series, 
founded  on  the  property  of  salts  of  manganese,  of 
developing  or  facilitating  oxidation  when  introduced  into 
an  oxidising  medium.  The  oxidation  of  oxalic  acid,  by 
hydrochloric  and  nitric  acids,  under  the  influence  of  sul- 
pjhate  of  manganese,  was  exhibited. 

M.  Hanriot  presented,  on  behalf  of  himself  and 
M.  Reynaud,  the  continuation  of  their  researches  on 
isoxazolones. 

M.  Le  Chatelier  found  in  the  residue  left,  after  the 
aftion  of  water  on  carbide  of  calcium,  besides  carbide  of 
silicon,  silicide  of  iron  and  silicide  of  calcium. 

M.  Behal  presented  a  note  on  behalf  of  M.  Prud'homme, 
who,  in  studying  the  adtion  of  a  mixture  of  soda  and 
dilute  alcohol  on  the  ^-nitrodiamidotriphenylmethanes, 
found  that  a  migration  of  one  of  the  atoms  of  oxygen  of 
the  NO2  group  was  produced,  and  that  there  was  formed 
carbinol,  or  the  base  of  a  diamidotriphenylmethane, 
having  the  group  NO  in  a  position  similar  to  that  in  the 
benzenic  nucleus,  not  aminised.  His  researches  also 
confirm  the  formula  attributed  to  the  fuchsines  by 
M.  Rosenstiehl. 

Liquefa(5tion  of  Fluorine. — H.Moissan  and  J.Dewar. 
—Already  inserted  in  full. 

Notes  on  the  Application  of  Acetylene  to  Lighting 
Purposes. — L.  M.  BuUier. — These  experiments  have  been 
carried  out  on  pure  acetylene,  and  on  mixtures  of  acetylene 
with  air,  nitrogen,  carbonic  acid,  carbonic  oxide,  hydro- 
gen, and  coal-gas,  and  they  prove  that  if  we  cannot  gene- 
rally replace  coal-gas  by  acetylene,  in  all  its  applications 
to  lighting  purposes,  the  addition  of  foreign  gases  will 
render  its  use  much  simpler,  and  enable  us  to  obtain 
results  which  can  now  only  be  obtained  with  great  diffi- 
culty, and  this  without  the  aid  of  recuperative  apparatus 
or  anything  delicate  and  costly. 

On  some  New  Methods  of  Transforming  Para- 
Ditrodiamidotriphenylmethanes  into  Fuchsines,  or 
into  Bases  of  corresponding  Fuchsines.— M.  Prud'- 


homme.— The  author  has  tried  four  methods,  viz. : — In 
an  acid  medium,  with  heat;  in  an  acid  medium,  in  the 
cold;  in  an  alkaline  medium;  and  with  sulphide  of  so- 
dium. He  finds  the  latter  method  the  most  advantageous, 
both  as  regards  quality  and  quantity;  but  it  does  not 
appear  to  be  possible  to  obtain  more  than  60  per  cent  of 
the  theoretical  quantity  available  :  this  is  attributed  to  a 
partial  redudtion  of  the  base  into  leucobase.  He  has 
demonstrated  the  existence  of  two  forms  of  the  bases  of 
fuchsines,  which  is  not  in  contradidtion  to  the  observations 
of  M.  Rosenstiehl  or  of  H,  Weil. 


MISCELLANEOUS. 


British  Association  for  the  Advancement  of 
Science. — The  following  are  the  names  of  the  Officers 
and  Committee  of  Sedtion  B  (Chemical  Science)  at  the 
Toronto  Meeting  of  the  British  Association  : — 

President— 'Ptoi.  W.  Ramsay,  F.R.S. 

Vice-Presidents  —  Proi.  G.  F.  Barker;  Prof.  F.  W. 
Clarke;  Prof.  H.  B.  Dixon,  F.R.S. ;  W.  R.  Dunstan, 
F.R.S. ;  Prof.  B.  J.  Harrington;  Prof.  E.  W.  Morley ; 
Prof.  W.  H,  Pike ;  Prof.  I,  Remsen  ;  Prof.  W.  C.  Roberts- 
Austen,  F.R.S. 

Secretaries  — Prof.  W.  H.  Ellis;  Arthur  Harden  (Re- 
corder) ;  Charles  A.  Kohn  ;  Prof.  R.  F.  Ruttan. 

Committee  —  Prof.  W.  W.  Andrews  ;  Prof.  H.  E.  Arm- 
strong, F.R.S.;  Prof.  B.  Brauner;  Prof.  C.  Le  Neve 
Foster,  F.R.S.;  Prof.  W.  L.  Goodwin;  A.  Vernon 
Harcourt,  F.R.S.;  O.  S.  James;  F.  B.  Kenrick ;  Prof. 
Loeb;  Prof.  H.  McLeod,  F.R.S. ;  Prof.  Meldola,  F.R.S.; 
Prof.  Meslans;  W.  L.  Miller;  Prof.  Nef;  H.  Ramage; 
W.  W.  Randall;  Prof.  T.  W.  Richards;  F.  J.  Smale ; 
Prof.  A.  Smith;  A.  Stansfield  ;  Prof.  W.  C.  Williams. 

The  Papers  brought  before  the  Sedtion  were  as  fol* 
lows : — 

President's  Address — "  An  Undiscovered  Gas." 

Prof.  W.  W.  Andrews — Reform  in  the  Teaching  of 
Chemistry. 

Report  of  the  Committee  on  the  Teaching  of  Science 
in  Elementary  Schools. 

Report  of  the  Committee  on  Preparing  a  New  Series 
of  Wave-length  Tables  of  the  Spedtra  of  the  Elements. 

Report  of  the  Committee  to  inquire  into  the  Proximate 
Chemical  Constituents  of  the  various  kinds  of  Coal. 

Report  of  the  Committee  on  the  Isomeric  Naphthalene 
Derivatives. 

Report  of  the  Committee  on  the  Adtion  of  Light  on 
Dyed  Colours. 

Prof.  Ramsay — Helium. 

Prof.  i5raMM«i'— Contributions  to  the  Chemistry  of  the 
Rare  Earth  Metals. 

Prof.  Brauner — The  Atomic  Weight  of  Thorium. 

Prof.  T.  W.  Richards—The  Atomic  Weights  of  Cobalt 
and  Nickel. 

M.  Travers — The  Occurrence  of  Hydrogen  in  Minerals. 

Proj.  W.  N.  Hartley  and  H.  i2a».a^<  —  Spedlroscopic 
Examination  of  Minerals  and  Metals. 

Prof.  Meslans — Demonstration  of  the  Preparation  and 
Properties  of  Fluorine. 

Profs.  Moissan  and  Dewar — The  Properties  of  Liquid 
Fluorine. 

Prof.  /?am5a^— Demonstration  of  the  Spedira  of  Helium 
and  Argon. 

Dr.  y.  Waddell—Thi  Permeability  of  Elements  of  Low 
Atomic  Weight  to  the  Rontgen  Rays. 

Dr.  J.  H.  Gladstone  and  W.  Htftt/rrf— Continuation  of 
Experiments  on  Chemical  Constitution  and  the  Absorption 
of  X  Rays. 

Dr.  W.  y.  Russell — On  the  Ajaion  exerted  by  Certain 
Metals  on  a  Photographic  Plate. 


Ohbuical  News,  ) 
Sept.  17,  1&97.    I 


Chemical  Notices  from  Foreign  Sources. 


147 


Prof.  H.  B.  £)i;toM— Photographs  of  Explosion  Flames. 

F.  P.  Dunmngton — Titanic  oxide. 

F.  P.  Dunnington — Deliquescence  and  Efflorescence  of 
Certain  baits. 

y.  Waddell  —  Notes  on  Concentrated  Solutions  of 
Lithium  and  other  Salts. 

W.  L.  T.  Addison— The  Formation  of  Crystals. 

E,  C.  C.  Baly—A  Compound  of  Ozone  and  Mercury. 

y.  W.  Walker — The  Interadion  of  Hydrobromic  and 
Brumic  Acids. 

P.  T.  Shutt — The  Composition  of  Canadian  Virgin 
Soils. 

Pro/.  W.  H.  £//».— Analysis  of  some  Pre-carboniferous 
Coals, 

Prof.  P.  C.  Freer  —  The  Constitution  of  Aliphatic 
Ketones. 

Prof.  y.  U.  Nef— The  Chemistry  of  Methylene. 

Dr.  A.  Lehmann  —  Formation  of  a  Benzene  Ring  by 
Redudtion. 

Dr.  C.  A.  Kohn  —  Condensation  Produdls  of  Aldehyds 
and  Amides. 

Dr.  Hugh  Marshall— A  New  Form  of  Bunsen-burner. 

Prof.  W.  C.  Roberts-Austen — Molecular  Movement  in 
Metals. 

Dr.  T.  K.  Rose  —  The  Causes  of  Loss  Incurred  in 
Roasting  Gold  Ores  containing  Tellurium. 

H.  C.  Jenkins  —  The  Behaviour  of  Lead  and  of  some 
Lead  Compounds  towards  Sulphur  Dioxide. 

Dr.  W.  L.  Miller  and  T.  R.  Rosebrough— The  Vapour- 
Tensions  of  Liquid  Mixtures. 

Dr.  C.  A.  Kohn  —  The  Eledlrolytic  Determination  of 
Copper  and  Iron  in  Oysters. 

Prof.  Henri— The  Nitro-Alcohols. 

Prof.  W.  W.  Andrews— The  Plaster  of  Paris  Method 
in  Blowpipe  Analysis. 

R.  Ransford— Some  Experiments  with  Chlorine. 

Report  of  Committees — 
The  Electrolytic  Methods  of  Quantitative  Analysis. 
Isomeric  Naphthalene  Derivatives. 
The  Diredt  Formation  of  Haloids  from  Pure  Mate- 
rials. 
The  Bibliography  of  Spedtroscopy. 
The  Carbohydrates  of  Barley  Straw. 

Schools  of  Chemistry,  &c.— The  following  informa- 
tion was  received  too  late  for  insertion  in  the  *'  Students' 
Number": — 

Sheffield  Technical  School  (University  College, 
Technical  Department). — Ledurer  in  Chemistry,  F. 
Ibbotson,  B.Sc,  F.C.S.  ;  Professor  of  Metallurgy,  J.  O. 
Arnold;  Ledurer,  A.  McWilliam,  A.R.S.M. ;  Demonstrator 
and  Ledurer  on  Fuel,  F.  K.  Knowles.  The  work  is  di- 
vided into  two  departments: — I.  The  Technical  Depart- 
ment of  the  University  College,  including  Mechanical, 
Eledrical,  Civil,  and  Mining  Engineering;  Metallurgy. 
II.  The  Evening  Department,  for  providing  Technical 
Instrudion  for  persons  engaged  during  the  day  in  the 
local  industries.  The  courses  of  Evening  instrudion  in- 
clude Magnetism  and  Eledricity,  Inorganic  Chemistry, 
Experimental  Laboratory,  and  Eledrical  Engineering. 
The  Metallurgical  Department  has  been  equipped  with  a 
view  to  thoroughly  meeting  the  requirements  of  the  local 
industries.  The  Laboratory  is  fitted  -with  the  most 
modern  apparatus  for  metallurgical  analysis,  more  espe- 
cially with  appliances  for  the  rapid  and  accurate  chemical 
examination  of  Iron  and  Steel,  Fuel,  and  Refradory 
materials.  It  also  contains  a  complete  pyrometric  in- 
stallation, and  a  new  laboratory  for  the  study  of  the 
micrographic  analysis  of  metals  has  been  completed  and 
fully  equipped  with  specially  designed  microscopes,  by 
Ross,  polishing  tables,  driven  by  an  eledric  motor, 
etching  appliances,  incandescent  light  for  evening  work, 
&c.  The  School  is  now  the  most  complete  of  its  kind  for 
teaching  the  pradical  manufadure,  the  chemical  constitu- 
tion, and  the  physical  properties  of  steel.  Special 
attention  is  given  to  the  determination  of  the  microscopic 


constituents  of  steel.  Although  the  chief  industry  of  the 
distrid  occupies  the  central  position  in  the  course  of 
instrudion,  general  metallurgy  is  not  negleded,  but  is 
dealt  with  in  a  separate  syllabus,  dealing  with  metals 
(other  than  iron  and  steel)  used  in  the  arts.  Students  are 
thus  enabled  to  seled  and  at  once  enter  upon  a  course  of 
scientific  metallurgical  training  of  immediate  pradical 
utility.  They  may  take  up  and  work  through  any  portions 
of  the  course,  but  certificates  will  be  granted  only  to 
those  who  follow  the  prescribed  courses  and  pass  the 
necessary  examinations.  The  course  of  study  is  as 
follows:  —  Preparatory  Chemistry,  Metallurgy  Ledures, 
Fuel  Ledures,  Pradical  Metallurgy,  Pradical  Fuel  Course, 
Geology  and  Mineralogy,  and  Eledro-Metallurgy. 


By    J.     T.     HEWITT,     M.A.,    D.Sc,     Ph.D., 

Fellow  of  the  Chemical  Societies  of  London  and  Berlin, 

Professor  of  Chemistry  in  the  East  London 

Technical  College. 

ORGANIC  CHEMICAL   MANIPULATION. 

With  63  Illustrations.    Crown  8vo,  272  pp.    7s.  6d.  net. 


Contents  : 

Purification  of  Organic  Substances— Ultimate  Analysis  of  Organic 
Compounds — Determination  of  Equivalent  and  Molecular  Weights 
— The  Estimation  of  Special  Groups  in  Organic  Compounds — Pre- 
paration of  Organic  Compounds  of  the  Fatty  Series  :  Hydrocarbons, 
Alcohols,  Monobasic  Acids,  Dibasic  Acids,  Esters,  Aldehyds,  Ketones 
and  Ketonic  Acids,  Sugars — Compounds  of  the  Aromatic  Series  : 
Hydrocarbons,  Nitro-compounds,  Amido-compounds,  Sulphonation, 
Phenols,  Quinones,  Aldehyds  and  Ketones,  Closed  Chain  Compounas 
—Colouring  Matters— &c.,  &c. 

"  A  work  which  will  be  of  great  service  to  many  teachers  of  pradi- 
cal chemistry." — Engineer. 

London:  WHITTAKER  &  CO.,  Paternoster  Square,  E.C. 


NOW  READY,  SECOND  EDITION,  Enlarged,  Crown  8vo., 
cloth  5s.,  leather  6s.  fid. 

THE  ANALYST'S  LABORATORY   COMPANION:   a 

CoUeAion  of  Tables  and  Data  for  Chemists  and  Students.     By 
ALFRED  E.  JOHNSON,  Assoc.  R.C.Sc. I.,  F.I.C.,  F.C.S. 
London  :  J.  &  A.  CHURCHILL,  7,  Great  Marlborough  Street. 


NOW  READY,  with  2  Plates  and  143  Woodcuts,  Crown  8vo.,  10s. 

A  MANUAL  OF  CHEMISTRY.     By  WILLIAM 

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Royal    College  of  Science,  London ;  Examiner  in  Chemistry  to 
the  Department  of  Science  and  Art, 
London:  J.  &  A.  CHURCHILL,  7,  Great  Marlborough  Street. 

Prof.  FRANK  CLOWES  and  Prof.  J.  B.  COLEMAN'S 

ILLUSTRATED 

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QUANTITATIVE  ANALYSIS.    Fourth  Edition.    10s. 

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London  :  J.  &  A,  CHURCHILL,  7,  Great  Marlborough  Street. 


148 


A  dverttsements. 


r  Chemical  News, 
I     Sept.  17,  1S97. 


CITY    OF    LONDON    COLLEGE. 

WHITE  STREET,  MOORFIELDS,  E.C. 
MICHAELMAS  TERM  Commences  on  SEPTEMBER  27th. 

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qphe    following    EVENING     CLASSES    in 

-■•  CHEMISTRY  (Leftures  and  Laboratory  work),  under  the 
direftionofF.  MOLLWO  PERKIN,  Ph.D.,  commence  MONDAY, 
SEPTEMBER  27th,  1897:— 

Elementary  Course  —  Leftures,  Mondays,  7.15— 8.30  ;  Praftical 
work,  Monda  s  or  Thursdays,  8.30 — 10.  Advanced  Course — Le(5tures, 
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nrhe  work  of  the  Chemical  Department,  under 

-*      the  Principal  and  Mr.  H.  C.  L.  BLOXAM,  begins  on  Monday, 
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DAY    TECHNICAL     COLLEGE, 
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Dr.  Alexander   Scott,  M.A.,  D.Sc. 

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Chemical  NbWS, 

Sept.  24,  1897. 


Properties  of  Nitrobenzene. 


149 


THE    CHEMICAL     NEWS 


Vol.  LXXVI.,  No.  1974. 


ON     THE    PROPERTIES     OF     NITROBENZENE. 
By  RICHARD  J.  FRISWELL. 

During  the  severe  winter  of  January,  1886,  a  drum  of 
nitrobenzene  crystallised,  and  I  succeeded  in  removing 
from  it  a  large,  tabular,  transparent  crystal,  2j  inches 
long,  I  inch  broad,  and  |  inch  thick,  weighing  over  15 
grms.  It  was  irregular,  had  no  faces,  and  resembled 
a  mass  of  ice  in  appearance.  I  took  advantage  of  this 
circumstance  to  make  determinations  of  the  specific 
gravity  of  solid  nitrobenzene.  An  Oertling  balance  was 
placed  in  the  open  air,  and  allowed  to  remain  until  the 
temperature  of  an  accurate  thermometer  registered  3-5°, 
and  the  crystal  was  then  weighed  in  air  and  in  water  in 
the  usual  manner. 

Weight  in  air,  15*849  grms. 

Weight  in  water,  4*059  grms. 

Weight  of  water  displaced,  11*790. 

Temperature  of  water,  1*5°. 
This  gives  the  sp.  gr.  as  i '34391  which  is  corredt  to 

-{-0*0001. 

A  large  portion  of  the  crystalline  mass  was  then  freed 
from  liquid  and  fused  in  a  paper  filter;  during  the  fusion 
a  small  quantity  of  moisture  from  the  air  condensed  on 
the  melting  crystals,  but  these  traces  of  water  were  in- 
tercepted by  the  filter,  which  was  rendered  waterproof  by 
being  saturated  with  the  melted  nitrobenzene. 

The  sp.  gr.  of  the  liquid  nitrobenzene  was  ascertained 
by  a  very  accurate  Westphal  balance.  At  3*8°  this  was 
found  to  be  i'22io,  compared  with  water  at  15°,  for  which 
temperature  the  balance  is  standardised. 

During  the  cooling  to  3'8''  the  liquid  became  slightly 
turbid,  indicating  that  the  moisture  condensed  on  the 
fusing  crystals  had  been  dissolved  to  a  minute  extent. 

Correding  the  above  numbers  for  water  at  4°,  we  ob- 
tain i'344o  as  the  sp.  gr.  of  solid  nitrobenzene,  and 
1*2220  as  that  of  the  liquid  nitrobenzene.  The  temper- 
ature of  the  liquid  nitrobenzene  was  adtually  3-8",  but 
this  I  have  taken  as  equal  to  4°.  I  have  not  attempted  to 
corredt  the  solid  nitrobenzene  for  the  increment  between 
1*5°  and  4°,  as  I  have  no  data  for  the  expansion  of  the 
solid  substance. 

There  is  thus  a  contradion  of  volume  amounting  to 
0*099837,  or  nearly  ^^  as  nitrobenzene  passes  from  the 
liquid  to  the  solid  state,  whilst  conversely,  on  fusing,  the 
substance  expands  from  I'oooooo  to  1*099804. 

Temperature  oj  Solidification  of  Nitrobenzene. 

After  the  specific  gravity  of  the  fused  mass  of  crystals 
had  been  taken,  a  thermometer  was  immersed  in  the 
liquid,  and  a  crystal  having  been  dried  on  filter-paper  was 
introduced,  and  the  whole  stirred.  It  almost  imme- 
diately commenced  to  solidify,  and  the  thermometer  rose 
sharply  to  5°,  at  which  it  remained  constant ;  a  thermo- 
meter kept  in  a  large  mass  of  the  fusing  crystals  also 
registered  this  temperature. 

It  has  been  already  stated  that  the  liquid  obtained  from 
the  fused  crystals  exhibited  a  slight  opalescence  or  tur- 
bidity, due  to  the  presence  o'  moisture  condensed  from 
the  atmosphere  and  dissolved  by  the  nitrobenzene  to  a 
minute  extent.  As  soon  as  the  crystal  was  added,  and 
the  temperature  of  the  liquid  began  to  rise,  the  whole 
became  clear,  thus  indicating  in  a  striking  manner  the  in- 
creased power  of  dissolving  water  caused  by  even  so 
small  a  thermometric  rise  as  from  3*8°  to  5*0°. 

Schultz  (in  Die  Chemie  des  Steinkohlentheers,  &c.,  1882, 
first  edition,  p.  355)  states,  without  quoting  his  authority, 


that  nitrobenzene  has  a  fusion-point  of  3°,  a  sp.  gr. 
=  1*2002  at  0°  and  i'i866  at  4°,  no  statement  as  to  the 
temperatures  of  the  water  with  which  comparison  is  made 
being  given.  In  the  second  edition  of  this  work  the  sp.  gr. 
is  stated  to  be  1*208   at  15°. 

Beilstein  gives  the  same  numbers,  and  quotes  Mits- 
cherlich  as  his  authority  for  the  fusing-point  and  Kopp 
for  the  specific  gravity.  Gmelin  gives  Mitscherlich  as 
authority  for  both  numbers,  giving  3°  as  the  fusion-point 
and  1*209  ^s  the  specific  gravity.  It  would  appear  that  no 
recent  observation  of  these  constants  has  been  made. 

This  year  I  have  repeated  the  experiments  (with  the 
exception  of  that  on  the  specific  gravity  of  the  solid)  with 
a  specimen  of  nitrobenzene  prepared  from  benzene  of  the 
highest  purity,  the  nitrobenzene  itself  being  also  very 
carefully  purified  and  twice  distilled.  The  temperature  of 
fusion  was  obtained  with  great  care  by  immersing  a 
standard  thermometer  in  a  large  mass  of  the  solidified 
nitrobenzene.  The  thermometer  is  one  made  by  Casella 
in  1872  ;  it  has  a  Kew  certificate,  and  has  been  tested  at 
Kew  on  two  occasions  since  the  date  of  the  original  cer- 
tificate, the  last  being  in  1S91.  It  is  a  Fahrenheit 
thermometer,  and  the  corredion  at  40°  to  50°  is  —2°. 

Repeated  readings  of  the  former  point  were  taken  with 
this  thermometer,  and  were  found  to  be  43°  to  43*1°  F. 

Several  experiments  were  also  made  with  nitrobenzene 
obtained  by  melting  well-drained  crystals  used  in  the  last 
experiment,  cooling  below  the  solidifying  point,  and  in- 
troducing the  same  thermometer,  to  which  some  crystals 
were  adhering.  The  thermometer  fell  sharply  to  41°  F., 
and  then  the  liquid  instantly  crystallised,  the  temperature 
rising  as  sharply  to  43°  F.,  long  crystals  shooting  with 
extraordinary  rapidity  through  the  mass.  The  number 
above  given,  on  applying  the  correction,  becomes 
41°  F.  =  5°  C. 

The  specific  gravity  was  1*2123  at  13°  and  1*1974  at  28° 
compared  with  water  at  15°.  Compared  with  water  at  4° 
these  numbers  become  1*2116  and  1*1931. 

Boiling-point  of  Nitrobenzene. 

Gmelin,  quoting  Mitscherlich,  gives  the  boiling-point 
of  nitrobenzene  as  213°,  whilst  Schultz  {loc.  cit.,  1882), 
in  his  first  edition,  gives  210°,  and  in  his  second  (1886) 
206°  to  207°.  Beilstein  quotes  Stadeler  as  giving  205°  at 
730  m.m. 

The  sample  was  boiled  on  fragments  of  platinum  foil 
in  one  of  the  pear-shaped  flasks  used  for  determining  the 
boiling-points  of  the  aromatic  hydrocarbons.  A  Geissler 
normal  thermometer  was  used.  When  the  boiling  had 
become  steady,  the  readings  were  203*4°,  203*4°,  203*5°, 
203*5°,  203*5,  ^^'^  the  liquid  was  distilled  to  dryness 
without  further  rise.  The  barometer  stood  at  755  m.m., 
or  29*73  inches.  Corredting  for  760  m.m.,  the  boiling- 
point  2035°  becomes  203*77°. 

The  boiling-point,  when  the  mercurial  column  was 
totally  immersed  in  the  boiling  vapour,  was  209*8,°  209*9°, 
209*8°,  209*9°,  210*0°,  209'9'',  pressure  being  756  m.m. 
Taking  209*9°,  and  correcting  for  barometer  at  760  m.m., 
this  becomes  210*2°.  The  distillation  was  not  continued 
to  dryness,  as  the  previous  experiment  had  proved  the 
liquid  to  be  homogeneous. 

The  Geissler  thermometer  had  been  in  my  possession 
for  many  years ;  but  having  noted  the  faift  that  the  cor- 
rection for  the  Fahrenheit  thermometer  had  changed  from 
-f  0*1°  to  —2*0°  in  twenty  years,  the  zero  point  of  the 
Geissler  thermometer  was  re-determined  and  found  to  be 
4-1°.  This  corresponds  with  i*8°F.  It  is  interesting 
that  two  thermometers  repeatedly  used  for  liquids  boiling 
near  200°  C.  should  exhibit  so  very  similar  an  alteration 
in  the  zero  point. 

If  this  correction  is  applied,  the  boiling-points  become 
uncorrected  for  immersion  of  column  202*8°.  With 
column  immersed,  209*2°. 

Summary  of  Results. 
The  specific  gravity  of  solid  nitrobenzene  d  i'5°/4°  is 


150 


Separation  and  Quantitative  Determination  of  Chlorine,  &c.  i  ^sepT."^^^^"' 


I '3440,  whilst  for  liquid  nitrobenzene  it  is  dy8°(^°,  1*2220 ; 
d  ii°l4.°,  I*2ii6;  d  28°/4°,  1-1931. 

Expansion  on  fusion,  0*099804. 

Contraction  on  solidification,  0*099837. 

Boiling-point  at  760  m.m.,  209°  corre(5ted  (that  is,  with 
column  immersed  in  the  vapour). 

Nitrobenzene  is  remarkable  as  giving  a  strongly- 
coloured  vapour.  The  colour,  which  resembles  that  of 
diluted  chlorine,  is  visible  in  a  layer  of  2  inches,  and  is 
very  marked  in  a  layer  of  6  or  8  inches.  The  vapour 
does  not  exhibit  a  banded  spedtrum  when  examined  by 
transmitted  light. — Transactions  of  the  Chemical  Society, 
1897. 


REMARKS    ON    THE    PART    PLAYED    BY 
CHEMISTRY    IN     PERFUMERY. 

By  LOUIS  OLIVIER. 

The  fears  expressed  by  M.  J.  Rouche  on  the  subjeft  of 
the  introduction  of  chemistry  into  the  perfumery  industry 
suggest  a  remark  that  he  would  certainly  not  wish  me  to 
express.  It  is  only  natural  that  French  perfumery,  en- 
dowed by  nature  with  a  kind  of  monopoly,  fears  seeing 
itself  robbed  of  this  monopoly,  and  that  through  the 
progress  of  chemistry.  But  this  evolution  is,  if  I  mistake 
not,  a  law  of  Nature.  As  it  spreads  through  civilisation, 
science,  an  international  possession,  tends  to  destroy,  for 
the  good  of  the  many,  the  privileges  of  the  few.  It  is  to 
the  multitude  of  consumers  that  it  holds  out  its  blessings, 
and  thanks  to  them  a  larger  number  of  human  beings  are 
enabled  to  enjoy,  and  it  is  continually  lowering,  the 
selling  price. 

Whether  we  rejoice  or  are  sorry,  there  is  the  law. 
Should  we  therefore  on  this  account,  simply  with  the 
view  of  postponing  the  end  of  a  privilege,  turn  our  backs 
on  this  science,  in  which  our  foreign  rivals  see  their 
safety,  and  which  will  permit  them  to  beat  us  in  our  own 
products  ? 

To  try  and  avoid  an  inevitable  evolution,  should  the  French 
perfumery  industry  go  on  rather  to  a  revolution,  which  would 
be  fatal  to  it?  Instead  of  letting  Germans,  English,  and 
Americans  make  artificial  products,  of  mediocre  value 
perhaps,  but  of  large  sale,  and  thus,  to  the  detriment  of 
the  French,  take  possession  of  the  International  market, 
would  it  not  be  better  to  put  oneself  in  the  van  of  pro- 
gress, direct  it,  and  assure  oneself,  independently  of  the 
present  market,  of  the  acquisition  of  new  ones  ? 

A  chemical  laboratory  and  good  chemists  doubtless 
represent  a  serious  expense,  the  more  difificult  to  bear 
inasmuch  as  in  scientific  research  there  is  always  the  risk 
of  not  being  immediately  successful.  But  in  commerce 
sacrifices  are  necessary ;  we  must  learn  to  prepare  for 
the  future.  If  French  perfumery  decides  to  have  a  merry 
life,  it  will  undoubtedly  run  the  risk  of  having  a  short 
one. — Revue  Ginirale  des  Sciences,  8th  year,  No.  16, 
Aug.  30,  1897. 


ON  THE 

ESTIMATION    OF    OXIDE     OF    IRON    AND 

ALUMINA    IN     PHOSPHATES. 

By   N.  BLATTNER  and   J.   BRASSEUR. 

The  following  methods  have  been  studied  in  the  labora- 
tory of  the  Kuhlmann  works  at  Loos  : — 

1.  The  acetic  method,  or,  to  be  more  exaCt,  the  acetic 
acid  and  ammonia  method,  carried  out  in  the  manner 
proposed  by  Maret  and  Delattre. 

2.  Glaser's  method,  based  on  the  preliminary  separation 
of  the  lime. 

3.  Lasoe's  method,  by  separating  the  aluinina  in  the 


state  of  phosphate,  by  means  of  caustic  soda,  hyposul- 
phite, and  acetate  af  ammonium. 

4.  Gruber's  method,  analogous  to  the  preceding  one. 

5.  Gladding's  method,  based  on  the  same  principle,  but 
making  use  of  caustic  potash  instead  of  soda. 

6.  Thomson's  method,  by  the  direCt  precipitation  of 
phosphate  of  iron  and  alumina  with  ammonia. 

MM.  Blattner  and  Brasseur  have  been  led  to  the  fol- 
lowing conclusions : — 

1.  Acetic  method.  This  should  be  disused  :  the  figures 
found  for  alumina  are  nearly  always  much  too  low,  the 
acetic  liquid  keeping  in  solution  a  sensibly  constant 
quantity  of  alumina. 

2.  Glaser's  method  (the  alcoholic)  gives  sufficiently 
accurate  results  when  the  phosphates  are  free  from  man- 
ganese ;  it  is  rapid  and  easily  performed. 

3.  The  caustic  soda  method  gives  results  scientifically 
exaCt,  when  we  observe  all  the  details  of  the  process  such 
as  they  were  described  by  H.  Lasne  {Bull.  Soc.  Chim., 
XV.,  p.  118). 

4.  Gruber's  method  (described  in  the  Zeitsch.  f.  Ang. 
Chemie,  p.  741,  1896)  is  nothing  but  an  abridgment  or 
mutilation  of  Lasne's.  It  gives  inexaCt  results,  and  should 
be  rejected  without  hesitation. 

5.  The  caustic  potash  method,  published  by  Gladding 
{jfournal  of  the  American  Chemical  Society,  No.  8,  1896), 
is  analogous  to  that  of  Lasne,  from  which  it  differs  only 
by  modifications  in  the  details  of  procedure,  which  might 
become  sources  of  error. 

6.  The  method  of  direCt  precipitation,  sufficiently  diffi- 
cult to  obtain  complete  neutralisation  (which  is  indis- 
pensable), gives  varying  results,  according  to  the  nature 
of  the  phosphate,  and  the  precipitate  always  contains 
lime. — Bull.  Soc.  Chim.,  Series  3,  vol.  xvii.-xviii..  No,  15. 


THE     DIRECT     SEPARATION     AND     THE 

QUANTITATIVE    DETERMINATION 

OF    CHLORINE,     BROMINE,     AND     IODINE     IN 

ORGANIC     SUBSTANCES. 

By    P.    JANNASCH    and    E.    KOLITZ. 

For  this  purpose  the  specimen  is  opened  up  either  by  the 
method  of  Carius  or  by  combustion  with  caustic  lime. 

The  method  of  Carius,  especially  if  the  quantity  of 
substance  is  but  small,  cannot  be  carried  out  as  quickly 
and  safely  as  the  decomposition  in  the  lime  tube. 

The  further  treatment  of  the  melt  is  the  same  as  in  the 
following  lime  method  : — 

For  its  execution  we  use  potash  glass  tubes  of  50  cm. 
in  length  and  4  m.m.  interior  diameter,  and  charge  them 
as  follows  : — The  tube  is  first  filled  by  means  of  a  tube- 
funnel,  to  the  depth  of  3  to  4  cm.,  with  quicklime  ;  then 
the  weighed  substance  loosely  ground  up  in  a  tall  porce- 
lain mortar  is  added;  the  mortar,  funnel,  and  tube  are 
then  repeatedly  rinsed  out  with  finely-ground  quicklime, 
with  which  47  cm.  of  the  tube  are  filled.  The  tube  is 
then  closed  with  a  loose  plug  of  asbestos,  through  which 
a  channel,  not  too  narrow,  is  formed  from  end  to  end  by 
tapping  it  from  side  to  side. 

After  the  tube  has  become  cool  again,  the  reacting  mix* 
ture  is  transferred  into  a  litre  fiask  capable  of  being  closed 
with  a  ground  stopper,  and  filled  to  one-third  with  water. 
The  tube  is  then  rinsed  out,  at  first  with  water  alone  and 
finally  with  dilute  nitric  acid. 

With  continuous  shaking  and  repeated  refrigeration, 
strong  nitric  acid  is  added  by  portions  until  there  is  left 
only  a  small  residue  of  undissolved  caustic  lime,  and  fiU 
tered  off  from  this  and  the  liberated  carbon.  The  caustic 
soda  and  residual  carbon  are  well  washed  out  with  hot 
water ;  the  liquid  on  standing  (before  filtration)  must 
appear  absolutely  colourless,  and  the  air  in  the  fiask  must 
be  inodorous.  The  filter-paper  during  filtration  must  not 
assume  a  bluish  tint. 


CbbmicalNbws.  I 

Sept.  24, 1807.     » 


A  Flavour-producing  Micrococcus  of  ButteK 


151 


The  silver-haloid,  colledled  and  washed,  is  introduced 
whilst  still  wet  along  with  the  paper  into  a  silver  crucible, 
and  fused  with  5  to  6  grms.  of  chemically  pure  soda,  so 
as  to  form  a  clear  quiet  liquid. 

When  the  crucible  has  become  cold  the  melt  is  taken 
up  with  water,  preferably  on  the  water-bath. 

The  caustic  lime  resulting  was  found,  in  every  experi- 
ment, perfedlly  free  from  halogens. — Zeit.  Anorg.  Chemie, 
XV.,  p.  68. 


SEPARATION     OF    CHLORINE    AND     BROMINE 

IN     PRESENCE     OF 

ACETATES,  SULPHATES,   AND   NITRATES. 

By  P.  JANNASCH  and  E.  KOLITZ. 

As  regards  the  diredl  quantitative  separation  of  chlorine 
and  bromine  by  permanganate  in  a  strong  acetic  solution, 
the  attempt  was  made  to  effed  it  in  presence  of  large 
quantities  of  sodium  acetate.  The  obje<5l  in  view  was  to 
raise  the  boiling-point  by  the  presence  of  the  acetate,  and 
in  this  manner  to  facilitate  the  liberation  of  the  bromine. 
But  it  appeared  that  this  purpose  was  not  only  not 
effedled,  but  that  the  quantitative  liberation  of  the  bromine 
was  adually  hindered  by  the  addition  of  acetates.  In  a 
series  of  such  attempted  separations  only  very  small 
quantities  of  bromine  distilled  over,  whilst  the  main 
quantity  remained  behind.  Analogous  experiments  were 
made  with  additions  of  sodium  sulphate  and  sodium 
nitrate,  with  results  showing  that  the  presence  of  each  is 
favourable  to  the  readlion,  and  does  not  in  any  manner 
interfere  with  the  accuracy  of  the  determination  of  the 
two  halogens  then  jointly  present. 

From  the  observations  of  the  authors  and  of  Azoff,  it 
may  be  concluded  in  general  that  in  presence  of  alkaline 
fluids  the  latter  may  be  neutralised  or  slightly  acidulated 
with  sulphuric  or  nitric  acid,  but  never  with  acetic  acid. — 
Zeit.  Anorg.  Chemie,  xv.,  p.  66. 


A    FLAVOUR- PRODUCING     MICROCOCCUS    OF 

BUTTER. 

By  SIMEON  C.  KEITH,  Jun.,  S.B. 

In  April,  1896,  I  was  studying  the  effecfts  of  various 
badleria  upon  cream,  and  in  the  course  of  my  experiments 
I  isolated  from  a  mixture  of  bafteria  growing  in  an  agar 
tube  a  micrococcus  that  was  found  to  produce  a  decided 
butter  flavour  and  aroma  when  grown  in  milk  or  cream. 
This  proved  to  be  a  new  species,  for  which  I  propose  the 
name  Micrococcus  butyri-arotnafaciens. 

It  has  always  been  the  custom  to  allow  cream  to  sour 
or  "  ripen  "  before  churning  it  for  butter,  because  after 
this  process  the  butter  comes  better  and  more  quickly,  is 
of  better  texture  and  flavour,  and  keeps  better  than  butter 
made  from  sweet  cream.  Lord  Lister  and  Pasteur,  many 
years  ago,  showed  that  the  souring  of  milk  and  cream  is 
due  to  a  process  of  fermentation  during  which  the  milk 
sugar  is  converted  into  ladtic  acid,  and  that  this  is  due  to 
the  adlivity  of  minute  micro-organisms.  It  remained  for 
Professor  Vilhelm  Storch,  of  Copenhagen,  however,  to 
introduce  the  use  of  pure  cultures  of  milk-souring  baderia 
in  butter  making.  Storch  found  that  several  kinds  of 
acid-producing  badteria  are  concerned  in  the  normal 
souring  of  cream,  and  he  isolated  three  species  that  im- 
part especially  fine  flavours  to  butter  under  favourable 
conditions. 

A  similar  line  of  work  was  taken  up  by  Professor 
Weigmann,  of  the  Agricultural  Experiment  Station  at 
Kiel,  in  Germany,  and  by  Professor  H.  W.  Conn,  of 
Wesleyan  University  in  the  United  States. 

Of  the  badleria  that  have  been  described  as  producing  a 
beneficial  eifed  in  the  ripening  of  cream,  Micrococcus 


butyri  -  aromafaciens  most  nearly  resembles  Conn's 
Bacillus  No.  41  (Storrs  Agricultural  Experiment  Station, 
Bulletin  12,  and  Report  for  1894)  in  its  effedts  upon  milk, 
but  it  differs  in  its  morphological  and  in  many  of  its 
physiological  charadlers.  It  is  a  micrococcus  growing  at 
37°  and  20°  C.  It  liquefies  gelatin  slowly,  and  does  not 
grow  well  on  potato.  It  may  be  noted  in  this  connexion, 
however,  that  recent  cultures  on  gelatin  seem  to  show 
that  the  organism  has  lost  to  a  considerable  extent  its 
power  to  liquefy  gelatin  during  a  year's  cultivation  in  the 
laboratory. 

The  culture  of  the  micrococcus  for  use  in  creameries  is 
propagated  in  bouillon  in  Fernbach  flasks  (broad  flasks  so 
constructed  that  a  large  surface  of  liquid  is  presented  to 
the  air).  When  ready  for  shipment,  the  culture  is  trans- 
ferred  to  sterilised  bottles  under  aseptic  conditions  and 
hermetically  sealed  by  means  of  sterilised  corks  and 
melted  paraffin.  Put  up  in  this  way,  the  culture  may  be 
kept  for  an  indefinite  time  without  danger  of  infedion  by 
any  other  organism,  but  in  the  sealed  bottles  the  micro- 
coccus loses  its  vitality  so  rapidly  that  after  eight  days  it 
will  no  longer  produce  the  best  results.  Experiments 
made  on  a  commercial  scale  show  that  cream  ripened 
with  the  aid  of  fresh,  pure  cultures  of  this  organism  pro- 
duces generally  better  butter  than  the  same  cream 
ripened  in  the  usual  way.  The  distinguishing  charaders 
of  the  species  are  given  in  the  following  systematic 
description. 

Micrococcus  butyri-arotnafaciens,  Nov,  Sp. 
Occurrence. 
Isolated  from  a  mixed  culture  growing  on  agar  in  April, 
1896. 
General  Characters. 
Shape  and  Arrangement. — A    micrococcus    occurring 

generally  in  pairs. 
Size. — o'5  to  07  n  in  diameter,  occasionally  reaching  i/x. 
Motility. — Non-motile. 
Spore  Formation. — No  spores. 
Relation  to  Temperature. — Grows  rapidly  at  37°  and 

20°  C. 
Relation  to  Air. — Aerobic. 
Relation  to  Gelatin. — Slow  liquefier. 
Colour. — Non-chromogenic  (white). 
Stain. — Stains  well  with  carbolfuchsin. 
Gelatin. 
Stick  Culture. — Five  days.    The  gelatin  is  liquefied  in 
the  form  of  a  deep  cup  |  inch  in  diameter.     The 
liquefied  gelatin  remains  clear,  with  a  white  film 
and   sediment.      The  growth  below  the   point  of 
liquefadion  is  a  moderately  thick  white  dotted  line. 
Plate  Culture. — 
Surface  colonies  :  The  colony  first  appears  as  a  white 
raised  dot  which  soon  sinks  in  a  pit  of  liquefied 
gelatin,  and  ultimately  becomes  surrounded  by  a 
slight  whitish  ring  along    edge  of  the  liquefied 
gelatin. 
Submerged  colonies:  The  submerged  colonies  occur 
as  smooth  spherical  dots. 
Agar. 
Streak  Culture. — A  very  white,  smooth,  shining  growth, 
which  is  fairly  abundant.      The  growth  is  of  equal 
thickness  throughout. 
Plate  Culture. — Charadlers  of  no  diagnostic  value. 
Lactose-litmus-agar. — Litmus  reddened  slightly. 
Potato. 
There  is  very  little  growth  on  potato.     In  two  weeks  it 
appears  as  a  very  thin  white  line,  barely  visible. 
Milk. 
Not  coagulated.    A  slightly  sourish,  pleasantly  aromatic 
"  buttery  "  flavour.    Slightly  acid. 
Smith  Solution. 

No  gas  produced.  The  growth  occurs  mostly  in  the 
open  limb  of  the  fermentation  tube,  the  bouillon  of 
the  closed  limb  being  only  very  faintly  turbid. 


152 


Simple  Lecture  Apparatus. 


i  Chemical  Nkws, 
1     Sept.  24,  1807. 


Nitrate. 
Reduced  to  nitrite.    Recent  cultures  do  not  seem  to 
give  this  reaftion  very   strongly,   although   when 
Hrst  isolated  it  was  very  marked. 
Bouillon. 
Two  days,  25°  C.    Very  cloudy  with  sediment.     One 

week,  no  further  change. 
Two  days,  37°  C.    Very  cloudy  with  sediment  and  ring 
growth  on  tube  at  surface  of  the  liquid. 

—Technology  Quarterly,  vol.  x.,  No.  3. 


SIMPLE    LECTURE    APPARATUS. 

By  Prof.   W.    R.  HODGKINSON.    Ph.D.,   F.R.S.E. 
VOLUMEMETER. 

The  apparatus  here  figured  was  construdled  from  the 
absorption  tube  of  an  Orsat-Muencke's  gas-analysis  appa- 
ratus, which  had  broken  at  the  bend,  and  an  ordinary  50 
c.c.  burette,  the  two  being  joined  by  sealing  a  short  stop- 
cock tube  between  (c). 


Evidently  any  convenient  liquid  may  be  used  for  a 
relative  weight  or  specific  gravity  determination.  Suffi- 
cient liquid  is  introduced  to  exadtly  fill  the  wide  tube  to  the 
mark  b  and  to  stand  at  a  moderately  low  mark  on  the  c.c. 
tube  (rf),  which  is  read  off;  the  liquid  is  then  lowered 
from  the  wide  tube  to  some  distance  below  the  stopper, 
the  latter  carefully  taken  out,  and  allowed  to  hang  by  the 
rubber  tube,  and  the  weighed  substance  (in  powder  or 
small  pieces)  introduced,  the  stopper  replaced,  and  the 
liquid  carefully  brought  back  to  the  mark  (6).  The  liquid 
will  now  stand  higher  in  the  graduated  tube  (d) ;  the  dif- 
ference in  reading  gives  the  volume  in  c.c. 


The  whole  apparatus  may  be  sunk  in  a  deep  beaker  or 
cylinder  of  water,  which  may  be  retained  at  any  particular 
temperature  during  the  experiment.  The  rubber  tube 
attached  to  the  top  of  the  burette  serves  to  apply  air  pres- 
sure to  drive  the  liquid  to  the  mark  in  the  wide  tube. 
This  is  best  done  by  closing  the  bottom  tap  (c),  blowing 
strongly  into  the  burette,  and  closing  the  top  tap.  On 
carefully  opening  the  bottom  tap  the  liquid  will  rise  in  the 
wide  tube  and  the  height  can  be  easily  adjusted. 

The  ancient  experiment  by  which  is  shown  that  water 
boils  in  a  closed  inverted  flask  when  cold  water  is  poured 
over  it  can  be  somewhat  improved  upon  by  employing  a 
distilling  or  fradlionating  flask  with  a  stopcock  sealed  on 
the  side  tube  and  a  wide  thermometer,  wedged  by  rubber 
ring  in  the  neck,  just  dipping  into  the  water.  In  this  case 
the  flask  need  not  be  inverted.  Other  liquids  besides 
water  may  be  used.     The  temperature  can  be  read  off  at 


which  the  liquid  goes  through  the  process  of  boiling. 
The  size  of  flask  depends  to  some  extent  on  the  liquid  to 
be  employed.  For  liquids  of  higher  boiling-point  than 
water,  a  500  c.c.  capacity  is  enough,  and  water  must  not 
be  used  for  cooling;  air  from  a  small  bellows  is  sufficient. 
For  water  a  1000  or  even  1500  c.c.  flask  is  not  too  large  if 
the  experiment  is  to  be  seen  at  a  distance.  The  mode  of 
working  is  apparent  from  the  sketch. 
Royal  Military  Academy,  Woolwich. 


Oxidising  Adion  of  a-Monochlorised  Camphor. — 
H.  Vittenet. — In  the  rea(5tion  between  the  aromatic 
amines  and  a-monochlorised  camphor  the  authors  were 
surprised  to  find  that,  with  certain  of  these  bases, 
colouring-matters  were  formed  which  are  generally  ob- 
tained by  the  direct  adtion  of  oxidising  agents. — Bull.  Sac. 
Chim.  de  Paris,  xvii.-xviii.,  No.  14. 


Chemical  News,} 
Sept.  24, 1897.     ( 


Purification  and  A  tomic  Weight  of  Cerium, 


153 


ON  THE 

PURIFICATION     AND    ATOMIC     WEIGHT 
OF    CERIUM.* 

By  MM.  WYROUBOFF  and  VERNEUIL. 
(Concluded  from  p.  139). 

Atomic  Weight. — Here  we  come  across  altogether  unex- 
pedled  difficulties.  The  sulphate  is,  up  to  the  present, 
the  only  well-crystallised  salt  of  which  we  can  make  use, 
very  stable  and  very  easy  to  purify;  now  nothing  is  more 
difficult  than  to  separate  the  sulphuric  acid  from  the 
cerous  oxide.  Precipitation  by  oxalate  of  ammonium 
(Wolf,  Wing)  is  no  good,  for  oxalate  of  cerium  is  not  in- 
soluble in  acetate  of  ammonium,  and,  further,  it  carries 
sulphuric  acid  with  it. 

The  twice-repeated  precipitation  with  soda-lime  (Schiit- 
zenberger)  has  two  drawbacks :  if  the  soda  is  not  in  great 
excess  it  will  not  completely  decompose  the  basic  sulphate 
which  is  formed  ;  in  fadt,  by  calcining  the  oxide  of  cerium 
obtained,  in  a  current  of  hydrogen,  we  notice  very  dis- 
tindly  a  more  or  less  considerable  disengagement  of 
sulphuretted  hydrogen. 

If  the  quantity  of  soda  is  sufficient  to  effedl  the  decom- 
position, it  dissolves  cerous  oxide,  which  can  be  detefted 
by  adding  a  little  peroxide  of  hydrogen.  It  is  true  we 
can  separate  the  cerium  and  the  sulphuric  acid  integrally 
in  another  manner;  to  do  this  it  suffices  to  add  to  the 
solution  an  excess  of  peroxide  of  hydrogen  and  caustic 
soda  until  the  readion  is  alkaline,  boil  to  transform  the 
reddish  brown  peroxide  into  yellow  ceroso-ceric  hydroxide. 
The  oxygen  thus  precipitated  and  calcined  in  a  current  of 
hydrogen  will  be  found  to  be  perfedly  free  from  sulphur. 
But  this  separation  does  not  remove  all  the  difficulties. 
Modern  researches  (Ripper,  Richards  and  Parker,  &c.) 
have  shown,  in  the  most  distinct  manner,  that  the  estima- 
tion of  sulphuric  acid  in  sulphates,  in  the  presence  of 
chlorides,  can  only  be  done  with  a  very  insufficient  ap- 
proximation, for  an  operation  so  delicate  as  the  deter- 
mination of  an  atomic  weight.  We  could  certainly  make 
the  correction  for  the  chlorine  entangled  by  the  sulphate 
of  baryta,  but  Messrs.  Parker  and  Richards  have  shown 
that  this  corredlion  does  not  always  lead  to  a  better  result, 
because  of  the  solubility  of  barytic  sulphate  in  an  acid 
solution,  and  further,  in  the  present  case  we  do  not  know 
in  what  condition  the  entangled  chlorine  is  present.  Is  it 
in  the  state  of  BaClj  or  NaCI,  or  both  together  ?  An 
example  will  show  what  variations  in  the  atomic  weight 
can  occur  according  to  the  method  adopted  of  making  the 
correcftion.  We  had  in  the  sulphate  of  the  first  fradion 
of  Series  I.  (see  Table),  for  100  parts  of  anhydrous  cerous 
sulphate,  123*384  of  80483,  which  gives  us  the  atomic 
weight —  II 

Ce  =  93 'oi. 

This  sulphate  of  baryta  contained  0*27  per  cent  of  Cl,t 
which,  counted  as  NaCl,  gives  I22'838  of  S04Ba  and  an 
atomic  weight  of  93"84;  counted  as  BaCl2,  it  gives 
I22'40i  of  S04Ba  and  an  atomic  weight  of  9453.  The 
true  atomic  weight,  as  we  shall  prove  further  on,  is  very 
close  to  92'7.  We  see  thus  that  the  method  of  estimating 
the  sulphuric  acid  cannot  be  applied  to  the  determination 
of  the  atomic  weight  of  cerium. 

M.  Brauner  made  use  of  another  method  which  at  first 
sight  appeared  to  be  quite  beyond  reproach.  He  strongly 
heated  the  dehydrated  sulphate,  and  calculated  the  atomic 
weight  from  the  weight  of  €6304  obtained.  The  average 
of  his  experiments,  which  were  very  closely  concordant, 
gave —  11 

Ce  =  93-48. 

Schiitzenberger  however  remarked,  with  very  good  reason, 

*  Bull.  Soc.  Chim.,  Series  3,  vol.  xvii.-xviii..  No.  14. 

+  This  figure  is  only  slightly  different  to  the  mean  of  seventeen 
analyses  made  by  Messrs.  Richards  and  Parker,  who  found  0*237  per 
cent  {2eit.  Anal.  Chem.,  viii.,  p.  4»7' 


that  the  ceroso-ceric  oxide  had  different  weights  according 
to  the  temperature  of  calcination,  and  that  therefore  one 
could  not  tell  with  accuracy  the  moment  when  its  com- 
position  was  really  Ce304.  These  variations  may  attain 
several  thousandths,  so  he  considered  that  the  process 
could  not  furnish  really  exa&  results. 

We  can  only  recall  from  memory  the  determinations 
made  by  starting  with  cerous  oxalate  (Jegel,  Biihrig, 
Rammelsberg).  We  consider  this  salt  as  altogether  unfit 
for  deciding  the  atomic  weight  of  cerium  ;  firstly,  because 
it  is  almost  impossible  to  obtain  it  in  a  state  of  purity, 
for  when  it  is  crystallised  it  always  retains  cerous  oxalo- 
nitrate;  and  secondly,  because  organic  analyses  are 
subjedl  to  errors  far  too  great  to  allow  of  their  application 
to  so  high  an  atomic  weight.  The  great  differences  found 
(Jegel,  gi'66;  Biihrig,  94*4;  Rammelsberg,  92'i6)  show 
the  inefficiency  of  the  method.  It  is  necessary  to  remark 
further — these  surprises  are  not  rare  in  the  history  of 
cerium — that  Biihrig's  figure  94-4,  generally  accepted  at 
the  present  time,  is  the  same  as  that  given  by  Marignac 
in  1848,  and  shortly  afterwards,  in  1853,  admitted  by  him 
to  be  incorredt.  He  obtained  it,  as  a  matter  of  fadt,  by 
the  direft  precipitation  of  the  sulphate  by  chloride  of 
barium.  Finally,  to  complete  the  history,  we  will  cite  the 
analysis  of  the  anhydrous  chloride  made  by  Mr.  Robinson, 
which  gave —  n 

Ce  =  93-5, 

a  figure  identical  with  that  obtained  by  M.  Brauner.  The 
chloride  is  too  deliquescent  a  salt,  and  too  difficult  to  free 
from  the  oxychloride  which  accompanies  it,  to  allow  of 
its  being  used  for  the  determination  of  the  atomic  weight 
with  any  chance  of  success.  All  the  old  methods  being 
rejedted  as  insufficient,  there  remains  now  to  find  a  better. 
We  noticed,  while  making  a  large  number  of  estimations 
in  water  in  the  hydrated  sulphate,  that  the  figures  ob- 
tained were  very  closely  concordant.  On  twenty  estima- 
tions none  varied  more  than  0*03  per  cent.  Thus  the  idea 
occurred  to  us  to  employ  this  estimation  for  the  deter- 
mination of  the  atomic  weight;  in  any  case  it  would 
serve  to  fix,  in  an  exadl  manner,  the  conditions  under 
which  the  ceroso-ceric  oxide,  obtained  by  calcination  at  a 
high  temperature,  would  have  the  formula  06304,  and  to 
check  with  certainty  Brauner's  method.  The  table,  in 
which  we  give  a  resume  of  our  experiments,  shows  in  a 
decisive  manner : — 

1st.  That  the  estimation  of  the  water  gives  less  varia- 
tions than  the  ceroso-ceric  oxide  calcined  at  awhite  heat, 
and  consequently  a  more  exadl  figure  for  the  atomic 
weight. 

2nd.  That  Brauner's  method  gives  a  fairly  exadl  figure 
when  the  sulphate  is  calcined  at  a  very  high  temperature 
(about  1500°),  because  it  is  only  at  this  high  temperature 
that  we  can  eliminate  the  last  traces  of  sulphuric  acid. 
In  this  state,  if  it  is  perfedtly  pure,  it  should  be  perfectly 
white,  without  the  least  trace  of  any  rose,  chamois,  or 
yellow  tint.  By  this  method  it  is  the  lowest  figures  which 
are  nearest  the  truth. 

But  to  be  able  to  estimate  the  water  accurately,  it  is  of 
importance  which  of  the  numerous  hydrated  cerous  sul- 
phates is  used.  We  therefore  commenced  by  carefully 
studying  the  conditions  of  the  formation,  and  the  proper- 
ties, of  these  salts,  about  which  there  is  great  want  of 
accord. 

The  hydrates  described  are  five  in  number : — 

A.  (S04Ce)«        ..     ..     5  aq. 

B.  S04Ce 2  aq. 

C.  (S04Ce)3        ..      ..     8aq. 

D.  S04Ce 3  aq. 

E.  S04Ce 4aq. 

The  crystalline  form  and  the  optical  properties  of  the 
salts  A,  C,  and  D  have  been  determined,  at  least  approx- 
imately, by  Marignac  and  Des  Cioizeaux.  The  salt  E 
occurs  in  an  efflorescent  form,  consisting  of  a  tangled 
mass  of  needles  quite  indeterminable ;  the  salt  B  only 


154 


Purification  and  A  tomic  Weight  of  Cerium, 


(Chbmicax,  Nsws, 
Sept.  24, 1897. 


Table  (0  = 

16;  S  =  32). 

Hydrated 
salt. 

Anhydrous            CegO}. 
salt. 

H.O  p.c. 

Ce,0«  p.c. 

from 

Hydrated 

salt. 

CcjO*  p.c. 

from 
Anhvdrous 

salt. 

Atomic 
H,0. 

weight  calculated  from— 
J. , 

CegO^  from     CcjO^  from 

the  Hydr.    the  Anhydr. 

salt.              salt. 

I. 

I. 
2. 
3. 

u* 

1-2385 
1*2730 
1*2030 
1*5420 

0-9875            0-5977 
1*0148            0-6138 
0-9590            0*5794 
1*2295            0*7430 

20*267 
20*282 
20-282 
20-265 

48-259 
48*216 
48-162 
48-184 

60-526 
60  484 
60*417 
60-431 

9284 
92-65 
9265 
92-85 

93 -08 
92-88 
92-64 
92-74 

93-16 

92-95 
9263 

9270 

Averages     . 

.     20-274 

48*205 

60-464 

92*74 

92-84 

92-86 

II.- 

I. 

2. 

3- 

0*9642 
1*3260 
1*1429 
0*9072 

0*7685            0*4642 
1*0571            0-6389 
0-9112            0-5518 
07232            0*4372 

20-296 
20-279 
20-273 
20*282 

48-143 
48*182 
48280 
48-192 

60*403 
60*438 

60-557 
60*453 

92-49 
9269 
92*76 
9266 

9255 
92-72 

93-17 
92-77 

92*56 

92-73 
93*30 
9280 

Averages     . 

.     20-282 

48*199 

60-463 

92-65 

92*80 

92-85 

""•11: 

1'2II4 

1*2411 

0*9658            0-5840 
0*9894            0*5984 

20*274 
20*280 

48-208 
48-215 

60*468 
60-481 

92-75 
92-68 

92-84 
9288 

9287 
9293 

Averages     . 

.     20-277 

48*211 

6o'474 

92-71 

Q2-86 

9290 

Averape 

of  the  three  s 
:e  between  mj 
ween  maxima 

eries 

.     20*278 

0*031 

i      o*oi8 

48*205 
0*137 
0*075 

60*467 

0-154 
0-090 

92-70 
0-36 
0*21 

92-83 

0-62 
0-34 

92-87 
0-74 
0-43 

Differ 
Diff. 

en( 
bet 

ixima  and  minima  ..     . 
and  the  general  averag 

has  been  vaguely  described  as  crystallising  in  needles 
similar  to  those  of  the  salt  A.  In  reality  this  salt  does 
not  exist,  and  every  time  we  obtain  quantities  of  water 
of  about  16  per  cent  we  are  sure  of  finding  under  the  micro- 
scope two  sorts  of  crystals  ;  prisms  of  the  salt  A  and 
odtahedra  much  less  bl-refrangible  of  the  salt  C. 

The  conditions  under  which  these  diverse  hydrates  are 
formed  are  very  different,  according  to  whether  the  liquid 
does  or  does  not  contain  a  little  free  sulphuric  acid.  We 
have  only  here  to  examine  the  particular  case  of  solutions 
absolutely  exempt  from  free  acid.  This  condition  is 
essential,  for  we  know  that  the  cerous  sulphate — no 
matter  how  well  it  may  be  crystallised — retains  sulphuric 
acid  with  a  remarkable  tenacity,  which  may  be  explained 
perhaps  by  the  facility  with  which  an  acid  sulphate, 
described  by  one  of  us  some  time  since  {Bull.  Soc.  Chim., 
Series  3,  vol.  ii.,  p.  745, 1889),  is  formed,  and  which  is  only 
difficultly  decomposed  at  a  relatively  very  high  tem- 
perature. 

To  remove  the  last  traces  of  sulphuric  acid  we  can 
proceed  in  several  different  ways.  We  can  either  precipi- 
tate two  or  three  times  with  alcohol,  or,  after  a  preliminary 
dehydration  carried  out  at  as  high  a  temperature  as 
possible  (400°  to  450°),  dissolve,  crystallise  the  greater 
part  at  75°  to  80°,  evaporate  the  mother-liquor  which 
retains  the  greater  part  of  the  existing  free  acid,  heat 
until  all  sulphuric  acid  vapours  are  driven  off,  dehydrate 
the  crystals,  dissolve  the  whole  in  water,  and  repeat  the 
operation  three  or  four  times ;  or  agam,  and  in  a  more 
simple  manner,  decompose  the  nitrates  with  an  insufficient 
quantity  of  sulphuric  acid,  and  heat  to  500°.  The  mass 
contains  either  ceroso-ceric  oxide,  or  a  basic  salt  which 
remains  on  the  filter,  and  cerous  sulphate  which  dissolves. 
The  salt  thus  prepared  gives,  at  all  temperatures  up  to 
about  85°,  only  the  hydrate  C,  sometimes  mixed— when 
the  temperature  does  not  go  beyond  45°— with  a  few  needle- 
like crystals,  generally  isolated  and  sharply  defined,  of 
the  hydrate  D.*  It  is  only  at  temperatures  of  about 
100^  that  we  obtain  clino-rhombic  crystals  of  the  salt  A 
always  mixed  with  the  hydrate  C.  On  removal  from  the 
mother-liquor  these  crystals  effloresce,  or  rather  appear 
to  effloresce  very  rapidly ;  in  reality  they  become  covered 

•  These  crystals  are  at  once  distinguished  under  the  microscope 
from  the  needles  of  the  hydrate  A,  with  which  they  might  be  con- 
founded. They  belong  to  the  hexagonal  system,  and  in  polarised 
light  disappear  in  the  direftion  of  their  length  ;  the  extinftion  of  the 
crystals  A  is,  on  the  contrary,  very  oblique  on  the  face  m  m. 


with  a  layer  of  crystals  of  the  higher  hydrate  C,  which  is 
only  normal  and  stable  under  these  conditions. 

It  follows  from  this  that  the  salt  {S04Ce)3,  8aq.,  is  the 
only  one  which  can  be  used  for  exadt  weighings.  It  keeps 
very  well  in  the  air,  easily  forms  limpid  crystals,  especially 
when  small.  Its  density  at  17°  is  2885.  To  obtain  it 
quickly  in  very  limpid  crystals  it  is  necessary  to  dissolve 
the  sulphate,  dehydrated  at  about  400°,  in  ten  times  its 
weight  of  water,  and  crystallise  at  60°.  In  twenty-four 
hours  we  get  an  abundant  crop  of  crystals,  not  more  than 
2  m.m.  in  diameter,  but  perfedly  transparent.  These  are 
drained  on  filter-paper  until  quite  dry  ;  they  are  then  pow- 
dered and  dried  anew.  In  this  state  they  are  ready  for 
analysis,  and  give  constant  results,  even  after  having  been 
exposed  to  the  air  for  two  or  three  days.  The  hydrate  C, 
like  all  the  others,  is  easily  dehydrated  at  about  250°;  if 
then  heated  to  redness  in  a  tube  it  will  not  give  a  trace  of 
moisture.  Once  dehydrated,  it  will  stand  a  temperature 
of  500°  without  undergoing  the  slightest  decomposition. 
On  these  two  points  we  are  in  complete  disaccord  with 
M.  Brauner,  who  maintains  that  the  water  cannot  be  en- 
tirely driven  off  even  at  400°,  and  that  a  temperature  of 
500°  turns  the  salt  yellow  by  oxidation  commencing  to 
take  place.  We  would  remark  that  if  our  estimation  of 
the  water  was  too  low,  the  atomic  weight  of  cerium — 
already  lower  than  that  of  M.  Brauner — would  be  still 
further  reduced;  on  the  other  hand,  the  oxidation  of 
cerous  sulphate  at  500°  clearly  shows,  as  Nilson  first  ob- 
served (Ann,  Chim.  Phys.,  Series  5,  vol.  xxx.,  p.  431, 1883), 
the  presence  of  thorium. 

If  the  dehydrated  salt  is  heated  to  about  1500°  it  only 
loses  its  acid  very  slowly,  and  it  requires  to  be  kept  at 
this  high  temperature  for  at  least  fifteen  minutes  before 
its  weight  remains  constant.  The  oxide  thus  obtained 
appears  to  be  free  from  sulphur,  at  least  that  in  the 
analysis  I.  2  (see  Table),  calcined  in  hydrogen,  did  not 
show  any  trace.  However,  the  extreme  difficulty  with 
which  this  salt  parts  with  its  acid  by  calcination  ought  to 
make  us  consider  this  method  as  less  exaift  than  that  by 
estimating  the  water. 

To  obtain  fairly  corred  results  it  is  necessary  to  do  the 
calcination  in  double  crucibles,  using  platinum  crucibles 
as  small  as  possible,  not  taking  more  than  1-5  grms.  of 
material,  and  weighing  in  an  atmosphere  free  from 
moisture. 

The  three  series  of  analyses  given  in  the  table  were 
performed  on  three  products,  essentially  different : — 


Chemical  Nbwb,  ) 
Sept.  24,  1897.    I 


A  tomic  Mass  of  Tungsten, 


155 


I.  Cerium  obtained  from  rough  oxalates  Jrom  monazite, 
by  the  process  we  have  described  above,  and  carefully 
purified  from  thorium. — This  cerium  was  transformed  into 
sulphate,  and  the  sulphate  fradtionated  in  nine  portions. 
The  analyses  i  and  2  were  done  on  the  first  portion,  the 
analyses  3  and  4  on  the  last. 

II.  Cerium  obtained  from  the  industrial  treatment  of 
oxalates  extracted  from  monazite,  very  rich  in  thorina 
(about  50  per  cent)  by  carbonate  of  ammonium. — This  re- 
agent dissolves  a  certain  quantity  of  cerium,  the  didymium, 
and  all  the  yttria  earths.  After  eliminating  the  great 
part  of  the  thorina  by  the  usual  methods,  the  remaining 
mixture  was  treated  the  same  as  the  cerium  I.  The  sul- 
phate gave  three  fradtions.  The  analyses  i  and  2  are  of 
the  first,  the  analyses  3  and  4  of  the  last. 

III.  Cerium  extracted  from  rough  oxalates  obtained  from 
cerite,  and  purified  like  I.  and  II. — The  sulphate  was 
separated  by  three  crystallisations  at  60°.  The  analysis  i 
is  of  the  first,  the  analysis  2  of  the  last. 

The  examination  of  this  table  shows  in  the  clearest 
manner  that  cerium,  no  matter  what  its  origin,  properly 
freed  from  impurities  and  especially  from  thorium,  is  an 
element,  pure  and  simple,  giving  always  a  perfedtly  white 
oxide,  €6304,  at  a  high  temperature.  The  indired 
methods  which  have  been  used  do  not  allow  of  its  atomic 
weight  being  definitely  determined,  but  we  can  say  with 
certainty  that  it  is  close  to  92*7,  with  an  approximation  of 
0'2  to  o'3  per  cent,  rather  less  than  more. 

Having  now  proved  the  identity  of  this  element,  we 
propose  to  study  its  principal  combinations,  more  espe- 
cially its  numerous  oxides. 


THE    ATOMIC     MASS     OF    TUNGSTEN.* 

By  WILLETT  LEPLEY  HARDIN. 

(Continued  from  p.  39). 

Preparation  of  Tungsten  Trioxide. 
The  material  used  in  the  first  few  series  of  determinations 
was  obtained  from  wolframite  from  Zinnwald,  Bohemia. 
The  greenish  yellow  oxide  obtained  by  digesting  this 
mineral  for  several  days  with  aqua  regia  was  washed  with 
distilled  water  and  afterwards  dissolved  in  ammonium 
hydroxide.  The  solution  was  evaporated  to  crystallisation, 
and  the  ammonium  tungstate  which  separated  out  was 
strongly  ignited.  The  resulting  oxide  was  again  dissolved 
in  ammonium  hydroxide,  the  solution  was  evaporated  to 
crystallisation,  and  the  resulting  ammonium  tungstate 
strongly  ignited.  The  oxide  thus  obtained  was  placed  in  a 
porcelain  boat  in  a  combustion  tube  and  gently  heated  in  a 
current  of  hydrochloric  acid  gas  to  remove  the  last  traces 
of  molybdenum.  The  material  was  then  re-ignited  and 
placed  in  a  large  porcelain  dish  filled  with  distilled  water. 
Ammonia  gas  was  conducted  into  the  water  for  several 
days,  after  which  the  supernatant  liquid  was  syphoned  off 
and  evaporated  to  crystallisation.  The  ammonium  tung- 
state which  separated  out  was  ignited  and  the  process 
repeated.  The  material  obtained  from  the  second  crys- 
tallisation was  used  in  the  first  series  of  experiments. 

Reduction  Series. 
Tungsten  trioxide  obtained  by  the  method  just  described 
was  used  in  these  experiments.  The  redudtions  were 
made  in  a  hard  glass  combustion-tube  in  a  current  of  hy- 
drogen, which  was  first  conduced  through  solutions  of 
ammoniacal  silver  nitrate,  potassium  permanganate,  alka- 
line lead  nitrate,  caustic  potash,  and  finally  through  sul- 
phuric acid  and  a  tube  containing  anhydrous  calcium 
chloride.  The  redudion  in  each  case  was  continued  for 
several  hours  at  a  temperature  almost  high  enough  to 
melt  the  glass  tube.    The  porcelain  boat  which  contained 

*  Contribution  from  the  John  Harrison  Laboratory  of  Chemistry. 
From  the  journal  of  the  American  Chemical  Society,  xix.,  No.  8. 


the  oxide  was  prote<5ted  from  the  glass  tube  by  means  of 
platinum  foil.  The  weighings  were  made  on  a  Troemner 
short-armed  balance  with  a  set  of  weights  which  had 
been  previously  calibrated.  The  balance  is  sensitive  to 
the  fortieth  of  a  m.grm.  The  results,  calculated  on  the 
basis  of  0  =  16,  are  as  follows  : — 


Weight  of  WO3. 

Weight  of  W. 

Atomic  mass 

Grms. 

Grms. 

of  tungsten. 

I 

1-64084 

1-30100 

18405 

2 

1-79728 

1-42550 

184-044 

3 

2-60739 

2-06788 

183-98 

4 

4-57390 

3-62890 

184-33 

At  this  point  an  unglazed  porcelain  tube  was  substituted 
for  the  glass  tube,  and  the  reductions  that  follow  were 
continued  for  three  hours  at  the  highest  temperature  ob- 
tainable in  a  combustion  furnace. 


Weight  of  WO3.      Weight  of  W. 
Grms.  Grms. 


1  332320 

2  6-II056 

3  9-23802 


2-63547 
4-84580 

7*32393 


Atomic  mass 
of  tungsten. 

183-94 
183-91 
18366 


The  last  experiment  was  continued  through  a  period  of 
eight  hours. 

The  first  three  results  agree  very  closely  and  give  184*02 
as  a  mean  for  the  atomic  mass  of  tungsten.  The  mean 
of  the  results  with  the  glass  tube  is  184-10.  The  maxi- 
mum deviation  is  0-35.  The  mean  of  the  results  obtained 
with  the  porcelain  tube  is  183-84,  with  a  maximum  differ- 
ence of  0-28.  The  maximum  deviation  in  the  whole 
series  is  0-67. 

Oxidation  Series. 

The  metal  obtained  in  the  foregoing  redud^ions  was 
used  in  these  experiments.  The  oxidations  were  made 
in  porcelain  crucibles.  The  material  was  protedted  from 
particles  of  dust  by  means  of  a  porcelain  dish  suspended 
a  short  distance  above  the  crucible.  The  oxidation  in 
each  case  was  continued  until  there  was  no  further  in- 
crease in  weight. 

Weight  of  W.     Weight  of  WO3.      Atomic  mass 
Grms.  Grms.  of  tungsten. 


I 

1*70220 

2*14400 

184-94 

2 

i'3765i 

173393 

184*86 

3 

2-05606 

2-58951 

185*00 

4 

I -10300 

1-38933 

184-91 

5 

1-85855 

2-34143 

184-75 

b 

7-28774 

9-18730 

184-15 

The  mean  of  the  first  five  results  of  this  series  is  184*89. 
This  value  is  almost  identical  with  that  obtained  by 
Pennington  and  Smith.  The  mean  of  the  whole  series  is 
184-77.     ^^®  maximum  deviation  is  0-85. 

Reduction  of  Oxide  obtained  by  the  Ignition  of  Metal. 

Inasmuch  as  the  value  obtained  in  the  oxidation  series 
is  almost  a  unit  greater  than  that  obtained  by  redudlion, 
it  was  thought  advisable  to  make  a  series  of  redudlions 
of  the  oxide  obtained  in  the  series  of  oxidations. 


Weight  of  WOa.      Weight  of  W. 
Grms.  Grms. 


Atomic  mass 
of  tungsten. 

184*88 
184-85 
184-94 
184-01 
i84'66 
183-99 

183-93 
183*91 

The  first  three  results  of  this  series  agree  very  closely 
and  give  184-89  as  a  mean  for  the  atomic  mass  of  tung- 
sten. The  last  three  results  are  equally  concordant  and 
give  183-94  as  the  mean  value.  The  mean  of  the  whole 
series  is  184-40.  The  maximum  deviation  is  1*03.  The 
oxide  used  in  these  experiments  was  very  light  and  flufiy. 


I 

2 

3 

2-02890 
215894 
2-35206 

1-61071 
171388 
I '86740 

4 
5 
6 

7 
8 

1-39137 
1-92125 
1-46746 

5-01313 
6-11056 

1*10351 
1-52487 
1-16383 
397560 
4-84580 

156 


A  tomic  Mass  of  Tungsten. 


I  Chbuical  Nswt 
I    Sept.  24,  1897. 


The  material  used  in  the  last  experiment  was  moistened 
and  re-ignited  to  render  it  more  compad. 

Oxidation  of  Metal  obtained  from  the  Second  Reduction. 
The  material  obtained  in  the  last  series  was  used  in 
these  experiments. 


Weight  of  W. 
Grms. 


Weight  of  WOs 
Grms. 


Atomic  mass 
of  tungsten. 

184-53 
i84"oi 
184-65 


1  3'g636o  4*99460 

2  2*63034  3*31647 

3  I  •60964  2'02804 

The  variations  in  this  series  are  similar  in  every  respedt 
to  those  of  the  preceding  series. 

In  view  of  the  wide  variations  in  all  the  preceding  work, 
an  attempt  was  made  to  weigh  the  water  formed  in  the 
redudtion  of  tungsten  trioxide.  The  moisture  was  col- 
ledled  in  a  small  glass-stoppered  U-tube  filled  with 
anhydrous  calcium  chloride.  To  this  tube  was  attached 
another  similar  tube  to  prevent  absorption  of  moisture 
from  the  air.  Several  determinations  were  made,  but  the 
results  were  too  discordant  to  establish  anything.  The 
removal  of  the  last  traces  of  air  from  the  generator  and 
wash-bottles  was  very  difficult  to  accomplish,  and  hence 
the  results  were  usually  too  high.  The  presence  of  air, 
even  in  small  quantities,  would  also  affe(5t  the  results  in 


The  stopcocks  of  the  different  separatory  funnels  were 
then  opened  and  the  solutions  allowed  to  pass  into  the 
corresponding  wash-bottles.  The  first  bottle  contained 
pure  water,  the  second  ammoniacal  silver  nitrate,  the 
third  and  fourth  potassium  permanganate,  and  the  fifth 
alkaline  lead  nitrate.  The  drying  tower  d  was  filled  with 
anhydrous  calcium  chloride  and  caustic  potash,  and  the 
tower  E  with  alternate  layers  of  glass-wool  and  phos- 
phorus pentoxide.  These  were  substituted  for  sulphuric 
acid,  for,  according  to  Dittmar  and  Henderson  (Proc.  Phil. 
Soc,  Glasgow),  hydrogen  when  passed  through  sulphuric 
acid  becomes  contaminated,  owing  to  the  redu(5tion  of  the 
acid  by  the  hydrogen.  From  the  drying-towers  the  hydro- 
gen passed  into  a  thin-walled  glazed  porcelain  tube, 
placed  in  a  combustion  furnace.  The  bottles  g  and  f 
aded  as  a  regulator ;  the  outlet  to  F  was  connedted  to  a 
sudlion  tube,  e.  When  the  suclion  was  greater  than  the 
backward  pressure  of  the  wash-bottles,  air  passed  in  at  h 
and  through  the  columns  of  sulphuric  acid  in  G  and  F. 
The  length  of  these  two  columns  of  acid  were  adjusted  so 
that  the  pressure  exerted  against  the  air  passing  through 
them  was  equal  to  the  backward  pressure  of  the  wash- 
bottles.  The  Sprengel  pump,  h,  was  attached  so  that  the 
metal  might  he  cooled  in  a  vacuum  and  thus  prevent  any 
occlusion  of  hydrogen.  When  the  redudtions  were  com- 
plete the  stopcocks  at  b  and  c  were  closed.    The  reservoir 


the  redudtion  series.  To  overcome  this  difficulty,  a  dif- 
ferent form  of  apparatus  was  construdled,  the  plan  of 
which  is  shown  in  the  accompanying  sketch. 

At  the  beginning  of  the  operation,  water,  which  had 
recently  boiled,  was  allowed  to  pass  from  the  bottle,  a, 
into  the  tower,  c.  containing  granulated  zinc.  When  c 
was  completely  filled,  the  water  passed  through  the  small 
outlet  tube  into  the  first  wash-bottle;  after  filling  this  it 
passed  into  the  second,  and  so  on.  When  the  water 
reached  the  bottom  of  the  cork  in  the  last  wash-bottle, 
the  stop-cock  at  a  was  closed.  The  stopcock  in  each  of 
the  separatory  funnels  was  then  opened  and  the  water 
allowed  to  rise  until  the  stems  of  the  funnels  were  com- 
pletely filled.  In  this  way  the  air  in  the  generator  and 
wash-bottles  was  completely  displaced  by  water.  The 
stopcock  at  the  bottle  A  was  now  closed  and  sulphuric 
acid  allowed  to  drop  from  the  bottle  b  upon  the  zinc  in  c, 
the  clip  at  x  being  opened  at  the  same  time.  The  hydro- 
gen formed  by  the  sulphuric  acid  and  zinc  forced  the 
water  out  of  c  into  the  beaker  below,  after  which  the  clip 
at  X  was  closed  and  the  clip  on  the  syphon  of  the  first 
wash-bottle  opened.  When  the  water  was  removed  from 
this  bottle,  the  clip  was  closed  and  that  of  the  second 
syphon  opened,  and  so  on  until  the  water  in  all  these 
bottles  was  displaced  by  hydrogen.  The  separatory 
funnels  were  then  filled  with  the  different  solutions 
used  in  purifying  the  hydrogen.  The  stopcocks  at 
a,  b,  and  c  were  opened,  while  that  at  d  was  closed ;  this 
allowed  the  hydrogen  to  pass  through  the  apparatus. 


of  the  vacuum  pump  was  exhausted  and  the  stopcock  at 
D  opened.  This  was  repeated  several  times,  until  the 
vacuum  was  almost  perfedl. 

This  form  of  apparatus  was  used  in  all  the  redudlions 
which  followed.  The  air  could  be  completely  removed 
from  the  apparatus  in  a  short  time.  The  redutSions  were 
continued  for  a  period  of  three  hours  at  the  highest  tem- 
perature obtainable  in  a  combustion  furnace.  When  the 
quantity  of  material  exceeded  3  grms.  the  time  was 
longer. 

Reduction  Series. 

All  the  material  resulting  from  the  preceding  experi- 
ments  was  ignited  and  digested  for  several  days  with  pure 
aqueous  ammonia.  A  residue  was  left  which  gave  the 
bead  test  for  silica.  It  is  evident  from  this,  that  tungstic 
acid,  when  reduced  in  a  porcelain  boat,  takes  up  silica. 
The  solution  of  ammonium  tungstate  was  syphoned  off 
and  evaporated  to  crystallisation.  The  crystals  of  am- 
monium tungstate  were  strongly  ignited,  and  the  resulting 
oxide  used  in  the  experiments.  For  the  first  time  the 
metal  was  allowed  to  cool  in  a  vacuum. 
Weight  of  W. 
Grms. 
2'8l560 
3-64461 

3'4i459 
2-09900 


Weight  of  WO3 
Grms. 


1  3'55i92 

2  4*59362 

3  430435 

4  2-64671 

The  mean  of  these  four  results  is  li 
mum  difference  is  079. 


Atomic  mass 
of  tungsten. 

183-55 
184-34 
184-21 

183-95 

I.      The  maxU 


Chemical  News,  i 
Sept.  24. 1897.    J 


Stamp  MtUttig  of  Gold  Ores, 


157 


Oxidation  Series, 
The  metal  obtained  in  the  preceding  series  of  results 
was  re-oxidised,  and  the  following  values  obtained  for  the 
atomic  mass  of  tungsten  : — 

Weight  of  W.     Weight  of  WO3.      Atomic  mass 
Grms.  Grms.  of  tungsten. 

1  280958  3*54370  18370 

2  3-63095  4-57662  184-30 

3  2*09740  2-64455  18399 

This  series,  like  the  preceding,  is  of  little  value,  owing 
to  the  wide  variation  in  the  results. 

Inasmuch  as  the  removal  of  air  from  the  present  form 
of  apparatus  was  a  matter  of  little  difficulty,  another 
attempt  was  made  to  colledl  the  water  formed  in  the  re- 
dudion  of  tungsten  trioxide,  and  from  its  weight  calculate 
the  atomic  mass  of  tungsten.  The  moisture  was  collected 
in  a  glass-stoppered  U-tube  filled  with  alternate  layers  of 
glass-wool  and  phosphorus  pentoxide.  From  a  series  of 
blank  experiments,  it  seemed  that  any  error  introduced 
by  the  presence  of  air  in  the  apparatus  would  be  almost 
inappreciable.     The  following  results  were  obtained  : — 

Weight  of  WOg.    Weight  of  HjO.     Atomic  mass 
Grms.  Grms.  of  tungsten. 

1  5-01313  1-16742  184-07 

2  2*02890  0-47090  184-86 

3  7*04192  1*63864  184-27 

4  3"34204  0-77832  184*07 

The  variations  in  this  series  are  similar  in  every  respedl 
to  those  of  the  different  redudion  and  oxidation  series. 
(To  be  continued). 


NOTICES  OF  BOOKS. 


The  Stamp  Milling  of  Gold  Ores.  By  T.  A.  Rickard, 
M.E.,  F.R.G.S.,  A.R.S.M.  New  York  and  London: 
The  Scientific  Publishing  Co,  1897.  Pp.  260. 
Probably  the  most  important  point  in  gold-winning,  and 
one  that  in  most  cases  is  entirely  negleded,  is  deciding 
on  the  best  and  most  economical  method  of  extrading  the 
gold  from  the  ore,  after  it  is  brought  to  bank.  Hundreds 
of  thousands  of  pounds  have  been  lost  and  wasted, 
through  the  ignorance  of  those  in  charge  of  the  mine,  on 
this  vital  question. 

A  new  gold-field  is  discovered;  there  is  a  rush;  mush- 
room experts  spring  up,  who  give  reports  on  properties 
(50  to  500  guineas,  according  to  the  proposed  capital) ; 
companies  are  fioated,  operations  commenced,  and 
when  a  certain  quantity  of  ore  is  being  raised  the 
Diredors  (who  as  a  rule  know  nothing  whatever  about 
the  subjedt)  decide  to  eredt  a  mill ;  they  do  so,  and  very 
good  mills  they  are,  but  in  ninety  cases  out  of  a  hundred 
they  are  quite  unfit  for  the  work  for  which  they  have  been 
bought,  and,  though  assays  show  a  payable  amount  of 
gold  in  the  quartz,  the  mill  cannot  extradt  it,  and  about 
60  per  cent  goes  away  in  the  tailings.  Now  this  enormous 
loss  could  be  avoided  if  only  the  Diretftors  would  consult 
a  known  pradlical  man,  with  a  reputation  to  keep,  who 
could  advise  them  whether  their  particular  grade  of  ore 
was  more  adapted  to  fast  or  slow  stamping,  long  or  short 
drop,  deep  or  shallow  boxes,  inside  or  outside  plates,  and 
all  those  other  little  details  of  construdion  and  working 
the  negledt  of  which  leads  to  60  per  cent  loss  (a  very 
common  figure  in  the  Transvaal). 

All  these  points,  and  many  others,  are  clearly  and 
thoroughly  discussed  in  these  pages. 

In  Chapter  I.,  the  Philosophy  of  the  Stamp-milling 
Process,  the  author  gives  examples  of  two  methods  of 
milling  very  wide  apart  in  their  details,  but  each  well 
adapted  to  the  class  of  ore  to  be  dealt  with.  In  Colorado 
the  ore  is  of  complex  pyritic  charadter,  containing  15  per 
.cent  of  sulphides,  and  the  gold  is  in  a  very  fine  state  of 


division  ;  it  is  therefore  necessary  to  have  a  long  20-inch 
drop  of  about  thirty  to  the  minute,  a  deep  box  of  about 
14  inches  discharge,  and  inside  plates ;  on  the  other  hand, 
in  California,  where  there  is  only  about  i  per  cent  of  sul- 
phides present  in  the  ore,  this  method  would  be  utterly 
inadequate;  so  in  that  distrid  they  use  a  5-  or  6-inch  drop 
of  100  or  105  per  minute,  a  shallow  box,  coarser  screens, 
and  outside  plates  only  :  both  these  methods,  which  are 
now  thoroughly  understood,  sprang  from  a  common 
origin  between  the  two  extremes,  and  were  taken  west  by 
the  miners  from  Georgia,  but  experience  and  observation 
has  modified  them  in  the  manner  indicated,  to  meet  the 
necessities  of  the  ore  dealt  with. 

In  succeeding  chapters  the  author  describes  the  methods 
of  milling  adopted,  after  long  and  costly  experience,  in  all 
parts  of  the  world  : — the  early  Australian  methods,  as 
used  at  the  Clunes,  Port  Philip,  and  Colonial  Mining 
Companies ;  the  more  modern  Australian  methods,  used 
at  Ballarat,  Star  in  the  East,  Britannia  United,  &c. ;  the 
Stamp  Mills  of  Otago,  New  Zealand  ;  and  in  Chap.  XIII. 
we  come  to  a  Review  of  Australian  Processes.  In  this 
chapter  the  relative  merits  of  wet  versus  dry  processes 
are  discussed,  and  Mr.  Rickard  seems  to  be  of  the  opinion 
that  the  adoption  of  one  or  the  other  is  largely  dependent 
on  the  proximity  of  the  gold-fields  to  the  railway  system. 
In  America,  as  the  railway  extends,  there  is  a  tendency 
for  the  smelter  to  replace  the  millman,  for  fire  redudion 
processes  to  supplant  wet  methods  of  gold  extradlion.  In 
Australia,  as  yet,  the  smelter  is  only  to  be  found  in  the 
silver  regions ;  elsewhere  the  stamp-mill  is  supreme. 

Chapters  on  Mills  and  Millmen,  and  the  Future  of  the 
Stamp-mill,  will  be  found  very  interesting  reading,  and 
they  bring  to  a  close  an  excellent  pradtical  work  by  a  man 
who  shows  throughout  that  he  is  a  thorough  master  of 
his  subjedt,  and,  from  a  pradtical  point  of  view,  we  can 
only  add  that  we  wish  there  were  many  more  like  him. 


Bulletin  of  the  Agricultural  Experiment  Station,  Baton 

Rouge.    By  D.  N.  Barrow,  Assistant-Diredor.   Issued 

by    the     Bureau    of    Agriculture    and    Immigration. 

Series  2,  No.  47.     1897. 

The  experiments  described  in  this  Bulletin  are  on  Corn, 

Cotton,  Forage  Crops,  and  Tobacco.     The  dry  weather 

has  materially  cut  down  the  yields,  by  depriving  the  crops 

of  the   moisture   necessary   for  taking   up   the   available 

plant  food,  with  the  result  that  all  the  results  have  been 

completely   vitiated   from    an    experimental   standpoint. 

Still  the  yields  of  cotton  and  corn  were  very  fair,  showing 

the  advantage  to  be  gained  by  a  thorough  preparation  of 

the  soil  and  frequent  cultivation. 

The  experiments  with  corn  were  a  repetition  of  those 
made  last  year.  The  yields  afforded  by  twenty  different 
varieties  are  here  given,  in  connexion  with  fertiliser  tests. 
The  highest  yield  per  acre  was  of  Farmer's  Pride,  viz., 
35-3  bushels  ;  the  lowest  being  Improved  Leoming,  which 
only  gave  13*5  bushels  per  acre.  The  fertiliser  tests  with 
corn  are  still  uncertain  and  unsatisfadory,  owing  to  the 
continued  recurrence  of  dry  weather  for  the  past  eight 
years  just  at  the  time  when  moisture  was  most  needed. 
Phosphoric  acid  in  its  various  forms  has  always  been  seen 
to  be  beneficial,  but  there  is  no  definite  evidence  in  favour 
or  one  form  or  another. 

■  The  work  on  the  station  with  regard  to  cotton  has, 
since  the  introdudion  of  tobacco,  been  confined  to  variety 
tests,  and  the  results  are  given  in  a  table.  The  short 
staples  were  ginned  and  the  percentage  of  lint  to  seed 
estimated  ;  the  long  staples  are  awaiting  the  arrival  of  a 
roller  gin  from  Europe. 

Twelve  varieties  of  forage  plants  were  experimented 
on,  the  best  results  being  obtained  from  Desmodium  molle, 
which  yielded  42,429  lbs.  per  acre ;  the  lowest  was  of 
Teosinte,  which  gave  only  6120  lbs.  per  acre. 

The  experiments  with  varieties  of  tobacco  were  carried 
out  on  Plot  No.  12,  which  was  formerly  devoted  to  nitro- 
gen experiments  on  cotton.    The  rows  were  3^  feet  wide, 


158 


Chemical  Notices  from  Foreign  Sources. 


I  CbbuicalRbws, 
1      Sept.  24.  1897. 


and  ran  at  right  angles  to  the  old  nitrogen  rows.  Twenty- 
two  varieties  were  set,  but  they  all  suffered  so  severely 
from  the  dry  weather  that  the  results  are  pradtically 
worthless — hence  the  tabulated  results  convey  no  informa- 
tion of  any  value.  In  the  experiments  on  fertilisers  and 
tobacco  it  is  singular  that,  though  emphatically  a  "  potash- 
loving"  plant,  there  is  no  indication  of  that  substance 
having  benefitted  tobacco  on  this  soil. 

Since  the  publication  of  No.  41  Bulletin  the  tobacco 
raised  on  the  experimental  station  has  been  worked  up 
into  cigars.  The  cigars  were  recently  on  exhibition  at 
the  State  Agricultural  Society,  and  were  pronounced  by 
experts  to  be  of  excellent  quality,  and  it  is  expedted  that 
they  will  soon  (in  eighteen  months  or  two  years)  compare 
favourably  with  Havanas. 

Catalogue  of  Standard  Second-hand  and  New  Books, 
English  and  Foreign.     On   Chemistry  and  the  Allied 
Sciences,  Technology,  Optical  and  Eledtrical  Science, 
Metallurgy,   Mineralogy,  Brewing,   Dyeing,   Manufac- 
tures, Agriculture,  &c.    By  William  F.  Clay.     Uni- 
versity Book  Warehouse,  18,  Teviot  Place,  Edinburgh. 
This  Catalogue  (No.  80,  1897),  '"  addition  to  its  usual 
features,  contains  an  account  of  works  on  the  constants 
employed  in  the  analysis  of  fats  and  oils.     There  is  also 
a  list  of   monographs  and  other  original  memoirs    on 
chemistry  not   at  present  to  be  obtained   in  any  other 
form.    We  feel  therefore  free  to  call  the  special  attention 
of  students,  and  also  of  librarians,  &c.,  to  this  list. 


CHEMICAL    NOTICES   FROM    FOREIGN 
SOURCES. 

Note.— All  degrees  of  temperature  are  Centigrade  unless  otherwise 
expressed. 

Comptes  Rendus  Hebdomadaires  des  Seances,  deVAcademit 
des  Sciences.     Vol.  cxxv.,  No.  8,  August  23,  1897. 

Critical  Constants  of  certain  Gases. — A.  Leduc  and 
P.  Sacerdote. — The  critical  temperatures  are  obtained  by 
us  at  less  than  about  0'5,  and  the  critical  pressures  at  less 
than  I  atmosphere. 

The  Absorption  of  the  X  Rays. — Abel  Buguet.— To 
determine  the  relations  existing  between  the  thickness  of 
a  body  and  its  opacity  for  the  X  rays  the  author  uses 
scales  of  thickness. 

No.  9,  August  30,  1897. 

Photography  of  the  Fluoroscopic  Image.— Charles 
Porchier.— To  oppose  an  absolute  barrier  to  the  X  rays  I 
arrange  the  experiment  as  follows  : — The  door  of  the  dark 
chamber  of  the  laboratory  is  perforated  with  an  aperture 
in  which  is  placed  the  objedt-lens  of  my  photographic 
apparatus.  Besides  a  barrier  of  lead  behind  the  door  and 
all  around  the  objedt-glass,  in  a  radius  of  0-50  metre,  I 
have  nailed  a  sheet  of  lead  of  0*003  metre  in  thickness. 
Thus  a  barrier  of  lead,  the  metal  screen,  and  the  objed- 
glass  protefls  the  gelatino-bromide  film  absolutely  against 
the  a<aion  of  the  X  rays.  The  fluoroscopic  image  is  the 
most  interfered  with,  and  can  aft  alone  upon  the  plate. 
The  screen  is  placed  at  0*57  metre  from  the  objedtive,  and 
the  focus  of  the  phial  is  only  0*03  behind  it. 

Bulletin  de  la  Societe  Chimique  de  Paris. 
Series  3,  Vol.  xvii.-xviii.,  No.  14. 

M.  Ponsot  made  some  observations  relative  to  the  con- 
gelation of  milk;  in  his  opinion  it  is  not  proved  that 
cryoscopy  alone  can  prove  the  addition  of  water  or  deter- 
mine its  extent. 

M.  Delipine  gave  the  results  of  his  thermo-chemical 
experiments  on  formic  aldehyd  ;  his  conclusions  as  to  its 
molecular  formation  conform  with  those  of  Tollens  and 
Grossmann. 

M.  Causse  described  his  experiments  on  the  a&ion  of 


salicylic  aldehyd  on  urea  ;  when  a  mixture  of  these  sub- 
stances  is  heated  to  110°  they  combine  with  elimination 
of  water,  forming  salicyl-triurea. 

M.  Hebert  presented,  on  behalf  of  M.  Rabaut,  his  re- 
searches  made  on  the  combinations  of  cupreous  chloride 
with  nitrites. 

A  Method  of  Oxidation  and  Chloridation.— A.  Vil- 
liers. — Already  noticed. 

Destrutftion  of  Organic  Matters  in  Toxicology.— 
A.  Villiers. — Already  noticed. 

Produdts  of  Decomposition  of  Carbide  of  Calcium 
by  Water. — E.  Chuard. — Already  noticed. 

Purification  and  Atomic  Weight  of  Cerium.— 
MM.  WyroubofFand  Verneuil.— (See  pp.  137  and  153). 

On  Sacchareines,  New  Colouring-matters  derived 
from  Benzoic  Sulphimide  (Saccharine).— P.  Monnet 
and  J.  Koetschet. — A  long  paper,  not  suitable  for  ab- 
stradtion. 

Isomerism  existing  between  Pilocarpidine  and 
Pilocarpine. —  A.  Petit  and  M.  Polonovski.— From  their 
recently-published  researches  on  these  bodies,  the  authors 
have  been  led  to  doubt  the  accuracy  of  the  formulae  they 
had  adopted,  and  to  suspedl  the  existence  of  isomerism 
between  these  two  bodies.  The  experiments  tried  con- 
firmed their  belief. 

Alkalimetric  Estimation  of  Metals:  Mercury.— 
H.  Lescoeur. — Not  suitable  for  abstraction. 


MISCELLANEOUS. 

South  West  London  Polytechnic  Institute. — 
Principal,  Professor  Herbert  Tomlinson,  B.A.,  F.R.S. 
Professor  of  Chemistry,  J.  B.  Coleman,  A.R.C.S.,  F.I.C., 
F.C.S.  This  Institute  was  opened  in  1895,  and  is  there- 
fore commencing  its  third  session's  work.  Two  and 
three  year  courses  of  instrudtion  are  given  in  Chemistry 
and  in  Mechanical  and  Eledtrical  Engineering,  suited  to 
the  requirements  of  analysts,  industrial  chemists, 
engineers,  and  others.  The  chemical  department  con- 
tains two  laboratories,  balance,  ledlure,  and  store  rooms, 
and  is  designed  and  equipped  for  advanced  chemical 
work.  In  addition  to  the  day  courses,  evening  instrudtion 
is  given  in  Pure  Chemistry,  Pharmacy,  Photography, 
Colours,  and  other  branches  of  Applied  Chemistry. 

City  and  Guilds  of  London  Institute. — A  special 
course  of  instrudtion  in  Eledlro-chemistry  will  be  given 
during  the  coming  session  at  the  City  and  Guilds  Central 
Technical  College.  The  course  will  include  pradlical  in- 
strudlion  in  eledlro-deposition,  the  use  of  the  eledlric 
furnace,  dynamos,  transformers,  and  accumulators.  A 
great  part  of  the  time  of  the  students  attending  the 
course  will  be  devoted  to  Eledtro-chemical  Research  and 
the  study  of  Eledlro-chemical  Adtion.  Candidates  for 
admission  will  be  required  to  submit  evidence  of  having 
a  general  knowledge  of  physics  and  chemistry,  and  of 
having  been  specially  trained  in  one  of  these  subjedls. 

On  the  Essence  of  Bitter  Fennel.— E.  Tardy.— The 
French  essence  of  bitter  fennel  was  first  washed  with  an 
aqueous  solution  of  potash,  then  with  distilled  water. 
The  washings,  treated  with  hydrochloric  acid,  gave  anisic 
acid.  The  washed  essence  was  then  treated  with  bisul- 
phite  of  soda,  when  an  abundant  precipitate  was  produced. 
This  precipitate,  after  being  thoroughly  washed  with 
ether,  was  decomposed  by  potash.  The  oily  liquid  pro- 
duced was  submitted  to  fradtional  precipitation,  by  which 
means  it  was  divided  into  seven  portions,  the  first  boiling 
below  240°  and  thelatterbetween265°and27o'.  Above  this 
point  a  produdl  is  obtained  of  a  fatty  appearance,  in  which 
are  a  large  number  of  crystalline  flakes  :  these  can  be 
separated  by  dissolving  them  in  ether  and  re-crystallising. 
This  body  combines  neither  with  acids  nor  alkalies,  and 
on  analysis  gives  the  formula  Ci3Hi40a. — Bull.  Soc.  Chim. 
de  Paris,  No.  13,  1897. 


OtisuicAL  News,  I 
Sept.  24, 1897.    f 


Active  Principles  of  Some  Aroides, 


15^ 


Researches  on  the  A(5\ive  Principles  of  some 
Aroides. — A.  Hebert  and  F.  Heim. — The  authors  have 
arrived  at  the  conclusion  that  the  ai^ive  principles  of  the 
Arum  and  allied  plants  are  more  or  less  rich  in  saponine, 
according  to  the  season,  but  the  maximum  proportion 
never  exceeds  i  part  per  thousand  of  the  weight  of  the 
living  plant;  that  the  acrid  principle,  which  has  not  yet 
been  properly  described  nor  even  extracted  by  any  one,  is 
a  liquid  alkaloid,  very  similar  to  conicine ;  and  that  it  is 
impossible  to  detedl  hydrocyanic  acid  in  the  aroids  they 
have  worked  on. — Bull.  Soc.  Chim.  de  Paris,  No.  13,  1897. 

"cheap  sets  of  standard  books. 

In  good  condition,  and  sent  Carriage  Free  in  Great  Britain. 
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Do.,  New  Ed.,  3  vols.  New,  1888-93  {Special  offer),  £6 14s.,  for  £4153. 
Thorpe's  Ditity.  of  Applied  Chemistry  (complete  set).     The  com- 
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Gmelin's  Handbook  of  Chemistry  (Organic  and  Inorganic),  by 

Hy.  Watts,  complete  set,  19  vols,  cl.,  scarce,  £20.  for  £8  8s. 
Iron  and  Steel  Instit.  Journal,  1876-89,  29  vols.,  cl.,  ^'lo  10s. 
Journal  of  the  Chemical  Society,  1863-1892,  45  vols.,  cl.,  ;^I9  los. 

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WM.  F.  CLAY,  Bookseller.  Teviot  Place,  EDINBURGH. 

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By  OSCAR  GUTTMANN,  Assoc.  M.Inst.  C.E.,  F.I.C., 
Member  of  the  Societies  of  Civil  Engineers  and  Architedts  of  Vienna 
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Chbmical  nBws,i 
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Permeability  of  Elements  to  the  Rontgen  Rays, 


161 


THE    CHEMICAL     NEWS 

Vol.  LXXVI.,  No.  1975. 


THE    PERMEABILITY    OF     ELEMENTS    OF 

LOW    ATOMIC    WEIGHT     TO     THE 

RONTGEN     RAYS.' 

By  JOHN    WADDELL,    B.A.  (Dal.   Coll.),   B.Sc.  (Lond.), 
Ph.D.  (Heidelberg),  D.Sc.  (Edin.). 

At  the  meeting  of  the  British  Association  held  last  year 
in  Liverpool,  a  paper  by  Dr.  Gladstone  and  Mr.  Hibbert 
was  read.  It  was  afterwards  published  in  the  Chemical 
News,  but  before  I  saw  their  article  I  had  sent  for  pub- 
lication, in  the  same  journal,  an  account  of  work  that  I 
had  done  along  somewhat  similar  lines,  though  starting 
from  a  different  point  and  undertaken  with  a  different 
objeft.  My  results  to  a  certain  extent  coincided  with 
theirs,  but  they  were  also  to  a  certain  extent  different, 
and  I  wish  to  bring  before  the  Association  some  of  these 
differences,  as  well  as  some  other  phenomena  connedted 
with  the  permeability  of  powders  to  the  Rontgen  rays. 

My  article  in  the  Chemical  News  dealt  not  only  with 
a  number  of  metals,  but  with  non-metals  as  well. 

In  the  case  of  the  metals  I  used  mainly  oxides  and 
carbonates,  whereas  Gladstone  and  Hibbert  used  formates 
and  acetates.  They  say  that  they  used  the  formate  be- 
cause of  the  low  equivalent  of  the  acid  radical  (CHO2). 
As  a  matter  of  fadl,  the  carbonate  is  better  from  that 
point  of  view,  as  may  be  seen  by  considering  that  37 
parts  by  weight  of  lithium  carbonate  contain  as  much 
lithium  as  52  parts  of  the  formate,  and  100  parts  of  cal- 
cium carbonate  contain  as  much  calcium  as  130  parts  of 
calcium  formate.  Of  course  the  disparity  between  car- 
bonate and  acetate  is  still  greater,  and  equally  of  course 
the  oxide  has  a  still  larger  proportion  of  metal.  In  any 
case  it  is  a  matter  of  comparative  indifference  which  of 
the  compounds  is  taken,  since  the  permeability  of  carbon, 
hydrogen,  and  oxygen  is  so  small. 

A  point  of  supreme  importance,  however,  is  to  define 
stridtly  what  is  meant  by  saying  that  one  substance  is 
more  permeable  or  has  less  absorption  than  another.  For 
instance,  Gladstone  and  Hibbert,  in  reference  to  potassium 
and  calcium,  say  "  It  was  found  that,  whether  tested  by 
the  uncombined  metals  or  by  their  salts,  the  absorption  of 
the  Rontgen  rays  by  the  two  metals  are  the  same  for 
thicknesses  answering  to  the  atomic  weights,  while  they 
are  very  different  for  thicknesses  answering  to  their  com- 
bining proportions."  It  all  depends  on  what  is  meant  by 
•'  thicknesses  answering  to  the  atomic  weights,"  whether 
the  above  statement  is  correft  or  not.  If  it  means  that  a 
plate  of  potassium  3-9  m.m.  thick  has  the  same  absorp- 
tion as  a  plate  of  calcium  4*0  m.m.  thick,  my  experiments 
tend  to  prove  that  it  is  not  corred ;  but  if  it  means  that 
two  plates  of  the  same  area,  and  of  such  a  thickness 
that  the  weight  of  potassium  would  be  0*39  grm.  and  of 
calcium  0*40  grm.,  would  absorb  equally,  I  should  agree 
that  the  statement  is  within  the  limits  of  experimental 
error.  My  statement  in  the  Chemical  News  (vol.  lxxiv.,p. 
298)  is  *'  The  potassium  carbonate  was  of  appreciably  the 
same  transparency  as  the  calcium  carbonate  containing 
the  same  amount  of  metal." 

I  suppose  that  when  the  statement  was  first  made  that 
the  absorption  by  metals  was  proportional  to  their  density, 
it  was  intended  that  equal  thicknesses  of  metal  foil  should 
be  used.  If  this  law  had  been  true,  it  would  follow  that  ' 
for  thicknesses  inversely  proportional  to  the  density,  the 
absorption  would  be  equal.     I  believe  that  this  statement 

♦  Read   before   the    British   Association   (Seftion   B),  Toronto 
Meetiot,  1897. 


is  not  very  far  from  correft  with  regard  to  the  metals  of 
high  atomic  weight, — say  all  of  those  above  iron,— but 
the  absorption  of  all  is  so  large  that  it  is  somewhat  diffi- 
cult to  establish  or  to  disprove  the  statement ;  but  there 
is  little  difficulty  in  proving  that  it  does  not  hold  in  com- 
paring metals  of  high  atomic  weight  with  those  of  low 
atomic  weight.  Sodium,  magnesium,  aluminium,  are  in 
quite  a  different  class  from  iron,  copper,  lead.  So  much 
must  be  admitted  by  any  one  who  has  done  work  in  this 
connexion  ;  but  when  a  comparison  is  made  among  the 
elements  of  low  atomic  weight  themselves,  it  seems  that 
there  is  room  for  difference  of  opinion. 

I  think  it  must  be  conceded  that  the  only  fair  way  to 
test  the  relative  permeability  is  to  have  the  radiations 
pass  through  the  same  weight  of  the  different  metals.  In 
order  to  do  this  I  took  pill-boxes  of  the  same  size,  and 
put  in  them  such  weights  of  the  compounds  that  they 
would  contain  I'o  grm.  or  0-5  grm.  of  the  metal.  This 
was  equivalent  to  taking  sheets  of  metal  inversely  propor- 
tional to  their  density,  and  was  of  course  available  for 
many  metals  which  it  would  be  impossible  to  obtain  in 
sheets  in  the  metallic  state.  So  far  as  could  be  deter- 
mined with  metals  of  high  atomic  weight,  the  permeability 
of  equal  weights  was  approximately  equal.  Tested  in 
this  way,  however,  the  permeability  of  potassium  was 
much  less  than  that  of  sodium,  or  magnesium,  or 
aluminium.  I  found  that  the  difference  between  lithium 
and  sodium  was  not  nearly  so  great  as  between  sodium 
and  potassium,  and  that,  if  anything,  lithium  was  less 
permeable  than  sodium.  This  is  opposed  to  the  statement 
of  Gladstone  and  Hibbert,  who  say  '•  that  the  order  of 
absorption  is  lithium,  sodium,  and  potassium,  while  the 
order  of  density  is  lithium,  potassium,  and  sodium."  If 
the  weights  of  lithium  and  sodium  tested,  or  even  the 
weights  of  their  formates,  were  in  the  ratio  of  7  :  23,  I 
should  agree  with  them  ;  but  that  this  is  an  unfair  mode 
of  comparison  will  be  apparent,  when  it  is  considered  that 
it  corresponds  to  taking  for  the  test  a  plate  of  lithium 
about  two-thirds  the  thickness  of  the  sodium  plate  ;  and 
no  one  would  think  of  comparing  a  plate  of  aluminium 
with  a  thicker  plate  of  platinum,  which  would  be  a  similar 
experiment. 

In  view  of  the  variance  that  appears  to  exist  in  the 
results  obtained  by  Gladstone  and  Hibbert  and  myself,  I 
have  made  a  careful  re-investigation  of  the  matter,  and 
compared  more  closely  not  only  lithium  and  sodium,  but 
beryllium  and  magnesium,  and  boron  and  aluminium. 
The  method  of  procedure  was  the  same  as  that  employed 
before,  namely,  prote^ing  the  photographic  plate  by  a 
sheet  of  lead  in  which  holes  were  punched  for  the  pill, 
boxes.  The  length  of  exposure  to  the  Rontgen  rays 
differed  in  the  different  experiments,  and  the  battery 
current  and  length  of  spark  varied  when  using  the  same 
tube,  and  two  different  tubes  even  were  employed.  I  had 
found,  from  previous  experience,  that  it  is  better  to  test 
the  permeability  of  substances  in  this  way  than  to  test 
their  absorptive  power  by  leaving  the  photographic  plate 
exposed  to  the  full  power  of  the  rays,  except  where  covered 
by  the  material  to  be  tested. 

In  the  new  investigation  I  took  two  sets  of  salts  of 
sodium  and  lithium,  namely,  the  nitrates  and  carbonates, 
and  I  took  varying  proportions.  In  the  case  of  the  ni- 
trates I  took  of  sodium  nitrate  2  grms.  and  of  lithium 
nitrate  5-4  grms.,  3*2  grms.  =  5-4  x  ^g,  the  ratio  of  the 
densities,  and  2  grms.  so  as  to  have  equal  weights  of  the 
two  salts  :  2  grms.  of  sodium  nitrate  and  5-4  grms.  of 
lithium  nitrate  contain  each  a  little  over  0*54  grm.  of  the 
metal. 

In  every  photograph  the  2  grms.  of  sodium  nitrate  was 
decidedly  more  permeable  than  the  5*4  grms.  of  lithium 
nitrate,  and  much  more  nearly  equal  to  the  3*2  grms.  of 
the  lithium  salt,  which  contained  only  three-fifths  as 
much  metal. 

I  usually  considered  that  the  sodium  nitrate  was  more 
permeable  than  the  3-2  grms.  of  lithium  nitrate,  but  the 
difference  was  so  slight  th^^t  it  was  hard  to  decide.    Suet) 


l62 


Permeabtlity  of  Elements  to  the  Rontgen  Rays, 


t  Chemical  Nbw», 
I      0&.  1, 1897. 


being  the  case,  it  naturally  follows  that  the  2  grms.  of 
lithium  nitrate  was  more  permeable  than  the  same 
amount  of  sodium  nitrate. 

In  the  case  of  the  carbonates  the  weights  employed 
were,  of  sodium  carbonate  i  grm.,  and  of  lithium  car- 
bonate 2*3  grms.,  which  contained  the  same  weight  of 
metal,  namely,  0*43  grm.  I  had,  in  addition,  two  other 
boxes  of  lithium  carbonate,  one  containing  i-o  grm.,  the 
other  07  grm.  In  this  last  the  weight  of  lithium  is  ^, 
the  weight  of  sodium  in  the  sodium  carbonate  employed. 
The  difference  between  the  carbonates  which  contained 
equal  weights  of  metal  was  not  so  marked  as  in  the  case 
of  the  nitrates — perhaps  because  of  the  smaller  adtual 
amount  of  the  metal  employed;  but  on  all  the  photo- 
graphs, except  one,  which  received  a  short  exposure,  and 
which  showed  several  abnormalities,  the  sodium  carbonate 
was  distinftly  enough  shown  to  be  the  more  permeable. 
When  the  smaller  weights  of  lithium  were  employed  they 
were  more  permeable  than  the  sodium  carbonate. 

Even  the  07  grm.  of  lithium  carbonate  which  contains 
less  than  o'i4  grm.  of  lithium  had  a  perceptible  absorp- 
tion, and,  if  it  is  considered  that  this  was  spread  over  an 
area  of  more  than  a  centimetre  diameter,  it  would  appear 
to  be  too  strong  a  statement  to  say  that  lithium  has 
"  next  to  no  absorbent  adlion  on  the  Rontgen  rays." 

A  result  that  surprised  me  was  that  lithium  nitrate  con- 
taining o'2  grm.  of  lithium  was  more  absorbent  than 
lithium  carbonate  containing  0*43  grm.  ot  lithium.  The 
total  quantity  of  lithium  nitrate  was  2  grms.  and  of 
lithium  carbonate  2*3  grms. 

I  therefore  tried  another  experiment  in  which  sodium 
and  lithium  nitrate  were  compared  with  sodium  and 
lithium  carbonate.  The  salts  were  taken  in  such  quanti- 
ties that  they  contained  each  o'27  grm.  of  metal,  that 
being  the  amount  of  sodium  in  i  grm.  of  sodium  nitrate. 
They  were  placed  near  the  centre  of  the  plate,  and  placed 
symmetrically  with  regard  to  the  Newton's  tube ;  that  is, 
the  line  joining  the  cathode  and  the  reileAing  anode  was 
in  the  same  plane  as  the  line  passing  through  the  middle 
of  the  photographic  plate,  and  on  each  side  of  this  line 
the  nitrates  and  carbonates  were  placed.  The  sodium 
nitrate  was  more  permeable  than  the  lithium  nitrate ; 
there  was  hardly  any  appreciable  difference  between  the 
carbonates,  but  the  sodium  was  if  anything  the  more 
permeable.  It  was  no  more,  however,  than  might  be  ac- 
counted for  by  the  difference  in  quantity  of  the  acid 
radical.  The  carbonates  were  very  considerably  more 
permeable  than  the  nitrates.  I  was  induced  to  compare 
the  permeability  of  substances  containing  only  carbon, 
hydrogen,  oxygen,  and  nitrogen,  with  salts  of  metals.  I 
tried  the  relative  absorption  of  i  grm.  of  dinitrobenzol, 
3  grms.  of  sugar,  and  2  of  ammonium  nitrate.  The 
dinitrobenzol  and  ammonium  nitrate  were  chosen  on 
account  of  the  considerable  quantity  of  nitrogen  in  them ; 
in  sugar,  of  course,  nitrogen  was  absent.  The  sugar  was 
decidedly  less  permeable  than  the  dinitrobenzol  (of  which 
there  was  only  half  the  amount),  and  slightly  more  per- 
meable than  the  equal  quantity  of  ammonium  nitrate. 
Sodium  fluoride  and  sodium  carbonate,  containing  the 
same  quantity  of  metal  as  the  ammonium  nitrate  did  of 
nitrogen,  were  somewhat  less  permeable,  though  the 
difference  was  not  so  great  as  would,  I  think,  be  generally 
supposed.  The  sodium  fluoride  was  very  slightly  less 
permeable  than  the  sodium  carbonate.  All  of  the  sub- 
stances, however,  even  the  i  grm.  of  dinitrobenzol,  had  an 
appreciable  absorbent  adtion. 

I  also  tried  potassium  and  calcium  nitrates  and  car- 
bonates. There  was  not  so  much  difference  between  the 
permeability  of  the  nitrates  and  carbonates  in  these  cases, 
partly  doubtless  because  the  acid  radical  is  not  so  large  a 
fradion  of  the  total  weight  as  in  the  case  of  lithium  and 
sodium,  and  mainly  that  the  great  absorbent  adtion  of 
potassium  and  calcium  hides  that  of  the  carbon,  nitro- 
gen, and  oxygen. 

Since  the  acid  radical  has  some  absorptive  adtion,  the 
greater  permQability  that )  found  in  the  sodium  compounds 


may  be  due  to  their  containing  a  smaller  quantity  of  the 
acid  radical ;  but  one  thing  is  certain,  that  it  is  not  corredt 
to  assert  that  lithium  is  of  small  absorbent  adtion,  while 
indicating  that  sodium  has  considerable  absorptive  power. 
Though  I  have  not  tested  it,  I  should  be  inclined  to  expedl 
that  lithium  chloride  containing  a  grm.  of  chlorine,  which 
has  a  very  considerable  absorptive  power,  would  not 
show  appreciably  greater  permeability  than  sodium  chloride 
containing  the  same  amount  of  chlorine.  I  am  quite 
ready  to  admit  that,  if  the  permeability  of  the  acid  radical 
of  the  carbonates  is  to  be  tested  or  compared  with  that  of 
the  nitrates,  the  lithium  salt  is  better  than  the  sodium 
salt,  because  there  is  less  than  one-third  the  quantity  of 
metal  in  the  former  as  in  the  latter. 

{Note. — Since  the  rest  of  the  paper  was  written  I  have 
experimented  on  the  absorptive  adlion  of  the  acid  radical 
of  the  carbonates.  I  made  the  comparison  with  the 
absorptive  adlion  of  metallic  sodium.  For  this  purpose  I 
took  four  different  quantities  of  sodium,  which  1  moulded 
into  flat  plates  to  cover  the  bottom  of  the  pill-boxes.  I 
protedted  the  sodium  by  a  thin  coating  of  vaseline. 
There  were  of  sodium  0*25  grm.,  0*50  grm.,  075  grm,, 
and  I'o  grm.  Of  sodium  carbonate,  I  had  in  another  box 
173  grms.,  which  contained  075  grm.  of  sodium,  and  of 
lithium  carbonate  i'2i  grms.,  which  had  the  same  quan- 
tity of  the  CO3  radical  as  the  sodium  carbonate.  The 
sodium  carbonate  was  less  permeable  than  the  075  grm. 
of  sodium,  and  more  permeable  than  the  I'o  grm.,  and 
would  I  think  be  about  equal  to  o'go  grm.  of  sodium. 
That  would  make  the  permeability  of  the  CO3  group  the 
same  as  of  0*15  grm.  of  sodium,  whereas  the  sodium  in 
the  salt  is  075  grm. — that  is,  the  permeability  of  the  CO3 
group  is  Ave  times  as  great  as  the  sodium  with  which  it 
combines.  It  was  found  that  the  permeability  of  the 
lithium  carbonate  was  less  than  that  of  0*25  grm.  of 
sodium,  and  greater  than  that  of  0*50  grm.  of  sodium, 
and  would  be  about  equal  to  0*40  grm.  of  sodium.  As  the 
CO3  group  has  a  permeability  of  o'i5  grm.  of  sodium, 
the  lithium  in  the  carbonate  has  a  permeability  of  0*25 
grm.  of  sodium.  In  order  to  compare  lithium  with  an 
equal  weight  of  sodium,  this  number  must  be  multiplied 
by  V'l  the  result  being  that,  if  a  plate  of  lithium  of  the 
same  weight  as  sodium  be  compared  with  it  as  regards 
permeability,  it  is  pradlically  equal,  being  in  the  ratio  of 
075  to  o'25  X  Vi  if  the  numbers  taken  above  be  re- 
garded as  corredt,  as  they  approximately  are.  In  the 
same  experiment  I  found  that  2  grms.  of  ammonium 
nitrate  are  not  so  permeable  as  0*50  grm.  of  sodium. 
This  probably  accounts  for  the  nitrates  being  less  per- 
meable than  the  carbonates.  The  lithium  carbonate  had 
a  very  appreciable  absorptive  power,  the  photographic 
plate  being  darkened  about  half  as  much  as  when  not 
protedted,  except  by  the  paper  covering  and  an  empty  box). 

While  making  the  experiments  with  lithium  and  sodium 
I  also  compared  beryllium  and  magnesium.  I  used  beryU 
Hum  oxide  obtained  by  heating  carbonate  which  had  been 
obtained  from  Schuchardt.  The  magnesium  was  taken  in 
the  form  of  carbonate.  There  was  0-53  grm.  of  the 
former,  and  0*67  grm.  of  the  latter,  each  containing  about 
o'lg  grm.  of  the  metal. 

The  difference  of  permeability  between  the  beryllium 
compound  and  the  magnesium  compound  was  slight,  and 
in  some  cases  was  in  the  one  diredlion,  and  in  some  cases 
in  the  other,  perhaps  depending  upon  the  relative  position 
on  the  plate  or  possibly  on  the  length  of  exposure ;  but 
in  all  instances  they  were  more  permeable  than  the 
lithium  carbonate  containing  the  same  amount  of  metal. 
It  must  be  remembered  that  there  was  a  greater  quantity 
of  the  lithium  salt,  and  though  the  acid  radical  has  not  a 
very  large  absorptive  power  it  is  not  without  influence. 

Aluminium  and  boron  also  were  compared,  the  oxides 
being  the  compounds  taken:  i  grm.  of  the  aluminium 
oxide  and  1-68  grms.  of  the  boron  oxide  were  employed. 
The  former  was  obtained  by  heating  ammonium  alum, 
and  the  latter  by  heating  boracic  acid. 

The  aluminium  compound  was  less  permeable  than 


rCnfiMicAL  News,  I 
oa.  1, 1897.    t 


Permeahiltty  of  Elements  to  the  Rdntgen  Rays 


[63 


than  that  of  boron,  but  even  it  had  a  greater  permeability 
than  the  sodium  nitrate  which  contained  the  same  amount 
of  metal  (0*54  grm.),  and  indeed  a  greater  permeability 
than  sodium  carbonate  containing  0*43  grm.  of  sodium 
only. 

Boracic  acid,  which,  assuming  its  formula  to  be  H3BO3, 
contained  the  same  amount  of  boron  as  the  aluminium 
oxide  did  of  aluminium,  was,  however,  not  more  permeable. 

As  a  result  of  these  experiments,  I  think  it  must  be  ad- 
mitted that  the  negative  is  given  to  the  statement  that 
"  In  dealing  with  metals,  whether  uncombined  or  in  salts, 
the  order  of  their  absorption  for  these  rays  is  in  i&&  that  of 
their  atomic  weight,  but  the  amount  of  absorption  in- 
creases much  more  rapidly  than  the  atomic  weights 
themselves." 

With  the  same  weight  of  lithium  and  sodium  the  per- 
meability is  not  far  from  equal,  and  for  the  same  thickness 
of  plate  of  metal  sodium  is  not  twice  as  absorptive  as 
lithium,  although  its  atomic  weight  is  more  than  three  times 
as  great.  Nor,  in  the  case  of  comparing  the  same  thick- 
nesses, does  sodium  differ  as  much  from  lithium  as  potas- 
sium does  from  sodium. 

My  present  experiments,  taken  along  with  the  earlier 
ones,  show  that  a  line  cannot  be  drawn  between  metals 
and  non-metals  as  regards  permeability.  Chlorine  is  less 
permeable  than  sodium,  but  fluorine  is  more  permeable. 
There  seems  to  be  a  very  rapid  increase  in  absorptive 
power  between  the  atomic  weight  of  aluminium  and  that 
of  potassium,  and  perhaps  the  same  or  a  slightly  less  rate 
of  increase  on  as  far  as  manganese.  Above  manganese 
the  variation  is  slight,  and  below  aluminium  not  very 
great ;  but  there  seems  to  be  the  group  of  elements,  car- 
bon, nitrogen,  oxygen,  with  perhaps  fluorine  and  boron, 
that  has  a  specially  low  absorptive  power.  Why  carbon 
should  be  so  much  more  like  fluorine  than  the  latter  is 
like  chlorine  is  a  little  difficult  to  say. 

A  phenomenon  which  I  noticed  before,  but  which  I  have 
since  more  fully  investigated,  without,  however,  arriving 
at  what  I  consider  an  adequate  explanation,  is  a  peculiar 
granular  strufture,  often  exhibited  by  photographs  of 
powders.  In  order  to  see  whether  the  granulation  was 
due  to  the  powder  being  in  lumps,  instead  of  being  re- 
duced to  an  impalpable  fineness,  I  experimented  with 
three  grades  of  powder  : — coarse  (passing  through  a  ten- 
mesh  sieve  but  not  through  a  forty-mesh),  medium 
(passing  through  a  forty-mesh  but  not  through  a  seventy- 
mesh),  and  fine  (passing  through  the  seventy-mesh  sieve)- 
The  materials  were  mainly  cryolite  and  magnesite,  and 
eight  different  boxes  of  each  were  taken  as  below  : — 

1.  Two  grms.  coarse  powder. 

2.  Four  grms.  coarse  powder. 

3.  Three  grms.  medium  powder. 

4.  Three  grms.  fine  powder. 

5.  li  grms.  coarse  at  bottom,  and   li  grms.  fine 

on  top. 

6.  i^  grms.  fine  at  bottom,  and  li  grms.  coarse 

on  top. 

7.  i^  grms.  fine  and  ij  grms.  coarse,  mixed. 

8.  Three    grms.   coarse,    raised  i    cm.   from  the 

photographic  plate. 

The  granulation  seemed  to  correspond  with  the  size  of 
particles,  and  was  quite  distindt  even  through  the  4  grms., 
which  made  a  layer  not  far  from  a  centimetre  thick. 
When  the  fine  and  coarse  were  mixed,  the  granulation  of 
the  coarse  still  showed ;  and  when  the  coarse  and  fine 
were  separate,  the  granulation  was  most  distind  when  the 
coarse  was  at  the  bottom.  When  the  coarse  powder  was 
on  top,  the  appearance  in  the  photograph  was  very  similar 
to  that  obtained  from  the  mixed  powders.  When  the  box 
containing  the  coarse  powder  was  raised  a  centimetre  from 
the  plate,  the  granulation  was  very  much  blurred.  This 
is  doubtless  due  to  the  overlapping  of  shadows,  and  this 
would  account  for  the  greater  distindness  mentioned 
above,  when  the  coarse  powder  was  next  the  plate  and 
the  fine  powder  on  top. 


The  phenomenon  is  certainly  peculiar,  because  one 
would  imagine  that  the  particles  would  lie  together  in 
such  a  way  that  the  average  thickness  would  be  the  same. 
This  is  especially  the  case  when  the  coarse  powder  is 
mixed  with  the  fine,  the  latter  (one  would  suppose)  filling 
in  the  interspaces.  It  is  true  that  a  crystal  of  cryolite  about 
2*4  m.m.  in  thickness,  placed  in  2  grms.  of  cryolite  fine 
powder,  the  total' thickness  being  about  7  m.m.,  was  out- 
lined in  the  photograph,  it  being  slightly  less  permeable 
than  the  powder  that  would  occupy  the  same  space. 

Indeed,  when  the  cryolite  powder  was  mixed  with  about 
half  its  weight  of  calcite  powder,  the  crystal  was  still 
fairly  well  outlined,  though  not  so  strongly  marked  as 
when  cryolite  powder  alone  was  used ;  and  I  think  a 
mixture  could  probably  be  made  such  that  the  powder, 
when  pressed  into  a  pretty  compadt  mass,  would  just 
equal  the  crystal  in  absorbent  power.  When  I  had  the 
mixed  cryolite  and  calcite  powder  it  showed  a  granular 
structure,  though  both  minerals  were  so  fine  that  they 
singly  did  not  show  granulation.  This,  doubtless,  was 
due  to  an  imperfect  mixture,  little  lumps  of  one  or  other 
mineral  being  unbroken.  I  fancy  that  if  the  mixed  powders 
had  been  sifted  through  a  6ne  sieve,  the  granulation 
would  not  have  shown. 

There  was  in  one  box  three  pieces  of  cryolite  crystal, 
crossed  in  such  a  way  that  one,  two,  and  three  thicknesses 
were  exposed  to  the  rays.  The  space  not  taken  up  by  the 
crystalline  pieces  was  filled  in  with  cryolite  powder. 

In  the  photograph  the  three  thicknesses  were  quite  dis- 
tinctly marked. 

I  suppose  anyone  would  expedt  that  if  ordinary  light 
were  passed  through  a  transparent  substance,  in  the  same 
way  as  was  done  with  the  Rontgen  rays  in  the  above  ex'^ 
periments,  no  granulation  would  appear  in  the  photograph. 
In  order  to  make  certain  that  such  is  the  case,  I  made  use 
of  glass,  in  fine  and  coarse  powder  and  in  the  form  of 
beads  of  a  somewhat  larger  size.  Burning  magnesium 
wire  was  used  for  illuminating. 

When  the  photographic  plate  was  developed,  it  was 
found,  as  was  expe.5ted,  that  there  was  no  granulation  in 
any  case.  Of  course,  ordinary  light  is  refradted  and  re* 
ileded  by  every  particle  of  the  glass,  and  perhaps  we 
must  consider  that  the  different  charader  of  the  Rontgen 
rays  in  this  respeiSt  is  the  cause  of  the  granulation  shown 
on  the  photographic  plate ;  perhaps  the  particles  do  not 
give  an  average  thickness,  and  the  interspaces  are  dis- 
tributed irregularly. 

A  fa(5t  which  would  seem  to  corroborate  this  idea  was 
that  when  a  grm.  of  coarse  calcite  was  mixed  with  a  grm. 
of  medium  cryolite  and  fine  magnesite,  the  dark  spaces 
were  larger  in  the  photograph  ;  the  spots  showing  the  less 
permeable  calcite  being  farther  apart  than  when  coarse 
powder  only  was  taken.  It  does  seem  strange,  however, 
that  the  granulation  should  so  nearly  correspond  to  the 
size  of  the  particles.  This  was  seen  most  plainly  in  the 
case  of  halite  and  calcite,  perhaps  because  of  the  less 
permeability  of  these  minerals.  The  bottom  layer  may 
give  the  final  impress,  and  where  the  particles  are  least 
permeable  this  impress  is  strongest.  I  cannot  say  that  I 
am  quite  satisfied  with  this  explanation,  but  no  better  has 
yet  occurred  to  me. 

The  granulation  shows  so  plainly  that  it  could  not 
escape  the  notice  of  any  one  who  looks  at  the  photographs 
in  my  possession,  except  where  the  powder  was  of  im- 
palpable fineness  ;  and  if  observations  made  with  a  photo- 
meter did  not  reveal  such  a  granular  strudture,  it  would 
merely  show  that  the  eye  is  more  delicate  than  the 
photometer  if  the  eye  is  assisted,  as  it  was  in  my  experi* 
ments,  by  the  sensitive  plate  being  kept  covered  by  the 
lead  sheet.  I  found  this  method  vastly  more  sensitive 
than  the  one  in  which  the  substances  formed  the  absorbent 
material,  the  rest  of  the  photographic  plate  not  being 
shielded  from  the  Rontgen  rays. 
Kingston,  Ontario. 


164 


A  tomic  Mass  of  Tungsten. 


CaitiiicAi.  Mbws, 
oa.  1, 1897. 


THE    ATOMIC     MASS     OF    TUNGSTEN.* 

By  WILLETT  LEPLEY  HARDIN. 

(Concluded  from  p.  157). 

The  next  line  of  investigation  was  to  make  a  number  of 
determinations  with  material  obtained  from  different 
minerals  and  different  localities. 

Reduction  of  Tungsten  Trioxide  obtained  from  Scheelite 
from  New  Zealand. 

The  oxide  was  extra(5ted  from  this  mineral  and  purified 
in  a  manner  similar  to  that  described  under  wolframite. 
No  trace  of  molybdenum  was  found  even  before  the  oxide 
was  heated  in  hydrochloric  acid  gas.  The  results  of  seven 
redudlions  are  as  follows  : — 


Weight  of  WOa 
Grms. 

3-41018 
2*99000 
3'ii6i3 
4-32830 
4-66735 
4-29620 
3"39i04 
2-93215 


Weight  of  W. 
Grms. 

2-70410 
2-37084 
2-47047 

3*43"8 
3-70050 
3-40623 
2-68885 
2-32515 


Atomic  mass 
of  tungsten. 

183-83 
183-80 
183-67 
183-56 
183-72 
183-71 
183-80 
183-87 


The  mean  of  this  series  is  183-745.  The  maximum 
deviation  is  0*20.  Considering  the  number  of  experi- 
ments, this  is  the  most  concordant  series  of  results  ever 
obtained  by  reducing  the  trioxide  of  tungsten  and  weigh- 
ing the  resulting  metal.  In  Experiments  2  and  7,  the 
metal  was  cooled  in  a  vacuum ;  in  all  the  other  experi- 
ments it  was  cooled  in  hydrogen. 

Oxidation  Series. 
The  metal  obtained  in  the  preceding  redudtions  was 
used  in  these  oxidations.     The  results  of  six  experiments 
are  as  follows: — 


Weight  of  W. 

Weight  of  WO3. 

Atomic  mass 

Grms. 

Grms. 

of  tungsten. 

X 

2-70219 

3-40775 

183-83 

2 

2-36771 

2-98620 

183-75 

3 

2-46705 

3'iioi6 

184-13 

4 

3-42163 

4-31472 

183-90 

5 

3-40086 

4-28890 

183-82 

6 

2-68249 

3-38145 

184-20 

This  series  gives  a  mean  of  183-94,  ^''^  ^  maximum 
difference  of  0*45. 

Reduction  of  Tungsten  Trioxide  obtained  from  Wolframite 
from  Connecticut, 
The  oxide  was  obtained  from  this  mineral  and  purified 
by  the  method  already  described.  The  details  of  the 
work  were  the  same  as  in  similar  series  which  precede. 
The  results  were  as  follows  :— 


Weight  of  WO3. 
Grms. 

3-14520 
3-IO516 
4-17792 


Weight  of  W. 
Grms, 

2-49330 
2*46141 
3-31244 


Atomic  mass 
of  tungsten. 

183-58 
183-51 
183-83 


Mean 

Maximum  difference 


=   183-64 
=       032 


Oxidation  Series. 

The  metal  was  obtained  from  the  preceding  readlions. 

Weight  of  W.    Weight  of  WOg.  Atomic  mass 

(irms.                     Grms.  oi  tungsten. 

I              2*48088                3-12790  18405 

a     2*44588     3*08318  184*22 

3     3-29370      4*15260  184*06 


♦  Contribution  from  the  John  Harrison  Laboratory  of  Chemistry. 
From  the  Journal  0/  the  American  Chemical  Society,  six.,  No.  8. 


The  mean  of  these  results  is  almost  one-half  a  unit 
greater  than  the  mean  of  the  reduAion  series.  It  seems 
that  the  results  from  oxidations  are  invariably  higher  than 
those  obtained  by  redudion. 

Experiments  on  Material  obtained  from  Hubnerite 
from  Colorado. 
The  usual  method  of  purification  was  used.     Two  re- 
ductions of  the  trioxide  gave  the  following  results  : — 


Weight  of  WOg. 

Weight  of  W. 

Atomic  mass 

Grms. 

Gtms. 

of  tungsten. 

I 

1-83600 

I -456 1 8 

184-03 

2 

4-31878 

3-42450 

183-81 

The   metal  resulting  from   these   reduiftions   was   re- 
oxidised. 

Weight  of  W.  Weight  of  WOg.      Atomic  mass 

Grms.  Grms.               of  tungsten. 

1  I -45 1 84  1-83090  183-85 

2  3-40470  4-29225  184-14 

Experiments  on  Material  obtained  from  Scheelite 
from  Bohemia. 
The  oxide  was  extraded   and    purified   by  the  usual 
method.    Two  redudions  were  as  follows : — 


Weight  of  WO3. 
Grms. 

2-77363 
2*13327 


Weight  of  W. 
Grms. 

2*19950 
1*69120 


The  re-oxidation  gave  : — 


Weight  ol  W. 
Grms. 

2-18985 
1-68208 


Weight  of  WOa. 
Grms. 

2-76060 
2*12070 


Atomic  mass 
of  tungsten. 

183*89 
183*63 


Atomic  mass 
of  tungsten. 

184-17 
184-08 


Throughout  this  work,  it  had  been  noticed  when 
tungsten  trioxide  was  heated  in  a  current  of  hydrochloric 
acid  gas  for  some  time  that  a  considerable  sublimate  was 
formed,  even  when  molybdic  acid  was  absent.  Enough 
of  this  sublimate  for  an  atomic  mass  determination  was 
obtained  as  follows : — Tungsten  trioxide  was  heated  for 
some  time  in  a  current  of  hydrochloric  acid  gas  at  a  tem- 
perature of  about  400°.  The  sublimate  was  removed  from 
the  tube,  strongly  ignited,  and  gently  re-heated  in  a  cur- 
redt  of  hydrochloric  acid  gas.  The  small  white  sublimate 
formed  did  not  respond  to  the  test  for  molybdic  acid. 
The  portion  left  in  the  porcelain  boat  was  removed  from 
the  tube  and  strongly  ignited  in  the  air  for  a  period  of  ten 
hours.  It  was  then  reduced  in  a  current  of  hydrogen  and 
the  following  result  obtained  : — 


Weight  of  WOj. 
Grms. 

1-12970 


Weight  of  W. 
Grms. 

o-8g6io 


Atomic  mass 
of  tungsten. 

184-13 


Upon  re-oxidation,  this  metal  gave  184*87  for  the  atomic 
mass  of  tungsten. 

The  results  from  the  sixty-four  determinations  made  in 
the  present  investigation  show  a  maximum  deviation  of  one 
and  a  half  units.  A  discussion  of  these  results,  with  a  view 
of  arriving  at  the  true  atomic  mass  of  tungsten,  would  be 
useless.  To  take  the  mean  of  all  the  results  would  be 
entirely  unsatisfadory,  and  yet  there  seems  to  be  no  reason 
why  any  one  result  should  be  accepted  in  preference  to 
any  other.  It  will  be  noticed,  in  several  instances,  that 
three  or  four  consecutive  results  agree  very  closely.  These 
different  series  of  concordant  results,  however,  do  not 
agree.  The  variations  in  these  results  are  similar  in 
every  respedt  to  those  in  the  results  of  earlier  experiments. 

Various  causes  suggest  themselves  as  possible  fadors 
in  producing  these  variations.  The  lower  values  obtained 
in  the  latter  part  of  the  investigation  are  undoubtedly  due 
to  a  better  form  of  apparatus  and  a  higher  temperature. 

The  redu&ions  were  all   made   in    a   porcelain    boat. 


CHbmicalNbws. 

oa.  1, 1807. 


Separations  with  Alkaline  Acetates 


165 


During  each  determination  the  boat  increased  in  weight 
by  from  i  to  3  m.  grms.  It  is  difficult  to  determine  whether 
this  absorption  of  tungsten  by  the  boat  would  affedt  the 
results  or  not.  If  the  tungsten  is  absorbed  as  metal  it 
would  produce  no  effedt  on  the  results,  if  not  absorbed  as 
metal  it  would.  It  was  shown  in  the  first  part  of  this  in- 
vestigation that  the  metal  obtained  in  the  reductions  con- 
tained silica.  This  may,  in  part,  account  for  the  higher 
values  obtained  in  the  oxidations.  In  view  of  these 
objeiStions  to  the  use  of  porcelain,  a  series  of  reduc- 
tions were  made  in  which  a  platinum  boat  was  used. 
This,  however,  did  not  remove  the  difficulty;  platinum 
absorbs  tungsten  and  tungsten  absorbs  platinum,  and  the 
results  obtained  were  just  as  variable  as  those  obtained 
with  the  porcelain  boat. 

A  series  of  observations  on  tungsten  trioxide  were  next 
made  with  a  view  of  determining  whether  or  not  this  com- 
pound is  suitable  for  atomic  mass  determinations. 

The  first  point  was  to  determine  how  rapidly  this  com- 
pound takes  up  moisture  from  the  air.  Several  series  of 
observations  were  made,  and  it  was  found  in  each  case 
that  the  absorption  of  water  was  inappreciable.  The  rate 
at  which  the  water  was  absorbed  is  best  shown  by  the  fol- 
lowing series  of  weighings  of  tungsten  trioxide,  which  had 
been  left  for  several  days  in  the  open  air.  The  oxide  was 
first  strongly  ignited,  then  placed  in  a  porcelain  boat, 
carefully  proteiSed  from  dust,  and  left  for  four  days  in  an 
open  window. 

Weight  of  the  oxide  at  the  beginning  5*34600  grms. 

„      after  one  day .5'346o5      „ 

„         ,,    two  days      5*34620     „ 

„  „     three  days 5"34625      „ 

„  „     four  days      5'3463o      1. 

From  these  observations  it  is  evident  that  no  appreciable 
error  can  be  introduced  by  the  absorption  of  moisture 
during  the  weighing  of  this  compound. 

A  series  of  observations  was  also  made  to  ascertain 
the  adlion  of  light  on  this  oxide.  A  weighed  quantity  of 
the  material  was  placed  in  a  desiccator  and  left  for  some 
time  in  diredt  sunlight.  Weighings  made  at  different 
intervals  showed  that  no  redu(5lion  had  taken  place.  In 
working  with  this  compound  it  is  unnecessary  to  cover 
the  desiccator  with  a  black  cloth. 

Upon  examining  the  porcelain  tube  after  a  redudion,  a 
slight  sublimate  was  usually  noticed.  Whether  the 
tungsten  trioxide  is  volatile  at  that  temperature,  or 
whether  the  moisture  formed  in  the  redui^ion  carried 
mechanically  small  particles  of  the  oxide  from  the  boat, 
was  not  determined.  In  either  case  an  error  is  introduced, 
but  in  all  probability  a  very  small  one. 

A  series  of  observations  v.ras  next  made  to  determine 
whether  or  not  tungsten  trioxide  contains  nitrogen.  A 
number  of  redudions  were  made  in  the  usual  way  and  the 
products  set  free  were  conducted  through  a  U-tube  con- 
taining pure  water  and  a  few  drops  of  Nessler's  reagent. 
The  oxide  used  was  obtained  by  strongly  igniting  ammo- 
nium tungstate  for  two  days.  Hydrogen  was  allowed  to 
pass  through  the  redudion  apparatus  for  some  time  in 
order  to  completely  remove  the  air.  When  the  redudlion 
was  started,  the  solution  in  the  U-tube  began  to  assume 
a  yellowish  colour,  even  when  the  temperature  was  com- 
paratively low.  Before  the  redudtion  was  half  completed, 
the  solution  was  of  a  deep  yellowish  brown  colour.  In 
some  instances  a  slight  precipitate  was  formed  at  the  sur- 
face of  the  solution.  Several  observations  were  made,  and 
the  ammonium  test  distinctly  obtained  in  each  case.  A 
series  of  blank  experiments  were  made  and  no  colouration 
was  produced.  The  experiments  proved  conclusively  that 
the  oxide  obtained  by  the  ignition  of  ammonium 
tungstate  contains  nitrogen.  No  attempt  was  made  to 
determine  the  quantity  of  nitrogen  present.  The  oxide 
obtained  by  the  ignition  of  metal  was  also  examined  and 
found  to  contain  a  trace  of  nitrogen.  Whether  the  nitro- 
gen in  the  former  oxide  was  present  as  an  oxynitride  or 
as  an  ammonium  residue,  was  not  determined.      If  it 


exists  as  an  ammonium  residue,  then  hydrogen  must  also 
be  present.  A  number  of  experiments  were  made  by 
fusing  the  oxide  with  lead  oxide  and  also  with  anhydrous 
sodium  carbonate,  with  a  view  of  converting  any  hydro- 
gen present  into  water.  Nothing  definite  was  established, 
but  there  were  some  indications  that  a  small  quantity  of 
water  was  formed.  If  the  nitrogen  is  present  in  large 
enough  quantities  to  affedt  the  atomic  mass  determina- 
tions, it  would  probably  lower  the  results  and  also  pro- 
duce variations,  for  it  is  not  likely  that  the  quantity  would 
be  the  same  in  all  cases. 

In  regard  to  the  occlusion  of  hydrogen  by  the  metal, 
nothing  definite  was  established.  The  results  obtained 
by  cooling  the  metal  in  a  vacuum  were  pradtically  the 
same  as  those  obtained  when  the  metal  was  cooled  in 
hydrogen. 

It  has  been  shown  in  the  foregoing  observations  that 
tungsten  attacks  the  vessels  in  which  the  atomic  mass 
determinations  have  been  made,  that  the  oxidation  of 
tungsten  is  either  slightly  volatile,  or  that  a  small  portion 
is  carried  mechanically  by  the  water  formed  in  the  reduc- 
tions, and  that  the  supposed  trioxide  of  tungsten  contains 
nitrogen  and  probably  hydrogen.  In  view  of  these  fadts 
and  of  the  fai^  that  there  is  no  means  of  determining  when 
the  redu(ftion  of  oxide  to  metal  is  complete,  and  Anally, 
in  view  of  the  fadt  that  more  than  one  hundred  and  fifty 
determinations  have  been  made  of  this  oxide,  and  nothing 
definite  established,  it  is  evident  that  the  method  usually 
employed  in  the  determination  of  the  atomic  mass  of 
tungsten  must  be  regarded  as  unsatisfadory. 


SEPARATIONS  WITH  ALKALINE  ACETATES. 

By  HARRY  BREARLEY. 
(Continued  from  p.  51). 

III. — Cobalt  and  Manganese  from  Iron, 
In  view  of  the  large  number  of  tests  it  is  desirable  to 
make  on  the  separation  of  each  element  under  various 
conditions,  it  is  important  to  choose  the  most  rapid — if  at 
the  same  time  undoubtedly  accurate— means  available  of 
estimating  that  element. 

With  the  view  of  making  subsequent  tests  more  intel- 
ligible, the  method  of  estimating  the  separated  cobalt  is 
here  set  forth. 

It  has  been  previously  noticed  that  in  estimating  nickel 
by  means  of  potassium  cyanide  and  silver  iodide,  if  cobalt 
be  present  it  will  be  estimated  along  with  the  nickel;  but, 
80  far  as  I  can  find,  nobody  has  determined  whether  the 
titration  which  serves  so  accurately  for  nickel  is  equally 
applicable  to  cobalt.  The  suggestion,  however,  is  so 
forcible  that  it  must  have  been  attempted  by  most  people 
who  have  made  the  nickel  titration. 

In  attempting  the  titration  of  cobalt  solutions,  under 
the  conditions  previously  used,  the  first  noticeable  change 
is  the  immediate  darkening  of  the  solution  on  adding  the 
cyanide.  If  the  cyanide  be  further  added  without  un- 
necessary delay  it  is  seen  that  the  Agl  indicator  becomes 
slowly  dissolved,  and  that  some  time  before  enough 
cyanide  has  been  added  to  combine  with  all  the  cobalt. 
On  allowing  the  just-cleared  solution  to  stand,  the  Agl 
turbidity  reappears ;  a  few  more  drops  of  KCN  clear  it, 
further  standing  causes  it  to  reappear,  and  so  on,  but  not 
indefinitely.  A  point  is  quickly  reached  at  which  the 
solution  can  stand  for  hours  without  becoming  turbid;  or 
if  an  excess  be  added  in  the  first  instance,  there  is  no 
turbidity  on  standing.  In  this  latter  way — that  is,  by 
adding  cyanide  in  excess,  allowing  to  stand  awhile,  and 
going  back  with  silver  nitrate — it  is  easy  to  obtain  con- 
sistent values  when  titrating  similar  amounts  of  cobalt. 

The  darkening  of  the  solution  just  noticed  is  not  per- 
manent. The  usual  change  is  from  the  deep  golden 
brown  to  a  salmon-coloured  liquid  which  very  gradually 


66 


Separations  with  A  ikaline  A  ceiiiies. 


]  CrbmiCal  NBw&t 

1     oet.  1. 1807. 


bleaches.  The  colour  changes,  however,  are  not  always 
the  same,  except  in  identical  liquids  treated  alike.  The 
precise  colour  effedt  of  each  reagent  has  not  been  deter- 
mined, but  the  addition  of  potassium  iodide  before  or  after 
the  cyanide  gives  distindlly  different  tints. 

It  is  pradticable  to  replace  ammonium  by  the  corres- 
ponding sodium  salts,  and  to  make  the  final  alkalinity 
with  sodium  carbonate.  This  change  gives  us  a  coloura- 
tion which  is  neither  so  deep  nor  so  variable,  and  the  dis- 
appearance of  the  precipitated  carbonate  on  adding 
cyanide  is  some  indication  of  the  progress  of  the  readtion. 
Personally,  this  soda  modification  has  proved  eminently 
satisfadtory,  almost  rivalling  in  delicacy  the  cyanide  titra- 
tion of  nickel ;  in  other  hands  it  has  not  behaved  so  well. 
A  comparison  of  soda  and  ammonia  salts,  kindly  made  by 
a  friend,  led  him  to  prefer  the  latter. 

Unfortunately  whether  soda  or  ammonia  is  used,  the 
dilution  of  the  solution  titrated  is  not  without  influence. 
Results  from  two  sets  of  solutions  are  appended. 

Table  VIII. 

Volume  of  solution.    C.c. 


Ammonia.. 
Soda . .     . . 


120. 
17-84 

l8'22 


200. 

I7"52 
I7'93 


300. 
i6'92 
17-58 


400. 

—   c.c.  KCN 
1714  .1       » 


The  tests  in  each  set  varied  only  in  volume.  They 
contained  the  same  total  quantity  of  free  alkali,  so  that 
the  proportion  of  this  reagent  is  less  in  the  larger  volumes. 
This  difference  would  tend  to  give  more  concordant 
values. 

Lacking  at  present  the  recommendation  of  extended  use 
in  various  hands,  it  was  deemed  undesirable  to  use  this 
method  alone  and  unchecked.  Corresponding  titrations 
were  therefore  made  here  and  there  according  to 
Winkler's  method  (see  "Fresenius's  Quant.  Anal.,"  or 
"  Sutton's  Vol.  Anal."),  which  is  regarded  as  •'  thoroughly 
satisfactory  for  technical  purposes  "  at  least.  It  may  be 
worth  while  to  notice  that,  contrary  to  expetStations,  there 
was  no  noticeable  trouble  experienced  on  account  of  the 
organic  (acetic)  acid. 

Any  error  due  to  traces  of  manganese  in  the  bar  iron 
was  exadtly  balanced  by  treating  a  sample— lacking 
cobalt — exa(5ily  like  the  test,  and  standardising  the  per- 
manganate or  cyanide  in  an  equal  portion  of  the  filtrate. 

The  details  of  the  separation  to  be  now  applied  to 
cobalt  are  the  same  as  those  followed  with  nickel  and 
iron,  and  presuming  an  acquaintance  with  the  Ni  titra- 
tion, that  for  cobalt  may  be  summed  briefly : — The  idea 
is  to  get  an  excess  of  cyanide  into  the  solution,  but  not  a 
large  excess.  Make  the  solution  alkaline,  and  then, 
without  unnecessary  delay,  add  cyanide  to  completion  or 
thereabouts;  add  the  indicator  (KI-i-AgN03+Am2S04 
or  NaaS04),  and  then,  if  necessary,  enough  cyanide  to 
clear  the  solution  and  2  or  3  c.c.  in  excess.  I  prefer  to 
use  a  very  dilute  solution  of  silver  nitrate — so  dilute  that 
10  c.c.  is  only  equal  to  i  c.c.  KCN  where  about  16  KCN 
equals  o-oi  grm.  cobalt.  The  KCN  is  standardised  with 
a  similar  amount  of  cobalt  in  exadtly  the  same  way,  and 
the  two  are  allowed  to  stand  awhile — say,  fifteen  minutes. 
If  they  are  then  perfectly  clear,*  silver  nitrate  is  added 
until  the  turbidity  reappears.  This  is  most  satisfadlorily 
accomplished  by  allowing  the  nitrate  to  run  down  the 
side  of  the  flask.  A  very  copious  turbidity  is  soon 
formed  on  the  surface  of  the  solution,  and  the  readiness 
with  which  this  disappears  on  shaking  is  some  indication 
of  the  amount  of  silver  nitrate  yet  to  be  added.  It  is 
easier,  too,  in  this  way  to  note  the  first  appearance  of  the 
turbidity.  2  c.c.  of  the  silver  nitrate  makes  a  decided 
difference  in  half  a  litre  of  solution  ;  2  c.c.  AgN03  equals 
o*2  c.c.  KCN,  equals  0-00013  grm.  cobalt. 

Samples  containing  i  grm.  (separations  will  always  be 


*  A  slight  turbidity,  due  to  traces  of  manganese,  should  be  filteied 
off  if  it  is  so  decided  as  to  prevent  the  Agl  turbidity  being  readily 
recognised. 


from  I  grm.  unless  otherwise  stated)  of  iron  and  o-i  grm. 
of  cobalt  gave  the  values  shown  in — 


Table  IX. 


Method  of  titration. 


KCN. 

Ammonia  salts 00995 

Soda  salts 0-0997 


Winkler. 


0-1015 


Nor  is  the  separation  less  perfetft  with  other  proportions 
of  cobalt.  In  parallel  columns  there  are  arranged  some 
results  by  Messrs.  LefHer  and  Jervis,  to  whom  my  best 
thanks  are  due.  Apart  from  their  confirmatory  value, 
such  results  are  testimony  to  the  fadt  that  the  method 
may  be  satisfadlorily  worked  without  lengthy  experience. 
Their  results  are  with  ammonia  salts  throughout,  and  on 
mixtures  of  bar  iron  and  cobalt  nitrate.  My  own  results 
are  with  soda  salts  throughout. 


Added. 
Grm. 

0-0200 
0-0300 
0*0500 

o-iooo 

0-2000 
0-3000 


Table  X. 

Cobalt  found. 


Brearley.  LefHer.  Jervis. 

—  0-0196  0-0198 

—  0-0294  0-0301 

—  0-0496  0-0508 
0-0997  o'looi  0-0995 
0-2006  —  — 
0-2982*  —  — 

*  Titration  irregular. 


For  the  rest,  it  remains  only  to  notice  a  few  variations 
similar  to  those  observed  with  the  preceding  metal.  To 
prevent  repetition,  the  corresponding  tables  in  the  nickel 
series  will  be  placed  in  brackets  so  that  the  details  of  the 
tests  can  be  referred  to. 

Further  addition  of  acetate  may  be  made  to  the  heated 
solution  (p.  50,  col.  i). 

Table  XI. 


Soda  salts  . 
Ammonia  salts 

Co  added. 

. .        . .       O'lOOO 
..        ..       O-IOOO 

Found. 
0-1003 
00997 

rolonged  boiling 

introduces  no  error 
Table  XII. 

(VI.). 

Boiled. 

Cobalt  added. 

Cobalt  found 

15  minutes 
30       ,, 

o-iooo 
o-iooo 

0-0997 
o-iooo 

Deservedly  or  otherwise,  the  separation  of  cobalt  from 
iron  by  means  of  acetates  is  less  favourably  looked  upon 
than  the  corresponding  separation  of  nickel.  Thus, 
T.  Moore  (Chemical  News,  Ixv.,  75),  who  seems  to  have 
made  a  special  study  of  these  two  elements,  says: — "A 
very  short  experience  will  suffice  to  demonstrate  that  the 
basic  acetates  of  iron  must  be  re-precipitated  at  least  four 
times  before  one  can  be  assured  that  the  separation,  so 
far  as  cobalt  is  concerned,  is  complete." 

Whether  cobalt  is  less  readily  separated  from  iron  than 
is  nickel  would  be  seen  by  adding  varying  amounts  of 
acetate  in  excess  and,  making  every  other  condition 
alike,  noticing  in  which  the  percentage  recovery  fell  the 
more  rapidly.  The  results  of  such  experiments  are 
arranged  in  Table  XIII.  The  agreement  between  the 
temperatures  of  turbidity  should  not  be  overlooked.  It 
afforded  additional  evidence  that  the  two  sets  of  solutions 
were  very  similar.  The  minimum  amount  of  acetate  for 
solutions  made  up  as  these  were  would  be  about  12  c.c. 


Acetate. 
C.c. 

20 

50 
100 


Table  XIII. 

Percentage  recovery  of — 

, <- , 

Nickel.  Cobalt. 

990  9904 

95'2  97'5 

90-0  938 


RespeAive 
Temp,  turbiditiesi 


72°,  70°  G. 
60°,  59°  C. 
53°.  54°  C. 


CHkmicAl  NbW8, 
0«.  1,  1897. 


Estimation  of  Silver  in  Stiver -plating  So/uttons. 


167 


This  table  can  claim  to  answer  the  question  at  issue 
only  for  the  particular  modus  operandi  used,  which  was 
that  generally  adopted  for  the  previous  separations.  It 
does  not  necessarily  follow  that  the  same  order  would 
hold  whatever  variations  might  be  introduced,  though  for 
two  so  closely  related  elements  as  nickel  and  cobalt  the 
result  may  perhaps  be  considered  generally  true. 

A  table  similar  to  XIII.  will  be  given  later  embracing 
all  the  metals  whose  ^separations  from  iron  have  been 
attempted. 

Separation  of  Manganese. 

A  previous  paper  on  the  estimation  of  manganese  in 
spiegels  (Chemical  News,  Ixxv.,  13)  makes  it  needless 
to  repeat  any  array  of  experiments.  This  circumstance 
affords  us  an  opportunity  of  looking  about  more  casually 
than  it  might  otherwise  be  thought  proper  to  do.  The 
paper  mentioned  contains  an  error  of  some  moment ;  a 
few  words  will  set  things  right.  The  use  of  ammonium 
acetate  is  restridted,  because  in  heated  solutions  salts  of 
ammonia  readl  with  the  permanganate  in  the  subsequent 
titration.  It  may  be  noticed  that  as  much  as  10  c.c.  of 
strong  ammonium  acetate  is  used  to  precipitate  the  one 
grm.  of  iron  ;  this  is  several  times  larger  in  amount  than 
the  soda  acetate  used,  or  than  it  need  be.  This  correc- 
tion made,  the  danger  of  the  permanganate  reaction  would 
be  lessened. 

It  is  noteworthy  that  while  the  separation  of  nickel  and 
cobalt  from  iron  by  means  of  acetate  are  commonly 
deprecated,  and  are  fast  disappearing  from  the  arena  of 
usefulness,  the  separation  of  manganese  by  these  means 
has,  on  the  whole,  and  particularly  for  low  percentages, 
been  well  spoken  of.  This  argues  in  a  general  way  that 
the  former  metals  are  less  accurately  separated  from  iron 
under  similar  conditions  than  is  manganese.  Indeed,  if  a 
series  were  arranged  parallel  with  those  first  given  (Table 
XIII.),  it  would  be  seen  that  as  perfeiS  a  separation 
accompanied  the  larger  amount  of  acetate  as  the  smaller. 
In  {&&,  Mr.  Jervis  has,  in  this  laboratory,  increased  the 
acetate  to  200  c.c,  and  finds  still  a  perfedt  separation. 
The  instruiflions,  therefore,  for  separating  iron  and  man- 
ganese perfedtly  and  without  re-precipitation,  may  be 
condensed  into  a  word — ditto. 

One  frequently  hears  the  use  of  soda  salts  in  the  gravi- 
metric estimation  of  manganese  justified  by  the  belief 
that  they  give  a  better  separation  than  the  corresponding 
ammonium  salts.  There  is  no  doubt  but  that  either  will 
give  a  perfed  separation  when  used  sparingly  enough. 
That  there  could  be  any  question  of  their  comparative 
merits  reminds  one  of  the  careless  way  in  which  the 
acetates  are  generally  used — as  though  an  excess  were  of 
no  moment,  or  perhaps  improved  the  separation.* 

The  relative  efficiency  of  these  two  acetates  was  tested 
by  using  such  large  excesses  as  to  cause  imperfcdt  sepa- 
rations. As  the  point  is  not  an  important  one,  it  may  be 
sufficient  to  notice  that  the  result  was  so  slightly  in  favour 
of  ammonium  acetate  that  they  may  be  regarded  as 
pradlically  equal.  It  is  to  be  feared  that  the  higher 
results  with  soda  acetate  are  sometimes  due  to  the  well- 
known  difficulty  of  washing  away  the  non*volatile  pre- 
cipitant. 

It  appears  plainly  that  alkaline  acetates  have  been  ill- 
spoken  of  and  negleded,  not  because  of  any  inherent  short- 
coming in  the  reagents  themselves,  but  on  account  of  the 
thoughtless  way  in  which  they  have  been  used.  There  are 
other  highly-prized  reagents  which  would  fail  under  like 
treatment.  That  I  may  not  be  accused  of  unduly  magni- 
fying this  error  of  excessive  acetate,  I  quote  below  a  few 
instances  from  such  recently  described  methods  as  retain 
this  means  of  separation.  The  figures  in  brackets  give 
the  approximate  volume  if  diluted  to  such  strength  as  is 
used  throughout  this  investigation. 


*  Parry  and  Morgan  {Industrtes,  1893;  also  Uhemical  News, 
Ixvii.,  30B),  respefting  the  separation  ot  nickel  and  cobalt  from  iron, 
recommend  that  the  solution  be  "  made  neutral  with  soda  carbonate 
and  the  iron  precipitated  by  the  addition  of  a,  large  excess  (italics 
cepied)  of  soda  acetate  And  the  solution  boiled  for  some  time"  (italics 
not  copied). 


Parry  and  Morgan  (Chem.  News,  Ixvii.,  295,  1893) — 
250  c.c.  hot  ammonium  acetate,  strength  not 
stated. 

Arnold  ("  Steel  Works  Analysis,"  1895) — Half  a  grm. 
of  Spiegel  is  precipitated  with  20  c.c.  [260]  ammo- 
nium acetate.  And  25  c.c.  [more  than  250  c.c] 
saturated  solution  of  sodium  acetate  is  used  to 
separate  o'l  grm.  nickel  from  similar  quantity  of 
iron. 

Dittmar  ("Quant.  Chem.  Anal.,"  1887)—"  Add  acetate 
of  ammonia  solution  (not  too  little)." 

Phillips  ("Engineering  Chemistry,"  1891) — later  edition 
not  available — Half  grm.  of  Spiegel  precipitated 
with  20  c.c.  [290]  5  E  ammonium  acetate. 

Hiorns  ("  Pradical  Assaying,"  1892) — 1'3  grms.  steel 
20  c.c.  [260]  acetate. 

These  large  excesses  become  more  curious  when  it  is 
noticed  that  (with  the  exception  of  Phillips)  strong 
emphasis  is  usually  laid  on  the  necessity  of  neutralising 
with  great  exadness. 

The  last  writer  (Hiorns)  says : — "  If  the  basic  acetate 
precipitate  be  dark  red  an  insufficient  amount  of 
acetate  has  been  added,  and  more  of  that  salt  must  be 
introduced "  (p.  397),  I  have  previously  heard  this 
remark  made  to  beginners  in  laboratory  practice,  though 
it  is  rarely  repeated  in  text-books.  Altogether  apart  from 
the  peculiar  appearance  due  to  iron  in  the  ferrous  state, 
the  basic  acetate  may  vary  from  a  fine  compad  brick-red 
precipitate,  which  remains  long  suspended  in  the  solution 
and  can  be  eliminated  only  by  repeated  filtration  through 
ordinary  paper,  to  an  open  fiocky  purple-brown  precipi- 
tate, which  settles  readily  and  leaves  a  crystal  clear  solu- 
tion. The  former  occurs  in  presence  of  large  volumes  of 
acetic  acid,  the  latter  by  precipitating  with  little  more 
than  minimum  acetate.  Similar  precipitates,  and  any 
variety  between,  can  be  produced  with  other  amounts  of 
acetate.  The  inference  is  that  the  colour  of  the  precipi- 
tate alone  is  of  no  value  in  determining  whether  enough 
acetate  has  been  added  or  not. 

(To  be  continued). 


NOTES    ON    THE    ESTIMATION    OF    SILVER 

IN     SILVER-PLATING    SOLUTIONS. 

By  T.  J.  BAKER. 

I.  The  method  of  weighing  the  precipitate  obtained  with 
HCl  is  untrustworthy  in  the  case  of  old  solutions,  unless 
precautions  are  taken  to  separate  the  copper  cyanide  and 
other  impurities  precipitated  along  with  the  silver  chloride. 

II.  The  method  of  fusing  the  impure  silver  chloride 
with  sodium  carbonate  and  nitre  is  often  attended  with 
the  disadvantage  of  small  globules  of  silver  adhering  to 
the  crucible. 

III.  The  following  method  devised  by  the  writer  avoida 
the  disadvantages  referred  to  above : — 

Precipitate  say  50  c.c.  of  the  solution  by  boiling  with 
slight  excess  of  nitric  acid.  The  precipitate  will  contain 
all  the  silver  as  silver  cyanide,  together  with  copper 
cyanide  and  other  impurities.  Wash  and  dry  the  pre-* 
cipitate. 

Burn  the  filter-paper,  and  wrap  up  the  ash,  together 
with  the  precipitate,  in  assay  lead.  Compress  into  a 
small  bulk,  and  cupel,  employing  the  usual  precautions  of 
duplicate  assays  and  checks. 

Note. — Silver  cyanide  is  completely  reducible  to  metallic 
silver  by  simple  ignition,  and  the  effedtiveness  of  cupelling 
the  precipitate  depends  upon  this  reaction. 

The  method  has  been  attested  in  the  metallurgical 
laboratories  of  the  School,  and  has  given  uniformly  good 
results. 

Elearo-Metallurgical  Laboratory, 

Birmingham  Municipal  Technical  School, 
September  2,  1897. 


i68 


Permeation  of  Hot  Platinum  in  Gases. 


I  Cbbmical  News, 
•      oa.  1, 1897. 


ON   THE 

PERMEATION     OF    HOT     PLATINUM 
GASES. 
By  WYATT  W.  RANDALL. 


BY 


In  connexion  with  a  research  which  has  been  in  progress 
for  some  time,  and  in  which  the  attempt  is  being  made  to 
prepare  absolutely  pure  hydrogen  for  spedlroscopic  exam- 
ination, the  author  has  endeavoured  to  free  the  gas  from 
impurities  by  filtering  it  through  a  diaphragm  of  hot 
platinum.  The  spectroscopic  results  obtained  will  be 
published  later ;  it  seemed  worth  while,  however,  to  give 
at  this  time  a  short  account  of  the  work  which  has  been 
done  in  the  past  in  the  matter  of  the  permeation  of  metals 
by  hydrogen,  and  also  of  the  measure  of  success  which 
has  attended  the  attempt  to  free  the  gas  from  impurities 
by  the  method  mentioned. 

The  fadl  of  the  permeability  of  hot  platinum  by  hydro- 
gen was  first  announced  by  Deville  and  Troost  {Compt. 
Rend.,  Ivi.,  977,  1863  ;  Phil.  Mag.  [4],  xxvi.,  336;  Abstr. 
ysb.,  1863,  23  ;  Chem.  News,  vii.,  294).  When  hydrogen 
was  introduced  into  a  hot  platinum  tube  surrounded  by 
one  of  porcelain  filled  with  air,  the  former  gas  passed 
through  the  walls  of  the  metal  tube,  but  no  passage  of 
air  into  the  inner  tube  could  be  dete(5ted.  Later  papers 
by  the  same  authors  (a,  Compt.  Rend.,  Ivii.,  894,  1863  ; 
b,  Ibid.,  Ivii.,  965;  also  Ann.  Chem.,  Liebig,  cxxx,,  254; 
e,  Compt.  Rend.,  lix.,  102,  1864;  Abstr.  Jsb.,  1864,  89  ; 
Phil.  Mag.  [4],  xxviii.,  229;  Chem.  News,  x,,  57)  esta- 
blished the  results  claimed,  and  showed  that  iron  also 
was  permeable  by  certain  gases  at  high  temperatures. 

A  year  or  two  later  Graham  (Phil.  Trans.,  clvi.,  399, 
1866 ;  Phil.  Mag.  [4],  xxxii.,  503 ;  jf.  Chem.  Soc,  xx., 
257;  Abstr.  Proc.  Roy.  Soc,  xv.,  223)  repeated  the  ex- 
periments of  Deville  and  Troost,  taking,  however,  greater 
precautions  to  avoid  error.  His  method  differed  in  that, 
by  means  of  a  Sprengel  pump,  a  vacuum  was  maintained 
within  a  platinum  tube,  which  was  closed  at  one  end,  and 
which  was  heated  in  an  atmosphere  of  hydrogen.  The 
gas  was  found  to  penetrate  rapidly  into  the  interior  of  the 
tube.  When  air  was  substituted  for  hydrogen,  pradically 
no  gas  was  delivered  by  the  pump,  but  Graham  was  of  the 
opinion  that  air  did  penetrate  to  a  slight  extent.  As, 
however,  the  conneiStions  of  his  apparatus  were  not  above 
suspicion,  and  as  he  employed  air  which  had  been  dried 
by  sulphuric  acid  alone,  the  evidence  for  the  penetration 
by  air  is  by  no  means  convincing.  At  the  temperature 
employed,  any  water-vapour  present  in  the  air  would 
probably  have  been  at  least  partially  dissociated  and  free 
hydrogen  have  been  formed.  The  same  objection  might 
hold  good  for  all  his  experiments  in  this  series.  When 
carbon  dioxide  was  tried  0*3  c.c.  of  gas  was  coUeifted  by 
the  pump,  and  "an  indeterminate  small  portion  of  this 
was  condensed  by  baryta  water  and  appeared  to  be  car- 
bonic acid."  In  view  of  the  power  of  carbon  dioxide  to 
cling  to  the  walls  of  a  vacuous  glass  tube,  and  to  be  but 
slowly  removed,  the  evidence  here,  again,  is  inconclusive. 
Negative  results  were  obtained  with  chlorine,  hydrochloric 
acid  gas,  steam,  and  ammonia.  When  coal-gas  containing 
hydrogen,  methane,  carbon  monoxide,  and  ethylene  was 
employed,  hydrogen  penetrated,  but  no  evidence  of  car- 
bon compounds  could  be  obtained  on  exploding  the  gas 
coUeiSted  with  oxygen.  Graham  concluded  that  a  little 
nitrogen  might  penetrate  the  platinum  wall,  provided 
hydrogen  was  passing  through  at  the  same  time  in  the 
opposite  diredion,  since  he  obtained  evidence  of  such 
penetration  when  the  tube  was  filled  with  hydrogen  and 
heated  in  an  atmosphere  of  nitrogen. 

In  accordance  with  conclusions  arrived  at  by  a  study  of 
the  passage  of  gases  through  various  septa,  Graham 
assumed  that  the  penetration  of  platinum  by  hydrogen 
was  due  to  the  liquefa(5tion  of  the  gas  on  the  surface,  the 
diffusion  of  the  condensed  gas  through  the  material  of 
the  wall,  and  the  evaporation  of  the  liquid  from  the  inner 
surface  of  the  tube  into  the  vacuum. 


Nearly  all  research  in  this  field  since  the  publication  of 
these  results  has  had  to  do  with  the  nature  of  the 
occluded  gases,  and  not  with  questions  of  penetration 
considered  by  itself.  Morse  and  Burton,  however,  have 
shown*  that  the  hydrogen  contained  in  the  fiame  of  an 
ordinary  blast-lamp  will  penetrate  a  platinum  vessel  heated 
by  that  means  ;  and  Ramsay,  in  studying  the  phenomena 
conneded  with  the  passage  of  hydrogen  through  a  palla- 
dium septum,  has  found  (Phil.  Mag.  [5],  xxxviii.,  206, 
1894)  that  this  power  was  apparently  possessed  by  no 
other  gas  examined.  As  palladium  is  permeable  to  a  far 
higher  degree  than  platinum,  it  would  naturally  be 
assumed  that  the  latter  metal  would  resist  the  passage  of 
all  gases  except  hydrogen  completely. 

In  his  studies  of  the  properties  possessed  by  hydrogen 
when  occluded  in  platinum  and  palladium,  Graham  found 
that  the  metals  could  be  more  highly  charged  with  the 
gas  by  making  them  serve  as  the  negative  pole  of  galvanic 
cells,  than  by  heating  them  and  allowing  them  to  cool  in 
an  atmosphere  of  hydrogen  (Proc.  Roy.  Soc,  xvi.,  422, 
1868).  "  The  occluded  hydrogen,"  he  says,  *'  is  certamly 
no  longer  a  gas,  whatever  may  be  thought  of  its  physical 
condition."  Oxygen  was  not  occluded  when  the  current 
was  reversed.  The  evidence,  he  considered,  was  on  the 
whole  against  the  view  that  chemical  combination  takes 
place  between  the  metal  and  the  gas.  Careful  examination 
of  the  change  in  volume  suffered  by  palladium  and  its 
alloys  on  absorbing  hydrogen  led  to  the  view  that  the  gas 
was  converted  into  a  metal-like  substance  and  formed  a 
species  of  alloy  with  the  palladium  (Proc.  Roy.  Soc,  xvii., 
212,  500,  1869;  Compt.  Rend.,  Ixmi'i.,  1511).  Hydrogen  in 
this  particular  condition  — "  Hydrogenium,"  as  Graham 
calls  it — is  magnetic,  shows  eledtric  condudivity,  and 
possesses  some  tenacity.  Its  density  varies  :  in  palladium 
alloys  it  is  0711 — 0.7545;  in  palladium  itself,  0*854 — 
o"872. 

This  conclusion  was,  however,  challenged  in  the  more 
recent  work  of  Berthelot  (Compt.  Rend.,  xciv.,  1377, 
1882;  Ann.  Chim.  Phys.  [5] ,  xxx,  519),  who,  as  a  result 
of  thermo-chemical  investigations,  returned  to  the  view 
that  definite  complex  hydrides  ol  palladium  and  platinum 
are  formed.  The  results  obtained  by  Thoma  (Ztschr. 
Phys.  Chem,,  iii.,  69,  1889)  had  to  do  with  the  absorption 
of  the  gas  considered  as  a  case  of  solution  capable  of 
supersaturation.  The  conclusions  of  Berthelot  have  been 
offset  by  a  research  by  Mond,  Ramsay,  and  Shields  (Phil. 
Trans.,  i86a,  657,  1895;  Abstr.  Proc.  Roy.  Soc,  Iviii., 
242)  upon  platinum-black,  in  which  doubt  was  cast  upon 
the  purity  of  the  material  used  by  the  French  chemist, 
and  evidence  given  to  show  the  untrustworthiness  of 
his  thermo-chemical  data  for  establishiing  the  condition 
of  the  occluded  gas. 

The  method  of  spectroscopic  examination  seemed 
capable  of  yielding  so  much  more  accurate  results  in 
determining  the  presence  of  foreign  gases  in  the  filtered 
hydrogen  than  any  of  the  analytical  methods  to  my 
knowledge  used  hitherto  in  this  work,  that  it  seemed 
worth  while  to  put  it  to  trial.  Tubes  filled  with  gas  were 
examined  in  the  Physical  Laboratory  of  this  University, 
with  the  aid  of  a  large  concave  grating  specially  pre- 
pared for  such  work,  and  photographs  were  made  of  each 
m  turn.  For  their  kindness  in  making  these  examina- 
tions I  am  indebted  to  Dr.  J.  S.  Ames  and  Mr.  W.  J. 
Humphreys. 

The  essential  features  of  the  apparatus  used  in  the 
produiSlion  of  the  gas  to  be  tested  are  represented  in  the 
accompanying  hgure.  It  consists  of  a  platinum  tube,  A  a', 
about  350  m.m.  long,  and  of  about  3  m.m.  internal 
diameter,  closed  at  one  end  and  sealed  at  the  other,  by 
means  of  fusible  glass,  into  a  soft-glass  tube,  which  is  in 
turn  connected  witn  the  sparking-tube  D  and  the  Topler 
pump.  The  closed  end  of  the  platinum  tube  projeds  into 
a  piece  of  hard-glass  tubing,  b  b',  through  which  a  current 


♦  American  Chemical  Journal,  x.,  148(1888).    It  is  to  Professor 
I  Morse  thut  1  owe  the  suggestion  of  employing  a  platinum  septum  in 
this  work.— W.  \V.  R. 


Chbhical  Nbws,  I 
oa.  1, 1897.    I 


Permeation  of  Hot  FLatinum  in  Gases. 


i6g 


of  dry  gas,  entering  at  L,  could  be  passed,  while  at  the 
same  time  the  platinum  tube  can  be  heated  by  means  of 
a  Bunsen  burner,  n,  below  the  combustion-tube.  The 
latter  is  covered  for  a  portion  of  its  length  with  a  layer  of 
thick  copper  foil  to  distribute  the  heat,  and,  with  the  aid 
of  asbestos-board  screens,  the  temperature  of  the  two 
tubes  can  be  raised  to  a  white  heat.  A  plug  of  asbestos 
was  pushed  into  the  annular  space  between  the  two  tubes 
to  give  support.  A  short  piece  of  black  rubber  is  drawn 
over  the  place  where  the  platinum  tube  is  sealed  into  the 
glass  tube,  is  wired  on  and  well  shellaced,  to  guard  against 
possible  leakage  from  fradlure. 

The  tube  c  is  filled  with  phosphorus  pentoxide.  The 
gas  entering  at  l  has  been  made  to  pass  through  sulphuric 
acid,  calcium  chloride,  soda-lime,  and,  finally,  through  a 
long  tube  611ed  with  phosphorus  pentoxide.  It  passes 
out  at  B  through  the  guard-tubes  b  containing  the  pent- 
oxide, and  F  containing  calcium  chloride  and  soda-lime. 
When  hydrogen  was  the  gas  employed,  it  was  first  passed 
through  four  wash-bottles  filled  with  acid,  and  two  filled 
with  alkaline  permanganate  solution,  and  then  through  a 
tube  filled  with  red-hot  copper  turnings,  on  its  way  to  the 
drying-tubes.  It  was  hoped  the  latter  device  would  free 
the  gas  from  any  admixture  of  oxygen,  whether  present 
as  a  constituent  of  air,  or  given  off  from  the  perman- 
ganate solution  (see  footnote  at  end  of  paper). 


/C^ 


of  course  taken  to  have  the  air  as  dry  as  possible,  in  order 
to  avoid  the  presence  of  hydrogen  through  the  dissocia- 
tion of  water-vapour.  The  vacuum  within  the  metal  tube 
could  be  maintained  apparently  indefinitely  under  these 
conditions. 

The  tubes  were  filled  with  hydrogen  as  follows : — The 
carefully  cleansed  tube  was  sealed  to  the  apparatus,  and, 
when  the  air  had  been  completely  exhausted,  was  left  for 
twenty-four  hours  or  more  ;  by  this  time  all  moisture  was 
probably  removed  by  the  phosphorus  pentoxide.  By  con- 
tinuous sparking  and  exhaustion  the  gas  occluded  by  the 
ele(5trodes  was  then  removed,  and  a  condition  of  brilliant 
green  fluorescence  readily  obtained.  On  raising  the  mer- 
cury in  the  Topler  pump  so  as  to  compress  all  the  gas  in 
its  bulb  and  tubes  into  a  space  of  not  more  than  a  fraction 
of  a  cubic  centimetre,  and  at  the  same  time  noting  the 
change,  if  any,  which  took  place  in  the  height  of  the 
mercury  column  in  the  delivery-tube,— in  other  words,  on 
using  the  pump  itself  as  a  McLeod  gauge, — it  could  be 
shown  that  the  pressure  within  the  exhausted  space  was 
not  more  than  one  or  two  millionths  of  an  atmosphere. 
Connection  between  the  pump  and  the  rest  of  the  appa- 
ratus was  then  cut  off  by  turning  a  glass  tap,  and  hydro- 
gen was  admitted  slowly  into  the  sparking-sube  by 
heating  the  metal  tube  while  a  current  of  dry  purified  gas 
was  circulating  about  it.     When  the  pressure  inside  the 


^ — ^ 


The  sparking-tubes  were  of  several  forms,  at  first  with 
wire  eledtrodes,  afterwards  with  cylindrical  eledtrodes  of 
aluminium  tubing  or  foil.  In  some  cases  photographs 
were  made  of  the  spedtrum  of  the  light  emitted  through 
the  walls  of  the  capillary  tube  ;  in  others,  of  that  ob- 
served "end  on"  through  a  disk  of  quartz  sealed  as  a 
window  to  one  of  the  bulbs.  In  one  case  the  tube  was 
specially  construdled  so  that  the  light  observed  through 
the  window  was  that  produced  at  the  eledtrode  and  not 
that  in  the  capillary  tube ;  the  light  thus  obtained  was, 
however,  so  weak  that  no  photograph  could  be  made  of 
the  spedrum. 

Having  demonstrated  the  tightness  of  the  apparatus, 
and  the  fadt  that  at  the  temperature  employed  hydrogen  is 
capable  of  permeating  the  walls  of  the  platinum  tube, 
experiments  were  made  which  afforded  evidence  that  a 
similar  power  of  penetration  is  not  possessed  by  oxygen 
or  nitrogen.  Air  was  drawn  through  the  apparatus  while 
the  metal  tube  was  maintained  at  a  white  heat.  Care  was 


sparking-tube  had  reached  about  i  cm.,  the  heating  was 
discontinued  and  the  apparatus  exhausted  as  before.  The 
process  of  filling  and  exhausting  was  repeated  from  three 
to  six  times,  after  which  the  tube  was  filled  to  the  desired 
pressure — which  was  between  3  and  8  m.m. — and  was 
sealed  off.  In  some  cases,  as  an  extra  precaution,  the 
tube  was  enclosed  in  a  copper  air-bath,  and  heated  during 
the  process  of  exhaustion  to  a  temperature  of  150°  to 
200^*,  the  sparking  being  meantime  continued. 

It  may  be  as  well  to  say  that  the  passage  of  the  hydro- 
gen into  the  exhausted  space  was  very  slow  as  compared 
with  what  the  statements  of  Graham  had  led  me  to 
expert.  It  may  be  that  the  tube  employed  by  me  was 
thicker  and  more  thoroughly  hammered,  and  that  the 
temperature  obtained  was  not  so  high.  At  all  events  the 
pressure  in  the  sparking-tube  rose  only  at  the  rate  of 
about  a  millimetre  in  three  to  five  minutes,  the  volume  of 
all  the  tubes  and  connections  open  to  the  gas  being  about 
100  c.c.     On  this  account  the  time  required  to  cleanse, 


f/O 


New  Class  of  Oxidising  Substances. 


exhaust,  and  fill  the  tube  in  the  manner  described,  waiting 
in  each  case  for  diffusion  to  equalise  the  pressure  through- 
out the  long  system  of  tubes,  rendered  the  work  very  slow 
and  tedious,  especially  as  only  a  short  time  was  available 
on  any  one  day  to  be  devoted  to  the  work. 

The  sparking-tubes  had  at  first,  except  for  the  tube  c, 
been  in  diretS  connexion  with  the  Topler  pump  and  mer- 
cury gauges.  On  photographing  the  spedtrum  it  was 
found  that  the  gas  was  contaminated  with  the  vapour  of 
mercury.  To  avoid  this  difficulty  the  tubes  G,  H,  and  i 
were  introduced  between  the  pump  and  gauges  and  the 
system  to  be  exhausted,  i  is  a  long  tube  filled  with 
powdered  sulphur,  h  a  similar  one  containing  bright 
copper  turnings,  and  g  contains  gold-leaf,  h  and  i  are 
shown  in  the  figure  much  shorter  in  proportion  than  they 
are  in  reality.  So  perfeftly  do  these  guard-tubes  serve 
their  purpose,  that  after  one  year  the  gold-leaf  shows  no 
signs  of  amalgamation.  The  copper  has  apparently  held 
back  all  sulphur-vapours  from  the  sparking-tubes,  whereas 
the  mercury  in  the  manometers  have  become  fouled  from 
not  being  proteded  in  its  turn  by  copper.  No  trace  of 
mercury-vapour  has  been  detected  in  the  gas  contained  in 
any  of  the  sparking-tubes  since  the  precautions  mentioned 
were  taken  to  exclude  it. 

Results. 

A  careful  examination  of  the  photographic  negatives 
obtained,  when  the  hydrogen  produced  as  described  and 
contained  in  the  sparking-tubes  was  used  as  the  source  of 
light,  has  failed  to  reveal  the  presence  of  any  other  sub- 
stance— unless  the  so-called  "  compound  "  spedrum  is  to 
be  considered  an  indication  of  such  contamination.  The 
purified  hydrogen  drawn  through  the  combustion-tube  B  b' 
probably  frequently  contained  nitrogen,  but  no  signs  of 
that  gas  could  be  detedted  in  the  spectrum  of  what  had 
passed  into  the  inner  tube.  If  the  compound  specSrum  is 
due  to  the  presence  of  water-vapour,  it  is  not  clear  how 
it  can  be  eliminated,  no  more  efficacious  drying  agent 
than  phosphorus  pentoxide  being  available. 

It  may  be  well  to  mention  here  that  the  results  obtained 
in  the  examination  of  the  spedrum  of  hydrogen  purified 
as  described  in  this  paper,  do  not  seem  to  agree  with 
those  obtained  by  Messrs.  Trowbridge  and  Richards  {Am. 
yourn.  Sci.  [4]  ,  iii.,  118  ;  Phil.  Mag.  [5],  xliii.,  137,  1897). 
According  to  these  authors,  an  oscillatory  discharge  from 
their  powerful  storage-battery  through  hydrogen  did  not 
yield  the  compound  spedtrum,  whereas  the  direft  discharge 
produced  the  compound  spedtrum  as  usual.  In  the  ex- 
periments performed  with  hydrogen,  as  described  in  this 
paper,  the  discharge  was  that  of  a  large  Ruhmkorff  coil, 
sometimes  with  and  sometimes  without  a  Leyden  jar  in 
the  secondary  circuit  and  with  considerable  variations  of 
current  in  the  primary  coil.  In  no  case  was  the  com- 
pound spedtrum  absent.  Messrs.  Trowbridge  and 
Richards  do  not  mention  the  charai5ter  of  the  tubes  they 
employed,  nor  give  any  account  of  the  method  of  purifica- 
tion used  for  the  gas,  or  that  of  cleansmg  and  filling  the 
tubes.  It  is  just  possible  that  were  these  data  available, 
some  explanation  of  the  difference  in  our  results  might  be 
forthcoming.  It  is  true  that  the  pressures  used  in  this 
work  were  on  the  average  a  little  higher  than  those  em- 
ployed by  Trowbridge  and  Richards,  but  not  to  an  extent, 
in  all  probability,  sufficient  to  account  for  so  marked  a 
discrepancy. 

As  has  been  stated,  oxygen  and  nitrogen  do  not  pene- 
trate hot  platinum  under  the  conditions  described  above  ; 
it  remained  an  interesting  question  to  determine  whether 
this  was  due  in  any  degree  to  the  relatively  high  specific 
gravity  of  these  gases  as  compared  with  hydrogen.  Ac- 
cordingly an  experiment  was  made  to  see  if  marsh-gas, 
with  a  density  only  half  that  of  oxygen,  would  penetrate 
into  the  inner  tube.  A  large  gasometer  was  filled  with 
the  gas  prepared  by  heating  a  mixture  of  dehydrated 
sodium  acetate  and  soda-lime,  and  washed  with  water 
and  acid  sodium  sulphite  solution  to  remove  the  vapours 
of  acetone.    After  standing  several  weeks  in  contadt  with 


/Chemical  ^E'Ws, 

1     oa.  1, 1&97. 

water  in  the  gasometer,  it  was  passed  again  through  a 
solution  of  the  sulphite,  through  soda-lime,  calcium 
chloride,  and  sulphuric  acid,  to  mix  with  the  purified 
hydrogen  as  it  entered  the  tube  filled  with  hot  copper 
turnings  mentioned  above.*  After  the  air  had  been  re- 
moved, and  a  gas  mixture,  consisting  of  about  four-fifths 
marsh-gas  and  one-fifth  hydrogen,  was  being  passed 
through  the  combustion-tube  b  b',  the  latter  was  heated. 
Gas  passed  very  slowly  into  the  sparking-tube  ;  after 
about  three  hours  the  pressure  had  risen  to  only  about  3 
m.m.  Examination  of  the  gas  by  means  of  a  large  prism 
spedlroscope  failed  to  show  the  presence  of  any  carbon 
compound ;  but,  on  account  of  the  low  pressure  the  light 
was  too  feeble  to  give  any  result  with  the  photographic 
method,  even  after  a  very  long  exposure,  and  so  this  ex- 
periment will  still  require  further  and  more  accurate  con- 
firmation. 

It  is  proposed  to  continue  this  work  with  hydrogen  and 
other  gases. 

Since  this  paper  was  written  a  note  has  been  published 
by  Ramsay  and  Travers  (Chemical  News,  Ixxv.,  253),  in 
which  they  describe  their  attempts  to  pass  helium  and 
argon  through  septa  of  platinum,  palladium,  and  iron, 
under  conditions  similar  to  those  described  in  this  paper. 
No  evidence  of  such  penetration  was,  however,  obtained. 
— American  Chemical  journal,  xix.,  No.  8. 


NEW     CLASS     OF    OXIDISING     SUBSTANCES: 
THE     PERCARBONATES. 

In  a  recent  number  of  the  Zeitschrift  fur  Electrockimie 
MM.  Constam  and  A.  von  Haussen  announced  the  dis- 
covery of  a  new  series  of  compounds  which  are  of  very 
great  interest.  We  know  that  on  eledlrolysing  the  alkaline 
carbonates,  M2CO3,  we  obtain  hydrogen  and  the  hydrate 
of  the  constituent  base  at  the  cathode,  and  at  the  anode 
oxygen  and  carbonic  acid,  which  re-combines  with  a  part 
of  the  base  to  form  bicarbonate. 

The  authors  have  observed  that  if  we  eledtrolyse  a 
saturated  solution  of  carbonate  of  potash,  and  gradually 
lower  the  temperature,  the  disengagement  of  oxygen 
gradually  diminishes  at  the  anode,  and  finally  ceases 
completely  at  about  — 10°  C.  And  further,  instead  of  a 
crystalline  bicarbonate  being  formed,  we  have  a  bluish 
amorphous  powder,  shown  by  analysis  to  consist  of 
K2C2O6 :  this  is  percarbonate  of  potassium.  We  can 
thus  explain  its  formation  :  the  carbonate  of  potassium 
in  saturated  solution  first  of  all  becomes  dissociated  into 
ions  K  and  KCO3 ;  when  eledtrolysis  intervenes,  the  two 
ions  KCO3  unite,  to  form  the  body  KjCaOe.  The  phe- 
nomenon does  not  occur  in  dilute  solutions,  as  the 
carbonate  of  potassium  splits  up  into  the  ions  K2  and 
CO3.  The  percarbonate  obtained  in  the  above  manner 
should  be  quickly  thrown  on  a  filter,  and  dried  over  phos- 
phoric anhydride.  It  is  very  hygrometric,  and  decom- 
poses water  at  the  ordinary  temperature  : — 

K2C2O6  +  H2O  =  2KHCO3  -f-  O. 
When  gently  heated  it  decomposes  according    to  the 
following  equation : — 

K2C2O6  =  K2CO3  -f  CO2  +  O. 
In    the  presence  of   oxidisable    matters   it   adts   as    an 
oxidising  agent.      But  it  can  also  ai^  as    a  reducing 
agent : — 

Mn02  +  K^CzOi  =  MnCOa  +  K2CO3  +  Oj. 

*  It  is  not  generally  known  that  comparatively  large  quantities  of 
oxygen'are  set  free  when  hydrogen  is  made  to  biibble  through  potas- 
sium permanganate  solution.  Unless  care  is  taken  to  remove  this 
oxygen,  say  with  red-hot  copper  and  a  drying  agent,  an  oppor- 
tunity is  given  for  a  very  berious  error  in  all  experiments  where  pure 
hydrogen  is  desired.  This  reduftion  of  permanganate  by  hydrogen 
is  now  under  investigation  in  this  laboratory  by  Prof.  Morte.— 
W.  W.R. 


Sbbuical  News,  i 
0€t.  1, 1897.      I 


Chemical  Notices  from  Foreign  Sources. 


171 


From  these  rea(5tions  the  authors  conclude  that  this 
new  body  is  in  reality  the  neutral  carbonate  of  a  higher 
oxide,  peroxide  of  potassium.  Besides  it  produces,  like 
the  higher  alkaline  oxides  and  the  alkaline  earths,  per- 
oxide of  hydrogen  in  the  presence  of  acids.  —  Revue 
Generale  des  Sciences,  No.  17,  1897. 


CORRESPONDENCE. 


SUPPOSED     NEW    ELEMENT    WITH     IRON. 

To  the  Editor  of  the  Chemical  News. 
Sir, — With  reference  to  the  article  by  Mr.  G.  G.  Boucher 
(Chemical  News,  vol.  Ixxvi.,  p.  99),  on  the  discovery  of 
a  possible  new  element  with  iron,  I  should  like  to  point 
out  that  the  rea(5tions  given  by  him  in  that  article  for  his 
unknown  metal  are  almost  identical  with  those  of  molyb- 
denum, the  only  exception  being  with  NajSOs,  which 
with  dilute  solutions  gives  no  perceptible  change  as  in  his 
case,  but  with  a  fairly  strong  solution  gives  a  blue  colour- 
ation on  boiling,  while  with  SnClj,  in  the  case  of  the 
metal  separated  from  iron,  no  change  takes  place ;  with 
the  metal  produced  from  boiler  dust,  SnClz  gives  the 
usual  molybdenum  colourations  of  dark  blue  in  the  cold 
and  brown  on  boiling  with  HCl ;  and  further,  the  most 
characteristic  readtion  for  his  unknown  metal,  viz.,  the 
intense  blue  colour  produced  by  evaporation  with  sulphuric 
acid,  is  »lso  one  of  the  more  chara^eristic  tests  for 
molybdenum,  and  therefore  —  seeing  that  from  Mr. 
Boucher's  description  of  the  process  for  separating  his 
unknown  metal  no  steps  are  taken  to  remove  molybdeum 
should  such  be  present — I  would  suggest  that  this  metal 
may  prove  to  be  molybdenum. — I  am,  &c., 

Charles  H.Jones. 

Laboratory,  Minas  de  Rio  Tinto,  S.  Spain, 
September  3, 1897. 


CHEMICAL  NOTICES  FROM  FOREIGN 
SOURCES. 

NoTB.— All  degrees  of  temperature  are  Centigrade  unieii  otherwise 
expressed. 

Comptes  Rendus  Hebdomadaires  des  Seances,  deVAcaiemit 

des  Sciences.    Vol.  cxxv.,  No.  10,  September  6,  1897. 

The  Minister  of  Public  InstruAion  and  the  Fine  Arts 
addressed  to  the  Academy  the  amplification  of  the  decree 
by  which  the  President  of  the  Republic  authorises  the 
Academy  to  receive  the  donations  offered  by  Henry  Wilde 
for  the  foundation  of  an  annual  perpetual  prize  of  4000 
frs.  to  be  awarded  to  the  person  whose  discoveries  or 
researches  in  astronomy,  physics,  chemistry,  mineralogy, 
geology,  or  experimental  mechanics  shall  be  judged  most 
worthy  of  reward. 

The  Magnetic  DeflecStion  of  the  Cathodic  Rays  and 
of  the  X  Rays.— G.  de  Metz. 

A(!lion  of  the  X  Rays  on  the  Luminescence  of 
Gases. — A.  de  Hauptinne. — A  tube  containing  a  gas  at 
a  low  pressure  becomes  luminous  under  the  adlion  of 
eledtric  vibrations,  and  becomes  luminous  at  a  much 
higher  pressure  if  submitted  to  the  a^ion  of  the  X  rays. 


Revue  Generale  des  Sciences  Pures  et  Appliques. 
No.  15,  August  15,  1897. 
This  number  contains  no  original  matter  of  chemical 
interest. 


Bulletin  de  la  Societe  d' Encouragement  pour  f  Industrie 
Nationale.     Series  5,  Vol.  ii.,  No.  7,  July,  1897. 

This  number  contains  an  account  of  the  annual  general 
meeting  of  the  Society,  which  took  place  on  June  25th 
under  the  presidency  of  M.  Mascart,  who  delivered  an 
address.  The  reports  of  various  committees  were  pre- 
sented and  a  number  of  medals  conferred. 


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upwards  of  two  years  in  construdtion,  were  formally 
opened  on  Odlober  ist.  They  are  situated  in  close  prox- 
imity to  King's  College  Hospital  and  to  the  rear  of  the 
New  Bankruptcy  Court,  and  occupy  a  site  of  7900  square 
feet. 

Outwardly  the  building  is  a  plain  one,  of  red  brick  ;  the 
rooms  (which  occupy  three  floors  and  a  basement)  are 
lofty  and  well  lighted,  their  walls  of  faced  bricks  are 
white  with  a  dado  of  pale  blue ;  the  floorings  are  of 
cement  overlaid  with  pine  blocks.  Ventilation  is  eff'e6led 
by  a  fan  in  the  basement,  the  means  of  artificially  heating 
and  lighting  the  establishment  being  steam  and  eledlricity 
respedlively.  There  are  three  distinft  water  systems, — 
one  in  connexion  with  the  Water  Company's  main,  a 
second  supplied  by  a  reservoir  situated  under  the  base- 
ment, and  a  third  of  cooled  water,  a  small  reserve  of 
which  is  kept  in  a  tank  near  the  roof.  The  pipes  con- 
veying these  services,  as  well  as  those  of  gas  and  steam, 
are  easily  accessible  and  naked  throughout  their  length, 
and  painted  in  different  colours  according  to  the  use  to 
which  they  are  put.  Those  of  each  bench  are  separately 
connedled  with  their  several  mains,  so  that,  should  any 
leakage  occur  in  them,  they  can  be  thrown  out  of  use 
without  other  than  local  inconvenience.  Dirty  waste 
liquid  is  conveyed  away  by  V-shaped  wooden  troughs 
covered  with  lead  thickly  coated  with  paint ;  the  difficulty 
of  corrosion  accompanying  the  use  of  leaden  pipes  for 
this  purpose  is  thus  avoided. 

The  basement  is  mainly  devoted  to  store-  and  engine- 
rooms.  A  sample  receiving  room  contains  an  ingenious 
bottle-washing  apparatus.  The  steam  leads  of  the 
boiler  are  fitted  with  reducing-valves  for  the  steam  drying 
and  heating  contrivances,  the  main  work  of  the  engine 
being  the  pumping  of  the  water  supplies,  and  driving  the 
ventilating  fan  and  also  a  carbon  dioxide  freezing 
machine,  which  provides  the  supplies  of  ice  and  cooled 
water.  The  reagents  room,  the  mechanical  laboratory, 
the  water  analysis  room,  and  the  hydrometer  room,  in 
which  all  the  instruments  in  use  are  standardised,  also 
partly  occupy  the  basement. 

The  ground  floor  is  allotted  to  the  rooms  of  the  Prin- 
cipal and  Deputy  Principal,  the  reference  sample  labora- 
tory, the  Crown  contra&s  department,  and  the  research 
laboratory.  The  reference  sample  laboratory,  which  is 
typical  of  most  of  the  rooms  as  regards  arrangements 
and  fittings,  may  perhaps  be  described  here.  The  tops 
of  the  working  benches  are  of  Honduras  mahogany,  the 
cupboards  beneath  them  of  oak ;  the  bench  reagent 
shelves  of  plate-glass  on  gun-metal  brackets  padded  with 
indiarubber.  Each  bench  is  fitted  with  a  metal  filter- 
pump  and  manometer,  a  sink  for  the  reception  of  dirty 
waste  liquid,  and  a  pipe  leading  to  the  reservoir  under  the 
basement,  for  conducing  away  clean  used  water.  On  one 
of  the  walls  is  placed  a  steam  drying  oven  of  copper 
packed  in  asbestos  and  cased  in  oak,  and  fitted  with  plate- 
glass  doors.  Orifices  at  bottom  and  top  allow  of  the 
passage  through  it  of  a  current  of  air  which  is  first  heated 
by  being  caused  to  pass  through  pipes  surrounded  by  the 
hot  packing.  The  waste  steam  escaping  from  the  oven  is 
led  through  a  worm  lined  with  pure  tin  contained  in  a 
drum  through  which  cold  water  circulates,  and  the  result' 
ing  distilled  water  for  ordinary  purposes  coUei^ed  in  a 


large  earthenware  jar  fitted  with  gauge  and  overflow- 
pipe.  The  water  used  for  this  condensation  and  all 
similar  purposes  is  returned  to  the  clean  water  reservoir. 
Beneath  the  drying  oven  stands  an  oak  chest  which 
carries  at  its  top  a  small  copper  tank,  tin-plated  inside, 
and  having  a  tray-shaped  copper  top.  The  heated  water 
formed  by  the  condensation  of  the  steam  in  the  pipes  of 
the  drying  apparatus  falls  into  this  tank,  and  thus  yields 
a  supply  of  hot  distilled  water,  while  the  hollow  cover 
serves  as  a  bath  for  heating  at  moderate  temperatures. 
The  cupboard  below  is  used  for  drying  towels,  dusters,  &c. 
The  floors  of  the  evaporating  cupboards  and  draught 
chambers  are  of  slate,  the  top  and  sides  being  of  plate- 
glass  in  oak  frames;  the  fronts  open  by  sliding  upward, 
and  are  each  connedled  with  a  counterpoise  by  a  chain 
passing  over  a  block.  Each  chamber  is  connected  with 
the  ventilating  system  by  an  air  passage  in  the  wall  of  the 
room.  The  evaporating  apparatus  consists  of  a  copper 
cone  sunk  in  the  slate  slab,  and  fitted  at  its  upper  part 
with  a  removable  porcelain  collar.  This  carries  a  cover  of 
heat-  and  acid-resisting  material  perforated  with  holes  of 
difl'erent  sizes  for  the  accommodation  of  basins  and  cap- 
sules. Two  holes  are  pierced  at  opposite  sides  of  the 
cone  at  slightly  different  heights,  the  higher  being  an 
inlet  for  steam.  This,  condensing,  fills  the  cone  to  the 
level  of  the  lower  orifice,  and  the  water  thence  runs  to  a 
gauge  arranged  so  as  to  maintain  a  constant  height  of 
water  in  the  cone.  Should  it  for  any  reason  be  found 
impradticable  to  employ  steam,  the  copper  cone  can  be 
diredtly  heated  by  a  Bunsen  burner  fixed  beneath  it,  any 
loss  by  evaporation  being  automatically  replaced  from  the 
gauge,  which  is  conneAed  both  with  the  water  supply  and 
waste  cistern.  An  oak  cupboard  with  top  and  front  of  plate 
glass  contains  standard  solutions.  The  burettes  are 
fixed  on  a  brass  rack  immediately  above,  and  are  con- 
nedted  by  indiarubber  tubes  to  the  bottles  containing  the 
standardised  reagents ;  they  are  filled  from  the  stock 
supply  by  suAion,  the  ingress  of  CO2,  &c.,  being  guarded 
against  by  bulb-tubes  filled  with  soda-lime. 

In  addition  to  the  apparatus  already  described,  a 
counterpart  of  which  is  to  be  found  in  most  of  the  rooms, 
the  Reference  Sample  Laboratory  is  also  provided  with  a 
hot  cupboard  with  sliding  plate-glass  doors,  and  a  hot 
trough  for  melting  and  filtering  butters  and  fats — a  class 
of  substances  largely  dealt  with  in  this  room. 

The  Crown  Contracts  Department  has  for  its  work  the 
examination  of  samples  submitted  on  tender  for  supplies 
to  various  Crown  Offices  and  their  comparison  with  the 
adtual  deliveries.  Besides  the  fittings  common  to  all  the 
rooms  the  one  allotted  to  this  work  has  an  automatic  gas- 
blast  for  long-continued  ignitions,  muffle  gas-furnaces  for 
similar  purposes,  self-regulating  hot-air  baths,  and  a  sul- 
phuretted hydrogen  cupboard  with  a  ventilating  passage 
entering  direAly  into  the  boiler  flue. 

The  Research  Laboratory  is  fitted  similarly  with  the 
addition  of  a  hood  for  combustion  work. 

Adjacent  to  the  Principal's  room  is  a  Reference  Li- 
brary. 

On  the  first  floor  are  the  main  laboratory,  the  tobacco 
laboratory  and  incinerating  room,  and  the  Superintending 
Analyst's  rooms.  The  former,  the  largest  room  in  the 
building,  is  used  for  work  connected  with  the  beer  and 
spirit  duty  samples.  Leading  out  of  it  are  a  polarimeter 
room  and  a  cold-storage  room,  the  latter  having  walls  of 
some  12  in.  thick,  containing  tanks  of  cold  brine  and 
cased  with  non-condu6ting  material.  The  water  used  in 
the  main  laboratory  itself  for  condensing  purposes  is  the 
cooled  supply  already  mentioned  :  it  is  kept  at  a  certain 
fixed  temperature  convenient  for  the  work. 

The  fittings  of  the  tobacco  laboratory  are  in  the  main 
similar  to  those  of  the  other  rooms,  with  the  exception 
that  extra  accommodation  for  microscopical  work  is  pro- 
vided. In  the  incinerating  room  there  is  a  new  device 
for  the  first  ignition  of  the  samples.  This  consists  of  a 
compaft  arrangement  of  small  Bunsen  burners,  the  height 
of  the  flame  of  each  being  independently  regulated  from 


1^4     interaction  of  Ammonium  Phosphate  and  dorrosive  Sublimate.  { ^"SaXiSi^!!"' 


the  front.  The  platinum  vessels  used  are  oblong  in  shape 
and  are  supported  on  a  frame  of  cobalted  iron.  This 
material  is  also  used  for  the  inner  shell  of  the  muffle  fur- 
naces, which  are  somewhat  broader  and  flatter  than  is 
usual.  There  are  three  ovens  for  moisture  estimations. 
These  are  of  the  type  in  general  use  in  the  laboratory, 
but  have  in  addition  packed  shelves  through  which  the 
air  current  passes,  entering  and  leaving  them  at  opposite 
ends  so  as  to  ensure  complete  circulation  in  every  part  of 
the  drying  space.  As,  also,  it  is  necessary  for  the  tem- 
perature of  these  ovens  to  be  maintained  throughout  the 
night,  they  are  heated  by  steam  supplied  by  a  self-filling 
and  self-regulating  gas-boiler. 

Two  small  staircases  lead  upwards  from  the  first  floor ; 
the  one  to  the  photographic  dark  room,  the  other  to  the 
museum,  to  the  room  in  which  instruction  in  chemical 
matters  of  interest  from  the  Revenue  point  of  view  is 
given  to  the  Supervisors  of  Excise,  and  to  the  typists'  and 
copyists'  room.  Cloak-rooms  on  each  floor,  and  a  goods 
lift  fill  the  remaining  available  space. 


THE    DETERMINATION     OF 

UNSAPONIFIABLE     OIL     IN     GREASES     WITH 

A   LIME    BASE. 

By    HENRY    BAILEY,    F.C.S. 

The  determination  of  unsaponifiable  oil  in  greases  whose 
base  is  an  insoluble  soap,  by  the  usual  method  of  complete 
saponification  with  caustic  alkali  and  extradling  the  un- 
saponified  oil  from  the  dried  soap  with  a  suitable  solvent, 
has,  in  the  hands  of  the  writer,  yielded  results  which  at 
best  are  unsatisfying,  owing  to  the  prolonged  drying 
required  to  free  the  soap  from  water,  and  the  difficulty  of 
completely  extradting  the  unsaponified  oil  from  the  pulpy 
mass. 

The  following  scheme,  in  which  the  base  is  separated 
from  the  assay  in  an  early  stage  of  the  operation,  yields 
results  of  maximum  accuracy  in  a  minimum  of  time. 

Ten  grms.  of  the  sample  are  weighed  accurately  into  a 
beaker  of  about  6  ounces  capacity,  and  boiled  with  water 
to  v/hich  an  excess  of  hydrochloric  acid  has  been  added, 
with  constant  stirring  until  the  grease  is  completely  de- 
composed and  free  from  lumps.  When  decomposition  is 
judged  to  be  complete,  the  floating  oils  and  fatty  acids 
are  separated  from  the  acid  solution  by  filtering  through 
a  close-pored  filter-paper  which  has  been  previously 
moistened  with  water,  and  washed  with  boiling  water 
until  the  washings  are  free  from  hydrochloric  acid.  In 
some  cases  the  filtrate  may  have  a  slight  iridescent  ap- 
pearance, but  the  quantity  of  oil  sufficient  to  cause  this 
is  so  small  that  it  may  safely  be  ignored.  The  apex  of 
the  filter-paper  is  now  pundured,  and  the  liquid  oil  washed 
back  into  the  beaker  by  a  very  fine  jet  of  boiling  water. 
About  2  grms.  of  caustic  potash  in  concentrated  solution 
is  now  added,  together  with  a  little  alcohol,  and  the  solu- 
tion heated  with  constant  stirring  until  saponification  is 
complete,  preferably  with  the  addition  of  a  little  more 
alcohol  to  replace  the  solution  as  it  evaporates. 

Evaporate  most  of  the  alcohol,  add  about  loo  c.c.  of 
water,  and  warm  until  clear.  The  solution  is  now  trans- 
ferred to  a  separator,  any  oil  adhering  to  the  beaker  being 
washed  in  by  means  of  a  jet  of  boiling  water  :  cool, 
when  cold  add  30  c.c.  of  methylated  ether  or  petroleum 
spirit ;  shake  well,  and  allow  to  stand.  When  the  line  of 
demarcation  between  the  aqueous  and  the  ethereal  solu- 
tions is  indistindt,  the  cautious  addition  of  a  few  drops  of 
alcohol  will  improve  matters. 

Draw  off  the  soap  solution,  and  wash  the  ethereal  solu- 
tion two  or  three  times  with  water,  adding  the  washings 
to  the  soap.  Transfer  the  ethereal  solution  to  a  small 
tared  wide-mouthed  flask.  The  soap  solution  is  replaced 
in  the  separator,  and  again  shaken  With  20  c.c.  of  ether 


to  completely  free  it  from  an  oil  that  may  have  escaped 
extradion,  and  the  washed  ethereal  solution  added  to  the 
weighed  flask  containing  the  first  extraction. 

The  ether  is  now  evaporated,  and  the  residue  of  oil 
dried  in  an  air-bath  at  a  temperature  a  little  over  100°  C. 
until  of  constant  weight. 

My  thanks  are  due  to  Mr.  J.  L.  Wade,  of  Nine  Elms 
Lane,  S.W.,  in  whose  laboratory  I  have  experimented 
with  this  method. 


THE    INTERACTION     OF    AMMONIUM 

PHOSPHATE     AND      CORROSIVE     SUBLIMATE 

IN    THE    LIGHT    OF    THE 

lONISATION     THEORY     OF     SOLUTION. 

By  D.  CARNEGIE  and  F,  BURT. 

Let  AB,  A'B',  A'B,  and  AB'  represent  four  soluble 
salts,  having  as  their  proximate  components  the  two 
acid  radicles  A  and  A',  and  the  two  basic  radicles  B 
and  B'. 

By  means  of  very  careful  measurements  of  physical 
properties,  it  can  in  general  be  proved  that  when  solutions 
of  AB  and  A'B'  are  mixed,  partial  mutual  decomposition 
of  the  salts  takes  place,  an  equilibrium  being  established 
in  which  all  four  salts— A B,  A'B',  A'B,  and  A  B'— 
partake. 

A  B  Aq  -f.  A'  B'  Aq  IS^;  A'B  Aq  -f  A  B'  Aq. 

But  the  cases  are  rare  where,  by  purely  qualitative 
examination  involving  no  measurements,  one  can  demon- 
strate the  occurrence  of  chemical  interat5lion  in  such 
homogeneous  systems.  As  one  of  these  rare  cases  may 
be  cited  the  interaftion  of  solutions  of  sodium  chloride 
and  copper  sulphate.  That  solution  of  these  salts  do 
interact  with  the  production  of  some  copper  chloride  and 
sodium  sulphate  is  evident  from  the  colour  change  from 
blue  to  green  which  accompanies  the  addition  of  salt  to 
solution  of  blue  vitriol. 

The  following  faCts  furnish  a  new  case  where  inter- 
action in  homogeneous  aqueous  solution  can  be  proved  by 
purely  qualitative  means — a  case  well  suited  for  leClure 
demonstration. 

Neither  a  dilute  solution  of  sodium  phosphate 
(Na2HP04)  nor  a  dilute  solution  of  ammonium  oxalate 
will  give  a  precipitate  when  added  to  a  dilute  solution  of 
mercuric  chloride  ;  but  a  mixture  of  solutions  of  sodium 
phosphate  and  ammonium  oxalate  at  once  interacts  with 
mercuric  chloride,  giving  a  dense  curdy  precipitate. 
Exactly  the  same  precipitate  is  produced  when  ammonium 
phosphate  solution  is  added  to  mercuric  chloride.  Hence 
it  necessarily  follows  that  solutions  of  sodium  phosphate 
and  ammonium  oxalate  partially  interact  with  the  pro- 
duction of  sodium  oxalate  and  ammonium  phosphate. 

One  would  off-hand  expeCt  the  precipitate  formed  by 
the  interaction  of  ammonium  phosphate  and  mercuric 
chloride  to  be  a  mercuric  phosphate, — to  be  the  result  of 
an  ordinary  double  decomposition  between  the  salts.  But 
if  this  were  the  case,  then  sodium  phosphate  should  aCt 
in  a  similar  way.  As  we  have  already  stated,  this  is  not 
the  case. 

As  a  matter  of  faCt,  a  quantitative  examination  showed 
the  precipitate  produced  by  ammonium  phosphate  to  be 
infusible  white  precipitate,  NHjHgCl— a  substance  which 
is  usually  obtained  as  a  product  of  the  interaction  of 
mercuric  chloride  and  free  ammonia. 

Let  us  now  glance  at  the  whole  series  of  these  reactions 
in  the  light  of  the  new  theory  of  the  constitution  of  salt 
solutions. 

Mercuric  chloride  undergoes  extremely  little  ionisation 
when  dissolved.  This  follows  at  once  from  the  very  low 
electrical  conductivity  of  aqueous  solutions  of  the 
chloride.    Consequently  the  concentration  of  the  mercuric 


CbkuicalNbws.  ) 

Oa.  8,  i«Q7.       ( 


Separations  with  Alkaline  Acetates. 


175 


ions  in  HgCljAq  is  jvery  low — so  low,  in  facft,  that  the 
produ(5t  of  the  concentration  of  mercuric  ions  and  the 
concentration  of  C2O4"  ions  from  soluble  oxalate  solu- 
tions does  not  exceed  the  "  solubility  produd  "  for  mer- 
curic oxalate.  Hence  mercuric  oxalate  cannot  be  obtained 
by  interadlion  of  dilute  solutions  of  mercuric  chloride  and 
an  oxalate. 

Similar  statements  may  be  made  with  respecSt  to  the 
absence  of  any  precipitation  when  solutions  of  mercuric 
chloride  and  any  soluble  phosphate  other  than  ammonium 
phosphate  are  mixed. 

When  ammonium  phosphate  is  dissolved  in  water,  we 
get  the  ions  NH4',  NH4',  and  HPO4".  But  phosphoric 
acid  has  a  very  low  ionisation  tendency;  it  is,  in  other 
words,  a  very  weak  acid.  Hence  the  HPO4"  ions  com- 
bine with  H'  ions  (resulting  from  the  ionisation  of  water) 
to  form  undissociated  phosphoric  acid.  More  water  and 
more  ammonium  phosphate  undergo  ionisation  in  the 
effort  to  re-establish  the  equilibrium  disturbed  by  the 
removal  from  the  sphere  of  adtion  of  H'  ions  and  HPO4" 
ions  thus  brought  about.  The  end  result  is,  that  we  have 
in  a  solution  of  ammonium  phosphate  a  considerable  con- 
centration of  free  ammonium  hydroxide,  both  in  the 
ionised  and  un-ionised  condition. 

Similar  statements  might  be  made  with  regard  to  the 
solution  of  ammonium  oxalate,  with  this  difference,  how- 
ever, that  oxalic  acid  being  a  much  stronger — more  highly 
ionised — acid  than  is  phosphoric  acid,  the  ammonium 
ions  never  reach  a  sufficient  concentration  to  cause  the 
visible  formation  of  NHaHgCl.  Some  of  the  NH4'  and 
Hy"  ions  do  undoubtedly  interad  in  this  case,  but  the 
produdt  of  the  concentration  of  the  thus-formed  NHaHg' 
ions  and  of  the  concentration  of  CI'  ions  never  reaches  the 
solubility  produdt  for  NHaHgCl. 

We  found  that  infusible  white  precipitate  is  soluble  in 
excess  of  (NH4)2HP04Aq,  though  it  is  insoluble  in  excess 
of  either  NH40HAq  or  Na2HP04Aq.  In  a  solution  of 
ammonium  phosphate  there  must  be  more  free  phosphoric 
acid  than  in  a  solution  of  sodium  phosphate  of  about 
equal  molecular  concentration.  For  ammonia,  unlike 
soda,  being  a  very  weak  base,  the  OH'  ions  of  the  water 
of  solution  are  removed  from  the  sphere  of  adtion  as  un- 
dissociated NH4OH  molecules.  Hence  the  concentration 
of  H'  ions  must  form  by  far  the  more  considerable  fadlor 
in  the  solubility  produdl  for  the  water  which  holds  the 
ammonium  phosphate  in  solution.  But  this  means  the 
existence  in  ammonium  phosphate  solutions  of  a  com- 
paiatively  large  amount  of  phosphoric  acid. 

We  therefore  attributed  the  solvent  adion  of  solution 
of  ammonium  phosphate  on  white  precipitate  to  the 
phosphoric  acid  which  the  former  contains.  This  being 
so,  white  precipitate  should  dissolve  readily  in  concen- 
trated solutions  of  phosphoric  acid.  We  found  this  to 
be  the  case,  and  the  beautiful  crystals  which  separate 
from  the  phosphoric  acid  solution  are  now  under  investi- 
gation. 

As  the  concentration  of  aqueous  salt- solutions  rises, 
the  ionisation  becomes  absolutely  less,  but  the  concen- 
tration of  the  ions  becomes  greater.  And  as  chemical 
interadion  is  a  fundtion,  not  of  the  absolute  amounts  of 
the  readlions  but  of  their  concentrations,  we  concluded 
that  it  might  be  possible  to  prepare  a  mercuric  phosphate 
by  precipitation  from  saturated  solutions  of  mercuric 
chloride  and  ammonium  phosphate.  The  dark  red  preci- 
pitate which  forms  when  such  solutions  are  mixed  is  now 
undergoing  examination.  All  that  can  be  said  at  present 
about  it  is,  that  it  contains  a  mercuric  phosphate. 

Quite  apart  from  the  possible  establishment  of  the 
existence  of  a  new,  and  probably  quite  worthless,  phos- 
phate of  mercury,  this  precipitate  demands  careful  exam- 
ination. For  if,  after  long  washing,  it  still  be  found  to 
contain  chlorine,  it  is  clear  that  m  this  case  (and  perhaps 
in  others  also)  another  explanation  of  its  presence  lies  to 
hand  than  the  customary  one  given  in  such  cases,  viz., 
co-precipitation  by  adsorption. 

Clifton  College. 


LABORATORY     EXPERIMENTS. 
By  J.  THOMPSON. 

One  of  the  simplest  experiments  to  be  performed  by 
students  of  elementary  chemistry  is  the  determination 
of  the  combining  proportion  of  magnesium  and  oxygen. 

As  the  magnesium  is  generally  burnt  in  a  limited  supply 
of  air,  the  produdls  of  combustion  are  grey.  If  a  fairly  large 
quantity  of  this  grey  substance  be  exposed  to  the  air  for 
a  short  time,  it  will  be  found  to  give  off  the  charadteristic 
odour  of  ammonia. 

The  grey  substance  is  a  mixture  of  the  oxide  and  the 
nitride  of  magnesium.  Water  vapour  adls  upon  the  latter, 
with  the  produdtion  of  ammonia  and  magnesium  oxide. 

Platinum  and  tin,  in  the  proportion  of  10  of  the  former 
to  I  of  the  latter  (by  weight),  form  a  very  brittle  alloy, 
giving  off  a  very  large  quantity  of  heat.  The  combina- 
tion takes  place  at  a  red  heat,  and  the  globule  formed 
quickly  becomes  nearly  white  hot. 


SEPARATIONS  WITH    ALKALINE   ACETATES. 

By  HARRY  BREARLEY. 

(Continued  from  p.  167). 

IV. — Chromium  from  Iron. 
That  in  ordinary  acetate  precipitations  chromium,  if 
present  as  a  chromic  salt,  would  go  down  with  the  iron, 
is  accepted  without  question.  Even  with  minimum 
acetate  and  10  c.c.  of  free  acetic  acid  the  chromium  is 
almost  completely  precipitated  with  the  iron;  and  yet  the 
hydrate,  as  well  as  the  acetate,  of  chromium  is  easily 
soluble  in  dilute  acetic  acid. 

There  are  two  phases  of  the  acetate  precipitation 
which,  it  was  thought,  might  give  at  least  a  partial 
separation.  These  are — (a)  when  no  free  acid  is  present 
and  barely  enough  acetate  to  precipitate  the  iron,  and 
(b)  when  large  volumes  of  acetic  acid  are  used  with 
minimum  acetate. 

The  first  case  was  tested  by  neutralising  a  mixture  of 
ferric  and  chromic  chlorides,  diluting,  and  heating.  At 
90°  C.  there  was  no  sign  of  turbidity  ;  near  the  boiling- 
point  the  turbidity  formed  and  deepened  as  the  boihng 
was  prolonged,  until  nearly  all  the  iron  was  precipitated. 
Only  traces  of  chromium  were  to  be  found  in  the  filtrate. 
The  mixture,  as  in  succeeding  cases,  contained  i  grm.  of 
iron  and  o"i  grm.  of  chromium.  The  second  case  was 
tested  by  preparing  solutions — both  T.  H.  and  N.H. — 
and  precipitating  in  presence  of  30,  50,  70,  100  c.c.  acetic 
acid,  The  percentage  recovery  of  chromium  from  the 
filtrate  ranged  from  375  to  77*5.  With  other  degrees 
of  dilution  these  results  might  be  improved.  With  larger 
amounts  of  acid,  if  an  inference  from  the  general  trend  is 
admissible,  a  perfedt  separation  might  be  approximated. 
But,  however  possible  the  separation  might  thus  become, 
there  are  inherent  difficulties  which  would  prevent  the 
operation  ever  becoming  pradlicable. 

The  chief  drawback,  apart  from  the  expense  of  the  re- 
agents, is  the  colour  of  the  filtrate.  This  with  the  better 
separations  was  a  deep  reddish  purple — so  deep  that  in  a 
half-litre  flask  it  was  almost  opaque.  It  will  readily  be 
seen  that  on  this  account  the  precipitate  can  only  be  dis- 
tinguished from  the  filtrate  by  careful  examination,  and 
so  faulty  filtration  would  often  go  undetedted.  Nor  would 
faulty  filtration  be  an  unlikely  occurrence,  because  the 
iron  precipitate  is  so  finely  divided  that  no  paper  I  have  seen 
and  only  a  carefully  made  asbestos  filter  can  completely 
retain  it.  The  desire  to  estimate  chromium  gravimetrically 
is  the  chief  reason  for  seeking  its  separation  from  iron. 
In  this  case  that  operation  would  be  greatly  complicated 
b^  (the  passive  nature  of  chromium  acetates  formed  in 


176 


Separations  with  Alkaline  Acetates. 


f  Cbbmical  Nbws, 

\    oa.  ,  1897. 


this  manner  (see  Chemical  News,  xlviii.,  114,  Reinitzer ; 
also  "  Bowman's  Pradlical  Chemistry,"  1878  edition). 

The  results  quoted  above  were  obtained  by  oxidising 
with  permanganate  and  titrating  with  ferrous-ammonium 
sulphate  and  bichromate. 

The  separation  of  chromium  and  iron,  after  oxidising 
the  former  to  chromic  acid,  is  attributed  to  Gibbs  and  is 
well  known.  Enquiries  lead  one  to  conclude  that  it  is 
rarely  used  in  steel  works'  laboratories,  and  it  is  rarely 
seen  in  text-books.  The  only  recent  instance  that  I  know 
of,  having  made  no  special  search,  in  published  methods 
of  iron  and  steel  analysis  is  to  be  found  in  Chemical 
News,  Ixvii.,  307  (Parry  and  Morgan).  However,  it  still 
holds  a  place  in  "  Seledl  Methods,"  and  thence  one 
might  infer  that  it  was  at  least  approximately  accurate. 
I  do  not  mind  confessing  that  I  was  disappointed  to  find 
the  method  so  unsatisfadlory,  until  I  refledled  that  it  was 
no  part  of  my  endeavour  to  satisfy  expedlations.  The 
avowed  principle  of  the  reaftion  is  indeed  a  prepossessing 
one.  The  method,  briefly  described,  is  to  neutralise,  add 
acetate,  oxidise  with  bromine  or  chlorine,  and  boil,  whence 
the  iron  is  precipitated,  and  the  excess  of  oxidant 
eliminated  simultaneously. 

Naturally,  the  usual  amount  of  acetate,  hydrate,  and 
acid  were  first  tried.  The  tests  throughout  were  made 
on  mixtures  of  an  acidified  solution  of  ferric  chloride  and 
potassium  chromate  (i  grm.  Fe,  o-i  grm.  Cr).  The  first 
few  separations  were  consistently  very  bad  ones  (per- 
centage recovery,  26  to  27).  It  was  thought  that  the  pre- 
sence of  a  strong  oxidant  throughout  the  precipitation 
was  the  condition  wanting;  considerable  bromine  was 
therefore  added  to  a  mixture,  but  the  result  showed  no 
material  improvement.  Several  repetitions  of  the  first 
experiment  emphasized  the  surprisingly  low  percentage 
recovery  and  drew  attention  to  the  unusually  low  turbidity 
temperature— 50°  to  60°  C,  instead  of  the  expedled  80°  to 
90°.  Corresponding  results  were  obtained  when  the 
chromate  was  replaced  by  bichromate,  or  the  mixture  by 
a  sample  of  chromium  steel. 

The  low  turbidity  temperature  suggested  that  something 
in  the  solution  was  adting  along  with  the  acetate  as  a  pre- 
cipitant,  and  that  this  something  could  be  made  to  aft 
alone  under  suitable  conditions.  The  mixture  of  iron  and 
chromate,  therefore,  was  neutralised,  &c.,  as  usual,  except 
that  no  acetate  whatever  was  added.  The  solution  became 
turbid  at  80°  C,  and  the  precipitate  and  filtrate  had  much 
the  usual  appearance.  Less  chromium  was  recovered 
than  in  any  previous  experiment.  In  a  precisely  similar 
experiment,  except  that  the  possible  formation  of  acetates 
was  avoided  by  replacing  the  10  c.c.  acetic  acid  by  10  c.c. 
normal  hydrochloric  acid,  the  turbidity  appeared  at 
87°  C,  and  the  chromium  in  the  filtrate  was  less  than 
before.  Attempts  were  made  to  completely  precipitate  the 
chromate  by  having  present  more  ferric  chloride  than  could 
be  precipitated  at  boiling  heat,  and  then  adding  dilute 
acetate  until  the  precipitation  was  just  accomplished. 
An  impression  that  the  chromate  was  much  the  more 
energetic  precipitant  of  the  two  suggested  this  course  ;  it 
was  not  successful. 

It  may  be  desirable  to  do  more  than  merely  record 
these  observations;  here  and  now,  however,  it  would 
interfere  too  much  with  the  purpose  of  these  papers.  But 
it  is  neither  premature  nor  out  of  place  to  suggest  that 
the  deficient  recovery  and  the  allied  low  turbidity  tem- 
peratures are  due  to  a  readion  between  the  chromic  acid 
and  the  ferric  chloride,  in  which  an  insoluble  chromic 
compound  is  formed.  "  Watts'  Didlionary  "  notices  two 
ferric  chromates— a  basic  salt,  Fe23Cr04.2Fea03,  formed 
by  adingwith  K2Cr04Aq  on  iron-alum  solutions  ;  and  an 
acid  salt,  Fe23Cr04.Cr03,  said  to  be  formed  by  digesting 
CrOsAq  with  Fe206H6.  If  the  said  compound  is  either, 
the  probability  is  that  it  is  the  former ;  anyway,  it  is  a 
compound  of  iron  with  chromic  acid,  because  if  the  total 
precipitate  be  dissolved  in  dilute  hydrochloric  acid,  and 
the  chromium  estimated  by  Penny's  process,  as  much  is 


found  as  makes,  with  that  obtained  from  the  filtrate,  an 
amount  exadtly  equal  to  that  introduced. 

Such  a  method  as  the  preceding  can  by  no  stretch  of 
favour  be  classed  as  a  quantitative  one.  It  is  capable  of 
better  behaviour  surely,  else  how  came  it  to  move 
amongst  "  seledt "  methods.  It  may  be  noticed  on 
re-reading  the  instrudions  that  an  excess  of  acetate  is 
recommended.  Whether  this  is  an  express  statement  or 
the  customary  formulae  for  acetate  precipitations  it  is  diffi- 
cult to  say,  but  the  word  "  excess"  is  so  important  that 
it  should  have  been  printed  in  italics  and  then  qualified 
by  "  very  large."  I  cannot  resist  the  opportunity  of  re- 
peating that  in  the  separation  of  nickel  and  cobalt  from 
iron  this  course  has  been  adopted.  The  same  eminent 
metallurgical  chemist  dismisses  the  separation  of  iron 
and  chromic  acid  with  "  an  excess  of  sodium  acetate  "  in 
ordinary  type.*  This  point  strongly  emphasizes  the  need 
of  scrutinising  methods  before  adopting  them,  and  the 
shallowness  of  the  economy  which  imagines  that  labora- 
tory operators  are  dead  losses  if  not  producing  long  rows 
of  results. 

It  must  be  admitted  that  with  chromium  steels  con- 
taining  only  from  several  tenths  to  2  or  3  per  cent  much 
better  results  are  possible  than  I  obtained  with  the  pre- 
viously-mentioned proportions,  else  such  a  deficiency 
could  not  have  gone  undetected  in  the  most  ill-conditioned 
laboratory.  Where  the  method  has  been  tested  on 
armour  plate  borings,  with  stridt  adherence  to  instruc- 
tions, I  am  informed  that  some  50  to  70  per  cent  of  the 
contained  chromium  has  been  estimated.  This  may 
readily  be  explained.  The  less  the  percentage  of  chro- 
mium, the  greater  the  proportion  of  acetate  to  chromate 
in  the  oxidised  solution,  and  the  greater  the  proportion 
of  acetate  to  chromate  (?)  precipitated.  If  this  explana- 
tion be  true,  it  should  happen  that  all  else  being  equal, 
the  greater  volume  of  acetate  should  accompany  the 
greater  percentage  recovery.  In  Table  XIV.  this  is 
shown  to  be  so. 

Table  XIV. 


Volume  of 

strong  acetate. 

C.c. 

10 

50 

100 

200 


Per  cent  recovery  with — 


Ammonia  acetate. 

47-2 
72*0 
81-5 


Soda  acetate. 
50-5 
70*0 


The  amounts  of  iron  and  chromium  are  as  before.  The 
solutions  contained  total  hydrate  and  10  c.c.  acetic  acid. 
The  acetates  previously  used  are  too  dilute  to  use  in  this 
case,  within  the  limit  of  our  standard  volume  (1000  c.c). 
They  were  therefore  made  about  13  times  as  strong  as 
usual,  e.g.,  the  ammonium  acetate  is  approximately  that 
made  by  neutralising  33  per  cent  acetic  acid  with  880 
ammonia. 

The  effedl  of  increasing  volumes  of  acetic  acid  is  to 
give  higher  results,  but  only  so  in  a  slight  degree. 

The  foregoing  may  help  to  explain  why  the  acetate 
separation  of  iron  and  chromium  has  fallen  into  disuse. 
With  such  modification  as  we  are  now  able  to  make,  it 
is  scarcely  worth  while  to  formulate  the  method  anew.  If 
there  are  ever  circumstances  which  make  the  method  a 
desirable  one,  well.  For  determining  chromium  in  iron 
and  steel  such  methods  as  Galbraith's,  or  Stead's  modifi- 
cation of  it,  are  all  that  can  be  desired,  and  if  a  gravi- 
metric method  were  needed,  the  separation  in  question 
is  almost  as  troublesome  and  less  accurate  than  fusion 
with  alkalis. 

After  oxidising  the  chromium,  the  acetate  is  frequently 
replaced  by  a  pure  or  carbonated  alkali.  A  few  tests 
rapidly  made  tend  to  show  that  in  such  cases  a  similar 
error — though  smaller — is  introduced,  and  may,  similarly, 
be  more  and  more  nearly  eliminated  by  adding  increasing 

♦  It  is  only  fair  to  say  that  the  author  of  these  instruftions  says  at 
the  same  time  "  a  satisfaftory  method  for  the  determination  of 
<  chromium  has  yet  to  be  devised." 


Chbmicai.  News,  i 

oa.  8, 1897.     / 


Concentrated  Solutions  of  Lithium  and  other  Salts. 


177 


quantities  of  alkalis.  It  may  be  noteworthy,  too,  that 
aluminium  and  chromium  are  separated  under  precisely  the 
same  conditions  as  iron  and  chromium  (see  "  Fresenius," 
7th  edition,  page  428),  and  a  corresponding  basic  salt, 
Al23Cr04.2Al203.2iH20,  is  said  to  be  formed  in  a  like 
manner.  This  makes  it  desirable  to  examine  the  separa- 
tion of  these  two  elements.  Quite  casually,  too,  I  learn 
from  an  abstradt  in  the  yourn.  Chem.  Soc.  that  Marchal 
and  Wiernik  {Zeit.  Angew.  Chem.,  1891,  511 — 513)  claim 
to  have  obtained  perfedi  separations  of  iron  and  chromium 
by  oxidising  the  chromic  salt  with  freshly-precipitated 
manganese  dioxide.  Thus  it  appears  that  there  are  a 
number  of  methods  over  which  suspicion  is  cast.  If  I 
may  reserve  this  study  to  myself,  it  shall  not  be  negledled 
when  "  Separations  with  Alkaline  Acetates  "  have  been 
completed.  There  is  evidence  that  the  use  of  an  alkaline 
chromate  w^ill  effed  separations  which  with  alkaline 
acetates  are  impossible. 

(To  be  contiDued). 


SOME     NOTES    ON     CONCENTRATED 

SOLUTIONS    OF    LITHIUM     AND     OTHER 

SALTS.* 

By  JOHN  WADDELL,  B.A.,  D.Sc,  Ph.D. 

In  an  article  published  nearly  two  years  ago  in  the 
Chemical  News  (Ixxii.,  p.  201),  I  gave  a  record  of  ex- 
periments on  the  relative  amounts  of  water  absorbed  by 
the  molecular  weights  of  lithium  nitrate  and  calcium 
nitrate  when  they  were  enclosed  in  the  same  bottle  along 
with  a  limited  quantity  of  water.  Each  of  the  salts  and 
the  water  were  in  tubes  like  small  test-tubes,  the  quantity 
of  water  being  small,  so  that  the  solutions  of  the  lithium 
and  calcium  salts  were  concentrated.  It  was  found  that 
the  lithium  nitrate  absorbed  more  water-vapour  than  the 
amount  calculated  on  the  assumption  that  lithium  nitrate 
and  calcium  nitrate  are  dissociated  equally;  the  indica- 
tion being,  that  while  neither  of  the  salts  is  completely 
dissociated  in  concentrated  solutions,  lithium  nitrate  is 
more  largely  dissociated  than  calcium  nitrate.  Lithium 
nitrate  was  also  found  to  be  dissociated  to  a  greater 
extent  than  potassium,  strontium,  or  barium,  nitrate.  It 
was  mainly  with  a  view  to  seeing  whether  lithium  chloride 
and  sulphate  would  show  similarly  greater  dissociation 
than  other  chlorides  and  sulphates  that  the  few  experi- 
ments described  in  these  notes  were  undertaken. 

The  experiments  are  not  all  complete,  the  weight  of 
the  tubes  not  being  in  every  case  constant;  but  they  have 
been  carried  on  long  enough  to  make  the  general  conclu- 
sions pretty  certain,  and  the  results  are  therefore  given 
without  longer  delay. 

Lithium,  strontium,  barium,  and  potassium  chlorides 
were  investigated  with  the  results  given  below  : — 

Table  of  Quantities  of  Water  in  Grms,  taken  up  by  the 
Molecular  Weight  (in  M.grms.)  of  the  Chlorides. 
I  LiCl       ..     0709        o'sSo        o'597        o*40i 
I  BaCl2     ..     0'966        0807  —  — 

I  SrCl2      ..     i'02i  —  —  0604 

I  KCl        ..       —  —  0-513        0-323 

The  figures  in  the  last  column  show  that  while  potassium 
chloride  is  not  so  largely  dissociated  as  lithium  chloride, 
strontium  chloride  is  dissociated  to  a  greater  extent. 
The  only  alternative  to  this  last  conclusion  is  that  both 
the  lithium  chloride  and  the  strontium  chloride  are 
completely  dissociated — a  conclusion  which  is  not  only 
a  priori  unlikely,  but  is  negatived  by  the  results  given  in 
the  first  column,  because  there  it  is  seen  that  the  water 

*  Read  before  the  British  Association  (Section  B),  Toronto 
Meeting,  1897. 


absorbed  by  the  lithium  chloride  is  more  than  two-thirds 
as  much  as  that  absorbed  by  the  strontium  chloride, 
which  would  seem  to  prove  that  the  rate  of  dissociation 
of  the  former  salt  is  increasing  as  compared  with  the 
latter.  If  two-thirds  of  the  lithium  chloride  and  three- 
fourths  of  the  strontium  chloride  were  dissociated,  the 
number  of  ions  in  the  one  case  would  be  just  two-thirds 
of  that  in  the  other;  or  the  same  result  would  follow  if 
one-third  of  the  lithium  chloride  and  one-half  of  the 
strontium  chloride  were  dissociated.  These  are  two  out 
of  an  indefinite  number  of  solutions  of  the  problem,  so 
that  it  is  evident  that  the  experiment  does  not  give  suffi- 
cient data  for  determining  to  what  extent  the  various 
salts  are  dissociated 

The  amount  of  water  absorbed  by  the  barium  chloride 
is  not  far  short  of  that  absorbed  by  the  strontium  chloride, 
so  that  it  too  is  probably  more  dissociated  than  the 
lithium  chloride. 

In  the  case  of  the  sulphates,  lithium  was  compared 
with  magnesium  and  zinc.  The  last  two  were  weighed 
out  in  the  form  of  MgS04,H20  and'ZnS04,H20,  that  this 
was  their  composition  being  proved  by  precipitating  a 
portion  of  the  salts  with  barium  chloride. 

As  the  tubes  have  not  attained  constant  weight,  the 
last  two  weighings  are  given,  so  that  it  may  be  seen 
which  tubes  were  gaining  weight  and  which  losing,  and 
at  what  relative  rate. 

Table  of  Quantities  of  Water  in  Grms.  taken  up  by  the 
Molecular  Weight  (in  M.grms  of  the  Sulphates). 
Those  marked  -f  were  increasing,  those  marked  — 
were  decreasing. 

1108  1-114+ 
0-693  0*687 — 
o"620        0"6i6- 


Li2S04 
MgS04 
ZnS04 
Li2S04 


1-790 

i-797-f 

1-078 

0-067  — 

1-070 

1053- 

1-924 

1-925 

The  magnesium  sulphate  is  slightly,  but  only  slightly, 
more  absorbent  than  the  zinc  sulphate.  That  the  difference 
of  absorption  is  not  large  may  be  seen  by  noticing  that 
where  the  magnesium  and  zinc  salts  had  nearly  equal 
quantities  of  water,  the  zinc  sulphate  was  losing  more 
rapidly  than  the  magnesium  sulphate  ;  but  when  the  zinc 
sulphate  had  only  six-sevenths  as  much  water  as  the  mag- 
nesium sulphate,  the  zinc  sulphate  lost  more  slowly.  The 
lithium  sulphate  was  far  more  absorbent  than  the  other 
two,  and  plainly — if  dissociation  into  ions  is  indicated  by 
absorption — the  lithium  salt  is  considerably  more  disso- 
ciated than  the  others. 

There  were  also  some  further  experiments  with  nitrates, 
and,  in  order  to  show  in  what  diredtion  the  adtion  was 
going  in  the  cases  in  which  the  condition  was  not  con- 
stant, or  so  nearly  so  that  the  difference  in  six  or  seven 
days  was  not  noticeable,  a  plus  or  minus  sign  is  given, 
with  the  increase  or  decrease  in  the  time  mentioned. 

Table  of  Quantities  of  Water  in  Grms.  taken  up  by  the 
Molecular  Weight  (in  M.grms.)  of  the  Nitrates. 

I  KNO3       ..  0-402  0-683  i"233  +  3  i"635-4  3*275 

I  LiN03      ..  0-647  0-969  1-6x1-1-4  1-968  — 

I  NaNOs     ..  —  —  1*649  2-2i8  — I  — 

I  Ca(N03)2..  —         —  1-933  +  2  2-081  — 

I  Sr(N03)2..  —          —             —  2-045  — 

I  Ba(N03)2..  —         —              —            —  _ 

I  AgNOj     ..  —  —             —            —  3300 

The  most  noticeable  feature  in  this  table  is  that,  though 
potassium  nitrate  is  not  so  absorbent,  and  therefore  pre- 
sumably not  so  much  dissociated  as  lithium  nitrate, 
sodium  nitrate,  in  both  cases  observed,  has  taken  up 
more  water.  Strontium  and  calcium  are  not  far  apart 
when  the  dilution  is  that  given  above ;  the  difference  in 
more  concentrated  solutions,  as  I  showed  in  my  former 
paper,  is  greater.  The  barium  nitrate  weighings  are  not 
given,  because  in  the  first  case  water  had  been  added  in 


178 


Titration  of  Sodium  Thiosulphate  with  Iodic  A  cid. 


\  Crbhical  Nbws 
I      0(ft.  8, 1897. 


large  quantity,  and  all  of  the  gain  in  the  other  tubes  came 
from  it ;  in  the  second  case  the  tube  contained  crystals. 

In  the  comparatively  dilute  solutions  of  potassium  and 
silver  nitrate,  the  absorption  was  pracftically  equal. 
Along  with  these  solutions  two  tubes  containing  mer- 
curous  nitrate  were  introduced,  in  order  if  possible  to  see 
whether  the  formula  Hga(N03)2  or  HgNOj  would  cor- 
respond  best  with  the  result  obtained,  but  the  absorption 
of  vapour  by  the  salts  was  so  slow  that  they  were  not 
brought  into  solution,  and  so  nothing  could  be  determined 
regarding  the  formula, 

I  described,  in  the  former  paper,  some  experiments 
with  potassium  chloride,  bromide,  and  iodide,  which 
proved  that  the  invaporation  of  these  salts,  provided  there 
is  enough  water  present  to  bring  them  all  into  solution,  is 
approximately  equal.  I  have  since  compared  potassium 
chloride  and  potassium  nitrate,  and,  as  the  table  shows, 
the  chloride  is  very  considerably  more  absorbent. 

Table  of  Quantity  of  Water  in  Grms.  taken  up  by  the 
Molecular  Weight  (in  M.grms.), 
I  KCl       ..     ..        0-641  0-902 

I  KNO3   .,     ,.        0*482  0780 

The  dissimilarity  between  the  chloride  and  nitrate  is  all 
the  more  remarkable  because  they  agree  much  more 
nearly  as  to  solubility  than  the  chloride  does  with  the 
bromide  and  iodide.  If  the  first  table  containing  the 
chlorides,  and  the  table  containing  the  nitrates,  be  referred 
to,  it  will  be  seen  that  lithium  and  potassium  chloride 
differ  less  in  the  amount  of  water  absorbed  (or,  in  other 
words,  have  more  nearly  the  same  vapour  pressure  for  the 
same  strength  of  solution)  than  lithium  and  potassium 
nitrate.  Indeed,  though  with  the  concentrated  solution 
that  I  had,  the  lithium  chloride  is  more  dissociated  than 
the  potassium  chloride;  the  table  of  eledlrical  condudtivi- 
ties  given  by  Kohlrausch  indicates  that  if  the  dilution 
were  twice  as  great  the  potassium  chloride  would  be  the 
more  dissociated. 

The  conclusion  to  be  arrived  at  from  my  experiments  is, 
that  there  is  no  special  peculiarity  belonging  to  lithium 
salts  as  regards  invaporating  power,  there  being  some 
chlorides  and  some  nitrates  that  absorb  more  water  per 
molecule. 

The  behaviour  of  salts  in  the  concentrated  solutions  is 
so  haphazard  that  there  is  little  more  to  be  done  with 
them,  and  I  should  not  consider  the  investigation  worth 
pursuing  further  in  this  direction.  The  method  is,  how- 
ever, adapted  for  comparing  the  vapour  pressure  of 
different  solutions.  For  example,  if  it  is  desired  to  show 
the  student  that  molecular  weights  of  such  salts  as 
potassium  chloride  and  potassium  iodide,  having  equal 
quantities  of  water,  have  the  same  vapour  pressure,  it 
would  merely  be  necessary  for  him  to  make  two  such 
solutions,  and  arrange  three  experiments  in  one  of  which 
the  solutions  are  used  as  prepared  above,  a  second  in 
which  the  potassium  chloride  is  made  slightly  more  dilute, 
and  a  third  in  which  the  potassium  iodide  is  made  slightly 
more  dilute.  These  three  bottles  with  the  enclosed  tubes 
may  be  set  aside  for  a  few  days,  and  then  on  weighing 
there  will  be  found  to  be  no  change  in  the  tubes  in  the 
first  bottle;  in  the  second,  the  tube  containing  potassium 
chloride  would  be  found  to  be  losing  weight  and  the  iodide 
gaining;  while  in  the  third,  the  reverse  adion  would  be 
seen  to  be  going  on. 

In  this  way  the  well-known  law  of  vapour  pressures 
could  be  illustrated  without  any  elaborate  apparatus. 
Moreover,  if  a  number  of  experiments  are  to  be  per- 
formed, it  is  easier  to  set  them  up  and  allow  them  to 
stand  for  a  few  days  than  to  go  on  with  a  series  of  deter- 
minations of  vapour  pressure  in  an  apparatus  which  must 
be  carefully  cleaned  and  dried  each  time. 

Why  my  experiments  took  so  long  was  because  I  was 
working  at  the  invaporation  from  the  beginning,  and  did 
not  make  use  of  solutions  made  up  to  a  suitable  strength, 
my  purpose  being  different  from  the  one  of  which  I  am 


now  speaking.  As  I  have  stated,  there  is  not  much  regu- 
larity in  the  concentrated  solutions,  no  law  having  been 
found  by  which  it  would  be  possible  to  predidt  which  of 
two  concentrated  solutions  would  have  the  greater  vapour 
pressure ;  but  this  method  of  comparing  vapour  pressures 
may  sometimes  be  found  valuable. 
Kingston,  Canada. 


THE  TITRATION   OF  SODIUM  THIOSULPHATE 

WITH    IODIC   ACID.* 

By    CLAUDE    F.    WALKER, 

This  investigation  was  undertaken  to  determine  the 
nature  and  limitations  of  the  readtion  between  iodic  acid 
and  thiosulphuric  acid,  and  to  show  the  expediency  of 
employing  iodic  acid  in  standard  solution  for  the  diredt 
titration  of  sodium  thiosulphate.  Riegler  states  that 
iodic  acid  is  readily  obtained  pure,  and  that  a  standard 
solution  can  be  kept  a  long  time  unaltered.  He  further 
states  that  when  a  solution  of  sodium  thiosulphate  is 
titrated  with  iodic  acid  the  readlion  takes  place  according 
to  the  equation — 

6Na202S3+6HI03=3Na2S406+5NaI03  +  NaI+3H20. 

Under  which  circumstances  no  free  iodine  will  be  evolved 
until  all  the  sodium  thiosulphate  has  been  oxidised  to 
tetrathionate.  The  first  drop  of  iodic  acid  in  excess, 
however,  will  readl  with  the  sodium  iodide  that  has  been 
formed  and  liberate  iodine,  as  shown  by  the  equation 
5NaI  +  6HI03<=5NaI03+3H20-H3l2i  thus  furnishing  an 
accurate  means  for  determining  the  end  of  the  reaiStion. 

A  careful  repetition  of  Riegler's  work  shows  that  his 
conclusions  are  to  a  great  extent  erroneous.  Thus, 
*'  chemically  pure"  iodic  acid  is  very  likely  to  contain  too 
much  iodine,  due  probably  to  the  presence  of  the  anhy- 
dride. Riegler's  proposed  method  of  titration  depends 
on  two  different  readtions,  and  these  must  be  definite, 
complete,  and  non-reversible  under  the  conditions  of  the 
analysis.  Thus  one  molecule  out  of  every  six  of  iodic 
acid  should  be  reduced  by  six  molecules  of  thiosulphate, 
forming  a  neutral  mixture  of  iodide  and  iodate,  when  it 
might  be  expedted  that  iodine  would  be  liberated  by  the 
first  trace  of  iodic  acid  in  excess.  There  was  striking 
evidence,  however,  of  some  obscure  readtion  of  the  thio- 
sulphate, which  influences  the  redudtion  of  the  iodic  acid, 
so  as  to  make  it  impossible  to  calculate  analyses  accord- 
ing to  Riegler's  readtion.  It  is  not  impossible  that  some 
third  unstable  compound  of  iodine  may  be  formed  as  an 
intermediate  produdt  and  delay  the  titration  of  iodine. 

It  appears,  however,  that  Riegler's  proposed  process  for 
standardising  sodium  thiosulphate,  is  impradticable  unless 
it  can  be  so  modified  as  to  do  away  with  a  number  of 
sources  of  error. 

The  analyses  of  solutions  of  iodic  acid  in  this  work 
was  invariably  performed  by  adding  to  the  portion  of  the 
solution  to  be  analysed  an  excess  of  potassium  iodide, 
acidifying  with  5  c.c.  of  dilute  (i  :  3)  sulphuric  acid,  and 
recovering  the  liberated  iodine  by  titrating  the  acid  solu- 
tion with  sodium  thiosulphate,  or  by  neutralising  with  an 
excess  of  potassium  bicarbonate,  and  titrating  the  alka- 
line solution  with  arsenious  acid.  In  either  case  one- 
sixth  of  the  iodine  recovered  was  calculated  to  iodic  acid, 
according  to  the  equation  sHI-HHI03  =  3l2-}-3H20. 

In  the  present  work  it  was  found  convenient  to  analyse 
the  iodic  acid  in  quantities  of  about  one-tenth  of  a  grm., 
when  the  variation  in  results  in  the  same  series  is  in- 
appreciable. 

By  blank  experiments  it  was  found  that  one  drop  of 
iodine  was  necessary  to  bring  out  the  starch  blue,  so  this 
was  uniformly  applied  in  the  analytical  work.     Two  dif- 

♦  Abridged  frona  the  American  Jourml  of  Scietue,yol,  iv.,  Sept., 
1897. 


CRBUICAL  NBW8,  ) 

Oft.  8, 1897.      ) 


Titration  0/ Sodium  Thiosulphate  with  Iodic  Acid, 


179 


ferent  samples  of  "  chemically  pure  "  iodic  acid  were  used 
to  determine  whether  its  purity  is  sufficient  to  admit  of 
its  dire(5l  application  in  standard  solutions.  Quantities 
of  both  these  were  dried  over  sulphuric  acid  to  constant 
weight.  A  third  sample  was  prepared  by  dissolving  the 
purest  obtainable  iodic  anhydride  in  water  and  evapo- 
rating at  ordinary  temperature. 

The  resulting  crystalline  mass  was  dried  over  sulphuric 
acid  for  a  week,  until  ceasing  to  lose  weight;  it  was  pre- 
sumed to  consist  of  the  pure  normal  acid.  Two  pre- 
sumably decinormal  solutions  of  each  of  the  first  two 
samples,  and  one  such  solution  of  the  third  sample  of 
iodic  acid,  were  made  by  dissolving  i7'585  grms.  in  i  litre 
of  water  at  15°  C.  Analyses  of  these  solutions  gave  the 
following  results : — 


Solution. 

I. 

II. 

III. 

IV. 

V. 


Sample 
used. 

A 
A 
B 
B 
C 


HIO3  taken. 
Grm. 

0-1055 
0-1055 
0-1055 
0-1055 
0-I055 


HlOg  found. 
Grm. 

o'io66 
0-1062 
0-1065 
0-1073 
0-1053 


Error. 
Grm. 

o-ooii-H 

00007  + 
0-0010  + 
0-0018  + 
O-0003  — 


These  results,  which  are  averaged  from  a  large  number 
of  determinations,  show  that  while  the  deviation  from  the 
theoretical  strength  of  the  solution  in  the  case  of  the  acid 
prepared  from  anhydride  is  hardly  appreciable,  the  solu- 
tions made  from  the  purchased  produd  contain  a  very 
appreciable  amount  of  iodine  in  excess  of  the  theoretical 
quantity. 

To  determine  whether  a  solution  of  iodic  acid,  once 
prepared  and  standardised,  will  retain  its  strength  for  a 
long  time,  two  such  solutions  were  kept  for  four  months 
(in  the  dark)  and  then  again  analysed.  The  results 
(averages  of  several  determinations)  given  below  sub- 
stantiate Riegler's  observation  that  a  solution  of  iodic 
acid  will  remain  of  constant  strength. 


Iodic  acid 
solution. 

I. 
II. 


Comtancy  of  Strength  of  Iodic  Acid  Solutions 

Second  analysis 
First  analysis,    (after  four  months) 
HIO3  found.  HlOa  found. 

Grm.  Grm. 


0-1073 
0-1049 


0-1072 
0-1046 


Variation. 

Grm. 

Q-OOOI  — 

0-0003  ~ 


A  series  of  analyses  made  by  oxidising  the  sodium 
thiosulphate  to  sulphate  and  precipitating  and  weighing 
as  barium  sulphate,  gave  results  identical  with  those  ob- 
tained with  iodine ;  proving  that  all  the  sulphur  present 
was  in  the  form  of  thiosulphate. 

According  to  Riegler's  equation,  sodium  thiosulphate 
and  iodic  acid  read  molecule  for  molecule,  and  solutions 
of  them  should  therefore  require  for  their  mutual  satura- 
tion volumes  inversely  proportional  to  their  concentration. 
It  was  found,  however,  that  when  a  one-twentieth  normal 
solution  of  sodium  thiosulphate  was  titrated  in  the  pre- 
sence of  starch  with  an  approximately  decinormal  solu- 
tion of  iodic  acid,  a  distindtly  blue  colour  was  produced 
long  before  the  theoretical  amount  of  iodine  had  been 
added.  It  was  further  noticed  that  the  end-point  of  the 
readion  was  far  from  distindi;  a  faint  tint  of  blue  at  first 
being  visible,  then  suddenly  becoming  deeper,  and  imme- 
diately reappearing  when  bleached  with  sodium  thio- 
sulphate. It  was  found,  however,  that  the  addition  of  a 
considerable  quantity  of  potassium  iodide  to  the  solution, 
either  before  or  during  the  titration,  had  the  marked  efifedl 
of  making  the  reaction  sharp  and  distindt,  entirely  pre- 
venting the  '*  after  separation  "  of  iodine,  and  at  the  same 
time  postponing  the  appearance  of  the  starch-blue  until 
a  quantity  of  iodic  acid  had  been  added  considerably  in 
excess  of  the  theoretical.  The  experiments  were  executed 
with  entirely  different  reagents,  and  under  varied  condi- 
tions of  concentration,  the  results  in  every  case  confirming 
those  already  observed. 


For  the  purpose  of  more  particularly  investigating  this 
subjedt,  there  were  prepared  and  standardised  an  approxi- 
mately decinormal  solution  of  sodium  thiosulphate  and 
an  approximately  one-fiftieth  normal  solution  of  iodic 
acid.  Measured  portions  of  the  sodium  thiosulphate  so- 
lution were  titrated  with  the  iodic  acid  in  presence  of 
starch  under  varying  conditions  of  mass,  time,  and 
dilution. 

To  determine  the  variability  of  the  end-point  of  the 
readtion,  a  series  of  experiments  was  made.  Measured 
amounts  of  the  thiosulphate  solution  were  drawn  into 
an  Erlenmeyer  beaker,  5  c.c.  of  starch  were  |added,  and 
the  iodic  acid  slowly  dropped  in,  with  constant  agita- 
tion, until  the  first  blue  tint  appeared.  The  results  ob< 
tained  were  as  follows  : — 

Variation  of  the  End-reaction  bttwein  N/io  Sodium 
Thiosulphate  and  H I ^0  Iodic  Acid  in  the  Absence  of 
Potassium  Iodide. 


I. 
2. 
3- 
4. 
5. 
6. 

7- 
8. 

9- 
10. 
II. 
12. 


NajSaOa  taken.  rilOg  added. 
C.c.  C.c. 

6 
6 
6 
6 
6 
6 
6 
6 
4 
4 
4 
4 


Mean  value. 
C.c. 


28-32 


18-68 


Variation. 
C.c. 

0-19  — 

0-53- 
0-29  — 
o-oo 

0-00 

0-39+ 
0-51  + 
0-11  + 
0-26  + 
o-oi  — 
o-i8- 
0-08- 


These  experiments  indicate  that  the  constancy  of  the 
end  of  the  readion  in  different  titrations  of  equal  volumes 
of  the  same  solution  depends  to  a  certain  degree  on  the 
volume  of  sodium  thiosulphate  taken.  The  probable 
error  which  these  irregularities  would  introduce  in  any 
series  of  pradtical  analyses  by  this  method  is  obviously 
greater  than  can  ordinarily  be  permitted  in  iodometric 
work. 

The  experiments  in  the  following  table  were  performed 
in  exadly  the  same  manner  as  those  in  the  last  series, 
except  that  2  grms.  of  potassium  iodide  were  added  to 
the  sodium  thiosulphate  before  titrating. 

Variation  of  the  End  Reaction  between  N/io  Sodium 
Thiosulphate  and  N/50  Iodic  Acid  in  the  Presence  of 
Potassium  Iodide. 

NajSaOg  taken.  HIO3  added. 
C.c.  C.c. 

1.  6  32-53 

2.  6  32-45 

3.  6  32-67 
4-  6  32-37 

5.  6  32-36 

6.  6  32-50 , 

7.  4  22-30 

8.  4  21-98 

9.  4  22-17 
10.  4  22-30 , 


Mean  value. 
C.c. 


32-48 


22*19 


Variation. 
C.c. 

0-05  + 
003- 
0-19  + 
O'll  — 
0-I2  — 
0-02  + 
0-II-i- 
0'2I  — 
0-02  — 
0*II  + 


These  experiments  show  that  in  the  presence  of  iodide 
of  potassium  the  end  readion  is  pradically  independent 
of  the  amount  taken  for  analysis.  It  is  therefore  evident, 
from  studying  the  above  figures,  that  the  presence  of 
potassium  iodide  in  the  sodium  thiosulphate  to  be 
titrated  will  bring  the  variation  of  the  formation  of  the 
reading  tint  within  permissible  limits. 

Another  series  of  experiments  was  made  to  determine 
the  nature  and  effed  of  the  "  after  colouration  "  observed 
to  take  place  when  a  solution  of  sodium  thiosulphate,  free 
from  potassium  iodide,  was  titrated  with  iodic  acid  to 
blue  colouration  and  then  bleached  with  sodium  thio- 
sulphate.   The  results  are  given  below : — 


I  So 


Acetylene  Gas. 


t  Chemical  Nbws, 
>     oa.  8, 1897. 


Effect  of  Dilution  and  Lapse  of  Time  on 
"After  Colouration." 

NajSzOg  added.    C.c. 


the 


NajSjC 
taken 

3  HIO3 

added. 

15 

45 

I  hr.  45 

2hrs. 

20 

Vol. 

C.c. 

C.c. 

inins. 

mins. 

mins. 

45  mins.  hrs. 

Total. 

C.c. 

I. 

6 

2768 

0*25 

013 

0-08 

o-co 

0*03 

0-49 

50 

2. 

6 

2770 

0-20 

O'lO 

0-03 

0-03 

0-03 

0-39 

50 

3- 

6 

28-17 

016 

O'lO 

0-03 

0"0I 

o-oo 

0-30 

50 

4- 

6 

27-03 

o-6o 

0-26 

0*09 

003 

O*0O 

0-98 

150 

5- 

6 

27  60 

093 

0-28 

o-o6 

0  04 

0*04 

1-35 

150 

6. 

6 

2860 

1-34 

0-46 

0-17 

0-03 

0*14 

2-14 

200 

7- 

6 

28-85 

1-20 

0-50 

0-28 

0-06 

0*27 

2-31 

200 

8. 

6 

31-63 

1-46 

074 

o-io 

0'2I 

0-23 

274 

250 

9- 

6 

29  90 

1-04 

o'6o 

0*23 

0-15 

0-46 

2-48 

250 

10. 

6 

36-09 

I  60 

1-23 

0-63 

0-34 

o-i8 

3'9« 

300 

II. 

6 

3759 

lbs 

1-33 

0-72 

0-27 

o-io 

4-07 

300 

12. 

6 

3723 

1-92 

1-05 

0-64 

0-33 

— 

300 

♦ 

No  observation. 

In  the  experiments  with  small  volumes,  the  evolution 
of  iodine  in  any  quantity  ceased  after  two  or  three  hours, 
though  the  solution  would  become  coloured  as  often  as  it 
was  bleached  for  a  number  of  days.  The  traces  of  iodine 
thus  set  free  were,  however,  only  equivalent  to  one  or  two 
drops  of  sodium  thiosulphate,  but  the  larger  volumes  con- 
tinued to  liberate  iodine  in  abundance  for  a  very  long 
time.  The  amount  of  iodine  thus  liberated  after  the  first 
colouration  evidently  varies  with  the  amount  of  iodic  acid 
required  for  the  titration;  both  of  these  quantities  increase 
at  a  regular  rate  with  the  volume  of  the  solution. 

To  try  with  what  accuracy  the  reaction  between  sodium 
thiosulphate  and  iodic  acid  may  be  applied  to  the  diredt 
estimation  of  one  of  these  substances  by  the  other,  the 
averaged  results  of  a  large  number  of  titrations  are  here 
given.  The  operations  were  conduced  as  diredled  by 
Riegler,  equal  volumes  of  standard  thiosulphate  being 
titrated  with  iodic  acid  of  known  strength  in  the  presence 
of  starch,  and  under  different  conditions  of  time,  dilution, 
and  mass,  the  volume  of  iodic  acid  required  being  in 
each  case  compared  with  the  volume  theoretically  re- 
quired by  Riegler's  equation. 

Titration  of  N/io  Sodium  Thiosulphate  with  N/50 
Iodic  Acid. 
HIO, 


NaoSjOa 

talcen. 

C.c. 

4 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 


t- 


HIO, 

added. 
C.c. 

/18-68 
2832 
27-32 
28-73 

.30-77 
36-97 

f  27-46 
26-15 
26-50 
27-16 

V32'93 
22-19 
32-48 


required 

by  theory. 

C.c. 

20-32 
30-48 
30-48 
3048 
30-48 
30-48 
30-48 
30-48 
30-48 
30-48 
30-48 
20-32 
30-48 


Error. 

C.c. 
1-64  — 
2-i6  — 
3-16- 
1-75- 
0-29  + 
6-49  + 
302- 
4-33- 
3-98- 
3-32- 
2-45  + 
1-87  + 
2-00+ 


Error.   Present.  Vol. 


Per  cent. 
8-0- 
7-0- 
7-0- 
6-0- 

0-01  + 

21-0+ 
lo-o  — 
14-0  — 
13-0- 

lO-O  — 

8-0+ 
9-0  + 
7-0  + 


Grm. 


C.c. 

50 
50 
150 
200 
250 
300 
50 
150 
200 
250 
300 
50 
50 


10. 

II. 

12.  4  ,122-19        20-32         i-»7+         9-0+       0-2 

13.  6      (32-48        30-48        2-00+         7-0+       02 

*  HIO3  added  until  first  blue  colour. 

\  Calculated  by  subtraiAing  from  the  amount  of  iodic  acid  origin- 
ally titrated  the  volume  of  thiosulphate  required  to  bleach  the  solu- 
tion after  standing  twenty  hours. 

These  results  show  plainly  that  the  amount  of  iodic 
acid  required  to  decompose  a  given  amount  of  sodium 
thiosulphate  may  be  considerably  above  or  below  that 
required  by  Riegler's  equation.  Thus,  with  small  volumes, 
and  in  the  absence  of  potassium  iodide,  the  thiosulphate 
is  destroyed,  and  the  separation  of  iodine  commences 
when  only  93  per  cent  of  the  theoretical  amount  of  acid 
has  been  titrated.  At  higher  dilutions  the  a(5tion  is 
retarded,  so  that  at  250  c.c.  very  nearly  the  theoretical 
amount  of  acid  is  required  to  produce  the  first  blue  colour, 
and  at  300  c.c.  an  excess  of  21  per  cent  over  the  theoreti- 


cal amount  must  be  added,  and  it  appears  that  for  all 
volumes  below  300  c.c.  the  original  thiosulphate  is 
destroyed  when  about  90  per  cent  of  the  theoretical 
amount  of  iodic  acid  has  been  added.  Potassium  iodide 
retards  the  adlion,  so  that  at  small  volumes  an  excess  of 
about  8  per  cent  of  iodic  acid  must  be  added  to  completely 
destroy  the  thiosulphate  and  commence  the  separation 
of  iodine.  It  is  obvious  from  the  preceding  experiments 
that  the  readlion  between  iodic  acid  and  sodium  thio- 
sulphate is  so  indefinite  in  its  nature,  and  so  dependent 
for  its  completeness  on  conditions  of  time,  dilution,  and 
mass,  that  its  diredt  application  as  a  means  of  standard- 
ising solutions  must  remain  impradicable. 


ACETYLENE    GAS. 

The  Explosives  Deparment  of  the  Home  Office  has 
recently  had  under  consideration  the  question  of  the 
restridtions  to  be  applied  to  the  manufadlure  and  keeping 
of  acetylene  gas,  and  has  conduded  various  experiments 
with  the  objedt  of  gaining  information  on  this  matter. 
The  results  show  conclusively  that  acetylene  gas  per  se, 
when  under  a  pressure  of  something  less  than  two  atmo- 
spheres, is  violently  explosive ;  whereas  at  a  pressure  of 
less  than  one  and  a  half  atmospheres  it  appears  to  be 
reasonably  free  from  liability  to  explosion,  provided  it  is 
not  admixed  with  oxygen  or  atmospheric  air. 

For  commercial  and  pradtical  purposes  it  is  considered 
sufficient  to  allow  a  pressure  of  20  inches  of  water  above 
that  of  the  atmosphere  {i.e.,  roughly,  about  one  and 
one-twentieth  atmospheres),  and  it  is  accordingly  pro- 
posed to  draw  the  safety  line  at  this  point,  and  to  declare 
acetylene  when  subjedt  to  a  higher  pressure  to  be  an 
"  Explosive  "  within  the  meaning  of  the  Explosives  Adt, 

1875- 

In  France  and  Germany  the  authorities  have  fixed  the 
limit  of  danger  at  one  and  a  half  and  one  and  one-tenth 
atmospheres  respedlively,  and  have  imposed  prohibitions 
or  restridions  on  the  keeping  or  manufadlure  of  the  gas 
when  it  is  at  a  higher  pressure. 

Whitehall,  Oftober  5, 1897. 


NOTICES  OF  BOOKS. 


An  Electrical  Method  of  Determining  the  Moisture  Content 

of  Arable  Soils.    By  M.  Whitney,  D.  Gardner,  and 

L.  J.   Briggs.      Washington :    Government   Printing 

Office.     1897. 

The  only  method  in  general   use  for  determining  the 

moisture  in  soils    is  the   very  simple  one   of    taking   a 

sample  of  the  soil  from  the  field,  at  any  desired  depth, 

and  drying  it  at  100°  C. ;  but  from  a  large  number  of 

observations  it  is  found  that  this  method  is  not  accurate 

to  within  2  per  cent,  plus  or  minus. 

Another  method  which  has  been  tried  is  that  of  burying 
bricks  about  8  inches  below  the  surface,  and  taking  them 
up  and  weighing  them  day  by  day ;  this  method  is 
obviously  of  no  use  whatever.  The  possibility  of  using 
the  eledrical  resistance  of  soils  for  the  determination  of 
moisture  was  suggested  by  the  necessity  of  getting  a 
good  "  earth  "  for  lightning  condudtors,  &c. 

Soils  are  composed  of  fragments  of  various  minerals 
and  salts,  all  more  or  less  soluble  in  water ;  even  quartz 
is  slightly  soluble  in  water  containing  carbonic  acid,  as 
soil  waters  usually  do,  and  this  dilute  solution  condudts 
the  eledtrtc  current.  The  specific  resistance  of  a  solution 
is  the  iresistance  of  i  c.c.  of  liquid  between  two  parallel 
eledtrodes  i  cm.  square  and  i  cm.  apart,  and  the  specific 
condudtivity  as  used  in  this  Bulletin  is  the  reciprocal  of 
the  specific  resistance. 


Crbmical  Nsws,  I 
oa.8, 1897.    I 


Manufacture  of  A  rtificial  Mineral  Waters. 


181 


The  Wheatstone  Bridge  method  was  used  with  an 
alternating  current  and  a  telephone  in  place  of  a  galvano- 
meter. The  eledrodes  finally  adopted  for  field-work 
consist  of  carbon  plates,  each  3  inches  long,  |  inch  wide, 
and  ^\  inch  thick,  copper-plated  at  one  end,  to  which 
a  copper  wire  was  soldered ;  the  plates  can  be  placed  at 
any  desired  depth,  but  i  to  2  feet  has  been  found  the  most 
convenient ;  but  we  are  unable  to  find  any  definite  state- 
ment as  to  how  far  apart  they  are  placed.  The  whole 
apparatus  is  standardised  by  comparing  the  readings  with 
a  number  of  observations  taken  by  the  old  method,  and  a 
table  of  values  is  construdted. 


An  Electrical  Method  for  Determining  the  Temperature  of 
Soils.  By  M.  Whitney  and  L.J.  Briggs.  Washington : 
Government  Printing  Office.  1897. 
In  perfeifting  the  electrical  method  of  determining  the 
moisture  in  soils,  a  compensation  cell,  having  the  same 
eledrical  temperature  coefficient  as  the  soil,  is  used  as 
one  arm  of  the  Wheatstone  Bridge,  in  order  to  eliminate 
temperature  effedts  in  determining  the  eledrical  resistance 
of  soils,  and  this  cell  can  be  very  easily  used  for  taking 
the  temperature  of  the  soil. 

These  cells  are  construdled  of  small  strips  of  glass, 
cemented  together  with  marine  glue;  their  dimensions 
are  3  inches  X  2  inches  X  i  inch  ;  the  eledrodes  consist 
of  strips  of  carbon,  to  which  wires  are  soldered,  cemented 
to  the  glass.  They  are  then  standardised,  and  the 
resistance  reduced  to  a  common  standard,  viz.,  1000 
ohms  at  eo**  F.  on  being  buried,  and  readings  taken 
with  the  Wheatstone  Bridge  ;  the  temperature  is  arrived 
at  by  calculation. 

An  Electrical  Method  of  Determining  the  Soluble  Salt 
Contents  of  Soils.  By  M.  Whitney  and  T.  H.  Means. 
Washington:  Government  Printing  Office.     1897. 

A  VERY  simple  and  delicate  method  has  been  devised  for 
determining  the  soluble  salt  contents  of  soils,  in  samples 
taken  from  the  field.  The  method  consists  essentially  of 
mixing  a  known  quantity  of  a  soil  with  a  known  propor- 
tion of  pure  water,  and  determining  the  specific  resistance  ; 
then  an  equal  weight  of  the  same  soil  is  mixed  with  a 
weak  salt  solution  equal  in  volume  to  the  pure  water 
added,  and  the  specific  resistance  again  taken  ;  the  amount 
of  salt  added  being  accurately  known,  and  also  the  effeft 
it  had  on  lowering  the  resistance,  it  is  easy  to  calculate 
the  quantity  of  salts  originally  present  in  terms  of  the 
salt  solution  used. 


Moser,  and  Breguet,  the  stratified  discharge  of  Crookes, 
the  experiments  of  Hertz  and  Lenard,  and  finally 
Rontgen's  discovery,  are  described  and  discussed. 

Chapters  II.  and  III.  are  devoted  to  the  enumeration 
of  the  different  sources  of  eledlrical  energy,  eledrolysis, 
accumulators,  &c. ;  while  in  Chapters  IV.  and  V.  dynamo- 
eledlric  and  eledrostatic  machines  are  dealt  with.  We 
next  come  to  currents  of  high  frequency,  radiations  both 
invisible  and  of  intense  therapeutic  adtion,  no  longer  in  a 
vacuum,  but  permeating  the  atmosphere  with  the  greatest 
ease.  A  lot  of  apparatus  of  special  forms,  adapted  to 
medical  wants,  is  described  in  the  succeeding  chapters, 
together  with  the  methods  of  manufadlure,  pumps, 
coils,  &c. 

The  form  of  the  bulbs  has  been  varied  considerably  by 
different  workers,  but  they  may  be  divided  into  three 
groups, — those  in  which  the  cathodic  rays  adt  diredlly  on 
the  sides  of  the  glass  tube  itself,  those  where  the  cathodic 
rays  are  concentrated  on  some  sort  of  a  mirror  which 
refledts  them,  and  those  in  which  the  two  preceding  ones 
are  combined.  The  first  is  the  most  simple,  but  the 
second  form  is  more  pradticable  and  is  the  one  mostly 
used,  the  indiredl  adlion  being  much  more  intense,  and 
requiring  a  shorter  time  to  obtain  good  results. 

The  radioscope,  which  we  find  in  Chapter  XIV.,  enables 
us  to  see  at  once  certain  parts  of  the  interior  of  human 
bodies,  as  well  as  through  other  substances,  and  a  very 
good  illustration  shows  the  manner  of  its  application. 
It  is  now  being  extensively  used  in  the  French  hospitals, 
not  only  for  examining  broken  bones  or  searching  for 
bullets,  but  also  for  diagnosing  diseases,  such  as  pleurisy, 
tuberculosis,  gout,  rheumatism,  &c.,  while  the  internal 
deformities  in  women  caused  by  tight  lacing  are  very 
easily  detedted.  In  fadl,  it  is  medical  and  surgical  science 
that  has  benefitted  principally  by  the  discovery  and  appli- 
cation of  the  X  rays. 

The  volume  is  one  of  great  interest  and  fascination  ;  it 
is  well  printed,  on  good  paper;  it  has  but  one  fault,  one 
very  common  to  French  books — there  is  no  Index. 


A  Treatise  on  Medical  and  Scientific  Radiography. 
("  Traite  de  Radiographic  Medicale  et  Scientifique.") 
By  Dr.  Foveau  de  Courmelles.  Pp.  470,  with  176 
Illustrations.  Paris:  Odlave  Doin.  1897. 
Professor  Rontgen's  discovery,  that  the  X  rays  emitted 
by  a  Crookes  tube  affedted  a  sensitised  photographic 
plate,  is  only  of  recent  date,  being  first  made  known  at 
the  latter  end  of  1895  ;  but  already,  in  this  short  space  of 
time,  enormous  developments  have  been  made  in  the 
subjedt,  more  especially  in  connedlion  with  surgery,  and 
the  subsequent  discovery  of  the  phosphorescent  screen 
enables  us  not  only  to  photograph  the  internal  organs,  but 
pradtically  to  see  them.  A  great  deal  has  already  been 
written  on  this  subjedl,  but  mostly  in  the  form  of  papers 
and  articles.  The  large  volume  now  before  us  treats  of 
the  whole  subjedt  from  its  beginning  up  to  as  far  as  it  is 
at  present  understood,  and  the  author  states  that  if  his 
book  rapidly  becomes  old-fashioned  he  will  be  the  more 
happy,  as  it  will  show  that  we  are  making  further  advances 
in  our  knowledge  of  the  subjedt. 

In  Chapter  I.  the  early  experiment  of  the  Abbe  Nollet, 
in  17531  is  first  mentioned,  but  we  rapidly  come  to  more 
modern  times,  when   the    so-called    "black  light"  of 


The  Manufacture  of  Artificial  Mineral  Waters  and  other 

Ejffervescent  Beverages.     ("  Die  Fabrikation  der  Kiinst- 

lichen    Mineral    Wasser    und     anderer    Mousserende 

Getranke."     By  Dr.  B.  Hirsch  and  Dr.  P.  Siedler. 

Third  Edition,  with  103  figures.     Brunswick:  Vieweg 

and  Sons.     1897.    8vo.,  pp.  386. 
The  work  before  us  is  written  not  merely  in  the  German 
language,  but  most  decidedly  from  a  German  point  of 
view. 

The  authors  treat,  in  the  first  place,  of  mineral  waters 
in  general,  of  the  origin  and  ingredients  of  the  springs, 
of  the  changes  to  which  they  are  liable,  their  synthesis 
and  classification.  Their  classification  is  complicated,  as 
it  is  founded  both  on  chemical  and  medicinal  considera- 
tions, or  on  a  combination  of  these  two  points  of  view. 

Thus  we  have  here  alkaline  waters,  sulphate  of  soda 
waters,  chalybeate  brines,  bitter  waters,  sulphated  waters, 
earthy  or  calcareous  waters,  neutral  thermae,  and  poor  in 
mineral  matters. 

As  a  distindl  class  are  mentioned  semi-natural  mineral 
springs.  Here  comes  the  admission  that  relatively  few 
springs  possess  well-marked  medicinal  properties,  but  serve 
merely  as  a  base  for  the  addition  of  drugs. 

There  exist  also  "  semi-mineral  waters,"  to  which  ex- 
traneous matter  has  been  added  to  improve  the  taste  ;  the 
principal  of  these  additions  is  carbonic  acid,  which  is 
employed  both  as  a  gas  and  as  a  liquid. 

The  admittedly  artificial  mineral  waters  were  men- 
tioned by  Pliny,  and  in  modern  times  were  produced  by 
Priestley  and  Lavoisier,  and  in  1787  artificial  Selzer 
water  was  produced  on  the  large  scale  by  Meyer  of 
Stettin,  and  the  manufadture  is  still  flourishing.  Some 
of  the  artificial  waters  consist  merely  of  water  saturated 
with  carbonic  acid,  but  in  other  cases  soluble  salts  are 


ig; 


Chemical  Notices  Jrom  Foreign  Sources, 


/  Chemical  News, 
\    oa.  8, 1897. 


added.  The  greatest  care  is — or  ought  to  be— used  in 
the  seledion  of  the  water.  It  should  be  colourless  and 
inodorous,  even  when  warmed  and  exposing  an  extensive 
surface.  Nor  should  it  have  a  sweetish,  bitter,  chalybeate, 
inky,  saline  savour. 

It  IS  to  be  noted  that  the  non-European  mineral  springs 
have  been  overlooked.  This  is  to  be  regretted.  South 
Africa  is  exceptionally  rich  in  mineral  waters,  as  was 
shown  in  the  Indian  and  Colonial  Exhibition,  The 
question  arises  whether  the  importation  and  sale  of  South 
African  waters  should  not  be  promoted  in  this  country,  so 
as  to  take  the  place  of  those  from  the  European  Conti- 
nent, which  by  vigorous  advertising  have  almost  secured 
a  monopoly  of  the  home  market. 


;tal   as  far  as  I 


The  Organised  Science  Series.  First  Stage  :  Sound,  Light, 
and  Heat.  By  John  Don,  M.A.,  B.Sc,  London : 
W.  B.  Clive,  University  Correspondence  College  Press. 
Pp,  307. 

This  book  is  ably  and  clearly  written,  and  no  one  need 
search  for  errors  in  its  teachings  unless  anxious  to  lose 
his  labour.  At  the  same  time  it  is  most  peculiar,  and  we 
may  venture  to  say  unhappy.  It  is  examinational  to 
the  core,  and  boasts  of  the  number  of  Correspondence 
College  students  who  have  "  passed  "  during  the  last  five 
years.  How  many  of  them  have  made  any  discovery — 
in  other  words,  have  contributed — to  the  sum  total  of 
human  knowledge  we  are  not  informed.  We  may  perhaps 
be  pardoned  for  doubting  whether  the  author  considers 
this  the  grand  objed  to  be  aimed  at  by  a  University,  or  is 
not  perhaps  fully  content  with  securing  for  his  students 
exhibitions,  scholarships,  and  "  places  in  honours." 


CORRESPONDENCE. 


SUPPOSED    NEW    ELEMENT    WITH     IRON, 

To  the  Editor  of  the  Chemical  News. 
Sir, — In  last  week's  number  of  the  Chemical  News 
(vol,  Ixxvi.,  p.  171)  I  noticed  a  letter  from  Mr.  Jones,  in 
which  he  suggests  that  the  metal  I  separated  from  iron 
might  prove  to  be  molybdenum.  The  properties  of  the 
metal  do  certainly  resemble  those  of  molybdenum  very 
closely — a  fadt  of  which  I  have  been  fully  aware.  In  my 
first  notes  on  the  readions  of  the  metal  I  find  that  "  a 
solution  of  the  metal  heated  with  Na2HP04  and  a  few 
drops  of  HNO3  produce  no  precipitate."  How  I  managed 
to  leave  out  this  readion  in  my  article  in  the  Chemical 
News  I  really  do  not  know.  The  metal  has  been 
repeatedly  tested  since  then  for  molybdenum,  but  without 
success, 

I  have  during  the  last  week  gone  over  the  readtions  of 
the  metal,  the  metal  used  being  specially  prepared  for  the 
purpose.  I  could  find  no  traces  of  molybdenum,  nor  was 
I  able  to  find  any  fault  with  the  readtions  of  the  metal  as 
described  in  my  article  in  the  Chemical  News, 

I  have  also  specially  prepared  some  metal  from  boiler- 
dust  ;  it  was  most  carefully  tested  for  molybdenum,  but 
without  success. 

A  small  quantity  of  metal  obtained  from  boiler-dust 
a  considerable  time  ago  yielded  a  very  small  quantity  of 
molybdenum,  but  not  sufficient  to  interfere  with  the  reac- 
tions of  the  metal  from  which  it  was  separated. 

The  fadt  that  the  metal  is  precipitated  by  zinc  (the 
charadteristic  blue  colour  produced  by  the  adtion  of  zinc 
on  molybdenum  being  conspicuous  by  its  absence),  that  it 
combines  with  hydrogen  (producing  a  gas  from  which  the 
metal  can  easily  be  deposited),  and  that  it  is  not  precipi- 
tated by  Na2HP04  and  HNO3  when  warmed,  led  me  to 
believe  that  the  metal  was  not  molybdenum,  as  these  are 


I  certainly  not  properties  of  the  latter  met 
know. — I  am,  &c., 

Gethen  Boucher. 

The  Laboratory, 

North  Lonsdale  Iron  and  Steel  Company,  Lim., 

Ulverston,  Lancashire,  Oftober  6,  1897. 


CHEMICAL 


NOTICES   FROM 
SOURCES. 


FOREIGN 


Note.— All  degrees  oftemperature  are  Centigrade  unless  otherwise 
expressed. 

Moniteur  Scientifique, 
Series  4,  Vol.  xi.,  Part  2, 
Review  of  Photography,— A.  Granger.— According  to 
recent  information  the  Americans  have  been  for  some  time 
using  chromo-photography  for  printing  advertisement 
posters.  This  has  been  done  by  means  of  three  mono- 
chromes, and  the  following  solutions  have  been  recom- 
mended. For  violet— 7  c.c.  of  concentrated  solution  of 
cupric  chloride,  17  c.c.  of  water,  and  3  c.c.  of  ammonia; 
after  filtration  3  c.c.  of  concentrated  methyl  violet  B  and 
5  c.c.  of  fuchsine  is  added.  For  orange— 15  c.c.  of  con- 
centrated solution  of  chloride  of  cobalt,  35  c.c.  of  water, 
25  c.c.  of  bichromate  of  ammonium,  and  2  c.c.  of  ammonia. 
For  green— a  solution  of  sulphate  of  nickel.  These  solu- 
tions are  placed  in  reservoirs  of  plate  glass  Jth  of  an  inch 
thick. 

New  Methods  of  Converting  Paranitrodiamino- 
triphenylmethanes  into  Fuchsines,  or  into  Bases  of 
the  corresponding  Fuchsines.— Maurice  Prud'homme. 
— Already  noticed. 

Contribution  to  the  Study  of  the  Formation  of 
Amylic  Alcohol  in  Commercial  Fermentations.  — 
Lucien  Gentil.— The  presence  of  amylic  alcohol  in  indus- 
trial fermentations  has  always  been  observed  in  more  or 
less  quantity,  and  the  question  of  whether  this  alcohol 
was  a  constant  produdt  of  alcoholic  fermentation,  as  are 
succinic  acid  and  glycerin,  has  been  the  subjedt  of  a  good 
deal  of  discussion,  and  the  author  is  led  to  conclude  that 
it  is  not  formed  in  a  perfedlly  sterile  medium,  which  is 
then  infedled  with  a  pure  cultivation  of  yeast. 

Some  Reainions  of  Phospham.— R.  Vidal.— When 
phospham,  PN2H,  is  heated  to  a  bright  or  strong  red  heat 
in  the  presence  of  alkaline  carbonates  the  following  reac- 
tion  takes  place  :— PN2H-f2C03R2  =  P04R2H-f-2CN0R. 
That  is  to  say,  an  alkaline  cyanate  is  formed  ;  the  intro- 
dudtion  of  a  reducing  agent,  such  as  carbon,  into  the 
mixture  gives  an  alkaline  cyanide.  If  iron  is  used  instead 
of  carbon  a  ferrocyanide  is  produced,  and  with  sulphur  a 
sulphocyanide.  Methylic  and  ethylic  alcohols  readt  on 
phospham,  giving  a  free  secondary  amine  and  the  meta- 
phosphate  of  a  primary  amine.  The  readlion  of  phospham 
on  normal  propylic  alcohol  is  more  complex,  for  besides 
the  formation  of  propylamine  we  observe  a  notable  quan- 
tity of  oxide  of  propyl.  With  ethylenic  glycol  the  readtion 
is  entirely  reversed,  and  a  complete  dehydration  only  is 
observed;  the  phospham  taking  away  two  molecules  of 
water,  forming  di-ammonium  orthophosphate  and  setting 
acetylene  at  liberty. 


Bulletin  de  la  Societi  d' Encouragement  pour  P Industrie 
Nationale.     Series  5,  Vol.  ii.,  No,  8,  August,  1897, 

Report  on  M.  Gossart's  Acetylene  Lamp, —  M, 
Violle  (for  the  Committee  of  Economic  Arts). — In  this 
lamp  the  acetylene  is  generated  as  is  usual  by  the  adlion 
of  water  on  carbide  of  calcium,  but  its  inventor  has  made 
use  of  the  adlion  of  capillary  tubes,  whereby  the  water  is 
brought  in  contadt  with  the  carbide  in  very  minute  quan- 


Chbmical  Nswfe,  I 

oa.  8, 1897.     f 


chemical  Notices  from  Foreign  Sources, 


183 


titles,  and  automatically  only  in  the  quantity  required. 
By  turning  off  the  water  tap  and  the  gas  outlet  tap  at  the 
same  time  the  apparatus  ceases  to  work,  and  no  more  gas 
is  formed  until  both  taps  are  turned  on  again.  By  turning 
off  the  water  tap  only,  the  disengagement  of  gas  becomes 
slower,  and  gradually  stops.  If,  on  the  other  hand,  the 
gas  tap  only  is  turned  off,  the  gas  continues  to  be  evolved 
until  the  pressure  is  sufficient  to  drive  back  the  water  in 
the  capillary  tubes,  which  thus  a.&.  as  a  safety  valve.  The 
production  of  gas  is  thus  intimately  dependent  on  its  con- 
sumption. 

journal  de  Pharmacie  et  Chemie. 
Series  6,  vol  vi..  No.  3. 

Decomposition  of  Iodoform  by  Light. — G.  Fleury. — 
There  is  a  great  diversity  of  opinion  with  regard  to  the 
adtion  of  light  on  iodoform  ;  the  author  shows  that,  as  a 
rule,  this  decomposing  adion  is  of  very  limited  extent,  and 
he  thinks  that  this  limit  may  be  attributable  to  immediate 
colouring  of  the  liquid  to  reddish  brown  by  the  liberated 
iodine  stopping  the  violet  and  ultra-violet  rays  on  the 
surface,  and  thus  preventing  the  continuance  of  the  che- 
mical readlion.  With  the  idea  of  proving  the  correctness 
of  this  theory,  some  iodoform — dissolved  in  a  mixture  of 
alcohol  and  ether — was  placed  in  a  flask  of  white  glass, 
in  the  presence  of  an  excess  of  finely  divided  silver.  It 
was  then  exposed  to  sunlight,  both  dire(5t  and  diffused, 
and  frequently  shaken  to  accelerate  the  combination  of 
the  liberated  iodine  with  the  silver.  After  several  days, 
the  liquid  no  longer  became  coloured,  and  on  colledting 
and  weighing  the  mixture  of  silver  and  iodide,  the  amount 
of  iodine  resulting  from  the  decomposition  was  calculated 
and  found  to  be  the  exadt  theoretical  amount. 

On  the  Essence  of  Bitter  Fennel.— E.  Tardy.— The 
result  of  this  research  shows  that  the  essence  of  cultivated 
French  bitter  fennel  contains  a  dextro-divalent  turpentinic 
carbide,  a  dextio-tetravalent  terpene,  an  inadtive  carbide 
called  cymen,  fenone,  estragol,  anethol,  anisic  aldehyd, 
anisic  acetone,  anisic  acid,  and  a  crystalline  body  corres- 
ponding to  the  formula  C13H14O2. 

Estimations  of  Commercial  Albumen . — P.  Carles.^ 
Already  noticed. 

Colorimetric  Reaction  of  Disulpburic  Acid. — 
£.  Barral. 

Analysis  of  an  Artificial  Roasted  Coffee. —  F. 
Coreil. — The  sample  examined  was  found  to  be  made  by 
moulding  a  mixture  of  flour  and  husk  of  wheat,  potato, 
leguminous  fiour,  gum,  vegetable  refuse,  &c.,  and  to  con- 
tain none  of  the  elementary  constituents  of  true  coffee 
berries. 


BuUetin  de  la  Societe  Chimique  de  Paris. 
Series  3,  Vol.  xvii.-xviii..  No.  15. 

M.  Tanret  delivered  a  discourse  on  the  lamented  death 
of  M.  Schiitzenberger,  paying  tribute  to  his  bold  and  lofty 
views,  aided  by  a  rare  talent  of  observation  and  experi- 
mentation. Thanks  to  his  numerous  researches,  of  which 
only  a  small  number  could  be  here  mentioned,  the  name 
of  Schiitzenberger  will  live  for  ever  in  Science,  and  will 
find  a  place  among  the  foremost  of  modern  chemists. 

M.  Tanret  presented  a  note,  on  behalf  of  M.  Sabatier, 
«'  On  Blue  Nitrodisulphonic  Acid  and  some  of  its  Salts." 

On  Exadt  Cryoscopy.  Correjftion  for  SurfusiOn> 
and  a  Means  of  Recognising  a  Good  Cryoscopic 
Method.  —  A.  Ponsot.  —  Amongst  the  methods  used  for 
making  the  corredion  foi  surfusion,  that  of  M.  Raoult 
consists  of  finding  experimentally  the  points  of  congela- 
tion of  the  solution  A',  A",  corresponding  to  degrees  of 
surfusion  5',  i",  &c.  ;  a  graphic  curve  gives  A.  The 
variation  for  1°  of  surfusion  from  the  point  of  congela- 
tion observed  in  a  solution  divided  by  the  lowering  is 
called  K.    He  shows  that  K  is  variable  with  the  concen- 


tration of  a  solution,  and  with  the  nature  of  the  body 
dissolved. 

On  a  Colorimetric  Readlion  of  Disulphuric  Acid. 
— E.  Barral. 

On  the    Thermic    Study  of    Suberic    Acid.  —  G. 

Massol.  —  Suberic  acid  occurs  in  the  form  of  brilliant 
white  laminated  crystals,  melting  at  139-5°,  and  slightly 
soluble  in  cold  water.  It  forms  suberate  of  potash  easily 
at  the  ordinary  temperature.  The  neutral  salt  dried  at 
100°  is'  anhydrous,  and  easily  dissolves  in  water.  The 
acid  suberate  of  potash  is  very  little  soluble  in  water  ; 

^  its  heat  of  solution  at  about  40'  is  5*26  calories,  that  of 

\  the  neutral  salt  being  0*92  calories. 

On  the  Thermic  Study  of  Sebacic  Acid.  —  G. 
Massol.  —  The  acid  salts  of  potash  and  soda  are  but 
slightly  soluble  in  water;  the  anhydrous  neutral  sebate 
of  potash  dissolves  in  absorbing  i-33  calories.  The  heat 
of  formation  of  neutral  suberate  of  potash  is  considerable 
for  an  acid  of  so  high  a  molecular  weight,  viz.,  43*99 
calories. 

General  Considerations  on  the  Normal  Di-acids 
of  the  Oxalic  Series.— G.  Massol.— The  heats  of  forma- 
tion of  the  neutral  anhydrous  salts  of  potash  for  the  six 
acids  the  author  has  studied  are  as  follows  :— C2,  oxalic, 
=  58-97  cals. ;  C3,  malonic,  =48-57  cals.;  C4,  succinic, 
=46-40  cals. ;  C5,  glutaric,  =44-23  cals. ;  Cs,  suberic, 
=44-76  cals. ;  Cio,  sebacic,  =43-99  cals.  ;  2  molecules  of 
acetic  acid  =4372  cals.  He  considers  that  the  quanti- 
ties of  heat  which  measure  the  chemical  affinity  decrease 
as  the  molecular  weights  increase,  the  heat  of  formation 
tends  to  become  low,  the  reciprocal  influence  of  two 
carboxyls  decreases  very  rapidly  by  the  introdudtion  of 
one  or  two  CH2  intermediaries.  The  influence  of  two 
carboxyls  ought  to  betray  itself  by  the  possibility  of  the 
formation  of  internal  anhydrides.  The  acid  normal 
alcohols  of  the  ladtic  series  present  analogous  fadts  ;  for 
instance,  the  reciprocal  influence  of  acid  oxhydriles  and 
alcohol  is  shown  by  the  formation  of  ladlones. 

On  Acetylmethylheptenone. —  Ph.  Barbier  and  G. 
Leser.— Acetylmethylheptenone  soda,  treated  with  iodide 
of  ethyl,  gives  ethylacetylraethylheptenone,  boiling  at 
133—135°  under  15  m.m.  pressure. 

Contribution  to  our  Knowledge  of  Aliphatic 
Nitramines.— A.  P.  N.  Franchimont.— All  the  aliphatic 
nitramines,  acid  and  neutral,  when  treated  with  an  acetic 
solution  to  which  is  added  either  a-naphthylamine, 
aniline,  dimethylaniline,  &c.,  give,  with  a  scrap  of  zinc, 
either  yellow,  red,  or  green  colouring-matters.  Nitrourea 
behaves  in  the  same  manner.  The  detailed  examination 
only  of  one  of  these  colours  can  throw  any  light  on  this 
readtion. 

Boiled  Milk.— Experiments  undertaken  by  Dr.  Cha« 
mouin,  first  on  kittens  and  afterwards  on  infants,  show 
that  those  fed  on  boiled  milk  thrive  much  better  than 
those  fed  only  on  milk  in  its  natural  state.  Not  only  does 
the  boiling  sterilise  the  milk,  but  it  also  renders  it  much 
more  easy  of  digestion.  The  milk  must  of  course  be  kept 
covered  after  it  is  boiled.— rA«  Public  Health  journal 
(New  York),  August,  1897. 

A  Rapid  and  PracStical  Method  for  Determining 
Carbon  in  Iron.  —  J.  George  Heid.  —  The  sample  is 
treated  with  copper  ammonium  chloride  in  the  usual 
manner,  and  the  separated  carbon  is  colledled  on  an 
asbestos  filter,  where  it  is  washed  successively  with  water 
alcohol,  and  ether;  it  is  then  transferred  to  a  Rose  cru- 
cible, dried  at  120°,  and  weighed.  A  stream  of  oxygen  is 
led  into  the  crucible  which  is  heated  over  a  Bunsen 
flame,  and  the  carbon  is  thus  burned  off  in  from  three  to 
five  minutes  ;  the  difference  in  the  weight  is  the  "  total 
carbon."  The  "graphitic  carbon"  is  obtained  by  dis- 
solving  the  iron  in  dilute  hydrochloric  acid  and  determining 
the  separated  carbon  as  before.  —  Eng.  Min,  j^ourn., 
Ixiii.,  64. 


1 84 


Cause  of  Arsenical  Poisoning  by  Wall  Papers, 


{Obbuical  News, 
oa.  8, 1897. 


MISCELLANEOUS. 

Improvements  in  the  Colorimetric  Tests  for 
Copper.  —  George  L.  Heath.  —  Standard  ammoniacal 
copper  solutions  which  are  permanent  for  long  periods, 
may  be  prepared  by  replacing  nitric  acid  by  sulphuric 
acid  after  the  solution  of  the  pure  copper  in  the  former, 
provided  a  considerable  excess  of  ammonia  is  added  and 
the  solution  preserved  in  bottles  with  stoppers  sufficiently 
tight  to  prevent  any  escape  of  ammonia.  In  the  analysis 
of  lean  material  for  copper,  a  double  precipitation  of  the 
iron  and  alumina  by  ammonia  is  found  to  yield  better 
results,  and  in  less  time  than  either  the  precipitation  by 
aluminum  or  a  single  precipitation  by  ammonia.  —  y. 
Am.  Chetn.  Soc,  xix.,  24  - 

International  Conferenci  of  Leather  -  Trades' 
Chemists. — A  Conference,  as  above,  holden  on  Tuesday 
and  Wednesday,  Sept.  28th  and  29th,  at  Herold's  Insti- 
tute, Bermondsey  (Leathersellers  Company's  Tanning 
School),  and  at  which  Great  Britain,  the  United  States  of 
America,  Austria,  Denmark,  France,  Germany,  Norway, 
and  Sweden  were  the  countries  represented,  concluded 
its  proceedings  on  the  30th  ult.,  by  a  joint  meeting  of 
the  leather  trade  and  its  allies  at  Leathersellers'  Hall, 
kindly  lent  by  the  Worshipful  Company  of  Leathersellers. 
The  obje«5t  of  the  Conference  was  to  arrive  at  uniformity 
in  the  matter  of  tanning  analyses,  and  formally  establish 
an  International  Association  of  Leather-Trades' Chemists, 
&c.  The  Conference  was  opened  by  Mr.  C.  T.  Millis, 
Principal  of  Herold's  Institute,  and  representing  the 
Governors  of  the  Borough  Polytechnic,  of  which  the 
Institute  is  a  Branch  ;  the  chair  being  afterwards  taken  by 
Dr.  Perkin,  F.R.S.  The  Rt.  Hon.  W.  L.  Jackson  pre- 
sided at  the  Leathersellers'  Hall  Meeting.  As  the  first 
President  of  the  International  Association  the  Conference 
elefted  Mr.  Alfred  Seymour-Jones,  F.C.S.,  F.I.C,  ;  Hon. 
Secretaries,  Prof.  H.R.Prodter  (Yorkshire  College,  Leeds), 
and  Dr.  J.  Gordon  Parker  (Herold's  Institute,  London). 

The  Cause  of  Arsenical  Poisoning  by  Wall  Papers. 
— Thomas  Bolas,  F.C.S. — It  has  long  been  recognised  that 
arsenical  wall  papers  do  serious  mischief,  but  the  work 
of  Gosio  and  of  Emmerling  seems  to  have  cleared  up 
that  mystery  which  has  surrounded  the  matter.     Certain 
moulds,  including  the  very  common  mucor  mucedo,  have 
a  remarkable  property  of  decomposing   arsenical  com- 
pounds with  the  evolution  of  volatile  produdls  containing 
arsenic,  and  the  highly  poisonous  charaAer   of  volatile 
arsenical  compounds,  coming  into  the  system  by  way  of 
the  respiratory  organs,  is  well  known.     Arsenious  acid  is, 
even  in  small  quantities,  a  highly  antiseptic  substance, 
and   poisonous  to  moulds,  so   the  throwing   off  of  the 
arsenic  in  a  volatile  form  may  be   an  effort  of  nature  to 
cast  out  the  poison.     The  arsenical  copper  greens,  and 
other  colouring^matters  containing  arsenic,  are  still  used, 
and,  paradoxical  as  it  may  appear,  it  is  by  no  means  im- 
probable that  the  most  dangerous  wall  papers  are  those 
containing  a  mere  trace  of  arsenic,  as  when  the  quantity 
is  large  the  moulds  cannot  exist.      Traces  of  arsenic  may 
come  into  wall   papers   from  the   imperfedt  washing  of 
vessels  used  to  contain  the  more  highly  arsenical  colours. 
Now  that  boric  acid  is  very  cheap,  the  old  and  perhaps 
forgotten  suggestion  of  Bolley  to  use  a  precipitated  borate 
of  copper  as  a  green  pigment  in  place  of  the  arsenical 
green  deserves  attention.     Bolley's  green  is  prepared  by 
taking  two  parts  of  blue  vitriol  (crystallised  cupric  sul- 
phate) and  three  parts  of  borax  in  separate  quantities  of 
cold  water  and  mixing;    after  which  the  precipitate  is 
washed  and  dried.      Dyed  and  printed  fabrics  now  very 
frequently  contain  traces  of  Arsea\c.—yournal  of  the 
Society  of  Arts. 


Swiss  Chemist  and  Badleriologist  seeks  posi- 
tion. Speaks  French,  German,  and  Italian.  Best  references. 
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gato  Hill,  IiondoOt  E.C. 


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BY 

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Professor  of  Technical  Chemistry,  Zurich, 

AND 

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"  That  excellent  book."— The  late  Prof.  W.  Dittmar. 


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Composition  of  Certain  Canadian  Virgin  Soils. 


185 


THE    CHEMICAL     NEWS 


Vol.  LXXVI.,  No.  1977. 


ON     THE    COMPOSITION     OF    CERTAIN 
CANADIAN    VIRGIN    SOILS.* 

By  FRANK  T.  SHUTT,    M.A.    F.I.C.,    F.C.S., 
Chemist,    Dominion  Experimental  Farms. 

Of  the  many  investigations  carried  on  by  the  Chemical 
Division  of  the  Dominion  Experimental  Farms  during  the 
past  ten  years,  not  the  least  in  scientific  interest  nor  in 
agricultural  value  have  been  those  which  have  had  for 
their  objedl  the  determination  of  the  amounts  of  plant 
food  in  certain  typical  and  virgin  soils  of  the  Dominion. 
The  data  are  not  as  yet  voluminous,  for  this  work  is  one 
that  consumes  much  time,  and  other  and  more  pressing 
demands  have  only  permitted  an  intermittent  attention  to 
it ;  nevertheless  we  have  been  able  to  place  on  record 
results  which  go  far  towards  indicating  the  charafler  of 
many  soils  representative  of  large  untilled,  or,  at  all 
events,  but  partially  settled  districts  in  Canada. 

In  all,  we  have  submitted  to  complete  analysis  about 
ninety  samples.  These  comprise  surface  and  sub-soils 
taken  from  the  Atlantic  to  the  Pacific  in  the  various 
provinces  of  the  Dominion,  and,  to  the  best  of  our 
knowledge,  from  areas  which  had  never  been  manured  or 
cropped. 

It  is  not  my  purpose  to  present  in  this  paper  all  the 
data  obtained,  nor  to  attempt  an  interpretation  of  all  the 
figures,  chemical  and  physical,  that  have  resulted  from 
this  work,  for  such  would  scarcely  be  possible. f  My 
intention  rather  is  to  bring  before  you  the  percentage 
composition  of  these  soils  as  regards  certain  of  the  more 
important  elements  of  fertility,  and  to  draw  such  de- 
ductions as  to  relative  richness  or  deficiency  in  plant  food 
as  may  seem  warranted  when  comparing  the  figures  with 
those  obtained  from  the  examination  of  soils  in  other 
countries. 

The  Value  of  an  Ordinary  Soil  Analysis. 
The  exadt  value  of  a  chemical  analysis  towards  ascer- 
taining the  fertility  of  a  soil  is  a  question  that  probably 
will  always  be  open  to  discussion,  and  all  present  are 
doubtless  aware  that  no  problem  in  agricultural  science 
has  excited  more  interest  or  been  debated  with  greater 
warmth.  We  are  obliged  to  confess  that  a  knowledge  of 
the  amounts  of  nitrogen,  potash,  phosphoric  acid,  &c.,  as 
estimated  by  our  present  methods  of  determining  "total  " 
or  maximum  amounts  of  plant  food  constituents  by  strong 
solvents,  is  not  in  itself  sufficient  for  making  a  diagnosis 
as  to  the  crop-producing  power  of  a  soil.  Why  this  is  so 
will  be  apparent  upon  refledtion.  In  the  first  place, 
hydrochloric  acid  of  the  strength  employed  in  the  analysis 
dissolves  from  the  soil  the  mineral  constituents  in  much 
larger  amounts  than  are  present  in  an  immediately  avail- 
able condition ;  and,  secondly,  there  are  faftors  other 
than  the  amount  of  plant  food  present  that  are  equally 
important  in  determining  a  soil's  fertility.  The  physical 
condition  of  the  soil, — including  retentivity  of  moisture, 
capillarity,  permeability,  &c., — the  climatic  conditions, 
including  rainfall,  mean  temperature,  sunshine,  &c., 
must  all  be  carefully  considered  in  conjundion  with  the 
analytical  figures  when  endeavouring  to  interpret  the 
latter  with  a  view  of  ascertaining  a  soil's  probable  crop- 
producing   ability.     The  case  is  very  similar  to  that  of 

*  Read  before  the  Britiah  Association  (Seftion  B),  Toronto 
Meeting,  1897. 

+  The  data  here  referred  to  are  to  be  found  in  the  Reports  of  the 
Chemical  Division  of  the  £xperimeatal  Farms,  1888—1896. 


water  analysis,  in  which  it  is  universally  held  that  all 
possible  information  respeding  the  source  and  its  environ- 
ment must  be  in  the  possession  of  the  chemist  before  he 
can  intelligibly  and  corre<5tiy  give  judgment  from  his 
figures  upon  the  quality  of  the  water  under  examination. 
It  is  often  urged  that  our  usual  method  of  soil  analysis, 
using  hot,  strong,  hydrochloric  acid  as  a  solvent,  only  in- 
dicates the  amounts  of  plant  food  that  may  become 
available,  not  the  amounts  that  are  immediately  assimi- 
lable. This  is  true,  and  it  is  certainly  a  serious  drawback, 
but  it  in  no  wise  makes  the  results  of  no  value,  as  some 
would  have  us  believe.  It  gives,  we  may  suppose,  the 
maximum  amounts  of  the  mineral  elements  present  which 
under  the  influence  of  favourable  climatic  and  mechanical 
conditions  may  become  useful  to  crops.  It  shows  de- 
cisively deficiencies  in  any  of  the  plant  food  constituents, 
if  such  exist,  and  consequently  affords  valuable  informa- 
tion regarding  the  suitability  of  the  soil  for  various  farm 
crops,  and  further  indicates  the  diredtion  in  which  fer- 
tilisation may  be  economically  and  profitably  carried  on. 
Soils  with  large  stores  of  plant  food,  even  if  such  be  par- 
tially or  largely  in  a  locked-up  condition,  have  repeatedly 
been  shown  to  have  a  greater  agricultural  value  than 
those  that  furnish  to  the  same  solvent  much  less  amount?, 
The  probabilities  are  that,  other  things  being  equal,  soils 
of  the  former  class  will  contain,  or  at  all  events  under 
favourable  circumstances  yield,  larger  amounts  of  readily 
assimilable  food  than  those  possessing  smaller  "  totals  " 
or  maximums.  Soils  showing  percentages  of  maximums 
above  the  average  invariably  prove  fertile,  if  climatic  in- 
fluences are  favourable.  We  cannot  argue  very  closely, 
I  admit,  but  from  such  an  analysis  we  are  able  to  predidl 
possibilities  as  to  productiveness,  provided  agencies 
favourable  to  the  unlocking  of  soil  plant  food  are  present 

Soil  Tests  for  ascertaining  Available  Plant  Food. 
Pot  or  plot  experiments  are  as  yet,  we  confess,  the  only 
tests  that  can  infallibly  indicate  a  deficiency  in  available 
fertilising  constituents.  Such  methods  consume  much 
time,  are  cumbersome,  and  from  their  very  nature  scarcely 
suited  to  wide  application.  What  is  needed  is  a 
laboratory  method  or  methods,  in  addition  to  those  we 
now  use,  which  will  furnish  data  in  accordance  with  the 
results  obtained  by  adtual  soil  trials  with  crops.  This  is 
a  question  that  at  present  many  agricultural  chemists  are 
engaged  upon,  and  I  venture  to  hope  that  ere  long  the 
renewed  interest  in  this  work  will  result  in  satisfactory 
methods  being  established,  both  for  available  mineral 
constituents  and  nitrogen. 

Dr.  Dyer^s  Work, 
In  March,  1894,  Dr.  Bernard  Dyer's  work  on  available 
plant  food  in  soils  appeared.  It  was  the  beginning  of  a 
new  era  in  soil  analysis.  Since  that  date  increased 
attention  has  been  paid  to  this  branch  of  research,  and 
especially  so  on  this  continent.  Every  year  sees  new  and 
interesting  data,  the  results  of  the  labours  of  agricultural 
chemists  of  the  Experiment  Stations  of  the  United  State;s. 
Dr.  Dyer,  it  will  be  remembered,  showed,  among  other 
valuable  results,  that  the  root  sap  and  the  exudation  of 
rootlets  possessed  an  acidity  approximately  equivalent  to 
that  of  a  I  per  cent  solution  of  nitric  acid.  From  this  he 
argued  that  such  a  solution  would  have  a  solvent  adtion 
on  the  mineral  constituents  of  the  soil  similar  and  equal  to 
that  exerted  by  growing  crops.  Further,  he  showed  that 
results  obtained  by  this  method  were  stridtly  in  line  with 
the  deductions  made  from  the  data  of  at^ual  field  trials. 
He  therefore  proposed  that  this  solvent  should  be  used  to 
determine  available  potash  and  phosphoric  acid  in  soils. 
Workers  in  the  United  States,  members  of  the  Association 
of  Agricultural  Chemists,  besides  using  this  solvent,  have 
proposed  and  worked  with,  during  the  past  few  years, 
other  solutions,  such  as  ammonium  chloride  and  calcium 
chloride.  None  of  these,  however,  have  had  the  support 
or  corroboration  of  experiments  to  show  that  they  were 
similar  or  comparable  in  their  adtion  upon  the  soil  to  the 


i86 


solvent  action  of  root  exudations.  Consequently  they  do 
not  as  yet  appeal  to  agricultural  chemists  with  the  same 
force  as  the  solvent  proposed  by  Dr.  Dyer. 

Solvents  employed. 

The  solvent  used  by  us  in  the  determination  of  "total" 
or  maximum  percentages  of  the  mineral  constituents  has 
been  hydrochloric  acid,  sp.  gr.  1-115  (corresponding  to 
22'86  per  cent  HCl),  10  grms.  of  the  air-dried  soil  being 
digested  with  100  c.c.  of  the  acid  at  the  temperature  of 
the  water-bath  for  ten  hours. 

For  the  estimation  of   the  "available"   potash   and 
phosphoric  acid,  i  per  cent  citric  acid  solution  has  been  ; 
employed,  digesting  loogrms.  of  air-dried  soil  with  500C.C. 
of  the  solvent  for  five  hours  at  room  temperatures. 

Standards  of  Fertility. 

It  has  been  remarked  that  climate  and  the  physical 
condition  of  a  soil  are  potent  factors  in  determining  fer- 
tility. To  this  might  be  added  the  statement  that  fertility 
(i.e.,  crop-producing  power)  is  a  relative  quality,  depending 
to  a  large  extent  on  the  crop  grown.  The  ability  of 
plants  to  forage  for  and  appropriate  their  food  varies 
greatly,  so  that  what  might  be  an  adequate  supply  of 
food  for  one  might  prove  an  insufficiency  for  another. 
Buckwheat  and  wheat  will  very  well  illustrate  this  varia- 
tion in  foraging  and  assimilating  ability.  For  these 
reasons  chiefly — for  of  course  there  are  others — it  is  im- 
possible to  establish  rigid  standards  as  regards  the 
minimum  amounts  of  plant  food  for  all  crops  that  must 
be  present  in  order  that  a  soil  may  be  classed  as  econo- 
mically produdtive. 

It  is  not  impossible,  however,  using  a  large  number  of 
analyses  of  soils,  the  produdtive  power  of  which  soils  is 
approximately  known,  to  deduce  percentages  or  limits  in 
plant  food,  below  which,  under  ordinary  circumstances, 
soils  may  be  considered  as  deficient  or  lacking,  and  above 
which  they  may  be  considered  as  well  supplied  or  rich  in 
the  essential  mineral  elements.  Professor  Hilgard,  of  the 
California  Experiment  Station,  the  highest  authority  on 
American  soils,  considers  that  less  than  o'og  per  cent 
potash  indicates  a  deficiency  in  this  element,  and  that  the 
limits  of  this  constituent  in  good  soils  range  approxi- 
mately from  o'8  to  0-5  per  cent  in  heavy  clays,  from  0*45 
to  0*30  per  cent  in  medium  loams,  and  from  0-3  to  o'l 
per  cent  in  sandy  loams.  Regarding  phosphoric  acid,  he 
says  that  o'2  per  cent  is  sufficient  when  associated  with 
a  good  supply  of  lime,  though  it  may  in  certain  soils 
reach  or  exceed  0*3  per  cent.  Respedling  lime,  Hilgard 
states  O'l  per  cent  in  sandy  loams  as  the  lowest  limit  for 
good  crops,  0*25  per  cent  in  clay  loams,  and  0*3  per  cent 
in  heavy  clay  soils. 

Standards  of  Fertility  in  Canadian  Virgin  Soils. 

Our  data  indicate  that  good  agricultural  soils  in  Canada 
possess  usually  between  0*25  and  0*5  per  cent  potash  ; 
less  than  0*15  per  cent,  in  our  experience,  points  to  the 
necessity,  or  at  all  events  to  the  value,  of  potassic  fer- 
tilisers, though  with  good  climatic  and  soil  conditions  the 
limit  might  be  reduced  to  that  suggested  by  Hilgard. 

The  phosphoric  acid  in  Canadian  virgin  soils  of 
average  fertility  lies  usually  between  0*15  and  o'25  per 
cent.  Some  good  soils  contain  from  0'25  to  0*3  per  cent, 
and  a  few  exceed  the  latter  figure.  The  adequacy,  or 
otherwise,  of  phosphoric  acid  in  a  soil  would  appear  to 
depend  largely  on  the  accompanying  amount  of  lime. 
Increased  crop  production  has  usually  followed  the  appli- 
cation of  phosphatic  fertilisers  to  soils  containing  less 
than  0*15  per  cent  phosphoric  acid. 

Lime  ranks  next  in  importance  to  potash  and  phos- 
phoric acid  in  a  consideration  of  the  mineral  con- 
stituents of  plant  food.  I  am  led  to  the  conclusion  that 
clay  soils  containing  less  than  o'l  per  cent  will  have  their 
productiveness  increased  by  a  dressing  of  lime  in  one  or 
other  of  its  agricultural  forms.  Peaty  soils,  and  soils 
generally  that  are  exceedingly  rich  in  organic  matter,  are 


Analysis  0/ some  Pre-cafboniferous  Coals,  '    { ^^^oSI^^'s^T"' 


frequently  poor  in  this  element.  All  such  have  been 
found  to  respond  to  an  application  of  lime,  and  more  par- 
ticularly so  when  given  in  conjundlion  with  potash  and 
phosphoric  acid.  For  these  classes  of  soils,  therefore,  I 
deem  it  advantageous  that  they  should  contain  at  least 
I  per  cent  of  lime. 

Richness  in  nitrogen  may  be  measured  to  a  large  degree 
by  the  organic  matter  or  humus  content,  though  the  con- 
dition or  stage  of  decomposition  of  this  organic  matter 
is  an  important  fadtor  in  determining  nitrogen's  avail- 
ability. A  large  number  of  our  good  soils  contain  between 
O'l  and  0*2  per  cent,  though  many  reach  5  per  cent,  and 
some  exceed  i  per  cent  nitrogen. 

In  the  following  brief  review  of  Canadian  virgin  soils  I 
have  not  given  any  detailed  data  of  their  physical  con- 
dition or  composition,  for  the  determinations  in  our 
laboratory  have  been  confined  simply  to  the  separation  of 
the  mineral  components  into  (a)  clay  and  fine  sand,  and 
(b)  coarse  sand,  according  to  the  method  of  Schloesing. 
The  results  of  this  separation,  together  with  remarks  on 
the  physical  condition  or  tilth  of  the  soils,  have  been  in- 
dicated in  general  terms  in  discussing  the  samples.  If  it 
had  been  possible  to  have  made  a  more  extended  physical 
examination  I  believe  the  data  would  have  proved  most 
valuable,  for  the  degree  of  permeability  of  water  and  air, 
the  relative  size  of  the  soil  particles,  compadtness, 
water-holding  capacity,  &c.,  are  important  fadtors  towards 
establishing  a  soil's  suitability  for  the  various  agricultural 
crops. 

(To  be  continued). 


ANALYSIS    OF    SOME    PRE-CARBONIFEROUS 

COALS.* 

By  W.  HODGSON  ELLIS. 

The  occurrence  of  anthracite  in  the  calciferous  sand-rock 
of  New  York,  near  the  base  of  the  Lower  Silurian,  was 
recorded  by  Vanuxem  in  1842  ("Geology  of  New  York," 
iii.,  33).  It  was  found  in  cavities  in  the  rock  associated 
with  quartz  crystals,  sometimes  existing  within  the 
crystals.  He  stated  that  it  contained  "  86^  per 
cent  of  carbon;  2  of  light  cream-coloured  ashes,  which 
were  of  silex  ;  and  11^  per  cent  of  water,"  i.^.,  volatile 
matter.  He  attributed  its  origin  to  the  adtion  of  heat  on 
bituminous  matter  contained  in  the  rock. 

Sterry  Hunt  subsequently  described  ("  Geology  of 
Canada,"  1863,  p.  524)  a  substance  of  like  nature  filling 
veins  and  fissures  in  rocks  of  similar  age  near  Quebec  and 
on  the  north  shore  of  Lake  Superior. 

E.  J.  Chapman  (Canadian  journal,  vol.  x.,  p.  410) 
described  an  anthracite  from  Lake  Superior,  occurring  in 
a  banded  vein  with  quartz  and  iron  pyrites,  an  analysis  of 
which  gave — 


Moisture 
Volatile  matter 
Fixed  carbon 
Ash        .... 


208 
..  356 
..     94-36 

O'OO 
100-00 

In  his  "  Minerals  and  Geology  of  Central  Canada,"  p. 
143,  Chapman  proposed  the  name  "  anthraxolite  "  for  this 
pre-carboniferous  anthracite,  chiefly  because  its  mode  of 
occurrence  differs  from  that  of  the  anthracite  of  the  coal 
measures. 

In  Bulletin  No.  2  of  the  Ontario  Bureau  of  Mines, 
November,  1896,  the  discovery  is  reported  of  a  remarkable 
deposit  of  coaly  material  occurring  as  an  irregular  vein, 
about  g  feet  thick,  in  black  fissile  seats  of  Cambrian  age, 
situated    near    Sudbury,    the    locality    of    the    famous 

*  Read  before  the  British  Association  (SeAion  B),  Toronto 
Meeting,  1897. 


CrbhicalNbws.  I 

oa.  15, 1897.    f 


Analysis  of  some  P  re-carboniferous  Coals, 


187 


Canadian  nickel  mines.  The  discovery  roused  great 
public  interest,  and  hopes  were  entertained  that  the  coal 
would  prove  of  commercial  value.  Specimens  were  sent 
to  Dr.  Dawson  and  Mr.  Hoffmann,  of  the  Geological 
Survey  of  Canada,  who  reported  it  as  consisting  of 
anthraxolite  and  quartz,  the  latter  constituting  55'g5  per 
cent  of  the  whole.  Dr.  A.  P.  Coleman  was  sent  by  the 
Ontario  Government  to  examine  the  deposit,  and  he 
described  it  as  a  lustrous  black  mineral,  forming  "  small 
plates  or  irregular  cubical  blocks,  the  largest  observed 
being  three-quarters  of  an  inch  square.  Between  the 
plates  or  cubes  there  is  generally  more  or  less  quartz, 
and  in  some  weathered  portions  on  the  surface  the  quartz 
remains  as  a  porous  cellular  mass."  Dr.  Coleman  con- 
sidered that  "  the  source  of  the  anthraxolite  is  probably 
bituminous  matter  contained  in  the  adjoining  beds  of 
slate.  By  metamorphic  adlion  most  of  the  volatile 
matter  has  been  removed  from  the  once  fluid  or  plastic 
bitumen,  leaving  the  present  cracked  and  quartz-cemented 
anthraxolite." 

In  the  Proceedings  of  the  Canadian  Institute  for 
February,  1897,  will  be  found  a  detailed  account  of  this 
interesting  deposit  by  Mr.  G.  R.  Mickle,  and  also  a 
chemical  analysis  by  Mr.  W.  Lawson  and  myself. 

The  pure  coaly  substance  has  a  specific  gravity  of 
1865  and  a  hardness  between  3  and  4.  It  burns  with 
diflficulty,  giving  off  a  good  deal  of  heat  (a  sample  con- 
taining 3-99  per  cent  ash  gave,  in  Fischer's  calorimeter, 
7*490  calories  per  grm.)  and  leaving  a  light  fawn-coloured 
ash  consisting  of  silica  with  a  trace  of  oxide  of  iron.  The 
quantity  of  ash  varies  in  different  samples,  some  con- 
taining as  high  as  60  per  cent.  The  average  as  far  as  yet 
examined  is  about  20  per  cent. 

The  following  is  the  proximate  analysis  of  an  average 
and  of  a  selected  sample  : — 

Average.  SeleAed. 

Moisture        4*0  4*0 

Volatile  matter     ..     ..       1-3  i-8 

Fixed  carbon 74*2  go-i 

Ash 20'5  4*1 


The  ultimate  analysis  of  a  carefully  picked  specimen, 
freed  from  moisture,  was  as  follows  : — 

Carbon 94*92 

Hydrogen      0-52 

Nitrogen       1*04 

Sulphur 0*31 

Oxygen 1*69 

Ash        i'52 


The  striking  point  in  thisanalysis  is  the  small  percent- 
age of  hydrogen,  which  is  less  than  that  given  in  any 
published  analysis  that  I  have  been  able  to  find  of  anthra- 
cite of  the  carboniferous  age. 

In  this  respedt,  as  well  as  in  its  physical  properties,  it 
bears  a  striking  resemblance  to  the  mineral  schungite 
described  by  Inostranzeff  as  occurring  in  Huronian  rocks 
on  the  shore  of  Lake  Onega,  in  Russia.  This  mineral 
has  a  specific  gravity  of  1*84  and  a  hardness  of  3*5  to  4, 
and  contains  99*2  per  cent  of  carbon  and  0*4  per  cent  of 
hydrogen.  The  Sudbury  coal  contains  more  oxygen,  but 
otherwise  the  resemblance  between  the  two  is  very 
striking.  The  so-called  graphitoid  of  Sauer,  from  the 
Saxon  Erzgebirge,  with  99'8  per  cent  of  carbon  and  oa 
per  cent  of  hydrogen,  is  another  closely  allied  mineral. 

It  seemed  of  interest  to  compare  the  composition  of  the 
Sudbury  anthraxolite  with  that  of  specimens  from  other 
Canadian  localities,  and  accordingly  Mr.  Lawson  and  myself 
made  an  analysis  of  a  specimen  from  the  neighbourhood 
of  Kingston,  for  which  we  were  indebted  to  Mr.  W.  G. 
Miller.  It  occurs  in  a  vein  of  barite  cutting  Lower 
Silurian  limestones.     The  anthraxolite  coats  and  fills 


crevices  in  the  barite.  The  mineral  is  duller  and  softer 
than  the  Sudbury  anthraxolite.  Its  specific  gravity  is 
1*365.  The  analysis  of  the  dry  substance  gave  the  fol- 
lowing figures  : — 

Carbon 90*25 

Hydrogen      4*16 

Nitrogen        0*52 

Sulphur 0*66 

Oxygen 3*69 

Ash         0*72 


Since  then,  through  the  kindness  of  Dr.  G.  M.  Dawson, 
Director  of  the  Geological  Survey  of  Canada,  I  have  had 
the  opportunity  of  examining  three  other  specimens  of 
anthraxolite — one  from  Cap  Rouge,  near  Quebec,  and  two 
from  the  peninsula  of  Labrador. 

Anthraxolite  from  Cap  Rouge, — A  black  coaly  substance 
occurring  in  cracks  of  "  beds  of  a  hard  jaspery  charader," 
associated  with  black  bituminous  shales  of  Lower  Silurian 
age  ("  Geology  of  Canada,"  1863,  p.  203). 

The  analysis  of  this  specimen  was  as  follows : — 

Moisture       o'lg 

Ash        9-02 

Carbon 8290 

Hydrogen     5*50 

Oxygen 237 


lOO'OO 

(Including  nitrogen  and  sulphur  not  determined). 

Anthraxolite  from  Lake  Mistassini. — A  bituminous 
mineral,  with  the  lustre  and  colour  of  anthracite,  filling 
cavities  in  calcite  veins  in  limestones  of  Cambrian  age 
(A.  P.  Lowe,  "  Report  of  the  Geological  Survey  of 
Canada,"  1895,  267  L.).  I  found  the  composition  of  this 
specimen  to  be — 

Moisture       1*75 

Ash        1*07 

Carbon 9271 

Hydrogen      1*02 

Oxygen,  &c 345 


Anthraxolite  from  Lake  Petitsikapau,  District  of 
Ungava,  Labrador  Peninsula. — In  veins,  with  quartz  in 
Cambrian  shales.  Foliated  with  plates  at  right-angles  to 
the  walls.  Colledted  by  Mr.  A.  P.  Low.  A  purer  speci- 
men gave  Mr.  Hoffmann  ("  Report  of  the  Geol.  Survey  of 
Canada,"  1894,  66  R.)  the  following  results  on  proximate 
analysis  : — 

Water 3*56 

Volatile  matter  ..  ..  2-48 
Fixed  carbon  . .  . .  86  83 
Ash        7-13 


My  specimen  had  the  following  composition: 

Moisture       o'8i 

Ash        4837 

Carbon 49*39 

Hydrogen      0*67 

Oxygen,  &c 0*76 


It  will  be  seen  that  in  none  of  these  is  the  hydrogen  so 
low  as  in  the  Sudbury  anthraxolite.  It  will  also  be  seen 
that  they  vary  among  themselves  as  much  as  do  the 
varieties  of  coal  which  occur  in  the  beds  of  the  carbon- 
iferous period.    This  variability  is  in  stiiSt  accordance 


i88 


Analysis  of  a  Black  Silk  Dress. 


(Chemical  News, 
I     oa.  15, 1897. 


with  the  view  that  they  result  from  the  metamorphosis  of 
bitumen,  of  the  various  stages  of  which  metamorphosis 
they  serve  as  excellent  illustrations.  To  make  this  more 
striking,  I  have  calculated  the  analysis  to  the  dry  ash  free 
substance,  and  for  the  sake  of  comparison  I  have  added 
the  analyses  of  petroleum,  asphalt,  and  albertite — the 
latter  a  coal  like  mineral  occurring  in  a  vein  in  rocks  of 
lower  carboniferous  age  in  Nova  Scotia,  for  some  time 
successfully  worked  as  fuel.  At  the  other  end  of  the  scale 
I  have  given  the  analyses  of  schungite  and  graphitoid. 


Locality. 

1.  Petroleum   ..     Pennsylvania 

2.  Asphalt  .     ..     Mexico      .. 

3.  Albertite.     ..     Nova  Scotia 
Anthraxolite  .     Kingston  . . 

„  Cap  Rouge. 


Hydro-  Oxygen, 

Carbon,  gen.  &c. 

82-0  148  3-2 

83-3  IO-8  5-9 

860  9'o  5-0 

90-5  4'2  5'5 

913  6-2  2-5 


Lake  Mistassini     95-2         i-2       yd 
,1  Sudbury    ..      ..     964         0-5       3'i 

„  LakePetitsikapau  gj-i         1*3       16 

4.  Schungite    ..     Lake  Onega     ..     99-2        0-4      0-4 

5.  Graphitoid  ..     Erzgebirge.     ..     998        0-2      o-o 

1.  Ste.-Claire  Deville,  Comptes  Rendus,  Ixvi.,  442. 

2.  H.  Endemann,  Journ.  Soc.  Chim.  Ind.,  xv.,  872. 

3.  Wetherill,  Trans.  Am.  Phil.  Soc.  Philad.,  353,  1852. 

4.  Inostranzeff,   "  Neues  Jahrbuch   fiir   Mineralogie," 

i.,  97,  1880;  i.,  92,  1886. 

5.  Sauer,  Zeit.  Geol.  Gesel,,  xxxvii.,  441,  1885. 

From  these  latter  to  graphite,  the  transition  is  rather 
one  of  crystalline  form  than  of  chemical  composition,  as 
indicated  by  analysis. 

Chemical  Laboratory, 

School  of  Praaical  Science,  Toronto, 

August  18,  1897. 


clearly  indicates  that  they  are  pentose-derivatives,  and 
most  probably  methylene  ethers  of  the  C5  sugars  of  the 
general  formula — 

C5H8O3/     \CH2. 

It  is  difificult  to  devise  readtions  of  decomposition  or 
synthesis  by  which  such  a  constitutional  formula  could 
be  finally  verified.  The  literature  of  the  analogous  com- 
pound diperonal — 

/°\ 
HOC.C6H3/      >CH2, 

but  with  an  aromatic  in  place  of  a  pentose  residue,  may 
be  cited  in  evidence  of  the  exceptional  difficulty  of  the 
problem  presented. 

The  authors  are  glad  to  report  that  through  the  kind- 
ness of  friends  they  have  now  access  to  a  vessel  enabling 
them  to  operate  upon  a  large  weight  (7  kilos.)  of  the  raw 
materials. 

Working  upon  this  extended  scale,  and  upon  the  basis 
of  the  results  established  by  long  investigation  and  pre- 
viously reported  to  the  Sedtion,  we  may  confidently  exped 
more  positive  and,  we  hope,  final  results. 


CARBOHYDRATES  OF  THE  CEREAL  STRAWS.* 

The  work  upon  the  barley  crop  of  1896,  which  was 
reported  in  outline  to  the  Chemical  Sedion  in  a  paper 
read  by  Mr.  Cross,  has  been  more  fully  dealt  with  in  a 
paper  read  subsequently,  and  published  in  the  Journal  of 
the  Chemical  Society,  1896,  pp.  804—818.  The  subjedt 
was  also  dealt  with  from  the  more  special  point  of  view 
of  the  relation  of  the  furfuroic  constituents  of  these  straws 
to  the  important  problems  of  animal  digestion  and 
alcoholic  fermentation  in  a  paper  published  in  the 
Journal  0/  the  Fed.  Inst,  of  Brewing,  1897,  Pt-  i- 

The  investigations  have  been  continued  without  inter- 
ruption. We  have  further  and  more  closely  studied  the 
products  of  acid  hydrolysis  of  the  cereal  straws  and  of  the 
celluloses  isolated  from  them,  and  the  main  results  of 
these  researches  are  embodied  in  a  paper  read  at  the 
meeting  of  the  Chemical  Society,  London,  on  June  17. 

Generally  the  results  of  the  preceding  paper  {loc.  cit.) 
are  amplified  and  confirmed.  As  it  had  been  previously 
shown  that  the  furfural-yielding  constituents  of  fodder 
plants  are  in  large  measure  hydrolysed  and  assimilated 
by  the  animal  organism,  so  the  evidence  is  accumulating 
that  certain  of  these  compounds  when  fully  hydrolysed 
(to  monoses)  by  artificial  processes  are  susceptible  of 
alcoholic  fermentation. 

It  having  been  finally  established  that  the  pentoses 
themselves  are  entirely  resistant  to  the  attack  of  the 
yeast  cell,  it  follows  that  we  are  dealing  with  a  class  of 
furfural-yielding  carbohydrates,  not  pentoses. 

At  the  present  time  the  reaftions  of  these  compounds 

♦  Report  of  the  Committee,  consisting  of  Professor  R.  Warington 
(Chairman),  C.  F.  Cross  (Secretary),  and  Manning  Prentice.  (Drawn 
up  by  the  Secretary).  Read  before  the  British  Association  (Seftion 
B),  Toronto  Meeting,  1897. 


ANALYSIS    OF    A    BLACK    SILK    DRESS. 

By  Dr.  T.  L.   PHIPSON, 

formerly  of  the  University  of  Brussels  and  the  Laboratoire  de  Chimie 

l:'ratique,  Paris. 

A  LADY  paid  a  visit  to  my  laboratory  a  short  time  ago 
and  enquired  whether  I  had  ever  made  an  analysis  of  a 
silk  dress.  I  confessed  that  among  the  many  hundreds 
of  various  things  examined  in  the  course  of  a  long  series 
of  years,  I  had  only  been  called  upon  hitherto  to  discover 
the  nature  of  certain  poisonous  colours  applied  to  silk 
gloves  and  silk  stockings,  but  I  could  find  no  analysis  of 
a  silk  dress  on  my  books. 

Nevertheless,  my  fair  visitor  was  anxious  that  I  would 
undertake  this  analysis  for  her,  and  also  expressed  the 
desire  that  I  would  publish  the  results  in  the  Chemical 
News,  a  journal  which,  she  said,  she  was  in  the  habit  of 
reading. 

Her  husband  was  interested  in  the  silk  trade,  but  had 
little  knowledge  of  chemistry,  whilst  she  herself  had  gone 
through  a  course  of  pradical  science,  and  wished  to  con- 
vince him  that  the  value  of  silk  material  might  be  ascer- 
tained by  analysis.  She  explained,  moreover,  that  the 
material  she  placed  in  my  hands  was  intended  for  a  silk 
blouse,  that  it  was  a  medium  quality  of  silk  (neither  the 
most  expensive  nor  the  cheapest),  and  she  had  heard  that 
certain  black  silks,  when  stored  in  large  bulk,  in  dry  hot 
weather,  were  liable  to  spontaneous  combustion,  that  two 
such  cases  were  already  known  (one  in  Paris  and  one  in 
New  York),  and  she  was  therefore  anxious  that  her 
husband  should  increase  his  insurance  upon  his  stock  of 
silk  goods. 

The  following  days  I  devoted  myself  to  the  work  in 
question,  and  I  found  that  the  material  contained  a  very 
large  amount  of  substance  that  was  not  silk  at  all ;  in 
(&&,  that  it  was  considerably  "  weighted,"  as  all  silks  are 
to  a  greater  or  less  extent.  It  would  not  burn  with  flame, 
but  smouldered  away  like  tinder  and  left  a  large  amount 
of  ash,  the  principal  ingredient  of  which  was  oxide  of  tin. 
Indeed,  I  have  examined  specimens  of  poor  tin  ore  from 
Cornwall  that  did  not  contain  more  tin  than  this  material 
for  a  lady's  blouse ;  and  I  at  once  realised  the  fadt  that 
the  silk  dresses  worn  by  the  ladies  we  see  daily  parading 
in  Regent  Street  and  Bond  Street,  taken  together,  would 
represent  a  Cornish  mine  of  very  fair  quality. 

But  this  enquiry  has  brought  to  light  a  new  and 
powerful  application  of  chemical  analysis— already  one  of 


Chbmical  Nbws,  I 

o<a.  15, 1897.    / 


Modification  of  the  Cyanide  Titrations  of  Copper, 


189 


the  greatest  powers  in  the  hands  of  man — namely,  that 
the  duration  or  wear  of  a  silk  dress  can  be  determined  by 
analysis.  It  used  to  be  said  that  a  garment  of  pure  silk 
would  last  a  life-time ;  but  I  happen  to  be  acquainted 
with  a  very  clever  young  milliner  who  has  assured  me 
that  the  silk  material  I  have  examined,  if  worn  every  day, 
would  not  last  more  than  three  months — meaning,  of 
course,  that  by  that  time  it  would  be  "  utterly  shabby, 
greasy-looking,  and  showing  the  threads." 
The  figures  obtained  in  my  analysis  are  as  follow : — 

Water ii'43 

Ash  (mostly  tin  oxide  and  silica)    ..     ..  i4'3o 

Real  silk       28*14 

Organic  miitters,  &c.,  not  silk 46*13 


ioo*oo 
Nitrogen       476 

The  weighting  of  silk  is  now  carried  on  to  so  great  an 
extent  in  France,  Germany,  and  Switzerland,  that  some 
foreign  silks  get  shabby  with  a  few  weeks'  wear  ;  and  we 
are  seriously  told  that  the  public  prefer  these  cheap  pro- 
dudts,  as  the  fashions  of  jackets,  blouses,  and  skirts  change 
so  rapidly  that  it  would  be  useless  to  purchase  silk  of 
better  quality  ! 

Casa  Mia,  Putney,  S.W. 


A     MODIFICATION     OF 

THE     CYANIDE     TITRATIONS     OF    COPPER. 

By  HARRY  BREARLEY. 

This  paper  is  offered  with  some  diffidence ;  its  subject- 
matter  has  been  so  often  examined  and  discussed  by  those 
daily  interested  in  its  accuracy.  A  belief  that  the  modifi- 
cation is  also  an  improvement,  and  its  general  bearing  on 
a  subsequent  paper  must  stand  as  an  apology  for  any 
seeming  presumption  on  the  part  of  one  only  rarely  en- 
gaged with  copper  estimations. 

For  each  element  in  the  *'  alkaline  acetate  "  separations 
the  question — "  How  shall  the  separated  element  be 
estimated  ?  "  had  in  all  cases  to  be  primarily  settled.  For 
obvious  reasons,  when  a  large  number  of  estimations  had 
to  be  made  a  volumetric  process  was  preferred. 

The  cyanide  method  of  Parkes  and  the  iodide  method 
of  De  Haen  are,  of  all  volumetric  methods  for  copper, 
perhaps  the  most  widely  known  and  pradlised.  Both, 
however,  are  at  a  disadvantage  when  the  copper  per- 
centage is  low  and  the  bulk  of  the  solution  also  large. 
This  being  so,  the  proposed  acetate  separations  of  iron 
and  copper  would  entail  an  additional  operation  before 
the  estimation  could  be  made,  and  thus  destroy  for  the 
particular  purpose  a  volumetric  method's  chief  charm — 
rapidity. 

The  latter  stages  of  the  cyanide  titration  are  rather  in- 
distind.  The  solution  assumes  a  pale  violet  or  lavender 
tint,  which  fades  very  gradually  independently  of  any 
cyanide  additions  ;  and  so  it  becomes  not  altogether  im- 
possible, in  following  the  changes — unconsciously,  of 
course — to  have  one's  expedations  warping  one's 
judgment.  The  suggestion  to  titrate  only  to  a  pale 
lavender  tint  (Clowes  and  Coleman,  "  Quant.  Anal.," 
2nd  edition,  p.  195)  does  not  greatly  amend  this 
uncertainty. 

The  proposed  modification  lies  in  the  application  of  the 
silver  iodide  indicator  to  the  usual  titration. 

If  the  silver  iodide  be  formed  in  the  solution  before  the 
cyanide  is  added  it  is  no  indicator  whatever ;  because  the 
suspended  iodide  is  equally  or  more  adtive  to  tne  cyanide 
than  is  the  ammoniacal  copper,  and  so  the  solution 
clears  sometime  before  the  blue  colour  is  discharged. 
This  difficulty  is  obviated  by  adding  cyanide  to  the  usual 
point,  or  thereabouts,  and  then  adding  potassium  iodide 


and  going  back  to  a  permanent  turbidity  with  silver 
nitrate.  As  a  matter  of  fa6t,  the  turbidity  is  not  really 
permanent,  but  only  persistent ;  because,  on  standing, 
any  turbidity  would  disappear  on  account  of  its  greater 
affinity  for  the  cyanide,  and  a  corresponding  amount  of 
copper  being  displaced  would  reproduce  the  charadteristic 
blue  colouration.*  By  this  means,  the  end-readtion  be- 
comes certain,  and  with  identical  liquids  gives  good  re- 
sults. .  In  the  presence  of  additional  compounds  it  ex- 
hibits its  usual  waywardness. 

In  1888,  Mr.  J.  L.  Davies  (Chemical  News,  Iviii.,  131) 
very  modestly  suggests  the  substitution  of  soda  carbonate 
for  ammonia.  The  carbonate  is  to  be  added  in  such 
excess  as  to  partly  dissolve  the  precipitated  copper,  and 
then  the  usual  end-readtion  is  relied  on.  Mr.  Merry 
modifies  the  original  idea  by  adding  enough  tartaric  acid 
to  re-dissolve  the  precipitated  carbonate  to  a  clear  blue 
solution,  and  then  titrating.  Eighteen  months  later 
(Chemical  News,  Ixi.,  183),  Mr.  Fessenden  suggests  a 
like  change,  especially  stipulating  that  the  soda  carbonate 
be  added  to  a  solution  containing  free  nitric  acid,  so  as 
to  completely  effed  the  re-solution  of  the  precipitated 
copper. 

It  was  claimed  for  this  modification  that  the  final 
colouration  did  not  lag,  as  with  ammonia,  and  that  the 
values  are  not  so  greatly  aiTedled  by  additional  alkali  or 
alkaline  salts. 

These  suggestions  occupy  only  two  short  letters  to  the 
editor  ;  and,  judging  from  the  persistent  way  in  which  the 
ammonium  titration  is  still  pradtised  and  recommended, 
seem  to  have  been  undeservedly  negledled. 

A  mere  comparison  of  similar  solutions  made  alkaline 
with  ammonia  and  soda  carbonate  respedtively,  shows  the 
latter  under  unfavourable  conditions.  But  an  addition  of 
cyanide  to  the  latter  both  changes  and  deepens  the  tint, 
and  this  deepening  keeps  pace  with  the  progressing  titra- 
tion for  some  time.  It  cannot  even  be  pretended  that  the 
colour  vanishes  like  phenolphthalein  in  alkalimetry,  but 
it  is  no  exaggeration  to  say  that  its  sensitiveness  is  two 
or  three  times  greater  than  when  ammonia  is  used. 

There  are  arranged  below  some  titrations  with  soda 
carbonate  and  with  ammonia  under  varying  circum- 
stances. Attention  is  chiefiy  paid  to  the  former  on 
account  of  its  evident  superiority. 

The  iodide  indicator  cannot  be  added  before  the  titra- 
tion with  the  soda  any  more  than  with  the  ammonia  solu- 
tion, although  the  turbidity  holds  out  much  longer  in  the 
former  case;  and  the  copper  having  once  combined  with 
the  cyanide  is  not  decomposed  by  the  silver  iodide 
turbidity. 

It  should  be  noticed  that  if  cyanide  be  added  to  an 
alkaline  solution  of  copper  until  the  colour  is  just  dis- 
charged, the  whole  of  the  cyanide  has  not  combined  with 
the  copper.  For  instance,  a  solution  containing  0*03 
grm.  of  copper,  if  titrated  as  usual,  would  contain  as 
"  surplus  "  cyanide  about  10  per  cent  of  the  total  quantity 
used.  Of  course,  by  proionged  titration  this  surplus 
could  be  materially  decreased,  but — within  reasonable 
time — it  cannot  be  eliminated  altogether. 

For  the  following  tests  the  cyanide  is  added  until  the 
colour  is  discharged,  or  very  nearly  so,  and  the  solution 
allowed  to  stand  five  or  ten  minutes.  Prolonged  standing 
very  slightly  increases  the  amount  of  cyanide  used,  or 
more  intelligibly  perhaps,  decreases  the  surplus.  The 
bulk  of  solution  throughout  is  250  c.c,  the  amount  of 
copper  0*02  or  0*03  grm. 


*  The  following  remarks  by  Field  (Chemicai.  News,  i.,  26)  are 
interesting  :  — "  W  lien  a  soluble  cyanide  ii>  added  to  a  solution  of  a 
salt  of  copper,. in  a  con^^iderable  excess  of  ammonia,  until  the  liquid 
is  perfe(5lly  colourless,  the  addition  of  nitrate  of  silver  restores  the 
deep  blue  colour,  and  an  argento-cyanideof  ammonia  or  of  ammonia 
and  copper  is  formed.  There  are  a  great  variety  of  compounds  con- 
sisting of  silver,  copper,  cyanogen,  and  ammonium  ;  one  especially 
crystallises  in  splendid  dark  blue  oAahedra,  and  contains  more  than 
60  per  cent  of  silver.  Another  compound  separates  in  pearly  scales 
and  contains  a  larger  proportion  of  copper." 


I  go 


Modification  of  the  Cyanide  Titrations  of  Copper. 


Cbhmicai.  .Nbws 

I    oa.  15. 1897. 


Influence  of  Alkali. 

Excess  of  ammonia  .      ..5          10  15  20    c.c. 

Nett  KCN       277     27-35  26-55  2612    „ 

Excess  of  soda  carbonate                   10  20  40      ,, 

Nett  KCN       20-42  20*65  20-75    „ 

The  strength  of  the  alkalis  were — Ammonia,  o'SSo, 
diluted  to  four  times  its  bulk ;  soda  carbonate,  200  grms. 
per  litre.  The  results  in  the  ammonia  series  seem  to  be 
at  variance  with  common  experience  ;  they  are  not  really 
so.  The  amount  of  cyanide  needed  to  discharge  the 
colour  did  increase  with  the  volume  of  the  ammonia,  but 
in  a  greater  degree  the  needful  surplus  cyanide  also  in- 
creased, and  hence  the  reversed  order  of  progression. 

With  an  excess  of  only  5  c.c.  of  dilute  ammonia,  a  final 
turbidity  equivalent  to  one  or  two  tenths  of  a  m.grm.  of 
copper  will  persist  for  several  hours.  As  the  ammonia 
increases  in  amount  this  time  would  decrease  until,  with 
an  excess  of  40  or  50  c.c,  it  becomes  impossible  owing  to 
the  rapid  interchange  of  silver  and  copper,  to  observe  the 
disappearance  of  the  last  traces  of  free  cyanide  other  than 
by  the  returning  blue  colouration. 

Influence  of  Volume, 
Volume  titrated     . .     100        200        300  c.c. 

Soda 2i-i6*    20*42     2o*oi  ,,    KCN  nett. 

Ammonia 19-13       1805     17-37  „       „        ,, 

When  the  sample  marked  with  an  asterisk  was  made 
up  to  about  300  c.c.  with  water,  the  final  turbidity  dis- 
appeared, and  to  reproduce  it  required  silver  nitrate 
equivalent  to  1*02  c.c.  KCN,  which  subtraded  from  2fi6 
brings  the  value  into  line  with  the  "  300  c.c."  sample. 
The  corresponding  ammonia  sample  behaved  similarly, 
but  not  with  so  great  accuracy. 

Proportion  oj  Copper. — The  volume  of  the  solution  was 
constant,  200  c.c. 

Copper..     ..     0*005        b'oi        0*02        0*03  grm. 
Soda       . .     . .     4'85        io*i        20*4        30-67  c.c.  KCN 
Ammonia       ..       —  8-8        18-05      27*5      „       „ 

Excess  of  Cyanide. — These  tests  are  intended  to  show 
the  influence  of  adding  more  or  less  cyanide  than  a 
proper  amount.  This  irregularity  might  happen  either 
inadvertently  or  otherwise. 

I.  11.  III.         IV. 

Total  cyanide  added  25*5  30*5  370  40  c.c. 
Nett  cyanide    ..     ..     21-6        2595      28-55      28-95,, 

This  is  an  ammonia  series.  Test  I.  was  decidedly,  and 
test  II.  very  faintly,  coloured  on  adding  the  silver  nitrate. 
The  very  considerable  variation  in  the  nett  cyanide  make 
the  proposed  iodide  indicator  of  lessened  value ;  because 
any  error  in  noting  the  colour  indication — the  uncertainty 
of  which  provides  the  only  excuse  for  using  the  Agl — 
would  be  only  partially  correfted  by  the  added  silver  salt. 
The  soda  titration  under  like  conditions  is  almost  free 
from  this  error.    Thus — 

Total  KCN     ..     ..     25*1  27*0  30      c.c. 

Nett      „         ..     ..     20*5  20*6  20*78    „ 

This  degreeof  constancy,  taken  in  conjundlion  with  the 
increased  delicacy  of  the  decolourisation,  makes  the  end- 
readtion  of  a  soda  titration  as  delicate  as  the  silver  iodide 
is  known  to  be  under  the  most  favourable  circumstances. 
It  is  indifferent  also  to  the  soda  titration  in  what  manner 
the  cyanide  is  added.  Thus,  when  the  required  amount 
was  run  in  quickly  and  then  shaken,  the  net  result  was 
20*38  c.c.  KCN  ;  when  added  in  drops,  shaking  mean- 
while, the  result  was  20-33  c.c.  KCN 

Alkali  Chloride. 
Ordinary  HCl  as  Na(Am)Cl.    C.c. 


Soda..     .. 
Ammonia  . 

0 

20*4 

28-41 

5 
20*4 

31-4 

10 

20*52 
32-65 

20 
20-52  c.c.  KCN 

333       ..        /r, 

Alkali  Nitrate. 
HNO3  (1-20)  as  Na(Am)N03 


C.c. 


Soda  ..     ..     20-4 
Ammonia.,     1805 


5 
20-38 
ig  62 


20*43 
20*32 


20-61  c.c.  KCN 


With  the  larger  amounts  of  soda  chloride  and  nitrate 
the  final  turbidity  is,  in  the  former  case  very  slightly,  and 
in  the  latter  unmistakably,  ill-defined.  Only  the  nitrate 
deserves  more  than  a  passing  notice. 

The  whole  of  the  variations  at  present  under  considera- 
tion were  made  on  a  solution  containing  an  exaggerated 
indicator,  but  no  copper.  They  were  all  without  appre- 
ciable  influence,  except  soda  nitrate.  The  nature  of  the 
difficulty  is  set  forth  in  the  table. 

HNOg  (1-20)  as  NaNOg.    C.c. 


Excess  soda  carbonate 


5  c.c.        6*3        727        7*5 
10    „         —        6-37        7-12 
20    „         —        6-35        6*35 


The  values  are  c.c.  KCN.  The  table  also  points  to  the 
remedy,  namely,  an  increasing  excess  of  soda  carbonate 
with  increasing  quantities  of  soda  nitrate.  Any  error  due 
to  this  irregularity  could  be  detedted  by  adding  more  soda 
carbonate.  In  case  there  was  a  previous  insufficiency, 
the  turbidity  would  clear,  and  then  titration  would  finish 
in  the  usual  way.  A  proper  titration  is  not  appreciably 
affeded  by  the  further  addition  of  carbonate. 

Alkali  Acetate. 


33  per  cent  acetic  acid  as  acetate.    C.c. 


Ammonia 


Soda 


o  5  10 

29*1  31*2  32*1  c.c.  KCN 

Grms.  crystal,  ssda  acetate. 


20*35  20*4 


5 
20*63 


20*63 


The  most  casual  comparison  of  the  two  series  of  results 
greatly  favours  the  soda  cyanide  process.  R.  T.  Thomson, 
in  a  paper  on  "  The  Interference  of  certain  Metals  with 
the  Accuracy  of  the  Cyanide  Estimation  of  Copper " 
(Chemical  News,  xxxiii.,  152),  shows  that  in  ammoniacal 
solutions  the  salts  of  sodium  and  potassium  have  no 
appreciable  effedt.  J.  J.  and  C.  Beringer  (Chemical 
News,  xlviii.,  iii,  reprint  from  the  Proceedings  of  the 
Cornwall  and  Devon  Miners^  Association)  come  nearer 
still  to  discovering  the  advantage  of  complete  soda  titra- 
tions. They  say  :— "  It  seemed  to  us  that  the  interfer- 
ence  of  the  ammonia  salts  is  due  to  a  reacftion  with 
potassic  cyanide  by  which  ammonium  cyanide  is  formed, 
and  that  the  excess  of  cyanide  is  required  either  because 
ammonium  cyanide  decomposes  more  rapidly  or  because 
it  is  less  adtive  than  the  corresponding  potassic  salt.  In 
this  case,  the  use  of  soda  or  potash  for  neutralising  the 
excess  of  acid  used  for  dissolving  the  ore  would  eliminate 
the  disturbing  element."  And  subsequently  they  show 
that  the  sulphates,  nitrates,  and  chlorides  of  potash  and 
soda  have  little  or  no  effedt  on  the  cyanide  titration  ;  but 
the  advisability  of  avoiding  ammonia  altogether  does  not 
seem  to  have  suggested  itself  to  them. 

It  has  been  previously  noticed  that  Mr.  Davies  per- 
forms the  titration  without  completely  re  dissolving  the 
precipitated  carbonate,  Mr,  Merry  effedts  the  complete 
solution  with  tartaric,  and  Mr.  Fessenden  with  nitric  acid. 
So  far  as  the  colour  readtion  is  concerned,  it  may  be  per- 
fedily  indifferent  which  acid  is  used.  But  if  the  iodide 
end-rea(^ion  be  adopted,  it  is  no  longer  an  indifferent 
matter.  One  objedlionable  feature  of  nitrates  has  been 
already  pointed  out.  There  is  another;  and,  if  nitric  acid 
is  used  alone,  a  more  unpleasant  one. 

If  four  vessels  containing  solutions  of  copper  acidified 
respedtively   with  nitric,  acetic,  sulphuric,   and   hydro- 


ChbmicalNsws,  ) 
Oa.  15, 1897.      J 


London  Water  Supply. 


191 


chloric  acid  are  treated  with  an  excess  of  soda  carbonate, 
each  will  hold  a  clear  solution.  Let  the  solution 
be  titrated  with  cyanide,  and  then,  on  the  clear  and 
colourless  solution,  after  adding  potassic  iodide,  carefully 
superstratify*  dilute  silver  nitrate.  In  the  first  solution 
(nitric)  the  silver  iodide  will  lose  its  lemon  colour  and 
become  a  dirty  brown.  The  same  change  will  take  place 
decreasingly  in  the  acetate  and  sulphate  solutions.  When 
these  turbidities  are  dissolved  by  shaking  they  produce  a 
more  or  less  inky  tinted  solution,  and  make  the  final  tur- 
bidity less  easily  recognisable.  Hydrochloric  acid  is  per- 
fedly  free  from  this  defed. 

In  case  the  salts  producing—or,  perhaps  better,  allowing 
— this  dirty  colouration  to  be  produced  (because  it  is  not 
noticeable  except  in  presence  of  copper),  are  unavoidably 
present,  the  addition  of  soda  chloride  will  ensure  a  clean 
turbidity.  The  inky  tint  is  not  permanent,  but  it  dis- 
appears very  slowly. 

Interference  of  certain  Metals. 

The  interference  of  nickel,  cobalt,  zinc,  mercury,  silver, 
and — less  noticeable  because  of  rarer  occurrence — gold, 
platinum,  and  palladium,  is  known  to  be  of  such  extent 
as  to  invalidate  the  cyanide  titration  of  copper.  Indeed 
nickel,  cobalt,  mercury,  and  silver  may  be  quantitatively 
estimated  by  these  means.  There  are,  however,  a  large 
number  of  compounds  whose  effed  it  would  be  well  to 
study  anew  under  conditions  which  are  altogether  inde- 
pendent of  colour  reaction.  The  presence  of  those 
compounds  which  form  a  precipitate  either  before  or 
during  the  titration  are  especially  noteworthy  in  this 
connection. 

Only  the  following  three  metals  have  been  already  ex- 
perimented with.  In  each  case  0*05  grm.  of  copper  was 
present. 

/>'o«.— Added  as  FeaCIe. 


0 

O'OI 

0*03 

o'05  grm.  Fe 

50-3 

50-4 

50*35 

50-0  c.c.  KCN 

0-0500 

0*0501 

0*0500 

o"0496  grm.  Cu 

— 

O'OOOI 

O'OOOO 

0*0004  Error. 

It  is  quite  impossible  under  these  conditions  to  make 
any  use  of  colour  readlion.  The  precipitate  remains  sus- 
pended for  some  time,  and  is  so  finely  divided  as  to  pass 
through  a  moderately  porous  paper.  An  expansive  as- 
bestos filter  gives  a  clear  filtrate. 

Aluminium. — Added  as  AljClg. 


0 

O'l 

0*03 

0*05  grm.  Al 

50-3 

50-6 

5i'i 

51-1  c.c.  KCN 

0-0500 

00503 

00508 

00508  grm.  Cu 

— 

0-0003 

o"ooo8 

o'oooS  Error. 

The  colour  readlion  can  be  distindly  followed.  The 
variations  accord  with  ammon.  cyan,  titration  when  per- 
formed as  usual. 

Manganese, — Added  as  MnCIj- 


0 

o-oi 

0-03 

0*05  grm.  Mn 

50-3 

47  35 

47 '3 

47*4  c.c.  KCN 

0-0500 

0-0471 

0*0470 

0-0471  grm.  copper 

— 

0*0029 

0*0030 

0-0029  Error. 

The  colour  change  is  no  guide.  The  results  are  in 
accord  with  those  by  the  usual  titration. 

Considerable  attention  has  been  paid  to  the  cause  of  these 
low  values,  though  without,  so  far  as  I  know,  any  satis- 
faftory  explanation  being  come  to.  The  deficiency  here 
is  somewhat  less  than  the  usual  amount.  Thus  Field 
(Chemical  News,  i.,  63)  finds  a  deficiency  of  12  per  cent, 
Thomson  a  deficiency  of  20  per  cent. 

It  is  noteworthy  that  the  deficiency  seems  to  be  inde- 

♦  I  have  elsewhere  pointed  out  that  the  rapidity  with  which  the 
resulting  turbidity  disappears  indicates  the  approaching  end- 
read^ion. 


pendent  of  the  amount  of  manganese  present.  No 
especial  emphasis  is  laid  on  this  point.  The  tests  were 
arranged  merely  to  decide  whether  or  no  the  manganese 
would  a£t  as  usual,  and,  although  interesting  in  the  above 
charader  so  far  as  they  go,  they  are  altogether  inadequate 
to  support  a  far-reaching  pronouncement. 

A  more  extended  list  of  added  metals  will  be  given  later, 
together  with  some  means  of  obviating  the  interference 
and  applying  the  correded  process  to  the  determination 
of  copper -in  copper  alloys. 


LONDON     WATER   SUPPLY. 
Report  on  the  Composition  and  Quality  of  Daily 
Samples    of  the  Water   Supplied  to    London 
for  the  Month  Ending  August  31ST,  1897. 

By  SIR  WILLIAM  CROOKES,  F.R.S., 

and 

PROFESSOR  DEWAR,  F.R.S. 

To  Major-General  A.  De  Courcy  Scott,  R.E., 
Water  Examiner,  Metropolis  Water  Act,  1871. 

London,  September  loth,  1897. 
Sir, — We  submit  herewith,  at  the  request  of  the 
Diredors,  the  results  of  our  analyses  of  the  175  samples 
of  water  colleded  by  us  during  the  past  month,  at  the 
several  places  and  on  the  several  days  indicated,  from  the 
mains  of  the  London  Water  Companies  taking  their 
supply  from  the  Thames  and  Lea. 

In  Table  I.  we  have  recorded  the  analyses  in  detail  of 
samples,  one  taken  daily,  from  August  ist  to  August  3i8t 
inclusive.  The  purity  of  the  water,  in  respedt  to  organic 
matter,  has  been  determined  b<y  the  Oxygen  and  Com- 
bustion processes;  and  the  results  of  our  analyses  by 
these  methods  are  stated  in  Columns  XIV.  to  XVIII. 

We  have  recorded  in  Table  II.  the  tint  of  the  several 
samples  of  water,  as  determined  by  the  colour-meter 
described  in  a  previous  report. 

In  Table  III.  we  have  recorded  the  oxygen  required  to 
oxidise  the  organic  matter  in  all  the  samples  submitted 
to  analysis. 

Of  the  175  samples  examined  during  the  month  all  were 
found  to  be  clear,  bright,  and  well  filtered. 

The  rainfall  at  Oxford  during  August  was  3*94  inches, 
and  was  very  fairly  distributed,  with  the  exception  of  0-88 
inch  which  fell  on  the  30th  ;  the  average  fall  for  the  last 
30  years  during  this  month  is  2'32  inches;  we  have  there- 
fore had  an  excess  of  1-62  inches.  This  figure  is  also  the 
adual  excess  for  this  year,  to  the  end  of  August. 

Our  bacteriological  examination  of  235  samples  taken 
by  us  have  given  the  following  results  ;  we  have  also  ex- 
amined 41  other  samples,  from  special  wells,  stand-pipes, 
&c.,  making  a  total  of  276  in  all : — 

Microbes 
per  c.c. 

Thames  water,  unfiltered  (mean  of  25  samples)  3420 
Thames  water,  from  the  clear  water  wells  of 
five  Thames-derived  supplies  (mean  of  117 

samples) 51 

Ditto        ditto               highest  775 

Ditto        ditto              lowest  10 

New  River,  unfiltered  (mean  of  25  samples)  ..  3420 

New  River,  filtered  (mean  of  23  samples)      ..  44 

River  Lea,  unfiltered  (mean  of  25  samples)   ..  5846 
River  Lea,  from  the  clear  water  well  of  the 
East  London  Water  Company  (mean  of  21 

samples) 64 

The  fad  that,  in  spite  of  the  great  excess  of  rain,  the 
number  of  microbes  per  c.c.  has  decreased  in  the  case  of 
every  Water  Company's  supply,  except  one,  which 
remains  the  same  as  during  the  previous  month,  shows 


ig2 


Action  0/ Nitric  Acid  on  Tnphenylmethane, 


f  Chemical  News, 


Oa.  15, 1897. 


that  the  filtering  appliances  of  the  companies  are  in  ex- 
cellent working  order. 

We  are,  Sir, 

Your  obedient  Servants, 

William  Crookes. 
James  Dewar. 


THE    ACTION     OF     NITRIC     ACID     ON 

TRIPHENYLMETHANE. 

By  E.  S.  SMITH. 

The  method  of  preparing  trinitrotriphenylmethane  by  the 
adtion  of  fuming  nitric  acid  on  triphenylmethane  is 
described  by  Fischer  (Ann.  Chem.,  Liebig,  cxciv.,  254). 
In  an  attempt  to  make  this  preparation  I  departed  from 
the  exadt  diredtions  of  Fischer,  and  obtained  a  substance 
shown  by  analysis  to  be  triphenylcarbinol,  C. OH. (05115)3. 
Following  are  the  details  of  the  work : — I  placed  in  a 
flask  an  unweighed  quantity  of  triphenylmethane  recently 
crystallised  from  benzene,  and  probably  still  retaining  a 
little  benzene ;  poured  in  an  unmeasured  quantity  of 
nitric  acid  (sp.  gr.  i'34),  and  then  some  fuming  nitric 
acid  ;  allowed  the  mixture  to  stand  a  short  time,  then 
heated  on  the  sand-bath  for  a  few  minutes.  After  the  re- 
adion  was  ended  a  large  amount  of  water  was  poured  in. 
The  reddish  yellow  precipitate  formed  was  filtered  off  on 
a  platinum  cone.  By  pressing  down  the  precipitate  a 
small  amount  of  a  red  oil,  having  the  smell  of  nitro- 
benzene, was  forced  out.  The  solid  substance  was  puri- 
fied by  treating  it  with  hot  glacial  acetic  acid,  crystallising 
it  from  a  mixture  oi  benzene  and  glacial  acetic  acid,  re- 
crystallising  from  benzene,  and  finally  from  alcohol.  The 
purified  substance  is  white,  resembles  triphenylcarbinol, 
and  melts  sharply  at  161°  (uncorr.).  A  test  for  nitro- 
gen by  the  Prussian-blue  method  showed  absence  of 
nitrogen. 

o'i38  grm.  gave  0*0773  grm.  water,  and  0'4458  grm. 
carbon  dioxide,  indicating  the  following  composition: — 


Ci,    . 

HI6  . 

0       . 

Calculated  for 
triphenylcarbinol. 

.       . .      87-80 
.       ..        615 
.     ..       6-15 

Found. 

88-IO 

6-22 

Several  attempts  to  confirm  this  work  by  repeating  it 
were,  on  the  whole,  unsuccessful,  though  various  modifi- 
cations in  the  strength  of  acid,  manner  of  heating,  &c., 
were  tried.  In  one  case  a  very  small  quantity  of  a  white 
crystalline  substance  was  obtained,  which,  after  re-crystal- 
lising from  benzene,  melted  at  161°. 

Nitric  acid  of  sp.  gr.  1-42  does  not  adl  upon  triphenyl- 
methane until  the  temperature  is  raised  to  about  100° ; 
but  the  produA  obtained  in  this  case,  as  in  most  of  the 
other  experiments,  was  a  waxy  substance  of  salmon 
colour,  from  which  I  was  not  able  to  get  a  crystalline 
compound. 

I  could  find  no  record  of  triphenylcarbinol  having  been 
made  in  this  manner ;  the  usual  method  of  preparation  is 
to  oxidise  the  triphenylmethane  with  chromic  acid. — 
American  Chemical  journal,  xix.,  702. 


Condy's  Fluid.— Notice  of  Removal.— The  Proprie- 
tors of  "  Condy's  Fluid  "  notify  that  they  find  it  necessary 
to  remove  to  more  extensive  and  commodious  premises. 
All  communications  should  in  future  be  addressed  to 
Condy's  Fluid  Works,  65,  Goswell  Road,  London,  B.C. 


PROCEEDINGS    OF    SOCIETIES. 

THE    CHEMICAL    AND     METALLURGICAL 

SOCIETY    OF     SOUTH     AFRICA. 

Meeting  held  on  July  17,  1897,  «^  Johannesburg. 

Mr.  Chas.  Butters,  President,  in  the  Chair. 

The  President  delivered  his  Inaugural  Address,  in 
which  he  first  referred  to  the  history  of  chemistry  and 
metallurgy  on  the  Johannesburg  gold-fields.  Until  now 
there  has  been  but  one  industry,  viz.,  gold-mining.  Pro- 
perly speaking  there  is  no  Chemical  Industry,  as,  whatever 
chemical  processes  there  may  be  at  work,  all  have  to  do 
intimately  with  the  extradtion  of  gold.  Silver  and  copper  are 
both  at  the  Willows  and  the  Albert  silver-mines,  and  silver- 
lead  at  the  Transvaal  silver-mines  ;  these  mines,  however, 
have  not,  owing  to  the  excessive  cost  of  production,  been 
yet  made  to  pay.  An  attempt  is  being  made  to  establish 
the  manufadture  of  sulphuric  acid,  but  the  only  fadlory  yet 
at  work  produces  acid  of  low  commercial  strength  only. 
This  is  an  important  matter,  as  it  will  largely  influence 
the  produdlion  of  cheap  and  trustworthy  dynamite. 
Glass  is  being  manufadtured  successfully  at  Pretoria. 
The  coal  in  the  Transvaal  may  be  considered  as  pradli- 
cally  inexhaustible,  but  the  percentage  of  ash  is  extremely 
high,  viz.,  20  to  25  per  cent,  and  the  quality  is  very 
variable.  Galena  is  very  plentiful  in  the  Transvaal,  going 
as  high  as  80  per  cent  of  lead  ;  the  smelting  of  the  ore  is 
done  locally,  but  the  demand  is  limited.  But,  as  was 
pointed  out  above,  the  one  industry  that  can,  to  a  certain 
extent,  survive  the  repressive  measures  of  the  authorities, 
is  gold-mining,  and  it  is  to  gold  only  that  the  country  can 
at  present  look  for  commercial  prosperity.  A  great  deal 
of  money  and  thought  is  now  being  expended  on  re- 
covering the  last  traces  of  the  precious  metal  which  only 
a  few  years  ago  was  allowed  to  run  to  waste  ;  tailings 
have  been  regularly  treated,  and  now  managers  are 
turning  more  attention  to  slimes. 

IVIr.  D.  J,  William's  paper  on  "  Some  Notes  of  the 
Estimation  of  Lead  in  Slags  "  was  next  discussed,  after 
which  followed  the  discussion  of  Mr,  E.  H.  Johnson's 
paper  "  On  the  Reduction  of  Zinc-Gold  Slimes." 

Mr,  Caldecott  mentioned  that  he  had  used  acid  sul- 
phate of  soda  or  potash  instead  of  sulphuric  acid  for  this 
operation  ;  he  found  it  cheaper  and  better. 

Mr.  McBride,  after  paying  tribute  to  the  excellence  of 
Mr.  Johnson's  paper,  could  not  agree  with  him  as  to  the 
increased  cost  of  the  acid  process ;  he  found  three- 
quarters  of  a  pound  of  acid  enough  for  one  pound  of 
liioist  zinc-gold  chips.  He  then  gave  details  of  his  own 
system  of  cleaning  up,  which  is  so  intimately  connedled 
with  the  acid  treatment  as  to  be  almost  inseparable  from 
it  in  a  discussion  of  this  kind. 

Mr.  Crosse  had  noticed  that  some  bars  assayed  as  high 
as  825  fine,  while  others  went  very  much  lower ;  he 
therefore  analysed  some,  and  found  iron,  nickel,  cobalt, 
and  lead,  the  three  latter  not  being  removable  by  sulphuric 
acid. 

Mr.  J.  R.  Williams  then  read  a  paper  "  On  the  Treat- 
ment of  Battery  Slimes.'"  It  is  four  years  since  the  author 
first  commenced  experimenting  on  the  recovery  of  gold 
from  battery  slimes,  and  he  has  now  succeeded  in  evolving 
a  process  which  works  in  a  most  satisfadory  manner'! 
Briefly  it  is  as  follows  : — After  separating  the  tailings,  the 
slime  water  flows  through  a  launder,  where  enough  lime 
(in  the  form  of  milk  of  lime)  is  added  to  precipitate  the 
slimes  in  a  flocculent  form  ;  regularity  of  feeding  the 
lime  plays  an  important  part  in  this  process  ;  an  excess 
is  as  bad  as  too  little.  After  mixing,  the  liquid  passes 
through  a  series  of  large  settling  pits,  10  feet  deep,  from 
whence  the  water  runs  away  pradtically  clear.  The 
sediment,  with    about   10  per  cent  of   water,  is  then 


Crbmical  News,  i 

oa.  15, 1897.    J 


Patents  /or  Inventions, 


193 


pumped  up,  and  treated  with  a  o-6i  per  cent  solution  of 
cyanide,  and  the  gold  recovered  in  the  usual  manner. 
The  profit  made  during  the  months  of  April  and  May  on 
this  process  alone  was  equal  to  a  15  per  cent  per  annum 
dividend  on  the  capital  of  the  Company  (Crown  Reef 
G.  M.  Co.).  The  discussion  of  the  paper  was  postponed. 
Mr.  W.  A.  Caldecott  then  read  the  following  paper: 
"  The  Solution  of  Gold  in  Accumulated  and  other  Slimes.^' 
When  battery  slimes  are  settled  in  dams  or  pits,  certain 
readions  take  place  which  result  in  the  formation  of  de- 
composition produds,  among  which  is  ferrous  sulphide, 
FeS,  derived  from  the  decomposition  of  pyrites,  FeSj. 
This  compound  imparts  a  dark  grey  or  black  colour  to  the 
slimes  where  it  occurs  in  any  quantity,  and  is  easily  iden- 
tified by  the  smell  of  sulphuretted  hydrogen  given  off  on 
the  addition  of  acid.  The  exacft  stages  of  the  decompo- 
sition may  be  open  to  discussion,  but  the  author  inclines 
to  the  opinion  that  the  main  stages  of  increasing  oxida- 
tion are  as  follows  : — 

1.  FeS2 Iron  pyrites. 

2.  FeS-f-S        ..     ..   Ferrous  sulphide  and  sulphur. 

3.  FeS04-j-H2S04..   Ferrous     sulphate     and     sul- 

phuric acid. 

4.  Fe2(S04)3    ..     ..   Ferric  sulphate. 

5.  2Fea03,S03        ..   Insoluble,    basic,    ferric    sul- 

phate. 

6.  Fe203 Ferric  oxide. 

During  the  treatment  of  slimes  by  cyanide,  the  presence 
of  finely  divided  ferrous  sulphide  causes  abstradion  of 
oxygen  from  the  solutions,  whereby  the  solution  of  gold 
is  prevented.  Other  ferrous  compounds,  such  as  ferrous 
hydrate,  readt  in  the  same  manner,  as  does  also  the  de- 
composing organic  matter  always  present  in  slimes.  The 
obvious  way  to  prevent  this  interference  is  to  supply 
oxygen,  either  by  pumping  in  air  and  agitating,  or  by 
chemical  means;  the  cheapest  and  best  of  the  latter  is 
found  to  be  permanganate  of  potash,  about  one-eighth  to 
half  a  pound  per  ton  of  dry  slimes  was  found  to  be  suffi- 
cient. Speaking  generally,  old  slimes  are  considerably 
more  acid  than  old  tailings,  and  a  consumption  of  from 
8  lbs.  to  20  lbs.  of  lime  per  ton  of  dry  slimes  is  by  no 
means  uncommon.  The  use  of  air  is  far  cheaper,  and  in 
some  cases  it  is  an  absolute  necessity,  as  the  gold  simply 
will  not  dissolve  until  after  aeration,  so  that,  instead  of 
merely  accelerating  the  aftion  of  the  cyanide,  it  becomes 
as  necessary  as  that  substance  itself.  After  a  few 
remarks  the  discussion  of  the  paper  was  postponed  and 
the  meeting  adjourned. 


NOTICES  OF  BOOKS. 


Patents  for  Inventions.  A  bridgments  of  Specifications 
Class  I. — Acids,  Alkalies,  Oxides,  and  Salts.  Inorganic 
Period,  A.D.  i88/|— 88.  Published  at  the  Patent  Offi  ce 
1896.  Price  IS. 
The  Patent  Laws  of  this  country  make  no  provision  for 
an  official  search  as  regards  novelty,  and  all  patents  are 
taken  out  at  the  risk  of  the  inventors.  It  is  therefore 
incumbent  on  any  person  desiring  to  obtain  a  valid 
patent  for  an  invention  either  to  cause  a  search  to  be 
made,  or  himself  to  make  a  search  as  to  the  novelty  of 
his  invention.  By  omitting  such  a  search,  many  a 
patentee  has  found,  after  paying  his  fees,  that  his  treasured 
patent  is  worthless,  because  it  has  been  anticipated.  Of 
course,  in  this  case  the  first  applicant  or  patentee  pos- 
sesses all  the  Patent  rights,  and  the  second  one  has 
absolutely  no  rights  at  all. 

A  complete  and  exhaustive  search  through  published 
Specifications  of  Patents  is  a  task  of  considerable  diffi- 
culty, even  for  the  trained  expert  with  all  the  resources  of 
the  Patent  Office  Library,  for  at  this  moment  the  number 


of  printed  Specifications  of  Patents  is  well  over  a  quarter 
of  a  million. 

A  series  of  Indexes  and  Abridgments  has  been  published 
by  the  Patent  Office  as  a  guide  to  the  specifications  them- 
selves, and  is  freely  distributed  to  the  principal  public 
libraries  in  this  country.  The  Abridgments  give  a 
general  description  of  the  nature  of  every  invention 
patented,  and  the  objedl  of  their  publication  is  to  enable 
the  would-be  patentee  to  carry  out,  at  any  rate  in  some 
cases,  what  may  be  termed  a  fireside  search.  By  the 
study  of  these  Abridgments  he  will  generally  be  able  to 
seledt  certain  inventions  which  have  already  been 
patented,  and  which  resemble  his  own  invention  suffi- 
ciently to  render  it  desirable  for  him  to  examine  their 
specifications  in  detail.  A  printed  copy  of  any  specifica- 
tion can  be  obtained  at  an  inclusive  price  of  8d.,  through 
any  Post  Office,  by  a  special  Postcard  (Patents  Form  C). 
The  Abridgments  are  published  in  volumes,  each  volume 
dealing  with  one  particular  class  of  inventions,  such  as 
"  Steam  Engines,"  and  "  Cooking  and  Kitchen  Appli- 
ances,  &c."  for  a  period  of  some  years.  The  volumes  up 
to  1877  are  not  illustrated,  and  all  the  subjedts  have  not 
yet  been  dealt  with,  but  from  1877  onwards  a  systematic 
series,  very  fully  illustrated,  is  now  in  course  of  publica- 
tion at  a  uniform  price  of  one  shilling  per  volume 
(including  inland  postage).  The  volumes  for  the  periods 
from  1877  to  1883  an<i  ^^om  1884  to  1888  have  been  com- 
pleted, those  for  the  periods  from  1889  to  1892  and  from 
1893  to  1896  are  in  adtive  preparation,  and  later  volumes 
will  follow  in  due  course.  For  the  purposes  of  the 
Abridgments  the  whole  field  of  invention  has  been 
divided  into  146  **  Abridgment  Classes,"  and  the  list  of 
these  classes  in  itself  shows  what  an  enormous  field  this 
is,  and  how  greatly  its  produdts  vary.  Every  triumph  of 
applied  science,  such  as  the  locomotive,  the  telegraph, 
and  the  dynamo,  is  to  be  found  here,  and  every  one  of  our 
great  national  manufadtures  and  industries  finds  its 
appointed  place.  Each  volume  contains  abridged  descrip- 
tions of  the  inventions  falling  under  one  of  the  146 
classes  during  the  period  of  which  it  treats  (illustrated 
by  diagrams  or  drawings  wherever  possible),  a  detailed 
Index  to  the  inventions  according  to  their  subjedt-matter, 
and  an  Index  to  the  names  of  patentees  or  applicants. 

For  the  use  of  those  who  desire  to  make  a  careful 
study  of  Patents,  the  Patent  Office  also  publishes  an 
"Abridgment-Class  and  Index  Key  "  (price  is.,  parcel 
postage  5d.),  which  shows  in  detail  how  inventions  are 
classified,  abridged,  and  indexed  throughout  its  pub- 
lications. 


X  Rays  in  Surgery.  ("  Razele  X  in  Chirurgie.")  By 
Prof.  C.  Severeanu.  With  26  Radiographic  Plates. 
Bucharest :  F.  Gobi.     1897.     ^P-  94- 

This  latest  contribution  to  our  knowledge  of  X  rays  goes 
over,  to  a  great  extent,  the  same  ground  as  the  earlier 
books  on  the  same  subjedt. 

In  discussing  the  theory  of  the  origin  of  the  X  rays, 
the  author  is  of  the  opinion  that  they  do  not  emanate 
from  the  cathode  itself;  that  is  to  say,  they  are  not 
cathode  rays  proper,  but  they  are  set  up  by  the  impinging 
of  the  cathode  rays  on  some  other  body,  either  the  glasi 
envelope  of  the  Crookes  tube  or  the  anti-cathode. 

The  illustrations  are  very  good,  and  include  a  number 
of  deformities,  fradlures,  and  freaks — such  as  a  hand  with 
six  fingers,  a  foot  with  six  toes,  and  such  like. 


The  Chemical  Composition  of  Waters.  ("  La  Composicion 
Quimica  de  las  Aguas."  By  Juan  J.  J.  Kyle,  D.Sc, 
Professor  of  Chemistry  at  the  University  of  Buenos 
Aires.     Buenos  Aires  :  680  Calle  Peru.     1897. 

We  find  in  this  pamphlet  a  large  number  of  analyses  of 
water  from  all  parts  of  Brazil ;  some  are  ordinary  potable 


194 


Chemical  Notices  from  Foreign  Sources, 


(Cbbuical  Nbws, 
OA.  15,  18Q7. 


waters,  but  many  contain  a  large  quantity  of  dissolved 
salts.  The  results  are  expressed  in  parts  per  100,000,  and, 
though  they  represent  a  great  amount  of  time  and  work, 
they  are  of  no  particular  interest  to  English  readers. 


Manuali  Hoepli, — Manual  for  Chemists  and  Industrialists. 
A  Colledion  of  Tables  of  Physical  and  Chemical  Data, 
and  of  Processes  of  Technical  Analysis,  (''  Manuale 
del  Chimico  e  dell'  Industriale."  Raccolta  de  Tabelle, 
di  Dati,  Fisici  e  Chimici,  e  di  Processi  d'Analisi  Tech- 
nica  ad  uso  di  Chimici  Analitici  e  Technici,&c.).  By  Dr, 
LuiGi  Gabba.  Second  Editon,  Enlarged  and  Enriched 
with  the  Analytical  Tables  of  H.  Will.  Milan  :  Ulrico 
Hoepli.     1898.     Pp.  442- 

The  physical  tables  are  extremely  copious,  and  are  satis- 
fadory  in  every  resped  save  the  prominence  awarded  to 
the  hydrometric  scale  of  Baume,  which  seems  to  take  its 
stand  on  its  essentially  irrational  charader. 

There  is  a  useful  table  of  molecular  weights  and  solu- 
bilities in  cold  water,  boiling  water,  and  alcohol. 

The  fourth  chapter,  headed  "Applied  Chemistry,"  in- 
cludes the  chemical  examination  of  potable  waters. 
Here  are  given  the  chief  components  of  the  subsoil  water 
of  Milan ;  the  regulations  for  the  analysis  of  potable 
waters  in  Paris ;  diredlions  for  the  assay  of  ores  and 
metals,  including  pyrites,  burnt  ores,  ores  of  copper, 
zinc,  and  lead  ;  the  eledric  assay  of  metals  and  alloys. 
Then  follow  assays  concerning  the  heavy  chemical  indus- 
tries, such  as  the  analysis  of  the  gases  of  pyrites  kilns,  and 
of  chamber  and  tower  gases. 

According  to  Wedding  i  Hefner  =  to  approximately 
j^j  Carcel,  the  luminous  power  of  an  Auer  gas  burner  on 
and  after  400  hours  is  the  loss  of  about  25  per  cent. 

The  assay  of  soaps,  of  wax,  of  mixtures  of  wax  and 
tallow,  and  of  spurious  butters,  is  fully  discussed. 

Methods  are  given  for  determining  the  acidity  of  oils, 
for  detecting  cotton-seed  oil,  colza,  sesame,  and  arachis. 

After  instrudtions  for  the  examination  of  varnishes,  we 
come  to  the  assay  of  soaps,  of  textile  fibres,  tissues,  and 
paper;  and  the  analysis  of  soils,  manures,  &c. 

The  work  is  exceedingly  rich  in  valuable  and  rare  in- 
formation. We  can  especially  recommend  it  to  the 
tropical  and  subtropical  farmer  and  explorer. 


Manuali  Hoepli.  —  La  Grande  Industria  Chimica.  La 
Fabricazione  dell'  Acido  Solforico  et  dell'  Acido  Nitrico 
del  Solfato  Sodico,  dell'  Acido  Muriatico.  By  Dott.  V. 
Vender,  Chimico  Consulante  a  Milano, formerly  Chemist 
and  Diredtor  of  Water  Works.  With  107  Cuts  and  many 
Tables.     Milan  :  Ulrico  Hoepli.     1897.     Pp*  279. 

The  volume  before  us  belongs  to  the  useful  series  of 
Manuals  now  being  produced  by  the  firm  of  Hoepli,  and 
treats  of  the  most  important  branches  of  heavy  chemical 
industry.  The  work  opens  with  statistical  generalities, 
which  confirm  the  statement  that  among  the  chemical 
industries  sulphur  plays  a  part  analogous  to  that  held  by 
iron  in  the  mechanical  world.  In  1890  the  world's  pro- 
dudtionof  sulphuric  acid  amounted  to  2800  thousand  tons, 
of  which  870,000  were  manufaftured  in  Britain,  506,000 
in  Germany,  and  234,000  in  France.  Italy  contributes  to 
the  sum-total  120,000  tons.  The  American  yield  is  not 
quoted.  Among  the  various  qualities  of  pyrites  quoted, 
the  highest  grades  are  those  obtained  from  Spain  and 
Portugal. 

The  approximate  table  of  atomic  weights  is,  in  one 
case  at  least,  misleading,  since  it  ranks  platinum  higher 
than  gold. 

The  only  objedlionable  feature  in  this  work  is  that  it 
persists  in  the  exclusive  use  of  the  hydrometric  or 
areometric  scale  of  Baume— distinguished  for  nothing 
but  its  disadvantages. 


CHEMICAL     NOTICES    FROM    FOREIGN 
SOURCES. 


Note,— All  degrees  of  temperature  are  Centigrade  unless  otherwise 
expressed. 

Comptes  Rendus  Hebdomadaires  des  Seances,  deVAcademie 
des  Sciences.    Vol.  cxxv,,  No.  11,  September  13,  1897. 

Ele(5trolytic  Separation  of  Nickel  and  Cobalt  from 
Iron.  Application  to  the  Determination  of  Nickel  in 
Steels. — O.  Durn,— Will  be  inserted  in  full. 

Contributions  to  the  Determination  of  Iron  in 
Urine, — Dr,  Adolf  Jolles. — Hamburger's  volumetric  pro- 
cedure has  been  modified  so  as  to  require  less  time.  For 
the  gravimetric  determination  nitroso-j8-naphthol  is  recom- 
mended as  a  suitable  reagent.  The  iron  is  separated  from 
a  hydrochloric  solution  by  a  concentrated  solution  pf 
nitroso-j8-naphthol  in  acetic  acid  at  50 — 52  per  cent.  The 
precipitate  has  the  composition  CioH60,NO3Fe. 

Simplification  of  the  Determination  of  Potassium. 
— Adolf  Meyer.  —  The  reagents  necessary  are  normal 
barium  chloride,  normal  oxalic  acid,  solution  of  platinum 
chloride  containing  i  grm.  Pt  in  10  c.c.  free  from  nitric 
acid,  and  lastly  alcohol  at  80  per  cent  by  volume. 

Iodine  Number  of  Cacao  Butter. — Dr.  D.  Held.— 
The  value  51  is  admittedly  an  error. 

Determination  of  Boric  Acid  according  to  Gooch. 
— K.  Kraut. — This  paper  requires  the  accompanying  illus- 
tration. 

No.  12,  September  20. 

On  Oxycellulose. — L.  Vignon. — Under  the  microscope 
oxycellulose  appears  to  consist  of  very  short  filaments. 
It  turns  yellow  at  100°  and  is  insoluble  in  neutral  reagents. 
It  is  turned  blue  by  iodine  and  sulphuric  acid.  The 
colouration  is  more  rapid  and  more  distindl  than  with  cellu- 
lose.     The  centesimal  composition  is — 

Cellulose,  Oxycellulose, 

C 44'44        43*55 

H 6*17  6'o3 

O 49*39        50'42 

But  if  we  submit  oxycellulose  to  Lang's  procedure  (fusion 
with  potassa  at  180°)  we  find — 

Cellulose.  Oxycellulose. 
P.c.  P.c. 

Soluble  in  fused  KOH     ..       12  87-58 

Insoluble     ..      ..      ..      ..       88  i2'42 

We  are  led  to  consider  this  oxycellulose  as  a  mixture  of 
75  per  cent  oxycellulose  and  25  cellulose.  The  heat  of 
combustion  is  as  follows  : — 

Cellulose        4224  to  4190 

Oxycellulose 4133    „  4T24 

Absorption  of  Basic  Colouring  Matters, — Cellulose 
and  oxycellulose  have  been  compared  from  this  point  of 
view  by  steeping  in  baths  of  known  strength,  obtained 
with  safranine  and  methylene  blue,  for  thirty  minutes  at 
ebullition.  Their  impoverishment  serves  to  measure  the 
absorption.  Schiff's  reagent  (magenta  and  sulphuric 
acid),  prepared  according  to  Villiers  and  Fayolle,  yields, 
with  oxycellulose,  an  intense  violet  colouration.  It 
possesses,  therefore,  aldehydic  functions. 

On  Retamine. — J.  Battandier  and  Th.  Malasse. — 
Retamine  is  capable  of  yielding  neutral  salts  containing 
two  mols.  of  monobasic  acid  or  one  mol.  of  bibasic  acid 
to  one  mol.  of  alkaloid,  and  basic  salts  containing  one 
mol.  of  monobasic  acid  to  one  mol.  of  alkaloid. 

Influence  of  Colouring-matters  upon  the  Fermen- 
tation of  Highly-coloured  Red  Wines.— P.  Carles  and 
G.  Riviere.— The  incomplete  transformation  of  sugar  in 
highly-coloured  musts  is  due  to  the  colouring-matter,  and 


Cbbmical  News,  ) 

oa.  15, 1897.    I 


Chemical  Notices  from  Foreign  Sources, 


195 


not  to  the  acidity;  for  decodlions  of  elder,  whether  acidi- 
fied  or  not,  give  the  same  results.  This  colouring-matter, 
allied  to  the  tannins,  adls  as  an  antiseptic  upon  the 
microbia  of  fermentation. 

No.  13,  September  27. 

Stability  of  the  Phosphorescent  Strontium  Sul- 
phides.— J.  R.  Moureto.— In  general  the  phosphorescent 
strontium  monosulphides  are  of  little  stability.  Like  the 
alkaline  or  alkaline-earthy  sulphides,  they  have  a  ten- 
dency  to  become  partially  polysulphised  or  sulphatised, 
forming  hydrosulphates  of  sulphides.  These  properties, 
common  to  combination  of  sulphur  with  various  metals, 
have  no  direft  influence  on  the  phosphorescence  of 
strontium  sulphide. 

On  Parastannyl  Chloride.  —  R.  Engel.  —  The  fadls 
summarised  in  this  paper,  and  which  will  be  developed  in 
a  subsequent  memoir,  readily  explain  the  contradictions 
of  former  authors.  The  so-called  metastannic  acid,  ob- 
tained at  a  low  temperature,  is  in  reality  a  mixture  of 
stannic  and  metastannic  acids. 

On  various  Double  Chlorides  formed  by  Cincho- 
namine. — Leon  Boutroux  and  P.  Genvresse. — A  know- 
ledge of  the  fa<5ls  observed  by  the  authors  permits  us  to 
avoid  a  cause  of  error  in  the  detection  of  nitrates  by 
cinchonamine. 


journal  de  Pharmacie  et  Chemiei 
Series  6,  vol  vi.,  No.  4. 

Histological  and  Chemical  Study  of  the  A(5tion 
of  Antiseptics  on  Muscular  Fibres.  —  A.  Riche.— 
This  research  is  exclusively  devoted  to  the  adtion  of  anti- 
septics in  the  preservation  of  meat,  in  connexion  with  a 
certain  very  dilute  liquid ;  analysis  has  shown  that  it  is 
formed  of  nearly  pure  bisulphide  of  lime.  It  is  slightly 
acid,  and  gives  off  a  slight  smell  of  sulphurous  acid ; 
similar  solutions  of  the  same  density  were  made  from 
commercial  sulphites  of  lime  and  soda.  The  matters 
examined  were  from  the  fillet  of  beef.  Experiments  were 
made  by  immersion  in  water,  and  in  the  reagents  for 
seven  hours,  and  the  results  compared.  After  immersion 
for  thirty  hours,  the  fibres  were  dissociated  mechanic- 
ally and  examined  under  the  microscope,  and  very 
important  differences  were  found.  Measurements  of  the 
diameters  of  the  fibres  were  made,  and  there  was  found 
to  be  a  remarkable  difference  between  those  treated  in 
these  three  solutions  and  others  treated  with  other  re- 
agents, such  as  boric  acid,  formol,  &c. 

A(5tion  of  Iodine  on  Albumenoid  Matters.  —  E. 
Lepinois. — The  author  considers  that  iodocasein  might  be 
susceptible  of  a  therapeutic  application  in  the  case  when 
thyroiodine  and  other  iodised  substances  have  been  used 
or  recommended. 

On  Aloines. — E.  Leger. — Aloines  have  been  derived 
from  aloes  from  many  parts  of  the  world,  but  they  may 
all  be  divided  into  two  groups  :  the  flrst  comprises,  ac- 
cording; to  various  authorities,  barbaloine,  socaloine, 
zanaloine,  and  curacaloine  ;  and  the  second  only  nat- 
aloine.  This  latter  differs  entirely  from  the  others  by  its 
almost  complete  insolubility  in  water,  even  when  warmed. 
It  is  also  very  slightly  soluble  in  alcohol.  According  to 
some  writers  there  appears  to  be  no  doubt  that  the  first- 
mentioned  four  are  identical. 


Bulletin  des  Travaux  de  la  Society  de  Pharmacie  de 
Bordeaux.    August,  1897. 

Hygienic  Value  of  Table  Mustard.— P.  Carles.— 
Not  suitable  for  abstradlion. 

New  Pra(!\ical  Apparatus  for  Lixiviation. —  L. 
Barthe.— The  apparatus  proposed  by  M.  Fonzes-Diacon 


is  incontestably  superior  to  that  of  Soxhlet,  but  it  is  too 
difficult  and  expensive  to  make  and  too  fragile  for  general 
use.  The  author  therefore  recommends  one  that  is  very 
simple  in  construiStion  and  easy  to  use,  A  small  tube, 
contradted  at  the  lower  end,  is  placed  inside  another  of 
similar  shape  but  larger,  but  they  are  prevented  from 
touching  closely  by  a  thin  glass  rod  which  is  placed 
between  them  :  the  large  tube  is  fitted  to  a  flask  by  means 
of  a  cork,  and  a  vertical  condenser  is  conneded  to  its 
upper  end;  the  vapour  of  the  solvent  passes  through  the 
interstices  between  the  two  tubes,  and  being  condensed, 
falls  down  on  to  the  substance  to  be  lixiviated  in  the  inner 
tube. 

Coefficient  of  Partage  of  the  Monobasic  Fatty 
Acids  of  the  Series  C»  Haw  O2  from  the  Condensation 
of  Ci  to  the  Condensation  of  Cj  inclusive.— Th.  Gar- 
raud.— A  long  paper,  not  suitable  for  abstradion. 


Bulletin  de  la  Societe  Chimique  de  Farts. 
Series  3,  Vol.  xvii.-xviii.,  No.  15. 

On  the  Oxidising  Power  of  Manganous  Salts,  and 
on  the  Chemical  Constitution  of  Laccase. — G.  Ber- 
trand. — Continuing  his  researches  on  this  subje(5t,  the 
author  finds  that  bioxide  of  manganese,  stable  in  acidulated 
water,  is  reduced  as  soon  ashydroquinoneis  added,  giving 
a  manganous  salt,  at  the  same  time  forming  quinone.  It 
follows  from  this  that  a  definite  weight  of  a  manganous 
salt  ought  to  oxidise,  at  the  expense  of  the  air,  an  un- 
limited amount  of  hydroquinone,  or  any  other  body 
equally  oxidisable.  The  principal  interest  in  the  observa- 
tions made  in  this  paper  is  to  complete,  so  far  as  concerns 
the  chemical  constitution  and  the  mode  of  adtion  of 
oxidases,  an  idea  which  sprung  from  the  researches  the 
author  has  already  published,  on  the  intervention  of  man- 
ganese in  the  oxidations  provoked  by  laccase. 

Existence  of  a  Proteic  Body  foreseen  by  M.  Ber* 
trand  in  the  Constitution  of  Oxidases.— J.  de  Rey- 
Pailhade. — The  substance  discovered  by  the  author  in 
i88g,  and  called  by  him  "  philothion,"  possesses  the  pro- 
perties required  by  M.  Bertrand. 

On  Cryoscopy  of  Milk  and  Organic  Liquids. — A. 
Ponsot. — Two  solutions  having  the  same  congealing 
point  are  not  always  equimolecular,  and  two  solutions 
having  the  same  point  of  congelation,  under  conditions 
of  a  given  pressure,  are  in  osmotic  equilibrium  under 
this  pressure  at  the  temperature  of  congelation  ;  but  they 
are  not  so  as  a  rule  at  all  temperatures,  and  in  particular 
at  the  temperature  of  the  organism. 

On  the  Estimation  of  Caffein  in  Coffee. — E.  Tas- 
silly. — The  methods  of  estimating  caffein  in  coffee  may 
be  divided  into  three  groups: — i.  Exhaust  with  warm 
chloroform  alone,  in  the  presence  of  a  base,  such  as  lime, 
magnesia,  ammonia.  2.  Exhaust  with  warm  water,  and, 
after  various  treatments,  the  aqueous  solution  is  agitated 
with  chloroform,  or  evaporated  with  magnesia  and  treated 
by  the  same  warm  solvent  in  a  digester.  3.  The  coffee 
alone  or  mixed  with  an  alkali  (lime  or  magnesia),  is  ex> 
hausted  by  a  solution  of  an  organic  salt  (benzoate  or 
salicylate  of  soda),  then  the  mass  is  exhausted  by  cold 
chloroform.  These  three  methods  are  briefly  described 
and  critised,  and  the  author  concludes  that  the  methods 
of  No.  I  group  generally  give  but  uncertain  results;  the 
methods  by  using  benzoate  or  salicylate  of  soda  give  a 
very  pure  produdt,  but  it  takes  up  too  much  time ;  but 
none  of  them  are  entirely  satisfadlory. 

On  a  New  Method  for  the  Estimation  of  Caffein 
in  Coffee. — E.  Tassilly. — The  author  proposes  to  treat 
the  coffee  with  water,  and  then  evaporate  to  dryness; 
the  residue  is  then  treated  with  sulphuric  acid,  and  the 
caffein  dissolved  in  boiling  water ;  at  this  point  one  can 
either  evaporate  to  dryness  in  the  presence  of  sand  and 


196 


chemical  Notices  jrom  Foreign  Sources. 


magnesia,  followed  by  an  exhaustion  by  warm  chloroform 
in  a  digester,  or,  add  ammonia  and  exhaust  with  cold 
chloroform  in  a  flask. 

On  the  Estimation  of  Oxide  of  Iron  and  Alumina 
in  Phospbatss. — N.  Blattner  and  J.  Brasseur. — Already 
inserted, 


CARPENTERS'      COMPANY'S 

TECHNICAL   INSTITUTE, 

STRATFORD, 


E. 


'VENING  CLASSES  are  held  in  Inorganic 

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Further  Experiments  on  the  Liquefaction  of  Fluorine. 

THE    CHEMICAL     NEWS. 

Vol.  LXXVI.,  No.  1978. 


197 


FURTHER     EXPERIMENTS 
ON     THE    LIQUEFACTION     OF    FLUORINE. 

By    M.    MOISSAN    and   J.    DEWAR. 


THE     PERMEABILITY    OF 

ELEMENTS     OF     LOW     ATOMIC     WEIGHT     TO 

THE    RONTGEN    RAYS. 

By  J.  H.  GLADSTONE,  D.Sc,  F.R.S.,  and 
W.  HIBBERT,  F.I.C. 

In  the  Chemical  News  (vol.  Ixxiv.,  p.  235)  there  was 
published  a  condensed  account  of  a  communication  made 
by  us  to  the  British  Association,  on  the  action  of  metals 
and  their  salts  on  the  Rontgen  rays.  On  December  i8th 
(Ixxiv.,  298)  appeared  a  longer  paper,  by  Dr.  Waddell, 
on  the  same  subjed ;  and  in  the  Chemical  News  of 
Odlober  ist  of  this  year  (Ixxvi.,  161)  tncre  appears  a 
second  paper  which  Dr.  Waddell  sent  to  Toronto.  In 
this  he  attacks  our  general  conclusions,  specially  with 
reference  to  the  order  of  permeability  of  the  alkaline 
metals  lithium,  sodium,  and  potassium. 

While  Dr.  Waddell's  knowledge  of  lithium  is  entirely 
derived  from  its  salts,  we  determined  its  permeability  in 
comparison  with  sodium  and  potassium  from  plates  of 
the  metals  of  known  thickness.  We  thus  got  rid  of  any 
error  due  to  the  presence  of  the  acid  radicals. 

Marangoni  has  repeated  our  experiments  with  larger 
quantities  of  the  three  metals,  and  come  to  the  same 
conclusion  as  ourselves,  namely,  that  lithium  has  an 
extremely  small  absorption.  He  finds  that  the  metallic 
lithium  must  be  ten  times  as  thick  as  the  sodium  to  pro- 
duce the  same  absorption. 

In  judging  the  statements  of  Dr.  Waddell  and  our- 
selves, it  must  be  borne  in  mind  that  when  we  give  the 
order  of  comparative  permeability,  we  mean  the  perme- 
ability of  an  equal  number  of  atoms,  that  is,  equal  atomic 
weights, — seven  parts  of  lithium  compared  with  twenty- 
three  of  sodium  and  thirty-nine  of  potassium,  whereas 
Dr.  Waddell  compares  equal  absolute  weights. 

It  is  clear  that  in  his  method  of  observation  the  quantity 
of  the  acid  radical  cannot  be  the  same  in  the  salts  wtiich 
he  compares.  Yet  the  eff-dt  of  this  acid  radical  is  very 
important.  He  does  not  seem  to  have  perceived  this  at 
first.  Even  when  further  experiment  gave  him  results 
which  "surprised  "  him,  he  still  retained  in  large  part  the 
opinions  previously  formed. 

When  the  comparison  is  made  for  equal  thicknesses  of 
the  three  alkaline  metals  (not  their  salts),  the  order  of 
permeability  is  still  decidedly  lithium,  sodium,  and 
potassium. 

On  attentively  reading  Dr.  Waddell's  last  paper,  we  do 
not  see  that  any  one  of  his  experiments  is  inconsistent 
with  our  conclusions,  but  in  many  cases  our  conclusions 
throw  light  on  his  difficulties. 

The  most  original  part  of  Dr.  Waddell's  paper  is  that 
on  the  peculiar  granular  appearance  presented  by  the 
shadows  of  salts  in  his  pill-boxes.  We  have  frequently 
noticed  the  same  phenomenon,  but  have  never  seriously 
investigated  it. 

We  hope  shortly  to  publish  quantitative  measurements 
of  the  intensity  of  some  of  these  Rontgen  ray  shadows,  a 
small  number  of  which  were  in  faiSt  communicated  to  the 
British  Association  at  Toronto. 


Chemist  to  the  London  County  Council. —  At  the 
recent  meeting  of  the  London  County  Council,  the 
recommendation  of  the  General  Purposes  Committee, 
that  Dr.  Frank  Clowes,  of  Notingham,  be  appointed 
successor  to  Mr.  W.J.  Dibdin,  F.I.C,  F.C.S.,  as  Cnemist 
and  Superintending  Gas  Examiner,  was  unanimously 
confirmed. 


In  May,  1897  (Comptes  Rendus,  cxxiv.,  1202)  we  had  the 
honour  of  presenting  to  the  Academy  our  first  experi- 
ments  on  the  liquefadtion  of  fluorine ;  we  will  now 
describe  "some  fresh  experiments  we  have  made  on  this 
subjeft. 

Liquefaction  of  Fluorine. — Our  latest  experiments  on 
liquetadion  were  carried  out  by  means  of  an  apparatus 
similar  to  that  which  we  have  already  described, — that  is 
to  say,  a  glass  bulb  fused  to  a  platinum  tube,  which  con- 
tained another  similar  smaller  tube;  but  each  of  these 
tubes  was  fitted  with  a  screw  valve,  in  such  a  manner 
that,  at  any  moment,  communication — either  with  the 
outer  air  or  with  the  current  of  fluorine — could  be  inter- 
rupted. This  little  apparatus  was  placed  in  a  cylinarical 
glass  receptacle  with  double  sides,  containing  liquid  air. 
rhe  whole  was  conneded  with  a  vacuum  pump,  and  fur- 
nished with  a  manometer. 

In  a  series  of  preliminary  experiments,  we  determined 
exadlly  the  boiling-points  of  liquid  oxygen  at  various 
pressures,  as  shown  by  the  manometer. 

In  some  former  experiments  we  had  shown  that  fluorine 
does  not  become  liquid  at  the  temperature  of  boiling 
oxygen  at  the  ordinary  atmospheric  pressure. 

We  now  find  that,  by  repeating  the  same  experiment 
with  freshly  prepared  liquid  air,  the  fluorine  becomes 
liquid  as  soon  as  the  air  begins  to  boil,  at  the  ordinary 
pressure. 

We  have  repeated  our  former  experiment,  with  liquid 
oxygen  as  refrigerant,  and,  on  making  a  vacuum,  we  find 
that  the  liquefadlion  of  fluorine  takes  place  by  the 
evaporation  of  the  oxygen  at  a  diminution  of  pressure 
of  325  cm.  of  mercury. 

From  these  two  experiments  we  are  enabled  to  state 
that  the  boiling  temperature  of  fluorine  is  very  close 
to  -187°. 

Experiments  on  Solidification. — When  the  little  glass 
bulb  was  three-quarters  full  of  liquid  fluorine,  we  closed 
both  the  valves,  and  then  caused  the  liquid  air  serving  as 
refrigerant  to  boil  rapidly,  at  a  diminution  of  pressure  of 
725  cm.  Under  these  conditions  we  obtained  a  tem- 
perature of  —210°.  The  fluorine  did  not  show  any  sign 
of  solidification,  but  retained  its  charadleristic  mobility. 
To  complete  this  experiment  it  becomes  necessary  to 
cause  the  rapid  ebullition  of  the  liquid  fluorine  thus  ob- 
tained ;  we  hope  to  achieve  this  in  future  experiments. 
When  we  had  repeated  this  experiment  f-everal  times,  a 
slight  accident  occurred  to  one  of  our  little  in>truments 
containing  the  fluorine.  The  screw  of  one  of  the  valves 
becoming  worn,  allowed  the  air  to  enter  the  bulb.  This 
air  was  immediately  liquefied,  and  in  a  few  moments  we 
had  two  distindt  layers  of  liquid ;  the  upper,  colourless 
layer,  consisted  of  liquid  air;  the  lower  one,  of  a  pale 
yellow  colour,  being  fluorine. 

In  another  experiment,  taking  great  precautions  to 
prevent  the  ingress  of  any  air,  the  fluorine  was  introduced 
in  its  liquid  state  into  a  glass  tube,  the  end  of  which  was 
then  sealed  before  the  blowpipe.  Tlie  sealed  tube,  con- 
taining the  liquid  fluorine,  was  kept  for  a  long  time  at 
—  2X0°,  by  the  rapid  evaporation  of  a  large  quantity  of 
liquid  air,  but  it  gave  no  trace  of  a  solid  body. 

Density  of  Liquid  Fluorine. — To  determine  the  density 
of  liquid  fluorine,  we  biought  it  into  contadt  with  a  number 
of  bodies  whose  density  is  known  exadtlv.  By  takmjj 
groups  of  bodies  whose  densities  are  very  close  to  each 
other,  it  is  easy  to  see  which  sink  and  which  float  in  the 
liquid.  This  well-known  though  indiredl  methofi  was  the 
most  suitable  for  these  delicate  experiments.  We  first  of 
all  satisfied  ourselves  that  the  fluorine  had  no  adtion  on 
the  materials  used.  To  fffedt  this  we  placed  a  crystal  of 
sulphocyanide  of  ammonium  (density  =  i°3i)  in  a  glas$ 


iqS 


Further  Experiments  on  the  Liquefaction  of  Fluorine, 


Chbuical  Nbwb, 

oa,  32, 1897. 


tube  surrounded  with  boiling  liquid  air;  we  then  turned 
in,  to  the  bottom  of  the  tube,  a  current  of  fluorine  gas, 
by  means  of  a  platinum  jet.  The  fluorine  was  rapidly 
liquefied,  and  the  sulphocyanide  of  ammonium  was  not 
attacked.  We  repeated  the  experiment  with  a  fragment 
of  ebonite  (D  =  1-15),  of  caoutchouc  (D  =  o-gg),  of  wood 
(D  =  o*g6),  of  amber  (D  =  1-14),  and  of  oxalate  of 
methyl  (D  =  I'lS).  It  is  of  importance,  in  the  experi- 
ments  we  have  just  mentioned,  that  the  various  materials 
used  should  be  first  kept  at  a  temperature  of  -200°,  for 
some  little  time. 

In  one  of  our  experiments  a  piece  of  caoutchouc, 
having  been  insufficiently  cooled,  took  fire  on  the  surface 
of  the  liquid,  and  burnt  completely  away  with  a  brilliant 
flame,  without  leaving  any  residue  of  carbon.' 

The  experiment  was  carried  out  in  the  following 
manner :— In  a  glass  tube  closed  at  one  end,  and  of  which 
the  lower  part  had  been  slightly  drawn  out,  we  placed 
fragments  of  the  five  substances  we  have  just  mentioned. 
The  tube  was  then  plunged  to  a  third  of  its  length  into 
boiling  liquid  air.  When  it  was  all  reduced  to  a  tem- 
perature  of  about  —200°  we  carefully  introduced  the 
fluorine  gas.  This  soon  became  liquefied,  and  we  saw 
the  wood,  the  caoutchouc,  and  the  ebonite  floating  easily 
on  the  surface  of  the  pale  yellow  liquid.  On  the  other 
hand,  the  oxalate  of  methyl  remained  at  the  bottom, 
while  the  amber  rose  and  fell  in  the  liquid,  appearing  to 
be  of  the  same  density.  The  apparatus  was  shaken 
several  times,  and  the  quantity  of  liquid  fluorine  increased, 
but  the  results  were  always  the  same. 

We  therefore  arrive  at  the  conclusion,  from  these  ex- 
periments, that  the  density  of  liquid  fluorine  is  i'i4. 
Another  point  which  appears  to  be  of  interest  is  the 
following :  —  The  fragment  of  amber  floating  in  the 
fluorine  was  very  difficult  to  distinguish,  which  would 
seem  to  indicate  that  the  index  of  refraftion  of  liquid 
fluorine  is  very  close  to  that  of  solid  bodies. 

In  another  experiment  we  liquefied  fluorine  in  a  glass 
tube  which  had  been  previously  graduated;  we  then 
sealed  the  tube,  which  had  been  weighed  before  the  ex- 
periment, and  left  it  alone  in  a  beaker  full  of  liquid  air  at 
the  ordinary  pressure.  An  hour  and  a  half  afterwards,  the 
tube  still  being  in  i  cm.  of  liquid  air,  the  fluorine  had  not 
changed  in  appearance.  But  shortly  afterwards,  when 
the  air  had  all  evaporated,  a  violent  detonation  occurred  ; 
the  sealed  tube  and  the  double  beaker  in  which  it  had 
been  placed  were  smashed  and  reduced  to  powder.  The 
sealed  tube  showed  us  that  liquid  fluorine  sustains,  at 
from  —187°  to  —210°,  a  diminution  of  volume  of  i/i4th. 

Absorption  Spectrum. — We  examined  with  the  spedtro- 
scope  different  samples  of  liquid  fluorine  through  a  thick- 
ness of  about  I  cm.,  either  in  sealed  tubes  or  by  means 
of  our  little  condensing  apparatus,  but  we  have  never 
been  able  to  deleft  absorption-bands. 

Magnetism. — Liquid  fluorine  placed  between  the  poles 
of  a  powerful  eleftro-magnet,  does  not  show  any  magnetic 
phenomena.  These  experiments  are  the  more  decisive 
as  we  made  comparative  ones  with  liquid  oxygen,  as  be- 
fore ;  they  were  repeated  several  times. 

Capillarity.  —  The  capillary  constant  of  fluorine  is 
weaker  than  that  of  liquid  oxygen.  A  capillary  tube, 
plunged  successively  in  fluorine,  oxygen,  alcohol,  and 
water,  gave  the  following  figures  :— 

Height  of  liquid  fluorine  . .     ..  3*5  m.m. 

„  „     oxygen    ....  5'°    » 

„        alcohol       14*0    ti 

„        water 22*0    „ 

The  Action  of  some  Substances  on  Liquid  Fluorine. 
Hydrogen. — Liquid  fluorine  in  a  glass  tube  was  cooled 
down  by  liquid  air  boiling   at   a  low  pressure.     A  slow 
current  of  hydrogen  gas  was  made  to  impinge  on  the  sur- 

*  This  piece  of  caoutchouc  ran  about  the  surface  Qf  the  liquid  like 
sodium  on  water,  giving  a  very  intense  light. 


face  of  the  yellow  liquid  by  means  of  a  platinum  jet. 
There  was  immediate  combination,  with  the  produdtion  of 
a  flame  which  lighted  up  the  tube.  The  experiment  was 
repeated  by  dipping  the  platinum  jet  below  the  surface  of 
the  liquid.  At  this  temperature  (  —  210°)  complete  com- 
bination still  took  place,  with  a  considerable  evolution  of 
light  and  heat. 

In  another  experiment  the  hydrogen  apparatus  ter- 
minated with  a  fine  glass  tube  dipping  into  the  liquid 
fluorine  ;  when  the  hydrogen  was  turned  on  the  combina- 
tion took  place  immediately  and  with  violence. 

Oil  of  Turpentine. — Oil  of  turpentine,  frozen  and  cooled 
down  to  —210°,  is  attacked  by  liquid  fluorine.  To  per- 
form this  experiment  we  placed  a  little  oil  of  turpentine 
at  the  bottom  of  a  glass  tube  surrounded  with  boiling  liquid 
air.  As  soon  as  a  small  quantity  of  fluorine  was  liquefied 
on  the  surface  of  the  carbide  the  combination  took  place 
with  explosive  force,  a  brilliant  flash  of  light,  and  deposi- 
tion of  carbon.  After  each  explosion,  the  current  of 
fluorine  gas  was  kept  up  slowly,  a  fresh  quantity  of  liquid 
fluorine  was  formed,  and  the  detonations  succeeded  each 
other  at  intervals  of  from  six  to  seven  minutes.  Finally, 
after  a  longer  interval  of  about  nine  minutes,  the  quantity 
of  fluorine  formed  was  sufficient  to  cause,  at  the  moment 
of  the  readtion,  the  complete  destrudtion  of  the  apparatus.* 

Oxygen. — The  adlion  of  liquid  oxygen  has  been  studied 
with  much  more  care,  since  we  observed  from  our  earliest 
experiments  that  by  passing  a  current  of  fluorine  through 
liquid  oxygen,  we  obtained  a  detonating  body. 

If  we  bring  a  current  of  fluorine  on  to  the  surface  of 
liquid  oxygen  in  a  glass  tube,  the  fluorine  dissolves  in  all 
proportions,  imparting  a  yellowish  colour,  and  giving  the 
liquid  a  graded  tint  from  the  upper  to  the  lower  part ;  the 
bottom  of  the  tube  is  hardly  coloured.  If,  on  the  con- 
trary, we  introduce  the  fluorine  gas  at  the  bottom  of  the 
liquid  oxygen,  the  yellow  colour  is  produced  at  the 
bottom  and  diffuses  slowly  to  the  upper  layers. 

This  phenomenon  indicates  that  the  densities  of  liquid 
fluorine  and  oxygen  are  very  near  each  other.  When  we 
have  obtained  a  mixture  of  liquid  oxygen  and  fluorine,  if 
we  allow  the  temperature  to  rise  slowly,  the  oxygen  evapo- 
rates first.  The  liquid  becomes  more  and  more  concen- 
trated as  to  fluorine,  and  finally  the  latter  begins  to  boil 
in  its  turn.  In  fadt,  at  the  commencement  of  this  boiling 
the  gas  coming  off  will  light  a  match  which  has  only  a 
red-hot  point,  and  will  not  make  lamp-black  or  silicon  red- 
hot;  but,  on  the  other  hand,  the  gas  coming  off  at  the 
end  of  the  experiment  will  instantly  cause  these  two  latter 
bodies  to  burst  into  flame.  When  the  glass  bulb  is  com- 
pletely empty  and  its  temperature  is  rising,  we  suddenly 
notice  a  distindt  disengagement  of  heat,  and  the  interior 
of  the  glass  loses  its  polish.  This  rise  of  temperature  is 
due  to  the  fluorine  gas  attacking  the  glass.  In  this  ex- 
periment, when  using  perfedlly  dry  oxygen,  no  precipitate 
is  produced.  If,  on  the  contrary,  we  use  oxygen  which 
has  been  some  hours  in  contadt  with  the  air,  the  deton- 
ating substance  we  mentioned  in  our  previous  communi- 
cation is  produced  with  great  readiness. 

In  one  of  our  experiments,  in  which  we  tried  to  obtain 
a  notable  quantity  of  this  body,  we  had  an  explosion 
strong  enough  to  smash  the  glass  in  which  the  experiment 
was  being  performed. 

To  sum  up,  this  body,  which  is  produced  by  the  adtion 
of  fluorine  on  moist  oxygen,  seems  to  be  hydrate  of  fluor- 
ine, decomposing,  with  detonation,  by  a  simple  rise  of  tem- 
perature. 

Water. — We  froze  and  cooled  down  to  —210°  a  small 
quantity  of  water  at  the  bottom  of  a  glass  tube.  Liquid 
fluorine  formed  on  the  surface  of  the  ice  as  a  mobile 
liquid  without  adtion,  and  it  evaporated  on  the  tempera- 
ture rising.  As  soon  as  the  apparatus  became  warmer  the 
remaining  gaseous  fluorine  attacked  the  ice  with  great 
energy,  and  we  noticed  a  strong  smell  of  ozone. 


*  In  several  of  our  experiments  we  accidentally  let  a  little  liquid 
flourine  fall  on  the  floor;  the  wood  instantly  took  fire. 


ChbUical  Nbwb,  ) 

Oft.  22, 1897,    r 


Apparatus  for  Students. 


199 


Mercury, — We  solidified  a  globule  of  mercury  at  the 
bottom  of  a  tube.  The  surface  remaining  very  brilliant, 
the  liquid  fluorine  surrounded  it  without  causing  it  to 
lose  its  appearance  or  polish.  Onallowingthetemperature 
to  rise  to  —187°  the  fluorine  began  to  boil,  the  liquid  dis- 
appeared completely,  but  the  attack  of  the  mercury  by  the 
fluorine  gas  did  not  take  place  until  the  apparatus  had 
almost  reached  the  temperature  of  the  laboratory. 

Conclusions. 

Fluorine  gas  is  easily  liquefied  at  the  temperature  of 
boiling  atmospheric  air.  The  boiling-point  of  liquid 
fluorine  is  —187°.  It  is  soluble  in  all  proportions  in 
liquid  oxygen  and  in  liquid  air.  It  does  not  solidify  at 
—  210°.  Its  density  is  1*14,  its  capillarity  is  less  than  that 
of  liquid  oxygen ;  it  has  no  absorption  spedlrum,  and  it  is 
not  magnetic. 

Finally,  at  —210°  it  hasnoadtion  on  dry  oxygen,  water, 
or  mercury,  but  it  reafts,  with  incandescence,  on  hydrogen 
and  oil  of  turpentine.— Cow^^«  Rendus,  cxxv.,  No.  15,  p. 
505,  1897. 


NOTE   ON   THE 

ASSAY    OF   ELECTRO-PLATING   AND   GILDING 

SOLUTIONS. 

By  ALFRED  H.  ALLEN. 

The  "  Note  on  the  Estimation  of  Silver  in  Silver-plating 
Solutions,"  by  Mr.  T.  J.  Baker  (Chemical  News,  Ixxvi., 
p.  167),  appears  to  show  that  very  imperfeift  methods  of 
analysis  for  the  assay  of  plating  solutions  are  still  in 
vogue.  The  method  employed  by  Mr,  Baker,  namely,  pre- 
cipitation of  the  metals  with  cyanide  by  adding  nitric  acid, 
and  cupellation  of  the  precipitate,  will  no  doubt  give 
accurate  results.  It  appears  to  me,  however,  to  be  less 
satisfadlory  on  the  whole  than  the  following  method  de- 
vised and  published  by  me  some  twenty  years  since: — 

From  20  to  50  c.c.  of  the  plating  solution  to  be  tested 
is  largely  diluted  with  water,  and  the  liquid  raised  to  the 
boiling-point.  Sulphuretted  hydrogen  is  then  passed 
through  the  liquid,  or  ammonium  sulphide  gradually 
added.  The  silver  falls  as  a  black  sulphide,  which  is 
liable  to  be  contaminated  with  copper  and  zinc.  The 
washed  precipitate  is  rinsed  off  the  filter  into  a  flask  or 
beaker,  and  treated  with  an  excess  of  bromine  water, 
which  converts  it  rapidly  and  completely  into  argentic 
bromide.  If  any  sulphur  appears  to  have  separated,  a 
drop  of  bromine  should  be  added  to  the  residue,  so  as  to 
ensure  complete  oxidation.  Boiling  water  is  now  added, 
and  the  silver  bromide  is  washed,  dried,  fused,  and 
weighed.  18S  parts  by  weight  of  the  precipitate  represent 
I08  of  metallic  silver. 

For  the  determination  of  the  precious  metal  contained 
in  the  solution  of  the  double  cyanide  of  gold  and  potassium 
used  for  electro-gilding,  I  have  found  the  following  method 
very  satis faftory : — A  measured  quantity  of  the  gilding 
solution  is  introduced  into  a  porcelain  crucible  and 
cautiously  concentrated.  When  in  a  syrupy  condition,  a 
few  grms.  of  pure  red-lead  or  litharge  should  be  added, 
and  the  evaporation  continued  to  complete  dryness. 
There  is  little  or  no  tendency  to  spitting.  The  crucible 
containing  the  residue  is  covered  and  raised  for  a  short 
time  to  a  moderate  red-heat.  The  lead  oxide  is  reduced 
by  the  cyanide  present,  with  produ(£tion  of  metallic  lead 
and  cyanate,  and  the  reduced  metal  unites  with  the  gold. 
The  resultant  button  of  metal  is  separated  from  the 
slag,  and  the  gold  contained  in  the  alloy  isolated  either 
by  cupellation  or  by  treatment  with  pure  nitric  acid. 

Electro-iilvering  solutions  may  be  assayed  in  a  precisely 
similar  manner;  but  in  this  case  treatment  of  the  rich 
lead  with  nitric  acid  is,  of  course,  inadmissible,  and  cupel- 
lation must  be  resorted  to. 

Sheffield,  Oftober  4i  x897- 


APPARATUS     FOR    STUDENTS 

IN     ELEMENTARY    PRACTICAL    CHEMISTRY. 

By  GEORGE  GEORGE. 

The  teaching  of  elementary  chemistry  has  undergone  a 
great  change  since  1889,  when  the  Committee  of  the 
British  Association  made  their  Report  upon  the  subjeft. 

One  of  the  outcomes  of  this  progressive  movement  is 
that  the  student  himself  now  performs  a  good  many 
experiments  which  previously  were  shown  only  by  the 
teacher.  In  consequence,  the  latter  is  constantly  on  the 
look-out  for  simple,  effedlual,  and  inexpensive  apparatus, 
by  means  of  which  a  large  number  of  students  can 
simultaneously  establish  for  themselves  well-known 
chemical  truths  or  repeat  chemical  experiments. 

The  accompanying  diagrams  represent  apparatus  which 
I  have  found  most  satisfadtory,  and  trust  other  teachers  of 
chemistry  may  do  likewise. 

In  Fig.  I  is  shown  a  large  thistle  funnel,  used  for  de- 
termining the  equivalent  weights  of  the  metals,  and  by 
means  of  which  boys — using  a  balance  costing  about 
thirty  shillings— can  obtain  results  involving  less  than 
o'5  per  cent  of  an  error. 

The  funnel,  which  has  a  capacity  of  about  100  c.c,  is 
made  of  thin  glass,  and  weighs  about  30  grms.  b  is  a 
small  bulb,  in  which  asbestos  wool  is  placed. 


HGi 


FIQU 


The  modus  operandi  is  as  follows : — The  bulb  b  is  filled 
with  asbestos  wool  that  has  previously  been  well  washed 
with  distilled  water  and  dried.  A  short  glass  rod  (about 
2  inches),  rounded  at  both  ends,  is  then  placed  with  the 
funnel,  and  the  whole  accurately  weighed.  Then,  sup- 
posing it  is  required  to  find  the  weight  of  magnesium 
which  will  replace  loo  grms.  of  silver,  about  o'i5  grm.  of 
magnesium  ribbon  is  weighed  out  and  placed  in  the 
funnel  A.  A  short  piece  of  glass  rod  is  fastened  to  the 
stem  of  the  funnel  at  k,  by  means  of  a  bit  of  rubber 
tubing.  About  50  c.c.  of  a  solution  of  silver  nitrate 
(2  per  cent)  is  now  poured  into  A,  and  the  magnesium 
ribbon  well  stirred  with  the  glass  rod,  to  remove  the  silver 
deposited  upon  it.  After  a  short  time  the  solution  is 
allowed  to  run  off,  by  removing  the  stopper  at  K.  The 
stopper  is  then  replaced,  and  a  fresh  quantity  of  solution 
placed  in  A. 

When  all  the  magnesium  has  been  dissolved,  the  pre- 
cipitated silver  is  washed  repeatedly  with  distilled  water, 
and  finally  with  a  little  methylated  spirits.  The  whole 
is  then  removed  to  the  oven,  dried,  and  weighed,  the 
increase  in  weight  representing  the  weight  of  the  silver 
deposited. 

Of  course  the  same  performance  can  be  gone  through 
with  other  metals  and  solutions,  it  being  necessary,  how- 
ever, in  some  cases  to  heat  the  solution  before  placing  it 
in  A. 

Fig.  2  needs  little  explanation.  It  represents  a  cross 
se(5lion  of  a  flask  designed  to  facilitate  the  colledion  ot 


200  Determination  of  Phosphorus  m  Steel,  Iron,  and  Iron  Ores.    {""oa.'k^'^S;*^* 


water  produced  hy  a  burning  jet  of  hydrogen.  The 
flask  F  is  about  300  c.c.  capacity,  with  rather  a  wide  neck, 
and  at  the  bottom  drawn  in  all  the  way  round  as  seen  at 
G  g',  whilst  a  cone  proje(5ts  downwards  and  has  its  apex 
at  p.  Cold  tap  water  is  kept  circulating  in  the  flask  by 
means  of  the  tubes  c  and  d,  so  that  the  cone  P  is  always 
cold.  The  burning  jet  of  hydrogen  impinges  upon  this 
cone,  and  the  water  produced  is  there  condensed,  drips 
from  P,  and  is  caught  in  a  vessel  below.  By  means  of 
this  apparatus,  pracftically  the  whole  of  the  water  pro- 
duced by  the  burning  hydrogen  is  coUeded,  and  in  a  short 
time  sufficient  can  be  obtained  to  determine  boiling  and 
melting  points,  density,  &c. 

Both  of  these  pieces  of  apparatus  can  be  made  by  the 
teacher  himself,  if  he  is  at  all  expert  in  glass-blowing, 
or  they  can  be  obtained  at  a  small  cost  from  any  glass- 
blower. 

Allan  Glen's  School  (Glasgow  and  W.  of  Scotland 
Technical  College). 


ELECTRICAL  ENERGY  CAUSED  BY  THE 

DIRECT  ACTION   OF  THE   ATMOSPHERE. 
By  H.  N.  WARREN,  Principal,  Liverpool  Research  Laboratory. 

The  atmosphere,  or,  more  corredlly  speaking,  the  gaseous 
constituent  oxygen  contained  therein, — not  only  when  in 
a  combined  form,  as  observed  in  most  of  the  more  ener- 
getic primary  depolarisers.  but  even  in  the  ordinary 
gaseous  condition, — has,  since  the  introduction  of  Sir  W. 
Groves's  well-known  gas  battery,  been  continuously  ex- 
perimented by  various  scientific  men,  in  the  hope  of 
securing  at  least  a  somewhat  economical  supply  of  that 
subtle  force  now  so  largely  employed  over  the  entire  field 
of  civilisation. 

Experiments  of  a  lengthy  nature  which  have  also  been 
engaged  m,  at  the  above  laboratory,  have  at  last  termi- 
nated in  the  successful  introdudion  of  an  eledtrical 
generator,  which,  even  at  the  present  time,  although  only 
in  its  infancy,  is  more  than  promising  as  a  liberal  source  of 
eledtricity,  not  only  on  account  of  the  extremely  low  rate  of 
the  chemicals  employed,  but  also  at  the  same  time  ranking 
next  to  perpetual  motion  on  account  of  its  perfed  resus- 
citation, whereas  the  simplicity  of  its  construtStion  enables 
any  one,  without  any  special  knowledge,  to  obtain  at  a 
trifling  expense  an  electrical  current  of  almost  any  required 
pressure. 

The  positive  element  of  this  powerful  generator  is  com- 
posed of  plates  consisting  of  a  special  porous  compressed 
graphite,  of  which  one  quarter  of  the  plate  is  rendered 
adtive  by  immersion  in  platinic  oxalate,  and,  after  drying, 
igniting  the  same  in  an  atmosphere  of  hydrogen  gas.  By 
this  operation  a  very  finely  divided  platinum  surface  is 
obtained,  which,  when  in  contadt  with  a  solution  of  ferrous 
sulphate,  readily  induces  the  oxygen  of  the  atmosphere  to 
combine  with  and  to  oxidise  the  iron  present  to  the  state 
of  a  ferric  salt.  In  order  to  construd  the  cell,  several  of 
these  so-prepared  plates  of  graphite  are  attached  to  a  cir- 
cular lead  beam,  which  surrounds  a  porous  diaphragm 
containing  as  a  negative  element  a  rod  of  amalgamated 
zinc,  the  carbons  being  so  arranged  as  to  allow  the  platin- 
ised portion  to  project  above  the  solution  consisting  of  a 
strongly  acidified  portion  of  ferric  sulphate.  On  comple- 
tion of  the  circuit  a  powerful  current  is  at  once  set  free, 
and  continues  until  the  complete  redudion  of  the  ferric 
salt  has  taken  place,  which  naturally  terminates  the 
aiftion.  On  now  withdrawing  the  zinc  from  the  interior 
solution,  an  exadtly  reverse  adion  is  observed,  the  adive 
platinum  surface  of  the  carbon  condensing  the  atmo- 
spheric oxygen,  which  steadily  re-oxidises  the  ferrous  salt, 
and  thus  renews  the  adion  when  required.  With  four 
ounces  of  ferric  salt,  contained  in  a  generator  7  inches 
by  5,  an  eledric  current  may  be  maintained  with  very 
slight  fall  at  2  v.  8  amp.  for  twenty-four  hours. 


A  further  modification  of  the  above  cell  is  now  under 
experiment,  in  which  it  is  hoped  to  be  able  to  absorb  the 
hydrogen  gas  by  means  of  special  manganese  compounds, 
thus  replacing  the  more  expensive  element  platinum.  For 
laboratories,  and  indeed  any  spot  where  a  long-continued 
adiun  is  required,  such  as  eledro-dissolution,  they  com- 
pare very  favourably  with  nitric  acid  cells,  and  all  other 
depolarisers  which  evolve  noxious  vapours. 

Liverpool  Research  Laboratory, 
18,  Albion  Street,  £verton,  Liverpool. 


DETERMINATION     OF     PHOSPHORUS     IN 

STEEL,     IRON,     AND     IRON     ORES. 

By  JULIUS  OHLY,  Ph.D. 

In  the  determination  of  phosphorus  according  to  the 
molybdate  method  it  has  been  customary  either  to  obtain 
the  yellow  precipitate  in  the  usual  manner, — to  dissolve  it 
in  ammonia  water,  reduce  it  by  means  of  zinc,  and  titrate 
the  ammoniacal  solution  with  permanganate, — or  to  de- 
termine the  amount  of  phosphorus  present  by  means  of  a 
standard  solution  of  sodium  hydrate.  In  the  first  method 
the  only  indication  for  the  completeness  of  the  redudion 
has  been  found  in  the  colour  of  the  reduced  liquid,  which 
is  supposed  to  be  of  an  olive-green  colour  before  the 
addition  of  the  permanganate  is  admissible. 

It  has  been  found,  however,  that  the  operating  chemist 
must  be  extremely  careful  and  thoroughly  experienced,  in 
order  to  strike  this  point  properly,  and  even  then  the  re- 
sults obtained  have  been  found  to  be  wanting.  Besides 
the  reducing  operation  with  zinc,  &c.,  is  of  a  very  tedious 
nature,  and  the  tendency  has  been  for  these  reasons  to  do 
away  with  the  redudion  of  the  ammoniacal  solution  en- 
tirely, and  to  substitute  a  more  speedy  and  reliable 
procedure  instead. 

The  following  method  is  considered  by  the  author  as  an 
improvement,  as  it  does  not  leave  anything  to  be  desired 
in  speed  or  reliability,  being  fully  equal  in  results  to  those 
obtained  by  the  gravimetric  method. 

Two  grms.  of  sample  (steel)  are  dissolved  in  45  c.c. 
nitric  acid,  sp.  gr.  ii5,  in  an  8-ounceErlenmeyer  flask,  by 
heating  until  in  solution.  While  hot,  5  c.c.  saturated  so- 
lution of  potassium  permanganate  are  added,  and  the 
whole  allowed  to  boil  until  the  pink  colour  has  disappeared. 
Five  or  six  drops  of  a  saturated  solution  of  sugar  are  then 
added,  and,  if  these  do  not  dissolve  the  precipitated  oxide, 
a  few  drops  more  are  added,  avoiding  carefully  all  excess. 
Let  the  flask  cool  now  to  about  60°  C,  add  5  c.c,  am- 
monia, shake  until  clear,  add  30  to  40  c.c.  molybdate, 
shake  well,  allow  to  settle  for  a  moment,  filter  with  sudion, 
wash  with  2  per  cent  nitric  acid  six  times,  and  rinse  the 
flask  with  same.  Then  wash  precipitate  and  flask  with  a 
2  percent  solution  of  potassium  nitrate,  remove  filter  and 
precipitate  from  funnel,  and  put  them  back  into  the  flask. 
Add  25  c.c.  standard  sodium  hydrate  solution,  shake  until 
the  yellow  precipitate  is  in  solution,  wash  sides  of  flask 
down  with  water,  add  3  or  4  drops  of  phenolphthalein, 
and  titrate  with  standard  nitric  acid. 

The  standard  nitric  acid  is  made  of  such  strength  that 
I  c.c.  =  o'oi  percent  phosphorus,  t.«.,  100  c.c.  nitric  acid 
(1*42)  to  II  litres  of  water. 

The  nitric  acid  is  standardised  by  running  it  against  a 
steel  whose  phosphorus  value  has  been  determined  gravi- 
metrically. 

The  sodium  hydrate  may  be  of  any  strength ;  generally 
a  solution  is  used  of  which  25  c.c.  =  16  c.c.  of  the  acid. 
A  blank  on  the  sodium  hydrate  ought  to  be  run  every  day. 
The  molybdate  solution  used  is  made  by  dissolving  one 
pound  of  M0O3  in  1200  c.c.  water  +  700  c.c.  ammonia 
(o'go).  The  solution  obtained  is  filtered,  and  300  c.c. 
nitric  acid  (1*42)  added.  This  forms  the  stock  solution. 
To  1200  c.c.  water  and  475  c.c.  nitric  acid  (1*42)  add  575 


CrbHicaL  Nbws,  I 

0«.  22,  1897.       1 


A  bsorption  Spectra  of  some  Melted  Salts, 


iol 


C.C.  of  the  stock  molybaie,  and  use  the  solution  thus  ob- 
tained for  determinations. 

The  method  given  above  is  used  for  pig-iron  and  ores 
with  equal  success.  Unless  there  is  a  large  percentage  of 
insoluble  carbon  in  the  pig-iron  it  need  not  be  filtered  off. 
For  ores  it  is  necessary  only  that  the  phosphorus  be  all  in 
solution  in  a  nitric  acid  menstruum. 

As  the  most  important  point  to  be  reached  by  the 
chemist  in  these  determinations  consists  in  being  enabled 
to  give  a  reliable  result  in  the  possibly  shortest  time, 
another  process,  which  gives  very  satisfadtory  results  for 
all  technical  purposes,  has  also  found  introdu(5lion  in  some 
of  the  most  prominent  iron  and  steel  works.  It  consists 
in  the  application  of  Goez's  phosphorus  tubes,  of  the 
following  shape: — 


^ 


These  tubes  are  charged  with  the  properly  prepared  so- 
lution of  iron  or  steel,  as  given  above,  the  molybdate 
solution  added,  and  are  then  placed  into  the  circular 
openings  of  a  disk  which  holds  six  or  more  of  these  filled 
tubes  and  rotates  on  a  pivot.  When  charged  it  is  set  in 
motion  by  the  application  of  the  eledtric  current,  the  latter 
giving  to  the  mixture  in  the  several  tubes  that  motion 
which  is  generally  given  by  the  hand  of  the  operating 
chemist.  The  scale,  marked  at  the  lower  extremity  of 
the  tube  i,  2,  3,  4,  tells  diredly  the  amount  of  phosphorus 
indicated  by  the  bulk  of  the  precipitate.  The  latter 
settles  very  rapidly  in  the  lower  part  of  the  tube,  and  be- 
comes very  compadt,  and  that  to  such  an  extent  that  the 
tube  may  be  inverted  without  the  operator  incurring  any 
risk  of  losing  a  part  of  the  precipitate. 

These  tubes  have  been  used  for  all  technical  purposes 
with  great  success  for  steel  and  iron  exclusively,  but  there 
is  no  reason  apparent  why  they  should  not  be  applied  for 
the  determination  of  phosphorus  in  ore  as  well. 


DISSOCIATION    SPECTRA    OF    SOME    MELTED 

SALTS. 

METALLOIDS;  CHLORINE,  BROMINE,  IODINE. 

By  A.  DB  GRAMONT. 

Most  melted  salts  give,  under  the  adtion  of  a  condenser 
spark  of  large  capacity  (which  dissociates  them),  line- 
8pe«5lra  in  which  each  body  is  represented  by  the  charadler- 
istic  lines  of  its  own  spedlrum  (Comptes  Rendus,  July  8, 
1895).  I  was  by  this  means  enabled  to  obtain  some 
beautiful  spedtra  of  metalloids  at  the  ordinary  atmo- 
spheric pressure  without  having  recourse  .to  Pliicker  or 
balet  tubes. 
I  will  now  describe  the  spedtra  of  chlorine,  bromine* 


and  iodine,  obtained  by  the  same  method,  principally 
from  their  alkaline  salts,  in  which  the  small  number  of 
metallic  lines  to  dedudl  renders  their  study  more  easy. 

In  these  experiments  I  used,  for  the  puropse  of  holding 
the  fused  salts,  two  thick  platmum  wires,  flattened  out  at 
the  ends,  arranged  in  V  shape,  the  flattened  ends  forming 
the  angle,  the  salts  being  then  kept  fused  by  means  of  a 
Bunsen.  When  the  short  spark  is  made  to  traverse  the 
pasty  ormelted  salt  between  the  wires  the  air  lines  dis- 
appear. The  platinum  lines  rarely  appear,  and  then  only 
by  accident,  so  long  as  a  trace  of  the  salt  remains  on  the 
wire.  I  used  a  dired-vision  specftroscope  with  two  com- 
pound prisms,  construdled  according  to  M.  Cornu's 
design.  It  gives  very  good  dispersion,  but  is  rather 
absorbent.  By  removing  one  of  the  two  systems  of 
prisms,  the  entire  spedlrum  could  be  examined,  and  even 
then  the  D  line  was  distindly  doubled.  That  part  of  the 
spedtrum  between  A  700  and  \  430  was  then  measured 
over  again  with  the  two  systems  of  prisms.  The  disper- 
sion thus  obtained  gave  for  the  lines  Di  and  D2  a  separa- 
tion on  the  micrometer  which  could  easily  be  read  to  the 
tenth  of  a  degree.  The  coil  gave,  without  the  condenser, 
and  excited  by  four  bichromate  cells,  a  spark  50  m.ra. 
long.  The  condenser  was  formed  of  Leyden  jars,  each 
surface  of  which  was  about  0*12  square  metres,  interposed 
in  quantity  in  the  secondary  current.  In  these  experi- 
ments I  found  it  best  to  use  from  four  to  six  of  these  jars, 
thus  getting  a  condensing  surface  of  from  0-46  to  070 
square  metres. 

Condensers  used  in  previous  researches  of  this  nature 
were  much  smaller  in  comparison  with  the  coils  used. 
We  can  now  understand  why,  in  the  descriptions  of 
metallic  spedtra  produced  from  salts  (notably  Sir  J.  N. 
Lockyer,  "  Studies  in  Spedlrum  Analysis,"  5th  edition. 
Chap.  VI.,  1894),  we  find  no  mention  of  the  appearance 
of  the  spedtra  of  metalloids,  which  would,  however,  have 
been  observed  if  a  greater  condensation  had  been  used. 

The  wave-lengths  here  given  were  obtained  by  means 
of  transformation  curves  of  the  readings  of  the  scale  of 
the  spedtroscope.  I  made  them  for  one  and  for  two 
prisms  by  the  aid  of  the  figures  given  by  M.  Thalen  for 
the  principal  lines  of  the  metals,  and  more  especially  for 
those  of  iron.  These  numbers  were  compared  with 
Angstrom's  normal  solar  spedtrum ;  to  compare  them 
with  recent  observations  of  the  same  photographic  spec- 
trum by  Rowlands,  we  have  only  to  refer  to  the  table  of 
corredtions  given  in  Appendix  B  of  Watts's  "  Index  of 
Spedtra." 

It  is  almost  impossible  to  obtain  in  the  ordinary  work 
of  a  chemical  laboratory  a  greater  degree  of  accuracy 
than  I  have  attained  in  the  measurements  of  wave- 
lengths, even  when  giving,  as  I  have,  the  averages  of 
twenty  readings  in  series  of  different  observations. 

If  it  is  in  the  salts  of  the  alkaline  metals  that  one 
seeks  the  spedtra  of  the  metalloids,  and  this  seems  to  be 
most  probable,  we  should  at  first  sight  recognise  the 
principal  lines  of  potassium  and  sodium  by  simple  com- 
parison with  Plate  V.  of  M.  Lecoq  de  Boisbaudran's 
Ijeautiful  Map  of  Luminous  Spedtra.  We  should  also 
be  able  to  study  them  with  advantage  in  the  alkaline 
carbonates;  for,  under  the  conditions  of  the  experiment, 
these  latter  only  give  as  carbon  lines,  and  those  very 
faintly,  C  a  658'3  and  657  8,  in  the  neighbourhood  of  the 
red  hydrogen  line  (the  first  hardly  visible,  even  doubtful), 
and  C  j3  4266  in  the  indigo.  It  is,  further,  necessary  to 
bear  in  mind  the  fadl  of  the  widening  of  the  lines  of  the 
alkaline  metals — the  great  condensation  of  the  spark  used 
makes  this  so  diffuse  as  to  almost  completely  efface  the 
faint  lines,  leaving  hardly  any  but  the  following  lines 
visible  : — 

For  sodium — 

Na  S  (6160)  (6i5"4),  Na  /3  (5687)  (568-2), 
Na  y  (497  9)  double,  Na  a  (589-5)  (588-9), 
Na  E  (515*5)  (515*2)  dififused. 


^02 


Dissociation  Spectra  of  some  Melted  Salts. 


I  Cbbmical  Nbws 

I    oa.  22, 1897. 


Table  I. 


Chlorine  (from  melted  chloride). 
A.  de  Gramont. 


CI  a 


Cl/3 


—  Not  seen. 
6io'5  Doubtful  in  the  salts,  T. 

(1,    545-6  Well  marked,  T. 

2.    544*3  Fairly  strong,  T. 

3-  542*3         ..  ..       T. 

4-  539*2         „  „       T. 

532-5  Very  faint,  and  of  uncertain  origin. 

—  Not  seen. 

Clr{       '^\  |;;-|  T;}Firs.pri„cipal  group.  } 


Not  seen. 


1 

I. 

510-3 

CI  *■ 

509-9 

1 

2. 

5077 

499*4 
497*3 

.492*4 
1 491-6 

V.\f  ■ 

2. 

490*3 

13. 

489-7 

I. 

482-0 

CI  c 

2. 

481-0 

13. 

479'4 
478-1 
476-8 
474-0 

Cl^ 

457*2 

cu 

\ 

n 

■  Seen  by  Thal6n. 


Fairly  strong,  T. 

T. 
Strong,  T. 
Fairly  strong,  T. 
Rather  faint,  T. 
Not  seen. 
Not  seen. 
Faint, 

Very  plain,  T. 
Fairly  strong,  T. 

T 
Very  strong,  T.^ 

„  T.  I  Second  principal  group 

Well  marked,  T. 
T 
Faint. 

Diffused ;  doubtful. 
Not  seen. 


-Chlorine. 
Hasselberg. 


545'fi7 
544*36 
543*40 
539*24 

528*47 
521-98 
521-62 

1518-88 
517-22 
516-08 
511-28 
510-24 
509-82 
507-76 

499  77 
497-24 

494*53 
493*79 
492*53 
491-72 

490*44 
48969 
481-98 
480-97 
47930 
478-08 
47690 
473*97 


Free  chlorine  (in  tubes). 
Salet. 

I A  band  divisible  into  four  lines. 

Quite  visible. 


675 

667 

610-7 

5460 

544*5 

5423 

538*9 


Very  strong.  [S''^°ng- 


522-0  IVery    strong; 

521-6    The  strongest.  J     double. 


5^°'2l  Double. 
5098  j 

507-9    Strong. 

499*3 
497-2 


01 


491-8 

490*3 

4896 

482 

481 

479*3 

478 

477 

473*5 

457*8 

436 

434*5 

432 

431 

427 

425 
413*3 


I  Double. 

Strong. 
Strong. 
Strong. 
Strong. 
Very  strong. 


Diffused. 
Band. 

'  Diffused. 

^  Diffused. 

Band. 
Band. 


Bra 

635*15 

Br)8 

614-6 
587*0  ? 

Br  7 

58295 

Br^ 

571*9 

Bre 

55895 

551*0 

549*75 

549*1 

5447 

543  5 

5424 

.1. 

5331 

2. 

530-4 

BrC- 



3. 

523*65 

4- 

51825 

^5- 

516-4 
51065 

Melted  bromides  (A.  de  Gramont), 


Well  marked,  T. 

Well  seen,  T. ;  appears  single 


Weak ;  uncertain. 

Well  marked,   rather   diffuse ;  appears 

single,  T. 
Very  weak,  often  hardly  visible;  appears 

single,  T. 
Well  marked  ;  appears  single,  T. 
Well  marked,  T. 


Table  II. — Bromine. 

Free  bromine  in  tubes  (Salet). 
700  approximately. 
678 

663  „ 

658-2 
655-8 
6545 

635-2     Fairly  good. 

6147     Small  group  ;  the  widest  line,  and  the  least 
refrangible. 

5875 

583       Double ;  the  strongest  and  the  most  refran* 

gible. 
572-2     Double;  the  most  refrangible. 


559       Double  ;  the  most  refrangible ;  fairly  strong. 
550-8 


Br?; 


505*4 


T. 

5496 

'  Resoluble  band. 

T. 

549 

Weak,  often  hardly 

visible, 

T. 

545 

Fairly  good,  T. 

'  Resoluble  band. 

Good  ;  double  ?,  T. 

542-2 

Very  strong,  T. 

5326 

Strong. 

Strong,  T. 

5304 
527*3 
5265 

Fairly  strong. 

Very  strong,  T. 

524*0 

Strong. 

Very  strong,  T. 

518*3 

Strong. 

Well  marked,  T. 

5165 

Fairly  strong;    var 

able; 

of  doubtful 

origin  ;  seen  by  Pliicker. 

Well  marked,  T. 

506 

^HBWICAL  NBWB,  I 
Oft.  22.  1897.        I 


Dissociation  Spectra  of  some  Melted  Salts, 


^03 


Br  9 

Brv 

Brir 
Btp 


Melted  bromides  (A.  de  Gramont). 

492*9  Fairly  strong,  T. 

481-6  Very  strong,  T. 
478-6  „  T. 

4767  Easily  visible,  T. 
474-3  „  T. 

472-0  „  T. 

470-35  Very  strong,  T. 

469-15  Fairly  visible  ;  often  weak. 

46765  Fairly  strong,  T. 

462-2  Easily  visible. 

436-5  » 


Table  II. — Bromine  {continued) 


Free  bromine  in  tubes  (Salet) 

493 

Easily  visible. 

4815 

M 

478-7 

Fairly  strong. 

4766 

474-2 

472-0 

470-4. 

Fairly  strong. 

467-6 

461-7 

4542 

436-5 

428-7 

:S ''?."'}  Vague. 

398 

Table  III. — Iodine. 

Free  iodine  in  tubes  (Salet). 

625-7 

621-0 

612-5 

Easily  seen. 

597-8 

Double. 

595*2 

Fairly  strong. 

579 

577-3 

Easily  seen. 

576 

573-8 

Fairly  strong. 

57i'i 

11 

568-8 

Easily  seen. 

567-3 

Fairly  strong. 

562-4 

i» 

561 

la 


I  s  i 


I  c 


625- 
620- 
612- 
6o8- 
607- 
595- 
578- 
577 
576' 
573' 
570' 
569- 
567' 
562 

561 
560 

559 
555 
552' 
550' 
(l-  549 
549 
2.    546 

3-     543 

\4-    540 

536 

I   »    -12.     533 


I    C 


■I' 


u 


lo 


In- 


Melted  iodides  (A.  de  Gramont). 
7       Fairly  well  marked. 


■45 
o 

75 

9 

I 

■75 
-6 

•3 
1 

'5 
•3 
•4 
■7 
8 

•5 
•5 
7 
•4 
9 
•3 
65 


10 

526-7 
526-35 
524-45 
521-55 

I/* 
Iv 

517-55 
516-15 
510-6 
506-5 

Very  well  marked. 
Fairly  visible.  | 
Fairly  strong. ) 
Strong. 
Fairly  visible. 
Well  marked. 
Fairly  well  marked. 
Well  marked. 

)> 
Fairly  well  marked. 
Well  marked. 

»> 
Very  faint. 

Faint  (seen  by  Pliicker). 
Faint. 
Very  faint. 

II 
Faint. 

Strong,  ) 

Fairly  visible.  J 
Very  strong. 
Strong. 

II 
Fairly  strong. 
Very  strong. 
Very  strong  ;    almost 

Cd  No.  3. 
Easily  seen.     1 
Fairly  visible.  J 
Well  marked. 
Well   marked;  almost  coincides  with 

017(521-6). 
Faint. 

Very  strong. 
Well  marked  ;  variable. 
Fairly  visible. 

Easily  seen ;  diffused. 

Faint. 


Well  marked ;  almost   coincides  with 

Cd  No.  6. 
Well  marked. 


coincides  with 


I<r 


486-4 

484-96 

48045 

476-5 

473-15 

467-65 

466-7 

464-15  „ 

463  I  u 

4622  „ 

44535     Fairly  well  seen  ;  very  diffused. 
444-9      Fairly    visible ;    very    diffused  5    ofteii 
confounded  with  the  previous  one. 
,       443*9      Rather  faint ;  diffused. 

441-1      Faint;  diffused. 

422-45    Very  well  seen. 


559*6 


550*1 

549-4 
546-1 
543*3 
541^-3 
5366 

534-4 
533-6 

526-5 

524*3 
521-5 


Fairly  strong. 

Strong. 
Easily  seen. 
Strong. 

Fairly  strong. 


516-2    Strong. 


506-5 

497  5 
486-5 

485 
480-3 

4763 
472-9 
467-7 

466'8 
464 
463-4 
462 

445-6 

445 

444 
[441 
1 440 

442 


Easily  seen. 
Faint. 
Very  faint. 


Easily  seen. 


204 


Composition  of  certain  Canadian  Virgin  Soils. 


I  ChBUICAL  itBWS, 

•    oa.  22, 1897. 


And  for  potassium — 

K  S  (769-8)  (766-5)  K  /3  (536-0)  (534-4)  (534-0) 

Ky  1693-9)  (691-1)  KC  (482-8) 

(6308)  (4264) 

(611-7)  (418-5) 

Ka  (583-2) (580-1)  (578-3)    K«  (4045) 

The  alphabetical  designations  which  precede  are  from 
M.  de  Boisbaudran's  map,  and  the  figures  are  those  which 
I  obtained. 

The  spe&ra  of  free  chlorine,  bromine,  and  iodine  are 
those  which  have  up  to  the  present  been  principally 
studied  first  by  Pliicker  and  later  by  Salet.  The  former 
made  some  excellent  maps,  but  did  not  make  any  dired 
measurements  of  wave-lengths ;  these  have,  however, 
been  deduced  approximately  by  Watts,  and  will  be  found 
in  his  "  Index  of  Spedlra." 

M.  Salet  then  took  up  the  question,  and  measured  the 
wave-lengths  obtained  by  a  spark  traversing  a  tube  con- 
taining the  free  metalloid  at  ordinary  pressure.  He  has 
since  made  some  corrections  in  these  figures,  and  I  have 
reproduced  them  in  this  paper  to  facilitate  comparison 
with  those  obtained  by  me. 

For  free  chlorine  only,  more  precise  measurements  than 
those  of  M.  Salet  have  since  been  made  by  Thal6n  and 
Hasselberg,  and  I  have  thought  it  worth  while  to  give 
M.  Hasselberg's  figures  as  being  more  recent.  The  lines 
marked  T  were  observed  also  by  Thalen.     (See  Table  I.). 

The  following  lines  seen  by  Thalen  in  free  chlorine 
were  not  perceived  either  by  Salet,  Hasselberg,  nor  by  me 
in  melted  chlorides : — 

559"35.  55277.  535'55.  533'20,  53i'25.  520'55.  5i7'40. 
514-20,  503-05,  502-05,  477-35,  47045.  469"8o,  466-00, 
464-80,  464-00,  46380,  460-80,  459'6o,  459*05,  452-70. 

AUthe  chlorides  tried  gave,  with  the  greatestdistinftness, 
the  chlorine  lines — with  the  exception,  of  course,  of  those 
which  were  effaced  by  their  closeness  to,  or  apparent 
coincidence  with,  the  intense  metallic  lines.  In  a  general 
way  we  may  add  that  the  entire  specftrum  of  chlorine  is 
much  finer,  the  lines  are  brighter  and  sharper  in  the 
melted  chlorides  with  a  condenser  spark  than  with 
free  chlorine  in  tubes.  The  most  charafteristic  groups  of 
chlorine  in  the  melted  salts  are  principally  CI  y  and  CI  2, 
and,  secondly,  CI  j3  and  CI  d.  The  speftrum  of  chlorine 
has  been  examined  in  this  manner  in  the  melted  salts  of 
the  chlorides  of  sodium,  potassium,  lithium,  rubidium, 
cadmium,  and  zinc. 

Bromine, 

Since  M.  Salet's  memoir,  the  emission  speArum  of 
bromine  has  not,  to  my  knowledge,  been  the  object  of  any 
Bpedtroscopic  research  ;  its  spedrum,  much  richer  in  lines 
than  that  of  chlorine,  is  as  clear  and  as  easily  observed 
in  the  melted  salts.  Free  bromine  gave  M.  Salet  a  series 
of  faint  lines  in  the  red,  from  654  to  700,  but  I  was  not 
able  to  detetSt  them  in  the  bromides.  The  most  charac- 
teristic   groups    of   bromine    in    the    melted    salts    are 


tension,  is  increased  in  the  same  manner  as  their  atomic 
weights,  and  the  sensitiveness  of  the  observation  appears 
to  be  in  the  same  order.     (See  Table  III.). 


ON     THE    COMPOSITION     OF    CERTAIN 
CANADIAN    VIRGIN    SOILS.* 

By  FRANK  T.  SHUTT,    M.A.    F.I.C.,    F.C.S., 

Chemist,    Dominion   Experimental  Farms. 


(Continued  from  p.  186). 

British  Columbia. 
Beginning  on  the  west,  or  Pacific,  coast,  your  attention 
is  first  direded  to  the  tabular  statement  of  the  composi- 
tion  of  certain   typical   British   Columbian   soils.     (See 
Table  I.). 

These  include  three  well  marked  groups  : — 

1.  Deltaic  Soils.— ^Wety  rich  in  plant  food.  These  are 
formed  by  the  accumulation  of  detritus,  as  at  the 
mouths  of  the  Eraser,  Pitt,  and  other  rivers. 

2.  Valley  Soils. — Largely  alluvial  as  regards  origin  ; 
rich,  as  a  rule,  in  both  mineral  constituent  and 
organic  matter. 

3.  Bench  and  Plateau  Soils. — At  varying  altitudes  on 
the  sides  and  summits  of  elevations  and  mountains ; 
variable,  but  usually  light  and  sandy ;  of  medium 
fertility,  though  sometimes  very  poor. 

Possibly  there  may  be  other  classes  of  soils  in  the  pro- 
vince, but  our  investigation  has  as  yet  only  included  those 
now  referred  to. 

Soil  No.  I. — Taken  from  a  valley  near  Vidtoria,  Island 
of  Vancouver,  and  representative  of  a  large  area  that  is 
considered  good  farming  land.  When  air-dried,  it  is  a 
dark  brown,  almost  black  loam,  of  excellent  texture, 
homogeneous  throughout,  and  containing  clay  and  humus 
in  good  proportions. 

In  nitrogen  and  organic  matter  this  soil  ranks  very 
high,  and — though  not  as  rich  in  total  potash  and  phos- 
phoric acid  as  many  of  our  virgin  soils — it  is  by  no  means 
deficient  in  these  important  constituents. 

Soils  Nos,  2  and  3.— Represent  the  soil  immediately 
beneath  the  preceding  sample  at  the  depth  of  12  to  18 
inches  and  18  to  24  inches  respectively.  In  physical 
appearance  and  condition,  as  well  as  in  composition, 
No.  2  is  very  similar  to  sample  Np.  i ;  showing  that  the 
surface  soil  has  pradtically  a  depth  of  18  inches.  While, 
as  might  be  expedted,  the  lower  sample  (No.  3)  is  some- 
what poorer  in  organic  matter  and  nitrogen,  the  percent- 
ages  of  potash  and  phosphoric  acid  are  identical  with 
those  in  the  overlying  soil.  It  is  of  a  yellowish  grey 
colour  with  streaks  of  black  soil  throughout  its  mass.  It 
will  be  seen  to  be  of  excellent  quality  for  a  subsoil. 

It  will  be  interesting  now  to  consider  the  proportions 

o — r-  \     n    /■    /■       °^  percentages  of  these  elements  that  may  be  looked  upon 

principally  Br  v,  Br  n,  Br  C3.  U'  a"^'  secondly,  Br  f„  Q.     as  more  or  less  immediately  available  for  plant  use,  i.e.. 
The  observations  have  been  carried  out  with  brornides  of  |  ^^^  amounts  extracted  by  the  i  per  cent  citric  acid  solu- 
tion before  referred  to.     (See  Table  II.) 


(See  Table  II.) 


sodium,  potassium,  cadmium,  and  zinc 

Iodine. 

Like  bromine,  the  emission  spedlra  of  iodine  has  not 
been  made  the  subjed  of  any  research  since  that  of 
M.  Salet.  It  is  richer  in  lines  than  are  the  speCtra  of 
either  chlorine  or  bromine,  notably  in  the  orange  red. 
The  principal  lines  in  this  part  of  the  spedtrum,  I  a,  I  ^, 
I  7,  are  easily  seen,  even  with  only  a  small  quantity  of 
iodine  in  the  salt  under  examination.  The  most  charac- 
teristic groups  or  lines  of  iodine  in  melted  iodides  are — 
Firstly,  I  7?,  I  ;t,  I  C2 ;  and  secondly,  I  C  (»»  a  whole),  I  t, 
I  a,  I  /3,  I  7.  rhe  experiments  were  performed  on  iodides 
of  sodium,  potassium,  and  cadmium. 

The  three  spedlra  of  chlorine,  iodine,  and  bromine  have 
their  most  charadteristic  lines  in  the  green  and  the  blue, 
and  the  complexity  of  these  spedtra,  as  well  as  their  ex- 


In  speaking  of  minimum  limits  of  available  plant  food, 
Dr.  Dyer  says : — "  From  a  careful  consideration  of  the 
whole  of  the  results,  it  would  perhaps  not  be  unreasonable 
to  suggest  that,  when  a  soil  is  found  to  contain  as  little  as 
about  o-oi  per  cent  of  phosphoric  acid  soluble  in  a  i  per 
cent  solution  of  citric  acid,  it  would  be  justifiable  to 
assume  that  it  stands  in  immediate  need  of  phosphatic 
manure." 

In  potash  he  obtained  results  that  led  him  to  finally 
suggest  that  the  limit  to  be  regarded  as  indicating  the 
non-necessity  of  the  application  of  special  potash  fer- 
tilisers at  0-005  per  cent  of  potash  soluble  in  the  solvent 
now  spoken  of. 


*  Read   before  the 
Meeting,  1697. 


British    Association  (Sedtion   B),    Toroa 


Cl^BMicAL  News,) 

Oft.  22,  1897.       f 


Composition  of  Certain  Canadian  Virgin  Soils, 


255 


No. 


Locality. 


Table  I. — Analyses  0/ Soils  {Water-free),  British  Columbia. 

Surface 

or  Charafter  of  soil.  Potash.  Phosphoric  Nitrogen. 

acid. 


subsoil. 
Surface Valley  soil,  black  loam    0*23 


Loss  on  ignition 
Lime,    (organic  and 
volatile  matter). 


1.  Vidoria,  Vancouver 

Island 

2.  Vidloria,  Vancouver 

Island Depth,  12 — 18  ins. 

3.  Vidloria,  Vancouver 

Island „      18— 24  ins. 

4.  Alberni,    Vancouver 

Island Surface Dark  red  clay  loam 

5.  Alberni,   Vancouver 


Island 

6.  Cowichan,  Vancouver 

Island 

7.  Ladners,  New  West- 

minster 

8.  Squamish,     New 

Westminster 

9.  Pitt  Meadows,  New 

Westminster     .. 

10.  Pitt  Meadows,  New 
Westminster 

ir.  Agassiz, New  West- 
minster 

12.  Agassiz,  New  West- 

minster 

13.  Agassiz,  New  West- 

minster 

14.  Agassiz,  New  West- 

minster 

15.  Chilliwack,       New 

Westminster     .. 

16.  Chilliwack,       New 

Westminster     .. 

17.  Mission,  Yale  .     .. 
18 

19.  Guisachan,  Yale  .. 

20.  „  „      •• 
ai.            „  .... 

22.  „  „      •• 

23.  „  „      .. 

24.  Quesnelle,  Cariboo 

25 


Dark  red  sandy  loam . . 


0-23 
0*26 
032 
0*17 


Dark  red  sandy  loam,  0*39 
Bench  soil       ..     .. 

Alluvial  grey  -  black  0*52 
loam         

Valley  soil 0*38 


Alluvial  black  loam 


Subsoil Greyish  yellow  sandy 

loam 

Surface First  Bench 


Second  Bench    .. 

Valley 

Valley 

Valley  soil,  alluvial 


0-36 
0-45 
0*32 
0-35 
0-39 

o'35 
063 


Subsoil 

Surface Light  grey  clay  loam . . 

Subsoil 

Surface Light  grey  sandy  loam 

,t       • »     •  •      •  •     L'arK         ••  •• 


0-51 
0-45 
0-62 
032 
o*53 

»         n  »  065 

II      •  •     •  •     •  •         11           II            II  '^'SS 

, Light  grey  sandy  loam  0*45 

, Dark  grey  sandy  loam  0*39 

Subsoil..     ..      ..  o'53 

26.  Cottonwood  River..     Surface Yellowish  sandy  loam  0-32 

27.  „  ,,     ..     Subsoil Very  sandy o*i6 

28.  ,,  House.     Surface Dark  grey  sandy  loam     0*57 

29.  „  „     .     Subsoil Yellowish  grey  ..     ..     0*47 


o*ig 
0*19 

0'12 

o-o8 

o"34 
032 
0-28 
0*20 
0*52 
0-13 
0*24 
0*14 
o-i8 
0*26 

0'2I 

0-23 

0'28 

033 
0-30 
0*30 

0-38 
034 

0-27 

0-22 
0'19 

034 
0*29 
0*24 
O'lO 


0*594 
0-506 
0-146 
0*127 
0163 

0'102 

o'6io 

o'ogi 

1*050 

0-095 

0-159 

o-ioz 

0-I54 

0-155 

0-166 

0-108 
0*124 
0-076 
0-077 
0-236 

0-255 
0-259 
0-045 

0399 
o-io8 
0-234 
0-057 
0412 
0-050 


1*29 
I -12 
I-OI 

114 

I'OO 

1*37 
0-50 
x-68 
0-32 
0-33 
0-86 
0*78 
0*96 
0-97 
0*98 

0-90 
1-86 
1-90 

1*22 
1-70 
1-76 
1-25 
I-6l 
17-77 
3-80 

1*14 
0-99 
1-07 
1-22 


1569 

I361 

4*63 

10-79 

11-32 

7-10 

1725 
3*38 

31-14 
6*37 
6-87 

4*34 
6*92 
7*12 
77* 

590 
396 

3*35 
2-66 
618 
6-59 

7-13 
2-02 

12-01 
4'6o 
828 
303 

13-04 

3'02 


Table  II. — Comparison  of  "Available  "  with  "  Total  "  Amounts  0/  Potash  and  Phoiphoric  Acid, 


Potash. 


Phosphoric  acid. 


No. 

I. 
2. 

3- 


doil. 


Total  potash. 


Surface 0*23 

Between  12  and  18  inches  0-23 
Between  18  and  24  inches  0-26 


Available 
potash. 

0*00483 
0-00299 
0*00169 


Percentage  of 

total  potash  available 

for  plant  use. 

2-20 
1-36 
0-64 


Total 

phosphoric 

acid. 

0-19 
0*19 
0'12 


Available 

phosphoric 

acid. 

0-0I020 
0-01055 
0*00588 


Percentage  of 
total  phosphorie 
available  for 
plant  use, 

5-66 
585 
490 


In  available  mineral  plant  food  the  surface  soil  now 
under  consideration  is  seen  to  give  results  approximating 
these  limits.  The  estimations  above  tabulated  are,  how- 
ever, more  particularly  useful  in  showing  that  the  upper 
or  surface  portions  of  the  soil  contain  much  larger 
amounts  of  available  food  than  the  underlying  soil.  We 
are  thus  furnished  with  data  to  support  the  view  that  the 
greater  produdliveness  of  a  surface  soil,  compared  with 
its  sub-soil,  apart  from  the  presence  of  nitrogen,  in  large 
part  is  due  to  the  availability  rather  than  to  the  total 
amounts  of  mineral  fertilising  constituents  present. 

Soil  No.  4. — From  Alberni,  Island  of  Vancouver;  a  clay 
loam  of  a  deep  red  colour,  masking  entirely  the  presence 


of  the  large  amount  of  organic  matter  present.  This 
sample  is  said  to  represent  the  soil  to  a  depth  of  9  inches 
over  an  approximate  area  of  10,000  acres.  The  sub-soil 
of  this  area  is  variable,  sometimes  clay,  sometimes  gravel 
and  sand.  In  potash  this  soil  (No.  4)  is  comparatively 
rich ;  in  phosphoric  acid,  however,  it  is  much  below  the 
average.     As  regards  nitrogen  it  is  of  medium  quality 

Soil  No.  5.  —  Also  from  the  distrift  of  Alberni,  but 
differing  from  No.  4  in  certain  important  features.  It  is 
known  locally  as  "  Fern  and  Sallal "  soil,  for  the  reason 
that  on  this  virgin  soil  these  plants  grow  most  luxuriantly, 
crowding  out  to  a  great  extent  other  vegetation.  At  first 
this   soil    gives   but   poor   returns,   but    after   several 


2o6 


London  Water  Supply. 


f  Chbhical  Nbwii, 

I        Oa.  22,  1897. 


ploughings — i.  e,,  several  seasons  working — the  yield  in- 
creases, and  good  crops  are  obtained.  An  examination  of 
the  soil  showed  it  to  be  distindtly  acid  to  litmus  paper. 
There  is  in  this,  no  doubt,  an  indication  of  the  cause  of 
the  infertility.  The  efleca  of  exposure  to  the  air  through 
culture  would  be  to  corredt  this  sourness,  while  at  the 
same  time  locked-up  plant  food  would  be  set  free.  Lime 
and  wood  ashes  have  given  excellent  returns  on  this  soil. 

The  very  large  percentage  of  oxide  of  iron  in  these 
soils — exceeding,  frequently,  20  per  cent — is  a  feature 
worthy  of  note.  It  is  probable  that  in  the  virgin  soil  a 
part  of  this  iron  is  in  the  ferrous  condition,  due  to  the 
presence  of  organic  matter  and  to  certain  other  fadtors. 
The  oxidising  of  this  iron  through  cultural  methods 
would  free  the  soil  of  compounds  injurious  to  the  tender 
rootlets  of  agricultural  crops.  It  is  further  important  to 
point  out  that  this  soil,  though  yielding  i*o  per  cent  of 
lime  to  hydrochloric  acid,  sp.  gr.  i*ii5,  had  a  distindlly 
acid  readtion,  and  was  much  benefitted  by  an  application 
of  lime. 

Soil  No.  6. — A  Bench  soil,  deep  red,  of  sandy  charadler, 
from  Cowichan,  Island  of  Vancouver,  similar  in  appear- 
ance to  N08.  4  and  5.  It,  however,  contains  less  organic 
matter  and  nitrogen  than  these,  but  is  not  to  be  regarded 
as  deficient  in  any  of  the  essential  elements, 

A  determination  of  the  amounts  of  available  potash  and 
phosphoric  acid,  ascertained  by  the  citric  acid  method, 
afforded  the  following  data : — 


Available  potash 
Available  phosphoric  acid 


0*0089 
0*0171 


While  these  amounts  do  not  fall  below  the  limits  named 
by  Dr.  Dyer,  they  are,  however,  such  as  to  suggest  that 
both  potash  and  phosphoric  acid  would  prove  beneficial, 
and  give  good  returns  in  increased  crop  yield. 

Soil  No.  7.— A  greyish  black  soil  of  excellent  texture, 
from  the  valley  of  the  Fraser  river  near  one  of  its  mouths, 
and  resulting  from  the  deposition  of  silt  brought  down  by 
this  river.  An  area  of  over  30  square  miles  is,  it  is  stated, 
covered  by  soil  of  this  origin  and  charadter.  Both  from 
chemical  and  physical  data,  this  soil  would  be  judged  an 
extremely  fertile  one,  and  pradtical  results  confirm  this 
opinion.  Of  phosphoric  acid,  potash,  and  nitrogen  it 
possesses  quantities  considerably  above  the  averages 
already  discussed  for  fertile  soils. 

Soil  No.  8. — From  the  Squamish  Valley,  in  the  distrid 
of  New  Westminster.  The  valley  is  said  to  have  an  area 
of  14,000  acres  of  arable  land.  Its  sub-soil  is  clay,  though 
sometimes  running  into  sand.  Though  containing  ade- 
quate amounts  of  mineral  food  for  crop  requirements,  it 
is  below  the  average  in  nitrogen  and  humus.  The 
ploughing  under  of  green  crops — preferably  one  of  the 
legumes — has  been  found  to  improve  this  soil,  both  as 
regards  tilth  and  produftive  power. 

Soil  No.  9.— From  the  Pitt  Meadows,  New  Westmin- 
ster, An  alluvial  deposit,  composed  of  the  detritus 
brought  down  by  the  Pitt  River.  It  is  black  loam,  in  a 
moderately  fine  granular  condition,  and  possessing  a 
large  amount  of  vegetable  organic  matter.  On  moistening 
it  does  not  become  plastic  or  sticky,  and  easily  crumbles 
when  dry.  The  soil  granules  display  a  remarkable  homo- 
geneity, proving  the  very  intimate  incorporation  of  the 
vegetable  organic  matter  with  the  inorganic  basis  of  the 
soil. 

Its  mechanical  texture  seems  to  be  such  as  would  allow 
freedom  for  root  development,  for  permeation  of  air  and 
percolation  of  water,  while  at  the  same  time  it  is  suffi- 
ciently compadt  and  heavy  to  prevent  easy  leaching  and 
to  be  retentive  of  moisture. 

In  potash  and  phosphoric  acid  it  is  seen  to  be  well 
supplied,  comparing  most  favourably  in  this  respedl  with 
soils  of  great  productiveness. 

In  nitrogen  this  soil  is  particularly  rich,  possessing 
about  34,000  lbs.  per  acre,  estimating  the  weight  of  an 
acre  of  soil  to  the  depth  of  i  foot  to  be  3,500,000  lbs. 
The  physical  condition  of  this  soil  being  such  that  nitri- 


fication would  proceed  satisfadtorily,  the  value  of  this  large 
amount  of  organic  nitrogen  becomes  obvious. 

Soil  No.  10  is  the  sub-soil  of  the  above,  and  is  a  greyish 
yellow  sandy  loam.  From  its  texture  I  should  expedt  it 
to  offer  a  very  fair  drainage  to  the  surface  soil. 

Soils  Nos.  II,  12,  13,  and  14  are  surface  soils  from  the 
Experimental  Farm  at  Agassiz.  They  are  all  of  medium 
quality ;  in  tilth  rather  light,  and,  though  possessing  a 
fair  amount  of  clay,  sand  predominates.  Though  not 
presenting  any  marked  differences,  that  of  the  first  bench 
approaches  closely  in  composition  to  that  of  the  valley 
soil  No.  14.  The  valley  soils  are,  as  a  rule,  distindtly 
richer  than  those  occurring  at  higher  elevations. 

Soils  Nos.  15  and  16  are  from  Chilliwack,  on  the 
Fraser  River.  They  are  valley  soils,  alluvial  in  origin. 
While  not  so  rich  as  the  delta  soils  of  the  Fraser  and 
Pitt  Rivers  already  discussed,  they  are  by  no  means  poor, 
possessing  a  good  supply  of  potash  and  fair  amounts  of 
phosphoric  acid  and  potash.  They  probably  represent 
more  or  less  truly  the  charadler  of  those  soils  of  medium 
fertility  found  in  British  Columbia  in  many  of  her  river 
valleys. 

Soils  Nos.  17  and  18.— A  surface  and  sub-soil  from 
Mission  on  Okanagan  Lake,  Yale  distridt.  Both  are  ex- 
cellent as  regards  potash  and  phosphoric  acid,  but  of 
poor  tilth,  caking  on  being  dried  into  hard  masses.  The 
surface  soil  is  somewhat  deficient  in  organic  matter,  and 
might  be  much  improved  by  drainage,  judicious  culture, 
and  the  turning  under  of  a  green  crop — technically  known 
as  green  manuring. 

Soils  Nos.  19,  20,  21,  22,  and  23  are  surface  soils  from 
the  ranch  of  His  Excellency  the  Governor-General  at 
Guisachan.  They  are  sandy  loams  of  varying  shades  of 
grey,  and,  with  the  exception  of  Nos.  19  and  23,  might 
be  termed,  as  far  as  composition  is  concerned,  soils  of 
more  than  average  fertility.  These  latter  are,  however, 
somewhat  deficient  in  humus  and  nitrogen. 

Soils  Nos.  24  to  29  inclusive,  are  from  plateaux  and 
upper  benches  of  the  Fraser  in  the  Cariboo  distridt,  a 
pradtically  as  yet  unsettled  area.  Clover  and  indigenous 
grasses  of  good  quality,  it  is  stated,  grow  well  upon  them, 
and  the  probabilities  are  that  the  area  here  represented 
will  be  found  suited  for  grazing  purposes.  Surface  soils 
Nos.  24  and  28  are  particularly  rich,  judging  from  the 
chemical  analysis,  and  should  prove  very  fertile  if  climatic 
conditions  are  favourable. 

(To  be  continued). 


LONDON     WATER    SUPPLY. 

Report  on  the  Composition  and  Quality  of  Daily 
Samples  of  the  Water  Supplied  to  London 
FOR  THE  Month  Ending  September  30TH,  1897. 

By  SIR  WILLIAM  CROOKES,  F.R.S., 

and 

PROFESSOR  DEWAR,  F.R.S. 


To  Major-General  A.  De  Courcy  Scott,  R.E., 
Water  Examiner,  Metropolis  Water  Act,  1871. 

London,  October  I4tb,  1897. 
Sir, — We  submit  herewith,  at  the  request  of  the 
Diredtors,  the  results  of  our  analyses  of  the  182  samples 
of  water  colledted  by  us  during  the  past  month,  at  the 
several  places  and  on  the  several  days  indicated,  from  the 
mains  of  the  London  Water  Companies  taking  their 
supply  from  the  Thames  and  Lea. 

In  Table  I.  we  have  recorded  the  analyses  in  detail  of 
samples, one  taken  daily,  from  September  ist  to  September 
30th inclusive.  Thepurityofthewater,inrespedltoorganic 
matter,  has  been  determined  by  the  Oxygen  and  Com- 
bustion processes;  and  the  results  of  our  analyses  by 
these  methods  are  stated  in  Columns  XIV.  to  XVIH. 

We  have  recorded  in  Table  II.  the  tint  of  the  several 


Cbbuical  Rbws,  I 

oa.  22. 1897.    I 


Chemical  Notices  from  Foreign  Sources, 


207 


samples  of  water,  as  determined  by  the  colour-meter 
described  in  previous  reports. 

In  Table  III.  we  have  recorded  the  oxygen  required  to 
oxidise  the  organic  matter  in  all  the  samples  submitted 
to  analysis. 

Of  the  182  samples  examined  during  the  month  all  were 
found  to  be  clear,  bright,  and  well  filtered. 

The  rainfall  at  Oxford  during  September  was  2'25 
inches,  the  average  for  30  years  is  275  inches,  making  a 
deficiency  of  o"5  inch.  Rain  fell  on  nine  days  only,  but 
1-13  inches  fell  on  the  29th.  The  total  excess  for  this 
year  is  now  i'i2  inches. 

In  order  to  prevent  any  misapprehension  in  the  public 
mind  with  regard  to  our  monthly  reports  on  the  quality  of 
the  London  waters,  it  may  be  advisable  to  repeat  that  the 
Water  Companies  in  no  way  interfere  with  our  position 
as  absolutely  independent  scientific  authorities.  Further, 
they  have  no  information  antecedent  to  publication  as  to 
what  will  appear  in  our  report.  Our  communications 
with  the  Companies  are  chiefly  confined  to  calling  their 
immediate  attention  to  the  least  anomaly  appearing  in 
the  charader  or  the  quality  of  the  filtered  water ;  our 
chief  aim  being  to  advise  the  engineers  at  the  works  as  to 
the  efficiency  of  storage  and  filtration. 

There  is  no  city  in  the  world  where  such  minute  and 
incessant  care  is  taken  daily  and  almost  hourly  to  detedt 
and  report  on  the  slightest  deviation  from  purity  in  its 
water  supply. 

The  following  table  shows  that  the  water  supply  of  last 
month  was  adtually  in  a  higher  state  of  purity  than  it  was 
in  the  corresponding  month  of  last  year. 

Comparison  of  the  Averages  of  the  Five  Thames  derived 
Supplies  for  the  Months  of  September,  1896  and  1897. 

Common  Nitric  Oxygen.  Organic  Organic 

Salt.  Acid.  Hardness,  reqd.     Carbon.  Carbon.     Colour. 

Per  Per  Per  Per         Per 

gall.  gall.    Degrees,     gall.         gall.  gall.     Br'n:Blue. 

Means.  Means.    Means.    Means.    Means.    Max.      Means. 
Sept, 

1896.2*228  0*834     13*41      0*048     o*o87  0*146  14*0:20 

1897.  2"I37     0*835       14*25        0*034      0087     0*104    ll'l''20 

Our  baderiological  examination  of  255  samples  taken 
by  us  have  given  the  following  results  ;  we  have  also  ex- 
amined 9  other  samples,  from  special  points,  making  a 
total  of  264  in  all : — 

Microbes 
per  c.c. 

Thames  water,  unfiltered  (mean  of  26  samples)  98,485 
Thames  water,  from  the  clear  water  wells  of 
five  Thames-derived  supplies  (mean  of  126 

samples) 72 

Ditto        ditto              highest  992 

Ditto        ditto              lowest  2 

New  River,  unfiltered  (mean  of  26  samples)  ..  387 

New  River,  filtered  (mean  of  26  samples)       . .  26 

River  Lea,  unfiltered  (mean  of  26  samples)    ..  3168 
River  Lea,  from   the  clear  water  well  of  the 
East  London  Water  Company  (mean  of  26 

samples) 36 

Apart  from  the  daily  badleriological  examination  of  the 
clear  water  wells  of  the  Companies,  we  frequently  make 
specific  tests  for  the  presence  of  pathogenic  organisms. 
If  any  other  than  a  negative  result  had  been  obtained  the 
fad  would  have  been  recorded. 

It  will  be  observed  in  the  above  table  that  there  was  an 
occasion  in  which  the  microbes  rose  to  far  above  the  average. 
This  was  quite  exceptional,  and  was  conneded  with  the 
atmospheric  conditions  following  an  unusually  violent 
thunderstorm,  when  1*13  inch  of  rain  fell  in  less  than  an 
hour.  We  are  in  a  position  to  say  these  microbes  were 
harmless. 

We  are.  Sir, 

Your  obedient  Servants, 

William  Crookes. 
Jamks  Dewar. 


CHEMICAL 


NOTICES    FROM 
SOURCES. 


FOREIGN 


Note.— Ail  degrees  of  temperature  are  Centigrade  nnless  other  wise 
expressed. 

Comptes  Rendus  Hebdomadaires  des  Seances,  deVAcademie 
des  Sciences.    Vol.  cxxv.,  No.  14,  Odober  4,  1897. 

On  Antique  Glass  Mirrors  Lined  with  Metal. — M. 
Berthelot. — Such  metallic  mirrors  are  mentioned  by  Pliny 
as  manufadured  at  Brinduvium  with  an  alloy  of  tin,  in 
which  I  find  the  origin  of  the  word  bronze,  which  has  been 
so  long  uncertain. 

New  Method  for  the  Assay  of  Metals.— A.  Fremont. 
— The  points  to  be  determined  are  merely  the  tenacity, 
the  dudility,  the  fragility,  and  the  homogeneity  of  the 
metal  in  question,  and  the  procedure  employed  is  of  course 
purely  mechanical. 

On  the  Photographic  "  Veil  "  in  Radiography.— V. 
Chabaud. — The  author  concludes  that— (i).  Setting  out 
from  a  given  resistance,  the  two  eledrodes  of  the  tube 
emit  alternately  cathodic  rays,  and  consequently  create 
two  foci.  (2).  Setting  out  from  the  same  resistance,  the 
tube  emits  X  rays  in  all  diredions  ;  in  fad,  those  rays 
which  take  their  rise  on  the  second  focus  do  not  encounter 
any  obstacle  in  the  tube,  and  propagate  themselves  in  all 
diredions.  (3).  A  hard  tube  will  require  a  shorter  expo- 
sure than  a  soft  tube,  but  will  yield  proofs  more  veiled 
and  less  distind  than  those  furnished  by  the  latter.  (4).  A 
voluminous  tube  with  large  eledrodes  will  give  on  the 
screen  a  greater  luminosity  than  a  tube  of  small  dimen- 
sions and  small  eledrodes,  but  the  former  gives  a  less 
definite  image. 

Solubility  of  Liquids.— A.  Aignon  and  E.  Duzes.— 
Not  suited  for  useful  abstradion. 


Journal  de  Pharmacie  et  Chemie. 
Series  6,  vol  vi..  No.  5. 
Adtion  of  Sulphuric  Acid  on  Levo-turpsntine. — 
G.  Bouchardat  and  J.  Lafont. — The  authors  incorporated 
with  essence  of  French  levo-turpentine  a  tenth  part  of  its 
weight  of  sulphuric  acid  ;  the  produd  was  heated  to  150° 
with  excess  of  potash-alcohol ;  this  was  treated  with 
plenty  of  water.  The  supernatant  oils  consist  of  un- 
changed  turpentine,  a  little  camphene,  terpilenes,  and 
their  liquid  polymers  boiling  at  310'  to  320°,  and  of 
others  solid  at  a  low  temperature.  The  water  retains  in 
solution  the  potassic  salts  formed  by  this  readion. 
These  salts  were  first  re-crystallised  in  water,  to  eliminate 
the  large  excess  of  alkali,  and  then  in  concentrated  alco- 
hol. They  ad  on  polarised  light ;  they  consist  of  two 
distind  bodies  of  the  same  chemical  composition,  and 
have,  after  repeated  crystallisations,  been  separated. 
The  least  soluble  of  these  salts,  which  we  call  levo- 
terebenthenosulphate  of  potash,  is  in  the  form  of  lamellar 
crystals,  similar  to  boric  acid ;  its  rotatory  power  in  50 
per  cent  alcohol  is  [oJd  =  -  25°.  The  second  salt  is 
found  in  the  form  of  long,  felted,  silky,  anhydrous  needles, 
but  its  rotatory  power  is  different ;  under  the  same  con- 
ditions  of  dilution  we  get  [ajo  =  +  10°.  The  mother- 
liquors  of  the  preceding  salts  contain  two  other  saline 
compounds  of  a  different  nature ;  we  are  now  investi- 
gating them. 

Composition  of  Haricots,  Lentils,  and  Peas. — M. 
Balland. 

No.  6. 

Estimation  of  Lime,  Alumina,  and  Iron  in  Mineral 
Phosphates. — L.  Lindet. — Will  be  inserted  in  full. 

On  the  Question  of  Matches,  Pbosphorism.  —  A. 
Riche. — A  long,  interesting,  historical  paper,  to  be  con* 
tinued,  but  unsuitable  for  abstradion. 


208 


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Distribution  of  Carbonic  Acid  in  the  Air, 


209 


THE    CHEMICAL    NEWS 

Vol.  LXXVI.,  No.  1979. 


THE    DISTRIBUTION    OF    CARBONIC    ACID 
IN    THE    AIR.' 

By  W.  CARLETON  WILLIAMS. 

It  is  well  known  that  the  method  of  estimating  carbonic 
acid  in  the  air,  as  originally  proposed  by  Pettenkofer,  con- 
tains a  source  of  error  arising  from  the  a(5tion  of  oxalic 
acid  on  barium  carbonate.  Another  source  of  error,  due 
to  the  adtion  of  the  baryta  on  the  walls  of  the  glass 
cylinder,  in  which  the  experiment  is  condu(Sled,  has  been 
pointed  out  by  W.  Spring  (Mem,  Acad.Royale  de  Belgique, 
vol.  xxxvii.),  and  more  recently  by  Letts  and  Blake  (them. 
Soc.  Proc,  1896,  p.  192). 

A  series  of  determinations  made  by  a  modification  of 
Pettenkofer's  method,  in  which  these  inaccuracies  were 
avoided,  gave  the  following  results  for  air  colle(fted  in  the 
suburbs  of  Sheffield,  one  and  a  half  miles  W.S.W.  of  the 
centre  of  the  town. 


Number  of 

experiments.  Average. 

Suburbs       . .     . .     142  3*26 

Fog 7  3-94 

No  fog     ..     ..     135  324 

Snow       ..     ..       32  3*58 

No  snow..      ..     no  3'24 

Rain —  3'i2 

Fine —  3*14 

Centre  of  the  town      21  385 


Minimum. 
2  16 


2-8o 


Maximum^ 
5'H 


6*22 


The  carbonic  acid  is  distin^ly  higher  in  the  town  than 
in  the  suburbs.     A  marked  increase  is  produced  by  fog 

*  Abstraft  of  paper  communicated  to  the  Commemoration  Volume 
of  the  University  College,  Sheffield. 


and  snow;  rain  does  not  exert  any  decided  influence. 
The  observations  were  made  during  the  months  of 
December  to  April,  and,  as  far  as  they  go,  the  results 
show  a  maximum  of  CO2  in  January  (3"65),  with  a  steady 
fall  to  April  (2'64).  The  carbonic  acid  diminishes  as  the 
temperature  rises.  This  is  probably  accounted  for  by  the 
decrease  in  the  consumption  of  fuel  for  household  pur- 
poses during  the  warmer  weather.  An  increase  in  the 
amount  of  carbonic  acid  is  observed  with  a  very  high  or 
very  low  pressure  of  the  atmosphere. 

A  difference  of  opinion  appears  to  exist  with  reference 
to  the  question  of  the  uniform  distribution  of  the  carbonic 
acid  in  the  air  of  inhabited  buildings.  In  the  well-known 
"  Handbook  of  Hygiene"  by  Parkes  it  is  stated,  on  the 
authority  of  Lassaigne,  Pettenkofer,  and  Roscoe,  that  the 
carbonic  acid  of  respiration  is  equally  diffused  through 
the  air  of  a  room.  Angus  Smith,  on  the  other  hand, 
asserts  ("  Air  and  Rain,"  p.  68)  that  '•  the  air  at  the 
ceiling  is  generally  the  worst.  This,  however,  depends 
upon  circumstances;  if  it  has  time  to  cool  from  the 
height  and  space  being  great,  the  carbonic  acid  may  be 
arrested  before  reaching  a  great  height." 

Every-day  experience  would  lead  us  to  suppose  that 
Angus  Smith  is  right :  our  sense  of  smell  indicates  that 
the  air  near  the  ceiling  of  a  room  is,  as  a  rule,  appre- 
ciably less  pure  than  the  air  four  or  five  feet  above  the 
floor. 

In  order  to  decide  between  these  conflicting  statements, 
samples  of  air  colledted  in  public  rooms,  class-rooms  in 
Firth  College,  and  dwelling-rooms  in  private  houses, 
were  examined.  The  results  clearly  show  that  Angus 
Smith  is  corredt.  In  lofty  rooms,  from  26  to  31  feet  in 
height,  the  air  near  the  ceiling  contained  less  carbonic 
acid  than  the  air  near  the  floor,  but  in  rooms  of  a  height 
between  gi  and  16  feet,  the  air  collected  2  feet  below  the 
ceiling  invariably  contained  more  carbonic  acid  than  the 
air  taken  at  2  feet  above  the  floor.  As  is  naturally  to  be 
expefted,  the  difference  is  greater  at  night  when  gas  or 
lamps  are  burning  than  it  is  in  the  day  time.  During  the 
day,  the  mean  difference  is  17  volumes  in  10,000,  but  at 
night  the  air  at  the  top  of  the  room  contained,  on  an 
average,  37  volumes  of  CO2  in  10,000  in  excess  of  that 
present  in  the  air  2  feet  above  the  floor.  These  results 
show  that  the  distribution  of  CO2  in  the  air  of  an  inhabited 
room  is  not  uniform.     (See  accompanying  Table). 


Small  class-room . . 


Private  House. 
Bedroom 


Height. 
Ft.  Ins. 

16    o 


II    6 


Space. 
In  cubic  feet. 

2656 


Dwelling-room  A . . 
»» •  • 
B.. 

II  •• 
If  •  • 
11  •  • 
C. 
»»  •  • 
D.. 

»i  •  • 
II  •• 
»i  •• 
E.. 

»i  •  • 
II  •  • 
i»  •  • 
F.. 


9    6 


10    6 


9    6 


3812 


4285 


2907 


2520 


2090 


Ceiling 
Floor, 
Ceiling 
Floor, 

Ceiling 

Floor, 

Ceiling 

Floor, 

Ceiling, 

Floor, 

Ceiling, 

Floor, 

Ceiling 

Floor, 

Ceiling. 

Floor, 

Ceiling 

Floor, 

Ceiling 

Floor, 

Ceiling 

Floor, 

Ceiling 

Floor, 

Ceiling 

Floor, 


11.30  a.m. 

3  p.m. 
II 

8  a.m. 

9  p.m. 
II 

3  p.m. 
II 

9  p.m. 

II 
8  p.m. 

>i 
II 

II 

4  p.m. 

II 

II 

II 

8  p.m. 

II 
6  p.m. 

II 
7.40  p.m. 


17 

16 

17 
16 


14-5 

14 

15 

13 

17-5 

17-25 

19 
16 
i8-2 

13-5 

205 

18 

15 

14 

i6"4 

13-6 

18-4 

14*6 

14-4 

12'5 

18 
138 


Vols.  CO,  ia 
10,000. 

5*  19  1 

5-15  J 

10-48  ) 

10-23  I 


4-15 
3-51 

11-28 

991 

7-09 

5-27 

16-66 

10-31 

13  08 

11-28 

10-45 
7*63 

5*59 
5'04 
5"3i 
331 
10-47 

5 '07 
662 
4-18 
10-48 
573 


7  persons. 
Gas-stove  burning. 
4  persons. 
Gas-stove  burning. 

2  persons. 


Open  fire ;  3  persons. 

Open  fire ;  3  people. 

2  gas  jets;  i  oil  lamp. 

3  persons  in  the  room. 
Open  fire,  lamp,  and  candles. 

Open  fire  ;  3  people. 

Open  fire  ;  i  person. 

Open  fire  ;  i  lamp, 

1  gas  jet ;  i  person  present. 

Open  fire  ;  2  people. 

Open  fire  ;  3  people  present. 

2  gas  jets  burning. 


210 


Separations  with  Alkaline  Acetates. 


Chemical  NbITs, 
Oft.  29,  1897. 


SEPARATIONS  WITH    ALKALINE   ACETATES. 

By  HARRY  BREARLEY. 

(Continued  from  p.  177). 

V.  Aluminium  and  Copper  from  Iron. 
A  SOLUTION  of  aluminium  chloride  containing  consider- 
able free  acetic  acid  cannot  be  precipitated  by  an  excess 
of  alkaline  acetate;  and  precipitates  formed  locally  are 
dissolved  on  immediate  stirring,  although  if  such  a  pre- 
cipitate is  allowed  to  roll  about  unbroken  it  becomes 
difficultly  soluble. 

Qualitative  tests  made  some  months  ago  induced  one  to 
believe  that,  as  in  the  case  of  chromic  salts,  a  very  con- 
siderable separation  of  aluminium  from  iron  might  be 
made  in  presence  of  large  amounts  of  free  acetic  acid. 

A  very  short  experience,  under  well-defined  conditions 
showed  an  altogether  unexpedled  difficulty.  An  example 
will  readily  illustrate  the  point.  Say  that  a  solution  con- 
taining I  grm.  iron,  o'l  grm.  Al,  its  maximum  amount  of 
dissolved  hydrate,  10  c.c.  acetic  acid,  and  10  to  12  c.c 
acetate,  is  heated  to  boiling.  A  similar  solution,  lacking 
only  the  aluminium,  would  have  its  iron  precipitated 
during  the  operation  ;  but  the  sample  would  not  thow  the 
least  trace  of  turbidity.  An  additional  10  c.c.  of  acetate 
would  form  a  local  precipitate,  which  would  be  readily 
dissolved  as  it  moved  through  the  liquid.  With  about 
40  c.c.  of  acetate  the  solution  would  become  turbid,  but 
if  the  boiling  were  continued  for  an  hour  or  so  there  would 
be  no  considerable  separation  of  iron.  Indeed  it  would 
need  about  60  c.c.  of  acetate  to  separate  the  iron  so  far 
as  to  produce  a  colourless  filtrate.  If  the  deep-coloured 
supernatant  solution  of  a  partial  precipitation  is  poured 
on  to  a  large  asbestos  disc,  the  filtration  is  sharply  arrested 
in  a  manner  very  suggestive  of  alumina. 

This  peculiarity,  in  a  similar  degree,  is  noticeable 
whether  the  acetic  acid  be  increased  or  decreased,  and 
whether  the  dissolved  hydrate  be  as  stated  or  none  what- 
ever. These  observations  show  that  the  practice,  in  co- 
precipitating  iron  and  aluminium,  of  adding  considerably 
more  than  enough  acetate  to  precipitate  the  iron,  is  a 
necessary  one ;  they  also  take  the  edge  off  one's  surprise 
at  finding  only  a  small  percentage  of  aluminium  separated 
by  any  modification  of  the  acetate  separation. 

Any  useful  separation  of  Al  and  Fe  by  means  of 
alkaline  acetates  appears  to  be  hopeless.  On  this  account 
the  alumina  separated  from  the  filtrate  was  never  quanti- 
tatively estimated. 

It  is  only  necessary  now  to  remark  that,  in  the  presence 
of  large  quantities  of  aluminium,  some  of  the  separations 
previously  noticed  may  not  be  performed  with  perfedt 
accuracy.  To  precipitate  i  grm.  of  iron,  after  neutralising 
and  adding  10  c.c.  acetic  acid,  would  require — 

In  presence  of  o.i     grm.  Al  60  c.c.  acetate. 
„  0-05        „       35        „ 

„  o*oi        „       20        „ 

„  0*0025     „       14        ), 

Luckily  the  proportion  of  Al  in  steel  usually  falls  near 
the  last-named  amount,  and  would  therefore  occasion  no 
appreciable  change.  For  the  sake  of  completeness,  how- 
ever, it  is  desirable  to  enquire  how  the  60  c.c.  of  acetate 
would  adt  in  a  nickel  estimation  (say)  if  as  much  as  10 
per  cent  aluminium  chanced  to  be  present.  Two  tests, 
with  o'l  grm.  of  Ni  present,  yielded  percentage  recoveries 
of  g8*o  and  98-4  respeftively.  A  reference  to  Table  XIII. 
(p.  166)  will  show  that  this  is  a  much  better  result  than  is 
obtainable  with  pure  mixtures  of  iron  and  nickel.  If  it  be 
not  too  great  a  liberty  to  say  so,  it  seems  as  though  the 
additional  acetate  was  too  busily  engaged  with  the  alumi- 
nium to  give  much  attention  to  the  nickel. 

A  more  complete  separation  of  iron  and  nickel,  under 
like  circumstances,  might  be  made  by  adding  large 
amounts  of  ammonium  chloride.  With  this  modification 
less  acetate  would  be  needed,  and,  on  the  authority  of 


Jewett  (Chemical  News,  xl.,  273)  )  a  more  perfedl  sepa- 
ration is  ensured. 

Assuming  a  perfeA  separation  of  Fe  and  Ni,  a  substitu- 
tion of  alkaline  chromate  for  acetate  would  readily 
precipitate  the  iron,  but  a  very  considerable — how  much 
has  yet  to  be  determined — amount  of  aluminium  is  to  be 
found  in  the  filtrate.  When  precipitated  as  alumina  in 
the  subsequent  titration,  this  element  would  be  highly 
objedtionable,  not  only  on  account  of  its  interference  with 
the  indicator,  but  also  on  account  of  its  possible  influence 
on  the  titration  itself. 

According  to  Moore  (Chemical  News,  Ixxii.,  92),  "in 
presence  of  alumina,  either  citric  acid,  tartaric  acid,  or  soda 
pyrophosphate,  may  be  employed  to  keep  it  in  solution." 
The  points  raised  in  these  two  paragraphs  will  be  con- 
sidered in  a  later  paper. 

Copper  from  Iron. 

The  acetate  separation  of  copper  cannot  be  said  to  have 
ever  been  greatly  favoured,  partly,  it  may  be  surmised, 
because  a  casual  separation  would  almost  certainly  be  a 
bad  one.  Wherever  the  separation  is  now  used,  it  is 
generally  accompanied  by  the  volumetric  estimation  of 
the  copper,  without  a  preliminary  separation  of  the  pre- 
cipitated iron. 

The  possibilities  of  acetate  separation  will  be  best  un- 
derstood by  comparing  its  behaviour  when  an  excess  of 
acetate  is  used  with  one  of  the  previously  separated  ele- 
melts  under  like  conditions. 

Table  XV.  sets  forth  this  comparison.  The  correspond- 
ing precipitations  were  made  under  as  identical  conditions 
as  could  be  maintained  in  two  sets  of  experiments  made 
so  widely  apart.  Attention  is  again  called  to  the  turbidity 
temperatures  as  evidence  of  the  similarity.  What 
difference  there  is  favours  the  copper. 


Table  XV. 

Acetate. 
C.c. 

Percentage  recovery  of 

r- ' — ^ 

Nickel.                Copper. 

Respeaive 
Temp,  turbidities 

10 

I0O"O 

gS'o 

—    91°  C. 

20 
50 

gg-O 

929 
69-6 

72°.  74°  C. 
6o»,  62°  C. 

100 

go'o 

531 

53°.  54°  C. 

Like  most  of  the  preceding  elements,  the  separation  is 
increasingly  accurate  as  the  free  acid  rises,  and  decreas- 
ingly  so  as  the  acetate  rises.  Any  attempt  to  increase 
the  volume  of  acetic  acid  necessarily  entails  an  increase 
of  the  acetate  required  to  eifecSt  a  separation.  So  far  as 
copper  is  concerned  this  is  a  disadvantage  in  that  a  less 
perfect  separation  is  obtainable  with  a  minimum  acetate, 
and  somewhat  of  an  advantage  in  that  a  given  excess  of 
acetate  causes  a  slighter  decrease  in  the  recovery.  This 
advantage  or  disadvantage  is  probably  true  of  nickel, 
cobalt,  manganese,  and  every  other  element  —  except 
chromium  as  chromic  acid  —  whose  acetate  separation 
from  iron  is  pradticable,  although  none  of  the  preceding 
metals  have  been  nearly  so  sensitive  as  is  copper  in  this 
respe(5t. 

Table  XVI.— With  30  c.c.  Acetic  Acid. 

Acetate.  Per  cent  recovery.  Turb.  temps. 

30  c.c.  952  93"  C. 

50   „  gi'a  84°  C. 

It  might  be  presumed,  from  the  foregoing,  that  a 
smaller  volume  of  acid  (acetic)  with  only  so  mUch  acetate 
as  would  precipitate  the  iron  after  prolonged  boiling 
would  give  improved  results. 

Two  samples  were  boiled—" 


Minutes. 

Per  cent  recovery 

18 

98-6 

40 

98-8 

The  filtrate  of-  the  first  sample  was  distindlly  tinted  with 


Chemical  News,  ) 

oa.ag,  1897.    ; 


Laboratory  Notes. 


2lt 


unprecipitated  iron.  Evidently  mere  prolonged  boiling 
has  no  effedl  on  the  separation. 

To  go  a  step  further,  and  passing  over  decreasing 
volumes  of  acid  and  acetate,  which  wrould  give  increas- 
ingly better  results,  it  might  be  predicted  that  Schwarzen- 
berg's  or  Herschell's  method,  which  consists  of  boiling 
a  solution  containing  the  maximum  amount  of  dissolved 
hydrate,  would  give  the  best  results  of  all. 

Truly  it  might  be  objedied  that  this  would  not  be  an 
acetate  separation,  nor  would  it,  although  in  a  mathe- 
matical sense  it  may  be  regarded  as  the  limiting  case  of 
such  separations.  In  a  pradtical  sense,  too,  it  may  often  be 
convenient  to  convert  a  Schwarzenberg  into  an  acetate 
separation,  when  the  neutralisation  has  not  been  performed 
with  the  necessary  exadtness.  The  Schwarzenberg  re- 
a&ioa  is  generally  assured  by  adding  large  amounts  of 
alkaline  chlorides.  In  the  two  cases  given  below  no  such 
addition  was  made.  In  neither  case  was  the  solution 
filterable  when  the  boiling  point  was  reached.  I.  was 
boiled  five  minutes;  II.  thirty  minutes. 


Table  XVII. 

Temp.  turb. 

Per  cent  recovery 

I. 
I. 

81°  C. 

83°  c. 

99'45 
99-10 

These  results  are  particularly  noteworthy,  because 
copper  is  not  one  of  the  metals  where  separation  from 
iron  by  these  means  is  generally  recommended. 

The  preceding  tests  were  all  made  with  soda  salts,  so 
as  to  accommodate  the  filtrate  to  the  modified  cyanide 
estimation  of  copper,  an  account  of  which  is  to  be  found 
on  page  189. 

The  presence  of  soda  chloride  in  unusual  quantities 
rather  improves  the  separation. 

Separations  made  with  ammonia  salts  yield  somewhat 
better  results,  under  like  conditions,  than  do  soda  salts. 
The  presence  of  large  amounts  of  ammonia  chloride 
would  presumably  still  further  increase  the  accuracy  of  the 
separation. 

In  the  following  table  there  are  summarised  some  re- 
sults with  varying  proportions  of  copper.  The  separations 
are  made  with  soda  acetate,  without  any  unusual  amount 
of  soda  chloride  being  present.  For  reasons  just  stated 
this  circumstance  places  the  acetate  separation  in  its 
most  unfavourable  light,  and  is  only  adopted  on  account 
of  the  greater  constancy  of  the  soda  cyanide  estimation 
of  copper.  Many  other  means  of  estimating  the  sepa- 
rated copper  are,  of  course,  indifferent  to  this  demerit  of 
the  ammonia  salts.  In  case  such  are  allied  to  the  acetate 
separation,  it  is  well  to  remember  that  ammonia  salts  are 
better  than  soda,  and  Schwarzenberg's  precipitation  best 
of  ail. 

Table  XVIII. 


Present. 

Recovered. 

Percentage 

0-02  grm. 

0-0196 

97*8 

0-03     „ 

0-0294 

98-0 

0-05     „ 

0-0489 

97-8 

010     „ 

0-0986 

98-6 

0*20      „ 

0*1956 

978 

Copper  in  Steel. 

When  estimating  copper  in  steel  and  such  iron  com- 
pounds as  contain  less  than  half  per  cent,  it  is  necessary 
to  weigh  off  from  5  to  10  grms.  of  the  sample.  Such 
large  amounts  of  iron  could  not  be  precipitated  as  basic 
acetate  without  involving  a  very  cumbersome  volume  of 
liquid. 

The  procedure  in  such  cases  (and  in  many  others  which 
will  suggest  themselves)  so  as  to  make  use  of  the  soda 
cyanide  titration  is  as  follows  : — 

Dissolve  the  sample  in  dilute  sulphuric  acid,  and  pre- 
cipitate as  sulphide  with  sulphuretted  hydrogen,  or  as 
■ubsulphide  with  soda  hyposulphite.  The  latter  is  per- 
haps the  more  convenient  for  occasional  use,  and  for  thp 


sake  of  clearness  we  will  describe  its  processes  beyond 
the  point  at  which  they  diverge  from  the  usual  in- 
strudions. 

It  is  very  convenient  to  perform  the  preliminary  opera- 
tions in  a  flask.  Having  filtered  the  supernatant  solution 
from  the  precipitated  subsulphide,  wash  two  or  three 
times  by  decantation.  The  precipitate  settles  so  readily 
that  little  more  than  traces  of  copper  will  have  passed  on 
to  the  small  paper.  Ignite  it,  replace  the  residue  in 
the  flask,  Snd  add  a  small  quantity  of  nitro-hydrochloric 
acid — 10  to  20  c.c.  Heat  to  boiling,  and  add  separately 
a  few  crystals  of  potassium  chlorate.  A  large  excess  of 
hyposulphite  should  be  avoided,  else  the  decomposition  at 
this  stage  becomes  troublesome.  When  no  solid  matter  re- 
mains save  a  few  pieces  of  sulphur,  cool,  dilute,  neutralise, 
make  alkaline  with  soda  carbonate,  and  titrate  with 
standard  cyanide  as  previously  explained. 

It  is  unnecssary  to  offer  any  array  of  figures  in  this 
connexion.  The  separation  is  one  already  well  established, 
and  that  the  estimation  may  be  made  as  proposed  has 
been  abundantly  proved. 


LABORATORY  NOTES. 

By  H.  JERVIS, 

A  CASUAL  visit  to  many  laboratories  reveals  the  presence 
of  pieces  of  apparatus  which  would  be  far  less  cumbersome 
if  its  composite  pieces  had  been  such  as  were  known  to  be 
obtainable,  but  considered  to  be  too  expensive. 

A  common  example  of  this  is  seen  in  the  number  of 
makeshifts  for  tubulated  bottles  and  other  articles  requiring 
a  hole  here  or  there.  This  of  itself  would  show  that  the 
ability  to  perforate  glass  is  not  largely  possessed  by  the 
everyday  operator. 

The  process  is  so  serviceable  that  a  few  lines  explaining 
the  modus  operandi  will  be  acceptable  to  many  who  have 
never  previously  tried  to  do  the  job,  and  perhaps  helpful 
to  those  who  have  previously  left  the  matter  to  the 
"  engineering  shop,"  and  finally  concluded  that  it  needed 
special  apparatus.  The  operation  really  belongs  to  that 
great  class  of  "tricks"  pradUsed  by  itinerant  repairers  and 
scientific  amateurs. 

Take  a  hole  through  a  cover-glass  as  the  simplest  case. 
Make  a  few  scratches  in  the  form  of  an  asterisk  with  the 
point  of  a  broken  three-square  file  dipped  in  turpentine. 
Rest  the  cover  on  a  wooden  block  or  piece  of  cork  ;  then 
turn  the  sharp  point  of  a  similar  file  backwards  and  for- 
wards on  the  mark,  or  use  the  point  of  a  broken  file  fitted 
in  a  brace,  and  the  hole  is  through  in  a  few  minutes.  In 
some  cases,  usually  with  sheet  glass,  it  is  better  to  bore 
from  each  side. 

Take  now  a  Winchester.  Say  we  need  an  aspirator  or 
some  form  of  HjS  apparatus,  and  want  to  make  a  hole  f 
inch  diameter.  Scratch  on  the  asterisk.  If  only  old  files  are 
available,  use  first  the  point  of  a  three-square  to  start  the 
hole.  Then  break  the  point  off  and  work  with  new  and 
larger  point,  and  so  on  until  the  hole  is  |  or  ^  inch  dia- 
meter. A  smart  tap  will  break  the  file  as  required,  and 
the  new  edges  are  very  able  cutters.  When  the  indenta- 
tion is  thus  enlarged,  one  of  the  sharp  corners  of  the 
broken  file  can  be  used  to  groove  it  towards  the  centre 
with  almost  as  much  facility  as  a  bradawl  could  be  used 
on  an  indent  in  hard  wood.  A  few  turns  of  the  file  clears 
off  the  ridges  and  leaves  the  indent  much  deeper.  If  the 
hole  is  much  cupped  and  nearly  through,  a  smart  tap  with 
a  file  tang  invariably  makes  a  clean  hole :  there  must  be 
no  hesitation  in  giving  the  tap  and  no  blundering  brute 
force.  The  hole  made,  it  can  be  readily  widened  by 
working  with  a  tapering  file.  An  ordinary  fiat  file  is  as 
good  as  any  other  shape,  perhaps  better — it  does  not  jam 
so  readily.     Porcelain  can  be  similarly  perforated. 

Throughout  these  operations  the  tool  should  be 
moistened  with  turpentine,  or  turpentine  and  citmphor, 


212 


Calcination  of  Carbonated  Mangam/erous  Minerals.       { 


Crbhical  Nbws, 
Odt,  29,  ieS97. 


and  such  articles  as  bottles  can  be  conveniently  fixed  in 
position,  resting  on  a  partly  opened  heavy  drawer.  As  an 
alternative  the  boring  may  be  done  under  water  in  a  wash 
basin  or  deep  sink.  In  this  latter  way,  too,  it  is  possible 
to  shape  sheet  glass  with  a  pair  of  scissors,  but  one  must 
make  haste  carefully. 

To  those  whose  while  it  is  worth  a  set  of  bits  made 
from  old  files  will  suggest  itself.  The  Archimedean  brace 
is  a  good  variety  for  small  work.  For  very  small  holes  the 
bow  brace  used  largely  by  watchmakers  and  crockery 
rivetters  is  an  acquisition  which  can  be  readily  made. 


The  breaking  of  thick  glass  combustion  tubing  is  really 
an  easy  operation.  Teachers  often  break  it  by  heating  a 
nicked  portion  between  coils  of  wetted  paper,  and  dealers 
by  working  on  brown  paper  with  string ;  twine  soaked 
with  alcohol  is  another  means.  I  have  found  all  to  be 
inferior  to  the  following.  Make  a  decided  scratch  at  one 
portion  of  the  tube,  and  then  complete  the  circle  in  a 
fainter  line— not  necessarily  fainter.  An  iron  rod  (J  or  i 
inch)  meanwhile  pushed  up  the  burner  of  a  muffle  will 
now  have  become  hot ;  lay  it  on  the  deeper  scratch  until 
it  approaches  blackness,  and  then,  if  the  fratJlure  has  not 
already  occurred,  touch  the  heated  glass  with  the  tip  of  a 
wetted  finger.  The  fradture  is  in  most  cases  as  even  as 
possible.  Occasional  irregularities  are  levelled  up  with 
the  pliers.  The  effeft  is  greater  and  the  danger  of  fradure 
less  if  the  pliers  are  used  from  the  outer  diameter  of  the 
tube. 


ON  THE 

ESTIMATION   OF  LIME,  ALUMINA,  AND   IRON 

IN     MINERAL    PHOSPHATES. 

By  M.  L.  LINDET. 

The  attention  of  agricultural  chemists  has  often  been 
drawn  to  the  part  played  by  alumina  and  oxide  of  iron  in 
the  retrogradation  of  superphosphates,  and  to  the  diffi- 
culties which  attend  the  estimation  of  these  two  elements 
in  commercial  phosphates.  The  numerous  methods  which 
have  been  proposed  to  effedl  this  estimation  all  require  a 
certain  amount  of  delicate  manipulation,  and  many  of 
them  give  but  uncertain  results  ;  they  have  further  been 
the  subjedt  of  a  critical  examination  by  M.  Lasne  {Bull. 
Soc.  Chim.,  pp.  Ii8,  148,  237,  1896),  which  enables  me  to 
dispense  with  any  description  of  them  or  to  pomt  out 
their  relative  disadvantages.  The  estimation  of  lime  is, 
as  a  rule,  conduced  in  the  liquors  from  which  the  iron  and 
alumina  have  already  been  separated;  its  exaftness 
therefore  depends  on  the  processes  to  which  I  have  just 

referred.  ,  ,      .  •       •         c 

The  most  generally  used  method  for  the  estimation  of 
phosphoric  acid  consists  of  precipitating  as  ammonio- 
magnesic  phosphate,  in  the  presence  of  a  large  excess  of 
citrate  of  ammonia,  which  keeps  the  lime,  alumina, 
oxides  of  iron,  manganese,  &c.,  in  solution.  To  then 
separate  these  oxides  from  the  filtrates  it  is  necessary  to 
destroy  the  citric  acid,  either  by  evaporation,  which  never 
takes  place  without  bumping,  and  calcination  of  the 
residue,— and  this  is  always  a  long  operation,— or  by 
oxidation  of  this  residue  with  fuming  nitric  acid,  or  a 
mixture  of  nitrate  and  chloride  of  potassium.  These 
oxidations  are  in  general  very  incomplete,  inasmuch  as 
the  iron  and  alumina  remain,  in  spite  of  everything,  in 
solution,  in  the  presence  of  ammonia. 

It  occurred  to  me  that  one  might,  with  advantage,  and 
for  the  purpose  of  destroying  this  citric  acid,  use  the 
beautiful  reaftion  recently  described  by  M.  Villiers 
(Comptes  Rendus,  cxxiv.,  p.  1349).  that  is  to  say,  the 
oxidation  of  organic  matters  by  nitric  acid  in  the  presence 
of  manganese.  The  readion,  as  a  matter  of  fad,  can  give 
find  has  given  perfeft  results, 


The  operation  should  be  condudted  in  the  following 
manner : — The  ammoniacal  liquors,  from  which  the 
ammonio-magnesic  phosphate  has  been  removed,  are 
saturated  with  nitric  acid,  and  0-5  grm.  of  sulphate  or 
nitrate  of  manganese,  and  about  50  c.c.  of  nitric  acid  for 
every  20  grms.  of  citric  acid,  are  then  added.  This  mix- 
ture placed  in  a  fiask  is  gently  heated,  and  the  attack 
proceeds  during  the  evaporation;  nitric  acid  is  added  every 
time  the  adtion  decreases  ;  this  can  be  easily  seen  by  re- 
moving the  flame.  When  a  fresh  addition  of  acid  no 
longer  causes  any  evolution  of  gas,  we  may  rest  assured 
that  there  is  no  longer  any  nitric  acid  present,  and  that  it 
can  no  longer  prevent  the  precipitation  of  iron  and 
alumina  by  ammonia.  The  precipitate  is  colledled  and 
re-dissolved,  and  separated  by  the  ordinary  methods. 

Chloride  of  vanadium  (dichloride  of  vanadyle,  VaOClj) 
may  with  advantage  be  substituted  for  the  salts  of  man- 
ganese. Its  adlion  is  much  more  energetic,  and  o'l  grm. 
suffices  for  the  rapid  oxidation  of  20  grms.  of  citric  acid. 
Hypo-vanadate  of  ammonium,  precipitated  at  the  same  time 
as  the  iron  and  alumina,  is  insoluble  under  the  conditions 
of  the  experiment,  above  all  in  the  presence  of  ammonia  in 
excess.  Instead  of  trying  to  separate  the  iron  and  the 
alumina,  we  can  subtradt  from  the  weight  of  the  calcined 
precipitate  the  weight  of  oxide  of  vanadium  added ;  it 
therefore  suffices  to  make  use  of  a  i  per  cent  solution  of 
chloride  of  vanadium,  and  to  take,  for  precipitating  with 
ammonia,  10  c.c.  of  the  liquid,  in  presence  of  a  known 
weight  of  sesquioxide  of  iron. 

Whether  we  use  salts  of  manganese  or  salts  of  vana- 
dium for  the  destrudtion  of  the  citric  acid,  it  is  easy,  in 
the  liquors  from  which  the  iron  and  alumina  have  been 
eliminated,  to  estimate  the  lime  in  the  ordinary  manner, 
— jfourn.  de  Pharm.  et  de  Chim.,  Series  6,  vol.vi.,  No.  6. 


THE    CALCINATION    OF 

CARBONATED     MANGANIFEROUS     MINERALS, 

AND   THEIR   ASSAY.' 

By  N.  DEVISSE. 

Before  commenting  on  the  different  metallurgical  appli- 
ances for  the  calcination  of  carbonated  manganiferous 
minerals,  it  is  indispensable  to  point  out  the  thermo- 
chemical  properties,  whose  interpretation  will  largely 
contribute  to  the  elucidation  of  divers  phenomena,  and  to 
the  determination  of  the  best  conditions  to  allow  of  the 
minimum  consumption  of  fuel. 

In  the  first  place,  the  chemical  composition  of  these 
minerals,  when  subjedl  to  ordinary  atmospheric  conditions, 
is  in  a  state  of  unstable  equilibrium,  tending  towards  the 
formation  of  pyrolusite,  the  original  pink  mineral  becoming 
black.  Owing  to  this  conversion,  heaps  of  manganiferous 
ore  have  been  known  to  so  alter  that  the  percentage  of 
manganese  increased  from  46  to  52  in  a  few  years. 

Dialtogite,  under  the  influence  of  air  and  rain,  behaves 
in  a  similar  manner,  while  the  rain  waters— by  dissolving 
the  carbonate  of  lime  and  magnesia  which  are  generally 
present— render  the  mass  porous,  enriching  it  considerably, 
as  in  the  previous  case. 

This  metamorphosis  is  further  in  harmony  with  the 
thermo-chemical  laws  of  M.  Berthelot,  according  to  which 
for  I  ton  of  ore,  at  45  per  cent  contents  of  Mn,  there 
would  be  a  disengagement  of  63"47  calories,  equivalent  to 
the  heat  of  combustion  of  8*4  kilos,  of  coal,  from  which 
we  may  conclude  that  pure  diallogite  is  a  combustible 
material. 

This  being  established,  we  can  now  approach  the  study 
of  the  calcination  of  carbonated  manganiferous  minerals. 

The  roasting  of  these  minerals  may  be  carried  out 

*  Abridged  from  the  Rtvue  UniverselU  des  Mines  et  de  la  Metal- 
lurgie,  Series  3,  vol.  xuiz.,  August,  1897. 


Chemical  News,  i 
oa.  29, 1897.     I 


Calcination  0/  Carbonated  Mangani/erous  Minerals. 


213 


either  in  heaps,  kilns,  or  ovens.  The  first  may  be  passed 
over.  In  new  installations  the  choice  of  apparatus  depends 
on  the  quantity  of  silica  present  in  the  mineral ;  if  it  is 
low,  kilns  are  the  best  to  use,  having  at  the  same  time 
one  or  two  ovens  for  the  calcination  of  lumps  when  their 
proportion  in  the  ore  to  be  treated  is  considerable.  If  the 
ore  contains  as  much  as  8  per  cent  of  silica,  it  is  better  to 
use  only  ovens. 

As  soon  as  the  ore  attains  the  temperature  necessary 
for  the  dissociation  of  the  carbonic  acid,  this  silica  unites 
energetically  with  the  protoxide  of  manganese,  forming  a 
silicate,  agglomerating  the  ore  in  masses  whose  volume 
will  frequently  entirely  upset  the  operation,  the  charge 
descending  in  the  most  unexpedted  manner.  It  is  then 
necessary  to  empty  the  furnace  and  break  up  the  hard 
lumps,  in  which  good  crystals  of  the  silicate  may  be  often 
found. 

In  using  the  kiln,  the  ore  and  the  fuel  charged  at  the  top 
absorb  the  heat  of  the  produdts  of  combustion  as  they 
ascend,  while  the  air  entering  below  is  warmed  at  the 
expense  of  the  already  calcined  material ;  on  arriving  at 
the  intermediate  zone  the  air  gives  up  its  oxygen,  pro- 
ducing, in  conjundlion  with  the  combustion  of  the  fuel 
and  of  the  protoxide  of  manganese,  the  heat  which  will 
be  absorbed  by  the  dissociation  of  the  carbonic  acid  and 
in  the  upper  zone  of  decarbonisation. 

The  calcined  ore  is  drawn  out  from  time  to  time,  at 
regular  intervals,  stopping  when  it  appears  warm,  and  the 
space  formed  at  the  furnace  mouth  is  filled  with  a  fresh 
charge. 

Although  pure  diallogite  is  a  combustible  mineral,  we 
must  not  conclude  that  the  carbonated  manganiferous 
ores,  when  once  alight,  will  continue  roasting  of  them- 
selves ;  there  is  none  in  nature  sufificiently  pure  to  effedl 
this. 

Being  always  in  conjundtion  with  the  isomorphous 
carbonates  of  lime  and  magnesia,  with  a  certain  propor- 
tion of  silica,  it  requires  for  its  calcination  such  a  quan- 
tity of  heat  that  we  must  still  have  recourse  to  fuel,  but 
in  amounts  smaller  according  to  the  efficiency  of  the 
furnace,  which  must  allow  of  the  easy  combustion  of  the 
protoxide  of  manganese  and  the  regular  descent  of 
the  charge. 

The  combustion  of  the  protoxide  of  manganese  depends 
on  the  uniform  distribution  of  a  sufficient  quantity  of  air  ; 
this  is  best  obtained  by  means  of  a  damper.-  The  regular 
descent  of  the  charge  depends  entirely  on  the  shape  and 
sedtion  of  the  kiln,  ovoids,  and  cylindro-conical  furnaces; 
widening  towards  the  top  should  be  absolutely  rejefted, 
the  best  shape  being  cylindro-conical  in  vertical  sedion, 
slightly  widening  towards  the  base.  This  form  allows  of 
the  uniform  descent  of  the  charge  and  the  parallel  ascent 
of  the  currents  of  gas. 

The  sedtion  of  the  outlet  should  not  be  too  large,  or 
there  will  always  remain  a  quantity  of  ore  which  cannot 
be  removed. 

Among  the  well-known  blast-furnaces  used,  the  best 
would  probably  be  the  Ayresome  (Cleveland),  and  it  is  to 
this  class  that  we  are  indebted  for  the  principle  on  which 
the  above-mentioned  one  was  construdted. 

When  the  ore  to  be  calcined  is  siliceous,  or  for  the  cal- 
cination of  large  lumps,  we  have  already  said  that  the 
kiln  is  unsuitable ;  in  these  cases  it  is  best  to  make  use 
of  large  parallel  ovens,  about  7  metres  long  by  i"5  metres 
wide,  and  about  8  metres  high.  The  floor  which  carries 
the  ore  is  formed  of  rows  of  bricks,  with  spaces  in  between 
of  about  0-15  metre  in  width,  forming  an  arch  0*35  metre 
high  in  front  of  each  oven  door.  The  oven  being  empty, 
we  begin  by  charging  it  with  the  unroasted  ore  from  the 
previous  operation,  to  about  0*25  metre  thickness,  putting 
the  largest  lumps  over  the  spaces  between  the  bricks  ;  we 
then  spread  the  first  layer  of  fuel,  and  alternate  layers  of 
fuel  and  raw  ore  up  to  0*4  metre  high.  When  the  charge 
reaches  the  height  of  the  door  it  is  bricked  up,  and  the 
fire  started  with  wood  under  each  arch.  The  charging 
continues  day  by  day,  taking  care  to  gradually  diminish 


the  quantity  of  fuel,  especially  for  the  last  two  layers, 
when  finer  ore  must  be  used.  As  soon  as  the  first  charge 
becomes  of  a  dull  red  heat,  the  fire  below  is  allowed  to 
go  out,  and  the  combustion  proceeds  from  layer  to  layer. 
After  four  or  five  days  the  fire  reaches  the  upper  layers  ; 
when  cool  the  door  at  the  bottom  is  opened,  and  the 
mineral — which  is  in  what  is  called  the  "liquid"  state — 
runs  out  with  ease.  The  operation  lasts  eight  or  nine 
days  from  beginning  to  end,  and  gives  a  return  of  about 
400  tons  per  month. 

The  problem  of  calcining  pulverulent  minerals  has  not 
yet  been  satisfadlorily  solved  ;  it  cannot  be  done  in  a  kiln 
or  an  oven  as  just  described.  It  has  been  done  in  a 
"  Pelatan  "  furnace,  but  at  the  expense  of  12  to  13  per 
cent  of  coke. 

The  Assay  of  Ores. 

Without  reviewing  the  known  methods  of  estimating 
manganese,  we  will  simply  point  out  a  few  fadls  deduced 
from  the  beautiful  experiments  made  by  Gorgeu  {Ann.  de 
Phys.  et  de  Chim.,  "  On  Manganous  Acid,"  Series  3,  vol. 
Ixvi.,  p.  153),  the  importance  of  which  does  not  seem  to 
have  been  sufficiently  appreciated. 

When  we  precipitate  manganese  m  the  presence  of  an 
oxidising  agent,  such  as  chlorine,  bromine,  &c.,  this 
metal  tends  to  separate  in  the  form  of  manganate,  ac- 
cording to  the  formula  5Mn02,MO,  MO  being  either 
protoxide  of  manganese,  oxide  of  zinc,  lime,  &c.  For 
example,  when  we  add  permanganate  to  chloride  of  man- 
ganese all  the  permanganate  is  decomposed;  at  the  same 
time  the  liquid  becomes  acid,  and  a  brown  precipitate 
takes  place.  If  we  neutralise  the  acid  set  at  liberty,  as 
it  is  produced,  we  notice,  after  having  added  one  equiva- 
lent of  permanganate  of  potash  to  four  of  chloride  of 
manganese,  that  three-quarters  of  the  hydrochloric  acid 
have  been  set  at  liberty,  and  that  there  is  no  longer  any 
manganese  remaining  in  solution  : — 

4MnCl  +  Mn207KO -h3H0  =  5Mn02,MnO-t-KCl+3HCl. 

The  presence  of  salts  of  lime,  zinc,  &c.,  thus  casts  sus- 
picion on  gravimetric  estimations,  while  on  the  contrary 
it  is  necessary  to  the  accuracy  of  volumetric  methods,  in 
which  the  objedt  is  to  measure  the  quantity  of  oxygen 
absorbed  by  the  manganese  in  its  precipitation  in  the 
state  of  binoxide,  or,  rather  of  manganous  acid.  We 
strongly  recommend  the  use  of  volumetric  methods, 
which  are  of  extreme  accuracy  whenever  we  add  to  the 
solutions  a  sufficient  quantity  of  a  soluble  salt  of  zinc  or 
lime;  we  even  advise  keeping  a  certain  quantity  of  these 
bases  in  suspension  at  the  moment  of  precipitation. 

Under  these  conditions  all  the  manganese  will  be  pre- 
cipitated in  the  state  of  manganous  acid,  in  the  manga- 
nites  of  zinc  or  lime  which  are  formed  ;  the  manganite  of 
manganese  is  not  formed  except  when  this  metal  is  alone, 
as,  for  example,  when  we  submit  precipitated  carbonate 
of  manganese  to  the  adtion  of  chlorine  in  excess. 

Finally,  in  Volhard's  method,  the  most  elegant  and 
rapid  of  all  the  volumetric  methods,  it  is  not  necessary  to 
transform  the  chlorides  into  sulphates,  if  we  make  it  a 
rule  to^add  precipitated  oxide  of  zinc  to  the  dilute  neutral 
liquid  to  which  the  permanganate  of  potash  is  to  be 
added.  In  fadt,  the  hydrochloric  acid  set  at  liberty  in 
the  readlion — 

3MnCl  +  MnaOyKO  +  2H0  =  KC1  +  2HCI  +  sMnOj, 
is  in  this  manner  neutralised  immediately  on  its  formation. 


Jubilee  Medal.  —  The  Queen  has  been  graciously 
pleased  to  bestow  upon  Mr.  Walter  Hills,  President  of 
the  Pharmaceutical  Society  of  Great  Britain,  a  mark  of 
Royal  favour  in  connedlion  with  the  sixtieth  anniversary 
of  Her  Majesty's  reign,  by  presenting  him  with  a  medal 
to  be  worn  as  a  decoration  commemorative  of  that 
event. 


214 


Composition  of  certain  Canadian  Virgin  Soits. 


I  Crbmical  Nxws, 
\     Oa.  39i  1*97' 


ON     THE    COMPOSITION     OF    CERTAIN 
CANADIAN   VIRGIN    SOILS.* 

By  FRANK  T.  SHUTT,    M.A.    F.I.C.,    F.C.S., 
Chemist,    Dominion  Experimental  Farms. 

(Continued  from  p.  206). 

North-West  Territories  and  Manitoba. 
The  prairie  soils  of  the  North-West  Territories  and 
Manitoba  are  justly  noted  for  their  produdiveness.  They 
contain,  as  a  rule,  large  percentages  of  all  the  essential 
constituents,  and  are  chara(5ierised  by  percentages  of 
humus  and  nitrogen  far  above  the  average.  The  pre- 
vailing surface  soil,  speaking  generally,  is  a  black  or 
greyish  black  loam  in  which  the  vegetable  matter  is  wrell 
decomposed  and  thoroughly  incorporated  with  the  in- 
organic  compounds  of  the  soil.  It  varies  in  depth  from  a 
few  inches  to  one,  two,  or  even  more  feet,  and  over  large 
areas  is  underlaid  with  a  heavy  clay  subsoil. 

Occasionally  we  have  had  sent  to  us  soils  from  certain 
distrias  in  the  North-West  Territories,  in  which  it  is 
•tated  that  poor  yields  are  obtained.  On  examination, 
these  soils  have  been  found  to  possess  plant  food  in 
adequate  quantities  for  crop  requirements.  Further,  they 
have  usually  been  found  to  be  free  from  alkali.  Investiga- 
tion has  shown  that  the  trouble  was,  not  in  the  lack  of 
plant  food,  but  rather  in  the  climate ;  a  scanty  rainfall 
being  really  the  cause  of  the  poverty  of  growth.  In  distridls 
subjedt  to  drought  irrigation,  if  feasible,  would  render  such 
soils  most  fertile.  An  illustration  of  this  is  afforded  by 
the  late  irrigation  trials  at  Calgary,  which  have  proved  so 
successful  from  an  agricultural  point  of  view.  In  this 
conneftion  we  have  to  add  that  unfortunately  no  means 
for  extensive  irrigation  appear  pradticable  for  several 
of  the  distridls  here  referred  to  in  the  North- West 
Territories. 

The  presence  of  "  alkali  "  in  the  soil  in  patches  over 
certain  areas  in  Manitoba  and  the  North- West  Terri- 
tories is  intimately  connefted  with  the  question  of  rain- 
fall. An  alkali  area  may  be  restriaed  to  a  few  square 
feet,  or  it  may  cover  some  acres.  Patches  of  alkali  soil 
occur  surrounded  by  land  of  great  produftiveness. 

The  formation  and  retention  of  alkali  are  dependent 
upon  the  amount  of  water  the  soil  receives  and  the  facility 
for  subsoil  drainage.  We  need  not  now  discuss  the 
occurrence  of  alkali  nor  its  nature,  but  it  is  valuable  to 
note  that,  though  the  amounts  of  alkali  found  in  samples 
submitted  to  us  are  often  so  great  as  to  render  the  growth 
of  wheat  impossible,  we  have  invariably  found  such  soils 
to  be  rich  in  mineral  and  organic  constituents.  This  shows 
that  the  soil  proper  is  capable  of  afting  as  a  fertile  one, 
provided  the  alkali  were  got  rid  of  by  drainage,  irrigation, 
or  treatment  with  gypsum. 

In  Table  III.  we  have  given  analytical  data  of  seven 
surface  soils  from  the  North- West  Territories.  Though 
there  is  a  greater  uniformity  in  the  texture  and  composi- 
tion of  soils  upon  the  prairies  than  among  soils  of  the 
Eastern  provinces,  no  claim  is  made  that  the  vast  extent 

of  the  Territories  is  represented  by  these  samples they 

are  altogether  too  few  in  number.  They  may  serve,  how- 
ever, to  indicate  the  general  charadter  of  the  soils  over 
certain  large  areas. 

Without  discussing  these  soils  in  detail,  attention  may 
be  called  to  their  high  nitrogen  content  and  the  large 
amounts  of  organic  matter  that  are  almost  invariably  pre- 
sent. These  soils  also  contain  above  the  average  amount 
of  potash.  Our  results  do  not  show  them  to  be  noted  for 
phosphoric  acid,  though  they  possess  quantities  quite 
equal  to  those  in  many  very  fertile  soils.  The  great 
depth  of  the  surface  soil  over  large  areas  accentuates  our 
deduaions  respefting  the  vast  stores  of  plant  food  laid  up 
in  the  plains  for  future  crops.     We  are  of  the  belief  that 


♦  Read   before  the   British    Association  (Sedtion   B),    Toronto 
lleettng,  1897. 


where  poor  crops  only  are  procurable  the  climatic  condi- 
tions are  rather  at  fault  than  that  there  is  a  lack  of  plant 
food.  Even  in  soils  containing  injurious  amounts  of 
alkali  we  have  found,  as  already  pointed  out,  an  abundance 
of  fertilising  ingredients ;  drainage,  if  there  is  an  adequate 
rainfall,  frequently  being  all  that  is  necessary  to  bring  them 
into  a  state  of  produ(5liveness. 

Soil  No.  37  represents  the  unfertilised  and  uncropped 
prairie  soil  of  the  Red  River  Valley,  Manitoba.  It  was 
taken  from  Sedtion  31,  Township  4,  Range  i.  West.  The 
uniformity  in  the  charadler  of  the  soil  over  a  very  large 
area  in  Manitoba  makes  the  data  here  presented  of  more 
than  ordinary  importance. 

The  surface  soil,  which  is  fairly  uniform  throughout  its 
depth,  averages  a  little  over  2  feet  in  thickness  and 
merges  gradually  into  the  subsoil,  which  is  blue  clay. 
The  latter,  as  tested  by  boring  for  water  at  this  spot,  ex- 
tends at  least  to  a  depth  of  250  feet. 

The  soil  is  deep  black  loam,  of  a  fine  and  peculiarly 
charaderistic  granular  order.  It  reduces  easily  between 
the  fingers  in  the  air-dried  condition  to  a  greyish  brown 
powder.  Though  there  is  present  a  considerable  amount 
of  undecomposed  root-fibre,  the  soil  proper  exhibits  a  re- 
markable homogeneity,  indicating  a  process  of  physical 
refining  in  its  formation  and  a  uniformity  in  the  chemical 
composition.  The  very  large  amount  of  organic  matter 
present  is  undoubtedly  most  intimately  incorporated  with 
the  clay  and  sand  which  constitutes  the  basis  of  the  soil. 

Though  containing  a  large  amount  of  clay,  laboratory 
experiments  show  that  this  soil  does  not  readily  •'  puddle  " 
on  moistening,  nor  on  subsequent  drying  does  it  form  into 
a  hard  mass,  but  readily  granulates  on  slight  pressure. 

The  large  amount  of  organic  matter  present  has  already 
been  remarked ;  it  exceeds  25  per  cent  of  the  water-free 
soil.  The  nitrogen  is  found  to  be  pra^ically  i  per  cent, 
which  would  show  that  there  is  contained  in  an  acre  of 
soil  to  the  depth  of  i  foot  more  than  30,000  pounds  of 
this  element.  Since  ordinary  fertile  soils  to  a  like  depth 
contain  from  3500  to  10,000  lbs.  of  nitrogen  per  acre,  the 
vast  reserve  of  this  valuable  constituent  in  this  prairie 
soil  is  apparent. 

This  soil  is  also  very  rich  in  potash,  containing  an 
amount  far  in  excess  of  that  ordinarily  met  with  in  fertile 
soils.  But  two  other  virgin  soils  examined  by  us  approach 
its  potash  content,  1*03  per  cent. 

Of  phosphoric  acid  it  contains  0*29  per  cent.  This 
also  is  above  the  average,  most  of  our  good  soils  shov/ing 
between  o"i5  per  cent  and  o'25  per  cent  phosphoric  acid. 

We  may  safely  conclude  that  there  is  here  ample  scientific 
proof  of  the  well-nigh  inexhaustible  stores  of  plant  food, 
and  that  this  prairie  land,  as  regards  the  elements  of 
fertility,  ranks  with  the  richest  of  known  soils. 

Concerning  the  prairie  soil  of  the  Red  River  Valley, 
Dr.  Geo.  M.  Dawson,  Diredor  of  the  Geological  Survey 
of  Canada,  wrote  some  years  ago  as  follows  : — 

"  Of  the  alluvial  prairie  of  the  Red  River  much  has 
already  been  said,  and  the  uniform  fertihty  of  its  soil  can- 
not be  exaggerated.  The  surface,  for  a  depth  of  two  to 
four  feet,  is  a  dark  mould,  composed  of  the  same  material 
as  the  subsoil,  but  mingled  with  much  vegetable  matter. 
Its  dark  colour  is  no  doubt  due  in  part  to  the  gradual  ac- 
cumulation of  the  charred  grasses  left  by  the  prairie  fires. 
The  soil  may  be  said  to  be  ready  for  the  plough,  and  in 
turning  the  tough  thick  prairie  sod,  the  first  year  a  crop 
of  potatoes  may  be  put  in,  though  it  is  not  efficiently 
broken  up  till  it  has  been  subjecSed  to  a  winter's  frost. 
When  the  sod  has  rotted,  the  soil  appears  as  a  light 
friable  mould,  easily  worked  and  most  favourable  for 
agriculture.  The  marly  alluvium  underlying  the  vegetable 
mould  would,  in  most  countries,  be  considered  a  soil  of 
the  best  quality,  and  the  fertility  of  the  ground  may, 
therefore,  be  considered  as  pra(5licaily  inexhaustible. 

•'  The  area  of  this  lowest  prairie  has  been  approxi- 
mately stated  as  6goo  square  miles,  but  the  whole  is  not 
at  present  suitable  for  agriculture.  Small  swamps  are 
scattered  pretty  uniformly  over  its  surface.      The  greater 


^oaf.'29^897^^'^  Composition  of  certain  Canadian  Virgin  Soils. 

Table  111.— Analyses  of  Soils  {Water-free),  North-West  Territories  and  Manitoba 

Surface 

No.                Locality.                                 or  Charafter  of  soil.           Potash.  Phosphoric  Nitrogen 

subsoil.  acid. 

30.  Yorkton,  N.W.T.  • .     Surface Black  sandy  loam     ..     0-49        0*21        0*504 

31.  ,,            ,,        ..     Subsoil 0*42        cog        o'i3o 

32.  Saltcoats,     „        ..     Surface „          „        „        ..     0-34        o-ai        0-571 

33.  Moosomin,   „        ..  , Black  loam 036        o-ii        0-479 

34.  Calgary „       044         0-17         0-447 

35.  Tilley       Township, 

N.W.T „      0-27        o-i8        0398 

36.  Vermillion       Hills, 

N.W.T 0-17        017        0-354 

37.  Red    River    Valley, 

Manitoba  ....          „      1*03        0-29        1-005 


215 


Lime. 

Loss  on  ignition 

(organic  and 
volatile  matter) 

0'o6 

075 
2-90 

095 
092 

14-01 
8-l8 

13-54 
11-79 
12-23 

037 

II-13 

0-50 

10-43 

1-89 

26-29 

38.  Sinclair   Township, 

Muskoka    .. 

39.  Chaffey    Township, 

Muskoka    .. 

40.  Chaffey    Township, 

Muskoka    .. 

41.  Franklin  Township, 

Muskoka    .. 

42.  Franklin  Township, 

Muskoka    .. 

43.  Perry      Township, 

Muskoka    . . 

44.  Perry     Township, 

Muskoka    . . 

45.  Brunei      Township, 

Muskoka    ..     .. 

46.  Brunei      Township, 

Muskoka    .. 


Table  IV. — Analyses  of  Soils  {Water- free),  Ontario. 

Surface Sandy  loam o-ii  0*27 

II      I o-o8  0-12 

Subsoil Sand 0-08  0-18 

Surface Light  grey  loam  .     ..  0-61  o-i8 

Subsoil 0-02  0-08 

Surface Sandy  loam 0-04  o'i8 

Subsoil 0-06  0-18 

Surface Clay  loam 0-46  0-17 

Subsoil 0-29  0-09 

Table  V. — Analyses  of  Soils  (Water-free),  Quebec. 

Surface Sandy  loam 0-16  0-17 

Subsoil 0-17  o'i8 

Surface Red  sandy  loam..      ..  0*44  0-07 

„      Grey  sandy  loam       ..  0*39  0-33 

Subsoil 0-47  0*30 

Surface Clay  loam o-ii  0-19 

Subsoil o-io  0-19 

Surface Black  clay  loam..      ..  0*40  0*28 

Subsoil 0-44  0-29 

Surface..     ..      ..     Reddish     yellow    clay 

loam        1*17  0-19 


o-i86 

0-I2 

8-74 

0-139 

0-40 

6-79 

0-074 

0'20 

3-53 

0-103 

0-76 

6-31 

trace 

0-66 

370 

0-296 

0-08 

9-40 

0-119 

0-13 

5-10 

0-084 

1-28 

2-94 

0-064 

1-07 

2-39 

47.  Arthabaska,  Quebec 

48.  II  II 

49.  St.  Adelaide  dePabos 

50.  Soulanges,  Gaspe. 

51-  I*  • 

52.  Lievre  River,   ,, 

53- 

54.  Joilette,  „ 

55'  n  y< 

56.  Bonaventure,  ,1 


0-296 

0-35 

8-68 

0-184 

0-29 

5-46 

0-215 

o-i6 

7-85 

0198 

0-47 

776 

0049 

073 

367 

0-179 

1-23 

577 

0-I7I 

I-I7 

562 

0-218 

0-82 

8 -06 

0-030 

1-05 

2-09 

0-249 


1237 


part  of  these  swamps  are,  however,  so  situated  as  to  be 
easily  drained,  either  into  the  Red  River  or  some  of  its 
tributaries,  which  are  usually  depressed  30  or  40  feet  be- 
low the  level  of  the  surface. 

*'  As  a  measure  of  the  possible  agricultural  capacity  of 
this  great  valley,  take  one-half  of  the  entire  area,  or 
3,4000  square  miles,  equalling  2,176,000  acres,  and  for 
simplicity  of  calculation,  let  it  be  supposed  to  be  sown 
entirely  in  wheat ;  then,  at  the  rate  of  17  bushels  per  acre, 
which,  according  to  Prof.  Thomas,  is  the  average  yield 
for  Minnesota,  the  crop  of  the  Red  River  Valley  would 
amount  to  40,992,000  bushels." 

Ontario. 
The  review  of  soils  in  this  province  will  be  restridled  to 
certain  surface  and  subsoil  samples  collected  in  the  district 
of  Muskoka  (Table  IV.)  —a  district  lying  somewhat  over 
100  miles  north  of  Toronto,  and  considered,  for  the  most 
part,  more  piduresque  than  agricultural ;  it  is  rocky  and 
abounding  in  lakes,  well  timbered — save  where  destructive 
fires  have  swept  through, — with  stretches  of  fairly  good, 
though,  as  a  rule,  light  soils  along  the  river  valleys  and 


on  the  tower  levels.  Our  data  respecting  virgin  soils  in 
other  parts  of  the  province  are  too  fragmentary  to  warrant 
their  insertion  in  this  paper. 

Soil  No.  38.— From  Sinclair  Township.  A  shallow 
very  loose  sandy  soil ;  the  subsoil  of  hard  pan  is  found  at 
a  depth  of  from  6  to  12  inches.  Though  moderately  rich 
in  phosphoric  acid,  nitrogen,  and  humus,  it  is  below  the 
average  in  potash  and  lime. 

Soils  Nos.  39  and  40. — Surface  and  subsoil  from  Town- 
ship of  Chaffey.  A  shallow  sandy  loam  running  into  a 
subsoil  of  sand.  Hard  pan  exists  at  a  depth  of  15  inches. 
The  surface  soil  is  deficient  in  potash,  but  otherwise  of 
medium  quality  as  regards  plant  food. 

Soils  Nos.  41  and  42. — From  Franklin  Township.  The 
surface  soil  is  a  light  grey  clay  loam,  high  in  potash,  fair 
in  phosphoric  acid,  and  low  in  nitrogen ;  lime  is  present 
in  an  amount  that  might  be  considered  large  for  Muskoka 
soils. 

Soils  Nos.  43  and  44.— Perry  Township,  Parry  Sound 
district.  Soil  and  subsoil.  The  country  is  described  as 
level  or  gently  sloping,  with  no  rocky  bluffs,  and  w^l 
timbered  with  excellent  hardwood. 


2l6 


Early  A  merican  Chemical  Societies. 


I  Crbmical  Nbwb 
I      Oft.  29, 1897. 


Both  samples  are  light  and  sandy  in  charadter,  and  ex-  ^ 
ceedingly  low  in  potash  and  lime.    Regarding  the  surface 
soil,  we  may  say  that  the  percentage  of  phosphoric  acid 
is  fair,  and  that  in  nitrogen  it  is  above  the  average,  com- 
pared with  soils  of  this  charadter  in  this  distridt, 

Soils  Nos.  45  and  46. — Surface  and  Subsoil  from  Brunei 
Township.  The  surface  soil  is  a  clay  loam  of  a  light 
grey  colour,  from  8  to  12  inches  in  depth.  It  is  a  fairly 
strong  and  retentive  soil,  and  in  this  respedt  differs  from 
the  preceding  members  of  this  series.  The  features  in 
its  favour  are  the  comparatively  high  percentages  of  potash 
and  lime.  In  nitrogen  and  humus,  however,  the  soil  is 
poor. 

It  is  thus  seen  that  the  soils  of  this  northern  part  of 
Ontario  are  charadterised  by  a  preponderance  of  sand,  the 
larger  number  being  such  as  would  be  classed  as  light  or 
very  light  loams.  They  are  loose  in  texture  and  very  apt 
to  dry  out  in  season  of  drought.  Though  scarcely  heavy 
enough  for  wheat,  they  grow  good  crops  of  oats  and 
potatoes.  Being  responsive  to  manures,  large  yields  of 
root  and  fodder  crops  can,  under  good  system  of  culture, 
readily  be  obtained  in  favourable  seasons.  The  distridt  is 
better  adapted  for  grazing  and  dairying  than  for  the  growth 
of  cereals. 

Quebec. 

Table  V.  presents  the  data  obtained  from  the  examina- 
tion  of  ten  soils  from  the  province  of  Quebec.  They,  as 
the  preceding  samples,  have  been  seledled  as  typical 
average  soils ;  not,  on  the  one  hand,  representing  the 
richest,  nor,  on  the  other,  the  poorest,  lands. 

Soil  No.  47.— Surface  soil  from  Arthabaska  county.  A 
sandy  loam  of  fair  quality ;  nitrogen  and  organic  matter 
are  present  in  quantities  somewhat  above  the  average,  but 
the  soil  ranks  rather  low  as  regards  mineral  constituents. 

Soil  No.  48.— Subsoil  to  the  above,  and  very  similar  in 
its  proportion  of  potash  and  phosphoric  acid.  For  a  sub- 
soil it  may  be  considered  high  in  nitrogen. 

Soil  No.  49. — A  surface  soil  from  Gaspe.  It  is  a  red 
sandy  loam,  containing  fair  quantities  of  potash  and 
nitrogen,  but  low  in  phosphoric  acid  and  lime. 

Soil  No.  50.— A  dark  grey  sandy  loam  from  Soulanges 
county.  A  light,  warm,  responsive  soil.  In  all  the  ele- 
ments of  plant  food  it  may  be  placed  with  soils  of  good 
average  fertility. 

Soil  No.  5:.— Subsoil  to  the  above,  in  which  the  mineral 
elements  are  present  in  fair  amounts. 

Soil  No.  52. — A  heavy  clay  loam  from  the  valley  of  the 
Li6vre  River,  Ottawa  county.  A  strong  retentive  soil. 
With  drainage  it  should  be  well  adapted  to  the  growth  of 
cereals.  Though  low  in  potash  for  a  clay  soil,  it  may  be 
regarded  as  of  average  fertility.  Drainage  and  the  appli- 
cation of  lime  have  vastly  improved  its  produdtiveness. 

Soil  No.  53. — Subsoil  to  above,  and  very  similar  to  it, 
both  chemically  and  physically. 

Soil  No.  54. — A  clay  loam  from  Joliette  county ;  greyish 
black  in  colour,  compadt,  and  cohesive.  Both  in  mineral 
constituents  and  nitrogen  this  soil  is  above  the  average. 
An  application  of  20  bushels  of  lime  per  acre,  however, 
resulted  in  almost  doubling  the  yield. 

Soil  No.  55.— Subsoil  to  No.  54.  Stiff  clay,  grey  to 
reddish  brown. 

Soil  No,  56.— A  surface  soil  from  the  county  of  Bon- 
aventure.  A  reddish  yellow  loam,  containing  a  slight 
preponderance  of  sand.  The  large  amount  of  iron  present 
masks  the  presence  of  the  organic  matter,  of  which  there 
is  a  notably  high  percentage.  Not  unfrequently— indeed, 
one  may  say  usually— a  rough  estimate  of  the  organic 
matter — and,  incidentally,  nitrogen— present  can  be  made 
from  the  colour  of  the  air-dried  soil.  In  soils,  however, 
such  as  the  one  under  discussion,  containing  high  per- 
centages of  iron,  the  colour  can  no  longer  be  used  as  a 
criterion  of  the  soils  richness  in  these  constituents. 

Much  variation,  as  might  be  expedled,  in  charadler  and 
composition  is  to  be  observed  among  these  soils.  Though 
some  possess  but  small  amounts  of  certain  constituents, 


indicating  inadequate  quantities  for  the  best  returns,  yet 
none  fall  below  the  limits  of  fertility  previously  discussed, 
and  many  are  seen  to  compare  most  favourably  with  soils 
of  recognised  produdtiveness, 

(To  be  continued). 


EARLY    AMERICAN     CHEMICAL    SOCIETIES.* 
By  Prof.  H.  CARRINGTON  BOLTON. 

Three  chemical  societies  were  organised  in  the  United 
States  before  the  close  of  the  first  quarter  of  this  century; 
one  as  early  as  1792,  the  second  in  1811,  and  the  third  in 
1821.  These  societies  were  short-lived,  local  in  jurisdic- 
tion, and  without  much  influence  on  the  progress  of  the 
science ;  but  it  is  interesting  to  note  that  professional, 
teaching,  and  amateur  chemists  in  America  formed  asso- 
ciations for.mutual  improvement,  and  for  the  advancement 
of  their  calling,  long  before  their  European  brethren.  The 
Chemical  Society  of  London,  the  oldest  in  Europe,  was 
founded  in  1841,  forty-nine  years  after  the  first  American 
society ;  that  of  Paris  dates  from  1858,  and  that  of  Ger- 
many  from  1868.  American  chemists  were  not  impelled 
to  form  independent  societies,  owing  to  a  lack  of  organisa- 
tions for  men  of  science,  but  they  early  felt  the  advantages 
of  a  specialised  association.  The  society  of  1792,  and 
that  of  i8ii,  were  both  founded  in  a  city  honoured  by  the 
presence  of  the  venerable  and  dignified  American  Philo- 
sophical Society,  established  by  Benjamin  Franklin  in 

1743- 

The  existence  of  these  societies  has  long  been  known, 
but  only  through  casual  references  to  them  by  writers  on 
the  beginnings  of  science  in  the  United  States ;  Prof. 
Benj.  Silliman,  in  his  essay  on  "  American  Contributions 
to  Chemistry,"  read  at  the  centennial  celebration  of  the 
discovery  of  oxygen,  held  at  Northumberland  in  1874, 
alludes  to  them  incidentally;  and  Dr.  Brown  Goode,  in 
his  historical  addressss  to  the  Biological  Society  of  Wash- 
ington, barely  mentions  them. 

The  publications  too,  of  the  earlier  societies,  are  very 
little  known,  being  rarely  found  in  the  best  libraries. 

Under  these  circumstances  it  has  seemed  not  altogether 
useless  to  summarise  what  information  concerning  these 
societies  I  have  been  able  to  gather,  and  to  offer  it  as  a 
contribution  to  the  history  of  chemistry  in  the  United 
States. 

The  three  societies  are  : — 

I.  The  Chemical  Society  of  Philadelphia,  founded  in 
1792. 

II.  The  Columbian  Chemical  Society  of  Philadelphia, 
founded  in  1811. 

III.  The  Delaware  Chemical  and  Geological  Society, 
founded  in  1821. 

I.  The  Chemical  Society  of  Philadelphia. 

The  Chemical  Society  of  Philadelphia  was  undoubtedly 
the  earliest  organised  body  of  chemists  in  either  hemi- 
sphere, having  been  '•  instituted  "  in  1792.  The  society 
does  not  seem  to  have  published  records  of  its  meetings, 
nor  of  the  papers  presented  thereat,  and,  since  at  that 
early  day  the  primitive  local  newspapers  paid  little  atten- 
tion to  items  of  scientific  interest,  information  concerning 
it  is  not  readily  obtained.  I  find,  however,  that  it  was 
flourishing  in  1801-2,  when  it  had  the  following  officers: — 

President — Dr.  James  Woodhouse. 

Vice-Presidents — Felix  Pascalis  and  John  Redman. 

Librarian — William  S.  Jacobs. 

Curators — William  Brown  and  John  S.  Dorsey. 

Treasurer— John  Y.  Bryant. 

Secretary — Thomas  Brown. 

The  society  held  stated  meetings  each  week. 

The  President  of  the  Society,  Dr.  James  Woodhouse 

*  Read  before  the  Washington  Chemical  Society,  April  8, 1897. 
From  the  Journal  of  the  American  Chemical  Society,  August,  1897. 


Crbuical  NBWS,  I 

oa.  29, 1897.    J 


Production  of  Haloids  from  Pure  Materials. 


(1770 — i8og),  was  at  the  time  professor  of  chemistry  in 
the  medical  department  of  the  University  of  Pennsylvania, 
of  which  he  was  a  graduate. 

This  chair  had  been  held  by  Dr.  James  Hutchinson, 
and  on  his  death,  in  1793,  Dr.  Joseph  Priestley,  who 
arrived  from  England  a  few  months  later,  was  invited  to 
succeed  him,  but  he  declined,  preferring  the  quiet  life  of 
Northumberland,  and  Dr.  Woodhouse  was  chosen  instead. 
Dr.  Woodhouse  contributed  several  medical  papers  to  the 
New  York  Medical  Repository,  and  to  Coxe's  Medical 
Museum ;  he  also  edited  Chaptal's  "  Elements  of  Che- 
mistry" (fourth  edition,  1807,  2  vols.),  and  Parkinson's 
"Chemical  Pocket-Book"  (1802).  He  is  said  to  have 
been  the  first  to  prove  by  comparative  experiments  the 
superiority  of  anthracite  coal  from  Pennsylvania  over 
bituminous  coal  from  Virginia  for  intensity  and  regularity 
of  heating  power  (Silliman). 

The  first  vice-president,  Felix  Pascalis  Ouvriere  (1750- 
1840),  had  an  interesting  career.  He  was  born  in  France, 
where  he  received  his  medical  education ;  he  emigrated 
to  Santo  Domingo,  and  while  practising  medicine  there 
acquired  an  extensive  knowledge  of  botany  and  other 
branches  of  natural  history.  In  1793  a  revolt  among  the 
negroes  compelled  Pascalis  to  flee,  and  he  took  refuge  in 
the  United  States,  first  at  Philadelphia,  and  later  at  New 
York,  where  he  resided  for  more  than  thirty  years.  He 
was  the  founder  of  the  Linnean  Society  of  New  York, 
and  the  author  of  several  medical  papers  and  reports. 

The  second  vice-president,  Dr.  John  Redman,  (1722- 
1808),  was  a  native  of  Philadelphia,  and  educated  in 
European  medical  schools  and  hospitals.  In  1786  he 
was  made  president  of  the  Philadelphia  College  of  Phy- 
sicians. He  was  regarded  as  one  oi  the  foremost  pradi- 
tioners  of  medicine  of  Philadelphia,  but  his  methods  now 
appear  super-heroic. 

Dr.  John  Syng  Dorsey  (1783-1818),  one  of  the  curators, 
was  professor  of  surgery  and  afterwards  of  materia  medica 
in  the  University  of  Pennsylvania.  He  had  a  high  reputa- 
tion as  a  surgeon,  but  his  qualifications  for  membership 
in  a  chemical  society  seem  to  have  been  based  chiefiy  on 
the  fa(5t  that  in  his  youth  he  had  attended  the  chemical 
lediures  of  Sir  Humphry  Davy  (1803). 

I  have  not  found  the  roll  of  members  of  this  early 
society,  but  it  appears  that  Priestley,  Hare,  and  Seybert 
were  adtive  in  it.  The  ambition  of  the  members  is  shown 
by  the  circumstance  that  in  1802  there  was  a  standing 
committee  prepared  to  "  annalize  every  mineral  pro- 
dudtion  "  brought  before  them,  and  to  give  "  an  accurate 
account  of  each  specimen  free  of  expense." 

The  meeting  heldO(5tober24,  i8oi,was  made  memorable 
by  the  appointment  of  a  committee  for  the  "  discovery  of 
means  by  which  a  greater  concentration  of  heat  might  be 
obtained  for  chemical  purposes."  On  this  committee  was 
placed  among  others  Robert  Hare,  then  only  twenty  years 
of  age ;  but  so  soon  as  December  loth  of  the  same  year 
he  reported  to  the  society,  on  behalf  of  the  committee, 
his  invention  of  the  "  hydrostatic  "  (oxy-hydrogen)  blow- 
pipe. I  need  not  here  eulogise  this  important  and  useful 
invention,  which  yielded  such  a  fruitful  harvest  of  dis- 
coveries. This  alone  justified  the  existence  of  the  first 
of  chemical  societies.  In  the  following  year  the  society 
caused  Dr.  Hare's  account  of  this  blowpipe  to  be  printed 
in  a  pamphlet  of  thirty-four  pages,  i2mo.,  with  one 
plate.  This  now  rare  booklet  bears  the  title  "  Memoir  on 
the  Supply  and  Application  of  the  Blowpipe,  containing 
an  account  of  a  new  method  of  supplying  the  blowpipe 
either  with  common  air  or  oxygen  gas ;  and  also  of  the 
eiTe&s  of  the  intense  heat  produced  by  the  combustion 
of  the  hydrogen  and  oxygen  gases.  Illustrated  by  en- 
gravings. Published  by  order  of  the  Chemical  Society  of 
Philadelphia,  to  whom  it  was  presented  by  Robert  Hare, 
jun..  Corresponding  Member  of  the  Society.  Philadelphia. 
Printed  for  the  Chemical  Society  by  H.  Maxwell,  Co- 
lumbia House,  1802."* 

*  A  copy  of  this  is  found  in  the  Army  Medical  Library,  Washing- 
too,  D.C. 


217 

Robert  Hare's  subsequent  career  as  professor  of  che- 
mistry in  the  medical  school  of  the  University  of  Penn- 
sylvania from  1818  to  1847,  is  well  known  and  accessible 
to  all  enquirers. 

How  much  longer  this  association  of  chemists  con- 
tinued to  meet,  I  have  not  ascertained.  But  the  work  of 
this  society  was  evidently  remembered  by  those  who,  ten 
years  later,  founded  a  new  one,  inasmuch  as  they  designated 
it  by  the  prefix  "Columbian"  to  avoid  confusion. 

(To  be  continued). 


THE    PRODUCTION     OF    HALOIDS    FROM 
PURE     MATERIALS.* 

This  Report  consists  mainly  of  an  abstradl  of  portions  of 
a  paper  lately  published  by  the  Secretary  in  the  journal 
of  the  Chemical  Society. 

It  is  well  known  that  many  chemical  changes  depend 
upon  the  presence  of  water  among  the  adling  substances, 
and  some  chemists  have  been  tempted  to  suspedl  that 
possibly  chemical  change  may  not  occur  at  all  in  the 
absence  of  moisture.  On  the  other  hand,  there  remain  a 
very  substantial  number  of  changes  which  have  not 
hitherto  been  "  stopped  "  by  the  careful  withdrawal  of 
water  from  the  sphere  of  adlion.  Among  these  are  the 
forming  of  ozone  from  oxygen,  and  the  combining  of 
certain  metals  (for  example,  mercury)  with  chlorine. 

For  some  time  past  members  of  the  Committee  have 
been  occupied  in  re-examining  some  of  these  latter  phe- 
nomena.  Great  care  was  taken  in  preparing  the  various 
materials  required  ;  and  novel  and  stringent  methods  of 
drying  them  were  employed.  Advantage  has  been  taken 
of  the  opportunities  which  occurred  during  the  progress 
of  the  work  to  re-examine  the  influence  of  sunlight,  and 
of  the  silent  ele(Stric  discharge  on  highly  purified  chlorine. 

The  following  is  a  summary  of  the  results  obtained: — 

1.  Carefully  purified  specimens  of  mercury,  made  by 
three  distinti  methods,  were  found  to  combine  rapidly  and 
completely  with  carefully  dried  chlorine. 

2.  Carefully  purified  mercury  was  also  found  to 
combine  rapidly  and  completely  with  well-tried  bromine 
and  iodine. 

3.  Chlorine  prepared  by  the  eledtrolysis  of  silver  chloride 
and  dried  by  a  brief  exposure  to  phosphoric  anhydride 
is  not  condensed  when  submitted  to  the  adlion  of  the 
silent  eledtric  discharge. 

4.  Chlorine  from  the  same  source  (see  3)  becomes  more 
sensitive  than  before  to  the  adtion  of  sunlight,  after  the 
addition  of  a  trace  of  damp  air. 

5.  Lead  glass,  which  is  readily  corroded  when  heated 
in  damp  chlorine,  is  unaffedted  by  the  same  gas  after  it 
has  been  well  dried. 

As  bearing  on  the  general  question,  it  may  be  mentioned 
that  it  was  shown  in  the  original  memoir  {loc.  cit.)  that 
well-dried  ozone  undergoes  spontaneous  decomposition 
far  more  rapidly  than  the  damp  gas.  That  is  to  say,  the 
readtion  203  =  302  is  retarded,  and  not  facilitated,  by  the 
presence  of  water.  It  remains  to  be  seen  if  other  and 
analogous  readlions,  some  of  which  will  shortly  be  investi- 
gated, are  effedted  in  a  similar  manner. 


Contribution  to  the  Biological  History  of  the  Phos- 
phates.— L.  Joly.— The  solution  of  ammonium  molybdate 
in  dilute  nitric  acid  so  often  employed  in  analytical  che- 
mistry for  the  detedtion  of  phosphoric  acid  serves  us  to 
detedt  its  presence  in  animal  tissues. — Comptes  Rendus, 
cxxv..  No.  15. 

*  The  substance  of  a  Report  of  a  Committee  consisting  of  Pro- 
fessors Armstrong  and  Dunstan,  and  Messrs.  J,  D.  Cundall,  C,  H. 
Bothamley,  and  W.  A.  Shenstone  (Secretary).  Read  before  the 
British  Association  (Section  £),  Toronto  Meeting,  1897. 


2l8 


The  Induction  Coil  in  Practical  Work. 


I  Chbhical  Nbwi, 

1      Oa.  29, 1897. 


NOTICES  OF  BOOKS. 


The  True  Chemistry.   ("  Chemie  Vraie  ").     The  Rigorous 

Application  of  Two  General  Laws  of  Chemical  Adion. 

By  E.  J.    Maumene,  Dr.  es  Sc.     Pp.  205.      Paris  :  P. 

Vicq-Dunod  and  Co.  1897. 
For  thirty-seven  years  M.  Maumene  has  been  working  on 
his  theory,  and  claims  to  have  given  thousands  of  proofs 
of  the  accuracy  of  the  two  laws  discovered  by  him,  viz., 
the  "  Law  of  Contadt  "  and  the  "  Law  of  Mixture."  In 
a  previous  work,  "  A  Treatise  on  the  General  Theory  of 
Chemical  Adlion  "  (1880),  the  author  admits  that  some  of 
his  calculations  were  only  approximate,  and  that  this 
might  have  prejudiced  some  persons  against  them  ;  but  in 
this  last  volume,  just  published,  every  calculation  is  exaft, 
simple,  and  uniform,  and  can  be  followed  by  any  one. 
These  two  laws,  he  claims,  will  greatly  simplify  the  theory 
of  chemistry,  by  superseding  it,  through  their  sim- 
plicity. Basicity,  affinity,  dissociation — all  can  be  shown, 
and  worked  out  in  plain  figures,  by  one  or  the  other  of  M. 
Maumen£'s  two  fundamental  laws,  which  make  •'  The 
True  Chemistry." 

The  essential  aim  of  chemistry  is  to  know  exaftly  what 
takes  place  in  any  change,  so  that  under  given  circum- 
stances the  result  of  any  other  readion  can  be  foretold  ; 
this  we  can  already  do  to  a  certain  extent,  but  there  is 
generally  sowe^Aing' which  does  not  fit;  it  maybe  called  the 
exception  which  proves  the  rule,  but  it  may  also  be  said  that 
it  is  the  exception  which  proves  the  rule  to  be  wrong.  If 
by  calculation  all  the  unknown  reactions  can  be  predidted, 
then  it  must  be  admitted  that  there  is  much  to  say  in 
favour  of  M.  Maumen6's  theory.  It  must,  however,  be 
left  for  the  chemical  world  at  large  to  judge ;  true  philo- 
sophers will  always  accept  new  ideas,  however  startling, 
when  ,once  they  are  proved  beyond  any  doubt  to  be 
corredt. 

This  volume  gives  ample  evidence  of  an  enormous 
amount  of  trouble  and  thought,  spread  over  many  years, 
and  the  author  deserves  the  thanks  of  all  chemists  for  the 
ideas  he  has  given  them ;  it  also  stands  before  many 
other  works  hailing  from  across  the  channel, — it  has  an 
excellent  index. 


The  Induction  Coil  in  Practical  Work,  including  Rontgen 

X  Rays.      By  Lewis  Wright.     London  :  Macmillan 

and  Co. 
In  view  of  the  considerable  interest  that  has  recently  been 
direfted  to  eleftrical  discharge  in  high  vacua  by  Dr. 
Rontgen's  discovery  involving  the  use  of  powerful  and 
costly  indu<aion  coils,  the  book  before  us  supplies  a  want, 
and  is  likely  to  be  greatly  appreciated.  The  author  in 
his  preface  explains  that  his  objedl  has  been  to  give  prac- 
tical help  to  the  efficient  and  safe  use  of  an  indudtion  coil; 
and  this  idea  seems  to  have  been  faithfully  adhered  to 
throughout  the  book. 

In  the  first  chapter,  of  twenty-two  pages,  the  simple 
principles  of  eledlrical  indudtion  are  lightly  touched  upon, 
the  woodcuts,  by  the  way,  strike  us  as  old  acquaint- 
ances,—but  the  matter  is  fresh  and  quite  up  to  date. 

In  Chapter  II.,  after  briefly  describing  the  early  Du 
Bois-Reymond  apparatus,  the  modern  coil  is  thoroughly 
explained,  diagrams  and  drawings  being  given  of  the 
various  parts,  not  as  a  guide  to  amateur  coil-makers,  but 
simply  to  give  the  general  principle  upon  which  the 
modern  coil  is  built. 

In  Chapter  III.  the  instrudions  for  the  "  care  of  a  coil  " 
and  the  use  of  primary  batteries  are  well  worth  noting  by 
any  who  are  using  this  class  of  apparatus  for  the  first  time, 
for  a  little  negledt  will  easily  ruin  a  most  expensive  coil, 
and  by  simple  attention  to  the  details  noted  both  coil  and 
battery  will  be  kept  in  good  order. 

A  short  chapter  is  devoted  to  "  Miscellaneous  Experi- 
ments,"  probably  to  whet  the  appetite  of  the  beginner, 


and  then  three  chapters  are  given  to  the  eledtrical  dis- 
charge in  rarefied  gases  ;  brief  accounts  are  given  of  De 
la  Rive's  experiments,  Pliicker's  researches  on  stratified 
discharges,  and  others. 

Chapter  VII.,  on  "  The  Discharge  in  High  Vacua,"  is 
almost  exclusively  devoted  to  the  researches  of  Sir  W. 
Crookes,  whose  papers  on  Molecular  Physics  and  Radiant 
Matter  are  extensively  quoted  and  illustrated. 

The  remaining  portion  of  the  book  is  occupied  by  a 
discussion  of  Professor  Rontgen's  discoveries  and  their 
developments.  Lenard's  early  work  on  the  kathode  rays 
is  noted,  and  then  the  now  old  story  of  the  X  rays  is  re- 
told. Some  good  pradlical  advice  is  given  as  to  the  use  of 
the  Crookes  tube  in  pradlice,  which  will  repay  the  atten- 
tion of  any  one  using  this  expensive  and  easily  damaged 
apparatus.  It  is  easy  to  see  that  the  author  is  writing 
from  pradlical  experience,  and  his  instrudlions  will  be 
found  of  great  value. 

There  is  a  very  "made  in  England"  style  about  the 
book,  and  the  author  shows  a  great — and  one  is  inclined 
to  think  almost  too  great  —  contempt  for  Continental 
apparatus. 

A  footnote  at  the  end  of  the  book  refers  to  a  new  form 
of  contad-breaker  recently  described,  in  which  the  chief 
novelty  lies  in  the  fadl  that  the  swinging  hammer  of  the 
break  has  to  swing  some  distance  before  the  contadt  is 
broken,  thus  making  a  very  sudden  break,  causing  less 
sparking  and  more  indudtive  efifedt.  It  does  not  seem  to 
be  generally  recognised  that  this  principle  is  embraced  in 
the  very  simple  and  primitive  form  generally  used  on 
Continental  coils,  where  the  mass  of  iron  forming  the 
hammer  is  fixed  on  the  end  of  a  somewhat  long  flexible 
spring,  the  platinum  contadl  being  placed  some  inch  or  so 
lower  than  the  iron  head. 

The  book  is  well  printed  and  plenty  of  illustrations  are 
given,  making  it  both  interesting  and  instruaive. 


Report  of  the  Council  of  the  Institute  of  Mines  and  Forests 
on  the  Gold  and  Forest  Industries  of  British  Guiana  Jor 
the  Year  ending  June  30,  1897.  Demerara :  W.  H. 
Hinds,  Echo  Office,  1897. 

It  is  satisfadlory  to  note  that  the  gold  industry  of  British 
Guiana  shows  signs  of  improvement,  the  output  for  the 
year  ending  June  30.  1897,  being  128,333  ounces,  as 
against  119,422  ounces  in  the  previous  year.  It,  however, 
still  falls  short  of  the  outputs  for  1892-3,  1893-4,  ^"d 
1894-5,  which  were  respedtively  138,279  ounces,  137,822 
ounces,  and  128,760  ounces. 

The  past  year  has  been  marked  by  the  first  returns  of 
any  importance  from  quartz  crushing,  the  Barima  mine 
having  produced  over  7000  ounces. 

Of  the  five  distridts  into  which  the  gold-bearing  territory 
is  divided,  the  most  encouraging  increase  of  all  is  to  be 
found  in  the  Potaro  Distridl ;  it  has  shown  a  steady  in- 
crease since  1892,  and  now  heads  the  list  with  30,434 
ounces,  and  it  is  hoped  that  with  the  extra  facilities 
afforded  by  the  Demerara-Essequebo  Railway  and  the 
Government  Road  that  the  next  twelve  months  will  see  a 
still  further  increase  in  the  prosperity  of  this  important 
distridt. 

The  number  of  labourers  employed  in  the  gold  mining 
industry  throughout  the  colony  on  June  30,  1897,  was 
registered  as  17,050. 

The  Governor  has  placed  the  services  of  Prof.  Harrison, 
the  Government  analyst,  at  the  disposal  of  the  Institute 
for  the  examination  of  minerals  free  of  cost,  on  condition 
that  the  samples  are  of  public  interest  and  that  the  results 
are  published  for  general  information. 

The  exports  of  forest  produdls,  including  timber, 
shingles,  charcoal,  &c.,  also  show  a  most  encouraging  in- 
crease over  last  year,  especially  viewed  with  regard  to 
the  prevailing  depression  in  the  staple  produdt — sugar. 
The  export  of  timber  alone  has  almost  doubled  itself, 


CBBMltAL  ^BW^,  I 

0&.  29.  1897       ' 


chemical  Notices  from  Poreign  Source^, 


^19 


being  for  the  year  ending  June  30,  1897,  404i234  cubic 
feet,  valued  at  over  148,000  dollars. 


CHEMICAL 


NOTICES  FROM 
SOURCES. 


FOREIGN 


NoTB.— All  degrees  of  temperature  are  Centigrade  unless  otherwiat 
expressed. 

Comptes  Rendus  Hebdomadaires  des  Seances,  del' Academic 
des  Sciences.    Vol.  cxxv.,  No.  15,  Odlober  11,  1897. 

Further  Experiments  on  the  Liquefaction  of  Fluor- 
ine.—H.  Moissan  and  J.  Dewar. — Already  inserted. 

Direcft  Transformation  of  Heat  into  Eledtric 
Energy. — Marcus  Deprez. 

Spedra  of  the  Coloured  Components  of  Double 
Stars. — Sir  William  Huggins. 

SpecJtra  of  the  Principal  Stars  of  the  Trapezium  of 
the  Nebula  of  Orion. — Sir  William  Huggins. 

New  Mixed  Platinous  Salt. — M.  Vezes. — The  limited 
ailion  of  the  hydrochloric,  hydrobromic,  orhydriodic  acids 
upon  potassium  platinonitrate,  Pt(N02)4K2,  gives  rise  to 
the  elimination  of  half  the  nitrous  acid  contained  in  this 
salt,  and  to  the  formation  of  mixed  chloro-,  bromo-,  or  iodo- 
nitro-salts  very  stable  in  aqueous  solution  ;  the  platino- 
dichloro-nitrite,  Ptl2(N02)2K2;  lastly,  the  platino-diiodo- 
nitrite  already  obtained  by  Nilson.  Oxalic  acid  gives  rise 
to  an  analogous  readlion  with  the  sole  difference  that,  by 
reason  of  its  basicity,  a  single  molecule  of  acid  in  place  of 
two  intervenes  in  the  rea(5tion.  The  properties  of  potas- 
sium platino-oxalonitrite  are  capable  of  being  utilised  in 
the  separation  of  the  platinum  metals. 

Procedure  of  Separating  and  Distilling  Bromine 
from  a  Mixture  of  Alkaline  Chloride  and  Bromide. — 
H.  Baubigny  and  P.  Rivals. 

Reversible  Transformation  of  Styrolene-meta-sty. 
rolene  under  the  Influence  of  Heat. — G.  Lemoine. — 
The  reversible  transformation  of  styrolene  into  meta-styro- 
lene  under  the  influence  of  heat  recalls  by  its  general 
course  that  of  phosphorus,  cyanogen,  and  cyanic  acid  ;  it 
tends  progressively  towards  a  limit  expressed  by  a  tension 
of  the  vapour  of  styrolene. 

On  Two  Coloured  Reactions  of  Pyruvic  Acid.— L. 
Simon. — Pyruvic  acid,  with  the  addition  of  potassa  and 
then  of  sodium  nitroprusside,  yields  a  beautiful  and  intense 
violet-red  colouration.  This  is  a  readion  which  appears 
to  belong  to  all  the  fatty  amines  ;  it  has  been  verified  for 
the  three  methylamines,  for  mono-  and  diethylamine, 
amylamine,  and  benZylamine ;  with  the  last-mentioned 
base  the  colouration  is  that  of  lye  of  wine. 

Adtion  of  Nitric  Acid  upon  Potassium  Cobalti- 
cyanide. — E.  Fleurent. — A  note  which  the  author  merely 
gives  to  "  take  date." 

Bulletin  de  la  SociSte  de  Pkarmacie  de  Bordeaux. 
September,  1897. 
Colorimetric  Estimation  of  Manganese.  —  M. 
Lemaire. — Manganese  is  found  in  small  quantities  in  a 
large  number  of  plants,  and  many  botanists  consider  it 
necessary  to  their  proper  nourishment.  The  ordinary 
gravimetric  and  volumetric  methods  of  analysis  are  not 
suitable  for  estimating  these  small  quantities  ;  but,  on  the 
other  hand,  the  colorimetric  method  is  very  convenient. 
It  depends  on  the  readlion  pointed  out  by  Hoppe-Seyler : 
If,  to  a  substance  free  from  chlorine,  and  containing 
manganese,  we  add  binoxide  of  lead  and  nitric  acid, 
We  obtain,  on  heating  to  boiling,  a  violet  colouration  due 
to  the  formation  of  permanganic  acid.  This  readtion  is 
very  sensitive,  and  will  detedt  i/2,ooo,oooth  part  of  man- 


ganese. The  leaves  of  a  sample  of  wild  chicory,  dried  at 
100°,  gave  19*20  per  cent  of  ash  and  00004  per  cent  of 
manganese.  The  roots  of  another  sample  contained 
o'ooo2  per  cent  of  this  element. 


The  Agricultural  yournal  of  the  Cape  of  Good  Hope, 
Vol.  xi..  No.  5. 

Rinderpest  Conference. — At  the  conference  held  on 
August  19th  on  this  important  subject,  the  several 
methods  which  have  been  employed  for  immunising 
cattle  were  discussed.  It  was  at  first  expedled  that  Dr. 
Koch's  method  of  inoculating  the  healthy  animals  with 
the  bile  of  a  diseased  one  would  confer  immunisation  on 
them,  but  there  has  since  been  a  considerable  difference 
of  opinion  as  to  its  value.  Unfortunately  we  are  not  in 
possession  of  a  simple  pradtical  test  which  will  enable  us 
to  distinguish  between  a  safe  bile,  permanent  in  its  effedts, 
and  biles  which  are  either  too  strong  or  too  weak.  Even 
with  biles  which  were  to  all  appearances  of  standard 
quality,  very  varying  results  were  obtained  ;  and,  further, 
it  was  found  that  the  disease  itself  could  be  communicated 
in  this  manner.  It  is  this  uncertainty  which  is  the  most 
disappointing  part  of  Koch's  bile  inoculation.  Immunity 
has  lasted  as  long  as  three  or  four  months,  but  then  the 
effedl  seems  to  wear  off.  As  bile  did  not  give  the  modi- 
fied form  of  disease,  it  was  found  to  be  necessary  to 
inoculate  afterwards  with  virulent  blood,  and  the  present 
experience  seems  to  be  that  Edington's  method  of  inocu- 
lating a  second  time  with  virulent  blood  gives  very  good 
results. 


Revue  de  Chemie  Analytique. 
Vol.  v.,  No.  18. 
Calibration  of  Graduated  Glass  Vessels. — M.  Van- 
devyver. — The  author  thinks  that  the  method  recom- 
mended by  M.  Demichel,  for  corredting  the  error  due  to 
surface  tension  when  calibrating  glass  vessels,  is  insuffi- 
cient, as  it  assumes  that  the  surface  tension  is  constant 
and  invariable,  whereas  such  is  not  the  case.  For  ex- 
ample, in  gradually  filling  a  glass  with  water,  one-quarter 
at  a  time,  the  surface  tension  varies  as  follows : — \  full 
6*35,  i  full  5-22, 4  full  5*09,  full  but  not  overflowing  4*89,  full 
and  overflowing  7-32.  The  author  considers  the  following 
the  best  method  to  adopt  for  getting  accurate  results:  — 
The  vessel  must  first  be  cleaned  with  the  greatest  care,  by 
washing  it  in  acetic  acid,  caustic  potash,  then  ether, 
alcohol,  and  finally  rinsing  several  times  with  distilled 
water.  It  is  then  dried  by  inspiration,  taking  care  to 
keep  out  dust  by  lightly  plugging  with  cotton-wool, 
through  which  the  glass  tube  passes ;  when  dry,  distilled 
water  is  run  in  up  to  the  mark,  and  the  operation  proceeded 
with  in  the  ordinary  manner :  by  this  plan  the  possible 
error  due  to  the  variation  of  the  surface  tension  is  reduced 
to  a  minimum. 

Estimation  of  Copper  as  Iodide.  ^  M.  Willenz.— 
Will  be  inserted  in  full. 

Calibration  of  Flasks  by  Weighing.— A.  Demichel. 
— The  author  gives  a  number  of  equations  and  formulse 
for  calibrating  flasks,  which  he  claims  will  considerably 
simplify  the  operation. 


A  Tabular  Atlas  of  the  Chemistry  of  the  Metals 
is  being  prepared  by  Mr.  John  Freemont  Sleeper.  It  com» 
prises  the  arrangement  on  a  novel  plan  in  sedtional  and 
tabular  form,  devised  to  rapidly  convey  information  of  the 
data  relating  to  the  history,  distribution,  properties,  &c., 
of  the  metals  of  the  alkalies,  csesium,  rubidium,  and  potas- 
sium. The  author  has  been  preparing  this  work  for  the 
past  tea  years,  and  hopes  to  have  it  published  before 
long. 


220 


Meetings  for  the  Week. 


MISCELLANEOUS. 


The  Goldsmiths'  Institute,  New  Cross. — A  course 
of  25  leftures  on  "  Coal  Tar  Distillation,"  to  be  given  on 
Wednesday  evenings  at  8.30  p.m.,  by  Mr.  W.  J.  Pope, 
was  commenced  on  the  27th  inst.  The  course  comprises 
the  determination  of  boiling-points,  the  latent  heat  of 
vapours,  specific  heat  of  liquids;  the  composition  and 
valuation  of  tars ;  plant  and  methods  used  :  separation 
and  purification  of  benzene,  toluene,  xylene,  &c. ;  prepara- 
tion of  anthracene,  carbazole,  pyridene,  &c.,  &c.  Special 
attention  will  be  paid  to  methods  of  analysis  and  to  the 
plant  used  in  this  country  and  abroad. 

Salicylic  Acid  and  Calcium  Sulphite  as  Preserva- 
tives of  Cider. — Salicylic  acid  was  unanimously  con- 
demned in  1882  as  a  preservative  of  beer,  and  very  little 
can  be  inferred  as  to  the  physiological  effedls  of  its  con- 
tinuous use.  Kolbe  took  a  daily  dose  of  it  for  over  a  year, 
increasing  from  0*5  grm.  to  1-5  grm.,  without  any  notice- 
able effe6t.  On  the  other  hand,  a  case  is  recorded  where 
48  grains  caused  death  in  forty  hours.  Salicylic  acid  is 
easily  detedted;  the  sensitiveness  of  the  ferric  chloride 
test  has  been  put  as  high  as  i  part  in  100,000,  Dr.  A.  B. 
Griffiths  found  that  a  i/soooth  solution  of  salicylic  acid 
had  no  aftion  on  the  true  alcoholic  ferment.  Messrs. 
£.  Bailey  and  Chas.  Palmer  have  made  a  series  of  experi- 
ments with  various  strengths  of  salicylic  acid  on  cider. 
Six  flasks  of  cider  were  used  containing  salicylic  acid  of 
the  following  strengths: — i/20,oooth,  i/ro,ooolh,i/5oooth, 
i/ioooth,  i/500th,  and  a  blank.  Distillations  were  made 
after  twenty-four  hours,  seventy-two  hours,  eight  days, 
twenty-four  days,  and  fifty-two  days.  Though  the  efifeft 
of  the  preservative  is  not  very  marked  till  a  i/ioooth  solu- 
tion is  used,  yet  it  does  seem  that  a  i/soooth  solution 
has  a  noticeable  effedl  upon  the  alcoholic  ferments,  and 
the  micoderma  seems  to  do  very  well  in  a  i/ioooth  solu- 
tion. The  action  of  sulphurous  acid  and  its  salts  as  pre- 
servatives has  not  been  studied  to  the  same  extent,  though 
it  is  known  to  be  an  adtive  germicide.  Its  deteftion  in 
small  quantities  is  difficult,  but  in  quantities  sufficient  to 
exercise  any  preservative  adlion,  sulphurous  acid  may  be 
readily  detedked  by  zinc  and  HCl.  Experiments  on  the 
effedts  of  various  amounts  of  calcium  sulphite  on  cider 
show  that  the  adlion  is  retarding  only,  for  a  considerable 
amount  of  alcohol  is  produced  after  the  fifty-second  day, 
even  in  a  x/250th  solution. 

Histological  and  Chemical  Study  of  the  A(5tion 
of  Aritiseptics  on  Muscular  Fibres.— A.  Riche.— 
Continuing  his  paper  from  the  last  number,  the  author 
describes  further  experiments  on  the  albumen  and  juice 
of  meat,  and  he  come  to  the  conclusion  that  sulphurous 
acid  and  the  bisulphites— notably  that  of  lime— alter  the 
normal  strudtureof  the  meat,  and  that  the  muscular  fibre 
does  not  remain  intadt  under  their  adlion,  even  at  ordinary 
temperatures;  that  the  soluble  albumenoid  matters  do 
not  behave  in  the  same  manner  as  in  the  presence  of 
water,  even  when  subjedled  to  a  temperature  below  100°, 
or  even  at  50°.  For  these  and  other  reasons  it  is  not  to 
antiseptics,  but  to  refrigeration,  that  we  must  look  to  solve 
the  problem  of  the  preservation  of  m&Ai.—jfournal  de 
Pharmacie  et  Chimit,  Series  6,  vol.  vi..  No.  5. 

On  a  New  Alkaloid.  —  MM.  Battandier  and  T. 
•Malosse.— The  authors  have  extradled  a  perfeaiy  definite 
alkaloid  from  the  young  roots  and  from  the  bark  of  the 
Retatna  spharocarpa ;  they  have  given  it  the  name  Reta- 
mine.  One  kilogrm.  of  the  plant  gave  4  grms.  of  the 
alkaloid.  A  number  of  its  properties  are  here  given.  It 
melts  at  162" ;  it  possesses  extremely  energetic  reducing 
properties,  &c. ;  chloride  of  gold  and  phospho-molybdic 
acid  are  instantly  reduced,  but  salts  of  silver  and  ferri- 
cyanide  of  potassium  more  slowly.  The  salts  of  retamine 
crystallise  very  easily  and  with  great  sharpness,  with  the 
exception  of  the  nitrate,  which  has  up  till  now  only  been 


I  Chemical  News 
I     Odl.  29, 1897. 

obtained  as  a  varnish.  The  average  of  eight  analyses 
comparing  the  carbon  and  hydrogen,  and  of  twelve  of  the 
nitrogen,  give  it  the  formula  CisHjeNaO.  Retamine  is 
therefore  an  oxy-spartein,  but  different  to  any  other  one 
known. — y,  de  Pharm.  et  Chim.,  Series  6,  vol.  vi.,  No.  6. 


MEETINGS    FOR    THE    WEEK. 


Monday,  Nov.  ist,— Royal  Institution,  5.  General  Monthly  Meeting. 
Society  of  Chemical  Industry,  8.   "  The  Adulter- 
ation of  Portland  Cement,"  by  W.H.  Stanger, 
M.I.C.E.,  and  Bertram  Blount,  F.I.C.    "An 
Improved  Adjustable  Drip-proof  Bunsen,"  by 
W.  P.  Evans,  M.A.,  Ph.D. 
Wednesday,  3rd.— Society  of  Public  Analysis,  8.    "  Estimation  ot 
Acetates  in  the  presence  of  Inorganic  Salts," 
by  Bertram  Blount.  "  Estimation  of  Carbonic 
Acid  in  Natural  Waters,"  by  C.  A.  Seyler,  B.Sc. 
"Deteftionof  Gelatin  in  Cream,"  "A   New 
Milk  Preservative,"  "A  New  Milk  Adulterant," 
by  A.  W.  Stokes.     "  Note  on  the  Graduation 
of  Leffman-Beam   Bottles,"  by  G.   E.   Scott 
Smith  and  A.  B.  Searle.    "  An  Improved  Milk 
Scale,"  by  H.  Droop  Richmond. 
Thursday,  4th.— Chemical,  8.    "  Properties  of  Liquid  Fluorine,"  by 
Professors  H.  Moissan  and  J.  Dewar.    "  Lique- 
faftion  of  Air  and  the  DeteAion  of  Impurities," 
"  Absorption  of  Hydrogen  by  Palladium  at  High 
Temperatures  and  Pressures,"  by  Prof.  Dewar. 


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Distribution  of  Titanic  Oxide  upon  the  Surface  of  the  Earth,       22 1 


THE    CHEMICAL    NEWS 


Vot.  LXXVI.,  No.  198Q. 


DISTRIBUTION     OF    TITANIC    OXIDE    UPON 

THE    SURFACE    OF    THE    EARTH.* 

By  F.  P.  DUNNINGTON,  F.C.S. 

So  far  as  I  know,  the  discovery  of  the  universal  distribu- 
tion of  titanic  oxide  in  the  soil  over  the  surface  of  the 
earth  originated  in  the  analysis  of  a  cinder-like  mass 
found  about  four  miles  from  the  University  of  Virginia 
and  about  a  mile  from  "  Monticello,"  the  house  of  Thos. 
JefTerson  being  upon  the  slope  of  the  same  mountain. 

This  mass  proved  to  contain  5*4  per  cent  of  titanic 
oxide,  and  subsequently,  upon  analysis,  to  be  of  identical 
composition  with  the  soil  upon  which  it  was  found.  The 
most  probable  suggestion  of  its  formation  is  that  it  is  a 
result  of  lightning.  Other  soil  in  that  neighbourhood 
was  examined  for  titanic  acid,  in  all  of  which  it  was  found  ; 
and  subsequently,  as  many  as  eighty  specimens  of  soil 
from  various  quarters  of  the  globe.  An  account  of  these 
results  was  published  by  the  author  in  the  American 
Journal  of  Science  for  December,  1891. 

It  may  be  well  here  to  give  the  averages  for  certain  of 
these  determinations : — 

Titanic  Acid  in  Soils,    Averages  of  Determinations  made. 

Percentage. 

United  States  (40) 077 

Great  Britain  (7) 075 

Europe  (10) 0*42 

Igneous  rocks — 

Germany  (8)       0*56 

Asia  (8; 071 

Japan  (2) 0*55 

Total  average 0*63 

Sandwich  Islands  (5) 317 

It  appears  strange  that  any  body  existing  in  so  consider- 
able an  amount  in  the  soil  should  have  been  so  constantly 
overlooked  m  the  numerous  analyses  of  soils  that  have 
been  made ;  but  this  is  in  part  to  be  accounted  for  by  the 
fadt  that,  for  the  purposes  for  which  soil  analyses  are 
usually  made,  titanic  oxide  is  considered  as  adting  like 
alumina,  and  a  distindtion  between  them  is  regarded  as 
a  matter  of  little  import. 

This  oversight  is  no  doubt  in  part  also  due  to  the  somewhat 
troublesome  and  unsatisfactory  nature  of  the  process  of 
detecting  and  estimating  this  element  which  was  employed 
prior  to  1882,  when  Prof.  A.  Weller  published  in  the 
Berichte  d.  Chem.  Gesell.  (xv.,  2592)  a  method  based  upon 
the  intense  yellow  colour  of  titanium  trioxide,  which  is 
produced  upon  the  addition  of  hydrogen  peroxide  to  a 
solution  of  titanic  sulphate. 

Since  publishing  the  foregoing  results,  I  have  been  able 
to  secure  samples  of  soil  from  portions  of  the  earth's  sur- 
face not  then  represented  ;  in  these  also  the  amounts  of 
titanic  oxide  have  been  estimated  as  a  percentage  of  the 
original  soil  and  also  of  the  ignited  soil,  which  latter 
figures  should  be  compared  with  what  is  found  in  igneous 
rocks.  For  a  few  of  these  determinations  (which  were 
made  in  duplicate)  I  am  indebted  to  some  of  the  students 
working  in  the  Chemical  Laboratory  at  the  University  of 
Virginia ;  those  of  the  deep  well  borings  were  made  by 
Mr.  David  Hancock,  of  Virginia. 

*  Read  before  t|ie  British  Association  (SeAion  B),  Toronto 
(Heeting,  1897. 


No.  81. — Red    loam  ;  and    No.   82,    dark   grey    loam  ; 

Brazil. 
„    83.— Grey  sandy  loam,  Liberia  ;  per  Mr.  Apperson 

at  the  Chicago  Exposition. 
„    84.— Grey  brown  loam,  St.  Helena ;  per  Professor 

Cleveland  Abbe,  Washington,  D.C. 
„     85.— Dark   grey  clay;    and   No.   86,   light  brown 

clay,  Cerraloo,  Mexico ;  per  Mr.  J.  T.  De 

Bell. 
„     87.--A  light  brown  clay;  and  No.  88,  white  clay, 

Sydney,  Australia  ;  per  Prof.  A.  Liversidge. 
M    89. — Brown-yellow  loam,  Launceston,  Tasmania; 

and    No.  90,  brown-grey  loam,  Auckland, 

New  Zealand  ;  per  Mr.  H.  J.  Boyd. 
It    91-  —Light  yellow  clay,  Araki,  Japan  ;  and  No.  92, 

dark  grey  loam,  Kawaja,  Japan ;  per  Mr. 

Apperson. 
II     93' — Fine   brown   and   green    gravel,  from   earth- 
quake eruption,  Nayaya,  Japan  ;  per  Rev. 

R,  B.  Grinnan. 
(Nos.  94  to  104,  from  Dominion  of  Canada,  were  sent 
by  Dr.  G.  M.  Dawson,  of  Ottawa). 

No.  94.— Pale  yellow  fine  sand  ;  Champlain,  Quebec. 
„     95.— Brown  loam;  Ottawa. 
„    96.— Grey  clay;  near  St.  Luis  Dam,  Ottawa. 
II     97- — Brown  loam  ;  Beechwood,  Ottawa. 
„    98.— Pink  loam  ;  Murilio,  Algomo. 
II    99-— Black  earth;  Rosser,  Manitoba. 
„  100. — Fine  black  sand  ;  MacGregor,  Manitoba. 
,,  loi.— Fine    grey    siliceous    sand;     Maple    Creek, 

Assimboya. 
„  102. — Dark  grey  sand  ;  Canmore,  Alberta. 
„  103. — Light  brown  ciay;  Griffin  Lake,  B.C. 
„  104.— Light  red  loam  ;  Glacier,  B.C. 

(Nos.  105  to  114,  drillings  from  the  deep  well  at 
Wheeling,  W.  Va.,  obtained  through  Prof.  Wm.  Halieck, 
then  at  the  Physical  Laboratory  of  the  U.S.  Geological 
Survey). 

The  percentage  of  titanic  acid  found  in  these  respec- 
tively is  as  follows  : — 


No.  Air-dried.     Ignited. 

No. 

Air-dried.    Ignited 

81.     1-33 

179 

93- 

0-49 

048 

82.     074 

083 

94- 

o'34 

0-41 

83.     062 

0-66 

95- 

0-68 

1*37 

84.     2-33 

3  00 

96. 

068 

074 

85.       0-22 

0'25 

97- 

0  61 

067 

86.     0T4 

020 

98. 

030 

032 

87.     0*69 

079 

99. 

0  64 

079 

88.     043 

0-48 

100. 

0-22 

0-24 

89.     050 

0  6i 

lOI. 

022 

023 

90.     140 

1-57 

102. 

o-i8 

0-25 

91-     052 

o'55 

103. 

o'i7 

0*17 

92.     0-43 

0*46 

104. 

052 

0-54 

No. 

From  depth  of— 

Air-dried, 

Ignited. 

105. 

275  feet    , 

o'og 

0-13 

106. 

500    ,, 

079 

0-89 

107. 

992    „ 

0'12 

0-13 

108. 

1460     „ 

0'12 

013 

109. 

2010     ,, 

074 

077 

no. 

2520    ,, 

035 

0-36 

III. 

3075     .. 

o-8o 

085 

112. 

3500         M 

077 

0-82 

"3- 

4"5o     .. 

0-49 

0-53 

114. 

4490     „ 

0'48 

0-51 

Average, 


0-475 


0*512 

These  fadls  point  plainly  to  the  universal  distribution 
of  this  element  over  the  earth's  crust.  I  would  draw 
attention  to  the  figure  0*56  per  cent  of  titanic  acid  from 
the  alluvial  soil  of  the  Yellow  River  in  China,  as  deter- 
mined in  the  former  set  of  observations,  as  most  probably 
presenting  a  fair  average  of  the  amqunt  present  upon  th^ 
earth's  surface. 


222 


Separations  with  A  Ikaline  A  cetales. 


I  Chemical  News, 
I      Nov.  5,  1897. 


For  all  the  above  figures  the  total  averages  are  0*57 
and  0-66.  Omitting  the  Island  of  St.  Helena,  as  excep. 
tional,  we  have  0-515  and  0-588  respedtively  for  the  air- 
dried  and  ignited  soils. 

University  of  Virginia,  August,  1897. 


SEPARATIONS  WITH  ALKALINE  ACETATES. 

By  HARRY  BREARLEY. 
(Concluded  from  p.  211). 

VI.  Zinc  from  Iron.  General  Considerations. 
Zinc  and  manganese  are  the  only  two  metals  whose 
acetate  separation  from  iron  is  so  far  favoured  as  to  be 
commonly  employed.  In  the  case  of  Zn  the  fault  is  again 
the  operators:  carried  out  in  the  previously  reiterated 
manner,  the  separation  is  one  of  the  easiest  and  most 
complete  of  the  series. 

Two  tests  were  made  on  solutions  of  i  grm.  iron  and 
o'l  grm.  zinc.  The  zinc  was  estimated  by  precipitating 
as  carbonate,  and,  so  as  to  balance  any  errors,  the  value 
of  the  stock  zinc  solution  was  estimated  under  like  con- 
ditions.   The  separations  were  carried  out  as  before. 


Acetate  used. 

Zinc  recovered 

20  C.C. 

o'looS  grm. 

50    .. 

0-0976     „ 

No  further  observations  on  the  separation  of  iron  and 
zinc  were  made.  If  it  be  protested  that  such  scant 
attention  to  zinc  is  by  no  means  commensurate  with  its 
importance,  it  should  be  remembered  that  these  papers 
are  written  from  the  standpoint  of  a  Steel-works  Analyst, 
who  must  make  them  as  far  as  possible  of  momentary 
utility.  In  this  light  zinc  is  not  an  important  element  in 
combination  with  iron,  and  its  separation  therefrom  is 
relatively  of  little  value.  It  is  by  no  means  overlooked 
that  in  the  larger  world  of  analytical  chemistry  the  sepa- 
ration is  an  important  one,  and  therefore  the  tests  were 
made  with  a  view  of  allocating  the  element  in  the  table  of 
relative  separability,  if  I  may  so  term  it,  of  the  elements 
treated.  There  is,  moreover,  independent  testimony  to 
the  claim  of  zinc  to  occupy  its  allotted  place,  in  the  fadt 
that  Mr.  Jewett— whose  paper  I  am  unable  to  refer  to— 
has  found,  in  a  somewhat  different  way,  that  manganese 
and  zinc  could  be  completely  separated  from  iron  by  the 
acetate  process,  but  not  so  nickel  or  cobalt. 

The  above  defeft  is  not  really  a  very  serious  one.  The 
influence  of  a  particular  variation  can  be  readily  made  by 
anyone  specially  interested  in  the  separation.  It  may  be 
noticed,  too,  by  those  pradtically  acquainted  with  the 
separation  and  estimation  of  the  metals  in  Table  XIX., 
that  their  relative  behaviour  with  increasing  acetate  is  a 
reliable  indication  of  the  liberties  that  may  be  taken  with 
the  processes  without  incurring  the  penalty  of  an  imper- 
fedl  separation. 

And  now,  so  far  as  I  am  aware,  every  metal  whose 
acetate  separation  from  iron  is  pradlised  has  been  dealt  with. 
There  are,  it  is  true,  the  alkaline  earths  ;  and  as  they  are, 
more  or  less,  always  to  be  found  in  iron  ores,  slags,  &c., 
they  should  not  be  omitted  without  reason.  Good 
enough  reason  is  to  be  found  in  the  fadt  that  the  separa- 
tion has  long  ago  been  established  as  a  perfeft  one,  no 
writer  in  standard  books  ever  doubting  its  accuracy  so 
far  as  to  recommend  a  re-solution  and  precipitation  of  the 
basic  ferric  acetate. 

A  noteworthy  point,  not  stridtly  within  the  scheme,  is 
the  behaviour  of  phosphoric  acid.  This  compound  inva- 
riably goes  down  with  the  iron  in  an  ordinary  acetate 
precipitation.  Three  tests  were  made  to  detedt  any 
possible  variation  from  this  course.  Each  test  solution 
was  made  up  of  i  grm.  of  iron  and  about  i  a  grm.  of 
soda  phosphate. 


I.  contained  total  hydrate  and  10  c.c.  acetic  acid, 

^^-  M  ..  30     „  „ 

ni.        „  no  hydrate,  and  no  free  acid  other  than 

30  c.c.  acetic. 

The  iron  was  precipitated  in  each  with  minimum  ace- 
tate. The  filtrates  were  boiled  to  dryness ;  the  residue  of 
soda  salts  ignited,  re-dissolved  in  dilute  hydrochloric, 
neutralised  with  ammonia,  acidified  slightly  with  nitric 
acid,  treated  with  the  usual  molybdate  reagent,  and 
placed  side  by  side  in  a  warm  place.  In  I.  there  was  only 
the  faintest  trace  of  a  precipitate  visible,  and  that  chiefly 
where  the  rod  had  rubbed  against  the  beaker.  In  II. 
there  was  somewhat  more,  but  not  enough  to  make  any 
material  difference  to  an  analysis  conduded  in  this  way. 
In  III.  there  was  a  very  decided  precipitate;  such  a 
quantity  as  makes  a  very  serious  difference  when  regarded 
as  a  deficiency.  The  amount  was  not  determined  quanti- 
tatively, it  being  rather  the  purpose  of  these  remarks  to 
guard  against  any  possible  error  than  to  state  definitely 
how  great  a  percentage  recovery  is  possible  by  these 
means. 

The  accompanying  table  (XIX.)  affords  perhaps  the  best 
general  summary  that  could  be  given.  It  is  only  necessary 
to  point  out  that  each  separation  was  made  from  a  solution 
containing  i  grm.  of  iron  and  o-i  grm.  of  the  respedive 
metal.  Total  hydrate  was  formed  in  the  solution,  and 
10  c.c.  acetic  acid  added.  The  volume  of  the  solution 
was  I  litre.  In  some  cases  soda  salts  have  been  used,  in 
others  ammonia.  This  is  the  only  difference  in  the 
treatment  of  the  respedtive  elements,  and  does  not,  I 
believe,  involve  in  any  case  a  change  in  the  percentage 
recovery  large  enough  to  give  any  element  precedence  of 
its  neighbour. 

It  was  not  pradticable  to  include  in  Table  XIX.  the 
turbidity  temperatures,  although  they  afford  the  best  proof 
I  can  give  that  the  separations  were  made  under  com- 
parable  conditions. 

The  temperature  at  which  a  turbidity  forms  seems  to 
have  been  generally  overlooked.  The  observations  are  so 
readily  made,  and  such  reliable  accompaniments  of  better 
or  worse  separations,  according  to  their  value  and  general 
conditions  of  working,  that  I  venture  to  recommend  the 
use  of  a  thermometer  for  confirmatory  purposes  whenever 
a  large  number  of  estimations  are  made  rapidly  after  the 
manner  here  set  forth. 

Wollcott  Gibbs  (Chemical  News,  xi.,  102)  has  pointed 
out  that  the  acetate  should  be  added  to  the  solution  when 
cold,  and  then  heated  to  boiling.  This  precaution  has 
been  repeated  by  Crookes  ("  Seledt  Methods,"  p.  227, 
3rd  edit.),  by  Arnold  "  Steel  Works  Analysis,"  p.  166), 
and  others.  Its  advantage,  when  large  excesses  of 
acetate  are  used,  is  not  questioned,  otherwise  the  precau- 
tion  becomes  an  unnecessary  time  absorber. 

The  fa<ft  that  a  perfedl  separation  of  Mn,  Ni,  &c.,  may 
be  made  by  adding  dilute  acetate  to  the  boiling  solution, 
is  one  that  in  every-day  pradlice  has  been  regularly  made 
use  of.  In  dissolving  the  sample  of  (say)  nickel  steel, 
an  approximately  equal  amount  of  acid  is  always  used, 
and  so  one  has  some  idea  of  the  volume  of  alkali  needed 
to  efledt  neutralisation.  Something  less  than  this  amount 
may  be  added  at  once,  and  then  the  neutralisation  com- 
pleted  by  adding  in  rapid  succession  several  c.c.  of  the 
carbonate  at  a  time.  It  is  really  unnecessary  to  wait  for 
all  traces  of  the  preceding  turbidity  to  disappear,  because 
finally  an  addition  of  carbonate  will  cause  a  precipitate 
altogether  unlike  the  preceding  ones.  Though  hard  to 
describe,  the  difference  is  easy  to  distinguish.  The  final 
precipitate  is  thicker,  and  pulls  irregularly  on  the  hand  as 
the  flask  is  whirled.  In  small  volumes  of  solution  it  is 
almost  like  a  jelly.  This  is  an  unmistakably  permanent 
turbidity,  produced  almost  as  quickly  as  the  description 
may  be  read,  and  not  by  any  great  excess  of  alkali 
either.  To  this  turbid  solution  add  10  to  12  c.c.  acetic 
acid.  The  turbidity  quickly  disappears,  part  of  the  acid 
going  to  form  acetate.     Dilute  with  hot  water,  heat  fur- 


CHEMICAL  News, 
Nov.  5, 1897.      I 


Separations  with  Alkaline  Acetates 


22j 


Dilute  acetate. 
C.c. 

10 

20 

50 

100 

Table  XIX. 

Percentage  separation 

from 

iron  of — 

Mn. 
lOO'O 

loo-o 

lOO'O 
lOO'O 

Zn. 
1 00 '8 

97-6 

Co. 
100*0 

99-0 
97'5 
93-8 

Ni. 
lOO'O 

99-0 

95  "2 
900 

Cu. 

98-0 

929 

696 

531 

Cr 

as  CrOs. 

26-8 

30-8 

388 

47-5 

Cr  as  CrjOg. 

trace 
(See  p,  175). 

A). 
Precipitation 

of  iron 
not  possible 
(see  p.  210). 

Synopsis. 

Metal.  Acetate.  Oxide. 

Manganese Crystallises  in  plates  ;  permanent  in  air..     Easily  soluble  in  acids.      Readily  soluble  in 

(NH4)C1  aq. 
Zinc     Crystals  may  be  sublimed  as  zinc  acetate    Easily  soluble  in  acids.     Soluble  in  hot  solu- 
tions of  ammonium  salts. 

Cobalt  ..     „ Crystallises;  red  needles Easily  soluble  in  acids;  only  slowly  when 

cold.     Soluble  in  hot  NH4CI. 

Nickel Apple-green  prisms      Insoluble  in  acetic  acid  (!)      Only  slightly 

soluble  in  hot  NH4CI. 

Copper Dark  green  crystals.  There  are  also  sesqui-, 

bi-,  and  tri-basic  cupric  acetates.  These 
form  when  Cu  is  exposed  in  contadt  with 

acetic  acid,  as  in  common  verdigris     ..     Soluble    in    acids;     slowly  in  NH4   salts. 

Soluble  in  boiling  H2O  solutions  of  AI2, 
Cr2,  Fez,  with  precipitation  of  oxides  of 
the  bases  of  these  salts.  Unadled  upon  by 
boiling  solutions  of  Mn,  Ni,  Co,  Zn.* 

Chromic  acid      The  deficiency  is  due  to  an  altogether  different  cause.    The  percentage  recovery  increases 

diredtly  as  the  acetate.    Acetic  acid  not  notably  advantageous. 

Aluminium ..     Decomposes  on  evaporation.     There  is  a 

soluble  basic  acetate ;  but  if  this  is 
heated  or  left  to  evaporate  at  ordinary 
temperature  it  deposits  insoluble  basic 
salts — 

The  relative  separation  of  an  element  varies  direftly  as  the  stability  of  the  acetate  and  the  solubility  of  the  oxide 
under  experimental  conditions.  The  general  behaviour  of  the  acetates  and  oxides  in  the  above  synopsis  is  in  accord 
with  this  statement. 

♦  This  division  is  exadlly  that  Cu  makes  in  the  Table.    The  aftive  below ;  the  inaftive  above. 


ther,  and,  if  the  solution  does  not  become  turbid  about 
90°  C.  (it  should  never  be  turbid  below  80°  unless  large 
amounts  of  alkaline  salts  are  present),  a  few  c.c.  of  dilute 
acetate  should  be  added.  The  process  may  have  been 
clumsily  pidured,  but  it  has  been  practised  scores  of  times, 
and  in  experienced  hands  renders  the  estimation  of 
nickel  in  steel  the  most  rapid  of  all  laboratory  estimations 
save  colour  carbon. 

The  addition  of  free  acetic  acid  is  not  a  new  idea.  "A 
few  drops  to  prevent  the  formation  of  basic  acetate  of  the 
protoxide"  is  a  familiar  injunction.  Phillips  ("  Engineering 
Chemistry")  adds  2  c.c.  of  10  E  HCl  after  just  dissolving 
the  permanent  turbidity.  Eggertz  (Chemical  News, 
xviii.,  232)  adds  li  c.c.  HCl.  I  believe  that  Jewett  gives 
other  and  earlier  examples  in  his  paper.  These  additions 
of  HCl  serve  a  good  purpose  when  large  amounts  of  ace- 
tate are  used,  in  that  they  provide  more  ferric  chloride  to 
be  decomposed,  and  leave  a  smaller  excess  of  acetate  to 
aA  undesirably  on  the  Mn,  Ni,  or  Co,  as  the  case  may  be. 

The  addition  of  HCl  or  HNO3  to  a  hydrate-free  solu- 
tion finally  resolves  itself  into  the  same  thing  as  adding 
free  acetic  acid,  because,  owing  to  their  superior  avidity, 
they  read  so, — 

Na-CaHaOa  +  HCl  =  NaCl  +  CaH402, 
and  a  similar  change  takes  place  when,  through  added 
hydrochloric  acid,  the  proportion  of  ferric  chloride  is 
increased.  These  theoretical  considerations  may  be  veri- 
fied by  noticing  that  it  is  indifferent  to  the  turbidity 
temperature  and  the  accuracy  of  a  separation  whether — 
havmg  a  solution  containing  a  known  amount  of  free  acid — 
it  be  treated  by  neutralising  and  adding  acetate  and  acetic 
acid,  or  by  reversing  the  order  in  which  the  reagents  asr 
added,  or  by  mixing  them  up  in  any  way  whatever. 


I  am  persuaded  to  indulge  in  the  following  speculations 
by  the  fadt  that  the  only  author  (J.  O.  Arnold,  "  Steel 
Works  Analysis,"  Whittaker  and  Co.,  1895)  who  makes  a 
special  feature  of  explaining  the  processes  of  steel  analysis 
dismisses  the  acetate  separation  with  "  On  the  addition 
of  ammonium  acetate  the  iron  is  precipitated  as  an  inde- 
finitely constituted  mixture  of  ferric  acetate  and  hydrate 
generally  known  as  basic  ferric  acetate,  and  some  free 
acetic  acid  is  liberated.  The  complex  readions  bringing 
about  this  result  are  not  clearly  known,"  I  am  encouraged 
also  by  the  hope  that  if  I  miss  the  mark,  which  is  very 
possible,  I  may  hit  some  one  else  into  providing  a  better 
explanation. 

The  precipitation  of  a  solution  of  ferric  chloride  may 
be  represented  so, — 

FezCle  +  6NaC2H302  =  Fe2(C2H302)6  +  6NaCl, 
and  previous  experiment  has  shown  that  the  proportion 
of  Fe2Cl6  and  NaC2H302  required  to  effedt  the  precipita- 
tion are  in  fair  accord  with  the  equation's  requirements. 

A  solution  of  ferric  acetate  on  heating  is  precipitated. 
The  temperature  at  which  precipitation  takes  place  has 
been  shown  to  be  moderately  constant.  An  excess  oi' 
acetate,  however,  above  that  necessary  to  decompose  the 
ferric  chloride  effedls  a  separation  at  a  lower  temperature, 
and  this  decreasing  of  the  temperature  takes  place  in  a 
quite  regular  manner  for  increasing  acetate. 

The  precipitated  ferric  acetate  is  not  a  very  stable  body. 
In  the  boiling  solution  it  becomes  converted  into  ferric 
oxide  and  free  acetic  acid.  This  I  surmise  is  the  free 
acetic  acid  Prof.  Arnold  refers  to,  though  I  do  not  know 
that  its  liberation  is  necessarily  concurrent  with  the  pre- 
cipitation, which  may  take  place  at  very  low  temperatures. 
The  volume  of  acetic  acid  formed  is  proportional  to  the 


^H 


Carminic  Acid, 


fCHEUicAL  News, 
Nov.  5,  1B97. 


amount  of  ferric  acetate,  that  is  to  the  amount  of  ferric 
chloride  previously  unchanged  into  dissolved  ferric  hydrate 
by  the  neutralisation.  This  explains  why,  in  the  copper 
separations,  the  solutions  free  from  dissolved  ferric  hy- 
drate behaved  similarly  to  those  having  large  amounts  of 
acetic  acid  present.  It  also  provides  another  reason  why 
the  addition  of  a  few  c.c.  of  HCl,  as  pra(5tised  by 
Eggertz,  Philips,  &c.,  lead  to  a  more  accurate  separation. 
Plainly,  then,  the  composition  of  the  "  basic  acetate" 
will  depend  on  the  proportion  of  dissolved  hydrate — which 
is  dehydrated  in  the  boiling  solution — and  ferric  chloride 
in  the  first  instance  ;  and  then  on  the  extent  to  which  the 
ferric  acetate  and  hydrate  are  decomposed  by  heating. 
Thus  the  composition  of  the  precipitate  must  always  be 
the  indefinite — 

X  Fe2{C2H302)6.  y  Fe2(HO)6.  z  FeaOj, 
but  the  readions  by  which  it  is  formed  seems  to  be  as 
understandable  as  readions  generally  are. 

With  some  misgivings  I  go  a  step  further,  and  attempt 
to  explain  the  imperfedt  separation  and  the  relative  posi- 
tions of  the  elements  in  Table  XIX.  It  is  remarkable 
that  with  the  exception  of  copper,  the  elements  are  all 
members  of  the  iron  group ;  indeed  they  constitute  the 
whole  group. 

The  explanations  required  are  why  an  increasing  excess 
of  acetate  gives  a  decreasing  separation,  and  why  the 
addition  of  acetic  acid  arrests  this  defedion. 

Having  seen  that  an  addition  of  soda  acetate  to  a  solu- 
tion of  ferric  chloride  forms  ferric  acetate,  there  is  no 
difficulty  in  understanding  that  a  similar  change— and  the 
more  readily  effeded  the  larger  the  proportion  of  alkali 
acetate — can  occur  with  manganese,  zinc,  cobalt,  &c. 

When  heated  the  ferric  acetate  is  precipitated.  A 
similar  course  is  not  followed  by  the  other  metallic 
acetates,  at  least  not  in  pure  solutions.  Heating  at 
boiling  temperatures  decomposes  ferric  acetate  in  the 
manner  previously  mentioned,  and  through  an  analogous 
behaviour  of  the  acetates  of  the  other  metals  the  defedive 
recovery  may  be  accounted  for. 

I  find,  on  turning  to  Watts'  "Didionary  of  Chemistry" 
(vol.  i.,  p.  9),  that  "  many  acetates  may  be  decomposed 
by  water  into  acetic  acid  and  metallic  oxide."  This 
decomposition  in  the  case  of  aluminic  and  ferric  acetates 
occurs  at  100°,  while  at  175°  the  acetates  of  Mn,  Co,  Ni, 
Zn,  and  Cu  are  slowly  decomposed. 

It  is  true  that  the  acetate  separation  never  involves  a 
temperature  beyond  103°  to  104"  C,  and  that  a  defedtive 
separation  may  be  obtained  at  much  lower  temperatures 
than  that  even  (60^  to  70°),  if  enough  acetate  has  been 
used.  It  is  also  true  that  what  takes  place  in  a  solution 
of  pure  salt  is  frequently  modified  when  the  same  salt 
A&s  in  a  mixture.  I  admit  the  presumption,  and  yet  I 
beg  to  be  allowed,  tentatively  at  least,  to  state  that  these 
metallic  acetates,  in  company  with  the  iron,  are  decom- 
posed at  a  much  lower  temperature.  The  evidence,  then, 
for  framing  a  palpable  explanation  to  the  first  query  is 
complete. 

The  solubility  of  one  of  the  produdts  of  the  decompo- 
sition— the  metallic  oxide — in  dilute  acids  is  a  sufficient 
explanation  of  the  adtion  of  acetic  acid. 

If  these  explanations  are  true  ones  we  should  be  able 
to  justify,  in  an  independent  manner,  viz. ,  by  the  beha- 
viour of  their  acetates  and  oxides,  the  position  of  the  ele- 
ments in  Table  XIX.  This  I  believe  we  may  do  fairly 
satisfadtorily. 

Perhaps  the  most  effeAive  way  will  be  to  let  a  short 
Synopsis  speak  for  itself  (see  p.  223).  The  data  are  taken 
from  Watts*  "  Didionary  "  and  Comey's  "Solubilities," 
The  adlion  of  alkali  chlorides,  which  have  been  occasion- 
ally noticed,  are  also  explained. 

It  is  hoped  that  the  foregoing  papers  may  do  something 
to  restore  alkaline  acetates  to  the  favour  they  deserve. 

Attention  was  drawn  months  ago  to  the  fadt  that  am- 
monium acetate  was  said  to  be  unstable  and  needed  to  be 


made  as  required.  It  may  not  be  amiss  to  say  that  the 
solution  then  in  use  is  being  used  now,  and  so  far  as  I  can 
detedt  in  the  working  is  quite  unaltered. 

In  conclusion,  I  most  warmly  tender  my  thanks  to  Mr. 
R.  L.  Leffler  and  Mr.  Jervis,  respedlively  chemist  and  co- 
assistant  in  this  laboratory,  for  their  general  interest  and 
appreciated  aid  in  the  work. 

The  Laboratory, 

Messrs.  Thos.  Firth  and  Sons,  Lim., 

Norfolk  Works,  Sheffield. 


ON    CARMINIC    ACID. 
By  W.  VON  MILLER  and  ROHDE. 

Carminic  acid,  dried  in  vacuo  at  an  ordinary  temperaturet 
yielded  on  combustion  with  lead  chromate : — 

Carbon 53*65 

Hydrogen      432 

Carminic  acid  dried  in  a  stream  of  hydrogen  at  115°  to 
120°:— 

Carbon 5377 

Hydrogen      427 

(Burnt  with  copper  oxide). 

Carminic  acid  dried  in  vacuo  at  80°: — 

Carbon     1 53*^8 

11 53-80 

..       in 53-75 

Hydrogen     1 45 

II 47 

„        III 4-4 

(All  burnt  with  lead  chromate). 

A  sample  of  crystallised  acid  prepared  according  to  the 
procedure  of  Schunck  and  Menschutkin  gave  similar 
values  dried  in  a  current  of  hydrogen  at  115°: — 

Carbon 53*^9 

Hydrogen     424 

Berichte  der  Deut.  Chem.  Gesell.,  No.  13,  p.  1759. 


ON     THE    COMPOSITION     OF     CERTAIN 
CANADIAN   VIRGIN    SOILS.* 

By  FRANK  T.  SHUTT,    M.A.    F.LC,    F.C.S,, 
Chemist,    Dominion   Experimental  Farms. 

(Concluded  from  p.  21C). 

The  Maritime  Provinces, 
The  soils  from  New  Brunswick  and  Nova  Scotia  exam^ 
ined  by  us  have  been  so  few  in  number  that  it  would  be 
unwise  to  draw  from  the  data  conclusions  as  to  the 
general  chafadler  of  the  soils  of  these  provinces.  A  few 
examples  are  here  given  which,  though  representative  of 
large  areas,  must  not  be  considered  as  the  only  provincial 
types ;  the  figures  are  inserted  here  to  render  the  data 
somewhat  more  complete  than  they  otherwise  would  be. 
(See  Table  VI.). 

New  Brunswick. 
Soil  No.  57. — From  the  Sackville  Marsh,  at  the  head  of  the 
BayofFundy.  A  clay  loam;  of  interest  as  an  example  of  a 
soil  area  very  uniform  in  charadter — a  fadt  no  doubt  due  to 
the  origin  of  the  soil,  which  is  pradtically  a  tidal  deposit* 
When  thoroughly  drained,  which  frees  them  from  salt 
and  improves  their  texture,  these  reclaimed  Marsh  soils 
are  found   to  be   exceedingly   fertile.    A  glance   at  the 


*  Read   before  the    British    Association  (Sedtion    B),    Toronto 
Meeting,  1897. 


btlBHicAL  News,  1 
Nov.  5,  1897.      I 


Composition  of  certain  Canadian  Virgin  Soils. 


225 


Table  VI. — Analyies  of  Soils  [Water-free),  The  Maritime  Provinces. 


No. 

57- 

58. 
59- 
60. 
61. 


Locality. 


Sackville        Marsh, 

N.B 

Restigouche,  N.B.  . 
Cumberland,  N.S... 
S.W.  Mabou,  N.S.  . 
King's  Co.,  P.E.I... 


Surface 

or 
subsoil. 


Chara(5ter  of  soil. 


Potash.  Phosphoric  Nitrogen, 
acid. 


Loss  on  ignition 
Lime,    (organic  and 
volatile  matter). 


Surface Clay  loam  ..      .. 

Yellow  sandy  soil 

„      Sandy  loam  . 


o*i6 

I'02 

0'i6 

037 
0-47 


o*i6 

CIO 

cog 
cog 
cog 


0131 
0-113 
o"ogo 

0'2I2 

0106 


013 

C23 
C06 
005 

008 


5-83 

5*46 

3  37 
6-97 
5-IO 


analytical  data  shows  that  this  is  not  to  be  altogether 
ascribed  to  large  percentages  of  plant  food,  and  it  is  more 
than  probable  that  the  fine  state  of  division  and  the  inti- 
mate incorporation  of  the  soil  particles— due  to  the 
manner  of  the  soils  formation  and  deposit — render  the 
elements  of  fertility  more  easily  obtained  and  assimilated 
by  the  plant. 

Soil  No.  58.— Balmoral  Settlement,  Restigouche.  A 
yellow  loam,  derived  principally  from  the  decomposition 
of  felspar,  though  showing  some  quartz  fragments.  The 
percentage  of  potash  is  considerably  above  that  found  in 
average  fertile  soils — a  fa«a  undoubtedly  due  to  the 
felspathic  origin  of  the  soil.  With  the  exception  of 
potash,  however,  the  soil  cannot  be  considered  one  equal 
to  Canadian  soils  of  average  fertility. 

Nova  Scotia. 

Soil  No.  sg.— A  reddish  sandy  soil  from  Hansford, 
Cumberland  Co.  It  is  below  the  average  in  the  more 
important  elements,  and  to  be  regarded  as  a  poor  soil,  but 
responding  well  to  judicious  culture  and  manuring. 

Soil  No.  60.— A  soil  from  South-west  Mabou,  Inver- 
ness ;  very  similar  in  appearance  to  No.  sg,  but  analysis 
shows  it  to  be  much  richer.  The  small  percentage  of 
lime  is  particularly  noticeable  in  these  soils  ;  the  know- 
ledge of  this  fad  has  assisted  towards  the  economical 
treatment  of  them  with  fertilisers. 

Prince  Edward  Island. 

Soil  No.  61.— This  soil  partakes  of  the  same  colour  as 
the  light  red  Triassic  sandstone  from  which  it  is  derived, 
and  in  this  respetft  at  least  this  sample  is  representative 
of  the  charadleristic  soil  of  the  province.  It  differs  from 
the  preceding  specimens  in  that  it  is  not  a  truly  virgin 
soil.  Some  difficulty  was  experienced  in  procuring  a 
sample  which  had  not  been  cropped  or  manured  ;  indeed, 
no  guarantee  of  such  could  be  obtained.  This  soil,  how- 
ever, is  said  to  fairly  represent  the  unmanured  but  culti- 
vated soil  that  extends  over  a  large  area  in  the  Eastern 
portion  of  the  Island.  It  is  light  sandy  loam,  the  texture 
of  which  is  fairly  good.  Though  containing  a  more  than 
average  amount  of  potash,  this  soil  could  not  be  ranked, 
from  a  chemical  standpoint,  with  our  richer  Canadian 
soils-^possessing  but  small  percentages  of  nitrogen,  phos- 
phoric acid,  and  lime. 

This  agricultural  province  is  justly  known  as  a  fertile 
one  ;  and  we  presume,  judging  from  such  data  as  we  have 
at  hand,  that  this  fertility  is  due  rather  to  good  soil  tex- 
ture and  favourable  climatic  influences  than  to  richness 
of  its  land  in  plant  food  constituents. 

The  last  table  (Table  VII.)  that  is  presented  for  your 
consideration,  showing  the  average  amounts  of  fertilising 
ingredients  in  the  surface  soils  that  have  been  examined, 
taken  province  by  province,  has  been  prepared  with  no 
little  diffidence.  If  it  were  to  be  interpreted  as  placing 
before  you  data  from  which  dedudlions  could  be  made  as 
to  the  average  soil  fertility  of  the  yet  untilled  areas  of 
the  respedtive  provinces,  it  might  be  regarded  as  mis- 
leading. It  is  not  my  intention  that  such  a  conclusion 
should  be  drawn.  A  hundred  or  so  samples,  though  they 
are  typical,  and,  as  far  as  possible,  thoroughly  representa- 
tive of  large  areas,  taken  from  the  thousands  of  square 
miles  of  untilled  soil  in  the  Dominion,  do  not  afford  suffi- 
cient basis  for  such  generaUsations.  They  are  not  pro- 
vincial  averages  ;  they  are  rather  averages  from  large  un- 


tilled areas  in  the  several  provinces,  and  may  therefore 
serve  to  indicate  the  general  charader  of  much  of  the  yet 
untilled  lands  in  Canada. 

Table  VII. — Analyses  oj  Soils.    Averages. 
Surface  boils. 

Ne.  of  Phosphoric    Nitro- 

samples.  Province.  Potash.        acid.  gen.  Lime. 

21     British  Columbia    042        0*27        0*262         I'lj 

7  North-West  Ter- 
ritorities  and 
Manitoba       ..     0*44        o'lg        0-537         108 

6    Ontario  (Muskoka 

only)       ..     ..     0-22        0-15        o'i35        0-44 

6    Quebec       ..     ..     0*44        0*20        0-226        0-52 

5  Maritime  Pro- 
vinces    ..     ..     o'44        o'li        0-130        on 

45      Average  of  all..     o-3g        o-i8        0-258        o-66 

When  we  remember  that  care  and  judgment  were 
exercised  in  the  seledion  and  colledlion  of  these  samples, 
that  the  analyses  were  carefully  conduced  according  to 
modern  and  approved  methods,  that  very  few  of  the  indi- 
vidual samples  fall  below  the  standards  or  limits  fixed  by 
agricultural  chemists,  and  that  many  contained  such 
ample  stores  of  plant  food  as  to  warrant  them  in  being 
classed  among  the  most  fertile  soils,  we  may,  I  think, 
safely  conclude  that  the  data  here  set  forth  clearly  indi- 
cate that  while  there  are  many  types  of  soils  represented 
in  Canada,  there  are  in  all  her  provinces  large  tradts  of 
land  that,  as  far  as  plant  food  is  concerned,  compare 
favourably  with  the  most  produdtive  of  other  countries. 

Canada  is  fast  becoming  known  in  the  markets  of  the 
world  as  a  great  food-producing  country.  Soils  rich  in 
plant  food  and  favourable  climatic  influences  are  the  chief 
fadtors  that  have  assisted  the  Canadian  agriculturist  in 
building  up  this  reputation.  These  are  the  fadtors,  to- 
gether with  intelligent  rational  methods  of  farming  and 
safe  cheap  means  of  transportation,  that  will  continue  in 
the  future  to  make  agriculture  here  a  prosperous  industry. 
It  is  therefore  gratifying  to  learn  that  ample  scientific 
proof  is  now  on  record  to  show  that  in  our  virgin  soils 
there  is  in  such  abundance  the  crude  materials  upon 
which  crops  must  diredtly,  and  farm  animals  indiredtly, 
thrive. 


EARLY   AMERICAN    CHEMICAL    SOCIETIES.' 

By  Prof.  H.  CARRINGTON  BOLTON. 

(Continued  from  p.  217). 

II.  The  Columbian  Chemical  Society  of  Philadelphia. 
The  Columbian  Chemical  Society  was  founded  in  the 
month  of  August,  1811,  by  "  a  number  of  persons 
desirous  of  cultivating  chemical  science  and  promoting 
the  state  of  philosophical  inquiry."  The  names  of  the 
gentlemen  who  attended  this  meeting  are  not  certainly 
known,  but  it  may  be  presumed  that  they  included  most 
of  those  who  were  then  eledted  to  office ;  these  were  as 
follows : — 

*  Read  before  the  Washington  Chemical  Society,  April  8. 1897. 
From  the  Journal  of  the  American  Cfiemical  Society,  August,  1897. 


226 


Early  American  Chemical  Societies. 


I  Chbmicai.  Niiwt 
1      Nov.  5,  1897. 


Patron— Hoa.  Thomas  Jefferson,  Esq. 

President— Pcol.  James  Cutbush. 

Vice-Presidents— G&orgQ  F.   Lehman   and   Franklin 

Bache. 
Secretary— John  C.  Heberton. 
Treasurer— J&iaes  J.  Hamm. 
Orator — John  R.  Barnhill. 
And   a  "  Corresponding  Committee "  of    Three :   John 
Barnes,  M.D. ;  John  Lynn,  M.D. ;  and  Charles  Edwards. 
Thomas  Jefferson's  commanding  position  in  the  world 
of  science   and   arts,  as  well  as  his  literary  attainments, 
well  qualified  him  for  the  dignified  office  of  patron.     He 
bad  held  the  office  of  president  of  the  most  prominent 
scientific  body  in   the  United   States   (American  Philo- 
sophical Society)  for  many  years,  and  only  relinquished  it 
to   accept  the  higher  one  of    Chief    Magistrate   of   the 
Nation.      Seventeen  months  before  the  founding  of  the 
Chemical  Society,  Jefferson  had  retired  from  the  presi- 
dency,  after  serving  his   country  eight  years,   and   was 
living  at  his  country  seat,  Monticello. 

James  Cutbush,  president  of  the  Columbian  Society, 
was  at  that  time  professor  of  natural  philosophy,  che- 
mistry, and  mineralogy  at  St.  John's  College.  Little  is 
known  of  his  early  history  :  in  1814  he  was  appointed  to 
the  army  with  rank  of  Assistant  Apothecary  General,  and 
he  held  the  position  of  chief  medical  officer  of  the  United 
States  Military  Academy  at  West  Point,  from  June,  1820, 
to  November,  1821 ;  the  army  being  re-organised,  he  be- 
came assistant  surgeon  and  adling  professor  of  chemistry 
and  mineralogy  at  the  same  institution,  positions  which 
he  held  until  his  death,  December  15,  1823. 

Dr.  Cutbush's  papers,  presented  to  the  Columbian 
Society,  will  be  considered  below.  He  published  also  the 
following  : — "  On  the  Formation  of  Cyanogen  in  some 
Chemical  Processes  not  before  noted  "  (Am.  y.  Sci.,  vi., 
1822),  •'  On  the  Composition  and  Properties  of  the  Chinese 
Fire"  [Ibid.,  vii.,  1823),  "  On  the  Composition  and  Pro- 
perties of  Greek  Fire  "  (ibid.,  vi.,  1822).  He  was  also  the 
author  of  several  books:  —  "Useful  Cabinet"  (i8o8), 
"Philosophy  of  Experimental  Chemistry"  (Philadelphia, 
1813),  and  "A  System  of  Pyrotechny "  (Philadelphia, 
1825).  The  last-named  is  an  elaborate  work  of  more 
than  600  pages,  oAavo. 

George  F.  Lehman,  the  first  vice-president,  published 
articles  in  Mitchill's  Medical  Repository,  chiefly  on 
medical  subjedts. 

Franklin  Bache,  the  second  vice-president,  was  at  that 
date  a  youth  of  only  twenty  years,  who  had  graduated  at 
the  University  of  Pennsylvania  the  year  before  the 
founding  of  the  society.  He  was  a  grandson  of  Benjamin 
Franklin,  and  a  member  of  the  distinguished  Bache 
family,  which  numbered  so  many  eminent  men  of  science. 
He  afterwards  became  professor  of  chemistry  at  the 
Franklin  Institute,  and  in  1841  at  the  Jefferson  Medical 
College,  which  chair  he  held  until  his  death  in  1864.  He 
is  remembered  also  as  the  author  of  "  A  System  of 
Chemistry  for  the  Use  of  Students  of  Medicine  "  (Phila- 
delphia, 1819),  and  of  other  chemical  treatises. 

The  constitution  adopted  by  the  founders  of  the  society, 
besides  the  usual  provisions  for  regulating  business,  con- 
tained some  unusual  features ;  the  officers  included  an 
orator,  and  Article  VIL  prescribed  : — •'  An  oration  on  some 
chemical  subjedt  within  two  months  after  the  commence- 
ment of  the  medical  leftures  in  the  University  of  Penn- 
sylvania, in  each  year."  Since  the  "  Memoirs  "  published 
by  the  society  contain  no  "  oration,"  it  is  to  be  feared 
that  the  incumbent's  efforts  were  not  satisfa<5tory. 

Two  articles  in  the  constitution  deal  with  fines  : — 
"  Every  member  shall  be  fined  12J  cents  for  absence  each 
roll,  unless  satisfactory  reasons  be  offered."  And  again, 
"  Any  member  being  eleAed  to  ofiQce  and  refusing  to  serve 
shall  be  fined  one  dollar." 

Another  notable  provision  is  as  follows :— "  The  society 
shall  appoint,  once  in  each  month,  some  member  to  read 
an  original  chemical  essay,  for  negledl  of  which  the 
member  £0  appointed  shall  be  fined  ooe  dollar."    These 


fines,  with  the  annual  fee  of  two  dollars,  were  evidently 
expeded  to  maintain  a  full  treasury. 

To  become  a  member  of  the  society  special  qualifica- 
tions were  prescribed  ;  after  being  proposed  and  seconded 
the  candidate  "  shall  read  an  original  essay  on  some 
chemical  subjedt,  on  which  any  member  may  speak  not 
more  than  ten  minutes."  After  this  trial  of  his  ability,  a 
two-thirds  vote  of  the  members  present  at  a  subsequent 
meeting  were  required  to  secure  eledion. 

It  seems  to  have  been  easier  to  be  put  out  of  the  society 
than  it  was  to  get  in,  for  "  any  member  behaving  in  a 
disorderly  manner  shall  be  expelled  by  consent  of  two- 
thirds  of  the  members  present." 

This  mandatory  "  shall "  is  used  throughout  the  regu- 
lations ;  the  president  "  shall  preserve  order,"  the  secretary 
"  shall  keep  fair  minutes,"  the  constitution  "  shall  be  re- 
vised annually,"  and  so  on.  To  insure  against  members 
withdrawing  early  from  a  dull  meeting,  the  "  secretary 
shall  call  the  roll  at  the  opening  and  close  of  each  meeting 
and  mark  down  absentees,"  each  of  whom  is  then  fined 
i2i  cents  as  stated.  Never  did  a  society  undertake  to 
control  its  members  with  more  stringent  rules! 

The  members  who  subscribed  to  these  regulations  were 
divided  into  two  classes,  "Junior"  and  "Honorary" 
members,  the  former  corresponding  to  aclass  which  would 
now  be  styled  "  Associates,"  and  the  latter  including  both 
American  and  foreign  chemists  of  distindtion.  The  junior 
members  numbered  thirteen,  the  honorary  members  num- 
bered sixty-nine,  thirty-one  of  whom  were  Europeans. 
The  home  list  included  most  of  those  chemists,  then 
living  in  America,  whose  labours  contributed  largely  to 
the  foundations  of  the  science  in  the  New  World.  Brief 
notices  of  some  of  the  members  will  serve  to  summarise 
the  status  of  chemistry  in  the  United  States  for  the  years 
1811  to  1813. 

Dr.  Benjamin  Smith  Barton  (17661815)  held  the  chair 
of  medicine,  natural  history,  and  botany  in  the  University 
of  Pennsylvania.  Or.  Barton  has  been  called  by  his 
admirers  "  the  father  of  American  natural  history,"  though 
there  are  other  claimants  for  this  honourable  designation 
— Mitchill,  of  New  York,  and  Thomas  Jefferson.  Dr. 
Browne  Goode,  writing  of  Barton,  says  he,  of  all  the 
early  Philadelphia  naturalists,  "  had  the  most  salutary 
influence  on  the  progress  of  science."  He  was  a  leader 
in  the  American  Philosophical  Society,  and  an  agreeable 
writer  on  natural  history  topics,  and,  though  he  made  no 
contributions  to  chemistry,  was  a  worthy  member  of  the 
society. 

Dr.  Archibald  Bruce  (1777-1818),  one  of  the  pioneers  of 
mineralogical  science  in  America:  he  had  established  the 
American  Mineralogical  jfournal  one  year  before  the  date 
of  which  I  write.  His  analyses  of  minerals  mark  him  as 
a  skilful  chemist.  He  held  the  chair  of  mineralogy  in 
Columbia  College,  New  York. 

Joseph  Cloud  (1770- 1845)  was  assay  master  of  the 
United  States  Mint  in  Philadelphia,  and  already  distin- 
guished by  his  researches  on  palladium  (1807). 

Thomas  Cooper  (1759  1840),  born  in  London,  had  come 
to  America  in  1792,  with  his  friend  Priestley,  whose 
radical  views  in  politics  and  religion  he  shared.  Dr. 
Cooper  wrote  much  on  political,  ethical,  and  philosophical 
subjeds,  and  published  some  essays  on  chemistry.  In 
1811-14,  the  period  of  the  Columbian  Chemical  Society, 
he  held  the  chair  of  chemistry  at  Dickinson  College, 
Carlisle,  Pa.,  and  in  1819-34  he  held  the  same  position  at 
the  College  in  Columbia,  S.C„  of  which  be  afterwards 
became  president. 

Dr.  John  Redman  Coxe  was  professor  in  the  medical 
department  of  the  University  of  Pennsylvania,  having 
succeeded  Dr.  Woodhouse.  He  made  several  original 
observations  in  chemistry  published  in  current  periodicals. 
Dr.  Edward  Cutbush  (1772-1843)  was  surgeon  of  the 
United  States  Navy  and  professor  of  chemistry  in  the 
medical  school  of  the  Columbian  University,  Washington 
(1825-27).  He  has  another  honourable  claim  to  dis- 
tin^ion,    having   been    the   founder   in    1819   of    the 


CksutcAi  News,  i 
Nov.  5,  1897.     / 


Early  Americati  Chemical  Societies. 


iij 


Columbian  Institute  for  the  Promotion  of  Arts  and 
Sciences  in  Washington,  a  sort  of  precursor  of  the  Smith- 
sonian Institution. 

Passing  with  brief  mention  Dr.  Elisha  de  Butts,  pro- 
fessor of  chemistry  in  the  College  of  Maryland,  Prof, 
Benjamin  de  Witt,  of  New  York,  and  Dr.  John  Syng 
Dorsey,  already  mentioned  as  a  member  of  the  society 
founded  in  1792,  we  reach  the  more  familiar  name  of 
Dr.  John  Griscom,  "  the  acknowledged  head  of  all 
teachers  of  chemistry  in  New  York  City,"  for  more  than 
thirty  years. 

The  next  name  in  the  alphabetical  list  of  members  is 
that  of  Robert  Hare,  professor  of  natural  philosophy  in 
the  University  of  Pennsylvania,  whose  career  we  have 
already  noticed. 

Dr.  David  Hosack  (1769-1835),  professor  of  botany  and 
materia  medica  in  Columbia  College,  New  York,  is  best 
known  as  the  founder  of  the  first  public  botanic  garden 
in  the  United  States,  in  i8oi.  His  contributions  to 
science  were  chiefly  in  medicine.  The  tragic  circum- 
stances of  his  death  have  been  nearly  forgotten  ;  he  died 
of  shock  at  the  disastrous  conflagration  in  New  York 
City  in  1835,  which  swept  away  his  property  to  the  value 
of  $300,000. 

Dr.  Henry  Jackson,  professor  of  chemistry  at  Athens 
College,  Georgia,  is  followed  by  His  Excellency  James 
Madison,  LL.D.,  President  of  the  United  States  of 
America,  whose  name  added  lustre  to  the  rolls  of  the 
society,  but  whose  claim  to  the  membership  can  only  be 
based  on  extensive  general  information. 

Dr.  John  Manners,  of  Philadelphia,  affixes  to  his  name 
the  initials  F.A.N.S.,  the  Academy  of  Natural  Sciences, 
having  been  founded  one  year  before  the  printing  of  the 
list  of  members.  His  contributions  to  the  Chemical 
Society  will  be  noted  below. 

Dr.  John  Maclean  (1771-1840)  was  the  first  professor  of 
chemistry  in  the  College  of  New  Jersey,  now  Princeton 
University,  to  which  chair  he  was  eledled  in  1797.  In 
accordance  with  the  prevailing  custom,  he  also  gave  the 
instruiftion  in  astronomy,  mathematics,  natural  philosophy, 
and  natural  history  ;  this  fadt  is  ample  apology  for  his  not 
appearing  in  the  ranks  of  original  investigators.  Prof. 
Maclean  published  in  1797  "Two  LeAures  on  Com- 
bustion," in  which  he  upheld  the  views  of  Lavoisier,  as 
opposed  to  the  phlogistic  theory  maintained  by  Dr. 
Priestley. 

The  Hon.  Samuel  L.  Mitchill,  M.D.,  F.K.S.E.  (1764- 
1831),  professor  of  chemistry  and  natural  history  in 
Columbia  College  from  1792,  was  adlive  in  many  branches 
of  scientific  research.  In  1798  he  established  the  New 
York  Medical  Repository,  which  for  sixteen  years  was  an 
influential  organ  in  recording  and  diffusing  progress  in 
general  science,  as  well  as  in  medicine.  His  zeal  for 
science  did  not  prevent  his  taking  part  in  national  affairs, 
for  he  occupied  a  seat  in  the  senate  of  the  United  States 
from  1804. 

Dr.  Thomas  D.  Mitchell,  F.A.N. S.,  was  one  of  the 
most  adive  members  of  the  society,  frequently  contributing 
to  its  memoirs. 

Passing  by  Dr.  John  C.  Osborne,  professor  of  the  insti- 
tutes and  pradtice  of  medicine  in  Columbia  College,  New 
York;  Dr.  Joseph  Parish,  of  Philadelphia;  Mr.  Robert 
Pattesron  (1743-1824),  professor  of  mathematics  and 
ledurer  on  natural  philosophy  in  the  University  of  Penn- 
sylvania, director  of  the  United  States  Mint,  and  after* 
wards  (1819)  president  of  the  American  Philosophical 
Society;  Dr.  Nathaniel  Potter,  professor  of  the  theory 
and  praaice  of  medicine,  University  of  Maryland,  we 
reach  the  eminent  Dr.  Benjamin  Rush,  professor  of  the 
institutes  and  pradice  of  medicine  in  the  University  of 
Pennsylvania.  Dr.  Rush  (1745-1813)  has  been  charac 
terised  by  Benjamin  SiUiman  as  "  undoubtedly  the  first 
Professor  of  Chemistry  in  America,  his  appointment 
dating  August  i,  1769.  In  his  busy  life,  besides  his  pro- 
fessorial chair,  he  filled  the  positions  of  surgeon-general 
of  the  United  States  Army  (1777),  treasurer  of  the  Mint, 


president  of  the  Society  for  the  Abolition  of  Slavery, 
vice-president  of  the  Bible  Society  of  Philadelphia,  and 
conduced  a  large  medical  pradlice  in  the  same  city. 


(To  be  continued). 


PROCEEDINGS    OF    SOCIETIES. 

PHYSICAL    SOCIETY. 
Ordinary  Meeting,  October  2gth,  1897. 

Mr.  Shelford  Bidwell,  President,  in  the  Chair. 

Prof.  Stroud  exhibited  and  described  the  "  Barr  and 
Stroud  Range-finder."  The  problem  of  finding  the  dis- 
tance of  a  given  objedt  at  sea,  or  in  the  field,  is  compli- 
cated by  the  shortness  of  the  trigonometrical  "  base  "  and 
by  restridtions  of  time.  As  a  rule  the  apparatus  must  be 
self-contained,  and  '•  snap-shot"  readings  are  obligatory, 
— i.e.,  the  range  has  to  be  determined  from  a  single  in- 
strument and  from  a  single  observation.  At  3000  yards 
the  errors  must  not  exceed  3  per  cent.  In  foggy  weather, 
or  when  viewing  a  nebulous  objeft,  this  degree  of  precision 
is  difficult  to  attain;  but  under  favourable  circumstances 
the  authors  have  determined  ranges,  at  that  distance, 
within  I  per  cent  of  accuracy.  At  shorter  ranges 
measurement  is  more  exadt ;  thus  an  objedl  at  about 
2000  yards  may  be  estimated  to  within  about  12  yards. 
Prof.  Stroud  gave  some  account  of  the  history  and  of  the 
general  methods  employed  in  these  instruments.  Two 
images  of  the  distant  objedt,  preferably  of  a  line  such  as 
a  flag-staff,  are  received  respedlively  upon  two  mirrors, 
two  lenses,  or  two  prisms,  placed  one  at  each  end  of  a 
fixed  support.  From  each  of  these  the  light  is  then  di- 
redted  towards  the  middle  of  the  instrument,  where  the 
two  images,  after  further  refledtion,  are  viewed  by  one 
eyepiece.  The  optical  system  has  finally  to  be  adjusted 
so  that  the  two  images,  as  now  seen  in  the  eyepiece,  lie 
in  the  same  straight  line.  In  the  instrument  designed  by 
the  authors  this  coincidence  is  attained  by  translating  a 
small  prism  parallel  to  the  axis  of  the  supporting  rod. 
The  extent  of  this  translation  is  a  measure  of  the  range. 
Both  eyes  are  used  ;  the  right  for  bringing  the  two  images 
into  alignment ;  the  left  for  "  finding  "  the  objedl  through  a 
small  field-glass,  and  for  reading  the  scale  of  distances. 
At  night,  sightings  have  to  be  taken  from  "points"  of 
light,  and,  as  these  are  unsuited  to  measurement,  the 
authors  convert  them  into  "  lines"  by  the  use  of  cylin- 
drical lenses.  Various  devices  are  introduced  to  prevent 
over-lapping  of  the  images.  The  instrument  is  about 
5  feet  long  and  tubular  in  form ;  it  is  made  of  copper,  so 
as  to  have  high  thermal  condudlivity  to  reduce  differential 
heating.  Within  the  outer  tube  is  the  interior  supporting 
rod,  designed  to  equalise  so  far  as  possible  the  effedts  of 
interior  radiations.  Several  forms  of "  separating  "  prisms 
were  exhibited  :  the  best  for  the  purpose  consists  of  two 
"  refledting "  prisms ;  these  receive  the  two  rays,  and 
diredt  both  of  them  into  a  third  prism,  whose  angle  lies  in 
the  space  between  the  angles  of  the  others. 

Mr.  Barr  drew  attention  to  the  gimbal  arrangement 
and  the  three  struts  that  keep  the  supporting  rod  central 
in  the  tube.  To  give  some  idea  of  the  precision  and 
scope  of  the  range-finder,  he  observed  that  they  were 
there  using  the  equivalent  of  a  25-ft.  •'  circle,"  and  their 
measurements  were  comparable  to  the  measurement  of 
20  sees,  of  angle,  on  such  a  circle.  The  instrument  is 
handled  by  ordinary  seamen,  and  stands  rough  usage  on 
board  ship  for  years  without  injury. 

Prof.  Stroud  then  exhibited  a  "  Focometer  and  Sphere 
meter.'''  He  explained  that  in  determining  curvatures  and 
focal  lengths  some  telemetric  method  was  necessary,  and 
that,  owing  to  want  of   parallelism  of  the  beam  an4 


228 


The  Principles  of  Chemistry i 


I  Chemical  News, 
•      Nov  5,  i8g7. 


duplication  of  images,  a  short-focus  telescope  was  always 
an  inefficient  telemeter.  For  the  measurement  of  inac- 
cessible lengths  it  was  therefore  better  to  use  some  simple 
form  of  "  range-finder."  .Such  an  apparatus  could  be 
made  with  a  set  of  small  mirrors,  arranged  in  such  a 
manner  as  to  diredl  two  images  of  the  distant  objed  into 
an  eyepiece,  with  a  fixed  prism  in  the  path  of  one  of  the 
incident  beams.  By  sliding  this  instrument  along  the 
optical  bench,  one  position  could  always  be  found  at  which 
the  two  images,  as  seen  through  the  eyepiece,  were  in 
coincidence.  He  also  described  a  method  for  determining 
curvature  by  interposing  a  plate  of  plane  glass  between 
the  curved  mirror  and  a  source  of  light. 

Mr.  AcKERMANN  exhibited  two  experiments:  (i)  The 
blowing-out  of  a  candle-flame  by  the  air  from  a  deflating 
soap-bubble.  The  bubble  was  blown  at  the  mouth  of  an 
inverted  beaker  by  breathing  into  a  hole  cut  out  at  the 
top.  This  hole  was  then  presented  to  the  flame,  and  the 
flame  was  immediately  quenched.  But  if  the  bubble  was 
blown  from  ordinary  air,  with  bellows,  the  flame  was 
merely  deflefted  without  being  extinguished.  {2)  It  was 
shown  that  a  miniature  boat,  provided  with  a  false  stern, 
consisting  of  a  linen  diaphragm,  could  be  propelled  by 
filling  the  hollow  stern-space  with  ether,  or  with  some 
liquid  similarly  miscible  with  water.  The  motion  is  due 
to  the  continuous  release  of  surface-tension  behind  the 
boat, 

Prof.  Bovs  said  that  when  he  tried,  some  years  ago,  to 
blow  out  a  candle  with  a  soap-bubble  filled  with  common 
air,  he  found  the  operation  very  difficult,— so  diSicult 
that,  having  once  succeeded,  he  never  repeated  the 
attempt.  It  had  not  occurred  to  him,  as  it  had  to  Mr. 
Ackermann,  that  the  CO2  present  in  the  breath  played  a 
part  in  the  quenching.  With  regard  to  the  second  ex- 
periment, he  had  seen  a  small  boat  propelled  by  dissolving 
camphor  astern,  but  he  thought  the  use  of  a  liquid  for 
that  purpose  was  a  novelty. 

The  President  proposed  votes  of  thanks,  and  the 
meeting  was  adjourned  until  November  lath. 


NOTICES  OF  BOOKS. 


the  Principles  of  Chemistry.  By  D.  MendeleeFF. 
Translated  from  the  Russian  (Sixth  Edition)  by  George 
Kamenskv,  A.R.S.M.,  of  the  Imperial  Mint,  St.  Peters- 
burg; Member  of  the  Russian  Physico  -  Chemical 
Society.  Edited  by  T.  A.  Lawson,  B.Sc,  Ph.D.  In 
Two  Volumes.  London,  New  York,  and  Bombay : 
Longmans,  Green,  and  Co.     1897. 

It  is  not  surprising  that  a  new  edition  of  D.  Mendeleeff 's 
opus  magnum  has  been  required  and  has  accordingly 
appeared.  ,  .        , 

The  introdudlion,  besides  other  useful  and  necessary 
matter,  contains  correifl  definitions  of  a  variety  of  terms 
occurring  in  technical  and  scientific  discussions,  and  at 
present  grossly  misused.  A  signal  instance  may  be  found 
in  the  word  "  phenomenon  "  and  its  paronyms. 

Of  the  principles  or  generalisations  of  chemical  science, 
the  Periodic  Law  is  justifiably  spoken  of  as  the  most  im- 
portant step  in  the  development  of  chemistry  since  the 
establishment  of  the  atomic  theory.  The  author  does  not 
discuss  thh  various,  and  to  some  degree  confliding,  claims 
of  different  chemists  to  the  honour  of  the  first  or  original 
discovery. 

In  the  introdudlion  it  may  be  questioned  whether  the 
phlogistic  theory  and  its  leaders  Becher  and  Stahl  are 
not  treated  with  a  too  benevolent  neutrality.  Indeed, 
Professor  Mendeleeff  is  evidently  no  controversialist;  he 
draws  a  parallel  between  Lavoisier  and  Dalton  on  the 
one  hand,  and  Copernicus  and  Kepler  on  the  other ;  but 
he  recognises  that  the  molecular  world  has  not  yet  found 


its  Newton.     He  calls  attention  to  the  study  of  Professor 
Kononaloff  on  compadl  phenomena. 

Concerning  the  waters  of  well  known  rivers,  the  author 
points  out  that  the  Neva  is  remarkable  for  the  small 
amount  of  solid  matter  which  it  contains,  i.e.,  per  cubic 
metre  55  grms.,  of  which  32  grms.  are  incombustible  and 
23  grms.  organic. 

The  constitution  of  salts  was  a  matter  of  much  discus- 
sion. The  binary  theory  dates  from  Rouelle  and  Lavoisier ; 
the  eledro-chemical  phase  of  the  question  was  especially 
upheld  by  Berzelius  ;  and  the  hydrogen  theory,  which  is 
at  present  dominant,  is  due  to  Davy  and  Liebig. 

Ozone  has  also  proved  a  bone  of  contention  ;  the 
question  of  its  presence  in  atmospheric  air  is  still  open. 
Ilosvay  de  Uosva  concludes,  from  a  prolonged  course  of 
experiments,  that  the  phenomena  recently  ascribed  to 
ozone  are  probably  due  to  nitrous  acid. 

In  Volume  II.,  after  a  table  of  the  periodicity  of  the  ele- 
ments, we  find  an  account  of  the  elements  as  demon- 
strating the  author's  theory.  We  find  the  relations  of 
platinum,  palladium,  and  nickel,  and  again  gold,  silver, 
and  copper,  distindly  brought  into  view. 

The  author  contends  that  the  periodic  law  enables  us 
to  see  a  regularity  in  the  variation  of  all  chemical  and 
physical  properties  of  elements  and  compounds,  and  has 
rendered  it  possible  to  foretell  the  properties  of  elements 
and  compounds  as  yet  uninvestigated  by  experimental 
means. 

Copper,  silver,  and  gold  melt  far  more  easily  than 
platinum,  palladium,  and  nickel,  whilst  zinc,  cadmium, 
and  mercury  melt  still  more  easily.  Nickel,  palladium, 
and  platinum  are  very  slightly  volatile ;  copper,  silver, 
and  gold  more  volatile;  whilst  zinc,  cadmium,  and 
mercury  are  among  the  most  volatile  metals.  Zinc  is 
oxidised  more  readily  than  copper,  and  is  reduced  with 
more  difficulty,  and  the  same  holds  good  for  mercury  as 
compared  with  gold,  whilst  the  properties  of  cadmium  are 
intermediate  in  their  respedive  groups. 

Attention  is  briefly  called  to  the  want  of  two  elements 
whose  existence  is  not  sufficiently  demonstrated— ekacad- 
mium  and  adtinium. 

Crystalline  boron  is  very  closely  analogous  to  diamond, 
i.e.,  crystalline  carbon.  It  has  the  lustre,  the  high  refrac- 
tive power  of  the  diamond,  with  which  mineral  it  also 
competes  in  hardness. 

We  find  here  the  comparative  analysis  of  four  soils, 
among  which  the  famous  "  black  earth"  claims  the  first 
rank  on  account  of  its  richness  in  potassium,  phosphoric 
acid,  and  nitrogen. 

As  regards  the  localities  for  bauxite,  the  north-west  of 
Ireland  is  unfortunately  omitted.  Graham's  charadteristic 
names  for  the  different  states  of  aluminium  hydroxide— 
•'  hydrogel"  and  "  hydrosol" — are  quoted  with  approval ; 
and  the  part  played  by  aluminium  acetate  iu  the  dyer's 
procedures  is  explained. 

The  practical  importance  of  the  aluminium  alloys, 
especially  that  with  copper,  is  duly  appreciated.  Pure 
aluminium  is  now  employed  only  forobjeds  which  require 
hardness  in  combination  with  a  low  specific  gravity. 
Notes  are  given  on  the  separation  of  the  rare  metals  as 
indicated  by  Sir  William  Crookes  and  others.  Doubts  are 
entertained  as  to  whether  Welsbach's  fradtionation  of 
didymium  into  neodymium  and  praseodymium  can  be 
regarded  as  final.  Becquerel  resolves  didymium  into  six 
individual  elements  and  Sir  William  Crookes  has  pro* 
ceeded  still  further. 

The  reader  is  reminded  that  the  researches  of  Graham 
point  to  the  transition  from  inorganic  to  organic  com* 
pounds. 

The  author  gives  the  general  average  distribution  of 
phosphoric  acid  in  soils  and  earthy  substances  in  nature 
as  I  to  10  parts  in  10,000  parts.  Its  presence  in  excess 
is  no  less  pernicious  to  vegetation  than  its  absence.  The 
red  variety — commonly,  but  erroneously,  known  as 
amorphous  phosphorus— >does  not  appear  to  be  poisonous. 
There  is  a  further  variety  known  as  metallic  phosphorus ; 


Nov.  5.  1897. 


Chemical  Notices  from  P'oreign  Sources. 


2ig 


t  stands  nearer  to  nitrogen  than  the  yellow  variety.  The 
spontaneous  inflammability  of  the  hydride  PH2  is  men- 
tioned as  an  interesting  faift ;  possibly  the  formation  of 
a  trace  of  this  variety  may  account  for  the  phenomena  of 
the  Ignis  fatuus. 

The  difference  between  the  reaftions  of  ortho-,  meta-, 
and  pyro-phosphoric  acids  the  author  considers  of  the 
deepest  interest  as  regards  the  theory  of  hydrates  and 
solutions,  which  has  not  yet  been  fathomed. 

Though  arsenic  is  closely  analogous  to  phosphorus,  it 
has  a  certain  resemblance  and  even  isomorphism  with  the 
corresponding  compounds  of  sulphur. 

The  arsenical  mirror  is  a  special  variety  of  metallic 
arsenic,  whilst  the  brown  produdt  found  simultaneously 
in  the  Marsh  apparatus  is  AsH. 

The  whole  of  this  work  has  the  merit  of  presenting  the 
loftiest  generalisation  in  harmony  with,  and  based  upon,  a 
careful  study  of  fafis. 


Elements  of  Chemistry.     By  Rufus  P.  Williams.      Pp. 

412.     Boston,   U.S.A.,   and   London :  Ginn   and   Co., 

The  Athenaeum  Press.  1897. 
The  method  of  teaching  adopted  in  this  book  is  the  result 
of  the  author's  experience  with  some  2500  pupils;  one 
great  point  being  his  endeavour  to  make  the  work  have  a 
real  fascination  for  the  student  by  awakening  in  him  his 
sense  of  enquiry. 

What  proportion  of  time  should  be  devoted  to  labora- 
tory work  has  long  been  a  matter  of  discussion.  Students 
differ  considerably,  but  after  some  experiments  on  a  large 
scale,  Mr.  Williams  concludes  that,  with  four  or  five 
hours  a  week  for  chemistry,  less  than  half  should  be  spent 
in  laboratory  work. 

The  book  is  divided  into  forty-one  chapters,  so  we  can- 
not take  them  seriatim  ;  suffice  it  to  say  that  the  whole 
Bubjedt  of  elementary  chemistry  is  carefully  explained  and 
amply  illustrated  by  formulae,  equations,  and  exercises. 

The  subjecSt  of  valence,  Chapter  X.,  may  be  noted  as 
being  treated  in  a  specially  clear  manner. 

In  Chapter  XLI.  a  brief  reference  is  made  to  microbes 
and  badteriology,  but  the  subjeA  is  naturally  too  far  ad' 
vanced  to  be  thoroughly  treated  in  a  book  for  beginners. 


CHEMICAL    NOTICES   FROM    FOREIGN 
SOURCES. 


MoTB.— All  degreei  of  temperature  are  Centigrade  ualess  otherwise 
expresaed. 

Moniteur  Scientifique, 
Series  4,  Vol.  xi.,  September,  1897. 

Application  of  Ele(5\rolysis  to  the  Manufa(!\ure  of 
Inorganic  ProdU(!\s. — L.  Gourwitsch. — The  applications 
of  eledrolysis  to  inorganic  chemistry  are  not  very  varied ; 
they  consist  for  the  most  part  in  decomposing  salts,  and 
the  secondary  reactions  which  occur  are  only  very  rarely 
synthetical.  The  objeA  of  this  paper  is  to  review  the 
present  state  of  the  question,  and  numerous  references  are 
made  to  the  original  papers.  The  principal  subjedls 
touched  upon  are  the  ele(^rolytic  manufacture  of  alkalis 
and  chlorine,  by  the  eledrolysis  of  melted  chlorides,  by 
methods  founded  on  the  use  of  mercury  as  the  cathode, 
and  by  the  electrolysis  of  hydrochloric  acid.  The  eledlro- 
lyticmanufadure  of  chlorates,  hypochlorites,  persulphates, 
permanganate  of  potash,  chromates,  bichromates,  &c.,  is 
also  described. 

Chemical  Modifications  which  take  place  in  Fruits 
during  their  Growth.-^C>  Gerber.-^The  author  finds 
that  the  acids  in  fruits  disappear,  giving  off  at  the  same 
time  more  carbonic  acid  gas  than  they  can  borrow  from  the 


atmospheric  oxygen  ;  they  form  hydrates  of  carbon.  The 
tannins  disappear,  on  the  contra,,ry,  when  the  respiratory 
quotient  is  below  unity.  They  do  not  form  hydrates  of 
carbon :  so  long  as  tannins  exist  the  fruit  will  not  soften. 
As  soon  as  the  tannins  have  disappeared  softening  com- 
mences; then  follows  obstruction  of  the  intercellular 
meatus,  alcoholic  fermentation,  and  the  formation  of  per- 
fumed ethers ;  at  the  same  time  the  respiratory  quotient 
becomes  greater  than  unity. 

Estimation  of  Sulphuric  Acid.  Gravimetric  and 
Volumetric  Methods.— F.  Marboutin. — Will  be  inserted 
at  length. 

On  some  New  Sulphurised  Colouring  Matters. — 
R.  Vidal. — In  1893  the  author  patented  a  process  for  the 
manufacture  of  black  dyes  for  cotton,  resulting  from  the 
action  of  sulphur  on  hydroquinone  in  the  presence  of  am- 
monia. Some  time  after  that  the  Societe  des  Matieres 
Colorantes,  at  St.  Denis,  took  out  a  patent  for  the  same 
purpose,  by  the  aCtion  of  sulphur  on  paramidophenol. 
This  reaction  the  author  claims  to  depend  entirely  on  his 
first  patent.  It  is  a  very  general  reaction,  and  can  be 
applied  to  all  the  di-  and  tri-substituted  derivatives  of  ben- 
zene and  naphthalene  which  have  two  amidised  functions, 
or  one  amidised  and  one  hydroxylised  function,  situated 
in  para-. 


MISCELLANEOUS. 


The  Commercial  Development  Corporation,  Lim> 

— This  Company  has  been  formed  primarily  to  purchase, 
and  thereafter  work  and  commercially  develop,  Mr.  J.  G. 
A.  Rhodin's  patent  improved  EleCtrolyser,  which,  the 
Prospectus  states,  is  "  an  improved  process  for  the 
electrolytic  production  of  alkali  and  bleaching- powder, 
which  are  two  of  the  staple  commodities  of  the  world  in  con- 
stant and  ever-increasing  demand."  Patents  have  already 
been  granted  or  applied  for  in  Great  Britain,  the  Colonies, 
the  United  States,  and  the  various  Continental  countries. 
The  purchase  price  for  the  patents  has  been  fixed  at 
£■90,000,  payable  as  to  ;^20,ooo  in  fully-paid  shares, 
;^io,ooo  in  deferred  shares,  and  ;^6o,ooo  in  cash.  Dr. 
John  Hopkinson,  F.R.S.,  has  been  retained  as  Technical 
Adviser.  The  Company  also  proposes  to  acquire,  as  OC' 
casion  arises,  other  patents,  business,  and  properties. 
The  capital  is  fixed  at  ;^2oo,ooo,  divided  into  190,000 
'  Ordinary  Shares  of  £1  each  and  10,000  Deferred  Shares 
of;^i  each.  The  present  issue  consists  of  90,000  Ordinary 
Shares  of  £1  each  and  10,000  Deferred  Shares  of  £1  each, 
of  which  70,000  Ordinary  Shares  are  offered  for  subscrip* 
tion ;  £'100,000  being  reserved  for  further  issue  if  and 
when  required.  The  ProspeCtus  states  that  "  sufficient 
capital  for  the  present  needs  of  the  Company  having  been 
subscribed  by  the  Directors  and  their  friends,  the  Company 
will  at  once  proceed  to  allotment  on  the  closing  of  the 
lists,"  the  date  of  which  is  fixed  at  Monday  next, 
November  8th,  at  4  p.m.,  for  both  Town  and  Country. 

Brussels  International  Exhibition.  —  The  Horsfall 
Furnace  Syndicate  have  been  awarded,  at  the  Brussels 
International  Exhibition,  a  Gold  Medal  for  their  patent 
Refuse  Destructors,  and  a  Bronze  Medal  for  their  patent 
Smoke-consuming  Boiler  Furnace. 

Royal  Institution.  —  A  General  Monthly  Meeting  of 
the  Members  of  the  Royal  Institution  was  held  on  the 
1st  inst..  Sir  James  Crichton^Browne,  M.D.,  F.R.S,, 
Treasurer  and  Vice-President,  presiding.  The  following 
was  elected  a  Member:— Mr.  John  W.  Woodall,  J. P. 
The  special  thanks  of  the  Members  were  returned  to  Dr. 
A.  j.  Hipkins  for  his  valuable  present  of  the  Collection  of 
Tuning-Forks  made  by  the  late  Dr.  Alexander  J.  Ellis, 
F.R.S.,  M.C.I. 


13^ 


Meetings  for  the  Week, 


Chemical  Nbws 
Nov.  5,  ieg7. 


Technical  Instru(5tion  at  Manchester. — In  July  and 
August  of  the  present  year  a  Committee  of  gentlemen, 
nominated  by  the  Technical  Instrudtion  Committee  of  the 
city  of  Manchester,  was  deputed  to  visit  certain  institu- 
tions and  schools  on  the  Continent  devoted  mainly  to  sci- 
entific and  artistic  instrudiion  as  applied  to  commercial 
and  industrial  pursuits.  Nine  towns  in  Germany  and 
Austria  were  visited,  and  the  report  of  the  Committee  is 
now  issued.  The  Adt  of  i8Sg  establishing  technical  in- 
8tru(5lion  in  England  and  Wales  has  awakened  much  inte- 
rest throughout  the  country  on  the  subje<5t  of  industrial 
scientific  teaching  and  training  ;  it  has  also  direded  the 
attention  of  the  educational  authorities  of  foreign  countries 
to  the  efforts  being  made  in  England,  with  the  conse- 
quence that  there  has  been  a  considerable  development, 
throughout  Germany  at  least,  of  educational  means  and 
resources.  To  this  may  be  attributed  Germany's  great 
commercial  and  industrial  progress  of  recent  years.  It 
was  therelore  considered  to  be  of  the  highest  importance 
to  see  what  the  Continential  countries  have  done  of  late  ; 
hence  the  appointment  of  this  committee.  That  Germany 
is  in  a  prosperous  condition,  due  to  her  successful  manu- 
fa(5turing  and  commercial  enterprise,  is  evident  in  the  ex- 
tension of  her  cities,  the  making  of  new  streets,  and  the 
erection  of  handsome  buildings  which  is  going  on  in  every 
town,  and  it  seems  certain  that  it  is  the  technical  teaching 
which  is  at  the  root  of  this  surprising  development. 
We  sincerely  hope  that  the  report  of  this  Committee 
will  arouse  many  of  our  large  towns  from  the  apathy 
which  they  now  show,  and  be  the  means  of  further 
endeavours  for  the  maintenance  of  our  commercial 
supremacy,  once  unchallenged,  but  now  so  seriously 
threatened,  both  by  competitors  abroad  and  so-called 
"  labour  leaders  "  and  Trades  Unions  at  home. 


NOTES    AND    QUERIES, 

Enamelling  Cast-iron  Pots.— I  should  be  obliged  for  information 
as  to  the  best  material  and  process  for  enamelling  cast-iron  pots  to 
withstand  180°  Tw.,  or  the  names  of  enamel  pot  makers.— Enamel. 


MEETINGS    FOR    THE    WEEK. 


Friday,  rath.— Physical, 3.  "On  the  Isothermals  of  Ether,"  by  J. 
Rose  Innes.  "  On  the  Variation  with  Temperature 
of  the  EleAromotive  Force  of  the  H-iorm  of  Clark 
Cells,  by  F.  S.  Spiers  and  F.  Twyman, 


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Interaction  of  Hydrogen  Sulphide  and  Copper  Salts. 


231 


THE    CHEMICAL    NEWS. 

Vol.  LXXVI.,  No.  1981. 


THE     SPECTROGRAPHIC    ANALYSIS    OF 

MINERALS    AND    METEORITES.* 

By  Professor  W.  N.  HARTLEY,  F.R.S.,and  HUGH  RAMAGE. 

In  the  course  of  a  spedlrographic  study  of  the  basic  Bes- 
semer flame  at  Middlesborough  the  element  gallium  was 
found  in  the  iron  and  was  traced  to  the  Cleveland  clay 
ironstone.  The  process  employed  in  the  analysis  of  the 
ore  was  partly  chemical  and  partly  spedtrographic,  and 
other  samples  of  ores  were  examined  in  a  similar  way 
(Proc.  Roy.  Soc,  Ix.,  p.  393).  The  results  were  satisfaiftory 
as  far  as  the  deteiftion  of  gallium  was  concerned,  but  the 
process  occupied  too  much  time.  The  same  ores  were 
then  examined  by  a  simpler  process,  in  which  0*5  grm.  of 
the  powders  were  rolled  in  filter-paper  and  heated  in  the 
oxyhydrogen  flame,  the  spedtrum  of  the  flame  being  mean- 
while photographed.  This  operation  lasted  only  about 
three  minutes,  and  the  test  for  gallium  was  almost  as 
sensitive  as  the  combined  chemical  and  spedtrographic 
method  performed  on  a  much  larger  quantity,  and,  in 
addition,  it  revealed  the  presence  of  many  other  elements. 

A  large  number  of  minerals,  commercial  produ(5ts,  mete- 
oric irons,  and  meteorites  have  been  examined  by  this  pro- 
cess and  very  interesting  results  have  been  obtained  (jfourn. 
Chetn.  Soc,  1897,  PP-  533  ^^^  547)*  The  spe(ftrograph 
used  in  this  work  was  described  by  the  aid  of  a  photograph, 
and  spectrograms  taken  with  the  instrument  were  projected 
diredtly  on  the  screen. 

The  simple  character  of  the  oxyhydrogen  flame  spedtra 
as  compared  with  spark  spedtrawas  illustrated  by  examples 
of  the  spedtra  of  iron.  The  former  spedtra  are  such  that, 
with  the  aid  of  a  superimposed  spark  spedtrum  of  two 
alloys  which  give  easily  recognised  lines,  the  elements 
may  be  identified  without  scale  or  micrometer  measure- 
ment. In  a  mineral  or  complex  mixture  of  substances  the 
presence  or  absence  of  about  one-third  of  the  elements 
may  in  this  way  be  decided  upon  in  a  few  moments. 

Spedlrograms  of  the  following  elements  were  projedted 
on  the  screen  and  the  lines  by  which  they  are  most  easily 
recognised  indicated : — 

Lithium,  sodium,  potassium,  rubidium,  and  ctesium. 

Copper,  silver,  and  gold. 

Calcium,  strontium,  and  barium. 

Zinc  and  cadmium. 

Gallium. 

Manganese. 

Iron,  cobalt,  and  nickel. 

The  spedtrograms  of  a  number  of  minerals  and  meteoric 
irons  were  also  exhibited,  special  attention  being  drawn 
to  the  lines  of  the  more  interesting  constituents. 

Tabulated  results  of  the  analyses  of  169  minerals  were 
given,  as  in  Engineering,  Ixiv.,  p.  395,  and  of  13  meteor- 
ites, as  in  a  paper  read  before  the  Royal  Dublin  Society 
in  May  last,  but  not  yet  published  in  the  Proceedings. 


The  Sanitary  Institute. — A  Sessional  Meeting  of  the 
Institute  will  be  held  at  the  Parkes  Museum,  Margaret 
St.,W.,  on  Wednesday,  November  17th,  at  8 p.m.,  when  a 
Discussion  will  take  place  on  ••  The  Pollution  of  Water 
Supplies  by  Encampments  of  Hop  -  Pickers,  Casual 
Workers,  Tramps,  &c."  To  be  opened  by  Prof.  W.  H. 
Corfield,  M.A.,  M.D.  (Oxon),  F.R.C.P.,  in  reference  to  the 
Dangers  of  Pollution  of  Municipal  Water  Supplies  ;  and 
by  Miss  M.  A.  Chreiman,  in  reference  to  the  Sanitary 
Control  of  Hop-Pickers,  &c.  The  chair  will  be  taken  by 
Sir  Douglas  Galton,  K.C.B.,  D.C.L.,  LL.D.,  F.R.S. 

*  Abstra<5t  of  a  Paper  read  before  the  British  Association  (SeAion 
B),  Toronto  Meeting,  18^. 


THE  INTERACTION  OF  HYDROGEN  SULPHIDE 

AND  COPPER  SALTS. 

By    JOHN     B.    COPPOCK,    F.C.S. 

In  the  Chemical  News  (vol.  Ixxiii.,  No.  1906)  I  gave  an 
account  of  some  results  obtained  in  connedtion  with  the 
ineradtion  of  hydrogen  sulphide  and  copper  sulphate,— 
investigations  which  took  their  origin  in  the  statement 
that  cupric  suiphide  (CuS)  was  not  produced  in  the  inter- 
adtion,  but  Cu4S3. 

Dr.  Brauner  in  an  article  (vol.  Ixxiv.,  p.  99)  pointed 
out  that  the  precipitates  he  obtained  in  working  upon 
this  subjedt  contained  varying  proportions  of  copper  and 
sulphur,  that  their  composition  was  not  always  CU4S3, 
and  they  never  contained  copper  and  sulphur  in  the 
atomic  proportion  CuS,  except  when  the  original  precipi- 
tate was  left  unwashed  with  carbon  bisulphide.  Then  the 
precipitate  contained  copper  and  sulphur  "in  the  exadt 
atomic  proportions  Cu  :  S  =  i  :  i,"  but  some  of  the  sulphur 
existed  in  the  free  state. 

Thus  it  appeared  as  a  point  worth  noticing  that  a  sub- 
stance in  the  process  of  formation  should  exert  an 
influence  in  forming  a  mechanical  mixture  of  itself  and 
the  uncombined  negative  radicle  in  exadt  atomic  propor- 
tions. This  may  be  but  a  coincidence,  but  it  suggests  tha 
idea  that  when  a  lower  sulphide  is  being  produced,  if  free 
sulphur  is  formed  at  the  same  time,  then  the  lower  sul- 
phide and  the  free  sulphur  are  in  the  exadt  atomic  propor- 
tions required  by  the  higher  sulphide. 

Analyses  of  these  unwashed  precipitates  led  me  to  the 
conclusion  that  the  free  sulphur  mixed  with  the  copper 
sulphide  precipitate  was  a  very  variable  quantity,  which 
depended  very  much  upon  the  time  the  current  of  gas  was 
passing  through  the  copper  salt  solution. 

There  can  be  no  doubt  that  the  precipitate  yielded  by 
the  interadtion  of  copper  salts  and  hydrogen  sulphide  do 
not  always  agree  with  the  formula  CuS. 

Dr.  Brauner  points  out  that  these  precipitates  can  be 
represented  dualistically  as  a  mixture  of  Cu^S  and  CuS. 
Several  of  the  precipitates  obtained  by  me,  deviating 
from  the  formula  CuS,  I  found,  after  reading  Linder  and 
Pidton's  work  (Chemical  Society's  Transactions,  1892), 
could  be  represented  as  compounds  of  their  suggested 
type.  They  showed  that  compounds  of  the  form 
nCuS.HjS  were  formed  by  interadtion  of  the  two  above 
specified  substances,  establishing  the  existence  of — 

7CuS,HaS  9CuS,HaS  22CuS,H2S. 

What  interpretation  is  to  be  put  upon  the  fadt  that  the 
precipitate  yielded  by  the  interadtion  of  hydrogen  sulphide 
and  copper  salts — omitting  free  sulphur  from  consideration, 
as  undoubtedly  this  may  be  removed  by  washing — does 
not  always  agree  with  the  formula  CuS. 

Dr.  Brauner  argues  in  favour  of  the  produdlion  of  mix- 
tures of  CujS  and  CuS,  which  he  says  finds  support,  in 
the  adtion  of  hydrogen  sulphide  upon  solutions  of  anti- 
monic  and  arsenic  salts,  where  mixtures  of  the  lower  and 
higher  sulphides  are  formed,  and  the  tendency  which 
copper  has  of  forming  sulpho-salts,  as  is  the  case  with 
arsenic  and  antimony. 

That  copper  does  form  sulpho-salts— double  sulphides 
—is  a  fadt,  but  whether  it  forms  a  basis  for  any  analogy 
with  arsenic  and  antimony  is  doubtful.  From  considera- 
tions of  relationship  one  would  expedt  the  produdtion  of 
the  compounds  MCuS.HaS  to  be  most  likely,  as  demon- 
strated by  Linder  and  Pidton's  work.  If  hydrogen  finds 
its  proper  place  at  head  of  Group  I.  (Periodic  Law),  we 
should  expedl  it  to  resemble  the  other  high  members  of 
this  group,  and  give  combinations  with  cupric  sulphide, 
as  in  the  cases  of  sodium  and  potassium  sulphides. 
Double  sulphides  are  thus  known,  but  they  are  not 
formed  with  the  ease  and  diredl  manner  as  are  the  double 
sulphides  of  antimony  and  arsenic,  whose  sulphides  are 
very  soluble  in  alkali  sulphides,  but  cupric  sulphide  is 
relatively  insoluble.    The  very  little  analogy  between  the 


i42 


Estimation  of  Sulphuric  A  cid. 


f  Chbwical  Nt\n, 
1     Nov.  12,  i8g7. 


two  cases  does  not  warrant  the  idea  of  an  exadl  resem- 
blance in  the  interad^ion  of  antimonic  and  arsenic  salts 
with  hydrogen  sulphide  and  copper  salts  with  hydrogen 
sulphide.  Moreover,  the  sulphides  of  nickel  and  mer- 
cury show  a  slight  solubility  in  alkali  sulphides  like 
copper. 

The  following  method  gave  almost  uniform  results  in 
testing  whether  cupric  sulphide  could  be  prepared  by 
adlion  of  hydrogen  sulphide  upon  copper  salt  solutions  : — 

An  unweighed  quantity  of  copper  sulphate  was  dis- 
solved in  water,  acidified  with  nitric  acid.  Nitric  acid 
was  added  on  the  idea  that  any  reducing  adtion  hydrogen 
sulphide  may  possess  would  be  spent  upon  the  acid  rather 
than  upon  the  copper  sulphate,  and  so  preventing  the  pro- 
duction of  cuprous  sulphide. 

The  copper  sulphate  solution  was  run  gradually  into 
hydrogen  sulphide  solution.  The  precipitate,  after  col- 
lei^ion,  was  washed  in  a  cylinder  by  agitation  with  dilute 
acid,  then  washed  free  from  acid,  then  left  in  contadl  with 
carbon  bisulphide  for  days,  seven  at  least,  during  which 
shaking  up  went  on  at  times  ;  finally  it  was  washed  with 
alcohol.  The  precipitate  was  of  a  very  dark  olive-green 
colour.  It  is  needless  to  say  during  these  operations 
oxidation  was  reduced  to  a  minimum,  and  apparently 
none  went  on. 

The  precipitate  was  then  dried  in  an  atmosphere  of 
carbon  dioxide  at  a  temperature  never  higher  than  ioo°, 
inasmuch  as  it  has  been  shown  cupric  sulphide  reduces  to 
cuprous  sulphide  when  heated  to  130°.  The  precipitate 
was  then  fractionated  upon  the  idea  that  if  there  were 
CU2S  or  free  sulphur  in  it  such  might  not  be  uniformly 
diffused.  Weighed  portions  were  taken  and  determined  by 
conversion  into  sulphate  and  precipitation  as  barium  sul- 
phate, and  other  portions  were  digested  with  strong 
hydrochloric  added,  got  into  solution,  oxidised,  and  the 
copper  determined  as  cupric  oxide.  In  the  oxidation  to 
barium  sulphate  a  little  sodium  chloride  was  added,  to 
convert  any  free  sulphuric  acid  into  sodium  sulphate, 
inasmuch  as  free  sulphur  was  liberated.  The  following 
results,  and  others,  were  got : — 


CuS  taken. 
033 
0*56 

CuS  taken. 
0*276 
0432 


CuO  found. 
0"274i 
0-4652 

BaSO«  found. 
06775 
i'o6i5 


Theory  for  CuS. 
0-2744 
0-4654 

Theory  for  CuS. 
0-6770 
1-0596 


We  may  therefore  conclude  that  cupric  sulphide  may 
be  prepared  by  this  interaction.  Linder  and  Pidon,  in 
1892,  concluded  that  in  the  presence  of  acid  the  molecule 
(CuS)h  was  formed  as  a  final  breaking-up  produdt  of  com- 
pound between  it  and  hydrogen  sulphide. 

These  investigations  have  suggested  the  possible  power 
that  precipitates,  particularly  fiocculent  ones,  may  have  of 
retaining  finely  divided  sulphur  and  hydrogen  sulphide, 
physically  or  chemically,  in  their  pores,  and  experiments 
are  contemplated  under  these  headings  with  other  sub- 
atances  than  sulphides. 

Chemical  Laboratory, 

Harris  Institute,  Preston. 


ON  THE    ESTIMATION   OF   SULPHURIC  ACID. 
Gravimetric   and   Volumetric   Methods.* 

By  FELIX  MARBOUTIN. 

The  large  number  of  volumetric  methods  for  the  estima- 
tion of  sulphuric  acid  contrasts  strangely  with  the  one 
gravimetric  method  used.  We  propose  to  give  a  short 
resume  of  the  more  frequently  used  volumetric  methods, 
classifying  the  various  processes ;  we  will  then  describe 

*  Abridged   from  the  Moniteuf  Seientifique,   Series  4,  vol.  xi., 
September,  1897. 


in  detail  a  volumetric  method  which  has  given  us  excel- 
lent results  in  the  analysis  of  water.  We  also  think  it 
advisable  to  describe  in  some  detail  the  gravimetric 
method  we  employed,  as  it  has  served  as  a  check  on  our 
volumetric  method. 

1.  Gravimetric  Analysis.— A  volume  of  water,  sufficient 
to  contain  50  to  100  m.grms.  of  sulphuric  anhydride,  is 
concentrated  to  about  100  c.c.  after  the  addition  of  a  few 
drops  of  hydrochloric  acid.  It  is  kept  at  a  temperature 
near  boiling,  without,  however,  quite  reaching  that  point ; 
we  then  add,  drop  by  drop,  10  c.c.  of  a  solution  of  chloride 
of  barium,  of  175  grms.  of  the  crystalline  salt  per  litre. 
This  done,  we  leave  it  in  a  warm  place  (40°)  for  twelve 
hours,  wash  by  decantation  with  warm  water,  until  ni- 
trate of  silver  no  longer  gives  a  precipitate  in  the  washings ; 
throw  on  a  filter,  and  again  wash  with  warm  water,  then 
place  the  funnel  in  an  oven,  and  leave  it  at  110°  for  three 
hours ;  then  put  the  filter  and  its  contents  in  a  platinum 
crucible,  the  point  of  the  filter  upwards,  and  calcine 
strongly  in  an  oxidising  flame;  there  is  then  no  risk  of 
reducing  the  sulphate  of  barium. 

This  method  gives  perfed  satisfaction  ;  the  precipitate 
is  granular,  and  never  passes  through  the  filter,  and  the 
use  of  sulphuric  or  nitric  acid  to  re-convert  the  sulphide 
of  barium  to  sulphate  is  rendered  unnecessary,  an 
appreciable  advantage  when  there  are  many  estimations 
to  make. 

In  certain  cases  (highly  coloured  waters)  it  is  as  well  to 
make  sure  that  the  precipitate  does  not  contain  any 
foreign  matters  ;  for  this  purpose,  after  weighing,  we  fuse 
with  carbonate  of  soda,  then  dissolve  in  water.  The 
solution,  acidulated  with  hydrochloric  acid,  is  precipitated 
as  before. 

Ferrous  or  ferric  salts  might  give  a  precipitate  con- 
taining  iron,  by  the  formation  of  a  hydrated  ferrico- 
barytic  sulphate ;  it  is  therefore  advisable  to  get  rid  of 
these  salts  if  they  are  present  in  too  great  quantity. 

When  concentrating  large  volumes  of  water  it  is  as  well 
to  use  a  vacuum,  for  the  sulphurous  products  from  the  gas 
flame  may  easily  cause  the  formation  and  absorption  of 
10  to  14  m.grms.  of  sulphuric  acid  in  six  hours  if  the 
vessel  is  uncovered.  In  the  case  of  sewage  waters,  &c., 
it  is  necessary  to  get  rid  of  the  organic  matters  by 
evaporating  with  fuming  nitric  acid,  or  by  treating  with 
bromine ;  but  care  should  be  taken  not  to  use  an  excess 
or  to  carry  the  evaporation  too  far. 

2.  Volumetric  Analysis.  —  Many  methods  have  been 
proposed  ;  some  specially  for  alkaline  sulphates,  others 
for  cases  when  no  chlorides  are  present,  others  again  are 
almost  universal,  but  all  require  several  titrated  solutions, 
which  causes  a  considerable  amount  of  uncertainty.  Our 
method,  which  we  shall  describe  after  reviewing  those 
more  generally  known,  presents,  we  think,  certain  advan- 
tages  over  those  in  common  use. 

I.  Direct  Method  by  Chloride  of  Barium. 
A.  Houzeau  in  France,  and  Wildenstein  in  Germany, 
proposed  precipitating  the  sulphuric  acid  by  a  titrated  so- 
lution of  chloride  of  barium,  the  end  of  the  operation 
being  determined  by  the  absence  of  precipitation.  The 
determination  point,  however,  is  very  difficult  to  decide, 
and  it  must  not  be  forgotten  that  there  is  a  neutral  point, 
where— though  there  is  still  some  sulphuric  acid  present — 
no  precipitate  is  formed  unless  excess  of  chloride  of 
barium  be  added. 

11.  Direct  Alkalimetric  Methods. 

1.  Using  Salts  of  Barium. — F.  Mohr  added  an  excess 
of  carbonate  of  barium  in  the  presence  of  a  current  of 
carbonic  acid ;  the  alkaline  sulphates  form  sulphate  of 
barium,  and  the  alkaline  carbonates  formed  are  estimated 
by  means  of  a  titrated  acid  solution.  Bohlig  has  im- 
proved this  method  by  working  at  the  boiling-point,  but 
it  is  not  applicable  except  to  the  sulphates  of  the  alkaline 
earths. 

2.  Using  Salts  of  Strontium.— Rose  showed  the  com- 


CbbhicalNbws.  1 

Nov.  la,  i8q7. 


Estimation  of  Sulphuric  Acid, 


233 


plete  transformation  of  sulphate  of  strontium  into 
carbonate,  by  digesting  with  alkaline  carbonates.  Mohr 
and  Classen  devised  a  method  founded  on  this  principle. 
The  sample  was  acidulated  with  HCl,  treated  with 
chloride  of  strontium,  and  an  equal  volume  of  alcohol 
added.  The  washed  precipitate  is  digested  with  car- 
bonate of  soda,  and  dissolved  in  excess  of  titrated  HCl. 
The  excess  is  measured  with  a  titrated  potash  solution. 

3.  Using  Salts  of  Lead. — The  sulphate  of  lead  obtained 
by  precipitating  with  the  nitrate  is  washed,  transformed 
into  carbonate  by  digesting  with  carbonate  of  ammonium, 
dissolved  in  excess  of  titrated  nitric  acid,  and  the  excess 
of  acid  measured  with  titrated  soda.  This  method  cannot 
be  used  in  the  presence  of  chlorides. 

4.  Using  Caustic  Baryta. — J.  Grossmann  precipitates 
the  sulphuric  acid  by  caustic  baryta ;  the  excess  of  hy- 
drate of  baryta  is  treated  with  a  current  of  carbonic  acid, 
the  excess  of  which  is  driven  off  by  boiling.  The  soda 
is  titrated  alkalimetrically. 

5.  Transforming  the  Precipitated  Sulphate  into  Sulphide. 
—According  to  Linossier  the  acid  may  be  separated  from 
the  solution  as  an  insoluble  compound  and  converted  into 
■ulphide.  This  latter  is  titrated  alkalimetrically  with  a 
normal  soda  solution,  using  Poirrier  orange  as  indicator. 
In  the  case  of  sulphuric  acid  it  is  precipitated  by  acetate 
of  lead,  and  changed  into  sulphide  with  sulphuretted 
hydrogen. 

III.    Indirect  Alkalimetric  Methods, 

1.  C.  Mohr  precipitates  the  sulphuric  acid  by  an  excess 
of  chloride  of  barium,  in  a  neutral  or  very  faintly  acid 
solution.  The  excess  of  chloride  of  barium  is  treated 
with  carbonate  of  ammonia  or  soda,  the  precipitate  is 
washed  thoroughly,  and  the  carbonate,  dissolved  in  an 
excess  of  titrated  acid,  is  determined  by  means  of  a 
titrated  alkaline  solution.  Ad.  Clemm  has  made  this 
method  more  pradticable  by  adding,  after  precipitating 
with  chloride  of  barium,  a  quantity  of  carbonate  of  soda 
capable  of  precipitating  all  the  chloride  of  barium  used. 
The  excess  of  carbonate  of  soda  remaining  measures  the 
quantity  of  sulphuric  acid  present. 

2.  Bohlig  precipitates  with  carbonate  of  baryta  in 
presence  of  a  current  of  carbonic  acid  ;  the  alkaline  sul- 
phates are  transformed  into  bicarbonates,  and  the  sulphuric 
acid  is  precipitated.  The  carbonates  obtained  by  boiling 
are  estimated  with  titrated  acid  in  excess,  and  titrating 
back  with  an  alkaline  solution. 

3.  Knofler  makes  the  sample  neutral  with  titrated  hy- 
drochloric acid,  then  boils  to  drive  off  the  carbonic  acid, 
and  makes  the  solution  neutral  to  phenolphthalein  by 
means  of  a  titrated  solution  of  carbonate  of  soda.  The 
sulphuric  acid  is  precipitated  with  titrated  chloride  of 
barium,  the  phthalein  showing  when  the  precipitation  is 
complete  ;  he  then  adds  a  slight  excess  of  chloride  of 
barium,  which  is  estimated.  Altogether  this  method  re- 
quires four  titrations,  each  liable  to  error,  and  we  do  not 
think  it  can  be  employed  advantageously  in  most  cases. 
It  is  worth  noting  that  readings  with  phenolphthalein  in 
the  presence  of  carbonates  should  be  made  in  boiling 
solutions. 

IV.    Methods  by  Precipitation  with  Chloride  of  Barium, 
and  Measurement  of  the  Excess, 

X.  Wildenstein  proposed  to  neutralise  the  solution  from 
which  the  sulphate  had  been  precipitated,  and  to  measure 
the  excess  of  chloride  of  barium  by  means  of  chromate 
of  potassium,  the  end  of  the  operation  being  shown  by  the 
yellow  colour  of  the  liquid;  the  results,  however,  are 
never  exaA. 

2.  Precht,  using  an  acid  solution,  transforms  the 
chromate  into  bichromate,  which  he  treats  with  soda  to 
change  the  colour  from  red  to  yellow;  the  excess  of 
chromate  is  then  measured  with  a  salt  of  iron,  by  the 
touch  test.  This  latter  operation  allows  of  the  use  of 
cloudy  solutions. 

3.  A.  Pellet  precipitates  the  sulphuric  a9id  with   an 


excess  of  chloride  of  barium ;  the  excess  is  then  precipi- 
tated  by  a  quantity  of  potassic  chromate  equivalent  to  the 
total  quantity  of  chloride  of  barium  used.  The  chromic 
acid  remaining  in  the  solution  is  thus  proportionate  to 
the  quantity  of  sulphuric  acid  in  the  sample.  The 
chromic  acid  is  estimated  by  means  of  ferrous  chloride 
and  titrated  permanganate  of  potash. 

M.  Quantin  claims  priority  for  the  above  method.  His 
process  is  very  little  different,  but  he  considers  it  neces- 
sary to  have  solutions  of  chromate  and  chloride  which 
are  in  absolute  agreement,  and  he  even  gives  corredtions 
to  use  in  case  the  chromate  is  the  stronger. 

4.  Mohr  and  Classen  have  described  a  process  based  on 
the  same  principle,  but  the  chromic  acid  is  titrated  with 
iodide  of  potassium  and  hyposulphite  of  soda,  using 
starch  as  an  indicator;  this  process  cannot  be  recom- 
mended, as  it  requires  too  many  reagents. 

5.  Windisch  proposed,  for  estimating  the  sulphates  in 
brewery  waters,  a  method  of  estimation  very  similar  to 
the  one  we  have  just  described,  but  the  excess  of  chromic 
acid  is  titrated  by  means  of  arsenious  acid  and  iodine. 
The  disadvantage  of  this  process  is,  that  it  is  almost  as 
long  as  the  gravimetric  method. 

V.  Methods  based  on  Precipitation  in  the  form  of  Sulphate 
of  Lead. 

1.  Levol  was  the  first  to  propose  the  use  of  salts  of 
lead.  He  poured  a  titrated  solution  of  lead  into  the 
solution  containing  the  sulphates :  the  end  of  the  opera- 
tion is  shown  by  the  colour  assumed  by  the  iodide  of 
potassium  which  is  used  as  an  indicator. 

2.  A.  Guyard,  using  the  same  reagents,  puts  the  solu- 
tion to  be  titrated  into  the  burette,  and  runs  off  the 
quantity  necessary  to  decolourise  a  known  volume  of 
titrated  acetate  of  lead,  coloured  with  a  drop  of  iodide  of 
potassium.  Again,  we  can  precipitate  the  sulphates  with 
an  excess  of  acetate  of  lead,  and  measure  the  excess  with 
bichromate  and  salts  of  silver.  None  of  the  methods 
based  on  the  adtion  of  salts  of  lead  can  be  applied  in  the 
presence  of  chlorides  ;  this  is  their  weak  point,  for  there 
are  many  analyses  made  where  we  do  not  detedl  the 
chlorine  in  the  state  of  combination  in  which  it  exists  in 
the  sample,  or  where  its  presence  is  due  to  the  preliminary 
solution  of  the  sample. 

VI.  Method  of  Felix  Marboutin, 

We  precipitate  the  sulphuric  acid  with  chloride  of 
barium;  the  excess  of  baryta  is  then  precipitated  by  a 
quantity  of  chromate  greater  than  that  required  by  all  the 
chloride  of  barium  used;  the  chromic  acid  remaining  in 
the  solution  is  oxidised  by  a  known  volume  of  an  arsenious 
solution  ;  the  excess  of  arsenious  acid  is  measured  with 
titrated  iodine. 

The  reading  of  iodine  obtained  in  an  analysis  of  water, 
subtracted  from  the  reading  obtained  with  distilled  water 
free  from  sulphuric  acid,  gives  the  volume  of  iodine  solu- 
tion equivalent  to  the  sulphuric  acid  in  the  sample. 

The  following  is  our  method  of  working: — 

One  hundred  c.c.  of  the  water  to  be  analysed  are  acid- 
ulated with  HCl,  then  boiled  to  drive  ofi  carbonic  acid  ; 
the  temperature  is  then  lowered  to  just  below  boiling,  and 
30  c.c.  of  chloride  of  barium  are  added  drop  by  drop;  it 
is  then  allowed  to  stand  twelve  hours  at  40°,  for  the  pre- 
cipitate to  become  well  agglomerated.  Neutralise  with  a 
few  drops  of  ammonia,  and  add  30  c.c.  of  chromate  of 
potassium. 

The  liquid  is  gently  heated,  and  then  after  cooling 
made  up  to  300  c.c.  100  c.c.  of  the  clear  liquid  is  taken 
and  2  c.c.  of  ^  sulphuric  acid,  and  5  c.c.  of  arsenious  acid 
are  added ;  it  is  then  gently  warmed  and  shaken  until 
completely  decolourised.  To  the  solution,  neutralised 
with  carbonate  of  potassium,  we  add  from  a  burette  a 
titrated  solution  of  iodine,  with  starch  as  an  indicator. 

t  =  the  value  of  i  c.c.  of  iodine  in  m.grms.  of  I. 

n  =  the  number  of  c.c.  of  iodine  used  with  100  c.c.  o( 
distilled  water. 


234 


Relations  connecting  the  Thermal  Constants  of  the  Elements.   {^n"I"M^i"' 


ni=s  the  number  of  c.c.  of  iodine  used  with  loo  c.c.  of 

the  sample. 
X  =  the  number  of  m.grms.  of  sulphuric  anhydride  in 
the  sample. 
Then— 

4x80 

^=^°  ("-«')  3<3X4X  127- 

N 
If  the  solution  of  iodine  is  exaAly  ~,  that  is  to  say, 

if  I  c.c.  of  iodine  is  equal  to  2-54  m.grms.  of  iodine, 

;¥  =  i6  {n  —  n^). 

The  reaflions  which  take  place  in  the  above  analysis  are — 

S04K2+BaCl2  =  S04Ba+2KCl, 
BaCl2+Cr04K2  =  Cr04Ba+2KCl, 
4Cr04Ka+2A6203+7S04H2=3As205  + 

+  2  [Cr2(S04}3]  +4SO4K2  +  7H2O, 
4l+As203+2H20  =  A8205+4m. 

The  solutions  used  are— 

N 
Crystallised  chloride  of  barium,  4*8  grms.per  litre,   — » 

N 
Crystallised  chromate  of  potassium,  3-9  „  —' 

Arsenious  solution,  4-95  grms.  arsenious  acid  per  litre. 

Dissolve  4*95  grms.  of  arsenious  acid  in  water  con 
taining  10  grms.  of  potash,  heat  gently ;  after  cooling 
make  acid  with  sulphuric  acid,  and  make  up  to  a  litre. 
Iodide  solution :  weigh  out  2*54  grms.  of  bi-sublimated 
iodine,  dissolve  in  water  with  5  grms.  of  iodide  of  potas- 
sium ;  make  up  to  a  litre  and  titrate  with  a  known  weight 
of  hyposulphite  of  soda. 

Our  method  has  several  advantages  over  the  others  we 
have  mentioned ;  it  has  a  distindt  determination  ;  it  does 
not  require  fiitrations  or  washings  ;  only  one  titrated  solu- 
tion is  necessary;  it  takes  cognisance  of  the  possible 
impurities  in  the  reagents  used,  by  a  comparative  reading 
with  distilled  water.  It  gives  results  absolutely  com- 
parable with  those  obtained  gravimetrically,  and  that 
with  a  considerable  saving  of  time — of  at  least  three- 
quarters. 

It  differs  from  the  method  described  by  Windisch,  and 
other  methods  based  on  the  use  of  solutions  of  chloride 
of  barium  and  chromate  of  potassium,  in  that  it  is  not 
necessary  to  use  a  volume  of  chromate  exactly  equivalent 
to  the  volume  of  chloride  of  barium  used.  We  measure, 
in  fa(5t,  the  diiTerence  between  the  readings  made  with  a 
water  deprived  of  sulphuric  acid  and  a  water  containing 
some.  The  absolute  value  of  these  readings  is  therefore 
a  matter  of  indifference. 

Our  method  can  be  applied  to  all  estimations  where 
sulphuric  acid  can  be  isolated  by  precipitation  with 
chloride  of  barium.  We  must,  however,  point  out  that 
in  the  case  of  waters  containing  much  organic  matter, 
such  as  sewage,  it  is  first  of  all  necessary  to  get  rid  of 
this  matter,  the  reading  of  iodine  being  in  such  cases  too 
high,  and  varying  with  the  nature  of  the  organic  matter 
present.  In  the  case  of  water  from  sprmgs,  rivers,  wells, 
and  surface  drainage,  the  method  gives  excellent  results. 

M.  Marcel  Molime  has  compared  the  figures  obtained 
by  our  method  with  those  obtained  by  Windisch's.  The 
difficulty  of  obtaining  solutions  of  bariumjand  of  chromate, 
stridtly  equivalent  in  the  latter  case,  has  led  him  to  deter- 
mine, the  corredtions  necessary  from  the  fadt  of  using 
solutions  not  absolutely  equivalent. 

Ti  being  the  value  of  arsenious  acid  in  iodine. 

T2        „  „  chromate  in  arsenious  acid. 

I  the  reading  of  iodine  in  the  analysis. 

The    weight  of   sulphuric    anhydride    in    Windisch's 
method  is  giren  by- 
la  '^'-^ 


Five  c.c.  of  arsenious  acid  decolourises  25*2  c.c.  of 
iodide  solution,  from  which  we  get  Ti=:25'2. 

Ten  c.c.  of  chromate  added  to  100  c.c.  of  water  and 
10  c.c.  of  arsenious  acid,  required  20  6  c.c.  of 
iodine.  10  c.c.  of  chromium  =  (25*2x2)  — 2060 
or  29*80  of  iodine. 

T2  =  5  .i?:!  = 

2     25-2 

If  we  use  a  solution  of  iodide  which  is  not  exadtly 
50/N,  we  must  corre(5t  the  readings,  so  that  they 
do  represent  a  solution  of  50/N  ;  in  the  present 
case  the  coefificient  by  which  the  readings  must  be 
multiplied  is — 


2-956. 


25'0 

25-2 


0*992. 


From  30  c.c.  of  chromate  +  30  c.c.  of  baryta,  made 
up  to  300  c.c.  with  distilled  water,  we  take  100  c.c, 
to  which  we  add  5  c.c.  of  arsenious  acid.  The 
reading  shows  24*70  c.c.  of  iodine.  The  difference 
25*2  — 247=  0*5  c.c,  measures  one-third  of  the 
value  of  the  difference  which  exists  between  the 
30  c.c.  of  chromate  and  the  30  c.c.  of  barium.  The 
tormula,  calling  x  the  correction  to  be  made,  is  as 
follows : — 

r(T,-I-;.)]-°'992XU 


J.    ?2J 

2        25-2 

0992      2 
298    ■   5 
(25*2- I -AT)      15*98. 


25*2. 


(T,-I-;r) 


RELATIONS    CONNECTING  THE   THERMAL 

CONSTANTS    OF   THE    ELEMENTS. 

By  NOEL  DEERR. 

Empirical  relations  existing  between  the  thermal  con- 
stants of  the  elements  have  been  proposed  by  Pi(5tet, 
Richards,  Crompton,  and  Deerr.  As  these  relations  are 
all  very  similar,  and  in  some  cases  identical,  it  is  here 
intended  to  colie(ft  together — and  to  some  extent  to  criti- 
cise— the  work  that  has  been  already  done. 
The  following  notation  is  used  in  this  article : — 

T   =  Melting-point  absolute  in  degrees  Centigrade. 

L  =  Latent  heat  of  fusion  per  unit  mass. 

S    =  Mean  specific  heat  between  -273°  and  T. 

C   =  Mean  coefficient  of  expansion  between    -273° 

and  T. 
A  =  Atomic  weight. 
V   =  Atomic  volume. 
W  s=  Valence. 

To  the  various  calculations  the  quantities  S  and  C  are 
generally  those  determined  between  0°  and  100°.  The 
relations  it  is  proposed  to  discuss  are — 


I.  TC 


We  have  found  that— 


TixT, 


C^' 


constant.    (Pidtet). 


2.  T  C  =  constant.  (Deerr,  Chemical  News,  vol.  Ixxi., 

P*  303)- 

L  C 

3.  Z_  a  constant.  (Deerr,  Chemical  News,  vol. Ixxi., 

S 

p.  303)- 

T  S 

4.  ■  ■      =  constant.     (Deerr,  Proc.  Chem.  Soc,  xvii., 

L 

6,  95)- 
In  the  relations  2,  3,  4,  the  constant  is  stated  to  hold 
only  between  such  elements  as  bear    a  close  relationship 
to  each  other,  and  hence  generally  for  members  of  any 
one  periodic  group. 


^Nov'.M^'s^'!*'}  Relations  connecting  the  Thermm  Constants  of  the  Elements, 


235 


AT 


LW 


=  constant.      (Crompton,  Trans.  C.  S,,  145, 

240)^ 
6.  ALCi  /V  =  constant.    (Richards,  Chem.  News, 

vol.  Ixxv.,  p.  278). 
7. =  J.      (Richards,    journal    of   the    Franklin 

Institute,  1893). 

Before  proceeding  to  discuss  these  relations,  the  writer 
would  draw  attention  to  the  widely  variant  values  given 
by  different  observers  to  much  of  the  data  in  question ; 
the  writer  has  been  at  great  pains  to  use  the  most  reliable 
determinations,  and  in  such  cases  where  he  has  not  been 
able  to  discriminate  between  different  values,  both  are 
given. 

Of  the  relations  given  above,  those  numbered  4,  5,  7 
are  identical,  with  differences  of  detail ;  and  the  main 
idea  of  i  and  2  is  the  same ;  the  relation  3  follows  from  a 
combination  of  2  with  4,  precisely  as  6  is  obtained  by 
Richards  by  combining  i  with  7,  and  putting  S  .A  S  =  6'4. 

In  discussing  the  dependency  of  the  latent  heat  of 
fusion  on  the  total  heat  at  the  melting-point,  Crompton, 
who  does  not  introduce  the  specific  heat,  but  uses  by  pre- 
ference the  atomic  weight,  attempts  to  reduce  the  values 
he  obtains  to  one  constant  by  the  introdu(5tion  of  the 
valency.  The  introdudtion  of  this  quantity  into  the  equa- 
tion is,  in  the  opinion  of  the  writer,  a  disadvantage  ;  for, 
besides  destroying  the  dimensions  of  the  equation  and 
making  the  law  almost  unintelligible,  the  values  so  ob- 
tained are  not  constant,  varying  quite  regularly  from  0*972 
for  lead  to  i'789  for  silver,  with  a  mean  value  of  1*370; 
and,  further,  in  the  case  of  bromine  and  iodine,  Crompton 
has  to  assume,  on  very  slender  grounds,  a  hypothetical 
triadic  valency,  whilst  in  the  case  of  phosphorus  and  sul- 
phur he  has  recourse  to  the  quantity  "  reciprocal  of  the 
valency."  Richards,  in  discussing  the  relation,  gives  it  a 
definite  physical  meaning,  stating  the  latent  heat  of 
fusion  to  bear  a  constant  ratio  (^)  to  the  total  heat  at  the 
melting-point,  but  he  does  not  appear  to  realise  the 
bearing  of  chemical  relationships  upon  the  value  of  the 
ratio.  Deerr  expressed  the  relation  in  terms  of  tempera- 
ture, naming  the  quantity  —   the  "  temperature  equiva- 

lent  of  the  latent  heat  of  fusion,"  and  he  restrided  the 
law  as  only  holding  between  elements  of  the  same 
valency. 

In  Table  I.  are  given  values  of  T,  T  S,  L,  and  of  the  ratio 
TS 


Element. 


Table  I. 

T.  TS. 


Sodium 365  108 '6 

Potassium      ..      ..  335  56*6 

Copper 1470  140' 

Silver      1220  69*5 

Silver      1220  69-5 

Thallium 560  174 

Zinc 695  660 

Zinc 695  660 

Cadmium       ..     ..  601  34*2 

Aluminium     ..     ..  1150  256* 

Mercury 233  7*2 

Palladium       ..      ..  1700  98*7 

Gold        1330  427 

Platinum        ..     ..  2300  713 

Gallium 286  21-9 

Bismuth 535  i4'4 

Lead       603  18-7 

Tin 503  28*2 

Bromine 266  27-5 

Iodine      386  20-8 

Snlphnr 38*  ^'^ 

Phosphorus    ..     ..  317  59 '9 


32-7 
157 
430 

2I'I 
247 

5-1 

281 

22*6 

13-6 

loo- 

2-8 

363 

i6'3 
27-1 

I9'2 

12-5 

5*4 

14-5 

i6-2 

117 
II& 

50 


T  S 
L 

3-27 
3*67 
3'25 
3-29  1 
2-8i  I 

3-41 

2*35  I 

2-92  / 

2-51 

2*56 

2*57 

272 

2-62 

2  "60 

1*14 

1*15 

3'47 
i'90 
176 
178 

5*19 
I2"0 


Referring  to  the  table,  it  is  seen  that  the  elements  Na, 
K,  Cu,  Ag,  Tl  give  a  constant  well  within  the  limits  of 
experimental  error.  Of  these,  the  first  four  all  belong  to 
the  same  periodic  family  ;  and  Tl,  although  a  member  of 
a  different  family  in  the  thallous  compounds,  is  very 
similar  to  the  alkaline  metals.  Following  these,  there  are 
seven  elements  giving  a  value  closely  approximating  to 
2*5.  Of  these,  Zn,  Cd,  Hg  are  members  of  one  family; 
Pt,  Pd,  Au  are  elements  closely  allied,  although  they  can- 
not be  stridlly  said  to  belong  to  one  family  ;  AI,  too,  gives 
a  value  the  same  as  for  these  elements,  but  the  data  of 
this  element  is  so  uncertain  as  to  render  discussion  futile. 
The  closeness  of  the  values  for  the  zinc  elements  and  the 
platinum  elements  is,  in  the  writer's  opinion,  accidental, 
and  does  not  point  to  an  absolute  identity.  Ga  and  Bi, 
although  not  in  the  same  family,  give  identical  values. 
These  elements  are,  however,  allied  ;  both  being  trivalent 
and  presenting  many  analogies.  The  values  given  by  Br 
and  I  require  no  comment.  Following  on  what  has  been 
written  above,  an  identity  in  the  values  for  Pb  and  Sn 
would  be  expedted ;  the  discrepancy  is  not,  however,  so 
startling  when  the  marked  non-metallic  nature  of  Sn  is 
remembered.  The  values  for  P  and  S,  compared  with 
others,  appear  abnormal.  The  specific  heat  of  these  ele- 
ments is  obtained  near  to  their  melting-point,  at  which  it 
is  at  its  greatest  value ;  as  this  quantity  varies  largely, 
the  cause  of  the  high  values  may  lie  therein. 

The  discussion  of  this  relation  can  be  best  concluded  by 
using  the  law  to  predidt  unknown  latent  heats  of  fusion. 
In  doing  so,  the  writer  was  at  times  in  doubt  in  deciding 
which  of  the  various  values  to  use ;  in  the  table  subjoined 
in  such  cases  the  writer  has  given  both  values.  In  the 
case  of  In  he  thinks  preference  should  be  given  to  the 
value  obtained  from  the  constant  for  Na,  &c. ;  the  analogy 
between  In  and  Tl  being  so  marked.  And  in  the  case  of 
arsenic  he  prefers  the  value  obtained  by  a  comparison 
with  phosphorus. 

Table  II. 


Element. 
Lithium     ., 
Magnesium, 
Indium 
Indium 

Antimony  .. 

Arsenic 

Arsenic 
Cobalt 
Iron     ..     ., 
Nickel 
Rhodium    . , 
Ruthenium 
Osmium 
Iridium       ., 
Selenium    ., 
Tellurium  ., 
Chlorine     ., 


T. 

450 

1020 

450 

450 

700 
685 


L(by 
T  S.  calculation). 

41-0     12*4       3*3 

275-     io6*         2*6 

23*2       7-0  3*3 

23-2     20-4  1-14 

37*1     32*  1*14 

57'2    50*  i'i4 


685 
1700 
1800 

57-2 

182- 
198* 

1900 

215- 

2000 

122* 

2300 

143- 

3000 
2800 

94- 
90* 

490 

653 

200 

41*2 

309 
36- 

4-8 
68* 

75' 
8i* 
46* 
53" 
35" 
33* 

8* 

6* 
20* 


12*0 
2*65 
265 
2  65 
2  65 
2-65 
2  65 
2  65 
5*2 
5*2 
I  77 


Constant  used. 
Mean  of  Na,  &c. 
Meanof  Zn,&c. 
Mean  of  Na,&c, 
Mean  of  Ga  and 

Bi. 
Mean  of  Ga  and 

Bi. 
Mean  of  Ga  and 

Bi. 
Value  for  P. 
Meanof  Pt, &c. 


Value  for  S. 

))        )• 
Meanof  Br  and 

I. 

The  discussion  of  the  relations  T  C.  Vv  =  constant 

and  of  T  C  =  constant  is  rendered  difficult  by  reason  of 
various  observers  obtaining  different  values  for  both  T 
and  C.  In  calculating  Table  III.  the  writer  has  not  given 
the  different  values  obtained,  but  has  used  those  values 
which  he  has  considered  most  reliable.  In  considerint^ 
the  relation,  then,  a  fairly  wide  margin  must  be  allowed 
for  experimental  error.  The  writer  is  so  placed  as  not  to 
have  access  to  Pidlet's  paper,  and  doubtless  some  of 
the  values  of  the  thermal  constants  used  by  him  differ 
slightly  from  those  used  by  the  writer.  In  Table  III.  the 
values  of  T  are  those  already  given  in  Table  I. 

On  reference  to  the  values  of  T  Ci  Vv  it  is  seen  that 


236 


Element.  C  x  10,000. 

Sodium        0*71 

Potassium 0*84 

Silver . .  0'20 

Copper o'i8 

Magnesium 0*27 

Zinc      0'28 

Cadmium 0*32 

Mercury       0'6i 

Aluminium 0*23 

Thallium      0*31 

Indium 0*42 

Lead 0*27 

Tin       0-28 

Phosphorus >  o'i2 

Arsenic        0*056 

Antimony o'li 

Bismuth       0-14 

Sulphur        0*64 

Selenium      0*37 

Tellurium 0*17 

Iron       o-ii 

Cobalt o'i3 

Nickel o'i2 

Rhodium      0*096 

Ruthenium 0*085 

Palladium 0*11 

Osmium       o'o66 

Iridium        0*070 

Platinum     0*088 

Gold     0145 

Bromine       3*5 

Iodine 2*35 


e  Thermal  Constants  of  the  Elements, 

(Ohbuical  News, 
I    Nov.  13, 1897. 

Table  III. 

TC. 

TC»/V. 

LC 
S 

ALCVV. 

0*026 

0*074 

0*0078 

0*151 

0*028 

0*099 

0*0079 

0-175 

0024 

0*052 

00074—0*0086 

0*099— o-i  16 

0*027 

0*052 

0*0081 

0094 

0*028 

0*077 

— 

— 

0*019 

0*040 

0*0067— o'ooS  I 

0*086 — 0*107 

0*019 

0*044 

0*0081 

0*113 

0*014 

0*034 

0*0054 

0*081 

0*027 

0*059 

0*0094 

0*136 

0*017 

0*044 

0*0050 

0*096 

0*019 

0*047 

— 

— 

0016 

0*042 

0*0047 

0077 

0*014 

0*035 

0*0071 

0*120 

0*0039 

0*009 

0*0003 

0*005 

0*0038 

0*009 

— 

— 

0*0077 

0*020 

— 

— 

0*0075 

0*021 

0*0061 

0'102 

0*025 

0*063 

0*0037 

o'o6o 

0-022 

0*055 

— 

— 

0*013 

0036 

— 

— 

0*020 

0*039 

— 

— 

0*022 

0*041 

— 

— 

0*023 

0*043 

— 

— 

0*019 

0*039 

— 

— 

o'oig 

0*040 

— 

— 

0*019 

0*039 

0*0069 

0*094 

0*020 

0*042 

— 

— 

0*020 

0*042 

— 

— 

0*020 

0*042 

0*0077 

0*099 

0*019 

0*041 

0*0074 

0*102 

0*093 

0*278 

0*053 

1-39 

o'ogo 

0*268 

0051 

i'i3 

twelve  elements  give  values  lying  between  0*04  and  0*05, 
that  ten  give  values  lying  between  0*03  and  0*06,  and  that 
an  absolute  disagreement  is  presented  by  the  remaining 

ten.  Now,  if  the  values  of  T  Ci/  V  are  constant  in 
preference  to  values  of  T  C,  the  introdudlion  of  the 
quantity i/V  should  at  least  tend  to  correal  the  values 
of  T  C ;  but  it  is  this  quantity  which  makes  the  value  of 
T  C » /  V  so  high  for  Na  and  K,  and  in  the  other  dis- 
cordant cases  its  introduftion  has  no  effedl.  Then,  again, 
however  much  the  atomic  volume  varies,  its  cube  root 
shows  but  little  variation,  and  the  introduAion  of  this 
quantity  has  but  seldom  a  deciding  effedl,  and  when  it 
does  happen  to  do  so  its  introduction  is  hostile  to  the 
equation ;  to  say  the  least,  the  readtion  cannot  hold  in 
the  case  of  Na,  K,  Mg,  P,  As,  Sb,  Bi,  S,  Br,  I,  and  for 
the  remaining  elements  the  agreement  demanded  by  the 
equation  is  by  no  means  perfeift. 

When,  however,  the  relation  is  put  in  the  form  T  C  = 
constant,  and  restrided  as  holding  only  between  related 
elements,  regularities  at  once  appear ;  between  Na,  K, 
Cu,  Ag ;  between  In  and  Cd ;  between  Br  and  I ;  between 
P  and  As  ;  between  Sb  and  Bi ;  and  between  the  elements 
in  the  short  periods  of  four  in  the  periodic  classification 
the  agreement  is  all  that  could  be  desired.  A  partial 
agreement  is  shown  by  Tl  and  In,  and  by  S  and  Se.  The 
relation  fails  to  hold  between  Pb  and  Sn,  and  also  fails  in 
the  case  of  Mg  and  Hg  when  compared  with  Zn  and  Cd, 
and  in  the  case  of  Te  compared  with  S  and  Se. 

A  point  which  is  worthy  of  notice  in  comparing  the 

relations  TC  =  constant  and  TCkVV-  constant  is 


al  m( 


that  the  former  has  a  definite  physical  meaning  which  is 
not  possessed  by  the  latter.  Expressed  in  words,  this 
relation  signifies  that  the  expansion  from  —273°  to  the 
melting-point  is  constant  for  related  elements,  and  so  is 
a  fun^ion  of  the  atomic  weight. 


There  remain  for  discussion  the  relations — 
LC 


=  constant     and     A  L  Q 


v/v. 


constant. 


The  dependency  of  latent  heat  of  fusion  upon  total  heat 
at  the  melting-point  in  conne(flion  with  chemical  relation- 
ships has  already  been  shown.  It  follows,  then,  that  this 
relation  must  also  hold.  In  this  relation  the  eiTedl  of 
chemical  relationships  is  not  so  well  shown  ;  most  of  the 
values  obtained  approximating  to  0*0075.     The  rejedion 

of  the  relation  T  C 1  /v  =  constant  implies  the  rejecftion 

of  A  L  C    /  V  =  constant ;    a  conclusion  borne  out  by 

reference  to  the  table. 

The  relation  TC  =  constant  is  not  without  a  theoretical 
basis,  and  was  obtained  by  the  writer  on  an  argument  like 
this  : — At  the  absolute  zero  the  sum  total  of  the  attra(5lion8 
exercised  on  and  by  the  particles  composing  a  body  is  at 
its  greatest  value.  When,  by  the  influence  of  a  rise  of 
temperature,  the  body  has  become  liquid,  no  appreciable 
error  is  introduced  if  the  attradion  is  put  equal  to  zero. 
Using  the  same  notation  as  before,  the  heat  supplied  is 
T  S  -j-  L.  Assuming  that  the  proportion  of  heat  supplied 
used  in  overcoming  internal  attraction  is  constant,  the 
equation  T  S  +  L  =  »i  a  results;  where  m  is  a  constant 
and  a  represents  the  total  internal  attraction  at  —273°. 

On  similar  grounds,  the  heat  necessary  to  cause  a  body 
to  expand  through  any  fraction  of  its  original  length  is  a 
measure  of  the  internal  attraction.      Taking  the  fraction 

as  unity  the  equation  ^  =  na  results.  From  these  is  ob- 
tained the  relation — 


(--I) 


C  =  !Z; 


but  since,  for  related  elements,  the  latent  heat  has  been 
shown  to  be  dependent  on  the  total  beat  at  the  melting- 


Chbmical  Nkws,  I 
Nov.  12, 1897,    I 


Early  American  Chemical  Societies. 


237 


point,  it  follows  that  T  C  »  constant  and  —    =  constant 

for  related  elements. 
The  paper  can  be  best  concluded  by  using  the  relation 

—  =  constant  to  predidt  unknown  latent  heats  of  fusion. 
o 

It  appears  that  those  obtained  from  this  equation  coincide 
remarkably  with  those  given  in  Table  II. 

Table  IV. 

L(by 
Element.  calculation).  Constant  used. 

Magnesium..     ..  70-  0-0077  Mean  of  Zn  and  Cd. 

Indium 67  0*0055  Value  for  Tl. 

Antimony      ..     ..  32-  o-oo6i  „       Bi. 

Arsenic 4-6  0-0003  „        P. 

Iron 75-  0-0075  Mean  of  Pt,  Pd,  Au. 

Cobalt    ..      ..      ..  63-  0-0075  ,,              ,, 

Nickel 66*  00075  „              „ 

Rhodium       ..     ..  48*  0-0075  „              „ 

Ruthenium    ..     ..  55*  0-0075  „             „ 

Osmium 35-  0-0075  „              „ 

Indium 33'  0-0075  „              „ 

Selenium      . .     . .  8*4  0-0037  Value  for  S. 

Windsor  Forest,  West  Coast,  Demerara. 


A    THEORY    OF    THE    AURORA    BOREALIS. 

By  GUSTAV  WENDT, 


We  have  here  abstraSs  from  and  comments  on  the  re- 
searches of  Halle,  Celsius,  Hiorten,  Canton,  and 
especially  Fritz  in  his  work  "  Das  Polarlicht "  (1881, 
Brockhaus). 

We  may  be  reminded,  as  a  not  unimportant  point  in 
establishmg  the  polar  light  theory,  that  oxygen  is  a  mag- 
netic— or,  more  stridly  speaking,  a  paramagnetic — 
element,  that  it  assumes  polarity  by  the  presence  of  the 
earth  as  a  magnet  permanently  present.  As  Humboldt 
remarks,  "  Every  atom  of  oxygen  represents  a  minute 
magnet,  and  in  the  solid  or  in  the  liquid  state  possesses 
strong  magnetic  properties."  Hence  near  the  magnetic 
pole  the  magnetic  attradion  occasions  the  descent  of  para- 
magnetic matter,  especially  oxygen  or  condensed  oxygen, 
and  also  dust  of  all  kinds,  occasionally  metallic  dust, 
especially  dust  of  meteoric  iron  and  of  nickeliferous 
nature.  If,  according  to  a  large  series  of  recent  accurate 
analyses,  the  airof  the  mountains  and  moors  of  the  Scottish 
highlands  generally  contain  21  per  cent  of  oxygen,  whilst 
in  the  large  towns,  especially  in  fogs,  it  sinks  to  208,  and 
in  deep  mines  to  20-2  per  cent,  this  fad  may  be  explained 
by  the  circumstance  that,  besides  the  general  diffusion, 
the  magnetic  attradtion  is  here  brought  into  play.  Every 
large  mountain  mass  possesses,  in  a  larger  or  smaller 
degree,  the  so-called  mountain  magnetism.  The  agree- 
able sensation  in  lofty  yet  protedled  regions  is  chiefly  due 
to  the  presence  of  condensed  oxygen,  which  is  continually 
drawn  downwards  in  consequence  of  the  "  mountain 
magnetism."  That  the  strength  of  northern  lights  is 
diredtly  connecfted  with  the  adivity  of  the  sun  must  be 
considered  as  demonstrated,  and  is  easily  explained  by  the 
fadt  that  the  strength  of  terrestrial  magnetism  increases 
and  decreases  in  proportion  to  the  adlivity  of  the  sun. 

If  Fritz  demands  categorically  that  a  theory  of  the 
northern  lights  should  explain  why  the  phenomenon  is 
only  manifested  by  night,  he  forgets  the  observations  of 
Humboldt  ("  Kosmos,"  iv.,  1858,  p.  145),  that  the  pheno- 
menon  has  been  observed  near  the  sun  on  December  3rd, 
1827.  Humboldt  adds,  in  a  note,  that  the  arches  of  the 
northern  lights  were  seen  near  the  sun  in  North  America, 
in  Parma,  and  at  London. 

Another  feature  of  the  northern  lights,  i.  e.,  the  origin 
of  the  so-called  spearal  polar  light  ray  (X  =  5567)  has 


been  explained  byWiillmer  {Poggend.  AnnaUn,  N.F.  388, 
p.  619). 

Hence  the  northern  lights  may  be  regarded  as  an  elec- 
tical  phenomenon  arising  when  oxygen  and  other  para- 
magnetic matter  is  continuously  drawn  down  from  the 
higher  regions  of  the  atmosphere,  thus  setting  up  eledlric 
caneats.—-Naturu;issenschaftliche  Wochenschrift, 


EARLY   AMERICAN    CHEMICAL    SOCIETIES.' 

By  Prof.  H.  CARRINGTON  BOLTON. 

(Concluded  from  p.  227). 

Columbian  Chemical  Society  of  Philadelphia  {continued). 
Dr.  Adam  Seybert  (d.  1825)  was  one  of  the  earliest 
American  chemists  to  make  a  series  of  analyses  of  the  air 
by  eudiometric  methods.  Having  made  twenty-seven  air 
analyses  during  a  voyage  across  the  Atlantic,  he  compared 
the  results  with  others  made  on  land,  and  drew  the  con- 
clusion that  the  sea  exerted  purifying  power  over  the  air ; 
his  paper  before  the  American  Philosophical  Society  bore 
the  date  1797. 

Benjamin  Silliman  is  a  name  so  familiar  to  American 
chemists  as  to  require  no  eulogium  in  this  place.  At  the 
founding  of  the  Chemical  Society  he  was  forty  years  of 
age,  and  had  held  the  chair  of  chemistry  in  Yale  College 
for  ten  years.  It  should  be  remembered  that  he  did  not 
begin  publishing  the  American  Journal  of  Science  until 
1818. 

Dr.  John  S.  Stringham,  professor  of  chemistry  in  New 
York  (institution  not  specified) ;  Dr.  Jared  Troust  (whose 
name  should  be  written  Gerard  Troost),  lecSurer  on 
minerology  in  the  Academy  of  Natural  Sciences,  Phila- 
delphia, and  afterwards  professor  of  chemistry,  mineralogy, 
and  geology  in  Nashville  University  (1828  50) ;  Lawrence 
Washington,  Esq.,  of  Virginia;  and  Dr.  Caspar  Wistar, 
professor  of  anatomy  in  the  University  of  Pennsylvania, 
with  his  relative  Charles  Wistar,  complete  the  roll  of 
home  members. 

The  prominence  of  medical  men  on  this  list  is  evident, 
and  is  easily  explained.  Before  the  days  of  schools  of 
science,  and  before  colleges  devoted  a  portion  of  their 
curricula  to  scientific  studies,  almost  the  only  training  in 
science  received  by  American  youth  was  in  the  medical 
schools.  The  chairs  of  natural  history  and  of  the  physical 
sciences  were  almost  exclusively  held  by  physicians  whose 
education  more  nearly  qualified  them  for  teaching  these 
branches  of  knowledge  than  the  graduates  of  the  classical 
courses  customary  in  all  colleges. 

To  elevate  the  standard  of  membership  in  the  Colum- 
bian Chemical  Society,  a  number  of  distinguished  foreigners 
were  enrolled.  France  contributed  Adet,  BerthoUet, 
Chaptal,  Deyeux,  Abbe  Hauy,  BouiHon-Lagrange,  Gay- 
Lussac,  Monge,  Guyton  de  Morveau,  Parmentier,  Pelletier, 
Sequin,  Thenard,  and  Vauquelin.  Great  Britain  was  re- 
presented by  Sir  Joseph  Banks,  John  Dalton,  Sir  Humphry 
Davy,  John  Davy,  J.  A.  de  Luc,  Hatchett,  Dr.  William 
Henry,  Sir  William  Herschel,  Dr.  John  Hope,  John 
Murray,  William  Nicholson,  Dr.  G.  Pearson,  Mr.  W.  H. 
Pepys,  Dr.  Thomas  Thomson,  Alexander  Tilloch,  and  Dr. 
William  Hyde  Wollaston.  Spain  was  represented  by 
Professor  Troust  of  Madrid,  and  the  other  countries  of 
Europe  had  not  a  single  representative.  The  absence  of 
such  eminent  names  as  Richter,  Klaproth,  Stromeyer 
Trommsdorff,  and  Gehlen,  of  Germany,  as  well  as  of 
Berzelius,  the  Swede,  presumably  indicates  that  at  this 
early  date  communications  and  exchange  of  courtesies 
with  Germany  and  Northern  Europe  was  less  common 
than  with  England  and  France. 

The  Columbian  Chemical  Society  of  Philadelphia  pub- 
lished  in  1813  one  volume  of  "  Memoirs."  -f     This  forms 

*  Read  before  the  Washington  Chemical  Society,  April  8. 1807. 
From  the  Journal  of  the  American  Chemical  Society,  August,  1897 

+  Copies  of  the  "  Memoirs  "  are  found  in  Philadelphia  libraries, 
and  in  the  private  library  of  the  writer. 


238 


Early  A  merican  Chemical  Societies. 


Crbmical  Nbw6 
Nov.  12,  i8(j7 


a  book  of  221  pages,  oAavo,  and  bears  the  imprint  of 
Isaac  Peirce,  No.  3,  South  Fourth  Street,  Philadelphia. 
It  contains  twenty-six  essays,  by  ten  writers,  on  a  great 
variety  of  topics,  original,  speculative,  and  practical. 

No  less  than  eight  of  the  papers  are  from  the  pen  of 
Dr.  Thomas  D.  Mitchell,  and  these  I  proceed  to  review. 
Dr.  Mitchell's  "  Remarks  on  the  Phlogistic  and  Anti- 
phlogistic Systems  of  Chemistry  "  opens  the  volume.  In 
this  essay  he  supports  the  Lavoisierian  theory  of  combus- 
tion, stating  that  there  is  "no  necessity  for  the  principle 
of  inflammability  ;"  he  cites  the  experiment  of  Wood- 
house,  who  obtained  an  inflammable  air  by  heating  char- 
coal with  scales  of  iron,  both  being  free  from  water,  and 
points  out  that  Cruikshank,  of  Woolwich,  demonstrated 
that  the  inflammable  gas  thus  obtained  is  gaseous  oxide 
of  carbon  (carbon  monoxide),  discovered  by  Priestley  in 
1799,  and  combustible  although  containing  no  hydrogen. 
He  compares  combustion  with  neutralisation  of  an  acid 
and  base,  saying  "  Inflammation  and  acidity  are  effedts 
resulting  from  the  adtion  of  relative  causes,  and  not 
attributable  to  a  single  agent  or  principle." 

Dr.  Mitchell's  second  paper,  "  Remarks  on  Heat,"  deals 
with  speculations  on  latent  heat,  objecting  to  this  term 
and  to  Dr.  Black's  theories. 

In  a  paper  entitled  "  On  Muriatic  and  Oxy-muriatic 
Acids,"  Dr.  Mitchell  vehemently  attacks  the  views  of  Sir 
Humphry  Davy  as  to  the  non-existence  of  oxygen  in 
muriatic  acid,  clinging  to  the  statement  of  Lavoisier, 
that  all  acids  contain  oxygen.  In  a  sedtion  on  combustion 
he  remarks  '*  we  have  incontestible  proof  that  oxygen  gas 
contains  light,"  and  he  regards  combustion  as  accom- 
panied by  the  decomposition  of  oxygen  gas. 

Dr.  Mitchell's  fourth  paper  is  of  a  more  pradtical 
charadler,  being  the  *'  Analysis  of  Malachite "  from 
Perkioming,  Pennsylvania.  The  result  is  given  as  fol- 
lows : — "  120  grains  of  the  green  carbonate  contained 
carbonic  acid,  30  grains ;  quartz  and  siliceous  earth, 
68  grains;  brown  oxide  of  copper,  15  grains;  loss  in  the 
process,  7  grains." 

The  specimen  was  evidently  a  poor  one;  no  account 
was  taken  of  the  water,  and  reporting  results  in  per- 
centages was  not  in  vogue. 

In  some  "  Remarks  on  Putrefadtion  "  the  same  writer 
discusses  the  adtion  of  antiseptics,  and  attributes  the 
virtue  of  nitrate  of  potash  to  the  increase  of  cold  pro- 
duced by  the  muriate  of  soda. 

Dr.  Mitchell's  '•  Chemical  View  of  Secretion,"  and  his 
"  Analysis  of  Professor  Coxe's  Essay  on  Combustion  and 
Acidification,"  are  polemical  and  speculative ;  in  his 
"  Remarks  on  the  Atmosphere "  he  argues  to  prove  the 
atmosphere  a  chemical  union  of  oxygen  and  nitrogen. 

Franklin  Bache  contributes  three  essays  to  the  volume. 
••  An  Inquiry  into  What  Circumstances  Will  Warrant  us 
Justly  to  Reckon  any  Substance  a  Principle  of  a  Common 
Property  of  Any  Set  of  Bodies,"  discusses  the  much  dis- 
puted question  of  that  day,  whether  hydrogen  as  well  as 
oxygen  can  be  an  acid-forming  principle.  His  conclu- 
sion being,  "  it  may."  Bache's  second  paper  is  entitled, 
"  An  Inquiry  Whether  Mr.  BerthoUet  was  Warranted 
from  Certain  Experiments  in  Framing  the  Law  of 
Chemical  Affinity,  that  it  is  diredtly  Proportional  to  the 
Quantity  of  Matter."  In  this  essay  the  author  points  out 
"  the  probable  way  in  which  this  great  philosopher  fell 
into  this  great  error."  In  a  third  paper  styled  "  Thoughts 
on  the  expediency  of  Changing  Parts  of  the  Chemical 
Nomenclature,"  Mr.  Bache  proposes  the  following  names  : 
Nitral  acid  forming  nitrotes,  nitril  acid  forming  nitrutes, 
nitrous  forming  nitrites,  and  nitric  acid  forming  nitrates, 
for  the  several  acid-forming  oxides  of  nitrogen.  Fortu- 
nately his  influence  was  insufficient  to  infliA  these  names 
on  chemical  language. 

Dr.  John  Manners  contributed  four  papers  to  the 
Memoirs,  (i)  "  Experiments  and  Observations  on  the 
Effect  of  Light  on  Vegetables  and  upon  the  Physiology  of 
Leaves,"  which  abounds  in  quotations  from  Darwin's 
"  Botanic  Garden."    (2)  "  Analysis  of  a  Mineral  Spring 


at  the  Willow  Grove,"  (fourteen  miles  from  Philadelphia). 
In  this  the  author  was  assisted  by  Dr.  Mitchell.  They 
report  the  adtion  of  each  testing  solution  on  the  water, 
and  conclude  that  the  water  contains  iron  and  sulphur- 
etted hydrogen,  and  show  the  absence  of  lime,  copper,  and 
carbonic  acid."  (3)  "On  the  Produdlion  of  Sulphuretted 
Hydrogen  by  the  adtion  of  Black  Sulphuric  Acid  Diluted 
with  Water  on  Iron  Nails."  The  acid  had  been  blackened 
by  a  piece  of  cork  which  had  fallen  in.  (4)  "  Experiments 
and  Observations  on  Putrefadlion."  In  this  paper  Dr. 
Manners  tested  the  influence  of  carbonic  acid,  hydrogen, 
and  other  gases  on  putrefying  flesh,  and  also  attempted  to 
coiledt  and  analyse  the  gases  generated  by  the  same.  He 
concludes  that  "  putrefadi  on  depends  on  a  destrudlion  of 
the  equilibrium  of  attradlions  which  exist  in  the  elementary 
principles  of  which  the  animal  substance  is  composed  in  a 
healthy  state,  occasioned  by  the  loss  of  vitality  in  conse- 
quence of  which  new  compositions  and  decompositions 
ensue." 

Professor  Cutbush,  President  of  the  Society,  wrote  *•  On 
the  Prognostic  Signs  of  the  Weather,"  and  "  On  the 
Oxyacetite  of  Iron  as  a  test  for  the  Discovery  of  Arsenic  ;" 
the  latter  being  a  good  presentation  of  his  discovery, 
subsequently  used  as  a  quantitative  method  by  Kot- 
schoubcy. 

Mr.  Samuel  F.  Carl,  one  of  the  junior  members,  has  two 
papers  containing  analyses,  the  first  of  the  mineral  spring 
at  Bordentown,  New  Jersey,  which  proved  to  be  a  "  car- 
bonated chalybeate  water,"  and  the  second  of  two  speci- 
mens referred  to  him  by  the  society  ;  these  proved  to  be 
respedtively  an  iron  ore  and  a  ferruginous  copper  ore.  The 
method  of  reporting  results  seems  very  crude  to  a  modern 
analytical  chemist. 

Dr.  Joel  B.  Sutherland  contributes  "  Speculations  on 
Lime,"  in  which  he  claims  that  if  mortar  be  made  with 
sand  containing  common  salt,  the  resultant  compound 
gives  so  much  coldness  to  the  mass  that  during  the  whole 
summer  vapour  is  almost  incessantly  precipitated  on  the 
wall  with  which  it  is  plastered.  He  also  wrote  "  A  Few 
Remarks  on  the  Nature  of  the  Nervous  Influence."  Akin 
to  the  latter  are  the  "Thoughts  on  the  Principle  of  Excita- 
bility," by  George  Ferdidand  Lehman,  who  also  wrote 
"  On  the  Emission  of  Oxygen  by  Plants." 

Mr.  William  Hembel,  Jr.,  has  two  papers,  one  entitled 
"  Observations  on  the  Formation  of  Muriate  of  Potash  in 
the  Process  of  Preparing  the  Hyperoxymuriateof  Potash," 
which  is  complicated  by  the  belief  that  hydrochloric  acid 
is  an  oxygen  compound  ;  and  another  entitled  "  A  New 
Method  of  Mounting  Woulfe's  Apparatus,"  which  is  un- 
intelligible owing  to  the  omission  of  a  woodcut  to  which 
the  text  refers. 

Mr.  Edward  Brux,of  France,  one  of  the  junior  members, 
writes  "  Upon  the  Effedts  of  Various  Gases  upon  the  Liv- 
ing Animal  Body,"  which  consists  largely  of  speculations  : 
notwithstanding  which  he  cites  an  admirable  passage  from 
Dr.  Bostock;  "  Physiologists  have,  in  general,  been  more 
inclined  to  form  hypotheses  than  to  execute  experiments, 
and  it  has  necessarily  ensued  from  this  unfortunate  pro- 
pensity that  their  science  has  advanced  more  slowly  than 
perhaps  any  other  department  of  natural  philosophy." 
Unfortunately  this  truth  was  not  fully  recognised  by  the 
members  of  the  Columbian  Chemical  Society. 

A  contemporary  journal  (N.  Y.  Medical  Repository),  in 
reviewing  the  "Memoirs,"  uses  the  following  quaint 
language :  "  It  is  highly  gratifying  to  behold  a  band  of 
worthies  like  those  before  us,  laboring  to  analyse  the  com- 
pounds which  they  find  ready  made,  to  form  by  synthesis 
new  combinations  in  the  laboratory,  and  thereby  to  de- 
duce corredt  dodtrines  from  the  fadts  which  are  disclosed. 
We  cordially  congratulate  them  on  their  noble  occupation 
and  on  the  progress  they  have  made.  We  hope  they  will 
be  persevering  and  undaunted.  And  if  from  this  begin- 
ning there  shall  arise  great  improvements  in  theoretical 
disquisition,  as  well  as  in  economical  exercise,  we  shall 
rejoice  with  a  mingled  glow  of  amicable  and  patriotic 
sentiment." 


Chemical  News,) 
Nov.  12, 1897.     t 


Separating  and  Distilling  Bromine, 


239 


III.  The  Delaware  Chemical  and  Geological  Society. 

The  Delaware  Chemical  and  Geological  Society  was 
organized  at  Delhi,  Delaware  County,  New  York,  Sep- 
tember 6,  1821 ;  the  first  meeting  was  held  at  the  hotel  of 
G.  H.  Edgerton  in  the  village,  and  the  following  officers 
were  chosen : 

President — Charles  A.  Foote. 
Vice-President— Rev.  James  P.  F.  Clark. 
Recording  Secretary — Charles  Hathaway. 
Corresponding  Secretary — Dr.  Calvin  Howard. 
Treasurer — Selah  R.  Hobbie. 

Directors— Cornelius  R.  Fitch,  R.  W.   Stockton,  Eben- 
ezer  Steele. 

The  society  was  composed  of  "  between  forty  and 
fifty  well-informed  and  respectable  inhabitants  "  of  the 
County  of  Delaware.  The  following  gentlemen  were 
eleded  corresponding  members  :  Colonel  Henry  Leaven- 
worth, U.S.A. ;  Edwin  Crosswell,  of  Catskill,  and  O. 
Rice,  of  Troy. 

The  society  had  for  its  objed  the  improvement  of  the 
members  in  literature  and  science,  especially  in  chemistry 
and  mineralogy.  The  members  planned  to  form  a  library 
and  to  secure  a  chemical  laboratory ;  they  made  a  col- 
le(5tion  of  the  minerals  and  rocks  of  the  region,  which 
was  still  preserved  in  the  Delaware  Academy  in  1856. 
The  meetings  of  the  society  were  held  quarterly,  and  at 
each  an  essay  or  an  "original  scientific  discourse"  was 
presented  ;  it  was,  however,  not  long  sustained. 

In  reviewing  the  condition  of  chemical  science  in  the 
United  States,  as  indicated  by  the  membership  and 
achievements  of  these  early  societies,  we  note  that  those 
who  held  the  most  prominent  places  were  handicapped 
by  the  necessity  of  devoting  a  large  part  of  their  intel- 
le(5tual  energy  to  topics  quite  outside  of  the  domain  of 
chemistry  itself.  The  aftive  members  were  either  busy 
with  the  art  of  healing,  or  with  teaching  several  branches 
of  the  physical  and  natural  sciences,  and  too  often 
chemistry  was  regarded  in  the  colleges  as  a  kind  of  side 
issue,  or  appendix  to  the  more  important  subjeds  of  in- 
strudtion.  This  was  caused  by  the  necessity  of  earning 
a  competence  at  a  time  when  there  was  no  opportunity 
of  reaping  pecuniary  rewards  by  skill  as  an  analyst,  or  by 
the  application  of  science  to  the  manufacture  of  produds 
involving  chemical  knowledge.  Indeed,  in  default  of  this 
stimulus  to  laboratory  work,  it  is  not  surprising  that  the 
papers  read  to  the  societies  were  largely  either  reviews  of 
the  grand  discoveries  made  by  Europeans,  or  essays  in 
which  the  imaginative  faculty  was  given  free  play,  it 
being  far  easier  to  indulge  in  speculation  than  to  discover 
new  fa(fts. 

In  the  early  struggles  of  a  country  to  secure  a  place 
among  nations,  few  men  of  ability  can  devote  their 
energies  to  the  pursuit  of  science  for  science's  sake  ;  the 
environment  is  more  favourable  to  development  of  the 
inventive  faculty  than  of  the  peculiar  talent  for  condu(5t- 
ing  abstruse  researches  in  an  exaCt  science.  Add  to  this 
the  limited  facilities  for  acquiring  chemical  knowledge  in 
the  New  World,  and  the  distance  of  amateurs  from  the 
European  head-centres  of  learning,  and  it  is  certainly 
noteworthy  that  American  chemists  combined  to  form 
associations  for  mutual  improvement  and  the  advance- 
ment of  their  calling  at  so  early  a  period. 

A  fourth  attempt  to  establish  a  chemical  society  was 
made  at  New  York  City  in  1876 ;  the  organisation  was  at 
first  somewhat  restricted  in  its  plan,  but  in  1892  a  change 
in  its  constitution  was  elTedted,  which  broadened  its  scope, 
and  it  now  forms  a  strong,  influential,  and  truly  national 
society.  Its  1106  members,  working  in  nine  chartered 
sections,  represent  forty-seven  states  and  territories,  be- 
sides several  countries  of  Europe,  South  Americe,  spd 
distant  Australia.  Its  Journal,  comprising  1150  p^s 
annually,  is  an  authoritative  medium  for  the  preserv^on 
and  diffusion  of  the  researches  made  in  the  United  States, 
and  its  annual  meetings,  held  in  diverse  localities,  streng- 
then the  bonds  which  unite  its  members  in  good  fellow- 


ship, and  in  the  pursuit  of  their  common  profession.  Long 
may  the  American  Chemical  Society  continue  in  its  prosper- 
ous career  I 


PROCESS   FOR   SEPARATING  AND   DISTILLING 

BROMINE  FROM  A  MIXTURE  OF 

ALKALINE    CHLORIDE    AND     BROMIDE. 

By  H.  BAUBIGNY  and    P.  RIVALS. 

The  decomposition  of  bromides  by  the  aCtion  of  a  solu- 
tion of  copper  sulphate  and  potassium  permanganate  does 
not  permit  us  to  collect  the  bromine  or  to  determine 
it  directly  by  diffusing  when  operating  in  a  vacuum.  It 
partly  attacks  the  grease  which  serves  as  a  lutmg.  We 
can  therefore  know  the  weight,  having  previously  deter- 
mined that  of  the  chlorine  and  the  sum  of  the  weights  of 
the  two  elements.  But  every  process  of  indirect  deter- 
mination is  imperfect,  especially  when  the  body  in 
question  is  the  smaller  in  quantity. 

We  have  therefore  sought  to  remove  mechanically  the 
bromine  from  the  liquid,  either  by  ebullition  or  by  a 
current  of  air. 

The  method  of  ebullition  in  which  the  watery  vapour 
formed  has  the  objeCt  of  expelling  the  free  bromine  has 
also  revealed  the  inconveniences  involved.  The  first  is 
the  formation  of  enormous  volumes  of  condensed  water. 
Secondly,  theebullition  causes  rapidvariationsof  the  liquid 
volumes.  Now  the  alkaline  chlorides,  stable  at  100°,  if  the 
solution  is  not  too  strongly  charged  with  salts  of  copper, 
are  decomposed  if  the  concentration  exceeds  certain 
limits.  The  use  of  a  current  of  air,  on  the  contrary,  has 
permitted  the  easy  solution  of  the  question,  and  can  be 
used  at  any  temperature.  —  Comptes  Rendus,  No.  15, 
October  11,  1897. 


NOTICES  OF  BOOKS. 


Annali  del  Lahoratorio  Chimico  Centrale  delle  Gabelle, 
pubblicati  da  Vittorio  Villavecchia.  Vol.  III.  Roma, 
1897.  242  pp.  8vo. 
The  first  volume  of  the  Annals  of  the  Central  Chemical 
Laboratory  of  the  Customs  was  issued  in  i8gi,  and 
covered  the  period  from  1886-89 ;  the  second  volume  bore 
the  date  1893 !  ^^^  present  volume  chronicles  the  work 
done  in  the  years  1890-96.  More  than  four  thousand 
eight  hundred  analyses  were  made  in  the  year  i8g6,  the 
total  number  for  the  period  1890-96  being  24,913.  The 
substances  examined  included  wines,  vermouth,  beer, 
spirits  ;  fixed,  mineral,  and  volatile  oils ;  mineral  waters ; 
coffee,  chocolate,  spices,  confectioners'  preserves,  candy, 
&c. ;  condensed  milk;  effervescent  magnesium  citrate, 
salts  of  Stasfurt ;  vegetable  and  mineral  colouring  sub- 
stances, varnishes,  inks,  minerals,  cements,  cereals ;  fats, 
soaps,  waxes ;  and  a  variety  of  chemical  and  pharma* 
ceutical  products. 

The  volume  contains  records  of  the  following  re- 
searches : — 

I.  *'0n  the  Substance  found  in  Sesame  Oil,  and  on 
the  Relation  which  it  bears  to  the  characteristic  Colour 
Readion  of  this  Oil."     By  V.  Villavecchia  and  G.  Fabris. 

II.  "  On  the  Composition  of  Italian  Flour."  By  G. 
Fabris  and  O.  Severini. 

III.  "  On  the  Paper  Mulberry."    By  M.  Tortelli. 

IV.  "  Soap  Analysis."     By  R.  Moreschini. 

V.  "  On  Illuminating  Oil  and  its  Consummation  in 
Italy."     By  A.  Volpi  and  R.  Ruggieri. 

VI.  "  On  Dulcina,  or  Paraphenetol  Carbamide,  and  a 
Method  of  Recognising  it."    By  R.  Ruggieri. 

VII.  "Analysis  of  Candies."  By  A.  Bianchi  and  0. 
Severini. 


240^ 

VIII.  "  On  the  Chemical  Composition  of  some  Greek 
Wines."    By  R.  Moreschini. 

IX.  "Researches    on    Dlgras    (Fish    Oil)."      By    M. 
Tortelli. 

X.  ••  On  the  Estimation  of  Glycerin  in  Sweet  Wines." 
By  G.  Fabris. 

The  volume  is  well  printed,  but  the  absence  of  running- 
headlines  makes  it  difficult  to  find  the  several  essays. 

The  monograph  on  the  paper-mulberry  is  accompanied 
by  a  plate. 

H.  C.  B. 


CORRESPONDENCE. 


ARGON   AND   HELIUM. 

To  the  Editor  of  the  Chemical  News. 
Sir,— I  would  like  to  call  the  attention  of  chemists  who 
are  working  at  the  gases  argon  and  helium  to  the  ia&  that 
there  is  near  Mallow,  Co.  Cork,  a  mineral  spring  which 
evolves  large  quantities  of  nitrogen.  According  to  an 
analysis  by  Prof.  Daubeny  the  constitution  of  the  evolved 

gas  is— 

Nitrogen      935  parts 

Oxygen 65     ,. 

lOO'O 

Near  Hillsbrook,  in  the  parish  of  Killererin  {Barony  of 
Clare),  is  another  spring,  of  which  the  following  analysis 
of  tha  evolved  gas  was  made: — 

Analysis  of  a  Wine  Pint  of  Water  in  May,  1842. 
Nitrogen. „..     ..     0-59  cub.  ins. 
Carbon  dioxide      ..     I'o  ,, 

Most  probably  the  above-mentioned  gases  contain  argon 

or  even  helium.— I  am,  &c.,  ^    „    ^ 

C.  P.  Finn. 
The  Yorkshire  College,  Leeds, 
November  1, 1897. 


Chemical  Notices  from  Foreign  Sources. 


r  Crsmical  News, 

•      Nov  12.  1I07. 


Nov.  12,  1I97. 


THORIUM  ACETYL-ACETONATE. 

To  the  Editor  of  the  Chemical  News. 

Su^ If  my  request  is  not  unreasonable  I  should  feel  ex- 

treinely  favoured  if  anyone  could  inform  me  whether  the 
aceiylacetone  referred  to  in  the  article  on  "  Thorium," 
which  appeared  in  No.  1971  of  the  Chemical  News  (vol. 
Ixxvi.,  p.  no),  is  the  ordinary  acetone  or  no. 

If  it  is  not  acetone  I  am  at  a  loss  to  understand  to  what 
the  author  refers,  and  am  unable  to  find  any  information 
on  the  subjeft  either  in  "  Dift.  Chem."  Thorpe  and  Muir, 
or  Gmelin  or  Watts.  .  ,      *         t 

Presuming  acetone  to  be  meant  by  acetylacetone  I 
have  carefully  followed  the  process,  but  failed  to  prepare 
the  acetylacetonate  of  thorium  mentioned  therein. 

Taking  an  exceptionally  pure  thoria  salt,  which  was 
prepared  for  a  special  purpose  by  repeated  precipitations, 
as  ''hypo,"  "oxalate,"  and  ultimately  re-crystallising  the 
double  ammonium  salt  several  times,  I  converted  it  mto 
the  chloride,  precipitated  with  ammonia,  washed,  and 
removed  excess  of  water  by  pressure.  ^  .  ^.,  ^  ,  ,  , 
This  purified  hydrate  was  suspended  m  dilute  alcohol 
(I  ab.  to  5  aq.),  mixed  with  acetone,  and  evaporated  to 
dryness  on  water-bath.  The  process  failed,  however,  to 
yield  any  substance  soluble  in  chloroform,  nor  were 
repeated  trials  more  successful.  ^      .... 

As  the  commencement  of  paragraph  2  is  slightly  am- 
biguous I  tried  a  further  experiment  by  afting  on  the 
Th(H0)4  with  peroxide  of  hydrogen  before  the  acetone 
treatment,  after  which  I  carefully  followed  the  process  as 
given  by  M.  Urbain.     Obtaining  no  better  results  I  am 


forced  to  conclude  that  acetylacetone  is  some  unusual 
substance  beyond  the  knowledge  of  an  ordinary  inorganic 
chemist,  and  have  therefore  ventured  to  trouble  you  in 
this  matter. — I  am,  &c., 

Allamite. 


CHEMICAL     NOTICES    FROM    FOREIGN 
SOURCES. 

Note.— All  degrees  of  temperature  are  Centigrade  unless  otherwise 
expressed, 

Comptes  Rendus  Hebdomadaires  des  Seances,  deVAcademit 
des  Sciences.    Vol.  cxxv.,  No.  16,  Odtober  18,  1897. 

Impurities  of  Crude  Copper. — M.  Schlagdenhauffen. 
— The  treatment  by  nitric  acid  of  the  sublimate  in  one  of 
the  author's  tubes  yields  on  analysis  all  the  chara(5ters  of 
selenious  acid. 

Eledtrolytic  Condu(5livity  of  Trichloracetic  Acid. — 
Paul  Rivals. — Not  adapted  for  useful  abstraction. 

The  Mean  Molecular  Weight  of  the  Soluble  Matter 
in  Seeds  during  Germination. — M.  Maquenne. 

No.  17,  Odtober  26, 
Novel  Procedure  for  obtaining  Instantaneous 
Radiographs. — G.  Segny. — Following  the  indications  of 
Dr.  Max  Levy  the  author  takes  a  very  thin  plate  of  glass, 
which  he  coats  on  both  sides  with  silver  gelatino- bromide 
and  then  allows  it  to  dry  in  this  emulsion.  He  prepares 
meantime  two  flexible  screens  of  cloth  with  violet  calcium 
suspended  in  celluloid.  When  the  screens  are  dry  they 
are  applied  to  each  side  of  the  double  emulsion  plate,  the 
whole  being  then  placed  in  a  frame  exerting  a  pressure  on 
the  surfaces  by  means  of  two  plates  of  cardboard,  and 
proceed  as  usual. 

A  New  Bianodic  Vessel  for  Red  Phosphorescence. 
G.  Segny  and  E.  Gundelag. — The  authors  have  prepared 
the  glass  for  these  vessels  by  incorporating  with  coloured 
glass  transparent  and  not  fluorescent  powdered  albumen 
and  calcium  carbonate  ,  or  preferably  didymium  chloride. 
The  glass  thus  prepared  has  the  following  properties : — 
I.  Its  fluorescence  is  in  red  and  not  green.  2.  It  emits 
twice  as  many  X  rays  as  the  ordinary  glass.  3.  The 
fluorescence  which  it  excites  upon  the  screen  is  more 
brilliant  and  of  yellowish  green  colour. 

Researches  on  Saline  Solutions.  Lithium  Chloride. 
— Georges  Lemoine. 

On  Basic  Magnesium  Salts.  —  M.  Tassilly. — The 
researches  of  various  savants  on  magnesium  oxychlorides 
and  the  author's  own  on  the  oxybromide  tend  to  establish 
an  approximation  between  this  metal  and  zinc  as  regards 
the  basic  salts. 

Separation  and  Dire(5t  Determination  of  the  Chlor- 
ine and  Bromine  contained  in  a  Mixture  of  Alkaline 
Salts.— H.  Baubigny  and  P.  Rivals. 

Some  Compounda  of  Metallic  Acetates  with 
Phenylhydrazine.  —  J.  Moitessier.  —  Phenylhydrazine 
forms  with  metallic  acetate  of  the  magnesian  series  com- 
pounds analagous  to  the  phenylhydrazinic  chlorides, 
bromides,  iodides,  and  nitrates.  The  author  has  prepared 
the  zinc,  cadmium,  manganese,  cobalt,  and  nickel  phenyl- 
hydrazines  by  heating  in  the  water-bath  a  mixture  of 
phenylhydrazine  in  an  alcoholic  solution  and  of  a  pulver- 
ised metallic  acetate. 

Methods  of  Determining  Diabetic  Sugar.— F.  Lan- 
dolph.— I.  The  polaristrobometer  alone  indicates  the 
real  quantity  of  adtive  diabetic  sugar.  2.  The  coefficient 
of  redudtion  gives  double  and  even  threefold  the  polari- 
strobometric  sugar.     3.  Fermentation  shows  averyvari- 


Nov.  12,  1897.      I 


Chemical  Notices  from  Foreign  Sources, 


24t 


able  quantity  of  sugar  according  to  the   duration  of  the 
fermentation. 

Optical  and  Reductive  Power  of  the  Flesh  of  Flies. 
— F.  Landolph. — The  author  finds  that  a  filtered  solution 
.  of  the  flesh  of  flies  obtained  by  trituration  with  cold  water 
is  opalescent  and  strongly  levo-rotatory.  Its  redudtive 
power  is  certainly  greater  than  that  of  diabetic  sugar. 
The  reductive  power  of  the  aqueous  extratSt  of  spiders  is 
also  very  high. 

journal  de  Phartnacie  et  de  Chimie, 
Series  6,  vol  vi.,  No.  7. 

On  the  Question  of  Matches.  Phosphorism. — 
A.  Riche. — A  long  paper,  to  be  continued,  not  suitable  for 
abstradtion. 

Detecftion  of  Acetone  in  Urine. — A.  Mallat. — In 
i8g6  the  author  published  the  method  of  detefting  acetone 
in  urine,  which  consists  of  precipitating  100  c.c.  of  urine 
with  10  c.c.  of  subacetate  of  lead,  then  distilling  a  portion 
of  this  liquid  with  caustic  soda,  then  adding  to  a  small 
portion  a  solution  of  iodine  and  iodide  of  potassium.  On 
reversing  the  test-tube  once,  the  presence  of  iodoform  is 
shown  by  the  smell  and  the  cloudy  appearance  of  the 
solution,  indicating  that  acetone  was  present  in  the  urine. 
M.  Bretet,  who  has  used  this  method,  has  modified  it  in 
the  following  manner: — He  does  not  treat  the  urine  with 
subacetate  of  lead,  but  he  distils  it  in  the  presence  of  tar- 
taric acid ;  he  stops  the  operation  when  about  one-tenth 
has  been  distilled  over.  Then,  in  two  test-tubes,  he 
makes  the  mixture  of  caustic  soda  and  of  iodine  in  iodide 
of  potassium,  and  thus  obtains  an  absolutely  clear  and 
limpid  reagent.  To  one  of  these  tubes  he  adds  the  dis- 
tilled urine  under  examination,  and  the  second  tube  he 
uses  as  a  check.  The  slightest  formation  of  iodoform 
causes  a  cloudiness  in  the  tube,  and  denotes  the  presence 
of  the  smallest  traces  of  acetone. 

Composition  of  Potatoes. — M.  Balland. — The  author 
finds  that  3  kilogrms.  of  potatoes  before  or  after  cooking, 
equal  to  about  1200  grms.  of  fried  potatoes  or  700  grms. 
of  desiccated  potatoes,  contain  the  same  amount  of  nitro- 
genous and  amylaceous  matters  as  i  kilogrm.  of  ordinary 
white  bread. 

Assay  of  Alloys  of  Copper  and  Nickel. — A.  Riche. — 
The  use  of  coins  made  of  an  alloy  of  copper  and  nickel  in 
two  of  the  French  colonies,  has  rendered  necessary  at  the 
Mint  a  rapid  and  exadt  method  for  the  analysis  of  these 
alloys.  They  are  not  of  the  same  composition  :  one  con- 
taining 25  per  cent  of  nickel,  and  the  other  only  15  per 
cent.  The  alloys  being  binary,  it  is  only  really  necessary 
to  determine  one  of  the  metals— the  copper,  for  instance. 
But  as  the  nickel  is  the  most  expensive  of  the  two  metals, 
it  is  preferable  to  estimate  it  diredly  rather  than  to 
deduce  its  weight  by  difference.  The  operation  is  carried 
out  as  follows : —  About  i  grm.  is  attacked  with  the 
smallest  quantity  possible  of  nitric  acid  on  a  sand-bath  ; 
when  finished,  add  a  little  water  containing  5  or  6  drops 
of  sulphuric  acid  and  evaporate  to  dryness.  Take  up  with 
water  still  containing  a  little  sulphuric  acid,  and  again 
evaporate  to  dryness  to  make  sure  that  all  the  nitric  acid 
is  driven  off;  re-dissolve  in  water  with  a  little  sulphuric 
acid,  and  pour  into  an  eledtrolytic  crucible,  filling  it  about 
one-third  full.  The  copper  alone  is  deposited.  The  re- 
maining solution  is  saturated  with  ammonia  and  eledlro- 
lysed  with  three  Daniell  cells.  This  brings  down  the 
nickel,  and  the  whole  process  gives  very  concordant 
results.  The  difference  between  the  total  weights  found 
and  100  represents  the  impurities — consisting  of  sesqui- 
oxide  of  iron,  also  oxides  of  manganese  and  aluminium — 
in  the  nickel.  In  the  case  of  a  bronze  coin,  475  m.grms. 
of  copper  were  deposited  in  four  hours  with  a  current  of 
half  an  ampere. 

No.  8. 

On  Antimonic  Acids  and  Antimoniates.  —  M. 
Delacroix. — Fremy  described  two  antimonic  acids  and 


their  salts,  but  many  chemists  will  not  admit  the  existence 
of  more  than  one.  M.  Delacroix  has  taken  up  the  study 
and  is  convinced  that  there  are  really  two  :  pyroantimonic 
acid,  giving  acid  pyroantimoniates  and  neutral  salts;  and 
orthoantimonic  acid,  giving  acid,  neutral,  and  basic  salts. 
The  solution  of  pyroantimonic  acid  was  prepared  from 
the  hydrate  by  pouring  SbCls  into  20  or  25  times  its 
weight  of  cold  water,  or  by  treating  SbCls  (previously  dis- 
solved in  a  little  water),  in  the  same  manner,  then  satu- 
rating with  chlorine.  The  excess  of  chlorine  is  driven  off 
by  a  current  of  air  diredled  on  to  the  mixture.  After 
standing  an  hour  or  two,  the  hydrate  is  transferred  to  a 
filter,  washed  a  little,  and  pressed  strongly  between 
blotting-paper.  It  retains  a  little  HCl  very  tenaciously, 
but  not  more  than  if  it  had  been  washed  for  a  much 
longer  time.  The  hydrate  is  then  placed  in  cold  water, 
in  which  it  slowly  dissolves.  The  solution,  which  is 
colourless,  is  evaporated  to  dryness  and  calcined,  forming 
Sb204,  from  the  weight  of  which  the  amount  of  anhydride 
is  calculated.  Pyroantimonic  acid,  when  warmed  for 
some  time  at  100°,  becomes  transformed  into  the  more 
basic  orthoantimonic  acid.  The  same  transformation  takes 
place  spontaneously  at  the  ordinary  temperature  in  a 
few  days.  The  solutions  thus  prepared  are  slightly 
opalescent.  The  author  intends  studying  the  basic  ortho- 
antimoniates  and  the  neutral  pyroantimoniates,  which  are 
new  salts. 


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242 


Meetings  for  the  Week, 


ohbmical  Mews 
Nov.  12,  1&97. 


NOTES   AND   QUERIES, 


%*_Oar  Notes  and  Queries  column  was  opened  for  the  purpose  of 
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MEETINGS    FOR    THE    WEEK. 


Wednesday,  I7tb.— Sanitary  Institute,  8.    (See  p.  231). 

Society  of  Arts,  8.  Opening  Address  of  Session 
by  Major-General  Sir  Owen  Tudor  Burne,  on 
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and  Commerce." 

Thursday,  i8th.— Chemical,  8.  "  Decomposition  of  Camphoric  Acid 
by  Fusion  with  Potash  or  Soda,"  by  A.  W. 
CroBsley,  M.Sc,  Ph.D.,  and  W.  H.  Perkin, 
jun.,  F.R.S.  "  Experiments  on  the  Synthesis 
of  Camphoric  Acid,"  by  W.  H.  Bentley,  B.Sc, 
andW.  H.  Perkin,  jun.,  F.R.S.  "Aftion  of 
Magnesium  on  Cupric  Sulphate  Solution,"  by 
Frank  Clowes,  D.Sc,  and  R.  M.  Caven,  B.Sc. 
"Properties  and  Relationships  of  Dihydroxy- 
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Nov.  19,  :897.     I 


Estimation  of  Copper  as  Iodide, 


243 


THE    CHEMICAL    NEWS. 

Vol.  LXXVI.,  No.  1982. 


ON   THE 

ESTIMATION     OF    COPPER    AS     IODIDE. 
By  M.  WILLENZ. 

The  volumetric  estimation  of  copper  as  iodide,  though 
old  and  well  known,  is  being  gradually  abandoned,  not 
having  given,  according  to  a  great  number  of  writers,  such 
satisfaiflory  results  as  were  expeded.  For  the  last  few 
years,  however,  chemists  have  again  taken  up  the  study  of 
this  question,  and  the  estimation  of  copper  as  iodide  is 
being  revived,  and  is  even  officially  adopted  in  some 
countries,  notably  the  United  States  of  America. 

This  method  is,  in  fadt,  simple  and  rapid,  and  only  requires 
the  use  of  ordinary  reagents.  We  were  desirous  of  testing 
the  accuracy  and  value  of  the  process  in  question,  and 
we  now  submit  our  results  to  the  readers  of  the  Revue. 

We  have  attempted  to  apply  this  method  to  cupreous 
pyrites,  minerals  containing  at  the  most  6  per  cent  of 
copper,  and  we  are  able  to  state  that  the  results  obtained 
by  following  the  plan  we  are  about  to  describe  have  been 
very  favourable,  provided  always  that  certain  precautions 
are  taken,  and  that  the  conditions  of  working  are  always 
identical. 

We  proceed  as  follows : — 

A  solution  of  hyposulphite  of  soda  is  prepared,  con- 
taining  992  grms,  of  the  crystallised  salt  (Na2S203,5Aq) 
per  litre ;  this  makes  a  N/25  solution,  of  which  each  c.c. 
is  equivalent  to  0'00252  grm.  of  copper.  But  as  the 
hyposulphite  is  hardly  ever  pure,  it  is  absolutely  indis- 
pensable to  control  the  titration  by  means  of  metallic 
copper,  and  further,  as  the  hyposulphite  alters  more  or 
less  rapidly,  and  as  its  titration  value  is  always  going 
back,  it  becomes  necessary  to  verify  it  before  each  series 
of  experiments,  and  for  this  purpose  it  is  well  to  keep  a 
standard  cupric  solution. 

To  prepare  this  solution  we  dissolve  10  grms.  of  eledtro- 
type  copper  in  a  mixture  of  equal  volumes  of  water  and 
nitric  acid,  D  =  i'4.  When  all  the  copper  is  dissolved, 
we  boil  for  a  long  time  until  all  the  nitrous  vapours  are 
driven  off,  let  cool,  and  make  up  to  i  litre. 

To  determine  the  titration  value  of  the  hyposulphite, 
we  take  10  c.c.  =  o*i  grm.  of  the  cupric  solution,  in  an 
Erlenmeyer  flask  of  200  c.c.  capacity,  having  a  mark  at 
50  c.c. ;  add  dilute  ammonia  drop  by  drop  until  the  blue 
precipitate  of  the  basic  salt  no  longer  forms,  then  add 
dilute  acetic  acid  drop  by  drop  to  re-dissolve  the  basic 
salt,  and  finally  make  the  solution  strongly  acid  with  5  or 
6  c.c.  of  concentrated  acetic  acid;  dilute  to  50  c.c,  and 
add  10  c.c.  of  a  10  per  cent  solution  of  potassic  iodide, 
free  from  iodate,  =  I  grm.  KI. 

The  addition  of  potassic  iodide  causes  the  formation  of 
cupric  iodide,  which  immediately  splits  up  into  cupreous 
iodide  and  free  iodine;  the  latter  gives  the  solution  a 
brown  colour. 

CuCCaHgOa)*  +  2KI  =  Culj  +  2KC2H302 
2CUI2  =  CU2I2  +  2I. 

The  result  of  this  is  that  63  parts  of  copper  require 
332  parts  of  iodide  of  potassium,  or,  in  other  terms, 
o'l  grm.  of  copper  requires  0*527  grm.  of  iodide;  but  as 
the  readion  occurs  but  slowly  when  we  take  only  the 
theoretical  quantity,  it  is  better  to  add  o'l  grm.  of  iodide, 
especially  as  an  excess,  even  when  considerable,  has  no 
interfering  influence  on  the  final  results.  We  allow  the 
iodide  to  read  for  two  minutes,  but  no  longer,  and  titrate 
with  the  hyposulphite,  which  is  run  in  until  the  liquid 


takes  a  clear  yellowish  brown  tint ;  we  then  add  a  little 
starch  solution,  and  while  agitating  we  add  more  hypo- 
sulphite. As  soon  as  the  colour  of  the  iodide  of  starch 
begins  to  change  to  a  dirty  gre>ish  violet,  we  add  the 
hyposulphite  by  only  a  drop  at  a  time,  shaking  thoroughly 
after  each  addition. 

We  have  remarked,  in  fadt,  that  the  violet  tint  will  still 
persist  even  after  all  the  iodine  has  been  transformed  into 
sodic  iodide,  but  violent  agitation  will  make  it  disappear, 
and  the  straw  colour,  due  to  cuprous  iodide,  shows  itself, 
thus  indicating  the  end  of  the  titration.  To  get  con- 
cordant results  it  is  necessary  always  to  stop  at  the 
same  point ;  this  is  not  difficult  after  a  little  pradlice. 

Wfien  carried  out  in  this  manner  the  method  gives  per- 
fedtly  concordant  and  very  satisfadlory  results.  We  have 
never  noticed  the  re-appearance  of  the  blue  colour,  even 
after  standing  several  hours. 

We  give  below  several  titrations  made  with  pure  cupric 
sulphate,  CuS04,5aq.,  containing  25*421  per  cent  of  me- 
tallic copper.  The  aqueous  solution  of  the  salt  was 
acidulated  with  0*5  c.c.  of  nitric  acid,  D  =  i'4,  then  treated 
with  ammonia  and  acetic  acid  as  above,  diluted  to  50  c.c. ; 
10  c.c.  gf  10  per  cent  iodide  of  potassium  was  then  added, 
the  whole  let  stand  for  two  minutes,  and  then  titrated,-- 

I  c.c.  Na3S203  =  o'oo249375  grm.  Cu. 

Application  of  the  Method  to  the  Estimation  of  Copper 
in  Pyrites, — Ten  grms.  of  finely  powdered  and  dried 
pyrites  are  placed  in  a  tall  narrow  beaker,  8  c.c.  of  water 
and  2  c.c.  of  concentrated  sulphuric  acid  are  added. 
Cover  the  beaker  with  a  watch-glass,  and  add  nitric  acid, 
D  =  i'4,  in  small  quantities,  until  there  is  no  longer  any 
effervescence;  this  will  require  about  25  to  30  c.c.  of 
HNO3,  then  add  3  c.c.  more  of  H2SO4.  Boil  well,  over  a 
naked  flame  for  preference,  and  after  a  few  minutes  take 
off  the  watch-glass,  and,  without  washing  it,  place  it  tem- 
porarily on  one  side.  Continue  boiling,  and  at  the  same 
tin^  keep  the  beaker  constantly  turning — this  is  an  indis- 
pensable precaution — until  the  mass,  becoming  thicker 
and  thicker,  will  no  longer  run,  but  becomes  quite  pasty. 
Treat  it  now  with  hot  water  and  replace  the  watch-glass, 
boil  for  a  short  time  and  allow  to  cool  :  make  up  to  half 
a  litre  and  filter. 

The  residue,  which  is  quite  free  from  copper  if  the  ope- 
ration has  been  properly  conduced,  consists  of  silica, 
sulphur,  PbS04,  (BaS04,CaS04).  This  operation  requires 
a  certain  amount  of  skill,  and  special  care  must  be  taken 
lest  the  sulphur  set  at  liberty  envelopes  the  unattacked 
particles  of  mineral,  and  thus  prevents  them  being  adled 
upon,  but  with  a  little  pradice  this  is  easily  avoided;  the 
operation  requires  but  half  an  hour  at  the  most. 

Take  100  c.c.  =  2  grms.  of  pyrites,  of  the  sulphuric 
solution  thus  obtained,  in  a  conical  flask,  and  add  a  few 
c.c.  more  of  H2SO4 ;  boil,  and  without  stopping  the  heat 
add,  little  by  little,  a  warm  concentrated  solution  of  hypo- 
sulphite of  soda. 

The  addition  of  the  first  few  drops  produces  no  change, 
but  there  is  soon  a  lively  disengagement  of  sulphurous 
acid  gas,  and  the  liquid  becomes  cloudy,  then  successively 
greenish,  brownish,  chocolite-brown,  and  finally  black, 
without  any  precipitate  appearing.  But  by  keeping  up 
the  boiling  the  precipitate  ccmesdown,  agglomerates,  and 
falls  to  the  bottom  of  the  flask,  while  the  supernatant 
liquid  becomes  limpid. 

This  precipitate  consists  of  sulphides  of  copper,  arsenic, 
antimony,  and  tin,  mixed  with  free  sulphur,  but  it  must 
be  remembered  that  the  last  three  sulphides  are  only  par- 
tially precipitated  when  not  in  the  presence  of  a  great 
excess  of  acid  ;  it  may  even  happen  that  they  are  not 
precipitated  at  all  if  the  bases  are  present  in  small  quan- 
tities only.  The  other  bases  of  the  copper  group  are  not 
precipitated,*  the  iron  is  reduced  to  the  state  of  ferrous 


*  It  is,  however,  worthy  of  remark  that  bismuth  is  precipitated 
under  these  conditions,  but  we  have  never  come  across  this  metai  in 
pyrites. 


244 


Dissociation  Spectra  of  Melted  Salts, 


I  Chbmical  Mbws, 
1     Nov.  19. 1897. 


C.c.  of  NagSgOg  used. 


Grmi. 
CuSO^.saq, 

Cu 
calculated. 

I. 

II. 

Mean. 

O'lO 

0'02542I 

10*15 

10*20 

10-18 

0-15 

0-038131 

1535 

15-30 

15-33 

0-20 

0-050842 

20*40 

20*40 

20-40 

0*25 

0063552 

2550 

25*50 

25-50 

0-30 

0*076263 

30'55 

30*60 

30-58 

0-35 

0*088973 

35-65 

35-65 

35-65 

0*40 

0*101684 

40-75 

40*70 

40-73 

o'45 

0*114394 

45-85 

45-90 

45-87 

0*50 

0*127105 

51-05 

51*00 

51  02 

o'6o 

0*152526 

61*20 

61 '20 

61*20 

070 

0-177947 

71-45 

71-40 

71*42 

080 

0*203368 

81-50 

81*50 

81-50 

o-go 

0-228789 

91*90 

92-00 

91*95 

I'OO 

0-254210 

10220 

102-20 

102*20 

Cu 
found. 

0*025386 
0*038229 
0*050873 
0*063591 
0.-076259 
0*088902 
0*101571 
0*114389 
0-127232 
0*152618 
0*178104 
0*203241 
0*229301 
0-254862 


Difference. 

—  0-000035 
+  0*000098 
+  0*000031 
+  0*000038 

—  0-000004 

—  0*000071 
-0*000113 

—  0*000005 
+  0*000127 
+0*000092 
+0-000157 

—  0*000127 
+0*000512 
+  0*000652 


salt ;  the  aluminium,  zinc,  manganese,  nickel,  and  cobalt 
remain  in  solution. 

The  precipitate  is  washed  several  times  with  boiling 
water,  first  by  decantation,  and  afterwards  on  the  filter. 
When  obtained  under  the  above-mentioned  conditions  it 
oxidises  very  slowly,  and  may  be  washed  with  pure  water 
without  any  risk,  but  the  washing  should  be  done  rapidly. 
When  the  wash  waters  no  longer  precipitate  BaClj,  we 
take  the  filter  and  its  contents  out  of  the  funnel,  squeeze 
it  gently  between  blotting-paper  to  get  rid  of  most  of  the 
moisture,  then  place  it,  point  uppermost,  in  a  porcelain 
crucible.  Heat  very  gradually,  and  when  all  the  water  is 
driven  off  increase  the  temperature,  and  finally  roast,  so 
that  all  the  sulphur  is  burnt,  and  the  arsenic,  antimony, 
and  tin  volatilised;  there  then  remains  in  the  crucible 
nothing  but  a  mixture  of  oxide  and  sulphide  of  copper. 

This  is  dissolved  in  1  c.c.  of  a  mixture  of  equal  volumes 
of  water  and  nitric  acid,  0  =  1-4,  ^^^  boiled  to  completely 
drive  off  all  nitrous  fumes;  transfer  to  a  200  c.c.  Erlen- 
meyer  flask,  with  a  mark  at  50  c.c. ;  add  dilute  ammonia, 
drop  by  drop,  until  the  precipitate  of  the  basic  salt  is  no 
longer  formed  ;  this  is  re-dissolved  in  weak  acetic  acid, 
acidulated  strongly  with  5  or  6  c.c.  of  strong  acetic  acid  ; 
10  c.c.  of  iodide  of  potassium  are  then  added,  and  the 
whole  left  for  two  minutes  ;  it  is  then  titrated  with  hypo- 
sulphite, observing  the  precautions  mentioned  above. 

As  we  have  already  said,  this  method  gives  very  satis- 
faftory  results ;  it  is  easy  to  perform,  and  requires  but  very 
little  time.     Examples  : — 

1  c.c.  NajSzOj  =  0*0025  grm-  Cu. 


we  prefer  a  weak  solution,  the  inherent  errors  being  then 
reduced  to  a  minimum. —  Revue  de  Chetn.  Analytique, 
Vol.  v.,  No.  18. 


c.c.  of             Cu 

Grm.Cu. 

Grm.  As. 

NajSjOg.           found. 

Difference. 

0-0972 

+0*4013 

39-0              0*0975 

+  0*0003 

0-0647 

+0-4735 

26*0              0*0650 

+  0*0003 

0*0892 

+0*7102 

35*75          0*08937 

+  0-00017 

0*1241 

+0-8284 

49*8            0*1245 

+  0-0004 

0*2004 

+  1-4672 

80-25          0-20062 

Cu  found 

+  0-00022 

Contents  of 

By  Fresenius's 

By  this 

Pyritei. 

As,  per  cent. 

method,  per  cent,  method,  per  cent. 

I. 

0-320 

3-267 

3*272 

II. 

0*024 

0-069 

0*081* 

III. 

0-062 

4-584 

4-601 

IV. 

0-182 

0*074 

o*o8i* 

V. 

traces 

1*823 

1-872 

VI. 

0-307 

5749 

5771 

VII. 

Not  determined           2*218 

2*330 

*  Five  grms,  of  material  used. 

It  is  evident  that  this  method  can  be  applied  equally  to 
copper  ores  properly  speaking,  to  bronzes,  alloys,  &c.,  but 
in  these  cases  the  quantity  taken  for  assay  must  be  less, 
and  the  solution  of  hyposulphite  used  may  be  more  con- 
centrated, a  decinormal  solution  for  instance ;  however 


ON  THE  DISSOCIATION  SPECTRA   OF  MELTED 

SALTS. 

ALKALINE    METALS  :     SODIUM,    LITHIUM, 

POTASSIUM. 

By  A.  DB  GRAMONT, 

The  easiest  dissociation  speftra  to  study  with  the  con- 
denser spark  are  those  of  the  salts  of  the  alkaline  metals, 
on  account  of  their  fusibility,  stability,  and  simplicity. 

To  do  this,  it  suffices  to  deduft  from  the  total  spedtrum 
the  metallic  lines,  to  get  the  complete  spedlrum  of  the 
metalloid  without  having  recourse  to  Plijcker  or  Salet 
tubes.  I  therefore  preferred  commencing  with  the  speftra 
of  the  common  alkaline  metals  as  they  appear  in  the  dis- 
sociation  of  their  fused  salts.  They  differ  to  a  certain 
extent  from  those  yet  obtained,  either  with  the  pure  metal 
and  not  much  condensation,  or  with  the  fused  salt  and 
the  coil  only.  Many  of  the  lines,  especially  those  in  the 
most  refrangible  part  of  the  spedrum,  become  wider  and 
more  diffused ;  the  component  parts  of  double  lines  being 
difficult  to  separate,  no  matter  what  dispersion  is  used, 
and  appearing  as  fairly  wide  bands. 

Most  precise  measurements  of  the  wave-lengths  of 
sodium  will  be  found  in  the  paper  by  MM.  Eder  and 
Valenta  (Deutschr.  Kais.  Akad.  d.  Wissenschaft,  vol.  Ixi., 
Vienna,  1894),  who  worked  with  the  metal  itself  in  an 
atmosphere  of  hydrogen  and  with  a  small  condenser. 

The  spedlrum  of  lithium  has  been  measured  with  great 
accuracy  by  MM.  Kayser  and  Runge  [Abhandlung  Berliner 
Akad.,  1890)  in  the  arc,  where  the  lines  are  the  same  as 
those  now  given  and  described. 

I  have  established  the  lines  peculiar  to  each  metal 
under  the  following  conditions: — 1.  By  subtradling  from 
the  complete  speftrum  of  a  salt  the  lines  of  the  combined 
metalloid,  and  repeating  the  experiment  with  several  salts 
of  the  same  metal.  2.  By  observing  the  specftrum  of  a 
carbonate,  where  the  carbon  lines  appear  only  under 
special  conditions.  This  has  been  recently  proved 
{Comptei  Rendus,  vol.  cxxv,,  July  19  and  26,  1897).  The 
dissociation  of  the  salt  is  more  or  less  easy  to  effedl 
according  to  its  nature ;  it  is  easy  with  chlorides, 
bromides,  iodides,  sulphides,  sulphates,  phosphates,  &c. ; 
it  is  more  difficult  with  carbonates  and  fluorides,  which 
require  a  much  higher  temperature  and  a  greater  differ- 
ence of  potential.  The  measurements  of  the  wave-lengths 
here  given  were  obtained  with  a  direiSl-vision  spedtroscope 
with  two  compound  prisms,  easily  doubling  the  D  line  of 
sodium  (Na  a),  which  appeared  to  be  one  division  of  the 
micrometer  apart ;  these  divisons,  with  a  little  pra^ice, 


Crbmicai.  NbwS.  \ 
Nov.  19, 1807.      '' 


Dissociation  Spectra  of  Melted  Salts. 


H^ 


could  be  read  to  one-tenth.  These  values  were  compared 
with  the  normal  solar  spedtrum  photographed  by  Rowland. 
I  have  kept  the  alphabetical  description  for  Na  and  K 
given  by  M.  Lecoq  de  Boisbaudran  in  Plate  V.  of  his 
'•  Atlas  of  Luminous  Spedra." 


M 


6i6-i 

615-5 
5896 
589-0 
568-8 
568-3 
567-5 
567-0 

515-5 

515-1 

49831 

497  9 1 

467-2 

467-0 

454-5 

449-9 


Sodium. 
Strong,  bright. 

»»  i> 

Intense. 

Strong,  bright. 

II  II 

Faint. 

II 
Fairly  strong. 

II 

Easily  seen,  very  diffuse,  almost  joined. 

Faint,  diffused. 
Fairly  bright,  diffused. 
Faint,  diffused. 
Fairly  bright,  diffused. 


Pradtically,  and  above  all  in  the  presence  of  metalloids, 
the  spedtrum  of  sodium  is  reduced  to  three  double  lines, 
bright  and  charafteristic,  Na  S,  Na  a  (D  of  Frauenhofer), 
and  Na  /3,  each  one  being  seen  as  a  single  line  in  a  mono- 
prismatic  instrument  with  a  medium  slit.  Na  c  comes  next 
in  strength.  The  value  I  give  it  appears  rather  high  (MM. 
Kayser  and  Runge  give  515-37  and  514-92).  The  remaining 
double  lines  are  much  weaker  and  indistindt,  almost  forming 
a  single  diffuse  band.  Those  marked  *  could  not  be  split 
up  on  account  of  the  condenser  used. 


670-8 
610-3 
497-2 
460-3 

4273 
413-2 


Lithium. 
Strong,  bright. 
Very  strong. 
Strong. 

Strong,  wide,  diffuse. 
Well  marked. 
Well  marked,  very  diffuse. 


A  spedlrum  of  such  simple  character,  of  six  lines  only, 
and  so  easily  seen,  renders  the  use  of  lithium  salts  particu- 
larly favourable  for  the  study  of  the  spedlra  of  metalloids. 
The  first  four  lines  are  always  seen  with  the  disrup- 
tion discharge,  either  on  the  metal  or  on  the  solution 
of  one  of  its  salts,  but  the  relative  intensities  of  the  lines 
vary  in  the  two  cases.  427-3  has  never  been  seen  before 
except  in  the  eledtric  arc ;  it  is  here  very  distind,  even 
with  a  small  condenser.  The  existence  of  413-2  was 
foretold  by  M.  Lecoq  de  Boisbaudran,  who  calculated  its 
existence  from  theoretical  considerations,  before  dis- 
covering it  in  a  concentrated  solution  ;  it  is  much  easier 
to  detedt  in  melted  LijCOs.  In  the  condenser  spark  it  is, 
on  the  other  hand,  very  wide  and  cloudy. 

The  principal  papers  relating  to  the  spedlrum  of  potas- 
sium are  based  on  experimental  conditions  very  different 
to  those  under  which  I  have  worked ;  that  is  to  say,  the 
adtion  of  a  strong  condensation  effedting  the  complete 
dissociation  of  a  melted  salt.  By  this  means  I  obtained, 
united  in  one  spedtrum,  the  different  lines  which  have 
been  detedted  singly,  by  very  different  methods,  and  be- 
tween which  we  can  notice  the  relations  between  relative 
intensities ;  these  do  not  resemble  the  corresponding  lines 
found  in  the  preceding  researches. 

M.  Lecoq  de  Boisbaudran  worked  with  anon-condensed 
spark  on  fused  sulphate  of  potassium ;  Sir  William 
Huggins  and  MM.  Eder  and  Valenta  with  slight  conden- 
sation at  the  ordinary  temperature ;  Profs.  Liveing  and 
Dewar  and  MM.  Kayser  and  Runge,  in  the  eledtric  arc, 
where  the  spedtrum  of  potassium  is  notably  less  rich  in 
lines  than  in  the  spark.  The  eledtrical  and  optical 
arrangements  here  used  were  the  same  as  those  in  my 
previous  experiments  already  described. 


(769-9 
(7666 
(693-9 

1 691-4 
630-8' 

624-55* 

6ii-75f 
f583-2 

581-1 

580-1 
15783 

551-5* 
'5360 

534-4 

534-0 
I53235 

5"-3l 
1509-91 

505-it 

500-7 

485-55§ 

485-i§ 

482-9 

465-211 

46o-6iT 

45065  IT 

446-611 

438-811 

430-95 II 
430-6511 
426-4§ 

422-55 II 
422-2511 
421-0 II 
4i8-55ir 
404-55 


Potassium, 
Difficult  to  see. 

II         II 
Fairly  strong. 
Well  marked. 

II 
Easily  seen. 
Very  well  marked. 
Strong. 

Fairly  well  seen. 
Strong. 

Very  well  marked. 
Weak. 

Easily  seen,  diffuse. 
Fairly  well  seen,  diffuse. 
Easily  seen,  diffuse. 
Fairly  well  seen,  diffuse. 
Fairly  well  seen,  diffuse,  and  almost  con- 
founded with  one  another. 
Weak. 
Weak. 
Fairly  well  seen. 

II  11 

Fairly  strong. 
Fairly  well  seen. 

II  li 

Weak. 

•I 
Fairly  well  seen. 


Fairly  strong. 
Fairly  well  seen. 

II  II 

Weak. 

Fairly  strong,  wide. 
Strong,  very  wide,  diffuse. 


*  Seen  by  Sir  William  Huggins  only. 

t  Seen  by  Sir  William  Huggins,  afterwards  by  M.  Lecoq  de  Bois- 
baudran only. 

t  Seen  by  M.  Lecoq  de  Boisbaudran  only. 

§  Seen  by  Profs.  Liveing  and  Dewar  only. 

II  Seen  by  MM.  Eder  and  Valenta  only. 

%  Seen  by  M.  Lecoq  de  Boisbaudran,  afterwards  by  MM.  Eder 
and  Valenta  only. 

Several  lines  in  the  violet,  deteAed  by  MM.  Eder  and 
Valenta  by  means  of  photography,  which  is  more  sensi- 
tive  than  the  eye  in  this  part  of  the  spedtrum,  were  not 
visible  to  me. 

To  get  greater  accuracy  with  regard  to  wave-lengths, 
we  can  refer  to  the  memoir  by  MM.  Kayser  and  Runge  on 
the  arc  spedtrum  of  potassium  (Abhand.  Berliner  d.  Akad., 
1890},  and  for  the  lines  which  do  not  show  in  the  arc,  to 
the  work  of  MM.  Eder  and  Valenta  already  quoted.  All 
these  observers  had  at  their  disposition  either  a  Rowland's 
apparatus  or  a  spedlrograph — instruments  which  are  not 
to  be  found  at  the  Faculte  des  Sciences  in  Paris.  The 
approximation  here  given,  however,  amply  suffices  for 
the  identification  of  the  lines  in  any  current  research  in 
a  chemical  laboratory. 

The  classic  red  lines,  K  S,  situated  at  the  end  of  the 
spedtrum,  always  rather  diffused,  are  only  visible  when 
working  with  instruments  of  little  absorption;  further, 
they  are  not  mentioned  in  the  work  of  Sir  William 
Huggins  or  of  M.  Thalen.  The  double  line,  K  y,  on  the 
contrary,  is  very  bright  and  charadteristic ;  the  second, 
or  more  narrow  line,  is  slightly  fainter  than  its  companion. 
There  are,  again,  three  lines  in  the  red — 630*8,  624-55, 
and  611-75 — which,  though  mentioned,  but  considered  to 
be  doubtful  by  Sir  William  Huggins,  were  either  not  seen 
by  subsequent  observers,  or  else  attributed  by  them  to 
impurities.  However,  the  strongest  and  most  refrangible, 
611-75,  was  seen,  though  very  faintly,  by  M.  Lecoq  de 
Boisbaudran,  using  a  simple  spark  only,  with  pure  fused 
sulphate   of  potash.      MM.    Edtr   and   Valenta   con- 


246 


Combustion  of  Organic  Substances  in  the  Wet  Way. 


CHBMICALNsWb, 

Nov.  ig,  1897. 


sidered  these  rays  as  not  belonging  to  potassium,  but 
made  no  endeavour  to  define  their  origin.  I  have  always 
found  them  in  company  with  the  double  line  K  7  in 
melted  salts  of  potassium,  when  using  a  sufficient  con- 
densation. I  repeat,  that  I  have  always  succeeded  in  ob- 
taining them  eventually  with  complete  absence  of  lines  of 
other  foreign  matters ;  I  consider  them,  therefore,  as 
characteristic  of  the  spedrum  of  dissociation  of  potassium 
in  its  salts. 

The  brightest  group  is  K  a,  in  the  green,  and  appears 
to  show  the  most  sensitive  reaction  of  potassium  in  the 
spark.  K  /3  is  fainter  and  diffuse,  and  the  two  middle 
lines  cannot  be  separated  with  a  single  prism.  K  77  is 
still  fainter,  and  more  diffuse  than  under  ordinary  condi- 
tions ;  it  is  easily  seen  as  a  single  band  about  510*5. 

In  the  blue,  K  is,  on  the  contrary,  sensibly  stronger 
and  becomes  charadteristic :  this  line  is,  however,  entirely 
missing  in  the  arc. 

In  the  same  manner,  426"4  in  the  indigo,  and  418*55  in 
the  violet,  become  more  intense  with  condensation,  the 
augmentation  of  which  makes  itself  particularly  felt  in 
this  region  of  the  spetStrum.  K  {,  the  last  line  visible,  is 
a  double  line  which,  in  the  condenser  spark,  becomes 
transformed  into  a  strong  diffuse  band  which  cannot  be 
divided;  it  is  very  bright  and  charadleristic  of  potassium. 
— Bull.  Soc.  Chim,,  Series  3,  vols,  xvii.-xviii.,  Nos.  16-17. 


THE  COMBUSTION  OF  ORGANIC  SUBSTANCES 

IN    THE   WET    WAY.* 

By  I.  K.  PHELPS. 

In  a  former  paper  (Am.  jfourn.  Set.,  vol.  ii.,  p.  70)  I  have 
shown  that  carbon  dioxide  may  be  estimated  iodometri- 
cally  with  a  fair  degree  of  accuracy.  Inasmuch  as  this 
method  is  not  dependent  upon  the  rate  of  flow  or  rapidity 
of  generation  of  the  carbon  dioxide,  it  seemed  possible 
that  some  advantage  might  follow  its  application  to  the 
determination  of  organic  carbon,  oxidised  by  liquid  re- 
agents. 

Method  of  Oxidation  by  Potassium  Permanganate. 

The  first  experimental  test  in  this  diredtion  was  made 
with  oxalic  acid,  which  was  oxidised  according  to  the 
well-known  readtion  of  potassium  permanganate  in  the 
presence  of  sulphuric  acid.  The  apparatus  used  was  the 
same  as  that  previously  described  in  the  iodometric  pro- 
cess referred  to  above.  It  consisted,  in  the  main,  of  an 
evolution  flask  and  an  absorption  flask,  properly  con- 
nedted.  As  an  evolution  flask,  a  wide-mouthed  flask  of 
about  75  cm.*  capacity  was  used.  This  was  closed  by  a 
doubly  perforated  rubber  stopper,  carrying  a  separating 
funnel  for  the  introdudtion  of  liquid  into  the  flask  and  a 
glass  tube  of  07  cm.  internal  diameter,  which  was  ex- 
panded to  a  small  bulb  just  above  the  stopper,  to  carry  off 
the  gas.  This  exit  tube  was  joined  by  means  of  a  rubber 
connedtor  to  a  tube  which  passed  through  the  rubber 
stopper  of  the  absorption  flask,  which  was  an  ordinary 
round-bottomed  flask  of  250  cm.'  capacity.  This  tube 
ended  in  a  valve  of  the  Kreider  pattern  {Am.  yourn.  Set., 
1.,  p.  132),  which  was  enclosed  in  a  larger  tube,  reaching 
nearly  to  the  bottom  of  the  absorption  flask.  The  second 
hole  of  the  stopper  of  this  absorption  flask  was  filled  by  a 
glass  tube  closed  by  a  rubber  connedtor  and  screw  pinch- 
cock. 

The  barium  hydroxide  solution  for  use  in  the  deter- 
mination of  the  carbon  dioxide  was  prepared  by  filtering 
a  cold  saturated  solution  of  the  commercial  salt  into  a 
large  bottle,  which  was  .connedled  with  a  self-feeding 
burette.  The  solution  was  standardised  in  the  manner 
described  in  my  former  paper,  by  boiling  with  an  excess 
of  decinormal  iodine  solution  in  an  ether  wash  bottle. 
The  short  tube  of  the  glass  ground  stopper  ol  the  bottle 

^♦Contributions  from  the  Kent  Chemical  Laboratory  of  Yale  Uni- 
versity. From  the  American  jfourHal  0/  Science, Series  4,  Vol.  iv., 
ho.  23,  November,  1897. 


was  sealed  to  a  Will  and  Varrentrapp  absorption 
apparatus,  which  was  charged  during  the  operation  with 
a  solution  of  potassium  iodide  to  prevent  the  loss  of  ele- 
mentary iodine  in  the  boiling  ;  the  long  tube  of  the  bottle 
was  used  as  an  inlet  tube,  and  was  closed  externally  by  a 
rubber  cap  during  the  boiling.  After  cooling,  the  excess 
of  iodine  used  was  determined  by  titration  with  deci- 
normal arsenious  acid  solution  and  the  iodine  lost  cal- 
culated on  barium  hydroxide  molecule  for  molecule. 

Potassium  permanganate  was  prepared  for  use  by  dis- 
solving the  commercial  salt  in  water,  and  boiling  this  so- 
lution made  acid  with  sulphuric  acid,  until  free  from  car- 
bon dioxide.  Water  was  also  prepared  free  from  carbon 
dioxide  by  boiling  distilled  water  until  one-third  had  been 
driven  off  in  steam  and  was  kept  until  used  in  full- 
stoppered  flasks. 

For  the  first  determinations  of  carbon,  crystallised  am- 
monium oxalate  was  weighed  out  and  introduced  into  the 
boiling  flask  with  10  to  15  cm.*  of  pure  water  and  the 
flasks  connedled  as  described  above  with  an  appropriate 
amount  of  barium  hydroxide  solution  (3  to  5  c.m.»  in  excess 
of  the  amount  required  to  precipitate  the  carbon  dioxide  to 
be  determined)  in  the  absorption  flask.  The  whole  system 
v/as  then  evacuated  with  the  water-pump  to  a  pressure 
of  200 — 225  m.m.  and  the  oxalate  solution  in  the  boiling- 
flask  warmed.  An  excess  of  potassium  permanganate 
solution  was  then  run  in  through  the  funnel  tube  and  the 
mixture  warmed  again,  when  the  oxidation  of  the  oxalate 
was  shown  by  the  carbon  dioxide  evolved.  The  carbon 
dioxide  was  completely  set  free  by  the  introdudlion  of  10 
cm.'  of  sulphuric  acid  (i  :  4)  and  was  driven  completely 
to  the  absorption  flask  by  boiling  for  five  minutes.  During 
the  passage  of  the  gas  into  the  absorption-flask,  it  was 
shaken  frequently  and  was  kept  cool  by  standing  in  a  dish 
of  water  and  by  pouring  cold  water  over  it  from  time  to 
time.  If,  during  the  boiling,  any  fears  are  entertained  as 
to  the  strength  of  the  vacuum  in  the  flasks,  they  may  be 
easily  allayed  by  opening  momentarily  the  stopcock  of 
the  funnel-tube  and  noting  the  diredtion  of  the  flow  of 
water  contained  in  the  funnel.  After  the  boiling  was 
ended,  the  atmospheric  pressure  was  restored  by  allowing 
air,  purified  from  carbon  dioxide  by  passage  through 
potash  bulbs,  to  enter  through  the  funnel-tube  of  the 
boiling  flask.  Then  the  flasks  were  disconnedted  and  the 
stopper  of  the  absorption-flask  with  its  attachments  was 
removed,  the  valve  and  its  tube  being  carefully  washed 
free  from  barium  hydroxide.  A  second  stopper,  which 
was  provided  with  a  separating  funnel,  and  a  Will  and 
Varrentrapp  absorption  apparatus,  containing  water  to 
serve  as  a  trap,  was  inserted  into  the  mouth  of  the  absorp- 
tion flask  and  the  emulsion  brought  to  the  boiling  point, 
Decinormal  iodine  solution  was  then  run  in  through  the 
funnel-tube  in  sufficient  quantity  to  destroy  the  larger 
part  of  the  excess  of  barium  hydroxide,  and  the  emulsion 
brought  to  the  boiling-point  again,  after  which  iodine 
was  again  run  in,  but  this  time  to  the  permanent  red 
colour  of  the  excess  of  free  iodine.  After  cooling,  this 
excess  of  iodine  was  determined  by  titration  with  deci- 
normal arsenious  acid  solution.  Thus,  the  excess  of 
barium  hydroxide  used  being  determined  by  the  iodine 
lost,  the  barium  hydroxide  used,  now  in  the  form  of  car- 
bonate, was  known,  from  which  the  carbon  dioxide  which 
precipitated  this  carbonate  may  be  calculated. 

The  following  results  were  obtained  by  this  procedure. 

Table  I. 


Ammonium 

Error 

oxalate 

BaOjHj 

BaOjH, 

COj 

CO, 

on 

taken. 

taken. 

found. 

found. 

calculated. 

CO4. 

Grm. 

Grm. 

Grm. 

Grm. 

Grm. 

Grm. 

I. 

0-2522 

07267 

O-I170 

0-1565 

O-I561 

0-0004 -f 

2. 

02542 

0-7267 

0-tll3 

0-1579 

0-1574 

0-0005-1- 

3. 

05020 

I'4535 

0-2417 

0-3110 

0-3  ro8 

O-0O02-f 

4' 

0-5058 

i'3954 

0-1753 

0-3131 

0-3131 

o'ooooi 

5- 

I-0033 

2-6163 

0-1955 

0-6213 

0-6211 

0  0002-h 

6. 

1-0003 

2*5951 

0-1836 

0-6189 

06192 

00003  — 

7- 

I'OOIO 

2'6i63 

0-2037 

o-6ig2 

0-6197 

0-0005- 

CRbmical  News,  ) 

Nov.  19, 1897.     ; 


London  Water  Supply. 


247 


In  Experiments  5  and  6  a  few  drops  of  ammonia  were 
added  to  the  oxalate  solution  before  running  in  the  per- 
manganate; in  3  and  7,  the  permanganate  was  treated  to 
alkalmity  with  barium  hydroxide;  in  the  remaining  ex- 
periments, I,  2,  and  4,  the  permanganate  was  slightly  acid 
with  the  sulphuric  acid  used  in  its  purification  from  car- 
bon dioxide,  as  already  described.  The  results  obtained 
are  good,  and  it  is  plain  that  the  oxidation  proceeded 
regularly,  whether  the  first  adlion  of  the  permanganate 
was  in  the  alkaline  or  slightly  acid  solution. 

Jones  (Am.  Chem.  jfourn.,  xvii.,  539)  has  shown  that 
formates  may  be  determined  volumetricaliy  by  titration 
with  potassium  permanganate  in  alkaline  solution.  In 
an  attempt  to  determine  formates  by  the  process  outlined 
above,  the  pure  barium  salt  was  used.  This  was  pre- 
pared by  treating  the  aqueous  solution  of  formic  acid  with 
pure  barium  carbonate  to  neutrality  and  crystallising  the 
produdt.  It  was  proven  pure  by  ignition  and  weighing  in 
the  form  of  carbonate. 

In  making  determinations  of  carbon  in  this  formate, 
weighed  portions  were  introduced  into  the  boiling  flask, 
together  with  sodium  hydroxide  solution,  which  was  taken 
in  such  quantity  as  to  more  than  neutralise  the  acid  in 
the  potassium  permanganate.  Naturally,  the  sodium 
hydroxide  must  be  free  from  carbonate — which  was 
e^edted  by  treatment  with  an  excess  of  barium  hydroxide 
and  filtering.  An  excess  of  potassium  permanganate  is 
then  run  into  the  flask  and  the  solution  heated  to  boiling. 
An  excess  of  dilute  sulphuric  acid  is  introduced  into  the 
mixture,  and  the  carbon  dioxide  thus  set  free  completely 
driven  over  to  the  absorption  flask  and  determined  as 
before.    Table  II.  shows  results  obtained  by  the  process. 

Table  II. 


Barium 

Error 

formate 

BaOjHj 

BaOjHj 

CO2 

CO,j 

on 

taken. 

taken. 

found. 

found. 

calculated. 

CO,. 

Grm. 

Grms. 

Grm. 

Grm. 

Grm. 

Grm. 

X. 

0'500I 

0'9302 

0-1745 

0-1939 

,0-1935 

0*0004 -F 

2. 

0-5033 

0'9  JI2 

0'i402 

0-1953 

0-1947 

OOOo6-f 

3- 

1'0002 

I-686I 

0-1793 

0-3867 

0-3870 

00003  — 

4- 

i"0059 

1*6279 

0-1093 

0-3897 

0*3892 

0-0005 -H 

.■)• 

1-3750 

22529 

0'l820 

0-5315 

0-5320 

0*0005  — 

6. 

I -5028 

2-4419 

0-I754 

0-5816 

0-5814 

0*0002 -f- 

These  results  show  plainly  that  the  carbon  of  formic 
acid  may  be  determined  accurately  by  the  method  out- 
lined. 

It  was  found  incidentally  that  ammonia  cannot  take  the 
place  of  the  sodium  hydroxide  in  this  process,  probably 
because  the  ammonia  volatilises  to  the  absorption  flask 
during  the  boiling  and  is  adted  on  by  the  iodine  subse- 
quently used,  and  is  thus  registered  as  barium  hydroxide. 

It  is  a  well  known  fadt  that  tartrates  are  oxidised  by 
permanganates.  I  have  found,  however,  that  when  tar- 
taric acid  is  treated  under  the  conditions  of  analysis  out- 
lined above  in  acid  solution,  the  oxidation  is  incomplete  ; 
but  that  oxidation  is  complete  if  the  tartrate  is  heated  in 
a  solution  alkaline  with  sodium  hydroxide  and  then  acidi- 
fied with  sulphuric  acid. 

The  tartrate  used  was  a  re-crystallised  tartar  emetic, 
dried  at  100°  C.  The  following  results  were  obtained 
with  such  a  tartrate  by  this  process. 

Table  III. 


Tartar 

Error 

emetic 

BaOjH, 

BaO,H, 

CO, 

COj 

on 

taken. 

taken. 

found. 

found. 

calculated. 

COj. 

Grm. 

Grms. 

Grm. 

Grm. 

Grm. 

Grm. 

I. 

0*5051 

1*2450 

0*1709 

0*2756 

0*2751 

0*0005  -f 

2. 

0-5030 

1*2226 

0-1536 

0*2743 

0*2739 

0*0004-1- 

3- 

0-7509 

1-7355 

0-1401 

0-4094 

0*4091 

0*0003  -1- 

4- 

0-7541 

1-7430 

0*1410 

0*4111 

0*4107 

0*0004 -f 

S* 

I'ooiS 

2-3456 

0*2187 

0-5458 

0-5456 

00002 -1- 

6. 

I '0005 

22435 

o-iig6 

0-5451 

0-5450 

o-oooi-i- 

oxidised  completely  by  the  permanganate  may  be  deter- 
mined by  the  process  outlined  above.  It  will  also  be 
seen  that  the  use  of  the  rubber  stopper  in  the  boiling  flask, 
with  due  care  to  prevent  its  contadt  with  the  solution, 
does  not  introduce  an  appreciable  error. 

Wanklyn  and  Cooper  (Phil.  Mag.,  [5],  vii.,  138)  and 
others  have  noted  the  fadl  that  potassium  permanganate, 
whether  in  acid  or  alkaline  solution,  will  not  oxidise  all 
organic  substances  (acetates,  for  example),  even  at  the 
boiling  temperature.  It  is  well  known  that  a  mixture  of 
concentrated  sulphuric  and  chromic  acids  has  a  much 
wider  field  of  adtion  in  oxidising  organic  compounds  than 
the  permanganate.  With  hopes  of  applying  this  reagent 
more  widely  to  the  determination  of  organic  carbon,  the 
experiments  about  to  be  recorded  were  tried. 

(To  be  continued). 


It  seems  possible  to  draw  the  general  conclusion  from 
the  results  recorded  that  organic  substances  which  are 


LONDON     WATER   SUPPLY. 

Report  on  the  Composition  and  Quality  of  Daily 
Samples  of  the  Water  Supplied  to  London 
for  the  Month  Ending  October  31st,  1897. 

By  SIR  WILLIAM  CROOKES,  F.R.S., 

and 

PROFESSOR  DEWAR,  F.R.S. 


To  Major-General  A.  De  Courcy  Scott,  R.E., 
Water  Examiner,  Metropolis  Water  Act,  1871. 

London,  November  lotb,  1897, 
Sir,— We  submit  herewith,  at  the  request  of  the 
Diredlors,  the  results  of  our  analyses  of  the  182  samples 
of  water  colledted  by  us  during  the  past  month,  at  the 
several  places  and  on  the  several  days  indicated,  from  the 
mains  of  the  London  Water  Companies  taking  their 
supply  from  the  Thames  and  Lea. 

In  Table  I.  we  have  recorded  the  analyses  in  detail  of 
samples,  one  taken  daily,  from  Odtober  ist  to  Odlober  31st 
inclusive.  The  purityof  the  water,  in  respedl  to  organic 
matter,  has  been  determined  by  the  Oxygen  and  Com- 
bustion processes;  and  the  results  of  our  analyses  by 
these  methods  are  stated  in  Columns  XIV.  to  XVIII. 

We  have  recorded  in  Table  II.  the  tint  of  the  several 
samples  of  water,  as  determined  by  the  colour-meter 
described  in  previous  reports. 

In  Table  III.  we  have  recorded  the  oxygen  required  to 
oxidise  the  organic  matter  in  all  the  samples  submitted 
to  analysis. 

Of  the  182  samples  examined  during  the  month  all  were 
found  to  be  clear,  bright,  and  well  filtered. 

The  rainfall  at  Oxford  during  the  month  shows  a  great 
deficiency,  only  1*22  inches  of  rain  having  fallen,  while 
the  average  for  the  last  30  years  is  2-75  inches,  making  a 
deficit  of  1*53  inches.  The  total  rainfall  for  the  year  now 
shows  a  deficit  of  0-41  inch. 

Our  badleriological  examination  of  253  samples  taken 
by  us  have  given  the  following  results  ;  we  have  also  ex- 
amined 72  other  samples,  from  stand-pipes,  special  points, 
wells,  &c.,  making  a  total  of  325  samples  in  all : — 

Microbes 
per  c.c. 

Thames  water,  unfiltered  (mean  of  26  samples)  3547 
Thames  water,  from  the  clear  water  wells  of 
five  Thames-derived  supplies  (mean  of  124 

samples) ..     ..     51 

Ditto        ditto               highest  434 

Ditto        ditto              lowest  o 

New  River,  unfiltered  (mean  of  26  samples)  ..  397 

New  River,  filtered  (mean  of  26  samples)       ..  35 

River  Lea,  unfiltered  (mean  of  26  samples)    ..  1588 
River  Lea,  from   the  clear  water  well  of  the 
East  London  Water  Company  (mean  of  25 

samples)     ..     ..     39 


54^ 


Ethers  of  Camphoroxime. 


(Chemical  t^ews, 
I    Nov.  19,  1897. 


The  filtration  and  settling  appliances  of  all  the  Com- 
panies have  been  in  a  high  state  of  efficiency  during  the 
past  month. 

The  water  of  every  Company  has  been  specially  tested 
for  pathogenic  organisms,  but  with  negative  results. 
We  are,  Sir, 

Your  obedient  Servants, 

William  Crooxes. 
James  Dewar. 


ELECTROLYTIC  SEPARATION  OF  NICKEL 

AND  COBALT  FROM  IRON. 

APPLICATION  TO.  THE  DETERMINATION  OF 

NICKEL  IN  STEEL. 

By  O.  DURN. 

The  accurate  separation  of  nickel,  and  nickel  and  cobalt, 
from  large  quantities  of  iron  presents  notable  difficulties. 
The  great  number  of  methods  already  published  proves 
that  no  really  satisfaAory  solution  of  the  difficulty  has 
been  reached. 

For  some  years  nickel  steels  have  taken  an  important 
industrial  rank,  whence  an  expeditious  and  precise  method 
presents  a  certain  interest.  In  his  chemical  study  on  the 
methods  of  analysis  of  irons  and  cast  metals,  Ad.  Carnot 
gives  the  preference  to  the  method  of  Rothe,  and  this 
method,  which  has  been  simultaneously  devised  in  France 
by  Hanrich,  depends  on  the  separation  of  ferric  chloride 
in  an  acid  solution  by  means  of  ether.  Latterly  Pinerua 
has  modified  this  method.  He  uses,  at  a  low  temper- 
ature,  ether  saturated  with  hydrochloric  acid. 

It  is  easy  to  arrive  at  the  same  result  by  means  of 
eledrolysis.  If  we  precipitate  by  ammonia  in  excess  a 
ferric  solution  containing,  e.g.,  nickel,  a  part  of  this  metal 
is  carried  down  by  the  ferric  hydrate.  If  we  submit  to  elec- 
trolysis  the  ammoniacal  liquid  holding  the  precipitate  in 
solution,  we  may  obtain  on  the  kathode  the  entire  deposit 
of  the  nickel.  The  separation  is  not  absolutely  accurate. 
Almost  always  a  minute  quantity  of  iron  is  also  deposited 
upon  the  kathode,  but  in  suitable  conditions  this  quantity 
ranges  about  i  to  2  m.grms.  when  the  iron  present  may 
reach  400  to  500  m.grms.  For  precise  experiments  it  is 
necessary  to  make  correction  in  the  weight  of  the  metal 
deposited,  which  is  easily  done  by  dissolving  the  deposit 
in  hydrochloric  acid  and  precipitation  with  ammonia  after 
for  oxidising. 

The  use  of  the  nitric  solution,  which  under  the  like 
conditions  enabled  M.  Riche  to  separate  copper  from  iron, 
presents  certain  inconveniences.  It  is  the  same  with 
the  hydrochloric  solution.  We  obtain  good  results  by 
operating  on  the  sulphuric  solution  to  which  ammonium 
sulphate  has  been  added.  The  following  is  the  process  : 
— The  solution  containing  nickel  and  iron  as  per-salts, 
with  the  addition,  if  needful,  of  a  slight  excess  of  sul- 
phuric acid,  is  evaporated  to  dryness,  is  then  taken  up  in 
a  minimum  of  water  with  the  addition  of  5  to  10  grms. 
ammonium  sulphate,  and  heated  until  a  clear  solution  is 
obtained.  This  liquid  is  poured  whilst  stirred  into  the 
crucible  of  Riche's  apparatus,  in  which  have  been  placed 
60  to  70  c.c.  of  concentrated  ammonia. 

As  a  source  of  electricity  we  use  two  or  three  accumu- 
lators,  arranged  in  tension  so  as  to  regulate  the  intensity 
of  the  current  at  the  outset  at  from  1-5  to  2*5  amperes. 
Under  these  conditions  the  nickel  is  entirely  deposited  in 
less  than  four  hours. 

The  method  has  been  checked  by  means  of  standard- 
ised solutions  of  iron  and  nickel,  some  of  the  resultB 
being—    . 


Metal       CorreAion     Ni  reco-      Differ- 
Iron.      Ni  (added),    deposited,      for  iron,         vered.         ence. 

1.  404-3  298  30*8  I'O  29-8  O'O 

2.  2695        74'6  759  i'3  746  o'o 

3.  269'5       149-2  150-1  0-8  149-3       +0*1 

The  same  procedure  is  equally  applicable  to  cobalt : — 

4.  404*2        62*5  63-4  1*9  61-5       -i-o 

Determination  of  Nickel  in  Steels.— V/e  attack  from 
250  to  300  m.grms.  of  the  sample  with  aqua  regia  in  a 
porcelain  capsule.  When  the  aiftion  is  complete  we  add 
I  c.c.  of  sulphuric  acid,  and  evaporate  until  white  fumes 
are  produced.— Com^^^s  Rendus,  cxxv.,  No.  11. 


PROCEEDINGS    OF    SOCIETIES. 


CHEMICAL  SOCIETY. 

The  following  are  the  abstradts  of  papers  received  during 
the  vacation,  and  published  in  the  Transactions  .- — 

96.  "  The  Ethers  of  Catnphoroxime."  By  M.  O. 
FORSTER,  Ph.D. 

The  methyl  ether  of  camphoroxime  boils  at  i8i'5— 182'5' 
under  a  pressure  of  357  m.m. ;  it  has  the  sp.  gr.  =0*9631, 
and  the  specific  rotatory  power  [a]o  =  — 13'05*  at  20*. 
It  does  not  reduce  an  ammoniacal  solution  of  silver 
nitrate,  and  dissolves  in  mineral  acids  without  under- 
going change.  The  nitrate  crystallises  from  benzene  in 
needles  melting  at  81 — 82',  and  has  [a]D=  — 16-9°  in 
benzene ;  the  hydriodide  is  amorphous,  and  melts  at  157° 
with  vigorous  effervescence. 

The  ethyl  ether  (Nigeli)  boils  at  185°  under  a  pressure 
of  336  m.m.,  and  has  the  sp,  gr.  =  09470  ;  the  specific 
rotatory  power  [o]d=  -  190°  at  23-5°. 

The  benzyl  ether  is  a  colourless  oil,  which  on  distilla- 
tion is  in  part  resolved  into  benzaldehyde  and  camphor- 
imine,  as  represented  by  the  equation — 

C,oHj6:  NO-CH2-C6H5  =  CioHi6:  NH  +  CeHj-CHO  ; 

it  has  [alD=  — 16'4°  in  alcohol,  and  forms  an  amorphous 
hydriodide  which  melts  at  91°.  Concentrated  sulphuric 
acid  resolves  the  ether  into  camphoroxime  and  the 
resinous  hydrocarbon,  C14H12,  obtained  on  dissolving 
benzylic  alcohol  in  concentrated  sulphuric  acid.  Alcoholic 
hydrochloric  acid  eliminates  a-benzylhydroxylamine  from 
the  ether ;  the  piatinochloride  of  this  base  forms  golden- 
yellow  scales,  and  does  not  melt  below  250°. 

The  acetyl  derivative  of  camphoroxime  is  a  colourless 
liquid,  and  is  completely  converted  into  acetic  acid  and 
campholenonitrile  on  distillation ;  it  has  the  specific 
rotatory  power  [a]o=  —45*8°  in  alcohol,  and  on  treatment 
with  cold  phenylhydrazine  yields  symmetrical  acetyl- 
phenylhydrazine  and  camphoroxime. 

The  benzoyl  derivative  crystallises  from  acetone  in 
magnificent  six-sided  prisms,  and  melts  at  88 — 90° ;  it  has 
[a]D=— 40-7°  in  alcohol,  and  yields  benzanilide  when 
heated  with  aniline.  Cold  phenylhydrazine  gives  rise  to 
benzoylphenylhydrazine  and  camphoroxime.  Camphor- 
oxime hydrobromide  melts  and  evolves  hydrogen  bromide 
at  174°;  it  has  [o]d=  —  SS'S"  in  alcohol,  and  is  converted 
by  glacial  acetic  acid  into  campholenonitrile  and  hydrogen 
bromide.  Camphoroxime  piatinochloride  crystallises  in 
transparent  prisms  which  become  opaque  in  the  desic- 
cator, and  melts  at  1565°  with  vigorous  effervescence ; 
cold  water  regenerates  the  oxime.  Inactive  camphoroxime 
melts  like  the  a^ive  modification  at  118°;  it  crystallises 
from  petroleum  in  diamond-shaped  plates,  and  is  racemic 
according  to  the  classification  recently  suggested  by 
Kipping  and  Pope  (Proe.  Chtm.  Soc,  1897,  p.  135). 


Chemical  News,  i 
Nov.  19, 1897.    I 


Phenanthrone, 


249 


97.  ••  The  Action  of  Nitrogen  Trioxide  and  Tetroxide 
on  Alcohols.''  Pari  I.  By  JuLius  Berend  Cohen,  Ph.D., 
and  Harry  Thornton  Calvert,  B.Sc. 

The  authors  have  found  that  when  nitrogen  trioxide  or 
tetroxide  dissolved  in  chloroform  is  allowed  to  a6t  upon 
benzyl  alcohol,  that  water  is  in  both  cases  eliminated, 
and  compounds  of  the  formula  C6H5CHN2O3  and 
C6H5CHN2O4  are  probably  formed,  which  rapidly  decom- 
pose on  standing  into  benzaldehyde,  with  the  separation 
in  the  first  case  of  nitric  oxide,  and  in  the  second  of  nitro- 
gen trioxide,  according  to  the  following  equations: — 
(r)  C6H5CHN203  =  C6HsCOH+2NO, 
(2)     C6H5CHN204  =  C6H5COH  +  Na03. 

The  latter  substance,  which  may  be  termed  benzylidene 
nitrosate,  is  decomposed  by  water  into  a  compound  of  the 
formula  C7H7NO3,  which  is  probably  identical  with  a  sub- 
stance obtained  by  Lippmann  and  Hawliczek  [Ber.,  1876, 
ix.,  1463)  by  the  adlion  of  nitric  acid  upon  benzaldehyde. 
By  the  acftion  of  reducing  agents  it  is  converted  into 
benzyl  alcohol,  benzylamine,  and  ammonia. 

98.  •'  The  Action  of  Nitrogen  Tetroxide  on  Ortho-  and 
Para-nitrohemylalcohol."  By  Julius  B.  Cohen,  Ph.D., 
and  William  H.  Harrison,  B.Sc. 

The  authors  have  discovered  a  simple  method  for  pre- 
paring the  aldehydes  corresponding  to  ortho-  and  para- 
nitrobenzylaicohol.  The  readtion  consists  in  treating  the 
alcohol  with  a  small  quantity  of  nitrogen  tetroxide  in 
presence  of  air.  A  nearly  theoretical  yield  of  these  alde- 
hydes, hitherto  very  difficult  to  prepare,  has  been  effefted 
by  this  method. 

99.  "  The  Action  of  Aromatic  Amines  upon  Diacetyl- 
tartaric  Anhydride."  By  Julius  Berend  Cohen,  Ph.D., 
and  William  Hudson  Harrison,  B.Sc. 

In  attempting  to  prepare  the  isomeric  toluido-acetyl 
tartaric  acids,  by  acting  upon  diacetyltartaric  anhydride 
with  the  isomeric  toluidines,  with  a  view  to  comparing 
their  optical  charadters,  the  authors  were  unsuccessful  ; 
but  obtained,  on  the  other  hand,  by  this  readtion  with 
different  aromatic  amines,  a  series  of  golden-yellow 
crystalline  compounds.  The  formula  of  the  aniline  com- 
pound is  probably  C16H12N2O3,  that  of  the  paratoluidine 
compound  C18H16N2O3,  and  of  the  onaphthylamine  com- 
pound C27H16N2O3.  The  constitution  of  these  compounds 
has  not  yet  been  ascertained.  The  readtion  in  all  cases 
is  very  complex,  and  the  yield  of  the  yellow  substances 
very  small. 

100.  "  Studies  on  Citratinic  Acid."  Part  V.  By  W.  J. 
Sell,  M.A.,  and  F.  W.  Dootson,  B.A. 

This  investigation  was  commenced  with  the  view  of 
obtaining  some  evidence  of  the  positions  of  the  hydroxyl 
groups  in  citrazinic  acid,  by  preparing  the  corresponding 
dichlorisonicotinic  acid,  and  then  replacing  the  chlorine 
atoms  either  by  cyanogen  or  methyl,  and  thus  by  well- 
known  methods  obtaining  one  of  the  tricarboxy-acids 
whose  constitution  has  been  established.  In  the  prepara* 
tion  of  the  dichlorisonicotinic  acid  by  the  interadlion  of 
phosphorus  pentachloride  on  citrazinic  acid,  however, 
such  a  number  of  interesting  substances  were  found  to  be 
produced  that  it  was  determined  to  publish  this  part  of 
the  work  at  once,  leaving  the  remainder  for  a  further 
communication.  The  following  substances,  amongst 
others,  have  been  isolated,  and  are  described  in  the 
paper  : — 

(i)  Chlorhydroxyisonicotinic  acid;  (2)  dichloriso- 
nicotinic acid ;  (3)  tetrachlorisonicotinic  acid  chloride ; 
(4)  ajSa'^'-tetrachlorisonicotinic  acid  ;  (5)  tetrachlorpyri- 
dine ;  (6)  pentachlorpyridine  ;  (7)  pentachlorpicoline. 

101.  •'  The  Condensation  of  Chloral  with  Resorcinol." 
Part  II.  By  J.  T.  Hev^tt,  M.A.,  D.Sc,  and  Frank  G. 
Pope. 

In  an  earlier  paper  (Trans.,  1896,  Ixix.,  1265)  the  view 
was  expressed  that  the  substance  of  the  formula 
Cx4Hx»03,  obtained   by   the   condensation    of    chloral 


hydrate  with  resorcinol,  was  a  ladlone  of  2  :  4  :  2'  :  4'- 
tetrahydroxydiphenylacetic  acid.  The  authors  had  over- 
looked a  paper  by  Michael  and  Comey  {Amer.  Chetn. 
jfourn.,  1883-4,  v.,  350),  in  which  the  formula  C8H6O3 
was  attributed  to  the  compound  in  question.  The  deter- 
mination of  the  molecular  weight  by  the  lowering  of 
freezing-point  of  a  phenolic  solution  gave  as  result  232  ; 
the  values  required  by  the  formulae  CgHeOs  and  C14H10O5 
being  150  and  258  respeAively.  The  analyses  of  the 
acetate  and  benzoate  have  further  confirmed  the  authors' 
views  that  the  compound  possesses  three  hydroxyl 
groups.  In  addition  to  this,  it  has  been  found  that  a  red 
salt  is  precipitated  when  an  excess  of  sodium  ethylate 
solution  is  added  to  an  absolute  alcoholic  solution  of  the 
ladlone:  the  salt  was  found  to  contain  22*10  per  cent  of 
sodium,  whilst  the  formula  Ci4H705Na3  requires  2i'3o 
per  cent  of  sodium. 

The  analysis  of  the  salt,  obtained  by  boiling  the  ladlone 
with  water  and  barium  carbonate,  led  to  the  formula 
Ba(Ci4HiiOe)2;  the  soluble  zinc  salt  obtained  in  a  similar 
way  gave  a  percentage  of  zinc  which  agrees  with  the 
formula  Zn(Ci4Hii06)2. 

102.  "On  ^-oxy  cellulose."  By  Benjamin  Samuel  Bull, 
M.A.,  B.Sc. 

/S-oxycellulose  has  been  studied  by  several  workers,  and 
Cross  and  Bevan  have  prepared  a  trinitro-derivative.  In 
this  paper  a  benzoate  and  nitrate  obtained  from  /3  oxy- 
cellulose  are  described.  These  compounds  are  probably 
hexa-derivatives  of  a  substance  having  the  empirical 
formula  C16H27O14. 

103.  "^  New  Synthesis  of  Phloroglucinol."  By  David 
S.  Jerdan,  B.Sc. 

When  finely  divided  sodium  is  dissolved  in  a  benzene 
solution  of  ethylic  acetone-di-carboxylate,  and  the  solu- 
tion is  boiled  for  some  hours,  a  gummy  deposit  is  slowly 
formed.  The  whole  is  then  shaken  with  water,  and  the 
aqueous  solution,  after  separation  of  the  benzene,  is 
acidified  with  sulphuric  acid.  The  solution  becomes 
milky,  and  a  granular  precipitate  falls  after  a  short  time. 
The  new  substance  may  be  re-crystallised  from  glacial 
acetic  acid,  and  then  possesses  a  composition  correspond- 
ing with  the  formula  C12H10O7. 

This  compound,  when  boiled  with  methylic  alcohol 
containing  3  per  cent  of  hydrogen  chloride,  took  up  a 
molecule  of  alcohol,  giving  a  crystalline  ester,  Ci3Hi40|. 
The  substance  C12H10O7  must  therefore  be  a  ladtone. 
Further,  on  hydrolysis  with  baryta  solution,  the  ladtone 
gave  carbon  dioxide,  alcohol,  malonic  acid,  and  phloro- 
glucinol. The  new  compound  is  therefore  a  phloroglucinol 
derivative. 

It  is  probably  formed  according  to  the  equation — 

2CioHi405-f-3Na  =  Ci2Hio07+3NaOCaH5-f3H. 

The  immediate  produdt  of  the  readtion  must  of  course  be 
a  sodium  derivative,  the  ladtone  Ci2Hio07  being  formed 
from  this  on  addition  of  sulphuric  acid. 

104.  "  Phenanthrone."  By  Francis  R.  Japp,  F.R.S., 
and  Alexander  Findlay,  M.A.,  D.Sc. 

Phenanthrone  was  regarded  by  its  discoverer,  Lachowicz 
(y.  Pr.  Chem,,  1883,  [zj,  xxviii.,  173),  as  a  ketone  of  the 
formula — 

C5H4'CH2 

I  I       . 

C6H4CO 

Japp  and  Klingemann  (Trans.,  1893,  Ixiii.,  770)  suggested 
that  it  might  be  a  phenol  of  the  formula — 

C6H4CH 

I        II        {0-phenanthrol). 
CeHvCOH 

In  the  hope  of  deciding  between  these  two  formula,  the 
present  authors  have  prepared  various  derivatives  of 
phenanthrone.  The  evidence,  however,  points  in  both 
diredtions.     The  compound  rta&i  both  in  the  kttoni* 


250 


Derivatives  of  Cotoin  and  Phloretin. 


'  Chemical  Nbws 
1     Nov.  19.  1897 


and  in  the  phenolic  form,  although  more  frequently  in  the 
latter.  In  the  great  majority  of  its  readions  it  is  a  stridt 
analogue  of  )3-naphthol. 

In  preparing  phenanthroneby  the  method  discovered  by 
Japp  and  Klingemann— reduction  of  phenanthraquinone 
with  hydriodic  acid — the  authors  find  that  two  other  sub- 
stances are  simultaneously  formed  :  ^-phenanthrylic  oxide, 
(Ci4Hg)20  (m.  p.  210°),  and  tetraphenylenefur/uran,— 

CeH^C C-C6H4 

I  II        II  I 

C6H4.C-0-CC6H4 

(m.  p.  306°),  The  latter  was  obtained  by  Japp  and 
Klingemann  by  the  destrudlive  distillation  of  monacetyl 
phenanthraquinol. 

Phenanthrone  and  /3-phenanthrylic  oxide  both  yield 
molecular  compounds  with  picric  acid, — 
Ci4HioO,C6H2(N02)30H 
fm.  p.  185°)  and  (Ci4H9)20,2C6H2(N02^30H  (m.  p.  148°). 
Phenanthrone,  when  in  solution,  is  converted  by  aerial 
oxidation  into  the  compound  C28H18O3  (obtained  by 
another  process  by  Japp  and  Klingemann),  which  crys- 
tallises in  dark  red  laminae  melting  at  156—157°.  This 
compound  is  broken  up  by  acetic  anhydride  into  phen- 
anthrone and  phenanthraquinone,  the  former  undergoing 
acetylation.  It  may  be  synthesised  by  the  diredl  union  of 
phenanthrone  and  phenanthraquinone.  The  authors 
regard  it  as  an  aldol  condensation  compound  of  these  two 
substances,  and  ascribe  to  it  the  constitution — 

C6H4-C(OH)CH-C6H4 

II  II- 

C6H4-CO       CO-C6H4 

On  boiling  with  fuming  hydriodic  acid,  it  is  converted 
quantitatively  into  tetraphenylenefurfuran.  Acetic  an- 
hydride converts  phenanthrone  into  ^  -  phenanthrylic 
acetate,  Ci4H9-0-C2H30  (m,  p.  77—78°).  When  heated 
with  methylic  alcohol  and  sulpnuric  acid,  phenanthrone 
yields  methylic-fi.phenanthrylic  oxide,  Ci4HgO*CH3  (m.  p. 
96—97°).  When  heated  with  ammonic  it  yields  a  mix- 
ture of  $-phenanthrylamine,  Ci4Hg'NH2  (m.  p.  I39°).  and 
^-diphenanthrjlamine,  (Ci4Hg)2NH  (m.  p.  237°).  With 
phenylhydrazine  at  200°  it  interadls,  eliminating  water 
and  ammonia  and  yielding  2' :  ^'-diphenyleneindole  (ra.  p. 
188—189°). 

105.  '•  The  Yellow  Colouring:  Principles  of  various 
Tannin  Matters."    IV.     By  A.  G.  Perkin. 

Cape  sumach,  the  leaves  of  the  Colpoon  cotnpressum,  is 
used  in  South  Africa  as  a  substitute  for  sumach  {Rhus 
Coriaria)  under  the  name  of  "  Pruim-bast."  According 
to  H.  ProiSer  (private  communication),  it  contains  23  per 
cent  of  a  catechol  tannin.  Its  dyeing  property  is  due  to 
the  presence  of  a  new  glucoside,  osyritrin,  C27H30O17, 
pale  yellow  needles,  m.  p.  185°,  which  is  decomposed  by 
acid  into  quercetin  and  glucose, — 

C27H3oOi7-l-2H20  =  Ci5Hio07-f-2C6Hx206. 
This  is  not  identical  with  viola-quercetrin  (Mandelin,  y., 
1883,  1369),  C42H42O24,  which  exists  in  the  Viola  tricolor 
fiorensis.  The  tannin,  obtained  as  an  orange-coloured 
transparent  mass,  is  a  glucoside  yielding,  with  acid,  an 
anhydride  or  phlobophane  and  a  sugar.  By  fusion  with 
alkali,  protocatechuic  acid  is  formed.  A  re-examination 
of  gambler  catechu  (Ungarica  Gambler)  corroborated  the 
statement  of  Lowe  {Zeit.  Anal.  Chem.,  1874,  xii.,  127) 
that  this  contains  quercetin.  Acacia  catechu  not  pre- 
viously examined  was  found  to  contain  the  same  colouring 
matter. 

The  dyeing  properties  of  a  commercial  sample  of 
Venetian  sumach  {R,  Cotinus)  are  due  to  myricetin  and 
not  to  quercetin  as  stated  by  Lowe  {loc.  cit).  This  result 
will  be  corroborated  by  the  examination  of  a  specially 
picked  sample. 

Valonia    (Quercus    JEgilops),    divi  -  divi    [Ceesalpina 


Coriaria),  myrabolans  (Terminalia  chebula),  agarobilla 
(Ccesalpma  brevifolia),  pomegranate  rind  {Punica  grana- 
tum),  and  gall-nuts  [Quercus  infectoria),  owe  their  tinc- 
torial property  to  ellagic  acid,  and  contain  no  member  of 
the  quercetin  group.  It  is  here  pointed  out  that  the 
plants  examined  hitherto  contain,  respedtively,  a  tannin 
and  colouring  matter  which  yield  on  decomposition 
identical  acids,  and  in  some  cases  the  same  phenol. 

106.  ^*  Ammonia  and  Phenylhydrazin  Derivatives  of 
afS-Dibenzoylcinnatnene  (AnhydracetophenonebenzU)."  By 
Francis  R.  Japp,  F.R.S.,  and  Alfred  Tingle,  B.Sc. 

By  oxidising  dibenzoylcinnamenimide,  C22H17NO — the 
first  produ(5t  of  the  adtion  of  ammonia  on  dibenzoyK 
cinnamene — with  chromium  trioxide,  the  authors  have 
obtained  a  mixture  of  dibenzamide,  benzamide,  and  re- 
generated dibenzoylcinnamene. 

By  reducing  dibenzoylcinnamenimide  with  zinc  dust 
and  acetic  acid  in  the  cold,  A.  Smith's  triphenylpyrrhole, — 

CeHj-C— CH 

II     II 
C6H5C    C-CeHs 

NH 

melting  at  140 — 141°  {Trans.,  1890,  lvii.,645),  is  formed. 

The  authors  discuss  the  various  reaftions  of  dibenzoyl- 
cinnamene and  dibenzoylcinnamenimide,  and  ascribe  to 
these  compounds  the  formulae — 

C6H5-C:=CH  CeHs'C CH 


O 


and 


CeHs-c/Nc-CeHj 
O 


o 


CeHjc/NcCeHs. 


NH 


It  seems  to  be  impossible  to  assign  to  dibenzoylcinna- 
menimide, for  example,  any  other  formula  which  will  ac- 
count for  the  formation  of  dibenzamide  during  oxidation. 
By  the  oxidation  of  triphenylpyrrholone — the  trans- 
formation produd  of  dibenzoylcinnamenimide  under  the 
influence  of  heat — with  chromium  trioxide,  the  authors 
have  obtained  a  compound  which  they  regard  as  triphenyU 
hydroxypyrrholone  (m.  p.  168°), — 


(C6H5)2C CH 

I 


CO     C-CeHs 

\/ 

NH 


+  0  = 


(C6H5)aC COH 

I  II 

CO     C-CeHs, 

\/ 

NH 


or  one  of  its  possible  tautomeric  forms.  Heated  with 
caustic  potash,  this  compound  evolves  ammonia,  and 
yields  a  mixture  of  benzilic  and  benzoic  acids. 

The  authors  have  also  studied  the  destrudtive  distilla- 
tion of  the  compound  C28H22N2  (m.  p.  about  230°),  ob- 
tained by  Japp  and  Huntly  {Trans.,  1888,  liii.,  184)  by  the 
adlion  of  phenylhydrazin  on  dibenzoylcinnamene.  They 
find  that  it  yields  the  1:3:  /^.triphenylpyrazole  obtained 
by  A.  Smith  {Annalen,  1896,  cclxxxix.,  332)  by  the 
destrudive  distillation  of  tetraphenyldihydro-i :  2-diazine. 
They  point  out  that  result  renders  it  very  improbable  that 
the  compound  C28H22N2  has  the  constitution  of  an 
anilidotriphenylpyrrhole,  ascribed  to  it  by  Japp  and 
Klingemann  {Trans.,  i8go,  Ivii.,  671). 

107.  "  Derivatives  of  Cotoin  and  Phloretin."  By  A.  G. 
Perkin  and  H.  W.  Martin. 

A  study  of  the  acetylisation  of  the  diazobenzene  deriva- 
tives  of  cotoin  and  phloretin. 

Cotoin,  C14H12O4,  a  constituent  of  coto-bark,  is, 
according  to  Ciamician  and  Silber,  a  monometbyl  ether 
of  benzoylphloroglucinol,  C6H2(OCH3)(OH)2-CO— C6H5 
{Ber.,  1894,  xxvii.,  409).     Cotoinazobenzene, — 

C14H11O4C6H5N2, 
forms  orange-yellow  needles,   m.  p.  183 — 184".    Cotoin* 
azo'O-toluene,  Ci4Hii04*CH3-C6H4Nai  m.  p.   303—204", 


Chemical  Kbws, 
Nov.  19, 1897. 


hothermals  6/  Eth&r^ 


251 


and    cotoinazo-p -toluene,    m.   p.    207 — 208°,    crystallise 
similarly.    Diacetyl-azo-benzene  cotoin, — 

C,4H904(C2H30)2-C6HsN2, 
crystallises  in  scarlet  needles,  m.  p.  155 — 156°.     As  with 
the  maclurin   compound   {Trans.,  1897,  Ixxi.,    186),   the 
acetyl-groups    could     be    determined    by    Liebermann's 
method. 

Phloretin,  C15H14O5,  occurs  in  the  root  bark  of  the 
apple  tree  as  a  glucoside  phloridzin.  According  to 
Ciamician  and  Silber,  it  has  the  constitution 
C6H2(OH)3-COCH(CH3)  •C6H4-OH.  Phloretin  -  disazo- 
benzene,  Ci5Hi205(C6H5N2)2,  red  needles,  m.  p.  254— 
256",  phloretin-dtsazo-o-toluene,  m.  p.  250 — 251°,  and 
phloretindisazo -p -toluene,  m.  p.  250 — 251°,  closely 
resemble  the  corresponding  maclurin  derivatives.  Acetyl 
phloretindisazobenzene,  Ci5Hii05(C2H30)(C6H5N2),  forms 
orange-red  needles  meltmg  at  217 — 219°.  No  higher 
acetyl  derivative  could  be  obtained.  Comparing  this  re- 
sult with  those  previously  obtained  with  maclurin  and 
phloroglucinoldisazobenzenes  {Trans.,  1897,  '"'''••  ^tSS),  it 
would  thus  appear  that  phloretin  contains  only  three 
hydroxyl  groups.  From  Ciamician  and  Silber's  work 
there  appears  to  be  no  doubt,  however,  as  to  the  correft- 
ness  of  their  constitution  for  phloretin  {loc.  cit.).  Thus, 
all  hydroxyls  in  the  phloroglucinol  nucleus  of  phloretin 
must  in  diazobenzenephloretin  be  in  the  ketonic  form,  a 
peculiarity  which  in  some  way  is  therefore  due  to  the  in- 
fluence of  the  phloretol  group. 

108.  "  Azobeneene  Derivatives  0/ Phloroglucinol."  By 
A.  G.  Perkin. 

Though  phloroglucinol  is  known  to  yield  azo-  and 
disazo-derivatives  as  phloroglucinol-^-azobenzene  sul- 
phonic  acid,  C6H503-N2-C6H4-S03H  (Stebbins,  Am. 
Chem.  Soc.  J.,  1880,  ii.,  240),  and  disazobenzenephloro- 
glucinol,  C6H403(N2-C6H5)2  (Weselsky  and  Benedikt, 
Ber.,  1879,  xii.,  226),  no  irisazo-compounds  have  been 
previously  obtained,  though  judging  from  its  constitution 
the  formation  of  such  should  be  expeded. 

Phloroglucinoltrisazobenzene,  C6H303(C6H5N2)3,  fine 
needles  possessing  a  green  iridescence  which  do  not  melt 
below  300°,  is  formed  by  addition  of  diazobenzene  sul- 
phate to  a  solution  of  phloroglucinol  in  aqueous  sodium 
carbonate.  Its  production  is  independent  of  the  amount 
of  diazobenzene  sulphate  employed.  It  contains  no  free 
hydroxyl  groups,  being  insoluble  in  alkaline  solutions. 

Phloroglucinol-o  trisazoanisol  is  prepared  from  phloro- 
glucinol and  odiazoanisol  in  either  sodium  carbonate  or 
acetate  solution.  No  corresponding  disazo-compound 
could  be  obtained  in  this  manner.  It  forms  maroon 
coloured  needles  melting  above  300°,  insoluble  in  alkaline 
solutions. 

Phloroglucinol  -  disazobenzene  -  m  -  azonitrobenzene,  ob- 
tained from  phloroglucinol-disazobenzene  and  w-diazo- 
nitrobenzene,  forms  dull  red  needles,  m.  p.  290°. 

It  is  proposed  to  study  the  readtion  of  other  substituted 
diazobenzenes  with  phloroglucinol  under  similar  condi- 
tions. 

109.  "The  Action  of  Phosphorus  Pentachloride  on 
Fenchone."    By  J.  Addyman  Gardner,  M.A.,  and  G.  B. 

COCKBURN,  B.A. 

Fenchone  is  adled  on  at  the  ordinary  temperature  very 
much  more  slowly  than  camphor,  and  the  produfts  of  the 
a&ion  are  different,  for  on  pouring  into  water  to  get  rid  of 
the  excess  of  phosphorus  pentachloride  and  oxychloride, 
the  authors  obtained  a  crystalline  compound  of  the  for- 
mula CioHi4ClPO(OH)2,  which  they  name  chlorofenchone- 
phosphoric  acid,  and  an  oil  consisting  of  unchanged  fen- 
chone and  a  substance  containing  chlorine,  probably 
chlorofenchone. 

Chlorofenchone  phosphonic  acid  is  a  white  crystalline 
solid,  melting  at  196'.  It  is  very  soluble  in  ether,  alcohol, 
chloroform,  and  benzene,  but  more  sparingly  soluble  in 
water.  It  is  a  dibasic  acid,  and  the  sodium  salt  crystal- 
lises in  white  needle-shaped  crystals.    The  lead,  barium, 


and  copper  salts  are  insoluble  in  water.      The  oil  con- 
taining chlorine  is  at  present  under  investigation. 

no.  "  Ketolactonic  Acid  and  its  Homologues"  By 
C.  H.  G.  Sprankling,  B.Sc. 

In  1882,  Young  {Trans.,  1883,  xliii.,  172)  observed  that 
when  /8-eihylacetosuccinic  ether  is  slowly  distilled,  a  little 
alcohol  is  liberated,  and  on  hydrolysis  of  the  distillate 
with  hydrochloric  acid  a  crystalline  acid,  C8H10O4,  is 
formed  in  addition  to  a-ethyl-/3  acetopropionic  acid  and  a 
small  quantity  of  ethylsuccinic  acid. 

The  barium  salt,  Ba{C8Hg04)2,  is  obtained  by  the  adtion 
of  barium  carbonate;  a  cold  solution  of  barium  hydrate 
gives  the  salt  of  )3-ethylacetosuccinic  acid,  whilst  at  100° 
barium  carbonate  is  precipitated  and  the  salt  of  a-ethyK 
j3  acetopropionic  acid  is  formed. 

From  its  composition,  method  of  formation,  and  be- 
haviour it  was  concluded  that  the  crystalline  acid,  to 
which  the  name  ketola(5tonic  acid  was  given,  has  the  con- 
stitution— 

COaH 


C    . 

EfCH 


C-Me 


CO— O 

At  Prof.  Young's  suggestion,  these  experiments  have 
been  repeated,  and  a  much  larger  yield  of  the  crystalline 
acid  has  been  obtained  by  prolonged  heating  of  the  /8- 
ethylacetosuccinic  ether  before  hydrolysis. 

The  lower  homologues  of  the  acid  have  also  been  pre- 
pared in  a  pure  state  from  acetosuccinic  ether  and  /S- 
methylacetosuccinic  ether  respeftively,  and  it  has  been 
found  that  by  prolonged  heating  of  jS-isopropylaceto- 
succinic  ether  and  subsequent  hydrolysis  with  hydro- 
chloric acid  a  very  small  quantity  of  the  higher  homo- 
logue  is  formed. 

It  is  thus  shown  that  the  crystalline  acid  obtained  by 
Young  is  the  third  member  of  a  series  to  which  the 
general  name  ketoladtonic  acid  may  conveniently  be 
given.  It  will  be  necessary,  however,  to  call  the  lowest 
member  of  the  series  ketoladtonic  acid,  the  others  being 
named  methyl,  ethyl,  isopropylketoladtonic  acid. 

Ketoladtonic  acid, C6H6O4, does  not  crystallise;  methyl- 
ketoladtonic  acid,  like  the  ethyl-compound,  forms  colour- 
less crystals,  m.  p.  176°. 

The  barium  salts  corresponding  to  those  derived  from 
the  ethyl-compound,  were  prepared  from  ketoladtonic  acid 
and  methyl-ketoladtonic  acid. 

The  rate  of  adtion  of  sodacetoacetic  ether  on  the 
brominated  fatty  ethereal  salts,  the  rate  of  elimination  of 
ethyl  alcohol  from  the  )3-alkylacetosuccinic  ethers,  and 
the  rate  of  hydrolysis  of  the  ethers  differ  greatly  in  the 
four  cases  examined,  the  rate  in  general  diminishing 
rapidly  with  rise  of  molecular  weight. 

The  hydrolysis  of  the  /3-alkylacetosuccinic  ethers  may 
take  place  in  two  ways— (a)  The  acetyl-group  is  replaced 
by  hydrogen  and  an  alkylsuccinic  acid  is  formed;  (b) 
carbon  dioxide  is  evolved  and  an  a  alkyl-j8-acetopropionic 
acid  formed.  With  the  ethers  investigated,  the  higher 
the  rnolecular  weight  of  the  alkyl-group  the  larger  is  the 
relative  yield  of  the  alkyl  succinic  acid. 


PHYSICAL    SOCIETY. 
Ordinary  Meeting,  November  12th,  1897. 

Mr.  G.  Johnstone  Stoney,  Vice-President,  in  the  Chair. 

Mr.  J.  Rose-Innes  read  a  paper  on  "  The  Isothermals  of 
Ether." 

The  well-known  generalisations  of  Boyle  and  Gay* 
Lussac  with  regard  to  the  pressure,  volume,  and  temper- 
ature  relations  of  gases,  were  examined  by  Ramsay  and 


252     

Young,  who  deduced  the  law  p^bt  —  a,  i.  e.,  that  pressure 
is  a  linear  funflion  of  temperature,  at  constant  volume, 
where  b  and  a  are  fundions  of  volume  only.  It  yet  re- 
mains to  discover  the  form  of  these  two  fundtions,  b  and  a. 
The  author  finds  b  and  a  for  a  large  number  of  volumes, 
and  from  them  devises  an  empirical  formula.  As  a  pre- 
liminary step  he  examines  whether  any  single  algebraical 
expression  can  represent  the  case,  so  as  to  determine  the 
probability  of  discontinuity.  For  this  purpose  a  graphic 
method  is  applied.  By  plotting  (a  V*)- ',  against  V -i, 
a  curve  is  obtained  of  "  cusp  "-shape.  The  point  of  the 
cusp  occurs  very  near  critical  volume;  it  suggests  dis- 
continuity in  the  slope  of  (aV*)-^  The  author  concludes 
that  there  is  extremely  rapid  change  of  behaviour  of  the 
gas  at  this  point.  Again,  it  is  known  that  the  temper- 
ature at  which  pressure  is  accurately  given  by  the  laws  of 
a  perfe(5t  gas  at  a  particular  volume  it>  constant  for  large 
volumes  until  critical  volume  is  approached.  The  author 
observes  that  at  the  critical  volume  this  temperature 
diminishes  somewhat  from  its  value  for  large  volumes. 
These  conclusions  were  embodied  in  a  previous  paper,  and 
an  algebraical  expression  for  pressure  in  terms  of  tem- 
perature and  volume  were  then  given  for  isopentane. 
In  the  present  paper  the  author  investigates  a  similar 
formula  for  ether. 

Prof.  Ramsay  said  that  experimental  errors  might 
account  for  some  of  the  lack  of  agreement  between 
proposed  formulae  and  diredt  observation  of  the  behaviour 
of  gases.  Isopentane  was  probably  a  better  investigated 
body  than  ether,  for  it  was  simpler.  Ether  tended  to 
form  complex  molecular  groupings,  but  isopentane  was 
probably  a  mono-molecular  liquid. 

Prof.  Perry  did  not  quite  agree  with  the  author's  con- 
clusions. It  was  necessary  to  distinguish  between  a 
formula  founded  on  a  physical  hypothesis  and  a  mere 
empirical  formula.  The  author  had  assumed  that  the 
Ramsay  and  Young  formula  was  very  exadt;  its  originators 
did  not  put  it  forward  as  being  infinitely  exadt.  Probably 
the  best  test  for  such  a  formula  as  that  under  discussion 
would  be  derived  from  some  thermo-dynamical  conclusion 
deduced  from  it.  The  Rose-Ihnes  formula  with  five  con- 
stants and  implying  discontinuity,  was  to  be  distrusted, 
for  there  was  no  such  thing  as  discontinuity  in  the 
problem.  In  any  case,  an  empirical  formula  should  have 
a  very  simple  form. 

Mr.  Rose-Innes  admitted  that  a  formula  founded  on 
Bound  hypothesis  was  to  be  preferred  to  empirical 
expressions.  But  mathematicians  had  not  yet  provided 
a  hypothesis  applicable  to  a  substance  whose  molecular 
arrangement  was  so  complicated  as  that  oi  ether. 
Mathematicians  must  therefore  improve  their  methods 
before  working  formulae  could  be  deduced  from  their 
hypotheses.  The  use  of  an  empirical  formula  with  five 
constants  was  justified  by  Kepler  for  the  planetary  orbits. 
Kepler  used  that  formula  with  no  other  justification  than 
his  experience  that  an  ellipse  fitted  his  observations 
better  than  a  circle.  Similar  instances  might  be  cited 
from  recent  work  on  the  theory  of  solution,  and  osmotics. 

Mr.  Johnstone  Stoney  was  disposed  to  look  for  a 
mathematical  cause  for  the  cusp ;  it  was  improbable  that 
the  physical  change  was  so  abrupt  as  that  represented 
graphically  by  the  author.  The  question  might  be  tested 
by  plotting  the  two  curves  y  =  V  -  4  and_y=aV»,  and  by 
observing  whether  these  also  suggested  discontinuity. 

Mr,  W.  L.  Waters  then  read  a  paper  on  the 
"  Variations  in  the  E.M.F.  of  the  H-form  of  Clark  Cells 
with  Temperature." 

The  authors,  Messrs.  F.  S.  Spiers,  F.  Twyman,  and 
W.  L.  Waters,  have  investigated  how  nearly  the  true 
E.M.F.  of  Clark  cells  can  be  computed  at  different 
temperatures  by  applying  the  ordinary  temperature 
corre&ion.  As  a  standard,  two  cells  of  the  Muirhead 
type  are  employed.     The  four  cells  under  test  could  be 

Eut  through  cycles  of  temperature  in  a  special  heating- 
ath|  tontaining  oil  tirculated  by  t  cantrifagal  pumpiog- 


Treatment  of  Battery  Slimes. 


I  Cbbmical  News, 
«     Nov.  ig,  1897. 


vane.  E.M.F.'s  were  determined  by  a  potentiometer 
method,  and  a  careful  study  was  made  of  the  "lag"  of 
E.M.F,  behind  temperature.  The  results  are  given  in 
the  form  of  curves.  It  is  shown  that  "lag,"  in  the 
H-form  of  cell,  is  less  than  in  the  "  Board  of  Trade  " 
form.  Under  ordinary  conditions,  when  the  rate  of 
variation  of  temperature  is  less  than  2°  C.  per  hour,  by 
applying  temperature-corredtions  the  true  E.M.F.  of  the 
H-form  can  be  found  to  within  a  ten-thousandth  of  a 
volt.  In  this  respedt  there  is  little  to  choose  between  the 
H-form  and  the  "  Muirhead  "  cell. 

Mr.  W.  R.  Cooper  thought  the  authors  did  not  express 
the  case  clearly.  The  E.M.F.  of  the  "  Board  of  Trade" 
cell  could  not,  with  reason,  be  itself  stated  within  i  per 
cent.  But  in  some  cases,  when  for  instance  cells  were 
used  differentially,  greater  accuracy  might  be  required,  as 
for  example  when  a  constant  source  of  E.M.F.  was  being 
compared  with  the  variations  of  another  source ;  here  it 
might  be  necessary  to  know  the  "  lag."  He  would  like 
to  know  with  what  degree  of  accuracy  the  E.M.F.  of  the 
standard  cell  was  determined  by  the  authors.  The  lag 
that  occurred  in  the  "  Board  of  Trade  "  cell  was  probably 
due  to  diffusion,  crystallisation,  and  solution. 

Mr.  Waters  said  the  E.M.F.  of  the  standard  was 
measured  by  a  Kelvin  balance,  to  one  in  ten-thousand. 

The  Vice-President  proposed  a  vote  of  thanks  to  the 
authors,  and  the  meeting  adjourned  until  Nov.  26ch. 


THE    CHEMICAL    AND     METALLURGICAL 

SOCIETY    OF     SOUTH     AFRICA. 

Meeting  held  August  21,  1897,  «*  Johannesburg. 

Mr.  Chas.  Butters,  President,  in  the  Chair. 

After  the  eledlion  of  several  new  members,  the  meeting 
proceeded  to  discuss  a  number  of  amendments  to  the  bye- 
laws  of  the  Society,  principally  with  regard  to  the  reduc- 
tion of  the  subscription  and  widening  the  qualifications 
for  membership.  After  the  general  business  had  been 
disposed  of,  a  special  meeting  was  held  at  which  the 
amendments  were  all  carried  unanimously. 

The  meeting  proceeded  to  discuss  the  President's 
Address. 

Mr.  J.  R.  Williams  paid  a  well-deserved  compliment 
to  the  ability  of  the  President  and  the  excellence  of  his 
address,  but  asked  for  an  explanation  of  one  or  two  points 
concerning  the  roasting  and  cyaniding  of  the  ore. 

Mr.  Crosse  confirmed  Mr.  Williams's  experience  of 
having  obtained  poor  results  from  extradting  with  cyanide, 
even  after  partial  roasting ;  Barberton  ore  contained  30  to 
50  per  cent  of  pyrites,  and  the  results  from  cyaniding  were 
very  poor. 

After  a  few  remarks  from  other  gentlemen  with  regard 
to  the  effedt  of  arsenic,  the  debate  on  Mr.  Williams's  paper 
on  the  "  Treatment  of  Battery  Slimes"  was  opened. 

Mr.  Franklin  White,  who  spoke  at  some  length,  criti- 
cised the  figures  given  as  to  the  percentage  efficiency  of 
treating  the  slimes,  and  pointed  out  that  Mr.  Williams 
distindtly  hinted  that  the  number  of  tons  treated  was  less 
than  6643,  though  that  figure  was  used  in  calculating  the 
cost  out  to  the  hundredth  of  a  penny,  and  further,  that  by 
an  error  on  the  part  of  the  accountant,  the  cost  of  working 
is  arrived  at  by  using  the  total  number  of  tons  crushed  as 
a  divisor,  viz.,  54,531.  instead  of  21,539,  '^^  adtual  weight 
of  slimes ;  this  of  course,  he  contended,  introduces  a 
serious  error. 

In  reply,  however,  Mr.  Williams  ridiculed  Mr.  White's 
contention,  and  claimed  that  his  method  of  calculation 
was  corredl. 

Mr.  Caldecott  pointed  out  that  dry  crushing  and  dire(^ 
cyanide  treatment  is  largeiy  prai^ised  in  New  Zealand  and 
America,  and  that  there  was  in  the  Transvaal,  though  not 
on  the  Randt,  a  Company  using  this  method  at  a  total 
cost  of  only  ttn  ihillingi  per  ton. 


Shbmical  Sbwi,  I 
Nov.  19, 1897.     I 


Chemical  Notices  from  Foreign  Sources, 


253 


A  few  remarks  were  then  made  by  Mr.  Cross  on  Mr. 
Caldecott's  paper  oa  "■  The  Solution  of  Gold  in  Accumu- 
lated and  Other  Slimes,"  the  further  discussion  of  which 
was  postponed  to  the  next  meeting. 

Meeting  held  September  18,  1897. 
Mr.  Chas.  Butters,  President,  in  the  chair. 

In  the  further  discussion  of  Mr.  Williams's  paper  on  the 
"Treatment  of  Battery  Slimes,"  the  point  was  raised  as  to 
the  most  efficient  method  adopted  for  stirring  the  slimes, 
either  by  mechanical  stirrers  or  by  the  introduiftion  of  air. 

The  President  was  of  the  opinion  that  a  larger 
volume  could  be  agitated  at  a  less  cost  by  using  paddles 
than  by  air ;  but  he  thinks  there  is  possibly  a  field  for  the 
younger  men  who  adopt  agitation  solely  by  air.  The  time 
necessary  for  agitation  depends  entirely  on  whether  the 
material  is  fresh  or  old,  and  whether  it  contains  much 
reducing  matter ;  at  the  City  and  Suburban  it  is  as  high 
as  18  hours,  but  they  are  not  even  then  quite  satisfied 
with  their  gold  solution. 

Mr.  Macintyre,  who  has  been  treating  slimes  at  Spitz- 
kop  for  about  six  months,  found  that  by  increasing  the 
number  of  blades  in  the  mechanical  stirrers  the  cone 
towards  the  centre  was  entirely  got  rid  of ;  the  time  for 
treatment  was  about  two  days,  and  in  a  small  plant  about 
15  tons  a  day  were  treated. 

After  a  few  remarks  from  one  or  two  other  gentlemen 
the  further  discussion  on  this  paper  was  adjourned,  and 
the  discussion  on  Mr.  Caldecott's  paper  on  "  The  Solution 
of  Gold  in  Accumulated  and  Other  Slimes"  was  resumed. 

Mr.  Crosse  referred  to  the  variation  in  the  specific 
gravity  of  different  slimes,  five  samples  of  which  were  as 
follows: — Robinson,  2'38 ;  Meyer  and  Charlton,  2*59; 
Geldenhuis  Estate,  2*31;  Lancaster,  2-50  ;  and  Bonanza, 
262.  This  is  an  important  subje(5t,  as,  for  the  purpose  of 
calculating  the  amount  of  slimes  in  the  liquid,  the  specific 
gravity  will  have  to  be  determined  before  the  necessary 
fadtor  can  be  applied. 

The  President,  in  referring  to  the  use  of  air,  said  he 
considered  it  as  one  of  the  most  important  discoveries  we 
have  had  in  connexion  with  the  cyanide  process. 

Dr.  LoEVY  considered  that  the  question  of  the  succes- 
sion in  which  oxidation  takes  place  in  pyritic  ores  was  an 
open  one,  and  will  require  more  discussion  and  experi- 
menting on  before  it  can  be  decided. 

This  concluded  the  discussion,  and  Mr.  Caldecott  will 
reply  at  the  next  meeting. 

Mr.  Crosse  then  read  a  paper  entitled  "  Some  Notes  on 
Assaying  Ground  Graphite  Crucibles,'^  What  is  needed 
for  this  assay  is  a  reagent  that  will  give  enough  oxygen 
to  burn  away  all  the  graphite,  and  then  lose  its  excess  of 
oxygen,  so  that  a  nearly  neutral  body  is  left.  Mr.  Crosse 
finds  that  [powdered  dioxide  of  manganese  satisfies  the 
required  conditions.  He  mixes  10  grms.  of  the  sample 
with  35  grms.  of  the  dioxide  in  a  H  crucible  and  raises 
the  temperature  to  a  bright  red  heat ;  he  then  reduces  the 
temperature  and  adds  a  mixture  of — 

100  grms.  fiux  (carb.  potash  2  parts,  borax  i,  salt  i). 
50      ,,      litharge. 

2      ,,      fiour. 
20      „     silica. 
The  whole  fuses  together  perfedlly :  when  finished  the 
crucible  is  cooled  and  broken  open,  and  a  soft  lead  button 
is  obtained  containing  all  the  gold. 

During  the  discussion  which  followed  this  paper  the 
President  introduced  some  notes  on  the  by-produdts 
from  the  gold  industry,  viz.,  from  the  mills,  the  chlorin- 
ation  works,  the  cyanide  works,  and  the  melting  room, 
and  after  thoroughly  treating  the  subjedi  he  recommended 
that  the  attention  of  managers  and  directors  should  be 
given  to  these  sources  of  income,  remarking  that  fre- 
quently the  battery  is  utilised  as  the  great  sewer  through 
which  these  valuable  products  disappear. 


CORRESPONDENCE. 

THORIUM  ACETYL.ACETONATE. 

To  the  Editor  of  the  Chemical  News. 
Sir, — In  reply  to  "Allanite,"  no  doubt  his  question  will 
be  answered  by  M.  G.  Urbain,  the  author  of  the  article  on 
"Thorium,"  but,  if  not,  it  will  please  "Allanite"  to  learn 
that  acetylacetone  is  not  ordinary  acetone.  Acetylacetone, 
CH3— CO— CHj— CO— CH3,  is  prepared  by  either  of  two 
methods,  viz., — (i)  by  the  adtion  of  AljClg  upon  acetyl 
chloride;  (2)  by  the  adlion  of  Na  upon  a  mixture  of 
aceto-acetic  ether  and  "ordinary  "  acetone.  It  is  a  liquid 
with  a  b.-p.  137°. 

The  works  he  refers  to  in  his  letter  are  too  old,  but  it  is 
described  in  Bernthsen,  p.  238. 

Hoping  now  he  will  get  over  his  difficulty — I  am,  &c., 

J.  A.  Foster,  A.I.C. 
Assist.  Admiralty  Chemist, 
H.M.  Dockyard,  Portsmouth, 
November  13, 1897. 


WIRE  GAUZE. 


To  the  Editor  of  the  Chemical  News. 

Sir, — No  doubt  many  of  your  readers,  like  myself,  have 
had  great  trouble  with  their  wire  gauze  for  the  tops  of 
burners  and  stands.  I  have  tried  many  different  kinds, 
and  find  that  ordinary  nickel  steel  gauze,  costing  about 
threepence  a  square  foot,  is  very  satisfadtory.  It  does  not 
rust  or  perish  to  anything  like  the  extent  that  other  gauzes 
do. — I  am,  &c., 

H.  L.  Robinson. 

Chemical  Laboratory,  Vickers,  Sons,  &  Maxim, 
Erith,  Kent,  Nov.  14, 1897. 


CHEMICAL 


NOTICES   FROM 
SOURCES. 


FOREIGN 


Note.— All  degrees  of  temperature  are  Centigrade  unless  otherwise 

expressed, 

Comptes  Rendus  Hebdomadaires  des  Seances^  deVAcademie 
des  Sciences.    Vol.  cxxv.,  No.  18,  November  2,  1897. 

Preparation  and  Properties  of  Calcium,  Strontium, 
and  Barium  Borides. — H.  Moissan  and  P.  Williams. — 
The  authors  arrive  at  the  following  conclusions : — The 
three  alkaline  earthy  metals,  calcium,  barium,  and  stron- 
tium, yield  with  boron  compounds  of  the  formula  BeR, 
a  formula  identical  with  that  of  the  nitrides  of  Curtius. 
These  compounds  are  perfedtly  crystalline  ;  they  scratch 
ruby,  possess  a  great  stability,  do  not  decompose  cold 
water  as  do  the  carbides,  and  are  especially  destroyed  by 
oxidising  agents  ;  they  are  not  comparable  to  the  alkaline- 
earthy  carbides  and  silicides  in  composition  and  in 
properties. 

On  the  Atomic  Weights  of  Argon  and  Helium. — 
H,  Wilde. — This  paper  will  be  inserted  at  some  extent. 

On  Stannic  Acids.  —  R.  Engel.  —  The  results  of  the 
author's  researches  may  be  summarised  as  follows  :— 
Pure  metastannic  acid,  isolated  from  a  metastannate  or 
from  metastannyl  chloride,  and  dried  in  a  dry  vacuum,  has 
the  composition  (SnOzJs.sHaO)  assigned  to  it  by  Fremy 
in  his  second  study.  It  contains  about  11  per  cent  of 
water  (or  theoretically  107). 

The  Use  of  Fluoresceine  for  the  Detedlion  of 
Traces  of  Bromine  in  a  Saline  Mixture. — H.  Baubigny. 

The  Crystallographic  Identity  of  Dextro-rotatory 
and  of  Levo-rotatory  Asparagine.-P.  Freundler. 


254 


Meetings  for  the  Week. 


(Chemical  News 
1     Nov.  19,  1&97. 


A  Study  of  the  Transformation  of  Saccharine 
Matter  into  Oil  in  Olives. — C.  Gerber. — Olives  present 
a  quotient  superior  to  unity  when  tlie  proportion  of  man- 
nite  decreases  and  that  of  oil  increases.  This  quotient  is 
due  to  the  formation  in  the  oil  itself  of  more  olive  oil  at 
the  expense  of  the  mannite. 


MISCELLANEOUS. 


Royal  Institution. — Professor  Oliver  Lodge,  F.R.S., 
will  deliver  the  first  of  a  Course  of  Six  Christmas 
Leisures  (specially  adapted  to  young  people)  on  •'  The 
Principles  of  the  Eledlric  Telegraph,"  at  the  Royal  Insti- 
tution, on  December  28th.  The  remaining  Ledtures  will 
be  given  on  Dec.  30,  1897,  and  January  i,  4,  6,  8,  189S. 

Imperial  Institute. — The  Winter  Course  of  Ledlures 
at  the  Imperial  Institute  will  be  opened  on  Friday, 
November  19th,  at  9  p.m.,  when  His  Royal  Highness  the 
Prince  of  Wales,  President  of  the  Institute,  will  occupy 
the  chair  at  an  illustrated  Ledlure  by  Mr.  F.  G.  Jackson, 
F.R.G.S.,  leader  of  the  Jackson-Harmsworth  Expedition, 
entitled  "  Three  Years  in  the  Arftie." 

On  Monday,  the  22nd  of  November,  at  8.30  p.m.,  Mr. 
E.  S.  Bruce,  M.A.,  will  read  a  paper  on  "  Eledlric 
Balloon  Signalling  applied  to  Scientific  Exploration  in 
Ardlic  and  Antardlic  Expeditions,"  fully  illustrated  by 
working  models  and  experiments,  at  which  Major  P.  A. 
MacMahon,  R.A.,  F.R.S.,  will  preside. 

On  Monday,  November  29th,  at  8.30,  Sir  George  Scott 
Robertson,  D.C.L.,  will  deliver  an  illustrated  Ledture  on 
•'  The  Wild  Kafirs  of  the  Hindu  Kush." 

On  Monday,  December  6th,  an  illustrated  Lediure  on 
"The  Mineral  Resources  of  British  Columbia  and  the 
Yukon"  will  be  given  by  Mr.  A.  J.  MacMillan,  ol  Ross- 
land,  B.C.,  formerly  British  Agent  for  the  Government  of 
Manitoba,  who  has  been  specially  supplied  with  speci- 
mens, &c.,  to  illustrate  this  Ledlure,  by  the  Government 
of  British  Columbia.  The  Hon.  Forbes  G.  Vernon, 
Agent-General  for  British  Columbia,  will  take  the  chair. 

On  Monday,  December  13th,  Professor  W.  C.  Roberts- 
Austen,  C.B.,  F.R.S..  will  Ledlure  on  "  Canada's 
Medals  " ;  the  Right  Hon.  Lord  Strathcona  and  Mount 
Royal,  G.C.M.G.,  High  Commissioner  for  Canada,  will 
preside. 

On  Monday,  December  20th,  Mr.  Boverton  Redwood, 
F.R.S.E.,  will  Ledture  on  "The  Petroleum  Sources  of  the 
British  Empire." 

Of  the  above  Ledlures,  those  on  the  6th  and  13th  of 
December,  by  Mr.  A.J.  MacMillan  and  Professor  Roberts- 
Austen  respedlively,  will  be  open  free  to  the  public  (seats 
being  reserved  for  Fellows  of  the  Institute) ;  the  others 
are  open  only  to  Fellows  of  the  Imperial  Institute  and 
persons  introduced  by  them. 


NOTES   AND    QUERIES. 


♦*♦  Our  Notes  and  Queries  column  was  opened  for  the  purpose  of 
giving  and  obtaining  information  likely  to  be  of  use  to  our  readers 
eenerally  We  cannot  undertake  to  let  this  column  be  the  means 
of  Uansmitting  merely  private  information,  or  such  trade  nouces 
as  should  legitimately  come  in  the  advertisement  columns. 

Calcium  Sulphate.— Will  any  reader  kindly  inform  me  whether 
there  is  any  considerable  demand  for  crude  calcium  sulphate  and  the 
approximate  price  per  ton.— B. 

Pinishine  Woollen  Goids.- 1  am  anxious  to  ascertain  a  simple 
and  inexpensive  mode  of  washing  and  finishing  large  quantities  of 
woollen  goods  without  ihem  shrinking.  1  should  therefore  be  much 
oblieed  it  you  couid  put  me  incommunication  with  any  person  having 
this  special  knowledge.-G.  W.  WALKER,  Springfield  Bleach  Works, 
Bulwell,  Noitingbam. 


MEETINGS    FOR    THE    WEEK. 


Wednesday,  24th.— Society  of  Arts,  8.  "  Progress  of  Metallurgy 
and  Metal  Mining  in  America  during  the  Last 
Half  Century,"  by  Prof.  James  Douglas. 


ARGENTAURUM  GOLD. 

N'  umerous  requests  having  reached  us 
from  all  parts  of  the  world  for 
specimens  of  ARGENTAURUM  GOLD, 
we  have  now  arranged  for  a  supply  of  the 
same  in  sheets  weighing  i,  2,  5,  and  10  grms. 
respedtively. 

Tlie  Price  is  75  cents  per  Gramme. 

Orders  and  remittances  should  be  addressed 
to  us  as  follows  :~EMMENS,  STRONG,  d  CO., 
1  Broadway,  New  York  City,  U.S.A. 

THE   ALKALI-MAKER'S   HANDBOOK. 

BY 

GEORGE   LUNGE,  Ph.D., 

Professor  of  Technical  Chemistry,  Zurich, 

AND 

FERDINAND  HURTER,  Ph.D., 

Consulting  Chemist  to  the  United  Alkali  Co.,  Limited. 

Second  Edition,  revised.     los.  6d. ;  half  leather,  12*. 

"  The  present  Edition  gives  abundant  evidence  that  care  is  being 
taken  to  make  the  Book  a  laithful  record  of  the  condition  of  contem- 
porary quantitative  analysis."— Prof.  T.  E.  Thorpe  ia  Nature. 

"  That  excellent  book."— The  late  Prof.  W.  Dittmar. 


London:  WHITTAKER  &  CO.,  Paternoster  Square,  E.C. 


AQ^li/TONE Answering  all  requirements. 

-A-OIID  J^CIETIC-Purest  and  sweet. 

BOIRJLCIO-Cryst.  and  powder. 

CI'X'JWIC— Cryst.  made  in  earthenware. 

C3-.A.XjXjIO— From  best  Chinese  galls,  pure. 

S^^XjIG"2"XjIC-By  Kolbe's  process. 

'X'.A.IsrinG-For  Pharmacy  and  the  Arts. 

LIQUID  CHLORINE 

(Compressed  in  steel  cylinders). 
POTASS.  PERMANGANATE— Cryst.,  large  and  small, 
SULPHOCYANIDE    OF    AMMONIUM. 
BARIUM. 

SODA  PHOSPHATE. 
THORIUM,  ZIRCONIUM,  and  CERIUM  SALTS. 

TARTAR    EMETIC-Cryst.  and  Powder. 

PUMICE.     TRIPOLI   AND   METAL  POWDERS. 

ALL  CHEMICALS   FOR  ANALYSIS   AND  THE  ARTS. 

Wholesale  Agents— 

Aa  <&  M.  ZIMMERMANN, 

9  &  10,  ST.  MARY-AT-HILL,  LONDON,  E.C. 


CbbmicalNbws.  I 
Nov.  26,  i8g7.     f 


Spectra  of  Oxygen,  Sulphur,  and  Selenium. 


255 


THE    CHEMICAL     NEWS 


Vol.  LXXVI.,  No.  1983. 


SPECTRA    OF 


ON   THE 

OXYGEN,    SULPHUR,    AND 

SELENIUM.* 


By  C.  RUNGE  and  F.  PASCHEN. 

Two  years  ago  Prof.  Pasteur  and  I  showed  that  the  spec- 
trum of  helium  consisted  of  six  so-called  series,  which 
may  be  arranged  in  two  sets  of  three,  each  set  resembling 
very  closely  the  spedtrum  of  one  of  the  alkali  metals. 
From  this  fad  we  drew  the  conclusion  that  helium  probably 
consisted  of  two  elements,  one  element  corresponding  to 
each  of  the  two  sets.  Since  then  we  have  made  an  inves- 
tigation of  the  spedtrum  of  oxygen  as  it  is  exhibited  by 
the  eledtric  current  passing  through  a  vacuum  tube  con- 
taining oxygen,  when  no  spark  gap  or  Leyden  jar  is  inter- 
posed in  the  circuit ;  and  we  have  found  that  this  spedtrum 


row  contradl,  the  second  one  on  the  right  being  much 
narrower  than  the  one  on  the  left.  Secondly,  whereas  in 
the  triplets  of  the  second  and  third  row  the  strongest  line 
has  the  lowest  wave-number,  and  the  weakest  line  the 
highest,  this  order  is  reversed  in  the  triplets  of  the  first 
row.  This  is  in  perfedt  accordance  with  the  spedlra  of  the 
alkalis.  There  we  have  doublets  instead  of  triplets  ;  but 
■ws  find  the  same  two  circumstances.  Whereas  in  the  so- 
called  secondary  series,  corresponding  here  to  the  second 
and  third  row,  the  difference  of  wave-numbers  remains 
the  same,  it  grows  smaller  with  increasing  wave-number 
in  the  so-called  principal  series  corresponding  to  the  first 
row.  Secondly,  whereas  in  the  secondary  series  the 
stronger  line  has  the  lower  wave-number,  this  order  is 
reversed  in  the  principal  series.  This  is  connedted  with  a 
law  discovered  by  Rydberg.  Rydberg  showed  that  in  the 
spedlra  of  the  alkalis  the  difference  between  the  wave- 
numbers  of  the  common  limit  of  the  two  secondary  series 
and  the  wave-number  of  the  limit  of  the  principal  series 
is  equal  to  the  wave-number  of  the  first  member  of  the 
principal  series.  Now  there  are  two  limits  of  the  secondary 
series,  one  for  the  stronger  lines  and  one  for  the  weaker 
lines  of  the  doublets  ;  but  there  is  only  one  limit  of  the 
principal  series.  Therefore  there  are  two  differences,  a,  b, 
between  the  limits  of  the  secondary  series  and  the  limit 
of  the  principal  series,  a  corresponding  to  the  limit  of  the 


jK 


SOM  pSW      70W>        6.900 


M 


eoioo 


m:. 


cs\oo. 


:ml 


_gl2_ 


ZMl 


Highest  Series. 
Second  Series. 
Third  Series. 

Highest  Series. 
Second  Series. 
Third  Series. 

Highest  Series.. 
Second  Series. 
Third  Series. 

Highest  Series. 


'OXYGEJV= 


=SULPHUR= 


Highest  Series. 
Second  Series. 
Third  Series. 

Highest  Series 


Jt 


^SELLUIUM" 


of  oxygen  closely  resembles  that  of  helium.  You  see  a 
drawing  of  it  here,  together  with  the  spedlra  of  sulphur 
and  selenium  plotted  to  the  scale  of  wave-numbers,  20,  for 
instance,  corresponding  to  the  wave-length  1/20,000  cm., 
equal  to  5000  Angstrom's  units. 

But  this  is  only  a  very  crude  representation  of  what  is 
adtually  seen.  The  drawing  only  gives  the  lines,  not  their 
intensity,  which  decreases  with  the  increasing  wave- 
number.  Neither  does  it  render  the  beautiful  details  of 
the  lines  giving  an  untiring  sense  of  pleasure  to  the  eye. 
The  lines  of  the  second  and  third  row,  for  instance,  are 
triplets  of  very  charadteristic  appearance, — so  charadler- 
istic  that  Piazzi  Smyth,  who  was  the  first  to  observe  some 
of  them,  very  justly  remarks  that  it  is  as  easy  to  recognise 
one  of  them  in  the  spedlrum  of  a  vacuum  tube  swarming 
with  impurities  as  it  is  to  pick  out  from  among  a  crowd  of 
civilians  a  soldier  with  scarlet  coat  and  cross-belts.  The 
first  row  also  consists  of  triplets ;  but  they  differ  in  two 
very  remarkable  ways  from  the  triplets  of  the  second  and 
third  row.  Whereas  here  the  differences  of  wave-numbers 
are  the  same  for  all  the  triplets,  the  triplets  of  the  first 

*  Read  before  the  British  Association  (Seftioa  A),  Toronto 
Meeting,  1897.     See  also  Wied.  A  nn. ,  Bd.  61, 1897. 


Stronger  lines,  b  to  that  of  the  weaker  lines.  Now  as  the 
principal  series  overlaps  the  secondary  series,  a  is  larger 
than  b,  and  therefore  the  first  member  of  the  principal 
series  consists  of  a  doublet  with  the  wave-numbers  a  and 
b,  the  larger  number  a  corresponding  to  the  stronger  line. 
Rydberg  had  the  boldness  to  predidt  that  his  law  would 
hold  good  for  triplets,  although  principal  series  of  triplets 
had  not  yet  been  observed ;  and  he  was  right.  We  see 
his  law  obeyed  in  the  spedlrum  of  oxygen,  and  similarly 
in  that  of  sulphur  and  selenium. 

I  cannot  enter  into  the  details  of  the  mathematical 
formulae  representing  the  wave-numbers  of  each  series, 
and  proving  the  analogy  of  the  three  series  of  each  set 
with  the  three  series  of  each  of  the  alkali  metals.  But 
what  Professor  Paschen  and  I  wish  to  convey  is  this  : — 
There  is  about  as  much  spectroscopic  evidence  for  the  du- 
plicity of  oxygen  that  there  is  for  the  duplicity  of  helium. 
Therefore,  if  on  chemical  reasons  we  are  not  allowed  to  con- 
sider oxygen  as  consisting  of  two  elements,  then  spectroscopy 
does  not  give  us  any  reason  to  believe  in  the  duplicity  of 
helium. 

At  the  same  time  we  have  investigated  the  spedlrum  of 
sulphur  and  of  selenium,  two  bodies  chemically  related  to 
oxygen,  and  we  have  found  that  under  analogous  conditions 


iS6 


Combustion  of  Organic  Substances  in  the  Wet  Way. 


Chemical  Nbws, 
Nov.  26,  1897. 


both  emit  a  spedtrum  very  similar  to  the  set  of  the  first 
three  series.  Whether  the  three  other  series  also  find 
their  analogy  we  do  not  venture  to  contend.  There  is, 
however,  a  strong  line  in  the  spedtrum  of  sulphur,  as  well 
as  in  that  of  selenium,  that  seems  to  correspond  to  the 
strong  violet  oxygen  line. 

The  three  series  of  the  spedlrum  of  sulphur  and  of  sele- 
nium are  triplets  of  the  same  build  as  the  oxygen  triplets; 
only  they  are  wider,  the  difference  of  wave-numbers  being, 
roughly  speaking,  proportional  to  the  square  of  the  atomic 
weights,  a  law  that  also  holds  good  for  several  other 
groups  of  chemically  related  elements. 

The  spe(5lrum  of  oxygen  has  been  partly  observed  by 
other  spedtroscopists.  Piazzi  Smyth  and  A.  Schuster 
should  be  named  in  particular  ;  but  these  spedtra  of  sulphur 
and  selenium  have  now  been  observed  for  the  first  time. 
It  is  strange  that  it  should  be  possible  to  find  new  spedtra 
of  bodies  so  well  known  as  sulphur  and  selenium  ;  and  we 
can  perhaps  infer  from  this  fadt  that  many  of  the  lines 
which  astronomers  observe  in  the  spedtra  of  the  sun  and 
of  the  stars,  the  origin  of  which  is  not  known,  may  after 
all  belong  to  well-known  elements. 

The  spedtrum  of  sulphur  as  a  whole  consists  of  lines  of 
smaller  wave-numbers,  that  is  to  say  of  slower  oscilla- 
tions, than  that  of  oxygen  ;  and  the  spedtrum  of  selenium 
consists,  again,  of  slower  oscillations  than  that  of  sulphur. 
This  is  what  we  should  expedt  from  the  atomic  weights  of 
the  substances,  the  heavier  atoms  oscillating  slower  than 
the  lighter  ones. 

In  analysing  the  radiations  emitted  by  the  elements, 
spedlroscopy  can  as  yet  give  us  very  little  insight  into  the 
nature  of  these  complex,  variable,  and  mysterious  things 
that  science  pleases  to  call  elements ;  but  we  think  a 
time  will  come  when  the  regular  distribution  of  lines  in 
what  we  call  series  will  find  a  mechanical  explanation. 
And  that,  we  think,  will  shed  a  flood  of  light  on  the 
nature  of  things. 


ON   THE 

IMPURITIES    OF    COMMERCIAL    CARBIDES 

OF    CALCIUM. 

By    H.    LE    CHATELIER. 

The  study  of  the  impurities  of  carbide  of  calcium  is 
interesting  on  account  of  the  indications  it  can  give  as  to 
the  reciprocal  affinities  of  certain  bodies  when  heated  to 
a  temperature  of  about  2000°. 

After  calcium  and  carbon,  the  two  most  abundant 
elements  present  ar^  silicon  and  iron.  It  is  possible  that 
definite  combinations  of  either  of  these  bodies  may  exist 
with  each  of  the  other  three  ;  which  are  those,  we  may 
ask,  which  are  formed  by  preference  at  the  temperature 
of  solidification  of  calcium  carbide  ? 

The  iron,  which  is  the  least  abundant  of  the  four  ele- 
ments under  consideration,  might  be  entirely  saturated 
by  one  or  the  other  of  the  remaining  three.  As  a  matter 
of  fadt  it  is  combined  exclusively  with  the  silicon.  It  is 
detedted  by  treating  the  hydrated  carbide  with  an  acid, 
and  suspending  the  insoluble  residue  in  iodide  of  methyl. 
Small  crystals  of  silicidc  of  iron  are  precipitated ;  these 
have  been  studied  by  M.  Moissan  ;  by  analysis  they  have 
been  proved  to  be  SiFej. 

The  excess  of  silicon  combines  either  with  the  carbon 
or  with  the  calcium,  according  to  the  relative  proportions 
of  these  two  bodies  ;  if  the  quantity  of  carbon  present  is 
in  excess  of  the  calcium,  a  silicide  of  carbon  is  formed, 
crystallising  in  apparently  hexagonal  plates,  and  gene- 
rally of  a  blue  colour.  It  is  found,  with  the  excess  of 
graphite,  floating  on  the  surface  of  the  iodide  of  methyl. 
If,  on  the  contrary,  the  quantity  of  calcium  is  in  excess 
of  the  quantity  of  carbon  present,  a  silicide  of  calcium 
is  formed,  which  is  disseminated  throughout  the  mass  of 


the  carbide  in  the  form  of  metallic  grains,  having  the 
colour  and  lustre  of  zinc.  These  can  be  isolated  by 
rapidly  quenching  the  carbide  in  a  large  excess  of  cold 
water,  separating  by  levigation  the  coarser  residues,  and 
washing  them  for  a  few  moments  with  a  solution  of  acetic 
acid.  The  final  residue  is  composed  of  silicide  of  iron, 
and  of  the  coarsest  grains  of  silicide  of  calcium,  which 
have  withstood  the  rapid  washings  intended  to  isolate 
them.  In  such  a  case  there  would  be  neither  graphite 
nor  silicide  of  carbon  present,  for  this  reason,  that  the 
calcium  must  be  in  excess  to  allow  of  the  formation  of 
silicide  of  calcium.  In  fai^,  the  determining  affinities 
which  govern  the  combination  of  these  elements  are 
those  of  iron  for  silicon,  and  of  calcium  for  carbon. 
These  are  first  satisfied,  and  the  remaining  bodies  com- 
bine amongst  themselves  in  a  manner  varying  according 
as  one  or  the  other  is  in  preponderating  proportion. 

There  seem  to  exist  two  distindt  silicides  of  calcium  ;  one 
of  them  is  hardly  attacked  by  nitric  acid,  but  is,  on  the 
contrary,  easily  attacked  by  hydrochloric  acid,  with  the 
formation  of  an  insoluble  yellow  matter,  called  silicone 
by  Wohler.  The  other,  easily  attacked  by  nitric  and 
acetic  acids,  gives,  with  hydrochloric  acid,  a  deposit  not 
yellow  but  white,  which,  like  silicone,  is  soluble  in  potash, 
with  an  abundant  disengagement  of  hydrogen. 

In  the  attack  of  silicide  of  calcium  we  more  frequently 
get  the  yellow  and  white  compounds  together.  The 
analyses  of  these  mixtures  lead  one  to  suspedt  compounds 
between  those  corresponding  to  Si204H4  and  Sia03H4. 
For  example,  one  analysis  gave — 

Yellow  matter 0*52  grm. 

Hydrogen  given  off  (0°  and  760  m.m.) . .     630  c.c. 
Silica 0-57  grm. 

which  corresponds  exadtly  to  the  second  formula. — Bull. 
Soc.  Chim.,  Series  3,  xvii.-xviii.,  Nos.  16,  17. 


THE  COMBUSTION  OF  ORGANIC  SUBSTANCES 

IN    THE   WET    WAY.* 

By  I.  K.  PHELPS. 

(Concluded  from  p.  247). 

Method  of  Oxidation  with  Chromic  Acid. 
A  CONCENTRATED  mixture  of  chromic  and  sulphuric  acids, 
although  a  much  more  powerful  oxidiser  than  potassium 
permanganate  in  aqueous  solutions,  fails  to  oxidise  com- 
pletely many  organic  compounds.  Thus,  Cross  and 
Higgin  {yourn,  Chem.  Soc,  1882,  113)  have  shown  that 
carbohydrates  are  among  the  number  of  organic  sub- 
stances ;  later,  Cross  and  Sevan  find  that  carbohydrates 
and  many  other  substances  are  oxidised  completely  to  a 
mixture  of  carbon  dioxide  and  monoxide.  Messinger 
{Ber.,  xxiii.,  2756)  has  proven  that  carbon  may  be  deter- 
mined in  organic  compounds  by  passing  the  mixed  pro* 
dudls,  resulting  from  the  oxidation  with  chromic  and  sul- 
phuric acids,  through  a  short  combustion-tube  filled  with 
granular  copper  oxide  and  heated  in  a  furnace — all  of 
which  fadts  have  been  confirmed  in  my  own  experience. 

Ludwig  (Am.  Chem,  Pharm.,  clxii.,  47)  has  observed 
that  the  contadt  of  carbon  monoxide  with  a  mixture  of 
chromic  and  sulphuric  acids,  especially  when  hot,  results 
in  the  oxidation  of  that  gas  to  carbon  dioxidel  This  fadt 
suggested  the  idea  of  substituting  for  the  apparatus 
described  above  a  new  form,  adapted  to  retain  the  first 
produdts  of  oxidation  in  prolonged  contadt  with  the 
oxidising  mixture.  This  apparatus,  shown  in  the  accom- 
panying figure^  by  means  of  which  as  the  sequel  shows, 
it  has  been  found  possible  to  extend  the  availability  of 
the  oxidising   mixture,   is  put  together  as   follows : — A 

*  Contributions  from  the  Kent  Chemical  Laboratory  of  Yale  Uni- 
versity. From  the  Amencan  Journal  0/  Scitnce,Sa'm  4,  Vol.  iv., 
Ho.  23,  November,  ttgy. 


CHBMICAL  NBW8,I 

Nov.  26, 1897.    I 


Combustion  of  Organic  Substances  in  the  Wet  Way, 


257 


thick.walled  round  bottomed  flask  of  a  litre's  capacity, 
serving  as  an  oxidising  chamber,  was  closed  by  a  rubber 
stopper  with  two  parforations,  through  one  of  which 
passes  the  tube  of  a  separating  funnel  of  about  100  cm.* 
capacity.  The  tube  of  this  funnel  reached  nearly  to  the 
bottom  of  the  flask  and  is  drawn  out  at  the  lower  end.  A 
disc  of  platinum  foil  is  hung  in  the  neck  of  the  flask,  nearly 
closing  it,  and  held  in  place  by  a  platinum  wire  passing 
through  the  foil  and  tucked  under  the  rubber  stopper  where 
the  funnel  tube  enters.  The  second  hole  of  the  stopper 
is  filled  by  the  exit  tube,  a  glass  tube  of  07  cm.  internal 
diameter.  This  tube  is  expanded  just  above  the  stopper 
to  a  small  bulb  which  serves  to  prevent  mechanical  loss 
of  the  solid  contents  of  the  flask  during  the  boiling.  This 
tube  is  joined  by  means  of  a  rubber  connedtor  (provided 
with  a  screw  pinchcock)  to  the  inlet-tube  of  the  absorp- 
tion flask,  which  is  an  ordinary  500  cm.*  round-bottom 
flask.  This  flask  is  also  closed  by  a  rubber  stopper  with 
two  perforations,  through  one  of  which  passes  the  inlet- 
tube  described  above  and  through  the  other  the  exit  tube, 
which  is  also  enlarged  to  a  small  bulb  just  above  the 
stopper  and  is  closed  by  a  rubber  connector  and  screw 
pinchcock.  The  glass  ground  stopper  of  the  funnel  tube 
is  carefully  cleaned  and  lubricated  with  a  thick  solution 
of  metaphosphoric  acid, 


Instead  of  getting  the  vacuum  by  the  water-pump,  it 
may  be  gotten  almost  as  quickly  and  certainly  more 
simply  by  boiling  water  in  the  evolution  flask  and  the 
barium  hydroxide  solution  in  the  absorption  flask  at  the 
same  time— both  flasks  being  connected  ready  for  making 
a  determination.  When  steam  issues  in  good  quantity 
from  the  exit  tube  of  the  absorption  flask,  the  burner  is 
removed  from  under  the  evolution  flask  and  its  screw 
pinchcock  closed,  and  then  the  burner  under  the  absorp- 
tion flask  and  its  screw  pinchcock  also  quickly  closed.  The 
flasks  are  then  allowed  to  cool. 

In  making  a  determination,  the  organic  substance  is 
weighed  out  in  a  counterbalanced  bulb,  so  thin  that  it 
may  be  easily  broken  later,  and  made  with  a  wide  mouth 
for  convenience  in  introducing  the  solid  substance.  After 
the  substance  is  weifjhed,  the  mouth  of  the  bulb  is  sealed 
by  heating  in  a  small  blowpipe  flame,  and  the  tube  intro- 
duced into  the  evolution  flask,  together  with  an  amount 
of  pure  potassium  dichromate,  which  is  known  to  be  in 
excess  of  that  required  to  oxidise  the  organic  substance. 
The  flasks  are  conneAed,  as  already  described,  with  an 
appropriate  amount  of  barium  hydroxide  solution  in  the 
absorption  flask  and  10  c.m.»  of  pure  water  in  the  evolu- 
tion flask,  and  the  vacuum  obtained  (as  described  above) 
by  boiling  both  flasks,  the  boiling  being  stopped  when  the 
water  in  the  evolution  flask  has  decreased  to  2  or  3  cm.*. 
Naturally,  this  boiling  must  be  so  regulated  as  not  to 
allow  loss  of  the  solid  material  in  either  flask.  The 
vacuum  obtained,  the  tube  containing  the  organic  sub- 
stance is  broken  by  shaking  the  flask,  and  ao  cm*  of  con- 


centrated sulphuric  acid,  previously  purified  from  organic 
material  by  heating  to  the  fuming  point  with  a  few  crys- 
tals of  potassium  dichromate,  are  run  in  through  the 
funnel  tube,  when  reduAion  of  the  chromic  acid  soon  be- 
comes evident.  While  still  hot,  the  acid  is  shaken  in  the 
flask  violently,  the  platinum  foil  hung  in  the  neck  serving 
to  protedt  the  rubber  stopper.  The  flask  is  warmed  to 
approximately  105°  C,  the  highest  temperature  to  which, 
as  shown  by  Cross  and  Bevan  (yourn.  Chetn.  Soc,  liii., 
88g),  a  mixture  of  chromic  and  sulphuric  acid  may  be 
safely  heated  without  the  disengagement  of  oxygen  gas. 
Water  is  then  run  in  until  the  crystals  of  chromic  anhy- 
dride have  disappeared  and  the  danger  of  the  evolution 
of  oxygen  is  passed.  The  solution  is  heated  to  its  boiling- 
point,  care  being  taken  that  it  shall  not  get  under  pres- 
sure, which  can  easily  be  observed  by  opening  momentarily 
the  stopcock  of  the  funnel  tube  and  noting  the  direction 
of  the  flow  of  water  contained  in  the  funnel.  The  flask 
is  shaken  and  heated  alternately  for  five  minutes — a 
period  of  time  which  appears  to  be  suflicient  to  bring 
about  the  oxidation  of  the  small  amount  of  carbon  mon- 
oxide originally  produced.  Then  more  water  (60  to  70 
cm.*)  is  introduced  through  the  funnel  and  the  stopcock 
between  the  boiling  and  absorption  flasks  opened,  when 
the  carbon  dioxide  enters  the  absorption  flask,  which  is 
kept  cool  and  shaken  as  before.  The  contents  of  the 
evolution  flask  are  then  heated  to  boiling  and  a  slow  cur- 
rent of  air,  freed  from  carbon  dioxide  by  passage  through 
potash  bulbs,  allowed  to  enter  through  the  funnel  tube  to 
keep  the  liquid  from  undue  bumping.  The  boiling  is  con- 
tinued for  fifteen  minutes,  after  which  the  excess  of  barium 
hydroxide  is  determined  iodometrically,  and  thus  the  car- 
bon dioxide  present  estimated  as  before.  Table  IV.  shows 
results  obtained  by  the  treatment  of  crystallised  ammo- 
nium oxalate  and  cane-sugar,  re-crystallised  from  dilute 
alcoholic  solution,  in  this  manner. 

Table  IV. 

Sub8tance]!BaO,H,  BaOaH,  CO, 
taken.  taken.  found.  found. 
Grm.         Grm.  Grm.         Grm. 

Analysis  of  Ammonium  Oxalate. 

I.    0*5009  i'3534  0*1469  0*3097  0*3101  0*0004  — 

0*5006  1*3400  0*1308  0*3103  0*3099  0*0004 -f- 

0*5005  1*3400  0*1343  0-3094  0*3098  0*0004- 

1*0002  2*5460  0*1347  o*6i88  0*6192  0*0004- 

1*0010  2*5192  0*1094  o'6i85  0*6197  00012  — 

Analysis  of  Cane-sugar. 

1.  0*2001      1*3926     0*1905     0*3085     0*3088  0-0003 — 

2.  0*2000     1*3926     0*1936     0*3077     0*3086  0*0009  — 

3.  o*aooi     1*3926     0*1857     o'3097     0*3088  0*0009+ 

4.  0*2014     1*3400     0*1279     0*3x11     0*3108  0*0003-1- 

The  results  are  evidently  very  satisfadtory. 

The  Determination  of  the  Oxygen  required  to  Oxidise  an 
Organic  Substance. 
Several  different  methods  have  been  proposed  for  esti- 
mating the  oxygen  present  in  organic  substances, 
depending  in  general  upon  the  determination  of  the  oxy- 
gen which  must  be  supplied  to  burn  the  substance  to  a 
known  amount  of  carbon  dioxide  and  water — thus  dis- 
covering by  difference  the  oxygen  originally  contained  in 
the  substance.  Lavoisier  is  said  to  have  measured  direAly 
the  oxygen  used  in  burning  organic  substances  ;  Gay- 
Lussac  and  Thenard  determined  the  oxygen  used  by 
measuring  the  amount  of  potassium  chlorate  reduced  by 
burning  the  organic  compound  ;  Baumhauer  {Ann.  Chem. 
Pharm.,  xc,  228)  determined  the  oxygen  used  by 
measuring  the  volume  of  oxygen  entering  the  combustion 
furnace  and  subtradling  the  measure  of  the  gas  coming 
from  the  combustion  tube,  which  was  set  up  according 
to  the  well-known  method  for  determining  carbon  and 
hydrogen;  Stromeyer  (Ann.  Chem.  Pharm.,  cxvii.,  247) 
determined  the  amount  gf  copper  reduced  by  the  ignition 


CO  J         Error  on 
calculated.      CO,. 
Grm.         Grm. 


258 


Combustion  of  Organic  Substances  in  the  Wet  Way. 


I  ORRMICAL  NBWt, 

I     Nov.  26  18Q7. 


of  the  substance  in  copper  oxide ;  Ladenburg  [Ann.  Chem, 
Phartn.,  cxxxv.,  i)  oxidised  the  substance  by  heating  in  a 
sealed  tube  with  a  known  amount  of  iodic  acid,  deter- 
mining at  the  end  of  the  operation  the  amount  of  iodic 
acid  left;  Mitscherlich  {Pogg.  Ami.,  cxxx.,  $^6)  has  esti- 
mated the  oxygen  in  organic  substances  direiStly  by  de- 
composing the  substance  by  ignition  in  a  stream  of 
chlorine  gas,  estimating  the  oxygen  content  by  determining 
the  resulting  carbon  dioxide  and  monoxide. 

As  it  has  been  shown  in  the  work  described  that  carbon 
may  be  determined  in  organic  substances  by  oxidation  with 
chromic  and  sulphuric  acids  without  the  evolution  of  oxy- 
gen gas,  it  would  seem  that  the  determination  of  the  oxy- 
gen in  the  substance  might  be  effected  by  determining  the 
amount  of  chromic  acid  used  in  the  operation,  taking  into 
consideration  the  produdts  of  combustion.  This  can  be 
readily  accomplished  by  taking  a  weighed  amount  of  pure 
potassium  dichromate  as  the  oxidising  agent  and  deter- 
mining, at  the  end  of  the  operation,  the  amount  of 
chromic  acid  left  by  treatment  of  the  residue  with  hydro- 
chloric acid,  absorption  of  the  chlorine  evolved  in  an  alka- 
line arsenite  of  known  strength,  and  titration  of  the  ex- 
cess of  that  substance  with  decinormal  iodine  solution. 

To  test  the  accuracy  of  the  determination  of  chromic 
acid  under  these  conditions  of  analysis,  weighed  portions 
of  pure  fused  potassium  dichromate  were  introduced 
into  a  Voit  flask,  whose  outlet  tube  was  sealed  to  the  in- 
let tube  of  a  Drexel  wash  bottle,  the  outlet  of  which,  in 
turn,  was  sealed  to  a  Will  and  Varrentrapp  absorption 
apparatus.  An  amount  of  hydrochloric  acid,  more  than 
enough  to  completely  reduce  the  chromate  (15  to  40  cm.* 
of  the  strongest  acid),  was  added  with  20  cm.*  of  strong 
sulphuric  acid,  and  the  total  volume  made  up  to  120 — 140 
cm.*  of  liquid.  The  sulphuric  acid  used  here  was  puri- 
fied from  carbonaceous  matter  (as  in  the  carbon  deter- 
mination above)  by  heating  with  a  few  crystals  of  potas- 
sium dichromate,  the  excess  of  which  was  reduced  by 
holding  the  acid  at  a  fuming  point  for  about  two  hours, 
when  a  portion  diluted  with  water  gave  no  colour  with 
potassium  iodide  and  starch  paste.  Pure  arsenious  oxide, 
in  amount  slightly  in  excess  of  that  required  to  take  up 
the  oxygen  to  be  given  up  by  the  chromate,  was  dissolved 
by  the  aid  of  heat  in  a  solution  of  pure  sodium  hydroxide, 
taken  in  such  quantity  as  to  more  than  neutralise  the 
arsenious  acid  and  the  hydrochloric  acid  used  to  reduce 
chromate,    and    this   solution   was   introduced   into   the 


Drexel  wash  bottle.  The  flask  was  then  connected  with 
the  wash  bottle,  using  a  thick  solution  of  metaphosphoric 
acid  to  lute  the  joint  between  the  flask  and  its  stopper. 
The  absorption  apparatus  was  charged  with  a  dilute  solu- 
tion of  sodium  hydroxide.  Carbon  dioxide  was  generated 
in  a  Kipp  generator  by  the  adion  of  hydrochloric  acid  on 
marble  and  purified  from  reducing  matter  by  bubbling 
through  a  strong  solution  of  iodine  in  potassium  iodide, 
and  finally  washed  with  a  solution  of  potassium  iodide 
alone.  A  slow  stream  of  this  purified  carbon  dioxide  was 
allowed  to  enter  the  inlet  tube  of  the  Voit  flask,  the 
contents  of  which  were  then  boiled.  When  a  concentra- 
tion to  a  volume  of  30  1040  cm.*  was  reached,  the  boiling 
was  discontinued,  and,  after  cooling  and  disconnedting 
the  flask,  the  contents  of  the  receiver  were  made  acid 
with  sulphuric  acid  and  then  alkaline  with  acid  potassium 
carbonate,  when  the  excess  of  arsenite  was  determined 
by  titration  with  decinormal  iodine  solution.  Sometimes 
during  the  redudlion  of  the  chromic  acid,  the  red  fumes 
of  the  chlorochromic  anhydride  volatilised  to  the  receiver  ; 
but  since  the  chromic  acid  thus  produced  is  reduced  later 
by  the  arsenite  (Browning,  Am.  jfourn.  Sci.,  i8g6,  vol.  i., 
35),  this  transfer  is  of  no  account  in  the  working  of  the 
process.    The  following  results  were  thus  obtained  : — 


KjCrjO, 
taken. 
Grms. 

5  0002 
5'OOl8 
5-0005 
5-0013 


AsjOj 
taken. 
Grms. 

5-1025 
5-0799 
5-0801 
5-0706 


Table  V. 

As^Og 
found. 
Grm. 

O-II44 
0-0526 
0-0582 
0-0908 


KjCrjOj 
found. 
Grms. 

4"9447 
4-9849 
49782 
4*9365 


Error  on 

KjCrjO,. 

Grm. 

0-0555- 
o  0169  — 
0-0233  — 
0-0648  — 


The  cause  of  the  error  shown  in  these  experiments  was 
traced  finally  to  too  great  concentration  of  the  sulphuric 


KgCr,0, 

taken. 
Grms. 

1-0004 
1-0007 
2-0013 
20037 
5*0020 

5'0037 


As^Os 
taken. 
Grms. 

1-0500 
10531 
2-0501 
2-0727 
5-1002 

5*ioi8 


Table  VI. 

AsjOg 
found. 
Grm. 

0-0398 
00437 
0-0299 
0-0502 
0-0495 
00513 


KjCfjOr 
found. 
Grms. 

I-0014 
l'OOo6 
2-0026 
2-0049 
5-0068 
5-0066 


Error  on 

KjCrsOj, 

Grm. 

o-ooi4-f- 

O'OOOI  — 

0-0013-I- 
o-ooi2-f- 
0-0048  + 
0-0029 -i- 


Table  VII. 


Substance 
taken. 
Grm. 


1-0122 
I-0019 


O'I002 

0'i093 


0*2025 
0*4012 


0-3034 
0-4523 


0*5057 

1*0099 


1*0079 

1*5014 


C02 

found. 
Grm. 


0-6265 
0-6212 


0*2138 
0*2324 


0*3117 
o'6i66 


0-4932 
07334 

0*2671 
0-5321 


03906 
o  5814 


Error  on 
COj. 
Grm, 


KjCrjOy 
taken. 
Grm. 


ASjOg 
taken. 
Grm. 


AsjOg 
found. 
Grm. 


Analysis  of  Ammonium  Oxalate. 
o'oooi-         2-0009        1-3002        o-oooo 
0-00I0+         2-0002        i'35i7         0-0440 

Analysis  of  Phthalic  Acid. 
0*0014+         2-0012         1-2004        0*0814 
0-0007+         2*0000         1*1031         0*0634 

Analysis  of  Cane-sugar. 
0*0008—         3-0000        1*7002        0-0796 
0-0024—         5-0000        2-3022        0-0366 

Analysis  of  Paper. 
0-0010—         3'5oi5         1*4017        0-0879 
0-0033—         5'oo35        1-8000        0-0710 

Analysis  of  Tartar  Emetic. 
0*0009—         2-5018        1-7000        0-0766 
0-0030—         35003         1-7520        0-0198 

Analysis  of  Barium  Formate. 
0-0006+         3-0026        2-2002        00496 
00005+         3-0010         1*8080        00890 


Oxygen  Oxygen  required  Error  on 
used.  by  theory.  oxygen. 

Grm.  Grm.  Grm. 


on6o 
0*1147 


0*1456 
0*1582 


0-2275 
0-4495 


0*3589 
0-5368 


0-1459 
O-2911 


0-1423 
o  2118 


0-II39 

0-II28 


0*1448 
0-1580 


0-2273 
0-4502 


0-3598 
0-5358 


0-1462 
0-2919 


0-1422 
0-2II8 


o  0021  + 
0-0019  + 


0-0008  + 
0-0002  + 


0-0002  + 

00007  — 


0-0005- 
00010  + 


0-0003  — 
0*0008  — 


o  0001  + 

0-OOOoj; 


Crbmical  Nbwb,  ) 
Nov.  26, 1897.     I 


Properties  of  Liquid  Fluorine. 


259 


acid  in  the  process.  When  the  boiling  begins  the  chro- 
mate  is  reduced  gradually  and  if  the  evaporation  of  the 
water  is  pushed  too  rapidly,  the  sulphuric  acid  may  reach 
a  strength  at  which  it  begins  to  cause  the  redudlion  of  the 
chromic  acid  with  the  evolution  of  oxygen  instead  of 
chlorine. 

The  obvious  remedy  is  to  condudt  the  boiling  operation 
more  slowly.  It  was  found  that,  if  from  five  to  six  hours 
time  was  taken  for  the  proper  concentration  of  the  con- 
tents of  the  Voit  flask,  the  presence  of  the  sulphuric  acid 
worked  no  harm,  as  will  be  seen  from  the  following  re- 
sults. Experiments  i  and  5  were  made  with  5  cm.*  of 
sulphuric  acid  present  and  the  others  with  20  c.m.»  as 
used  before.    (Table  VI.). 

In  applying  this  method  to  the  determination  of  oxy- 
gen used  in  the  oxidation  of  an  organic  substance,  the 
carbon  determination  was  made  as  already  described,  the 
amount  of  water  used  being  such  as  to  leave  60  to  80 
cm.*  of  liquid  in  the  boiling  flask  after  the  carbon  dioxide 
had  been  driven  to  the  absorption  flask  by  boiling.  This 
liquid  was  then  washed  into  the  Voit  flask  and  the  chromic 
acid  remaining  determined  by  a  second  distillation  (this 
time  with  hydrochloric  acid)  in  the  manner  described 
above.  In  each  of  the  experiments  recorded  in  Table  VII., 
20  c.m.»  of  purified  sulphuric  acid  were  used  in  the  carbon 
determination,  and  35  cm.«  of  hydrochloric  acid  (sp.  gr. 
1*2)  in  the  chromic  acid  determination.  The  ammonium 
oxalate  used  was  the  pure  crystallised  salt  ;  the  phthalic 
acid  was  re-crystallised  from  its  water  solution  and  dried 
for  a  short  time  over  sulphuric  acid  ;  the  cane-sugar  was 
seledled  crystals  of  rock  candy,  re-crystallised  from  dilute 
alcoholic  solution  and  dried  for  a  long  time  over  sulphuric 
acid  ;  the  paper  was  ashless  filter-paper,  dried  to  a  con- 
stant weight  over  sulphuric  acid  ;  the  tartar  emetic  was 
re-crystallised  from  water  solution  and  air  dried;  the 
barium  formate  was  prepared  by  treating  formic  acid  with 
an  excess  of  pure  barium  carbonate,  filtering  hot,  and 
allowing  the  produdt  to  crystallise. 

From  these  results,  it  will  be  seen  that  the  process 
works  with  accuracy  upon  a  great  variety  of  organic 
substances.  It  was  found  impossible,  however,  to  deter, 
mine  the  elements  in  bodies  which  are  at  the  same  time 
volatile  and  hard  to  oxidise;  for  instance,  ether  oxidises 
easily  to  acetic  acid  but  difficultly  beyond  that  stage  ; 
although  the  liquid  acid  is  oxidised  vigorously  by  chromic 
and  sulphuric  acids,  the  gaseous  acid  is  hardly  attacked 
at  the  temperature  used;  naphthaline  was  also  found  to 
be  volatilised,  and  hence  not  attacked,  to  such  an  extent 
as  to  render  its  determination  by  this  process  valueless. 

In  conclusion,  the  author  wishes  to  express  his  thanks 
to  Prof.  F,  A.  Gooch  for  many  helpful  suggestions. 


PROCEEDINGS    OF    SOCIETIES. 

CHEMICAL  SOCIETY. 
Ordinary  Meeting,  November  4th,  1897. 

Professor  Dewar,  F.R.S.,  President,  in  the  Chair. 

Messrs.  Harold  W.  Harrie,  W.  R.  Lang,  W.  H.  Barlow, 
and  A.  V.  C.  Fenby  were  formally  admitted  Fellows  of  the 
Society, 

Certificates  were  read  for  the  first  time  in  favour  of 
Messrs.  Ernest  George  Annis,  Health  Office,  Town  Hall, 
Huddersfield;  William  Ball,  54,  Stretton  Road,  Leicester; 
Richard  Oxley  Burland,  J.P.,  Poolstock  House,  Wigan ; 
Alexander  McLean  Cameron,  Daylesford,  Vidloria;  Owen 
Aly  Clark,  12,  Abbey  Gate  Street,  Bury  St.  Edmunds ; 
Alexander  Clarkson,  2,  Waveney  Crescent,  Ballymena, 
Ireland;  Frank  Collingridge,  B.Sc,  Kenmore,  Shepherd's 
Hill,  Highgate,  N. ;  James  Murray  Crofts,  B.A.,  Rich- 
leigh,  Gloucester ;  David  Crole,  Primrose  Studios,  Wel- 
lington Square,  Chelsea,  S.W. ;  John  Daniell,  Council  of 
Education  Laboratory,  Johannesburg,  S.A.R. ;   Andrew 


James  Dixon,  Dapto,  N.S.W. ;  Robert  Hamilton,  11, 
Ibrox  Place,  Glasgow  ;  John  Harger,  B.Sc,  Ph.D.,  The 
Nook,  St.  James's  Mount,  Liverpool ;  Charles  Kelly, 
Oakmere,  Hawarden,  Cheshire;  Tom  Lemmey,  B.A., 
Wellington  College,  Berks  ;  James  Scott  Maclaurin,  D.Sc, 
Mount  Eden,  Auckland,  N.Z. ;  Allen  Macmullen,  82, 
James  Street,  Dublin ;  Edward  Masters,  The  Aloes, 
Hinckley  Road,'  Leicester ;  John  A.  Mathews,  4,  First 
Place,  Brooklyn,  N.Y.  ;  Philip  George  Gregory  Moon, 
129,  Rosary  Road,  Thorpe,  Norwich ;  Joseph  John 
Mooney,  34,  Easter  Road,  Edinburgh ;  James  Charles 
Philip,  B.Sc,  Ph.D.,  i6a,  Merton  Road,  Vidtoria  Road, 
Kensington,  W. ;  Alexander  Ferguson  Reid,  Stair  Bridge, 
Stair,  Ayrshire ;  Ernest  Henry  Roberts,  Hollydale,  All- 
farthing  Lane,  Wandsworth,  S.W. ;  Edward  Sydney 
Simpson,  34,  Pier  Street,  Perth,  West  Australia ;  Robert 
Francis  Woodsmith,  89,  Bartholomew  Close,  E.C. ; 
Frederick  William  Steel,  Tamunua,  Navua  River,  Fiji ; 
Michael  Edmund  Stephens,  Avenue  House,  Finchley, 
N. ;  George  Stubbs,  Arnside,  Hertford  Road,  East  Finch- 
ley,  N.;  Edward  Howard  Tripp,  Ph.D.,  Kent  House, 
Blackheath  Hill,  S.E. ;  John  Scriven  Turner,  20,  Bury 
Street,  Bloomsbury,  W.C.;  Framjee  Khursedjee  Viccajee, 
Hyderabad,  Deccan,  India;  Percy  John  Vinter,  Wesley 
College,  Sheffield ;  Arthur  James  White,  Whinsfield, 
Barrow-in-Furness. 

Sir  William  Crookes  then  took  the  Chair,  and  of  the 
following  papers  those  marked  *  were  read  : — 

•in.  "On  the  Properties  of  Liquid  Fluorine."  By 
Professors  Moissan  and  Dewar. 

The  nearest  approach  to  the  properties  of  the  mythical 
alkahest  or  universal  solvent  of  the  alchemist  is  to  be  met 
with  in  fluorine.  The  transparent  vessels  in  which  it  can 
be  manipulated  have  to  be  made  of  some  fluoride  like 
fluor-spar,  and  such  vessels  are  equally  difficult  to  con- 
strudt  and  ill-adapted  for  chemical  manipulation.  Modern 
research  has,  however,  revealed  the  fadt  that  the  most 
powerful  chemical  affinities  are  completely  suspended  by 
allowing  substances  to  come  into  contadl  at  very  low 
temperatures,  and  it  appeared  possible  that  even  fluorine, 
which  has  the  most  powerful  chemical  adtivity  of  all  the 
elements,  might  be  manipulated  in  glass  vessels  under 
such  conditions. 

In  a  paper  communicated  to  this  Society  entitled  "The 
Liquefadlion  of  Air  and  Research  at  Low  Temperatures  " 
(Proc,  1895,  xi.,  221),  speaking  of  fluorine,  the  author 
remarked,  "  This  is  the  only  widely  distributed  element 
that  has  not  been  liquefied.  Some  years  ago,  Wallach 
and  Hensler  pointed  out  that  an  examination  of  the 
boiling-points  of  substituted  halogen  organic  compounds 
led  to  the  conclusion  that,  although  the  atomic  weight  of 
fluorine  is  nineteen  times  that  of  hydrogen,  yet  it  must  in 
the  free  state  approach  hydrogen  in  volatility.  This  view 
is  confirmed  by  the  specific  refradlive  index  which  Glad- 
stone showed  was  rather  lower  than  hydrogen.  If  the 
chemical  energy  of  fluorine  at  low  temperatures  is 
abolished  like  that  of  other  adlive  substances,  then  some 
kind  of  glass,  or  other  transparent  material  not  so  brittle 
as  calcium  fluoride,  could  be  employed  in  the  form  of  a 
tube,  and  its  liquefadtion  achieved  by  the  use  of  hydrogen 
as  a  cooling  agent." 

The  inference  that  fluorine  approached  hydrogen  in 
volatility  was  deduced  by  Wallach  and  Hensler  froin  a 
consideration  of  the  boiling-points  of  the  fluorine  deriva- 
tives of  the  benzene  series. 

The  following  table— 


Benzene. 

Boiling 
point. 

..      80° 

Differ- 
ence. 

•     5° 

.  47° 

Boiling 
Toluene.       point. 

C6H5CH3       ..    111° 

Differ- 
ence. 

■     5- 

C6H5F1  .. 
C6H5C1  ,, 

P.C6H4FICH3   116°, 
P-C6H4CI-CH3  160° 

r   '''^° 

26o 


Properties  of  Liquid  Fluorine. 


1  Chemical  Nswb, 
Nov.  26, 1897. 


Aniline. 
C6H5NH2 


Benzene. 


183" 


p-CeHsFl-NHa   187' 


p.C6H4Cl-NH3  230' 


CsHe 


80' 


43' 


p.C6H4Fla    ..     88« 
p.C6H4Cla  ..   I72» 


84' 


shows  that  the  substitution  of  i  atom  of  hydrogen  in 
these  compounds  by  fluorine  only  causes  an  increase  of 
the  boiling-point  of  from  4°  to  5°,  whereas  chlorine  causes 
an  increase  of  from  45°  to  50°.  Such  a  relatively  large 
ratio  as  i  to  10  in  the  increment  of  boiling-points 
suggests  a  great  difference  in  the  volatility  of  the  elements 
fluorine  and  chlorine  in  the  free  state.  A  further  examina- 
tion of  the  properties  of  fluorine  compounds,  however, 
showed  that  the  volatility  of  fluorine  was  not  likely  to 
approach  that  of  hydrogen.  This  will  be  apparent  from 
the  following  table  . — 


Boiling 
Me-       point 
thane,  (absolute). 

CH, 


110' 


Difference. 


90" 


II. 

Ethane. 
C2H6 


Boiling 

point 

(absolute), 

..  184' 


CH3FI     200^ 
CH3CI      250 


CH4 

CFI4 


259' 


I 
\ 

\  C-H4     ..  iio°] 

[i49°=4X37°     ^,  A 

>)  C'Cl4    ..  351°) 


C2H5FI..  242"= 
CaHsCl     286« 


Difference. 


58» 


44" 


24i''=4X6o'' 


Aldehyde.  B.  p.  (C.) 
CH3COH  21 


CH3COFI  10' 


1  -' 


4 


41^ 


Benzaldehyde.  B.p.(C.) 
C6H5COH  179° 

C6H5COFI 161° 

CeHjCOCligg" 


-18° 


38= 


CH3COCI5 

where  it  is  seen  that  the  substitution  of  hydrogen  by 
fluorine  in  methane  and  ethane  raises  the  boiling-point 
by  90°  and  60°  respedtively,  and  that  the  ratio  of  the  in- 
crements of  boiling-point  in  corresponding  fluorine  and 
chlorine  compounds  is  now  not  greater  than  i  :  2.    The 
boiling-point  of  methyl  fluoride  was  calculated  from  the 
critical  point  and  vapour  pressure  of  this  substance   as 
recorded  by  Professor  Collie  {Trans.,  1889,  Iv.,  no).    It 
will  be  noted  as  a  curious  fa(5t  that  the  substitution  of 
fluorine  in  the  aldehyde  radicle  causes  a  lowering  of  the 
boiling-point  and  not  an  increase,  and  that  the  difTerence 
in  boiling-point  between  the  chlorine  and  fluorine  substi- 
tution body  in  either  series  is  always  between  40°  and  50°. 
These  considerations  induced   the  hope  that  liquid  air 
might  give  the  command  of  a  sufficiently  low  temperature 
for  the  liquefaction  of  fluorine,   and   that  glass  vessels 
might  be  used  to  colleA  the  liquid.    This  view  was  sup- 
ported by  a  consideration   of  the  melting-points  of  the 
halogens  and  the  corresponding  critical  points  deduced  by 
following  the  suggestions  of  Clarke  {Am.  Chetn.  Soc.  y., 
i8g6,  xviii.,  618)  as  to  these  relations.    Thus  the  absolute 
melting-points    of   chlorine,    bromine,    and    iodine    are 
respedtively  171°,  267°  and  388°,  and,  assuming  the  same 
mean  difference  in  melting-point  extended  to   fluorine, 
then  its  melting-point  would  be  64°  absolute.     Now  the 
critical  points  of  chlorine  and  bromine  are  about  2k  times 
the  absolute  melting-points,  thus  giving  149°  absolute,  or 
—  125°,  as  the  probable  critical   point  of  fluorine.     This 
critical  value  is   only  a  few   degrees  lower  than  oxygen, 
and  from  this  calculation  the  authors  were  entitled  to 
assume  that  the  position  of  fluorine  as  regards  volatility 
would    be    somewhere    between    that    of    oxygen    and 
nitrogen. 

The  following  research  was  conducted  in  the  Chemical 
(laboratory  of  th^  {loyal  Institution,  to  which  Professor 


Moissan  brought  the  apparatus  for  the  production  of 
gaseous  fluorine  with  which  his  name  will  always  be 
identified,  and  the  authors  had  the  invaluable  assistance 
of  Messrs.  Lebeau,  Lennox,  and  Heath  in  the  condudt  of 
the  experiments. 

Fluorine  was  prepared  by  the  eleArolysis  of  potassium 
fluoride  in  solution  in  anhydrous  hydrofluoric  acid.  The 
fluorine  gas  was  freed  from  vapours  of  hydrofluoric  acid 
by  being  passed  through  a  serpentine  of  platinum  cooled 
by  a  mixture  of  solid  carbonic  acid  and  alcohol.  Two 
platinum  tubes  filled  with  perfectly  dry  sodium  fluoride 
completed  the  purification. 

The  apparatus  used  for  liquefying  the  gas  consisted  of 
a  small  cylinder  of  thin  glass,  to  the  upper  part  of  which 
was  fused  a  platinum  tube.  This  latter  contained  in  its 
axis  another  smaller  tube,  likewise  of  platinum.  The  gas 
to  be  liquefied  enters  by  the  annular  space,  passes  through 
the  glass  envelope,  and  escapes  through  the  small  inner 
tube.  The  glass  envelope  was  fused  to  the  platinum  tube 
by  which  the  fluorine  was  supplied. 

The  glass  cylinder  being  cooled  down  to  the  temper- 
ature of  boiling  liquid  oxygen  (  —  183°),  the  current  of 
fluorine  gas  passed  through  the  bulb  without  becoming 
liquid.  At  this  low  temperature,  however,  the  gas  has 
lost  its  chemical  activity,  and  no  longer  attacks  the  glass. 
On  lowering  the  temperature  of  the  liquid  oxygen  by 
exhaustion,  a  yellow  liquid  is  seen  colleding  in  the  glass 
envelope,  while  gas  no  longer  escapes  from  the  apparatus. 
At  this  moment  the  tube  by  which  the  gas  had  been 
escaping  is  stopped,  so  as  to  prevent  air  from  entering 
and  liquefying,  and  the  glass  bulb  soon  becomes  full 
of  a  clear  yellow  liquid,  possessed  of  great  mobility. 
The  colour  of  this  liquid  is  the  same  as  that  of  fluorine 
gas  when  examined  in  a  stratum  i  metre  thick.  Fluorine 
thus  becomes  liquid,  according  to  this  experiment,  at 
about  -185°. 

When  the  bulb  containing  the  liquid  fluorine  is  lifted 
above  the  surface  of  the  liquid  oxygen,  the  yellow  liquid 
begins  to  boil  with  an  abundant  disengagement  of  gas, 
having  all  the  energetic  reactions  of  fluorine. 

Silicon,  boron,  carbon,  sulphur,  phosphorus,  and  re- 
duced iron,  cooled  in  liquid  oxygen  and  then  placed  in  an 
atmosphere  of  fluorine,  did  not  become  incandescent.  At 
this  low  temperature,  fluorine  did  not  displace  iodine  from 
iodides.  However,  its  chemical  energy  is  still  sufficiently 
great  to  decompose  benzene  or  oil  of  turpentine  with 
incandescence.  It  would  thus  seem  that  the  powerful 
affinity  of  fluorine  for  hydrogen  is  the  last  to  disappear. 
The  authors  have  noticed  on  some  occasions  that  a  current 
of  fluorine  gas  passed  into  liquid  oxygen  gives  a  flocculent 
precipitate  of  a  white  colour,  which  quickly  settles  to  the 
bottom.  If  this  mixture  is  shaken  and  thrown  on  a  filter, 
the  substance  can  be  collected.  It  possesses  the  curious 
property  of  deflagrating  with  violence  as  soon  as  the 
temperature  rises. 

A  new  apparatus  (Fig.  i)  was  constructed  similarly  to 
that  already  described  (that  is  to  say,  a  glass  bulb,  e,  fused 
to  a  platinum  tube,  A,  which  contained  another  similar 
smaller  tube,  d),  but  having  each  of  the  platinum  tubes,  b 
and  c,  fitted  with  a  screw  valve,  in  such  a  manner  that 
at  any  moment  communication — either  with  the  outer  air 
or  with  the  current  of  fluorine — could  be  interrupted. 
This  little  apparatus  [was  placed  in  a  cylindrical  glass 
vacuum  vessel  containing  liquid  oxygen,  connected  with  a 
vacuum  pump  and  manometer. 

On  repeating  the  former  experiment  with  freshly  pre- 
pared liquid  air,  instead  of  oxygen,  fluorine  easily  becomes 
liquid  at  - 190°  C.  With  liquid  oxygen  as  refrigerant, 
the  liquefadion  of  fluorine  takes  place  at  a  temperature 
corresponding  to  the  evaporation  of  the  oxygen  under  a 
pressure  of  437  m.m.  of  mercury. 

From  these  two  experiments  it  results  that  the  boiling- 
point  of  fluorine  is  very  close  to  - 187°.  This  number  is 
identical  with  Olszewski's  boiling-point  of  argon,  so  that 
this  seems  to  be  the  first  example  of  two  gaseous  elements 
boiling  at  the  same  temperature.    It  is  a  justifiable  infer- 


Chbmical  Nbws,  I 

Nov.  26, 1897.    J 


Properties  of  Liquid  Fluorine, 


261 


ence  from  the  boiling-point  that  the  critical  point  must 
be  about  — 120*,  and  thus,  in  all  probability,  the  critical 
pressure  is  about  40  atmospheres,  or  less  than  half  that 
of  the  critical  pressure  of  chlorine,  which  is  84  atmo- 
spheres. This  would  make  the  critical  constant  for 
fluorine  4  as  contrasted  with  chlorine,  which  has  the 
value  5. 

The  following  table    gives  the    boiling-point    of  the 
halogens : — 

Absolute 
temperature.    Difference. 

..     87< 


Fluorine 
Chlorine 
Bromine 
Iodine 


..  240' 

..  337° 
..  460' I 


153' 


97° 

123" 


When  the  little  glass  bulb  was  three-quarters  full  of 
liquid  fluorine,  both  the  valves  were  closed,  and  then  a 
good  air-pump  caused  the  liquid  oxygen  serving  as 
refrigerant  to  boil  rapidly  at  a  pressure  of  25  cm.  Under 
these  conditions  a  temperature  of  —210°  is  reached,  yet 
the  fluorine  did  not  show  any  sign  of  solidification,  but 
retained  its  characteristic  mobility.  In  future  experiments 
it  will  be  interesting  to  try  the  rapid  ebullition  of  the 
liquid  fluorine  itself.  During  the  repetition  of  this  ex- 
periment a  slight  accident  occurred.  The  screw  of  one 
of  the  valves  becoming  worn,  allowed  air  to  leak  into  the 
exhausted  bulb.  This  air  was  immediately  liquefled,  and 
in  a  few  moments  two  distin(5t  layers  of  liquid  were  seen  ; 
the  upper  colourless  layer,  consisted  of  liquid  air;  the 
lower  one,  of  a  pale  yellow  colour,  being  fluorine. 

To  prevent  the  possible  ingress  of  any  air,  the  fluorine 
was  introduced  in  its  liquid  state  into  a  glass  tube,  the 
end  of  which  was  then  sealed  before  the  blowpipe.  The 
sealed  tube,  containing  the  liquid  fluorine,  was  kept  for  a 
long  time  at  —210°  by  the  rapid  evaporation  of  a  large 
quantity  of  liquid  air,  but  it  gave  no  trace  of  a  solid  body. 

To  determine  the  density  of  liquid  fluorine,  it  was 
brought  into  contadt  with  a  number  of  bodies  whose 
density  is  known,  comparing  their  behaviour  at  the  same 
time  in  liquid  oxygen,  which  has  about  the  same  boiling- 
point  and  density.  By  taking  groups  of  bodies  whose 
densities  are  very  close  to  each  other,  it  is  easy  to  see 
which  sink  and  which  float  in  the  liquid.  This  well- 
known  though  indiredt  method  was  the  most  suitable  for 
these  delicate  experiments.  The  authors  flrst  satisfied 
themselves  that  the  fluorine  had  no  adtion  on  the  materials 
used.  To  effeA  this,  a  crystal  of  ammonium  thiocyanate 
(density  =  1*31)  was  placed  in  a  glass  tube  surrounded 
with  boiling  liquid  air  to  the  bottom  of  the  tube,  a  current 
of  fluorine  gas  was  introduced  by  means  of  a  platinum 
jet.  The  fluorine  was  rapidly  liquefled,  and  the  ammonium 
thiocyanate  was  not  attacked.  The  same  experiment  was 
repeated  with  a  fragment  of  ebonite  {d  =  1*15),  of  caout- 
chouc (d=o'gg),  of  wood  {d  =  0*96),  of  amber  (d  =  i*ii), 
and  of  methyl  oxalate  (d  =  1*15).  It  is  of  importance,  in 
the  experiments  just  mentioned,  that  the  various  mate- 
rials used  should  be  first  kept  at  a  temperature  of  —  igo° 
for  some  little  time  before  coming  in  conta(5t  with  liquid 
fluorine. 

In  one  of  the  experiments  a  piece  of  caoutchouc, 
having  been  insufficiently  cooled,  took  fire  on  the  surface 
of  the  liquid,  and  burnt  completely  away  with  a  brilliant 
flame  without  leaving  any  residue  of  carbon.  The  piece 
of  caoutchouc  ran  about  the  surface  of  the  liquid  like 
sodium  on  water,  giving  a  very  intense  light. 

The  density  experiment  was  carried  out  in  the  following 
manner: — In  a  glass  tube  closed  at  one  end,  and  of 
which  the  lower  part  had  been  slightly  drawn  out,  frag- 
ments of  the  five  substances  just  mentioned  were  placed. 
The  tube  was  then  plunged  to  a  third  of  its  length  into 
boiling  liquid  air.  When  it  was  all  reduced  to  a  temper- 
ature of  about  —  igo*  the  fluorine  gas  was  carefully  intro- 


duced. This  soon  liquefied,  and  the  wood  and  the 
caoutchouc  floated  easily  on  the  surface  of  the  pale  yellow 
liquid.  On  the  other  hand,  the  methyl  oxalate  and  ebonite 
remained  at  the  bottom,  while  the  amber  rose  and  fell  in 
the  liquid,  appearing  to  be  of  the  same  density.  The 
apparatus  was  shaken  several  times,  and  the  quantity  of 
liquid  fluorine  increased,  but  the  results  were  the  same. 


s 


Fio.  X. 

The  authors  thus  arrive  at  the  conclusion  from  these 
experiments  that  the  density  of  liquid  fluorine  is  about 
1*14.  Another  point  which  appears  to  be  of  interest  is 
the  following  : — The  fragment  of  amber  floating  in  the 
fluorine  was  very  difficult  to  distinguish,  which  would 
seem  to  indicate  that  the  index  of  refraction  of  liquid 
fluorine  is  in  any  case  greater  than  that  of  liquid  air  or 


262 


Properties  of  Liquid  Fluorine. 


I  Chbmical  Mkw* 
I     Nov.  a6, 1897. 


oxygen,  although  it  is  not  likely  to  be  so  high  as  that  of 
amber  itself. 

Fluorine  was  liquefied  in  a  thick-walled  glass  tube 
which  had  been  previously  graduated,  and  the  tube 
sealed.  On  cooling  the  tube  and  its  contents  to  —210°,  a 
contradtion  of^'^th  in  the  volume  of  the  liquid  fluorine  took 
place.  A  similar  tube  was  left  alone  in  a  vacuum  vessel 
full  of  liquid  air.  An  hour  and  a  half  afterwards,  the  tube 
still  being  in  liquid  air,  the  Huorine  had  not  changed  in 
appearance.  But  shortly  afterwards,  when  the  air  had  all 
evaporated,  a  violent  detonation  occurred  ;  the  sealed  tube 
and  the  double  beaker  in  which  it  had  been  placed  were 
smashed  and  reduced  to  powder. 

Different  samples  of  liquid  fluorine  examined  with  the 
spedlroscope  through  a  thickness  of  about  \  cm.  showed 
no  specific  absorption-bands  in  the  visible  spedtrum. 

Liquid  fluorine  placed  between  the  poles  of  a  powerful 
eledro-magnet  does  not  show  any  magnetic  phenomena. 
These  experiments  are  the  more  decisive,  as  comparative 
ones  with  liquid  oxygen  were  made  at  the  same  time. 

The  capillary  constant  of  fluorine  is  smaller  than  that 
of  liquid  oxygen.  A  capillary  tube,  plunged  successively 
in  fluorine,  oxygen,  alcohol,  and  water,  gave  the  following 
figures : — 

Height  of  liquid  fluorine     ..     ..     3*5  m.m. 
„  „       oxygen     ..     ..     5-0     „ 

„  alcohol 14-0     ,, 

,,  water 22*0     „ 

Liquid  fluorine  placed  in  a  glass  tube  surrounded  with 
liquid  air  (temperature  about  —  igo°  C.)  had  a  slow 
current  of  hydrogen  gas  directed  on  to  its  surface  by 
means  of  a  fine  platinum  jet.  There  was  immediate 
combustion  with  the  production  of  flame.  The  experi- 
ment was  repeated  by  dipping  the  platinum  jet  well  below 
the  surface  of  the  liquid.  At  this  temperature  complete 
combination  still  took  place,  with  a  considerable  evolu- 
tion of  light  and  heat. 

Oil  of  turpentine,  in  the  solid  state,  is  attacked  by 
liquid  fluorine.  To  perform  this  experiment  a  little  oil  of 
turpentine  was  placed  at  the  bottom  of  a  glass  tube  sur- 
rounded with  boiling  liquid  air,  As  soon  as  a  small 
quantity  of  fluorine  was  liquefied  on  the  surface  of  the 
solid,  combination  took  place  with  explosive  force,  a  bril- 
liant flash  of  light,  and  deposition  of  carbon.  After  each 
explosion  the  current  of  fluorine  gas  was  kept  up  slowly, 
a  fresh  quantity  of  liquid  fluorine  was  formed,  and  the 
detonations  succeeded  each  other  at  intervals  of  from  six 
to  seven  minutes.  Finally,  after  a  longer  interval  of  about 
nine  minutes,  the  quantity  of  fluorine  formed  was  sufificient 
to  cause,  at  the  moment  of  the  reaction,  the  complete 
destruction  of  the  apparatus.  In  several  of  these  experi- 
ments a  little  liquid  fluorine  accidentally  fell  on  the  floor; 
the  wood  instantly  took  fire. 

The  a(5tion  of  liquid  oxygen  has  been  studied  with  more 
care,  since  the  authors  observed  that  by  passing  a  current 
of  fluorine  through  liquid  oxygen  a  detonating  powder 
could  be  produced. 

If  a  current  of  fluorine  is  ^diredted  to  the  surface  of 
liquid  oxygen  in  a  glass  tube,  the  temperature  being 
about  -  igo°,  the  fluorine  dissolves  in  all  proportions, 
imparting  a  yellowish  colour,  and  giving  the  liquid  a 
graded  tint  from  the  upper  to  the  lower  part ;  the  bottom 
of  the  tube  is  hardly  coloured.  If,  on  the  contrary,  the 
fluorine  gas  is  introduced  at  the  bottom  of  the  liquid 
oxygen,  the  yellow  colour  is  produced  at  the  bottom  and 
diffuses  slowly  to  the  upper  layers. 

This  phenomenon  indicates  that  the  densities  of  liquid 
fluorine  and  oxygen  are  very  near  each  other.  When  the 
temperature  of  the  mixture  of  liquid  oxygen  and  fluorine 
is  allowed  to  rise  slowly,  the  oxygen  evaporates  first. 
The  liquid  becomes  more  and  more  concentrated  as  re- 
gards fluorine,  and  finally  the  latter  begins  to  boil  in  its 
turn.  In  fadt,  at  the  commencement  of  this  boiling  the 
gas  coming  off  will  light  a  match  which  has  only  a  red- 
hot  point,  and  will  not  make  lamp-black  or  silicon  red-hot ; 


but,  on  the  other  hand,  the  gas  coming  off  at  the  end  of 
the  experiment  will  instantly  cause  these  two  latter  bodies 
to  burst  into  flame.  When  the  glass  bulb  is  completely 
empty  and  its  temperature  is  rising,  a  distind  disengage- 
ment of  heat  is  suddenly  noticed,  and  the  interior  of  the 
glass  loses  its  polish.  This  rise  in  temperature  is  due  to 
the  fluorine  gas  attacking  the  glass.  In  this  experiment, 
using  perfe(5tly  dry  oxygen,  no  precipitate  is  produced.  If, 
on  the  contrary,  oxygen  is  used  which  has  been  some 
hours  in  contact  with  the  air,  the  detonating  substance 
mentioned  in  previous  experiments  is  produced. 

The  body  which  is  produced  by  the  adtion  of  fluorine  on 
oxygen  containing  in  suspension  minute  crystals  of  ice 
seems  to  be  a  hydrate  of  fluorine,  decomposing,  with 
detonation,  by  a  simple  rise  of  temperature.  This  view 
must,  however,  be  taken  as  conjedture,  until  the  real 
composition  is  ascertained.  A  small  quantity  of  water  at 
the  bottom  of  a  glass  tube  being  cooled  down  to  —190°, 
liquid  fluorine  formed  on  the  surface  of  the  ice  as  a  mobile 
liquid  without  showing  any  chemical  adlion,  and  evapor- 
ated on  the  temperature  rising.  As  soon  as  the  apparatus 
became  warmer  the  remaining  gaseous  fluorine  attacked 
the  ice  with  great  energy,  causing  a  strong  smell  of 
ozone. 

A  globule  of  mercury  was  treated  in  the  same  way  as 
the  water  described  above.  The  surface  remaining  very 
brilliant,  the  liquid  fluorine  surrounded  it  without  causing 
any  diminution  of  metallic  lustre.  On  allowing  the  tem- 
perature to  rise,  the  fluorine  began  to  boil,  and  the  liquid 
disappeared  completely,  without  any  attack  of  the 
mercury.  The  experiments  seem  to  warrant  the  following 
conclusions. 

Fluorine  gas  is  easily  liquefied  at  the  temperature  of 
boiling  atmospheric  air.  The  boiling-point  of  liquid 
fluorine  is  — 187°.  It  is  soluble  in  ail  proportions  in  liquid 
oxygen  and  in  liquid  air.  It  does  not  solidify  at  —210°. 
Its  density  is  1-14,  its  capillarity  is  less  than  that  of 
liquid  oxygen ;  it  has  no  absorption  spedtrum,  and  it  is 
not  magnetic. 

Finally,  at  — 190°  it  has  no  adlion  on  dry  oxygen,  water, 
or  mercury,  but  it  readls,  with  incandescence,  on  hydrogen 
and  oil  of  turpentine.  Future  experiments  must  decide 
whether  cooling  below  —200°  can  suspend  the  powerful 
chemical  adlion  of  liquid  fluorine  on  hydrogen  and  hydro- 
carbons. 

One  of  the  most  important  questions  for  future  investi- 
gation is  the  specific  refradlive  and  dispersive  indices  of 
the  fluid.  Davy,  in  his  paper  on  the  substances  produced 
in  different  chemical  processes  on  fluor-spar  {Phil.  Trans., 
1813,  278),  says,  "  Dr.  Woliaston  has  found  that  the  fluoric 
combinations  have  very  low  powers  of  refradling  light, 
and  particularly  the  pure  fluoric  acid ;  so  that  the  re- 
fradling powers  of  fluorine  will  probably  be  found  lower 
than  those  of  any  other  substance,  and  it  appears  to 
possess  higher  acidifying  and  saturating  powers  than 
either  oxygen  or  chlorine." 

Gladstone  has  shown  that  the  specific  atomic  refradtion 
of  the  combined  element  does  not  exceed  o'g,  taking  the 
Lorentz  formula,  and  that  the  atomic  dispersion  diminishes 
instead  of  increasing  for  short  wave-lengths.  Further,  he 
found  that  the  other  halogen  substitution  compounds  gave 
atomic  refradlions  nearly  agreeing  with  the  same  sub- 
stances in  the  free  state.  It  has  been  found  that  liquid 
gases  give  the  same  atomic  refradlion  as  the  gaseous 
body,  so  that  the  reiradlive  index  of  liquid  fluorine  may 
be  at  once  deduced  provided  it  behaves  like  chlorine, 
bromine,  or  iodine.  Taking  0*9  as  the  atomic  refradlion, 
the  value  would  be,  according  to  the  Gladstone  formula, 
1*054,  and  the  Lorentz  I'oSi.  Both  values  are  far  lower 
than  those  of  liquid  oxygen  or  air,  1-226  and  1*205 
respedlively.  The  general  appearance  of  the  liquid  and 
the  experiment  with  amber  described  above  lead  to  the 
conclusion  that  liquid  fluorine  must  have  a  retradtive  index 
much  higher  than  that  calculated.  If  the  refradlive  indeX 
is  as  great  as  1*41,  then  the  atomic  refradlion  (Lorentz) 
will  be  4'i3;  but  if  it  is  only  about  I'igz,  then  the  atomic 


Chbuical  News,  I 
Nov.  26, 1897.     i 


Reform  of  Chemical  and  Physical  Calculations, 


263 


refradiion  will  be  2.  On  both  assumptions  the  atomic  re- 
fradtion  of  liquid  fluorine  is  much  greater  than  the  value 
0"9  found  by  Gladstone.  Should  the  smaller  value  2  turn 
out  to  be  the  corredl  one,  then  the  inference  might  be 
fairly  drawn  that  the  critical  constant  was  also  about  3, 
or  nearly  the  value  for  oxygen.  This  view  would  make 
the  critical  pressure  of  fluorine  about  the  same  as  that  of 
oxygen,  or  50  atmospheres.  From  this  it  would  follow 
that,  unlike  chlorine,  bromine,  and  iodine,  which  have  the 
same  atomic  refradtion  in  combination  and  in  the  free 
state,  fluorine  has  a  different  value  in  the  one  state  as 
compared  to  the  other.  In  this  respedt  it  would  appear  to 
resemble  oxygen,  whose  atomic  refradtion  in  combination 
may  be  only  three-fourths  of  what  it  is  in  the  free  state. 
This  view  is  confirmed  by  an  examination  of  the  atomic 
volume  of  fluorine.  The  other  members  of  the  halogen 
series  have  approximately  the  same  atomic  volume  in  com- 
bination as  in  the  free  state.  Now,  the  atomic  volume  of 
fluorine  in  fluorbenzene  is  11*5,  or  about  half  the  atomic 
volume  of  chlorine,  or  taking  chlorobenzene  as  standard, 
with  chlorine  as  22'7,  then  the  atomic  volume  would  be 
10.  The  value  for  the  free  element  appears  to  be  16  6, 
and  the  number  deduced  from  liquid  hydrofluoric  acid 
about  15.  Many  metallic  fluorides  have  relatively  small 
atomic  volumes.  Thus  the  fluorides  of  cadmium,  lithium, 
calcium,  magnesium,  and  aluminium  have  an  atomic 
volume  just  about  half  of  that  of  the  corresponding 
chloride.  This  difference  is,  however,  easily  explained  if 
fluorine  in  the  combined  state  has  only  half  the  atomic 
volume  of  chlorine.  Dr.  Thorpe's  value  for  the  atomic 
volume  of  fluorine,  deduced  from  a  study  of  the  chloride 
and  fluoride  of  arsenic,  is  g'2,  or  free  fluorine  at  its 
boiling-point  ought  to  have  a  density  of  2,  provided  it 
behaved  like  the  other  halogens.  This  density  for  the 
free  element  is  much  too  high,  the  experimental  value 
being  about  1*14.  Such  changes  in  atomic  volume  again 
suggest  a  resemblance  with  oxygen,  and  would  lead  to 
the  inference  that  the  refradtive  constants  must  also  differ 
in  the  free  and  combined  states.  These  interesting 
problems  must,  however,  be  left  for  future  investigation. 

(To  be  continued). 


EDINBURGH     UNIVERSITY    CHEMICAL 

SOCIETY. 

Monday,  November  15th,  1897. 

This  meeting  was  held  in  the  Chemistry  TutoHal  Class- 
room. 

The  President,  Professor  Crum  Brown,  delivered  an 
address  on  "  The  Chemical  Work  of  Pasteur." 

The  President  gave  a  short  account  of  Pasteur's  life, 
with  an  outline  of  his  chemical  and  biological  work, 
treating  with  more  detail  the  discovery  of  left  tartaric 
acid,  and  of  the  relation  between  crystalline  and  optical 
enantiomorphism. 

With  reference  to  Pasteur's  views  as  to  the  connedtion 
between  life  and  asymmetry,  he  said,  "  We  often  hear 
surprise  expressed  that  Pasteur  should  have  continued  to 
hold  that  asymmetric  molecules  cannot  be  produced  with- 
out the  aid  of  living  organisms,  after  he  had  himself 
shown  that  Perkin  and  Duppa's  acid  is  racemic  acid 
capable  of  yielding  right  and  left  tartaric  acid.  A  careful 
study  of  what  Pasteur  adlually  said  and  wrote  shows  that 
this  surprise  is  founded  on  a  misunderstanding.  Pasteur 
certainly  believed  at  the  time  when  he  delivered  his 
ledtures  to  the  Chemical  Society  of  Paris  (i860)  that  not 
only  asymmetric  substances,  such  as  tartaric  acid  or 
glucose,  but  also  racemoids,  such  as  racemic  acid,  required 
the  adlive  presence  of  living  things  for  their  produdtion.  ' 
But  in  the  note  in  the  Annates  de  Chimie  et  de  Physique 
in  which  he  announces  his  discovery  that  Perkin  and 
Duppa's  acid  is  racemic  acid,  we  see  that  he  had  already 
modified  his  view,  and  allowed  that  racemoids  could  be 


produced  by  purely  laboratory  processes.  And  in  1874 
and  1875,  in  communications  to  the  Academy,  he  states 
his  mature  opinion  in  perfedlly  clear  language.  We  may 
or  may  not  agree  with  him,  but  his  notions  on  the  subject 
are  not  in  contradidtion  to  any  observed  fadt." 

As  to  the  origin  of  the  asymmetry  in  living  things — as 
shown,  for  instance,  in  the  fermentation  of  right  but  not 
of  left  tartaric  acid  by  PenicilUum  glaucum — the  speaker 
suggested  that  there  may  be  some  analogy  between  this 
and  the  development  of  asymmetrical  habits  in  ourselves, 
such  as  the  habit  of  following  a  definite  order  in  putting 
on  our  stockings,  shoes,  &c. 

On  concluding  his  address  Prof.  Crum  Brown  was,  on 
the  motion  of  Dr.  Macdonald,  awarded  a  hearty  vote  of 
thanks  for  his  very  interesting  address. 


CORRESPONDENCE. 

REFORM     OF    CHEMICAL    AND     PHYSICAL 
CALCULATIONS. 

In  the  Chemical  News  for  6th  of  August  last  (vol.  Ixxvi., 
p.  70)  we  published  a  review  of  a  book  having  the  above 
title.  Mr.  C.  J.  T.  Hanssen,  the  author  of  the  book, 
objedled  to  some  expressions  used  in  the  review,  con- 
sidering we  had  held  him  up  to  ridicule.  The  editor  at 
once  wrote  to  Mr.  Hanssen  assuring  him  that  no  such 
impression  was  intended,  nor  could  it  be  fairly  gathered 
from  the  tone  of  the  review,  which  on  the  whole  was  dis- 
tinaiy  favourable  to  the  work.  Our  explanation  not  being 
considered  satisfadtory,  and  wishing  to  be  scrupulously 
accurate  in  our  statements  and  just  to  the  author  of  the 
book,  we  think  it  will  be  better  to  let  Mr.  Hanssen  speak 
for  himself  in  the  following  letter,  which  we  publish  with- 
out further  comment. 

Matt.,  vii.,  2.—"  With  what  judgment  ye  judge,  ye  shall  be  judged." 

3  Vaidemarsgade, 
Copenhagen,  V.,  20th  November,  1897. 

Professor  Sir  William  Crookes,  F.R.S., 

7,  Kensington  Park  Gardens, 

London,  W. 

Dear  Sir, 

I  received  your  esteemed  and  friendly  letter 
of  the  13th  inst.,  and  day  after  day  I  have  read  it  and 
compared  it  with  your  review  of  my  book  in  the  Chemical 
News,  but  I  regret  to  say  I  cannot  in  the  review  dis- 
cover that  you  recognise  the  merit  or  any  merit  in  my 
book.  The  first  35  lines  are  merely  quotations  from  the 
book;  then  (oUows  your  judgment :  "weird  and  forbidding 
aspea  "  of  vulgar  fradtions  ;  "  a  certain  amount  of  fascina- 
tion "in  author's  idea,  but  impossible  to  adopt  it,  gradual 
or  universal ;  it  would  only  increase  the  existing  confu- 
sion ! 

A  more  sweeping  condemnation  of  my  book  I  can 
hardly  conceive;  and  such  a  judgment,  from  a  first-rate 
scientific  authority,  of  course  kills  my  book,  and  me  as 
an  author  on  scientific  objedts,  unless  you — in  a  distindt 
and  prominent  form,  with  your  own  signature — publish 
another  review  of  my  book  in  the  Chemical  News.  Your 
friendly  private  letter,  and  the  prefix  Dr.,  which  I  am  not 
entitled  to,  cannot  mend  the  harm  and  damage  done  by 
the  public  condemnation. 

If  you  had  known  my  book,  which,  to  judge  from  your 
letter,  you  do  not,  I  am  sure  you  would  have  written  the 
review  in  a  different  style;  but  as  matters  now  stand,  I 
expedl  of  you,  as  a  gentleman,  the  satisfadlion  mentioned. 

If  you  kindly  will  refer  to  the  book,  you  will  find  that 
I  by  no  means  wish  to  do  away  with  decimals,  but  freely 
use  them  myself  where  an  approximately  exadl  result  is 
sufiicient,  but  that  I  use  vulgar  fradtions  in  the  deter- 


264 


Molecular  and  Liquefaction  Heats, 


I  Crkuical  Kews, 
'     Nov.  26,  1897. 


tnination  of  txact  standard  values,  which  only  in  few 
cases  can  be  found  by  decimals  and  by  logarithms. 

It  was  my  aim  to  calculate  standard  values  exact ;  ap- 
proximate values,  with  unreasonable  long  tails  of  decimals, 
we  have  plenty  of  in  the  text-books  of  all  nations,  and 
they  are  the  cause  of  the  confusion  which  I  wish  to  reform. 

If  we  take  Lord  Rayleigh's  determination  of  the  weight 
of  I  cbm.  of  oxygen  (latitude  of  London)  =  1*42952  kg., 
the  weight  of  hydrogen  =  exadlly  ^  thereof,  nitrogen  = 
14,  carbon  »  12  times  the  weight  of  H,  then — 

I  cbm.  Kg.  Kg.  Cbm. 
H weighs =0089345=  i.and  i  i8  =  i/o-o89345  =  ii'i2945 

O      „  =0-42952  =16,  „    „  =1/1-42952  =  069953 

N      „  =1-250830=14,  „    „  =1/1-25083  =  0-79496 

C      „  =1-072140=12,  „     „  =1/1-07214  =  0-92745 

Argon,,  =1786900  =  20,  „     „  =1/1-78690  =  0-55647 

Helium  0-357380=  4,  „    „  =1/0-35738  =  2-78236 

These  are  calculated  from  Lord  Rayleigh's  standard  for 
oxygen,  as  exadt  as  can  be  done  by  decimals,  but  they 
are  only  approximate.  Volume  x  weight  is  not  —  i,  as  it 
should  be. 

In  my  system  the  conversion  of  weight  to  volume  and 
vice  versa  is  done  without  calculation,  and  the  relation 
between  both  is  always  correft.  The  standard  values  (for 
latitude  41°  10')  corresponding  to  those  above  are  expressed 
thus  (page  3  §  9)  :— 

I  cbm.  Kg.  And  i  kg.—     Cbm.  Cbm. 

H  weighs        5/56=  1,  H  =56/5     =  ii'2 

O  „  80/56  =  16,0  =56/10  =   7/10  =  0-7 

N         „  70/56=14,  N  =56/70  =  4/5  =0-8 

C         „  60/56  =  12,0  =56/60=14/15  =  0-9333 

Argon    „  100/56=20,  Argon   =56/100=14/25  =  0-56 

Helium,,  20/56=  4,  Helium =56/20  =14/5  =28 

In  the  DowBon  gas  calculations,  quoted  with  so  much 
emphasis,  you  have  overlooked  that — 


240   X  867/140  18  = 


12  X  867 


(not  so  dreadful  after  all),  and  that  this  line  belongs  to 
the  calculation  of  calors.  per  cbm. ;  and  anyone  looking 
over  the  next  line  may  see  at  a  glance  that — 


64/185  X  4335  >8 


64  X  867 
37 


another  very  plain  calculation.  From  §  25  the  calors.  per 
cbm.  and  per  kg.  may  further  be  found  by  a  very  plain 
method,  absolute  exa^. 

In  Table  XXIII.  the  calors  per  cbm.  and  per  kg.  given 
for  various  gases.  They  are  found,  per  kg.,  by  multiplying 
4335  cal.  X  ratios  in  col.  2  ;  and  per  cbm.  by  multiplying 
6192^  =  43350/7  calors.  X  ratios  in  col.  6.  Where,  for  mixed 
gases,  the  ratios  are  given  in  decimals,  the  results  vary  a 
trifle  from  the  exadt  figures  in  cols,  i  and  5  ;  the  ratios  in 
vulgar  fraAions  for  simple  gases  and  chemical  compounds 
give  the  exadt  values. 

1  think  the  chapters  on  evaporation  and  combustion  are 
well  worth  your  attention. 

As  the  scientific  world  has  adopted  such  complicated 
systems  as  the  "  Natural,"  the  M.G.S.,  and  the  F.G.S.,  I 
think  my  plain  arithmetic  must  be  a  release  from  the  toil 
with  Dynes,  1/746  h..p.  =  io*  erg.,  &c.,  &c.  After  swal- 
lowing the  camel,  they  cannot  be  afraid  of  the  gnat. 

I  hope  soon  to  be  informed  that  this  matter  will  be 
settled  in  a  friendly  manner,  and  remain 

Very  truly  yours, 

C.  J.  T.  Hanssen,  C.E. 

Note.— ErratMw ;  Table  XXIII.,  col.  7,  3  lines  from 
bottom,  instead  of  0*171  please  read  0*240. 


MOLECULES   AND   LIQUEFACTION    HEATS. 

To  the  Editor  of  the  Chemical  News. 
Sir, — After  reading  the  interesting  paper  by  Noel  Deerr 
(Chemical  News,  vol.  Ixxvi.,  p.  234)  I  cannot  refrain 
from  sending  you  an  account  of  a  thermal  relation  which 
I  discovered  a  year  or  two  ago,  and  which  shows  no  less 
constancy  than  any  of  those  which  he  refers  to,  while  it 
has  the  important  charadteristic  of  being  grounded  on 
theoretical  considerations.  In  fadt,  it  was  an  d  priori 
consideration  of  theory  that  led  me  to  search  for  and  to 
discover  the  relation. 

Assume,  then,  in  accordance  with  van  't  Hoff's  theory 
of  solutions,  that  the  molecules  of  a  liquid  have  the  same 
translational  kinetic  energy  as  they  would  have  if  they 
belonged  to  a  gas  of  the  same  temperature.  The  specific 
heat  of  a  liquid  will  consist  of  three  parts  : — Firstly,  the 
heat  required  to  increase  the  kinetic  translational  energy 
of  the  individual  molecules ;  secondly,  the  heat  required 
to  increase  the  internal  energy  of  the  molecules,  which  in 
the  case  of  monatomic  molecules  is  nil ;  and  thirdly,  the 
heat  required  to  overcome  intermolecular  attradtion. 

The  ^rst  of  these  will  be  identical  with  the  gaseous 
specific  heat  at  constant  volume.  Now,  when  the  liquid 
is  changed  into  a  solid  the  energy  arising  from  this  cause 
no  longer  exists  in  the  translational  condition,  since  the 
molecule  becomes  fixed  in  position ;  that  energy  will 
therefore  be  liberated  as  heat.  The  energy  arising  from 
the  third  cause  possibly  does  not  undergo  any  great 
change  in  amount,  unless  in  solidifying  the  volume  of  the 
liquid  greatly  changes.  The  energy  due  to  the  second 
cause  I  negled,  in  order  to  deal  with  monatomic  molecules 
alone. 

If  these  assumptions  are  sufficiently  corred,  it  must 
follow  that  the  heat  set  free  in  passing  from  the  liquid  to 
the  solid  state  will,  in  the  case  of  a  monatomic  molecule, 
be  equal  to  the  translational  kinetic  energy  of  a  gas 
molecule  at  that  temperature.     Thus — 

The  molecular  liquefaction-heat  of  a  monatomic  liquid 

is  equal  to  the  total  kinetic  energy  of  a  monatomic  gas 

molecule  at  the  same  temperature. 

This  for  each  grm.>moIecule  can  easily  be  calculated, 
as  is  well  known.  Taking  t  the  absolute  temperature,  it 
is  equal  to  about  3  t  calories. 

Doubtless  the  molecules  in  the  liquid  state  are  to  some 
extent  polymerised.  Raoult's  investigations  on  solvents 
seem  to  indicate  that  the  ratio  of  the  theoretical  number 
of  grm.-molecules  is  to  the  true  number  as  i  :  0-9  or  as 
I'll  :  I,  this  having  a  rough  generality. 

Hence  the  law  just  laid  down  with  regard  to  liquefac- 
tion heats  will  be  incorredt  to  this  extent  (if  we  neglect 
the  internal  changes  in  the  heat  of  the  few  polymerised 
molecules).  Since  it  is  true,  by  a  rough  generalisation, 
that  the  theoretical  number  of  molecules  in  the  liquid  is 
to  the  real  number  as  I'li  to  i,  it  will  follow  that  the 
gaseous  molecular  kinetic  energy  calculated  at  the  tem- 
perature of  liquefaction  will  be  greater  than  the  true  heat 
of  liquefadtion  by  the  same  ratio. 

But  since  Raoult's  number  was  derived  from  liquids 
remote  from  their  solidifying-point,  we  exped^  greater 
polymerisation  at  that  point,  and  therefore  a  somewhat 
larger  ratio.  We  need  not  expedl  absolute  uniformity  be- 
tween different  liquids,  but  a  ratio  less  than  unity  is  in- 
explicable on  this  theory,  except  on  the  assumption  of  a 
great  internal  heat  in  molecules  polymerised. 

To  show  that  these  points  are  satisfadtorily  borne  out, 
I  give  a  table  which  I  calculated  some  time  ago,  with  the 
addition  of  six  elements  whose  liquefadtion  heat  was  at 
that  time  unknown  to  me;  I  now  take  that  constant  from 
Deerr's  paper. 

The  column  headed  M  gives  the  molecular  weight  of 
the  liquid  (0  =  16).  We  are  here  confined  to  liquid  metals, 
which  are  the  only  elements  that  have  any  probability  of 
possessing  a  monatomic  molecule  in  the  gaseous  (or 
liquid)  state.      M.-F.  is  the  melting-poiat  in   absolute 


Cbbmical  News,  t 
Nov.  26.  1897.      ' 


Chemical  Notices  from  Foreign  Sources, 


265 


degrees;  L,  the  heat  of  liquefaAion  per  unit  mass; 
K,  the  gaseous  kinetic  energy  calculated  per  unit  mass  at 
the  same  temperature.  The  last  column  is  the  ratio  be- 
tween these  two. 

M.  M.-P.         L.  K. 

Silver,            Ag  =  107-9  1227°  267  3372  127 

Cadmium,    Cd  =  ii2-i  588°  13-66  15-52  1-14 

Mercury,      Hg  =  200-4  233°  2-82  3-45  1-22 

Zinc,            Zn  =    65-5  685°  28-1  31-01  no 

Platinum,      Pt  =  194-8  2048°  272  31  24  115 

Lead,             Pb  =  206-9  605°  537  8-69  1-60 

Palladium,    Pd  =  106  1773°  36  2  49-6  1-37 

The  following  are  after  Deerr's  numbers  :— 

Sodium,        Na  =    23  365°  327  47-48  1-45 

Potassium,     K  =    39  335°  i57  25-6  1-63 

Copper,        Cu  =    63*3  1470°  43-0  55  3  1*29 

Thallium,      Tl  =  204  560°  5-1  8-i8  1-58 

Aluminium,  Al  =    27  1150°  loo-o  127-4  ^'^7 

Gold,            Au  =  197  1330°  16-3  20-2  1-24 

T.he  following,  which  I  calculated  before,  I  found  not 
to  fulfil  the  law : — 

Tin,  Sn  =  ii8*i  503°       13-62       1263     0-93 

Bismuth,       Bi  =  208  533°       12-64        76      0603 

Gallium,      Ga  =    69-9  303°      19-11       12'85     0*673 

The  first  two  have  non-metallic  tendencies,  and  their 
non-metallic  relatives  are  allotropic. 

On  seeing  Deerr's  constants,  I  proceeded  at  once  to 
make  use  of  them  in  the  calculation,  and  in  no  case  was 
I  disappointed.  The  result  was  six  new  metals  well  within 
the  law.  On  the  other  hand,  if  we  apply  the  principle 
to  liquids  of  known  polyatomic  vapour  or  gas,  we  meet 
at  once,  as  might  be  expedted  from  theory,  with  enormous 
and  disproportionate  divergencies  ;  this  is  in  itself  a  con- 
firmation.   For  example : — 

M.  M.-P,        L.  K. 

Bromine,        Br  =    79*9        266°      16*2  4*98    0'303 

Iodine,  I  =  126-9        386"      117  4-56    0*390 

Higher  molecules  show  still  greater  divergence.  Still, 
it  seems  likely  that  an  examination  of  such  molecules 
(particularly  those  of  similar  struifture)  in  the  light  of  this 
theory  would  be  fraught  with  important  information 
respedling  internal  specific  heats  ;  and,  indeed,  informa- 
tion of  a  yet  more  far-reaching  character. 

I  observe  that  Deerr  mentions  Crompton  as  giving  a 
formula  for  a  constant  which  involves  atomic  weight ; 
probably  it  is  similar  to  the  above,  or  derived  from  it. — I 
am,  &c. 

P.  J.  Beveridge,  M.A.,  B.Sc. 

St.  Ann's,  St.  Helens,  Nov.  15, 1S97. 


THE     LATE    VICTOR    MEYER. 

To  the  Editor  of  the  Chemical  News. 
StR, — There  appears  to  be  a  strong  desire  among  many 
of  the  British  students  who  worked  under  the  late  Prof. 
Vidtor  Meyer  to  give  expression  to  the  feelings  of  grati- 
tude and  admiration  with  which  they  remember  him,  by 
raising  some  form  of  memorial  to  be  placed  in  the 
Heidelberg  Ledlure  Theatre. 

It  has  therefore  been  decided  to  call  a  general  meeting 
of  Prof.  Meyer's  British  students,  to  be  held  in  Man- 
chester, on  Saturday,  December  nth,  at  5  p.m.  Prof. 
H.  B.  Dixon,  F.R.S.,  has  kindly  placed  the  Organic 
Leisure  Theatre  of  the  Owens  College  at  our  disposal. 

All  past  students  of  the  late  Vidtor  Meyer,  whether 
they  worked  with  him  in  Ziirich,  Gottingen,  or  Heidel- 
berg, are  earnestly  requested  to  be  present. 

I  shall  be  pleased  to  receive  suggestions  from  any  who 
may  be  unable  to  attend,  in  order  that  they  may  be  laid 
before  the  meeting. — I  am,  &c., 

J.  Jr  SudborouOh. 

University  College,  N«ttinghan)« 
November  23, 1897. 


ESTIMATION     OF    NICKEL     IN     STEEL. 

To  the  Editor  of  the  Chemical  News. 
Sir,— In  the  Chemical  News  (Ixxvi.,  p.  248)  you  publish 
an  eledlrolytic  method  of  estimating  nickel  in  nickel  steel. 
I  do  not  think  that  any  eledlrolytic  method  is  likely  to 
supersede  the  xanthate  process  of  Messrs.  Andrews  and 
Campbell,  described  in  the  Abstrads  y.  C.  S.  (Part  II., 
1895,  P-  421)- 

1  have  used  it  many  times,  always  with  good  results. 

No  figures  appear  to  be  given  in  support  of  Mr.  Durn's 
method,  where  the  percentage  of  nickel  is  very  low. — 
I  am,  &c., 

H.  L.  Robinson. 

Chemical  Laboratory,  Vickers,  Sons,  and  Maxim, 
Erith,  Kent,  Nov.  23,  1897. 


CHEMICAL  NOTICES  FROM  FOREIGN 
SOURCES. 

Comptes  Rendus  Hebdomadaires  des  Seances,  del'Aeademie 
des  Sciences.    Vol.  cxxv.,  No.  19,  November  8,  1897. 

Interpretation  applicable  to  Faraday's  Phenomena 
and  Zeemann's  Phenomena.— Henri  Becquerel. 

A  Study  of  the  Oysters  of  Cette  as  regards  Patho- 
genic Microbia.. — A.  Sabatier,  A.  Ducamp,  and  J.  M. 
Petit. — A  pathological  memoir. 

Variation  of  Energy  in  Isothermic  Transforma> 
tions.     On  ElecJtric  Energy. — H.  Pellet. 

Dissemination  of  the  X  Rays. — A.  Buguet. — The  use 
of  protedlive  screens,  which  is  not  indefensible  for  short 
exposures  before  tubes  of  little  penetrating  power,  becomes 
necessary  in  prolonged  exposures.  In  medical  applications 
they  also  render  it  possible  to  obtain  more  detailed  proofs 
by  shorter  exposures. 

On  the  Molecular  Volumes  and  the  Densities  of 
Gases  in  general  at  any  Temperature  and  at  Mean 
Pressures.— A.  Leduc. — A  mainly  mathematical  paper. 

On  some  Novel  Specftral  Lines  of  Oxygen  and 
Thallium. — H.  Wilde. — On  a  comparison  of  the  wave- 
lengths of  the  lines  it  is  found  that  none  of  them  coincide 
with  those  of  argon.  Observations  on  the  new  lines  of 
thallium  6955,  6560,  gives  the  author  occasion  to  again 
call  attention  to  the  spectroscopic  study  of  thallium  by 
Stas,  in  which  he  declared  that  the  eledtric  spectrum  of 
this  metal  consists  of  a  simple  green  line  incapable  of  being 
split  up  like  the  spedrum  of  the  flame.  As  the  eminent 
Belgian  chemist  used  in  this  research  a  current  derived 
from  a  series  of  only  30  Bunsen  elements  the  red  line  in 
the  arc  spedrum  escaped  his  observation.  To  resolve  the 
second  line  it  is  necessary  for  the  current  to  have  the 
intensity  of  100  volts  or  50  Bunsen  elements.  The  red 
line  6560  in  the  arc-spedtrum  has  been  observed  in  all 
specimens  of  thallium  and  its  compounds  which  have  been 
submitted  to  examination. 


The  Use  of  Fluorescsine  for  the  DsteAion  o< 
Traces  of  Bromine  in  a  Saline  Mixture. — H.  Baubigny. 
— The  author,  in  concert  with  P.  Rivals,  has  devised  a 
procedure  for  the  decomposition  of  the  bromides,  founded 
on  the  adtion  of  a  mixture  of  permanganate  and  a  soluble 
salt  of  copper.  He  has  sought  for  a  pradtical  means  of 
deciding  if  this  decomposition  is  complete  at  a  given 
moment.  The  fluoresceine  paper  is  obtained  very  easily. 
Fluoresceine  is  prepared  by  heating  for  three  hours  the 
desired  proportions  of  orthophthalic  acid,  and  of  resorcin, 
to  190  to  200° ;  it  is  purified,  and  then  treated  with  pure 
acetic  acid  at  40*^ — 30°  per  cent.  Into  the  filtered  solution 
the  paper  is  plunged,  and  allowed  to  dry.  To  use  this 
paper  it  is  moistened,  when  the  least  trace  of  bromine 
gives  a  distindt  rose  colour.  Organic  matter  must  be  ex* 
clad^d.—Comptei  R$ndus,  cxxv.,  No.  z8. 


266 


Meetings  for  the  Week. 


f  OHBuicAL  News 
1     Nov.  26,  1897. 


MEETINGS    FOR    THE    WEEK. 


Monday,  goth.— Society  of  Arts,  8,     (Cantor  Ledlures).     "Gutta 
Percha,"  by  Eugene  F.  A.  Obach.  Ph.D.,  F.C.S. 

Royal  Institution,  8.30.      "  The  Wild  Kafirs  of  the 

Hindu  Kush,"  by   Sir  George  Scott  Robertson, 
D.C.L. 
Wednesday,  Dec.  ist.— Society  of  Arts,  8.    "  The  American  Bicycle 
—The  Theory  and  Practice  of  its  Making," 
by  Pref.  Leonard  Waldo,  D.Sc. 
Thursday,  2nd.— Chemical,  8.     Ballot  for  the  Eleftion  of  Fellows. 
"  On  Collie's  Space-Formula  for  Benzene,"  by 
F.  E.  Matthews,  Ph.D. 


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Crkmical  News,  i 
Dec.  3.  1807.       ' 


Experiments  with  the  Cheavin  Filter. 


267 


THE    CHEMICAL    NEWS 


Vol.  LXXVI.,  No.  1984. 


RESULTS     OF    EXPERIMENTS    WITH 
CHEAVIN  FILTER. 


THE 


By    Dr.    T.    L.    PHIPSON, 

formerly  of  the  University  of  Brussels  and  the  Laboratoire  de  Chimie 

Pratique,  Paris. 

This  cylindrical  filter  is  made  of  porcelain  (unglazed 
biscuit)  like  that  known  as  the  Pasteur-Chamberland,  of 
which  it  is  a  modification,  and  in  some  respe<5ts  an  im- 
provement. The  objeft  of  this  filter  is  to  remove  bafteria 
from  water  used  for  drinking ;  and  it  is  applicable  to  other 
liquids  for. the  same  purpose. 

It  has  been  known  for  some  time  that  these  porcelain 
biscuit  filters,  when  properly  made  and  devoid  of  flaws, 
will  remove  microbes  of  all  kinds  from  water  which  passes 
through  them,  and  this  has  been  proved  in  the  present 
case  by  a  number  of  experiments  carried  on  in  my  labora- 
tory during  the  summer  months  of  the  present  year.  But 
the  passage  of  water  through  such  a  medium  is,  of  course, 
very  slow. 

The  yield  may  be  increased,  however,  in  three 
manners  :-^ 

I.  By  pressure  ;  exerted,  for  instance,  by  a  large  cistern 
at  the  top  of  the  house  upon  the  filter  in  the  base- 
ment. 

3.  By  employing,  with  or  without  extra  pressure,  a  certain 
number  of  cylinders  instead  of  only  one. 

3.  By  producing  a  partial  vacuum  in  the  filter  by  means 
of  asmall  hand  pump, which  pulls  the  water  through 
the  filter  into  the  receiving  vessel. 

In  the  first  case  the  cylinder  is  conne(5led  with  a  branch 
of  the  supply  pipe  at  the  basement;  a  single  tube  will 
thus  yield  each  day  sufficient  water  for  drinking  to  supply 
a  small  family.  When  a  larger  supply  is  required,  a  cer- 
tain  number  of  the  filters  are  joined  together  in  a  special 
cylindrical  receptacle,  and  all  a(51:  together. 

In  the  third  case,  the  use  of  a  small  hand  pump, 
worked  evenly  and  not  too  vigorously,  will,  by  producing 
a  partial  vacuum  in  the  receiving  vessel  and  the  porcelain 
cylinder,  give  a  much  more  rapid  yield  of  water  also 
devoid  of  microbes.  When  the  porcelain  cylinder  is 
placed  thus  in  a  vessel  of  stagnant  water  swarming  with 
the  "  green  matter  of  Priestley,"  consisting  of  extremely 
minute  unicellular  algae  and  various  kinds  of  microbes,  a 
few  ounces  may  be  pulled  through  in  a  few  minutes,  and 
the  filtrate  thus  produced  may  be  exposed  to  sunlight  for 
weeks  without  the  slightest  green  matter  appearing,  whilst 
ordinary  river  water  exposed  by  its  side  as  a  "  witness  " 
becomes  quite  green. 

In  other  experiments  the  water  was  filtered  by  means 
of  the  little  hand  pump  into  sterilised  beef-tea  and  other 
media,  with  similar  results. 

With  wines,  spirits,  beer,  vinegar,  solutions  of  sugar, 
solutions  of  salts.  &c.,  the  effedls  of  the  Cheavin  filter  are 
well  worth  attention.  Cloudy  wine  is  rendered  bright 
without  affedling  its  other  properties.  Cider,  beer,  and 
even  oils  can  be  thus  rendered  pure  in  a  very  short  time. 

When  slime  or  mucilage  has  colleifted  on  the  surface  of 
the  cylinders,  they  can  be  cleaned  by  brushing  in  boiling 
water,  or  by  passing  each  tube  slowly  through  a  larj^e 
naked  flame.  Being  light  and  delicate  in  construdtion, 
these  filters  require  some  care  in  handling  to  avoid  injury. 
At  the  old  Fulham  Potteries,  where  they  are  made  in 
large  quantities,  a  considerable  number  are  broken  up  as 
unfit  for  use  after  testing.  They  are  equally  efficient 
for  filtering  air  and  depriving  it  of  the  microbes  in 
suspension. 
Casa  Mia,  Putney,  S.W. 


LECTURE    EXPERIMENT. 
By  W.  FRENCH. 

I  HAVE  found  the  following  experiment  showing  the  efifedl 
of  burning  a  candle  in  air  to  work  extremely  well,  and  it 
possesses  the  advantage  of  being  very  simple.  It  is  a 
modification  of  an  experiment  well  known,  and  figured  in 
"  Perkin  and  Lean,"  and  dispenses  with  the  use  of  a 
battery,  which  in  a  small  laboratory  is  not  always  handy. 
The  round  bottom  flask,  a  (about  i  litre),  is  fitted  with 
an  indiarubber  stopper  through  which  passes  an  iron  rod 
having  a  small  candle  attacked.    Just  above  the  candle  is 


wired  a  small  "  match  end,"  b,'8o  that  the  head  nearly 
touches  the  wick  of  the  candle,  c  is  a  greased  glass  rod 
passing  easily  through  the  stopper.  The  indiarubber 
stopper  can  be  wired  down.  The  whole  apparatus  is 
counterpoised.  The  lower  portion  of  the  glass  rod  is 
heated,  the  cork  replaced  and  wired  in  ;  the  glass  rod  is 
now  momentarily  pushed  down  until  it  touches  the  match, 
which  readily  ignites  the  candle.  When  the  candle  ceases 
to  burn  re-weigh. 


Obituary,  —  On  November  5th  C.  W.  Blomstrand, 
Professor  of  Mineralogy  and  Inorganic  Chemistry  at  the 
University  of  Lund,  closed  his  laborious  and  successful 
career  in  his  71st  year. — Chemiker  Zeitung. 

Appointment. — Dr.  F.  Stanley  Kipping,  F.R.S.,  Lec- 
tuser  and  Assistant  in  the  Chemical  Research  Laboratory 
of  the  Central  Technical  College,  has  been  appointed  to 
the  Professorship  of  Chemistry  in  University  College, 
(Nottingham, 


268 


Estimation  of  Phosphoric  Acid. 


RESEARCHES    ON   SALINE   SOLUTIONS. 
LITHIUM    CHLORIDE. 

By  GEORGE  LEMOINE. 

I  HAVE  sought  to  bring  to  the  problem  of  the  constitution 
of  saline  solutions  new  data,  by  the  study  of  certain 
solutions  which  seem  to  present  a  peculiar  interest. 

Lithium  chloride  has  the  advantage  of  being  exceedingly 
soluble  ;  it  is  very  stable  and  its  molecular  weight  is  very 
small  (Li  =  7).  It  is  soluble  not  only  in  water,  but  in  the 
ethylic,  methylic,  &c.,  alcohols.  For  these  different  solu- 
tions I  have  determined  the  heat  of  dilution,  the  density, 
and  the  solubility  and  the  heat  of  solution,  where  it  is 
not  known.  The  calorimetric  measurements  have  been 
eflfedled  by  the  methods  of  Berthelot.  The  proportions  of 
the  salt  indicated  result  from  gravimetric  determinations 
of  chlorine  made  as  silver  chloride.  The  lithium  chloride 
employed  had  been  previously  purified  with  alcohol. 

Lithium  Chloride  and  Water. — We  know  a  hydrate, 
LiCl,2H20  (Troost).  The  anhydrous  salt,  when  dissolving 
in  an  excess  of  water,  evolves  8-4  cals.  per  LiCl  (Thorn- 
sen).  Its  solubility  has  been  determined  by  Kremers. 
We  can  prepare  solutions  containing  up  to  about  i3LiCl 
per  litre.     I  have  determined  the  specific  gravities  at  0°. 


(  Chemical  Nbwb, 
I      Dec.  3,  1897. 


Wt.  of  salt  for  100 
grms.  of  the  sol. 
Sp.  gr.  at  0° 


4'26    I2*i8  22'2     32*5     4i"4     43*2 
1*026    1*073  i'i33  i'203  1-267  1*282 


It  is  difficult  to  represent  these  experimental  data  by  a 
curve  without  an  inflexion  like  a  parabola ;  they  rather 
approach  a  group  of  two  right  lines.  There  seems  then 
to  be  a  modification  in  the  constitution  of  the  solution 
from  about  i3LiCl  to  about  6LiCl  per  litre  or  from 
LiCl,3H20  to  about  LiCl.SHjO. 

The  heats  of  dilution  were  measured  at  10°. 

Mols.  LiCl  per  litre  ....  12  9  6  3  i  0*5 
Mols.  H2O  for  LiCl.. (cals.)  3*34  4-9  8*3  17*0  53*1  116 
Quantities  of  heat  of  dilution 

starting  from  (i2LiCl  =  lit) 

(cals.) o      1*3   2*2    2*8    3*1   3-2 

whence  come  the  solution  heats  by  admitting  8*4  cals.  for 
excess  of  water,  5*2,  6*5,  7*4,  8*0,  8*3,  8*4  cals. 

It  seems  that  the  solution  heats  increase  regularly  with 
the  quantity  of  water.  Beyond  LiCl +  116H2O  there  is 
no  further  disengagement  of  heat.  Towards  20°  the  results 
were  nearly  the  same. 

Lithium  Chloride  and  Methylic  Alcohol  (prepared 
from  methyl  oxalate  and  distilled  over  baryta).  —  M. 
Simon  has  described  2LiC1.3CH40.  According  to  my 
determinations  the  anhydride,  when  dissolving  in  an  excess 
of  alcohol,  evolves  10*9  cals.  for  LiCl.  I  have  measured 
the  solubility  and  the  specific  gravity. 


23*0°      50° 


Temperature       .. 1° 

Ratio  of  the  weight  of  the  salt  to  the 

weight  of  the  saturated  solution . .  0*26  ? 

Weight  of  salt  for  100  grms.  of  sol.  5*2 

Specific  gravity  at  21*5° 0*836 

M  ,.       ato° 0*854 

The  dilution  heats  have  been  measured  at  about  18°; 
beyond  (LiCl-f  48CH4O)  there  is  no  appreciable  disengage- 
ment of  heat. 


0*27 

0*30 

145 

22*1 

0*910 

0*974 

0*926 

0988 

Mols.  LiCl  per  litre 5 


3 

79 


I 

24 


05 
48 


Mols.  CH4O  per  LiCl 4*7 

Quantities   of  [dilution    heat    starting 

from  5LiCl  + 1  litre  ..  ..  (cals.)  o  1*5  2-63*0 
Whence  come  the  solution  heats  with 

io*9cal8.foranexcessofalcohol  (cals.)    7*9  9*4  10*5  10*9 

Lithium  Chloride  and  Ethylic  Alcohol  (rendered 
anhydrous  by  distillation  with  baryta). — M.  Simon  has 
described   LiCl.aCitHeO ;    my  analyses  give   the   same 


formula.  The  anhydrous  salt,  on  dissolving  in  an 
excess  of  alcohol,  evolves  11*7  calories  for  LiCl  (M. 
Pick).     I  have  found  for  its  solubility — 


1*6°      5*7°    130'  25'o°  40-6'  626' 


Temperature  . . 
Ratio   of  weight  of 

the  salt  to  the  wt. 

of    the    saturated 

solution       ..      ..     0*14     0*14    0*13     0*14    015     0*18 

The  graphic  representation  corresponds  approximately 
to  two  right  lines  which  interse<ft  each  other  about  30°, 
a  very  small  angle;  the  more  oblique  line  being  inclined 
slowly  towards  the  temperature  of  fusion  (about  600°). 
The  solubility  decreases  progressively  from  water  to 
ethylic  alcohol,  and  thence  to  amylic  alcohol,  in  propor- 
tion as  the  molecular  weight  C»  H2»+20  increases. 

Weight  of  salt  in  100  grms. 

of  solution o 

Specific  gravity  at  14-2°     ..  0797 

I,           „       at  0°  ..      . .  0*809 


5*2  10*1  14-6 
0-839  0*871  0-903 
0-851     o-88i     0-903 


The  dilution  heats  have  been  measured  between  8°  and 
15';  beyond  LiCl-t-35C2H60  no  perceptible  degree  of  heat 
is  evolved. 


Mols.  LiCl  per  litre      3       2 

Mols.  C2H6O  per  LiCl ..     5-4    83 

Quantities  of  dilution   heat,  starting 

from  3LiCl  =  I  litre  ..     ..       (cals.)       o 
Hence  solution  heats  with  11*7  for  an 

excess  of  alcohol       ..      ..       (cals.)     9*1 
— Comptes  Rendus,  cxxv.,  No.  17. 


I      0*5 
169    35 

8*3    2-x    26 
8-3  n-2  11*5 


ON    THE   ESTIMATION  OF  PHOSPHORIC  ACID. 
By  HENRI  LASNE. 

I. 

Some  years  ago  I  communicated  to  the  French  Chemical 
Society  (Bull.  Sac.  Chim.,  18S9)  some  experiments  on  the 
estimation  of  phosphoric  acid.  All  that  I  have  since 
done  on  this  subjedt  has  confirmed  my  former  results, 
which  I  will  now  briefly  recal. 

1.  The  precipitation  of  the  ammonio-magnesic  phos- 
phate gives  rise  to  no  loss  when  carried  out  in  the  pre- 
sence of  citrate  of  ammonia  and  a  sufficient  excess  of 
magnesia. 

2.  The  lime,  oxide  of  iron,  alumina,  and  manganese  are 
not  carried  down  by  the  precipitate. 

3.  The  presence  of  silica  and  of  fluosilicates  causes  an 
excess. 

4.  Without  the  addition  of  an  excess  of  magnesia,  the 
precipitation  is  not  complete,  and  the  filtrate  will  give  a 
precipitate  either  with  magnesia  or  phosphoric  acid. 

These  results  have  been  recently  confirmed,  and  they 
demonstrate  that,  starting  with  the  ammonio-magnesic 
phosphate,  this  compound  can  be  reproduced  without  any 
loss  whatever ;  after  calcining,  we  obtain  exadly  the  same 
weight. 

The  question  is — Has  this  calcined  body  the  theoretical 
composition  of  the  pyrophosphate  ?  Nothing  seems  to 
prove  it;  since  the  sample  under  analysis  was  obtained 
under  exadtly  the  same  conditions  as  the  final  precipitate. 
We  shall  see  later  how  some  doubts  have  arisen  on  this 
subjeft — doubts  which  I  may  say  were  without  excuse. 
Because  of  the  great  importance  of  the  exadt  estimation 
of  phosphoric  acid,  and  of  the  very  great  accuracy  with 
which  it  can  be  carried  out,  a  detailed  account  of  my  ex- 
periments on  the  subjedt  may  prove  to  be  of  use. 

II. — On  the  Influence  of  Time  0/  Standing. 
It  is   well  known  that  the  precipitation  of  ammonio- 
magnesic  phosphate  requires  a  certain  amount  of  time, 


Cmbbiical  News, 
Dec.  3, 1897. 


Estimation  of  Phosphoric  A  ad. 


269 


and  it  has  been  generally  recognised  that  twelve  hours  at 
least  was  necessary.  Some  chemists  have  maintained 
that  filtration  could  be  proceeded  with  much  sooner ;  I, 
in  my  experiments  on  this  particular  point,  have  met 
with  some  anomalies,  of  which  the  following  is  a  good 
example : — 

From  a  solution  of  a  natural  phosphate,  freed  from 
silica,  I  took  nine  equal  volumes  of  50  c.c.  each  (corre- 
sponding to  J  grm.  of  the  phosphate).  To  each  of  these 
samples  I  added,  as  usual,  25  c.c.  of  citrate  of  ammonia 
at  100  grms.  of  citric  acid  per  litre,  60  c.c.  of  ammonia 
at  22°,  and  20  c.c.  of  ammonio-magnesic  chloride  at  20 
grms.  of  magnesia  per  litre. 

The  washings  were  effedted  with  45  c.c.  of  water  con- 
taining one-third  of  its  volume  of  ammonia  at  22°,  making 
a  total  volume  of  200  c.c. 

After  agitation  and  the  formation  of  the  precipitate,  the 
solutions  were  let  stand  for  varying  times.  The  results 
obtained  are  given  in  the  following  table  : — 


Time 

Weight  of 

No, 

of  standing. 

precipitate. 

Remarks. 

I. 

I  hour 

0-2329 

Filtrate  cloudy. 

II. 

2  hours 

0-2338 

Filtrate  slightly  cloudy 

III. 

4     .. 

0-2350 

Clear. 

IV. 

8     „ 

0-2351 

>i 

V. 

16     „ 

0-2345 

>i 

VI. 

32     „ 

0-2345 

VII. 

64     » 

0-2342 

VIII. 

128     „ 

0-2338 

Loss  probable. 

IX. 

256     „ 

0-2343 

It  is  seen  at  once  that  the  weight  of  the  calcined  pre- 
cipitate first  of  all  increases  for  eight  hours,  then  slowly 
declines  to  a  definite  limit  in  about  sixteen  hours  (Experi- 
ment No.  VIII.  would  appear  to  be  vitiated  by  some 
accident).  The  above  proves  the  occurrence  of  two 
superposed  phenomena,  which  may  be,  for  example  : — 

1.  The  precipitation  of  the  phosphoric  acid  which 
takes  place  at  once,  more  or  less,  in  the  state  of  tri- 
magnesic  phosphate  and  is  complete  in  about  eight  hours. 

2.  The  much  slower  transformation  of  the  tri-magnesic 
phosphate,  at  first  formed  as  ammonio-magnesic  phos- 
phate, which  takes  at  least  sixteen  hours. 

These  results  have  been  confirmed  by  a  large  number 
of  isolated  experiments — which  have,  as  a  matter  of  fadt, 
been  the  cause  of  the  present  systematic  research.  Two 
examples  are  here  given : — 

I.  II. 


C        Standing  for  4  to  6  hours..     0-2176  grm. 
Standing  for  16  to  22  hours    0-2163     ,, 


0-2175  grm. 
0-2166     „ 

The  excess  in  weight  of  the  precipitate  colledled  be- 
tween four  and  six  hours  may  therefore  exceed  that 
which  has  stood  for  sixteen  to  twenty-two  hours  by  at 
least  I  m.grm.  However,  these  fadts  being  susceptible 
of  different  interpretations, — different,  in  faift,  to  that 
which  has  been  given  above, — it  becomes  necessary  to 
look  for  a  definite  answer,  and  to  primarily  enquire  into 
other  experiments  showing  similar  variations. 

III. — Mechanical  Precipitation. 

It  has  been  well  known  for  some  years,  and  even 
adopted  officially  in  Belgium,  that  continuous  shaking  for 
a  quarter  of  an  hour  or  twenty  minutes  of  the  solution  to 
which  the  precipitant  has  been  added  is  of  great  advan- 
tage.    This  has  been  called  the  citro-mechanical  method. 

The  comparative  examination  I  have  made  of  this 
method  leads  me  to  the  conclusion  that  it  gives  exadtly 
the  same  results,  in  weight  of  the  calcined  precipitate,  as 
in  letting  stand  for  four  to  six  hours;  that  is  to  say,  an 
excess  of  about  i  m.grm.  above  the  results  obtained  after 
sixteen  to  twenty  hours.  This  conclusion  has  been  arrived 
at  from  a  large  number  of  estimations  carried  on  by  the 
two  methods  simultaneously. 

Is  there  really  an  excess  in  the  case  of  rapid  precipita* 


tions,  or  does  the  long  standing  bring  about  a  loss  ? 
What  has  been  written  up  to  now  only  shows  that  there 
is  a  decided  difference  between  the  two  methods. 

IV. — On  the  Influence  of  Dilution. 
Two  experiments  were  made  with  equal  volumes  of  the 
same  solution.  The  quantities  of  citrate  and  chloride  of 
magnesium  used' were  the  same  in  each  case;  but  in  the 
second  the  total  volume  was  doubled  by  the  addition  of 
water,  but  keeping  the  proportion  of  free  ammonia  con- 
stant. The  following  table  gives  the  conditions  and  the 
results  of  the  two  experiments  : — 

I.  II. 

Solution  of  phosphate 50  c.c.  50  c.c. 

Citrate  of  ammonia      25    „  25    ,, 

Ammonia  at  22°    ..      ..     ..     ..     60    „  120    „ 

Chloride  of  magnesia 20    „  20   „ 

Water      _  95    „ 

Wash-waters  (J  ammonia  at  22°)     40   „  80   „ 

Total  volume     iQS    ..  39°   „ 

Weight  of  calcined  precipitate..  0-2336  grm.  0-2353  gfiH' 

Contrary  to  what  might  be  expedled,  the  greater  dilu- 
tion causes  an  augmentation  in  the  weight  of  the  precipi- 
tate  collected. 

This  systematic  experiment  was  suggested  by  a  certain 
number  of  results  obtained  in  the  ordinary  course  which 
had  led  to  the  same  conclusions  ;  the  fadl  now  appears  to 
be  beyond  doubt. 

Here,  again,  several  explanations  are  possible.  Either 
the  nitrate  of  ammonia  exercises  a  solvent  adtion  on  the 
ammonio-magnesic  phosphate, — an  adtion  which  is  the 
more  marked  as  the  solutions  are  the  more  concentrated, 
— or  there  remains  in  the  precipitate  tri-magnesic  phos- 
phate or  phosphate  of  lime,  proportionally  greater  as  the 
solutions  are  more  dilute. 

V. — Does  the  Excess  come  from  Lime  ? 

One  might  suppose  that  in  the  first  moments  of  pre- 
cipitation lime,  in  the  state  of  phosphate,  would  be 
carried  down  ;  its  further  transformation  being  only  very 
gradiially  achieved.  I  was  the  more  inclined  to  this  be- 
lief, inasmuch  as  I  had  just  come  across  a  body  which 
did  not  appear  to  have  been  previously  noticed,  the  am- 
monia calcic  phosphate. 

This  compound  is  obtained  under  exadlly  the  same  con- 
ditions as  the  ammonio-magnesic  phosphate  in  the  pre- 
sence of  citric  acid  in  a  strongly  ammoniacal  solution. 
It  is  fairly  soluble  in  ammoniacal  water,  and  is  formed 
more  easily  at  a  low  temperature.  The  precipitate  is 
composed  of  small  brilliant  crystals,  sufficiently  large  to 
be  recognised  by  the  naked  eye.  Its  composition,  accor- 
ding to  an  analysis  I  have  made,  is  calculated  absolutely 
on  that  of  ammonio-magnesic  phosphate.  In  spite  of  its 
relative  solubility,  it  does  not  appear  impossible,  by  reason 
of  isomorphism,  that  this  phosphate  might  be  at  first 
carried  down  with  the  ammonio-magnesic  phosphate,  and 
then  slowly  decomposed.  I  have  searched — and  searched 
in  vain— to  see  if  there  is  any  trace  of  lime  in  the  precipi- 
tates showing  an  excess ;  but  there  is  none,  and  this  re- 
sult is  beyond  doubt ;  for  to  produce  an  excess  of  i  m.grm. 
it  would  be  necessary  for  3  m.grms.  of  magnesia  to  be 
replaced  by  4  m.grms.  of  lime— a  quantity  which  could 
not  fail  to  be  detedted.  It  is  therefore  necessary  to  put 
on  one  side  the  hypothesis  of  the  presence  of  lime  in 
ammonio-magnesic  phosphate. 

VI. 

With  the  objedt  of  finding  out  the  reason  for  these  slight 
divergencies  I  carried  out  another  series  of  experiments 
which  I  will  now  proceed  to  describe. 

Three  equal  volumes  of  a  similar  solution,  each  corre- 
sponding to  1-25  grm.  of  the  natural  phosphate,  were  pre* 


270 


Estimation  of  Phosphoric  A  cid. 


\  CREMICXL  MBWh, 

1       Dec.  3    1807. 


cipitated   with   proportional  quantities  of  the  usual   re- 
agents under  the  following  conditions : — 

I.  Let  stand  for  twenty-one  hours. 
II.  Let  stand  for  three  hours  and  a  half. 
III.  Mechanical  precipitation  in  twenty  minutes. 

After  thorough  washing,  the  three  precipitates  were  re> 
dissolved  in  hydrochloric  acid,  and  from  each  solution 
made  up  to 250  c.c.  two  quantities  of  100  c.c.  were  taken, 
corresponding  to  0*50  grm.  of  the  original  phosphate. 
Thus  we  get  two  series :  the  three  solutions  of  Series  a 
were  precipitated  with  10  c.c.  of  chloride  of  magnesium  to 
estimate  the  phosphoric  acid  ;  and  those  of  Series  b  with 
10  c.c.  of  a  solution  of  phosphate  of  ammonia  at  10  per 
cent  to  estimate  the  magnesia.  At  the  same  time,  50 
c.c.  of  the  original  solution  were  submitted  to  dire(5t  pre- 
cipitation and  gave  0*2507  grm.  of  calcined  precipitate 
(after  standing  sixteen  hours).  The  following  are  the  re- 
sults obtained  from  the  two  series,  a  and  b,  after  standing 
for  sixteen  hours. 

Difference : 
a,  b.  b-a. 

I.         0*2508  grm.        0*2700  grm.        0*0192  grm. 
II.         0*2506    „  02738    „  00232    „ 

III.         0-2498    ,,  0*2727    ,,  0*0229    ,, 

These  results  were  most  unexpeAed.  It  certainly  ap- 
pears as  if  the  Series  a  corresponds  with  the  usual 
method  for  the  estimation  of  phosphoric  acid,  since  the 
concordance  between  the  diredt  estimation  and  the  result 
(I.,  a)  which  corresponds  to  it  are  as  close  as  possible; 
but  II.,  and  above  all  III.,  in  spite  of  the  excess  always 
caused  by  rapid  precipitation,  contain  less  phosphoric 
acid.  This  excess  would  appear,  therefore,  to  be  due  to 
an  excess  of  magnesia  ;  and  this  would  be  confirmed  by 
the  figures  of  column  b,  which  we  may  consider  as  pro- 
portional to  the  quantities  of  magnesia  in  the  original 
precipitates. 

The  considerable  differences  between  the  corresponding 
figures  of  columns  a  and  6,  which  should  be  identical,  or 
at  least  very  close  to  each  other,  present  an  important 
question  to  be  solved. 

1.  Either  in  the  original  precipitates,  and  in  Series  a, 
there  is  a  large  excess  of  magnesia.  It  would  then  be 
necessary  that,  in  the  method  as  usually  practised,  tri- 
magnesic  phosphate  be  formed ;  the  estimation  of  the 
phosphoric  acid  being  in  such  a  case  tainted  by  a  serious 
error. 

2.  Or,  in  Series  b,  there  is  an  excess  of  phosphoric 
acid.  The  weighed  precipitate  would  then  contain  meta- 
phosphate  mixed  with  pyrophosphate,  and  to  explain  this 
fadt  it  is  necessary  to  admit  that  bi-ammoniacal  magnesic 
phosphate  is  precipitated  at  the  same  time  as  the  normal 
ammoniaco-magnesic  phosphate.  The  estimation  of  the 
magnesia  would  then  be  erroneous. 

3.  Or,  further,  that  the  two  causes  of  error  co-exist. 
To  decide  which  of  these  three  hypotheses  is  corretft, 

the  preceding  experiments  are  not  sufficient,  and  it  be- 
came necessary  to  have  recourse  to  rigorous  synthetical 
trials. 

Vil,— 'Trials  with  a  Known  Quantity  of  Phosphoric  Acid. 
It  is  not  advisable  to  use  ammonio-magnesic  phosphate 
to  obtain  a  known  quantity  of  phosphoric  acid ;  phos- 
phate of  ammonia  is  far  preferable.  But  if  we  can  make 
sure  of  the  purity  of  this  body,  in  so  far  that  it  contains 
nothing  but  phosphoric  acid  and  ammonia,  its  hygro- 
metric  state  and  its  degree  of  basicity  need  not  be  rigor- 
ously defined.  So  as  to  start  from  an  absolutely  certain 
base,  after  having  made  a  solution  containing  about  34 
grms.  per  litre  of  pure  phosphate  of  ammonia,  I  caused  10 
c.c.  of  this  solution  to  be  absorbed  by  pure  magnesia, 
strongly  calcined,  and  after  drying  at  loo*'  it  was  again 
calcined  (the  calcination  should  last  about  three-quarters 
of  an  hour).    The  difference  between  the  two  weighings 


gives,  for  10  c.c,  o-i8oi  of  phosphoric  acid,  with  possible 
variations  of  one-tenth  of  a  m.grm.,  more  or  less.  Other 
trials  made  with  20  and  30  c.c,  gave  proportional  results, 
with  the  same  limits  of  error.  We  can  therefore  feel  sure 
of  the  titration  value  of  the  solution. 

Samples  of  10  c.c.  each  were  precipitated  under  the 
ordinary  conditions  by  the  addition  first  of  40  c.c.  of 
water,  then  of  definite  quantities  of  citrate  of  ammonia  and 
chloride  of  magnesium.  The  average  of  these  experiments 
gave  a  weight  of  pyrophosphate  of  0*2823  grni-i  with 
variations  not  exceeding  two-tenths  of  i  m.grm.,  more  or 
less.  This  corresponds  to  o*i8oa  grm.  of  phosphoric  acid. 
From  this  we  conclude  that  the  precipitation  is  complete, 
and  that  the  pyrophosphate  of  magnesia  is  of  normal 
composition  under  the  afore-mentioned  conditions  ;  that 
is  to  say,  after  sixteen  hours  standmg  in  a  volume  of  150 
c.c.  containing  10  grms.  of  citric  acid  and  at  least  one- 
third  of  its  volume  of  free  ammonia,  and,  finally,  an  ex- 
cess of  magnesia. 

I  have  repeated  the  experiment  under  the  same  condi* 
tions,  but  using  hydrochlorate  of  ammonia  instead  of 
citrate.  This  seems  permissible,  since  there  is  no  other 
base  but  magnesium  to  keep  in  solution,  but  the  results 
cannot  be  depended  on,  and  there  is  always  a  large 
excess.  The  weight  of  the  calcined  precipitate  is  in- 
creased to  0*2976  grm.,  which  corresponds  to  0*1903  grm. 
of  phosphoric  acid,  taking  it  to  have  the  composition  of 
the  pyrophosphate.  This  precipitate  thus  contains  such 
a  large  proportion  of  tri-magnesic  phosphate  that  even 
standing  for  sixteen  hours  does  not  suffice  to  transform  it 
into  ammoniaco-magnesic  phosphate.  This  observation 
is  of  importance,  inasmuch  as  it  is  often  recommended  to 
precipitate  phosphoric  acid  after  the  molybdic  separation, 
for  example,  by  a  simple  addition  of  hydrochlorate  of 
ammonia  and  of  magnesia.  Results  obtained  in  this 
manner  are  quite  untrustworthy. 

VIII. — Exptriments  with  a  Known  Quantity  of  Magnesia. 

A  known  quantity  of  strongly  calcined  magnesia  was 
dissolved  in  hydrochloric  acid,  then  precipitated  in  the 
presence  of  citrate  of  ammonia  by  an  excess  of  phos- 
phoric acid  ;  the  quantity  of  phosphoric  acid  in  excess 
was  varied  by  using  increasing  quantities  of  a  solution  of 
100  grms.  per  litre  of  phosphate  of  ammonia  (titrating 
0*54  grm.  of  phosphoric  acid  per  10  c.c. 

Two  series  of  experiments  were  made  *.— 

A  on  0*0948  grm.  of  magnesia. 

B     „     0*1034  H  .. 

In  each  series  three  precipitations  were  made,  with  5, 
10,  and  20  c.c.  of  the  solution  of  ammonic  phosphate 
respeftively.     The  following  results  were  obtained  : — 

A.  B. 

Magnesia  used       0*0948  grm.  0*1034  grm. 

Corresponding  pyrophosphate  0*2630    „  0*2868  „ 

Weight  of  calcined  precipitate 
obtained  with — 

5  c.c.  ammonic  phosphate  0*2687  n  0*2929  „ 

*°  »»  II  0*2709  „  0*2981  „ 

2°  >»  11  02779  „  0-3107  „ 

We  can  see  from  the  above  that  even  with  a  slight 
excess  of  phosphoric  acid  (5  c.c.  leaving  not  more  than 
o-i  of  phosphoric  acid  in  the  solution)  there  is  an  excess 
—due,  without  doubt,  to  the  mechanical  carrying  down 
of  the  phosphoric  acid  by  the  precipitate.  This  excess 
further  increases  rapidly  as  the  solution  is  richer  in  phos- 
phoric acid. 

For  the  purpose  of  confirming  this,  a  third  series,  C, 
was  made  under  the  same  conditions  as  B;  but  instead 
of  weighing  the  precipitates  at  once,  they  were  dissolved 
for  the  purpose  of  estimating  the  phosphoric  acid  in  the 
ordinary  manner.   The  following  results  were  obtained  :— 


CtiBuicAt.  NbWs,  ) 
Dec.  3.  J897.      » 


Properties  of  Liquid  Fluorine. 


2)1 


Magnesia  used o'io34  grm. 

Corresponding  phosphoric  acid 0"l834     ,1 

Phosphoric  acid  obtained  in  the  precipitate 

by- 

5  c.c.  amnionic  phosphate     ..     ..     0*1940    „ 
ID  „  „  ....     0-1971     » 

20  „  >,  ....     o'2o64    „ 

It  is  seen  thus  that  the  precipitate  carries  down  a 
large  excess  of  phosphoric  acid,  which,  on  calcination, 
gives  metaphosphate. 

These  results  confirm  and  explain  those  which  have 
been  already  obtained,  notably  in  Seftion  V. 

Although  I  have  not  been  able  to  isolate  a  bi-ammoniacal 
magnesic  phosphate,  everything  points  to  the  existence 
and  formation  of  this  compound,  the  more  abundantly  as 
the  readtion  takes  place  in  a  greater  excess  of  ammonic 
phosphate. 

IX. — Conclusions. 

Finally,  we  deduce  from  what  has  been  stated  the  fol- 
lowing consequences : — 

1.  The  estimation  of  phosphoric  acid,  in  the  state  of 
pyrophosphate,  without  any  precautions  beyond  the  pre- 
liminary elimination  of  the  silica,  gives  trustworthy  re- 
sults, untainted  by  systematic  errors. 

2.  Rapid  precipitations  cause  an  excess,  due  to  the 
partial  formation  of  trimagnesic  phosphate,  which  is  only 
transformed  into  ammonio-magnesic  phosphate  after  six- 
teen hours  contadt  with  sufficiently  concentrated  citrate 
of  ammonia  (10  grms.  of  citric  acid  to  150  c.c.  of  solu- 
tion). It  therefore  follows  that  to  obtain  satisfa<aory  re- 
sults the  solution  should  be  allowed  to  stand  all  night. 

3.  In  spite  of  all  this,  the  excess  is  sufficiently  small  as 
not  to  completely  condemn  these  rapid  methods,  which 
can  with  advantage  be  used  commercially  if  due  notice  is 
given  that  this  is  being  done. 

4.  The  transformation  of  the  trimagnesic  phosphate 
into  ammonio-magnesic  phosphate  is  very  slow  in  the 
presence  of  hydrochlorate  of  ammonia  only,  and  it  should 
always  be  remembered  to  add  the  necessary  quantity  of 
citrate. 

5.  The  precipitation  of  the  magnesia  in  the  presence 
of  an  excess  of  ammoniacal  phosphate  gives,  at  the  same 
time,  with  the  ammonio-magnesic  phosphate  another 
phosphate,  not  only  poorer  in  magnesia,  but  also  poorer 
as  the  excess  of  phosphoric  acid  present  is  greater.  The 
estimation  of  the  magnesia  by  this  almost  classic  method 
is,  therefore,  always  erroneous.  This  is  a  subject  to  which 
we  shall  return  later  on. — Bull,  Soc.  Chim.,  vols,  xvii.- 
xviii.,  Nos.  16  and  17,  1897. 


PROCEEDINGS    OF    SOCIETIES. 

CHEMICAL  SOCIETY. 
Ordinary  Meeting,  November  4<A,  1897. 

(Continued  from  p.  363). 

Discussion. 

Dr.  Perkin  said  he  felt  much  interested  in  the  paper, 
because  of  the  remarkable  magnetic  rotation  of  combined 
fluorine,  for  example,  in  fiuorbenzene.  When  one  atom 
of  hydrogen  in  benzene  is  displaced  by  chlorine,  the  rota- 
tion is  considerably  increased.  The  substitution  of 
bromine  causes  a  still  higher  rotation,  and  that  of  iodine 
the  highest.  On  the  other  hand,  the  substitution  of 
fluorine  reduces  the  magnetic  rotation.  He  had  suggested 
that  this  might  be  accounted  for  if  fluorine  were  para- 
magnetic, because  its  magnetic  rotation  would  then  be 
the  reverse  of  that  of  carbon  and  hydrogen.  This,  how 
ever,  does  not  seem  to  be  a  probable  explanation  since  it 
is  DOW  found  that  liquid  fluorine  is  not  paramagnetic.     It 


is  possible  that  this  element  may  have  different  values 
depending  on  whether  it  is  free  or  combined.  The  nitro- 
gtonp  (NO2)  influences  magnetic  rotation  much  in  the 
same  way  as  fluorine. 

Dr.  Gladstone  remarked  on  the  importance  of  Prof. 
Dewar's  communication,  the  most  interesting  portion  to 
him  being  that,  on  the  optical  properties  of  the  liquid 
fluorine.  The  specific  refradtion  of  that  element  had 
been  calculated  by  him  and  his  brother  from  fiuorbenzene 
and  from  many  salts,  crystallised  or  in  solution,  with 
the  invariable  result  that  it  was  exceedingly  small.  In 
the  last  list  of  the  specific  refradtions  of  the  elements 
(Proc.  R.S.,  1897,  '''m  ^4^^)  '*  's  given  at  only  0*031,  which 
is  not  a  third  of  the  next  lowest  in  the  list.  Its  specific 
dispersion  is  also  low,  and  it  has  the  additional  peculiarity 
of  giving  a  reversed  spedtrum.  Now  Prof.  Dewar  finds 
that  liquid  fiuorine  has  about  the  same  refradtive  index 
as  that  of  amber ;  this  is  known  to  be  1*55  or  thereabouts. 
As  the  specific  gravity  of  the  fluorine  is  stated  to  have 
been  1*14,  we  can  easily  calculate  the  specific  relradtion, 
viz.,  o'482.  This  figure,  instead  of  being  the  lowest  in  the 
list  of  elements,  is  nearly  the  highest,  there  being  only 
six  with  higher  values. 

It  is  true  that  in  some  cases  the  specific  refradtion  of 
an  element  in  the  free  state  differs  somewhat  from  that 
deduced  from  its  compounds.  Fluorine  would  naturally 
be  compared  with  the  three  halogens,  chlorine,  bromine, 
and  iodine.  Liquid  chlorine  has  a  specific  refradtion  of 
about  0*27  ;  in  combination  028.  Bromine  has  a  specific 
refradtion  of  about  0*20;  in  combination  0*21.  Iodine 
vapour  has  a  specific  refradtion  of  about  0*19;  in  com- 
bination o'2i.  The  free  element,  therefore,  does  not  differ 
widely  in  specific  refradtion  from  the  same  element  when 
in  combination,  and  in  each  case  is  the  smaller  and  not 
the  greater  of  the  two.  A  certain  analogy  does  exist  be- 
tween fluorine  and  sulphur  or  phosphorus.  These  two 
when  mehed  have  high  specific  refradtions,  sulphur  being 
0-50  and  phusphorus  0-59  :  these  high  figures  are  generally 
much  reduced  when  the  elements  are  in  combination,  but 
the  extent  of  this  redudtion  is  by  no  means  comparable 
with  what  would  appear  to  be  the  case  with  fluorine. 
Although  Professor  Dewar's  method  is  corredt  in  principle. 
Dr.  Gladstone  expressed  a  strong  hope  that  accurate  de- 
terminations would  be  made  by  one  or  other  of  the  more 
direct  methods. 

Dr.  Thorpe  said,  in  reference  to  the  allusion  by  the 
President  to  his  determination  of  the  specific  molecular 
volume  of  fluorine  as  far  back  as  1880,  that  too  much 
stress  could  not  be  laid  upon  the  particular  value,  viz., 
9*2,  which  he  then  obtained.  It  was  deduced  from  a  study 
of  the  specific  gravity  and  thermal  expansion  of  arsenic 
fluoride,  a  substance  which  is  not  easy  to  obtain  pure,  and 
which  is  not  altogether  without  adtion  on  glass,  especially 
at  temperatures  approaching  the  boiling-point.  It,  more- 
over, presupposes  that  arsenic  fluoride  has  a  molecular 
constituent  analogous  to  that  of  arsenic  chloride.  Such 
an  assumption  is  probable ;  but  having  regard  to  the 
remarkable  complexity  of  many  fluorine  compounds,  as, 
for  example,  hydrogen  fluoride  itself,  when  compared 
with  the  corresponding  chlorine  compounds,  the  supposi- 
tion cannot  at  present  be  regarded  as  more  than  probable. 
The  particular  value  obtained,  however,  clearly  indicated 
the  order  of  the  magnitude,  as  shown  by  its  substantial 
agreement  with  the  other  values  quoted  by  the  author. 

With  respedt  to  the  question  raised  by  Dr.  Gladstone 
he  might  say  that  the  peculiar  behaviour  of  glass  when 
immersed  in  arsenic  fluoride  was  significant,  and  suggested 
a  method  by  which  the  refradtivity  of  liquid  fluorine  in 
the  free  state  might  be  ascertained  with  a  fair  approxima- 
tion to  accuracy,  viz.,  on  the  same  principle  as  that 
adopted  by  the  authors  in  determining  the  relative  density 
of  liquid  fluorine  —  that  is,  by  immersing  solids  of 
known  refradtivity  in  the  liquid,  and  observing  which 
became  invisible.  Arsenic  fluoride  is  a  highly  refra&ive 
liquid,  and  some  specimens  of  glass  threads  and  tubes 
I  become  almost  invisible  when  immersed  in  it. 


272 


Liquefaction  of  A  tr  and  the  Detection  of  Impuritiei 


{CtlEMICAL  NeWS, 
Dec.  3,  1B97. 


Professor  Dewar,  in  reply,  observed  that  he  did  not 
intend  to  convey  the  impression  that,  because  amber  in 
liquid  fluorine  might  be  difficult  to  define  clearly,  it  neces- 
sarily followed  that  the  refradtive  index  would  turn  out  to 
reach  1-55,  as  Dr.  Gladstone  seemed  to  infer.  His  present 
impression  was  that  it  exceeded  that  of  liquid  air,  but  he 
could  go  no  further.  No  doubt  the  next  time  Professor 
Moissan  and  he  had  the  opportunity  of  continuing  the 
experiment,  a  diredt  determination  of  the  refradive  index 
would  be  made. 

•112.  The  Liquefaction  of  Air  and  the  Detection  of 
Impurities.     By  Professor  Dewar. 

In  a  paper  on  "  The  Relative  Behaviour  of  Chemically- 
prepared  and  of  Atmospheric  Nitrogen,"  read  before  the 
Society  in  the  year  1894,  it  was  stated  that  all  samples  of 


holds  the  liquid  air  maintained  under  continuous  ex- 
haustion. As  this  low  temperature  had  to  be  kept  steady 
for  from  one  to  two  hours,  while  at  the  same  time  the 
bulb  B  had  to  be  completely  covered  with  liquid  air,  it 
was  necessary  to  arrange  some  means  of  keeping  up  the 
liquid  air  supply  without  disturbing  the  apparatus.  The 
plan  adopted  is  shown  at  h,  which  is  a  valve  arrangement 
which  can  be  so  regulated  as  to  suck  liquid  air  from  the 
large  vacuum  vessel  a,  and  discharge  it  continuously  along 
a  pipe  into  the  vacuum  test-tube  g,  the  latter  being  kept 
under  good  exhaustion.  In  working  the  apparatus  the 
tube  I  is  conneded  to  a  gasometer  containing  10  cubic 
feet  of  air,  so  that  the  volume  of  air  condensed  in  each 
experiment  may  be  observed.  This  was  generally  from 
2i  to  3  cubic  feet.  If  there  is  a  very  small  proportibn  of 
some  substance  not  liquefiable  or  soluble  in  liquid  air 


^        c      / 


To  Gasholder 

Apparatus  For  the  examination  oFthe 
least  condensible  portion  of  Air. 


II 


Fig.  2. 


nitrogen  and  oxygen  properly  purified,  are,  when  liquefied, 
clear  transparent  liquids,  so  that  the  solid  matter  which 
always  separates  when  air  or  nitrogen  or  oxygen  is  lique- 
fied on  the  large  scale  consists  of  impurites.  Ordinary 
air,  containing  4  parts  of  carbonic  acid  per  10,000  parts, 
gave  a  turbid  liquid  from  the  solidification  of  the  carbonic 
acid;  and  oxygen  containing  traces  of  chlorine  behaved 
in  a  similar  manner.  With  the  objedt  of  ascertaining  the 
proportion  of  any  gas  in  air  that  is  not  condensable  at 
about  —  2io''C.  under  atmospheric  pressure,  or  is  not 
soluble  in  liquid  air  under  the  same  conditions,  the  fol- 
lowing apparatus  has  been  devised  : — A  cylindrical  bulb 
of  a  capacity  of  loi  c.c,  marked  b  m  figure,  had  a  capil- 
lary tube  sealed  into  it  terminating  in  a  three-way  stop- 
cock, as  shown  at  e.  The  parts  marked  c  and  d  consist 
of  soda-lime  and  sulphuric  acid  tubes  for  removing  car- 
bonic  acid  and  water.  The  stand  marked  g  holds  the 
large  vacuum  test-tube   into  which  b  is  inserted  which 


then  we  should  expedl  the  vessel  b  would  not  fill  up  com- 
pletely into  the  capillary  tube.  This  is,  however,  exadly 
what  does  take  place.  After  forty  minutes'  cooling,  the 
vessel  B  and  the  cool  part  of  the  tube  were  filled  with 
liquid.  In  this  experiment  some  80  litres  of  air  were 
condensed,  and  any  accumulated  uncondensed  matter 
must  have  been  concentrated  in  the  upper  part  of  the 
capillary  tube  which  had  a  volume  of  0-5  c.c.  Under  the 
conditions,  therefore,  the  material  looked  for  must  be  less 
than  I  part  by  volume  in  180,000  of  air. 

To  test  the  working  with  an  uncondensable  gas  added 
to  air,  a  volume  of  10  cubic  feet  was  taken  in  the  gas- 
holder, and  to  that  500  c.c.  of  hydrogen  were  added. 
This  is  in  the  proportion  of  less  than  i  in  500.  Even 
after  two  hours'  cooling,  the  tube  B  could  only  be  filled 
four-fifths.  In  order  to  prove  that  the  gas  accumulated 
iu  the  upper  part  of  B  was  hydrogen,  the  three-way  stop- 
cock at  E  was  turned,  and  the  temperature  allowed  to  rise 


CDBMtcAL  News, 
Dec.  3.  1897. 


}       Liquefaction  of  Air  and  the  Detection  of  Impurities. 


273 


so  that  the  gas  was  expelled  from  the  evaporation  of  the 
liquid  air  and  coUeAed  over  mercury  as  shown  at  F.  The 
gas  thus  colledted  was  easily  combustible,  and  consisted 
chiefly  of  hydrogen.  The  amount  of  hydrogen  was  then 
reduced  to  1  part  in  1000  of  air,  and  it  was  found  that  after 
one  and  a  quarter  hour's  cooling  the  bulb  b  had  filled  to 
within  a  J  c.c.  of  the  capillary  tube,  A  new  sample  of 
air  containing  i  part  of  hydrogen  in  10,000  of  air  filled 
the  bulb  B  completely  as  if  it  were  ordinary  air. 

It  appears  from  these  experiments  that  i  part  of  hydro- 
gen in  looo  of  air  is  just  detedlable  by  this  plan  of 
working.  As  the  80  litres  of  air  condensed  contained 
some  80  c.c.  of  hydrogen,  it  appears  that  100  c.c.  of 
liquid  air  at  from  —200°  to  —  2io°C.  had  dissolved  nearly 
all  this  gas  ;  in  fa<ft,  that  20  c.c.  of  hydrogen  at  the  low 
temperature  is  dissolved  in  100  c.c.  of  liquid  air.     In  the 


precipitate  by  transmitted  light  looked  yellow-brown. 
This  solid  turns  out  to  be  of  organic  origin,  probably  of 
the  petroleum  order  of  compounds.  It  has  a  very  marked 
aromatic  smell  resembling  such  bodies.  The  trace  of  ma- 
terial left  gave,  after  treatment  with  concentrated  nitric 
acid,  the  smell  of  nitrobenzene  ;  and  as  itsdetedtion  can- 
not be  explained  by  the  presence  of  any  material  of  the 
kind  in  the  vessels  used  in  coUedling,  it  must  be  assumed 
to  be  a  normal  constituent  of  the  Bath  gas.  A  further 
quantity  of  the  Bath  gas  must  be  colledted  in  order  to 
confirm  the  presence  of  such  bodies  and  to  definitely 
make  out  their  nature.  Another  peculiarity  of  the  liquid 
is  that,  on  examining  it  with  the  spectroscope,  even 
through  a  thickness  of  2  inches,  no  trace  of  the  charatSter- 
istic  oxygen  absorption  spedlrum  could  be  detected.  In 
all  attempts  to  make  nitrogen  for  liquefadion  on  the  large 


Fig.  3. 


paper  on  "  The  Liquefadtion  of  Air  and  Research  at  Low 
Temperatures"  {Proc,  1895,  '''m  221)  it  was  shown  that  if 
hydrogen  containing  a  small  percentage  of  oxygen  were 
employed  for  the  purpose  of  getting  a  hydrogen  jet,  the 
liquid  colledled  from  it  was  oxygen,  containing,  however, 
so  much  hydrogen  dissolved  in  it  that  the  gas  coming  off 
for  a  time  was  explosive. 

In  order  to  press  this  inquiry  a  little  further,  some 
natural  gas  known  to  contain  a  different  constituent  like 
helium  suggested  itself  as  being  worthy  of  trial.  Lord 
Rayleigh's  results  of  the  examination  of  the  gas  from  the 
King's  Well  at  Bath  showed  that  it  contained  i'2  part  of 
helium  per  1000  volumes,  so  that  it  seemed  admirably 
adapted  for  such  experiments.  The  author  has  to  express 
his  thanks  to  the  Corporation  of  Bath  for  giving  permission 
to  colledl:  samples  of  the  gas. 

The  sample  of  gas  from  the  Bath  Spring  was  treated 
exadtly  in  the  same  way  as  the  hydrogen  mixtures  described 
above.  During  the  liquefadtion  there  was  a  marked  dif- 
ference in  the  appearance  of  the  liquefied  gas,  for  while 
the  hydrogen  and  air  mixtures  gave  a  clear,  transparent 
liquid,  the  produdt  from  the  Bath  gas  was  turbid,  and  the 


scale,  oxygen  could  always  be  detefted  in  the  liquid  with 
the  greatest  ease  by  means  of  its  absorption  spedlrum. 
After  the  cooling  had  continued  for  one  hour  the  gas 
ceased  to  flow  into  the  condensing  vessel,  and  some  20  c.c. 
at  the  upper  part  of  the  glass  cylinder  B  was  filled  with  a 
gas  that  had  not  undergone  liquefadtion  or  solution. 
About  70  litres  of  the  Bath  gas  were  condensed,  certainly 
the  largest  quantity  of  this  gas  ever  subjedled  to  chemical 
examination.  This  was  boiled  off  just  as  the  hydrogen 
was  treated  in  the  experiments  described  above,  and  as, 
by  accident,  too  much  nitrogen  had  volatilised  along  with 
the  gas,  oxygen  was  added  and  the  mixture  sparked  over 
alkali  to  get  rid  of  the  excess  of  nitrogen.  During  the 
sparking  the  helium  lines  were  well  marked  (along  with 
others  the  origin  of  which  must  be  settled  later),  and  a 
vacuum  tube  filled  with  the  produdl  of  the  sparking  gave 
a  splendid  spedtrum  of  the  gas.  The  sample  of  gas  di- 
redlly  colledted  from  the  liquid  nitrogen  contained  about 
50  per  cent  of  helium.  It  is  therefore  possible  to  separate 
helium  from  a  gas  when  it  is  only  present  to  the  extent  of 
one-thousandth  part  by  liquefadtion  in  the  manner 
described.     From  this  it  would  appear  that  helium  is  less 


574 


Absorption  of  Hydrogen  by  Palladium. 


Crbmical  Mbw* 
Dec.  3,  1897 


soluble  in  liquid  nitrogen  than  hydrogen  is  in  liquid  air, 
and  is  of  greater  volatility  tiian  either  of  the  constituents 
of  air,  as  Professor  Olszewski  found  (Bull.  Ac.  Crac,  i8g6, 
297)  by  diredl  experiment  on  a  pure  sample  of  the  gas 
sent  to  Cracow  by  Professor  Ramsay  with  the  objedt  of 
liquefaction.  In  the  author's  le(5lure  (Proc.  Roy.  Inst., 
l8g6),  entitled  "  New  Researches  on  Liquid  Air,"  the 
following  observation  occurs  : — "  The  exceptionally  small 
refraAive  value  observed  by  Lord  Rayleigh  in  the  case  of 
helium  shows  that  the  critical  pressure  of  this  body  is 
proportionately  high.  It  would  therefore  be  more  difficult 
to  liquefy  than  a  substance  having  about  the  same  critical 
temperature  but  possessing  a  lower  critical  pressure  than 
hydrogen."  Now  that  it  has  been  shown  by  Professor 
Moissan  and  the  author  that  two  substances  like  fluorine 
and  argon,  differing  by  two  units  in  molecular  weight, 
boil  at  nearly  the  same  temperature,  it  seems  reasonable 
to  extend  the  analogy  to  the  case  of  hydrogen  and  helium 
where  the  same  difference  occurs,  and  to  suggest  that  they 
also  probably  have  about  the  same  volatility.  If  the 
sample  of  uncondensed  gas  resulting  from  the  first  lique- 
fadlion  of  the  Bath  gas  were  again  treated  in  the  same 
way,  a  much  more  concentrated  specimen  of  helium 
could  be  obtained.  Provided  helium  were  wanted  on  a 
large  scale,  then  a  liquid  air  apparatus  similar  to  that  in 
use  at  the  Royal  Institution,  transported  to  Bath  and 
worked  with  the  gas  from  the  King's  Well,  could  be  made 
to  yield  a  good  supply.  With  a  modified  form  of  appa- 
ratus, it  will  be  possible  to  coUedt  any  residuary  gas  from 
the  use,  not  of  3  cubic  feet  of  air  or  Bath  gas,  but  from 
hundreds  of  cubic  feet  of  such  products.  This  investiga- 
tion will  be  continued  with  new  samples,  in  order  to  see 
if  the  composition  of  the  gases  changes  and  to  isolate  the 
hydrocarbons. 

The  author  has  to  thank  Mr.  Lennox  and  Mr.  Heath 
for  able  assistance  in  carrying  out  the  experiments. 

Discussion. 
Sir  William  Crookes  said  that  a  few  days  ago  he  re- 
ceived from  Professor  Dewar  a  tube  containing  some  of 
the  gas  at  atmospheric  pressure.  A  small  quantity  was 
let  into  a  new  and  completely  exhausted  spedlrum  tube, 
which  was  then  re-exhausted  and  filled  several  times.  On 
exhausting  to  5  m.m.  pressure  and  passing  an  indudtion 
spark  it  showed  the  nitrogen  spedlrum  brilliantly,  and  on 
intercalating  a  condenser  the  yellow  helium  line  was 
visible,  but  too  faint  to  be  measurable  in  the  large  speAro- 
scope.  To  remove  the  nitrogen,  47  c.c.  were  mixed  in  an 
eudiometer  with  an  equal  volume  of  oxygen,  and  sparked 
for  about  eight  hours,  absorption  of  the  produces  being 
effedted  by  strong  potash  solution  over  the  mercury. 
When  contradtion  had  ceased,  the  residual  oxygen  was 
absorbed  by  passing  pyrogallol  into  the  potash.  The  un- 
absorbed  gas  amounted  to  25  c.c.  This  gas,  dried  over 
phosphoric  anhydride,  was  examined  in  a  new  spedlrum 
tube,  end  on.  (Tube  shown  in  adtion).  It  gave  the 
helium  line  (wave-length  5875'87)  brilliantly,  together 
with  the  other  helium  lines.  No  argon  lines  could  be 
Been. 

•113.  "  The  Absorption  of  Hydrogen  by  Palladium  at 
High  Temperatures  and  Pressures."    By  Prof.  Dewar. 

One  of  the  author's  earliest  papers  was  entitled  "  The 
Motion  of  a  Palladium  Plate  during  the  Formation  of 
Graham's  Hydrogenium."  The  explanation  of  the  motion, 
together  with  a  record  of  other  experiments,  can  be  found 
in  the  Proc.  Roy.  Soc.  Edin.,  1868,  vi.,  504. 

A  subsequent  investigation  by  the  author  into  the 
physical  constants  ot  hydrogenium  appeared  in  the  Trans. 
Roy.  Soc.  Edin.,  1876,  xxvii.,  167,  and  had  reference  to  the 
specific  gravity,  specific  heat,  and  coefficient  of  expansion 
of  the  occluded  hydrogen.  These  observations  led  to  the 
conclusion  that  the  speciiic  gravity  was  independent  of 
the  amount  of  condensed  gas,  and  had  a  mean  value  of 
0-62.  The  specific  heat,  relatively  to  palladium  of  the 
condensed  hydrogen  appeared  to  vary  inversely  as  the 
quantity  occluded,  but    taken   relatively  to   successive 


charges  was  nearly  constant,  having  the  value  3*4,  which 
is  identical  with  that  of  gaseous  hydrogen  at  constant 
pressure.  The  coefficient  of  cubical  expansion  of  the 
alloy  is  about  twice  that  of  palladium,  and  that  of  the 
hydrogen  in  its  compressed  state  not  more  than  three 
times  that  of  mercury.  A  later  communication  was  made 
to  the  Philosophical  Society  of  Cambridge  (Proc,  1878, 
iii.,  207)  dealing  with  the  thermo-eledtric  relations  and 
eledlric  condudtivity  of  hydrogenium.  It  was  shown  that 
the  potential  difference  of  a  jundlion  of  hydrogenium- 
palladium  is  at  ordinary  temperature  nearly  equal  to  that 
of  an  iron-copper  jundtion,  and  that  it  increases  with  the 
temperature  according  to  the  general  parabolic  law  ;  the 
rate  of  the  increase  being,  however,  greater  than  iron* 
copper,  and  subjedl  to  a  regular  variation  on  account  of 
successive  heatings.  The  formation  of  thermo-eledlric 
piles,  and  of  neutral  points  in  a  wire  of  this  substance, 
along  with  the  continuous  formation  of  thermo-eledlric 
currents  through  the  application  of  a  hydrogen  flame  were 
explained.  Experiments  on  eledtric  resistance  proved  that 
it  increases  diredtly  with  the  amount  of  hydrogen  con- 
densed in  the  palladium. 

Subsequent  investigators  have  dealt  more  elaborately 
with  the  many  problems  suggested  by  hydrogenised  pal- 
ladium, but  so  far  the  essentia!  fadts  referred  to  above 
have  been  confirmed. 

In  the  course  of  the  early  observations  the  following 
experiment  is  recorded  as  illustrating  the  absorption  of 
hydrogen  by  palladium  at  a  red  heat  :  — 

Take  a  strip  of  thin  sheet  palladium,  4  or  5  cm.  long 
and  about  5  m.m.  in  breadth,  clamp  it  firmly  by  the  end 
in  a  suitable  support,  so  that  the  strip  is  free  to  vibrate, 
and  insert  it  edgeways  in  the  middle  of  a  hydrogen 
flame,  burning  from  a  nozzle  about  i  m.m.  in  diameter. 
If  the  palladium  be  now  depressed  into  the  inner  dark 
cone  it  immediately  begins  to  vibrate,  producing  a  low, 
musical  note. 

If  the  flame  be  extinguished  by  stopping  the  current  of 
hydrogen  for  an  instant,  on  allowing  the  gas  to  flow  the 
vibration  commences  again,  and  may  be  kept  up  without 
any  adlual  flame. 

The  motion  in  this  position  in  the  flame  is  due  to  the 
absorption  of  hydrogen  on  the  cool  side  next  the  inner 
cone,  with  its  attendant  increase  of  length,  producing  a 
bending  of  the  sheet  into  the  hot  portion  of  the  flame, 
where  the  hydrogen  is  instantly  expelled  from  the  palla* 
dium,  which  is  forced  to  return  to  its  original  position 
from  its  natural  elasticity. 

It  is  now  known  that  no  absorption  of  hydrogen  at 
atmospheric  pressure  by  palladium  takes  place  above 
145°  C,  so  that  the  cause  of  motion  must  originate  at  a 
comparatively  low  temperatue.  The  question  arises,— 
Can  palladium,  under  any  condition  of  pressure,  absorb 
hydrogen  at  a  red  heat  in  quantity  at  all  comparable  to 
what  it  can  do  at  lower  temperatures  ?  If  free  hydrogen 
and  palladium-hydrogen  are  compared  as  regards  volatility, 
the  one  boils  at  30°  (abs.),  the  other  at  420°  (abs.)  very 
much  like  two  isomeric  forms  of  the  same  substance.  This 
ratio  of  I  :  14  given  (and  certainly  the  ratio  could  not  be 
made  greater  than  i  :  16,  since  the  absolute  boiling-points 
may  be  taken  as  in  the  ratio  of  their  respedtive  critical 
points),  we  thus  arrive  at  a  hypothetical  palladium- 
hydrogen  critical  point  of  640°  (abs.)  or  366°  C.  An 
almost  exadt  parallel  may  be  drawn  between  palladium- 
hydrogen  in  its  relation  to  free  hydrogen,  and  iridium 
oxide  in  its  relation  to  free  oxygen.  Thus  liquid  oxygen 
boils  at  go°  (abs.)  and  the  tension  of  dissociation  of 
iridium  oxide  is  1  atmosphere  at  1423°  (abs.).  The  ratio 
of  the  absolute  boiling-points  of  liquid  oxygen  and  the 
oxygen  of  iridium  oxide  are  therefore  as  i:  15-9,  which  is 
almost  the  same  value  as  that  found  above  for  the  relative 
volatilities  of  hydrogen  and  palladium.  In  either  case, 
the  ratio  of  the  absolute  boiling-points  of  the  respe&ive 
substances  may  be  taken  as  approximately  representing 
the  ratio  of  the  latent  heats  of  transition  of  state.  It 
might  then  be  possible  that  palladium  no  longer  absorbed 


Chemical  b^EWs, ) 
Dec.  3,  1897.       I 


A  hsorption  of  Hydrogen  by  Palladium, 


575 


hydrogen  under  any  condition  of  pressure.  The  present 
experiments  were  undertaken  with  the  view  of  answering 
this  question. 

The  diagram  (3)  shows  the  general  arrangement  of  the 
apparatus  most  suitable  for  examining  the  behaviour  of 
the  metals  like  palladium,  sodium,  potassium,  &c.,  towards 
hydrogen  at  high  temperatures  and  pressures. 

A  rod  of  palladium,  A,  weighing  about  119  grms,,  kindly 
placed  at  my  disposal  by  Mr.  George  Matthey,  F.R.S., 
was  placed  in  a  strong  steel  cylinder,  d,  having  an  accu- 
rately.fitting  conical  joint.  As  little  extra  space  as  possible 
was  left  in  the  cyhnder,  which  was  heated  in  a  bath  of 
fusible  metal,  E.  The  vessel  was  connected  with  the 
manometer,  b,  by  a  strong  copper  tube,  and  the  latter 
was  similarly  joined  to  a  compressed  gas  cylinder,  h, 
containing  hydrogen.  The  apparatus,  without  the  pal- 
ladium, must  be  carefully  tested  at  high  pressures  and 
temperatures.  There  must  be  no  trace  of  a  leak.  An 
extra  stopcock  at  c  enabled  the  hydrogen  accumulated 
in  the  apparatus  to  be  blown  off  suddenly  when  re- 
quired, after  the  hydrogen  cylinder  stopcock  was  shut 
off.  Before  commencing  the  experiments  at  high  tem- 
peratures, it  is  well  to  charge  the  apparatus  to  a  pressure 
of  20  atmospheres  with  hydrogen,  and  then  blow  off  the 
gas  and  measure  it.  In  this  way  the  volume  of 
hydrogen  that  is  absorbed  for  every  diminution  of  the 
pressure  of  hydrogen  is  known.  In  the  first  experiments 
a  pressure  of  20  atmospheres  of  hydrogen  in  the 
apparatus  corresponded  to  780  c.c.  of  gas,  measured  at 
atmospheric  pressure.  When  the  fusible  metal  bath  was 
heated  to  420°,  and  hydrogen  at  a  pressure  of  80  atmo- 
spheres introduced  at  starting,  it  fell  to  a  pressure  of 
60  atmospheres  in  two  and  a  half  minutes.  Blowing  off 
the  gas  instantly  to  get  rid  of  accumulated  impurities, 
and  again  applying  a  pressure  of  80  atmospheres  of  hy- 
drogen, the  pressure  was  reduced  to  60  atmospheres  in 
six  minutes.  When  the  same  operations  were  repeated  a 
third  time,  the  diminution  of  pressure  by  20  atmospheres 
took  sixteen  minutes,  and  a  fourth  operation  required  28 
minutes.  In  all,therefore,upwardsof  3000  c.c.  of  hydrogen 
were  absorbed  in  less  than  an  hour.  If  the  palladium  could 
be  seen  at  a  low  red  heat,  then  during  the  rapid  absorp- 
tion of  the  hydrogen  as  described  in  the  last  experiment, 
the  temperature  must  rise  very  considerably,  and  the 
metal,  during  the  operation,  must  adually  appear  to  grow 
much  brighter.  Calculating  from  the  tensions  of  the  gas, 
the  evolution  of  heat  at  300**  must  be  about  4698  grm. -units 
of  heat  per  grm.  of  hydrogen  absorbed.  The  reverse  adion 
would  take  place  on  reducing  the  pressure  of  hydrogen 
in  the  charged  palladium.  After  the  four  charges  the 
pressure  remained  constant  at  80  atmospheres,  no  more 
hydrogen  being  absorbed.  The  hydrogen  gas  outside  the 
palladium  was  now  suddenly  blown  off,  the  stopcock  shut, 
and  the  pressure  allowed  to  rise  from  the  escape  of  gas 
absorbed  by  the  palladium.  In  this  way,  it  was  noted 
that  a  pressure  of  40  atmospheres  was  reached  in  half  an 
hour.  The  whole  amount  of  gas  that  had  been  absorbed 
by  the  metal  was  found,  on  measurement,  to  be  2980  c.c. 
After  the  first  charge  of  hydrogen,  the  steel  cylinder  was 
opened  and  the  palladium  examined.  It  was  found  to 
have  a  deep  rent  in  it  extending  along  nearly  the  whole 
length  of  the  rod.  During  the  occlusion  of  the  hydrogen 
the  volume  of  the  metal  is  increased  by  one-tenth,  so 
that  in  the  passage  of  hydrogen  in  and  out  of  the  metal 
enormous  strains  must  be  produced.  As  the  volume 
of  the  original  metal  is  a  little  less  than  10  c.c,  it  may 
be  taken  that  above  300  times  its  volume  of  hydrogen  had 
been  absorbed  at  the  tempetature  of  420°  and  under  a 
pressure  of  80  atmospheres.  The  free  space  in  the  mano- 
meter atid  conne(5tions  was  now  diminished,  so  that  a 
pressure  of  20  atmospheres  corresponded  to  a  volume  of 
300  c.c.  of  hydrogen  instead  of  780  c.c.  as  above.  The 
palladium  was  saturated  at  360°  C.  under  a  pressure  of 
80  atmospheres  in  the  manner  described  above,  except 
that  a  very  much  larger  number  of  charges  of  hydrogen 
had  to  be  employed.    After  saturation,  the  pressure  of 


hydrogen  was  slowly  reduced  to  25  atmospheres  :  it  rose 
to  30  atmospheres  from  gas  passing  outwards  from  the 
metal,  now  heated  up  to  500°  C,  and  finally  reached  100 
atmospheres;  on  cooling  to  400°  the  pressure  diminished 
from  re-absorption  of  the  hydrogen.  On  blowing  off  the 
gas  between  400°  C.  and  500°  C,  1400  c.c.  of  free  and 
3300  c.c.  of  combined  hydrogen  were  found.  A  rod  of 
palladium,  in  this  way,  can  be  quickly  charged  with  hy- 
drogen at  about  300°  C.  or  400°  C.,  and  as  it  is  only  the 
pure  gas  that  is  occluded,  this  process  may  be  used  as  a 
rapid  means  of  getting  pure  hydrogen  in  quantity  for  ex- 
perimental purposes. 

In  the  next  experiment,  the  palladium  was  heated  to 
500°  C.  before  any  hydrogen  under  pressure  was  applied. 
No  absorption  was  observed  till  the  pressure  of  hydrogen 
reached  60  atmospheres.  On  charging  as  before  at  pres- 
sures between  80  atmospheres  and  60  atmospheres,  the 
metal  was  found  to  absorb  igoo  c.c.  of  gas.  The  experi- 
ment was  repeated,  with  the  difference  that  the  charging 
pressure  of  hydrogen  was  raised  to  between  120  atmo« 
spheres  and  100  atmospheres,  and  it  was  found  that  the 
palladium  had  now  occluded  3700  c.c.  of  hydrogen.  Thus 
it  appears  from  these  experiments  that  at  500°  C.  palladium 
can  still  occlude  300  times  its  volume  of  hydrogen  under 
a  pressure  of  120  atmospheres.  The  observations  on  the 
tension  of  hydrogen  in  palladium  by  Troost  and  Haute- 
feuille  showed  that,  for  the  same  temperature,  the  values 
became  constant  and  independent  of  the  amount  of 
occluded  gas,  only  when  the  volume  of  hydrogen  absorbed 
lay  between  200  and  600  times  than  of  the  metal.  Any 
other  proportions  gave  variable  tensions  for  the  same 
temperature.  The  fadt  that  300  volumes  can  still  be 
occluded  at  500°  C.  seems  to  show  that  palladium  and 
hydrogen,  under  such  conditions,  still  follow  the  same 
laws  of  absorption  as  at  lower  temperatures.  Nothing 
analogous  to  a  critical  point,  where  no  combination  takes 
place  between  the  metal  and  hydrogen,  has  been  reached. 

Hoitsema  published  an  important  paper  on  palladium- 
hydrogen  tensions  in  the  Archives  Neerlandaises,  1896, 
xxx.,  44.  In  this  memoir,  Hoitsema  gives  also  a  series  of 
observations  on  the  same  subjedt  made  by  Roozeboom. 
Taking  the  tensions  given  by  the  latter  (simply  because 
the  curve  seems  more  regular)  for  the  horizontal  portions 
of  the  dissociation  curves  at  different  temperatures,  and 
calculating  a  Willard  Gibbs'  formula,  from  the  following 
data,  viz.,  20°  C.  pressure  7  m.m. ;  loo"  C.  pressure  205 
m.m. ;  170°  C.  pressure  1467  m.m.,  the  expression  results 
(where  T  is  the  absolute  temperature) — 

log.  p  »  7-00338  -  i2^  -f.  0-2378  log.  T. 

From  this  it  follows  that  the  latent  heat  of  dissociation 
of  the  palladium-hydrogen  per  atom  of  hydrogen  in  grm.- 
units  is  456I-I-0-2378  T.  This  would  seem  to  show  the 
latent  heat  of  dissociation  increases  instead  of  diminishing 
\vith  temperature.  In  other  words,  the  heat  of  combina- 
tion should  be  rather  greater  at  higher  temperatures,  in- 
stead of  diminishing  as  it  must  do  if  a  point  where  no 
occlusion  takes  place  were  being  approached.  Thus 
theory  and  experiment  would  seem  to  agree. 

The  best  and  safest  method  for  the  experimental  study 
of  the  relations  of  hydrogen  and  palladium  at  high  tem- 
peratures and  pressures  would  be  to  investigate  the 
change  of  eleftrical  resistance  in  a  heated  wire  of  the 
metal  when  subjedled  to  different  hydrogen  pressures. 
The  problem  is,  no  doubt,  more  complicated,  still  inter- 
esting results  must  follow  from  such  an  investigation. 
Some  of  the  eledtrical  properties  of  hydrogen  and 
palladium  at  low  temperatures  have  been  determined  by 
Professor  Fleming  and  the  author,  and  the  results  will 
appear  in  future  publications  bearing  on  the  subjedl. 

The  author  is  indebted  to  Mr.  Robert  Lennox  for  able 
assistance  in  the  condudt  of  the  experiments. 
Discussion. 

Mr.  R.  J.  Friswell  asked  whether  the  President  had 
made  any  measurements  of  the  tensile  strength  of  the 


276 


Failure  of  German  Silver  and  Platinoid  Wires,  { ^'^Stc'^^^S^^' 


steel.  He  was  astonished  to  hear  of  the  metal  standing 
100  atmospheres  at  over  500°  C.  He  was  asking  for  in- 
formation, as  he  had  been  unable  to  obtain  any  data  as 
to  the  strength  of  metals  near  a  red  heat,  a  point  at 
which  it  must  be  rapidly  falling  away.  The  matter  was 
of  great  interest  for  experimenters  using  autoclaves. 
Engineers  did  not  seem  to  have  done  any  work  on  tensile 
strength  at  points  above  the  temperatures  usual  in  steam 
boilers. 

Prof.  Dewar,  in  reply  to  Mr.  Friswell,  agreed  that  no 
engineering  formulae  existed.  The  experiments  were 
dangerous,  but  one  had  to  take  the  risk.  The  metal  used 
was  Whitworth  compressed  steel,  and  the  vessel  was 
made  by  drilling  out  a  solid  mass.  He  had  no  data  as  to 
tensile  strength,  the  results  were  desired  and  the  risk 
taken. 

(To  be  continued). 


PHYSICAL    SOCIETY. 
Ordinary  Meeting,  November  26th,  1897. 

Mr.  Shelford  Bidwell,  President,  in  the  Chair. 

Mr.  Rollo  Appleyard  read  a  paper  on  "  The  Failure  of 
German- silver  and  Platinoid  Wires." 

The  mechanical  defediveness,  and  the  consequent 
eledlrical  instability  of  alloys  used  for  eled^rical  wires, 
may  be  discussed  from  two  points  of  view: — (i).  As  to 
the  constitution  and  metallurgy  of  the  alloy.  (2).  With 
regard  to  the  subsequent  treatment  and  environment  of 
the  wire.  In  stating  the  case,  the  author  gives  instances 
of  the  failure  of  German-silver  and  platinoid  wire,  that 
have  occurred  among  several  thousands  of  resistance- 
coils  distributed  over  widely  different  latitudes.  In 
periods  of  time,  varying  from  six  weeks  to  several  years 
after  manufatfture,  the  wire  on  some  of  the  bobbins 
became  brittle,  and  broke,  not  only  on  the  outer  layers, 
but  also  within  the  coils.  The  towns  where  the  faults 
appeared  are  all  within  the  tropics,  and  included  nearly 
within  the  isotherm  of  25°  C.  Other  coils,  of  nominally  the 
same  material,  manufacture,  and  environment,  have  re- 
tained their  original  good  condition.  It  follows  that 
metallurgical  di^erences  exist  between  different  samples 
of  the  same  nominal  quality  of  alloy.  Examples  are 
given  to  prove  that  failure  sometimes  occurs  with  platinoid 
through  which  no  eledlricity  has  passed.  Provided  that 
the  wire  is  good,  the  eSeA  of  environment  is  almost  insig- 
nificant, i.e.,  the  question  is  one  of  metallurgy  rather  than 
of  instrument-making. 

The  author  introduces  a  distindtion  in  regard  to  brittle- 
ness.  He  discriminates  between  "  primary "  and 
"secondary"  brittleness.  "Primary"  brittleness  is 
charadteristic  of  certain  alloys  (for  instance  of  gold-lead 
or  of  gold-bismuth)  from  the  moment  of  their  solidifica- 
tion. But  the  brittleness  of  German-silver  and  of 
platinoid  is  of  a  different  order;  it  is  a  subsequent  pheno- 
menon. "Primary"  brittleness  is  thus  an  accident  of 
birth,  and  "secondary"  brittleness  is  a  disease  that 
develops  with  age  and  ciecumstance.  The  fradure  of  bad 
specimens  of  German-silver  and  platinoid  shows  patches 
of  dark  metal,  crevices,  and  fissures.  It  may  be  supposed 
that,  during  the  process  of  cooling,  "liquation"  occurs — 
the  metals  that  first  solidify  rejedting  yet  molten  por- 
tions, as  ice  rejedts  foreign  matter.  Consequently  the 
strength  of  the  final  alloy  varies  from  point  to  point  of  its 
mass,  and  in  passing  afterwards  through  the  die  the  weaker 
portions  give  way,  and  the  general  strudture  is  loosened. 
Moisture  can  then  intrude  through  the  capillary  channels. 
At  all  fissures  and  crevices  the  eledtric  current  produces 
undue  heating :  this  accounts  for  the  failure  of  resistance- 
coils  on  arc-light  and  other  circuits.  As  regards  the  pro- 
tedtion  of  coils  against  moisture,  paraffin-wax  is  of  no  use 
whatever;  it  is  highly  absorbent.  Shellac  varnish  is 
greatly  to  be  preferred.    Ebonite  does  not  seem  to  have 


any  deteriorating  effedt,  but  it  may  be  well  to  keep  the 
alloys  o  ut  of  adlual  contadt  with  it. 

In  conclusion,  Mr.  Appleyard  expressed  a  hope  that 
British  metallurgists  would  give  eledlrical  alloys  special 
consideration.  Already  British  cable-manufadturers  are 
importing  thousands  of  tons,  annually,  of  sheathing-wire 
from  Germany  :  this  is  sufficiently  to  be  regretted  ;  he 
had  good  reason  to  know  that  instrument-makers  were 
beginning  to  get  the  wire  for  their  resistance-coils  also 
from  Germany.  He  had  not  enough  experience  of  man- 
ganin  to  say  whether  that  material  would  stand  rough 
service  in  the  tropics. 

Prof.  Ayrton  said  the  paper  had  raised  the  extremely 
interesting  question  of  the  pemanence  of  metals  used  for 
resistance-coils.  Some  time  ago  he  had  immersed  bare 
platinoid  wires  in  running  water  in  metal  tanks,  and  the 
wires  all  broke  in  short  pieces.  He  thought,  at  the  time, 
this  might  be  due  to  eledtrolysis.  On  another  occasion 
he  had  found  that,  by  raising  the  temperature  of  platinoid 
to  a  dull-red  heat  in  the  air,  by  an  eledtric  current,  any 
acquired  faults  in  the  wire  were  corredted,  and  the  original 
resistance  and  flexibilty  were  restored.  Even  when  such 
metals  are  in  good  condition,  the  resistance-temperature 
curve  does  not  return  upon  itself;  it  encloses  a  loop,  indi* 
eating  two  distindl  values  for  resistance  at  each  temper- 
ature. He  had  been  told  by  Dr.  Muirhead  that  coils 
intended  for  hot  climates  should  be  enclosed  in  air-tight 
metal-cases.  English  manufadturers  were  still  dubious  in 
regard  to  manganin.  In  1892  he  had  twenty  coils  of  this 
material,  each  of  1000  ohms ;  the  wire  was  silk-covered. 
There  were  2000  volts  between  the  terminals.  Their  re- 
sistance had  certainly  not  changed  by  i  in  1000,  although 
there  was  some  amount  of  vagueness  regarding  the  fitth 
figure,  which  might  be  due  to  molecular  alteration,  for 
they  were  heated  more  than  was  good  for  resistance- 
coils.  He  confessed  that  this  manganin  had  come  from 
Germany. 

Dr.  S.  P.  Thompson  mentioned  an  alloy  that  was  pro- 
posed in  Germany  under  the  name  of  "  Constantine." 
He  would  like  to  know  whether  any  information  could  be 
obtained  as  to  the  employment  of  cast-iron  wire.  It  was 
a  metal  that  in  some  respedts  commended  itself.  He  had 
observed  the  failure  of  some  German-silver  coils,  but  he 
had  generally  attributed  it  to  rough  handling. 

Mr.  W.  Watson  referred  to  the  recent  work  done  at 
the  Reichsanstalt  with  regard  to  German-silver  and 
platinoid.  It  was  there  found  that  all  alloys  containing 
zinc  were  liable  to  erratic  change  of  resistance,  and  were 
unsuitable  for  standard  coils.  Moreover,  even  the  slight 
amount  of  zinc  introduced  into  manganin  during  soldering 
with  soft  solder  robbed  that  alloy  of  its  constancy.  Silver 
solder,  containing  75  per  cent  of  silver,  should  be  em- 
ployed for  manganin.  If  Prof.  Ayrton's  coils  were 
soldered  with  soft  solder,  that  was  sufficient  to  account 
for  the  change  in  the  fifth  figure.  Shellac  varnish  was 
undoubtedly  the  best  protedlion  for  coils.  Absolute  alco- 
hol should  be  used  as  the  solvent,  and  the  coils  should 
afterwards  be  heated  for  some  hours  at  140°  C.  If  a 
heating-current  was  passed  through  German-silver  or 
platinoid  coils  immersed  in  water,  the  general  result  was 
to  produce  brittleness.  Mr.  Watson  then  described  a 
thermostat  which  he  had  contrived  for  drying  the  coils 
after  applying  the  shellac  varnish.  A  hot-air  oven  con- 
tains a  thermometer  with  a  platinum  contadt  at  the  140" 
mark  and  an  8  c.-p.  lamp.  The  thermometer  is  in  circuit 
with  a  relay  adtuating  a  mercury-key  for  the  8  c.p.  lamp. 
The  key  consists  of  two  mercury-cups,  and  a  correspond- 
ing U-piece  of  copper,  inverted,  one  limb  to  each  cup.  It 
is  important  to  keep  the  heating-circuit  always  made  ;  for 
this  purpose  a  32  c.-p.  lamp  is  permanently  connedted  be- 
tween the  two  cups. 

Prof.  Perry  then  read  a  note  on  a  question  in  "  Thermo- 
Dynamics,'"  arising  from  correspondence  that  had  taken 
place  between  himself.  Prof.  Ramsay,  and  Mr.  Rose-Innes, 
with  regard  to  a  paper  in  the  Roy,  Soc.  Trans. 

Mr.  Rose-Innes  replied. 


Cbbmical  Nbws,  I 
Dec.  3, 1897.      I 


Chemical  Notices  from  Foreign  Sources, 


277 


The  President  proposed  a  vote    of    thanks  to   the 
authors,  and  the  meeting  adjourned  until  Dec.  loth. 


CORRESPONDENCE. 


MOUNTING     MICROSCOPIC     OBJECTS. 

To  the  Editor  of  the  Chemical  News. 
Sir, — In  the  course  of  preparing  the  catalogue  of  the 
colle(^ion  of  slides  belonging  to  the  Royal  Microscopical 
Society,  I  met  with  about  a  hundred  anatomical  prepara- 
tions mounted  in  fluid,  some  in  cells  of  considerable  size. 
They  are  the  work  of  the  late  R.  J.  Farrants,  formerly  a 
President  of  the  Society,  and  were  presented  with  his 
entire  coUedlion  soon  after  his  death.  The  date  of  the 
preparations  in  question  is  certainly  previous  to  i860. 

I  found  the  cells  leaky,  and  the  marine  glue  generally 
in  bad  condition  ;  indeed,  this  was  the  weak  point  of  the 
mounts  ;  the  cementing  of  the  cover  glasses  was  in  nearly 
every  case  perfectly  sound — as  might  be  expedted  from 
such  a  master  of  technical  details  as  the  late  Mr. 
Farrants. 

It  is  certain  that  marine  glue — so  much  in  use  many 
years  ago  for  attaching  cells  to  glass — is,  in  common 
with  many  other  compounds  of  indiarubber,  a  somewhat 
unstable  substance,  and  has  evidently  broken  down  after 
a  period  of  from  thirty  to  forty  years. 

The  mounting  fluids  employed  were  dilute  alcohol  and 
sometimes  a  weak  glycerin  preparation,  and  both  occa- 
sionally with  some  kreosote. 

I  have  also  found  marine  glue  has  failed  in  my  own 
collediion,  and  I  now  attach  cells  to  glass  with  a  mixture 
of  red  and  white  lead;  artist's  flake  white,  from  the  tube, 
worked  up  with  the  red  lead  until  it  is  too  stiff  to  use, 
and  then  mixed  a  little  at  a  time  with  japanner's  gold 
size.  No  more  should  be  mixed  at  once  than  is  sufficient 
to  fix  two  or  three  cells,  as  the  mixture  rapidly  becomes 
unworkable  after  the  introdudlion  of  the  gold  size. 

When  the  cells  are  in  place,  they  should  be  put  in  a 
warm  situation — I  use  the  top  of  the  hot-water  cistern — 
and  after  a  day  or  two  the  surplus  cement  should  be 
scraped  off;  they  are  then  left  for  a  fortnight  or  three 
weeks  to  thoroughly  harden;  the  final  cleaning  is  done 
with  a  little  alcohol.  The  cells  are  now  impervious  to 
ordinary  mounting  media. 

When  a  cell  contains  an  appreciable  quantity  of  fluid,  I 
adopt  the  unprofessional  plan  of  leaving  a  small  air  bubble, 
which  adts  as  a  spring  and  saves  the  cell  from  rupture  at 
some  weak  point,  which  sooner  or  later  happens  when 
cells  are  entirely  tilled  with  fluid. — I  am,  &c., 

W.  T.  Suffolk,  Treas.  R.M.S. 
143,  Beulab  Hill,  Norwood,  S.E. 


CHEMICAL    NOTICES   FROM    FOREIGN 
SOURCES. 


NoTB.— All  degrees  of  temperature  are  Centigrade  unless  otherwise 
expressed. 

Bulletin  de  la  Societe  Chimique  de  Paris. 
Series  3,  Vol.  xvii.-xviii.,  Nos.  16-17. 
Observations  on  the  Spe(5tra  of  Compound  Bodies. 
— A.  de  Gramont. — The  author  having  noticed  that  many 
mistakes  msy  be  made  by  using  salts,  oxides,  or  solutions 
haphazard,  has  found  that  the  spedra  given  by  such  com- 
pounds can  be  divided  into  two  fundamental  classes  : — 
(I),  the  line  spedlra,  and  (2)  the  band  spedlra.  The  first 
he  calls  atomic,  the  second,  owing  to  the  lower  temper- 
ature at  which  they  are  seen,  he  calls  molecular  spectra. 


'  Amongst  other  interesting  fads  M.  de  Gramont  finds  that 
the  proportion  of  an  element  in  a  compound  can  be  recog- 
nised  in  three  distindl  manners  : — ist,  by  a  persistent 
spedlriim,  reduced  to  certain  principal  lines ;  2nd,  by  a 
fleeting  spedtrum  of  unequal  duration  for  any  particular 
element ;  3rd,  by  an  intermittent  and  irregular  spedtrum. 
It  should  be  borne  in  mind  that  the  sensibility  of  the  spec- 
tral readlionsis  entirely  variable  from  one  element  to 
another. 

Dissociation  Spedlra  of  Melted  Salts.  Alkaline 
Metals  :  Sodium,  Lithium.— A.  de  Gramont.— Already 
inserted  in  full. 

Dissociation  Spedtra  of  Melted  Salts.  Alkaline 
Metals:  Potassium.— A.  de  Gramont.— Already  inserted 
in  full. 

On  Blue  Nitrosodisulphonic  Acid  and  some  of  its 
Compounds.— P.  Sabatier.— In  the  readtion  between 
oxide  of  copper  and  a  solution  of  nitrate  of  silver  the 
author  has  observed  that  the  produdl,  when  treated  with 
concentrated  sulphuric  acid,  gives  a  very  intense  purple- 
blue  colouration,  which  disappears  on  the  addition  of 
water.  He  finds  that  the  principal  cause  of  the  colour- 
ation is  due  to  the  acid  existing  in  the  solution,  this  being 
due  also  to  the  presence  either  of  nitrogen  or  of  sulphur. 
In  attempting  the  synthesis  of  nitrosodisulphonic  acid  the 
author  tried  several  methods  before  arriving  at  one  which 
now  appears  to  be  the  most  pradicable.  He  effedls  the 
readtion  by  means  of  a  carefully  diluted  sulphuric  acid, 
previously  saturated  with  sulphurous  acid,  and  kept  at  0°. 
The  mixture  of  nitric  oxide  and  air,  when  first  added,  gives 
no  colouration,  but  after  a  time,  varying  within  certain 
limits,  there  occurs  a  lively  ebullition  of  the  liquid,  accom- 
panied  by  a  violent  colouration,  so  intense  as  to  be  almost 
opaque.     The  final  readlion  may  be  expressed  as — 

2[N0(S03H)]  =  NO  -f-  NO(S03H)2. 

Deep  blue. 
Among  the  properties  of  nitrosodisulphuric  acid  may  be 
noticed  that  it  is  quickly  decolourised  by  agitation  with 
air,  peroxide  of  hydrogen,  or  persulphuric  acid  ;  chlorine 
gives  a  similar  result,  as  does  bromine,  but  more  slowly; 
iodine  has  apparently  no  effedt;  the  alkaline  chlorides  are 
violently  decomposed,  with  disengagement  of  hydrochloric 
acid  gas  and  free  chlorine.  Sulphurous  acid  dired  has  no 
apparent  adlion  on  the  nitrosulphuric  solution,  even  when 
concentrated,  but  when  diluted  by  one-fifth  of  its  volume 
of  water  the  blue  compound  is  immediately  obtained. 
The  research  tends  towards  the  preparation  of  the  various 
salts  of  nitrosodisulphuric  acid  apart  from  the  preliminary 
solution  in  concentrated  sulphuric  acid. 

Dissociation  of  Minium. — H.  Le  Chatelier.— Experi- 
ments  made  with  minium,  free  from  carbonate  of  lime  and 
other  impurities,  capable  of  giving  off  gas,  show  that  there 
is  still  a  gas  evolved  when  heated  up  to  temperatures 
varying  from  445°  to  636°;  from  which  it  appears  that  in 
ordinary  air  carrying  oxygen  at  a  tension  of  150  m.m., 
minium  can  be  formed  at  a  temperature  below  550°,  but 
the  temperature  of  most  rapid  oxidation  is  below  but  very 
close  to  500°. 

Impurities  of  Commercial  Carbides  of  Calcium. — 
H.  Le  Chatelier. — Already  inserted  in  full. 

Adlion  of  Chlorine  on  Chloral  in  the  presence  of 
Chloride  of  Aluminium.— A.  Mouneyrat. — The  formation 
of  the  hexachlorethane  is  due  to  the  fadt  that,  by  the 
adlion  of  chloral  and  chloride  of  aluminium,  there  is  first 
of  all  formed  a  pentachlorethane,  according  to  the  equa- 
tion— 

(CCl3,COH)3  -f  2(AlCl3)  =  AI2O3  -h  [CCl3,CCl2H]3; 
this,  under  the  influence  of  chlorine  in   the  presence  of 
chloride  of  aluminium,  gives  hydrochloric  acid  and  hexa- 
chlorethane :  the  total  readtion  is  therefore — 
(CCl3,C0H),  +  (AlCl3)2-f.Cl6  = 
=  (CCl3,CCl3)3  +  AljOa  -1-  (HC1)3. 


278 


Meetings  for  the  Week. 


Aif^ion  of  Bromine  on  Chloral  in  the  presence  of 
Chloride  of  Aluminium. — A.  Mouneyrat. — The  author 
first  thought  that  by  aifiing  on  chloral  in  the  presence  of 
chloride  of  aluminium  with  bromine  he  would  obtain  a 
mixed  chlorobromided  compound  ;  but  he  found  that  the 
body  obtained  did  not  contain  any  bromine  in  its  mole- 
cule. He  also  tried  the  adion  of  iodine  under  the  same 
circumstances,  but  with  similar  results  ;  he  has  obtained 
nothing  but  the  hexachlorethane,  Cade- 


MISCELLANEOUS. 


The  Royal  Society. — At  the  Anniversary  Meeting  on 
November  30th,  the  following  Council  and  Officers  were 
eledted  for  the  ensuing  year: — 

President— Lord  Lister,  F.R.C.S.,  D.C.L. 

Tr^asMr^r— Sir  John  Evans,  K.C.B.,  D.C.L.,  LL.D. 

Secretaries— Pro(.  Michael  Foster,  M.A.,  M  D.,  D.C.L. , 
LL.D. ;  Prof.  Arthur  William  Rucker,  M.A..  D.Sc. 

Foreign  Secretary — Sir  Edward  Frankland,  K.C.B., 
D.C.L.,  LL.D. 

Other  Members  of  the  Council — Prof.  William  Grylls 
Adams,  M.A. ;  Prof.  Thomas  Clififord  AUbutt,  M.D. ;  Sir 
Robert  Stawell  Ball,  M.A.;  Rev.  Thomas  George  Bon- 
ney,  D.Sc;  Prof.  John  Cleland,  M.D. ;  Prof.  Robert 
Bellamy  Clifton,  M.A. ;  Prof.  James  Alfred  Ewing,  M.A.; 
Alfred  Bray  Kempe,M.A.|;  John  Newport  Langley,  D.Sc; 
Joseph  Larmor,  D.Sc. ;  Prof.  Nevil  Story  Maskelyne, 
M.A.;  Prof.  Raphael  Meldola,  F.C.S. :  Prof.  Edward 
Bagnall  Poulton,  M.A. ;  William  James  Russell,  Ph.D.; 
Dukinfield  Henry  Scott,  M.A.  ;  Prof.  Walter  Frank 
Raphael  Weldon,  M.A. 


NOTES    AND    QUERIES, 

%*  Our  Notes  and  Queries  column  was  opened  for  the  purpose  of 
giving  and  obtaining  information  likely  to  be  of  use  to  our  readers 
generally.  We  cannot  undertake  to  let  this  column  be  the  means 
of  transmitting  merely  private  information,  or  such  trade  notices 
as  should  legitimately  come  in  the  advertisement  columns. 

■Wheat  Phosphates. — Will  some  correspondent  kindly  give  me 
address  of  a  manufadturer  of  wheat  phosphates,  or  the  name  of  a  book 
or  pamphlet  describing  the  process  of  producing  them  from  bran.— 
Cato. 


MEETINGS    FOR    THE    WEEK. 


MoHDAY,  6th.— Royal  Institution,  5.  General  Monthly  Meeting. 

——  Society  of  Chemical  Industry,  8.  "  The  Sulman-Teed 

Process  of  Gold  Extrad^ion,"  by  H.  L.  Sulman 
and  Dr.  F.  L.  Teed. 
—  Society  of  Arts,  8.     (Cantor    Leftures).      "  Gutta 

Percha,"  by  Eugene  F.  A.  Obach.  Ph.D.,  F.C.S. 
Wednesday,  8th.— Society  of  Arts,  8.  "The  Mining  and  Metallurgi- 
cal  Industries    of  Sweden   as    shown   at   the 
Stockholm  Exhibition  of  1897," by  Bennett  H. 
Brough. 


MICA 


Telephone 
No.  2248 
Avenue. 

F.  WIGGINS  <&  SONS,    10  Tower  Hin,E.»  Lcndoa. 

102  oc  103.  Minonet,  CxC, 
MICA  MERCHANTS, 
Manufacturers  0/  Utca  Goods  /or  Electrical  and  ALL  purpoits. 
Contractors  to  Her  Majeety'sGoverDmeot 


OLD    PLATINUM 

In  any  form   Purchased  for  Cash. 

Highest  prices  allowed  by 

ROBERT  PRINGLE  &  CO.,  Gold  and  Silver 

Refiners,  &c.,  40  and  42,  Clerkenwell  Rd.,  E.G. 

Send  for  Price  List. 
Photographic  Residues  reduced  and  purchased. 


/Chemical  News 
1      Dec.  3,  1697. 

THE* 

DAVY  FARADAY  RESEARCH  LABORATORY 

OP 

THE    ROYAL    INSTITUTION. 

Directors : 

The  Right  Hon,  LORD  RAYLEIGH,  M.A.,  D.C.L.,  LL.D.,  F.R.S. 

Professor  DEWAR,  M.A.,  LL  D.,  F.R.S. 

Superintendent  of  the  Laboratory  : 

Dr.  Alexander  Scott,  M.A.,  D.Sc. 

This  Laboratory,  which  has  been  founded  by 
Dr.  LuDwiG  MoND,  F.R  S.,  as  a  Memorial  of  Davy  and 
Faraday  for  the  purpose  of  promoting  original  research  in  Pure  and 
Physical  Chemistry,  is  now  open. 

Under  the  Deed  of  Trust,  workers  in  the  Laboratory  are  entitled, 
free  of  charge,  to  Gas,  Eledtricity,  and  Water,  as  far  as  available, 
and  at  the  discretion  of  the  Directors,  to  the  use  of  the  apparatus 
belonging  to  the  Laboratory,  together  with  such  materials  and 
chemicals  as  may  b«  authorised. 

All  persons  desiring  to  be  admitted  as  workers,  must  send  evidence 
of  scientific  training,  qualification,  and  previous  experience  in 
original  research,  along  with  a  statement  of  the  nature  of  the  investi- 
gation they  propose  to  undertake. 

The  terms  during  which  the  Laboratory  is  open  are  the  following — 
Michaelmas  Term— First  Monday  in  Oftober  to   Saturday 

nearest  to  the  l8th  of  December. 
Lent  Term— Monday  nearest  to  the  15th  of  January  to   the 

second  Saturday  in  April. 
Easter  Term— First  Monday  in  May  to  the  fourth  Saturday 
in  July. 
Candidates  must  apply  for  admission  during  the  course  of  the  pre- 
ceding Term. 

Forms  of  application  can  be  had  from  the  Assistant  Secretary, 
Royal  Institution,  Albemarle  Street,  W. 

ARGENTAURUM  GOLD.'" 


^Tumerous  requests  having  reached  us 
\  from  all  parts  of  the  world  for 
specimens  of  ARGENTAURUM  GOLD, 
we  have  now  arranged  for  a  supply  of  the 
same  in  sheets  weighing  i,  2,  5,  and  10  grms. 
respedlively. 

The  Price  is  75  cents  per  Gramme. 

Orders  and  remittances  should  be  addressed 
to  us  as  follows:— EMMENS,  STRONG,  d  CO., 
1  Broadway,  New  York  City,  U.S.A. 

ACETONE — Answering  all  requirements. 
.A.CIID      A  CTT! TIO-P"rest  and  sweet. 

SOIE2,J^CIC—Cryst.  and  powder. 

S-A-XjICyXjIC— By  Kolbe's  process. 

'X'.A.IiTIEnG— For  Pharmacy  and  the  Arts. 

BROMATE   OF   POTASH 

FOR  Gold  Extraction. 

POTASS.  PERMANGANATE— Cryst.,  large  and  small, 

SULPHOCYANIDE   OF   AMMONIUM. 
BARIUM. 

SODA  PHOSPHATE. 
PARIS   and    STEEL    BLUES,  Pure. 

TARTAR   EMETIC-Cryst.  and  Powder. 

PUMICE.     TRIPOLI   AND  METAL  POWDERS. 

ALL  CHEMICALS  FOR  ANALYSIS  AND  THE  ARTS. 


Wholesale  Agents— 

A.  &  M.  ZIMMERMANN, 

9  &  10,  ST.  MARY-AT-HILL,  LONDON,  E.G. 


CrbuicalNbw*. 
Dec.  10, 1S97. 


Electrolytic  Separation  oj  Nickel  and  Cobalt  from  Iron, 


279 


THE    CHEMICAL     NEWS 


Vol.  LXXVI.,  No.  1985. 


ON     THE    ELECTROLYTIC     SEPARATION    OF 

NICKEL    AND    COBALT     FROM     IRON. 

ITS    APPLICATION     TO    THE    ESTIMATION  OF 

NICKEL    IN     STEELS. 

By  O.  DUCRU. 

I,  The  complete  separation  of  nickel  and  cobalt  from 
large  quantities  of  iron  presents  considerable  difficulties, 
and  the  large  number  of  methods  already  published  does 
not  yet  shpw  that  there  is  any  8atisfa(5tory  method  known 
for  effe<5ting  it. 

The  principal  difficulty  arises  from  the  faA  that  the 
ferric  compound  (hydrate,  basic  acetate,  &c.)  always 
contains  a  considerable  proportion  of  other  metals  (Ni, 
Co,  Mn,  Cu,  &c.):  to  obtain  a  complete  separation  we 
are  therefore  obliged  to  multiply  the  precipitations,  which 
not  only  takes  up  a  great  deal  of  time,  but  also  leads  to 
the  accumulation  of  inconveniently  large  volumes  of 
liquid. 

II.  For  some  years  past,  owing  to  their  special  proper- 
ties, nickel  steels  have  taken  an  important  place  industri- 
ally. A  rapid  and  accurate  method  for  the  determination 
of  nickel  in  these  alloys  is  therefore  of  some  interest.  In 
his  masterly  work  on  the  "  Methodes  d'Analyse  des  Fers, 
des  Fontes,  et  des  Aciers,"  carried  out  by  the  desire  of  the 
Commission  on  the  Testing  of  Materials  for  Constru(5tion, 
M.  A.  Carnot,  for  this  purpose,  gave  preference  to  the 
method  proposed  by  Rothe.  This  method,  also  suggested 
in  France  by  M.  Hanriot,  rests,  as  is  well  known,  on  the 
separation  of  ferric  chloride  from  its  acid  solution,  by 
means  of  ether.  Latterly  M.  Pinuera  has  modified  this 
method  of  separation,  and  uses  ether  saturated  with  hy- 
drochloric acid  at  a  low  temperature  (E.  Pinuera,  Com^<«i 
Rendus,  1897,  vol.  cxxiv.,  p.  124). 

III.  It  is  easy  to  achieve  the  same  result  by  means  of 
eledtrolysis,  by  paying  attention  to  the  following  remarks; 
if  we  precipitate  a  ferric  solution  containing,  for  example, 
nickel,  with  an  excess  of  ammonia,  a  part  of  the  latter 
metal  will  remain  in  solution,  while  a  considerable  amount 
is  carried  down  with  the  ferric  hydrate.* 

If,  however,  we  submit  the  ammoniacal  liquid  holding 
the  precipitate  in  suspension  to  the  adtion  of  electrolysis, 
we  obtain  the  integral  deposition  of  nickel  on  the  cathode. 
The  separation  is  not  absolutely  complete,  as  a  small 
quantity  of  iron  is  also  nearly  always  deposited  on  the 
cathode ;  but  under  suitable  conditions  this  quantity  is 
nearly  constant;  it  varies  from  i  to  2m.grms.,  while  the 
iron  present  may  be  about  400  or  500  m.grms.  For  exadt 
work,  then,  it  is  necessary  to  make  a  correction  in  the 
weight  of  metal  deposited  :  this  is  easily  done  by  dissolving 
in  hydrochloric  acid,  and,  after  peroxidation,  precipitating 
by  ammonia. 

IV.  The  use  of  a  nitric  solution,  which  under  analogous 
conditions  enabled  M.  Riche  (Ann.  Chim,  Phys.,  series  5, 
vol.  xiii.,  p.  528,  1878)  to  separate  copper  from  iron,  pre- 
sents certain  difficulties.  It  is  the  same  with  hydrochloric 
solutions.  Good  results  can  be  obtained  by  using  a 
sulphuric  solution,  containing  sulphate  of  ammonia.  The 
following  is  the  method  of  procedure : — 

To  the  solution  containing  the  nickel  and  a  maximum 
of  iron  is  added  a  slight  excess  of  sulphuric  acid ;  it  is 
then  evaporated  to  dryness  ;  the  residue  is  taken  up  with 


*  This  preparation  reaches  27  per  cent  for  nickel,  and  48  per  cent 
for  cobalt,  in  the  experiments  described  by  Baumhauer  {Archives 
Nitrlandaises,  1870,  vol.  vi.),  and  under  Rome  conditions  it  may  be 
considerably  higher. 


the  smallest  quantity  of  water  possible,  5  to  10  grms.  of 
sulphate  of  ammonia  is  added,  and  the  solution  warmed 
until  it  becomes  clear.  This  solution,  while  agitating,  is 
poured  into  the  crucible  of  a  Riche  apparatus,  in  which 
60  or  70  c.c.  of  concentrated  ammonia  has  already  been 
placed.  We  then  proceed  with  the  eledtrolysis.  Two  or 
three  accumulators,  coupled  in  series  so  as  to  obtain  from 
1*5  to  2*5  amperes  at  the  commencement,  form  a  conve- 
nient source  of  eledricity.*  Under  these  conditions, 
after  about  four  hours,  the  nickel  is  entirely  deposited. 

V.  This  method  has  been  checked  by  means  of  titrated 
solutions  of  iron  and  nickel,  and  some  of  the  results  ob- 
tained were  as  follows : — 


Fe 

No.  m.grms, 

1.  4042 

2.  269-5 

3.  269-5 


Ni 

added 
m.grms. 

29-8 

746 

149-2 


Metal    CorreAion  Ni  re- 


deposited 
m.grms. 

30*8 

75  9 
150-1 


(iron) 
m.grms. 

I'O 

0-8 


covered 
m.grms. 

29-8 

74-6 

I49'3 


Differ- 
ence 
m.grm. 

O'O 
0"0 

-Foi 


The  same  method  may  be  applied  equally  well  to 
cobalt : — 

Co  Metal    CorreAion  Co  re-  Differ- 

Fe  added      deposited      (iron)      covered         ence 

No.  m.grms.      m.grms.     m.grms.    m.grms.   m.grms,       m.grm. 

4.     404*2  62-5  63*4  1*9        6i*5         —  I'o 

VI.  Estimation  of  Nickel  in  Steels. — 250  to  300  m.grms. 
is  dissolved  in  aqua  regia  in  a  porcelain  crucible.  When 
this  is  completed  we  add  i  c.c.  of  sulphuric  acid,  and 
evaporate  until  white  fumes  begin  to  be  evolved.  We 
then  proceed  as  above.  The  following  results  were  ob- 
tained in  the  analysis  of  a  series  of  steels,  containing 
from  1  per  cent  to  50  per  cent  of  nickel : — 


Approx- 

imate Weight 

Metal 

Per- 

CorreAed 

quantity      of 

depo- 

centage 

Correc- 

per- 

True  per- 

present sample. 

sited. 

found. 

tion. 

centage 

centage 

per  cent. 

found. 

present. 

No.           M.grms. 

M.grms. 

M.grms 

5       I       2565 

31 

I-2I 

o'35 

1-07 

1-00 

6     10      434-0 

44-1 

io*i6 

0-70 

10-00 

lO'OO 

7     20      297-5 

597 

20-10 

i-io 

1975 

20-00 

8     25       295-9 

76-6 

2595 

0-50 

2575 

2555 

9    50      2307 

114-8 

49'8o 

0-35 

49-40 

49  57 

The  figures  given  in  the  column  True  percentage  present 
were  obtained  by  a  series  of  precipitations  by  ammonia  in 
considerable  excess,  until  the  solutions  no  longer  gave  the 
nickel  reaction  with  sulpho-carbonate  of  potash;  i  grm. 
of  metal  was  used,  but  four  or  five  precipitations  were 
necessary  to  obtain  a  complete  separation.  The  ammo- 
niacal solutions  were  mixed,  evaporated,  and  precipitated 
while  boiling  by  caustic  soda;  the  nickel  was  then  esti- 
mated eledtrolytically  by  the  method  of  Fresenius  and 
Bergmann. 

An  examination  of  this  table  shows  that  in  adtual  prac- 
tice it  would  often  be  unnecessary  to  make  the  correction, 
a  sufficient  approximation  being  found  by  considering  the 
total  weight  of  metal  deposited  to  be  nickel ;  the  results 
thus  obtained,  in  the  column  headed  Percentage  found  are 
within  0-5  per  cent  of  being  corre<5l.t  The  estimation  of 
nickel  in  a  steel  of  any  percentage  can  be  effei^ed  in  a 
few  hours. 

VII.  Experience  shows  that  it  is  unnecessary  to  sepa- 
rate the  silicon  or  carbon  ;  neither  the  small  quantities  of 
manganese  and  phosphorus  (the  sample  of  steel  marked 
No.  6  contained  0-52  per  cent  Mn,  and  traces  only  of  P) 
found  in  steels,  nor  the  presence  of  chromium  (the  sample 
marked  No.  7  contained  28  per  cent  Cr.)  interfere  with 
the  use  of  this  method ;  but  traces  of  manganese  are 
nearly  always  found  with  the  small  quantity  of  iron  on  the 

*  That  is  to  say,  25  to  45  milliampires  per  square  centimetre  for 
the  aAing  part  of  the  cathode,  assuming  that  the  density  of  the 
current  is  uniform. 

t  Cobalt,  if  present,  is  reckaned  as  nickel  according  to  the  trade 
custom ;  the  small  quantity  of  copper  (x  to  2  milliemes)  which  is 
generally  present  in  nickel  steels  is  without  influence. 


26o 


Bsttmatton  of  the  Or  game  Matter  in  Water. 


Chbhical  News, 
Dec.  10, 1897. 


cathode.  To  obtain  an  exaA  corredlion  we  precipitate 
the  two  metals  at  once,  by  adding,  as  recommended  by 
M.  Carnot,  a  little  peroxide  of  hydrogen  to  the  solution 
of  the  deposited  metaU,  supersaturating  with  ammonia, 
and  boiling.    As  the  coefficients  of  the  transformation — 


Fe 
FejOj 


0*700  and 


Mn 
MnjO, 


r=  0721 


are  very  close,  there  is  not  room  for  much  error  in  ap- 
plying either  of  them  to  weights  of  oxides  of  about 
2  m.grms.  It  is  in  this  manner  that  the  figures  in  the 
column  marked  Correction  were  obtained. 

VIII.  It  is  only  natural  to  suppose  that  the  small 
quantities  of  iron  present  on  the  cathode  are  due  to  the 
redudtion,  by  contact  with  it,  of  the  ferric  and  ferrous 
hydrates  soluble  in  ammonia.  However,  no  deposition 
is  obtained  by  the  eledtrolysis,  under  the  conditions  men- 
tioned, of  the  ferric  hydrate  alone.  Further,  eletStrolysis 
carried  on  for  four,  or  even  sixteen  hours,  have  given  the 
same  results. 

On  the  other  hand,  if  we  add  to  the  ferric  solution 
notable  quantities  of  manganese  or  of  phosphoric  acid, 
the  proportion  of  iron  deposited  becomes  considerably 
augmented,  and  the  method  can  no  longer  be  trusted  ; 
the  traces  of  manganese,  almost  always  contained  in  pure 
solutions,  must  therefore  be  carefully  dealt  with  ;  as  man- 
ganese easily  changes  from  its  state  of  oxidation,  when  in 
the  near  neighbourhood  of  the  eledtrodes,  it  might  without 
difficulty  reduce  some  of  the  ferric  hydrate  to  the  ferrous 
state.  To  decide  this  question  a  ferric  solution  was  pre- 
pared by  decomposing  ferrocyanide  of  potassium,  purified 
by  crystallisation,  by  sulphuric  acid,  and  precipitating  the 
iron  in  the  state  of  sulphide  :  this  solution  was  periedlly 
free  from  both  manganese  and  phosphoric  acid.  It  was 
with  this  that  the  above-mentioned  experiments,  i,  2,  3, 
and  4,  were  performed,  all  of  which  gave  a  small  quantity 
of  iron.  It  is  therefore  probable  that  the  presence  of 
traces  of  iron  on  the  cathode  is  due  to  a  secondary 
electrolytic  a(5tion,  an  a(Sion  which  may  in  time  be  eluci- 
dated and  completely  avoided. 

IX.  It  is  also  necessary  to  remark  that,  although  it  is 
present  in  such  small  proportions,  the  iron  deposited  on 
the  cathode  is  present  in  two  different  states  ;  by  dissolving 
the  deposited  metal  in  weak,  warm  hydrochloric  acid,  we 
can  obtain  a  solution  containing  traces  of  iron.  On  the 
other  hand,  there  remains  a  very  small  black  residue, 
which  is  not  attacked  even  by  concentrated  hydrochloric 
acid,  but  which  is  dissolved  on  boiling  and  the  addition  of 
a  little  nitric  acid.  The  solution  of  this  black  residue  in 
nitric  acid  gives  the  rea&ions  of  ferric  salts.  The  ex- 
tremely small  quantity  I  was  able  to  obtain  (not  more 
than  o'4  m.grm.)  prevented  me  from  studying  it  any 
further. 

I  have  finally  established  that  a  very  small  proportion 
of  chromic  acid,  in  an  ammoniacal  solution  of  nickel,  is 
sufficient  to  entirely  stop  the  electrolytic  deposition  of  the 
nickel,  whether  iron  is  present  or  not. — Bull.  Soc.  Chim,, 
Series  3,  xvii.-xviii.,  Nos.  18-19. 


ON     THE    ESTIMATION     OF    THE 

ORGANIC   MATTER  IN   WATER  BY   MEANS  OF 

PERMANGANATE  OF  POTASH. 

By  FELIX  MARBOUTIN  and  MICHEL  FRANCK. 

We  have  estimated  the  amount  of  organic  matter  in  solu- 
tion in  various  waters  around  Paris  by  means  of  two  dif- 
ferent processes  ;  the  Albert-L6vy  method  as  used  in 
France,  and  the  Forchhammer  method  used  in  England. 
These  two  methods  of  estimation  give  very  different  re- 
sults for  the  same  water. 


M.grms.  of  Oxygen  Absorbed  to  Oxidise  the  Organic 
Matter  (per  Litre). 

Forchhammer  method, 

Albert-Levy  modified  by 

method.  Sir  £.  Frankland. 

Seine  at  Choisy-le-Roi     ..     2-92  1*53 

»       Ivry       300  1-66 

,,      Austerlitz    ..     ..     260  i"27 

„      Argenteuil   ..     ..     2-43  i'26 

Marne  at  Neuilly 1-22  0*69 

„         Saint-Maur.     .,     i*i3  0*56 

Ourcq  at  the  Vilette  basin  .     i"46  0'82 

Ayre  reservoir,  Rue  ViUejust    0*24  o"o8 
Drain    at    Epinay   (Genne- 

villiers) i'i3  0-39 

Drain  at  Gresillons  (Genne- 

villiers) 1-05  0*36 

Drain  at  Garenne  (Acheres)     0*65  0*24 

This  table  shows  that,  for  river  waters,  the  French 
method  gives  figures  double  those  of  the  English  method  ; 
while  for  certain  springs  and  surface  drainage  waters  the 
numberii  are  tripled. 

In  view  of  this  fadl,  it  may  be  interesting  to  compare 
the  tables  as  arranged  in  England  and  France  for  the 
classification  of  waters  by  the  estimation  of  organic 
matter. 

M.grms.  of  Oxygen  Absorbed  to  Oxidise  the  Organic 
Matter  {per  Litre). 
France,  England. 

Albert-Levy  Sir  E.  Frankland  by  the 

Nature  of  the  process.  Forchhammer  process, 

water,  , < . , 

Surface  waters    Surface  waters 
from  other  than 

uncultivated      from  unculti- 
land.  vated  land. 

M.grms.  M.grms.  M.grms. 

Very  pure      ..  Less  than  I'o  Less  than  i-o  Less  than  o'5 
Medium  purity      i-oto2"o         i-o  to  3*0        0-5  to  1*5 
Suspicious     ..       3*0  to  4*0         30  to  4*0         i'5  to  2*0 
Impure  ..      ..  Morethan4-o  Morethan4'o  More  than  2'0 

Thus  it  appears  that  river  waters  are  classified  in  the 
same  category  both  in  France  and  England,  in  spite  of 
the  difference  in  the  results  ;  but  such  is  not  always  the 
case  with  springs  and  surface  drainage  water.  In  France, 
the  Commission  on  Hygiene  did  not  think  it  worth  while 
to  make  any  difference  between  surface  waters  from  un- 
cultivated or  cultivated  sources,  and  it  is  noticeable  that 
they  are  more  strict  than  in  England  for  springs  and  sur- 
face drainage  waters.— £«//.  Soc.  Chim,,  Series  3,  vols, 
xvii.-xiii.,  Nos,  18-19. 


NOTE   ON   A 

SOMEWHAT     REMARKABLE    CASE    OF    THE 

RAPID    POLYMERISATION    OF    CHLORAL. 

By  J.  W.  MALLET. 

A  SPECIMEN  of  anhydrous  chloral — trichloracetaldehyde 
—of  about  250  grms,  was  contained  in  a  glass  vial  of  a 
form  commonly  used  in  Germany,  with  small  drawn-out 
neck,  hermetically  sealed.  It  had  been  on  hand  for 
more  than  a  year,  and  had  originally  been  quite  clear, 
but  doubtless  not  absolutely  pure,  very  likely  containing 
traces  of  sulphuric  acid,  as  a  few  small  white  fiocks  of 
the  polymeric  meta-chloral  had  begun  to  show  at  the 
bottom. 

This  specimen,  with  a  number  of  others,  had  been 
exhibited  on  the  ledture-table,  handled  by  several  persons, 
and  moved  back  to  the  colle(5tion-room  whence  it  had 
come.  It  was  placed  temporarily  on  a  table,  among 
other   bottles,   in  the    afttrnoon,  to  be  next  morning 


ChBMICAL  NBW8, 

Dec.  10, 1897.      I 


So-called  Selective  Action  of  Cyanide  oj  Potassium  for  Gold.         281 


restored  to  its  place  in  the  colledion  on  the  shelves. 
No  one  went  into  this  room,  which  is  in  a  locked  portion 
of  the  building,  before  the  following  day.  The  temper- 
ature was  moderate — about  20"  or  22°  C. — and  differed 
but  little  from  that  of  the  ledlure-room.  The  place  on  the 
table  occupied  by  the  bottles  did  not  receive  any  diredt 
rays  of  the  sun. 

On  coming  into  the  room  in  the  morning  a  strong 
odour  of  chloral  at  once  drew  attention  to  the  table, 
where  a  circle  of  half  a  metre  or  so  in  diameter  was 
covered  with  a  thin  crust  of  white  meta-chloral.  The 
remains  of  the  sealed  vial  were  found  as  small  fragments 
scattered  about  the  room,  some  of  them  as  much  as  two 
or  two  and  a  half  metres  away  from  where  the  vial  had 
stood,  and  some  of  them  on  the  shelves  at  a  higher 
level  than  the  top  of  the  table,  showing  clearly  that  the 
vial  had  not  fallen  down,  or  been  knocked  over  by  a 
mouse  or  rat,  but  had  burst,  and  with  some  considerable 
force,  although  no  other  bottle  standing  near  it  had  been 
broken. ' 

It  seems  that  polymerisation  must  have  taken  place  bo 
rapidly,  and  to  so  large  an  extent,  that  the  heat  evolved 
in  the  unison  of  the  smaller  into  larger  molecules  raised 
the  temperature  of  the  remaining  liquid  chloral  to  a  point 
at  which  the  tension  of  its  vapour  was  more  than  the  vial 
could  withstand. 

If  this  explanation  be  accepted,  the  occurrence  is  in 
three  respedts  noteworthy.  In  the  first  place,  the  amount 
of  heat  evolved  in  the  polymeric  change  must  have  been 
quite  large  to  produce  the  efifedt  observed,  remembering 
that  liquid  chloral  is  only  about  as  volatile  as  water — has 
about  the  same  boiling-point  under  atmospheric  pressure  ; 
I  do  not  know  of  any  recorded  measurements  of  the 
thermal  value  of  the  change  in  question.  Secondly,  the 
polymeric  change  must  have  occurred  with  a  degree  of 
suddenness  which  is  surprising  in  view  of  the  very 
gradual  transition  from  liquid  chloral  to  meta-chloral 
which  is  usually  observed  ;  other  specimens,  prepared  in 
this  laboratory,  have  taken  several  years  to  become  en- 
tirely solid.  Thirdly,  it  is  not  easy  to  imagine  what  cause 
can  have  provoked  this  sudden  polymerisation,  there 
having  been  less  mechanical  agitation,  less  change  of 
temperature,  less  external  disturbance  of  any  kind  that 
can  be  pointed  out,  at  the  time  when  the  change  occurred 
than  the  specimen  had  previously  been  exposed  to. — 
American  Chemical  jfournal,  xix.,  No.  9,  Nov.,  1897. 


NOTE   ON   THE 

SO-CALLED     "SELECTIVE    ACTION" 
OF     CYANIDE     OF     POTASSIUM     FOR    GOLD.» 

By  W.  A.  DIXON. 

For  some  years  past  there  has  been  considerable  dis- 
cussion as  to  a  "  seledlive  adtion  "  exhibited  by  very  much 
diluted  solutions  of  cyanide  of  potassium  for  gold,  so 
that  it  passes  into  the  liquid  as  aurocyanide  of  potassium, 
whilst  the  base  metals  are  left  behind  in  the  ore  mass 
during  treatment  by  the  cyanide  process.  This  is  held 
to  be  the  reverse  of  what  occurs  when  a  more  concen- 
trated solution  of  cyanide  is  employed,  as  in  that  case  a 
large  proportion  of  base  metal  in  comparison  to  the  gold 
is  obtained  in  solution.  I  think  the  following  considera- 
tions will  show  how  this  occurs,  and  that  there  is  really 
no  such  thing  as  **  seleAive  acftion."  By  a  seledtive 
adion  it  seems  to  be  generally  understood  that  in  the 
weak  solution  the  aAion  is  the  reverse  of  what  it  is  in  a 
strong  one,  an  idea  of  volition  on  the  part  of  the  cyanide 
being  implied  in  the  statement. 

*  Read  before  the  Institution  of  Mining  and  Metallurgy,  Nov. 
17th,  1897. 


The  readlion  by  which  gold  is  dissolved  by  cyanide  of 
potassium  is — 

2Au -f-4KCy-f  O -f- H2O  =  2AuKCya-f-2KH0, 

the  oxygen  being  supplied  by  that  present  in  solution  in 
the  water,  or  by  oxidising  agents,  as  chlorine,  bromine, 
ferricyanides,  peroxides,  &c. ;  in  pra(5lice  the  first  is  the 
usual  source. 

A  ton  of  ore  in  powder  requires  from  100  to  no  gallons 
of  water  to  thoroughly  wet  it,  or,  say,  an  average  of  105 
gallons,  which  at  70,000  grains  per  gallon  is  equal  to 
7,350,000  grains.  The  coefficient  of  solubility  of  oxygen 
at  30  ins.  barometric  pressure  and  60°  F.  is  o"0295.  which, 
divided  by  5  to  reduce  it  to  that  due  to  the  partial  pressure 
of  oxygen  in  air,  gives  as  the  coefficient  of  absorption  of 
oxygen  from  air  00059,  so  that  105  gallons  of  water 
would  contain  43,383  grain  measures  of  oxygen  in  solu- 
tion, which  would  weigh  62  grains.  These  62  grains  of 
oxygen  contained  in  105  gallons,  as  a  maximum,  would,  in 
conjundlion  with  cyanide  of  potassium,  dissolve  1527 
giains  of  gold,  that  is  3  ozs.  3  dwts.  15  grs,,  and  the  quan- 
tity of  cyanide  required  would  be  looi  grains,  so  that  the 
solution  would  be  very  dilute,  containing  only  0*0047  per 
cent  of  cyanogen. 

It  appears  clear  to  me  that  we  have  here  a  sufficient 
explanation  of  the  so-called  "  seledive  adtion."  Gold  in 
presence  of  oxygen  has  in  all  cases  a  superior  affinity  for 
soluble  cyanides,  or  the  soluble  cyanides  have  for  gold, 
than  the  soluble  cyanides  have  for  the  compounds  of  the 
base  metals.  These  compounds  have  the  same  affinity 
for  cyanogen  whether  oxygen  in  the  free  state  or  easily 
available  is  present  or  not,  whilst  if  oxygen  is  absent  the 
adion  on  gold  is  nil.  The  base  metals  always  occur  in 
gold  ores  as  oxides,  sulphides,  or  other  compounds,  whilst 
the  gold  is  in  the  free  state.  In  these  circumstances  the 
gold  is  first  dissolved  as  long  as  free  oxygen  is  available, 
and  then,  oxygen  being  exhausted,  base  metals  pass  into 
solution  until  either  they  are  exhausted  or  the  cyanide  is 
saturated,  whichever  happens  first,  a  sufficient  time  being 
given  to  complete  the  readlion.  A  much  diluted  solution 
of  cyanide  contains  much  free  oxygen  in  proportion  to  the 
cyanide,  and  therefore  dissolves  much  gold  in  proportion 
to  the  cyanide  present,  and  afterwards  little  base  metal, 
because  there  is  little  cyanide  left  to  saturate,  and  it 
therefore  appears  that  the  cyanide  has  selected  the  gold. 
In  a  solution  containing  more  cyanide,  gold  is  dissolved 
till  the  oxygen  is  exhausted,  and  then  the  excess  of 
cyanide  enters  into  double  decomposition  with  the  com- 
pounds of  the  base  metals,  which  are  then  found  in  solu- 
tion in  greater  proportion  relatively  to  the  gold,  and  the 
solution  appears  to  have  had  a  seledive  adlion  on  them. 

Some  metals  in  the  free  state,  as  zinc,  for  example, 
have  a  superior  affinity  for  cyanogen  to  gold,  but  these  do 
not  occur  free  in  ores,  but  when  a  solution  containing 
gold  as  cyanide  is  brought  in  contadt  with  one  of  them,  as 
zinc,  it  dissolves,  and  the  gold  is  precipitated.  Zinc, 
which  is  commonly  used  for  this  purpose,  is  moreover 
known  to  precipitate  gold  the  more  efficiently  the  more 
free  it  is  from  compounds  such  as  its  oxide. 

In  pradtical  work  the  oxygen  in  solution  in  the  water 
used  would  be  much  less  than  that  indicated,  as  it  would 
be  removed  by  organic  and  mineral  substances  undergoing 
oxidation,  but,  on  the  other  hand,  minerals  treated  by  the 
cyanide  process  have  usually  much  less  gold  than  3  ozs. 
per  ton,  or  they  are  treated  several  times  with  fresh  solu- 
tions. This  re-treatment  is  simply  a  renewal  of  the  con- 
ditions favourable  to  the  solution  of  gold,  an  oxygen- 
holding  solution  of  cyanide  replacing  one  which  is 
exhausted  of  that  element. 

In  the  current  literature  on  this  subjedl  two  distindl  sets 
of  readtions  have  become  mixed  up,  and  are  spoken  of  as 
one,  the  substances  which  caused  them  being  called 
"cyanicides."  This  word  should  be  confined  to  those 
substances  which  by  their  adtion  on  cyanides  decompose 
them,  or  set  free  hydrocyanic  acid,  which  soon  decom- 
poses.   These  substances  4o  not  pombine  with  c^apogeq 


282 


New  Derivatives  of  Diacetyl, 


I  CSBMieAL  Nbws, 

I    Dec.  10, 1807. 


or  alkaline  cyanides ;  they  kill  them,  and  to  such  the  word 
cyanicide  is  truly  applicable.  On  the  other  hand,  "cyan- 
icide  "  is  not  applicable  to  substances  which  by  entering 
into  combination  with  cyanogen  or  cyanides  may  be  rather 
regarded  as  causing  sleep  rather  than  death,  and  it  is  only 
on  these  that  the  so-called  "  selective  aftion"  can  be 
exercised,  and  the  compounds  of  only  three  of  these  are 
found  in  gold  ores,  namely,  iron,  copper,  and  zinc.  Iron 
present  in  the  ferric  state  may  be  inert  or  adt  as  a  cyanicide 
if  present  as  a  salt,  i.e.,  as  ferric  sulphate;  in  the  ferrous 
state  it  combines  with  cyanide  of  potassium  to  form  ierro- 
cyanide  of  potassium,  but  this  also  dissolves  gold  if 
sufficient  oxygen  is  present,  by  the  reaftion — 

6Au+2K4FeCy6+40+HaO  =  6AuKCya+2KHO  +  Fea03, 

and  therefore  it  is  not  entitled  to  a  position  amongst  the 
metals  which  may  be  sele(5ted.  These  are  therefore  re- 
duced  to  zinc  and  copper,  and  the  compounds  of  these  are 
only  dissolved  in  absence  of  sufficient  oxygen  with  the 
cyanide  of  potassium  to  dissolve  the  gold.  In  most  gold 
ores  these  metals  are  absent,  and  then  the  question  of  se- 
lection does  not  arise,  and  solutions  of  cyanide  of  any 
strength  may  be  used,  but  diluted  ones  would  be  most 
convenient,  as  they  supply  the  necessary  oxygen  and  con- 
sume less  cyanide.  It  is  to  be  supposed  that  sulphates  or 
other  cyanicide  compounds  are  removed  or  decomposed 
by  a  preliminary  treatment. 

In  praAice  it  must  necessarily  happen  that  solutions 
containing  more  than  the  theoretical  quantity  of  cyanide 
to  the  quantity  of  oxygen  present  must  be  used,  even 
when  cyanicides  are  absent,  in  consequence  of  the  gold 
being  distributed  in  granules  throughout  an  immense 
mass  of  ore.  A  granule  of  gold  exhausts  the  cyanide  and 
oxygen  in  its  immediate  neighbourhood,  and  adtion  then 
ceases  until  a  fresh  supply  of  both  arrives  by  diffusion 
from  the  surrounding  solution.  I  do  not  know  that  the 
relative  rate  of  diffusion  of  oxygen  and  cyanide  in  watery 
solution  has  been  determined,  but  it  must  be  that  16  of 
oxygen  will  diffuse  sooner  than  260  parts  of  cyanide  of 
potassium,  and  therefore  an  excess  of  cyanide  must  be 
used  to  compensate  for  this  difference. 


SOME    NEW    DERIVATIVES  OF    DIACETYL. 
By  HARRY  F.  KELLER  and  PHILIP  MAAS. 

Since  communicating  the  results  obtained  in  studying 
the  adtion  of  oxidising  agents  upon  diacetyl,  we  have  con- 
tinued our  work  on  this  diketone  in  several  dire(5tions. 

The  ready  and  quantitative  conversion  of  diacetyl  into 
acetic  acid  by  certain  oxidising  agents,  notably  hydrogen 
peroxide,  induced  us  to  try  whether  the  halogen-substituted 
produfts,  dibromo-diacetyl  and  tetrabromo-diacetyl,  would 
behave  in  an  analogous  manner.  If  they,  respedtively, 
yielded  bromacetic  acid  and  dibromacetic  acid,  their  sym- 
metrical strudture  might  be  regarded  as  definitely  estab.. 
lished.     Thus  :— 

CH2BrCOCOCH2Br-i-HOOH  =  2CH2BrCOOH 

and — 

CHBraC0-C0CHBr2+H0-0H  =  2CHBr2-C00H. 

While  both  compounds  were  found  to  be  readily  attacked 
by  the  oxidising  agent,  only  the  dibromo-derivative  gave 
something  like  the  expedted  result. 

A  weighed  quantity  of  this  substance  was  treated  in  the 
cold  with  a  moderate  excess  of  hydrogen  peroxide  solution. 
The  greasy  scales  gradually  disappeared,  and  the  liquid 
became  strongly  acid.  Upon  evaporating,  it  gave  off 
hydrobromic  acid,  and  left  a  residue  consisting  of  a  mix- 
ture of  bromacetic  and  glycollic  (oxyacetic)  acids.  This 
mixture  was  completely  converted  into  the  latter  acid  by 
prolonged  boiling  with  water,  according  to  the  equation — 
CHaBrC00H-l-Ha0=CHa(0H)C00H-l-HBr. 


The  characteristic  calcium  salt  was  prepared.  It  was 
obtained  in  stellar  aggregations  of  needles,  having  a  silky 
lustre,  insoluble  in  alcohol  and  only  sparingly  soluble  in 
cold  water.     It  contained  : — 


Ca    .. 
H2O.. 


I. 
i5"o6 
26-97 


H. 

15*54 
26-47 


Calculated  for 
(C,H,0,),Ca+4H,0. 

15-26 

27-48 


The  salt  is  understood  to  be  somewhat  efflorescent,  and 
the  percentage  of  water  therefore  a  little  too  low.  The 
dehydrated  salt  gave  Ca  =  2i-32  per  cent,  instead  of  21-05 
per  cent  required  by  theory. 

The  blue  copper  salt  was  also  obtained. 

A  mixture  of  several  acids  is  produced  when  dibromo- 
diacetyl  is  heated  with  nitric  acid.  We  have  not  been 
able  to  effe(5t  their  separation,  but  have  reasons  to  believe 
that  oxalic  acid  and  monobromacetic  acid  are  amongst 
them. 

When  tetrabromodiacetyl  was  treated  with  hydrogen 
peroxide,  its  yellow  colour  disappeared  slowly.  A  white 
fiocculent  precipitate  formed  while  the  dense  powder  dis- 
solved. The  colourless  solution  had  a  peculiar  pene> 
trating  odour,  and  deposited,  upon  standing,  another  crop 
of  the  produdt  in  the  form  of  long  colourless  needles  with 
a  silky  lustre.  From  3  to  4  grms.  of  this  substance  were 
thus  obtained  from  10  grms.  of  the  diketone. 

The  mother  liquor,  still  having  the  charadleristic  odour 
of  the  crystallised  produdt,  was  extradted  with  ether,  but 
the  latter,  on  evaporating,  left  only  a  small  quantity  of  an 
oily  liquid. 

The  crystals  were  found  to  be  insoluble  in  water,  and 
very  freely  soluble  in  alcohol,  ether,  benzene,  glacial 
acetic  acid,  and  other  organic  solvents.  From  an  ethereal 
solution  very  beautiful  prismatic  crystals,  more  than  a 
centimetre  long,  were  obtained.  They  belong,  without 
doubt,  to  the  rhombic  system,  and  consist  of  several 
prisms,  the  orthopinacoid  and  a  brachydome.  From  the 
solution  in  acetic  acid  the  substance  is  re-precipitated  in 
the  form  of  long  fine  needles  when  much  water  is  added. 
It  melts  at  72-8°,  and  at  higher  temperatures  sublimes, 
apparently  without  decomposition. 

Analyses  of  the  carefully  purified  substance  yielded : — 

Calculated  for 


I. 

n. 

C.HBrjC 

Per  cent. 

Per  cent. 

Per  cent 

c     . 

.      ..       813 

8-04 

7-94 

H      . 

.      . .       0-56 

0-26 

0-22 

Br     . 

.      . .     87-99 

88-04 

8830 

0      . 

..      [3-32] 

[3-66] 

353 

Determinations  of  the  molecular  weight  by  the  cryo- 
scopic  method,  by  means  of  Beckmann's  apparatus  and 
glacial  acetic  acid  as  the  solvent,  gave — 

I. 

Used  solvent 19*485    grms. 

Substance      0*1788  grm. 

Depression 0-084° 

II. 

Solvent 19-663    grms. 

Substance      0-3360  grm. 

Depression 0-146° 


I. 
461 


II. 
435 


Calculated. 
452 


The  composition  and  molecular  weight  correspond  to 
the  formula  C3HBrsO,  which  is  that  oi  pentabromacetone. 
That  this  is  really  the  compound  we  obtained  is  further 
proved  by  a  comparison  of  the  physical  properties*  with 
those  observed  by  other  chemists,  as  well  as  its  behaviour 


*  The  melting-point  is  given  by  Beilstein  (3rd  ed.,  p.  989)  as  76°. 
Although  we  repeated  the  determination  several  times,  using  material 
purified  with  scrupulous  care,  and  the  best  thermometers,  it  invari* 
ably  gave  the  same  result,  72'8<'. 


Chkmical  Nkwb, 

Dec.  10,  1807. 


Study  Of  Oxygen  at  Low  Pressures 


283 


upon  boiling  with  barium  hydroxide;  hromoform  was  pro- 
duced and  was  identified,  after  distilling  it  in  a  current  of 
steam,  by  its  odour  and  boiling-point,  and  the  formation 
of  phenylcarbylamine  when  the  alcoholic  solution  was 
treated  with  aniline  and  caustic  potash. 

It  is  remarkable  that  an  acetone  derivative  should  re- 
sult from  the  oxidation  of  a  diketone,  for  methyl-ethyl 
ketone  can  be  converted  by  oxidation  into  diacetyl  (Fileti 
and  Ponzio,  Gazz.  Chim.  Ital.,  xxv.,  233). 

The  oily  produtft  mentioned  above,  and  which  was  ex- 
traded  from  the  solution  after  the  pentabromacetone  had 
separated,  may  have  been  tribromacetone.  It  had  a 
powerful  odour,  decomposed  upon  heating,  and  did  not 
respond  to  the  carbylamine  readtion. 

Attempts  to  oxidise  tetrabromodiacetyl  with  nitric  acid 
have  not  as  yet  given  any  definite  results.  Although  the 
substance  dissolves  rapidly  on  warming  in  the  concen- 
trated, especially  the  red  fuming,  acid,  the  greater  part  of 
it  separates  again  on  cooling  or  diluting  with  water  in 
large  yellow  crystals. 

Cyanohydrins.— Another  class  of  diacetyl  derivatives  to 
which  we  have  lately  given  some  attention  are  the  cyano- 
hydrins. 

Fittig  and  one  of  us  have  shown  that  diacetyl  and 
hydrocyanic  acids  unite  quantitatively  to  form  a  dicyano- 
hydrin,  and  that  this  may  be  readily  converted  into  di- 
methylracemic  acid. 


CN 


COOH 


CH3.C 


/ 


\ 


CH3.C 


/ 


CH3.C 


/ 


OH 
OH 


-f4H20  = 


\ 


\ 


CH3.C 


/ 


OH 
OH 


+  2NH3. 


CN 


\ 


COOH 


Our  recent  experiments  were  undertaken — 

1.  To  attempt  the  preparation  of  a  monocyanohydrin  of 
diacetyl. 

2.  To  produce  halogen-substituted  cyanohydrins. 

If  we  succeeded  in  converting  the  latter  into  the  corre- 
sponding acids,  we  would  have  the  first  derivatives  of  tar- 
taric acid  in  which  hydrogen  is  replaced  by  halogen. 

Diacetyl  and  hydrocyanic  acid  (30  per  cent  solution) 
were  brought  together  in  molecular  proportions.  A  rise 
of  temperature  and  the  vanishing  of  the  yellow  colour 
indicated  that  combination  was  taking  place.  The  liquid 
was  gently  heated,  and  then  allowed  to  stand  for  some 
time  in  a  warm  place.  Alter  extrading  with  ether,  and 
evaporating  this  solvent,  there  remained  a  colourless 
viscous  liquid.  This  was  placed  over  dehydrating 
materials,  and  repeatedly  cooled  to  very  low  tempera- 
tures without  showing  any  signs  of  crystallising  or  con- 
gealing. It  was  doubtless  the  expeded  compound,  though 
probably  very  impure.  We  now  attempted  to  produce  the 
corresponding  acid — 


CN 


CH3.C 


/ 
\ 


CH3.C 


COOH 


OH 


CH,.CO 


+  2H2O  = 


>H 


CHo.CO 


+  NH3 


by  treatment  with  strong  hydrochloric  acid.  This  was 
tried  in  a  number  of  ways ;  but  although  even  the  most 
concentrated  acid  (saturated  at  0°)  had  no  appreciable 
effcdt  at  ordinary  temperatures,  the  slightest  warming 
destroyed  the  compound,  with  formation  of  dark  resinous 
produifts,  from  which  an  acid  of  definite  composition  could 
not  be  isolated. 

More  encouraging  were  the  results  of  our  experiments 


upon  dibromodiacetyl.  It  was  found  to  combine  with 
hydrocyanic  acid  quite  readily,  and  yielded  a  well-crystal- 
lised dicyanokydrin.  From  the  ethereal  extradl  it  was  ob- 
tained in  fine  colourless  crystals,  having  a  strong  lustre, 
and  melting  with  decomposition  at  177°. 

Its    composition   is   established  by  these  determina- 
tions:— 

Found.  Calculated. 


N  . 
Br. 


Per  cent. 

938 

54'35 


II. 
Per  cent. 


5474 


Per  cent. 

9*39 
53*69 


The  excess  of  bromine  is  probably  due  to  the  formation 
of  calcium  cyanide  when  the  substance  is  ignited  with 
lime. 

Experiments  are  in  progress  to  transform  the  nitrile  into 
the  acid  ;  the  amide  of  the  acid  has  been  obtained  in  small 
quantities. 

We  have  also  found  that  tetrabromodiacetyl  can  be 
made  to  combine  without  difficulty  with  two  molecules 
of  hydrocyanic  acid.  The  resulting  body  seems  to  be 
analogous  to  the  tetrachlorodiacetyl  dicyanohydrin 
described  by  Levy  and  Witte  (Ann.,  ccliv,  98).  As  yet, 
however,  we  have  not  prepared  a  sufficient  quantity  to 
warrant  the  publication  of  definite  data. 

Dichlorodiacetyl. —  As  Levy  and  his  pupils  {Ann., 
ccxlix.,  93)  obtained  their  tetrachlorodiacetyl  by  a  com- 
plicated process,  the  adlion  of  potassium  chlorate  and 
hydrochloric  acid  on  chloranilic  acid,  we  have  tried  to 
prepare  it  by  diredl  chlorination  of  diacetyl.  It  was  found 
that  at  first  the  adtion  of  chlorine  upon  the  diketone,  dis- 
solved in  carbon  disulphide  or  chloroform,  is  quite 
energetic,  but  the  only  produdl  we  have  so  far  obtained 
proves  to  be  dichlorodiacetyl.  It  closely  resembles  the 
dibromo-derivative  ;  soluble  in  carbon  disulphide,  chloro- 
form, boiling  petroleum  ether,  and  warm  benzene,  it  crys- 
tallises in  yellowish  unduous  scales  melting  at  I24'5°.  A 
chlorine  determination  gave — 

Required  for 
Found.  C«H«-ljO. 

Per  cent.  Per  cent. 

CI 4563  45"8o 

— journal  of  the  Franklin  Institute,  vol.  cxliv.,  No.  5, 


A    CONTRIBUTION    TO    THE 
STUDY    OF    OXYGEN     AT     LOW     PRESSURES.' 

By  R.  THRELFALL,  M.A.,  Professor  of  Physics  in  the 
University  of  Syoney,  and  FLORENCE  MARTIN. 

When  a  mass  of  oxygen  is  enclosed  in  a  tube  and  the 
mercury  pressure  on  it  continuously  diminished,  it  is  found 
that  at  about  o  7  m.m.,  and  over  a  certain  range  of  lower 
pressures,  the  gas  appears  to  undergo  a  change  of  con- 
dition. The  phenomenon  may  be  described  in  the  words 
of  Bohr,  its  discoverer  (PVi^rf.  i4««.,  xxvii.,  p.  475),  "A 
given  mass  of  oxygen  is  enclosed  in  a  tube,  and  the  mer- 
cury adjusted  ao  as  tu  give  to  a  pressure  rather  less  than 
07  m.m.  If  the  volume  of  the  gas  is  now  reduced  by 
raising  the  pressure,  say  to  08  m.m.,  it  is  noted  that  this 
pressure  will  not  remain  constant,  but  varies  more  or  less 
with  lapse  of  time.  In  three  to  five  hours  the  pressure 
will  tall  by  some  I2  per  cent  of  its  initial  value  (the 
volume  being  constant).  After  five  hours  the  pressure 
was  found  to  have  attained  its  steady  value,  so  far  as  ob- 
servations extending  over  twenty-four  to  thirty-six  hours 
could  determine." 

This  curious  behaviour  of  oxygen  was  also  noted  by 
Baly  and  Ramsay  (Phil.  Mag.,  xxxviii.,  p.  324,  1894),  who 
observed  that  at  a  pressure  of  about  075  m.m.  oxygen 
becomes  unstable  as  to  its  pressure-volume  relation,  and 

*  Read  before  the  Royal  Society  of  N.  S.  Wales,  June  2, 1897. 


284 


Revision  oj  the  A  tomic  Weight  of  Nickel, 


Ohbmicai,  News, 
Dec.  10, 1897. 


that  the  equilibrium  condition  is  not  attained  until  after 
seventy.eight  hours  rest.  The  slightest  change  of  pressure 
or  volume  then  upsets  the  equilibrium,  and  time  has 
again  to  elapse  before  a  steady  state  is  attained.  It 
appears  likely  either  that  the  oxygen  forms  an  allotropic 
modification  or  that  it  forms  some  compound  with  mer- 
cury or  other  material  present  and  with  which  it  is  in 
conta(%. 

It  will  be  noted  that,  according  to  Bohr,  the  volume  of 
the  gas  tends  to  increase  below  07  m.m..  indicating  that 
the  molecules  of  oxygen  are  partly  split  up.  In  this 
case,  therefore,  it  would  be  reasonable  to  infer  an  increase 
of  oxidising  power,  and  it  is  possibly  to  this  cause  that 
the  soiling  of  the  fall-tubes  of  Sprengel  pumps  is  to  be 
attributed.  It  appears  worth  while,  therefore,  to  try  to 
arrange  some  chemical  test  capable  of  showing  the 
presence  of  adtive  oxygen. 

The  two  following  test  solutions  were  found  to  satisfy 
the  conditions,  though  one  was  more  sensitive  than  the 
other.  One  condition  of  course  is  that  the  test  solution 
must  not  have  a  vapour-pressure  comparable  with  07  m.m. 
The  first  indicator  tried  was  a  solution  of  indigo  in  pure 
sulphuric  acid.  This  is  bleached  by  ozone,  but  experi- 
ment showed  that  the  reaftion  does  not  afford  a  very  deli- 
cate test  of  the  presence  of  that  gas.  Another  solution 
was  therefore  tried,  consisting  of  potassium  iodide  and 
starch  dissolved  in  glycerin.  The  glycerin  was  carefully 
dried  at  a  temperature  of  260°  C.  When  cool,  some  of  it 
was  mixed  with  a  small  quantity  of  powdered  potassium 
iodide.  A  very  small  quantity  of  starch  was  added  to  the 
remainder  of  the  glycerin,  which  was  then  slowly  heated 
till  the  starch  was  quite  dissolved  and  the  liquid  again 
became  transparent.  When  cold,  this  portion  was  mixed 
with  the  potassium  iodide  solution — a  solution  so  prepared 
is  not  affeifted  by  ordinary  oxygen,  but  one  bubble  of  the 
gas  which  has  passed  through  an  ozone  tube  turns  it 
bright  yellow,  and  three  bubbles  give  it  a  dark  blue, 
almost  black  colour.  This  seemed  sufificiently  sensitive, 
and  was  accordingly  adopted.  Of  course  the  starch  is  not 
absolutely  necessary,  iodine  being  liberated  in  large 
enough  quantities  to  colour  the  solution,  but  it  was  con- 
sidered to  be  of  some  advantage  to  use  it  as  an  additional 
verification.  Oxygen  was  prepared  and  purified  in  the 
usual  manner,  and  stored  in  a  gas-holder. 

On  leaving  the  gas-holder  the  gas  passed  through 
(i)  a  system  of  purifying  tubes  containing  (a)  nitrate  of 
silver,  (6)  solid  potash,  (c)  sulphuric  acid,  (d)  phosphorus 
pentoxide  ;  (2)  a  wash-bottle  containing  a  small  quantity 
of  the  potassium  iodide  solution ;  (3)  an  ozoniser  by 
which  the  oxygen  could,  when  required,  be  ozonised 
without  altering  any  of  the  apparatus. 

Two  diagonal  glass  taps,  in  series,  allowed  the  purified 
gas  to  pass  into  the  exhausted  part  of  the  apparatus. 
This  consisted  of  a  glass  tube  about  0*2  cm.  in  diameter 
and  30  cm.  long,  to  which  was  fixed  a  mercury  pressure 
gauge  of  the  U  'XP^t  O'*  '^•^'  ^^  diameter.  In  order  to 
prevent  a  possible  loss  of  aftive  oxygen  through  the 
adtion  of  the  mercury  in  the  gauge,  the  latter  was  con- 
nected to  the  exhausted  space  by  a  capillary  conneftion. 

The  exhausted  tube  was  connedted  through  a  small 
wash-bottle  with  a  Fleuss  pump,  the  wash-bottle  con- 
taining a  small  quantity  of  the  sensitive  solution.  A 
similar  wash-bottle,  containing  the  same  solution,  was 
arranged  to  stand  close  to  the  bottle  through  which  the 
gas  was  passed  in  order  to  enable  colour  comparisons  to 
be  made.  All  the  apparatus  was,  pradtically  speaking, 
either  fused  together  or  had  joints  protected  by  paraffin 
and  mercury,  the  use  of  indiarubber  being  of  course  inad- 
missible. The  Fleuss  pump  was  worked  by  an  eledlric 
motor,  and  the  taps  were  adjusted  until  a  steady  stream 
of  oxygen  could  be  passed  through  the  apparatus  at  a 
pressure  of  about  0*25  m.m.  of  mercury. 

The  apparatus,  after  having  been  made  entirely  air- 
tight, was  filled  with  oxygen  and  exhausted  several  times; 
a  steady  stream  of  oxygen,  at  atmospheric  pressure,  was 
then  run  through  it  for  an  hour,  in  order  to  get  rid  of 


traces  of  air.  It  was  then  exhausted  and  kept  at  a  con- 
stant pressure  of  nearly  0*25  m.m.  (never  less  than  o'l 
nor  greater  than  0*4  m.m.),  with  the  oxygen  bubbles 
coming  through  at  the  rate  of  twenty  per  minute.  Each 
bubble  of  oxygen,  on  reachine;  the  exhausted  tube,  was 
therefore  reduced  in  pressure  over  the  range  of  instability. 
After  six  hours,  no  change  having  taken  place  in  the 
potassium  iodide  solution,  the  apparatus  was  filled  with 
oxygen  at  atmospheric  pressure  and  left  for  several  hours. 
This  experiment  was  repeated  during  three  days;  that  is 
to  say,  the  oxygen  was  passing  through  the  apparatus  at 
a  pressure  of  0*25  m.m.  for  ly^  hours  altogether.  At  the 
end  of  this  time,  no  trace  of  the  ozone  reaction  being  ob- 
servable, it  was  considered  advisable  to  ascertain  whether 
if  a  very  small  proportion  of  the  oxygen  passing  through 
had  become  converted  into  ozone,  so  minute  a  quantity, 
at  so  low  a  pressure,  would  affedt  the  test  solution.  With 
this  objedt,  the  wires  of  the  ozoniser  were  now  joined  up, 
and  it  was  found  that  in  one  minute  a  faint  yellow 
colouring  of  the  solution,  slight  but  distindtly  visible,  oc- 
curred. Evidently,  therefore,  twenty  bubbles  of  eledlrically 
ozonised  oxygen  produce  more  eiledt  than  21,000  bubbles 
of  oxygen  which  has  been  simply  subjected  to  the  effedts 
of  low  pressure.  And  even  if  the  experiment  described 
above  is  not  considered  to  prove,  with  sufficient  conclu- 
siveness, that  low  pressure  alone  has  no  power  to  cause 
the  formation  of  ozone  in  oxygen,  it  must  at  least  be  ad- 
mitted that  the  ozone  so  formed  is  less  than  i/ioooth  of 
the  quantity  produced  by  an  ozoniser  in  the  ordinary  way 
in  the  same  volume  of  oxygen,  and  as  this  can  scarcely 
exceed  5  per  cent  of  the  whole  volume,  the  ozone  formed 
by  lowering  the  pressure  cannot  be  so  much  as  0*005  per 
cent  of  the  volume  of  oxygen  present. 

We  must  not  negledl  to  state  that  our  curiosity  in  this 
matter  was  stimulated  to  the  experimenting  point  by  a 
letter  from  our  friend,  Mr.  W.  Sutherland,  of  Melbourne, 
who  considered,  on  grounds  based  on  the  kinetic  theory  of 
gases,  that  allotropic  oxygen  of  some  kind  would  most 
likely  be  found  at  about  the  pressure  we  employed.  The 
soiling  or  Sprengel  pumps,  however,  as  well  as  the 
experiments  of  Baly  and  Ramsay,  had  previously  led  us, 
independently,  to  infer  the  possibility  of  a  produdtion  of 
adtive  oxygen  under  the  conditions  we  have  mentioned. 


A    REVISION     OF    THE    ATOMIC    WEIGHT    OF 

NICKEL.' 
First  Paper. — The  Analysis  of  Nickelous  Bromide, 
by  theodore  william  richards 

and 
ALLERTON  SEWARD  CUSHMAN. 


Introduction. 
Of  the  atomic  weights  to  day  those  of  nickel  and  cobalt 
are  among  the  most  interesting,  not  only  because  the  two 
values  are  so  close  together,  but  also  because  the  purely 
elementary  charadter  of  these  metals  has  been  recently 
doubted  (Zeit.  Anorg.  Cftem.,  ii.,  235  ;  Berichte,  i88g,  xi., 
2026).  A  careful  study  of  the  available  literature  upon  the 
subjedl  leaves  the  impartial  critic  in  grave  doubt  as  to  the 
true  values  to  be  accepted,  hence  an  experimental  revision 
seems  to  be  imperative  ;  and  the  present  work  is  a  part  of 
a  comprehensive  attempt  to  condudt  such  a  revision.  The 
very  useful  and  complete  index  of  the  work  which  has 
been  done  upon  this  subjedl,  recently  published  by  Pro- 
fessor Clarke  ("  Recalcnlation  of  the  Atomic  Weights," 
Smithsott.  Misc.  Coll.,  Constants  of  Nature,  Part  V.,  1897, 
p.  291),  makes  a  detailed  statement  of  the  various  re- 
searches unnecessary  here;  but  a  chronological  list  is 
appended. 

♦  Contribution  from  the  Chemical  Laboratory  of  Harvard  College. 
From  the  Proc$ediHgs  of  tht  Atntriean  Academy  of  Arts  and  Sciences, 
I  vol.  x»iii.|No.7. 


Chbmical  Niwi,  I 
Dec.  10, 1897.     f 


Revision  of  the  A  tomic  Weight  of  Nickel. 


285 


The  Atomic  Weight  of  Nickel. 
O  =  16. 
1826.    By  Analysis  of  Chloride. 

Rothoff      

1852.    RedutSiiion  of  the  Oxide  by  Hydrogen. 

Erdmann  and  Marchand        ..     ..  58*2 

1856.  Conversion  of  Nickel  to  Sulphate. 

Deville       

1857.  Analysis  of  the  Oxalate. 

Schneider 

1858.  Analysis  of  the  Sulphate  and  Chloride. 

Marignac 58*4 

i860.     Synthesis  of  the  Chloride. 

Dumas       

1863.     Reduction  of  the  Oxides  in  Hydrogen. 

Russell        

1866.  Analysis  of  Nickel  Potassic  Sulphate. 

Sommaruga       

1867.  By  relation  to  Gold,  out  of  Sodic  Auro- 

Chloride. 

Winkler     

1867.     Measurement  of  Hydrogen  evolved  by 
atfting  on  Nickel  with  HCl. 

Russell       

1871.    Analysis  of  Strychnine  and   Brucine 
Nickelo-cyanides. 

Lee     

1883.    Analysis  of  the  Sulphate. 

Baubigny 

1886.     Reduftion  of  Oxide  (NiO)  by  Hydrogen. 

Zimmermann 

1890.     Mond,  Langer,  and  Quincke 
1892.     Conversion  of  Sulphate  to  Oxide,  and 
Redudtion  in  Hydrogen. 

Schiitzenberger 

1892.     Kriiss  and  Schmidt       

1893  94.     Analysis  of  Nickelous  Chloride  and 
by  relation  to  Iodine. 
Winkler      59'05 


59- 1 
-58-6 
58-85 
58-07 
—5929 
59'02 
5874 
58-03 

59*45 
58-77 

58-01 
5873 

5871 
5858 


5854 
57—64 


Value  accepted  by  Ostwald,  1890.. 

(Lehrbuch,  i.,  p.  96). 
Value  accepted  by  Clarke,  1896  .. 

("Recalculation  of  the  Atomic 
Weights,"  he,  cit.). 
Value  accepted  by  Seubert,  1896  .. 

(Zeit.  Anorg.  Chem.,  xiii.,  229). 


-58-87 
58-5 
Ni  =  58-687 


Ni  = 


Ni  =  58-9 


by  securing  unanimous  results  from  a  number  of  com- 
pounds and  methods,  it  is  equally  obvious  that  a  single 
method,  well  worked  out,  is  far  better  than  twenty  in- 
complete ones  ;  hence  the  present  work  was  confined  for 
the  present  to  a  single  compound. 

In  our  choice  of  material,  we  were  guided  by  experi- 
ence already  gained  in  this  Laboratory.  The  advantage 
of  the  bromides  as  typical  compounds  in  atomic  weight 
determinations  has  been  discussed  by  one  of  us  in  preced- 
ing publications,  and  requires  no  further  mention.  The 
rather  meagre  current  descriptions  of  the  properties  of 
anhydrous  nickel  bromide  did  not  seem  encouraging,  but 
the  progress  of  the  research  showed  that  it  is  possible  to 
dry  this  salt,  weigh  it,  and  dissolve  it  in  water  in  a  per- 
fedlly  normal  condition.  Since  this  was  the  case,  nickel- 
ous bromide  was  naturally  chosen  as  our  starting  point. 

The  Preparation  and  Properties  of  Nickelous  Bromide. 

Finely  divided  nickel,  when  heated  to  a  red  heat  in  a 
stream  of  dry  bromine  vapour,  readily  forms  the  bromide, 
which  sublimes  at  bright  redness.  The  colour  of  the 
sublimate  varies  from  a  pale  straw-yellow  to  a  dark 
bronze-brown,  according  to  the  state  of  aggregation.  At 
a  red  heat  in  the  presence  of  traces  of  air  or  moisture,  the 
salt  loses  traces  of  bromine  with  the  formation  of  brigh} 
green  nickelous  oxide,  unless  much  hydrobromic  acid  is 
present.  We  have  never  obtained  evidence  that  an  oxy- 
bromide  is  formed  under  these  conditions. 

The  sublimed  bromide  is  almost  insoluble  in  cold  water, 
but  solution  soon  becomes  apparent  to  the  eye  in  water 
at  50°.  In  water  at  90°  the  salt  dissolves  less  slowly, 
but  a  grm.  still  requires  an  hour  or  two  for  its  complete 
solution.  When  originally  free  from  oxide,  the  sublimed 
bromide  dissolves  in  water  even  at  the  boiling  point  to  form 
a  solution  of  perfedt  clearness.  According  to  Berthelot 
{Anal.  Chim.  Phys.  [2],  xliv.,  389)  a  solution  of  nickel- 
ous bromide  left  for  some  time  in  contadt  with  air  deposits 
some  flakes  of  the  oxide.  We  have  never  met  with  the 
slightest  evidence  of  the  truth  of  this  statement  in  the 
case  of  a  dilute  solution.  If,  however,  the  nickelous 
bromide  contained  only  a  slight  admixture  of  the  oxide, 
this  oxide  might  escape  observation  until  it  had  settled 
out  upon  the  bottom  of  the  vessel.  Dilute  nitric  acid 
does  not  materially  hasten  the  solution  of  the  bromide. 
The  sublimed  crystalline  salt  is  hygroscopic  in  charadter, 
although  not  nearly  to  the  extent  which  we  had  been  led 
to  expedt.     From  several  experiments  carried  out  to  test 


FiQ.  I. — Section  of  Apparatus  for  Sublimation. 

A,  Glass  tube  for  admitting  bromine  vapour,    o,  Outer  porcelain  tube,    i,  Inner  porcelain  tube.    T,  Glass  outlet  tube. 
F,  Perforated  Fletcher  furnace,    r,  Boat  containing  nickel,    s,  Sublimed  bromide. 


A  glance  at  this  list  shows  the  lack  of  consistency  in 
the  results  obtained.  In  many  cases  this  is  sufficiently 
accounted  for  by  the  inadequacy  of  the  methods  and  the 
known  impurity  of  the  materials  used,  without  taking  into 
consideration  the  unconfirmed  admixture  of  unknown  im- 
purities. A  critical  investigation  of  the  data  already  pub- 
lished would  be  an  endless  and  perhaps  unprofitable 
labour,  and  we  prefer  at  this  time  rather  to  record  the 
method  and  results  of  our  own  work  than  to  enter  into 
any  discussion  of  claims  heretofore  advanced. 

While  it  is  obvious  that  certainty  is  to  be  obtained  only 


this  point  it  appeared  that  freshly  sublimed  nickelous 
bromide  exposed  to  the  free  air  of  the  room  absorbed  about 
o-i  milligrm.  per  grm,  in  ten  minutes. 

Since  the  value  of  the  seledtion  of  nickelous  bromide  as 
the  starting  point  in  the  determination  of  the  atomic 
weight  of  nickel  depends  on  the  possibility  of  dissolving 
the  salt  in  hot  water  without  the  slightest  loss  of  bromine, 
it  seemed  necessary  to  investigate  this  point.  To  this 
end,  a  mass  of  several  grms.  of  the  sublimed  compound 
was  suspended  in  a  flask  arranged  in  such  a  way  that 
the  atmosphere  of  the  flask  during  the  solution  could  be 


286 


Benzoylphenylsemicarbazide. 


I  Chkmical  Mbws 
I      Dec.  10,  1897. 


swept  through  a  bulb-tube  containing  a  mixture  of  potas- 
sic  iodide  and  starch.  Any  formation  of  nickelous  oxide 
or  oxybromide  during  the  heating  of  the  solution  could 
have  taken  place  only  by  disengagement  of  bromine, 
which  would  have  been  shown  by  the  blueing  of  the  indi- 
cator in  the  bulb.  Not  the  slightest  tinge  of  blue  colour 
appeared  at  any  time  during  the  experiment,  in  spite  of 
the  fad  that  the  solution  of  nickel  bromide  was  finally 
Bubjeifted  to  prolonged  boiling.  That  the  iodo-starch 
mixture  was  exceedingly  sensitive  to  very  minute  traces 
of  free  bromine  was  assured  by  experiment  in  the  first 
place.  This  experiment  is  detailed  here,  however,  merely 
as  corroborative  testimony,  and  is  not  advanced  as  being 
final  on  the  subjeft  ;  the  best  evidence  is  yielded  by  the 
quantitative  results  of  our  series  of  analyses. 

Being  now  sure  that  we  could  analyse  the  salt  if  we 
could  obtain  it  in  a  pure  state,  we  next  proceeded  to 
determine  whether  it  could  be  prepared  in  a  condition 
altogether  suitable  for  weighing  and  analysis.  The  first 
sublimations  were  performed  in  an  ordinary  combustion 
tube  in  an  atmosphere  of  carbon  dioxide.  These  sublima- 
tions yielded  in  no  case  material  that  was  above  suspicion, 
and  none  of  it  was  used  in  our  analyses,  the  experiments 
being  carried  out  merely  as  a  study  of  the  properties  of 
the  substance  under  examination.  Since  it  seemed  pos- 
sible that  the  carbon  dioxide  used  might  suffer  partial 
dissociation  at  the  high  temperature  necessary  for  the 
sublimation,  nitrogen  was  substituted  for  this  gas.  After 
many  experiments  with  nitrogen,  both  alone  and  when 
mixed  with  bromine  vapour,  it  was  found  best  to  carry  on 
the  sublimation  of  the  nickelous  bromide  in  a  stream  of 
nitrogen  mixed  with  hydrobromic  acid.  The  elaborate 
apparatus  constructed  by  Mr.  G.  P.  Baxter  for  supplying 
suitable  mixtures  of  any  or  all  of  these  gases  and  vapours 
for  preparing  and  subliming  the  salt  will  be  described  in 
a  later  paper,  upon  the  atomic  weight  of  cobalt. 

The  temperature  at  which  the  salt  sublimes  lies  not  far 
from  that  at  which  the  hardest  glass  begins  to  soften, 
hence  we  found  it  advantageous  to  conduit  the  sublima- 
tion in  porcelain.  In  order  to  colleift  the  produft  a  small 
porcelain  tube,  used  as  the  receiver,  was  fitted,  telescope 
fashion,  inside  of  the  larger  tube  containing  the  substance 
to  be  vaporised.  In  this  way  the  pure  crystals  could  be 
removed  without  contamination.  Since  nickelous  bro- 
mide is  decomposed  either  by  oxygen  or  by  water  at  a 
red  heat,  unless  a  very  large  excess  of  hydrobromic  acid 
gas  is  present,  both  oxygen  and  water  must  be  excluded 
with  scrupulous  care  during  its  final  sublimation.  At 
first  we  were  not  able  to  accomplish  this  complete  exclu- 
sion, so  that  most  of  the  bromide  used  in  the  preliminary 
series  of  analyses  contained  traces  of  green  crystallme 
oxide,  which  were  carefully  coUedted  and  weighed.  In 
making  the  final  calculation,  the  weight  of  this  oxide  was 
subtradled  from  the  total,  in  order  to  obtain  the  weight 
of  the  bromide.  Subsequently,  with  improved  apparatus, 
the  bromide  was  obtained  in  a  state  of  satisfadlory  purity  ; 
it  gave  a  perfedtlv  clear  solution  in  water,  leaving  nothing 
to  be  desired.  With  the  improved  arrangement  the  oxide 
itself  was  quickly  converted  at  a  dull  red  heat  into  the 
bromide,  by  means  of  a  stream  of  hydrobromic  acid  gas. 
Hence  it  was  possible  to  purify  nickelous  bromide  con- 
taminated with  oxide  by  simply  treating  it  for  a  few 
minutes  in  this  fashion  ;  in  pra«5lice,  the  scheme  worked 
very  well. 

Chemical  literature  contains  no  satisfaftory  determina- 
tion  of  the  specific  gravity  of  the  anhydrous  salt;  hence, 
in  order  to  reduce  our  weighings  to  the  vacuum  standard, 
the  following  determination  was  made: — 3'3i96  grms.  of 
pure  dry  nickelous  bromide  displaced  upon  one  occasion 
0*6162  grm.  and  upon  another  0-6136  grm.  of  rectified 
toluol  at  28°.  Since  the  specific  gravity  of  the  toluol  at 
this  temperature  was  o'86o,  referred  to  water  at  the  same 
temperature,  the  specific  gravity  of  the  bromide  must  be 
4-64.    Nickelous  bromide  is  insoluble  in  toluol. 

(To  be  continued). 


PROCEEDINGS    OF    bOClETiES. 

CHEMICAL  SOCIETY. 
Ordinary  Meeting,  November  4th,  1897. 

(Concluded  from  p.  276). 

114.  *^  On  some  Yellow  Vegetable  Colouring  Matters." 
By  A.  G.  Perkin. 

The  Rhus  rhodanthema,  a  tree  growing  to  the  height  of 
70  or  80  feet,  is  indigenous  to  northern  New  South 
Wales.  The  colouring  matter  CijHioOe  is  identical 
with  fisetin.  A  glucoside  of  fisetin,  C36H30O16  (C  =  6o'i8  ; 
H=4'45),  colourless  needles,  m.  p.  215 — 217°,  is  also 
present ;  it  is  decomposed  with  difficulty  by  boiling  dilute 
acids.  This  closely  resembles  fustin,  C58H46O23  or 
C36H26O14  (C  =  63-34;  H  =  3-8i),  m.  p.  217—219°,  the 
fisetin  glucoside  of  R.  Cotinus  (Schmid,  Ber.,  1886,  xix., 
1753)1  ^"'  differs  from  it  in  percentage  composition.  Its 
decomposition  with  acid  would  be  closely  expressed  by 
the  equation  C36H3oOi6  +  2H20  =  2Ci5Hio06+C6Hi406,  if 
rhamnose  or  glucose  are  liberated  by  this  readlion.  Gallic 
acid  was  also  isolated,  evidently  as  a  decomposition  pro- 
du'dt  of  gallotannic  acid  contained  in  the  wood. 

Berberis  ortuensis,  a  plant  resembling  Berberis  vulgaris, 
flourishes  in  Cyprus.  It  was  found  to  contain  berberine, 
but  no  colouring  matter  of  the  mordant  yellow  class. 

The  perianths  surrounding  the  seeds  of  Rumex  obtusi- 
folius  contain  a  trace  of  quercetin,  which  is  interesting, 
as  in  many  roots  of  this  species  methylanthraquinone 
derivatives  also  exist.  It  is  also  pointed  out  that  the 
leaves  and  green  stems  of  madder  {Rubia  tinctoria)  con- 
tain a  yellow  colouring  matter  which  will  be  examined. 

115.  Naphthylureas."  By  George  Young,  Ph.D.,  and 
Ernest  Clark. 

The  mononaphthylureas  may  be  prepared  by  the  adtion 
of  potassium  cyanate  on  the  hydrochloride  of  the  corre- 
sponding naphthylamine.  In  consequenceof  the  rapid  con- 
version of  the  mononaphthylureas  into  the  symmetrical  di- 
naphthylureas  which  takes  place  on  heating,  even  below  the 
melting-points  of  the  former,  the  true  melting-points  have 
escaped  the  observation  of  previous  authors.  a-Naphthyl- 
urea  melts  at  213 — 214°,  at  which  temperature  it  is  con- 
verted into  di-a-naphthylurea,  melting  at  284—286°.  fi- 
Naphthylurea  melts  at  213 — 215°,  and  immediately  forms 
di-/3-naphthylurea,  melting  at  289  —  290°.  Acetyl-a- 
naphthylurea,  m.  p.  214 — 215°;  benzoyl-a-naphthylurea, 
m.  p.  243  — 243"5°;  acetyl-)8-naphthylurea,  m.  p.  202 — 
203*5°;  benzoyl  /3-naphthylurea  m.  p.  219 — 220°. 

116.  "  Benzoylphenylsemicarbazide."  Preliminary 
Notice.  By  George  Young,  Pn.D.,  and  Henry 
Annable. 

In  a  previous  communication  presented  to  the  Society 
{Trans.,  1897,  Ixxi.,  200),  attention  was  drawn  to  the  dis- 
agreement Detween  the  melting-points  of  benzoylphenyl- 
semicarbazide, 202 — 203°,  as  observed  by  Michaelis  and 
Schmidt  [Ber.,  1887,  xx.,  1713),  and  210—211"  as  observed 
by  Widman  (Ber.,  1893,  xxvi.,  945).  It  described  the  pre- 
paration and  examination  of  this  substance — mtrlting  at 
202 — 203° — and  suggested  the  possible  existence  of  two 
bcnzuylphenylsemicarbazidcs  both  having  the  constitu- 
tional formula  C6H5NlCOC6H5)*NH-CO*NH2  Shortly 
after  the  publication  of  this  paper,  Di.  Widman  had  the 
courtesy  to  submit  a  sample  of  his  preparation  for  com- 
parison. This  sample  had  been  observed  by  Dr.  Widman 
to  melt  at  210—212° ;  the  authors  found  it  to  melt 
at  211 — 212°.  Their  thermometer  agreed  therefore 
with  Dr.  Widman's.  A  comparison  ot  the  properties 
of  the  two  preparations  led  to  exceedingly  interesting  re- 
sults. Widman's  benzoylphenslsemicarbazide  seemed  to 
be  almost,  if  not  quite,  insoluble  in  boiling  benzene,  the 
melting  -  point  remaining  unaffedted.  The  author's 
benzoylphenylsemicarbazide  was  fairly  soluble  in  boiling 
benzene,  crystallising  out  again  on  cooling.     Mere  re- 


CRBtiicAL  News,  ) 
Dec.  10, 1897.     • 


Sulphocamphylic  A  cid. 


2S7 


crystallisation  from  benzene  did  not  affedl  the  substance, 
but  prolonged  boiling  with  benzene  caused  a  gradual  rise 
of  the  melting-point.  On  the  other  hand,  the  substance 
was  easily  soluble  in  boiling  water  and  crystallised  out  on 
cooling  unchanged,  whereas  Dr.  Widman's  preparation 
dissolved  in  boiling  water  with  difficulty  and  crystallised 
out  on  cooling,  with  the  melting-point  considerably 
lowered.  These  results  induced  the  authors  to  undertake 
a  thorough  investigation  of  the  formation  and  properties 
of  benzoylphenylsemicarbazide.  They  have  been  able  to 
determine  that  the  adtion  of  benzoyl  chloride  on  phenyl- 
semicarbazide  produces  under  different  conditions  three 
distinca  forms  of  benzoylphenylsemicarbazide.  These 
three  forms  melt  respedively  at  202—203°,  205—206°, 
and  210 — 211°.  They  are  each  capable  of  conversion 
into  either  of  the  other  two.  They  exhibit  different  and 
characteristic  crystalline  strudtures  under  the  microscope. 
They  possess  different  solubilities  and  densities.  The 
form  of  highest  melting-point  seems  incapable  of  solution 
without  undergoing  at  least  partial  change  into  one  or 
other  of  the  lower  melting  forms,  but  pure  solutions  of 
these  latter  may  be  easily  prepared.  These  solutions 
have  no  a(5lion  on  polarised  light.  The  authors  are  at 
present  engaged  in  examining  the  physical  properties  of 
these  substances  and  in  extending  the  investigation  to  a 
number  of  other  closely  related  compounds,  in  the  hope 
of  being  able  to  determine  whether  they  are  capable  of 
existence  in  two  or  more  modifications. 

117.  "Sulphocamphylic  Acid."  By  W.  H.  Perkin, 
jun. 

In  a  previous  communication  (Proc,  1895,  xi.,  33)  it 
was  shown  that  when  the  potassium  salt  of  sulpho- 
camphylic acid  is  treated  with  phosphorus  pentabromide, 
the  sulphobromide,  C8Hi2(S02Br)-C02H,  is  produced, 
and  from  this  substance  by  elimination  of  sulphur  dioxide 
an  acid  of  the  formula  CsHiaBr'COjH  was  obtained, 
which,  as  it  gives  j8-camphylic  acid,  C8H11CO2H,  on 
treatment  with  alcoholic  potash,  may  be  called  brotno- 
dihydro-fi-catnphylic  acid. 

During  the  course  of  further  experiments,  the  corres- 
ponding camphylic  sulphochloride,  C8Hi2(S02Cl)C02H, 
has  been  obtained  by  treating  the  potassium  salt  of 
sulphocamphylic  acid  at  o°with  phosphorus  pentachloride. 
This  substance  melts  at  168—170°,  and  at  the  same  time 
slowly  undergoes  decomposition  with  evolution  of  sulphur 
dioxide  and  formation  of  chlordihydro-(3-camphylic  acid,  a 
crystalline  substance  which  melts  at  105 — 106°. 

Like  the  corresponding  bromo-compound,  it  is  decom- 
posed by  boiling  with  alcoholic  potash,  with  elimination 
of  hydrogen  chloride  and  formation  of  ;8-camphylic  acid. 

In  the  last  communication  on  sulphocamphylic  acid 
{Proc,  1896,  xii.,  189)  it  was  stated  that,  when  /3-cam- 
phylic  acid  was  treated  with  phosphorus  trichloride,  and 
the  produft  distilled  under  reduced  pressure,  the  chloride 
of  an  acid  melting  at  130°  is  obtained  which  was  called 
iso-j3-camphylic  acid,  because  at  the  time  it  was  thought 
that  this  acid  might  prove  to  be  isomeric  with  jS-camphylic 
acid.  It  has  since  been  found  that  the  reaction  does  not 
proceed  in  this  way,  but  that  the  following  much  more 
remarkable  change  takes  place.  When  the  chloride  of 
/3-campbylic  acid  is  distilled,  there  is,  as  already  men- 
tioned, some  decomposition  and  charring,  and  during  this 
distillation  the  chloride  is  reduced  almost  completely  to 
the  chloride  of  an  acid,  CgHi402,  which  on  investigation 
has  been  found  to  be  identical  with  isolauronolic  acid,  the 
acid  which  Koenigs  and  Hotthn  {Ber.,  1893,  xxvi.,  813), 
and  the  author  {Proc,  1893,  ix.,  109)  obtained  by  the 
elimination  of  sulphuric  acid  from  sulphocamphylic  acid. 

This  same  isolauronolic  acid  (together  with  a  liquid 
acid,  which  is  possibly  an  isomeride)  is  obtained  when  /3- 
camphylic  acid  is  reduced  with  sodium  amalgam  under 
certain  conditions,  and  quite  lately  it  has  also  been  ob- 
tained in  large  quantity  by  fusing  sulphocamphylic  acid 
with  soda  in  a  cast-iron  pot. 

When  fused  in  a  nickel  dish  with  caustic  soda,  sulpho* 


camphylic  acid  yields  a  mixture  of  a-  and  jScamphylic 
acids,  C9H12O2.  but  when  an  iron  pot  is  used,  the  iron 
at^s  as  a  reducing  agent,  and  the  product,  which  is  found 
to  contain  quantities  of  ferric  oxide,  on  treatment  in  the 
usual  way  yields  large  quantities  of  isolauronolic  acid, 
C9H14O2. 

Isolauronolic  acid  is,  as  Koenigs  and  Meyer  {Ber., 
i894>  xxvii.,  3466}  showed,  readily  oxidised  to  isolauronic 
acid,  CQH12O3,  a  ketonic  acid  which  gives  a  well  charac- 
terised oxime  and  a  semicarbazide.  On  reduction  with 
sodium  amalgam,  the  author  finds  that  isolauronic  acid 
is  readily  converted  into  dihydroisolauronic  acid,  C9H14O3 
(m.  p.  88°),  a  result  differing  somewhat  from  that  of 
Koenigs  and  Meyer,  who  obtained  in  this  way  a  ladone, 
C9H14O2,  melting  at  47—50°,  together  with  a  substance 
melting  at  80—81°,  which  they  consider  to  be  a  mixture 
of  two  acids,  C9H14O3  and  C9H16O3. 

The  author  has  further  studied  the  adlion  of  oxidising 
agents  on  isolauronic  acid,  and  finds  that,  under  certain 
conditions,  this  acid  is  split  up  into  dimethylsuccinic  acid, 
COOH-C(CH3)2CH2-COOH  and  a  ketonic  acid,  C8HX4O3, 
which  melts  at  51°. 

This  ketonic  acid  on  oxidation  is  converted  into  aa' 
dimethylglutaric  acid,  C02H-C(CH3)2-CH2'CH2-C0aH, 
and  it  therefore  evidently  has  the  constitution 
CH3-CO-C(CH3)2-CH3-CH2-C02H,  and  is  identical  with 
the  acid  previously  obtained  {Proc,  1896,  xii.,  190),  by 
oxidising  0-camphylic  acid. 

A  careful  study  of  the  results  obtained  in  this  long 
series  of  experiments  on  sulphocamphylic  acid  and  the 
acids  derived  from  it,  seems  to  the  author  to  clearly  indi- 
cate that  the  constitutions  of  isolauronolic  and  isolauronic 
acids  are  most  probably  represented  by  the  following  for- 
mulae : — 


CH9    CHa    CHs 

I     \> 

C C CHa 


CHj 


C CO2H 

Isolauronolic  acid. 


CHi    CHa    CH9 

J.    ^ 

C C CHa 

\/ 

CO C COaH 

Isolaurooic  acid. 


As  sulphocamphylic  acid  on  heating  is  resolved  into  iso- 
lauronolic acid  and  sulphuric  acid,  and  on  the  other  hand, 
isolauronolic  acid,  as  was  indicated  in  a  previous  com- 
munication {Proc,  1893,  ix.,  109)  and  has  since  been 
proved,  when  heated  with  sulphuric  acid  at  90°,  is  again 
converted  into  sulphocamphylic  acid,  it  follows  that  the 
determination  of  the  constitution  of  isolauronolic  acid 
will  throw  most  important  light  on  the  formula  of  sulpho- 
camphylic acid,  and  on  the  remarkable  changes  which 
take  place  during  the  formation  of  this  sulpho-acid  from 
camphoric  acid. 

The  discussion  of  these  points  and  of  their  bearing  on 
the  constitution  of  camphoric  acid,  the  author  must  reserve 
for  a  detailed  description  of  his  experiments,  which  he 
hopes  soon  to  be  able  to  lay  before  the  Society. 


ROYAL    INSTITUTION. 
General  Monthly  Meeting,  December  6th,  1897. 

Sir  James  Crichton-Browne,  M.D.,  F.R.S.,  Treasurer 
and  Vice-President,  in  the  Chair. 

The  following  were  eledled  Members :— The  Hon.  H.  M. 
Birdwood,  C  S.I. ;  Major  John  Leslie ;  Capt.  H.  G.  Lyons, 
R.E. ;  and  Mr.  Cecil  Powney. 

The  special  thanks  of  the  Members  were  returned  to 
Professor  Dewar,  LL.D.,  F.R.S.,  for  his  present  of  a 
portrait  of  Mr.  Benjamin  Vincent,  Honorary  Librarian  of 
the  Royal  Institution. 


288 


New  Spectral  Lines  of  Oxygen. 


Chemical  News, 
Dec  10,  1897. 


NOTICES  OF  BOOKS. 


Handbook  {A)    for   Chemists  of  Beet-sugar  Houses  and 
Seed'Culture  Farms.     Containing  Seledled  Methods  of 
Analysis,  Sugar-house  Control,  Reference  Tables,  &c. 
By  Guilford  L.  Spencer,  D.Sc,  of  the  U.S.  Depart- 
ment of  Agriculture.     New  York  :  John  Wiley  and  Sons. 
London :  Chapman  and  Hall,  Lim.   1897.   ^P-  "• — 475- 
i8mo.,  Limp  Morocco  Tuck. 
It  is  interesting  to  note  that  such  great  advance  has  been 
made  in  the  beet-sugar  industry  in  the  United  States  that 
already  there  is  an  opening  for  a  book  devoted  exclusively 
to  the  sugar-beet.     Less  than  ten  years  ago,  when  Dr. 
Spencer  published  his  "  Handbook  for  Sugar  Manufac- 
turers," the  manufadlure  of  sugar  was  confined  to  that 
from  cane  cultivated  in  the  Southern  States ;  sorghum 
was  attradting  some  attention,  but  had  been  nearly  aban- 
doned.    At  present   the  beet-sugar  industry  bids  fair  to 
attain  enormous  proportions  in  America. 

The  "Handbook"  contains,  in  acompadl  and  attra(5tive 
form,  a  fund  of  information  on  the  chemistry  and  treat- 
ment of  sugar-beets  that  cannot  be  found  elsewhere 
without  access  to  an  extensive  library.  It  treats  in  sec- 
tions of  sugar-house  control ;  sugar-analysis  by  optical 
methods  and  by  chemical  methods ;  sampling  and 
averaging,  analysis  of  the  beet,  juice,  syrup,  and 
molasses,  filter  press-cake,  and  residues  of  divers  kinds  ; 
analysis  of  saccharates,  bone-black,  chimney-gases,  as 
well  as  of  the  crude  materials  used,  such  as  limestone, 
sulphur,  coke,  and  water ;  seed  seledion,  seed  testing,  and 
special  reagents  have  their  share  of  space.  Seventy  pages 
of  useful  tables  are  followed  by  one  hundred  and  twenty- 
five  pages  of  blank  forms  for  pradlical  use  in  sugar-house 
work,  besides  thirty  pages  for  reporting  yield  and  losses. 

The   illustrations   illustrate   the   text,   and    the    type, 
though   small,  is  very  clear.     Full-face  type  heads  each 
paragraph. 
The  volume  contains  an  index.  H.  C.  B. 


CORRESPONDENCE. 


CONVERSION  OF  THERMOMETRIC  SCALES. 

To  the  Editor  of  the  Chemical  News. 
Sir, — In  the  Meteor ologische  Zeitschrift  for  the  month  of 
October,  G.  Hellmann  (see  also  Revue  Scientifique, 
November  20,  1897,  P-  ^^3)i  there  is  an  ingenious  formula 
for  the  conversion  of  Fahrenheit  degrees  into  those  of 
Centigrade,  which  may  interest  you  if  you  have  not  seen 
it.    The  usual  formula  is,  of  course, — 


(F-  -  32)  X  5 


=  C 


G.  Hellmann : — 


Let  88  be  the  number  of  degrees  Fahrenheit,  we  have 
then — 

56  _ 


88  -  32 


=  28. 


28 
2-8 
0-28 

31-08  C 

I  would  venture  to  point  out  that  Reamur's  scale  may 
be  converted  into  that  of  Celsius  in  a  somewhat  similar 
manner. 


4  =  o'4444  X  2'5  =  i-o  =  2-5  X  4  =  i-o, 

Example : — 

""  ^  -  3^  -  18  X  4  =  72-00 
10  J.20 

072 
0*07 
=  79'99 

While  the  conversion  of  Celsius  to  Fahrenheit  is  given  as 
follows : — 

2  =  o-i8o  X  5-555  =  I  =  0-5555  X  2  =  I, 

we  have  then — 

32  -  (SliU^  -h  C°  X  2  =  F». 

Example : — 

100  C   X   2  .  „„ 

32  —  =  32  -  20  -F  200  =  212°  F. 

10 

The  advantage  which  these  formulae  present  is,  as 
shown  by  M.  Hellmann,  that  these  conversions  may  be 
conduced  mentally. — I  am,  &c., 

Thos.  Palmer. 

4,  Rue  Haringrode,  Antwerp, 
November  27,  1897. 


ON    NEW    SPECTRAL    LINES    OF    OXYGEN. 

To  the  Editor  of  the  Chemical  News. 
Sir, — In  the  abstracts  from  foreign  journals  in  the 
Chkmical  News  of  November  26  (vol.  Ixxvi.,  p.  265), 
you  were  good  enough  to  notice  my  recent  discovery  of 
new  lines  in  the  spedtrum  of  oxygen,  but  the  wave-lengths, 
as  set  forth  in  the  Comptes  Rendus,  have  not  been  given. 
May  I  ask  you  to  kindly  publish  the  enclosed  copy  of  a 
letter  from  Dr.  Schuster,  addressed  to  me  in  May  last, 
which  supplies  the  omission,  and  at  the  same  time 
establishes — by  the  date — my  independent  discovery  of 
these  lines.  The  diagrams  of  the  spedlrum  of  oxygen 
published  by  Profs.  Runge  and  Paschen  in  Wiedemann's 
Annalen  of  July  last,  and  reproduced  in  the  Chemical 
News  of  November  26th,  shows  two  lines  in  about  the 
same  positions  as  those  which  I  have  observed. — I  am,  &c,, 

H.  Wilde. 
The  Manchester  Literary  and  Philosophical  Society, 
36,  George  Street,  Manchester,  Dec.  7, 1897. 

[Copy]. 

4,  Anson  Road,  ViAoria  Park, 
May  7th,  1897. 

Dear  Mr.  Wilde, 

I  saw  to-day  your  two  new  oxygen  lines,  and 
asked  Mr.  Hensalech  to  measure  them  so  as  to  make  sure 
they  were  the  same.  He  finds  the  wave-lengths  7759  and 
7165,  agreeing  well  with  yours  (7760  and  7160) ;  for  with 
the  small  specftroscope  we  had  today  we  could  not  be 
sure  to  a  few  units  of  these  numbers.  The  lines  Mr. 
Hensalech  saw  previously  must  have  been  nitrogen  lines. 
Yours  sincerely, 

(Signed)        Arthur  Schuster. 


SUGAR-BEET. 


To  the  Editor  of  the  Chemical  News. 
Sir, — I  shall  be  glad  if  you  will  announce  in  your  next 
issue  that  I  am  distributing  sugar-beetroot  seed  gratui- 
tously to  anyone  willing  to  grow  sugar-beetroots  experi- 


CfinMICAL  NBW8,  \ 

Dec.  10.  1897. 


Meetings  for  the  Week. 


289 


mentally  next  season,  and  that  I  will  analyse  the  roots 
and  report  thereon  free. 

The  consumption  of  sugar  in  the  United  Kingdom 
amounts  to  over  one  million  tons  per  annum,  repre- 
senting a  value  of  ;^i9,ooo,ooo,  which  all  goes  to  the 
foreign  exporter,  and  which  should  be  kept  in  this  country 
if  possible. 

I  was  closely  connedted  with  the  experiments  of  sugar 
beetroot  growing  carried  on  in  this  country  about  two  or 
three  years  ago,  and  by  which  it  was  proved  that  the  roots 
can  be  grown  here  quite  as  well,  if  not  better,  than  on  the 
Continent,  by  such  well-known  landed  proprietors  as 
Lord  Rosebery,  Lord  Winchilsea,  and  Lord  Jersey. 

Great  Britain,  with  its  large  consumption  of  78  lbs. 
per  head  per  annum,  should  grow  its  own  sugar,  and  thus 
prevent  the  closing  of  any  more  sugar-refineries,  and  also 
be  the  means  of  re-opening  the  large  fadories  now  closed 
in  London,  Liverpool,  Glasgow,  Greenock,  Bristol,  Ply- 
mouth, Manchester,  and  Dublin. 

If  gentlemen  will  send  me  their  names  and  addresses 
I  willforward  the  seed  to  them  in  time  for  next  spring's 
sowing,  and  I  shall  have  much  pleasure  in  aiding,  gratis, 
in  the  formation  of  any  syndicate  to  eredt  fadtories  to 
manufadlure  the  sugar.  — Thanking  you  in  anticipation, 

I  am,  &c., 

SiGMUND  Stein. 

323,  Vauxhall  Road,  Liverpool, 
December  i,  1897. 


MISCELLANEOUS. 

Royal  Institution.  — The  following  are  the  Ledlure 
Arrangements  before  Easter -.—Professor  Oliver  Lodge, 
six  Christmas  Ledtures  (specially  adapted  for  young 
people)  on  "  The  Principles  of  the  Eledric  Telegraph  "  ; 
Professor  E.  Ray  Lankester,  eleven  ledtures  on  "  The 
Simplest  Living  Things  " ;  Professor  Dewar,  three  lec- 
tures on  "The  Halogen  Group  of  Elements";  Dr.  J. 
Paul  Richter,  three  leftures  on  "  Some  Italian  Pictures  at 
the  National  Gallery  "  ;  Professor  J.  A.  Fleming,  five  lec- 
tures on  "  Recent  Researches  in  Magnetism  and  Dia- 
magnetism";  Professor  Patrick  Geddes,  three  lectures 
on  "Cyprus";  Mr.  Wm.  H.  Hadow,  three  ledures  on 
"The  Strudture  of  Instrumental  Music";  Mr.  Lionel 
Cust,  two  leiftures  on  "  Portraits  as  Historical  Documents, 
Portraits  as  Monuments."  The  Friday  Evening  Meetings 
will  begin  on  January  21st,  when  a  Discourse  will  be 
given  by  the  Right  Hon.  Sir  John  Lubbock,  Bart.,  M.P., 
on  "  Buds  and  Stipules "  ;  succeeding  Discourses  will 
probably  be  given  by  Professor  C.  Lloyd  Morgan,  Mr. 
A.  A.  Campbell  Swinton,  Dr.  J.  Hall  Gladstone,  Pro- 
fessor L.  C.  Miall,  Captain  Abney,  Professor  J.  E.  Thorpe, 
Mr.  James  Mansergh,  the  Dean  of  Canterbury,  Professor 
Dewar,  and  other  gentlemen.  Lord  Rayleigh  will  deliver 
ledlures  after  Easter. 

London  County  Council.— An  interesting  ceremony 
took  place  on  Saturday,  November  20th,  at  the  Holborn 
Restaurant,  when  the  members  of  the  staff  of  the  Chemi- 
cal and  Gas  Department  of  the  London  County  Council 
gave  a  complimentary  dinner  to  their  late  chief,  Mr. 
W.  J.  Dibdin.  The  new  chief  of  the  department.  Dr.  F. 
Clowes,  of  Nottingham  College,  took  the  chair,  and  in 
proposing  the  toast  of  the  evening,  pointed  out  that  the 
work  carried  out  by  Mr.  Dibdin  as  chief  of  the  department 
refiedted  credit  alike  on  the  Council  and  himself.  In  con- 
clusion, the  Chairman  presented  to  Mr.  Dibdin,  on  behalf 
of  the  officers  of  the  department,  an  illuminated  address. 
Mr.  Livingston,  senior  officer  of  the  department,  who 
read  the  Address  to  the  company,  bore  testimony  to  the 
invariable  kindness  and  courtesy  of  their  late  chief,  and, 
referring  to  his  public  usefulness,  gave  as  an  example  his 
successful  treatment  of  the  London  sewage.     The  nex^ 


toast,  "  The  Chairman,"  was  proposed  by  Dr.  Teed  in  an 
appropriate  and  somewhat  amusing  speech.  In  replying 
to  which  Dr.  Clowes  confided  to  the  company  the  "  nick- 
name "  by  which  he  is  known  among  his  students  at 
Nottingham,  and  which  promises  well  for  the  continuance 
of  the  good  feeling  between  chief  and  officers  that  has 
heretofore  existed.  On  account  of  the  recent  arduous 
task  imposed  upon  a  sister  Department,  the  toast  "  The 
Fire  Brigade,"  proposed  by  Mr.  Livingston,  was  enthusi- 
astically received.  The  evening's  proceedings  were 
further  enlivened  by  the  music  provided  by  Messrs.  T.  W. 
Heath  and  F.  Goddard,  professionally  assisted  by  Mr.  L. 
Thorne,  who  artistically  rendered  "  Mary  of  Argyle,"  &c., 
and  by  Mr.  J.  W.  Kipps,  F.R.C.O.,  A.R.A.M.,  whose  per- 
formance at  the  piano  was  greatly  appreciated.  Mr. 
Edward  Minshall  favoured  the  company  with  two  excel- 
lent recitations,  entitled  "  The  Benedidtion  "  and  "  My 
First  and  Last  Cricket  Match."  A  vote  of  thanks  to 
the  Hon.  Sec,  Mr.  £.  J.  Jackman,  terminated  the  pro- 
ceedings. 

Deterioration  of  Paper.  —  Sir  H.  Trueman  Wood 
writes  to  the  Atheneeum  : — A  committee  of  the  Society  of 
Arts  is  now  at  work  on  the  subjedt  of  the  deterioration  of 
modern  paper.  It  is  a  matter  of  general  repute  that  many 
books  are  now  printed  on  paper  of  so  inferior  a  charadter 
that  it  is  liable  to  perish  in  a  short  space  of  time  ;  but  the 
committee  are  anxious  to  have  definite  examples  before 
them  of  books  that  have  thus  suffered.  Might  I  ask  if 
any  of  your  readers  who  have  had  experience  of  such 
cases  would  kindly  communicate  the  fadts  to  me;  and  also 
if  they  would  send  me  any  examples  of  books  printed 
within  the  last  fifty  years  in  which  the  paper  shows  signs 
of  perishing  ?  I  need  not  say  that  any  such  books  will 
be  carefully  preserved,  and,  after  the  committee  have 
had  an  opportunity  of  inspedting  them,  returned  to  the 
lenders." 

On  the  Determination  of  Silica  in  Blast  Furnace 
Slag.— G.  H.  Meeker  (y.  Am.  Chem.  Soc.).— The  de. 
hydration  of  the  silicic  acid  by  means  of  concentrated 
sulphuric  acid,  instead  of  by  heat,  is  the  essential  feature 
of  the  procedure,  for  which  both  rapidity  and  accuracy 
are  claimed.  The  filtrate  from  the  silica  thus  obtained 
cannot,  however,  be  utilised  for  the  determination  of 
either  aluminum  or  calcium.  The  method  yields  satis* 
fadlory  results  in  the  presence  of  spinel. 


MEETINGS    FOR    THE    WEEK. 


Monday,  13th.— Society  of  Arts,  8.     (Cantor  Leftures).     "  Gutt« 
Percha,"  by  Eugene  F.  A.  Obach.  Ph.D.,  F.C.S. 

Wednesday,  15th.— Society  of  Arts,  8.  "  The  Purification  of  Sewage 
by  Badleria,"  by  Samuel  Kideal,  D.Sc. 

Microscopical,  8.     *'  A  New   Form    of    Photo- 

micrographic  Camera  and  Condensing  Sys- 
tem," by  E.  B.  Stringer,  B.A. 

— —  Institution     of     Mining    and     Metallurgy,    8. 

"  Mining  on  the  Black  Reef,  Witwatersrand 
Goldfields,  South  Africa,"  by  W.  Fischer  Wil- 
kinson.  "  Notes  on  Smelting  at  Broken  Hill," 
by  Henry  Watson.  "  Notes  on  the  Buying 
and  Sampling  of  Ores,  and  the  Working  of 
Mines  on  the  Tribute  System,  in  Chili,"  by 
Gerald  V.  Hopkins. 

Chemical,    8.       (Extra       Meeting).    "  Keknli 

Memorial  Ledture,"  by  F.  R.  Japp,  LL.D., 
F.R.S. 

Thursday,  i6th.— Chemical.  8.  "  Stereo- chemistry  of  Unsaturated 
Compounds— Part  I.,  Esterification  of  Substi- 
tuted Acrylic  Acids,''  by  J.  J.  Sudborough, 
Ph.D.,  and  Lorenzo  Lloyd.  "  Formation  and 
Hydrolysis  of  Esters,"  by  J.  J.  Sudborough, 
Ph.D.,  and  M.  E.  Feilmann,  B.Sc.  "A  New 
Method  of  Determining  Freezing-points  in  very 
Dilute  S(}lutionB,"  by  M.  Wilderman,  Ph.D. 


290 


Notes  and  Queries, 


(OhbmicalNkws 
1     Dec.  10,  1&97. 


NOTES    AND    QUERIES. 

*i,*  Our  Notes  and  Queries  column  was  opened  for  the  purpose  of 
giving  and  obtaining  information  likely  to  be  of  use  to  out   readers 
generally.     We  cannot  undertake  to  let  this  column   be  the  means 
of  transmitting  merely  private  information,  or  such  trade  notices 
as  should  legitimately  come  in  the  advertisement  columns. 
Penetration  of  X  Rays. — Could  anyone  inform  me  (per  Chemi- 
cal News)  in  what  ratio  the  X   rays  can  penetrate  plates   of  equal 
thickness  of  the  different  metallic  elements  as   regards  their  atomic 
weights.    Thus,  the  atomic  weight  ol  Fe  is  56  and  Al  27  ;  seeing  that 
the  atomic  weight  of  one  is  practically  double  the   atomic  weight  of 
the  other,  would  Fe  offer  twice  as  much  resistance  to  the  rays  as  Al 
would,  and,  if  not,  is  there  any  ratio  ? — X.  Y.  Z. 


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Chbmicai.  Nhws. 
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Estimation  oj  Copper  in  presence  of  other  Elements, 


291 


THE    CHEMICAL     NEWS. 

Vol.  LXXVI.,  No.  1986. 


THE   ESTIMATION   OF   COPPER   IN   PRESENCE 

OF     OTHER    ELEMENTS. 

By  HARRY  BREARLEY. 

In  a  previous  paper  (Chemical  News,  vol.  Ixxvi.,  p.  189) 
it  was  shown  that  the  claim  to  increased  accuracy  brought 
about  by  the  substitution  of  soda  carbonate  and  soda  salts 
for  ammonia  and  its  salts  in  the  cyanometric  estimation 
of  copper  was  a  just  one.  It  was  also  pointed  out  that 
the  silver  iodide  end-readlion,  which  has  already  been 
used  in  the  titration  of  nickel,  cobalt,  and  mercury  solu- 
tions, could  be  made  supplementary  to  the  colour  indi- 
cator, or,  if  need  be,  adt  alone. 

Two  lengthy  tables  setting  forth  the  influence  of  cer- 
tain associated  elements  on  the  estimation  of  copper  by 
cyanide,  when  performed  in  the  usual  way,  have  already 
appeared  in  the  Chemical  News  (Field,  i.,  61  ;  Thomson, 
xxxiii.,  15a),  while  a  writer  here  and  there  has  chronicled 
the  quantitative  behaviour  of  one  or  two  elements. 

It  is  proposed  now  to  state  the  observed  interference  of 
a  similar  series  of  elements,  using  the  Agl  turbidity  as 
indicator.  The  advantage  of  such  an  indicator  in  elimina- 
ting the  personal  error,  especially  when  a  precipitate 
forms  in  the  solution,  has  been  elsewhere  commented  on. 

It  must  not  be  presumed  that  the  writer  attempts  to 
decide  between  the  differences  of  previous  observers, 
although  the  results  are  not  without  value  in  this  respedl. 
The  aim  is  to  show  that  in  every  variety  of  circumstance 
the  new  method  of  operating  is  better  than  the  old  ;  the 
comparisons  of  Table  I.  are  made  to  that  end. 

The  new  mode  of  operating  is  found  to  be  especially 
serviceable  where  the  associated  element  is  precipitated 
in  the  titrated  liquid.  Very  few  of  such  precipitates  are 
entirely  without  influence  on  the  colour  indicator,  as 
Thomson's  results  show,  while  others  so  completely 
mask  it  as  to  make  any  reliable  observations  altogether 
impossible  until  the  precipitate  has  been  allowed  to  settle. 
This  delay  in  a  process  which  depends  in  any  degree  on 
the  rate  at  which  the  reagent  is  added  cannot  be  satisfac- 
tory. Nor  can  a  separation  at  any  stage  of  the  process 
always  overcome  this  difficulty,  on  account  of  the 
tenacity  with  which  ammoniacal  copper  solutions  adhere 
to  many  precipitates,  even  when  the  separation  chances 
to  be  complete. 

The  observations  are  summarised  in  Table  I.  The  fol- 
lowing are  details  common  to  each  test: — Amount  of 
copper,  o'looo  grm. ;  alkali  salts,  20  c.c.  HCI  (2  normal 
strength),  as  chloride  ;  excess  of  soda  carbonate,  30  c.c. 
(2  N) ;  excess  of  ammonia,  10  c.c.  (2  N).  A  decreased 
excess  of  ammonia  was  used  so  as  to  quite  avoid  the 
interchange  of  silver  and  copper.  Under  the  head  of 
•'Percentage  Interferences"  are  those  found  in  this  in- 
vestigation and  those  found  by  Field  and  Thomson.  The 
8oda  carbonate  series  explains  itself. 

Where  the  registered  interference  is  below  J  per  cent, 
it  may  be  taken  that  the  element  is  really  without  influ- 
ence, and  that  such  small  interferences  are  due  to 
experimental  error.  It  must  be  understood  that  the 
results  stated  were  obtained  by  operating  in  the  manner 
explained  in  the  previous  paper.  Where  the  interference 
is  considerable,  such  attempts  as  have  been  made  to 
obviate  it,  with  the  measure  of  success,  are  stated  in  the 
next  sedtion. 

The  behaviour  of  a  method  in  the  hands  of  different 
operators  is  a  good  index  of  its  value.  The  ordinary 
cyanide  titration  is  much  better  than  a  comparison  of  the 
results  of  Thomson  and  Field  ir-ight  suggest.    6ut  suQh 


'  a  comparison  does  show  how  very  susceptible  the 
ammoniacal  cyanide  procedure  is  to  more  or  less  of  what 
it  is  desirable  should  be,  in  the  final  operation,  inadlive 
reagents. 

The  Behaviour  of  the  Added  Elements,    Means  of 
Minimising  some  Interferences. 

The  most  obvious  means  of  overcoming  an  interference 
is  to  separate  the  offending  element  before  estimating  the 
copper.  Such  means  need  not  be  further  referred  to.  It 
is  intended  here  to  show  how,  by  modifying  the  titration, 
and  without  any  separation  whatever  in  a  quantitative 
sense,  the  copper  may  be  estimated  with  sufficient  exad- 
ness  to  meet  technical  demands. 

Where  the  form  in  which  the  element  was  added  is 
not  stated,  it  may  be  taken  that  the  chloride  was  used. 

Sodium  has  frequently  been  shown  to  be  without  in- 
fluence. 

Potassium  may  be  presumed  to  be  similarly  inadiive. 

Calcium. — Ammonia,  no  precipitate.  Soda,  precipitate 
easily  filterable.  The  precipitate  seems  to  hold  the 
colour  somewhat  even  when  the  solution  is  decolorised. 
A  greater  excess  of  cyanide  is  therefore  advisable. 
Thomson  explains  his  high  result  by  presuming  that  there 
is  some  readlion  between  the  cyanide  and  the  calcium 
salts.  His  cyanide  contained  considerable  quantities  of 
carbonate.  May  not  the  adherent  colour  more  truly 
account  for  the  error  ? 

Barium  and  Strontium. — Similar  remarks  apply  to  these 
metals. 

Magnesium. — No  precipitate  in  either  case. 

Zinc. — More  than  usual  interest  attaches  to  this  ele. 
ment,  because  the  alloys  of  copper  and  zinc  are  so  abundant. 
On  this  account  the  greatest  pains  have  been  taken  to 
minimise  its  influence.  Under  this  head  will  be  noticed 
a  number  of  modifications  which  may  be  applied  to  other 
elements. 

Zinc-Ammonia.— An  excess  of  loc.c.  2  normal  ammonia 
is  not  sufficient  to  precipitate  the  zinc  and  re-dissolve  it ;  30 
c.c.  was  used.  The  most  noticeable  feature  of  titration  is 
the  large  excess  of  cyanide,  over  and  above  that  adually 
required  to  combine  with  the  zinc,  needed  to  discharge 
the  colour. 

Zinc-Soda. — On  making  alkaline  with  soda  carbonate 
the  zinc  is  of  course  precipitated.  On  adding  the  cyanide 
the  colour  goes  as  usual,  until  the  theoretical  amount  of 
cyanide  is  added.  It  is  possible  at  this  point  to  get  a 
colourless  solution,  by  prolonged  standing,  holding  the 
greater  part  of  the  zinc  precipitated  ;  but  the  precipitate 
is  not  colourless.  It  remains  a  pale  green  in  the  most 
persistent  manner  until  enough  cyanide  has  been  added 
to  dissolve  it  completely,  or  nearly  so.  The  excess  of 
cyanide  required  to  do  this  when  copper  and  zinc  were 
together  in  equal  amounts  varied  from  60  to  80  per  cent 
more — according  to  volume,  time  of  standing,  &c. — than 
was  needed  to  readt  with  the  copper  alone. 

On  adding  the  potassium  iodide,  and  then  the  silver 
nitrate,  there  appeared  a  white  precipitate,  in  many  ways 
unlike  the  creamy  silver  iodide.  It  was  filtered  off,  more 
AgNOs  added,  and  again  the  white  precipitate  appeared, 
and  so  on  the  precipitation  and  filtration  might  alternate 
until  the  silver  iodide  turbidity  did  appear. 

This  at  once  suggests  that  the  zinc  which  had  com- 
bined with  the  cyanide  is  displaced  by  the  silver,  and 
that  the  repeated  precipitations  and  filtrations  are  un- 
necessary if  enough  silver  nitrate  is  at  once  added  to 
replace  the  whole  of  the  zinc. 

In  doing  this  it  was  possible  to  use  the  potassium  iodide 
to  indicate  when  enough  silver  had  been  added.  It  is  not 
difficult  to  observe  this  point  when  as  much  as  0*1  grm.  of 
zinc  is  present,  because  the  zinc  carbonate,  previously 
translucent  and  white,  becomes,  owing  to  admixed  Agl, 
opaque  and  yellowish,  and,  instead  of  settling  in  fiakes, 
remains  suspended  in  no  determinate  shape.  But  the 
indication  is  hardly  delicate  enough  to  accept  as  the  end 
of  the  operation,  and  so  a  little  cyanide  is  added,  which 


292 


Estimation  of  Copper  in  presence  of  other  Elements, 


f  Chbuical  Nbws, 
I     Dec.  17,  1897. 


Metal. 


Ammonia  Series. 


Table  I. 


Soda  Carbonate  Series. 


Copper  found. 


Percentage  error. 


Grm.  added  ., 

Calcium    . . 
Barium 
Strontium.. 
Magnesium 
Zinc  ..     .. 


,   O'OI 
O'lOOO 


005 

O'lOOO 
O'lOOO 

o'oggS 
o"ioo4 
O"i054 


o-io 

o'ioo5 
o'oggS 

O'lOOO 
0'1002 

O'iog4 


H.  B.     Thomson.      Field. 


Copper  found. 
J, 


Cadmium  ..     . 

Aluminium 
Iron 

Manganese 
Chromic  oxide . 
Chromic  acid 
Tin      ..     .. 
Molybdenum 
Arsenic 

Antimony ..  . 
Bismuth  .. 
Lead  ..  ..  . 
Mercury  (ous)  . 
»  (ic)  . 
Uranium  ..     . 


—  Q-IOIO  0'1028 


o"ioo3 

0'1002 

O'og68 


o'looS 

0'1002 

o-og64 
oo86g 

O'lOOO 

O'oggS 
o'oggS 

O'lOOO 

0'1002 
O"I062 

o'loSg 
0*1004 


0*1007 
o'oggS 
o*og6g 
0*0730 

o'oggS 
0*1000 
o*ogg8 
0*1004 

O'lOOO 
O'II20 

1 182 
0*1004 


0-5 
0*4 

O'O 
0*2 

9-4 

2*8 

0*7 

0'2 

31 
27*0 

0'2 
0*0 
0*2 
0*4 

o*o 

12*0 
18*2 

0*4 


i'35 
I  "go 

2*55 

o*go 

2065 


0*0 
o*o 
0*0 
0*0 
25*0 
34-6* 


0*1000 
O'lOOO 


Cos 

o'ogg7 

O-I002 
0'1002 

o*ogg8 
0*1015 


Percentage 
error. 


O'lO 

0*1000 
O'lOOO 
0*1000 
0'IO02 
0*1020 


6-85      - 


—  o'ioo4       O'lOOO 


3'53 
0-85 

24-85 


i'3S 
0*15 

O'O 

1*9 

2*45 

o*4 

ig-i 

23*2 
2*45 


15  H' 

O'O 

O'O 

12*0 

O'O 

00 

O'O 
O'O 
O'O 
0*0 

500 


o'ioo6 

O'lOOO 

o'og77 
o'ogg2 


o'loiS 


0'ioo7 
o'ogg4 
o'og66 

0'1002 
O'lOOO 

o'ioo4 

o'oggS 

0*1002 

01002 

o'oggS 

1070 

0'ii07 

0*0998 


0*1007 
0-0987 
0*0970 
o-og75 
o*ogg6 
0*1003 

0'1002 

0*0998 
0*1004 

O'lOOO 

0*1002 
113-9 

O'I20O 
O'IO02 


O'O 
O'O 
O'O 
0'3 

30 

O'O 

07 

I '3 
3-0 

2*5 

0'4 
0-3 

0'2 
0-3 
0*4 
O'O 
0'2 

13-9 

20'O 

0'2 


•  Dulin,  Joum.  Amtr.  Chem.  Soc,  May,  1895, 


dissolves  the  Agl  without  dissolving  more  than  traces  of 
the  zinc.  The  solution  is  then  filtered  and  finished  in  the 
ordinary  way.  An  alternative  is  to  add  an  excess  of  silver 
nitrate,  but  no  potassium  iodide,  filter,  and  titrate  the 
excess  with  cyanide.  The  soda  results  in  Table  I.  were 
obtained  in  this  way. 

Such  a  procedure  as  the  above  even  apart  from  the 
error  cannot  be  widely  serviceable,  on  account  of  the 
expense.  An  attempt  was  made  to  substitute  nickel  for 
silver,  for  economy's  sake,  and  with  the  idea  that  the 
error  on  using  silver  was  possibly  due  to  its  inability  to 
completely  displace  the  zinc.  The  fear  was  that  nickel, 
being  more  aiStive  to  cyanide  than  silver,  might  also  dis- 
place the  copper.  This,  however,  it  did  not  do,  but  being 
only  partially  soluble  in  soda  carbonate  it  did  necessitate 
an  examination  of  the  residue,  as  well  as  the  filtrate,  be- 
fore the  excess  could  be  found.  The  multiplicity  of 
operations  pending  such  a  procedure  led  to  its  rejedtion. 

One  point,  which  ought  never  to  have  been  overlooked, 
was  strongly  emphasised ;  that  is,  the  nickel  may  be  asso- 
ciated with  the  zinc  as  carbonate  in  a  solution  which 
contains  an  excess  of  free  cyanide.  This  recalls  the  tena- 
city with  which  the  copper  was  retained  in  the  zinc  car- 
bonate, and  suggests  that  an  examination  of  the  residue 
might  have  revealed  the  amount  of  silver  necessary  to 
corredl  the  2  per  cent  error. 

Other  reagents,  such  as  tartaric  and  citric  acids,  were 
tried.  They  did  not  eliminate  the  error.  They  are  ob- 
jedtionable,  too,  for  reasons  stated  below. 

The  most  satisfadtory  modification  lies  in  the  use  of 
sodium  pyrophosphate  (prepared  by  heating  Na2HP04  to 
redness).  A  saturated  solution  was  used.  Its  influence 
on  the  titration  of  pure  copper  solutions  is  shown 
below  :— 

O'O  25'0  50  c.c.  pyrophosphate. 

o'0500  0'0504  o'0502  gr.  Cu  indicated. 

This  reagent  was  suggested  by  T.  Moore  (Chem.  News, 
lix.,  160),  for  titrating  nickel  in  presence  of  zinc.  Its  only 
defedt  is  a  slight  lagging  in  the  readion  between  the 
cyanide  and  silver  iodide  which  accompanies  its  use. 

This  lagging  may  be  counterbalanced  by  adding  the 
same  volume  of  pyrophosphate  to  the  standard  copper. 
Two  results  obtained  in  this  way  are;— 


O'O 

O'lOOO 


0*05 

o'looS 


o'l  gr.  zinc  present. 
o'ioo6  gr.  copper  found. 


In  other  hands  it  has  given  as  good  and  better  results. 

Cadmium. — The  readlions  very  much  resemble  zinc,  but 
of  much  less  intensity.  The  precipitate  formed  on  making 
alkaline  is  in  each  case  dissolved  by  the  cyanide.  With 
sodium  carbonate  the  cadmium  was  re-precipitated  on 
adding  the  silver  nitrate,  as  explained  above,  and  as  no 
great  excess  of  cyanide  is  needed,  and  the  titration  offers 
no  other  difficulty,  there  was  no  need  to  try  further  modi- 
fications, although  doubtless  the  pyrophosphate  would 
answer  with  cadmium  as  well  as  with  zinc. 

Aluminium. — There  is  a  precipitate  with  either  alkali. 
These  precipitates  are  objedlionable  in  that  they  are 
difficult  to  filter  off,  and  the  prolonged  exposure  of  even 
dilute  cyanide  solutions  tends  to  give  high  results. 

The  difficulty,  and  a  similar  one  with  other  elements, 
may  be  overcome  in  several  ways : — 

I.  Fradlional  filtration ;  but  great  care  must  be  taken 
that  the  fraction  preserves  its  proportionate  volume 
throughout  the  succeeding  operations.  It  is  a  good  plan 
to  fradtionate  the  standard  similarly. 

II.  The  bulk  of  silver  nitrate  necessary  to  combine  with 
the  free  cyanide  may  be  added  before  filtration.  This 
precaution  may  also  be  taken  along  with  fradlional  filtra- 
tion. It  minimises  the  effedt  of  prolonged  exposure,  and 
may  be  safely  used  for  any  of  the  elements  (except 
chromium)  in  Table  I.,  without  fear  of  the  objedlionable 
features  accompanying  zinc  carbonate. 

III.  The  formation  of  precipitate  may  be  prevented. 
This  can  be  done  by  adding  tartaric  or  citric  acid,  soda 
pyrophosphate,  or  making  alkaline  with  soda  or  potassium 
hydrate.  The  two  acids  so  generally  employed  for  similar 
purposes  cannot  be  recommended  here.  So  small  a  quan- 
tity, about  I  grm.  of  tartaric  acid  (say),  as  sufiices  to  keep 
o'l  grm.  of  aluminium  in  solution  has  a  very  objedtiunal 
influence  on  the  titration.  Tha  colour  of  the  alkaline 
solution  is  less  deep  than  without  the  acid,  and  as  the 
proportion  of  aluminium  rises  the  later  colourations  on 
adding  cyanide  shade  off  into  pale  green,  and  are  of  little 
use  as  indicators ;  but  the  most  objedlionable  feature  is 
the  way  in  which  a  turbidity  once  formed  gradually  dis- 
appears, so  that  one  is  left  at  the  mercy  of  all  manner  of 
evil  suggestions,  however  conscientiously  the  work  may 


CHEMICAL  News,  I 
Dec.  17,  1897.     / 


Revision  of  the  A  totnic  Weight  of  Nickel. 


293 


be  done.  It  may  be  possible  to  wait  for  a  disappearing 
turbidity,  and  replace,  and  so  on,  until  all  errors  vanished, 
but  such  a  procedure  is  not  pradticable.  It  is  this  defeat, 
in  a  much  smaller  degree,  which  was  referred  to  under 
zinc  as  accompanying  pyrophosphate.  Citric  acid  be- 
haves similarly.  These  remarks  are  based  on  an  observance 
ot  soda  solutions  only. 

Seven  or  eight  of  the  tabulated  elements  give  no  preci- 
pitate when  soda  carbonate  is  replaced  by  soda  hydrate. 
The  behaviour  of  such  solutions  may  be  mentioned,  but 
the  procedure  can  be  recommended  only  within  narrow 
limits.  There  should  not  be  a  greater  excess  than  10  c.c. 
2  normal  NaHO  in  about  250  c.c.  of  solution,  else  the 
displacement  of  Cu  by  silver  takes  place;  and  the 
standard  should  be  worked  alongside  the  sample,  because 
the  turbidity  after  standing  awhile  becomes  brown. 
(To  be  continued). 


ZINC     IN    WATER. 
By    PERCY    A.    E    RICHARDS,    F.I.C. 

As  the  contamination  of  water  by  zinc  is  not  of  very 
frequent  occurrence,  perhaps  the  following  instance  may 
be  of  interest : — 

The  water  was  drawn  from  a  Berkshire  distrift,  and, 
after  being  stored  in  a  reservoir,  was  supplied  to  a  private 
residence  for  drinking  purposes,  by  a  galvanised  iron  pipe 
about  2  miles  in  length. 

When  first  received  the  sample  was  perfedly  bright  and 
clear,  but  when  left  exposed  to  the  air  for  about  an  hour 
it  developed  a  distindl  scum  on  the  surface. 

The  following  results  were  obtained  from  an  analysis  of 
the  water : — 


Free  ammonia      ..     .. 
Albumenoid  ammonia.. 

Nitrogen  as  nitrates    ..  0*035 

Chlorine  as  chlorides  ..  i'3 

Total  solid  constituents  14*35 

Zinc  bicarbonate  . .     ..  5*12 

Iron        ••     traces. 


0*0042  grain  per  gallon. 
0*0028     ,,  ,1 


grains 


The  presence  of  the  zinc  was  easily  detedted  in  the  un- 
concentrated  water  by  both  the  ammonium  sulphide  and 
potassium  ferrocyanide  tests.  Upon  boiling  the  water  a 
precipitation  of  carbonate  of  zinc  took  place. 

The  "total  hardness"  of  the  water  drawn  diredl  from 
the  reservoir  was  equivalent  to  4*5  grains  of  calcium  car- 
bonate, and  the  total  solid  constituents  were  only  10  grs. 
per  gallon. 


ESTIMATION    OF    CHLORINE,    BROMINE,    AND 

IODINE     IN     SALINE    WATERS. 

By  PERCY  A.  E.  RICHARDS,  F.I.C. 

Various  methods  have  been  suggested  at  dififerent  times 
for  the  separation  of  the  halogens  from  mixtures  of  the 
three.  For  instance,  Donath  has  propounded  a  process 
based  on  distillation  with  chromic  acid,  as  a  means  for 
the  separation  of  bromine. 

Again,  Vortmann  recommends  boiling  a  known  volume 
of  the  solution  containing  the  three  halogens,  in  the  first 
place  with  pure  manganese  dioxide  and  acetic  acid.  This 
causes  the  liberation  of  the  whole  of  the  iodine,  and  this 
can  then  be  boiled  off.  The  chloride  and  bromide  in  '.he 
residue  may  next  be  estimated  in  terms  of  decinormal  silver 
nitrate  solution,  when  the  difference  between  this  number 
and  the  equivalent  in  silver  nitrate  for  the  same  volume 
of  the  untreated  water  gives  the  amount  of  decinormal 
iodine  present. 

A  known  volume  of  the  water  is  next  boiled  with  per- 


oxide of  lead  and  acetic  acid,  and  the  bromine  and  iodine 
thus  liberated  boiled  off.  The  silver  nitrate  equivalent  of 
the  residue  is  determined  as  before,  and  the  bromine  cal- 
culated by  difference  between  this  number  and  the  previous 
determination. 

These  processes  giv.e  satisfadlory  results  so  long  as  one 
of  the  halogens  is  not  present  in  much  greater  amount 
than  either  of  the  other  two.  But  in  the  examination  of 
waters  it  is  afmost  invariably  the  case  that  the  amount  of 
chlorine  greatly  exceeds  that  of  both  bromine  and  iodine, 
sometimes  to  the  extent  of  1000  or  2000  to  i.  In  cases 
like  these,  the  estimation  of  iodine  and  bromine  by  differ- 
ence is  of  very  little  value.  I  had  occasion  recently  to 
examine  some  waters  of  this  charadler,  and  found  that 
the  following  methods  gave  very  good  and  concordant 
results  :— 

In  the  first  place,  the  total  halogen  equivalent  in  terms 
of  decinormal  silver  nitrate  solution  was  accurately  de- 
termined. The  iodine  present  was  then  estimated  by 
treating  250  or  500  c.c.  with  acetic  acid  and  hydrogen 
peroxide  for  about  half  an  hour,  and  extradting  with 
chloroform.  The  mixture  was  shaken  in  a  separating 
funnel,  with  successive  small  quantities  of  chloroform, 
and  these  washings  added  to  the  first  portion.  The 
solvent  was  then  well  washed  with  distilled  water  to  re- 
move any  peroxide  of  hydrogen,  and  was  then  titrated 
with  decinormal  sodium  thiosulphate  solution,  and  the 
amount  of  iodine  calculated.  This  process,  which  is  due 
to  Cook,  is  simple  and  accurate. 

The  bromine  was  next  estimated  by  shaking  the  iodine- 
free  liquid  left  in  the  separating  funnel,  with  chlorine 
water  and  chloroform,  avoiding  much  excess  of  the  former. 
The  solvent  was  drawn  off,  and  the  aqueous  solution 
shaken  several  times  with  small  quantities  of  chloroform, 
the  latter  being  added  to  the  first  portion.  Any  chlorine 
present  is  washed  out  of  the  chloroform  by  repeated 
agitation  with  distilled  water,  and  the  bromine  estimated 
by  adding  a  few  crystals  of  iodide  of  potasium  and 
titrating  with  thiosulphate  of  soda  solution. 

The  iodine  and  bromine  present  being  now  known,  the 
silver  nitrate  equivalents  can  be  calculated  andsubtradled 
from  the  total  halogen  equivalent,  and  from  this  result  the 
chlorine  present  is  deduced. 

This  process  enables  the  bromine  and  iodine  to  be  esti- 
mated direcStly  and  with  considerable  accuracy,  and  is 
therefore  specially  suited  to  the  examination  of  saline 
waters  where  the  quantities  present  are  relatively  small. 


A    REVISION    OF    THE    ATOMIC    WEIGHT    OF 

NICKEL.* 
First  Paper. — The  Analysis  op  Nickelous  Bromide. 

By  THEODORE  WILLIAM  RICHARDS 
and 
ALLERTON  SEWARD  CUSHMAN. 

(Continued  from  p.  286). 

Purification  of  Materials. 
Nickel, — Since  the  possibility  of  preparing  and  analysing 
pure  nickelous  bromide  had  now  been  proved,  the  next 
step  was  to  purify  all  the  materials  concerned  in  its  manu- 
fadture.  First  among  these  materials  comes  nickel,  which 
must  not  only  be  freed  from  all  known  impurities,  but 
must  also  be  so  treated  as  to  deted  and  eliminate  unknown 
ones.  With  this  latter  purpose  in  view,  our  material  was 
obtained  from  two  distindl  sources;  first,  the  "pure" 
nickel  of  commerce;  and,  secondly,  really  pure  nickel 
(containing  only  a  little  iron)   prepared   by   Dr.   Mond 

*  Contribution  from  the  Chemical  Laboratory  of  Harvard  College. 
From  the  Proceedings  of  the  American  Academy  a/Arts  and  Sciences, 
vol.  xxxiii.,  No.  7. 


^94 


kevision  of  the  A  tomic  Weight  of  Nickel. 


Chemical  Nbw&, 
Dec.  17, 1897. 


through  the  carbonic  oxide  process  and  kindly  presented 
by  Dr.  Wolcott  Gibbs. 

It  is  convenient  to  consider  first  our  treatment  of 
the  commercial  nickel.  In  proceeding  with  the  further 
purification  of  this  sample,  our  first  step  was  to  remove 
the  metals  of  the  copper  and  tin  groups.  The  simple 
treatment  with  hydric  sulphide  has  generally  been  con- 
sidered sufficient  to  insure  the  separation  of  the  metals  of 
these  groups,  in  spite  of  the  fadt  that  many  of  the  sulph- 
ides when  present  in  small  quantities  often  assume  a  col- 
loidal condition  in  which  they  cannot  be  separated  by  fil- 
tration, In  our  case  this  difficulty  was  avoided  by  regu- 
lating the  acidity  of  the  solution  so  that  a  certain  amount 
of  black  nickelous  sulphide  was  precipitated,  which 
effedlually  "swept"  this  liquid,  coagulating  small  quanti- 
ties of  foreign  sulphides.  After  filtration  the  liquid  was 
boiled  to  drive  off  the  hydric  sulphide,  oxidised  with  a  few 
drops  of  nitric  acid,  made  alkaline  with  ammonia,  and 
filtered.  The  precipitation  of  the  sulphide  was  now  con- 
tinued by  the  passage  of  a  little  washed  hydric  sulphide. 
This  first  comparatively  small  amount  of  sulphide  was 
filtered  out  and  discarded.  The  remaining  nickel  was 
then  as  nearly  as  possible  completely  precipitated  in  the 
form  of  sulphide.  After  the  precipitate  had  been  allowed 
to  settle  in  a  closed  flask  over  night,  the  liquid  was 
decanted,  and  the  precipitate  was  washed  by  decantation 
many  times  with  boiling  water  until  neutral.  Cold  dilute 
hydrochloric  acid  was  now  added,  and  the  precipitate  was 
digested  for  several  days.  Since  the  colour  of  the  super- 
natant liquid  showed  that  a  slight  amount  of  even  the 
comparatively  insoluble  nickel  sulphide  had  gone  into 
solution,  the  assumption  was  not  unreasonable  that  nearly, 
if  not  quite,  all  of  the  more  soluble  sulphides  must  have 
been  removed.  The  black  precipitate  was  now  repeatedly 
washed  with  hot  water  until  the  washings  were  quite 
neutral ;  it  was  next  dissolved  in  strong  hot  hydrochloric 
acid,  and,  after  the  separated  sulphur  had  been  removed, 
the  solution  was  evaporated  to  dryness,  and  the  residue 
was  taken  up  with  water.  The  material  was  now  con- 
sidered fairly  free  from  its  usual  impurities,  with  the  single 
exception  of  cobalt. 

In  commenting  on  the  work  of  an  early  experimenter 
upon  the  atomic  weights  of  nickel  and  cobalt,  Clarke  has 
objeded  that  "  his  results  are  entitled  to  no  especial 
weight  at  present,  since  it  cannot  be  certain  from  any 
evidence  recorded  that  the  oxide  of  either  metal  was  abso- 
lutely free  from  traces  of  the  other  "  ("  Re-calculation," 
1897,  p.  291).  Since  the  two  metals  have  atomic  weights 
only  differing  at  the  outside  by  half  a  unit,  "  traces  ''  of 
one  in  any  preparation  ol  the  other  metal  could  not  alone 
furnish  a  reason  for  invalidating  the  results.  Neverthe- 
less, for  our  purpose  it  seemed  desirable  to  prepare  nickel 
as  nearly  free  from  cobalt  as  possible.  In  order  to  attain 
this  end  with  any  degree  of  certainty,  it  is  obvious  that 
a  qualitative  test  must  be  found  that  should  show  with 
sufficient  accuracy  the  presence  or  absence  of  cobalt. 
Winkler  (Zeit.  Anal.  Chem.,  vi.,  20)  has  recommended  a 
test  for  which  he  claimed  greater  accuracy  than  the  better 
known  method  with  potassium  nitrite.  The  moderately 
dilute  solution  of  nickel  is  treated  with  ammonia  until  a 
clear  blue  colour  is  obtained,  and  then  one  or  two  drops 
of  potassic  permanganate  are  added.  If  no  cobalt  is  pre- 
sent, the  blue  solution  of  nickel  takes  on  a  purple  tinge  ; 
whereas  cobalt,  if  present,  reduces  the  permanganate. 
Winkler  does  not  state  the  dilution  of  the  permanganate 
solution,  or  how  much  should  be  added,  although  mani- 
festly the  degree  of  refinement  of  the  test  depends  on 
these  points.  The  permanganate  solution  which  worked 
well  with  us  contained  i  grm.  of  the  salt  in  a  litre.  To 
the  dilute  solution  of  nickel  to  be  tested,  contained  in  a 
colour-comparison  apparatus,  enough  ammonia  is  added 
to  render  the  solution  a  light  sky-blue,  and  then  one- 
tenth  of  a  c.c.  of  the  permanganate  is  dropped  in.  Under 
these  conditions,  the  mixture  appears  decidedly  purplish 
in  hue,  if  cobalt  is  absent.  Of  course,  the  test  is  of  value 
only  in  the  absence  of  any  foreign  substances  having  either 


a  reducing  or  an  oxidising  adlion  on  permanganate.  We 
have  found  it  possible  by  this  method  to  detedl  one  part 
of  cobalt  in  2500  parts  of  nickel,  an  amount  of  impurity 
which  could  cause  a  final  error  in  the  atomic  weight  of 
only  I  part  in  500,000. 

Anthon's  process  (see  Dammer,  Anorg.  Chem,,  iii.,490) 
for  eliminating  cobalt  was  adopted  for  the  purification  of 
our  sample.  The  nickel  was  twice  fradtionally  precipitated 
as  hydroxide  by  means  of  pure  sodic  hydroxide,  the  mix- 
ture being  thoroughly  boiled.  As  far  as  our  test  could 
show  it,  all  the  cobalt  remained  in  the  filtrate,  the  last 
precipitate  being  contaminated  only  with  a  small  amount 
of  alkali. 

When  ammonia  is  added  to  a  solution  of  nickelous 
bromide,  a  beautiful  violet  crystalline  compound  is  formed, 
having  the  formula  NiBr2.6NH3,  according  to  our  ana- 
lysis as  well  as  those  of  Rammelsberg  {Pogg,  Ann.,  Iv., 
243).  Since  this  compound  is  charadleristic  of  nickel, 
and  similar  compounds  are  not  formed  by  cobalt  or  most 
other  metals  under  similar  circumstances,  and  since  it  is 
soluble  in  strong  hot  ammonia  water,  but  almost  insoluble 
in  cold  ammonia,  it  affords  a  very  convenient  and  effeiflual 
means  of  purifying  nickel  preparations.  Our  purified 
oxide  was  hence  dissolved  in  pure  hydrobromic  acid, 
ammonia  was  added  in  excess,  and  the  mixture  contained 
in  a  platinum  flask,  was  cooled  to  zero.  The  beautiful 
purple  precipitate  was  colledled  upon  pure  filter-paper  and 
was  washed  v/ith  strong  ammonia.  All  the  material  used 
in  the  analyses  was  passed  through  this  treatment  at 
least  once,  although  the  various  samples  were  subse- 
quently subjedled  to  different  methods  of  further  treatment 
which  will  be  described  in  each  case. 

The  violet  compound  made  from  our  first  sample  of 
purified  nickel  was  treated  with  an  excess  of  water  and 
boiled  in  a  platinum  dish,  a  proceeding  which  completely 
precipitated  the  nickel  as  hydroxide.  The  greenish  mass 
was  thoroughly  washed,  and  was  then  dissolved  in  hydro- 
bromic acid.  The  nickelous  bromide  thus  obtained  was 
dried  in  a  vacuum  desiccator  over  dry  soda ;  but  even 
after  this  treatment  it  was  found  to  have  retained  con- 
siderable quantities  of  water,  an  impurity  which  greatly 
increased  the  difficulties  of  sublimation.  Hence  this 
sample,  numbered  I.,  was  used  only  for  two  preliminary 
analyses. 

Another  portion  of  this  same  sample  of  the  violet  com- 
pound was  re-crystallised  several  times  in  succession  by 
cooling  its  hot  ammoniacal  solution.  The  resulting 
magnificent  crystals  were  dissolved  in  water  and  the  solu- 
tion was  boiled  to  drive  off  the  ammonia.  The  precipi- 
tation being  thus  accomplished,  the  basic  hydroxide  was 
colleiSed,  carefully  washed,  dried,  and  ignited  over  an 
alcohol  flame  in  a  porcelain  vessel.  The  resulting  nickel 
oxide  was  reduced  to  the  metal  by  igniting  this  material, 
held  by  a  porcelain  boat  in  a  combustion-tube  through 
which  a  current  of  pure  dry  ammonia  gas  was  passing. 
The  spongy  nickel  thus  produced  was  changed  to  bromide 
and  sublimed  in  the  manner  already  described.  The  pure 
substance  thus  prepared  is  designated  below  as  Number 
II.  ;  it  also  served  for  two  of  the  earlier  analyses. 

The  further  purification  of  the  sample  of  nickel  ob- 
tained by  the  process  of  Mond,  Langer,  and  Quincke,  at 
first  proceeded  exadly  in  the  steps  just  described  ;  except 
that  no  attempt  was  made  to  remove  cobalt,  since  none 
was  present.  After  it  had  reached  the  stage  of  treatment 
represented  by  the  last  hydroxide  obtained  above,  the 
material  was  converted  into  the  sulphate  and  subjedted  to 
eledlrolysis  out  of  an  ammoniacal  solution  in  a  platinum 
dish.  The  objeft  of  this  procedure  was,  of  course,  to  free 
the  nickel  still  more  effedually  from  the  alkalis,  silica, 
and  many  other  impurities  which  are  not  precipitated  on 
the  cathode.  The  bright  heavy  deposit  of  pure  nickel  was 
dissolved,  with  a  great  deal  of  difficulty,  in  re-distilled 
strong  nitric  acid;  and  the  excess  of  acid  was  driven  off 
by  evaporation.  Ammonia  and  a  large  excess  of  pure 
water  were  now  added,  and  the  solution  was  boiled  until 
the  basic  hydroxide  was  completely  precipitated.     This 


Chemical  Mewis, 
Dec.  17, 1897.      / 

was  subsequently  changed  to  metallic  nickel  and  then 
into  the  sublimed  bromide,  in  the  manner  already 
described,  and  the  resulting  material,  labelled  III.,  served 
for  a  large  number  of  analyses.  A  small  portion  of  it, 
that  used  for  Experiment  8,  was  re-sublimed. 

The  sample  of  material  used  for  the  final  analysis  was 
even  more  carefully  purified  than  this,  however.  A  quan- 
tity of  the  pure  nickelous  oxide  of  about  the  grade  of 
purity  of  Sample  III.,  coming  originally  from  the  Mond 
nickel,  was  dissolved  in  sulphuric  acid,  and  the  solution 
was  made  alkaline  by  passing  in  pure  ammonia  gas,  in  a 
platinum  dish.  When  most  of  the  nickel  had  been 
deposited  eledtrolytically  from  this  solution,  the  portion 
remaining  in  the  eledtrolyte  was  thrown  away.  The  bright 
coating  of  nickel  was  washed,  pure  dilute  sulphuric  acid 


kevt^ion  of  the  A  tomic  Weight  of  Nickel. 


^95 


Thus,  while  all  of  our  samples  of  nickelous  bromide  ana- 
lysed had  been  sublimed,  the  several  samples  had  received 
previous  to  sublimation  very  varying  treatment.  The  fourth 
had  been  put  through  a  process  of  purification  far  more 
searching  than  the  first,  which  had  merely  been  freed  from 
the  ordinary  known  impurities.  Hence  the  essential 
identity  of  the  results  obtained  from  these  several  samples 
is  very  striking. 

Purification  of  other  Materials. — Silver  was  purified 
exadtly  in  the  manrier  described  by  Richards  and  Parker 
{Proc.  Amer.  Acad.,  xxxii.,  62)  in  a  recent  paper  upon  the 
atomic  weight  of  magnesium.  The  eleftrolytic  crystals 
were  finally  fused  upon  a  boat  of  pure  lime  in  a  vacuum. 
For  further  details  the  above-mentioned  paper  should  be 
consulted. 


Fig.  2.— Bottling  Apparatus,  Horizontal  Section. 

A,  Weighing  bottle,     b,  Stopper  of  bottle,    c  c,  Hard  glass  tube.    D,  Platinum  boat  centaining  nickelous  bromide. 


Fig.  3.— Apparatus  for  Igniting  Nickelous  Bromide  in  any  desired  Mixture  of  Gases. 

The  use  of  rubber  was  confined  to  the  first  part  of  this  train,  where  it  could  do  no  hartr.  (a  b  c  d  e  f  and  A  m  n  o  p). 


was  put  into  the  dish,  and  with  reversed  poles  a  strong  cur- 
rent was  sent  through  the  solution  until  nearly,  but  not  quite, 
all  of  the  nickel  was  dissolved.  The  solution  was  then 
decanted  into  another  dish,  ammonia  was  passed  in  until 
the  precipitate  formed  had  re-dissolved,  the  poles  were 
again  reversed,  and  then  nickel  was  once  more  almost  all 
deposited.  This  cycle  of  operations,  which  gives  an  ex- 
cellent method  of  fradtionation,  was  repeated  three  times. 
The  final  deposit  of  nickel  was  dissolved  by  filling,  the 
platinum  dish  with  pure  dilute  nitric  acid  and  reversing 
the  poles.  Only  one  who  has  tried  dissolving  a  deposit  of 
nickel  on  a  platinum  dish,  even  in  strong  nitric  acid,  can 
appreciate  the  ease,  cleanliness,  and  convenience  of  this 
method  of  procedure.  The  solution  of  nickel  nitrate  thus 
prepared  was  concentrated  by  evaporation,  and  ammonia 
was  passed  in  until  a  mass  of  crystals  of  the  blue  ammor.io- 
nickel  nitrate  was  formed.  After  the  mother  liquor  had 
been  poured  off,  the  crystals  were  washed  with  pure  am- 
monia water,  and  were  finally  boiled  in  an  excess  of  pure 
water  in  the  same  platinum  dish.  The  resulting  basic  hy- 
droxide was  then  changed  to  spongy  nickel  and  nickelous 
bromide  in  the  usual  fashion,  bearing  the  title  No.  IV. 


With  the  co-operation  of  Mr.  Baxter,  bromine  was 
purified  in  a  preliminary  fashion  by  solution  in  strong 
aqueous  calcic  bromide,  and  a  subsequent  separation. 
Carefully  washed  red  phosphorus  was  used  to  convert  the 
bromine  thus  obtained,  after  it  had  been  several  times  re- 
distilled, into  hydrobromic  acid,  and  the  hydrobromic  acid 
was  freed  from  iodine  and  organic  matter  by  several  frac- 
tional distillations  with  bromine  water.  From  this  pure 
hydrobromic  acid,  bromine  was  obtained  by  means  of 
manganese  dioxide  free  from  chlorine.  2*10289  grms.  (in 
vacuum)  of  silver  yielded  3*66o66  grms.  (in  vacuum)  of 
argentic  bromide  on  combination  with  this  bromine, — -a 
ratio  of  57 '445  :  ioo"oo.  Mr.  Baxter  found  57*444  in  a 
similar  experiment,  while  Stas's  value  was  57"445  :  hence 
the  purity  of  our  bromine  and  silver  was  proved. 

Sodic  hydroxide  was  freed  from  most  metallic  impurities 
(iron,  &c.)  by  eledtrolysis.  Ammonia  was  re-distilied  in 
platinum  vessels,  as  were  also  nitric  and  hydrochloric 
acids.  Sulphuric  acid  was  distilled  in  glass,  alkalis  being 
a  less  dangerous  impurity  than  platinum  in  the  instances 
where  it  was  used.    Water  was  purified  by  distillation, 


^96 


Decomposition  Of  Camphoric  A  cid. 


I  Crbuical  NBwk, 
I     Dec.  17,  18Q7. 


first  from  alkaline  permanganate  solution,  and  then  with 
a  trace  of  acid  potassic  sulphate. 

In  processes  where  the  presence  of  bromine  rendered 
the  use  of  platinum  impossible,  Jena  glass,  or  at  high 
temperatures  Berlin  porcelain,  was  used.  For  some  of 
the  platinum  and  other  apparatus  we  are  indebted  to  the 
Cj'rus  M.  Warren  Fund  for  chemical  research  in  Harvard 
University. 

The  Method  of  Analysis. 

Turning  now  to  the  method  of  analysing  the  carefully 
prepared  nickelous  bromide,  it  is  obvious  that  the  first 
point  to  be  considered  is  the  accurate  determination  of 
the  weight  of  the  salt  to  be  analysed.  This  process  was 
efre(5led  by  means  of  apparatus  similar  to  that  devised  for 
the  drying  and  weighing  of  magnesic  chloride,  and 
described  in  a  recent  paper  by  Mr.  H.  G.  Parker  and  one 
of  us  (Proc.  Amer.  Acad.,  xxxii.,  ^S),  upon  the  atomic 
weight  of  magnesium.  In  this  apparatus,  construdted 
wholly  of  glass  by  Mr.  Baxter,  the  bromide  under  con- 
sideration, contained  in  a  platinum  boat,  was  ignited  at 
about  400°  in  a  stream  of  mixed  nitrogen  and  hydrobromic 
acid  until  constant  in  weight.  It  was  then  allowed  to 
cool  in  a  stream  of  pure  dry  nitrogen,  and  when  cool  it 
was  pushed  in  pure  dry  air  into  its  weighing  bottle,  which 
was  immediately  closed  by  a  mechanical  device.  In  this 
fashion  it  is  possible  to  dry  and  weigh  accurately  the  most 
hygroscopic  of  substances,  and  repeated  ignitions  of  the 
same  specimen  have  shown  that  perfedt  constancy  in 
weight  may  thus  be  obtained.  It  is  hard  to  believe  that 
any  water  is  retained  by  nickelous  bromide  at  400°,  and 
certainly  none  could  be  absorbed  during  the  cooling,  for 
the  whole  apparatus  was  shut  off  from  the  outside  air, 
and  all  the  gases  admitted  were  first  passed  through 
phosphoric  oxide.* 

The  bromide  in  question  was  then  weighed  by  substi- 
tution, using  as  the  tare  to  be  substituted  a  weighing 
bottle  precisely  like  the  one  containing  the  platinum  boat 
and  substance.  In  this  way  alone  can  the  weight  of  a 
large  bottle  be  determined  within  the  fradtion  of  a  tenth 
of  a  m.grm,  The  balance  has  already  been  described  in 
detail  {Proc.  Amer.  Acad.,  xxvi.,  242) ;  the  weights  were 
of  course  compared  and  standardised  with  great  care,  and 
were  used  for  no  other  work  during  the  progress  of  this. 

Having  been  weighed  with  accuracy,  the  nickelous 
bromide  was  dissolved  in  pure  warm  water  in  a  ilask,  and 
from  this  was  transferred  to  the  large  beaker  flask  in  which 
the  precipitation  was  to  take  place.  The  platinum  boat 
in  which  the  salt  had  been  treated  remained  invariable  in 
weight,  showing  that  it  had  not  been  attacked  by  hydro- 
bromic acid  at  a  high  temperature. 

As  has  been  said  already,  the  salt  used  in  the  prelimi- 
nary series  was  contaminated  with  a  small  amount  of 
nickelous  oxide,  which  was  filtered  off  and  weighed. 
The  amount  of  this  impurity  is  given  simply  to  show 
that  the  slight  irregularity  of  the  results  was  not  dependent 
upon  the  adulteration  ;  the  weights  of  nickelous  bromide 
given  are  those  left  after  the  subtraction  of  the  weight  of 
the  oxide.  All  the  bromine  contained  in  the  solution  was 
precipitated  in  these  seven  analyses  by  means  of  an 
excess  of  argentic  nitrate,  and  the  argentic  bromide  was 
collected  and  weighed  with  the  usual  precautions. 

(To  be  continued). 


Estimation  of  Small  Quantities  01  Metbyl-alcohol, 
Formic  Aldehyd,  and  B'ormic  Acidt— M.  Nicloux. — 
The  author  has  extended  his  method  for  the  estimation  of 
alcohol  by  the  redudion  of  bichromate  of  potash  in  the 
presence  of  sulphuric  acid,  to  the  estimation  of  methylic 
alcohol,  formic  aldehyd,  and  formic  acid. — Bull,  Soc.  Chim. 
de  Paris,  Series  3,  xvii.-xviii.,  No.  16-17. 

*  A  detailed  description  of  this  apparatus  will  be  given  in  a  future 
paper,  upon  Cobalt. 


PROCEEDINGS    OF    SOCIETIES. 

CHEMICAL  SOCIETY. 
Ordinary  Meeting,  November  iSth,  1897. 

Professor  Dewar,  F.R.S.,  President,  in  the  Chair. 

Messrs.  W.  J,  Elliott,  H.  S.  Elworthy,  F.  F.  de  Morgan, 
Frank  Moul,  A.  Harden,  and  Charles  E.  Brown  were 
formally  admitted  Fellows  of  the  Society. 

Certificates  were  read  for  the  first  time  in  favour  of 
Messrs.  Cecil  Joslin  Brooks,  24,  Wood  Street,  Woolwich  ; 
Charles  Henry  Burge,  Iddesleigh  Crescent  Road,  Kingston 
Hill,  S.W. ;  M.  J.  Cannon.  loi.  The  Chase,  Ciapham 
Common,  S.W. ;  William  Ransom  Cooper,  M.A.,  B.Sc, 
87,  Upper  Tulse  Hill,  S.W. ;  Frederick  Robertson  Dodd, 
I,  Wesley  Street,  Liverpool;  Jules  Fuerst,  23,  Marlborough 
Road,  N.W. ;  James  Brown  Reid,  6,  Southfield  Terrace, 
Skepton  ;  Harold  Charles  Sayer,  Devon  Villa,  Summer- 
hill  Road,  Dartford. 

The  President  announced  that  he  had  received  a  letter 
from  Sir  Fleetwood  Edwards  stating  that  he  had  been 
commanded  by  the  Queen  to  forward  to  him  a  Medal  in 
commemoration  of  the  6oth  Anniversary  of  Her  Majesty's 
reign. 

Of  the  following  papers  those  marked  *  were  read  : — 

*ii8.  "On  the  Decomposition  of  Camphoric  Acid  by 
Fusion  with  Potash  or  Soda."  By  Arthur  W.  Crossley 
and  W.  H.  Perkin,  jun. 

The  authors  find  that  by  the  adion  of  fused  potash  on 
camphoric  acid  a  very  complicated  mixture  of  acids  is 
obtained.  The  volatile  portion  consists  of  acetic,  pro- 
pionic, isobutyric,  isovaleric,  and  methylisopropylacetic 
acids,  together  with  acids  of  the  formulae  C6H13CO2H, 
C7H15CO2H,  and  C8H17CO2H,  of  which  the  constitution 
is  doubtful.  The  non-volatile  acids  consist  of  pimelic 
(isopropylsuccinic)  acid  and  a  new  substance,  dihydro- 
camphoric  acid. 

Dihydrocamphoric  acid,  C10H18O4,  crystallises  in  nodu- 
lar masses  melting  at  105 — 106°,  and  on  oxidation  with 
dilute  nitric  acid  yields  succinic  acid,  oxalic  acid,  and  an 
acid  of  the  formula  C8H14O4,  which  is  in  all  probability 
the  a;3^-trimethylglutaric  acid  described  by  Balbiano. 

On  treatment  with  acetic  anhydride,  dihydrocamphoric 
acid  is  converted  into  its  anhydride,  which,  when  heated 
to  boiling,  decomposes  with  elimination  of  carbon  dioxide 
and  formation  of  a  cyclic  ketone  of  the  formula  CgHisO. 
Dihydrocamphoketone  is  a  liquid  boiling  at  180 — 181°  and 
smelling  strongly  of  peppermint.  It  forms  a  liquid 
ketoxime  and  a  semicarbazone  melting  at  202 — 203°. 

The  results  obtained  on  fusing  camphoric  acid  with 
caustic  soda  differ  markedly  from  the  above.  The  lower 
volatile  fatty  acids  appear  to  be  the  same  as  those  ob- 
tained from  caustic  potash,  but  there  is  also  present  an 
unsaturated  acid  of  the  formula  CgHijCOaH. 

The  acids  not  volatile  in  steam  consist  of  large  quan- 
tities of  pimelic  acid  and  some  unchanged  camphoric 
acid,  together  with  two  new  acids,  pseudocamphoric  acid, 
C16H16O4,  and  an  acid  of  the  formula  CgHj604,  boiling  at 
254 — 257°  at  50  m.m. 

Pseudocamphoric  acid  crystallises  from  water  in  colour- 
less six-sided  plates  with  bevelled  edges,  usually  grouped 
together  in  the  form  of  stars,  and  melts  at  119—120°.  It 
forms  a  crystalline  anhydride  melting  at  52 — 53°  and  an 
anilic  acid  melting  at  208".  A  further  difference  from  its 
isomeride  cf-camphoric  acid  is  that  when  treated  with  sul- 
phuric acid  it  does  not  evolve  carbon  monoxide  forming 
a  sulphonic  acid. 

The  authors  explain  the  results  of  the  adion  of  fused 
alkalis  on  camphoric  acid  and  deduce  constitutional  for- 
mulae for  the  various  compounds  obtained  on  the  assump- 
tion that  camphoric  acid  is  represented  by  the  formula^- 


C'^KMICAL  hiBWB, 

Dec.  17,  1807. 


}       Action  of  Magnesium  on  Cupric  Sulphate  Solution. 


297 


CH2 

'JJVC     CHCOaH 
Me— C    CH2 
CO2H 

•119.  '^Experiments  on  the  Synthesis  of  Camphoric 
Acid,"     By  W.  H.  Bentley  and  W.  H.  Perkin,  jun. 

The  authors  have  attempted  to  prepare  an  acid  of  the 
constitution  suggested  {Proc,  1896,  xii.,  i8g)  as  a  probable 
formula  for  camphoric  acid  (see  preceding  abstradl).  They 
prepared  isobutylmethylhydroxyglutaric  acid, — 

Me2-CH*-CH2-CH(C02H)-CH2-C(C0aH)Me-0H% 
but  did  not  succeed  in  eliminating  water  in  the  direction 
desired  (at  the  points  *  *),  the  produ(ft  in  most  of  the  ex- 
periments being  the  ladone-acid — 

.    Me2-CH'CH2-CH-CH2-C'Me-C02H 


CO- 


-0 


or  one  of  its  derivatives. 

The  following  substances  were  prepared  during  the 
course  of  the  work. 

Ethylic  bromisobutylacetate, — 

(Me2)-CH-CH2-CHBrC02Et, 
an  oil  boiling  at  100 — 103°  (17  m.m.). 

Ethylic  acetylisobutylsuccinate, — 

Mea'CH-CH/CHCOaEt 

I 
Me-CO-CHCOjEt 

prepared  by  the  adlion  of  ethylic  bromisobutylacetate  on 
ethylic  sodioacetoacetate.  It  is  a  colourless  oil  boiling  at 
160°  (25  m.m.),  and  when  hydrolysed  with  dilute  hydro- 
chloric acid  or  sulphuric  acid  yields  iiobutylsuccinic  acid, 
Me2CH-CH2-CH(C02H)-CH2-C02H,  m.  p.  109°.  When 
hydrolysed  with  concentrated  hydrochloric  acid,  however, 
isobutyllevulinic  acid, — 

Mea-CH-CH2CH(C02H)-CH3C0Me, 

is  formed.  This  is  a  colourless  oil  boiling  at  iqo°  (30 
m.m.),  and  yielding  a  semi-carbazone  melting  at  192  : 
bromine,  in  the  presence  of  potash,  oxidises  it  to  isobutyl- 
succinic  acid. 

Isobutyllevulinic  acid  readily  unites  with  hydrogen 
Cyanide,  forming  isobutylhydroxycyanovaleric  acid, 
Me'C(OH)(CN)-CH2-CH(C4H9)-C02H,  which  crystal- 
lises with  1H2O  in  needles  melting  at  95 — 96°.  This  acid 
on  distillation  yields  the  corresponding  lactone, — 


Me"C(CN)-CH2-CH'C4Hg 

I  I  ,  m.  p. 

O CO 


53° 


When  an  alcoholic  solution  of  the  hydroxy-cyano  acid 
is  saturated  with  hydrogen  chloride,  it  is  hydrolysed  and 
converted  into  the  ethereal  salt  of  isobutylmethylhydroxy- 
glutaric acid,  Me-C(0H)(C02Et)-CH2'CH(C4Hg)-C02Et. 
On  distillation,  this  loses  alcohol,  forming  the  ethereal 
salt  of  the  lactone  of  isobutylmethylhydroxyglutaric 
acid, — 

Me'C(C02Et)-CH2-CH(C4H9) 


O. 


■CO 


which  is  an  oil  boiling  at  168"  (17  m.m.).  This  on  hydro- 
lysis with  alcoholic  potash  is  converted  into  isobutyl- 
methylhydroxyglutaric acid, — 

Me-C(OH)(C02H)-CH2CH(C4H9)'C02H, 
a   crystalline   acid  melting   at   134°  with   elimination  of 
water  and  formation  of  the  lactone, — 
Me-C(C02H)'CH2-CH'C4Hg 

1  I  (m.  p.  80'). 

O CO 


•120.  "Synthesis  of  an  Isomeride  of  Camphoronic 
Acid."     By  S.  B.  Schryver,  Ph.D. 

The  compound — 

C02H-CH(Me)CH2-C(CH2-C02H)(Me)-C02H 
was  synthesised  by  adting  on  methylacrylic  ester, 
CH2:C(Me)C02Et,  with  sodiomethylmalonic  ester.  The 
addition  produdl  thus  obtained,  having  the  formula 
(C02Et)2C(Me)-CH2-CNa(Me)C02Et,  instead  of  being 
isolated,  was  aded  on  by  iodacetic  ester.  Among  the 
resulting  produces  was  the  compound — 

(C02Et)2C(Me)CH2-C(CH2-C02Et)(Me)'C02Et, 
which  on  hydrolysis  gave  an  acid  of  the  required  formula. 
This  was  isolated  by  means  of  its  lead  salt,  which  is  in- 
soluble in  acetic  acid,  in  the  form  of  a  syrup,  and  this  on 
treatment  with  nitric  acid  gave  a  crystalline  oxy-acid 
having  the  formula  C9H14O7.  It  is,  therefore,  an  isomeride 
of  camphoronic  acid. 

Discussion. 

Dr.  Kipping  said  that  it  was  very  difficult  to  criticise 
papers  which,  like  those  read  by  Dr.  Crossley,  contained 
so  many  new  and  important  fadts  relating  to  substances 
of  somewhat  complex  constitution.  It  seemed  to  him, 
however,  that  all  the  results  obtained  by  Dr.  Crossley  and 
Dr.  Perkin  in  their  study  of  the  substances  produced  by 
fusing  camphoric  acid  with  potash,  could  be  explained  on 
the  basis  of  Bredt's  formula ;  such  an  opinion  might  of 
course  be  altered  after  carefully  examining  the  details  of 
the  work  as  laid  out  in  the  published  papers. 

Dr.  Forster  pointed  out  that  the  formula  for  camphoric 
acid  employed  by  Drs.  Crossley  and  Perkin  appears  to  in- 
volve the  expression  of  the  constitution  of  camphor  by  one 
of  the  formulae — 


CHa"  '  "CH       CH2 

i 
CH2 

I 
CMe3— CMe— CO 


CMea— CMe—CHa 

I 
CH2 

CH2 — 'CH — CO 


The  behaviour  of  camphoroxime  on  dehydration,  and  the 
isomerism  of  two  series  of  campholenic  derivatives,  seem 
to  render  the  second  expression  the  more  probable  of  the 
two,  but  before  either  could  be  accepted,  an  explanation 
must  be  furnished  of  the  changes  involved  in  the  produc- 
tion of  such  compounds  as  cymene  and  carvacrol  from 
camphor — changes  which,  it  must  be  remembered,  are 
readily  explained  by  Bredt's  formula. 
The  produdlion  of  the  acid, — 

CHMei'CH2-CH2-CH2-CHMe'C02-H, 
obtained  by  the  authors  by  fusing  camphoric  acid  with 
alkali,  harmonises  with  the  new  camphoric  acid  formula* 
but  it  must  not  be  overlooked  that  Bredt's  formula  for 
camphoric  acid  affords  an  equally  plausible  explanation. 

Dr.  Crossley,  in  reply,  said  that  the  main  evidence 
for  accepting  the  formula  proposed  by  Professor  Perkin 
was  embodied  in  his  paper  on  sulphocamphylic  acid, 
which  had  not  yet  been  published  in  detail.  Whilst  the 
produdtion  of  most  of  the  compounds  described  by 
Professor  Perkin  and  himself  admit  of  explanation  by 
Bredt's  formula,  it  does  not  account  for  the  formation  of 
aajSjS-tetramethyladipic  (dihydrocamphoric)  acid. 

*i2r.  "  The  Action  of  Magnesium  on  Cupric  Sulphate 
Solution."  By  Frank  Clowes,  D.Sc,  and  R.  M.  Caven 
B.Sc. 

The  authors  have  examined  the  adlion  of  magnesium  on 
solutions  of  cupric  sulphate  of  different  strengths,  both  at 
atmospheric  temperature  and  at  a  temperature  near  their 
boiling-point.  They  find  that  the  evolution  of  hydrogeti 
which  always  takes  place  is  accompanied  by  the  precipi- 
tation  of  a  mixtui'e  of  cuprous  oxide  and  metallic  copper 
in  proportions  which  vary  with  the  conditions  of  the  ex- 
periment. 

When  a  dilute  solution  of  cupric  sulphate  is  employed, 
the  aboveoinentioned  produdts   are  accompanied  by  a 


Sg^ 


A  cHon  oj  Magnesium  on  Cupric  Sulphate  Solution.        { 


Chbmical  Nswb 
Dec.  17, 1897. 


quantity  of  a  green  substance,  which  consists  of  a  mixture 
of  basic  hydrated  sulphates  of  copper  and  magnesium. 
This  substance  was  observed  to  form  when  a  saturated 
solution  of  cupric  sulphate  was  employed,  but  it  was  de- 
composed again  before  the  readtion  was  completed. 

The  time  of  the  readtion  varies  from  ten  minutes  in  the 
case  of  a  hot  strong  solution  of  cupric  sulphate  to  several 
days,  or  even  a  week,  when  a  dilute  solution  is  employed 
at  atmospheric  temperature. 

The  quantities  of  the  three  reduftion  producfts,  cuprous 
oxide,  copper,  and  hydrogen,  were  determined  under 
various  conditions.  A  volumetric  process  depending  upon 
the  use  of  potassium  permanganate  was  employed  for  the 
estimation  of  the  cuprous  compound  when  it  occurred 
together  with  the  basic  sulphate  of  copper  and  magnesium 
before  mentioned. 

The  authors  found  in  each  case  that  they  investigated 
that  the  sum  of  the  magnesium  equivalents  of  the  cuprous 
oxide,  copper,  and  hydrogen  obtained  agrees  very  closely 
with  the  amount  of  magnesium  employed  in  the  experi- 
ment. The  magnesium  is  therefore  proved  to  have  dis- 
placed from  the  solution  of  cupric  sulphate,  substances 
which  are  chemically  equivalent  to  it,  though  only  a  small 
and  variable  proportion  of  these  substances  consists  of 
metallic  copper.  The  authors  have  shown  that  the 
nature  of  the  readtion  is  not  influenced  by  the  presence 
of  slight  impurities  in  the  cupric  sulphate  employed  by 
carrying  out  similar  experiments  with  a  specimen  of  the 
salt  obtained  by  six  successive  re-crystallisations  of  a 
sample  which  was  originally  almost  pure.  Pickering's 
observation  of  the  formation  of  a  basic  sulphate  of  copper 
by  the  decomposition  of  a  solution  of  cupric  sulphate  by 
boiling,  has  been  incidentally  confirmed,  but  the  formula 
which  the  authors  attribute  to  this  compound  is 
4CuS04,7Cu(OH)2,H20. 

Note — 24<A  November. — The  authors  have  now  referred 
to  the  paper  by  Commaille  (C.  i?.,  i865,  Ixiii.,  556),  and 
they  find  that  an  equation  is  given  which  is  supposed  to 
represent  the  readtion  between  magnesium  and  cupric  sul- 
phate solution.  This  equation,  when  it  is  put  into 
modern  form  and  corredted  for  an  obvious  error,  reads  as 
follows : — 

6CuS04-f5Mg+3H20  = 

= 5  Mgso4-i- + (aCucsOg) + CU2O  -^  cu  -1-3H2. 

No  details  are  given  as  to  the  temperature  or  the 
strength  of  the  cupric  solution  which  adted  on  the  mag- 
nesium, nor  are  the  analytical  data  stated  upon  which  the 
above  equation  is  founded.  It  will  be  noticed  that  the 
formation  of  basic  magnesium  compounds  is  not  accounted 
for  in  the  above  equation.  The  authors  consider  that  the 
results  of  their  own  analyses  and  examination  prove  that 
the  composition  of  the  basic  sulphate  of  copper  is  variable, 
but  that  it  does  not  correspond  to  the  above  formula,  and 
certainly  occurs  in  the  condition  of  hydroxysulphate. 
They  have  never  found  that  the  proportion  between  the 
quantities  of  cuprous  oxide  and  metallic  copper  is  such 
as  can  be  definitely  represented  by  means  of  an  equation, 
but  rather  that  it  varies  within  wide  limits  under  different 
experimental  conditions. 

It  will  therefore  appear  that  Commaille's  imperfedt 
study  and  statement  of  the  readion  may  well  be  supple- 
mented by  a  more  complete  investigation. 

The  authors  desire  to  place  on  record  the  fadt  that, 
when  zinc  adts  upon  a  cold  solution  of  copper  sulphate, 
small  bubbles  of  gas  are  evolved  ;  and  that  when  a  hot 
solution  of  cupric  salt  is  employed,  an  appreciable  quan- 
tity of  hydrogen  can  be  colledled,  and  cuprous  oxide  is 
found  in  the  residue.  They  intend  to  study  this  readtion 
in  detail. 

Discussion. 

Professor  Tilden  remarked  that  the  work  of  the  authors 
had  been  anticipated  by  the  experiments  of  Commaille, 
who  had  published  thirty  years  ago  the  results  of  an 
enquiry  into  the  adtion  of  magnesium  on  neutral  metallic 
salts,  including  copper  sulphate. 


When  magnesium  is  immersed  in  an  aqueous  solution 
of  copper  sulphate  free  from  acid,  the  adtion  seemed  to 
take  the  following  course  : — First,  there  was  a  precipita- 
tion of  spongy  metallic  copper,  which,  in  contadt  with  the 
magnesium,  gave  a  couple  capable  of  decomposing  water 
at  common  temperatures.  Hydrogen  was  then  evolved, 
and  a  crust  of  magnesia  formed  on  the  surface  of  the 
metal.  The  copper  salt  was  locally  reduced  by  the  hy- 
drogen to  the  cuprous  state,  and  this,  in  the  presence  of 
the  magnesium  oxide,  led  to  the  precipitation  of  cuprous 
oxide  and  of  a  basic  cupric  salt.  The  green  precipitate 
formed  therefore  consists  of  magnesia  and  basic  cupric 
salt,  the  proportion  varying  according  to  the  temperature 
and  strength  of  the  solution.  This  hypothesis  is  borne 
out  completely  by  the  results  both  by  Commaille  and  the 
authors  of  the  paper,  and  serves  to  account  for  the 
apparent  inadlivity  of  the  magnesium  which  is  mechani- 
cally protedted  by  the  crust  which  forms  upon  its  surface. 
The  speaker  had  tested  the  suggestion  that  the  metal  was 
rendered  inadtive  by  a  film  of  hydrogen  and  had  come  to 
the  conclusion  that  this  was  not  the  case. 

Professor  Clowes  said  that  the  origin  of  the  investiga- 
tion dated  back  some  two  years,  the  irregular  adion  of 
magnesium  on  the  cupric  solution  having  been  noticed  in 
the  course  of  experiments  made  in  connedtion  with  a 
laboratory  curriculum  which  he  was  then  drafting  for  ele- 
mentary students.  It  was  anticipated  that  the  readtion 
of  magnesium  on  cupric  sulphate  might  serve  to  establish 
the  relative  chemical  values  of  copper  and  magnesium, 
but  this  was  found  to  be  impradticable  owing  to  the  evolu- 
tion of  a  large  amount  of  hydrogen.  If  such  irregular 
adtions  occurred,  instead  of  the  simple  replacement  of  one 
metal  by  another  in  solutions  of  its  salts,  it  would  seem 
that  this  method  of  determining  chemical  equivalents  was 
not  of  general  application. 

Mr.  Caven,  in  reply,  said  he  regretted  that  he  had  over- 
looked  the  paper  by  Commaille  on  this  subjedt  to  which 
Dr.  Tilden  referred. 

It  seems  improbable  that  cuprous  salt  is  formed  by  the 
reducing  adtion  of  nascent  hydrogen  upon  the  cupric  salt 
in  the  solution.  This  would  lead  to  the  formation  of  free 
sulphuric  acid,  which  would  decompose  the  cuprous  oxide 
formed  at  the  commencement  of  the  readtion  into  cupric 
sulphate  and  metallic  copper.  If  nascent  hydrogen 
reduces  the  cupric  salt  at  all,  it  can  only  produce  metallic 
copper.  Sulphuric  acid  would  be  liberated  in  this  case 
also,  though  not  in  immediate  contadt  with  cuprous 
oxide.  It  may  be  that  the  process  of  solution  of  the  mag- 
nesium hydroxide  and  basic  copper  salt  which  occurs  at 
the  close  of  the  readtion  in  concentrated  solutions,  depends 
upon  the  adtion  of  the  free  acid  thus  produced. 

The  authors  suggest  that  the  magnesium  reduces  the 
cupric  solution  diredlly,  producing  cuprous  oxide  and  hy- 
drogen in  the  following  manner,  the  proportion  of  the 
hydrogen  evolved  in  the  gaseous  state  being  dependent 
upon  the  conditions  of  the  experiment : — 

2Mg-t-2CuS04+H20  =  2MgS04+Cu20  +  H2. 

Some  such  readtion  as  this,  proceeding  simultaneously 
with  the  adtion  of  the  couple,  may  account  for  the  imme- 
diate formation  of  cuprous  oxide,  and  the  vigorous  evolu- 
tion of  hydrogen  at  the  moment  of  immersion  of  the  mag- 
nesium. The  adtion  of  the  magnesium-copper  couple  on 
the  water  is  not  in  itself  sufficient  to  account  for  the  very 
large  quantity  of  hydrogen  which  is  obtained,  or  for  the 
rapidity  with  which  it  is  produced,  since,  when  the  couple 
adts  upon  pure  water,  the  hydrogen  is  evolved  only  very 
slowly.  This  view  of  the  origin  of  the  cuprous  oxide  is 
borne  out  by  the  fadl  that  it  occurs,  together  with  metallic 
copper,  quite  from  the  commencement  of  the  reafiion,  and 
that  the  formation  of  hydrogen  appears  to  begin  diredtly 
the  magnesium  is  plunged  into  the  solution.  This  would 
not  be  the  case  if  the  formation  of  a  metallic  couple  were 
necessary  for  the  evolution  of  the  gas. 

There  is  no  cessation  in  the  evolution  of  gas  during 
the  course  of  the  rea&ion  under  any  circumstances.    The 


Dec.  17,  1897. 


Molecular  A  ssociation  of  Liquids, 


29& 


length  of  time  necessary  for  the  completion  of  the  reac- 
tion in  dilute  solutions  is  undoubtedly  due  to  the  mechani- 
cal protedlion  of  the  magnesium  by  the  deposit,  as  Pro- 
fessor Tilden  suggested. 

•122.  •'  Properties  and  Relationships  of  Dihydroxy- 
tartaric  Acid."     By  Henry  J.  Horstman  Fenton,  M.A. 

Bearing  in  mind  the  highly  interesting  constitution  of 
hydroxytartaric  acid,  and  the  close  relationship  which  has 
been  shown  to  exist  between  this  acid  and  dihydroxy- 
maleic  acid,  a  further  investigation  of  its  properties  ap- 
peared to  be  desirable,  especially  as  the  free  acid  appears 
to  have  been  scarcely  studied. 

It  is  now  found  that  the  free  acid  may  very  easily  be 
prepared  in  a  pure  state  by  oxidation  of  dihydroxymaleic 
acid  in  presence  of  water.  The  yield  is  over  70  per  cent 
of  that  demanded  by  theory.  The  dry  acid  shows  no 
tendency  to  lose  water  at  go°.  In  aqueous  solution,  the 
acid  decomposes  when  heated  into  tartronic  acid  and  car- 
bon dioxide.  This  reaction  affords  a  very  convenient 
method  for  the  preparation  of  pure  tartronic  acid,  the 
yield  being  97  per  cent  of  that  theoretically  obtainable. 
On  titration  with  alkalis  at  0°  dihydroxytartaric  acid  be- 
haves normally  as  a  dibasic  acid.  But  the  results  ob- 
tained at  the  ordinary  temperature  with  caustic  alkalis, 
using  phenolphthalein  as  indicator,  are  considerably 
higher,  being  intermediate  between  those  required  for  a 
di-  and  a  tri-basic  acid.  These  high  results  are  shown 
to  be  due  to  the  partial  decomposition  of  the  salts  formed 
into  tartronates  and  carbon  dioxide. 

By  careful  treatment  with  certain  reducing  agents 
dihydroxytartaric  acid  may  be  reduced  to  dihydroxymaleic 
acid  or  its  isomeride.  Zinc,  in  calculated  quantity,  and 
dilute  acid  reduces  it  to  the  j8-form.  Hydrogen  bromide 
reduces  it  to  dihydroxymaleic  acid  (a-form)  with  libera- 
tion of  free  bromine. 

The  reaaionC4H406  +  2H20-f-Br2  =  C4H608-f-2HBr  is 
in  fadt  a  reversible  one,  the  final  distribution  depending 
upon  the  masses  of  the  reading  substances,  and  perhaps 
somewhat  on  the  temperature. 

•123.  "  The  Molecular  Association  of  Liquids  and  its 
Influence  on  the  Osmotic  Pressure."  By  Holland 
Crompton. 

In  a  paper  which  I  recently  had  the  honour  of  bringing 
before  this  Society  (Trans.,  1897,  Ixxi.,  925),  I  contended 
that  the  molecular  association  of  liquids  exercises  an 
influence  on  their  osmotic  pressure,  and  endeavoured  to 
show  how  this  influence  may  be  taken  into  account.  My 
attention  has  been  drawn  to  the  fadt  that  Planck,  more 
especially,  has  long  since  proved  that  association  could 
have  no  effedt  on  the  osmotic  pressure  of  liquids  (see  the 
discussion  between  Planck  and  Wiedemann,  Zeitsch, 
Physik.  Chetn.,  1888,  ii.,  pp.  241,  343).  This  being  the 
case,  I  wish  to  offer  the  following  brief  criticism  of 
Planck's  results. 

In  his  '•  Vorlesungen  iiber  Thermodynamik  "  (Leipsig, 
1897),  Planck  deduces,  on  p.  235,  the  following  formula 
for  the  osmotic  pressure  of  a  dilute  solution  : — 

p  =  _5L  {ni+n2+n3+ ). 

MqWoW 

Here  R  is  the  constant  of  the  gas  equation,  0  the  absolute 
temperature,  ni+n2+n^+  .  .  .  .  =  n  the  number  of  dis- 
solved molecules,  no  the  number  of  molecules  of  the 
solvent,  mo  its  molecular  weight,  and  v  its  specific  volume 
(volume  of  unit  weight).  Since  «oWoW  =  V  is  pradtically 
the  whole  volume  of  the  solution  P  =  ROm/V.  This  is,  of 
course,  van't  Hoff's  equation  for  the  osmotic  pressure,  and 
it  is  argued  that  the  produdl  «oWoW  being  simply  the  total 
volume  of  the  solution,  the  pressure  is  independent  of  any 
change  produced  by  association  in  mo.  In  other  words,  as 
long  as  V  is  constant  P  will  remain  constant,  no  matter 
what  the  value  of  mo. 

The  nature  and  derivation  of  this  relationship  will  per- 
haps be  best  understood  if  we  suppose  that  we  have  two 
gases,  and  that  n  molecules  of  the  first  are  dissolved  in, 


or  mixed  with,  no  molecules  of  the  second.  The  partial 
pressure  of  the  first  gas  in  the  mixture  is  n/(«o  +  «)  of 
the  total  pressure,  or  if  n  is  small  in  comparison  with  no, 
we  may  say  «/mo  of  the  pressure  of  the  second  gas.  The 
pressure  of  this  latter  is  RT/Va,  and,  in  order  that  R  may 
have  a  fixed  value,  let  Va  be  the  molecular  volume  moWo 
of  the  gas,  where  Wq  is  its  molecular  weight,  and  Vo  its 
specific  volume.  The  partial  pressure  of  the  dissolved 
gas  then  becomes  ^  =  RTn/noWoWoi  or,  since  no»«oVo=Vo, 
whole  volume  of  the  solvent  gas,  />  =  RT/«Vo. 

These  equations  for  the  partial  pressure  of  a  gas  present 
in  a  dilute  state  in  any  gaseous  mixture  are  identical  in 
form  with  those  of  Planck  for  the  osmotic  pressure  of 
dilute  solutions.  It  follows,  then,  that  we  have  apparently 
only  to  liquefy  the  solvent  gas,  to  substitute  the  molecular 
volume  of  the  resulting  liquid  solvent  for  that  of  the 
gaseous  solvent,  and  the  partial  pressure  of  the  dissolved 
gas  then  becomes  its  osmotic  pressure  in  the  solution. 

The  result  is  not  surprising,  for  it  is  obtained  by  a  prac- 
tical reversal  of  Planck's  line  of  argument.  It  will  be 
found  {loc.  cit.,  p.  215)  that,  in  his  treatment  of  the  thermo- 
dynamics of  dilute  solutions,  he  adopts  the  view  that  any 
such  solution  could  be  completely  gasified  without  any 
change  in  the  values  of  n  and  no,  and,  of  course,  the 
osmotic  pressure  of  the  dissolved  compound  in  the  solu- 
tion would  then  become  the  partial  pressure  of  the 
dissolved  gas  in  the  gaseous  mixture.  But  the  view  that 
a  solution  could  be  completely  gasified  without  any  change 
of  a  permanent  charadter  in  the  values  of  n  and  no  cannot 
be  regarded  as  justifiable  in  the  light  of  all  the  recent 
work  on  the  molecular  condition  of  liquids.  And  although 
it  is  not  surprising  to  find  that,  starting  with  this  view, 
Planck  subsequently  comes  to  the  conclusion  that 
association  of  the  solvent  does  not  influence  the  osmotic 
pressure  of  a  solution,  the  reasoning  evidently  moves  too 
completely  in  a  circle  to  carry  much  convidtion  with  it. 

For,  in  order  to  ascertain  what  effedl  a  change  due  to 
molecular  association  in  the  solvent  would  have  on  our 
formulae,  let  us  first  take  the  case  of  the  mixed  gases,  and 
suppose  the  gas  we  term  the  solvent  to  be  one,  say,  like 
nitrogen  dioxide,  NO2,  which  undergoes  association  as  the 
temperature  falls.  Such  association  will  bring  about  a 
change  of  mo  to  xnto,  of  no  to  no/*,  and  of  Vo  to  Vofx,  if  x 
represents  the  degree  of  association  (fadtor  of  association) 
for  any  temperature  T.  The  partial  pressure  of  the  dis- 
solved gas  now  becomes  p=xRTnlnomoVo,  or  since 
no»MoVo=Vo, /^=;trRTn/Vo.  Hence,  although  when  a  gas 
is  dissolved  in  any  other  gas,  and  is  present  only  in  a 
dilute  condition,  its  partial  pressure  will,  under  normal 
conditions,  follow  the  law  that  ^Vo=«RT  if  association 
of  the  solvent  sets  in,  the  law  for  perfedl  gases  no  longer 
holds,  but  the  relationship  becomes  ^Vo=JfMRT  where  x 
represents  the  fadtor  of  association  of  the  solvent  for  the 
temperature  T. 

In  fadt,  the  partial  pressure  of  the  dissolved  gas  is, 
under  the  above  conditions,  dependent  on  the  volume 
occupied  by  the  solvent.  Under  normal  conditions  the 
solvent  obeys  the  usual  gas  equation,  and  the  partial 
pressure  therefore  alters  in  accordance  with  this  relation- 
ship. But  if  association  or  dissociation  of  the  solvent 
sets  in,  the  gas  equation  will  not  immediately  apply,  but 
will  require  a  suitable  modification,  and  this  modification 
will  hold  also  for  the  partial  pressure  formula. 

Now  the  osmotic  pressure  of  a  dilute  solution  presents 
an  analogous  case.  As  long  as  the  solvent  is  a  mono- 
molecular  one  we  may  accept  Planck's  reasoning,  and 
hold  that  the  osmotic  pressure  follows  the  law 
P=nR0/«oWoW.  But  suppose  that  the  solvent  begins  to 
undergo  association,  so  that  for  any  given  temperature  t 
a  change  of  mo  to  xmo  has  taken  place.  At  the  same 
no  changes  to  noix,  and  a  simultaneous  change  will  be 
found  to  have  taken  place  in  v.  This  last  change  has,  it 
seems  to  me,  been  entirely  overlooked  up  to  the  present, 
although  any  one  who  gives  the  matter  a  moment's  con- 
sideration cannot  fail  to  admit  that  an  associated  liquid 
would  not  have  the  density  of  the  same  compound  in  the 


3^0 


Temperature  Compensators  for  Standard  Cells.  <  ^D^ec'"''i?"**'' 


xnonomolecular  condition.  All  the  evidence  at  present 
points  to  the  conclusion  that  association  increases  the 
density  of  a  liquid,  and  that  consequently  association 
would  alter  the  value  of  v  to  vja.  The  precise  magnitude 
of  a  cannot  at  present  be  ascertained  (unless  perhaps  with 
the  aid  of  Traube's  investigation  of  the  molecular  co- 
volume),  but  its  value  is  probably  not  far  removed  from 
that  of  X.  The  osmotic  pressure,  then,  of  any  dilute 
solution,  the  solvent  of  which  is  undergoing  association, 
would  be  given  by  P  =  aMR6/MoWoV.  or,  since  nonioV  —  W,  by 
V  —  anROjV,  an  expression  that  is  similar  to  the  partial 
pressure  formula.  While,  then,  the  osmotic  pressure  of 
any  substance  in  solution  in  a  monomolecular  solvent 
follows  the  gas  equation  PV  =  RO,  if  the  solvent  is  one 
which  is  undergoing  association  or  dissociation,  the  equa- 
tion for  the  osmotic  pressure  becomes  PV  =  aR9.  And 
here  another  point  which  has  apparently  always  been 
overlooked  by  those  who  contend  that  association  of  the 
solvent  does  not  influence  the  osmotic  pressure  may  be 
alluded  to.  It  has  been  usual,  hitherto,  to  compare  with 
one  another  two  stable  systems,  one  of  which  is  assumed 
to  contain  a  monomolecular  solvent,  and  the  other  the 
same  solvent  in  the  associated  condition,  and  to  show  that  i 
the  gas  equation  PV  =  Rfl  applies  to  each.  The  compari- 
son, however,  should  not  be  between  a  monomolecular 
and  an  associated  solvent,  but  between  a  monomolecular 
and  an  associating  solvent,  i.  e.,  one  in  which  the  associa- 
tion is  continually  altering  with  the  temperature.  The 
gas  equation  would  hold  for  the  gas  NOa,  and  it  would 
hold  equally  for  the  gas  N2O4,  but  it  will  not  apply 
throughout  the  range  of  temperature  in  which — 


N,0 


2»-'4 


■2NO-2 


The  gas  equation  might  in  like  manner  hold  for  the 
osmotic  pressure  of  a  substance  in  solution  in  water  of 
the  molecular  weight  18,  and  it  might  also  hold  for  water 
of  the  molecular  weight  3  X 18,  but  water,  as  we  know  it, 
is  neither  of  these  compounds.  It  is  a  substance  the 
association  of  which  is  continually  changing  with  the 
temperature,  and  the  attempt  is  therefore  being  made  to 
apply  the  gas  equation  in  the  range  of  temperature 
throughout  which — 

(HaO)»  ;^  nHaO. 

Van  Laar  has,  like  Planck,  treated  the  osmotic  pressure 
of  dilute  solutions  from  the  thermodynamical  standpoint, 
and  confirmed  the  latter's  conclusion  that  association  of 
the  solvent  does  not  influence  the  osmotic  pressure.  I 
quote  here  literally  what  Van  Laar  says  on  this  matter 
(Zeit.  Physikal.  Chem.,  1895,  xviii.,  274) : — 

"  We  found  that  the  osmotic  pressure  ir  =  Rrff{i+a)lva', 
where  a{i+a.)  has  the  value  Scj,*  and  Va',  the  volume  of 
I  grm.  molecule  of  the  pure  solvent.  For  water  Va'  was 
therefore  given  the  value  18.  I/,  however,  association 
occurs,  the  weight  of  the  grm.  molecule  would  be  i8a,  so 
that  for  Va'  the  volume  of  i8a  grms.  of  water  must  be  sub- 
stituted. Calling  this  last  Va,  then  Va'  =  ava'.  But  also  a, 
the  concentration  of  the  dissolved  substance,  becomes  a 
times  greater.  For  we  have  now  no  longer  one  molecule 
of  the  dissolved  substance  to  n  molecules  of  water  (taking 
the  mol.  wt.  of  water  =18),  but  one  molecule  to  Mi/a 
molecules  of  water,  so  that  the  concentration  must  be 
expressed  by  an  a  times  greater  number  than  before. 
Calling  this  C,  then  as  C  =  a(7,  the  expressions^ 

ir  =  Ri-C(i-f-a)/Va' 

does  not  differ  from  7r  =  Rr(r(i-f-a)/w«',  where  the  quantities 
va'  and  a  are  independent  of  the  association." 

The  italics  in  the  above  are  mine,  for  it  is  to  this  portion 
of  the  paragraph  that  I  wish  to  dired  attention  more 
especially.  The  molecular  volume  of  any  compound  is 
given  by  M/i,  where  M  is  the  molecular  weight  of  the 
compound  and  d  its  density.     Now  Van  Laar  supposes 

*  The  c  here  is  the  n  of  the  Planck  formula. 


that  if  liquid  water  had  the  molecular  weight  18,  its 
molecular  volume  would  be  18/1  ;  or  if  it  had  the  mole- 
cular weight  i8fl,  its  molecular  volume  would  be  i8fl/i. 
In  other  words,  the  same  density  is  to  be  assigned  indis- 
criminately either  to  the  monomolecular  or  to  the  asso- 
ciated compound.  But  can  any  one  doubt  if  liquid  water 
were  obtainable  having  the  molecular  weight  18,  that  it 
would  most  certainly  not  have  the  density  i  at  ordinary 
temperature  ?  Take  water  merely  as  the  first  term  of  the 
C»H2,t+i  OH  series  of  alcohols,  a  series  the  members  of 
which  are  themselves  associated,  but  not  to  the  same 
extent  as  water,  and  analogy  at  once  points  to  a  much 
lower  density  than  1  for  monomolecular  liquid  water,  a 
density  that  is  in  fadt  probably  not  far  removed  from  i/a. 
In  fadt  there  is  absolutely  no  evidence  that  the  molecular 
volume  of  an  associated  liquid  does  differ  greatly  from 
that  of  the  same  liquid  compound  in  the  monomolecular 
state.  Van  Laar's  argument  against  is  converted  there- 
fore into  an  argument  for  the  effedt  of  association  on  the 
osmotic  pressure. 


PHYSICAL    SOCIETY. 
Ordinary  Meeting,  December  loth,  1897. 

Mr.  Shelford  Bidwell,  President,  in  the  Chair. 

Mr.  Albert  Campbell  exhibited  (i)  An  experiment  to 
illustrate  alternate  exchange  of  Kinetic  Energy.  Two 
brass  spheres,  each  about  i  inch  diameter,  are  suspended 
from  the  same  point  by  equal  wires.  One  of  them  is  then 
thrown  so  as  to  describe  a  circular  orbit.  The  second 
sphere,  starting  from  rest,  gradually  takes  up  motion  from 
the  first  sphere,  and  in  turn  describes  a  circular  orbit. 
Tne  first  now  comes  to  rest,  and  the  reverse  process  takes 
place.  This  alternating  adtion  repeats  itself  until  all  the 
energy  is  lost  in  the  wires.  (2)  An  experiment  to  illus- 
trate the  Low  Heat-condudlivity  of  Glass  and  the 
Expansion  of  Glass  by  Heat.  A  long  tube  is  clamped 
at  the  lower  end,  in  a  vertical  position.  One  side  of  it  is 
then  heated  with  the  flame  of  a  Bunsen  burner,  and  the 
glass  is  observed  to  bend,  moving  over  a  fixed  mark  near 
the  top  of  the  tube.  When  the  flame  is  withdrawn,  the 
first  position  is  quickly  regained. 

Mr.  Campbell  then  read  a  paper  on  "  Temperature 
Compensators  for  Standard  Cells." 

Some  account  of  the  methods  adopted  by  the  author 
has  already  been  published ;  he  now  describes  the  appa- 
ratus. The  first  compensating  arrangement  {3)  can  be 
used  for  keeping  the  potential-difference  between  two 
points  of  a  conducting  system  constant  at  all  room- 
temperatures.  Or  it  can  be  adapted  to  modify  the  voltage 
of  a  standard  cell  to  some  convenient  whole  number. 
This  arrangement  (3)  resembles  a  Wheatstone's  bridge 
with  the  galvanometer-branch  removed.  One  pair  of 
opposite  arms  is  of  copper,  the  other  pair  is  of  manganin. 
The  bridge-battery  is  a  Leclanche  cell :  this  supplies  the 
auxiliary  voltage,  which  is  utilised  at  the  two  galvanometer- 
points  of  the  bridge,  and  is  there  applied  in  series  with 
the  standard  cell.  In  an  alternative  method,  suggested 
by  Mr.  C.  Crawley,  only  one  of  the  four  arms  is  made  of 
copper.  The  second  compensating  arrangement  (4)  is 
intended  to  maintain  constant  potential  between  two 
points,  at  all  room-temperatures.  For  this  purpose  two 
wires,  a  and  b,  are  conneded  in  parallel.  One  of  them, 
a,  is  all  of  manganin ;  the  other,  b,  is  partly  copper  and 
partly  manganin.  Constant  current  is  applied  at  the  ends 
of  a  and  b.  The  various  resistances  are  chosen  so  as  to 
give  constant  difference  of  potential  between  the  ends  of 
the  manganin  portion  of  b.  By  this  method  the  potential 
difference  can  be  maintained  to  within  i  in  2000, 

Mr.  Swinburne  said  that  twelve  or  thirteen  years  ago 
he  had  given  a  good  deal  of  thought  to  compensation  by 
wires  of  different  temperature-coefficients.  The  first 
thing  he  tried  was  a  Wheatstone's  bridge.    This  was 


i^HRMiCAL  News,  • 
Dec.  17.  1807.     ' 


Lord  Kelvin's  Absolute  Method  of  Graduating  a  Thermometer     301 


compensated  by  making  the  bridge-arms  of  wires  whose 
temperature-coefficients  differed — as,  for  instance,  platinoid 
and  copper.  He  then  applied  the  same  principle  to  the 
compensation  of  standard  cells,  using  a  potentiometer 
method  that  gave  diredt  readings,  and  to  the  compensation 
of  voltmeters  and  Watt-meters.  These  results  were  pub- 
lished between  1885  and  1890,  in  the  electrical  journals. 
He  believed  that  Mr.  Evershed  had  also  developed  this 
idea,  by  putting  "back"  turns  on  voltmeters,  and  by 
other  differential  devices.  The  details  of  Mr.  Campbell's 
apparatus  had  a  few  points  of  special  interest.  The  way 
in  which  he  conneded  up  the  bridge  (3)  seemed  particu- 
larly worthy  of  notice. 

Prof.  Ayrton  asked  whether  thermo-ele(5lric  effedts 
produced  difficulty  in  the  compounded  arrangement. 

Mr.  Campbell  said  the  system  was  symmetrical,  and 
the  thermal  currents  were  consequently  neutralised.  _ 

Mr.  Appleyard,  referring  to  experiment  {2),  said  it  was 
identical  with  one  that  had  been  shown  for  the  past  eight 
years  at  ledtures  at  Cooper's  Hill  College.  It  was 
specially  interesting  as  illustrating  the  defledion  that 
occurs  with  girders  and  bridges  when  exposed  on  one  side 
to  sunshine. 

Mr.  J.  Rose-Innes  read  a  mathematical  paper  on 
^'Lord  Kelvin's  Absolute  Method  of  Graduating  a  Thermo- 
meter.'^ 

Lord  Kelvin  has  investigated  the  cooling  effefls  exhi- 
bited by  various  gases  in  passing  through  a  porous  plug. 
He  found  that  for  any  gas,  kept  at  the  same  initial  tem- 
perature, the  cooling  effedls  were  proportional  to  the 
difference  of  pressure  on  the  two  sides  of  the  plug.  He 
also  found  that,  for  any  one  gas,  the  cooling  effed  per 
unit  difference  of  pressure  varies  approximately  as  the 
inverse  square  of  the  absolute  temperature.  This  rule 
holds  very  well  in  the  case  of  air  ;  it  is  not  so  satisfadlory 
for  carbonic  acid;  it  fails  for  hydrogen.  With  hydrogen 
there  is  a  heating  effecSt  that  increases,  if  anything,  when 
the  temperature  rises.  Mr.  Rose-Innes  proposes  an  em- 
pirical formula,  containing  two  disposable  constants, 
o  and  /3,  characteristic  of  the  gas  in  question.  Denoting 
by  T  the  absolute  temperature,  he  finds  that,  very  approx- 
imately,  the  cooling  effefl:  is  given  by  the  expression— 


(-T-)- 


This  relation  includes  the  three  cases— air,  hydrogen, 
carbonic  acid — undej  one  form,  and  thus  enables  them  to 
be  treated  in  one  common  investigation.  Moreover, 
the  differential  equation  concerned  in  the  thermodynamic 
scale  is  thereby  rendered  more  manageable,— it  leads 
to  simple  algebraic  results  after  integration.  The  paper 
discusses  the  thermo-dynamic  corredtion  for  a  con- 
stant-pressure gas-thermometer,  and  the  corredion  for  a 
constant-volume  gas-thermometer ;  also  an  estimate  of 
the  absolute  value  of  the  freezing-point  of  water:  the 
results  obtained  take,  for  the  most  part,  a  very  simple 
shape,  using  the  above  expression  for  the  cooling. 
Dr.  S.  P.  Thompson  said  the  empirical  expression, — 


(?-4 


indicated  that  at  some  particular  temperature  the  cooling 
effedl  vanished;  that  was  a  point  suggestive  of  useful 
results  if  investigated  by  experiment. 

Mr.  J.  Walker  read  a  communication  from  Mr.  Baynes 
on  the  paper,  and  remarked  on  the  desirability  of  adopting 
two  constants.  He  thought  that  further  experiments 
should  be  made  to  discover  how  specific  heat  at  constant 
temperature  depends  on  temperature.  The  calculated 
values  for  hydrogen  were  too  few  to  be  taken  as  evidence 
of  the  validity  of  the  rule. 

Mr.  Rose-Innes,  in  reply,  said  that  from  what  was 
known  of  hydrogen,  it  might  be  expeiSled  to  behave  at 
ordinary  temperatures  as  air  behaves   at  higher  tempent; ; 
atures.    His  objeft  was,  if  possible,  to  include  in  on6 


formula  the  case  of  the  three  investigated  gases.  This 
was  much  better  than  having  a  separate  formula  for  each 
gas.  Whether  or  not  hydrogen  was  conformatory  with 
air  and  carbonic  acid  might  be  considered  as  sub  judice  ; 
it  required  further  experimental  data  to  test  the  formula 
in  that  case. 

The  President  proposed  a  vote  of  thanks  to  the 
authors,  and  the  meeting  was  adjourned  until  January 
2ist,  i8g8. 


SOCIETE  D'ENCOURAGEMENT  POUR  L'lNDUS- 

TRIE   NATIONALE. 

November  26,  1897. 

M.  Mascart,  President,  in  the  chair. 

The  Secretaries  read  several  letters  received,  after 
which  M.  Groignard  exhibited  an  automatic  valve  for 
the  arrest  of  noxious  fumes,  and  an  automatic  water  level 
control-valve  of  similar  construdtion. 

M.  a.  Pouchet  exhibited  an  apparatus  for  aerial  navi- 
gation. 

Several  gentlemen  were  proposed  as  candidates  for  the 
position  of  member  of  the  committee  on  Mechanics,  and 
two  candidates  were  announced  as  having  been  eledled 
members  of  the  Society. 

An  interesting  paper  was  then  read  by  M.  Bechmann 
on  the  "Purification  of  the  Seine"  for  which  he  received 
the  thanks  of  the  Society.  This  paper  will  be  printed  in 
the  Bulletin. 

The  next  meeting  for  the  eleftion  of  officers  for  1898 
was  announced  to  take  place  on  December  10,  1897. 


NOTICES  OF  BOOKS. 


A  Complete  Catalogue  of  Practical  Physical  Apparatus 

Manufactured  by  W.  J.  George,  late  Becker  &  Co. 
This  catalogue  contains  a  complete  list  of  the  Physical 
apparatus  recommended  by  Professor  Schiister  and  Dr. 
Lees  in  their  text-book  on  "Pradtical  Physics,"  and  will 
doubtless  be  found  to  be  of  great  assistance  to  both 
teachers  and  students  not  already  provided  with  the 
necessary  apparatus  for  their  studies.  It  is  a  great 
advantage  and  saving  of  time  to  be  able  to  order  any  par- 
ticular piece  of  apparatus  which  may  be  required,  with  a 
knowledge  that  it  is  kept  in  stock  and  can  be  delivered 
at  short  notice,  thus  avoiding  those  tiresome  delays  to 
which  we  are  too  much  accustomed.  The  list  appears 
to  be  comprehensive,  well  illustrated,  and  conveniently 
arranged. 


OBITUARY. 


DR.  CAMPBELL   MORFIT. 

By  the  {death  of  Dr.  Campbell  Morfit,  M.D.,  formerly 
Fellow  of  the  Chemical  Society  and  of  the  Institute  of 
Chemistry,  which  took  place  on  the  8th  inst.  at  South 
Hampstead,  the  science  of  applied  chemistry  has  suffered 
a  severe  loss.  An  American  by  birth,  he  had  for  many 
years  past  been  a  London  resident.  In  1854  he  was  ap- 
pointed Professor  of  Applied  Chemistry  in  the  University 
of  Maryland,  and  was  one  of  the  scientific  advisers  of  the 
United  States  Government  previous  to  the  Civil  War. 

He  was  the  author  of  several  standard  works  on  industrial 
chemistry,    including    "  Chemical    and    Pharmaceutical 


302 


Separation  of  Nickel  and  Cobailjrom  Iron, 


(Ohbmical  News 
Dec.  17,  iSg^. 


Manipulation,"  "Arts  of  Tanning  and  Currying,"  "Oleic 
Soaps,"  and  with  Dr.  James  C.  Booth  was  joint  editor  of 
the  "American  Encyclopedia  of  Chemistry." 

His  work  included  researches  on  the  the  guanos,  salts, 
sugars,  analyses  of  coals,  gum  mesquite,  and  glycerin. 
During  the  latter  period  of  his  life  his  attention  was  de- 
voted to  the  improvement  of  technical  processes,  the 
preparation  of  condensed  food  rations,  the  manufadure  of 
paper,  and  in  especial  to  the  questions  of  the  refining  of 
cotton  and  linseed  oils  and  the  utilisation  of  cotton-seed 
oil  as  a  food  substance. 

His  loss  will  be  deeply  felt  by  a  wide  circle  of  scientific 
and  literary  friends. 


CORRESPONDENCE. 


SEPARATION  OF  NICKEL  AND  COBALT 
FROM  IRON. 

To  the  Editor  of  the  Chemical  News. 
Sir, — May  I  take  exception  to  the  opening  statements  of 
the  article  on  the  separation  of  Ni  and  Co  from  Fe,  &c., 
which  you  reprint  in  the  Chemical  News  (vol  Ixxvi.,  p. 
279). 

To  say  that  there  is  no  satisfaAory  method  known  for 
effeding  the  separation  of  Ni  and  Co  from  large  quanti- 
ties  of  Fe  is  surely  untrue. 

The  following,  if  test  analyses  are  to  be  credited,  are  a 
few  references  to  satisfactory  methods  already  described 
in  your  journal : — 

I.  Precipitation   of  the  iron  with   lead  oxide   (Field, 

Chem.  News,  i.,  4). 
2  and  3.  Precipitation    as   ferric  phosphate   in   acetic 

solutions  (Moore,  Chem.  News, liv., 300;  Campbell, 

Ixix.,  139). 

4.  Treatment  with    excess    of   soda    pyrophosphate ; 

whereby,  even  in  presence  of  much  iron,  a  clear 
colourless  solution  is  obtained,  which  is  subse- 
quently titrated  with  cyanide  of  potassium  (Moore, 
Chem.  News,  lix.,  292). 

5.  Conversion  of  the  iron  into  fcrricyanide,  Ni  into  nickelo- 

cyanide,  and  subsequent  precipitation  of  Ni  by  a 
solution  of  bromine  in  potash  (Moore,  Chem. 
News,  Ivi.,  3). 

This  is  not  a  complete  list  of  the  processes  to  be  found 
in  the  Chemical  News.  Other  well-known  and  largely 
used  processes  are  to  be  found  in  text-books  specially 
devoted  to  steel  analysis.  Two  other  processes  which 
have  been  well  tested  and  find  great  favour  are  Campbell 
and  Andrew's  xanthate  process  (JflMrM.  Amer.Chem.  Soc, 
Feb.,  1895),  and  Herschell's  hydrate  process  ("  Fresenius's 
Quantitative  Analysis,"  p.  437).  . 

The  second  paragraph  specifies  hydrate  and  basic 
acetate  precipitates  as"  always  containing  a  considerable 
proportion  of  other  metals  (Ni,  Co,  Mn,  Cu,  &c.). 

The  case  for  acetate  precipitations  has  already  been  pre- 
sented at  sufficient  length.  It  is  necessary  only  to  refer 
to  the  separate  papers— Nickel,  p.  49 ;  Cobalt  and  Man- 
ganese,  p.  165 ;  Copper,  p.  2io — to  see  that  respe<aing 
acetate  the  charge  is  unjustly  made. 

It  is  not  claimed  that  any  of  the  above  processes  are 
more  accurate  than  the  eledtrolytic  process,  although 
some  of  them,  with  their  accompanying  estimations,  are 
equally  so.  But  when  the  employment  of  the  process  in 
everyday  pradtice  comes  to  be  considered,  their  superiority 
in  point  of  quickness  and  general  convenience  is  most 
marked.— I  am,  &c., 

Harry  Brearley. 


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Estimation  oj  Copper  in  presence  of  other  Elements. 


303 


THE    CHEMICAL     NEWS 


Vol.  LXXVL,  No.  1987. 


THE   ESTIMATION   OF   COPPER   IN    PRESENCE 

OF     OTHER     ELEMENTS. 

By  HARRY  BREARLEY, 

fOoncluded  from  p.  293). 


Iron. — Precipitated  with  either  alkali,  the  chief  objeftion 
hitherto  has  been  the  colour  of  its  precipitated  hydrate. 
With  soda  the  colour  is  less  objedionable.  As  the 
cyanide  is  added  the  precipitate  becomes  redder,  and 
something'  may  be  deduced  from  watching  the  changing 
colour  contrasts  as  the  cyanide  falls  into  the  solution. 
There  has  been  some  question  as  to  how  this  element 
should  be  treated.  Some  are  all  for  filtering  it  off,  while 
others  objecSt  that  the  ammoniacal  copper  solution  and 
ferric  hydrate  cannot  be  completely  separated  even  by  re- 
precipitation  or  washing.  Indeed  it  is  claimed  that  its 
presence  "  is  rather  an  advantage,  as  it  a(5ts  as  an  indicator 
to  the  end  of  the  process"  (Sutton,  *'  Volumetric  Analysis," 
p.  146).  It  must  certainly  be  filtered  off  before  the  Agl 
end  rea(5lion  can  be  applied.  It  should  be  pointed  out,  how- 
ever, that  then  the  above  objedtions  apply  to  the  titrated 
solution  no  longer,  because  it  already  contains,  if  need  be, 
more  than  enough  cyanide  to  decolourise  the  copper  solu- 
tion, and  is  thus  more  likely  to  avoid  any  error  due  to 
the  presence  of  the  precipitate  than,  when  the  colour  only 
is  relied  on,  stopping  the  titration  when  the  liquid  only  is 
barely  decolourised. 

It  will  be  noticed  that  the  ammonia  series  gives  better 
results  than  the  soda  series.  The  following  suggestion 
covers  only  a  small  error,  but  as  it  applies  to  many  ele- 
ments it  is  placed  against  this  noted  difference. 

It  would  need  some  ammonia  to  precipitate  the  iron  in 
those  solutions  containing  it.  This  would  decrease  a  given 
excess  of  ammonia,  and  increase  the  amount  of  ammo- 
nium chloride.  Decreased  ammonia  means  increased 
cyanide,  and  increased  ammonium  chloride  adts  in  the 
same  diredion,  and  therefore  any  imperfedt  recovery  is 
partially  counterbalanced.  This  is  not  given  as  a  com- 
plete explanation  of  the  difference  between  the  values  of 
the  ammonia  and  soda  series,  but  only  as  a  circumstance 
which  favours  increased  accuracy  in  the  one  and  is  in- 
different to  the  other. 

Citric  or  tartaric  acid  are  less  applicable  here  than  before, 
on  account  of  the  coloured  ferric  solution.  Pyrophosphate 
is  said  to  give,  "even  in  the  presence  of  much  iron,  a  per- 
fedlly  clear,  colourless  solution  "  (Moore). 

Manganese. — There  is  finally  a  precipitate  in  each  case. 
With  ammonia  it  formed  only  while  the  cyanide  was  being 
added.  After  completing  the  cyanide  readion  and  filtering 
off,  a  slow  precipitate  of  manganese  may  occur  and  con- 
fuse the  end  readion.  With  soda  the  white  precipitate 
changes  immediately  on  adding  cyanide.  No  further  pre- 
cipitation was  noticed  after  filtering. 

Has  the  cause  of  these  low  results  ever  been  explained  ? 
Field  suggested  that  a  colourless  compound  of  the  two 
metals  existed,  and  tried,  but  vainly,  to  prepare  an  ammo- 
niacal cyanide  of  manganese  and  copper.  There  has  been 
no  new  attempt  made  during  this  investigation  to  separate 
such  a  double  cyanide  from  the  titrated  liquid,  but  it  is 
noticeable  that  such  a  compound  as  Field  sought  to  pre- 
pare has  since  been  shown  to  exist,  and  may  account  for 
the  low  results. 

The  compound  in  question  is  potassium  cupro-mangano 
cyanide,  K2Cu2Mn(CN)6,  which  may  be  prepared, according 
to  Straus  (jfourn.  Chetn.  Soc.  Abs.,  1895,  '•>  485)1  by  adding 
manganese  acetate  to  a  solution  of  potassium  copper 


cyanide  (KCN)6  (CuCN)2  ;  it  crystallises  in  cubes,  and  is 
stable  only  when  damp. 

On  adding  ammunia  to  a  solution  of  a  manganese  salt 
we  have  a  hydrate  precipitated  which  is  eager  to  oxidise 
Itself,  as  is  seen  by  the  changing  colour.  In  our  copper 
solution  such  a  precipitate  may  be  considered  as  a  reducing 
agent  with  power  to  prepare  a  cupro-cyanide  for  the 
already  unoxidised  manganous  salt,  and  so  to  form  the 
cupro-mangano-cyanide. 

A  comparison  of  the  cyanide, — 

K2Cu(CN)4  and  K2Cu2Mn(CN)6, 
shows  that  the  latter  requires  less  CN  per  atom  than   the 
former,  and  therefore  may  account  for  the  low  result. 

To  turn  to  the  more  congenial  task  of  describing  a 
means  of  avoiding  the  interference.  In  attempting,  a 
year  ago,  to  titrate  the  copper  separated  from  a  mixed 
solution  of  copper  and  Swedish  bar-iron,  it  was  found 
that  very  small  quantities  of  something  formed  a  cloud 
black  enough  to  nide  the  fading  copper  colour.  Without 
suspedting  that  what  seemed  so  insignificant  an  amount 
of  manganese  (o'l  per  cent)  was  the  cause  of  the  trouble, 
it  was  lound  that  if  the  solution  was  neutralised,  made 
faintly  acid,  and  the  KCN  added,  there  was  no  precipitate 
whatever  formed.     That  was  with  ammoniacal  solutions. 

A  similar  procedure  may  be  applied  to  the  soda  titration 
as  follows  : — To  the  acid  solution  of  copper  and  man- 
ganese, add  soda  carbonate  until  a  small  precipitate 
lorms,  dissolve  in  a  slight  excess  of  acid,  add  cyanide, 
and  then  the  usual  excess  of  soda  carbonate.  There  are 
no  distindive  colour  changes,  and  therefore  it  is  necessary 
to  know  beforehand  the  aproximate  amount  of  copper 
present.  On  adding  the  carbonate,  the  manganese  falls 
as  a  white  and  somewhat  crystalline  precipitate  of  con- 
siderable bulk,  but  on  standing  it  becomes  brownish, 
granular,  or  powdery,  and  more  compadl. 

The  following  results  were  obtained  in  this  way:— 


00  0*01 

O'lOOO     O'lOOO 


0*05  o'lo  grm.  Mn  present. 

0*1004      oioio  Cu  found. 


The  precipitate  should  not  be  filtered  off  until  the  above 
physical  changes  have  taken  place,  otherwise  a  precipi- 
tate may  form  in  the  filtered  solution  and  confuse  the 
iodide  turbidity.  The  chemistry  of  this  changed  physical 
state  has  not  been  studied.  When  a  bath  colour  has  been 
reached,  there  is  no  further  darkening  on  prolonged 
standing.     The  filtration  is  very  easy. 

Chromium  :  Soda. — A  precipitate  formed  which  is 
somewhat  soluble  in  the  excess  of  soda  carbonate,  and 
hence  the  filtered  solution  is  green.  This  colour  led 
Thomson  to  conclude  that  it  was  impossible  to  perform 
the  titration  in  presence  of  chromic  salts  ;  but  it  is  only 
one  of  a  number  of  cases  where  the  presence  of  large 
amounts  of  carbonate  in  his  cyanide  introduced  interfering 
circumstances. 

With  the  Agl  indicator  the  titration  is  not  satisfadory, 
because  in  the  first  place  the  colour  readion  cannot  be 
utilised,  and,  further,  it  is  believed  that  the  chromium, 
like  the  zinc  precipitate,  but  in  a  less  degree,  can  retain 
some  of  the  copper  in  presence  of  an  excess  of  cyanide. 

Ammonia. — A  precipitate  which  is  somewhat  soluble  in 
the  alkali,  but  with  the  excess  used  (10  c.c.  2  normal)  the 
filtrate  is  quae  colourless. 

The  tabulated  results  were  altogether  unexpeded.  It 
will  be  noticed  that  Field  registers  "  no  interference,"  but 
by  what  procedure  he  arrived  at  so  variant  a  result  it  is 
impossible  even  to  conjedure.  The  ammonia  titration 
has  been  repeated  again  and  again,  and  always  with 
similar  results. 

Such  a  wide  variation  could  not  be  caused  by  dissimilar 
indicators;  besides,  experiment  shows  that  if  the  colour 
only  be  adhered  to,  the  percentage  error  may  be  over  40 
per  cent. 

The  above  results  must  be  taken  only  as  approximation, 
for  this  reason  : — Each  sample  and  the  standard  were 
treated  with  equal  amounts  of  cyanide,  and  therefore 


304 


Exact  Weight  of  Oxygen^  Hydrogen^  and  Nitrogen. 


CitBMicAL  NsWk, 
Dec.  24,  1897. 


"005  "  contains  a  larger  excess  than  the  standard,  and 
'•  o"io  "  a  still  larger.  This  would  (if  the  influence  of  the 
excess  of  cyanide  on  the  copper  is  the  only  consideration) 
make  the  results  somewhat  high;  "o'lo"  more  so  than 
"0"05."  A  corre<5ted  result  might  even  show  the  propor- 
tional  action  of  increasing  amounts  of  chromium  which 
is  suggested  by  the  given  figures.  Elsewhere  this  source 
of  error  has  been  guarded  against. 

I  am  unable  at  present  to  propose  a  probable  explana- 
tion of  the  unexposed  results;  but  I  am  able  to  point  out 
that  the  chromium  existing  as  chromic  acid  exerts  no 
material  influence,  and  thence  an  obvious  means  of  over- 
coming the  difficulty. 

The  yellow  colour  of  the  chromate  does  not  very 
greatly  interfere  with  the  colour  observation.  The  change 
is  from  green  to  a  pure  yellow. 

Cobalt,  Nickel,  Sdver.-^These  were  not  done.  They 
would  interfere  in  a  regular  way,  and  if  estimated  by 
other  means  could  be  allowed  for  in  titrating  a  mixture. 
Thomson  found  it  impradlicable  to  estimate  copper  in 
presence  of  large  quantities  of  cobalt.  With  only  colour 
changes  to  rely  on,  this  is  undoubtedly  the  case.  Field 
states  the  interference  to  be  12  per  cent.  This  only  serves 
to  confirm  Thomson's  statement,  because  the  interference 
of  cobalt  is  really  as  great  as  that  of  nickel.  An  ex- 
planation of  how  this  12  per  cent  was  arrived  at  would  be 
interesting.  Thomson  finds  nickel  to  interfere  120-4  P^^^ 
cent ;  Field,  95  per  cent.  This  difference,  and  some 
others,  might  be  accounted  for  by  supposing  that  the 
amount  of  alkali  and  alkali  salts  varied  with  each  operator 
if  it  were  not  for  the  striking  agreement  in  their  values  for 
silver— 317  and  320. 

Gold,  platinum,  and  palladium  are  omitted  on  account 
of  their  cost.  Thomson  finds  them  to  interfere  32"65, 
19  25,  and  62*45  psr  cent  respedtively.  Such  large  inter- 
ferences suggest  the  possibility  of  estimating  them  by 
some  modification  of  the  cyanide  titration. 

Tin, — Precipitate  with  either  alkali;  not  easy  to  filter. 
The  effedt  of  stannous  salts  was  not  quantitatively 
measured  ;  they  cause  low  results. 

Molybdenum  [Soda  Molybdate), —  No  precipitate  in 
either  case. 

Arsenic  {Soda  Arsenate). — No  precipitate  in  either  case. 

Antimony. — A  precipitate  with  either  alkali ;  easily 
filterable. 

Bismuth  {Nitrate),  —  White  precipitate  ;  moderately 
filterable. 

Lead  {Acetate).  —  Precipitate  with  either  alkali  ; 
moderately  filterable. 

Mercury  {ous). — Final  precipitate  grey ;  only  slight  in 
ammoniacai  solution,  more  with  soda  ;  easily  filtered. 

Mercury  (ic).-^No  precipitate  in  either  case  after  titra- 
tion. It  is  noticeable  that  the  influence  of  mercury  is 
fairly  regular.  Deniges,  who  has  based  so  many  delicate 
analytical  methods  on  the  Agl-fKCN  rea(^ion,  has 
Recently  {jfourn.  Chem.  Soc,  Abs.,  1897,  ii.,  433)  applied 
it  to  the  estimation  of  mercury. 

Uranium  {Nitrate). — Soda:  No  precipitate.  Ammonia: 
Yellow  precipitate,  which  does  not  dissolve  on  adding  the 
cyanide,  unless  the  cyanide  contains  considerable  car- 
bonate; filters  rather  badly. 

Separating  and  Estimating  Copper. 
Precip.tation  of  copper  as  subsulphocyanide  by  sul- 
jjhurous  acid  and  a  sulphocyanide  is  a  well-known  means 
of  separating  copper  from  other  elements.  Hu20  Tamm 
(Chemical  News,  xxiv.,  91 ;  Crookes,  "  Seled  Methods," 
jp.  264)  uses  a  mixture  of  equal  weights  of  sulphocyanide 
and  soda  or  ammonia  bisulphite,  and  claims  by  these 
means  to  separate  copper  from  whatever  substance  may 
iiccompany  it.  As  the  above  table  does  not  include  all 
substances  whatever,  and  as  no  means  are  suggested  for 
avoiding  some  of  the  interferences,  I  gladly  draw  attention 
to  Tanim's  reagent.  So  far  as  I  have  had  occasion  to  use 
it,  or  rather  its  Lke  (H2SO3  and  KCNS),  the  separations 
have  been  very  8atisfa(5tory.      If  the   estimation  of  the 


copper  were  as  easy  as  its  separation,  all  would  be  well, 
but  at  the  very  next  operation  it  b-haves  badly  by  passing 
through  the  filter.  The  subsequent  drying  of  the  filter  is 
lengthy,  and  thus  an  admirable  separation  is  largely 
overlooked  on  account  of  the  difficulties  in  making  the 
estimation. 

The  following  recommendations  are  made  to  meet  this 
difficulty  : — 

Having  precipitated  the  copper,  decant  the  solution  on 
to  a  small  asbestos  or  paper  pulp  filter ;  if  necessary,  the 
filter  may  be  washed  with  a  dilute  solution  of  the  precipi- 
tating reagent  and  then  replaced  in  the  precipitating 
flask.  Add  a  few  c.c.  of  nitric  acid,  20  c.c.  2/N  hydro- 
chloric acid,  and  boil  for  a  few  minutes.  The  copper  and 
any  adhering  sulphurous  acid  are  oxidised,  and  the 
cyanogen  compounds  are  decomposed.  Cool,  neutralise 
with  soda  carbonate,  add  the  usual  excess,  and  titrate  as 
usual. 

No  test  analyses  are  given.  The  analyses  of  nickel, 
copper,  and  zinc  alloys,  to  be  given  in  a  subsequent  paper, 
will  serve  this  purpose  equally  well. 

The  Laboratory, 
Norfolk  Works,  Sheffield. 


EXACT  WEIGHT  OF  OXYGEN,   HYDROGEN, 

AND   NITROGEN. 

By  the  Author  of "  Reform  of  Chemical  aad  Physical  Calculations." 

Professor  Armstrong  said  at  the  Chemical  Society, 
March,  1896  :  "^  pure  substance  is,  and  must  ever  remain, 
tin  ideal  conception  ;  we  should  not  speak  of  a  substance  as 
pure,  when  such  a  condition  of  matter  is  known  to  be 
unattainable."  If  this  be  true  (and  many  eminent 
chemists  endorse  that  sentence),  how  can  we  rely 
upon  experiments  which  give,  for  instance,  the  weight 
of  hydrogen  with  five  decimals  when  we  know  that  the 
hydrogen  we  can  prepare  is  not  pure  ?  even  filtered 
through  a  diaphragm  of  hot  platinum,  it  shows  a  "  com- 
pound "  spe<5lrum  (Chemical  News,  vol.  Ixxvi.,  p.  X70), 
and  as  hydrogen  is  the  lightest  substance  known,  every 
admixture  must  increase  its  weight. 

The  weight  of  oxygen  can  be,  and  no  doubt  is,  deter- 
mined more  exadt  than  that  of  any  other  gas  ;  and  if  Lord 
Ravleigh's  determination  of  the  weight  of  i  litre  oxygen 
=  1*42952  grm.,  is  taken  as  corredt  for  the  latitude  of 
London,  the  experimental  determination  of  hydrogen, 
I  litre  =  0*09001  grm.,  is  more  than  1/16  of  the 
weight  of  oxygen,  and  so  are  the  results  found  by  all 
other  investigators;  i*42952/i6  is  only  0*089345  g""™* 
Tne  difference  between  the  experimental  and  the  calcu* 
lated  value  is  0090010  — o'o89345  =  o  000665  grm.  per  litre 
H  ;  and  such  a  difference  would  be  caused  it  0*39  c.c. 
argon  are  mixed  with  99961  c.c.  pure  hydrogen,  or  0*2 
c.c.  argon  +  0*3  c.c.  N  mixed  with  999*5  c.c.  pure 
hydrogen. 

If  puie  N  has  the  relative  weight  14,  O  being  ■=  16, 
then  a  mixture  of  999  c.c.  N  -f  i  c.c.  argon  would  oe 
=  14*005, — the  value  found  by  M.  Leduc's  latest  experi- 
ments. If  chemists  can  prove  that  they  are  able  to  detedt 
and  remove  these  or  oiher  impurities,  if  they  further  can 
prove  that  their  instruments  and  observations  aie  abso- 
lutely corredl,  and  that  every  experimenter  gets  the  same 
result,  then  they  may  dispute  the  relative  weights  H  =  i, 
N-14,  0«=i6, 

C.  J.  T.  Hanssen. 
Copenhagen,  December  11, 1897. 


The  Astronomer-Royal  of  the  Berlin  Observatory,  who 
has  closely  studied  my  "  Reform,"  has  authorised  me  to 
publish  the  following  : — 


Chemical  Nbws,  | 
Dec.  24,  1897.      I 


Solubility  of  Ammonia  in  Water. 


305 


(Translation). 

Berlin,  Sternwarte, 
.  .  .  My  opinion  is,  that  such  chemicil  and  physical 
investigations  as  are  developed  in  your  "  Reform  of  Cal- 
culations,"quite  apart  from  the  ordinary  course  of  research 
and  study,  not  only  now  are  of  high  importance,  but  ulti- 
mately may  lead  to  very  great  and  eminently  pradlical 
simplifications  of  scientiflc  work  and  study,  and  therefore 
are  worthy  of  public  acknowledgment  and  promotion. 
(Signed), 

Professor  Wm.  Foerster,  Dr.  phil. 

Note  to  Review,  Chemical  News,  August  6th,  1897. 
page  70. — The  "  Carlsberg  Foundation  "  is  one  of  the 
principal  institutions  for  the  advancement  of  science  in 
Copenhagen,  and  administrated  by  Professors  of  the 
University.  My  "Reform"  is  printed  under  the  patronage 
and  at  the  expense  of  that  Institution,  not  by  the  Carls- 
berg Foundation,  as  stated  in  the  Chemical  News. 

Errata. — Chemical  News,  November  26, 1897.  P-  264, 
col.  I.  instead  of  "  0*42952  "  read  "  i  '4^952  "  ;  and  instead 
0/"  56/10"  y^flrf"  56/80." 


QUALITATIVE    RESEARCH    ON    TRACES 

OF     ALKALINE     CARBONATES     IN     PRESENCE 

OF  AN  EXCESS   OF   BICARBONATES, 

OR    OF     BORAX. 

By  ALEX.   LEYS. 

For  the  purpose  of  differentiating  between  the  bicarbon- 
ates  and  the  alkaline  carbonates  we  make  use  ot  a  salt 
of  magnesium,  such  as  the  sulphate,  for  example :  the 
neutral  carbonates  give  a  white  precipitate,  while  with 
bicarbonates  the  solution  remains  clear. 

This  readlion,  which  gives  excellent  results  when 
applied  to  either  one  or  the  other  of  these  salts,  does  not 
answer  when  they  are  mixed.  Such  is  the  case  with  cer- 
tain  products  which  are  met  with  commercially,  under  the 
name  of  '•  milk  preservers."  In  them  we  find  mixtures 
of  carbonate  and  bicarbonate  of  sodium,  o(  carbonate  of 
sodium  and  borax,  or  all  three  of  these  salts  together. 

From  several  analyses  we  have  made  we  have  found 
that  with  a  mixture  of  crystallised  bicarbonate  and  car- 
bonate of  sodium,  in  the  proportion  of  32  of  the  former 
to  68  of  the  latter,  completely  dissolved  in  water,  no  pre- 
cipitate was  formed  with  sulphate  of  magnesium,  from 
which  it  might  be  concluded,  relying  only  on  this  readion, 
that  the  substance  was  formed  of  bicarbonate  of  sodium 
only.  In  the  same  manner  a  mixture  of  crystallised 
carbonate  of  sodium,  with  a  sufficiently  high  percentage 
of  borax,  such  as  40  of  borax  to  60  of  the  neutral  car- 
bonate, does  not  precipitate  sulphate  of  magnesium,  and 
leads  one  to  believe  in  the  same  way,  without  further  in- 
formation, that  the  substance  under  examination  is  nothing 
but  bicarbonate. 

It  is  thus  seen  that  a  small  quantity  of  bicarbonate  or 
of  borax  may  hide  a  considerable  proportion  of  neutral 
carbonate.  We  have  therefore  sought  for  a  more  trust- 
worthy and  sensitive  readlion.  A  saturated  solution  of 
sulphate  of  lime  seems  to  fulfil  our  requiiements. 

Such  a  solution  remains  limpid  durmg  a  certain  time 
onlv  when  we  a"d  to  it  pure  bicarbonate  ot  soda;  then 
we  see  gradually  appear,  throughout  its  mass,  microscopic 
crystals  which  eventually  make  the  liquid  cloudy.  V/ith 
pure  borax  we  also  do  not  observe  any  cloudiness  when 
the  solutions  are  first  mixed,  and,  further,  the  liquid  does 
not  become  cloudy  on  standing;  but  as  soon  as  the 
smallest  quantity  of  neutral  carbonate  is  present  with  one 
or  the  other  salts  in  solution,  the  former,  when  added  to 
a  solution  of  sulphate  of  lime,  immediately  gives  rise  to  a 


heavy,  opaque,  white  precipitate  of  carbonate  of  lime. 
This  readion  is  so  sensitive  that  if  we  pour  over  a  mass 
of  commercial  bicarbonate  of  soda,  usually  sold  as  pure, 
a  quantity  of  water  insufficient  to  dissolve  it  entirely,  we 
immediately  obtain  with  this  first  solution,  when  added  to 
sulphate  of  lime,  the  white  heavy  precipitate  charader- 
istic  of  the  neutral  carbonate.  If  we  throw  away  the 
first  water,  and  add  fresh,  the  second  solution  will  often 
give  the  immediate  precipitate,  and  it  is  only  at  the  third 
addition  of  water  that  the  presence  of  the  neutral  car- 
bonate no  longer  shows  itself,  and  that  we  usually  get  a 
solution  of  pure  bicarbonate  of  soda. 

It  is  easily  seen  from  this,  that  if  we  use  both  sulphate 
of  magnesium  and  sulphate  of  calcium,  we  cannot,  when 
dealing  with  a  mixture,  be  mistaken  as  to  the  nature  of 
its  constituents. 

It  will  suffice,  when  the  sulphate  of  magnesium  does 
not  give  a  precipitate,  to  try  the  sulphate  of  calcium  re- 
adion before  coming  to  any  conclusion.  If,  in  the  latter 
case,  we  do  not  obtain  an  immediate  precipitate,  then 
only  can  we  be  sure  of  the  absence  of  the  neutral  car- 
bonate.—^oMrw.  de  Pharm.  et  de  Chim.,  Series  6,  vol.  vi., 
No.  10. 


ON  THE  SOLUBILITY  OF  AMMONIA  IN  WATER 

AT   TEMPERATURES  BELOW  0°  C. 

By  J.  W.  MALLET, 

Roscoe  and  Dittmar's  table*  of  the  solubility  of  am- 
monia in  water  at  different  temperatures,  under  normal 
pressure,  begins  at  0°  C,  and  there  seems  to  be  no  re- 
corded measurements  of  solubility  at  any  lower  tempera- 
tures. It  is  stated  on  the  authority  of  Fourcroy  and  Van- 
quelint  that  a  "  concentrated  "  aqueous  solution  of  am- 
monia— the  exad  amount  in  solution  not  given  ;  probably 
not  determined — does  not  freeze  till  cooled  to  between 
-38'  and  -41°,  that  it  then  forms  brilliant  flexible 
needles, and  that  at  —49°  it  solidifies  to  a  grey  gelatinous 
mass,  almost  destitute  of  odour. 

It  seemed  inieresting  to  try  the  effed  of  continuing  to 
pass  gaseous  ammonia  into  an  already  strong  aqueous 
solution  at  temperatures  much  below  zero,  and  particu- 
larly to  see  whether  any  visible  change  of  behaviour 
would  mark  the  presence  of  enough  ammonia  to  represent 
the  hydroxide  of  ammonium,  often  assumed  to  exist  in 
the  ordinary  solution,  but  without  any  surplus  water.  The 
proportion  in  question — one  molecule  of  ammonia  for  one 
of  water,  might,  from  an  inspedion  of  Roscoe  and  Ditt- 
mat's  table,  be  expeded  to  occur  at  a  temperature  but 
little  below  zero.  Taking  advantage  of  a  fall  of  finely 
pulverulent  dry  snow,  followed  by  two  or  three  days  of 
cold  weather,  during  which  the  atmospheric  temperature 
was  about  —8°  to  —  i2°C.,the  following  experiments  were 
made  last  winter.  In  anticipation  of  such  an  opportunity, 
the  apparatus  had  been  made  ready  some  time  before. 

A  strong  solution  of  ammonia  in  water  was  placed  in  a 
burette-like  glass  tube  of  the  form  shown  in  Fig.  i,  of 
which  the  larger  cylindrical  part  was  about  220  m.m.  long 
and  25  m.m.  in  internal  diameter,  the  narrow  tube  below 
about  100  m.m.  long  and  only  about  i  m.m.  in  internal 
diameter,  with  a  small  glass  stopcock  about  30  mm.  above 
the  orifice.  The  cylinder  was  graduated  for  about  two* 
thirds  of  its  length  into  cubic  centimetres.  By  means 
of  an  india-rubber  stopper,  perforated  to  grasp  tightly  the 
narrow  tube,  and  then  cut  in  two  in  the  line  of  its  axis, 
this  part  of  the  bmette  was  fixed  in  the  neck  of  an  in- 
verted gas-jar,  the  body  of  which  was  about  180  m.m, 
high,  with  an  internal  diameter  of  about  T20  m.m,,  so 
that  the  cylindrical  body  of  the   burette  could    be  sur- 


*  J.Chem.  Soc,  xii.,  128— quoted  in  Roscoe  and  Schorlemmer's 
"  Treatise  on  Chemistry,"  i.,  385. 

i  Gmelin's  "  Haodbook  of  Chemistry"  (Cavendish  Soc.  tranal,}, 
ii,4a5. 


306 


Solubility  of  Ammonia  in  Water. 


I  Chkmical  NBwe, 
\      Dec.  24.  i8g7. 


rounded  by  a  freezing-mixture  contained  in  the  jar,  with- 
out any  leakage  occurring  at  the  neck,  the  narrow — 
almost  capillary — tube  and  stop-cock  being  below  and 
outside  the  jar.  The  open  mouth  of  the  burette  above 
was  loosely  closed  by  a  doubly-perforated  stopper,  through 
which  passed  a  small  tube  for  the  introdudiion  of  am- 
monia gas,  and  an  alcohol  thermometer,  each  fitting  so 
as  to  be  easily  slid  up  or  down.  The  thermometer  was 
carefully  made  by  Mr.  Henry  J.  Green,  of  Brooklyn,  N.Y., 
contained  pure  (uncoloured)  alcohol,  was  graduated  on 
the  glass  stem,  and  had  the  (centigrade)  scale  verified  by 
comparison  with  a  (Fahrenheit)  mercurial  thermometer, 
itself  tested  by  comparison  with  a  gas  thermometer,  at 
the  following  points:  +32°,  +12°,  —8°,  and  -28°  F.  The 
gaseous  ammonia  was  obtained  by  simply  heating  in  a 
flask  the  strong  aqueous  solution.  There  was,  of  course, 
no  need  for  drying  it,  but  it  was  cooled,  and  incidentally 
in  large   measure   dried,  by  passing  it   first  through^an 


graduation  marks,  from  which  a  measured  sample  might 
then  be  taken  off.  A  number  of  light  glass  flasks,  each 
of  about  300  c.c.  capacity,  furnished  with  stoppers,  were 
in  advance  about  three-fourths  filled  with  water  and 
severally  weighed  with  accuracy  on  a  good  analytical 
balance.  These  flasks  of  water  were  brought  down  to 
0°  C.  by  immersion  in  snow,  and — operating  out  of  doors 
— the  several  samples  of  liquid  ammonia  were  run  into 
them  from  the  burette,  producing  at  once  such  large 
dilution  that  there  was  no  further  fear  of  loss  of  ammonia 
by  standing  over,  with  the  stoppers  inserted,  until  the 
flasks  could  be  re-weighed — the  gain  of  weight  in  each 
case  representing  the  amount  of  liquid  taken  from  the 
burette — and  the  amount  of  real  ammonia  determined  by 
neutralisation  with  a  standard  solution  of  sulphuric  acid. 
The  first  sample  was  taken  at  —40°  C,  and  then,  by  sim- 
ply removing  the  freezing-mixture  of  snow  and  hydro- 
chloric acid  fiom  the  jar,  the  temperature  of  the  liquid  in 


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+40" 


+30° 


+20° 


H-IO" 


0°  -10° 

Fig.  2. 


-20° 


-30 


Fig.  I. 

empty  flask  surrounded  by  snow,  and  then  through  a 
spiral  coil  of  glass  tubing  immersed  in  a  bath  of  snow  and 
common  salt.  Thence  by  an  india-rubber  connedting 
tube  it  passed  into  the  already  strong  solution  in  water 
contained  in  the  burette.  This  was  surrounded  in  the  jar 
by  a  freezing-mixture  of  snow  and  commercial  hydro- 
chloric acid,  both  materials  having  been  separately  cooled 
down  in  advance  by  snow  and  salt.  In  consequence  of 
the  evolution  of  heat  as  more  ammonia  was  absorbed  by 
the  water  in  the  burette,  it  became  necessary  to  allow 
ample  time  for  cooling  down  again,  and  to  renew  the 
freezing-mixture  in  the  jar,  drawing  off  the  old  mixture 
by  means  of  a  specially  arranged  and  rapidly  ading 
syphon.  In  order  to  get  the  lowest  temperature  reached 
(between  -45°  and  —  46°C.)  it  was  necessary  to  doubly 
cool  the  last  portions  of  snow  and  hydrochloric  acid, 
first  by  snow  and  salt,  and  then  by  separate  exposure  to 
some  of  the  already  cooled  snow  and  hydrochloric  acid 
mixture.  The  passage  of  the  gas  into  the  solution  was 
continued  until  it  went  through  very  freely  unabsorbed. 
the  liquid  in  the  burette  continually  increased  in  volume, 
so  that,  when  samples  were  drawn  off  by  the  stopcock, 
enough  was  first  run  off  to  effedtually  cool  the  projecting 
part  of  the  narrow  tube  and  the  stop-cock  itself,  and  to 
bring  the  level  of  the  remaining  liquid  down  to  one  of  the 


the  burette  was  allowed  to  slowly  rise,  and  as  the  ther- 
mometer marked  different  desired  points  it  was  raised  for 
a  moment  out  of  the  liquid,  another  sample  drawn  off  into 
the  water  in  one  of  the  flasks  beneath,  and  the  ther- 
mometer lowered  again.  One  or  two  fairly  good  measure- 
ments of  the  volumes  of  the  samples  were  made,  but, 
owing  to  the  necessity  for  quick  work,  and  the  difficulty 
of  seeing  satisfadlorily  through  the  dimmed  surface  of  the 
glass,  most  of  these  measurements  were  little  to  be  re- 
lied on. 

The  following  results  were  obtained,  so  expressed  as  to 
form  a  continuation  of  Roscoe  and  Dittmar's  table.  The 
atmospheric  pressure  at  the  time  was  743 — 744*5  m.m., 
corredted  for  temperature  of  the  mercurial  column. 

At  -10' C.  I  grm.  of  water  dissolved  i*ii5  grms.  of 
ammonia. 

At   -20° 
ammonia. 

At   -30° 
ammonia. 

At  -40° 
ammonia. 

The  taking  up  of  enough  ammonia  to  form  ammonium 
hydroxide  was  not  attended  with  any  apparent  change  of 
behaviour,  and  continuous  liquefadion  went  on  smoothly 


I  grm.  of  water  dissolved  1768  grms.  of 
C.  I  grm.  of  water  dissolved  2"78i  grms.  of 
C.  I  grm.  of  water  dissolved  2*946  grms.  of 


ChkmicaL  Mbws, 

Dec.  24, 1S97. 


Revision  of  the  A  iomic  Weight  of  Ntcket. 


307 


to  the  lowest  temperature  reached,  with  no  separation  of 
any  solid  produdl.  After  the  freezing-mixture  had  been 
withdrawn  the  temperature  rose  at  first  very  gradually  in 
consequence  of  rapid  surface  evaporation  of  ammonia.  At 
—  25°  C.  (barometer  at  743'4  m  m.,  corr.),  steady  but  not 
tumultuous  ebullition  took  place  and  continued  for  several 
minutes.  A  sample  taken  at  this  point  had  the  compo- 
sition :   I  prm.  of  water  and  2  554  grms.  of  ammonia. 

By  interpolation  from  Regnault's  results,  the  tension  of 
the  vapour  from  liquefied  ammonia  at  —  25'6°  C.  would  be 
about  1167  m.m. 

A  sample  was  also  taken  at  -3-9°,  which  proved  to 
consist  of  I  grm.  of  water  and  0*947  §'''"•  of  ammonia — 
this  last  corresponding  almost  exadtly  with  the  calculated 
proportion  for  ammonium  hydroxide,  and  agreeing  also 
quite  closely  with  an  extension  of  Roscoe  and  Dittmar's 
table  to  the  temperature  named,  allowance  being  made  for 
the  pressure  bfing  a  little  below  normal. 

These  results  are  graphically  plotted  in  fig.  2,  which 
inclu(5es  also  the  determinations  of  Roscoe  and  Dittmar 
for  +40°  to  0°.  It  will  be  seen  that  the  curve  changes 
rapidly  a  little  below  the  temperature  corresponding  to  the 
formation  of  (NH4)0H,  and  the  amount  of  ammonia  ab- 
sorbed is  much  greater  than  would  be  called  for  by  an 
extension  of  Roscoe  and  Dittmar's  numbers. 

As  regards  the  reversal  of  curvature  before  —30°  is 
reached,  some  allowance  must  doubtless  be  made  for  loss 
of  ammonia  by  the  samples  drawn  at  the  lowest  temper- 
atures  in  dropping  through  the  air  into  the  ice-water  in  the 
flasks  in  spite  of  the  precautions  taken  to  minimise  loss 
from  this  source.  And,  in  view  of  the  fadl  that  liquefied 
ammonia  boils  at  -337°  under  a  pressure  of  749  3  m.m. 
(Bunsen),  the  amount  of  ammonia, found  in  the  contents 
of  the  burette  below  this  point  would,  01  course,  go  on 
increasing  indefinitely,  depending  simply  on  the  length  of 
time  allowed  for  condensation  and  the  moie  or  less  iree 
supply  of  the  gas.  It  appears  that  ammonium  hydroxide, 
if  such  a  substance  exist,  or  the  solution  01  ammonia  in 
water  in  proportion  corresponding  to  such  a  compound, 
continues  to  dissolve  gaseous  ammonia,  or  mixes  with 
liquefied  ammonia,  nown  to  and  bryond  the  normal 
boiling-point  of  the  latter,  but  the  proportion  dissolved  is 
much  greater  than  would  be  called  for  by  an  extension 
of  the  curve  representing  solubility  at  temperatures 
above  0°. 

As  has  been  stated,  measurement  of  the  volumes  of  the 
samples  taken  could  not  be  very  satisfadtorily  carried  out. 
It  may  be  mentioned,  however,  that  a  comparison  of 
volume  with  weight  gave  for  the  liquid  at  —30°  a  density 
of  about  0718,  and  for  that  at  -40°abouto  731,  as  referred 
to  water  at  +/^°.  The  latter  figure  being  greater  than  the 
former  may  probably  be  accounted  for  by  the  very  high 
value  of  the  coefficient  of  dilatation  for  liquefied  gases. 
Calculating  from  Jolly's  results,  the  density  of  liquefied 
ammonia  itself  at  -40°  ought  to  be  something  like  0673. 
— American  Chemical  jfournal,  xix.,  No.  9. 


LONDON     WATER    SUPPLY. 

Report  on  the  Composition  and  Quality  of  Daily 
Samples  of  the  Water  Supplied  to  London 
FOR  the  Month  Ending  November  30TH,  1897. 

By  SIR  WILLIAM   CROOKES,  F.R.S., 

and 

PROFESSOR  DEWAR,  F.R.S. 

To  Major-General  A.  De  Courcy  Scott,  R.E., 
Water  Examiner,  Metropolis  Water  Act,  1871. 

London,  December  10th,  1897. 
SiR,_We    submit    herewith,    at    the    request    of   the 
Diredors,  the  results  of  our  analyses  of  the  182  samples 
of  water  collected  by  us  during  the  past  month,  at  the 
several  places  and  on  the  several  days  indicated,  from  the 


mains  of  the  London  Water  Companies  taking  their 
supply  from  the  Thames  and  Lea. 

In  Table  I,  we  have  recorded  the  analyses  in  detail  of 
samples,  one  taken  daily,  from  Nov.  ist  to  Nov.  30th 
inclusive.  The  purityof  the  water,  in  respedt  to  organic 
matter,  has  been  determined  by  the  Oxygen  and  Com- 
bustion processes;  and  the  results  of  our  analyses  by 
these  methods  are  stated  in  Columns  XIV.  to  XVIII. 

We  have  recorded  in  Table  II.  the  tint  of  the  several 
samples  of  water,  as  determined  by  the  colour-meter 
described  in  previous  reports. 

In  Table  III.  we  have  recorded  the  oxygen  required  to 
oxidise  the  organic  matter  in  all  the  samples  submitted 
to  analysis. 

Of  the  182  samples  examined  by  us,  one  was  recorded 
as  "clear  but  dull,"  the  remainder  being  clear,  bright,  and 
well  filtered. 

The  rainfall  at  Oxford  shows  afurtherserious deficiency, 
the  adtual  fall  during  the  month  being  only  I"I5  inches, 
against  a  thirty  years'  average  of  210  inches,  making  a 
deficit  of  o'95  inch.  The  total  deficit  for  the  year  is  now 
1-36  inches. 

Our  baderiological  examinations  of  252  samples  have 
given  the  results  recorded  in  the  following  table  ;  wehave 
also  examined  77  other  samples,  from  special  wells,  stand- 
pipes,  &c.,  makmg  a  total  of  329  samples  in  all : — 

Microbes 
per  c.c. 

New  River,  unfiltered  (mean  of  26  samples)  ..  488 

New  River,  filtered  (mean  of  25  samples)       ..  13 
Thames,  unfiltered  (mean  of  26  samples)        ..   27,173 
Thames  water,  from  the  clear  water  wells  of 
five  Thames-derived  supplies  (mean  of  122 

samples) 27 

Ditto        ditto               highest  218 

Ditto        ditto              lowest  i 

River  Lea,  unfiltered  (mean  of  26  samples)    ..  593 
River  Lea,  from   the  clear  water  well  of  the 
East  London  Water  Company  (mean  of  26 

samples) 12 

The  very  small  rainfall  during  the  past  three  months 
has  had  the  usual  good  efTedt  on  the  quality  of  the  London 
water  supply,  which  is  now  both  chemically  and  badierio- 
Ipgically  excellent. 

We  are.  Sir, 

Your  obedient  Servants, 

William  Crookes. 
James  Dewar. 


A    REVISION     OF    THE    ATOMIC    WEIGHT    OF 

NICKEL.* 
First  Paper. — The  Analysis  of  Nickelous  Bromide. 

By  THEODORE  WILLIAM  RICHARDS 
and 
ALLERTON  SEWARD  CUSHMAN. 

(Concluded  from  p.  296). 

When  the  manipulation  had  thus  been  mastered,  the  art 
of  preparing  absolutely  pure  nickelous  bromide  had  been 
perfected  (-ee  Analysis  7),  and  the  atomic  weight  of 
nickel  had  been  approximately  determined,  the  method  of 
procedure  in  subsequent  analyses  was  changed.  The  now 
perfedly  clear  solution  was  treated  with  just  enough 
argentic  nitrate,  prepared  from  the  purest  weighed  silver, 
to  complete  the  precipitation.  The  mean  between  the 
two  possible  end-points  was  determined  by  titrating  back- 

♦  Contribution  from  the  Chemical  Laboratory  of  Harvard  College, 
From  the  /  roceeutngs  of  the  American  Academy  0/  Ars^ind  Sciences, 
vol.  xxxui.,  No.  7. 


3o8 


Chloronitrides  0/  Phosphorus. 


I  Chbuical  NBwa, 
'     Dec.  24,  1897. 


wards  and  forwards  with  hundredth  normal  argentic 
nitrate  and  hydrobromic  acid  solutions  (for  the  details  see 
Proc.  Amer.  Acad.,  xxx.,  384) ;  and  thus  was  determined 
the  ratio  of  silver  to  nickelous  bromide  entitled  Series  III. 
After  this  end-point  had  been  determined,  a  slight  excess 
of  argentic  nitrate  was  added  to  the  solution,  and  the 
whole  was  violently  shaken.  The  precipitate  was  colledted 
upon  a  Gooch  crucible,  washed  with  water  containing  a 
trace  of  argentic  nitrate,  later  with  pure  water,  and  finally 
dried  and  weighed.  The  traces  of  asbestos  carried  away 
by  the  wash  water  were  of  course  determined,  and  all 
the  usual  precautions  were  taken  to  insure  great  accuracy. 
Thus  was  obtained  the  series  of  results  given  in  Series  II. 


The  Atomic  Weight  of  Nickel. 
0=i6*ooq;  Ag  =  i07'93. 
First  Series  (Preliminary).— RATio=2AgBr; 


NiBra. 


Weight  of 

Weight  of 

Number 

Sample 

nickelous       Weight  of       argentic 

Atomic 

of 

of 

bromide         insolubU 

s        bromide 

weight  of 

expt. 

NiBr,. 

in  vacuum.        residue 
Grms.           M.grms 

in  vacuum. 
Grms. 

nickel. 

I. 

I. 

2'26lI3             3*22 

3-88769 

58-646 

2. 

I. 

2-8o668           7-08 

482431 

58-708 

3- 

II. 

1-4x317           3-05 

2-42880 

58716 

4- 

II. 

1 71759           o*88 

2-95307 

58650 

5- 

III. 

2-48565           5-24 

4-27357 

58651 

6. 

III. 

4-32997         15-83 

7  44280 

58-700 

7- 

III. 

218072          O'oo 
Average.. 

374856 

58693 
58-680 

Second  Series.— Ratio  = 

zAgBr  :  NiBrj. 

Weight 

Weight 

Number     Samp] 

e        of  nickelous 

of  argentic 

Atomic 

of 

of 

bromide 

bromide. 

weight  of 

expt. 

NiBra 

in  vacuum. 
Grms. 

in  vacuum. 
Grms. 

nickel. 

8. 

III. 

3*28039 

5-63892 

58-691 

g. 

III. 

2-70044 

4-64208 

58686 

10. 

III. 

3-38230 

5-81391 

58698 

II. 

III. 

i'33459 

2-29435 

58-670 

12; 

IV. 

1-25054 

2-14963 

58-693 

13" 

IV. 

1-32278 

2-27384 

58-690 

14. 

IV. 

2-24452 
Average. . 

385805 

58-705 
58-690 

Third 

Series.— Ratio  = 

2AgBr  :  NiB 

Weight 

Weight 

Number     Samp 

e        of  nickelous 

of 

Atomic 

of 

of 

bromide 

silver 

weight  of 

expt. 

NiBr, 

in  vacuum. 
Grms. 

in  vacuum. 
Grms. 

nickel. 

8. 

III. 

328039 

3-23910 

58701 

9' 

III. 

270044 

266636 

58709 

10. 

III. 

3-38230 

3-33990 

58689 

II. 

III. 

I"33459 

131787 

58689 

12. 

IV. 

1-25054 

1-23482 

58698 

I3' 

IV. 

i'32278 

1-30629 

58-675 

14. 

IV. 

2-24452 
Average.. 

2-21652 

58-676 
s8-6qi 

In  the  table  above,  the  first  column  records  the  number 
of  the  experiment,  the  second  records  the  number  of  the 
sample  of  nickelous  bromide  used,  while  the  third  records 
the  weight  of  this  salt  taken.  The  extreme  right  hand 
column  contains  the  atomic  weight  of  nickel  computed 
from  the  values  contained  in  the  one  just  to  the  left  of  it, 
and  those  contained  in  the  third. 

A  very  interesting  evidence  of  the  accuracy  of  these 
results  is  the  relationship  between  the  amount  of  silver 
taken  and  the  amount  of  argentic  bromide  obtained.  From 
the  second  and  third  series,  we  find  that  15*5 1556  grms. 
of  nickelous  bromide  yielded  26-67078  grms.  of  argentic 
bromide,  requiring  15-32086  grras.  of  silver.     This  leads 


to  the  inference  that  argentic  bromide  contains  57*444  P^'' 
cent  of  silver — a  quantity  which  agrees  essentially  with 
the  value  57*445  per  cent  found  by  Stas.  Since  the  bro- 
mine used  had  been  already  found  to  be  free  from  other 
halogens,  and  the  silver  was  known  to  be  perfedtly  pure, 
we  have  in  these  results  conclusive  proof  that  no  nickel 
salt  was  occluded  by  the  argentic  bromide,  as  well  as  a 
satisfa<5lory  "  check"  upon  the  accuracy  of  the  work. 

When  we  examine  the  results  with  respedl  to  the 
various  samples  of  the  salt  analysed,  we  find  a  very 
interesting  and  satisfying  uniformity.  The  four  samples 
of  nickelous  bromide  gave  the  following  results  for  the 
atomic  weight  of  nickel  :— 

Sample    1 58*677 

„        II 58683 

„      III 58688 

„       IV 58689 

The  slight  rise  in  the  value  with  increasing  purity  is 
not  large  enough  to  have  any  weight,  for  there  are  analyses 
in  the  lowest  series  giving  higher  individual  results  than 
any  in  thehighest  series.  Hence  we  are  forced  to  the  con- 
clusion that  the  least  carefully  purified  specimens  of 
nickelous  bromide  must  have  been  essentially  identical 
with  the  most  carefully  purified.  The  chances  are  evi- 
dently exceedingly  small  that  the  impurities  would  so 
combine  as  exactly  to  counterbalance  one  another. 

The  further  discussion  of  this  important  question  will 
be  reserved  until  more  experimental  work  has  been  done. 
For  the  present,  it  is  our  opinion,  at  this  first  halting 
place  in  a  long  investigation,  that  the  atomic  weight  of 
nickel  cannot  be  far  from  58 '6g  if  O  =  i6'oo,  or  58-25  if 
O  =  15-88. 


ON  THE  CHLORONITRIDES  OF  PHOSPHORUS.' 

By  H.  N.  STOKES, 

In  a  former  article  {Am.  Chem.  yourn.,  xvii.,  275,  1895; 
Ber.  d.  Chem,  Ges.,  xxviii.,  437)  I  have  shown  that  in 
addition  to  the  phosphonitrilic  chloride, f  P3N3CI6,  dis- 
covered by  Liebig,  there  exists  another,  P4N4CI8,  of 
similar  properties,  which  is  formed  at  the  same  time,  but 
in  smaller  quantity.  The  opinion  was  expressed  that 
these  bodies  belong  to  a  series  of  polymers,  (PNClj)!!, 
the  existence  of  other  members  of  which  was  indicated 
by  the  formation,  in  small  amount,  of  a  liquid  of  the  same 
empirical  composition  (Am.  Chem.  yourn.,  xvii.,  277,  280, 
290).  The  yield  of  this  secondary  produft — only  2  per 
cent  of  the  theoretical  or  i  per  cent  of  the  pentachloride 
used — was  too  small  to  allow  of  its  preparation  in  quanti- 
ties large  enough  to  admit  of  the  isolation  of  its  supposed 
constituents,  but  a  fra(5tional  distillation  of  the  few  grms. 
at  my  disposal  showed  that  it  contained  crystalline  sub- 
stances of  higher  boiling-points  than  those  of  the  two 
bodies  thus  far  known. 

The  method  of  preparation  then  employed  consisted  in 
distilling  phosphorus  pentachloride  with  a  large  excess  of 
ammonium  chloride  in  a  retort,  at  atmospheric  pressure  ; 
it  offered  but  little  prospedt  of  obtaining  the  higher 
members.  The  total  yield  of  phosphonitrilic  chloride  was 
but  15  per  cent  of  the  theoretical,  most  of  the  penta- 
chloride being  converted  into  "  phospham  "  by  the  excess 
of  ammonium  chloride,  while  only  those  members  could 
be  obtained  which  distil  unchanged  at  atmospheric  pres- 
sure. Decreasing  the  amount  of  ammonium  chloride  re- 
sulted only  in  a  loss  of  pentachloride  by  volatilisation, 
without  increasing  the  yield  of  the  bodies  sought  after. 


*  Published  by  permission  of  the  Director  of  the  United  States 
Geological  Survey.  From  the  American  Chemical  Journal,  vol.  xix., 
No.  9,  November,  1897. 

i  1  propose  in  future  to  use  the  term  phosphorus  chloronitride  to 
denote  any  body  composed  of  phosphorus,  nitrogen,  and  chlorine,  the 
name  phosphonitrilic  chloride  being  reserved  for  chloronitrides  be- 
longing to  the  series  (f  NCl,)», 


Chemical  Nbws,  1 
Dec.  24,  1897.      I 


Chloromtrides  of  Phosphorus . 


309 


The  following  method  has  been  found  to  give  entirely 
Batisfadlory  results  ;  several  new  bodies  have  been  ob- 
tained, and  the  simpler  phosphonitrilic  chlorides  at  least 
are  now  easily  accessible  substances  : — If  equal  molecular 
weights  of  phosphorus  pentachloride  and  ammonium 
chloride  be  heated  in  a  sealed  tube,  there  results  a  mix- 
ture of  chloronitrides,  which  is  partly  crystalline  and 
soluble  in  gasolene,  but  for  the  greater  part  liquid  and  in- 
soluble in  this  solvent,  and  of  a  high  degree  of  complexity. 
This  may  be  distilled  almost  without  residue,  the  distil- 
late being  a  crystalline  mass,  impregnated  with  an  oil, 
and  composed  almost  wholly  of  a  mixture  of  members  of 
the  series  (PNClaln  in  nearly  theoretical  amount,  con- 
taining about  50  per  cent  P3N3CI6,  and  25  per  cent 
P4N4CI8,  the  remainder  consisting  of  the  higher  homo, 
logues.  From  this  distillate  the  new  bodies,  with  one 
exception,  have  been  isolated. 

The  series,  as  at  present  known,  consists  of  the  fol- 
lowing  (the  melting-  and  boiling-points  are  corrected) : — 

Melting-  Boiling-point. 

point.  13  m.m.  760  m.m. 

Triphosphonitrilic 

chloride,  (PNCl2)3        114°  127°  256-5°' 

Tetraphosphonitril  i  c 

chloride,   (PNCl2)4      i23-5»  188°  328-5°t 

Pentaphosphonitrilic 

chloride,  (PNCIj^s  40-5-41°  223-224-3''  Polymerises 
Hexaphosphonitri  1  i  c 

chloride,  (PNC^e  91°         261-263°      Polymerises 

Heptaphosphonitrilic 

chloride,  (PNClz)?. 

Liquid  at      ..      ..         -18°       289-294°      Polymerises 

Polyphosphonit  r  i  1  i  c 
chloride,  (PNCIa)*    Below  red    Depolymerises  on  dis- 
heat.  tillation. 


♦  iSs'S"  at  100  m.m. 


+  242°  at  100  m.m. 


There  were  obtained,  further,  a  liquid  residue  of  the 
same  empirical  composition,  of  a  mean  molecular  weight 
corresponding  nearly  to  (PNClj)!!,  and  a  small  amount 
of  a  chloronitride,  PfiNyClg,  not  belonging  to  the  above 
series.  The  absence  of  the  lower  members,  PNClj  and 
(PNCl2)2,  is  remarkable,  and  theoretically  significant. 
Indications  of  a  trace  of  a  substance  more  volatile  than 
the  compound  (PNCl2)3  and  of  similar  but  stronger  odour, 
were  observed,  but  there  is  no  evidence  that  it  consists  of 
one  of  the  missing  bodies. 

One  of  the  most  remarkable  properties  of  the  phospho- 
nitrilic chlorides  is  that  each  member  of  the  series  is  con- 
verted by  heat  into  the  rubber-like  polyphoiphonitrilic 
chloride,  a  body,  or  mixture  of  bodies,  of  very  high  mole- 
cular weight,  which  is  highly  elastic  and  insoluble  in  all 
neutral  solvents,  but  which  swells  enormously  in  benzene, 
and  which,  on  distilling  at  a  higher  temperature,  breaks 
down  into  a  mixture  of  all  the  lower  members  mentioned 
above,  which  can  then  be  separated  by  appropriate 
means.  In  this  way  it  is  possible  to  convert  any  phos- 
phonitrilic chloride  quantitatively  into  any  other  by  heat 
and  distillation  alone.  In  preparing  any  desired  member, 
therefore,  we  are  not  limited  to  the  quantity  obtained 
from  the  first  readlion  produft,  but  may  work  the  residues 
over  and  over  again  until  completely  converted  into  the 
body  sought  after.  With  the  exception  of  a  few  cases,  in 
which  the  number  of  members  is  limited,  as  the  aldehyds 
and  cyanic  acids,  this  series  is  therefore  unique  ;  I  know 
of  no  other  series  of  inorganic  compounds  in  which  this 
is  possible.  Polymerisation  takes  place  slowly,  but  per 
ceptibly,  at  250°,  and  is  almost  instantaneous  at  350°, 
while  depolymerisation  begins  at  about  350°,  and  is  rapid 
at  a  temperature  close  to  incipient  red  heat.  Triphospho- 
nitrilic chloride,  P3N3CI6,  is  the  only  member  which  can 
be  distilled  in  considerable  amount  at  atmospheric  pres- 
sure without  considerable  polymerisation,  and  even  this 
polymerises  almost  completely  on  long  boiling;  at  760 


m.m.  pressure  the  tetra-compound,  P4N4CI81  boils  at 
328-5°,  a  temperature  at  which  polymerisation  occurs 
quite  rapidly,  but  this,  as  well  as  the  penta-compound, 
PgNsClio,  and  the  hexa-compound,  PfiNeCIn,  can  readily 
be  distilled  at  13  m.m. ;  the  hepta-compound,  PyN7Clj4, 
suffers  marked  polymerisation  on  distilling  even  at  this 
pressure,  and  its  isolation  is  therefore  attended  with  much 
loss.  Owing  to  the  rapid  change  at  higher  temperatures, 
I  have  been  unable  to  isolate  any  of  the  higher  members, 
which  remain  as  a  considerable  oily  residuum,  and  there 
seems  to  be  but  little  probability  of  this  being  effected  by 
any  known  method,  unless  by  distilling  in  a  nearly  abso- 
lute vacuum. 

The  greatest  difficulty  in  the  separation  of  the  members 
is  caused  by  polymerisation.  It  requires  but  a  small 
amount  of  polyphosphonitrilic  chloride  to  cause  the  liquid 
to  thicken  or  gelatinise,  and  therefore  to  be  incapable  of 
further  distillation ;  and  some  of  this  body  is  always 
formed  in  the  course  of  a  prolonged  fradtioning  of  the 
higher  members.  It  was  found,  however,  that  this 
polymer  is  much  more  easily  attacked  by  water  than  the 
lower  members  ;  when  signs  of  polymerisation  are  ob. 
served,  it  is  only  necessary  to  interrupt  the  distillation 
and  heat  the  residue  for  some  time  with  water,  when  the 
resulting  oil  is  again  in  a  condition  to  continue  fradlioning. 

The  loss  in  this  operation  is  small,  but  the  tediousness 
of  a  fradional  distillation  is  thereby  extraordinarily  in< 
creased. 

It  is  noteworthy  that  no  regular  progression  exists  in  the 
melting-points  of  the  phosphonitrilic  chlorides,  and  the 
same  is  true  of  their  solubility  in  the  ordinary  neutral  sol- 
vents, but  the  solubility  varies  in  the  same  sense  as  the 
fusibility.  Of  the  members  of  known  molecular  weight, 
the  second,  tetraphosphonitrilic  chloride,  is  the  least 
soluble  and  has  the  highest  melting-point,  while  the  cor* 
responding  tetrametaphosphimic  acid  is  the  least  soluble 
and  most  stable  of  the  derived  acids.  With  resped  to 
their  stability  towards  water,  the  new  members  (poly- 
phosphonitrilic chloride  excepted)  resemble  those  already 
described,  being  scarcely  attacked  by  prolonged  boiling. 
In  ethereal  solution,  however,  there  is  a  perceptible  de- 
crease of  stability  towards  water  as  we  rise  in  the  series 
— a  fadl  already  noted  with  regard  to  the  first  two  mem* 
bers  {Am.  Chem.  yonrn.,  xvii.,  289). 

Notwithstanding  the  high  molecular  weight  of  the  bodies 
isolated,  no  indication  of  isomers  has  been  observed, 
although  the  fradtioning  was  carried  out  very  thoroughly 
up  to  300°  at  13  m.m. 

The  investigation  will  be  continued  with  the  objeA  of 
obtaining  the  metaphosphimic  acids,  and,  if  possible,  the 
two  missing  lowest  members  of  the  phosphonitrilic 
chloride  series.  The  right  of  further  investigation  in  this 
field,  however,  is  )iut  reserved. 

Experimental  Part. 
A  mixture  (which  need  not  be  very  intimate)  of  4 
parts  perfedly  dry  phosphorus  pentachloride  and  i 
part  ammonium  chloride,  as  required  by  the  equation 
PCl5-HNH4Cl  =  PNC)24-4HCl,  is  introduced  into  an  or- 
dinary  "  bomb  "  tube,  which  has  previously  been  drawn 
out  to  a  neck.  It  is  practicable  to  fill  the  tube  entirely 
to  the  neck,  so  that  the  charge  for  a  tube  of  ordinary 
dimensions  is  about  125  grms.,  yielding  50 — 55  grms.  of 
chloronitrides.  After  sealing,  the  length  of  the  neck,  ex- 
clusive of  the  rather  long  capillary,  should  be  about  10 
cm.  As  the  mixture  liberates  55  per  cent  hydrochloric 
acid,  it  is  necessary  to  regulate  the  heating  with  great 
care  and  to  open  the  tube  repeatedly.  The  temperature 
of  the  furnace  is  allowed  to  rise  to  150°,  at  which  the  re- 
a(5lion  begins,  when  the  gas  is  at  once  shut  off,  and  the 
tube  opened  at  about  100°  (in  the  furnace  !j.  This  opera- 
tion is  repeated  several  times,  the  temperature  being 
allowed  to  rise  i — 2°  higher  each  time.  When  the 
evolution  of  hydrochloric  acid  has  slackened  and  the 
contents  of  the  tube  are  mainly  liquid  while  hot,  the 
temperature  may  be  carried  to  200°  or  higher,  until  little 


316 


Chloronitridcs  of  Phosphorus. 


I  Chemical  News, 
I     Dec   24,  1897. 


or  no  gas  is  given  off.  The  operation  requires  care  and 
judgment,  but  with  careful  working  it  is  possible  to  avoid 
explosions,  and  to  obtain  with  a  four-tube  furnace  about 
200  grms.  of  mixed  chloronitrides  in  sixteen  hours. 

The  contents  of  the  tube,  after  cooling,  generally  con- 
sist of  a  buttery  mass  or  of  a  thick  yellow  liquid  filled 
with  fine  prisms  and  plates  ;  if  heated  much  above  200°, 
the  liquid  frequently  separates  into  two  layers.  The  crys- 
tals are  soluble  in  gasoline,  but  the  bulk  of  the  produdt 
remains  as  an  immiscible  oil. 

The  neck  of  the  tube  is  now  bent  down,  the  tube  placed 
in  an  inclined  combustion  furnace,  and  by  cautious 
heating,  finally  to  incipient  redness,  the  contents  are  dis- 
tilled out.  There  remains  in  the  tube  a  very  voluminous 
spongy  black  residue,  of  inconsiderable  weight,  due  to 
unavoidable  impurities,  and  to  the  impossibility  of 
causing  complete  readlion  in  the  sense  of  the  above 
equation.  The  distillate  consists  of  a  crystalline  mass 
impregnated  with  a  yellow  oil,  and  contains  about  95  per 
cent  of  the  theoretical  amount  of  phosphonitrilic  chlorides, 
with  some  phosphorus  pentachloride,  the  chloronitride 
PeNyClg,  and  other  substances  of  unknown  nature.  Be- 
fore proceeding  further,  it  is  necessary  to  remove  the 
pentachloride,  and  for  this  purpose  the  distillate  is  melted, 
poured  into  cold  water,  and  the  flask  heated  in  the  water- 
bath  for  about  two  hours,  the  liquids  being  mixed  by 
blowing  air  through  them.  The  chloronitrides  are  then 
allowed  to  clear  under  the  hot  water,  and  forced  out  by 
means  of  a  wash-bottle  arrangement ;  a  separatory  funnel 
cannot  be  used,  as  the  substance  solidifies  in  the  neck, 
and  if  allowed  to  solidify  under  the  wash  water  it  absorbs 
so  much  of  this  as  to  cause  annoyance  in  the  subsequent 
distillation.  Special  drying  before  distilling  is  un- 
necessary. 

The  produdt  is  then  distilled  up  to  200°  at  13  to  15  m.m., 
using  an  Anschiitz  flask,  as  the  distillate  solidifies  in- 
stantly on  cooling.  The  residue,  containing  the  members 
PjNjCljo  up,  is  set  aside  for  later  systematic  fractional 
distillation. 

(This  residue  contains  the  small  amount  of  PeNyCIg, 
formed  as  a  secondary  produdt  of  the  original  reagents, 
and  as  this  is  apt  to  cause  inconvenience  at  a  later  stage, 
by  accumulating  with  the  PeNgClia,  it  is  perhaps  well  to 
remove  as  much  as  possible  at  this  point.  For  this  pur 
pose  the  residue  is  allowed  to  stand  for  a  day  or  two  at 
the  room  temperature,  and  the  crystals  removed  by 
sucking  out  under  a  good  vacuum,  best  in  a  large  Gooch 
crucible.  The  filtrate  is  cooled  for  a  day  or  two  in  a 
refrigerator,  and  the  new  crop  of  crystals  separated  in  the 
same  way,  the  filtering  flask  being  allowed  to  stand  in 
the  ice-box.  The  oily  filtrate  is  set  aside,  and  the  united 
crystalline  produdts  distilled  up  to  240°  at  13  m.m., 
whereby  most  of  the  P5N5CI10  passes  over.  The  resdue, 
consisting  of  PeNeClij,  the  small  amount  of  PfiNyClg, 
and  the  adhering  oil,  is  allowed  to  crystallise  in  the 
refrigerator,  and  the  viscous  mass  is  extradled  several 
times  with  small  amounts  of  gasoline  (boiling  at  50°  to 
80°).  The  residue  is  boiled  with  benzene,  which  extrads 
the  P6N7CI2,  which  crystallises  on  concentrating  and 
cooling.  The  portion  dissolved  by  the  gasoline  is  worked 
up  with  the  other  residues.  This  is  the  method  adtually 
employed,  but  I  am  not  entirely  convinced  of  its  ne- 
cessity, as  it  is  not  possible  to  remove  all  the  P6N7Clg  in 
this  way). 

The  distillate,  about  70  per  cent,  consists  essentially  of 
P3N3CI6  and  P4N4Ci8,  which,  if  desired,  may  be  easily 
separated  by  fradional  distillation  in  vacuo,  followed  by 
crystallisation  from  benzene.  This  is  more  convenient 
than  the  method  of  separating  by  steam  {Amer.  Chem. 
yourn.,  xvii.,  280).  If  it  is  desired  to  convert  it  into  the 
higher  members,  it  is  placed  in  a  combustion  tube  bent 
down  at  about  20  cm.  trom  the  open  end,  and  which  it 
should  not  fill  more  than  one-half  after  melting.  This  is 
laid  in  an  inclined  combustion  furnace,  and  heated  to 
gentle  boiling  of  the  contents.  It  is  well  to  heat  the  tube 
somewhat  strongly  at  a  short  distance  above  the  liquid,  as 


superheating  the  vapour  promotes  polymerisation.  The 
time  required  for  polymerisation  varies  greatly;  pure 
triphosphonitrilic  chroride  may  require  two  hours  or 
more;  with  the  above  mixture  the  time  is  less,  and  is 
shorter  the  higher  the  boiling-point ;  it  is  shortened  by 
adding  already  gelatinised  substance,  which  causes  the 
liquid  to  thicken,  and  may  then  be  but  a  few  minutes ;  it 
is  also  shortened  by  heating  under  pressure.  Sooner  or 
later  the  liquid  begins  to  thicken,  and  finally  it  is  converted 
into  a  stiff,  transparent  mass,  with  little  or  no  liquid,  and 
generally  discoloured  by  traces  of  organic  matter.  The  tube 
is  then  conneded  with  a  long-necked  receiver,  exhausted, 
and  the  depolymerisation  and  distillation  effeded  by 
heating,  from  the  front  backward,  to  incipient  redness. 
This  part  of  the  operation  proceeds  rapidly,  as  it  is  only 
necessary  to  guard  against  frothing  over,  and  to  ensure 
complete  condensation,  the  latter  being  easily  effeded  by 
having  the  limb  of  the  tube  at  least  20  cm.  long:  100 
grms.  can  be  worked  up  at  one  time,  and  the  tube  can  be 
used  repeatedly.  The  residue  does  not  weigh  more  than 
a  few  m.grms.  The  distillation  may  also  be  made  at 
atmospheric  pressure,  but  the  yield  of  higher  produdts  is 
thereby  diminished.  The  distillate,  which  entirely  re- 
sembles that  first  obtained,  except  in  containing  no 
phosphorus  pentachloride  and  no  P6N7Clg,  is  distilled  as 
before,  the  washing  being  omitted.  In  this  way  the 
whole  quantity  of  material  can  finally  be  convened  into 
a  mixture  of  members  higher  than  P4N4CI8- 

The  united  residues  boiling  above  200°  are  now  sub- 
mitted to  systematic  fradional  distillation  at  13  to  15 
m.m.,  using  an  Anschiitz  fl*sk,  provided  with  a  "trap," 
to  prevent  flowing  back.  During  the  first  distillation 
polymerisation  generally  begins  when  the  temperature  of 
the  bath  has  reached  270°,  but  with  later  distillations  at 
a  higher  temperature,  and  the  higher  the  purer  the  frac- 
tions are.  When  polymerisation  begins,  which  is  indi- 
cated by  frothing  and  thickening,  the  operation  is 
interrupted,  and  the  residue  heated  in  the  flask  with  water 
in  the  water-bath  until  it  has  completely  liquefied,  which 
is  assisted  by  agitation,  the  oil  separated,*  and  the  distil- 
lation continued.  It  has  not  been  found  practicable  to 
continue  the  distillation  at  a  higher  temperature  than  that 
obtained  by  heating  the  bath  to  370°,  for  the  liquid  begins 
to  polymerise  in  a  few  moments,  and  but  an  inconsider- 
able distillate  can  be  obtained.  Moreover,  at  this  temper- 
ature the  polymer  shows  signs  of  breaking  down  into 
simpler  bodies,  and  the  distillate  does  not  consist  only  of 
high-boiling  members.  The  total  amount  of  final  residue 
is  not  very  great,  and  as  shown  below  consists  likewise  of 
phosphonitrilic  chlorides  of  still  higher  molecular  weight. 
In  later  distillations,  from  200°  upward,  polymerisation 
usually  stops  the  process  at  260°  to  270°,  but  after  appro- 
priate washing  the  residue  maybe  distilled  to  a  much  higher 
temperature.  After  8  to  10  distillations  three  main  frac- 
tions are  obtained,  which  are  then  worked  up  separately. 
A8P5N5  Clio,  though  crystalline,  is  extremely  soluble,  it  is 
necessary  to  carry  out  the  distillations  with  the  first  main 
fraction  uutil  a  praClically  sharp  boiling-point  is  obtained, 
in  which  connection  it  may  be  noted  that  at  17  to  20  m.m. 
a  change  of  i  m.m.  pressure  causes  a  change  of  about  1° 
in  the  boiling-point,  and  at  13  m.m.  a  change  of  about  2°. 
P7N7Cii4,  being  liquid,  must  also  be  isolated  by  distilla- 
tion only,  but  at  its  boiling-point  polymerisation  is  so 
rapid  that  great  loss  ensues  during  a  series  of  distilla- 
tions. The  final  purification  of  PeNeClij  can  be  effected 
by  repeated  re-crystallisation  from  Denzene,  combined 
with  treatment  with  gasoline  to  remove  the  PgNyClg. 
which  always  accompanies  it,  having  nearly  the  same 
boiling-point:  a  complete  separation  of  these  two  bodies 
can  scarcely  be  effected  by  distillation  alone. 

Owing  to  many  modifications  introduced  in  developing 
the  above  method,  no  accurate  statement  of  the  yield 
can   be    given ;  the    final    produCt    was   about   225  grms. 

*'In  this  case  a  separatory  funnel  may  be  used,  as  the  higher 
cblorouitrides  are  liquid  below  80°. 


Dec.  24.  1897 


Chloromtrides  of  Phosphorus^ 


ti 


P5N5CI10.   no  grms.  PeNeClia,   10  grms.  P7N7CI14,  and 
5  grms.  P6N7CI9. 

Analytical  Methods. 

With  the  exception  of  polyphosphonitrilic  chloride,  the 
chloronitrides  were  analysed  by  decomposing  in  the  fol- 
lowing manner: — 

For  phosphorus,  by  warming  with  alcohol  and  a  little 
ammonia   in    a  platinum    crucible   until  completely    dis 
solved,  evaporating  to  dryness,  and  heating  to  fuming  for 
an  hour  with  strong   sulphuric  acid,  the  crucible  being 
kept  covered. 

For  nitrogen,  by  treating  as  above,  omitting  the  am- 
monia. 

For  chlorine,  by  heating  with  alcohol  and  ammonia.  It 
is  necessary  to  precipitate  with  silver  nitrate  in  the 
presence  of  a  large  volume  of  10  per  cent  nitric  acid  and 
to  filter  hot,  in  order  to  avoid  the  formation  of  silver 
metaphosphimates,  which  are  difficultly  soluble  in  dilute 
nitric  acid. 

In  decomposing  polyphosphonitrilic  chloride,  which  is 
attacked  by  water  alone,  the  alcohol  was  omitted.  The 
method  of  Carius  was  used  for  determining  chlorine,  as  it 
was  found  that  otherwise  compounds  insoluble  in  dilute 
nitric  acid  were  formed.  For  the  other  chloronitrides 
this  method  offers  no  advantage. 

Molecular  weight  determinations  were  made  by  the 
boiling-point  method  with  the  apparatus  of  Hite  [Amer. 
Chem.yourn.,  xvii.,512),  using  as  solvent  carefully  purified 
and  dried  benzene. 

(The  molecular  weight  of  P3N3CI6  has  been  determined 
by  the  vapour  density  method  (jf.  Chem.  Soc,  [2] ,  ii.,  225 ; 
Amer.  Chem.  jfourn.,  xvii.,  283).  A  series  of  determina- 
tions by  the  boiling-point  method  gave  346,  350,  353. 
Calculated,  347'9). 

Pentaphosphonitrilic  chloride,  P5N5CI10. —  This  body, 
carefully  purified  by  fradlional  distillation,  as  described 
above,  gave  on  analysis  : — 

Calculated  for 
PjNiClio.  Found. 

P         2675  2687 

N        I2'II  1205 

CI       ..      .,      ..         61-14  61-42 

Ratio,  P  :  N  :  CI  =  i  :  0-99  :  200. 

Molecular  Weight.     Solvent :  Benzene. 

Percentage 
OrniF.  Grms.  Molecular       variation  from 

solvent.  substance.        Elevation,    weight  tound.       theoretical. 

46-49  14688  0-137°  619  -f6-2 

„  2-9439  0-287°  589  +i'6 

»  4'4337  0-437°  583  -+0-5 

Calculated  for  P5N5CI10,  579*8. 

Pentaphosphonitrilic  chloride  fuses  at  405° — 41°,  and 
boils  at  223° — 224-3°  (corr.)  at  13  m.m.  Its  vapour  is 
without  the  pronounced  and  charadteristic  aromatic  odour 
possessed  by  that  of  triphosphonitrilic  chloride.  At  its 
melting-point  it  is  miscible  in  all  proportions  with  ben- 
zene, gasoline,  ether,  and  carbon  disulphide,  and  cannot 
be  rc-crystallised  from  any  of  these  solvents  ,  in  fadt, 
small  fragments  liquefy  instantly  in  their  concentrated 
vapours.  Glacial  acetic  acid  also  dissolves  it  quite 
readily,  and  from  this  solution  water  throws  it  out  as  an 
oil,  solidifying  at  once  on  touching.  It  shows  a  decided 
tendency  to  superfusion,  especially  when  not  absolutely 
pure;  when  left  by  evaporating  its  ether  or  benzene  solu- 
tion, it  may  remain  liquid  for  days,  but  solidifies  at  once 
on  touching  with  a  glass  rod,  usually  to  a  decidedly  crys 
talline  mass,  at  other  times  to  a  transparent  glass.  The 
pure  substance,  when  fused,  slowly  solidifies,  long  flai 
crystals  shooting  out  through  the  liquid,  which  are  limited 
only  by  the  size  of  the  vessel,  crystals  of  10  cm.  in  length 
being  readily  obtained.  It  contrads  greatly  on  solidifying. 
When  pure  the  solidified  mass  is  naturally  dry,  but  the 
least  contamination  with  other  members  of  the  series 
causes  a  portion  to  remain  liquid,  which  is  easily  detedted 
by  crushing  on  a  piece  of  filter-paper ;  this  is  a  very  good 


test  of  its  purity.  This  tendency  to  superfusion  must  be 
borne  in  mind  in  separating  it  by  fradtional  distillation  ;  a 
nearly  pure  sample  will  remain  liquid  much  longer  than 
the  higher  or  lower  fradions.  In  ether  solution  it  is  per- 
ceptibly more  easily  attacked  by  water  than  the  preceding 
chloronitride,  but  hot  water  alone  is  almost  without 
adlion. 

HexaphosphonilriHc  Chloride,  P6N6CI12. — After  re- 
peated crystallisation  from  benzene,'  tnis  gave — 

Calculated  for 

PoNe  .l,j.  Found. 

P         26-75  2698 

N       12-11  12-37 

CI      6ri4  6098 

Ratio,  P  :  N  :  CI  =  I  :  i-oi  :  1-98. 

Molecular  Weight.     Solvent :  Benzene. 

Percentage 
Grms.  Grms.  Molecular     variation  from 

solvent.  substance.         Elevation.         weight.  theoretical. 

4712  1-8058  0-152°  673  —3-2 

„  3-6190  0-293°  700  -1-0-6 

4572  I'OIOI  0083°  711  .f2-I 

,,  4-4898  0365°  718  -+-3-2 

„  8-0070  0664°  704  +V2 

Calculated  for  PeNeCliz,  695-8. 

Hexaphosphonitrilic  chloride  fuses  at  91°  (corr.),  and 
boils  at  261°— 263°  (corr.)  at  13  m.m.,  and  at  281°— 282° 
(corr.)  at  26  m.m.  It  maybe  re-crystallised  from  benzene, 
in  which,  however,  it  is  more  soluble  than  triphospho- 
nitrilic chloride;  ether,  gasoline,  and  carbon  disulphide 
also  dissolve  it  readily;  in  alcohol  it  dissolves  somewhat 
slowly  with  decomposition.  It  shows  no  tendency  to 
superfusion.  It  crystallises  well,  in  rather  large  crystals, 
which  were  examined  by  Mr.  Wirt  Tassin,  to  whom  I  am 
indebted  for  the  following  statement : — 

"  P6N6CI12  crystallises  in  the  orthorhombic  system  in 
long  prismatic  crystals,  showing  the  following  forms : — 
c  (001),  b  (010),  m  (no),  0  (iii),  n  (on).  Of  these  c  is 
the  dominant  form  ;  b  large  and  well  developed;  m  fair, 
though  usually  narrow  ;  and  0  and  n  small  and  usually  in 


m 


m 


similar  development,  c,  b,  m,  o  is  the  combination  occur- 
ring most  frequently ;  less  often  c,  b,  m,n,  0;  and  rarely 
c,  b,  m.  Angles  m  :  m  57°  28',  b  :  m  6i°  16',  b  :  n  40°  23', 
n  :  c  49°  37'.  Axial  ratio  a  :  b  :  <;  =  0-54824  :  i  :  i-i7568. 
The  crystals  are  optically  positive.  Plane  of  the  optic 
axes  (100) ;  colourless  to  white;  transparent;  and  have 
a  perfedt  basal  cleavage." 

It  is  scarcely  attacked  by  boiling  water,  but  if  kept  in 
moist  air  it  very  slowly  evolves  hydrochloric  acid.  Its 
ether  solution,  shaken  with  water,  slowly  gives  a  meta- 
phosphimic  acid ;  syrupy  chlorhydrines  are  formed  as 
intermediate  produds. 

(To  be  coDtioued). 


♦  A  contamination  with  PgNjClg  may  be  detedled  by  treatment 
with  gasoline,  when  the  much  smaller  cryitals  of  the  latter  are  seen 
to  dissolve  much  more  slowly. 


312 


kepresentation  of  the  Isomtric  Benzene  Hexachlorides, 


PROCEEDINGS    OF    SOCIETIES. 

CHEMICAL  SOCIETY. 
Ordinary  Meeting,  December  2nd,  1897. 

Professor  Dewar,  F.R.S.,  President,  in  the  Chair. 

CERTiFrcATES  Were  read  for  the  first  time  in  favour  of 
Messrs.  Charles  Edward  Britain,  B.Sc,  11,  Highfirld, 
Scarborough;  William  Arthur  Caldecott,  B.A.,  Box  1891, 
Johannesburs,  S.A.R.  ;  John  Cooper,  B.Sc,  20,  D^^rwent- 
water  Road,  Gateshead  ;  Frederick  Cowling,  Clay  Cross, 
near  Chesterfield  ;  Wilbraham  T.  A.  Edwards,  Reduit, 
Mauritius ;  Frederick  Gilderdale,  3,  Havelock  Street, 
Newcastle;  William  Setten  Gilles,  Coniston,  Cedars 
Road,  Beckenham  ;  Willam  Hobson  Mills,  B.A.,  Jesus 
College,  Cambridge;  Frank  Forster  Renwick,  Glengall, 
Woodford  Green,  E^sex ;  William  Colebrook  Reynolds, 
64,  Lydford  Road,  Paddington,  W. :  Andrew  Jamieson 
Walker,  B.A.,  Kilycadden,  Kiilysordon,  Co.  Donegal; 
Ernest  Charles  Weismiiller,  30,  Pepys  Road  S.,  New 
Cross,  S.E. 

The  following  were  duly  eledted  Fellows  of  the 
Society :— John  Ball,  Ph.D  ;  William  Ball;  Alec.  Alfred 
Beadle  ;  Richard  Oxley  Burland,  J.P. ;  Alexander  McLean 
Cameron;  Alexander  Clarkson  ;  Frank  CoUingridge, 
B.Sc;  James  Murray  Crofts,  B.A. ;  John  Daniell;  Andrew 
James  Dixon,  F.I.C.;  Oscar  Guttmann,  F.I.C;  Robert 
Hamilton ;  John  Harger,  B.Sc,  Ph.D. ;  James  Walter 
Horseman;  Charles  Kelly;  Tom  Lemmey.  B.A. ;  James 
Scott  Maclaurin,  D.Sc. ;  Alan  Macmullen,  B.A.  ;  Charles 
Jodrell  Mansford,  B.A. ;  Edward  Masters ;  John  A. 
Mathews,  M.A.  M.Sc  ;  Philip  George  Gregory  Moon  ; 
James  Charles  Philip,  B.Sc,  Ph.D. ;  Alexander  Ferguson 
Reid  ;  Ernest  Henry  Roberts  ;  Edward  Sydney  Simpson, 
B.E. ;  Robert  Francis  Wood  Smith  ;  Thomas  Southern, 
Jun. ;  Frederick  William  Steel;  Michael  Edmund 
Stephens;  George  Stubbs ;  Edward  Howard  Tripp, 
Ph.D. ;  John  Scriven  Turner ;  Framjee  Khursedjee  Vic- 
cajee  ;  Pejcy  John  Vinter,  M.A. ;  Arthur  James  While; 
Francis  Samuel  Young,  M.A. 

The  President  called  the  attention  of  Fellows  to  the 
{a(5t  that,  although  according  to  the  Council  regulations  no 
paper  could  be  announced  which  had  not  been  received, 
it  was  open  to  any  Fellow  to  make  a  communication  at  a 
meeting  of  the  Society  in  the  event  of  there  being  avail- 
able time,  provided  that  he  handed  a  written  statement  to 
the  Secretaries  of  the  essence  of  his  communication. 

In  answer  to  a  question  from  Dr.  Hake,  the  President 
said  that  the  appearance  of  such  communications  in  the 
Proceedings  would  be  subjeA  to  the  editorial  discretion  of 
the  Secretaries,  and  that  when  presented  as  full  papers 
they  would  come  before  the  Publication  Committee  in  the 
usual  way. 

The  following  papers  were  read  :— 

•124.  "  The  Representation  of  the  Isomeric  Benzene 
Hexachlorides  by  Collie's  Space-formula."  By  Francis 
Edward  Matthews,  Ph.D. 

This  paper  discusses  Collie's  space-formula  for  benzene 
from  the  point  of  view  of  the  halogen  hex-addition  com 
pounds.     The  formula  is  shown  to  explain  the  existence 
of  two  isomeric  hexachlorides  satisfadlorily,  and  the  ac- 
companying formulae  are  proposed  for  these  compounds. 

These  formulae  likewise  explain  the  differences  in  sta- 
bility towards  alcoholic  alkalis.  The  a-subsiance,  con- 
taining the  chlorine  in  the  ortho-position  to,  and  on  the 
same  side  of  the  carbon  nucleus  as  the  hydrogen  atoms 
with  which  it  is  removed  in  the  form  of  hydrogen  chloride, 
is  readily  decomposed ;  the  j3-substance,  in  which  the 
hydrogen  and  chlorine  are  on  opposite  sides  of  the 
nucleus,  has  much  greater  stability.  The  remainder  of 
the  paper  discusses  the  formation  of  benzene  di  derivatives 
from  mono-derivatives,  and  it  is  maintained  that  their 


I  Chemical  .News, 
1     Dec.  24,  1&97. 

formation  is  best  explained  by  assuming  the  previous 
formation  of  unstable  or/Ao-addition  compounds  instead 
of  unstable  m^^a-compuunds,  as  Collie  has  suggested. 


a-Cetnpound.  /3-Compoucd. 

Discussion. 

Dr.  Wynne  asked  whether  any  explanation  could  be 
given  of  the  formation  of  i  :  2  :  4 -trichlorbenzene  from 
the  banzene  hexachlorides  by  the  adlion  of  alcoholic 
potash.  The  usually  accepted  formulae  for  benzene  gave 
no  clue  to  the  reason  for  the  produdion  of  unsymmetrical 
derivatives  fn  such  cases,  and  he  was  unable  to  see  that 
the  formulae  now  proposed  were  more  satisfatftory  in  this 
respedt. 

Dr.  Lapworth  pointed  out  that  the  author's  statement 
as  to  the  impossibility  of  explaining  the  production  of  two 
different  hexachlorides  from  benzene  by  means  of  any 
formula  prior  to  Collie's,  appeied  to  need  qualification. 
It  is  easily  seen  that  Kekul6's  formula  represents  several 
stereoisomeric  substances,  as  each  *•  doubly  bound  "  pair 
of  carbon  atoms  may  form  a  fumaroid  or  maleoid  com- 
bination. Taking  into  consideration  the  circumstance 
that,  for  a  number  of  reasons,  the  formula  must  be  con- 
sidered as  a  labile  one,  the  positions  of  the  ethylenic  and 
single  linkings  being  supposed  to  alternate,  it  is  not  im- 
possible that,  under  the  conditions  of  interadtion  of 
chlorine  and  benzene,  the  latter  may  readt  in  the  form  of 
two  or  more  of  its  possible  stereoisomers.  The  addition 
of  chlorine  to  a  pair  of  carbon  atoms  double  bound  as  in 
fumaroid  compounds  would,  of  course,  afford  a  trans- 
dichloro-derivative,  whilst  a  cis-dichloro-compound  would 
result  if  the  original  combination  were  of  the  maleoid 
type.  Kekuld's  formula,  therefore,  would  appear  to  afford 
a  perfectly  satisfactory  explanation  of  the  production  of 
more  than  one  benzene  hexachloride. 

Mr.  E.  J.  Parry  asked  if  Dr.  Matthews  had  any  experi- 
mental evidence  for  assignmg  the  symmetrical  lormula 
to  the  a-hexachloride,  and  the  unsymmetrical  to  the 
0  compound.  If  the  explanations  of  substitution  offered 
by  Collie  and  the  author  were  correct,  there  should  cer- 
tainly be  twice  as  much  ortho-  as  para-dichlorbenzene 
produced  when  chlorbenzene  is  chlorinated.  Further,  he 
could  not  understand  why,  if  these  explanations  were 
correct,  the  nitration  of  chlor-benzene  should  give  ortho- 
and  para-compounds  whilst  the  chlorination  of  nitro- 
benzene, or  the  nitration  of  nitrobenzene,  should  yield 
meta-compounds. 

Dr.  Matthews,  in  reply,  stated  that  it  had  always 
seemed  to  him  a  remarkable  faCt  that  1:2:4-  trichlor- 
benzene  alone  was  produced  by  the  aCtion  of  alkalis  upon 
the  benze-ne  hexachlorides.  He  had  made  several  attempts 
with  large  quantities  of  material  to  isolate  the  symmetrical 
modification,  but  always  without  result.  The  formation 
of  the  1:2:  4-compound  could,  however,  be  easily  ex- 
plained,  either  by  Kekul^'s  or  Collie's  formula. 

With  regard  to  Dr.  Lapworih's  remaiks,  the  formulae 
proposed  above  account  for  the  production  of  two  and  not 
of  a  greater  number  of  isomerides  which  might  be  ex- 
pected if  these  hexachlorides  were  regarded  as  cis-  and 
trans-modifications  ;  whilst  certain  properties  of  the  com- 
pounds do  not  seem  to  harmonise  with  the  idea  that  they 
are  stereoisomerides. 


Chemical  NcWs,  i 
Dec.  24, 1897.     I 


Chemical  Notices  front  Poreign  Sources, 


313 


The  answer  to  Mr.  Parry's  questions  are  contained  in 
the  paper  itseli;  the  difference  in  stability  of  the  two 
hexachlotides  towards  alkalis  is  explained  by  assuming 
that  hydrogen  chloride  is  more  readily  removed  from  atoms 
in  the  ortho-position  and  on  the  same  side  of  the  carbon 
nucleus  than  from  those  in  which  these  conditions  do  not 
obtain.     Hence  the  above  formulae  were  assigned. 

•125.  *' Compounds  of  Piperidine  with  Phenols.^'  By 
Otto  Rosenheim,  Ph.D.,  and  Philip  Schidrowitz,  Ph.D. 

With  a  view  of  obtaining  substances  of  the  general 
formula  (C6H(,_«))(C5Hio:N)h,  which  seemed  to  be  of 
interest  on  account  of  their  relation  to  the  phenylene- 
diamines  and  polyamines,  the  authors  studied  the  adtion 
of  piperidine  on  phenols  and  their  derivatives  in  the 
presence  of  dehydreting  agents.  Although  so  far  un- 
successful in  this  diredlion,  a  series  of  addition  produds 
in  the  nature  of  salts  was  observed,  in  which  piperidine 
adls  as  the  base  and  the  phenol  as  the  acid.  They  are 
well  crystallised  compounds,  easily  obtained  by  the  inter- 
aAion  of  their  components,  usually  in  ethereal  solution. 
They  are  resolved  into  their  constituents  by  strong  acid 
or  alkalis.  M.  Oechsner  de  Coninck  (C.  R.,  1897,  cxxiv., 
563)  describes  a  number  of  colour  readlions  obtained  by 
the  adion  of  piperidine  and  other  bases  on  phenols  in 
dilute  aqueous  solution,  but  has  apparently  not  observed 
the  formation  of  the  addition  compounds  described  in  the 
paper. 

The  influence  of  the  number  and  position  of  the  oxy- 
and  nitro-groups  in  the  phenols  on  the  additive  capacity 
of  the  piperidine  molecule  was  studied,  but  no  general 
rule  could  be  deduced. 

The  following  compounds  were  analysed,  and  are 
described  in  the  paper  : — Compounds  of  piperidine  (i  mol.) 
with  pyrocatechol  (2  mols.),  guaiacol  (2  mols.),  hydro- 
quinone  (t  mol.),  pyrogallol  (i  mol.),  vanillin  (i  mol.), 
0'  and  ^"nitrophenol  (1  mol.),  picric  acid  (i  mol.),  1:2:4- 
dinitronaphthol  (t  mol.).  Phenol, ^-chlorphenol,  resorcinol, 
phloroglucinol,  m-nitrophenol,  and  a-  and  j3-naphthol  did 
not  furnish  crystalline  compounds. 


EDINBURGH     UNIVERSITY    CHEMICAL 

SOCIETY. 

Monday,  November  2gth,  1897. 

Mr.  W.  W.  Taylor,  M.A.,   B.Sc,  in  the  Chair. 

Dr.  Bolam  read  a  paper  on  "  Electrolysis  in  Organic 
Chemistry," 

The  paper  was  mainly  historical,  and  dealt  first  with 
the  work  of  Kolt^e,  Bourgoin,  and  Kekule.  It  was  pointed 
out  that  L6b  had  recently  given  a  confirmation  of 
Kckule's  "anhydride  theory"  by  eledtiolysing  phthalic 
acid. 

When  phthalic  acid  is  dissolved  in  alcohol  and  a  few 
drops  of  an  acid  added  to  increase  the  condudlivity,  the 
passage  of  a  weak  current  through  the  solution  for  some 
time  gives  an  almost  quantitative  yield  of  phthalic  anhy- 
dride. Longer  duration  of  the  current  results  in  the  for- 
mation of  phthalic  ether  in  large  quantity. 

Dr.  Bolam  also  referred  to  the  use  of  the  alternate  cur- 
rent, and  concluded  by  referring  to  some  technical  appli- 
cations in  organic  chemistry. 

There  was  a  large  attendance,  and  Dr.  Bolam  was 
thanked  for  his  paper. 


CORRESPONDENCE. 

ZINC      IN     WATER. 

To  the  Editor  of  the  Chemical  News. 
Sir,— I  read  in  the  Chemical  News  (vol.  Ixxvi.,  p.  293) 
that  Mr.  Percy  Richards  has  detedted  zinc  in  a  sample  of 


water  used  for  drinking  purposes,  in  Berkshire,  which  was 
supplied  by  a  galvanised  iron  pipe. 

It  may  be  interesting  to  note  that  among  the  samples 
of  water  examined  last  year  in  my  laboratory  there  were 
some  from  the  island  of  Madeira  which  presented  the 
same  charader,  and  which  had,  likewise,  been  condudted 
into  the  town  of  Funchai  by  galvanised  iron  pipes.  There 
was  a  large  deposit  of  oxide  and  carbonate  of  zinc  in  one 
of  the  bottles. 

Putting  aside  the  zinc  contamination,  the  water  was 
of  great  purity.  As  zinc  is  a  metal  whose  compounds 
have  a  noxious  adtion  upon  the  economy,  it  is  evident 
that  galvanised  iron  pipe  cannot  be  used  with  safety  to 
supply  water  for  drinking. — I  am,  &c., 

T.  L.  Phipson,  Ph.D. 

Casa  Mia,  Patney,  S.W., 
December  18, 1897. 


CHEMICAL 


NOTICES    FROM 
SOURCES. 


FOREIGN 


MoTB.— All  degrees  of  temperature  are  Centigrade  anliasotberwUe 
expressed. 

Bulletin  de  la  Societe  Chimique  de  Paris, 
Series  3,  Vol.  xvii.-xviii.,  Nos.  16-17. 

Acftion  of  Chlorine  on  Pentachloretbane  in  the 
presence  of  Chloride  of  Aluminium. — A.  Mouneyrat. — 
Although  chloride  of  aluminium  has  a  special  adtion  on 
chloral  (removing  oxygen),  it  seemed  to  the  author  to  be 
of  interest  to  verify  whether  or  not  this  powerful  syntheti- 
cal agent  might  not  be  a  chloridising  agent  in  the  acyclic 
series.  He  therefore  placed  150  grms.  of  pentachlor- 
etbane (CjCljH)  in  a  flask  heated  to  70°  and  provided 
with  a  vertical  condenser,  and  exposed  to  diffused  light. 
Dry  chlorine  was  passed  through  for  thirty  hours.  Tnis 
gas  was  not  absorbed,  no  hydrochloric  acid  gas  was  given 
off,  neither  was  there  any  hexachlorethane  formed.  He 
then  added  about  30  grms.  of  anhydrous  chloride  of 
aluminium,  and  again  passed  a  current  of  dry  chloride 
as  before.  This  time  the  gas  was  completely  absorbed, 
and  HCl  was  given  off.  Alter  four  hours  the  contents  of 
the  flask  were  solid.  On  throwing  small  portions  of  this 
white  mass  into  water,  hydrochloric  acid  is  given  off,  and 
a  white  powder  rises  to  the  surface.  This  powder  was 
dissolved  in  ether,  the  solution  dried  over  chloride  of  cal- 
cium, and  distilled.  A  body  smelling  strongly  of  cam- 
phor was  obtained,  sublimating  at  the  ordinary  tempera- 
ture. Analysis  showed  that  it  was  hexachlorethane 
(CgCie),  which  was  formed  according  to  the  following 
equation:— CCl3,CCl2H-fCla  =  CCIa.CClj-f  HCl.  It  is 
an  excellent  method  of  preparing  hexachlorethane,  and 
the  return  is  almost  theoretically  exadt. 

A(5tion  of  Chlorine  on  Tetrabromide  of  Acetylene 
in  tbs  presence  of  Chloride  of  Aluminium. — A. 
Mouneyrat. —  Thirty  grms.  of  anhydrous  chloride  of 
aluminium  were  added  to  100  grms.  of  tetrabromide  of 
acetylene,  in  a  flask  furnished  with  a  vertical  condenser 
and  heated  to  70 — 80°;  hydrochloric  acid  is  strongly 
given  off.  After  four  hours,  a  current  of  dry  chlorine  was 
passed,  and  at  first  more  hydrocnloric  acid  was  given  off, 
followed  by  torrents  of  bromine.  When  the  latter  ceased 
and  no  more  chlorine  was  absorbed,  the  mass  was  thrown, 
a  little  at  a  time,  into  water  containing  soda-lye;  a 
white  powder  came  to  the  surface  if  the  temperature  had 
not  exceeded  80°,  and  if  the  quantity  of  chloride  of  alu' 
minium  added  was  small ;  if,  on  the  other  hand,  the  tem- 
perature had  exceeded  80°,  and  if  the  quantity  of  chloride 
of  aluminium  was  in  excess,  the  powder  is  black.  After 
redlification,  analysis  showed  this  powder  to  be  hexa* 
chlorethane,  CtCle,  formed  according  to  the  following 
equation:  CHBra,CHBra-tCl8»CCl3,CCl3+Br4+(HCl}4. 


314 


Meetings  for  the  Week, 


{Chemical  News, 
Dec.  24,  IS97. 


On  Glucosines.— C,  Tanret. — The  author  finds  that 
by  adting  on  glucose  by  ammonia  at  100°  a  series  of 
bases  is  formed,  among  which  are  the  glucosines  a 
and  /3'  MM.  Brander  and  Stoehr  contest  the  formulas 
of  these  glucosines,  maintaining  that  the  glucosine  a, 
boiling  at  136°,  has  not  the  formula  C6H5N2,  but  is  a 
mixture  of  pyridine,  pyrazine,  and  methylpyrazine.  As 
for  the  glucosine  /3,  boiling  at  155 — i6i)°,  these  authors 
only  obtained  a  few  decigrms.  of  dimethylpyrazine  boiling 
at  147 — 155°.  M.  Tanret  shows  that  these  conclusions 
are  incorrecft,  and  that  the  formulae  he  gave  are  the  true 
ones. 

Hydrochlorate  of  Glucosamine. — C.  Tanret. — The 
hydrochlorate  of  glucosamine  possesses  bi-rotation,  but 
not  always  to  the  same  extent.  The  author  imagined 
that  there  must  be  modifications  of  this  body,  and  he 
found  that  hydrochlorate  of  giucosamine-a  had  a  rotatory 
power  of  ttD  =  +100°;  and  that  the  modification  (8,  in  a 
solution  of  I  part  in  25  parts  of  water  gave  ao  =  77'50°. 
The  two  modifications  of  hydrochlorate  of  glucosamine 
have  a  distindl  rotatory  power;  and  they,  moreover,  crys- 
tallise in  two  different  systems. 

On     A(J\ive     Methylbuiylenediamine     (Methyl-2, 
NHaCHj.CH.CHj.CHaNHa 
Diaminobutane     x'4),  | 

CH3 
— L.  Etaix  and  P.  Freundler. — The  authors  find  that  the 
successive  operations  to  which  they  submitted  the  primitive 
body  have  not  racemised  it  to  any  noticeable  degree, 
though  it  might  have  been  expedted  that  either  the  adtion 
of  hydrazin  or  of  hydrochloric  acid  at  150°  would  destroy 
its  rotatory  power.  It  would  appear  from  this  that 
racemisation  depends,  not  on  the  agents  of  transforma- 
tion, but  on  the  groupings  which  are  attached  to  the 
asymmetric  carbon. 

On  Dinitrophenyl-diacetyl-methane.  —  F.  Mottelet. 

Acetylacetonate  of  sodium  is  dissolved  in  strong  alcohol 

in  a  water-bath,  and  to  this  solution,  warm,  is  added  an 
equal  quantity  of  chlordinitrobenzene.  A  white  crystal- 
line deposit  is  immediately  formed.  When  this  deposit 
no  longer  increases  the  readtion  is  considered  to  have 
ended.  The  mass  is  thrown  into  water;  an  oil  is  de- 
posited ;  this  is  acidulated  slightly  with  hydrochloric  acid, 
and  the  oil  crystallises.  The  crystals  are  found  by  analysis 
to  consist  of  dinitrophenyl-diacetyl-methane. 

Adtion  of  Chloride  of  Eihyloxalyl  on  Diphenyl  in 
the  presence  of  Chloride  of  Aluminium. — L.  Rousset. 

If  small  portions  equal  to  one  molecule  of  chloride  of 

ethyloxalyl  are  dropped  into  a  boiling  sulphocarbonic 
solution  containing  one  molecule  of  diphenyl  and  133 
grms.  of  chloride  of  aluminium,  the  theoretical  quantity 
of  hydrochloric  acid  is  given  off,  and  a  brown  mass,  in- 
soluble in  sulphide  of  carbon,  is  left ;  this  is  treated  with 
water,  the  sulphocarbonic  layer  is  washed  with  water 
containing  HCl,  and  then  with  water;  the  sulphide  of 
carbon  is  driven  off,  and  the  residue  purified  in  vacuo.  It 
answers  to  the  formula  C6H5,C6H4,CO,COOC2H5. 

A(5tion  of  Chloride  of  Ethyl-oxalyl  on  Ethyl-a- 
napbthol  in  the  presence  of  Chloride  of  Aluminium. — 
L.  Rousset.  —  The  condensation  of  chloride  of  ethyl- 
oxalyl with  ethyl-a-naphthol  is  carried  out  in  the  same  way 
as  has  previously  been  described  for  methyl -a-naphthol. 
The  o-ethyloxynaphthylglyoxylic  ether  thus  obtained  boils 
at  240°  to  245°  under  a  pressure  of  10  m.m.  The  gly- 
oxylic  acid  which  results  from  its  saponification,  by  means 
of  soda  in  aqueous  solution,  melts  at  160°,  and  gives  with 
aniline  a  phenylimide  which  crystallises  in  benzene  in 
small  yellow  grains,  fusible  at  72°. 

On  the  Perkin  ReaAion  applied  to  some  Aldehyds 
of  the  Naphthalene  Series.— L.  Rousset.— Not  suit- 
able for  abstradtion. 

ProduiJls  of  Condensation  of  Saccharine  with  the 
Phenols.— P.  Sisley.— Saccharine  and  resorcine  heated 
together  with  sulphuric  acid   gives  a  yellowish  brown 


viscous  mass.  After  cooling  and  throwing  into  water, 
yellow-brown  crystals  are  formed  ;  they  are  soluble  in 
alcohol  and  acetic  acid,  but  not  in  ether  or  chloroform, 
and  they  do  not  contain  nitrogen.  Its  alkaline  salts  are 
very  soluble,  and  possess  a  beautiful  green  dichroism  ; 
they  dye  silk  in  the  same  way  as  uranine.  Analysis 
shows  it  to  be  identical  with  the  sulphurine  resorcine  of 
Remsen.  When  treated  with  bromine  in  alcoholic  solu- 
tion it  easily  gives  a  bromised  derivative  forming  red 
crystals,  slightly  soluble  in  water,  and  soluble  in  the 
alkalis,  forming  a  red  solution  with  a  yellow  fluorescence. 

On  Verairylene-diamine.— CI.  Moureu.— Not  suitable 
for  abstradtion. 

Estimation  of  Phosphoric  Acid.  —  H.  Lasne.  — 
Already  inserted  in  full. 

Apparatus  for  the  Ccmmercial  Analysis  of  Gas. 
— L.  Vignon. — Along  paper,  not  suitable  for  abstradtion. 

Estimation  of  Small  Quantities  of  Methyl-alco- 
hol, Formic  Aldehyd,  and  Formic  Acid. — M.  Nicloux. 
— Already  inserted. 

Cryoscopy  of  Milk.— A.  Ponsot. — Hamburger  found 
a  variation  of  0-013°  for  the  congealing  point  of  milk, 
with  a  mean  value  of  — o"56i,  his  results  agreeing  with 
those  obtained  by  Winter;  but  when  working  with  a 
Beckmann  apparatus  he  found  an  average  of  —0*520° 
(-0-512°  to  -0-529°).  A  large  part  of  this  difference 
must  be  due  to  defcdtive  working, — for  instance,  he  uses 
such  a  degree  of  cold  that  the  milk,  when  introduced  into 
the  cryoscopic  tube,  is  brought  to  a  condition  of  surfusion. 
It  is  necessary  that  the  same  method  should  be  followed 
by  all,  in  order  to  get  comparative  results. 


MEETINGS    FOR    THE    WEEK. 

Tuesday,  December  28th.  1  Royal  Institution,  3.  (Christmas  Lec- 
Thursday,  December  30th.  [•  tares).  "  Principles  of  the  Eledtric 
Saturday,  Jan.  ist,  1898       J      Telegraph,"  by  Prof.  Oliver  Lodge. 

ARGENTAURUM  GOLD. 


N'  umerous  requests  having  reached  us 
from  all  parts  of  the  world  for 
specimens  of  ARGENTAURUM  GOLD, 
we  have  now  arranged  for  a  supply  of  the 
same  in  sheets  weighing  i,  2,  5,  and  10  grms. 
respedtively. 

The  Price  is  75  cents  per  Gramme. 

Orders  and  remittances  should  be  addressed 
to  us  as  follows  :—EMMENS,  STRONG,  &  CO., 
1  Broadway,  New  York  City,  U.S.A. 

PLATINUM  "ST^E^Nof,^//' 

Purchased  at  highest  prices  by — 

DERBY  &  CO.,  44,  Clerkenwkll  Road,  London,  E.C. 

N.B.— Platinum  Sold. 


BRYAN  CORCORAN  Lim. 

MILLSTONE  BUILDERS, 

WIRE    WEAVERS.   MACHINE    MANUFACTURERS,    AND 

GENERAL  MILL  FURNISHERS. 

Sole    Makers    of    MilbuRn's 

Patent  Conoidal  Stone  Grinding  Mills. 

Especially  suitable forcertain  materials,  Wetor  Dry. 

Works  and  Warehouses  :  Back  Church  Lane. 
Parcel  Dept.:  Basement  of  the  Corn  Exchange, 

31,  MARK  LANE,  LONDON. 


CbBMICAL  NbWS. 

Dec.  31, 1897.     I 


Densities  0/  Carbonic  Oxide j  Carbonic  A  nhydride,  &c. 


315 


THE    CHEMICAL    NEWS 


Vol.  LXXVL,  No,  ic 


ON  THE  DENSITIES  OF  CARBONIC  OXIDE, 

CARBONIC  ANHYDRIDE,  AND  NITROUS  OXIDE.* 

By  Lord  RAYLEIGH,  F.R.S. 

The  observations  here  recorded  were  carried  on  by  the 
method  and  with  the  apparatus  described  in  a  former 
paper  ("  On  the  Densities  of  the  Principal  Gases,"  Roy. 
Soc.  Proc,  liii.,  p.  134,  1893),  to  which  reference  must  be 
made  for  details.  It  must  suffice  to  say  that  the  globe 
containing  the  gas  to  be  weighed  was  filled  at  0°  C,  and 
to  a  pressure  determined  by  a  manometric  gauge.  This 
pressure,  nearly  atmospheric,  is  slightly  variable  with 
temperature  on  account  of  the  expansion  of  the  mercury 
and  iron  involved.  The  a(5tually  observed  weights  are 
corredted  so  as  to  correspond  with  a  temperature  of  15°  C. 
of  the  gauge,  as  well  as  for  the  errors  in  the  platinum  and 
brass  weights  employed.  In  the  present  as  well  as  in  the 
former  experiments  I  have  been  ably  assisted  by  Mr. 
George  Gordon. 

Carbonic  Oxide. 
This  gas  was  prepared  by  three  methods.  In  the  first 
method  a  flask,  sealed  to  the  rest  of  the  apparatus,  was 
charged  with  80  grms.  re-crystallised  ferrocyanide  of 
potassium  and  360  c.c.  strong  sulphuric  acid.  The  gene- 
ration of  gas  could  be  started  by  the  application  of  heat, 
and  with  care  it  could  be  checked  and  finally  stopped  by 
the  removal  of  the  flame  with  subsequent  application,  if 
necessary,  of  wet  cotton-wool  to  the  exterior  of  the  flask. 
In  this  way  one  charge  could  be  utilised  with  great  ad- 
vantage for  several  fillings.  On  leaving  the  flask  the  gas 
was  passed  through  a  bubbler  containing  potash  solution 
(convenient  as  allowing  the  rate  of  production  to  be  more 
easily  estimated),  and  thence  through  tubes  charged  with 
fragments  of  potash  and  phosphoric  anhydride,  all  con- 
nected by  sealing.  When  possible,  the  weight  of  the 
globe  full  was  compared  with  the  mean  of  the  preceding 
and  following  weights  empty.  Four  experiments  were 
made  with  results  agreeing  to  within  a  few  tenths  of  a 
m.grm. 

In  the  second  set  of  experiments  the  flask  was  charged 
with  100  grms.  of  oxalic  acid  and  500  c.c.  strong  sulphuric 
acid.  To  absorb  the  large  quantity  of  CO2  simultaneously 
evolved  a  plentiful  supply  of  alkali  was  required.  A  wash- 
bottle  and  a  long  nearly  horizontal  tube  contained  strong 
alkaline  solution,  and  these  were  followed  by  the  tubes 
containing  solid  potash  and  phosphoric  anhydride  as 
before. 

For  the  experiments  of  the  third  set  oxalic  acid  was  re- 
placed hy  formic,  which  is  more  convenient  as  not  entailing 
the  absorption  of  large  volumes  of  COa.  In  this  case  the 
charge  consisted  of  50  grms.  formate  of  soda,  300c. c.  strong 
sulphuric  acid,  and  150  c.c.  distilled  water.  The  water  is 
necessary  in  order  to  prevent  aftion  in  the  cold,  and  the 
amount  requires  to  be  somewhat  carefully  adjusted.  As 
purifiers,  the  long  horizontal  bubbler  was  retained,  and 
the  tubes  charged  with  solid  potash  and  phosphoric  anhy- 
dride. In  this  set  there  were  four  concordant  experiments. 
The  immediate  results  stand  thus  :— 

Carbonic  Oxide. 

From  ferrocyanide 2*29843 

„     oxalic  acid      2*29852 

„     formate  of  soda    .,     ..  2*29854 


Mean «     2*29850 


*  A  Paper  read  before  the  Royal  Society,  December  gtb,  1897^ 


This  corresponds  to  the  number  2*62704  for  oxygen  {loc. 
cit.,  p.  144),  and  is  subjedt  to  a  correction  (additive)  of 
0*00056  for  the  diminution  of  the  external  volume  of  the 
globe  when  exhausted. 

The  ratio  of  the  densities  of  carbonic  oxide  and  oxygen 
is  thus  229906  :  2*62760;  so  that  if  the  density  of  oxygen 
be  taken  as  32,  that  of  carbonic  oxide  will  be  27*9989.  If, 
as  some  preliminary  experiments  by  Dr.  Scott  (Camb. 
Phil.  Proc,  ix.,  p.  144,  1896)  indicate,  equal  volumes  may 
be  taken  as  accurately  representative  of  CO  and  of  O2, 
the  atomic  weight  of  carbon  will  be  11*9989  on  the  scale 
of  oxygen  =  16. 

The  very  close  agreement  between  the  weights  of  car- 
bonic oxide  prepared  in  three  different  ways  is  some 
guarantee  against  the  presence  of  an  impurity  of  widely 
differing  density.  On  the  other  hand,  some  careful  ex- 
periments led  Mr.  T.  W.  Richards  (Amer.  Acad.  Proc, 
xviii.,  p.  279,  1891)  to  the  conclusion  that  carbonic  oxide 
is  liable  to  contain  considerable  quantities  of  hydrogen 
or  of  hydrocarbons.  From  si  litres  of  carbonic  oxide 
passed  over  hot  cupric  oxide  he  colleded  no  less  than 
25  m.grms.  of  water,  and  the  evidence  appeared  to  prove 
that  the  hydrogen  was  really  derived  from  the  carbonic 
oxide.  Such  a  proportion  of  hydrogen  would  entail  a 
deficiency  in  the  weight  of  the  globe  of  about  11  m.grms., 
and  seems  improbable  in  view  of  the  good  agreement  of 
the  numbers  recorded.  The  presence  of  so  much  hydro- 
gen in  carbonic  oxide  is  also  difficult  to  reconcile  with 
the  well-known  experiments  of  Professor  Dixon,  who 
found  that  prolonged  treatment  with  phosphoric  anhydride 
was  required  in  order  to  render  the  mixture  of  carbonic 
oxide  and  oxygen  inexpiosive.  In  the  presence  of  rela- 
tively large  quantities  of  free  hydrogen  (or  hydrocarbons) 
why  should  traces  of  water  vapour  be  so  important  ? 

In  an  experiment  by  Dr.  Scott  {Chem.  Soc.  Trans,, 
1897,  P'  564)  4  litres  of  carbon  monoxide  gave  only  1*3 
m.grms.  to  this  drying  tube  after  oxidation. 

I  have  myself  made  several  trials  of  the  same  sort 
with  gas  prepared  from  formate  of  soda  exadlly  as  for 
weighing.  The  results  were  not  so  concordant  as  I  had 
hoped,*  but  the  amount  of  water  collected  was  even  less 
than  that  given  by  Dr.  Scott.  Indeed  I  do  not  regard  as 
proved  the  presence  of  hydrogen  at  all  in  the  gas  that  I 
have  employed.! 

Carbonic  Anhydride. 
This  gas  was  prepared  from  hydrochloric  acid  and 
marble,  and,  after  passing  a  bubbler  charged  with  a  solu- 
tion of  carbonate  of  soda,  was  dried  by  phosphoric 
anhydride.  Previous  to  use,  the  acid  was  caused  to  boil 
for  some  time  by  the  passage  of  hydrochloric  acid  vapour 
from  a  flask  containing  another  charge  of  the  acid.  In  a 
secorid  set  of  experiments  the  marble  was  replaced  by  a 
solution  of  carbonate  of  soda.  There  is  no  appreciable 
difference  between  the  results  obtained  in  the  two  ways ; 
and  the  mean,  corrected  for  the  errors  of  weights  and  for 
the  shrinkage  of  the  globe  when  exhausted,  is  3*6349, 
corresponding  to  2*6276  for  oxygen.  The  temperature  at 
which  the  globe  was  charged  was  0°  C,  and  the  aCtual 
pressure  that  of  the  manometric  gauge  at  about  ao°,  re- 
duction being  made  to  15°  by  the  use  of  Boyle's  law. 
From  the  former  paper  it  appears  that  the  aCtual  height 
of  the  mercury  column  at  15°  is  762*511  m.m. 

Nitrous  Oxide. 
In  preliminary  experiments  the  gas  was  prepared  in  the 
laboratory,  at  as  low  a  temperature  as  possible,  from  ni- 
trate of  ammonia,  or  was  drawn  from  the  iron  bottles  in 
which  it  is  commercially  supplied.  The  purification  was 
by  passage  over  potash  and  phosphoric  anhydride.    Unless 


»  One  obstacle  was  the  difficulty  ol  re-oxidisitig  the  copper  reduced 
by  carbonic  oxide.  I  have  never  encountered  this  difficulty  after  re- 
duction by  hydrogen. 

t  In  Mr.  Richards's  work  the  gas,  in  an  impeffeaiy  dried  condi- 
tion, was  treated  with  hot  platinum-black.  Is  it  possible  that  the 
hydrogen  was  introduced  at  this  stage  ? 


3i6 


Electric  Conductivity  oj  Nitric  Acid, 


■  ChbhicXl  NbWs, 
«     Dec.  31,  1897. 


special  precautions  are  taken  the  gas  so  obtained  is  10  or 
more  m.grms.  too  light,  presumably  from  admixture  with 
nitrogen.  In  the  case  of  the  commercial  supply  a  better 
result  is  obtained  by  placing  the  bottles  in  an  inverted 
position  so  as  to  draw  from  the  liquid  rather  than  from 
the  gaseous  portion. 

Higher  and  more  consistent  results  were  arrived  at  from 
gas  which  had  been  specially  treated.  In  consequence 
of  the  high  relative  solubility  of  nitrous  oxide  in  water, 
the  gas  held  in  solution  after  prolonged  agitation  of  the 
liquid  with  impure  gas  from  any  supply  will  contain  a 
much  diminished  proportion  of  nitrogen.  To  carry  out 
this  method  on  the  scale  required,  a  large  (ii-litre)  flask 
was  mounted  on  an  apparatus  in  connexion  with  the  lathe 
so  that  it  could  be  vigorously  shaken.  After  the  dissolved 
air  had  been  sufficiently  expelled  by  preliminary  passage 
of  N2O,  the  water  was  cooled  to  near  0°  C,  and  violently 
shaken  for  a  considerable  time  while  the  gas  was  passing 
in  large  excess.  The  nitrous  oxide  thus  purified  was  ex- 
pelled from  solution  by  heat,  and  was  used  to  fill  the 
globe  in  the  usual  manner. 

For  comparison  with  the  results  so  obtained,  gas  puri- 
fied in  another  manner  was  also  examined.  A  small  iron 
bottle,  fully  charged  with  the  commercial  material,  was 
cooled  in  salt  and  ice,  and  allowed  somewhat  suddenly  to 
blow  off  half  its  contents.  The  residue  drawn  from  the 
bottle  in  one  or  other  position  was  employed  for  the 
weighings. 

Nitrous  Oxide  (1896). 

Aug.  15     Expelled  from  water 3'6359 

„      17 3-6354 

„      19    From  residue  after  blow  off, 

valve  downwards  3*6364 

„      21        Ditto  „      upwards  3*6358 

„     23        Ditto  II     downwards  3*6360 

Mean 3'6359 

The  mean  value  may  be  taken  to  represent  the  correfted 
Weight  of  the  gas  which  fills  the  globe  at  0°  C.  and  at  the 
pressure  of  the  gauge  (at  15°),  corresponding  to  a  6276  for 
oxygen. 

One  of  the  objefts  which  I  had  in  view  tn  determinmg 
the  density  of  nitrous  oxide  was  to  obtain,  if  it  were  pos- 
Bible,  evidence  as  to  the  atomic  weight  of  nitrogen.  It 
may  be  remembered  that  observations  upon  the  density 
of  pure  nitrogen,  as  distinguished  from  the  atmospheric 
mixture  containing  argon  which,  until  recently,  had  been 
confounded  with  pure  nitrogen  (Rayleigh  and  Ramsay, 
Phil.  Trans.,  vol.  clxxxvi.,  p.  190,  1895),  led  to  the  conclu- 
sion that  the  densities  of  oxygen  and  nitrogen  were  as 
16  :  14*003,  thus  suggesting  that  the  atomic  weight  of 
nitrogen  might  really  be  14  in  place  of  14-05,  as  generally 
received.  The  chemical  evidence  upon  which  the  latter 
number  rests  is  very  indiredt,  and  it  appears  that  a  dired 
comparison  of  the  weight  of  nitrous  oxide  and  of  its  con- 
tained nitrogen  might  be  of  value.  A  suitable  vessel 
would  be  filled,  under  known  conditions,  with  the  nitrous 
oxide,  which  would  then  be  submitted  to  the  adtion  of  a 
spiral  of  copper  or  iron  wire  rendered  incandescent  by  an 
eleftric  current.  When  all  the  oxygen  was  removed,  the 
residual  nitrogen  would  be  measured,  from  which  the 
ratio  of  equivalents  could  readily  be  deduced.  The  fadt 
that  the  residual  nitrogen  would  possess  nearly  the  same 
volume  as  the  nitrous  oxide  from  which  it  was  derived 
would  present  certain  experimental  advantages.  If  indeed 
the  atomic  weights  were  really  as  14  :  16,  the  ratio  [x)  of 
volumes,  after  and  before  operations,  would  be  given  by— 

2*2996  xjr  ^   14 

36359- 2*2996  X*         8 
whence— 

X  =.     7X3-6359     »  J.0061, 
11x2-2996 

3'6339  and  2*2996  being  the  relative  weights  of  nitrous 
oxide  and  of  nitrogen  which  (at  o"  C.  and  at  the  pressure 


of  the  gauge)  occupy  the  same  voluihe.  The  integral 
numbers  for  the  atomic  weights  would  thus  correspond 
to  an  expansion,  after  chemical  reduction,  of  about  one- 
half  per  cent. 

But  in  practical  operation  the  method  lost  most  of  its 
apparent  simplicity.  It  was  found  that  copper  became 
unmanageable  at  a  temperature  sufficiently  high  for  the 
purpose,  and  recourse  was  had  to  iron.  Coils  of  iron 
suitably  prepaied  and  supported  could  be  adequately 
heated  by  the  current  from  a  dynamo  without  twisting 
hopelessly  out  of  shape ;  but  the  use  of  iron  leads  to 
fresh  difficulties.  The  emission  of  carbonic  oxide  from 
the  iron  heated  in  vacuum  continues  for  a  very  long  time, 
and  the  attempt  to  get  rid  of  this  gas  by  preliminary 
treatment  had  to  be  abandoned.  By  final  addition  of  a 
smallquantity  of  oxygen  (obtained  by  heating  some  per- 
manganate of  potash  sealed  up  in  one  of  the  leading 
tubes)  the  CO  could  be  oxidised  to  CO2,  and  thus,  along 
with  any  H2O,  be  absorbed  by  a  lump  of  potash  placed 
beforehand  in  the  working  vessel.  To  get  rid  of  super- 
fluous oxygen,  a  coil  of  incandescent  copper  had  then  to 
be  invoked,  and  thus  the  apparatus  became  rather  com- 
plicated. 

It  is  believed  that  the  difficulties  thus  far  mentioned 
were  overcome,  but  nevertheless  a  satisfadory  concord- 
ance in  the  final  nutnbers  was  not  attained.  In  the  pre- 
sent position  of  the  question  no  results  are  of  value 
which  do  not  discriminate  with  certainty  between  14-05 
and  14*00.  The  obstacle  appeared  to  lie  in  a  tendency  of 
the  nitrogen  to  pass  to  higher  degrees  of  oxidation.  On 
more  than  one  occasion  mercury  (which  formed  the 
movable  boundary  of  an  overflow  chamber)  was  observed 
to  be  attacked.  Under  these  circumstances  I  do  not  think 
it  worth  while  to  enter  into  further  detail  regarding  the 
experiments  in  question. 

The  following  summary  gives  the  densities  of  the 
various  gases  relatively  to  air,  all  obtained  by  the  same 
apparatus  {Roy.  Soc.  Proc,  vol.  liii.,  p.  148,  1893  ;  vol.  Iv., 
p.  340,  1894;  Phil.  Trans,,  vol.  clxxxvi.,  p.  189,  1895; 
Roy.  Soc.  Proc,  vol.  lix.,  p.  201,  1896).  The  last  figure 
is  of  little  significance : — 

Air  free  from  H2O  and  C02 I'ooooo 

Oxygen      1*10535 

Nitrogen  and  argon  (atmospheric)      ..  0*97209 

Nitrogen 0*96737 

Argon 1-37752 

Carbonic  oxide 0-96716 

Carbonic  anhydride 1*52909 

Nitrous  oxide 1*52951 

Tlie  value  obtained  for  hydrogen  upon  the  same  scale 
was  0*06960;  but  the  researches  of  M.  Leduc  and  of 
Professor  Morley  appear  to  show  that  this  number  is  a 
little  too  high. 


ELECTRIC    CONDUCTIVITY  OF  NITRIC  ACID,* 

By  V.  H.  VELEY,  M.A.,  F.R.S.,  and 
J.  ].  MANLEY,  Daubeny  Curator  of  the  Magdalen  CollegS 


Laboratory,  Oxford. 


In  this  paper  an  account  is  given  of  determinations  of  the 
eledtric  condudtivity  of  nitric  acid  of  percentage  concen- 
trations varying  from  1-3  to  99*97,  purified,  so  far  as 
possible,  from  reduction  produdls  of  the  acid,  as  also  from 
sulphuric  and  the  halogen  acids,  with  which  it  is  likely 
to  be  contaminated  from  its  process  of  manufadture.  In 
the  preliminary  experiments  it  was  observed  that  the 
results  might  be  vitiated  by  (i)  a  trace  of  nitrous  acid 
either  diredily  acid  or  produced  by  decomposition  due  to 
exposure  to  sunlight,  and  (2)  imperfedt  insulation  of  the 

*  AbstraA  of  a  Paper  read  before  tba  Royal  Society,  December 
gtb,  1897- 


Chbhical  Nbwi,  I 
Dec.  31,  1897.      I 


Occlusion  0/  Hydrogen  and  Oxygen  by  Palladium. 


317 


eledlrolytic  cell  caused  by  metallic  clamps,  a  point  which 
seems  to  have  been  negleded  by  previous  observers. 

The  methods  adopted  for  the  purification  of  the  water 
and  nitric  acid,  as  also  for  the  detedtion  and  estimation  of 
the  impurities,  are  described  in  full.  The  greatest  quan- 
tity of  nitrous  acid,  sulphuric  acid,  and  the  halogen  acids 
found  in  any  sample  used  were  075,  4*3,  and  3*8  parts  per 
million  respedlively. 

The  thermometers,  resistance  coils,  and  other  instru- 
ments used,  were  compared  with  certain  standards  and 
corrected  accordingly ;  the  burettes  and  eledlrolytic  cells 
were  calibrated  by  one  or  more  methods,  and  the  mean  of 
the  values  accepted. 

The  method  adopted  for  the  determinations  was  in  out- 
line that  originally  described  by  Kohlrausch,  but  modified 
so  as  to  overcome  certain  difficulties  experienced.  A  par- 
ticular form  of  bridge  was  construdled,  in  which  the  wire 
was  an  air  line,  and  a  special  form  of  slider  adopted  to 
tap  without  sagging  the  wire,  so  arranged  that  it  could  be 
moved  by  the  observer  from  the  extremity  of  the  bridge, 
and  thus  all  thermo-currents  due  to  his  proximity  were 
avoided. 

A  rapidly  revolving  commutator  was  substituted  for 
the  usual  indudlion  coil,  as  the  latter  was  found  to  be  un- 
satisfadtory  owing  to  the  susceptibility  of  nitric  acid  to 
polarisation. 

Various  forms  of  eledrolytic  cells  were  used  according 
to  the  concentration  of  the  acid  and  the  temperature  of 
the  observations ;  these  were  provided  with  movable 
eledtrodes,  so  as  to  throw  into  circuit  different  lengths  of 
acid. 

A  special  form  of  apparatus  was  devised  to  prepare 
nitric  acid  of  9g'88  per  cent,  and  another  form  to  obtain 
acid  of  99*97  per  cent  from  the  latter.  As  a  considerable 
quantity  of  this  pradtically  anhydrous  acid  was  obtained, 
its  chemical  and  certain  physical  properties  were  ex- 
amined. It  has  no  adtion  on  (i)  copper,  (2)  silver, 
(3)  cadmium,  and  (4)  mercury,  all  of  high  degree  of  purity, 
and  (5)  commercial  magnesium,  at  ordinary  temperatures  ; 
purified  iron  and  commercial  granulated  tin  were  un- 
aifedted  by  the  acid,  even  when  boiling.  Purified  zinc 
was  slightly  adted  upon,  but;  sodium  immediately  caught 
fire.  The  acid  has  no  adlion  whatever  on  calcium  car- 
bonate at  ordinary  temperatures  or  the  boiling-point. 
Flowers  of  sulphur  and  iron  pyrites  dissolve  quickly  and 
completely  in  the  gently  warmed  acid.  The  following  re- 
sults were  obtained  for  the  density  of  the  99*97  per  cent 
acid,  corredted  for  weighings  in  vacuo  : — 

Density  4/4=  i'542i2;  i4'2/4=  1*52234;  24*2/4  =  i'50394, 

the  mean  values  of  two  concordant  observations. 

As  a  further  check  upon  the  measurements  obtained  by 
the  Kohlrausch  method,  certain  other  measurements  were 
made  by  Carey  Foster's  method  for  the  comparison  of 
resistances,  and  the  results  obtained  were  found  to  be 
concordant  within  the  limits  of  experimental  error.  In  a 
series  of  tables  the  values  are  given  for  thirty-two  samples 
of  acid  of  the  specific  resistance  in  true  ohms  at  temper- 
atures of  0°,  15°,  and  30°,  the  temperature  coefficients 
aiQ*  and  /Sio'  deduced  from  the  equation — 

R«=  Ro(i  +  a<-/8<»), 

as  also  for  KoXio*,  KjsXio*,  andKaoXio*  (the  con- 
dudtivity  of  mercury  at  o  being  taken  as  unity,  and  its 
specific  resistance  as  94*07  microhms  per  i  c.c). 

It  is  shown  that  the  specific  resistance  decreases  for 
percentage  concentrations  from  1*30  to  30,  at  first  more, 
then  less  rapidly  (thus  confirming  the  previous  observa- 
tions of  Kohlrausch) ;  from  this  point  the  resistance 
increases  slowly  up  to  76  per  cent,  thence  more  rapidly 
until  a  maximum  is  reached  at  96*12  per  cent,  when  a 
sudden  reversal  takes  place. 

Further,  whereas  nitric  acid  behaves  as  other  eledtro- 
lytes  in  possessing  a  positive  temperature  coefficient  of 
condudlivity  for  percentage  concentrations  from  1*3  to 
g6*i2,  yet  from  this  point  up  to  99*97  per  cent  it  behaves 


as  a  metallic  conductor  in  possessing  a  negative  temper* 
ature  coefficient. 

Similar  phenomena  have  been  observed  by  Arrhenius  in 
the  cases  of  moderately  dilute  solutions  of  hypophos- 
phorous  and  phosphoric  acids,  and  explained  by  him  by 
means  of  the  ionic  dissociation  hypothesis.  It  is  pointed 
out  that  nitric  acid  of  96  to  99*97  per  cent  would,  ex 
hypothesi,  coiltain  few,  if  any,  free  ions,  and  therefore  the 
theory  would  lead  to  a  totally  opposite  conclusion. 

The  results  of  the  experiments  are  also  discussed  in 
relation  to  the  hydrate  theory  of  solution,  and  the  illu8< 
trative  curves  in  which  the  percentages  of  acid  are  taken 
as  abscissae,  and  the  resistances  or  condudtivities  in  mer« 
cury  units,  show  points  of  discontinuity  markedly  at  per- 
centages corresponding  approximately  to  the  composition 
required  for  the  hydrates  HN03,2H20,  HNOa.HaO, 
2HN03,H20  (  =  H4N207),  and  less  markedly  for  the 
hydrate  HNOj.ioHaO.  Further,  if  the  values  of  aXio* 
and  /3X  io»  are  referred  to  molecular  proportions  of  water, 
the  minima  values  of  the  former  and  the  maxima  of  the 
latter  occur  in  the  cases  of  3*07,  1*84,  o  99,  and  0*55 
molecular  proportions  or  very  approximately — 

HN03,3H20,  HN03,2H20,  HNOa.HaO,  and  2HN03,H20. 

Further  evidence  is  thus  added  by  an  independent  method 
to  that  already  accumulated  as  to  the  existence  of  definite 
combination  of  nitric  acid  with  water.  Finally,  it  is 
pointed  out  that  if  a  curve  is  plotted  out  in  which  the 
molecular  proportions  of  water  are  taken  as  abscissae,  and 
the  values  for  a  10*  as  ordinates,  there  are  ascending  and 
descending  branches,  meeting  at  the  points  corresponding 
to  the  formation  of  the  respedtive  hydrates ;  the  pheno- 
mena are  compared  with  those  observed  by  Bakhuis< 
Roozeboom  for  the  solubility  curves  of  hydrates  of  ferric 
chloride  and  by  Le  Chatelier,  as  also  by  Heycock  and 
Neville  for  the  freezing-point  of  alloys. 


ON  THE 

OCCLUSION    OF    HYDROGEN    AND    OXYGEN 
BY     PALLADIUM.* 

By  LUDWIG  MOND,  Ph.D.,  F.R.S., 

WILLIAM  RAMSAY,  Ph.D.,  LL.D.,  Sc.D.,  F.R.S.,  and 

JOHN  SHIELDS,  D.Sc,  Ph.D. 

During  their  investigations  on  the  nature  of  the  occlu* 
sion  of  gases  by  finely  divided  metals,  and  in  particular 
on  the  occlusion  of  hydrogen  and  oxygen  by  platinum 
black,  the  authors  have  had  occasion  to  examine  the 
behaviour  of  palladium  to  these  gases. 

The  palladium  was  employed  in  three  states  of  aggre- 
gation, viz.,  in  the  form  of  (a)  black,  (b)  sponge,  and  {c) 
foil.  Palladium  black,  prepared  in  the  same  way  as 
platinum  black,  contains  1*65  percent  of  oxygen,  or, 
taking  the  density  of  palladium  black  as  12*0, 138  volumes 
of  oxygen.  It  differs  from  platinum  black,  however,  in- 
asmuch as  the  oxygen  cannot  be  removed  in  vacuo  at  a 
dull  red  heat,  and  consequently  had  to  be  determined  in 
the  ignited  substance  by  passing  hydrogen  over  it  and 
weighing  the  water  produced.  Palladium  black  dried  at 
100°  contains  0*72  per  cent  of  water,  and  hence,  on  the 
assumption  that  the  oxygen  exists  as  PdO,  we  have  for 
the  analysis  of  palladium  black: — 

Pd     ..     ..     86*59  per  cent. 

PdO..     ..     12*69      „  =>  1*65  per  cent  02< 

H2O  . ,     . .      0*72      „ 

On  heating  in  an  atmosphere  of  oxygen,  palladium 
black  goes  on  absorbing  oxygen  at  least  up  to  a  red  heat, 
with  the  formation  of  a  brownish  black  substance,  which 
does  not  again  lose  its  oxygen  at  a  dull  red  heat  in  vacuo. 

*  AbstraA  of  a  Paper  read  before  the  Royal  Society,  December 
i6tb,  1897. 


3i8 


Fehling's  Solution. 


.  Chkmical  .Nbwc, 
I      Dec.  3i,''i8g7 


The  amount  of  oxygen  absorbed  (nearly  looo  volumes) 
was  about  one  and  a  half  times  as  much  as  corresponds 
with  the  formula  Pd20;  and  if  the  ignition  had  been 
sufficiently  prolonged,  the  whole  of  the  palladium  would 
probably  have  been  converted  into  the  oxide  PdO. 

Palladium  black,  when  exposed  to  hydrogen  gas,  ab- 
sorbed  over  iioo  volumes,  but  of  this  only  873  volumes 
were  really  occluded,  the  remainder  having  formed  water 
with  139  volumes  of  oxygen  originally  contained  in  the 
black,  which  is  in  good  agreement  with  the  direft  gravi- 
metric  estimation. 

Of  the  hydrogen  occluded,  about  92  per  cent  was 
pumped  off  slowly  at  the  ordinary  temperature,  and  almost 
the  whole  of  the  remainder  at  444°.  Increase  of  pressure 
of  the  hydrogen  from  one  atmosphere  up  to  4*6  atmo- 
spheres had  no  influence  on  the  quantity  occluded  at  the 
ordinary  temperature. 

The  pure  palladium  sponge  remaining  in  the  experi- 
mental tube  after  the  above  experiment  was  over  occluded 
852  volumes  of  hydrogen,  and  about  98  per  cent  of  this 
was  extracted  in  vacuo  at  the  ordinary  temperature. 

New  palladium  foil  behaved  in  a  very  peculiar  fashion. 
At  first  it  scarcely  occluded  any  hydrogen  even  after 
ignition  in  the  gas  and  subsequently  cooling  down.  It 
was  therefore  charged  and  discharged  several  times 
eledlrolytically  with  hydrogen,  but  still  it  persistently  re- 
fused to  occlude  any  appreciable  quantity  when  replaced 
in  an  atmosphere  of  hydrogen. 

After  powerful  ignition  in  the  blowpipe  ilame,  when  it 
was  probably  oxidised  and  then  again  reduced  at  a  still 
higher  temperature,  it  was  introduced  once  more  into  the 
experimental  tube.  It  immediately  occluded  a  consider- 
able quantity  of  hydrogen,  and  by  maintaining  the  tem- 
perature between  100°  and  130°  a  large  additional  quantity 
was  slowly  absorbed.  On  cooling  down  to  the  ordinary 
temperature,  hydrogen  was  again  occluded,  and  it  was 
finally  found  to  have  taken  up  846  volumes,  i.e.,  approxi- 
mately the  same  quantity  as  the  black  or  sponge. 

The  hydrogen  occluded  by  palladium  foil  is  given  off 
again  very  slowly  at  the  ordinary  temperature  in  vacuo, 
but  rapidly  and  almost  completely  at  100°. 

The  paper  contains  some  attempts  to  explain  the  extra- 
ordinary behaviour  of  palladium  foil. 

The  heat  evolved  on  the  occlusion  of  hydrogen  by  pal- 
ladium black  was  measured  in  an  ice  calorimeter  (tem- 
perature of  the  room  20 — 24°)  in  nearly  the  same  way  as 
the  corresponding  heat  of  occlusion  of  hydrogen  by 
platinum  black,  thereby  avoiding  errors  due  to  the  pre- 
existence  of  oxygen  in  the  substance. 

Favre's  statement  that  the  heat  of  occlusion  remains 
constant  for  the  different  fraiJlions  of  hydrogen  occluded 
was  confirmed,  and  it  was  found  that  -t-46*4  K  (4640  g. 
cal.)  were  evolved  per  grm.  of  hydrogen  occluded. 

The  authors  consider  that  this  number  may  be  taken  as 
corredl  within  i  per  cent,  and  compare  it  with  the  dif- 
ferent values  found  by  Favre  and  those  calculated  by 
Moutier  and  Dewar. 

If  the  external  work  done  by  the  atmosphere  be  elimi- 
nated, the  heat  evolved  per  grm.  of  hydrogen  occluded 
becomes  +437  K. 

The  heat  evolved  per  grm.  of  oxygen  absorbed  was 
also  determined  in  an  indire(5t  manner,  and  found  to  be 
.fii'2  K  (1120  g.  cal.). 

This  number,  referred  to  16  grms.  of  oxygen,  lies  mter- 
mediate  between  the  values  given  by  Thomsen  for  the 
heat  of  formation  of  palladious  and  palladic  hydroxides, 
and  may  be  consistent,  considering  the  accuracy  of  such 
measurements,  with  the  formation  of  either  of  these  hy- 
droxides or  with  a  mixture  of  both.  In  any  case  it  is  of 
the  same  order  of  magnitude,  and  taken  in  conjundiion 
with  the  behaviour  of  palladium  black  when  heated  in  an 
atmosphere  of  oxygen,  is  undoubtedly  in  harmony  with 
the  view  that  the  absorption  of  oxygen  by  palladium 
black  (and  probably  also  by  platinum  black)  is  a  true 
phenomenon  of  oxidation. 
The  authors  have  also  investigated  the  atomic  ratio- 


palladium  :  hydrogen  for  fully-charged  palladium  black, 
sponge,  and  foil,  and  give  in  tabular  form  the  correspond- 
ing ratios  deduced  from  experiments  by  Graham  and 
Dewar  in  which  wire  and  block  palladium  were  charged 
with  hydrogen  eIe<5trolytically.  They  have  arrived  at  the 
conclusion  that  no  matter  whether  the  palladium  exists 
as  black,  sponge,  foil,  wire,  or  compact  metal,  or  whether 
it  is  charged  by  direiSl  exposure  to  hydrogen  gas  (the 
proper  conditions  being  observed),  or  charged  eledtro- 
lytically,  the  amount  of  hydrogen  occluded  in  each  case 
is  approximately  the  same,  the  atomic  ratio  varying 
between  1*37  and  i^j. 

Hoitsema  has  shown  that  Troost  and  Hautefeuille's 
dedudtion  that  a  compound  exists  having  the  formula 
PdaH  is  not  warranted.  The  constancy  of  the  heat  of 
occlusion  over  the  whole  range  of  absorption  is  also  op- 
posed to  the  view  that  such  a  compound  is  formed. 

The  composition  of  fully  charged  palladium  hydrogen 
corresponds  closely  with  the  formula  Pd3H2  first  suggested 
by  Dewar.  The  principal  and  almost  only  evidence,  up 
to  the  present,  in  favour  of  the  formation  of  such  a  defi- 
nite chemical  compound  is  to  be  found  in  the  approxima- 
tion of  the  above  atomic  ratios  to  the  theoretical  value  i'5, 
required  by  the  formula  Pd3H2.  Although  Hoitsema's 
arguments  may  be  equally  well  diredted  against  the  exist- 
ence of  this  compound,  the  authors  consider  that  ad- 
ditional and  independent  evidence  is  desirable,  and  hope 
to  be  able  to  provide  it. 

It  is  also  shown  that  the  heats  of  occlusion  of  hydrogen 
in  platinum  and  palladium  black  are  not  in  favour  of  the 
view  which  has  sometimes  been  put  forward  that  the  heat 
of  occlusion  of  a  gas  represents  the  heat  of  condensation 
or  liquefadtion  of  the  gas  in  the  capillary  pores  of  the 
absorbing  substance  or  the  heat  of  solidification  or  fusion. 


"ON    FEHLING'S    SOLUTION." 

By   OTTO   ROSENHEIM,  Ph.D.,  F.C.S.,  and 
PHILIP  SCHIDROWITZ,  PhD.,  F.C.S. 


The  Berichte  der  Deutschen  Chem,  Gesellschafi  (vol.  xxx., 
p.  2431)  contains  a  paper  by  M.  Z.  Jovitschitsch  under 
the  above  heading,  in  which  the  author  asserts  that,  ac- 
cording to  an  observation  made  by  Professor  Siegfried, 
mineral  acids  (hydrochloric,  nitric,  and  sulphuric)  possess 
the  property  of  reducing  Fehling's  solution— more  especi- 
ally when  the  latter  is  still  alkaline.  Granted  that  the 
author's  observations  are  corredt,  it  follows  that  the  re- 
dudtion  is  due  to  the  alkali  salts  of  the  acids  mentioned. 
As  salts  of  the  alkalis  are  almost  invariably  present  in 
liquids  in  which  matter  capable  of  oxidation  is  to  be 
tested  for  or  determined,  the  experimental  confirmation 
of  Jovitschitsch's  statements  seemed  to  us  to  be  highly 
desirable,  especially  as  no  analytical  data  were  recorded 
in  his  paper. 

Viewed  theoretically,  there  is  absolutely  no  reason  why 
salts  of  the  alkalis  should  influence  the  redudlion  of 
Fehling's  solution ;  and,  as  might  have  been  expedted, 
both  qualitative  and  quantitative  experiments  made  by  us 
yielded  negative  results.*  It  must  be  assumed  that 
Tovitschitsch's  paper  is  based  on  an  error  of  observation, 
and  as  T.  E.  Gerock  {Ber.,  xxx.,  2865)  has  meanwhile 
come  to  the  same  conclusion,  we  refrain  from  discussing 
the  subjedl  more  fully,  and  merely  record  the  data  of 
some  quantitative  experiments  which  are  diredlly  to  the 
point.  The  method  adopted  was  similar  to  that  usually 
employed  in  the  gravimetric  estimation  of  sugars.    Fifty 

*  Considering  that  Fehling's  solution  (io  various  modifications) 
has  now  been  in  use  for  close  on  fifty  years,  it  ia  indeed  remarkable 
that  the  phenomena  described  in  the  paper  quoted  have  not  been  ob- 
served before.  On  the  contrary,  Boivin  and  Loiseau  (Ber.,  vii., 
1790)  assert  that  the  presence  of  small  quantities  of  salts,  such  as 
CaCla,  BaCia,  NH4CI,  NaCl,  &c.,  prevents  the  spontaneous  reduiSion 
that  takes  place  on  boiling  the  solution  with  distilled  water. 


Chbmical  Mews, 
Dec.  31,  1897.      I 


Non-exisUnce  of  an  Intermediate  Iodide  of  Mercury. 


319 


c.c.  of  Fehling's  solution  (stored  in  two  solutions  and 
mixed  when  required),  diluted  with  25  c.c.  o\  distilled 
water,  were  heated  to  boiling,  25  c.c.  of  a  25  per  cent 
solution  of  the  salt  in  question  run  in  from  a  pipette,  and 
after  ebullition  had  re-commenced,  the  liquid  was  kept 
boiling  in  one  series  for  two,  in  the  other  for  four  minutes. 
The  perfedlly  clear  solution  was  filtered  hot  through  a 
Soxhlet's  asbestos  tube  under  reduced  pressure,  the  tube 
dried,  heated  in  hydrogen  in  the  usual  manner,  and  finally 
weighed.  As  will  be  seen  from  the  figures  below,  the  re- 
sults were  pradlically  identical  with  those  obtained  by  the 
boiling  of  Fehling's  solution  alone. 


Boiled  for 

two  minutes. 

Grm.  Cu. 


Fehling's  solution  alone*    ..  0-0028 

25  per  cent  potassium  chloride  0*0023 

25  per  cent  potassium  nitrate  o'oo36 
Potassium  sulphate  (saturated 

at  i3°  C.) o'oo20 


Boiled  for 

four  minutes. 

Grm.  Cu. 

00040 
0*0040 
0*0044 

0*0040 


ON   THE 

NON-EXISTENCE    OF    AN     INTERMEDIATE 

IODIDE     OF     MERCURY. 

By  MAURICE  FRANCOIS. 

Before  1827  only  two  iodides  of  mercury  were  accepted — 
the  yellowish  green  mercurous  iodide  and  the  red  mer- 
curic iodide.  At  this  date  BouUay  described  the  inter- 
mediate iodide,  which  he  simply  called  the  yellowish 
iodide,  calling  the  protoxide  simply  green  {Ann.  de  Chim. 
et  de  Phys.  [2],  xxxiv.,  p.  364,  1827).  This  new  com- 
pound of  the  atomic  formula,  Hg4l6)  has  been  described 
as  sublimable  without  decomposition,  and  as  insoluble  in 
boiling  alcohol.  Boullay  has  given  for  its  preparation  a 
method,  since  quoted  in  all  standard  chemical  works.  It 
consists  in  adding  to  a  slightly  acid  solution  of  mercurous 
nitrate  a  solution  of  iodide  of  potassium,  to  which  has 
been  added  a  quantity  of  free  iodine,  equal  to  half  the 
amount  it  already  contains  in  the  state  of  iodide.  Such 
an  operation  would  undoubtedly  give  a  produft  of  the 
desired  composition,  on  condition  that  the  precipitation 
was  complete,  and  that  its  composition  was  not  changed 
by  the  washings.  But  Boullay  recommended  stopping 
the  addition  of  iodide  of  potassium  at  the  moment  when 
the  precipitate,  originally  yellow,  takes  a  red  tint. 

I  have  endeavoured  to  verify  the  fads  put  forward  by 
Boullay,  fadts  which  have  not  up  till  the  present  time 
been  contested,  and  I  have  arrived  at  results  completely 
opposed  to  those  of  this  savant.  For  this  research  I  prepared 
the  compound  described  by  Boullay,  by  not  stopping  the 
addition  of  the  iodised  iodide  until  the  precipitate  was 
ended.  The  precipitate,  well  washed  with  water,  was  col- 
lected, analysed,  and  submitted  to  further  washings  with 
pure  ether.  I  also  fractionated  the  precipitate  and  analysed 
the  different  fractions. 

I.  I  prepared  a  solution  of  iodised  potassic  iodide,  con- 
taining 166  grms.  of  iodide  of  potassium  and  63*50  grms. 
of  free  iodine  per  litre.  I  also  made,  with  freshly  pre- 
pared and  well-dried  mercurous  nitrate,  a  solution 
containing  40  grms.  of  mercurous  nitrate,  and  2  c.c.  of 
pure  nitric  acid  per  400  c.c.  The  iodised  solution  was 
put  into  a  burette  and  allowed  to  fall  slowly,  drop  by  drop, 
into  the  solution  of  mercurous  nitrate,  which  was  kept 
constantly  stirred  with  a  glass  rod.  Each  drop  made  a 
red  splash,  which  rapidly  became  yellow. 

The  colour  of  the  precipitate  first  formed  is  of  a 
beautiful  yellow  ;  then,  as  we  continue  to  add  the  iodised 


♦  It  is  a  well-known  faft  that  even  the  most  carefully  prepared 
Fehling's  solution  gives  a  slight  precipitation  of  cuprous  oxide  on 
heating,  varying  in  amount  from  2  to  3  m.grms.  (see,  also,  Brown, 
Morris,  and  Millar,  Journ.  Chem.  Soc,  Ixxi.,  96). 


solution,  it  passes  to  a  reddish  orange,  and  finally  to  red. 
We  stop  the  addition  when  a  drop  of  the  iodised  iodide 
gives  no  further  precipitate  in  the  clear  solution,  but  only 
a  yellow  colouration.  At  this  moment  we  have  used  132 
c.c.  of  the  iodised  solution. 

The  whole  of  the  precipitate  is  now  red ;  it  is  washed 
with  water  by  decantation,  and  dried  at  60°.  It  weighs 
51  grms.     Its  composition  is  as  follows  : — 

Mercury       50*63  per  cent. 

Iodine 4^'50       „ 

The  theoretical  composition  of  the  intermediate 
iodide  is  : — 

Mercury      51*21  per  cent. 

Iodine 4879      „ 

As  I  stated  above,  the  composition  of  this  precipitate 
corresponds  closely  with  that  of  the  intermediate  iodide. 

This  precipitate  was  then  washed  with  cold  ether  by 
decantation,  in  the  dark.  As  I  have  said  elsewhere,  this 
is  a  method  of  separating  mercurous  from  mercuric 
iodide,  which  is  much  more  exadl  than  that  of  washing 
with  boiling  alcohol,  being  almost  irreproachable.  To 
exhaust  i  grm.  of  intermediate  iodide  we  use  three 
washings  of  50  c.c.  each  of  pure  ether,  decant  each  time 
on  a  filter,  and  evaporate  the  ether  under  a  bell-jar  over 
sulphuric  acid,  in  a  small  tared  crystallising  glass.  This 
treatment  has  removed,  from  i  grm.  of  intermediate 
iodide,  0*591  grm.  of  mercuric  iodide.  The  residue,  in- 
soluble in  ether,  is  of  a  very  pale  yellow  colour,  and 
weighs  0*411  grm.     Its  composition  is  as  follows: — 

Mercury       60*85  per  cent. 

Iodine 38*70       „ 

The  theoretical  composition  of  mercurous  iodide  is: — 

Mercury       6i-i6  per  cent. 

Iodine 38*84        ,, 

Thus  the  so-called  intermediate  iodide  can  be  split  up 
by  ether  into  mercurous  and  mercuric  iodides. 

2.  To  see  better  what  variations  the  precipitate  under- 
goes during  the  gradual  addition  of  the  iodised  iodide,  I 
carried  out  a  fractional  precipitation  in  the  following 
manner  : — 

I  operated  on  40  grms.  of  mercurous  nitrate  dissolved 
in  400  c.c.  of  water  and  20  c.c,  of  nitric  acid.  Knowing 
already  that  this  quantity  requires  for  complete  precipi- 
tation 132  c.c.  of  the  iodised  solution,  I  used  13-2  c.c.  of 
the  latter  for  each  precipitation,  so  as  to  obtain  ten  frac- 
tions of  the  precipitate.  The  affusion  of  the  iodised 
iodide  is  done  drop  by  drop  while  agitating  rapidly. 

The  first  precipitate  is  thrown  on  a  filter,  air-dried  with 
a  filter-pump,  and  the  filtrate  treated  as  before  for  the 
second  precipitate,  and  so  on  to  the  end.  Each  precipitate 
is  carefully  washed  with  water,  and  dried  at  60°. 

Analysis  gave  the  following  figures : — 

1st  fraction. — Pure  bright  yellow  colour.     Mercury  61 '02 

per  cent.    Iodine  38  66  per  cent. 
2nd  fraction. — Pure  bright  yellow  colour.    Mercury  61*29 

per  cent.     Iodine  38*50  per  cent. 
3rd  fraction.— Bright  yellow.      Mercury  61*19  per  cent. 

Iodine  38' 19  per  cent. 
^th  fraction.— Bright  rtd.  Mercury  44*23  per  cent.    Iodine 

55*32  per  cent. 
Sth fraction. —Bright red.    Mercury 44*81  percent.   Iodine 

54*55  per  cent. 
6th  fraction. — Brightred.  Mercury  44*95  per  cent.    Iodine 

5480  per  cent. 
jth  fraction. —Blight  red.  Mercury  45*72  per  cent.  Iodine 

53*65  per  cent. 
Sth  fraction. — Bright  red.   Mercury  45*93  per  cent.  Iodine 

54*00  per  cent. 
gth  fraction.— Bright  red.    Mercury  44*51  percent.  Iodine 

55*02  per  cent. 
lo^A  fraction. — Bright   red.      Mercury  44*30  per  cent. 

Iodine  5556  per  cent. 


320 


The  theoretical  composition  of  mercurous  iodide  is : — 

Mercury       6ri6  per  cent. 

Iodine 38*84      „ 


cerium, \   Dec.  31. 1897. 

rich  in  mercurous  iodide  in  proportion  as  the  precipitation 
has  been  pushed  less  far. — yourn.  de  Pharm.  et  de  Chim., 
Series  6,  vol.  vi.,  No.  10,  1897. 


and  that  of  mercuric  iodide : — 

Mercury       44"o5  per  cent. 

Iodine 5555      »« 

As  is  easily  seen,  the  first  three  fradtionations  are  of 
pure  mercurous  iodide,  the  others  of  fairly  pure  mercuric 
iodide.  It  is  worthy  of  remark  that  the  mercurous  iodide 
obtained  in  this  manner  is  of  a  very  pure  yellow  colour. 

This  readlion,  and  the  successive  appearance  of  the 
mercurous  and  mercuric  iodides,  can  be  explained  by  the 
two  following  experiments. 

When  we  put  about  i  grm.  of  mercuric  iodide,  recently 
precipitated  and  washed  but  not  dried,— that  is  to  say,  in 
the  finest  possible  state  of  division,— into  100  c.c.  of  our 
mercurous  nitrate  solution  at  40  grms.  per  400  c.c,  we 
notice,  after  about  fifteen  minutes,  that  the  red  mercuric 
iodide  changes  to  a  pure  yellow  colour,  being  transformed 
into  mercurous  iodide.  There  is  an  increase  in  weight  of 
the  iodide,  and  the  readtion  may  be  expressed  thus : — 

Hgl2+(N03)2Hg2  =  Hg2l2  +  (N03)2Hg. 

This  is  the  transformation  of  the  red  splash  into  yellow, 
already  mentioned  above. 

When,  on  the  contrary,  we  put  i  grm.  of  mercurous 
iodide  into  100  c.c.  of  a  solution  of  mercuric  nitrate  con- 
taining 40  grms.  of  nitrate  per  400  c.c,  we  notice  that, 
after  about  fifteen  minutes,  the  yellow  mercurous  iodide 
changes  into  the  red  mercuric  iodide,  according  to  the 
equation — 

Hg2l2+(N03)2Hg  =  HgIa+(N03)2Hg2. 

There  are  thus  two  limiting  contrary  readions. 

But  when  we  pour  the  iodised  solution  of  potassic 
iodide  into  mercuric  nitrate,  the  free  iodine  produces  mer- 
curie  nitrate,  since  the  mercury  of  the  mercurous  nitrate 
cannot  be  precipitated  except  by  producing  mercuric 
nitrate  or  nascent  oxygen,  which  comes  to  the  same 
thing. 

We  have  thus  a  liquid  in  which  the  proportion  of  mer- 
curous nitrate  goes  on  diminishing,  while  the  proportion 
of  mercuric  nitrate  goes  on  increasing :  this  sufficiently 
explains  why  the  nature  of  the  precipitate  changes  at  a 
given  moment,  and  why  the  precipitate  is  at  first  mer- 
curous iodide  and  afterwards  mercuric  iodide.  This 
oxidising  adtion  of  free  iodine  seems  to  have  escaped 
Boullay. 

It  seems  extraordinary  that  a  chemist  of  such  repute  as 
Boullay  should  have  been  mistaken  on  this  point.  Being 
fully  persuaded  that  mercurous  iodide  is  green,  and  the 
greener  it  is  the  purer  it  is,  he  could  not  admit  that  a  dis- 
tinctly yellow  substance  was  mercurous  iodide.  Further, 
he  was  at  this  time  much  preoccupied  in  proving  the 
existence  of  double  iodides,  in  which  one  of  the  iodides 
plays  the  part  of  an  acid,  and  the  other  the  part  of  a 
base ;  the  existence  of  an  intermediate  iodide  fitted  in 
with  his  theory,  for  he  regarded  it  as  a  combination  of 
mercurous  and  mercuric  iodides.  One  feels  convinced 
after  reading  Boullay's  paper  that  he  established  the 
existence  of  this  body  by  relying  on  his  theoretical  no- 
tions, and  on  the  colour  more  than  on  analysis,  for  he 
only  gives  one  estimation  of  mercury,  by  means  of  metallic 
iron,  the  iodine  being  estimated  by  difference.  Moreover, 
the  substance  analysed  by  him  had  not  been  previously 
purified. 

Conclusions. — In  attempting  to  prepare  the  intermediate 
iodide  by  Boullay's  method  (i),  we  obtain  a  mixture  of 
mercurous  and  mercuric  iodides,  separated  by  ether ; 
(2),  the  first  portions  of  the  precipitate  are  pure  mercurous 
iodide,  to  which  succeeds  pure  mercuric  iodide. 

The  intermediate  iodide  of  mercury  is  therefore  not  a 
chemical  compound,  but  a  mixture,  the  more  yellow  and 


ON    CERIUM. 
By    O.    BOUDOUARD. 

I  HAVE  the  honour  of  submitting  to  the  Academy  the 
results  of  researches  on  the  salts  of  cerium.  Continuing 
the  work  which  I  have  undertaken  with  my  regretted 
master,  Paul  Schiitzenberger,  I  have  chiefly  studied  the 
cerium  acetate  and  sulphate. 

Cerium  Acetate. 

174  grms.  cerium  sulphate,  free  from  thorium,  are  dis- 
solved in  water  and  treated  with  the  corresponding  quan- 
tity of  lead  acetate,  to  obtain  cerium  acetate.  The  ex- 
cess of  lead  is  removed  by  means  of  a  current  of  hydrogen 
sulphide.  After  filtering  off  the  lead  sulphide,  the  eerie 
solution  is  allowed  to  settle  in  the  cold,  and  in  a  very 
short  time  deposits  an  abundant  white  precipitate. 

A  portion  of  this  acetate  was  converted  into  sulphate, 
and  the  sulphate  was  analysed  by  ignition.    I  have  thus 
found  the  atomic  weight  of  the  corresponding  metal — 
Ce  =  i37'85. 

Having  made  fractionated  crystallisations  of  this  sul- 
phate, I  obtained — 

First  crystallisation Ce  =  i40'7 

Mother-liquor      Ce  =  138*5 

In  all  the  crystallisations  which  have  been  effected  the 
mother-liquors  were  always  precipitated  by  alcohol.  The 
sulphate  thus  obtained,  after  desiccation,  is  dissolved  in 
cold  water  and  again  crystallised ;  this  precaution  is  taken 
in  order  to  obtain  salts  absolutely  neutral. 

The  clear  solution  obtained  from  the  filtration  of  the 
basic  acetate  was  concentrated  in  the  water-bath.  The 
first  deposit  formed  gave  on  analysis  : — 

..     Ce=  137-35 
..     Ce  =  i35*i 

Proceeding  then  with  a  series  of  fradionated  crystallisa- 
tions, I  obtained  the  following  results  : — 

Second  deposit(CT>!!!^/l-     "-^     "     ^^^^^'"^ 


First  deposit..  I  S'-ystallisation  (a) 
'^  { Mother-liquors  (a) 


t  Mother-liquors  (6)     ..     Ce  =  i37*4 

Mother-liouors  /Crystals  (c) Ce  =  139*1 

^"''"'"l"°"-l  Mother-liquors  (c)     ..     Ce  =  136*05 

Using  Peroxide  of  Hydrogen. —  If  to  a  solution  of 
acetate  of  cerium  we  add  an  excess  of  peroxide  of  hydro- 
gen, a  yellow  precipitate  is  formed ;  this  precipitation  is 
facilitated  by  heat,  which,  however,  should  not  be.  kept 
up  for  too  long  a  time ;  and,  further,  the  precipitation  is 
only  partial. 

In  an  experiment  I  made,  I  obtained  6  grms.  of  oxide, 
which  was  transformed  into  sulphate  and  submitted  to 
fractional  crystallisations : — 

First  crystallisation 06  =  137*15 

Mother-liquor Ce  =  137*6 

The  oxides  were  mixed  afresh,  transformed  into  sulphates, 
and  these  submitted  to  another  fradional  crystallisation, 
which  gave— 

First  crystallisation Ce  =  i37'i5 

Second  „  06  =  137*35 

Third  , 06  =  137-6 

Oxalic  acid  was  added  to  the  part  not  precipitated  by  per- 
oxide of  hydrogen.  The  oxalate  of  cerium  was  calcined 
and  the  oxide  transformed  into  sulphate.  Fractional 
crystallisations  gave — 

First  crystallisation 06  =  137-85 

Second  „  Ce=  139-9 

Third  06=138*85 


Chbuical  NbW8,I 
Dec.  3t,  1897.     I 


Chloronitrides  of  Phosphorus. 


321 


Sulphate  of  Cerium. 
A  solution  of  cerous  sulphate,  to  which  had  been 
added  20  grms.  of  sulphate  of  potassium,  produced  a 
double  sulphate,  which  I  will  call  S.D.  No.  i.  The  clear 
liquid  was  re-precipitated  by  means  of  an  equal  quantity 
of  sulphate  of  potassium ;  this  gave  me  the  precipitate 
S.D.  No.  2.  Continuing  in  this  manner,  I  obtained  S.D. 
No.  3  and  S.D.  No.  4 ;  the  wash  waters  from  this  last 
precipitate  contained  nothing  further.  Each  of  these 
double  sulphates  was  decomposed  by  caustic  soda ;  the 
hydrate  obtained  was  washed  with  warm  water,  and 
finally  dissolved  in  nitric  acid  and  precipitated  by  oxalic 
acid.  This  oxalate  was  calcined,  and  the  oxide  trans- 
formed into  sulphate.  I  thus  made  a  series  of  crystal- 
lisations with  the  following  results : — 
S.D.  No.  I.— First  crystallisation..  ..  €6  =  13875 
Second  „  ....     06  =  137-3 

Third  Ce  =  133-0 

S.D.  No.  2.— First  €6  =  138-5 

Second         „  ....     06=136-95 

Third  06  =  137-9 

Fourth  06=137-7 

S.D.  N08. 3  and  4.— First  crystallisation     Oe  =  138-25 
Second        „  06=136-25 

All  these  results,  whether  obtained  with  acetate  or  sul- 
phate of  cerium,  show  that,  conformably  with  the  indica- 
tions already  given  by  Schiitzenberger  {Cotnptes  Rendus, 
cxx.,  p.  962),  oxide  of  cerium  is  accompanied  by  small 
quantities  of  another  earth  with  a  lower  atomic  weight. 
This  earth  should  be  susceptible  of  giving  a  binoxide  by 
oxidation,  and  its  sulphate  should  give  double  sulphates 
insoluble  in  the  alkaline  sulphates. 

Further,  peroxide  of  hydrogen  separates  an  oxide,  of 
which  the  atomic  weight  of  the  corresponding  metal  varies 
from  137-15  to  137-6 ;  while  the  part  not  precipitated 
gives  atomic  weights  varying  from  137-85  to  139-9 — varia- 
tions of  the  same  charadter  as  those  obtained  with  the 
double  sulphates  (from  133-0  to  138-75)  and  with  the 
acetate  (from  135*1  to  140-7).— Cow/'(«s  Rendus,  cxxv., 
No.  20. 


ON  THE  CHLORONITRIDES  OF  PHOSPHORUS.* 

By  H.  N.  STOKES. 

(Concluded  from  p.  311). 

Heptaphosphonitrilic  Chloride,    P7N7CI14. —  After   many 
distillations,  this  gave — 

Calculated  for 
PfN^Clit.  Found. 

P         26-75  26*57 

N         12-II  12*12 

CI      61*14  61*28 

Ratio,  P  :  N  :  01  =  I  :  i*oi  :  202. 

Molecular  Weight.     Solvent :  Benzene. 

Percentage 
Grms.  Grms.  Molecular     variation  from 

solvent.         substance.         Elevation.         weight.  theoretical. 

47"09  3'562i  0*250°  808  -0-5 

7-3979  0-523°  802  -1-2 

Calculated  for  P7N7CI14,  811*7. 

Heptaphosphonitrilic  chloride  is  a  nearly  colourless 
rather  viscous  liquid,  which  does  not  solidify  at  —  18°,  and 
which  boils  at  289—294°  (corr.)  at  13  m.m.,  undergoing 
some  polymerisation.  It  is  readily  miscible  with  benzene, 
gasoline,  and  ether,  and  towards  water  shows  the  stability 
manifested  by  the  preceding  chloronitrides. 

Residual  Oily  Phosphonitrilic  Chlorides.f — The  residue 

*  Published  by  permission  of  the  Director  of  the  United  States 
Geological  Survey.  From  the  American  Chemical  Journal,  vol.  xix., 
No.  9,  November,  1897.  .    ,       ,    ,  .     ,     ,       , 

t  It  is  unlikely  that  these  consist  entirely  of  the  original  depoly- 
merisation  products ;  a  portion  is  doubtless  formed  by  polymerisation 
during  distillation. 


which  did  not  distil  at  13  m.m.  when  the  temperature  of 
the  bath  was  370°,  was  boiled  with  water  to  remove  the 
solid  polyphosphonitrilic  chloride,  filtered,  and  carefully 
dried  in  vacuo  over  sulphuric  acid.  It  is  a  thick  liquid 
which  gave  on  analysis : — 

Calculated  for 
(PNClj)*.  Found. 

P        26*75  26-79 

N     ' 12*11  12*39 

01      61*14  62-00 

Ratio,  P  :  N  :  01  =  I  :  1-02  :  2*02. 

Although  the  oil  is  doubtless  a  mixture,  the  above 
figures  show  that  the  constituents  are  members  of  the 
series  (PN0l2)»-  A  determination  of  the  mean  molecular 
weight  was  made,  with  the  following  results: — 


Grms. 
solvent. 

46-72 
46-72 


Grms. 
substance. 

4*130 

7-853 


Elevation. 
0*178'' 
0*348° 


Molecular 
weight. 

1326 
1290 


Mean  1308.  This  does  not  lie  far  from  that  required 
by  the  formula  P11N11CI22  (calculated,  1276).  This  re- 
sult is  interesting  in  as  far  as  it  shows  that  a  phospho> 
nitrilic  chloride  of  this  molecular  weight  may  exist,  that 
it  is  stable  and  miscible  with  benzene,  gasoline,  and 
ether,  and  that  the  molecular  weight  of  the  solid  polymer 
described  below,  which  is  insoluble,  is  probably  very 
much  higher.  The  oil  has  a  reddish  brown  colour,  due  to 
dissolved  impurities,  which  are  destroyed  by  heating  with 
strong  nitric  acid.  It  cannot  be  distilled  even  at  13  m.m., 
as  it  polymerises  almost  instantly.  In  its  behaviour 
towards  water  it  resembles  the  preceding  members  of  the 
series. 

Polyphosphonitrilic  Chloride,  (PNOU);!?.  This  remark- 
able body,  frequently  alluded  to  above,  is  formed  when 
any  of  the  lower  members  are  heated ;  slowly  at  250*, 
and  very  rapidly  at  350°.  As  the  change  is  reversible, 
complete  transformation  cannot  be  eifeded,  but  reaches 
perhaps  go  per  cent,  the  remainder  consisting  not  only  of 
the  original  phosphonitrilic  chloride,  but  of  others.  These 
can  be  extracted  by  anhydrous  benzene.  The  sample,  the 
analysis  of  which  is  given,  was  prepared  by  heating  pure 
triphosphonitrilic  chloride  in  a  sealed  tube  at  350 — 360°. 
The  transparent  elastic  produdt  was  repeatedly  extraded 
with  benzene,  dried  over  sodium,  and  the  absorbed  ben- 
zene removed  in  a  vacuum  with  constant  exhaustion  over 
parafifin,  and  finally  by  heating  in  vacuo  at  110°.  Analysis 
gave — 

Calculated  for 
(PNCI,)*.  Found. 

P       26*75  26*78 

N       12*11  12*27 

CI      61*14  6o'45 

Ratio,  P  :  N  :  01  =  1  :  1*01 :  i*g8. 

Polyphosphonitrilic  chloride,  when  perfectly  pure,  is 
colourless  and  transparent,  but  is  generally  somewhat  dis- 
coloured by  traces  of  organic  matter.  Its  most  striking 
property  is  its  elasticity.  It  may  be  drawn  out  like  rubber, 
and  shows  even  a  greater  tendency  to  rebound  from  hard 
surfaces.  It  is  readily  cut  with  the  shears.  It  is  insoluble 
in  all  neutral  solvents,  but  absorbs  benzene,  swelling 
to  many  times  its  original  volume  and  forming  a  jelly  of 
but  little  coherence  ;  on  evaporating  the  benzene  it  returns 
to  its  original  condition ;  ether  is  absorbed,  but  less 
readily,  and  other  chloronitrides  are  taken  up  in  a  similar 
manner.  Hot  water  slowly  dissolves  it  with  decomposi- 
tion  ;  in  warm  dilute  ammonia  it  swells,  gelatinises,  and 
finally  dissolves ;  hot  caustic  soda  does  not  dissolve  it 
readily,  apparently  insoluble  sodium  salts  being  formed. 
It  begins  to  depolymerise  towards  350°,  and  this  change 
is  rapid  just  below  red  heat,  and  is  accompanied  by  partial 
fusion,  the  produdts  being,  as  described  above,  a  mixture 
of  lower  phosphonitrilic  chlorides.  These  transformations 
are  not  modified  by  heating  in  an  atmosphere  of  hydro- 


322 


International  Congress  of  Applied  Chemistry. 


I  Chemical  News, 
'     Dec.  31,  1897. 


chloric  acid.  When  perfedly  pure,  it  leaves  no  residue 
whatever  on  distilling.  No  difference  could  be  deteded 
in  the  produdt  formed  from  different  phosphonitrilic 
chlorides. 

Nitrilo-hexaphosphonitrilic  Chloride,  PeNyClg.—  The 
separation  of  this  chloronitride,  which  does  not  belong  to 
the  phosphonitrilic  chloride  series,  is  described  above. 
After  four  crystallisations  from  benzene,  it  gave — 


Calculated  for 
PaNjCla. 

P         ..      ..      ..  30-84 

N       i6'2g 

CI      52-87 


Found. 

3074 
16  29 

53'0i 


A  molecular  weight  determination,  kindly  made  for  me 
by  Dr.  H.  C.  Jones,  of  the  Johns  Hopkins  University, 
with  a  limited  quantity  of  material,  in  benzene  solution, 
gave  667 ;  calculated  for  PgNyClg,  603-5.  This,  with 
the  analysis,  suffices  to  establish  the  above  molecular 
formula. 

Nitrilo-hexaphosphonitrilic  chloride  strikingly  resembles 
the  phosphonitrilic  chlorides.  It  fuses  at  237  5°  (corr.) 
and  boils  at  251 — 261°  (corr.)  at  13  m.m.  without  change. 
The  boiling-point  coincides  closely  with  that  of  hexa- 
phosphonitrilic  chloride  (261 — 263°  corr.  at  13  m.m.), 
hence  it  is  found  associated  with  the  latter.  Heated  in 
small  quantities  on  foil,  it  volatilises  without  residue,  but 
at  a  higher  temperature  in  a  sealed  tube  it  undergoes  a 
change  the  exadt  nature  of  which  has  not  been  determined, 
but  which  involves  the  formation  of  a  substance  re- 
sembling polyphosphonitrilic  chloride,  which  yields  lower 
phosphonitrilic  chlorides  on  distilling.  It  crystal- 
lises in  transparent  prisms  of  not  more  than  i  m.m.  in 
length,  apparently  rhombic,  which  are  often  united  to 
acicular  forms.  When  pulverised  it  becomes  eledlrified. 
It  dissolves  in  about  20  parts  cold  and  5  parts  boiling 
benzene  (approximate  only),  is  more  soluble  in  carbon 
disulphide,  but  less  soluble  in  gasoline  and  in  ether. 
Towards  water  it  is  nearly  as  stable  as  hexaphospho- 
nitrilic  chloride,  but  is  slowly  attacked  when  exposed  to 
atmospheric  moisture.  Hot  dilute  ammonia  dissolves  it 
very  slowly,  but  more  rapidly  when  alcohol  is  added. 

This  body  is  obviously  a  secondary  produdt  of  the 
readlion  of  phosphorus  pentachloride  and  ammonium 
chloride,  as  it  is  never  found  when  a  pure  phosphonitrilic 
chloride  is  polymerised  and  depolymerised.  It  is  note- 
worthy that  no  indication  of  other  bodies  of  a  similar 
nature  has  been  observed,  although  no  reason  appears 
why  they  should  not  be  formed  at  the  same  time.  Whether 
it  is  in  reality  hexaphosphonitrilic  chloride  in  which  three 
chlorine  atoms  are  replaced  by  one  of  nitrogen  or  not, 
cannot  be  decided  at  present. 


Exanaination  of  Auriferous  Ores. — The  gold  present 
in  such  ores  can  be  rapidly  and  safely  determined  by  the 
following  method,  which  is  applicable  to  all  kinds  of  ores : 
— 75  grms.  of  borax  (anhydrous),  the  same  weight  of 
crude  tartar,  and  50  grms.  of  red  lead  are  mixed ; 
250  grms.  of  the  pulverised  ore  are  then  added,  along 
with  100  grms.  of  potash.  This  mixture  is  placed  in  a 
J  crucible,  and  above  it  is  spread  a  stratum  of  75  grms. 
soda,  and  over  this  again  a  layer  of  sodium  chloride 
1*5  cm.  in  thickness;  lastly,  50  grms.  of  red  lead.  The 
crucible  is  placed  in  a  gas-furnace,  cautiously  heated, 
at]  last  strongly  enough  to  bring  it  to  the  state  of  quiet 
flux.  The  melted  mass  is  poured  into  a  conical  form, 
at  the  bottom  of  which  it  arrives  as  a  lead  regulus,  which 
after  the  treatment  is  cupelled  in  a  mufHe  furnace.  If  the 
ore  contains  no  silver,  a  little  silver  free  from  gold  is 
added.  The  globule  of  silver — possibly  auriferous— is 
treated  with  nitric  acid.  The  silver  dissolves,  and  the 
residual  gold  is  weighed.  —  Chem.  Zeitung  and  Swed. 
Teknisk.  Tid. 


REGULATIONS 

OF  THE 

THIRD     INTERNATIONAL     CONGRESS     OF 
APPLIED  CHEMISTRY  IN  VIENNA,  1898. 

I.  The  Third  International  Congress  of  Applied  Chemistry 
will  be  held  in  July,  1898,  in  Vienna,  and  will  last  about 
five  days. 

2.  The  subjedls  of  the  Congress  are  as  follows  : — 
Consultations  concerning    important  questions    in  all 

departments  of  Applied  Chemistry,  and  particularly  of 
those  the  solution  of  which  is  a  matter  ot  public  interest. 

Agreement  upon  methods  to  be  considered  internation- 
ally valid  for  the  analysis  of  such  produdls  as  are  valued 
upon  the  basis  of  their  chemical  composition. 

Agreement  upon  methods  for  the  use  of  the  different 
chemical  industries,  to  be  considered  internationally  valid. 

Discussion  on  questions  of  instrudtion  in  Applied  Che- 
mistry, and  consultations  upon  general  affairs  of  Chemis- 
try; and  commencement  of  a  iriendly  understanding 
between  the  representatives  of  the  different  departments 
of  Applied  Chemistry  at  home  and  abroad. 

3.  For  the  settlement  of  the  tasks  of  the  Congress  there 
will  be  two  general  meetings  and  a  greater  number  of 
special  consultations.  Besides  these  there  will  be  excur- 
sions for  the  purpose  of  visiting  scientific  institutions  and 
establishments. 

4.  The  special  consultations  of  the  Congress  will  be 
divided  into  twelve  Sedtions. 

Section  I.  General  Analytical  Chemistry  and  Chemical 
Instruments.  (General  methods  of  analysis  ;  analytical 
apparatus,  measuring  instruments,  hydrometers,  &c.). 

Section  II.  Chemistry  of  Food,  Medical  and  Pharma- 
ceutical Chemistry.  (The  chemical  and  physical  analysis 
of  foods,  discussion  of  chemical  questions  regarding  foods 
in  trade  which  do  not  come  under  the  head  of  another 
sedtion  ;  further  questions  of  medical  and  pharmaceutical 
chemistry). 

Section  III.  Agricultural  Chemistry.  (Agricultural  che- 
mistry; experiments  and  analysis  of  dairy  produdls). 

Section  IV.  Sugar  Industry,  Starch  and  Grape  Sugar 
Manufadlure. 

1.  Brewery  and  Malt  Manufadlure. 

2.  Alcohol  and  Yeast  Industry. 
Section  V.  Zymology. 

Section  VI.  ffino-Chemistry. 

Section  VII.  Chemical  Industry  of  Inorganic  Sub- 
stances. (Sulphuric  acid,  soda,  and  chloride  of  lime 
manufadlure  ;  alkaline  industry  ;  artificial  manure  pro- 
dudlion  ;  lime  and  cement  industry;  industry  of  illumin- 
ants  ;  glass,  china,  and  earthenware  manufadlure). 

Section  VIII.  Metallurgy  and  Industry  of  Explosives. 

Section  IX.  Chemical  Industry  of  Organic  Substances. 
(Industryof  aniline  dyes  ;  dyeing  and  printing  ;  manufac- 
ture of  pharmaceutical  preparations ;  chemistry  of  fats, 
oils,  and  lubricants;  paper  and  xylonite  industry;  tannery 
and  glue  manufadlure). 

Section  X.  Chemistry  of  the  Graphic  Industry.  (Photo- 
chemistry, photographic  and  chemical  printing,  colour 
printing,  &c.). 

Section  XI.  Questions  of  instrudlions  and  general 
affairs  of  chemists. 

Section  XII.  Eledkro-chemistry. 

Questions  which  belong  to  several  departments  at  once 
will  be  discussed  in  common  meetings  of  the  Sections 
concerned. 

5.  Anyone  can  become  member  of  the  Congress  who  is 
concerned  with  the  theory  or  pradlice  of  chemistry  or 
pradtically  employed  in  any  department  of  chemistry,  as 
well  as  such  persons  and  corporations  as  are  interested  in 
an  undertaking  in  which  chemical  processes  are  applied, 
and  also  all  those  persons  and  societies  which  take  an 
interest  in  the  progress  of  Applied  Chemistry. 

6.  Every  member  has  to  pay  a  fee  of  10  florins,  for 


CRBMICAL  NBWt,  I 

Dec.  31,1897.     I 


Kekule  Memorial  Lecture^ 


323 


which  he  receives  a  members'  card,  which  admits  him  to 
the  general  meetings  and  special  sessions  and  all  other 
Congress  arrangements  and  entitles  him  to  all  publications 
of  the  Congress.  Members  who  subscribe  at  least  100 
florins  for  the  benefit  of  the  Congress  will  be  mentioned 
specially  in  the  Congress  publications  as  Patrons  of  the 
Third  International  Congress  for  Applied  Chemistry, 
Vienna,  1898. 

7.  Any  surplus  of  the  subscriptions  will  be  devoted  to 
benevolent  purposes,  and  this  will  be  decided  at  the  second 
general  meeting  of  the  Congress. 

8.  Every  member  must  enter  his  name  at  the  beginning 
of  the  Congress  in  the  lists  of  those  Sections  in  which  he 
will  take  part,  and  at  the  same  time  give  his  address 
during  the  Congress. 

g.  Every  member  of  the  Congress  has  a  right  to  take 
part  in  the  debates  of  the  special  consultations,  and  has 
the  right  of  voting  in  the  general  meetings  and  the  con- 
sultations of  those  Seftions  of  which  he  is  a  member. 

10/  The  languages  to  be  spoken  at  the  Congress  are 
English,  French,  and  German. 

11.  The  business  of  the  Congress  will  begin  at  the  first 
general  meeting.  This  will  be  opened  by  the  President 
of  the  organising  committee,  and  the  record  will  be  kept 
by  the  Council  of  the  organising  committee. 

This  meeting  elefts  the  Honorary  President  and  the 
Honorary  Vice-President,  and  nominates  the  President, 
the  Vice-Presidents,  the  General  Secretary,  and  Secre- 
taries of  the  Congress. 

12.  The  second  general  meeting  will  take  place  at  the 
end  of  the  Congress.  This  will  be  opened  and  presided 
over  by  the  President  of  the  Congress.  The  record  will 
be  kept  by  the  General  Secretary  and  the  Secretaries  of 
the  Congress.  In  this  an  account  will  be  given  of  the 
particulars  of  the  Congress  by  the  General  Secretary,  and 
the  meeting  will  decide  place  and  time  of  the  Fourth 
International  Congress  of  Applied  Chemistry. 

13.  The  first  sitting  of  each  branch  sedlion  or  sub- 
seiStion  will  be  opened  by  the  President  nominated  by  the 
organising  committee,  and  the  formation  of  the  council  of 
the  special  sedtion  or  sub-se(5tion  will  be  introduced  by 
him.  For  the  formation  of  the  latter  a  President  and  a 
corresponding  number  of  Vice-Presidents  must  be  elefted 
for  the  first  sitting,  and  once  for  all  a  chief  Secretary  and 
several  secondary  Secretaries  (according  to  the  length  of 
the  discussions)  for  all  the  sittings  of  the  sedlion  or  sub- 
sedlion.  At  the  end  of  each  sitting  the  President  and  the 
Vice-President  for  the  following  sitting  are  to  be  eledted. 

The  Presidents,  Vice-Presidents,  and  Secretaries 
eledted  by  the  organising  committee  remain  at  the  same 
time  members  of  the  council  of  the  special  sedtion  or  sub- 
sedtion  during  all  the  sittings  of  the  same. 

14.  The  order  of  the  day  and  the  succession  of  the 
subjedls  of  the  consultation  will  be  arranged  indepen- 
dently by  each  sedtion  and  sub-sedtion.  Reports  which 
are  printed  and  distributed  to  the  members  beforehand 
are  generally  not  read  aloud,  and  the  debate  upon  these 
will  be  commenced  at  once  by  the  President.  Verbal 
reports  should  not  last  longer  than  twenty  minutes.  In 
the  debate  a  speaker  may  not  speak  longer  than  ten 
minutes,  and  it  is  not  permitted  that  he  should  speak  on 
the  same  subjedt  more  than  twice.  The  voting  will  be 
based  on  the  members'  lists  of  the  special  sedtion  or  sub- 
sedtion,  and  the  simple  majority  decides.  In  case  of 
equal  votes  the  President  gives  the  casting  vote. 

15.  For  the  purpose  of  drawing  up  the  Congress 
Record  those  reporters  whose  reports  were  not  printed,  as 
well  as  all  speakers  in  the  debate,  must  give  a  short 
account  in  writing  of  their  speech  to  the  first  Secretary  of 
the  special  sedtion  or  sub-sedlion  not  later  than  half  an 
hour  after  the  close  of  the  meeting  in  question.  The 
first  Secretary  must  draw  up  the  Record  by  means  of  the 
accounts  received,  and  give  it  up  if  possible  on  the  same 
day,  together  with  the  list  of  those  present,  to  the  General 
Secretary  of  the  Congress. 

16.  The  addresses  to  be  given  during  the  Congress,  and 


the  reports  to  be  presented,  must  be  announced,  not  later 
than  30th  of  April,  1898,  to  the  Special  President  of  the 
sedlion,  or  diredl  to  the  organising  committee.  Later  an- 
nouncements can  only  be  accepted  by  the  decision  of  the 
branch  sedlion  or  sub-sedlion  of  the  Congress  concerned. 
Ledlures  or  reports  which  have  to  be  printed  must  be 
sent  at  the  latest  on  the  15th  of  April,  1898,  to  the 
General  Secretary  of  the  organising  committee  or  to  the 
President  of  the  sedlion  concerned.  The  reports  must 
not  take  more  than  five  8vo  pages  in  print.  The  or- 
ganising committee  will  decide  regarding  manuscripts  of 
greater  length  of  purpose  for  printing. 

17.  All  conclusions  or  resolutions  of  the  Congress  will 
be  laid  before  the  respedlive  Governments  by  the  or- 
ganising committee. 

18.  After  the  conclusion  of  the  Congress  a  printed 
report  will  be  given,  free  of  charge,  to  all  members. 

19.  About  all  other  matters  concerning  the  Congress 
not  mentioned  in  the  Congress  Regulations  the  organ< 
ising  committee  will  give  every  information. 


PROCEEDINGS    OF    SOCIETIES. 

CHEMICAL  SOCIETY. 
Extra  Meeting,  December  15th,  1897. 

Professor  Dewar,  F.R.S.,  President,  in  the  Chair. 

Professor  F.  R.  Japp,  LL.D.,  F.RS.,  delivered  the 
Kekule  Memorial  Lecture. 
Friedrich  August  Kekule  was  born  at  Darmstadt  on 
September  7th,  1829.  Originally  intended  for  the  pro- 
fession of  an  architedl,  he  was  induced,  by  hearing 
Liebig's  ledlures,  to  devote  himself  to  chemistry.  After 
studying  under  Liebig,  he  spent  a  year  in  Paris,  where  he 
became  intimate  with  Gerhardt.  Later  on  he  resided  for 
a  time  in  London,  making  the  acquaintance  of  Williamson 
and  Odling.  He  always  acknowledged  the  influence 
which  these  three  chemists  had  exercised  on  the  forma- 
tion of  his  opinions.  Kekule's  theories  are  based  on 
Gerhardt's  type  theory;  on  Williamson's  theory  of  poly- 
valent radicles,  which,  by  their  power  of  linking  together 
other  radicles,  render  possible  the  existence  of  multiple 
types  ;  and  on  Odling's  theory  of  mixed  types,  which  was 
a  dedudlion  from  Williamson's  theory.  Less  consciously 
perhaps  his  opinions  were  influenced  by  E.  Frankland's 
theory  of  the  valency  of  elementary  atoms,  and  by  Kolbe's 
speculations  on  the  constitution  of  organic  compounds. 
Kekule  gathered  together  the  various  ideas  which  he 
found  scattered  throughout  the  writings  of  his  prede- 
cessors, added  to  them,  and  welded  the  whole  into  the 
consistent  system  which  forms  our  present  theory  of 
chemical  strudlure.  In  1857,  in  the  course  of  a  memoir 
on  the  constitution  of  fulminic  acid,  he  gave  a  tabular 
arrangement  of  compounds  formulated  on  the  type  of 
marsh  gas,  this  being  the  earliest  statement,  although  put 
forward  only  in  an  imperfedl  form,  of  the  tetravalency  of 
carbon.  In  the  same  year  he  published  an  important 
theoretical  paper :  "  On  the  so-called  Conjugated  Com- 
pounds and  the  Theory  of  Polyatomic  Radicles,  which 
contains  a  complete  system  of  multiple  types  and  mixed 
types.  In  1858  the  celebrated  paper,  •'  On  the  Constitu- 
tion and  Metamorphoses  of  Chemical  Compounds,  and 
on  the  Chemical  Nature  of  Carbon,"  appeared;  it  em- 
bodies the  fully-developed  dodlrine  of  the  tetravalency  of 
carbon,  together  with  Kekule's  views  on  the  linking  of 
atoms  and  on  the  valency  of  such  chains  of  atoms— the 
foundation  on  which  our  modern  system  of  constitutional 
formulae  rests.  In  1865  Kekul6  put  forward  his  well- 
known  benzene  theory — the  crowning  achievement,  in  his 
hands,  of  the  dodlrine  of  the  linking  of  atoms,  and  the 


324 


Kekule  Memorial  Lecture. 


most  brilliant  piece  of  scientific  predidlion  to  be  found  in 
the  whole  range  of  organic  chemistry.  The  conception 
of  closed  chains,  or  cycloids,  which  he  thus  introduced, 
has  shown  itself  to  be  capable  of  boundless  expansion. 

Kekule  published  the  first  instalment  of  his  "  Lehrbuch 
der  Organischen  Chemie  "  in  1859.  The  work  was  never 
finished,  but  it  was  instrumental  in  widely  disseminating 
Kekul6's  views,  and  exercised  enormous  influence  on  the 
development  of  the  science. 

Kekule  obtained  the  venia  legendi  in  Chemistry  at  the 
University  of  Heidelberg  in  1856.  Two  years  later  he 
was  called,  as  ordinary  professor,  to  the  University  of 
Ghent,  where  he  remained  until  1867,  when  he  was  ap- 
pointed  to  the  Professorship  of  Chemistry  in  the  Uni- 
versity of  Bonn,  a  post  which  he  continued  to  hold  until 
his  death  on  July  13,  1896.  During  his  later  years  he 
suffered  from  bad  health. 

The  charaderistic  note  of  Kekule's  great  theoretical 
creation,  the  chemistry  of  struAure,  is  the  treatment  of 
the  problem  of  isomerism — the  problem  which  first  neces- 
sitated the  use  of  constitutional  formulae — as  one  of  geo- 
metrical symmetry.  Kekule's  formulae,  freed  from  the  fet- 
ters of  the  type  theory  with  which  he  had  first  encumbered 
them,  were  merely  more  or  less  symmetrical  geometrical 
figures.  In  order  to  predidt  the  number  of  substitution 
compounds,  it  was  only  necessary  to  consider  the  degree 
of  dissymmetry  of  the  parent  compound :  the  less  the 
symmetry,  the  grsater  the  number  of  isomeric  substitu- 
tion compounds.  The  extraordinary  fertility  of  this  con- 
ception is  shown  by  the  development  which  it  has  under- 
gone at  the  hands  of  van  't  Hoff,  J.  Wislicenus,  von 
Baeyer,  and  others. 

The  accuracy  of  Kekule's  prediAions  has  done  more  to 
inspire  a  belief  in  the  utility  of  legitimate  hypotheses  in 
chemistry,  and  has  therefore  done  more  for  the  dedudtive 
side  of  the  science,  than  that  of  almost  any  other  investi- 
gator. His  work  stands  pre-eminent  as  an  example  of 
the  power  of  ideas.  A  benzene  formula,  consisting  of  a 
few  chemical  symbols  jotted  down  on  paper  and  joined 
together  by  lines,  has  supplied  work  and  inspiration  for 
scientific  organic  chemists  during  an  entire  generation, 
and  affords  guidance  to  the  most  complex  industry  the 
world  has  yet  seen. 

Dr.  Hugo  Muller,  as  probably  the  oldest  personal 
friend  of  Kekule  present,  moved  a  cordial  vote  of  thanks 
to  Professor  Japp  for  his  eloquent  le(5ture,  and  added  his 
special  appreciation  of  the  admirable  and  exhaustive 
manner  in  which  the  ledturer  had  accomplished  his  task. 
A  considerable  effort  was  needed  to  realise  the  condition 
in  which  organic  chemistry  stood  fifty  years  ago,  in 
order  to  recognise  the  vast  advances  which  have  been 
made  in  the  interval.  It  may  be  truly  claimed  for 
Kekul6  that  he  holds  a  foremost  position  amongst  those 
reformers  who  have  initiated  this  progress.  It  was  here, 
in  London,  that  Kekule  first  conceived  the  ideas  which, 
in  their  further  development,  assumed  the  shape  of  his 
"  chemistry  of  carbon  "  and  "  benzene  theory,"  and, 
being  in  those  days  in  almost  daily  intercourse  with 
him,  he  well  recollected  the  eagerness  and  enthusiasm 
with  which  the  problems  which  occupied  his  mind  were 
discussed. 

Soon  afterwards,  in  Heidelberg,  and  then  in  Ghent,  his 
affable  manner  and  sociability  attradted  a  number  of  de- 
voted pupils,  who  became  adtive  fellow  workers,  and  thus 
his  teaching  bore  fruit  in  all  diredlions. 

Unfortunately,  not  long  after  he  had  been  settled  in 
Bonn,  his  health  gradually  gave  way,  and  he  suffered 
much  from  nervous  prostration  and  an  irksome  degree 
of  deafness,  which  at  times  much  depressed  him.  His 
power  of  work  became  greatly  impaired,  and  notwith- 
standing repeated  heroic  efforts,  even  his  Handbook 
had  to  remain  unfinished. 

Professor  Thorpe,  in  seconding  the  resolution,  also 
desired  to  give  expression  to  the  sense  of  obligation 
which  the  Society  was  under  to  Professor  Japp  for  the 
thoughtful  and  eminently  impartial  address  which  he  had 


(OHByicAL  News, 
I     Dec.  31,  1&97, 

given.  There  was,  however,  one  slight  but  charadteristic 
omission  in  the  ledture.  In  enumerating  Kekule's  stu< 
dents,  Dr.  Japp  had  negledled  to  make  any  reference  to 
himself.  It  was,  no  doubt,  that  same  feeling  of  piety  to 
which  he  had  borne  witness  in  the  course  of  his  ledture 
on  the  part  of  another  which  induced  Dr.  Japp  to  comply 
so  readily  as  he  had  done  with  the  request  of  the  Council 
that  he  should  undertake  the  weighty  and  responsible 
duty  of  delivering  this  address.  His  personal  intercourse, 
as  a  student,  with  the  master  had,  we  may  take  it, 
quickened  his  appreciation  of  his  work.  At  the  same 
time,  as  would  be  evident,  it  had  in  no  sense  diminished 
his  critical  faculty.  The  audience  had  recognised  that 
the  ledture  was  a  truthful  and  well-balanced  account, 
written  impartially  and  in  the  true  spirit  of  history,  of 
the  origin  and  fruit,  so  far  as  this  had  been  gathered,  of 
the  great  chemist's  labours. 

Some  reference  had  been  made  to  the  fadt  that  he  (the 
speaker)  had  enjoyed  the  good  fortune  of  also  being  a 
student  under  Kekule,  and  of  being  associated  with  him, 
in  some  small  degree,  in  certain  experimental  workwhicli 
he  undertook  during  the  first  years  of  his  professorship  in 
the  magnificent  institution  which  Germany  owes  to 
Hofmann.  It  is  a  curious  coincidence  that  Hofmann, 
like  Kekule,  might  have  become  an  architedt  if  destiny, 
as  in  Kekule's  case,  had  not  intended  that  he  should  be  a 
chemist.  During  the  late  sixties  there  was  no  sign  of 
the  decay  in  intelledtual  vigour  which  a  few  years  later 
became  so  sadly  obvious.  At  that  time  the  great  gene- 
ralisation which  we  associate  with  Kekule's  name  was 
still,  to  some  extent,  on  its  trial,  and  it  had  to  withstand 
the  assaults  which  were  from  time  to  time  delivered  by 
keen  and  ad^ive  opponents  in  other  schools  of  chemical 
thought.  It  happened  that  very  shortly  after  the 
speaker's  entrance  into  Kekule's  laboratory  he  was  called 
upon  to  handle  the  weapons  which  Kekule  himself  placed 
in  his  hands  in  order  to  defend  a  small  but  apparently 
vulnerable  point  in  the  theory.  That  circumstance 
proved  of  incalculable  benefit  to  him,  in  that  it  brought 
him  into  intimate  personal  contadt  with  Kekul^,  and 
enabled  him  to  see  something  of  his  methods  of  work, 
and  of  the  springs  of  his  inteliedtual  adtivity.  Dr.  Japp 
has  ably  testified  to  Kekule's  merits  as  a  teacher. 
Kekule,  indeed,  was  one  of  the  very  best  expositors,  with 
the  single  possible  exception  of  Kirchhoff,  to  whom  it  had 
been  the  speaker's  lot  to  listen.  As  a  laboratory  teacher 
he  was  excellent.  He  was  a  most  severe  judge  of  work, 
striving  to  exadt  the  same  high  manipulative  finish,  the 
same  neatness  and  order,  which  he  invariably  bestowed 
on  everything  he  did,  and  he  was  absolutely  intolerant  of 
anything  slovenly  or  "  sloppy."  But  it  was  as  a  ledlurer 
that  he  was  seen  at  his  best.  He  was  singularly  luminous 
as  a  thinker,  a  close  and  accurate  reasoner,  with  a  re- 
markable power  of  concentrated  expression.  He  was  not 
a  rapid  speaker,  and  he  never  indulged  in  those  rhetorical 
flights  with  which  Hofmann  occasionally  was  wont  to 
eledtrify  an  audience.  His  language  was  apt  and  well 
chosen,  and  his  delivery  easy  and  natural.  His  ledture- 
table  was  never  overburdened  with  "experiments"  ;  those 
he  showed  were  stridtly  proper  to  the  subjedt  in  hand. 
To  see  him  handle  the  chalk  was  in  itself  a  liberal  edu- 
cation. Although  everything  appeared  to  be  so  easy  and 
natural,  an  attentive  critic  could  hardly  fail  to  perceive 
that  the  lecture  had  been  carefully  thought  out  before- 
hand, possibly  over  a  longer  period  of  time  than  it  took 
to  utter.  Every  detail  would  seem  to  have  been  con 
sidered,  even  to  the  particular  places  on  the  blackboard 
where  the  formulae  should  appear. 

During  the  later  period  of  his  life,  Kekule,  unfortu- 
nately for  Science,  was  comparatively  sterile.  Those 
who  knew  him,  however,  would  be  the  first  to  affirm 
that  this  seeming  apathy  sprung  from  no  natural  in- 
dolence. There  is  no  doubt  that  he  suffered,  even  in  the 
early  period  of  middle  life,  from  the  intense  stress  and 
strain  of  his  mental  labours  prior  to  the  Ghent  period. 
He  had  too  surely  exemplified  the  sad  truth  of  Liebig's 


CtlBUlbAL  Nbws,  I 
Dec.  31, 1897.     I 


Chemical  Notices  from  Poreign  Source^, 


3  25 


saying,  to  which  Dr.  Japp  had  referred,  that  he  who 
would  become  a  great  chemist  must  pay  for  his  pre- 
eminence by  the  sacrifice  of  his  health.  There  is  reason 
to  know  that  it  was  the  consciousness  of  failing  power 
which  prevented  him  from  finishing  much  to  which  he 
had  put  his  hand,  and  that  his  fastidiousness  and  his 
sense  of  *'  finish,"  amounting  almost  to  hypercriticism, 
restrained  him  from  publishing  what  he  realised  fell  short 
of  his  ideal.  What  he  has  left  us,  however,  is  an  im- 
perishable monument  to  his  genius. 

The  President  said  that  there  was  little  to  add  to 
Professor  Japp's  exhaustive  eulogy  of  the  life  and  work  of 
Kekule.  His  own  early  relations,  however,  with  the  great 
chemist  whose  life  work  the  Society  was  commemorating 
might  have  some  interest  to  the  members  and  ought  to  be 
told.  While  a  student  with  Lord  Playfair  at  Edinburgh, 
in  the  session  1866-67,  he  made  his  first  contribution 
to  Science  in  the  shape  of  a  little  paper  entitled,  "  On  the 
Oxidation  of  Phenyl  Alcohol  and  a  Mechanical  Arrange- 
ment adapted  to  Illustrate  StruAure  in  the  Non-saturated 
Hydrocarbons."  This  note  appeared  in  the  Proceedings 
of  the  Royal  Society  of  Edinburgh,  and  he  was  so  de- 
sirous of  becoming  known  to  Kekule  as  a  student  of  his 
theory  of  the  aromatic  bodies  that  a  specimen  model  was 
sent  to  Ghent.  Lord  Playfair  addressed  a  letter  to 
Kekule  stating  that  he  (Professor  Dewar)  was  very 
anxious  to  work  in  his  laboratory.  The  reply  was, 
*•  Come,"  and  the  reception  and  kindness  he  received 
from  Kekule  has  always  had  his  profound  gratitude. 

The  summer  of  1867  was  thus  spent  in  the  private 
laboratory  of  Kekule.  Before  leaving  Edinburgh,  he  had 
been  working  on  the  coal  tar  bases,  and  a  supply  was 
taken  with  him  to  Ghent.  There  he  began  the  study  of 
the  oxidation  produdts  of  picoline,  and  at  the  British 
Association  Meeting  at  Norwich,  in  1868,  an  account  of 
the  separation  of  dicarbopyridinic  acid,  the  analogue  of 
phthalic  acid  in  the  benzene  series,  was  given.  At  the 
same  meeting,  he  gave  a  paper  on  "  Kekule's  Model  to 
Illustrate  Graphic  Formulae."  This  is  the  succinft  his- 
tory  of  the  beginning  of  the  pyridine-benzene  analogy. 
His  old  friend  Koerner  had  speculated  in  the  same  direc- 
tion, and  he  (Prof.  Dewar)  might  confess  that  in  his 
opinion  they  both  had  received  too  much  credit  for  an 
extension  of  the  benzene  theory  to  pyridine.  At  a  dis- 
tance of  thirty  years,  to  look  back  and  call  to  mind  the 
presence  and  personality  of  the  great  chemist  as  he 
knew  him  was  indeed  a  pleasure.  He  was  a  man  of 
noble  mien,  handsome,  dignified,  and  yet  of  a  homely 
and  kindly  disposition.  He  was  a  severe  critic,  having 
a  haughty  contempt  for  the  accidental  and  bizarre  in 
scientific  work.  His  originality  and  suggestiveness 
seemed  endless,  so  that  he  had  no  need  to  commit  sci- 
entific trespass  or  to  follow  just  in  the  wake  of  other 
people's  ideas.  Everything  that  passed  through  the 
Kekule  alembic  was  indeed  transmuted  into  pure  gold. 
His  precision  of  thought  and  didtion  rendered  his  papers 
profoundly  suggestive  to  other  workers.  His  great  work 
will  always  live  in  the  history  of  our  Science,  and  his 
loving  memory  will  be  for  ever  enshrined  in  the  hearts  of 
his  pupils. 


CORRESPONDENCE. 


tHE    EXPLOSION    AT    DARTFORD. 

To  the  Editor  of  the  Chemical  News. 
Slk,— Having  received  numerous  enquiries  in  resped  to 
the  fatal  explosion  which  occurred  at  our  Dartford  works 
on  Wednesday,  the  15th  inst.,  and  so  many  erroneous 
versions  having  appeared  in  the  public  press,  we  think  it 
well  to  state  the  simple  i&Gts  of  the  case. 
The  deceased,  Mr.  Lewis  Jones  (qualified  chemist),  was 


mixing  a  preparation  of  erythrol  tetranitrate — a  remedy 
which  is  now  somewhat  extensively  prescribed  by  the 
medical  profession  in  cardiac  affedtions.  The  process 
consisted  in  diluting  erythrol  tetranitrate  with  finely- 
powdered  ladtose  by  gently  stirring  the  substances  in  a 
mortar ;  no  pounding  or  grinding  was  required.  The 
quantity  of  erythrol  in  the  possession  of  the  deceased  was 
four  ounces.  Our  process  for  dealing  with  this  substance 
was  adopted  after  a  series  of  careful  experiments,  and  it 
has  always  been  performed  by  competent  chemists  who 
knew  the  dangers  of  such  nitrous  compounds.  The  pro- 
cess has  been  carried  out  by  us  many  times  during  the 
past  eighteen  months  without  the  slightest  mishap.  It 
has  been  the  rule  of  the  chief  of  the  department  to  caution 
those  who  handled  it ;  and  the  deceased  received  such  a 
warning.  The  erythrol  tetranitrate  was  kept  under  lock 
and  key  in  a  dark  closet.  The  cause  of  the  explosion  we 
can  only  attribute  to  some  extraordinary  accident ;  un- 
fortunately there  was  no  witness  to  the  adtual  carrying 
out  of  the  operation  by  the  deceased  on  this  occasion. 
The  force  of  the  explosion  was  violent,  but  local. 

We  need  hardly  add  that  we  are  deeply  pained  by  this 
sad  occurrence,  which  has  resulted  in  the  death  of  an 
employe  who  had  gained  our  high  esteem. — We  are,  &c., 

Burroughs,  Wellcome,  &  Co. 

Snow  Hill  Buildings,  London,  E.G., 
December  21, 1897. 


CHEMICAL    NOTICES   FROM    FOREIGN 
SOURCES. 

NoTB,— All  degrees  of  temperature  are  Centigrade  uniesBotberwiae 
expressed. 

Comptes  Rendus  Hebdomadaires  des  Seances,  deVAcademie 
des  Sciences.  Vol.  cxxv..  No.  20,  November  15,  1897. 
Readtion  of  Hydrogen  upon  Sulphuric  Acid.— M. 
Berthelot. — The  author  finds  that  there  is  an  important 
readtion  between  hydrogen  and  sulphuric  acid.  0*5  grm. 
of  H2SO4  (boiled)  was  sealed  in  a  glass  tube  with  11  c.c. 
of  hydrogen ;  at  the  end  of  six  hours,  at  a  temperature  of 
250",  all  the  hydrogen  was  absorbed,  with  the  produdtion 
of  water  and  sulphurous  acid.  The  readtion  takes  place 
also  at  the  ordinary  temperature,  but  it  is  much  slower ; 
it  does  not  occur  with  dilute  acid,  and  light  has  no  aporeci* 
able  effedt.  *^ 

Influence  of  Oxygen  upon  the  Decomposition  of 
the  Hydracids  by  Metals,  and  especially  by  Mercury. 
— M.  Berthelot.— Mercury  is  generally  considered  to  have 
no  particular  adtion  on  gases  with  which  it  may  be  in  con- 
tadt,  with  the  exception  of  a  few  such  as  chlorine,  nitrous 
acid,  &c.;  but  there  are  gases  which  have  a  slow  adtion, 
among  which  are  HCl,  under  certain  conditions  of  tem- 
perature and  time  and  in  the  presence  of  free  oxygen. 

Diredt  Readtion  of  Sulphuric  Acid  with  Mercury  at 
the  Ordinary  Temperatures.— M.  Berthelot, —Boiled 
sulphuric  acid  has  a  slow  adtion  on  mercury,  forming  a 
sulphate,  and  giving  off  sulphurous  acid  when  carbonic 
acid  is  passed  through  it.  The  readtions  described  in  this 
paper  only  take  place  when  the  sulphuric  acid  is  at  the 
maximum  of  concentration. 

Influence  of  Surfusion  upon  the  Congelation-point 
of  the  Solutions  of  Potassium  Chloride  and  Sugar 
— F.  Raoult.— Previous  experiments  have  shown  that  the 
value  of  K  in  the  equation  C  =  C'(I  -  KS)  for  aqueous  solu- 
tions of  chloride  of  sodium  and  alcohol  is  not  constant  as 
was  generally  admitted,  but  that  it  varies  sensibly  with 
the  concentration.  Further  experiments  show  that  this 
is  not  the  case  with  aqueous  solutions  of  chloride  of  pot- 
assium and  of  cane-sugar.  The  new  experiments  were 
carried  out  with  the  same  apparatus  as  the  former  ones 
and  the  table  of  figures  shows  that  the  molecular  lowering 


3^6 


i^eeiings  for  the  Week, 


rdiktEUiCAL  News, 
I     Dec.  31, 1897. 


of  the  congelation-point  varies  in  a  very  different  manner 
with  regard  to  the  concentration  of  the  substances  men- 
tioned. 

Adion  of  Water  upon  Phosphorous  Terchloride 
and  Phosphorous  Oxychloride. — A.  Besson. — The  re- 
action between  trichloride  of  phosphorus  and  water  in 
excess  gives  phosphorous  acid  and  hydrochloric  acid ;  but 
when  the  trichloride  is  in  excess,  several  peculiarities  are 
noticed.  No  matter  how  we  arrange  for  the  reaftion  be- 
tween a  small  quantity  of  water  and  PCI3,  we  always  find 
a  small  quantity  of  a  phosphorous  oxychloride  resulting 
from  the  incomplete  readlion  PCl3  +  H20  =  2HCl-fPOCl, 
This  latter  is  a  solid  body  of  the  consistence  of  paraffin, 
with  a  smell  similar  to  that  of  phosphoric  oxychloride  or 
chloride  of  phosphoryl,  POCI3.  This  body  is  insoluble  in 
the  usual  solvents,  and  is  analogous  in  the  phosphoric 
series  to  NOCl,  AsOCl,  &c. 

Produ(5lion  of  Strontium  Sulphide  by  means  of 
Sulphuretted  Hydrogen  and  Strontia  or  Carbonate 
of  Strontium.  Influence  of  Temperature. — J.  R. 
Mourelo. — It  was  found  that  temperature  had  a  curious 
influence  on  the  results  in  the  carrying  out  of  this  pro- 
cess. A  porcelain  tube  containing  either  strontia  or  car- 
bonate of  strontia  is  placed  in  a  furnace,  and  sulphuretted 
hydrogen  gas  is  passed  over  it,  at  first  in  the  cold.  The 
tube  is  then  gradually  warmed  to  a  bright  red  heat,  taking 
care  that  the  current  of  gas  is  strong  enough  to  carry  off 
the  water  formed  by  the  reaction.  When  the  transforma- 
tion is  complete,  a  slow  current  of  dry  hydrogen  is  sub- 
stituted for  the  sulphuretted  hydrogen ;  after  which  the 
tube  is  allowed  to  cool,  and  the  contents,  monosulphide 
of  strontium,  may  be  withdrawn  ;  this  sulphide  is  not 
phosphorescent.  At  a  red  heat  the  formula  of  the  reac- 
tion is  ;SH^-^SrO  =  SrS-^-H20.  It  the  temperature  is 
not  sufHciently  high,  the  water  condenses  in  the  tube 
and  attacks  the  sulphide  already  formed,  and  a  mass  has 
been  found  containing  22  per  cent  of  strontic  hydrate  and 
smelling  strongly  of  sulphuretted  hydrogen. 

Produdtion  of  Volatile  Patty  Acids  from  the 
Washing  Waters  of  Wools. — A.  and  P.  Buisine. — The 
V  Jthors  think  that  the  produdtion  of  these  volatile  acids  is 
now  of  commercial  importance,  and  they  give  a  risume 
of  the  method  of  procedure  by  which  they  are  distilled, 
entangled  with  and  condensed  by  watery  vapour.  The 
waters  are  first  allowed  to  ferment  for  eight  days,  then 
boiled  to  drive  off  the  ammonia,  then  acidulated  with  sul- 
phuric acid  and  distilled.  The  volatile  fatty  acids  found 
in  the  largest  quantities  are  acetic  and  propionic,  but  we 
also  get  a  fair  percentage  of  butyric,  valerianic,  caproic, 
and  benzoic  acids,  with  traces  of  formic  and  caprylic 
acids  and  phenol.  Amongst  other  applications,  this  mix- 
ture of  raw  fatty  acids  is  particularly  suitable  for  the  pro- 
duction of  acetone,  methyl-ethylacetone,  and  the  higher 
acetones  which  are  comprised  by  the  mixture  known  as 
"  oil  of  acetone." 

Decomposition  of  Chloroform,  Bromoform,  and 
Chloral  by  a  Solution  of  Potash. — A.  Desgrez. — 
Bright  sunlight  has  an  accelerating,  and  darkness  a  re- 
tarding, influence  on  the  decomposition  of  chloroform  by 
this  means,  but  potash  without  the  mediation  of  water 
has  no  effet^.  Chloral  has  the  same  adtion,  but  it  occurs 
more  rapidly. 


NOTES   AND   QUERIES, 

*^*  Our  Notea  and  Queries  eolumn  was  opened  for  the  purpose  of 

giving  and  obtaining  infot-mation  likely  to  be  of  use  to  out   readei-s 

generally.    We  cannot  undertake  to  let  this  column   be  the  means 

of  transmitting  merely  private  information,  or  such  trade   notices 

as  should  legitimately  come  in  the  advertisement  columns. 

Oxidation  of  Organic  Matter.— I  have  endeavoured  to  had  if 

any  records  exist  of  observations  on  the  oxidation,  by  atmospheric 

oxygen,  of  organic  matter  in  commercial  use,  e.  g.,  of  rope,  wood, 

gums,  caoutchouc,   &c.     The  conditions  which  favour  such  action 

appear  to  be  very  different  from  those  in  the  cases  of  metals.    If  any 

correspondent  can  give  any  information  they  will  obl.ge.— H.  V. 


Destruiition  of  Moths  by  Formic  Aldehyd.— Formic  aldehyd 
is  so  powerful  a  disinfeiftant,  and  so  destruftive  to  most  low  forms  of 
life,  that  I  think  it  will  help  us  to  solve  the  great  "  moth  "  problem 
of  the  household.  I  propose  to  pack  up  furs  and  winter  coats  as  soon  as 
they  are  done  with  in  the  spring  in  a  large  tin  box  containing  vapour 
of  formic  aldehyd  ;  but  before  doing  so  I  should  like  some  of  your 
correspondents  who  may  be  better  acquainted  with  the  properties  of 
formic  aldehyd  than  X  am  to  tell  me— (i)  Will  it  have  any  injurious 
aftion  on  the  fur?  (2)  Will  it  prevent  the  eggs  hatching  ?  (3)  Will 
it  kill  the  maggots  when  hatched  ?  (4)  Will  it  kill  the  moths  or  pre- 
vent them  from  laying  eggs  ?  I  am  sure  many  readers  of  the  Chemi- 
CAL  News  will  find  replies  to  these  questions  very  useful. — Moth- 
Eaten. 

MEETINGS    FOR    THE    WEEK. 

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of  Tanning   Analysis  as    adopted    by   the  Inter- 
national Association  of  Leather  Trades  Chemists, 
with  remarks  thereon,"  by  Prof.  H.  R.  Prober  and 
Dr.  J.  G.  Parker.    "  ExtraAion  of  Tanning  Mate- 
rials at  various  Temperatures,"  by  Dr.  J.  G.  Par- 
ker.    "  Neatsfoot  Oil,"  by  J.  H.  Coste,  F.I.C.,  and 
K.J.  Parry.  B.Sc,  F.I.C. 
Tuesday,  January  4th.         1  Royal  Institution,  3.    (Christmas  Lec- 
Thursday,  January  6th.       y     tures),    "  Principles  of  the  Eledtric 
Saturday,  January  8th.       J      Telegraph,"  by  Prof.  Oliver  Lodge. 

BATTERSEA     POLYTECHNIC, 

LONDON,  S.W. 

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INDEX. — SUPPLEMENT  TO  THE  CHEMICAL  NEWS. 


3^7 


INDEX. 


A  CETONE  in  urine,  241 

Aceiylene,  aftion  upon  silver  ni- 
trate, 35 
application    to    lighting    pur- 
poses, 146 
gas,  180 

lamp,  Gossart's,  182 
procedure  for  determining,  107 
Acetylmethyiheptenone,  183 
Acid,    blue     nitrosodisulphonic, 
277 
cafetannic,  82 
carminic,  224 
citrazinic,  249 
dihydroxytartaric,  299 
disulphuric,  no 
fuschine,  Schiff  reaction  applied 

to,  23 
hyponitrous,  118 
ketolaiStonic,  251 
nitric,  eleftric  conduftivity  of, 

316 
perthiocyanic,  reduAion  of,  68 
suberic,  183 
sulphocamphylic,  287 
sulphuric,  282 
Acids,  antimonic,  241 
production  of  volatile  fatty  from 
wash'ng  waters  of  wools,  326 
stannic,  253 
"Agricultural  Journal  of  the  Cape 
of  Good  Hope  "  (review),  34, 
46 
Aignon,    A.,  resin  oil  in  oil   of 

turpentine,  35 
Air,  carbonic  acid  in,  209 

liquefaftion  of,  272 
Albumen,  commercial,  23 
Alchemy,  modern,  117 

progress  in  America,  61 
Alcohols,  nitrogen   trioxide   and 

tetroxide  on,  249 
Aldehyd  in  ether,  estimating,  7 
"Alkali,    &c.,    Works,    Thirty- 
third  Annual  Report  on"  (re- 
view), 34 
Alkaline     acetates,    separations 
with,  49, 165, 175.  210,  222 
carbonates  in  bicarbonates,  305 
Alkaloid,  a  new,  220 
Alkaloids,  new,  isolated  from  a 

species  of  jaborandi,  48 
Aliphatic  nitramines,  183 
Allen,  A.   H.,  assay  of  eleftro- 
plating    and    gilding    solu- 
tions, 199 
Alloys  of  copper  and  nickel,  assay, 

241 
Aloines,  95,  I95        ,     ,       . 
Alumina  in  mineral  phosphates, 

212 

Aluminum  alcoholates,  55 
and  beryllium,   separation   of, 
III 
Aluminium  utensils,  23 
Amarine,  95 
Ambergris,  study  of,  93 


America,  progress  of  alchemy  in* 
6i 

American  chemical  societies, 
early,  216,  225,  237 

Ames,  J.  S.,  and  W.  J.  Hum- 
phreys, effeft  of  pressure 
upon  the  series  in  the  spec- 
trum of  an  element,  21 

Amidised  amidines,  60 

Amido-oxypicolines,  production 
of,  66 

Ammonia  and  phenylhydrazin  de- 
rivatives of  dibenzoylcinna- 
mene  (anhydracetophenone- 
benzil),  250 
solubility  of  in  water,  305 

Ammonium  phosphate  and  corro- 
sive sublimate,  interai5tion  of, 
174 

Amylic  alcohol,  formation  of,  182 

Anderson,  J.  W.,  "  The  Prospec- 
tor's Handbook"  (review), 58 

Aniline,  a<5tion  of  phosphorus 
pentachloride  on,  42,  54 

Animals,  X  rays  upon  tempera- 
ture of,  95 

Annable,  H.,  and  G.  Young, 
benzoylphenylsemicarbazide, 
286 

"Annali  del  Laboratorio  Chimico 
Centrale  delle  Gabelle  "  (re- 
view) 239 

Antimoniates,  241 

Antimonic  acids  and  antimoni- 
ates, 241 

Antimony,  separation  of  arsenic 
from,  137 

Antiseptics  on  muscular  fibres, 
195,  220 

Apparatus  for  students  in  elemen- 
tary practical  chemistry,  igg 
lecture,  152 

Appleyard,  R.,  failure  of  German 
silver  and  platinoid  wires,  276 

"  Arable  Soils,  an  EleCtrical 
Method  of  Determining  the 
Moisture  Content  of"  (re- 
view), 180 

Argon  and  helium,  240 

Arloing,  S,,  poisoning  by  the 
sweat  of  a  healthy  man,  119 

Armstrong,  H.  E.,  and  W.  P. 
Wynne,  constitution  of  tri- 
derivatives  of  naphthalene, 
68 

conversion  of  i :  i'-  into  i  :  4'- 
dichloronaphthalene,  69 

Aroids,  principles  of  some,  35, 
159 

Aromatic  hydrocarbides,  chloride 
of  chloracetyl  on,  23 

Aromatic  principles,  develop- 
ment of  by  fermentation,  71 

Arsenic,  separation  from  anti- 
mony, 137 

Arsenical  poisoning  by  wall- 
papers, 184 

Artificial  light,  73 


Arts,  Society  of,  241 
Atomic  weight  of  cerium,  23 
nickel,  284,  293,  307 
weights   of  nitrogen,  chlorine, 

and  silver,  119 
Attfield,  Prof.,  testimonial  to,  27 
Auriferous  ores,  examination   of, 

322 
Aurora  borealis,  theory  of,  237 
Australasian  Association  for  the 

Advancement  of  Science,  96 


D  AIt.EY,  H.,  determination  of 

*-'    unsaponifiable  oil  in  greases 
with  a  lime  base,  174 

Balland,  M.,  composition  of  po- 
tatoes, 241 
examination     of      aluminium 
utensils,  23 

Baker,  T.  J.,  estimation  of  silver 
in  silver-plating  solutions, 
167 

Barbier,  P.,  and  G.  Leser,  acetyl- 
methyiheptenone, 183 
dextro-licarhodol,  59 
G.  Lenz,  a  menthoglycol,  22 

Barium  borides,  253 

Barr  and  Stroud  range-finder, 
227 

Barral,  M.  E.,  coloriraetric  reac- 
tion of  disulphuric  acid,  no 

Barrow,  D.  N.,  "  Bulletin  of  the 
Agricultural  Experiment  Sta- 
tion, Baton  Rouge  "  (review), 
157 

Barthe  and  Boutineau,  MM.,  oil 
of  American    black  walnuts, 
145 
L.,  apparatus    for   lixiviation, 

„     195 

Basic  colouring  matters,  absorp- 
tion of,  194 
magnesium  salts,  240 

Battandier,  M.,  and  T.  Malasse, 
a  new  alkaloid,  220 
retamine,  194 

Battersea  Polytechnic,  135 

Battery  slimes,  192,  252 

Baubigny,  H.  and  P.  Rivals, 
separating  and  distilling  bro- 
mine, 239 
fluoresceine  for  detection  of 
bromine  in  a  saline  mixture, 
265 

Baude,  S.,  and  A.  Reychler,  deri- 
vatives of  piperonal,  59 

Beauregard,  H.,  study  of  amber- 
gris, 93 

Bentley,  W.  H.,  and  W.  H.  Per- 
kin,  synthesis  of  camphoric 
acid,  297 

Benzene,  space  formula  for,  76 

Benzoyl  upon  moij.o-substituted 
orthodiamines,  71 

Berthelot,  M.,  antique  glass  mir- 
rors lined  with  metal,  207 


Berthelot,    M.,  hydrogen     upon 
sulphuric  acid,  325 
influence  of  oxygen    upon  the 
decomposition  of  hydracids, 
325 
reaction  of  sulphuric  acid  with 
mercury,  325 
Bertin-Sans,    and      A.     Imbert, 
complexity  of  sheaf  of  X  rays, 
71 
Bertrand,  G.,  manganese  in  oxi- 
dations by  laccase,  6o 
oxidising  aCtion  of  manganese 
salts  and  chemical  constitu- 
tion of  oxidases,  35 
power  of  manganous  salts  and 
constitution  of  laccase,  195 
Beryllium  and   aluminum,  sepa- 
ration of.  III 
Besson,  A.,  history  of  phosphorus  ,g 
iodides,  34 
water   upon  phosphorous  ter- 
chloride    and     phosphorous 
oxychloride,  326 
Bevan,  E.  J.,  C.  Smith,  and  C.  F. 
Cross,  carbohydrates  of  cereal 
straws,  68 
Beveridge,  P.  J.,  molecular  lique- 
faction heats,  264 
Bianodic  vessel  for  red  phosphor- 
escence, 240 
Birkbeck  Literary  and  Scientific 

Institution,  135 
Bishop,  W.,  estimation  of  oxida- 
tion of  oils,  24 
Bitter  fennel,  essence  of,  158 
Blattner,   N.,  and   J.   Brasseur, 
oxide  of  iron  and  alumina  in 
phosphates,  150 
Bleier,  O  ,  combustion  of  nitro- 
gen, 36 
Blomstrand,  C.  W.  (obituary),  267 
Bluenitrosodisulphonic  acid,  277 
Boiled  milk,  183 

Bolam,  Dr.,  electrolysis  in    or- 
ganic chemistry,  313 
Bolas,  T.,  arsenical  poisoning  by 

wall-papers,  184 
Bolton,  H.  C,  early    American 
chemical  societies,  216,  225, 
237 
progress  of  alchemy  in  America, 
61 
Borate  of  lithium,  59 
Bordas,  F.,  and  S.  de  Raczowski, 
estimation  of  glycerin  by  bi- 
chromateof  potash  and  sulph- 
urica  cid,  64 
Borough    Polytechnic   Institute, 
„     '35 

Boucnardat,  G.,  and  J.  Lafont, 
sulphuric  acid  on  levo-tur- 
pentine,  71,  207 
Boucher,  G.  G.,  possible  new 
elements  in  cast-iron  and 
blast-furnace  boiler-dust,  99 
supposed  new  element  with 
iron,  182 


328 


INDEX. — SUPPLEMENT  TO   THE   CHEMICAL  NEWS. 


J  an.  7,  i8 


Boudouard,  O.,  cerium,  320 
Boutineau  and  Barthe,  MM.,  oil 
of  American  biack   walnuts, 

145 
Boutroux,  L„  and  P.  Genvresse, 
double  chlorides   formed    by 
cinchonamine,  195 
Bradford  Technical  College,  127 
Brasses  and  bronzes,  analysis  of, 

31 
Brasseur,   J.,   and    N.    Blattner, 
oxide  01  iron  and  alumina  in 
phosphates,  150 
Brearley,  H.,  copper  in  presence 
of  other  elements,  291,  303 
modification  of  cyanide   titra- 
tions of  copper,  189 
separation  of  nickel  and  cobalt 

from  iron,  302 
separations  with  alkaline  ace- 
tates, 49,  165,  175,  210,  222 
Bretagne,  antiquity  of  mining  for 

tin  in,  113 
Briggs,  L.  J.,  M.  Whitney,  and 
D.  Gardner,  "  An   Eleftrical 
Method  of  Determining  the 
Moisture  Content   of  Arable 
Soils"  (review),  180 
"An    Eleftrical    Method    for 
Determining  the  Tempera- 
ture of  Soils"  (review),  181 
British  Association,  Address   of 
the  President,  85 
address  to  Chemical  SeAion, 
91,97 
'*  British  Guiana,  Report  of  the 
Agricultural  Work  in  the  Bo- 
tanic   Gardens    for    1893-5 " 
(review),  58 
'•  British  Guiana,  Report  of  the 
Council  of  Institute  of  Mines 
and  Forests  on  the  Gold  and 
Forest   Industries  of,  1897 " 
review),  218 
"  British  Guiana,  Reports  of  the 
Government  Analyst  for,  for 
1894-97"  (review),  58 
Brixton  School  of  Chemistry  and 

Pharmacy,  135 
Bromoform,    decomposition     of, 

326 
Bromine,  adlion  of  on  chloral, 
278 
and  chlorine,  separation  of,  151 
dete£lion   of  in  a  saline  mix- 
ture, 265 
heat  liberated  on  addition  of  to 
non-saturated  substances,  23 
separating  and  distilling,  239 
Bromo- ketones,  iig 
Bronzes  and  brasses,  analysis  of, 

31 
Brown,    C,   chemical    work    of 

Pasteur,  263 
Brussels    International   Exhibi- 
tion, 229 
Bruylants,  J,,  composition  of  ex- 

trafts  of  meat,  35 
Bryant,   E.   G.,  precipitation  of 

copper  by  magnesium,  30 
Bucuresilor,  subterranean  water 
in  the  north-west  region  of, 
119 
Bupi'-t,  A.,  absorption  of  X  rays, 

158 

acuon  of  Rontgen  tubes  behind 
screens  opaque  to  X  rays,  145 
dissemii:ation  of  X  rays,  265 

Buisine,  A.  and  P.,  volatile  fatty 
acids  from  washing  waters  of 
wools,  326 

Bull,  B.  S.,  oxycellulose,  249 

"  Bulletin  of  the  Agricultural 
Experiment  Station,  Baton 
Rouge  "  (review),  157 

Bullier,  L.  M.,  application  of 
acetylene  to  lighting  pur- 
poses, 146 

Burke,  J.,  change  of  absorption 
by  fluorescence,  5 

Burroughs,  Wellcome,  and  Co., 
explosion  at  Dartford,  32J 

Burt,  F.,  and  D.  Carnegie,  inter- 
a(5tion  of  ammonium  phos- 
phate and  corrosive  subli- 
mat--,  174 

Butter,  flaviiur-producing  micro- 
coccus of,  151 


Bijttgenbach  and  Franz,  saline 
deposits  of  the  plains  of 
Northern  Germany,  83 

Butureanu,  V.  C,  sulpho-arseni- 
cal,  sulpho-antimonial,  and 
sulpho-bismuthic  minerals, 
119 


P  ADMIUM,  basic  salts  of,  16 

Csesium,  double  halogen  salts  of, 

31 
Cafetannic  acid,  82 
Caffein  in  coffee,  195 

properties  of,  59 
Calcium,  253 
carbide,  57 

and  Petroleum  Afts,  72 
decomposition  produAsof,  II 
sulphate,  254 

sulphite     as    preservative    of 
cider,  220 
Caldecott,  W.  A.,  gold  in  accu- 
mulated and    other   slimes, 
193 
Calibration  of  flasks  by  weighing, 
219 
of  graduated  glass  vessels,  219 
Calvert,  H.  T.,  and  J.  B.  Cohen, 
nitrogen  trioxide  and  tetrox- 
ide  on  alcohols,  249 
Cambridge  University,  122 
Camphoric    acid    and    ketopinic 

acid,  78 
Camphor,     stereoisomeric      di- 

derivatives  of,  78 
Camphoric  acid,    decomposition 
of,  296 

synthesis  of,  297 
synthesis  of  an  isomeride  of, 
297 
Camphoroxime,  ethers  of,  248 
Canadian  virgin  soils,  composi- 
tion of,  185,  204, 214,  224 
Cape  diamonds,  72 
Carbide,  C3H4,  59 
of  calcium,  57 
impurities  of,  256 
and  Petroleum  Afts,  72 
Carbohydrates  of  cereal  straws, 

68,  188 
Carbon  in  ferrochrome,  estima- 
tion of,  II 
in  iron,  183 

line  speftrum  of  in  fused  salts, 
107 
Carbonated  manganiferous  mice. 

rais,  calcination  of,  212 
Carbonic  acid  in  the  air,  209 
anhydride,  density  of,  315 
oxide,  density  of,  315 
Carles,  P.,  experiments  on  com- 
mercial albumen,  23 
and   G.   Riviere,    influence   of 
colouring  matters   upon   the 
fermentation    of    highly    co- 
loured red  wines,  194 
Carminic  acid,  224 
Carnegie,  D.,  and  F.  Burt,  inter- 
aAion  of  ammonium    phos- 
phate and  corrosive  sublim- 
ate, 174 
Carnot,  A.,  and  M.  Goutal,  ele- 
ments found  in  castings  of 
steels,  109 
Caroubinase,  71 
Carubine,  71 
Carubinose,  iig 

Cast-  iron  and  blast-furnace  boiler 
dust,  possible  new  elements 
in,  99 
pots,  enamelling,  230 
Castings     of     steels,    elements 

found  in,  109 
"  Catalogue  of  Standard  Second- 
hand and  New  Books,  Eng- 
lish and   Foreign"  (review), 
158 
Cathode  rays,  4 
Cattleya,  culture  of,  23 
Causse,  H.  M,,  hydrate  of  chloral 
on  phenylhydrazine,  diphenyl- 
glyoxazol,  35 
Caven,   K.   M.,  and   F.   Clowes, 
magnesium  on  cupric  sulph- 
ate solution,  297 


Cazeneuve,  P.,  and  M.  Haddon, 

•cafetannic  acid,  82 
Cereal   straw,  carbohydrates   of, 

68,  188 
Cerium,  320 

atomic  weight  of,  23,  137,  153 
Chabaud,  V.,  photograpliic   veil 

in  radiography,  207 
Cbardin,    C,    medical    use     of 

ozone,  47 
Chattaway,  F.  D.,  and  H.  P.  Ste- 
vens, reduction    of  perthio- 
cyanic  acid,  68 
Chauliaguet,   Mile.,  A.  Hubert, 

and-F.  Hein,  aroids,  35 
Chavastelon,  R.,  a(5tion  of  acetyl- 
ene upon  silver  nitrate,  35       -i 
procedure  for  determining  ace-  ' 
tylene,  107 
Cheavin  filter,  experiments  with, 

267 
Chemical  and  Bafteriological  La- 
boratory, Manchester,  136 
and    Metallurgical   Society    of 

South  Africa,  192,  252 
Johannesburg,  33,  57 
laboratory  at  Wiesbaden,  136 
leAures,  classes,  and  laboratory 

instruftion,  134,  147 
literature,  report  of  committee 

on  indexing,  75 
Society,   66,  76,  248,  259,  271, 

286,  296,  312,  323 
Societies,  early  American,  2i6, 

225, 237 
work  of  Pasteur,  263 
"Chemical  and  Physical  Calcu- 
lations, Reform  of"  (review), 
70 
Chemicals,  annual  consumption 

of,  12 
Chemistry,  annual  review  of  pure, 

107 
"  Chemistry,  Elements  of,  "  (re- 
view), 229 
part  played  by  in   perfumery, 
150 
"  Chemistry,  A  Course  of  Praifti- 
cal — Part    I.,     Elementary  " 
(review),  94 
"  Chemistry,  The  Principles  of  " 

(review),  228 
♦'  Chemistry,  The  Study  of  Tech- 
nical at  the  Universities  and 
Technical   High    Schools    of 
Germany"  (review),  10 
"  Chemists  of  Beet-sugar  Houses 
and     Seed -culture     Farms, 
Handbook  for  "  (review),  288 
Chevretin,  M.,  lead  in  artificial 

serums.  82 
"  Chilian  Hygienic  Review"  (re- 
view), 10 
,  Chloral,  aAion  of  bromine  on, 
278 

chlorine  on,  277 
condensation  of,  249 
decomposition  of,  326 
hydrate  with   ammonium   sul- 
phide, 41 
polymerisation  of,  280 
Chloride  of  chloracetyl   on   aro- 
matic hydrocarbides,  23 
of  ethyloxalyl  on  diphenyl  314 
on  ethyl-a-naphthol,  314 
Chlorides    formed    by    cinchon- 
amine, 195 
Chlorination  and  oxidation,  82 
*•  Chlorination  Process"  (review), 

33 
Chlorine,  ad^ion   of  on  chloral, 

277 
and  bromine,  separation  of,  151 
bromine,  and  iodine  in  organic 
substances,  150 
in  saline  waters,  293 
on  pentachlorethane,  313 
on   tetrabromide  ot  acetylene, 
313 
Chlorotorm,    decomposition     of, 

326 
Chloronitrides  of  phosphorus,  308, 

3-Ji 

Chlorophyll,  23 

Chlorophylls,  splitting  up  funda- 
mental band  of,  35 

Chuard,  E.,  decomposition  pro- 
duAs  of  calcium  carbide,  11 


Chrome  ore,  48 

Cider,  salicylic  acid  and  calcium 
sulphite  as  preservatives  of, 
220 
Cinchonamine,    double  chlorides 

formed  by,  195 
Citrazinic  acid,  249 
City  and  Guilds  of  London  Insti- 
tute, 134,  158 
City  of  London  College,  135 
Clark,  E.,  and  G.  Young,  naph- 

thylureas,  286 
Clark  cells,  variations  in  E.M.F. 

of,  252 
Classen,  A,,  "  Quantitative  Ana- 
lyse durch  Eleftrolyse"  (re- 
view), 70 
Clay,  W.  F.,  "Catalogue  of  Stan- 
dard  Second-hand  and  New 
Books,  English  and  Foreign" 
(review),  158 
Clifton  Laboratory,i35 
Clowes,  F.,  and  R.   M.  Caven, 
magnesium    on    cupric    sul- 
phate solution,  297 
Coals,  pre-carboniferous,  analysis 

of,  186 
Cobalt    and    nickel    from    iron, 

separation,  248,  279 
Cockburn,     G.    B.,    and    J.     A. 
Gardner,  phosphorus   penta- 
cbloride  on  fenchone,  251 
Cocoa    cultivation     in     French 

colonies..  71 
Coffee,  artificial  roasted,  183 

caffein  in,  195 
Cohen,  J.  B.,  and  H.  T.  Calvert, 
nitrogen  trioxide  and  tetroxide 
on  alcohols,  249 
and  W.  H.  Harrison,  aromatic 
amines  upon  diacetyltartaric 
anhydride,  249 

nitrogen    tetroxide   on  ortho- 
and  para-nitrobenzylalcohol, 
249 
Coleopterine,  47 
Colleges  and  universities,  121 
Collet,  A.,  bromo-ketones,  119 
chloride  of  chloracetyl  on  aro- 
matic hydrocarbides,  23 
Collie,  J.  N.,  a  space  formula  for 
benzene,  76 
and  A.  Lapworth,  produftion  of 
nitro-     and    amido-oxypico- 
lines,  66 
Colorimetric  tests  for  copper,  184 
Colouring-matters,  new  sulphur- 
ised, 229 
Combes,  A.,  life    and  works  of, 

48 
Commercial    Development   Cor- 
poration, Lim.,  229,  241 
Condy's  fluid,  192 
*'  Connedticut    Agricultural   Ex- 
periment Station,  Twentieth 
Annual  Report,  for  1896"  (re-  . 
view),  105 
Constants  of  certain  gases,  158 
Conversion       of      thermometric 

scales,  288 
Cooling  water,  96 
Copper  and  nickel  alloys,  assay 
of,  24 1 
as  iodide,  243 
colorimetric  tests  for,  184 
impurities  of  crude,  240 
in  presf-nce  of  other  elements, 

291,  303 
modification  of  cyanide  titra- 
tions of,  189 
precipitation  of,  30 
by  magnesium,  59 
salts   and    hydrogen    sulphide,- 
interaftion  of,  231 
Coppock,  J.  B.,  interadtion  of  hy- 
drogen sulphide  and  copper 
salts,  231 
Coreil.F  .artificial  roasted  coffee, 

183 
Cotoin,  derivatives  of,  250 
Coumarin,  23 

Cream  of  tartar  in  wines,  60 
Crompton,  H.,  molecular  associa- 
tion ot  liquids,  299 
Crookes,  Sir  W.,  and   J.  Dewar, 
London  water  supply,  40, 104, 
191,  206,  247,  307 
diamonds,  i,  13,  25 


Jan.  7,  i8 


INDEX. — SUPPLEMENT  TO   THE   CHEMICAL  NEWS. 


329 


Cross.  C,  F.,  E.  J.  Bevan,  and  C. 
Smith,  carbohydrates  of 
cereal  straws,  68 

Crossley,  A.  W.,and  W.  H.  Per- 
kin,  decomposition  of  cam- 
phoric acid,  296 

Crystalline  rocks  of  the  central 
zone  of  the  Roumanian  Car- 
pathians, 119 

Cryoscopy,  exa(5t,  183 
of  milk,  195,  314 

Cucu,  St.  N,,  subterranean  water 
in  the  north-west  region  of 
Bucuresilor,  119 

Cupric  hydrate  upon  solutions  of 
silver  nitrate  and  basic  ar- 
gentic cuprate,  95 

Cushman,  A.  S.,  and  T.  W. 
Richards,  atomic  weight  of 
nickel,  284,  293,  307 
A,  R.,  qualitative  separation  of 
iron,  aluminium,  chromium, 
manganese,  zinc,  nickel,  and 
cobalt,  65 

Cyanide  of  potassium,  seleftive 
adtion  of  for  gold,  281 

■pjARTFORD,     explosion      at, 

325  ,     .   .      , 

Davy,  L.,  antiquity  of  mining  for 
tin  in  Brelagne,  113 

Daw,  F.  W.,  occurrence  of  vana- 
dium, 145 

De  Boisbaudran,  L.,  examination 
of  spedlra,  12,  46 

De  Coninck,  0.,a6tion  of  tannin 
and  gallic  acid  upon  quinoleic 
bases,  70 

De  Courmelles,  F.,  "  Traite  de 
Radiographic  Medicale  et 
Scientifique  "  (review),  181 

De  Gramont,  A.,  dissociation 
spedtra  of  melted  salts,  201, 

244 
line  speftrum  of  carbon  in  fused 

salts,  107 
spedlra   of   compound    bodies, 

277 
De    Hauptinne,    A.,  X  rays    on 

luminescence  of  gases,  171 
De  Koninck,  L.  L.,  and  E.  Prost, 

determination     of    zinc     by 

potassium  ferrocyanide,  6, 15, 

29,38,51        ^ 

De  Launiy,  L.,  Cape  aiamonds, 
72 

De  Raczkowski,  S.,  and  F. 
Bordas,  estimation  of  gly- 
cerin by  bichromate  of  potash 
and  sulphuric  acid,  64 

De  Rey-Pailhade,  J.,  proteid 
body  foreseen  by  M.  Ber- 
trand,  195 

Deerr,    N..     relations     between 
melting  -  points    and    latent 
heats  of  fusion,  81 
thermal  constants  of  the  ele- 
ments, 234 

Deherain,  P.  P.,  composition  of 
drainage  waters,  io6 

Delacroix,  M.,  antimonic  acids 
and  antimoniates,  241 

Delepine,    M.,  hydrobenzamide, 

amarine,  and  lophine,  95 

pseudo-intestinal  calculus,  83 

Demichel,  A.,  calibration  of 
flasks  by  weighing,  219 

Denigfis,  Q.,  estimation  of  boric 
acid  in  milk,  83 

Desgrez,  A.,  decomposition  of 
chloroform,  bromoform,  and 
chloral,  326 

Deslandres,  H,,  kathodic    rays, 

23 

Devisse,  M.,  calcination  of  car- 
bonated manganifeious  mine- 
rals, 212 

Dewar,  ].,  and  H.  Moissan, 
liquefaftion    of    fluorine,  71, 

I97»  259 

and  Sir  W.  Crookes,  London 
water  supply,  40,  104,  191, 
206,  247.  307 

absorption  of  hydrogen  by  pal- 
ladium, 274 

liquefadtion  of  air,  272 
Dextro-licarhodol,  59 


Diabetic  sugar,  determining,  240 
Diacetanilide,  formation  of,  yy 
Diacetyl,  new  derivatives   of,  2S2 
Diacids  of  oxalic  series,  183 
Diamonds,  i,  13,  25 

Cape,  72 
Dichloronaphthalene,  conversion 

of  I  :  I'  into  I  :  4',  69 
Dihvdroxytartaric  acid,  299 
Dinitrophenyl-diacetyl -methane, 

314 
Dion,    M.,  fossil    phosphates    of 

lime  in  province  of  Oran,  146 
Diphenylglyoxazol,  35 
Dissociation    speftra    of   melted 

salts,  244 
Disulphuric    acid,     colorimetric 

reaftion  of,  no 
Divers,  E.,  hyponitrous  acid,  118 
Dixon,  W.  A.,  seleftive  aftion  of 

cyanide     of     potassium    for 

gold.  281 
Don,  J.,  "The  Organised  Science 

Series — First  Stage  :   Sound, 

Light,  and  Heat  "  (review), 

182 
Dootson,  F.  W.,  and  W.  J.  Sell, 

citrazinic  acid,  249 
Dorsey,  N.  E.,  surface  tension  of 

water  and  of  solutions,  22 
Drainage  waters,  composition  of, 

106 
Dublin  University,  123 
Ducru,    O.,  separation  of  nickel 

and  cobalt  from  iron.  279 
Dunnington,  F.  P.,   distribution 

of  titanic  oxide,  221 
Dupont,     F.,    yellow    light    for 

polarimetry,  59 
Durham  CoUegeof  Science,  New- 

castle-on-Tyne,  129 
Durn,   O.,   separation   of    nickel 

and  cobalt  from  iron,  24S 


pAST  London  Technical   Col- 

^     lege,  135 

Edinburgh   University  Chemical 

Society,  263,  313 
Effront,  J.,  a  novel  catbobydrate, 
carubine,  71 
carubinose,  119 
hydrolytic  enzyme,  carubinase, 

71 
Ehrmann,  Mr.,   precipitation  of 
gold  from  cyanide  solutions, 
33 
Eledtric    conduftivity    of   nitric 

acid,  316 
Eleftrical  energy  caused   by  ac- 
tion of  the  atmosphere,  200 
Eleftrified   ellipsoid,  steady  mo- 
tion of,  g 
Eleftro-magnet,  solenoid,  39 

plating  solutions,  assay  of,  199 
Eleftrolysis,    application    of    to 
manufacture     of     inorganic 
produdls,  229 
applications  to  organic  chemis- 
try, 95 
in  organic  chemistry,  313 
of  solid  bodies,  24 
"  Eleftrolytic  Quantitative  Ana- 
lysis "  (review),  70 
Elements  of  low  atomic  weight, 
permeability   of  to  Rontgen 
rays,  161 
thermal  constants  of,  234 
Ellis,   W.    H.,   analysis   of    pre- 

carboniferous  coals,  186 
Emmens,    S.    H.    and    >.    W., 
migrant  matter,  37 
modern  alchemy,  117 
Enamelling  cast-iron  pots,  230 
Engel,  R.,  parastannyl  chloride, 
195 
stannic  acids,  253 
Essence  of  bitter  fennel,  158,  183 
Etard,  A.,  annual  review  of  pure 
chemistry,  107 
splitting  up  fundamental   band 
of  chlorophylls,  35 
Ether,  estimating  aldehyd  in,  7 
isothermals  of,  251 
preparation  of,  35,  83 
common,  11 
Ethers  of  camphoroxime,  248 


Ethylene,  a£lion  of  nickel  upon, 
35 
dichloride,  and   ethylic  sodio- 
malonate,  79 

Ethylic  sodiomalonate  and  ethy- 
lene dichloride,  79 

Evans,  Sir  J.,  British  Association 
Address,  85 

Experiments,  laboratory,  175 
on  critical  phenomena,  9 

Expert  testimony,  142 

"  Explosives,  Twenty-first  An- 
nual Report  of  Her  Majesty's 
Inspeftors  of ''  (review),  94 

Extraft s  of  meat,  composition  of, 
35 

pALIERES,  E.,  officinal  solu- 

-*■      tion  of  perchlorideofiron,  146 

Fehling's  solution,  318 

Fenchone,  phosphorus  penta- 
chloride  on,  251 

Fenton,  H.  J.  H.,  dihydroxy- 
tartaric  acid,  299 

Fermentations  in  compound 
mediums  of  solid  panicles, 
71 

Ferrochrome,  estimation  of  car- 
bon in,  II 

Fertilisation  of  soils,  11 

Findlay,  A.,  and  F,  R.  Japp, 
phenanthrone,  249 

Finn,  C.  P.,  argon  and  helium, 
240 

Fischer,  F.,  "  Das  Studium  der 
Technischen  Chemie  am  den 
Universitiiten  und  Technis- 
cher  Hoch-Schulen  Deutsch- 
lands  "  (review),  10 

Flasks,  calibration  of,  219 

Fleury,  G.,  decomposition  of 
iodoform  by  light,  183 

Flies,  oDtical  and  reduftive  power 
of  flesh  of,  241 

Flowers,  extrafting  perfume  from, 
23 

Fluorescence,  change  of  absorp- 
tion by,  5 

Fluorine,  liquefaftion  of,  71,  197 
liquid,  259 

Fluoroscopic  image,  photography 
of  the, 158 

Focometer  and  spherometer,  227 

"  Food  and  Drugs,  the  Analysis 
of,— Part  I  :  Milk  and  Milk 
Produfts  "  (review),  80 

Foote,  H.  W.,  and  H.  L.  Wells, 
double  fluorides  of  zirconium 
with  lithium,  sodium,  and 
thallium,  44 

double  halogen  salts  of  caesium 
and  rubidium,  31 

Formic  acid,  estimation  of,  296 
aldehyd,  estimation  of,  296 

Forster,  M.  O.,  ethers  of  cam- 
phoroxime, 248 

Fortey,  E.  C,  hexanaphthalene 
and  its  derivatives,  79 

Fossil  phosphates  of  lime  in  pro- 
vince of  Oran,  146 

Foster,  J.  A.,  thorium  acetyl- 
acetonate,  253 

Frafture  of  wines,  47 

Franchimont,  A.  P.  N.,  aliphatic 
nitramines,  183 

Franck,   M.,  and   F.  Marboutin, 
organic  matter  in  water,  280 
L.,  formation  of  metallic  sul- 
phides, 23 

Francois,  M.,  estimating  aldehyd 
in  ether,  7 
non-existence  of  an  intermedi- 
ate iodide  of  mercury,  319 

Franz  and    BUttgenbach,  saline 
deposits    of    the    plains    of 
_  northern  Germany,  83 

Fremont,  A.,  assay  of  metals,  207 

French,  W.,  lefture  experiment, 
267 

"Fresenius's  Ouantitative  Ana- 
lysis,'' Vol.  IL,  Part  IV.  (re- 
view), 10 

Freundler,  P.,  caibide  C3H4,  59 
decomposition  of  pyromucates 

of  the  alkaline  earths,  59 
preparation  of  furfurane,  9 

Friedel.  C,  life  and  works  of 
Alphonse  Combes,  4^ 


Friswell,  R.  J.,  ai5lion  of  light  on 
a  solution  of  nitro-benzene, 
67 
fusing-point,  boiling-point,  and 
specific  gravity  of  nitro- 
benzene, 67 
properties  of  nitrobenzene,  149 

Fruits,  chemical  modifications 
during  growth,  229 

Furfurane,  preparation  of,  9 

Fusion,  relations  between  melt- 
ing-points and  latent  heats  of, 
81 


riABBA,    L.,    «  Manuale    del 

^-^    Chimico  e  dell'  Industriale  " 
(review),  194 

Gallic  acid  upon  quinoleic  bases, 

^     70 

Gardner,  D,  L,  J.  Briggs,and  M. 
Whitney,  "  An  Electrical 
Method  for  Determining  the 
Moisture  Content  of  Arable 
Soils  "  (review),  i8o 
J.  A.,  and  G.  B.  Cockburn, 
phosphorus  pentachloride  on 
fenchone,  251 

Garnier,  J.,  fluidity  of  melted 
nickel,  47 

Gas,  acetylene,  180 
an  undiscovered,  91,  97 
and  petroleum  engines,  71 

"  Gas  Analyses,  Tables  for,  &c." 
(review),  145 

Gases,    calculation    of    the    co- 
efficients of  expansion  of,  74 
critical    constants  of   certain. 

158 
permeation  of  hot  platinum  by, 
168 

Gautier,  A.,  humic  matter  in  fer- 
tilisation of  soils,  zi 

Gentil,  L.,  formation  of  amylic 
alcohol,  182 

Genvresse,  P.,  and  L.  Boutroux, 
double  .'chlorides    formed  by 
cinchonamine,  195 
isomer    of    disulphide    of    di- 
phenylene,  59 

George,  W.  J.,  "  A  Complete 
Catalogue  of  Praftical  Physi- 
cal Apparatus  "  (review),  301 
G.,  apparatus  for  students  in 
elementary  practical  chemis- 
try,  199 

Gerber,  0.,    chemical   modifica- 
tions in  fruits  during  growth, 
229 
transformation    of    saccharine 
matter  into  oil  in  olives,  254 

German   Association  of   Natural 
Science  and  Medicine,  83 
silver    and     platinoid     wires, 
failure  of,  276 

Ghersi,  S.,  "  Manueli  Hoepli — 
Metallic  Alloys  and  Amal- 
gams "  (review),  145 

Gilding  solutions,  assay  of,  199 

Giles,  W.  B.,  vanadium  in  rutile, 
137 

Gilles,  W.  S.,  and  F.  F.  Ren- 
wick,  ketopinic  acid  and  cara- 
phoic  acid,  78 

Gilpin,  J.  E.,  adtion  of  phos- 
phorus pentachloride  on  ani- 
line, 42,  54 

Gladstone,  J.  H.,  and   W.  Hib- 
bert,  molecular  refraftion  of 
dissolved  salts  and  acids,  66 
permeability   of   elements    of 
low  atomic  weight  to  Ront- 
gen rays,  197 

Glasgow  and  West  of  Scotland 
Technical  College,  133 

"  Glasgow  and  West  of  Scotland 
Technical  College,  Report  on 
the  Experiments  on  the 
manuring  ot  Oats,  Hay, 
Turnips,  and  Potatoes  "  (re- 
view), 57 

Glasses,  researches  on,  loi 

Glass  vessels,  calibration  of,  219 

Glucosines,  314 

Glycerin,  estimation  of,  64 

Gold  in  accumulated  and  other 
slimes,  193 


330 


INDEX. — SUPPLEMENT  TO  THE   CHEMICAL  NEWS. 


Jan.  7, 1898. 


Gold,  precipitation  from  cyanide 
solutions,  33 
selective   adtion  of  cyanide  of 
potassium  for,  2S1 

"  Gold  Ores,  Stamp  Milling  of" 
(review),  157 

Goldsmiths'  Institute,  135,  220 

Gordon,  J.  W.,  "  Monopolies  by 
Patents"  (review),  81 

Gossart's  acetylene  lamp,  182 

Gourwitsch,   L.,    application    of 
eledkrolysis    to    manufafture 
of  inorganic  produfts,  229 
applications  of  eleftrolysis  to 
organic  chemistry,  95 

Goutal,  M.,  and  A.  Carnot,  ele- 
ments found  in  castings  of 
steels,  109 

Government  laboratory,  173 

Granger,  A.,  review  of  photo- 
graphy, 182 

Grenet,  L.,  researches  on  glasses, 
loi 

Griffiths,  A.  B.,  coleopterine,  47 

Groves,  C.  E.,  "  Fresenius's 
Quantitative  Analysis,"  Vol. 
11.,  Part  IV.  (review),  10 

Guerin,  G.,  organic  compound 
rich  in  manganese  extrafted 
from  the  woody  tissue,  119 

Guichard,  M.,  reduftion  of 
molybdenum  anhydride,  71 

Guillaume,  C,  X  rays  and  disso- 
ciation, 72 

Gundelag,  E.,  and  G.  Segny, 
bianodic  vessel  for  red  phos- 
phorescence, 240 

G«ndlich,  C,  and  J.  Lesinsky, 
chloral  hydrate  with  ammo- 
nium sulphide,  41 

Guyot,  A.,  and  A.  Haller,  phthalic 
green,  lo5 

symmetric  tetramethyldi- 
amidodiphenyldianthranal  - 
tetramethyldiamide  of  the 
corresponding  oxanthranol, 
119 


"LJ ADDON,  M.,  and  P.  Cazen- 
■^     euve,  cafetannic  acid,  82 
Hake,  H.  W.,  absorption  of  mois- 
ture   by    deliquescent    sub- 
stances, 67 
Haller,  A.,  and  A.  Guyot,  phthalic 
green, 106 

symmetric  tetramethyldi- 

amidodiphenyldianthranal  - 
tetramethyldiamide    of  the 
corresponding  oxanthranol, 
119 
Halogens  in  organic  halxdes,  test 

for,  20 
Haloids,  production  of  from  pure 

materials,  217 
"  Handbook  for  Chemists  of  Beet- 
sugar   Houses  and  Seed-cul- 
ture Farms"  (review),  288 
Hanssen,   C.    J.    T.,    reform    of 
chemical  and  physical  calcu- 
lations, 263 
"Reform  of  Chemical  and  Phy- 
sical Calculations  "  (review), 
70 
weight  of    oxygen,    hydrogen, 
and  nitrogen, 304 
Hardin,  W.  L.,  atomic  mass  of 

tungsten,  140,  155,  164 
Haricots,  composition  of,  71 
Harrison,   W.    ri.,    and    J.    B. 
Cohen,      aromatic      amines 
upon    diacetyltartaric  anhy- 
dride, 249 

nitrogen  tetroxide  on  ortho- 
and  para-nitrobenzylalcohol, 
249 
Hartley   College,  Southampton, 

136 
Hartley,  W.  N.,  and  H.  Ramage, 
spe£trographic     analysis    of 
minerals  and  meteorites,  231 
Hasselberg,  B.,  chemical  compo- 
sition of  rutile,  102 
vanadium  in  Scandinavian  ru- 
tile, J12 
Havens,  F.  S.,  separation  of  alu- 
liiinum  and  beryllium,  iizj 


Heat  liberated  on  addition  of  bro- 
mine to  non-saturated  sub- 
stances, 23 

Heath,  G.  L,.,  colorimetric  tests 
for  copper,  184 

Hebert,  A.,  and  F.  Hein,  aftive 
principles  of   some   aroides, 

159 
and  Mile.  Chauliaguet.aroids, 

35 
and  G.  Truffaut,  culture  of  the 
cattleya,  23 
Held,  J.  G.,  carbon  in  iron,  183 
Hein,  F.,   and  A.  Hebert,  aftive 
principles  of  some   aroides, 

159 
and  Mile.  Chauliaguet,  aroids, 

35 
Helium  and  argon,  240 
Heriot-Watt  College,  Edinburgh, 

132 

Hewitt,  J.  T.,  and  F.  G.  Pope, 
condensation  of  chloral  with 
X'esorcinol,  249 
T.  S.  Moore,  and  A.  E.  Pitt, 
derivatives  of  phenetol  azo- 
phenols,  78 
"  Organic  Chemical  Manipula- 
tion "  (review),  145 

Hexanaphthene  and  its  deriva- 
tives, 79 

Hibbert,  W,  and  J .  H.  Gladstone, 
molecular  refraftion  of  dis- 
solved salts  and  acids,  66 
permeability    of    elements    of 
low  atomic  weight  to  Ront- 
gen  rays,  197 

Hillyer,  H.  W.,  aluminium 
alcoholates,  55 

Hirsch,  B.,  and  P.  Siedler,  "  Die 
Fabrikation  der  Kiinstlichen 
Mineral  Wasser  und  anderer 
Mousserende  Getrar.ke"  (re- 
view), i8i 

Hodgkinson,  W.  R.,  simple  lec- 
ture apparatus,  152 

Holland,  A.,  analysis  of  bronzes 
and  brasses,  31 

Honours  for  men  of  science,  9 

Humphreys,W.J.,andJ.  S.  Ames, 
efifeft  of  pressure  upon  the 
series  in  the  speCtrum  of  an 
element,  21 

Hydracids,  influence  of  oxygen 
upon  decomposition  of,  325 

Hydrate  of  chloral  on  phenyl- 
hydrazine,  35 

Hydrates  of  isopropyl  alcohol,  68 

Hydrobenzamide,  95 

Hydrochlorate  of  glucosamine, 
314 

Hydrochloric  acid  on  nitrates,  23 

Hydrog;en,  absorption  of  by  pal- 
ladium, 274 
and  oxygen,  occlusion  by  pal- 
ladium, 317 
sulphide  and  copper  salts,  inter- 

a(5):ion  of,  231 
upon  sulphuric  acid,  325 
weight  of,  304 

Hypoiodous  acid  and  hypoiodites, 
17.27 

Hyponitrous  acid,  118 


TMBERT,  A.,  and   M.   Bertin- 

■*•  Sans,  complexity  of  sheaf  of 
X  rays,  71 

Imperial    College  of   Chemistry 
and  Pharmacy,  135 
Institute,  241,  254 

"Incompatibilities  in  Prescrip- 
tions" (review),  116 

"  Indu(5tion  Coil  in  Pra(5tical 
Work,  including  Rontgen  X 
Rays"  (review),  218 

Inorganic  produ(5ts,  application 
of  ele(5trolysis  to  manufacture 
of,  229 

Institute,  Sanitary,  231 

Institution,  Royal,  36,  229,  254, 
287,  289 

International  Congress  of  Ap- 
plied Chemistry  in  Vienna, 

1898,  322 

Iodide,  copper  as,  243 
of  mercury,  non-existence   of 
an  intermediate,  319 


Iodine    on  albumenoid   matters, 

195 
Iodoform,  decomposition    of   by 

light,  183 
Iron,  alleged  new  element  in,  118 
aluminium,  chromium,     man- 
ganese,  nickel,   and    cobalt, 
qualitative  separation  of,  65 
and  Steel  Institute,  36 
carbon  in,  183 
in  mineral  phosphates,  2i2 
in  urine,  194 
separation  of  nickel  and  cobalt 

from,  248,  279 
supposed  new    element    with, 
171, 182 
Isomer  of  disulpbide  of  diphenyl- 

ene,  59 
Isomeric  benzene  hexachlorides, 

312 

Isopropyl  alcohol,  hydrates    of, 
6 


JACOBUS,    D.    S.,     artificial 
light,  73 

Jacquemin,  G.,  development  of 
aromatic  principles  by  fer- 
mentation, 71 

Jannasch,     P.,    and     E.    Kolitz, 
separation  and  determination 
of    chlorine,    bromine,     and 
iodine  in  organic  substances, 
150 
separation    of    chlorine    and 
bromine  in  presence  of  ace- 
tates,   sulphates,    and    ni- 
trates, 151 

Japp,  F.   R.,    Kekule    memorial 
lefture,  323 
and  A.  Findlay,  phenanthrone, 

249 
and  A.  Tingle,  ammonia   and 
phenylhydrazin     derivatives 
of  dibenzoylcinnamene   (an- 
hydracetophenonebenzil),  250 

Jay,  H.,  cream  of  tartar  in  wines, 
60 

Jerdan,  D.  S.,  synthesis  of  phloro. 
glucinol,  249 

Jervis,  H.,  laboratory  notes,  211 

Johnson,  E.  H.,reduftion  of  zinc- 
gold  slimes,  57, 192 

Johannesburg  Chemical  and  Me- 
tallurgical Society,  33,  57 

JoUes,  A.,  iron  in  urine,  194 

Joly,  L.,  biolological  history  of 
the  phosphates,  217 

Jones,  C.  H.,  supposed  new  ele- 
ment with  iron,  171 

"Journal  of  Tokyo  Chemical 
Society"  (review),  46 

Jubilee  medal,  213 

Juritz,  C.  F.,  nitrogen  in  analy- 
ses, 100 


TZABLUKOW,  J.,  and  W.  Lou- 

■'■*•  guinine,  heat  liberated  on 
addition  of  bromine  to  non- 
saturated  substances,  23 

Kastle,  J.  H.,  and  W.  A.  Beatty, 
test  for  halogens  in  organic 
halides,  20 

Kathodic  rays,  23 

Keith,  S.  C.,  flavour-producing 
micrococcus  of  butter,  151 

Kekule  memorial  ledlure,  323 

Keller,  H.  F.,  and  P.  Maas,  new 
derivatives  of  diacetyl,  282 

Kern,  S.,  small  Bessemer  process 
for  steel  castings,  8 

KetolaCtonic  acid,  231 

Ketopinic  acid  and  camphoic 
acid,  78 

King's  College,  123 

Kolitz,  E.,  and  P.  Jannasch, 
separation  and  determination 
of  chlorine,  bromine,  and 
iodine  in  organic  substances, 

separation    of    chlorine    and 
bromine     in     presence    of 
acetates,  sulphates,  and  ni- 
trates, 151 
Kuenen,    Dr.,    experiments    on 
critical  phenomena,  9 


Kyle,  J.  J,  J.,  "  La  Composicion 
Quimica  de  las  Aguas"  (re» 
view),  193 


LABORATORY    experiments, 
175! 
notes,  211 
from  New  Zealand,  109 
the  Government,  173 

Laccase,  constitution  of,  195 

Lachman,  A.,  zinc  ethyl,  20 

Lafont,  J.,  and  G.  Bouchardat, 
sulphuric  acid  upon  levotere- 
benthene,  71,  207 

Lagata,  M.,  frafture  of  wines,  47 

"  La  Grande  Industria  Chimica" 
(review),  194 

Landolph,  F.,  determining  diabe- 
tic sugar,  240 
optical  and  redu(5tive  power  of 
flesh  of  flies,  241 

Lapworth,  A.,  and  J,  N.  Collie, 
production  of  nitro-  and 
amido-oxypicolines,  65 

Lasne,  H.,  estimation  of  phos- 
phoric acid,  263 

Lauth,  C,  amidised  amidines,  60 

Lead  in  artificial  serums,  82 
in  slags,  192 

Lean,  B.,  and  F,  H.  Lees,  inter- 
action of  ethylene  dichlorida 
and  etbylic  sodiomalonate, 
79 

Leather  trades'  chemists,  inter- 
national conference  of,  1S4 

Lecercle  ,  L.,  aC^ion  of  X  rays 
upon  temperature  of  animals, 

,      95 

Le  Chatelier,  H.,  borate  of  lith- 
ium, 59 
dissociation  of  minium,  277 
impurities  of  carbides  of  cal- 
cium, 256 

Lecompte,  H.,  cultivation  of 
cocoa  in  French  colonies,  71 

Lecture  apparatus,  152 
experiment,  267 

Leduc,  A.,  atomic  weights  of  ni- 
trogen, chlorine,  and  silver, 
119 
and  P.  Sacerdote,  critical  con- 
stants of  certain  gases,  158 

Leeds  Technical  School,  135 
Yorkshire  College,  72 

Lees,  F.  H.,  and  B.  Lean,  inter* 
action  of  ethylene  dichloride 
and  ethylic  sodiomalonate, 
79 

Lefevre,  L.,  Schiif  reaction  ap- 
clied  to  acid  fuschine,  23 

Le£3er,  R.  L.,  estimation  oi  car- 
bon in  fcrro-chrome,  n 

Leger,  E.,  aloines,  95, 195 
naphthol,  35 

reaction  facilitating  the  recog- 
nition of  naphthol,  48 

Lemaire,  M.  colorimetric  esti- 
mation of  manganese,  219 

Lemoine,  G.,    reversible  trans- 
formation of  styrolene-meta- 
styrolene,  219 
saline  solutions,  268 

Lentils,  composition  of,  71 

Lsnz,  G.,  and  P.  Barbier,  a 
menthoglycol,  22 

Lepinois,  E.,  iodine  on  albumen- 
oid matters,  195 
sodium  on  albumenoid  matters, 
82 

Lesser,  G.,  and  P.  Barber,  ace- 
tylmethylheptenone,  183 

Leser.Q.,  and  P.  Barbier,  dextro- 
licarhodol,  59 

Levoterebenthene,  sulphuric  acid 
upon,  71,  207 

Lesinsky,  J.,  and  C.  Gundlich, 
chloral  hydrate  with  ammo- 
nium sulphide.  41 

Levy,  A.,  and  F.  Marboutin, oxy- 
gen in  sea-water,  37 

Leys,  A.,  alkaline  carbonates  in 
bicarbonaies,  305 

Light,  artiticial,  73 

Lime  in  mineral  phosphates,  212 

Lindet,  L.,  lime,  alumina,  and 
iron  in  mineral  phosphates, 
212 


Jan.  7, 1898. 


INDEX. — SUPPLEMENT  TO   THE   CHEMICAL  NEWS. 


331 


Line  specSirum  of  carbon  in  fused 
salts,  107 

Liquid  fluorine,  259 

Liquids,  molecular  association 
of,  299 

Lithium  chloride,  368 
and  other  salts,  concentrated 
solutions  of,  177 

Livache,  A.,  manganese  in  cer- 
tain oxidations,  47 

Lixiviation,  apparatus  for,  195 

London,  City  and  Guilds  of,  In- 
stitute, 134, 158 
County  Council,  289 
University,  121 

water  supply,  40, 104,  igi,  206, 
247,  307 

Lophine,  95 

Louguinine,  W.,  and  J.  Kablu- 
kow,  heat  liberated  on  addi- 
tion of  bromine  to  non-satu- 
rated substances,  23 

Lowry,  T.  M.,  stereoisomeric  di- 
derivatives  of  camphor  and 
ni,trocamphor,  78 

Lucium,  41 

Lunge,  G.,  "  Tabellen  fiir  Gas 
Analysen,  Gas  Volumetrische 
Analysen  StickstoiTbestim- 
mungen,  &c."  (review),  145 


TU^AAS,  P.,  and   H,  F.  Keller, 
■'■'•'■    new  derivatives  of  diacetyl, 

282 
Magnesium   on  cupric   sulphate 

solution,  297 
Malasse,  T.,  and  J.  Battandier, 
anew  alkaloid,  220 
retamine,  194 
Mallat,  A.,  acetone  in  urine,  241 
Mallet,  J.  W.,  polymerisation  of 
chloral,  280 
solubility  of  ammonia  in  water, 
305 
Manchester  College  of  Pharmacy, 
136 
technical  iostru£tion  at,  230 
Manganese,  colorimetric  estima- 
tion of,  219 
in  certain  oxidations,  47 
in  oxidations  by  laccase,  60 
organic  compound  rich  in  ex- 
tra(5led  from  the  woody  tissue, 
119 
salts,  oxidising  action  of,  35 
Manganomolybdate,  71 
Manganous  salts,  oxidising  power 

of,  193 
Manley,  J.  J.,  and  V.  H.  Veley, 
eledtric  condu(5tivity  of  nitric 
acid,  316 
"  Manual   for   Chemists  and  In- 
dustrialists" (review),  194 
"  Manufacture  of  Artificial  Mine- 
ral Waters  and  other  Effer- 
vescent Beverages"  (review), 
iSi 
"  Manuring  of  Oats,  Hay,  Tur- 
nips, and  Potatoes,  Reports 
on  Experiments  on"  (review), 

57 

Marboutin,    F.,  and   M.  Frank, 
organic  matter  in  water,  280 
and  A.  L6vy,  oxygen  in   sea- 
water,  37 
sulphuric  acid,  232 

Marking  inks,  36 

Martin,  H.  W.,  and  A.  G.  Par- 
kin, derivatives  of  cotoin  and 
phloretin,  250 
F.,  and  R.  Threlfall,  study  of 
oxygen, 283 

Mason  College,  Birmingham,  127 

Mason,  W.  P.,  expert  testimony, 
'42 

Massol,  G.,  normal  di-acids  of 
oxalic  series,  183 
suberic  acid,  183 

Mattalet,  F.,  benzoyl  chloride 
upon  mono-substituted  ortho- 
diamines,  71 

Matthews.  F.  E.,  isomeric  ben- 
zene hexachlorides,  312 

Maumene,  E.  J.,  "Chemie  Vraie" 
(review),  218 

Mayenyon,  M.,  eledlrolysis  of 
solid  bodies,  34 


Meads,  C.  J.,  the  Government 
laboratory,  173 

Means,  T.  H.,  and  M.  Whitney, 
"  An  Eleftrical  Method  of 
Determining  the  Soluble  Salt 
Contents  of  Soils"  (review), 
181 

Meeker,  G.  H.,  silica  in  blast- 
furnace slag,  289 

Melted  salts,  dissociation  spedtra 
of,  245 

Mendeleeff,  D.,  "  The  Principles 
of  Chemistry"  (review),  228 

Menthoglycol,  22 

Mercury,  reai5tion  of  sulphuric 
acid  with,  325 

Metals,  assay  of,  207 
tabular  atlas  of  the  chemistry 
of,  219 

Metallic    acetates    with   phenyl- 
hydrazine,  compounds  of,  240 
sulphides,  formation  of,  23 

"  Metallic  Alloys  and  Amalgams" 
(review),  145 

Meteorites  and  minerals,  analysis 
of,  231 

Methyl  alcohol,  estimation  of, 
296 

Metropolitan  College  of  Phar- 
macy, 13s 

Meyer,  A.,  determination  of  pot- 
assium, 194 
v.,  obituary,  83,  106,  265 

Microscopic    objedts,    mounting, 

Migrant  matter,  37 
"  Milk  and  Milk  Products,  Analy- 
sis of  Food  and  Drugs  "  (re- 
view), 80 
Milk  and  organic  liquids,  cryo- 
scopy  of,  19s,  314 
boiled,  183 

congealing-point  of,  48 
estimation    of    boric    acid    in, 

83 

"Mineral  Oils  and  their  By-pro- 
dudts,  Piadtical  Treatise  on" 
(review),  80 

"  Mineral  Waters,  Manufacture 
of  Artificial,  and  other  Effer- 
vescent Beverages"  (review), 
i8z 
phosphates,  lime,  alumina,  and 
iron  in,  212 

Minerals  and  meteorites,  analysis 
of,  231 
method  of  determining,  11, 139 

Minium,  dissociation  of,  277 

Mirrors  lined  with  metal, antique 
glass,  207 

Modern  alchemy,  117 

Moissan,   H.,  and  P.  Williams, 
calcium,  strontium,  and  ba- 
rium borides,  233 
and  J.  Dewar,  liquefadtion  of 
fluorine,  71,  197,  259 

Moisture,  absorption  of  by  deli- 
quescent substances,  67 

Moitessier,  J.,  compounds  of  me- 
tallic acetates  with  phenyl- 
hydrazine,  240 
phenylhydrazine  with  metallic 

iodides,  47 
phenylhydrazine  and  metallic 
nitrates,  95 
and  J.  Ville,  compounds  of  phe- 
nylhydrazine  with    metallic 
chlorides,  11 

Molecular  association  of  liquids, 
299 
refradtion  of  dissolved  salts  and 
acids,  66 

Molecules  and  liquefadtion  beats, 
264 

Molybdenum  anhydride,  reduc- 
tion, 71 

Monazite,  242 

Mond,  L.,  W.  Ramsay,  and  J. 
Shields,  occlusion  of  hydro- 
gen and  oxygen  by  palladium, 
317 

Monobromated  camphor,  35 

Monochlorised  camphor,  oxid- 
ising adtion  of,  152 

Moor,  C.  G.,  and  T.  H.  Pearmain, 
"  The  Analysis  of  Food  and 
Drugs— Milk  and  Milk  Pro- 
dudts"  (review),  80 


Moore,  T.  S.,  A.  E.  Pitt,   and  J. 
T.    Hewitt,    derivatives    of 
phenetol  azo-phenols,  78 
Morfit,  Dr.  C,  ■>bituary,  301 
Moths,  destruction  of  by  formic 

aldehyd,  326 
Mottelet,    F.,    dinitrophenyl-di- 

acetyl-methane,  314 
Mouneyrat,  A.,  adtion  of  bromine 
on  chloral,.  278 
chlorine  en  chloral,  277 
chlorine  on  pentachlorethane, 

313 
chlorine    on    tetrabromide   of 
acetylene,  313 
Mourelo,  J.    R  ,  colour  of  phos- 
phorescence of  strontium  sul- 
phide, 47 
phosphorescence  of   strontium 

sulphide,  11 
produdlion  of  strontium  sulph- 
ide, 326 
stability      of     phosphorescent 
strontium  sulphides,  195 
Moureu,  C,  monobromated  cam- 
phor, 35 
Mrazec,  L.,  crystalline   recks  of 
the  central  zone  of  the  Rou- 
manian Carpathians,  119 
Muir,    M.  M.  P.,  "A  Course  of 
Practical    Chemistry  —  Ele- 
mentary" (review),  94 
Municipal      Technical      School, 
Manchester.  135 


■NTAPHTHALENE,    constitu- 
•'■^     tioB  of  tri-derivatives  of,  68 
Naphthylureas,  286 
Naphthol,  35 
readtion  facilitating  recognition 
of,  48 
Newth,  G.  S.,  preparation  of  zinc 

ethyl,  34 
New  Zealand,  laboratory   notes 

from,  109 
Nickel,  adtion  of  upon  ethylene, 
35 
atomic  weight  of,  284,  293,  307 
and   cobalt  from  iron,  separa- 
tion, 248,  279,  302 
copper  alloys,  assay  of,  241 
in  steel,  248,  265 
melted,  fluidity  of,  47 
Nicloux,     M.,      estimation      of 
methyl  alcohol,  formic  alde- 
hyd, and  formic  acid,  296 
Nitrates,  nitric,  sulphuric,  hydro- 
chloric, and  phosphoric  acids 
on,  23 
Nitric  acid,  eledtric  conductivity 
of,  316 

on  nitrates,  23 
on  triphenylmethane,  192 
Nitrobenzene,  adtion  of  light  on 
a  solution  of,  67 
fusion-point,  boiling  point,  and 

specific  gravity  of,  67 
properties  of,  149 
Nitrocamphor,  78 
Nitrogen  in  analyses,  100 
combustion  of,  36 
tetroxide  on  ortho-  and  para- 

nitrohenzylalcohol,  249 
trioxide  on  alcohols,  249 
weight  of,  304 
Nitro  oxypicolines,  produdtion  of, 

66 
Nitrous  oxide,  density  of,  313 
Noyes,  A.  A.,  "  A  detailed  Course 
of  Qualitative  Chemical  Ana- 
lysis of  Inorganic  Substances" 
(review),  117 


rjBITUARY,    C.    W.    Blom- 

^-'    strand,  267 
Dr.  C.  Morfit,  301 
Professor  Vidtor  Meyer,  83,  106 
Prof.  Schiitzenberger,  10 

Officinal  solution  of  perchloride 
of  iron,  146 

Ohly,   J.,    phosphorus    in    steel, 
iron,  and  iron  ores,  200 

Oil  of  American   black  walnuts, 

unsaponifiable,  in  greases  with 
a  lime  base,  174 


Oils,  oxidation  of,  24 
Olives,  saccharine  into  oil  in,  254 
Olivier,  L.,  part  played  by  chem- 
istry in  perfumery,  150 
"Organic    Chemical    Manipula- 
tion "  (review),  145 
Organic   chemistry,  applications 
of  eledtrolysis  to,  93 
halides,  test  for  halogens  in,  20 
matter,  destrudtion  of  in  toxi« 
cology,  83 
in  water,  280 

substances,  chlorine,  bromine, 
and  iodine  in,  150 
combustion  of,  246,  256 
"  Organised     Science      Series- 
First   Stage:   Sound,   Light, 
and  Heat  "  (review),  182 
Osmond,  F.,  alloys  of  the  silver- 
copper  group,  IX 
Oven  for  desiccation  and   sterili- 
sation, 24 
Owens  College,  Victoria  Univer- 
sity, Manchester,  130 
Oxford  University,  122 
Oxidases,  chemical  constitution 

off  35 
Oxidation  and  chlor!dation,34,  82 

of  organic  matter,  3  j6 
Oxide  of   iron  and    alumina   in 

phosphates,  130 
Oxidising  substances,  new  class 

of,  170 
Oxycellulose,  194,  249 
Oxygen  and  hydrogen,  occlusion 
by  palladium,  317 
in  s»a-water,  37 
spectral  lines  of,  263,  288 
study  of,  283 
weight  of,  304 
Ozone,  medical  use  of,  47 


pAINT  tests,  104 

Palladium,  occlusion  of  hydrogen 
and  oxygen  by,  317 

Palmer,  T.,  conversion  of  thermo- 
metric  scales,  288 

Paper,  deterioration  of,  289 

Paranitrodiamidotriphenylraeth  - 
anes,  transforming  into  fuch- 
sines,  146 

Parastannyl  chloride,  195 

Paris  International  Fire  Preven- 
tion Congress,  1897,  60 

Paschen,  F.,  and  C.  Runge, 
spectra  of  oxygen,  sulphur, 
and  selenium,  235 

Passy,  J.,  extracting  perfume 
from  flowers,  23 

Pasteur,  chemical  work  of,  263 

"  Patents  for  Inventions,  Abridg- 
ments of  Specifications  "  (re- 
view), 193 

"  Patents,  Monopolies  by  "  (re- 
view), 81 

Patricroft  Higher  Grade  School, 
136 

Pearman,  T.  H.,  and  G.  G.  Moor, 
"  The  Analysis  of  Food  and 
Drugs— Part  I.:  Milk  and 
Milk  Produdts  "  (review),  80 

Peas,  composition  of,  71 

Pechard,  E.,  maaganoraolybdate. 

„     71 

Percarbonates,  170 

Perchloride  of  iron,  officinal  solu- 
tion of,  146 

Perfume  extradting  from  flowers. 
23 

Perfumery,  part  played  by  chem- 
istry in,  150 

Perkin,  A.  G.,  azobenzene  deriva- 
tives of  phloroglucinol,  231 
yellow  colouring   principles  of 
tannin  matters,  250 
vegetable  colouring   matters, 

286 
and  H.  W.  Martin,  derivatives 

of  cotoin  and  phloretin,  250 
W.   H.,  and  A.   W.  Crossley, 
decomposition  of  camphoric 
acid,  296 
and  W.  H.  Bentley,  synthesis 

of  camphoric  acid,  297 
sulphocamphylic  acid,  287 


332 


INDEX. — SUPPLEMENT  TO  THE   CHEMICAL  NEWS. 


Jan.  7, 1898, 


Perthiocyanic  acid,  reduAion  of, 

6S 
Petit,  A.,  and  M.  Poionovski,  iso- 
merism of  pilocarpidine  and 
pilocarpine,  48,  83,  158 
new  alkaloids  isolated  from  a 
species  of  jaborandi,  48 
Petroleum  and  gas  engines,  71 
Pharmaceutical  Society  of  Great 

Britain.  School  of,  125 
Phelps,  I.  K.,  combustion  of  or- 
ganic substances,  246, 256 
Phenanthrone,  249 
Phenetol  azo-pbenols, derivatives 

of,  78 
Phenols,  compounds  of  piperidine 

with,  313 
Phenylhydrazine      and    metallic 
nitrates,  compounds  of,  95 
compounds  of  metallic  acetates 
with,  240 

with  metallic  chlorides,  11 
iodides,  47 

hydrate  of  chloral  on,  35 
Philadelphia    College    of    Phar- 
macy, 1897,  seventy-seventh 
annual  announcement,  60 
Phipson,  T.   L.,   analysis    of   a 
black  silk  dress.  188 
experiments  with  the  Cheavin 

filter,  267 
zinc  in  water,  313 
Phloretin,  derivatives  of,  250 
Phloroglucinol,    derivatives    of, 
251 
synthesis  of,  249 
Phospham,    some    reaAions    of, 

182 
Phosphates,  biological  history  of, 
217 
oxide  of  iron  and  alumina  in, 
150 
Phosphorescence     of    strontium 

sulphide,  colour  of,  47 
Phosphorescent    strontium    sul- 
phide, stability  of,  195 
Phosphoric  acid,  268 

on  nitrates,  23 
Phosphorus  chloronitrides  of,  308, 
321 
in  steel,  iron,  and  iron  ores,  200 
pentachloride,  aftion  on    ani- 
line, 42,  54 
on  fenchone,  251 
terchloride     and      phosphorus 
oxychloride,  water  upon,  326 
Photographic  veiling  in    radio- 
graphy, 107,  207 
Photography  of  the  fluoroscopic 
image,  158 
review  of,  182 
"  Physical  and  Chemical  Calcula- 
tions,  Reform  of"  (review), 
70 
Society,  9,  227,  251,  276,  300 
Phthalic  green,  106 
Pilocarpidine,  48 
and  pilocarpine,  isomerism  be- 
tween, 83,  158 
Pilocarpine,  48 

Piloty,  O.  and  A.  Stock,  separa- 
tion of  arsenic  from  antimony, 

137 
Piperidine    with    phenols,   com- 
pounds of,  313 
Piperonal,  derivatives  of,  59 
Pitt,  A.  E.,  J   T.  Hewitt,  and  T. 
S.     Moore,    derivatives      of 
phenetol  azo-phenols,  78 
Platinous  salt,  new  mixed,  2ig 
Platinum,  permeation  of  hot  by 

gases,  168 
Poisoning    by   the    sweat    of   a 
healthy  man,  119 
by  wall-papers,  184 
Polarimetry,  yellow  light  for,  59 
Poionovski,   M.,    and    A.    Petit, 
new  alkaloids  isolated  from 
a  species  of  jaborandi,  48 
pilocarpine  and  pilocarpidine, 
48,  83,  158 
"Polyheorlc  Origin  of   Species, 
Contribution    to    the "    (re- 
view), 105 
Polymerisation  of  chloral,  280 
Polytechnic  Institute,  135 
Ponsot,  A.,  cryoscopy  of  milk,  195, 
314 


Ponsot,  A.,  exaA  cryoscopy,  183 
Poor,  C.  L.,  a  reflefting  telescope, 

27 
Pope,  F.  G.,  and  J.  T.  Hewitt, 

condensation  of  chloral  with 

resorcinol,  249 
Porchier,.  C,  photography  of  the 

fluoroscopic  image,  158 
Potassium  chloride  and  sugar,  in. 

fluence  of  surfusion  upon  the 

congelation.point  of  solutions 

of,  325 
determination  of,  194 
ferrocyanide,   determination  of 

zinc  by,  6,  15,  29,  38,  51 
sulphantimonites,  47 
Potatoes,  composition  of,  241 
Pouget,    M.,   potassium    sulph- 
antimonites, 47 
silver  sulphantimonites,  47 
Pre-carboniferous  coals,  analysis 

of,  186 
"  Prescriptions,  Incompatibilities 

in"  (review),  116 
"  Proceedings  of  the  Society  of 

Public      Analysts,     General 

Index  to  "  (review),  34 
"  Prospeftor'a    Handbook  "    (re- 
view), 38 
Prost,  E.,  and  L.  L.  de  Koninck, 

determination     of    zinc    by 

potassium  ferrocyanide,  6,  15, 

29.  38,  51 
Proteid  body  foreseen  by  M.  Ber- 

trand,  195 
Prud'homme,    M.,   transforming 

paranitrodiamidotriphenyl     - 

methanes  into  fuchsines,  146 
Prunier,  L.,  preparation  of  ether, 

11,35.83 
Pseudo-intestinal  calculus,  83 
Puggenheimer,  S.,  a<Stino-ele(ftric 

effedts  of  the  Rontgen  rays, 

95 
Pyromucates    of      the     alkaline 

earths,  decomposition  of,  59 
Pyruvic  acid,  coloured   reactions 

of,  219 


li  QUALITATIVE    Chemical 
Vc    Analysis      of     Inorganic 
Substances,    a    Detailed 
Course  of"  (review),  117 
"  Quantitative    Analysis,      Fre- 
senius's,''  Vol.   II.,  Part   IV. 
(review),  10 
Queen's  College,  Belfast,  133 
Cork,  133 
Galway,  134 


■p  ADIOGRAPHY,     photogra- 

■'■'■     phic  veil  in,  107,  207 

"  Radiography,  A  Treatise  on 
Medical  and  Scientific"  (re- 
view), 181 

Radiographs,  instantaneous, 240 

Ramage,  H.,  and  W.  N.  Hartley, 
speftrographic  analysis  of 
minerals  and  meteorites,  231 

Ramsay,    W..   an    undiscovered 
gas,  91,  97 
J,  Shields,  and  L.  Mond,  occlu- 
sion of  hydrogen  and  oxygen 
by  palladium,  317 

Randall,  W.  W.,  permeation  of 
hot  platinum  by  gases,  168 

Range-finder,  Barr  and  Stroud, 
227 

Raoult,  F,,  influence  of  surfusion 
upon  the  congelation-point 
of  solutions  of  potassium 
chloride  and  sugar,  325 

Rayleigh,  Lord,  densities  of  car- 
bonic oxide,  carbonic  anhy- 
dride, and  nitrous  oxide,  315 

Reagents,  reactions,  methods, 
and  formulas,  72 

Redwood,  I.  I.,  "  A  Practical 
Treatise  on  Mineral  Oils  and 
their  By-produdts"  (review), 
80 

Reform  of  chemical  and  physical 
calculations,  263 

Renwick,  F.  F.,  and  W.  S.  Gilles, 
ketnpinic  acid  and  camphoic 
acid,  78 


Resin  oil  in  oil  of  turpentine,  33 
Retamine,  194 
Reychler,  A.,  coumarin,  23 
and   S.   Baude,  derivatives  of 
piperonal,  59 
Richards,    J.    W.,     determining 
minerals,  114,  139 
P.   A.    E.,  chlorine,   bromine, 
and  iodine  in  saline  waters, 
.?93 
zinc  in  water,  293 
T.  W.,   and   A.   S.   Cushman, 
atomic  weight  of  nickel,  284, 
„.    293,307 

Riche,   A.,  aftion   of  antiseptics 
on  muscular  fibres,  195,  220 
assay  of  alloys  of  copper  and 
nickel,  241 
Rickard,    T.  A.,    "  The    Stamp 
Milling  of  Gold  Ores "  (re- 
view), 157 
Rinderpest  conference,  219 
Rivals,    P.,   and    H.    Baubigny, 
separating  and  distilling  bro- 
mine, 239 
Riviere,  G.,  and    P.  Carles,  in- 
fluence of  colouring  matters 
upon  fermentation  of  highly 
coloured  red  wines,  194 
Robinson,  H.  L.,  nickel  in  steel, 
265 
wire  gauze,  253 
Rohde,    and     VV.    von    Miller, 

carminic  acid,  224 
R6ntgen      rays,     aiStino-eledtric 
effedts  of,  95 

permeability  of  elements    of 

low  atomic  weight  to,  161, 

197 

tubes,  adtion  of  behind  screens 

opaque  to  X  rays,  143 

Rose-Innes,    J.,   isothermals    of 

ether,  251 
Rosenheim,  C,  and  P.  Schidro- 
witz,   compounds  of    piper- 
idine with  phenols,  313 
on  Fehling's  solution,  318 
Rousset,   L.,   chloride    of  ethyl- 
oxalyl  on  dipheuyl,  314 
on  ethyl-o-naphthol,  314 
Royal  Agricultural  College,  Ci- 
rencester, 128 
College  of  Science   and  Royal 

School  of  Mines,  124 
of  Science  for  Ireland,  134 
of  Surgeons   in  Ireland,  Dub- 
lin, 136 
Institution,  36,  229,  254,  287, 

289 
Society,  278 
Rubidium,  double  halogen  salts 

of.  31 
Ruddiman,   E.  A.,  "Incompati- 
bilities in  Prescriptions"  (re. 
view),  116 
Ruddock,  F.  G.,  alleged  new  ele- 
ment in  iron,  118 
Runge,  C.,and  F.  Paschen,  spec- 
tra of  oxygen,    sulphur,  and 
selenium,  255 
Rutile,  chemical  composition  of, 
102 
vanadium  in,  137 

SABATIER,  P.,  blue  nitroso- 
disulphonic  acid,  277 
cupric   hydrate  upon  solutions 
of  silver   nitrate   and    basic 
argentic  cuprate,  95 
and  J.  B.  Senderens,  adtion  of 
nickel  upon  ethylene,  35 
Sacerdote,    P.,    and    A.    Leduc, 
critical  constants  of  certain 
gases,  158 
Saccharine  matter,  transforma- 
tion into  oil  in  olives,  234 
produdts    of    condensation    of 
with  phenols,  314 
Sagnac,  G.,  transformation  of  X 

rays  by  metals,  107 
Salicylic  acid  and  calcium   sul- 
phite   as      preservatives    of 
cider,  220 
Saline  deposits  of  the  plains  of 
Northern  Germany,  83 
solutions,  268 

waters,  chlorine,  bromine,  and 
iodine  in,  293 


Sanitary  Institute,  231 

Scandinavian  rutile,  vanadium 
in, 112 

Schidrowitz,   P.,  and  O.  Rosen- 
heim, compounds  of  piperi- 
dine with  phenols,  313 
on  Fehling's  solution,  318 

Schiif  readtion  applied  to  acid 
fuschine,  23 

Schlagdenhauffen,  M.,  impuri- 
ties of  crude  copp-r,  240 

Schlcesing,  T.,  fermentations  in 
compound  mediums  of  solid 
particles,  71 

Scbryver,  S.  B.,  synthesis  of  an 
isomeride  of  camphoronic 
acid, 297 

Schiitzenberger,  Prof,  (obituary), 
10,47 

Searle,  G.  F.  C,  steady  motion 
of  an  eledtrified  ellipsoid,  9 

Sea-water,  oxygen  in,  37 

Segny,  G.,  instantaneous  radio, 
graphs,  240 
and    E.    Gundelag,     bianodic 
vessel    tor    red   phosphores- 
cence, 240 

Sell,  W.  J.,  and  F.  W.  Dootson, 
citrazinic  acid,  249 

Senderens,  J.  B.,  and  P.  Sabatier, 
adtion  of  nickel  upon  ethyl- 
ene, 33 

Serums,  lead  in  artificial,  82 

"  Sessions  of  the  Superior  Board 
of  Health,  Corresponding  to 
the  Year  1896"  (review).  117 

Severeanu,  C,  "  Razele  X  in 
Chirurgie  "  (review),  193 

Shapleigh,  W.,  lucium,  41 

Sheffield      Pharmaceutical     and 
Chemical  Society,  136 
Technical  School,  147 

Shields,  J.,  L,  Mond,  and  W. 
Ramsay,  occlusion  of  hydro- 
gen and  oxygen  by  palladium, 
317 

Shutt,  F.  T.,  composition  of  cer- 
tain Canadian  virgin  soils, 
:85,  204,  214,  224 

Siedler,  P.,  and  B.  Hirsch,  "  Die 
Fabrikation  der  Kiinstlichen 
Mineral  Wasser  und  anderer 
Mousserende  Getranke  "  (re- 
view), 181 

Silk  dress,  analysis  of,  188 

Silica  in  blast-furnace  slag,  289 

Silver-copper  group  alloys,  11, 
in    silver     plating      solutions, 

167 
nitrate,    adtion    oi     acetylene 

upon,  33 
sulphantimonites,  47 

Simon,  L.,  colour  readlions  of 
pyruvic  acid,  219 

Sisley,  P.,  produdts  of  condensa- 
tion of  saccharine  with  phe- 
nols, 314 

Skey,  W.,  laboratory  notes  from 
New  Zealand,  109 

Smith,  C,  C.  F.  Cross,  and  E.  J, 
Bevan,      carbohydrates       of 
cereal  straws,  68 
E.  S.,  nitric  acid  on  triphenyl- 
methane,  192 

Societe  d'Encouragement  pour 
I'lndustrie  Nationale,  33,  57, 
301 

Society,  Chemical,  66,   76,  248, 
259,  271,  286,  296,  312,  323 
of  Arts,  241 

Physical,  9,227,  251,  276,  300 
Royal,  278 

Sodium  on  albumenoid  ma'ters, 
82 
thiosulphate,  titration  of  with 
iodic  acid,  178 

"  Soils,  an  Eledtrical  Method  of 
Determining  the  Soluble  Salt 
Contents  of "  (review),  181 

"  Soils,  an  Eledtrical  Method  for 
Determiniig   the    Tempera- 
ture of"  (review).  181 
part  played  by  htimic  matter  in 
fertilisation  of"  11 

Solenoid  eledtro-magnet,  39 

Soria,  A.,  "Contribution  a  I'Ori- 
gine  Polyedrique  des  Es- 
peces"  (review),  103 


Jan.  7,  i8 


INDEX. — SUPPLEMENT  TO   THE   CHEMICAL  NEWS. 


333 


^oulard,  M.,  oven  for  desiccation 

and  sterilisation,  24 
South      Africa,     Chemical     and 
Metallurgical  Society  of,  192, 
252 
London  School   of   Pharmacy, 

135 
West  London  Polytechnic,  135, 
158 
Spe(5tra,  examination  of,  12,  46 
of  compound  bodies,  277 
of  melted  salts,  201 
of  oxygen,  sulphur,  and   selen- 
ium, 255 
Speftral  lines  of  oxygen,  288 

and  thallium,  265 
Spedtrum  of  an  element,  eSe&  of 
pressure  upon   the  series    in, 
21 
Spencer,  G.   L.,   "  Handbook  for 
Chemists     of      Beet  -  sugar 
Houses    and     Seed     Culture 
Farms  "  (review),  288 
Sperber,  J.,  calculation  of  coeffi- 
cients of  expansion  of  gases, 
74 
Spherometer  and  focometer,  227 
Sprankling,  C.  H.  G.,  ketoladtonic 

acid,  251 
"  Stamp-milling  of  Gold   Ores" 

(review),  157 
Stannic  acids,  253 
Steel   castings,  small   Bessemer 
process  tor,  8 
nickel  in,  248 
Steenstrup,  Dr.,  death  of,  71 
Stein,  S.,  sugar-beet,  288 
Stock,  A.,  and  O.  Piioty,  separa- 
tion ot  arsenic  from  antimony, 

137 
Stockport  Technical  School,  136 
Stokes,  Sir  G.  G.,  explanation  of 
a  phenomenon  attributed  tua 
magnetic  deviation  of  X  rays, 

73 
H.  N.,  chloronitrides  of  phos- 
phorus, 308,  321 
Stoklasa,  J.,  chlorophyll,  23 
Strontium,  253 
sulphide,  colour  of  phosphor- 
escence of,  47 
phosphorescence  of,  11 
produftion  of,  326 
Stroud,    Prof.,    focometer     and 

spherometer,  227 
Students,  a  word  to,  i2i 
in  elementary  pra<5tical  chemis- 
try, apparatus  for,  igg 
Styrolene-meta-styrolene,  rever- 
sible transformation  of,  219 
Suberic  acid,  183 
Sudborough,  J.  J.,  the  late  Vidtor 

Meyer,  265 
Suffolk,  W.  T.,  mounting  micro- 
scopic objects,  277 
Sugar-beet,  288 

determining  diabetic,  240 
Sulpho-arsecical,       sulpno-anti- 
monial,  and  sulpho-bismuthic 
minerals,  iig 
Sulphocampbylic  acid,  287 
Sulphuric  acid,  232 
hydrogen  upon,  325 
on  nitrates,  33 
reaction  with  mercury,  323 
upon      levoterebenthene,     yi, 
207 
Sworn,   S.    A.,    precipitation   of 

copper  by  magnesium,  59 
Symmetric  tetramethyldiamidodi- 
phenyldianthranaltetrame     - 
thyldiamide    of    the    corres* 
ponding  oxanthranol,  119 


TANNIN       matters,      yellow 
colouring  principles  of,  250 
upon  quinoleic  bases,  70 
Tanret,    C,    dilute    nitric,    sul- 
phuric,    hydrochloric,     and 
phosphoric  acids  on  nitrates, 
83 


Tanret,  C,  glucosinea,  314 
hydrochlorate  of  glucosamine, 
314 

Tardy,  E.,  essence  of  bitter  fen- 
nel, 158,  183 

Tassilly,  K.,  caffein  in  coffee,  195 
properties  of  caffeine,  59 
basic  magnesium  salts,  240 
salts  of  cadmium,  16 

Taylor,  R.  L.,  hypoiodous  acid 
and  hypoiodites,  17,  27 

Technical     Institute,     Swansea, 
136 
instrui5lion  at  Manchester,  230 

Telescope,  a  refleiSting,  27 

Tellurium,  preparation  of,  36 

Testimony,  expert,  142 

Tetroxide  on  alcohols,  249 

Thallium,  speftral  lines  of,  265 

Thermal  constants  of  the  ele- 
ments, 234 

Thermometric  scales,  conversion 
of,  288 

Thompson,  S.  P.,  cathode  rays,  4 

Thorium,  no 
acetyl-acetonate,  240,  253 

Thorpe,  T.  E.,  hydrates  of  iso- 
propyl  alcohol,  68 

Threlfall,  R.,  and  F.  Martin, 
study  of  oxygen,  283 

Tin,  antiquity  of  mining  for  in 
Bretagne,  113 

Tingle,  A.,  and  F.  R.  Japp,  am- 
monia and  pheny  Ihydrazin  de- 
rivatives of  dibenzoylcinna- 
mene  (anhydracetophenone- 
benzil),  230 

Titanic  oxide,  distribution  of,  221 

Toxicology,  destruftion  of  or- 
ganic matters  in,  47,  83 

Triphenylmethane,  nitric  acid 
on,  192 

"  True  Chemistry,  The"  (review), 
218 

Truffaut,  G.,  and  A.  Hebert,  cul- 
ture of  the  cattleya,  23 

Tungsten,  atomic  mass  of,  140, 
i55i  164 


TTNIVERSITIES  and  colleges, 
^     121 

University  College,  123 

Bristol,  126 

Dundee,  131 

Liverpool,  128 

Nottingham,  131 

Sheffield,  131 

of  North  Wales,  Bangor,  123 

of    South   Wales    and    Mon- 
mouthshire, Cardiff,  126 

of  Wales,  Aberystwyth,  125 
of  Cambridge,  122 

Dublin,  123 

Edinburgh,  132 

London,  121 

Oxford,  122 

St.  Andrews,  133 
Tutorial  College,  133 
Urbain,  G.,  study  of  thorium,  no 
Urine,  acetone  in,  241 
iron  in,  194 


T7ANADIUM  in  ruiile,  137 

in  Scandinavian  rutile,  112 
occurrence  of,  143 
Vandevyver,   M.,  calibration   of 

graduated  glass  vessels,  219 
Vegetable  colouring-matters,  286 
Veley,  V.  H.,  and   J.  J.  Manley, 

ele(5tric  condudtivity  of  nitric 

acid,  316 
Verneuil,  A.,  and  M.  Wyrouboff, 

atomic  weight  of  cerium,  23, 

137. 153 
Vender,  D.  V.,  "  La   Grande  In- 

dustria    Chimica "   (review), 

194 
V6ees,  M.,  new  mixed  platinous 

salt,  219 


Viftoria    University,    Yorkshire 

College,  Leeds,  128 
Vidal,      K..      new      sulphurised 

colouring  matters,  229 
some   reactions   of  phospham, 

182 
Vignon,  L.,  oxycellulose,  194 
ViUard,  P.,  photographic  veiling 

in  radiography,  107 
Villari,    E.,    EuStion    of    eleftric 

charges  on  the   property    of 

discharge   created    by  the  X 

rays  in  the  air,  95 
Ville,  ].,  and  J.  Moitessier,  com- 
pounds   of     phenylhydrazin 

with  metallic  chlorides,  11 
Villiers,  A.,  destrudtion  of  organic 

matter  in  toxicology,  47,  83 
oxidation  and  chloridation,  34, 

82 
Violle,   M.,  report  on  M.   Gos- 

sart's  acetylene  lamp,  182 
Vittenet,  H.,  oxidising  adtion  of 

monochlorised   camphor,  152 
Von  Miller,  W.,  and  Robde,  car- 

minic  acid,  224 


■IXTADDELL,  J.,  concentrated 
••     solutions    of    lithium    and 
other  salts,  177 
permeability  of  elements  of  low 
atomic  weight  to  the  Rontgen 
rays,  161 
Walker,   C.    F.,   titration  of  so- 
dium thiosulphate  with  iodic 
acid,  17S 
Warren,  H.  N.,  eledtrical  energy 
caused  byad^ion  ot  the  atmo- 
sphere, 200 
solenoid  eledtro-magnet,  39 
Water  cooling,  96 
organic  matter  in,  280 
subterranean,  in  the  north-west 

region  of  Bucuresilor,  119 
supply,  London,  40,   104,   191, 

206,  247,  307 
surface  tension  of,  22 
upon   phosphorous    terchloride 
and  phosphorous  oxychloride, 
326 
zinc  in,  293 
"  Waters,    Chemical    Composi- 
tion of  "  (review),  193 
composition  of  drainage,  106 
Waters,   W.    L.,   variations    in 
the  E.M.F.  of  Clark  cells,  252 
Welch,  J.  C,  "General  Index  to 
the      Proceedings      of      the 
Society  of  Public   Analysts  " 
(review),  34 
Wells,  H.  L.,  and   H.  W.  Foote, 
double  fluorides  of  zirconium 
with    lithium,    sodium,    and 
thallium,  44 
double  halogen  salts  of  cesium 
and  rubidium,  31 
Wendt,  G.,  theory  of  the  aurora 

borealis,  237 
Westminster  College  of  Chemis- 
try and  Pharmacy,  133 
Wheat  phosphates,  278 
Whitney,    M.,   and    L.    Briggs, 
"  An   Eledlrical   Method  for 
Determining   the  Tempera- 
ture of  Soils"  (review),  181 
and  T.  H.  Means,  "  An  Elec- 
trical Method  of  Determin- 
ing the  Soluble  Salt  Contents 
of  Soils  "  (review),  181 
D.  Gardner,  and   L.  J.  Briggs, 
"An   Eledtrical    Method    of 
Determining    the    Moisture 
Content  oi  Arable  Soils"  (re- 
view, 180 
Wiesbaden  Chemical  Laboratory, 

136 
Wilde,  H.,  spedlral  lines  of  oxy- 
gen, 288 
and  thalliumt  265 


Willenz,  M.,  estimation  of  cop- 
per as  iodide,  243 

William,  D.  J.,  estimation  of  lead 
10  slags,  192 

Williams,  J.  R.,   battery   slimes, 
232 
treatment    of   battery    slimes, 

192 
P.,  and   H.   Moissan,  calcium, 
strontium,   and   barium  bor- 
ides,  253 
R.   P.,  "  Elements  of  Chemis- 
try "  (review),  229 
W.  C,,  carbonic  acid  in  the  air, 
209 

Wilson,  E.  P.,  "The  Chlorina- 
tion  Process"  (review),  33 

Wines,   colouring-matters    upon 
fermentation      of      highly  - 
coloured  red,  194 
fradture  of,  47  ' 

Winter,  J.,  congealing-point  of 
milk,  48 

Wire  gauze,  253 

Witz,  A.,  gas  and  petroleum  en- 
gines, 71 

Woollen  goods,  finishing,  254 

Wright,  L.,  "  The  Indudlion  Coil 
in  Pradlical  Work,  including 
Rontgen  X  rays  "  (review), 
218 

Wynne,  W.  P.,  and  H.  E.  Arm- 
strong, constitution  of  tri- 
derivatives  of  naphthalene, 
68 

conversion  of  1  :  i'-  into  i  :  4'. 
dichloronaphthalene,  69 

Wyrouboff,  M.,  and  A.  Verneuil, 
atomic  weight  of  cerium,  23, 
137. 153 


V  RAYS,  absorption  of,  138 

adtion  of  eledlric  charges  on 
the  property  of  discbarge 
created  by  the,  in  the  air, 
93 

ana  dissociation,  72 

complexity  of  sheaf  of,  71 

dissemination  of,  263 

explanation  of  a  phenomenon 
attributed  to  a  magnetic  de- 
viation of,  73 

on  luminescence  of  gases,  171 

penetration  of,  290 

transformation  of  by  metals, 
107 

upon  temperature  of  animals» 
95 
"  X  Kays  in  Surgery"  (review), 

193 
"  X  Rays,  the   Indudtion  Coil  in 
Pradtical    Work,     including 
Rontgen  "  (review),  ai8 


YELLOW  colouring  principles 
■*■      of  tannin  matters,  250 
vegetable    colouring    matters, 
286 
Yorkshire  College,  Leeds,  72 
Young,   Q.,  formation  of  diacet- 
anilide,  77 
and   E.  Clark,   naphthylureas, 

206 
and  H.Annable,  benzoylphenyl- 
semicarbazide,  286 


^INC,  determination  of,  6, 15. 
^    29.38,51 
ethyl,  preparation  of,  20,  34 
gold  slimes,  redudlion  of.   S7 
192  ■"' 

in  water,  293,  313 
Zirconium,  double  fluorides   of 
4 


END  OF   VOLUME    LXXVl. 


Supplemeut  to  the  Chbeical  News, 
January  7,  i8g8. 


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